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* [PATCH 00/19] netfs: Prep for write helpers
@ 2022-03-02 14:01 David Howells
  2022-03-02 14:01 ` [PATCH 01/19] fscache: export fscache_end_operation() David Howells
                   ` (18 more replies)
  0 siblings, 19 replies; 20+ messages in thread
From: David Howells @ 2022-03-02 14:01 UTC (permalink / raw)
  To: linux-cachefs
  Cc: Jeffle Xu, Jeff Layton, linux-afs, dhowells, Anna Schumaker,
	Steve French, Dominique Martinet, Jeff Layton, David Wysochanski,
	Ilya Dryomov, Jeffle Xu, Linus Torvalds, linux-afs, linux-nfs,
	linux-cifs, ceph-devel, v9fs-developer, linux-fsdevel,
	linux-kernel


Having had a go at implementing write helpers and content encryption
support in netfslib, it seems that the netfs_read_{,sub}request structs and
the equivalent write request structs were almost the same and so should be
merged, thereby requiring only one set of alloc/get/put functions and a
common set of tracepoints.

Merging the structs also has the advantage that if a bounce buffer is added
to the request struct, a read operation can be performed to fill the bounce
buffer, the contents of the buffer can be modified and then a write
operation can be performed on it to send the data wherever it needs to go
using the same request structure all the way through.  The I/O handlers
would then transparently perform any required crypto.  This should make it
easy to perform RMW cycles if needed.

The potentially common functions and structs, however, by their names all
proclaim themselves to be associated with the read side of things.  The
bulk of these changes alter this in the following ways:

 (1) Rename struct netfs_read_{,sub}request to netfs_io_{,sub}request.

 (2) Rename some enums, members and flags to make them more appropriate.

 (3) Adjust some comments to match.

 (4) Drop "read"/"rreq" from the names of common functions.  For instance,
     netfs_get_read_request() becomes netfs_get_request().

 (5) The ->init_rreq() and ->issue_op() methods become ->init_request() and
     ->issue_read().  I've kept the latter as a read-specific function and
     in another branch added an ->issue_write() method.

The driver source is then reorganised into a number of files:

	fs/netfs/buffered_read.c	Create read reqs to the pagecache
	fs/netfs/io.c			Dispatchers for read and write reqs
	fs/netfs/main.c			Some general miscellaneous bits
	fs/netfs/objects.c		Alloc, get and put functions
	fs/netfs/stats.c		Optional procfs statistics.

and future development can be fitted into this scheme, e.g.:

	fs/netfs/buffered_write.c	Modify the pagecache
	fs/netfs/buffered_flush.c	Writeback from the pagecache
	fs/netfs/direct_read.c		DIO read support
	fs/netfs/direct_write.c		DIO write support
	fs/netfs/unbuffered_write.c	Write modifications directly back

Beyond the above changes, there are also some changes that affect how
things work:

 (1) Make fscache_end_operation() generally available.

 (2) In the netfs tracing header, generate enums from the symbol -> string
     mapping tables rather than manually coding them.

 (3) Add a struct for filesystems that uses netfslib to put into their
     inode wrapper structs to hold extra state that netfslib is interested
     in, such as the fscache cookie.  This allows netfslib functions to be
     set in filesystem operation tables and jumped to directly without
     having to have a filesystem wrapper.

 (4) Add a member to the struct added in (3) to track the remote inode
     length as that may differ if local modifications are buffered.  We may
     need to supply an appropriate EOF pointer when storing data (in AFS
     for example).

 (5) Pass extra information to netfs_alloc_request() so that the
     ->init_request() hook can access it and retain information to indicate
     the origin of the operation.

 (6) Make the ->init_request() hook return an error, thereby allowing a
     filesystem that isn't allowed to cache an inode (ceph or cifs, for
     example) to skip readahead.

 (7) Switch to using refcount_t for subrequests and add tracepoints to log
     refcount changes for the request and subrequest structs.

 (8) Add a function to consolidate dispatching a read request.  Similar
     code is used in three places and another couple are likely to be added
     in the future.


The patches can be found on this branch:

	http://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git/log/?h=fscache-next

This is based on top of ceph's master branch as some of the patches
conflict.

David
---
David Howells (17):
      netfs: Generate enums from trace symbol mapping lists
      netfs: Add a netfs inode context
      netfs: Rename netfs_read_*request to netfs_io_*request
      netfs: Finish off rename of netfs_read_request to netfs_io_request
      netfs: Split netfs_io_* object handling out
      netfs: Adjust the netfs_rreq tracepoint slightly
      netfs: Trace refcounting on the netfs_io_request struct
      netfs: Trace refcounting on the netfs_io_subrequest struct
      netfs: Adjust the netfs_failure tracepoint to indicate non-subreq lines
      netfs: Prepare to split read_helper.c
      netfs: Add a function to consolidate beginning a read
      netfs: Split fs/netfs/read_helper.c
      netfs: Split some core bits out into their own file
      netfs: Rename rename read_helper.c to io.c
      netfs: Change ->init_rreq() to return an error code
      netfs: Keep track of the actual remote file size
      afs: Maintain netfs_i_context::remote_i_size

Jeff Layton (1):
      netfs: Refactor arguments for netfs_alloc_read_request

Jeffle Xu (1):
      fscache: export fscache_end_operation()


 Documentation/filesystems/netfs_library.rst |   38 +-
 fs/9p/cache.c                               |   10 +-
 fs/9p/v9fs.c                                |    4 +-
 fs/9p/v9fs.h                                |   12 +-
 fs/9p/vfs_addr.c                            |   60 +-
 fs/9p/vfs_inode.c                           |   13 +-
 fs/afs/dynroot.c                            |    1 +
 fs/afs/file.c                               |   41 +-
 fs/afs/inode.c                              |   32 +-
 fs/afs/internal.h                           |   23 +-
 fs/afs/super.c                              |    4 +-
 fs/afs/write.c                              |   10 +-
 fs/cachefiles/io.c                          |   10 +-
 fs/ceph/addr.c                              |   45 +-
 fs/ceph/cache.c                             |   28 +-
 fs/ceph/cache.h                             |   15 +-
 fs/ceph/inode.c                             |    6 +-
 fs/ceph/super.h                             |   16 +-
 fs/cifs/cifsglob.h                          |   10 +-
 fs/cifs/fscache.c                           |   19 +-
 fs/cifs/fscache.h                           |    2 +-
 fs/fscache/internal.h                       |   11 -
 fs/netfs/Makefile                           |    8 +-
 fs/netfs/buffered_read.c                    |  429 +++++++
 fs/netfs/internal.h                         |   49 +-
 fs/netfs/io.c                               |  656 ++++++++++
 fs/netfs/main.c                             |   20 +
 fs/netfs/objects.c                          |  161 +++
 fs/netfs/read_helper.c                      | 1205 -------------------
 fs/netfs/stats.c                            |    1 -
 fs/nfs/fscache.c                            |    8 -
 include/linux/fscache.h                     |   14 +
 include/linux/netfs.h                       |  162 ++-
 include/trace/events/cachefiles.h           |    6 +-
 include/trace/events/netfs.h                |  188 ++-
 35 files changed, 1750 insertions(+), 1567 deletions(-)
 create mode 100644 fs/netfs/buffered_read.c
 create mode 100644 fs/netfs/io.c
 create mode 100644 fs/netfs/main.c
 create mode 100644 fs/netfs/objects.c
 delete mode 100644 fs/netfs/read_helper.c



^ permalink raw reply	[flat|nested] 20+ messages in thread

* [PATCH 01/19] fscache: export fscache_end_operation()
  2022-03-02 14:01 [PATCH 00/19] netfs: Prep for write helpers David Howells
@ 2022-03-02 14:01 ` David Howells
  2022-03-02 14:03 ` [PATCH 02/19] netfs: Generate enums from trace symbol mapping lists David Howells
                   ` (17 subsequent siblings)
  18 siblings, 0 replies; 20+ messages in thread
From: David Howells @ 2022-03-02 14:01 UTC (permalink / raw)
  To: linux-cachefs
  Cc: Jeffle Xu, dhowells, Anna Schumaker, Steve French,
	Dominique Martinet, Jeff Layton, David Wysochanski, Ilya Dryomov,
	Jeffle Xu, Linus Torvalds, linux-afs, linux-nfs, linux-cifs,
	ceph-devel, v9fs-developer, linux-fsdevel, linux-kernel

From: Jeffle Xu <jefflexu@linux.alibaba.com>

Export fscache_end_operation() to avoid code duplication.

Besides, considering the paired fscache_begin_read_operation() is
already exported, it shall make sense to also export
fscache_end_operation().

Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
---

 fs/cifs/fscache.c       |    8 --------
 fs/fscache/internal.h   |   11 -----------
 fs/nfs/fscache.c        |    8 --------
 include/linux/fscache.h |   14 ++++++++++++++
 4 files changed, 14 insertions(+), 27 deletions(-)

diff --git a/fs/cifs/fscache.c b/fs/cifs/fscache.c
index 33af72e0ac0c..b47c2011ce5b 100644
--- a/fs/cifs/fscache.c
+++ b/fs/cifs/fscache.c
@@ -134,14 +134,6 @@ void cifs_fscache_release_inode_cookie(struct inode *inode)
 	}
 }
 
-static inline void fscache_end_operation(struct netfs_cache_resources *cres)
-{
-	const struct netfs_cache_ops *ops = fscache_operation_valid(cres);
-
-	if (ops)
-		ops->end_operation(cres);
-}
-
 /*
  * Fallback page reading interface.
  */
diff --git a/fs/fscache/internal.h b/fs/fscache/internal.h
index f121c21590dc..ed1c9ed737f2 100644
--- a/fs/fscache/internal.h
+++ b/fs/fscache/internal.h
@@ -70,17 +70,6 @@ static inline void fscache_see_cookie(struct fscache_cookie *cookie,
 			     where);
 }
 
-/*
- * io.c
- */
-static inline void fscache_end_operation(struct netfs_cache_resources *cres)
-{
-	const struct netfs_cache_ops *ops = fscache_operation_valid(cres);
-
-	if (ops)
-		ops->end_operation(cres);
-}
-
 /*
  * main.c
  */
diff --git a/fs/nfs/fscache.c b/fs/nfs/fscache.c
index cfe901650ab0..39654ca72d3d 100644
--- a/fs/nfs/fscache.c
+++ b/fs/nfs/fscache.c
@@ -249,14 +249,6 @@ void nfs_fscache_release_file(struct inode *inode, struct file *filp)
 	}
 }
 
-static inline void fscache_end_operation(struct netfs_cache_resources *cres)
-{
-	const struct netfs_cache_ops *ops = fscache_operation_valid(cres);
-
-	if (ops)
-		ops->end_operation(cres);
-}
-
 /*
  * Fallback page reading interface.
  */
diff --git a/include/linux/fscache.h b/include/linux/fscache.h
index 296c5f1d9f35..d2430da8aa67 100644
--- a/include/linux/fscache.h
+++ b/include/linux/fscache.h
@@ -456,6 +456,20 @@ int fscache_begin_read_operation(struct netfs_cache_resources *cres,
 	return -ENOBUFS;
 }
 
+/**
+ * fscache_end_operation - End the read operation for the netfs lib
+ * @cres: The cache resources for the read operation
+ *
+ * Clean up the resources at the end of the read request.
+ */
+static inline void fscache_end_operation(struct netfs_cache_resources *cres)
+{
+	const struct netfs_cache_ops *ops = fscache_operation_valid(cres);
+
+	if (ops)
+		ops->end_operation(cres);
+}
+
 /**
  * fscache_read - Start a read from the cache.
  * @cres: The cache resources to use



^ permalink raw reply related	[flat|nested] 20+ messages in thread

* [PATCH 02/19] netfs: Generate enums from trace symbol mapping lists
  2022-03-02 14:01 [PATCH 00/19] netfs: Prep for write helpers David Howells
  2022-03-02 14:01 ` [PATCH 01/19] fscache: export fscache_end_operation() David Howells
@ 2022-03-02 14:03 ` David Howells
  2022-03-02 14:04 ` [PATCH 03/19] netfs: Add a netfs inode context David Howells
                   ` (16 subsequent siblings)
  18 siblings, 0 replies; 20+ messages in thread
From: David Howells @ 2022-03-02 14:03 UTC (permalink / raw)
  To: linux-cachefs
  Cc: dhowells, Anna Schumaker, Steve French, Dominique Martinet,
	Jeff Layton, David Wysochanski, Ilya Dryomov, Jeffle Xu,
	Linus Torvalds, linux-afs, linux-nfs, linux-cifs, ceph-devel,
	v9fs-developer, linux-fsdevel, linux-kernel

netfs has a number of lists of symbols for use in tracing, listed in an
enum and then listed again in a symbol->string mapping for use with
__print_symbolic().  This is, however, redundant.

Instead, use the symbol->string mapping list to also generate the enum
where the enum is in the same file.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
---

 include/trace/events/netfs.h |   57 ++++++++++--------------------------------
 1 file changed, 14 insertions(+), 43 deletions(-)

diff --git a/include/trace/events/netfs.h b/include/trace/events/netfs.h
index e6f4ebbb4c69..88d9a74dd346 100644
--- a/include/trace/events/netfs.h
+++ b/include/trace/events/netfs.h
@@ -15,49 +15,6 @@
 /*
  * Define enums for tracing information.
  */
-#ifndef __NETFS_DECLARE_TRACE_ENUMS_ONCE_ONLY
-#define __NETFS_DECLARE_TRACE_ENUMS_ONCE_ONLY
-
-enum netfs_read_trace {
-	netfs_read_trace_expanded,
-	netfs_read_trace_readahead,
-	netfs_read_trace_readpage,
-	netfs_read_trace_write_begin,
-};
-
-enum netfs_rreq_trace {
-	netfs_rreq_trace_assess,
-	netfs_rreq_trace_done,
-	netfs_rreq_trace_free,
-	netfs_rreq_trace_resubmit,
-	netfs_rreq_trace_unlock,
-	netfs_rreq_trace_unmark,
-	netfs_rreq_trace_write,
-};
-
-enum netfs_sreq_trace {
-	netfs_sreq_trace_download_instead,
-	netfs_sreq_trace_free,
-	netfs_sreq_trace_prepare,
-	netfs_sreq_trace_resubmit_short,
-	netfs_sreq_trace_submit,
-	netfs_sreq_trace_terminated,
-	netfs_sreq_trace_write,
-	netfs_sreq_trace_write_skip,
-	netfs_sreq_trace_write_term,
-};
-
-enum netfs_failure {
-	netfs_fail_check_write_begin,
-	netfs_fail_copy_to_cache,
-	netfs_fail_read,
-	netfs_fail_short_readpage,
-	netfs_fail_short_write_begin,
-	netfs_fail_prepare_write,
-};
-
-#endif
-
 #define netfs_read_traces					\
 	EM(netfs_read_trace_expanded,		"EXPANDED ")	\
 	EM(netfs_read_trace_readahead,		"READAHEAD")	\
@@ -98,6 +55,20 @@ enum netfs_failure {
 	EM(netfs_fail_short_write_begin,	"short-write-begin")	\
 	E_(netfs_fail_prepare_write,		"prep-write")
 
+#ifndef __NETFS_DECLARE_TRACE_ENUMS_ONCE_ONLY
+#define __NETFS_DECLARE_TRACE_ENUMS_ONCE_ONLY
+
+#undef EM
+#undef E_
+#define EM(a, b) a,
+#define E_(a, b) a
+
+enum netfs_read_trace { netfs_read_traces } __mode(byte);
+enum netfs_rreq_trace { netfs_rreq_traces } __mode(byte);
+enum netfs_sreq_trace { netfs_sreq_traces } __mode(byte);
+enum netfs_failure { netfs_failures } __mode(byte);
+
+#endif
 
 /*
  * Export enum symbols via userspace.



^ permalink raw reply related	[flat|nested] 20+ messages in thread

* [PATCH 03/19] netfs: Add a netfs inode context
  2022-03-02 14:01 [PATCH 00/19] netfs: Prep for write helpers David Howells
  2022-03-02 14:01 ` [PATCH 01/19] fscache: export fscache_end_operation() David Howells
  2022-03-02 14:03 ` [PATCH 02/19] netfs: Generate enums from trace symbol mapping lists David Howells
@ 2022-03-02 14:04 ` David Howells
  2022-03-02 14:04 ` [PATCH 04/19] netfs: Rename netfs_read_*request to netfs_io_*request David Howells
                   ` (15 subsequent siblings)
  18 siblings, 0 replies; 20+ messages in thread
From: David Howells @ 2022-03-02 14:04 UTC (permalink / raw)
  To: linux-cachefs
  Cc: dhowells, Anna Schumaker, Steve French, Dominique Martinet,
	Jeff Layton, David Wysochanski, Ilya Dryomov, Jeffle Xu,
	Linus Torvalds, linux-afs, linux-nfs, linux-cifs, ceph-devel,
	v9fs-developer, linux-fsdevel, linux-kernel

Add a netfs_i_context struct that should be included in the network
filesystem's own inode struct wrapper, directly after the VFS's inode
struct, e.g.:

	struct my_inode {
		struct {
			struct inode		vfs_inode;
			struct netfs_i_context	netfs_ctx;
		};
	};

The netfs_i_context struct so far contains a single field for the network
filesystem to use - the cache cookie:

	struct netfs_i_context {
		...
		struct fscache_cookie	*cache;
	};

Three functions are provided to help with this:

 (1) void netfs_i_context_init(struct inode *inode,
			       const struct netfs_request_ops *ops);

     Initialise the netfs context and set the operations.

 (2) struct netfs_i_context *netfs_i_context(struct inode *inode);

     Find the netfs context from the VFS inode.

 (3) struct inode *netfs_inode(struct netfs_i_context *ctx);

     Find the VFS inode from the netfs context.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
---

 fs/9p/cache.c          |   10 +---
 fs/9p/v9fs.c           |    4 -
 fs/9p/v9fs.h           |   12 +++-
 fs/9p/vfs_addr.c       |   43 +---------------
 fs/9p/vfs_inode.c      |   13 ++++-
 fs/afs/dynroot.c       |    1 
 fs/afs/file.c          |   28 +---------
 fs/afs/inode.c         |   31 +++++++----
 fs/afs/internal.h      |   21 +++++---
 fs/afs/super.c         |    4 -
 fs/afs/write.c         |    3 -
 fs/ceph/addr.c         |   27 +---------
 fs/ceph/cache.c        |   28 +++++-----
 fs/ceph/cache.h        |   11 ----
 fs/ceph/inode.c        |    6 +-
 fs/ceph/super.h        |   16 +++---
 fs/cifs/cifsglob.h     |   10 ++--
 fs/cifs/fscache.c      |   11 ++--
 fs/cifs/fscache.h      |    2 -
 fs/netfs/internal.h    |   18 +++++++
 fs/netfs/read_helper.c |  132 ++++++++++++++++++++++--------------------------
 fs/netfs/stats.c       |    1 
 include/linux/netfs.h  |   85 ++++++++++++++++++++++++++-----
 23 files changed, 260 insertions(+), 257 deletions(-)

diff --git a/fs/9p/cache.c b/fs/9p/cache.c
index 55e108e5e133..1c8dc696d516 100644
--- a/fs/9p/cache.c
+++ b/fs/9p/cache.c
@@ -49,22 +49,20 @@ int v9fs_cache_session_get_cookie(struct v9fs_session_info *v9ses,
 
 void v9fs_cache_inode_get_cookie(struct inode *inode)
 {
-	struct v9fs_inode *v9inode;
+	struct v9fs_inode *v9inode = V9FS_I(inode);
 	struct v9fs_session_info *v9ses;
 	__le32 version;
 	__le64 path;
 
 	if (!S_ISREG(inode->i_mode))
 		return;
-
-	v9inode = V9FS_I(inode);
-	if (WARN_ON(v9inode->fscache))
+	if (WARN_ON(v9fs_inode_cookie(v9inode)))
 		return;
 
 	version = cpu_to_le32(v9inode->qid.version);
 	path = cpu_to_le64(v9inode->qid.path);
 	v9ses = v9fs_inode2v9ses(inode);
-	v9inode->fscache =
+	v9inode->netfs_ctx.cache =
 		fscache_acquire_cookie(v9fs_session_cache(v9ses),
 				       0,
 				       &path, sizeof(path),
@@ -72,5 +70,5 @@ void v9fs_cache_inode_get_cookie(struct inode *inode)
 				       i_size_read(&v9inode->vfs_inode));
 
 	p9_debug(P9_DEBUG_FSC, "inode %p get cookie %p\n",
-		 inode, v9inode->fscache);
+		 inode, v9fs_inode_cookie(v9inode));
 }
diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
index 08f65c40af4f..e28ddf763b3b 100644
--- a/fs/9p/v9fs.c
+++ b/fs/9p/v9fs.c
@@ -623,9 +623,7 @@ static void v9fs_sysfs_cleanup(void)
 static void v9fs_inode_init_once(void *foo)
 {
 	struct v9fs_inode *v9inode = (struct v9fs_inode *)foo;
-#ifdef CONFIG_9P_FSCACHE
-	v9inode->fscache = NULL;
-#endif
+
 	memset(&v9inode->qid, 0, sizeof(v9inode->qid));
 	inode_init_once(&v9inode->vfs_inode);
 }
diff --git a/fs/9p/v9fs.h b/fs/9p/v9fs.h
index bc8b30205d36..8a8d363dfdab 100644
--- a/fs/9p/v9fs.h
+++ b/fs/9p/v9fs.h
@@ -9,6 +9,7 @@
 #define FS_9P_V9FS_H
 
 #include <linux/backing-dev.h>
+#include <linux/netfs.h>
 
 /**
  * enum p9_session_flags - option flags for each 9P session
@@ -108,14 +109,14 @@ struct v9fs_session_info {
 #define V9FS_INO_INVALID_ATTR 0x01
 
 struct v9fs_inode {
-#ifdef CONFIG_9P_FSCACHE
-	struct fscache_cookie *fscache;
-#endif
+	struct {
+		struct inode	vfs_inode;	/* the VFS's inode record */
+		struct netfs_i_context netfs_ctx; /* Netfslib context */
+	};
 	struct p9_qid qid;
 	unsigned int cache_validity;
 	struct p9_fid *writeback_fid;
 	struct mutex v_mutex;
-	struct inode vfs_inode;
 };
 
 static inline struct v9fs_inode *V9FS_I(const struct inode *inode)
@@ -126,7 +127,7 @@ static inline struct v9fs_inode *V9FS_I(const struct inode *inode)
 static inline struct fscache_cookie *v9fs_inode_cookie(struct v9fs_inode *v9inode)
 {
 #ifdef CONFIG_9P_FSCACHE
-	return v9inode->fscache;
+	return netfs_i_cookie(&v9inode->vfs_inode);
 #else
 	return NULL;
 #endif
@@ -163,6 +164,7 @@ extern struct inode *v9fs_inode_from_fid(struct v9fs_session_info *v9ses,
 extern const struct inode_operations v9fs_dir_inode_operations_dotl;
 extern const struct inode_operations v9fs_file_inode_operations_dotl;
 extern const struct inode_operations v9fs_symlink_inode_operations_dotl;
+extern const struct netfs_request_ops v9fs_req_ops;
 extern struct inode *v9fs_inode_from_fid_dotl(struct v9fs_session_info *v9ses,
 					      struct p9_fid *fid,
 					      struct super_block *sb, int new);
diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
index 9a10e68c5f30..495767616cf4 100644
--- a/fs/9p/vfs_addr.c
+++ b/fs/9p/vfs_addr.c
@@ -76,17 +76,6 @@ static void v9fs_req_cleanup(struct address_space *mapping, void *priv)
 	p9_client_clunk(fid);
 }
 
-/**
- * v9fs_is_cache_enabled - Determine if caching is enabled for an inode
- * @inode: The inode to check
- */
-static bool v9fs_is_cache_enabled(struct inode *inode)
-{
-	struct fscache_cookie *cookie = v9fs_inode_cookie(V9FS_I(inode));
-
-	return fscache_cookie_enabled(cookie) && cookie->cache_priv;
-}
-
 /**
  * v9fs_begin_cache_operation - Begin a cache operation for a read
  * @rreq: The read request
@@ -102,36 +91,13 @@ static int v9fs_begin_cache_operation(struct netfs_read_request *rreq)
 #endif
 }
 
-static const struct netfs_read_request_ops v9fs_req_ops = {
+const struct netfs_request_ops v9fs_req_ops = {
 	.init_rreq		= v9fs_init_rreq,
-	.is_cache_enabled	= v9fs_is_cache_enabled,
 	.begin_cache_operation	= v9fs_begin_cache_operation,
 	.issue_op		= v9fs_req_issue_op,
 	.cleanup		= v9fs_req_cleanup,
 };
 
-/**
- * v9fs_vfs_readpage - read an entire page in from 9P
- * @file: file being read
- * @page: structure to page
- *
- */
-static int v9fs_vfs_readpage(struct file *file, struct page *page)
-{
-	struct folio *folio = page_folio(page);
-
-	return netfs_readpage(file, folio, &v9fs_req_ops, NULL);
-}
-
-/**
- * v9fs_vfs_readahead - read a set of pages from 9P
- * @ractl: The readahead parameters
- */
-static void v9fs_vfs_readahead(struct readahead_control *ractl)
-{
-	netfs_readahead(ractl, &v9fs_req_ops, NULL);
-}
-
 /**
  * v9fs_release_page - release the private state associated with a page
  * @page: The page to be released
@@ -325,8 +291,7 @@ static int v9fs_write_begin(struct file *filp, struct address_space *mapping,
 	 * file.  We need to do this before we get a lock on the page in case
 	 * there's more than one writer competing for the same cache block.
 	 */
-	retval = netfs_write_begin(filp, mapping, pos, len, flags, &folio, fsdata,
-				   &v9fs_req_ops, NULL);
+	retval = netfs_write_begin(filp, mapping, pos, len, flags, &folio, fsdata);
 	if (retval < 0)
 		return retval;
 
@@ -387,8 +352,8 @@ static int v9fs_set_page_dirty(struct page *page)
 #endif
 
 const struct address_space_operations v9fs_addr_operations = {
-	.readpage = v9fs_vfs_readpage,
-	.readahead = v9fs_vfs_readahead,
+	.readpage = netfs_readpage,
+	.readahead = netfs_readahead,
 	.set_page_dirty = v9fs_set_page_dirty,
 	.writepage = v9fs_vfs_writepage,
 	.write_begin = v9fs_write_begin,
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 2a10242c79c7..a7dc6781a622 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -231,9 +231,6 @@ struct inode *v9fs_alloc_inode(struct super_block *sb)
 	v9inode = kmem_cache_alloc(v9fs_inode_cache, GFP_KERNEL);
 	if (!v9inode)
 		return NULL;
-#ifdef CONFIG_9P_FSCACHE
-	v9inode->fscache = NULL;
-#endif
 	v9inode->writeback_fid = NULL;
 	v9inode->cache_validity = 0;
 	mutex_init(&v9inode->v_mutex);
@@ -250,6 +247,14 @@ void v9fs_free_inode(struct inode *inode)
 	kmem_cache_free(v9fs_inode_cache, V9FS_I(inode));
 }
 
+/*
+ * Set parameters for the netfs library
+ */
+static void v9fs_set_netfs_context(struct inode *inode)
+{
+	netfs_i_context_init(inode, &v9fs_req_ops);
+}
+
 int v9fs_init_inode(struct v9fs_session_info *v9ses,
 		    struct inode *inode, umode_t mode, dev_t rdev)
 {
@@ -338,6 +343,8 @@ int v9fs_init_inode(struct v9fs_session_info *v9ses,
 		err = -EINVAL;
 		goto error;
 	}
+
+	v9fs_set_netfs_context(inode);
 error:
 	return err;
 
diff --git a/fs/afs/dynroot.c b/fs/afs/dynroot.c
index db832cc931c8..f120bcb8bf73 100644
--- a/fs/afs/dynroot.c
+++ b/fs/afs/dynroot.c
@@ -76,6 +76,7 @@ struct inode *afs_iget_pseudo_dir(struct super_block *sb, bool root)
 	/* there shouldn't be an existing inode */
 	BUG_ON(!(inode->i_state & I_NEW));
 
+	netfs_i_context_init(inode, NULL);
 	inode->i_size		= 0;
 	inode->i_mode		= S_IFDIR | S_IRUGO | S_IXUGO;
 	if (root) {
diff --git a/fs/afs/file.c b/fs/afs/file.c
index 720818a7c166..ee5fd2102a42 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -19,13 +19,11 @@
 #include "internal.h"
 
 static int afs_file_mmap(struct file *file, struct vm_area_struct *vma);
-static int afs_readpage(struct file *file, struct page *page);
 static int afs_symlink_readpage(struct file *file, struct page *page);
 static void afs_invalidatepage(struct page *page, unsigned int offset,
 			       unsigned int length);
 static int afs_releasepage(struct page *page, gfp_t gfp_flags);
 
-static void afs_readahead(struct readahead_control *ractl);
 static ssize_t afs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter);
 static void afs_vm_open(struct vm_area_struct *area);
 static void afs_vm_close(struct vm_area_struct *area);
@@ -52,8 +50,8 @@ const struct inode_operations afs_file_inode_operations = {
 };
 
 const struct address_space_operations afs_file_aops = {
-	.readpage	= afs_readpage,
-	.readahead	= afs_readahead,
+	.readpage	= netfs_readpage,
+	.readahead	= netfs_readahead,
 	.set_page_dirty	= afs_set_page_dirty,
 	.launder_page	= afs_launder_page,
 	.releasepage	= afs_releasepage,
@@ -364,13 +362,6 @@ static void afs_init_rreq(struct netfs_read_request *rreq, struct file *file)
 	rreq->netfs_priv = key_get(afs_file_key(file));
 }
 
-static bool afs_is_cache_enabled(struct inode *inode)
-{
-	struct fscache_cookie *cookie = afs_vnode_cache(AFS_FS_I(inode));
-
-	return fscache_cookie_enabled(cookie) && cookie->cache_priv;
-}
-
 static int afs_begin_cache_operation(struct netfs_read_request *rreq)
 {
 #ifdef CONFIG_AFS_FSCACHE
@@ -396,27 +387,14 @@ static void afs_priv_cleanup(struct address_space *mapping, void *netfs_priv)
 	key_put(netfs_priv);
 }
 
-const struct netfs_read_request_ops afs_req_ops = {
+const struct netfs_request_ops afs_req_ops = {
 	.init_rreq		= afs_init_rreq,
-	.is_cache_enabled	= afs_is_cache_enabled,
 	.begin_cache_operation	= afs_begin_cache_operation,
 	.check_write_begin	= afs_check_write_begin,
 	.issue_op		= afs_req_issue_op,
 	.cleanup		= afs_priv_cleanup,
 };
 
-static int afs_readpage(struct file *file, struct page *page)
-{
-	struct folio *folio = page_folio(page);
-
-	return netfs_readpage(file, folio, &afs_req_ops, NULL);
-}
-
-static void afs_readahead(struct readahead_control *ractl)
-{
-	netfs_readahead(ractl, &afs_req_ops, NULL);
-}
-
 int afs_write_inode(struct inode *inode, struct writeback_control *wbc)
 {
 	fscache_unpin_writeback(wbc, afs_vnode_cache(AFS_FS_I(inode)));
diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index 5964f8aee090..5b5e40197655 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -53,6 +53,14 @@ static noinline void dump_vnode(struct afs_vnode *vnode, struct afs_vnode *paren
 		dump_stack();
 }
 
+/*
+ * Set parameters for the netfs library
+ */
+static void afs_set_netfs_context(struct afs_vnode *vnode)
+{
+	netfs_i_context_init(&vnode->vfs_inode, &afs_req_ops);
+}
+
 /*
  * Initialise an inode from the vnode status.
  */
@@ -128,6 +136,7 @@ static int afs_inode_init_from_status(struct afs_operation *op,
 	}
 
 	afs_set_i_size(vnode, status->size);
+	afs_set_netfs_context(vnode);
 
 	vnode->invalid_before	= status->data_version;
 	inode_set_iversion_raw(&vnode->vfs_inode, status->data_version);
@@ -420,7 +429,7 @@ static void afs_get_inode_cache(struct afs_vnode *vnode)
 	struct afs_vnode_cache_aux aux;
 
 	if (vnode->status.type != AFS_FTYPE_FILE) {
-		vnode->cache = NULL;
+		vnode->netfs_ctx.cache = NULL;
 		return;
 	}
 
@@ -430,12 +439,14 @@ static void afs_get_inode_cache(struct afs_vnode *vnode)
 	key.vnode_id_ext[1]	= htonl(vnode->fid.vnode_hi);
 	afs_set_cache_aux(vnode, &aux);
 
-	vnode->cache = fscache_acquire_cookie(
-		vnode->volume->cache,
-		vnode->status.type == AFS_FTYPE_FILE ? 0 : FSCACHE_ADV_SINGLE_CHUNK,
-		&key, sizeof(key),
-		&aux, sizeof(aux),
-		vnode->status.size);
+	afs_vnode_set_cache(vnode,
+			    fscache_acquire_cookie(
+				    vnode->volume->cache,
+				    vnode->status.type == AFS_FTYPE_FILE ?
+				    0 : FSCACHE_ADV_SINGLE_CHUNK,
+				    &key, sizeof(key),
+				    &aux, sizeof(aux),
+				    vnode->status.size));
 #endif
 }
 
@@ -528,6 +539,7 @@ struct inode *afs_root_iget(struct super_block *sb, struct key *key)
 
 	vnode = AFS_FS_I(inode);
 	vnode->cb_v_break = as->volume->cb_v_break,
+	afs_set_netfs_context(vnode);
 
 	op = afs_alloc_operation(key, as->volume);
 	if (IS_ERR(op)) {
@@ -786,11 +798,8 @@ void afs_evict_inode(struct inode *inode)
 		afs_put_wb_key(wbk);
 	}
 
-#ifdef CONFIG_AFS_FSCACHE
-	fscache_relinquish_cookie(vnode->cache,
+	fscache_relinquish_cookie(afs_vnode_cache(vnode),
 				  test_bit(AFS_VNODE_DELETED, &vnode->flags));
-	vnode->cache = NULL;
-#endif
 
 	afs_prune_wb_keys(vnode);
 	afs_put_permits(rcu_access_pointer(vnode->permit_cache));
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index b6f02321fc09..9fec5fd70abc 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -619,15 +619,16 @@ enum afs_lock_state {
  * leak from one inode to another.
  */
 struct afs_vnode {
-	struct inode		vfs_inode;	/* the VFS's inode record */
+	struct {
+		/* These must be contiguous */
+		struct inode	vfs_inode;	/* the VFS's inode record */
+		struct netfs_i_context netfs_ctx; /* Netfslib context */
+	};
 
 	struct afs_volume	*volume;	/* volume on which vnode resides */
 	struct afs_fid		fid;		/* the file identifier for this inode */
 	struct afs_file_status	status;		/* AFS status info for this file */
 	afs_dataversion_t	invalid_before;	/* Child dentries are invalid before this */
-#ifdef CONFIG_AFS_FSCACHE
-	struct fscache_cookie	*cache;		/* caching cookie */
-#endif
 	struct afs_permits __rcu *permit_cache;	/* cache of permits so far obtained */
 	struct mutex		io_lock;	/* Lock for serialising I/O on this mutex */
 	struct rw_semaphore	validate_lock;	/* lock for validating this vnode */
@@ -674,12 +675,20 @@ struct afs_vnode {
 static inline struct fscache_cookie *afs_vnode_cache(struct afs_vnode *vnode)
 {
 #ifdef CONFIG_AFS_FSCACHE
-	return vnode->cache;
+	return netfs_i_cookie(&vnode->vfs_inode);
 #else
 	return NULL;
 #endif
 }
 
+static inline void afs_vnode_set_cache(struct afs_vnode *vnode,
+				       struct fscache_cookie *cookie)
+{
+#ifdef CONFIG_AFS_FSCACHE
+	vnode->netfs_ctx.cache = cookie;
+#endif
+}
+
 /*
  * cached security record for one user's attempt to access a vnode
  */
@@ -1063,7 +1072,7 @@ extern const struct address_space_operations afs_file_aops;
 extern const struct address_space_operations afs_symlink_aops;
 extern const struct inode_operations afs_file_inode_operations;
 extern const struct file_operations afs_file_operations;
-extern const struct netfs_read_request_ops afs_req_ops;
+extern const struct netfs_request_ops afs_req_ops;
 
 extern int afs_cache_wb_key(struct afs_vnode *, struct afs_file *);
 extern void afs_put_wb_key(struct afs_wb_key *);
diff --git a/fs/afs/super.c b/fs/afs/super.c
index 5ec9fd97eccc..e66c6f54ac8e 100644
--- a/fs/afs/super.c
+++ b/fs/afs/super.c
@@ -688,13 +688,11 @@ static struct inode *afs_alloc_inode(struct super_block *sb)
 	/* Reset anything that shouldn't leak from one inode to the next. */
 	memset(&vnode->fid, 0, sizeof(vnode->fid));
 	memset(&vnode->status, 0, sizeof(vnode->status));
+	afs_vnode_set_cache(vnode, NULL);
 
 	vnode->volume		= NULL;
 	vnode->lock_key		= NULL;
 	vnode->permit_cache	= NULL;
-#ifdef CONFIG_AFS_FSCACHE
-	vnode->cache		= NULL;
-#endif
 
 	vnode->flags		= 1 << AFS_VNODE_UNSET;
 	vnode->lock_state	= AFS_VNODE_LOCK_NONE;
diff --git a/fs/afs/write.c b/fs/afs/write.c
index 5e9157d0da29..e4b47f67a408 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -59,8 +59,7 @@ int afs_write_begin(struct file *file, struct address_space *mapping,
 	 * file.  We need to do this before we get a lock on the page in case
 	 * there's more than one writer competing for the same cache block.
 	 */
-	ret = netfs_write_begin(file, mapping, pos, len, flags, &folio, fsdata,
-				&afs_req_ops, NULL);
+	ret = netfs_write_begin(file, mapping, pos, len, flags, &folio, fsdata);
 	if (ret < 0)
 		return ret;
 
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 46e0881ae8b2..cb43c1397da5 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -364,8 +364,7 @@ static void ceph_readahead_cleanup(struct address_space *mapping, void *priv)
 		ceph_put_cap_refs(ci, got);
 }
 
-static const struct netfs_read_request_ops ceph_netfs_read_ops = {
-	.is_cache_enabled	= ceph_is_cache_enabled,
+const struct netfs_request_ops ceph_netfs_ops = {
 	.begin_cache_operation	= ceph_begin_cache_operation,
 	.issue_op		= ceph_netfs_issue_op,
 	.expand_readahead	= ceph_netfs_expand_readahead,
@@ -374,23 +373,6 @@ static const struct netfs_read_request_ops ceph_netfs_read_ops = {
 	.cleanup		= ceph_readahead_cleanup,
 };
 
-/* read a single page, without unlocking it. */
-static int ceph_readpage(struct file *file, struct page *subpage)
-{
-	struct folio *folio = page_folio(subpage);
-	struct inode *inode = file_inode(file);
-	struct ceph_inode_info *ci = ceph_inode(inode);
-	struct ceph_vino vino = ceph_vino(inode);
-	size_t len = folio_size(folio);
-	u64 off = folio_file_pos(folio);
-
-	dout("readpage ino %llx.%llx file %p off %llu len %zu folio %p index %lu\n inline %d",
-	     vino.ino, vino.snap, file, off, len, folio, folio_index(folio),
-	     ci->i_inline_version != CEPH_INLINE_NONE);
-
-	return netfs_readpage(file, folio, &ceph_netfs_read_ops, NULL);
-}
-
 static void ceph_readahead(struct readahead_control *ractl)
 {
 	struct inode *inode = file_inode(ractl->file);
@@ -419,7 +401,7 @@ static void ceph_readahead(struct readahead_control *ractl)
 		if (ret <= 0)
 			return;
 	}
-	netfs_readahead(ractl, &ceph_netfs_read_ops, (void *)(uintptr_t)got);
+	//netfs_readahead(ractl, (void *)(uintptr_t)got);
 }
 
 #ifdef CONFIG_CEPH_FSCACHE
@@ -1320,8 +1302,7 @@ static int ceph_write_begin(struct file *file, struct address_space *mapping,
 	struct folio *folio = NULL;
 	int r;
 
-	r = netfs_write_begin(file, inode->i_mapping, pos, len, 0, &folio, NULL,
-			      &ceph_netfs_read_ops, NULL);
+	r = netfs_write_begin(file, inode->i_mapping, pos, len, 0, &folio, NULL);
 	if (r == 0)
 		folio_wait_fscache(folio);
 	if (r < 0) {
@@ -1375,7 +1356,7 @@ static int ceph_write_end(struct file *file, struct address_space *mapping,
 }
 
 const struct address_space_operations ceph_aops = {
-	.readpage = ceph_readpage,
+	.readpage = netfs_readpage,
 	.readahead = ceph_readahead,
 	.writepage = ceph_writepage,
 	.writepages = ceph_writepages_start,
diff --git a/fs/ceph/cache.c b/fs/ceph/cache.c
index 7d22850623ef..ddea99922073 100644
--- a/fs/ceph/cache.c
+++ b/fs/ceph/cache.c
@@ -29,26 +29,25 @@ void ceph_fscache_register_inode_cookie(struct inode *inode)
 	if (!(inode->i_state & I_NEW))
 		return;
 
-	WARN_ON_ONCE(ci->fscache);
+	WARN_ON_ONCE(ci->netfs_ctx.cache);
 
-	ci->fscache = fscache_acquire_cookie(fsc->fscache, 0,
-					     &ci->i_vino, sizeof(ci->i_vino),
-					     &ci->i_version, sizeof(ci->i_version),
-					     i_size_read(inode));
+	ci->netfs_ctx.cache =
+		fscache_acquire_cookie(fsc->fscache, 0,
+				       &ci->i_vino, sizeof(ci->i_vino),
+				       &ci->i_version, sizeof(ci->i_version),
+				       i_size_read(inode));
 }
 
-void ceph_fscache_unregister_inode_cookie(struct ceph_inode_info* ci)
+void ceph_fscache_unregister_inode_cookie(struct ceph_inode_info *ci)
 {
-	struct fscache_cookie *cookie = ci->fscache;
-
-	fscache_relinquish_cookie(cookie, false);
+	fscache_relinquish_cookie(ceph_fscache_cookie(ci), false);
 }
 
 void ceph_fscache_use_cookie(struct inode *inode, bool will_modify)
 {
 	struct ceph_inode_info *ci = ceph_inode(inode);
 
-	fscache_use_cookie(ci->fscache, will_modify);
+	fscache_use_cookie(ceph_fscache_cookie(ci), will_modify);
 }
 
 void ceph_fscache_unuse_cookie(struct inode *inode, bool update)
@@ -58,9 +57,10 @@ void ceph_fscache_unuse_cookie(struct inode *inode, bool update)
 	if (update) {
 		loff_t i_size = i_size_read(inode);
 
-		fscache_unuse_cookie(ci->fscache, &ci->i_version, &i_size);
+		fscache_unuse_cookie(ceph_fscache_cookie(ci),
+				     &ci->i_version, &i_size);
 	} else {
-		fscache_unuse_cookie(ci->fscache, NULL, NULL);
+		fscache_unuse_cookie(ceph_fscache_cookie(ci), NULL, NULL);
 	}
 }
 
@@ -69,14 +69,14 @@ void ceph_fscache_update(struct inode *inode)
 	struct ceph_inode_info *ci = ceph_inode(inode);
 	loff_t i_size = i_size_read(inode);
 
-	fscache_update_cookie(ci->fscache, &ci->i_version, &i_size);
+	fscache_update_cookie(ceph_fscache_cookie(ci), &ci->i_version, &i_size);
 }
 
 void ceph_fscache_invalidate(struct inode *inode, bool dio_write)
 {
 	struct ceph_inode_info *ci = ceph_inode(inode);
 
-	fscache_invalidate(ceph_inode(inode)->fscache,
+	fscache_invalidate(ceph_fscache_cookie(ci),
 			   &ci->i_version, i_size_read(inode),
 			   dio_write ? FSCACHE_INVAL_DIO_WRITE : 0);
 }
diff --git a/fs/ceph/cache.h b/fs/ceph/cache.h
index 09164389fa66..69646587aa75 100644
--- a/fs/ceph/cache.h
+++ b/fs/ceph/cache.h
@@ -26,14 +26,9 @@ void ceph_fscache_unuse_cookie(struct inode *inode, bool update);
 void ceph_fscache_update(struct inode *inode);
 void ceph_fscache_invalidate(struct inode *inode, bool dio_write);
 
-static inline void ceph_fscache_inode_init(struct ceph_inode_info *ci)
-{
-	ci->fscache = NULL;
-}
-
 static inline struct fscache_cookie *ceph_fscache_cookie(struct ceph_inode_info *ci)
 {
-	return ci->fscache;
+	return netfs_i_cookie(&ci->vfs_inode);
 }
 
 static inline void ceph_fscache_resize(struct inode *inode, loff_t to)
@@ -91,10 +86,6 @@ static inline void ceph_fscache_unregister_fs(struct ceph_fs_client* fsc)
 {
 }
 
-static inline void ceph_fscache_inode_init(struct ceph_inode_info *ci)
-{
-}
-
 static inline void ceph_fscache_register_inode_cookie(struct inode *inode)
 {
 }
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 7b1e93c8a0d2..6a176d9d394a 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -453,6 +453,9 @@ struct inode *ceph_alloc_inode(struct super_block *sb)
 
 	dout("alloc_inode %p\n", &ci->vfs_inode);
 
+	/* Set parameters for the netfs library */
+	netfs_i_context_init(&ci->vfs_inode, &ceph_netfs_ops);
+
 	spin_lock_init(&ci->i_ceph_lock);
 
 	ci->i_version = 0;
@@ -538,9 +541,6 @@ struct inode *ceph_alloc_inode(struct super_block *sb)
 	INIT_WORK(&ci->i_work, ceph_inode_work);
 	ci->i_work_mask = 0;
 	memset(&ci->i_btime, '\0', sizeof(ci->i_btime));
-
-	ceph_fscache_inode_init(ci);
-
 	return &ci->vfs_inode;
 }
 
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 0b4b519682f1..f9f01ed6ffee 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -17,13 +17,11 @@
 #include <linux/posix_acl.h>
 #include <linux/refcount.h>
 #include <linux/security.h>
+#include <linux/netfs.h>
+#include <linux/fscache.h>
 
 #include <linux/ceph/libceph.h>
 
-#ifdef CONFIG_CEPH_FSCACHE
-#include <linux/fscache.h>
-#endif
-
 /* large granularity for statfs utilization stats to facilitate
  * large volume sizes on 32-bit machines. */
 #define CEPH_BLOCK_SHIFT   22  /* 4 MB */
@@ -317,6 +315,10 @@ struct ceph_inode_xattrs_info {
  * Ceph inode.
  */
 struct ceph_inode_info {
+	struct {
+		struct inode vfs_inode;
+		struct netfs_i_context netfs_ctx; /* Netfslib context */
+	};
 	struct ceph_vino i_vino;   /* ceph ino + snap */
 
 	spinlock_t i_ceph_lock;
@@ -427,11 +429,6 @@ struct ceph_inode_info {
 
 	struct work_struct i_work;
 	unsigned long  i_work_mask;
-
-#ifdef CONFIG_CEPH_FSCACHE
-	struct fscache_cookie *fscache;
-#endif
-	struct inode vfs_inode; /* at end */
 };
 
 static inline struct ceph_inode_info *
@@ -1215,6 +1212,7 @@ extern void __ceph_touch_fmode(struct ceph_inode_info *ci,
 
 /* addr.c */
 extern const struct address_space_operations ceph_aops;
+extern const struct netfs_request_ops ceph_netfs_ops;
 extern int ceph_mmap(struct file *file, struct vm_area_struct *vma);
 extern int ceph_uninline_data(struct file *file);
 extern int ceph_pool_perm_check(struct inode *inode, int need);
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 48b343d03430..0a4085ced40f 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -16,6 +16,7 @@
 #include <linux/mempool.h>
 #include <linux/workqueue.h>
 #include <linux/utsname.h>
+#include <linux/netfs.h>
 #include "cifs_fs_sb.h"
 #include "cifsacl.h"
 #include <crypto/internal/hash.h>
@@ -1402,6 +1403,11 @@ void cifsFileInfo_put(struct cifsFileInfo *cifs_file);
  */
 
 struct cifsInodeInfo {
+	struct {
+		/* These must be contiguous */
+		struct inode	vfs_inode;	/* the VFS's inode record */
+		struct netfs_i_context netfs_ctx; /* Netfslib context */
+	};
 	bool can_cache_brlcks;
 	struct list_head llist;	/* locks helb by this inode */
 	/*
@@ -1432,10 +1438,6 @@ struct cifsInodeInfo {
 	u64  uniqueid;			/* server inode number */
 	u64  createtime;		/* creation time on server */
 	__u8 lease_key[SMB2_LEASE_KEY_SIZE];	/* lease key for this inode */
-#ifdef CONFIG_CIFS_FSCACHE
-	struct fscache_cookie *fscache;
-#endif
-	struct inode vfs_inode;
 	struct list_head deferred_closes; /* list of deferred closes */
 	spinlock_t deferred_lock; /* protection on deferred list */
 	bool lease_granted; /* Flag to indicate whether lease or oplock is granted. */
diff --git a/fs/cifs/fscache.c b/fs/cifs/fscache.c
index b47c2011ce5b..a638b29e9062 100644
--- a/fs/cifs/fscache.c
+++ b/fs/cifs/fscache.c
@@ -103,7 +103,7 @@ void cifs_fscache_get_inode_cookie(struct inode *inode)
 
 	cifs_fscache_fill_coherency(&cifsi->vfs_inode, &cd);
 
-	cifsi->fscache =
+	cifsi->netfs_ctx.cache =
 		fscache_acquire_cookie(tcon->fscache, 0,
 				       &cifsi->uniqueid, sizeof(cifsi->uniqueid),
 				       &cd, sizeof(cd),
@@ -126,11 +126,12 @@ void cifs_fscache_unuse_inode_cookie(struct inode *inode, bool update)
 void cifs_fscache_release_inode_cookie(struct inode *inode)
 {
 	struct cifsInodeInfo *cifsi = CIFS_I(inode);
+	struct fscache_cookie *cookie = cifs_inode_cookie(inode);
 
-	if (cifsi->fscache) {
-		cifs_dbg(FYI, "%s: (0x%p)\n", __func__, cifsi->fscache);
-		fscache_relinquish_cookie(cifsi->fscache, false);
-		cifsi->fscache = NULL;
+	if (cookie) {
+		cifs_dbg(FYI, "%s: (0x%p)\n", __func__, cookie);
+		fscache_relinquish_cookie(cookie, false);
+		cifsi->netfs_ctx.cache = NULL;
 	}
 }
 
diff --git a/fs/cifs/fscache.h b/fs/cifs/fscache.h
index 55129908e2c1..52355c0912ae 100644
--- a/fs/cifs/fscache.h
+++ b/fs/cifs/fscache.h
@@ -61,7 +61,7 @@ void cifs_fscache_fill_coherency(struct inode *inode,
 
 static inline struct fscache_cookie *cifs_inode_cookie(struct inode *inode)
 {
-	return CIFS_I(inode)->fscache;
+	return netfs_i_cookie(inode);
 }
 
 static inline void cifs_invalidate_cache(struct inode *inode, unsigned int flags)
diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h
index b7f2c4459f33..82ce5c4228e4 100644
--- a/fs/netfs/internal.h
+++ b/fs/netfs/internal.h
@@ -5,6 +5,10 @@
  * Written by David Howells (dhowells@redhat.com)
  */
 
+#include <linux/netfs.h>
+#include <linux/fscache.h>
+#include <trace/events/netfs.h>
+
 #ifdef pr_fmt
 #undef pr_fmt
 #endif
@@ -55,6 +59,20 @@ static inline void netfs_stat_d(atomic_t *stat)
 #define netfs_stat_d(x) do {} while(0)
 #endif
 
+/*
+ * Miscellaneous functions.
+ */
+static inline bool netfs_is_cache_enabled(struct netfs_i_context *ctx)
+{
+#ifdef CONFIG_FSCACHE
+	struct fscache_cookie *cookie = ctx->cache;
+
+	return fscache_cookie_valid(cookie) && fscache_cookie_enabled(cookie);
+#else
+	return false;
+#endif
+}
+
 /*****************************************************************************/
 /*
  * debug tracing
diff --git a/fs/netfs/read_helper.c b/fs/netfs/read_helper.c
index 501da990c259..b0b237669561 100644
--- a/fs/netfs/read_helper.c
+++ b/fs/netfs/read_helper.c
@@ -14,7 +14,6 @@
 #include <linux/uio.h>
 #include <linux/sched/mm.h>
 #include <linux/task_io_accounting_ops.h>
-#include <linux/netfs.h>
 #include "internal.h"
 #define CREATE_TRACE_POINTS
 #include <trace/events/netfs.h>
@@ -37,26 +36,27 @@ static void netfs_put_subrequest(struct netfs_read_subrequest *subreq,
 		__netfs_put_subrequest(subreq, was_async);
 }
 
-static struct netfs_read_request *netfs_alloc_read_request(
-	const struct netfs_read_request_ops *ops, void *netfs_priv,
-	struct file *file)
+static struct netfs_read_request *netfs_alloc_read_request(struct address_space *mapping,
+							   struct file *file)
 {
 	static atomic_t debug_ids;
+	struct inode *inode = file ? file_inode(file) : mapping->host;
+	struct netfs_i_context *ctx = netfs_i_context(inode);
 	struct netfs_read_request *rreq;
 
 	rreq = kzalloc(sizeof(struct netfs_read_request), GFP_KERNEL);
 	if (rreq) {
-		rreq->netfs_ops	= ops;
-		rreq->netfs_priv = netfs_priv;
-		rreq->inode	= file_inode(file);
-		rreq->i_size	= i_size_read(rreq->inode);
+		rreq->mapping	= mapping;
+		rreq->inode	= inode;
+		rreq->netfs_ops	= ctx->ops;
+		rreq->i_size	= i_size_read(inode);
 		rreq->debug_id	= atomic_inc_return(&debug_ids);
 		INIT_LIST_HEAD(&rreq->subrequests);
 		INIT_WORK(&rreq->work, netfs_rreq_work);
 		refcount_set(&rreq->usage, 1);
 		__set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
-		if (ops->init_rreq)
-			ops->init_rreq(rreq, file);
+		if (ctx->ops->init_rreq)
+			ctx->ops->init_rreq(rreq, file);
 		netfs_stat(&netfs_n_rh_rreq);
 	}
 
@@ -850,8 +850,6 @@ static void netfs_rreq_expand(struct netfs_read_request *rreq,
 /**
  * netfs_readahead - Helper to manage a read request
  * @ractl: The description of the readahead request
- * @ops: The network filesystem's operations for the helper to use
- * @netfs_priv: Private netfs data to be retained in the request
  *
  * Fulfil a readahead request by drawing data from the cache if possible, or
  * the netfs if not.  Space beyond the EOF is zero-filled.  Multiple I/O
@@ -859,34 +857,31 @@ static void netfs_rreq_expand(struct netfs_read_request *rreq,
  * readahead window can be expanded in either direction to a more convenient
  * alighment for RPC efficiency or to make storage in the cache feasible.
  *
- * The calling netfs must provide a table of operations, only one of which,
- * issue_op, is mandatory.  It may also be passed a private token, which will
- * be retained in rreq->netfs_priv and will be cleaned up by ops->cleanup().
+ * The calling netfs must initialise a netfs context contiguous to the vfs
+ * inode before calling this.
  *
  * This is usable whether or not caching is enabled.
  */
-void netfs_readahead(struct readahead_control *ractl,
-		     const struct netfs_read_request_ops *ops,
-		     void *netfs_priv)
+void netfs_readahead(struct readahead_control *ractl)
 {
 	struct netfs_read_request *rreq;
+	struct netfs_i_context *ctx = netfs_i_context(ractl->mapping->host);
 	unsigned int debug_index = 0;
 	int ret;
 
 	_enter("%lx,%x", readahead_index(ractl), readahead_count(ractl));
 
 	if (readahead_count(ractl) == 0)
-		goto cleanup;
+		return;
 
-	rreq = netfs_alloc_read_request(ops, netfs_priv, ractl->file);
+	rreq = netfs_alloc_read_request(ractl->mapping, ractl->file);
 	if (!rreq)
-		goto cleanup;
-	rreq->mapping	= ractl->mapping;
+		return;
 	rreq->start	= readahead_pos(ractl);
 	rreq->len	= readahead_length(ractl);
 
-	if (ops->begin_cache_operation) {
-		ret = ops->begin_cache_operation(rreq);
+	if (ctx->ops->begin_cache_operation) {
+		ret = ctx->ops->begin_cache_operation(rreq);
 		if (ret == -ENOMEM || ret == -EINTR || ret == -ERESTARTSYS)
 			goto cleanup_free;
 	}
@@ -918,54 +913,42 @@ void netfs_readahead(struct readahead_control *ractl,
 cleanup_free:
 	netfs_put_read_request(rreq, false);
 	return;
-cleanup:
-	if (netfs_priv)
-		ops->cleanup(ractl->mapping, netfs_priv);
-	return;
 }
 EXPORT_SYMBOL(netfs_readahead);
 
 /**
  * netfs_readpage - Helper to manage a readpage request
  * @file: The file to read from
- * @folio: The folio to read
- * @ops: The network filesystem's operations for the helper to use
- * @netfs_priv: Private netfs data to be retained in the request
+ * @subpage: A subpage of the folio to read
  *
  * Fulfil a readpage request by drawing data from the cache if possible, or the
  * netfs if not.  Space beyond the EOF is zero-filled.  Multiple I/O requests
  * from different sources will get munged together.
  *
- * The calling netfs must provide a table of operations, only one of which,
- * issue_op, is mandatory.  It may also be passed a private token, which will
- * be retained in rreq->netfs_priv and will be cleaned up by ops->cleanup().
+ * The calling netfs must initialise a netfs context contiguous to the vfs
+ * inode before calling this.
  *
  * This is usable whether or not caching is enabled.
  */
-int netfs_readpage(struct file *file,
-		   struct folio *folio,
-		   const struct netfs_read_request_ops *ops,
-		   void *netfs_priv)
+int netfs_readpage(struct file *file, struct page *subpage)
 {
+	struct folio *folio = page_folio(subpage);
+	struct address_space *mapping = folio_file_mapping(folio);
 	struct netfs_read_request *rreq;
+	struct netfs_i_context *ctx = netfs_i_context(mapping->host);
 	unsigned int debug_index = 0;
 	int ret;
 
 	_enter("%lx", folio_index(folio));
 
-	rreq = netfs_alloc_read_request(ops, netfs_priv, file);
-	if (!rreq) {
-		if (netfs_priv)
-			ops->cleanup(folio_file_mapping(folio), netfs_priv);
-		folio_unlock(folio);
-		return -ENOMEM;
-	}
-	rreq->mapping	= folio_file_mapping(folio);
+	rreq = netfs_alloc_read_request(mapping, file);
+	if (!rreq)
+		goto nomem;
 	rreq->start	= folio_file_pos(folio);
 	rreq->len	= folio_size(folio);
 
-	if (ops->begin_cache_operation) {
-		ret = ops->begin_cache_operation(rreq);
+	if (ctx->ops->begin_cache_operation) {
+		ret = ctx->ops->begin_cache_operation(rreq);
 		if (ret == -ENOMEM || ret == -EINTR || ret == -ERESTARTSYS) {
 			folio_unlock(folio);
 			goto out;
@@ -1001,6 +984,9 @@ int netfs_readpage(struct file *file,
 out:
 	netfs_put_read_request(rreq, false);
 	return ret;
+nomem:
+	folio_unlock(folio);
+	return -ENOMEM;
 }
 EXPORT_SYMBOL(netfs_readpage);
 
@@ -1009,6 +995,7 @@ EXPORT_SYMBOL(netfs_readpage);
  * @folio: The folio being prepared
  * @pos: starting position for the write
  * @len: length of write
+ * @always_fill: T if the folio should always be completely filled/cleared
  *
  * In some cases, write_begin doesn't need to read at all:
  * - full folio write
@@ -1018,17 +1005,27 @@ EXPORT_SYMBOL(netfs_readpage);
  * If any of these criteria are met, then zero out the unwritten parts
  * of the folio and return true. Otherwise, return false.
  */
-static bool netfs_skip_folio_read(struct folio *folio, loff_t pos, size_t len)
+static bool netfs_skip_folio_read(struct folio *folio, loff_t pos, size_t len,
+				 bool always_fill)
 {
 	struct inode *inode = folio_inode(folio);
 	loff_t i_size = i_size_read(inode);
 	size_t offset = offset_in_folio(folio, pos);
+	size_t plen = folio_size(folio);
+
+	if (unlikely(always_fill)) {
+		if (pos - offset + len <= i_size)
+			return false; /* Page entirely before EOF */
+		zero_user_segment(&folio->page, 0, plen);
+		folio_mark_uptodate(folio);
+		return true;
+	}
 
 	/* Full folio write */
-	if (offset == 0 && len >= folio_size(folio))
+	if (offset == 0 && len >= plen)
 		return true;
 
-	/* pos beyond last folio in the file */
+	/* Page entirely beyond the end of the file */
 	if (pos - offset >= i_size)
 		goto zero_out;
 
@@ -1038,7 +1035,7 @@ static bool netfs_skip_folio_read(struct folio *folio, loff_t pos, size_t len)
 
 	return false;
 zero_out:
-	zero_user_segments(&folio->page, 0, offset, offset + len, folio_size(folio));
+	zero_user_segments(&folio->page, 0, offset, offset + len, len);
 	return true;
 }
 
@@ -1051,8 +1048,6 @@ static bool netfs_skip_folio_read(struct folio *folio, loff_t pos, size_t len)
  * @aop_flags: AOP_* flags
  * @_folio: Where to put the resultant folio
  * @_fsdata: Place for the netfs to store a cookie
- * @ops: The network filesystem's operations for the helper to use
- * @netfs_priv: Private netfs data to be retained in the request
  *
  * Pre-read data for a write-begin request by drawing data from the cache if
  * possible, or the netfs if not.  Space beyond the EOF is zero-filled.
@@ -1071,17 +1066,18 @@ static bool netfs_skip_folio_read(struct folio *folio, loff_t pos, size_t len)
  * should go ahead; unlock the folio and return -EAGAIN to cause the folio to
  * be regot; or return an error.
  *
+ * The calling netfs must initialise a netfs context contiguous to the vfs
+ * inode before calling this.
+ *
  * This is usable whether or not caching is enabled.
  */
 int netfs_write_begin(struct file *file, struct address_space *mapping,
 		      loff_t pos, unsigned int len, unsigned int aop_flags,
-		      struct folio **_folio, void **_fsdata,
-		      const struct netfs_read_request_ops *ops,
-		      void *netfs_priv)
+		      struct folio **_folio, void **_fsdata)
 {
 	struct netfs_read_request *rreq;
+	struct netfs_i_context *ctx = netfs_i_context(file_inode(file ));
 	struct folio *folio;
-	struct inode *inode = file_inode(file);
 	unsigned int debug_index = 0, fgp_flags;
 	pgoff_t index = pos >> PAGE_SHIFT;
 	int ret;
@@ -1097,9 +1093,9 @@ int netfs_write_begin(struct file *file, struct address_space *mapping,
 	if (!folio)
 		return -ENOMEM;
 
-	if (ops->check_write_begin) {
+	if (ctx->ops->check_write_begin) {
 		/* Allow the netfs (eg. ceph) to flush conflicts. */
-		ret = ops->check_write_begin(file, pos, len, folio, _fsdata);
+		ret = ctx->ops->check_write_begin(file, pos, len, folio, _fsdata);
 		if (ret < 0) {
 			trace_netfs_failure(NULL, NULL, ret, netfs_fail_check_write_begin);
 			if (ret == -EAGAIN)
@@ -1115,25 +1111,23 @@ int netfs_write_begin(struct file *file, struct address_space *mapping,
 	 * within the cache granule containing the EOF, in which case we need
 	 * to preload the granule.
 	 */
-	if (!ops->is_cache_enabled(inode) &&
-	    netfs_skip_folio_read(folio, pos, len)) {
+	if (!netfs_is_cache_enabled(ctx) &&
+	    netfs_skip_folio_read(folio, pos, len, false)) {
 		netfs_stat(&netfs_n_rh_write_zskip);
 		goto have_folio_no_wait;
 	}
 
 	ret = -ENOMEM;
-	rreq = netfs_alloc_read_request(ops, netfs_priv, file);
+	rreq = netfs_alloc_read_request(mapping, file);
 	if (!rreq)
 		goto error;
-	rreq->mapping		= folio_file_mapping(folio);
 	rreq->start		= folio_file_pos(folio);
 	rreq->len		= folio_size(folio);
 	rreq->no_unlock_folio	= folio_index(folio);
 	__set_bit(NETFS_RREQ_NO_UNLOCK_FOLIO, &rreq->flags);
-	netfs_priv = NULL;
 
-	if (ops->begin_cache_operation) {
-		ret = ops->begin_cache_operation(rreq);
+	if (ctx->ops->begin_cache_operation) {
+		ret = ctx->ops->begin_cache_operation(rreq);
 		if (ret == -ENOMEM || ret == -EINTR || ret == -ERESTARTSYS)
 			goto error_put;
 	}
@@ -1186,8 +1180,6 @@ int netfs_write_begin(struct file *file, struct address_space *mapping,
 	if (ret < 0)
 		goto error;
 have_folio_no_wait:
-	if (netfs_priv)
-		ops->cleanup(mapping, netfs_priv);
 	*_folio = folio;
 	_leave(" = 0");
 	return 0;
@@ -1197,8 +1189,6 @@ int netfs_write_begin(struct file *file, struct address_space *mapping,
 error:
 	folio_unlock(folio);
 	folio_put(folio);
-	if (netfs_priv)
-		ops->cleanup(mapping, netfs_priv);
 	_leave(" = %d", ret);
 	return ret;
 }
diff --git a/fs/netfs/stats.c b/fs/netfs/stats.c
index 9ae538c85378..5510a7a14a40 100644
--- a/fs/netfs/stats.c
+++ b/fs/netfs/stats.c
@@ -7,7 +7,6 @@
 
 #include <linux/export.h>
 #include <linux/seq_file.h>
-#include <linux/netfs.h>
 #include "internal.h"
 
 atomic_t netfs_n_rh_readahead;
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index 614f22213e21..fdb449dbb9fa 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -116,6 +116,16 @@ enum netfs_read_source {
 typedef void (*netfs_io_terminated_t)(void *priv, ssize_t transferred_or_error,
 				      bool was_async);
 
+/*
+ * Per-inode description.  This must be directly after the inode struct.
+ */
+struct netfs_i_context {
+	const struct netfs_request_ops *ops;
+#if IS_ENABLED(CONFIG_FSCACHE)
+	struct fscache_cookie	*cache;
+#endif
+};
+
 /*
  * Resources required to do operations on a cache.
  */
@@ -176,14 +186,13 @@ struct netfs_read_request {
 #define NETFS_RREQ_DONT_UNLOCK_FOLIOS	3	/* Don't unlock the folios on completion */
 #define NETFS_RREQ_FAILED		4	/* The request failed */
 #define NETFS_RREQ_IN_PROGRESS		5	/* Unlocked when the request completes */
-	const struct netfs_read_request_ops *netfs_ops;
+	const struct netfs_request_ops *netfs_ops;
 };
 
 /*
  * Operations the network filesystem can/must provide to the helpers.
  */
-struct netfs_read_request_ops {
-	bool (*is_cache_enabled)(struct inode *inode);
+struct netfs_request_ops {
 	void (*init_rreq)(struct netfs_read_request *rreq, struct file *file);
 	int (*begin_cache_operation)(struct netfs_read_request *rreq);
 	void (*expand_readahead)(struct netfs_read_request *rreq);
@@ -254,20 +263,70 @@ struct netfs_cache_ops {
 };
 
 struct readahead_control;
-extern void netfs_readahead(struct readahead_control *,
-			    const struct netfs_read_request_ops *,
-			    void *);
-extern int netfs_readpage(struct file *,
-			  struct folio *,
-			  const struct netfs_read_request_ops *,
-			  void *);
+extern void netfs_readahead(struct readahead_control *);
+extern int netfs_readpage(struct file *, struct page *);
 extern int netfs_write_begin(struct file *, struct address_space *,
 			     loff_t, unsigned int, unsigned int, struct folio **,
-			     void **,
-			     const struct netfs_read_request_ops *,
-			     void *);
+			     void **);
 
 extern void netfs_subreq_terminated(struct netfs_read_subrequest *, ssize_t, bool);
 extern void netfs_stats_show(struct seq_file *);
 
+/**
+ * netfs_i_context - Get the netfs inode context from the inode
+ * @inode: The inode to query
+ *
+ * Get the netfs lib inode context from the network filesystem's inode.  The
+ * context struct is expected to directly follow on from the VFS inode struct.
+ */
+static inline struct netfs_i_context *netfs_i_context(struct inode *inode)
+{
+	return (struct netfs_i_context *)(inode + 1);
+}
+
+/**
+ * netfs_inode - Get the netfs inode from the inode context
+ * @ctx: The context to query
+ *
+ * Get the netfs inode from the netfs library's inode context.  The VFS inode
+ * is expected to directly precede the context struct.
+ */
+static inline struct inode *netfs_inode(struct netfs_i_context *ctx)
+{
+	return ((struct inode *)ctx) - 1;
+}
+
+/**
+ * netfs_i_context_init - Initialise a netfs lib context
+ * @inode: The inode with which the context is associated
+ * @ops: The netfs's operations list
+ *
+ * Initialise the netfs library context struct.  This is expected to follow on
+ * directly from the VFS inode struct.
+ */
+static inline void netfs_i_context_init(struct inode *inode,
+					const struct netfs_request_ops *ops)
+{
+	struct netfs_i_context *ctx = netfs_i_context(inode);
+
+	memset(ctx, 0, sizeof(*ctx));
+	ctx->ops = ops;
+}
+
+/**
+ * netfs_i_cookie - Get the cache cookie from the inode
+ * @inode: The inode to query
+ *
+ * Get the caching cookie (if enabled) from the network filesystem's inode.
+ */
+static inline struct fscache_cookie *netfs_i_cookie(struct inode *inode)
+{
+#ifdef CONFIG_FSCACHE
+	struct netfs_i_context *ctx = netfs_i_context(inode);
+	return ctx->cache;
+#else
+	return NULL;
+#endif
+ }
+
 #endif /* _LINUX_NETFS_H */



^ permalink raw reply related	[flat|nested] 20+ messages in thread

* [PATCH 04/19] netfs: Rename netfs_read_*request to netfs_io_*request
  2022-03-02 14:01 [PATCH 00/19] netfs: Prep for write helpers David Howells
                   ` (2 preceding siblings ...)
  2022-03-02 14:04 ` [PATCH 03/19] netfs: Add a netfs inode context David Howells
@ 2022-03-02 14:04 ` David Howells
  2022-03-02 14:04 ` [PATCH 05/19] netfs: Refactor arguments for netfs_alloc_read_request David Howells
                   ` (14 subsequent siblings)
  18 siblings, 0 replies; 20+ messages in thread
From: David Howells @ 2022-03-02 14:04 UTC (permalink / raw)
  To: linux-cachefs
  Cc: dhowells, Anna Schumaker, Steve French, Dominique Martinet,
	Jeff Layton, David Wysochanski, Ilya Dryomov, Jeffle Xu,
	Linus Torvalds, linux-afs, linux-nfs, linux-cifs, ceph-devel,
	v9fs-developer, linux-fsdevel, linux-kernel

Rename netfs_read_*request to netfs_io_*request so that the same structures
can be used for the write helpers too.

perl -p -i -e 's/netfs_read_(request|subrequest)/netfs_io_$1/g' \
   `git grep -l 'netfs_read_\(sub\|\)request'`
perl -p -i -e 's/netfs_read_(origin|source)/netfs_io_$1/g' \
   `git grep -l 'netfs_read_\(origin\|source\)'`
perl -p -i -e 's/nr_rd_ops/nr_outstanding/g' \
   `git grep -l nr_rd_ops`
perl -p -i -e 's/nr_wr_ops/nr_copy_ops/g' \
   `git grep -l nr_wr_ops`

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
---

 Documentation/filesystems/netfs_library.rst |   38 +++---
 fs/9p/vfs_addr.c                            |    8 +
 fs/afs/file.c                               |    8 +
 fs/afs/internal.h                           |    2 
 fs/cachefiles/io.c                          |    6 -
 fs/ceph/addr.c                              |   14 +-
 fs/ceph/cache.h                             |    4 -
 fs/netfs/read_helper.c                      |  182 ++++++++++++++-------------
 include/linux/netfs.h                       |   32 ++---
 include/trace/events/cachefiles.h           |    6 -
 include/trace/events/netfs.h                |   14 +-
 11 files changed, 157 insertions(+), 157 deletions(-)

diff --git a/Documentation/filesystems/netfs_library.rst b/Documentation/filesystems/netfs_library.rst
index 4f373a8ec47b..5e1b25349c41 100644
--- a/Documentation/filesystems/netfs_library.rst
+++ b/Documentation/filesystems/netfs_library.rst
@@ -71,11 +71,11 @@ Read Helper Functions
 Three read helpers are provided::
 
 	void netfs_readahead(struct readahead_control *ractl,
-			     const struct netfs_read_request_ops *ops,
+			     const struct netfs_io_request_ops *ops,
 			     void *netfs_priv);
 	int netfs_readpage(struct file *file,
 			   struct folio *folio,
-			   const struct netfs_read_request_ops *ops,
+			   const struct netfs_io_request_ops *ops,
 			   void *netfs_priv);
 	int netfs_write_begin(struct file *file,
 			      struct address_space *mapping,
@@ -84,7 +84,7 @@ Three read helpers are provided::
 			      unsigned int flags,
 			      struct folio **_folio,
 			      void **_fsdata,
-			      const struct netfs_read_request_ops *ops,
+			      const struct netfs_io_request_ops *ops,
 			      void *netfs_priv);
 
 Each corresponds to a VM operation, with the addition of a couple of parameters
@@ -116,7 +116,7 @@ occurs, the request will get partially completed if sufficient data is read.
 
 Additionally, there is::
 
-  * void netfs_subreq_terminated(struct netfs_read_subrequest *subreq,
+  * void netfs_subreq_terminated(struct netfs_io_subrequest *subreq,
 				 ssize_t transferred_or_error,
 				 bool was_async);
 
@@ -132,7 +132,7 @@ Read Helper Structures
 The read helpers make use of a couple of structures to maintain the state of
 the read.  The first is a structure that manages a read request as a whole::
 
-	struct netfs_read_request {
+	struct netfs_io_request {
 		struct inode		*inode;
 		struct address_space	*mapping;
 		struct netfs_cache_resources cache_resources;
@@ -140,7 +140,7 @@ the read.  The first is a structure that manages a read request as a whole::
 		loff_t			start;
 		size_t			len;
 		loff_t			i_size;
-		const struct netfs_read_request_ops *netfs_ops;
+		const struct netfs_io_request_ops *netfs_ops;
 		unsigned int		debug_id;
 		...
 	};
@@ -187,8 +187,8 @@ The above fields are the ones the netfs can use.  They are:
 The second structure is used to manage individual slices of the overall read
 request::
 
-	struct netfs_read_subrequest {
-		struct netfs_read_request *rreq;
+	struct netfs_io_subrequest {
+		struct netfs_io_request *rreq;
 		loff_t			start;
 		size_t			len;
 		size_t			transferred;
@@ -244,17 +244,17 @@ Read Helper Operations
 The network filesystem must provide the read helpers with a table of operations
 through which it can issue requests and negotiate::
 
-	struct netfs_read_request_ops {
-		void (*init_rreq)(struct netfs_read_request *rreq, struct file *file);
+	struct netfs_io_request_ops {
+		void (*init_rreq)(struct netfs_io_request *rreq, struct file *file);
 		bool (*is_cache_enabled)(struct inode *inode);
-		int (*begin_cache_operation)(struct netfs_read_request *rreq);
-		void (*expand_readahead)(struct netfs_read_request *rreq);
-		bool (*clamp_length)(struct netfs_read_subrequest *subreq);
-		void (*issue_op)(struct netfs_read_subrequest *subreq);
-		bool (*is_still_valid)(struct netfs_read_request *rreq);
+		int (*begin_cache_operation)(struct netfs_io_request *rreq);
+		void (*expand_readahead)(struct netfs_io_request *rreq);
+		bool (*clamp_length)(struct netfs_io_subrequest *subreq);
+		void (*issue_op)(struct netfs_io_subrequest *subreq);
+		bool (*is_still_valid)(struct netfs_io_request *rreq);
 		int (*check_write_begin)(struct file *file, loff_t pos, unsigned len,
 					 struct folio *folio, void **_fsdata);
-		void (*done)(struct netfs_read_request *rreq);
+		void (*done)(struct netfs_io_request *rreq);
 		void (*cleanup)(struct address_space *mapping, void *netfs_priv);
 	};
 
@@ -420,12 +420,12 @@ The network filesystem's ->begin_cache_operation() method is called to set up a
 cache and this must call into the cache to do the work.  If using fscache, for
 example, the cache would call::
 
-	int fscache_begin_read_operation(struct netfs_read_request *rreq,
+	int fscache_begin_read_operation(struct netfs_io_request *rreq,
 					 struct fscache_cookie *cookie);
 
 passing in the request pointer and the cookie corresponding to the file.
 
-The netfs_read_request object contains a place for the cache to hang its
+The netfs_io_request object contains a place for the cache to hang its
 state::
 
 	struct netfs_cache_resources {
@@ -443,7 +443,7 @@ operation table looks like the following::
 		void (*expand_readahead)(struct netfs_cache_resources *cres,
 					 loff_t *_start, size_t *_len, loff_t i_size);
 
-		enum netfs_read_source (*prepare_read)(struct netfs_read_subrequest *subreq,
+		enum netfs_io_source (*prepare_read)(struct netfs_io_subrequest *subreq,
 						       loff_t i_size);
 
 		int (*read)(struct netfs_cache_resources *cres,
diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
index 495767616cf4..088d37944963 100644
--- a/fs/9p/vfs_addr.c
+++ b/fs/9p/vfs_addr.c
@@ -31,9 +31,9 @@
  * v9fs_req_issue_op - Issue a read from 9P
  * @subreq: The read to make
  */
-static void v9fs_req_issue_op(struct netfs_read_subrequest *subreq)
+static void v9fs_req_issue_op(struct netfs_io_subrequest *subreq)
 {
-	struct netfs_read_request *rreq = subreq->rreq;
+	struct netfs_io_request *rreq = subreq->rreq;
 	struct p9_fid *fid = rreq->netfs_priv;
 	struct iov_iter to;
 	loff_t pos = subreq->start + subreq->transferred;
@@ -56,7 +56,7 @@ static void v9fs_req_issue_op(struct netfs_read_subrequest *subreq)
  * @rreq: The read request
  * @file: The file being read from
  */
-static void v9fs_init_rreq(struct netfs_read_request *rreq, struct file *file)
+static void v9fs_init_rreq(struct netfs_io_request *rreq, struct file *file)
 {
 	struct p9_fid *fid = file->private_data;
 
@@ -80,7 +80,7 @@ static void v9fs_req_cleanup(struct address_space *mapping, void *priv)
  * v9fs_begin_cache_operation - Begin a cache operation for a read
  * @rreq: The read request
  */
-static int v9fs_begin_cache_operation(struct netfs_read_request *rreq)
+static int v9fs_begin_cache_operation(struct netfs_io_request *rreq)
 {
 #ifdef CONFIG_9P_FSCACHE
 	struct fscache_cookie *cookie = v9fs_inode_cookie(V9FS_I(rreq->inode));
diff --git a/fs/afs/file.c b/fs/afs/file.c
index ee5fd2102a42..0e247fd0abef 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -238,7 +238,7 @@ void afs_put_read(struct afs_read *req)
 static void afs_fetch_data_notify(struct afs_operation *op)
 {
 	struct afs_read *req = op->fetch.req;
-	struct netfs_read_subrequest *subreq = req->subreq;
+	struct netfs_io_subrequest *subreq = req->subreq;
 	int error = op->error;
 
 	if (error == -ECONNABORTED)
@@ -308,7 +308,7 @@ int afs_fetch_data(struct afs_vnode *vnode, struct afs_read *req)
 	return afs_do_sync_operation(op);
 }
 
-static void afs_req_issue_op(struct netfs_read_subrequest *subreq)
+static void afs_req_issue_op(struct netfs_io_subrequest *subreq)
 {
 	struct afs_vnode *vnode = AFS_FS_I(subreq->rreq->inode);
 	struct afs_read *fsreq;
@@ -357,12 +357,12 @@ static int afs_symlink_readpage(struct file *file, struct page *page)
 	return ret;
 }
 
-static void afs_init_rreq(struct netfs_read_request *rreq, struct file *file)
+static void afs_init_rreq(struct netfs_io_request *rreq, struct file *file)
 {
 	rreq->netfs_priv = key_get(afs_file_key(file));
 }
 
-static int afs_begin_cache_operation(struct netfs_read_request *rreq)
+static int afs_begin_cache_operation(struct netfs_io_request *rreq)
 {
 #ifdef CONFIG_AFS_FSCACHE
 	struct afs_vnode *vnode = AFS_FS_I(rreq->inode);
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 9fec5fd70abc..75ca3026457e 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -207,7 +207,7 @@ struct afs_read {
 	loff_t			file_size;	/* File size returned by server */
 	struct key		*key;		/* The key to use to reissue the read */
 	struct afs_vnode	*vnode;		/* The file being read into. */
-	struct netfs_read_subrequest *subreq;	/* Fscache helper read request this belongs to */
+	struct netfs_io_subrequest *subreq;	/* Fscache helper read request this belongs to */
 	afs_dataversion_t	data_version;	/* Version number returned by server */
 	refcount_t		usage;
 	unsigned int		call_debug_id;
diff --git a/fs/cachefiles/io.c b/fs/cachefiles/io.c
index 753986ea1583..6ac6fdbc70d3 100644
--- a/fs/cachefiles/io.c
+++ b/fs/cachefiles/io.c
@@ -382,18 +382,18 @@ static int cachefiles_write(struct netfs_cache_resources *cres,
  * Prepare a read operation, shortening it to a cached/uncached
  * boundary as appropriate.
  */
-static enum netfs_read_source cachefiles_prepare_read(struct netfs_read_subrequest *subreq,
+static enum netfs_io_source cachefiles_prepare_read(struct netfs_io_subrequest *subreq,
 						      loff_t i_size)
 {
 	enum cachefiles_prepare_read_trace why;
-	struct netfs_read_request *rreq = subreq->rreq;
+	struct netfs_io_request *rreq = subreq->rreq;
 	struct netfs_cache_resources *cres = &rreq->cache_resources;
 	struct cachefiles_object *object;
 	struct cachefiles_cache *cache;
 	struct fscache_cookie *cookie = fscache_cres_cookie(cres);
 	const struct cred *saved_cred;
 	struct file *file = cachefiles_cres_file(cres);
-	enum netfs_read_source ret = NETFS_DOWNLOAD_FROM_SERVER;
+	enum netfs_io_source ret = NETFS_DOWNLOAD_FROM_SERVER;
 	loff_t off, to;
 	ino_t ino = file ? file_inode(file)->i_ino : 0;
 
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index cb43c1397da5..a6452ca3482e 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -183,7 +183,7 @@ static int ceph_releasepage(struct page *page, gfp_t gfp)
 	return 1;
 }
 
-static void ceph_netfs_expand_readahead(struct netfs_read_request *rreq)
+static void ceph_netfs_expand_readahead(struct netfs_io_request *rreq)
 {
 	struct inode *inode = rreq->inode;
 	struct ceph_inode_info *ci = ceph_inode(inode);
@@ -200,7 +200,7 @@ static void ceph_netfs_expand_readahead(struct netfs_read_request *rreq)
 	rreq->len = roundup(rreq->len, lo->stripe_unit);
 }
 
-static bool ceph_netfs_clamp_length(struct netfs_read_subrequest *subreq)
+static bool ceph_netfs_clamp_length(struct netfs_io_subrequest *subreq)
 {
 	struct inode *inode = subreq->rreq->inode;
 	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
@@ -219,7 +219,7 @@ static void finish_netfs_read(struct ceph_osd_request *req)
 {
 	struct ceph_fs_client *fsc = ceph_inode_to_client(req->r_inode);
 	struct ceph_osd_data *osd_data = osd_req_op_extent_osd_data(req, 0);
-	struct netfs_read_subrequest *subreq = req->r_priv;
+	struct netfs_io_subrequest *subreq = req->r_priv;
 	int num_pages;
 	int err = req->r_result;
 
@@ -245,9 +245,9 @@ static void finish_netfs_read(struct ceph_osd_request *req)
 	iput(req->r_inode);
 }
 
-static bool ceph_netfs_issue_op_inline(struct netfs_read_subrequest *subreq)
+static bool ceph_netfs_issue_op_inline(struct netfs_io_subrequest *subreq)
 {
-	struct netfs_read_request *rreq = subreq->rreq;
+	struct netfs_io_request *rreq = subreq->rreq;
 	struct inode *inode = rreq->inode;
 	struct ceph_mds_reply_info_parsed *rinfo;
 	struct ceph_mds_reply_info_in *iinfo;
@@ -298,9 +298,9 @@ static bool ceph_netfs_issue_op_inline(struct netfs_read_subrequest *subreq)
 	return true;
 }
 
-static void ceph_netfs_issue_op(struct netfs_read_subrequest *subreq)
+static void ceph_netfs_issue_op(struct netfs_io_subrequest *subreq)
 {
-	struct netfs_read_request *rreq = subreq->rreq;
+	struct netfs_io_request *rreq = subreq->rreq;
 	struct inode *inode = rreq->inode;
 	struct ceph_inode_info *ci = ceph_inode(inode);
 	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
diff --git a/fs/ceph/cache.h b/fs/ceph/cache.h
index 69646587aa75..c20e43cade94 100644
--- a/fs/ceph/cache.h
+++ b/fs/ceph/cache.h
@@ -57,7 +57,7 @@ static inline int ceph_fscache_set_page_dirty(struct page *page)
 	return fscache_set_page_dirty(page, ceph_fscache_cookie(ci));
 }
 
-static inline int ceph_begin_cache_operation(struct netfs_read_request *rreq)
+static inline int ceph_begin_cache_operation(struct netfs_io_request *rreq)
 {
 	struct fscache_cookie *cookie = ceph_fscache_cookie(ceph_inode(rreq->inode));
 
@@ -134,7 +134,7 @@ static inline bool ceph_is_cache_enabled(struct inode *inode)
 	return false;
 }
 
-static inline int ceph_begin_cache_operation(struct netfs_read_request *rreq)
+static inline int ceph_begin_cache_operation(struct netfs_io_request *rreq)
 {
 	return -ENOBUFS;
 }
diff --git a/fs/netfs/read_helper.c b/fs/netfs/read_helper.c
index b0b237669561..a90b3fbcb93f 100644
--- a/fs/netfs/read_helper.c
+++ b/fs/netfs/read_helper.c
@@ -27,24 +27,24 @@ module_param_named(debug, netfs_debug, uint, S_IWUSR | S_IRUGO);
 MODULE_PARM_DESC(netfs_debug, "Netfs support debugging mask");
 
 static void netfs_rreq_work(struct work_struct *);
-static void __netfs_put_subrequest(struct netfs_read_subrequest *, bool);
+static void __netfs_put_subrequest(struct netfs_io_subrequest *, bool);
 
-static void netfs_put_subrequest(struct netfs_read_subrequest *subreq,
+static void netfs_put_subrequest(struct netfs_io_subrequest *subreq,
 				 bool was_async)
 {
 	if (refcount_dec_and_test(&subreq->usage))
 		__netfs_put_subrequest(subreq, was_async);
 }
 
-static struct netfs_read_request *netfs_alloc_read_request(struct address_space *mapping,
+static struct netfs_io_request *netfs_alloc_read_request(struct address_space *mapping,
 							   struct file *file)
 {
 	static atomic_t debug_ids;
 	struct inode *inode = file ? file_inode(file) : mapping->host;
 	struct netfs_i_context *ctx = netfs_i_context(inode);
-	struct netfs_read_request *rreq;
+	struct netfs_io_request *rreq;
 
-	rreq = kzalloc(sizeof(struct netfs_read_request), GFP_KERNEL);
+	rreq = kzalloc(sizeof(struct netfs_io_request), GFP_KERNEL);
 	if (rreq) {
 		rreq->mapping	= mapping;
 		rreq->inode	= inode;
@@ -63,19 +63,19 @@ static struct netfs_read_request *netfs_alloc_read_request(struct address_space
 	return rreq;
 }
 
-static void netfs_get_read_request(struct netfs_read_request *rreq)
+static void netfs_get_read_request(struct netfs_io_request *rreq)
 {
 	refcount_inc(&rreq->usage);
 }
 
-static void netfs_rreq_clear_subreqs(struct netfs_read_request *rreq,
+static void netfs_rreq_clear_subreqs(struct netfs_io_request *rreq,
 				     bool was_async)
 {
-	struct netfs_read_subrequest *subreq;
+	struct netfs_io_subrequest *subreq;
 
 	while (!list_empty(&rreq->subrequests)) {
 		subreq = list_first_entry(&rreq->subrequests,
-					  struct netfs_read_subrequest, rreq_link);
+					  struct netfs_io_subrequest, rreq_link);
 		list_del(&subreq->rreq_link);
 		netfs_put_subrequest(subreq, was_async);
 	}
@@ -83,8 +83,8 @@ static void netfs_rreq_clear_subreqs(struct netfs_read_request *rreq,
 
 static void netfs_free_read_request(struct work_struct *work)
 {
-	struct netfs_read_request *rreq =
-		container_of(work, struct netfs_read_request, work);
+	struct netfs_io_request *rreq =
+		container_of(work, struct netfs_io_request, work);
 	netfs_rreq_clear_subreqs(rreq, false);
 	if (rreq->netfs_priv)
 		rreq->netfs_ops->cleanup(rreq->mapping, rreq->netfs_priv);
@@ -95,7 +95,7 @@ static void netfs_free_read_request(struct work_struct *work)
 	netfs_stat_d(&netfs_n_rh_rreq);
 }
 
-static void netfs_put_read_request(struct netfs_read_request *rreq, bool was_async)
+static void netfs_put_read_request(struct netfs_io_request *rreq, bool was_async)
 {
 	if (refcount_dec_and_test(&rreq->usage)) {
 		if (was_async) {
@@ -111,12 +111,12 @@ static void netfs_put_read_request(struct netfs_read_request *rreq, bool was_asy
 /*
  * Allocate and partially initialise an I/O request structure.
  */
-static struct netfs_read_subrequest *netfs_alloc_subrequest(
-	struct netfs_read_request *rreq)
+static struct netfs_io_subrequest *netfs_alloc_subrequest(
+	struct netfs_io_request *rreq)
 {
-	struct netfs_read_subrequest *subreq;
+	struct netfs_io_subrequest *subreq;
 
-	subreq = kzalloc(sizeof(struct netfs_read_subrequest), GFP_KERNEL);
+	subreq = kzalloc(sizeof(struct netfs_io_subrequest), GFP_KERNEL);
 	if (subreq) {
 		INIT_LIST_HEAD(&subreq->rreq_link);
 		refcount_set(&subreq->usage, 2);
@@ -128,15 +128,15 @@ static struct netfs_read_subrequest *netfs_alloc_subrequest(
 	return subreq;
 }
 
-static void netfs_get_read_subrequest(struct netfs_read_subrequest *subreq)
+static void netfs_get_read_subrequest(struct netfs_io_subrequest *subreq)
 {
 	refcount_inc(&subreq->usage);
 }
 
-static void __netfs_put_subrequest(struct netfs_read_subrequest *subreq,
+static void __netfs_put_subrequest(struct netfs_io_subrequest *subreq,
 				   bool was_async)
 {
-	struct netfs_read_request *rreq = subreq->rreq;
+	struct netfs_io_request *rreq = subreq->rreq;
 
 	trace_netfs_sreq(subreq, netfs_sreq_trace_free);
 	kfree(subreq);
@@ -147,7 +147,7 @@ static void __netfs_put_subrequest(struct netfs_read_subrequest *subreq,
 /*
  * Clear the unread part of an I/O request.
  */
-static void netfs_clear_unread(struct netfs_read_subrequest *subreq)
+static void netfs_clear_unread(struct netfs_io_subrequest *subreq)
 {
 	struct iov_iter iter;
 
@@ -160,7 +160,7 @@ static void netfs_clear_unread(struct netfs_read_subrequest *subreq)
 static void netfs_cache_read_terminated(void *priv, ssize_t transferred_or_error,
 					bool was_async)
 {
-	struct netfs_read_subrequest *subreq = priv;
+	struct netfs_io_subrequest *subreq = priv;
 
 	netfs_subreq_terminated(subreq, transferred_or_error, was_async);
 }
@@ -169,8 +169,8 @@ static void netfs_cache_read_terminated(void *priv, ssize_t transferred_or_error
  * Issue a read against the cache.
  * - Eats the caller's ref on subreq.
  */
-static void netfs_read_from_cache(struct netfs_read_request *rreq,
-				  struct netfs_read_subrequest *subreq,
+static void netfs_read_from_cache(struct netfs_io_request *rreq,
+				  struct netfs_io_subrequest *subreq,
 				  enum netfs_read_from_hole read_hole)
 {
 	struct netfs_cache_resources *cres = &rreq->cache_resources;
@@ -188,8 +188,8 @@ static void netfs_read_from_cache(struct netfs_read_request *rreq,
 /*
  * Fill a subrequest region with zeroes.
  */
-static void netfs_fill_with_zeroes(struct netfs_read_request *rreq,
-				   struct netfs_read_subrequest *subreq)
+static void netfs_fill_with_zeroes(struct netfs_io_request *rreq,
+				   struct netfs_io_subrequest *subreq)
 {
 	netfs_stat(&netfs_n_rh_zero);
 	__set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags);
@@ -212,8 +212,8 @@ static void netfs_fill_with_zeroes(struct netfs_read_request *rreq,
  * - NETFS_SREQ_CLEAR_TAIL: A short read - the rest of the buffer will be
  *   cleared.
  */
-static void netfs_read_from_server(struct netfs_read_request *rreq,
-				   struct netfs_read_subrequest *subreq)
+static void netfs_read_from_server(struct netfs_io_request *rreq,
+				   struct netfs_io_subrequest *subreq)
 {
 	netfs_stat(&netfs_n_rh_download);
 	rreq->netfs_ops->issue_op(subreq);
@@ -222,7 +222,7 @@ static void netfs_read_from_server(struct netfs_read_request *rreq,
 /*
  * Release those waiting.
  */
-static void netfs_rreq_completed(struct netfs_read_request *rreq, bool was_async)
+static void netfs_rreq_completed(struct netfs_io_request *rreq, bool was_async)
 {
 	trace_netfs_rreq(rreq, netfs_rreq_trace_done);
 	netfs_rreq_clear_subreqs(rreq, was_async);
@@ -235,10 +235,10 @@ static void netfs_rreq_completed(struct netfs_read_request *rreq, bool was_async
  *
  * May be called in softirq mode and we inherit a ref from the caller.
  */
-static void netfs_rreq_unmark_after_write(struct netfs_read_request *rreq,
+static void netfs_rreq_unmark_after_write(struct netfs_io_request *rreq,
 					  bool was_async)
 {
-	struct netfs_read_subrequest *subreq;
+	struct netfs_io_subrequest *subreq;
 	struct folio *folio;
 	pgoff_t unlocked = 0;
 	bool have_unlocked = false;
@@ -267,8 +267,8 @@ static void netfs_rreq_unmark_after_write(struct netfs_read_request *rreq,
 static void netfs_rreq_copy_terminated(void *priv, ssize_t transferred_or_error,
 				       bool was_async)
 {
-	struct netfs_read_subrequest *subreq = priv;
-	struct netfs_read_request *rreq = subreq->rreq;
+	struct netfs_io_subrequest *subreq = priv;
+	struct netfs_io_request *rreq = subreq->rreq;
 
 	if (IS_ERR_VALUE(transferred_or_error)) {
 		netfs_stat(&netfs_n_rh_write_failed);
@@ -280,8 +280,8 @@ static void netfs_rreq_copy_terminated(void *priv, ssize_t transferred_or_error,
 
 	trace_netfs_sreq(subreq, netfs_sreq_trace_write_term);
 
-	/* If we decrement nr_wr_ops to 0, the ref belongs to us. */
-	if (atomic_dec_and_test(&rreq->nr_wr_ops))
+	/* If we decrement nr_copy_ops to 0, the ref belongs to us. */
+	if (atomic_dec_and_test(&rreq->nr_copy_ops))
 		netfs_rreq_unmark_after_write(rreq, was_async);
 
 	netfs_put_subrequest(subreq, was_async);
@@ -291,10 +291,10 @@ static void netfs_rreq_copy_terminated(void *priv, ssize_t transferred_or_error,
  * Perform any outstanding writes to the cache.  We inherit a ref from the
  * caller.
  */
-static void netfs_rreq_do_write_to_cache(struct netfs_read_request *rreq)
+static void netfs_rreq_do_write_to_cache(struct netfs_io_request *rreq)
 {
 	struct netfs_cache_resources *cres = &rreq->cache_resources;
-	struct netfs_read_subrequest *subreq, *next, *p;
+	struct netfs_io_subrequest *subreq, *next, *p;
 	struct iov_iter iter;
 	int ret;
 
@@ -303,7 +303,7 @@ static void netfs_rreq_do_write_to_cache(struct netfs_read_request *rreq)
 	/* We don't want terminating writes trying to wake us up whilst we're
 	 * still going through the list.
 	 */
-	atomic_inc(&rreq->nr_wr_ops);
+	atomic_inc(&rreq->nr_copy_ops);
 
 	list_for_each_entry_safe(subreq, p, &rreq->subrequests, rreq_link) {
 		if (!test_bit(NETFS_SREQ_WRITE_TO_CACHE, &subreq->flags)) {
@@ -334,7 +334,7 @@ static void netfs_rreq_do_write_to_cache(struct netfs_read_request *rreq)
 		iov_iter_xarray(&iter, WRITE, &rreq->mapping->i_pages,
 				subreq->start, subreq->len);
 
-		atomic_inc(&rreq->nr_wr_ops);
+		atomic_inc(&rreq->nr_copy_ops);
 		netfs_stat(&netfs_n_rh_write);
 		netfs_get_read_subrequest(subreq);
 		trace_netfs_sreq(subreq, netfs_sreq_trace_write);
@@ -342,20 +342,20 @@ static void netfs_rreq_do_write_to_cache(struct netfs_read_request *rreq)
 				 netfs_rreq_copy_terminated, subreq);
 	}
 
-	/* If we decrement nr_wr_ops to 0, the usage ref belongs to us. */
-	if (atomic_dec_and_test(&rreq->nr_wr_ops))
+	/* If we decrement nr_copy_ops to 0, the usage ref belongs to us. */
+	if (atomic_dec_and_test(&rreq->nr_copy_ops))
 		netfs_rreq_unmark_after_write(rreq, false);
 }
 
 static void netfs_rreq_write_to_cache_work(struct work_struct *work)
 {
-	struct netfs_read_request *rreq =
-		container_of(work, struct netfs_read_request, work);
+	struct netfs_io_request *rreq =
+		container_of(work, struct netfs_io_request, work);
 
 	netfs_rreq_do_write_to_cache(rreq);
 }
 
-static void netfs_rreq_write_to_cache(struct netfs_read_request *rreq)
+static void netfs_rreq_write_to_cache(struct netfs_io_request *rreq)
 {
 	rreq->work.func = netfs_rreq_write_to_cache_work;
 	if (!queue_work(system_unbound_wq, &rreq->work))
@@ -366,9 +366,9 @@ static void netfs_rreq_write_to_cache(struct netfs_read_request *rreq)
  * Unlock the folios in a read operation.  We need to set PG_fscache on any
  * folios we're going to write back before we unlock them.
  */
-static void netfs_rreq_unlock(struct netfs_read_request *rreq)
+static void netfs_rreq_unlock(struct netfs_io_request *rreq)
 {
-	struct netfs_read_subrequest *subreq;
+	struct netfs_io_subrequest *subreq;
 	struct folio *folio;
 	unsigned int iopos, account = 0;
 	pgoff_t start_page = rreq->start / PAGE_SIZE;
@@ -391,7 +391,7 @@ static void netfs_rreq_unlock(struct netfs_read_request *rreq)
 	 * mixture inside.
 	 */
 	subreq = list_first_entry(&rreq->subrequests,
-				  struct netfs_read_subrequest, rreq_link);
+				  struct netfs_io_subrequest, rreq_link);
 	iopos = 0;
 	subreq_failed = (subreq->error < 0);
 
@@ -450,8 +450,8 @@ static void netfs_rreq_unlock(struct netfs_read_request *rreq)
 /*
  * Handle a short read.
  */
-static void netfs_rreq_short_read(struct netfs_read_request *rreq,
-				  struct netfs_read_subrequest *subreq)
+static void netfs_rreq_short_read(struct netfs_io_request *rreq,
+				  struct netfs_io_subrequest *subreq)
 {
 	__clear_bit(NETFS_SREQ_SHORT_READ, &subreq->flags);
 	__set_bit(NETFS_SREQ_SEEK_DATA_READ, &subreq->flags);
@@ -460,7 +460,7 @@ static void netfs_rreq_short_read(struct netfs_read_request *rreq,
 	trace_netfs_sreq(subreq, netfs_sreq_trace_resubmit_short);
 
 	netfs_get_read_subrequest(subreq);
-	atomic_inc(&rreq->nr_rd_ops);
+	atomic_inc(&rreq->nr_outstanding);
 	if (subreq->source == NETFS_READ_FROM_CACHE)
 		netfs_read_from_cache(rreq, subreq, NETFS_READ_HOLE_CLEAR);
 	else
@@ -471,9 +471,9 @@ static void netfs_rreq_short_read(struct netfs_read_request *rreq,
  * Resubmit any short or failed operations.  Returns true if we got the rreq
  * ref back.
  */
-static bool netfs_rreq_perform_resubmissions(struct netfs_read_request *rreq)
+static bool netfs_rreq_perform_resubmissions(struct netfs_io_request *rreq)
 {
-	struct netfs_read_subrequest *subreq;
+	struct netfs_io_subrequest *subreq;
 
 	WARN_ON(in_interrupt());
 
@@ -482,7 +482,7 @@ static bool netfs_rreq_perform_resubmissions(struct netfs_read_request *rreq)
 	/* We don't want terminating submissions trying to wake us up whilst
 	 * we're still going through the list.
 	 */
-	atomic_inc(&rreq->nr_rd_ops);
+	atomic_inc(&rreq->nr_outstanding);
 
 	__clear_bit(NETFS_RREQ_INCOMPLETE_IO, &rreq->flags);
 	list_for_each_entry(subreq, &rreq->subrequests, rreq_link) {
@@ -494,27 +494,27 @@ static bool netfs_rreq_perform_resubmissions(struct netfs_read_request *rreq)
 			netfs_stat(&netfs_n_rh_download_instead);
 			trace_netfs_sreq(subreq, netfs_sreq_trace_download_instead);
 			netfs_get_read_subrequest(subreq);
-			atomic_inc(&rreq->nr_rd_ops);
+			atomic_inc(&rreq->nr_outstanding);
 			netfs_read_from_server(rreq, subreq);
 		} else if (test_bit(NETFS_SREQ_SHORT_READ, &subreq->flags)) {
 			netfs_rreq_short_read(rreq, subreq);
 		}
 	}
 
-	/* If we decrement nr_rd_ops to 0, the usage ref belongs to us. */
-	if (atomic_dec_and_test(&rreq->nr_rd_ops))
+	/* If we decrement nr_outstanding to 0, the usage ref belongs to us. */
+	if (atomic_dec_and_test(&rreq->nr_outstanding))
 		return true;
 
-	wake_up_var(&rreq->nr_rd_ops);
+	wake_up_var(&rreq->nr_outstanding);
 	return false;
 }
 
 /*
  * Check to see if the data read is still valid.
  */
-static void netfs_rreq_is_still_valid(struct netfs_read_request *rreq)
+static void netfs_rreq_is_still_valid(struct netfs_io_request *rreq)
 {
-	struct netfs_read_subrequest *subreq;
+	struct netfs_io_subrequest *subreq;
 
 	if (!rreq->netfs_ops->is_still_valid ||
 	    rreq->netfs_ops->is_still_valid(rreq))
@@ -534,7 +534,7 @@ static void netfs_rreq_is_still_valid(struct netfs_read_request *rreq)
  * Note that we could be in an ordinary kernel thread, on a workqueue or in
  * softirq context at this point.  We inherit a ref from the caller.
  */
-static void netfs_rreq_assess(struct netfs_read_request *rreq, bool was_async)
+static void netfs_rreq_assess(struct netfs_io_request *rreq, bool was_async)
 {
 	trace_netfs_rreq(rreq, netfs_rreq_trace_assess);
 
@@ -561,8 +561,8 @@ static void netfs_rreq_assess(struct netfs_read_request *rreq, bool was_async)
 
 static void netfs_rreq_work(struct work_struct *work)
 {
-	struct netfs_read_request *rreq =
-		container_of(work, struct netfs_read_request, work);
+	struct netfs_io_request *rreq =
+		container_of(work, struct netfs_io_request, work);
 	netfs_rreq_assess(rreq, false);
 }
 
@@ -570,7 +570,7 @@ static void netfs_rreq_work(struct work_struct *work)
  * Handle the completion of all outstanding I/O operations on a read request.
  * We inherit a ref from the caller.
  */
-static void netfs_rreq_terminated(struct netfs_read_request *rreq,
+static void netfs_rreq_terminated(struct netfs_io_request *rreq,
 				  bool was_async)
 {
 	if (test_bit(NETFS_RREQ_INCOMPLETE_IO, &rreq->flags) &&
@@ -600,11 +600,11 @@ static void netfs_rreq_terminated(struct netfs_read_request *rreq,
  * If @was_async is true, the caller might be running in softirq or interrupt
  * context and we can't sleep.
  */
-void netfs_subreq_terminated(struct netfs_read_subrequest *subreq,
+void netfs_subreq_terminated(struct netfs_io_subrequest *subreq,
 			     ssize_t transferred_or_error,
 			     bool was_async)
 {
-	struct netfs_read_request *rreq = subreq->rreq;
+	struct netfs_io_request *rreq = subreq->rreq;
 	int u;
 
 	_enter("[%u]{%llx,%lx},%zd",
@@ -648,12 +648,12 @@ void netfs_subreq_terminated(struct netfs_read_subrequest *subreq,
 out:
 	trace_netfs_sreq(subreq, netfs_sreq_trace_terminated);
 
-	/* If we decrement nr_rd_ops to 0, the ref belongs to us. */
-	u = atomic_dec_return(&rreq->nr_rd_ops);
+	/* If we decrement nr_outstanding to 0, the ref belongs to us. */
+	u = atomic_dec_return(&rreq->nr_outstanding);
 	if (u == 0)
 		netfs_rreq_terminated(rreq, was_async);
 	else if (u == 1)
-		wake_up_var(&rreq->nr_rd_ops);
+		wake_up_var(&rreq->nr_outstanding);
 
 	netfs_put_subrequest(subreq, was_async);
 	return;
@@ -691,10 +691,10 @@ void netfs_subreq_terminated(struct netfs_read_subrequest *subreq,
 }
 EXPORT_SYMBOL(netfs_subreq_terminated);
 
-static enum netfs_read_source netfs_cache_prepare_read(struct netfs_read_subrequest *subreq,
+static enum netfs_io_source netfs_cache_prepare_read(struct netfs_io_subrequest *subreq,
 						       loff_t i_size)
 {
-	struct netfs_read_request *rreq = subreq->rreq;
+	struct netfs_io_request *rreq = subreq->rreq;
 	struct netfs_cache_resources *cres = &rreq->cache_resources;
 
 	if (cres->ops)
@@ -707,11 +707,11 @@ static enum netfs_read_source netfs_cache_prepare_read(struct netfs_read_subrequ
 /*
  * Work out what sort of subrequest the next one will be.
  */
-static enum netfs_read_source
-netfs_rreq_prepare_read(struct netfs_read_request *rreq,
-			struct netfs_read_subrequest *subreq)
+static enum netfs_io_source
+netfs_rreq_prepare_read(struct netfs_io_request *rreq,
+			struct netfs_io_subrequest *subreq)
 {
-	enum netfs_read_source source;
+	enum netfs_io_source source;
 
 	_enter("%llx-%llx,%llx", subreq->start, subreq->start + subreq->len, rreq->i_size);
 
@@ -748,11 +748,11 @@ netfs_rreq_prepare_read(struct netfs_read_request *rreq,
 /*
  * Slice off a piece of a read request and submit an I/O request for it.
  */
-static bool netfs_rreq_submit_slice(struct netfs_read_request *rreq,
+static bool netfs_rreq_submit_slice(struct netfs_io_request *rreq,
 				    unsigned int *_debug_index)
 {
-	struct netfs_read_subrequest *subreq;
-	enum netfs_read_source source;
+	struct netfs_io_subrequest *subreq;
+	enum netfs_io_source source;
 
 	subreq = netfs_alloc_subrequest(rreq);
 	if (!subreq)
@@ -777,7 +777,7 @@ static bool netfs_rreq_submit_slice(struct netfs_read_request *rreq,
 	if (source == NETFS_INVALID_READ)
 		goto subreq_failed;
 
-	atomic_inc(&rreq->nr_rd_ops);
+	atomic_inc(&rreq->nr_outstanding);
 
 	rreq->submitted += subreq->len;
 
@@ -804,7 +804,7 @@ static bool netfs_rreq_submit_slice(struct netfs_read_request *rreq,
 	return false;
 }
 
-static void netfs_cache_expand_readahead(struct netfs_read_request *rreq,
+static void netfs_cache_expand_readahead(struct netfs_io_request *rreq,
 					 loff_t *_start, size_t *_len, loff_t i_size)
 {
 	struct netfs_cache_resources *cres = &rreq->cache_resources;
@@ -813,7 +813,7 @@ static void netfs_cache_expand_readahead(struct netfs_read_request *rreq,
 		cres->ops->expand_readahead(cres, _start, _len, i_size);
 }
 
-static void netfs_rreq_expand(struct netfs_read_request *rreq,
+static void netfs_rreq_expand(struct netfs_io_request *rreq,
 			      struct readahead_control *ractl)
 {
 	/* Give the cache a chance to change the request parameters.  The
@@ -864,7 +864,7 @@ static void netfs_rreq_expand(struct netfs_read_request *rreq,
  */
 void netfs_readahead(struct readahead_control *ractl)
 {
-	struct netfs_read_request *rreq;
+	struct netfs_io_request *rreq;
 	struct netfs_i_context *ctx = netfs_i_context(ractl->mapping->host);
 	unsigned int debug_index = 0;
 	int ret;
@@ -892,7 +892,7 @@ void netfs_readahead(struct readahead_control *ractl)
 
 	netfs_rreq_expand(rreq, ractl);
 
-	atomic_set(&rreq->nr_rd_ops, 1);
+	atomic_set(&rreq->nr_outstanding, 1);
 	do {
 		if (!netfs_rreq_submit_slice(rreq, &debug_index))
 			break;
@@ -905,8 +905,8 @@ void netfs_readahead(struct readahead_control *ractl)
 	while (readahead_folio(ractl))
 		;
 
-	/* If we decrement nr_rd_ops to 0, the ref belongs to us. */
-	if (atomic_dec_and_test(&rreq->nr_rd_ops))
+	/* If we decrement nr_outstanding to 0, the ref belongs to us. */
+	if (atomic_dec_and_test(&rreq->nr_outstanding))
 		netfs_rreq_assess(rreq, false);
 	return;
 
@@ -934,7 +934,7 @@ int netfs_readpage(struct file *file, struct page *subpage)
 {
 	struct folio *folio = page_folio(subpage);
 	struct address_space *mapping = folio_file_mapping(folio);
-	struct netfs_read_request *rreq;
+	struct netfs_io_request *rreq;
 	struct netfs_i_context *ctx = netfs_i_context(mapping->host);
 	unsigned int debug_index = 0;
 	int ret;
@@ -960,19 +960,19 @@ int netfs_readpage(struct file *file, struct page *subpage)
 
 	netfs_get_read_request(rreq);
 
-	atomic_set(&rreq->nr_rd_ops, 1);
+	atomic_set(&rreq->nr_outstanding, 1);
 	do {
 		if (!netfs_rreq_submit_slice(rreq, &debug_index))
 			break;
 
 	} while (rreq->submitted < rreq->len);
 
-	/* Keep nr_rd_ops incremented so that the ref always belongs to us, and
+	/* Keep nr_outstanding incremented so that the ref always belongs to us, and
 	 * the service code isn't punted off to a random thread pool to
 	 * process.
 	 */
 	do {
-		wait_var_event(&rreq->nr_rd_ops, atomic_read(&rreq->nr_rd_ops) == 1);
+		wait_var_event(&rreq->nr_outstanding, atomic_read(&rreq->nr_outstanding) == 1);
 		netfs_rreq_assess(rreq, false);
 	} while (test_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags));
 
@@ -1075,7 +1075,7 @@ int netfs_write_begin(struct file *file, struct address_space *mapping,
 		      loff_t pos, unsigned int len, unsigned int aop_flags,
 		      struct folio **_folio, void **_fsdata)
 {
-	struct netfs_read_request *rreq;
+	struct netfs_io_request *rreq;
 	struct netfs_i_context *ctx = netfs_i_context(file_inode(file ));
 	struct folio *folio;
 	unsigned int debug_index = 0, fgp_flags;
@@ -1147,19 +1147,19 @@ int netfs_write_begin(struct file *file, struct address_space *mapping,
 	while (readahead_folio(&ractl))
 		;
 
-	atomic_set(&rreq->nr_rd_ops, 1);
+	atomic_set(&rreq->nr_outstanding, 1);
 	do {
 		if (!netfs_rreq_submit_slice(rreq, &debug_index))
 			break;
 
 	} while (rreq->submitted < rreq->len);
 
-	/* Keep nr_rd_ops incremented so that the ref always belongs to us, and
+	/* Keep nr_outstanding incremented so that the ref always belongs to us, and
 	 * the service code isn't punted off to a random thread pool to
 	 * process.
 	 */
 	for (;;) {
-		wait_var_event(&rreq->nr_rd_ops, atomic_read(&rreq->nr_rd_ops) == 1);
+		wait_var_event(&rreq->nr_outstanding, atomic_read(&rreq->nr_outstanding) == 1);
 		netfs_rreq_assess(rreq, false);
 		if (!test_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags))
 			break;
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index fdb449dbb9fa..630b0400e9fa 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -106,7 +106,7 @@ static inline int wait_on_page_fscache_killable(struct page *page)
 	return folio_wait_private_2_killable(page_folio(page));
 }
 
-enum netfs_read_source {
+enum netfs_io_source {
 	NETFS_FILL_WITH_ZEROES,
 	NETFS_DOWNLOAD_FROM_SERVER,
 	NETFS_READ_FROM_CACHE,
@@ -140,8 +140,8 @@ struct netfs_cache_resources {
 /*
  * Descriptor for a single component subrequest.
  */
-struct netfs_read_subrequest {
-	struct netfs_read_request *rreq;	/* Supervising read request */
+struct netfs_io_subrequest {
+	struct netfs_io_request *rreq;	/* Supervising read request */
 	struct list_head	rreq_link;	/* Link in rreq->subrequests */
 	loff_t			start;		/* Where to start the I/O */
 	size_t			len;		/* Size of the I/O */
@@ -149,7 +149,7 @@ struct netfs_read_subrequest {
 	refcount_t		usage;
 	short			error;		/* 0 or error that occurred */
 	unsigned short		debug_index;	/* Index in list (for debugging output) */
-	enum netfs_read_source	source;		/* Where to read from */
+	enum netfs_io_source	source;		/* Where to read from */
 	unsigned long		flags;
 #define NETFS_SREQ_WRITE_TO_CACHE	0	/* Set if should write to cache */
 #define NETFS_SREQ_CLEAR_TAIL		1	/* Set if the rest of the read should be cleared */
@@ -162,7 +162,7 @@ struct netfs_read_subrequest {
  * Descriptor for a read helper request.  This is used to make multiple I/O
  * requests on a variety of sources and then stitch the result together.
  */
-struct netfs_read_request {
+struct netfs_io_request {
 	struct work_struct	work;
 	struct inode		*inode;		/* The file being accessed */
 	struct address_space	*mapping;	/* The mapping being accessed */
@@ -170,8 +170,8 @@ struct netfs_read_request {
 	struct list_head	subrequests;	/* Requests to fetch I/O from disk or net */
 	void			*netfs_priv;	/* Private data for the netfs */
 	unsigned int		debug_id;
-	atomic_t		nr_rd_ops;	/* Number of read ops in progress */
-	atomic_t		nr_wr_ops;	/* Number of write ops in progress */
+	atomic_t		nr_outstanding;	/* Number of read ops in progress */
+	atomic_t		nr_copy_ops;	/* Number of write ops in progress */
 	size_t			submitted;	/* Amount submitted for I/O so far */
 	size_t			len;		/* Length of the request */
 	short			error;		/* 0 or error that occurred */
@@ -193,15 +193,15 @@ struct netfs_read_request {
  * Operations the network filesystem can/must provide to the helpers.
  */
 struct netfs_request_ops {
-	void (*init_rreq)(struct netfs_read_request *rreq, struct file *file);
-	int (*begin_cache_operation)(struct netfs_read_request *rreq);
-	void (*expand_readahead)(struct netfs_read_request *rreq);
-	bool (*clamp_length)(struct netfs_read_subrequest *subreq);
-	void (*issue_op)(struct netfs_read_subrequest *subreq);
-	bool (*is_still_valid)(struct netfs_read_request *rreq);
+	void (*init_rreq)(struct netfs_io_request *rreq, struct file *file);
+	int (*begin_cache_operation)(struct netfs_io_request *rreq);
+	void (*expand_readahead)(struct netfs_io_request *rreq);
+	bool (*clamp_length)(struct netfs_io_subrequest *subreq);
+	void (*issue_op)(struct netfs_io_subrequest *subreq);
+	bool (*is_still_valid)(struct netfs_io_request *rreq);
 	int (*check_write_begin)(struct file *file, loff_t pos, unsigned len,
 				 struct folio *folio, void **_fsdata);
-	void (*done)(struct netfs_read_request *rreq);
+	void (*done)(struct netfs_io_request *rreq);
 	void (*cleanup)(struct address_space *mapping, void *netfs_priv);
 };
 
@@ -244,7 +244,7 @@ struct netfs_cache_ops {
 	/* Prepare a read operation, shortening it to a cached/uncached
 	 * boundary as appropriate.
 	 */
-	enum netfs_read_source (*prepare_read)(struct netfs_read_subrequest *subreq,
+	enum netfs_io_source (*prepare_read)(struct netfs_io_subrequest *subreq,
 					       loff_t i_size);
 
 	/* Prepare a write operation, working out what part of the write we can
@@ -269,7 +269,7 @@ extern int netfs_write_begin(struct file *, struct address_space *,
 			     loff_t, unsigned int, unsigned int, struct folio **,
 			     void **);
 
-extern void netfs_subreq_terminated(struct netfs_read_subrequest *, ssize_t, bool);
+extern void netfs_subreq_terminated(struct netfs_io_subrequest *, ssize_t, bool);
 extern void netfs_stats_show(struct seq_file *);
 
 /**
diff --git a/include/trace/events/cachefiles.h b/include/trace/events/cachefiles.h
index c6f5aa74db89..002d0ae4f9bc 100644
--- a/include/trace/events/cachefiles.h
+++ b/include/trace/events/cachefiles.h
@@ -424,8 +424,8 @@ TRACE_EVENT(cachefiles_vol_coherency,
 	    );
 
 TRACE_EVENT(cachefiles_prep_read,
-	    TP_PROTO(struct netfs_read_subrequest *sreq,
-		     enum netfs_read_source source,
+	    TP_PROTO(struct netfs_io_subrequest *sreq,
+		     enum netfs_io_source source,
 		     enum cachefiles_prepare_read_trace why,
 		     ino_t cache_inode),
 
@@ -435,7 +435,7 @@ TRACE_EVENT(cachefiles_prep_read,
 		    __field(unsigned int,		rreq		)
 		    __field(unsigned short,		index		)
 		    __field(unsigned short,		flags		)
-		    __field(enum netfs_read_source,	source		)
+		    __field(enum netfs_io_source,	source		)
 		    __field(enum cachefiles_prepare_read_trace,	why	)
 		    __field(size_t,			len		)
 		    __field(loff_t,			start		)
diff --git a/include/trace/events/netfs.h b/include/trace/events/netfs.h
index 88d9a74dd346..2d0665b416bf 100644
--- a/include/trace/events/netfs.h
+++ b/include/trace/events/netfs.h
@@ -94,7 +94,7 @@ netfs_failures;
 #define E_(a, b)	{ a, b }
 
 TRACE_EVENT(netfs_read,
-	    TP_PROTO(struct netfs_read_request *rreq,
+	    TP_PROTO(struct netfs_io_request *rreq,
 		     loff_t start, size_t len,
 		     enum netfs_read_trace what),
 
@@ -127,7 +127,7 @@ TRACE_EVENT(netfs_read,
 	    );
 
 TRACE_EVENT(netfs_rreq,
-	    TP_PROTO(struct netfs_read_request *rreq,
+	    TP_PROTO(struct netfs_io_request *rreq,
 		     enum netfs_rreq_trace what),
 
 	    TP_ARGS(rreq, what),
@@ -151,7 +151,7 @@ TRACE_EVENT(netfs_rreq,
 	    );
 
 TRACE_EVENT(netfs_sreq,
-	    TP_PROTO(struct netfs_read_subrequest *sreq,
+	    TP_PROTO(struct netfs_io_subrequest *sreq,
 		     enum netfs_sreq_trace what),
 
 	    TP_ARGS(sreq, what),
@@ -161,7 +161,7 @@ TRACE_EVENT(netfs_sreq,
 		    __field(unsigned short,		index		)
 		    __field(short,			error		)
 		    __field(unsigned short,		flags		)
-		    __field(enum netfs_read_source,	source		)
+		    __field(enum netfs_io_source,	source		)
 		    __field(enum netfs_sreq_trace,	what		)
 		    __field(size_t,			len		)
 		    __field(size_t,			transferred	)
@@ -190,8 +190,8 @@ TRACE_EVENT(netfs_sreq,
 	    );
 
 TRACE_EVENT(netfs_failure,
-	    TP_PROTO(struct netfs_read_request *rreq,
-		     struct netfs_read_subrequest *sreq,
+	    TP_PROTO(struct netfs_io_request *rreq,
+		     struct netfs_io_subrequest *sreq,
 		     int error, enum netfs_failure what),
 
 	    TP_ARGS(rreq, sreq, error, what),
@@ -201,7 +201,7 @@ TRACE_EVENT(netfs_failure,
 		    __field(unsigned short,		index		)
 		    __field(short,			error		)
 		    __field(unsigned short,		flags		)
-		    __field(enum netfs_read_source,	source		)
+		    __field(enum netfs_io_source,	source		)
 		    __field(enum netfs_failure,		what		)
 		    __field(size_t,			len		)
 		    __field(size_t,			transferred	)



^ permalink raw reply related	[flat|nested] 20+ messages in thread

* [PATCH 05/19] netfs: Refactor arguments for netfs_alloc_read_request
  2022-03-02 14:01 [PATCH 00/19] netfs: Prep for write helpers David Howells
                   ` (3 preceding siblings ...)
  2022-03-02 14:04 ` [PATCH 04/19] netfs: Rename netfs_read_*request to netfs_io_*request David Howells
@ 2022-03-02 14:04 ` David Howells
  2022-03-02 14:05 ` [PATCH 06/19] netfs: Finish off rename of netfs_read_request to netfs_io_request David Howells
                   ` (13 subsequent siblings)
  18 siblings, 0 replies; 20+ messages in thread
From: David Howells @ 2022-03-02 14:04 UTC (permalink / raw)
  To: linux-cachefs
  Cc: Jeff Layton, dhowells, Anna Schumaker, Steve French,
	Dominique Martinet, Jeff Layton, David Wysochanski, Ilya Dryomov,
	Jeffle Xu, Linus Torvalds, linux-afs, linux-nfs, linux-cifs,
	ceph-devel, v9fs-developer, linux-fsdevel, linux-kernel

From: Jeff Layton <jlayton@kernel.org>

Pass start and len to the rreq allocator. This should ensure that the
fields are set so that init_rreq can use them.

Also add a parameter to indicates the origin of the request.  Ceph can use
this to tell whether to get caps.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
---

 fs/netfs/read_helper.c |   25 ++++++++++++++++---------
 include/linux/netfs.h  |    7 +++++++
 2 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/fs/netfs/read_helper.c b/fs/netfs/read_helper.c
index a90b3fbcb93f..37125ed95d1a 100644
--- a/fs/netfs/read_helper.c
+++ b/fs/netfs/read_helper.c
@@ -36,8 +36,11 @@ static void netfs_put_subrequest(struct netfs_io_subrequest *subreq,
 		__netfs_put_subrequest(subreq, was_async);
 }
 
-static struct netfs_io_request *netfs_alloc_read_request(struct address_space *mapping,
-							   struct file *file)
+static struct netfs_io_request *netfs_alloc_read_request(
+	struct address_space *mapping,
+	struct file *file,
+	loff_t start, size_t len,
+	enum netfs_read_origin origin)
 {
 	static atomic_t debug_ids;
 	struct inode *inode = file ? file_inode(file) : mapping->host;
@@ -46,8 +49,11 @@ static struct netfs_io_request *netfs_alloc_read_request(struct address_space *m
 
 	rreq = kzalloc(sizeof(struct netfs_io_request), GFP_KERNEL);
 	if (rreq) {
+		rreq->start	= start;
+		rreq->len	= len;
 		rreq->mapping	= mapping;
 		rreq->inode	= inode;
+		rreq->origin	= origin;
 		rreq->netfs_ops	= ctx->ops;
 		rreq->i_size	= i_size_read(inode);
 		rreq->debug_id	= atomic_inc_return(&debug_ids);
@@ -874,11 +880,12 @@ void netfs_readahead(struct readahead_control *ractl)
 	if (readahead_count(ractl) == 0)
 		return;
 
-	rreq = netfs_alloc_read_request(ractl->mapping, ractl->file);
+	rreq = netfs_alloc_read_request(ractl->mapping, ractl->file,
+					readahead_pos(ractl),
+					readahead_length(ractl),
+					NETFS_READAHEAD);
 	if (!rreq)
 		return;
-	rreq->start	= readahead_pos(ractl);
-	rreq->len	= readahead_length(ractl);
 
 	if (ctx->ops->begin_cache_operation) {
 		ret = ctx->ops->begin_cache_operation(rreq);
@@ -941,11 +948,10 @@ int netfs_readpage(struct file *file, struct page *subpage)
 
 	_enter("%lx", folio_index(folio));
 
-	rreq = netfs_alloc_read_request(mapping, file);
+	rreq = netfs_alloc_read_request(mapping, file, folio_file_pos(folio),
+					folio_size(folio), NETFS_READPAGE);
 	if (!rreq)
 		goto nomem;
-	rreq->start	= folio_file_pos(folio);
-	rreq->len	= folio_size(folio);
 
 	if (ctx->ops->begin_cache_operation) {
 		ret = ctx->ops->begin_cache_operation(rreq);
@@ -1118,7 +1124,8 @@ int netfs_write_begin(struct file *file, struct address_space *mapping,
 	}
 
 	ret = -ENOMEM;
-	rreq = netfs_alloc_read_request(mapping, file);
+	rreq = netfs_alloc_read_request(mapping, file, folio_file_pos(folio),
+					folio_size(folio), NETFS_READ_FOR_WRITE);
 	if (!rreq)
 		goto error;
 	rreq->start		= folio_file_pos(folio);
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index 630b0400e9fa..a5434bc80e1c 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -158,6 +158,12 @@ struct netfs_io_subrequest {
 #define NETFS_SREQ_NO_PROGRESS		4	/* Set if we didn't manage to read any data */
 };
 
+enum netfs_read_origin {
+	NETFS_READAHEAD,		/* This read was triggered by readahead */
+	NETFS_READPAGE,			/* This read is a synchronous read */
+	NETFS_READ_FOR_WRITE,		/* This read is to prepare a write */
+} __mode(byte);
+
 /*
  * Descriptor for a read helper request.  This is used to make multiple I/O
  * requests on a variety of sources and then stitch the result together.
@@ -175,6 +181,7 @@ struct netfs_io_request {
 	size_t			submitted;	/* Amount submitted for I/O so far */
 	size_t			len;		/* Length of the request */
 	short			error;		/* 0 or error that occurred */
+	enum netfs_read_origin	origin;		/* Origin of the read */
 	loff_t			i_size;		/* Size of the file */
 	loff_t			start;		/* Start position */
 	pgoff_t			no_unlock_folio; /* Don't unlock this folio after read */



^ permalink raw reply related	[flat|nested] 20+ messages in thread

* [PATCH 06/19] netfs: Finish off rename of netfs_read_request to netfs_io_request
  2022-03-02 14:01 [PATCH 00/19] netfs: Prep for write helpers David Howells
                   ` (4 preceding siblings ...)
  2022-03-02 14:04 ` [PATCH 05/19] netfs: Refactor arguments for netfs_alloc_read_request David Howells
@ 2022-03-02 14:05 ` David Howells
  2022-03-02 14:05 ` [PATCH 07/19] netfs: Split netfs_io_* object handling out David Howells
                   ` (12 subsequent siblings)
  18 siblings, 0 replies; 20+ messages in thread
From: David Howells @ 2022-03-02 14:05 UTC (permalink / raw)
  To: linux-cachefs
  Cc: dhowells, Anna Schumaker, Steve French, Dominique Martinet,
	Jeff Layton, David Wysochanski, Ilya Dryomov, Jeffle Xu,
	Linus Torvalds, linux-afs, linux-nfs, linux-cifs, ceph-devel,
	v9fs-developer, linux-fsdevel, linux-kernel

Adjust helper function names and comments after mass rename of
struct netfs_read_*request to struct netfs_io_*request.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
---

 fs/9p/vfs_addr.c       |   12 +++---
 fs/afs/file.c          |    8 ++--
 fs/cachefiles/io.c     |    4 +-
 fs/ceph/addr.c         |    6 +--
 fs/netfs/read_helper.c |   99 ++++++++++++++++++++++++------------------------
 include/linux/netfs.h  |   28 +++++++-------
 6 files changed, 79 insertions(+), 78 deletions(-)

diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
index 088d37944963..840111da1172 100644
--- a/fs/9p/vfs_addr.c
+++ b/fs/9p/vfs_addr.c
@@ -28,10 +28,10 @@
 #include "fid.h"
 
 /**
- * v9fs_req_issue_op - Issue a read from 9P
+ * v9fs_issue_read - Issue a read from 9P
  * @subreq: The read to make
  */
-static void v9fs_req_issue_op(struct netfs_io_subrequest *subreq)
+static void v9fs_issue_read(struct netfs_io_subrequest *subreq)
 {
 	struct netfs_io_request *rreq = subreq->rreq;
 	struct p9_fid *fid = rreq->netfs_priv;
@@ -52,11 +52,11 @@ static void v9fs_req_issue_op(struct netfs_io_subrequest *subreq)
 }
 
 /**
- * v9fs_init_rreq - Initialise a read request
+ * v9fs_init_request - Initialise a read request
  * @rreq: The read request
  * @file: The file being read from
  */
-static void v9fs_init_rreq(struct netfs_io_request *rreq, struct file *file)
+static void v9fs_init_request(struct netfs_io_request *rreq, struct file *file)
 {
 	struct p9_fid *fid = file->private_data;
 
@@ -92,9 +92,9 @@ static int v9fs_begin_cache_operation(struct netfs_io_request *rreq)
 }
 
 const struct netfs_request_ops v9fs_req_ops = {
-	.init_rreq		= v9fs_init_rreq,
+	.init_request		= v9fs_init_request,
 	.begin_cache_operation	= v9fs_begin_cache_operation,
-	.issue_op		= v9fs_req_issue_op,
+	.issue_read		= v9fs_issue_read,
 	.cleanup		= v9fs_req_cleanup,
 };
 
diff --git a/fs/afs/file.c b/fs/afs/file.c
index 0e247fd0abef..aef0fbbd834d 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -308,7 +308,7 @@ int afs_fetch_data(struct afs_vnode *vnode, struct afs_read *req)
 	return afs_do_sync_operation(op);
 }
 
-static void afs_req_issue_op(struct netfs_io_subrequest *subreq)
+static void afs_issue_read(struct netfs_io_subrequest *subreq)
 {
 	struct afs_vnode *vnode = AFS_FS_I(subreq->rreq->inode);
 	struct afs_read *fsreq;
@@ -357,7 +357,7 @@ static int afs_symlink_readpage(struct file *file, struct page *page)
 	return ret;
 }
 
-static void afs_init_rreq(struct netfs_io_request *rreq, struct file *file)
+static void afs_init_request(struct netfs_io_request *rreq, struct file *file)
 {
 	rreq->netfs_priv = key_get(afs_file_key(file));
 }
@@ -388,10 +388,10 @@ static void afs_priv_cleanup(struct address_space *mapping, void *netfs_priv)
 }
 
 const struct netfs_request_ops afs_req_ops = {
-	.init_rreq		= afs_init_rreq,
+	.init_request		= afs_init_request,
 	.begin_cache_operation	= afs_begin_cache_operation,
 	.check_write_begin	= afs_check_write_begin,
-	.issue_op		= afs_req_issue_op,
+	.issue_read		= afs_issue_read,
 	.cleanup		= afs_priv_cleanup,
 };
 
diff --git a/fs/cachefiles/io.c b/fs/cachefiles/io.c
index 6ac6fdbc70d3..b19f496db9ad 100644
--- a/fs/cachefiles/io.c
+++ b/fs/cachefiles/io.c
@@ -406,7 +406,7 @@ static enum netfs_io_source cachefiles_prepare_read(struct netfs_io_subrequest *
 	}
 
 	if (test_bit(FSCACHE_COOKIE_NO_DATA_TO_READ, &cookie->flags)) {
-		__set_bit(NETFS_SREQ_WRITE_TO_CACHE, &subreq->flags);
+		__set_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags);
 		why = cachefiles_trace_read_no_data;
 		goto out_no_object;
 	}
@@ -475,7 +475,7 @@ static enum netfs_io_source cachefiles_prepare_read(struct netfs_io_subrequest *
 	goto out;
 
 download_and_store:
-	__set_bit(NETFS_SREQ_WRITE_TO_CACHE, &subreq->flags);
+	__set_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags);
 out:
 	cachefiles_end_secure(cache, saved_cred);
 out_no_object:
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index a6452ca3482e..78070296447f 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -259,7 +259,7 @@ static bool ceph_netfs_issue_op_inline(struct netfs_io_subrequest *subreq)
 	size_t len;
 
 	__set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags);
-	__clear_bit(NETFS_SREQ_WRITE_TO_CACHE, &subreq->flags);
+	__clear_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags);
 
 	if (subreq->start >= inode->i_size)
 		goto out;
@@ -298,7 +298,7 @@ static bool ceph_netfs_issue_op_inline(struct netfs_io_subrequest *subreq)
 	return true;
 }
 
-static void ceph_netfs_issue_op(struct netfs_io_subrequest *subreq)
+static void ceph_netfs_issue_read(struct netfs_io_subrequest *subreq)
 {
 	struct netfs_io_request *rreq = subreq->rreq;
 	struct inode *inode = rreq->inode;
@@ -366,7 +366,7 @@ static void ceph_readahead_cleanup(struct address_space *mapping, void *priv)
 
 const struct netfs_request_ops ceph_netfs_ops = {
 	.begin_cache_operation	= ceph_begin_cache_operation,
-	.issue_op		= ceph_netfs_issue_op,
+	.issue_read		= ceph_netfs_issue_read,
 	.expand_readahead	= ceph_netfs_expand_readahead,
 	.clamp_length		= ceph_netfs_clamp_length,
 	.check_write_begin	= ceph_netfs_check_write_begin,
diff --git a/fs/netfs/read_helper.c b/fs/netfs/read_helper.c
index 37125ed95d1a..74e510f9e11f 100644
--- a/fs/netfs/read_helper.c
+++ b/fs/netfs/read_helper.c
@@ -36,11 +36,11 @@ static void netfs_put_subrequest(struct netfs_io_subrequest *subreq,
 		__netfs_put_subrequest(subreq, was_async);
 }
 
-static struct netfs_io_request *netfs_alloc_read_request(
+static struct netfs_io_request *netfs_alloc_request(
 	struct address_space *mapping,
 	struct file *file,
 	loff_t start, size_t len,
-	enum netfs_read_origin origin)
+	enum netfs_io_origin origin)
 {
 	static atomic_t debug_ids;
 	struct inode *inode = file ? file_inode(file) : mapping->host;
@@ -61,21 +61,20 @@ static struct netfs_io_request *netfs_alloc_read_request(
 		INIT_WORK(&rreq->work, netfs_rreq_work);
 		refcount_set(&rreq->usage, 1);
 		__set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
-		if (ctx->ops->init_rreq)
-			ctx->ops->init_rreq(rreq, file);
+		if (ctx->ops->init_request)
+			ctx->ops->init_request(rreq, file);
 		netfs_stat(&netfs_n_rh_rreq);
 	}
 
 	return rreq;
 }
 
-static void netfs_get_read_request(struct netfs_io_request *rreq)
+static void netfs_get_request(struct netfs_io_request *rreq)
 {
 	refcount_inc(&rreq->usage);
 }
 
-static void netfs_rreq_clear_subreqs(struct netfs_io_request *rreq,
-				     bool was_async)
+static void netfs_clear_subrequests(struct netfs_io_request *rreq, bool was_async)
 {
 	struct netfs_io_subrequest *subreq;
 
@@ -87,11 +86,11 @@ static void netfs_rreq_clear_subreqs(struct netfs_io_request *rreq,
 	}
 }
 
-static void netfs_free_read_request(struct work_struct *work)
+static void netfs_free_request(struct work_struct *work)
 {
 	struct netfs_io_request *rreq =
 		container_of(work, struct netfs_io_request, work);
-	netfs_rreq_clear_subreqs(rreq, false);
+	netfs_clear_subrequests(rreq, false);
 	if (rreq->netfs_priv)
 		rreq->netfs_ops->cleanup(rreq->mapping, rreq->netfs_priv);
 	trace_netfs_rreq(rreq, netfs_rreq_trace_free);
@@ -101,15 +100,15 @@ static void netfs_free_read_request(struct work_struct *work)
 	netfs_stat_d(&netfs_n_rh_rreq);
 }
 
-static void netfs_put_read_request(struct netfs_io_request *rreq, bool was_async)
+static void netfs_put_request(struct netfs_io_request *rreq, bool was_async)
 {
 	if (refcount_dec_and_test(&rreq->usage)) {
 		if (was_async) {
-			rreq->work.func = netfs_free_read_request;
+			rreq->work.func = netfs_free_request;
 			if (!queue_work(system_unbound_wq, &rreq->work))
 				BUG();
 		} else {
-			netfs_free_read_request(&rreq->work);
+			netfs_free_request(&rreq->work);
 		}
 	}
 }
@@ -127,14 +126,14 @@ static struct netfs_io_subrequest *netfs_alloc_subrequest(
 		INIT_LIST_HEAD(&subreq->rreq_link);
 		refcount_set(&subreq->usage, 2);
 		subreq->rreq = rreq;
-		netfs_get_read_request(rreq);
+		netfs_get_request(rreq);
 		netfs_stat(&netfs_n_rh_sreq);
 	}
 
 	return subreq;
 }
 
-static void netfs_get_read_subrequest(struct netfs_io_subrequest *subreq)
+static void netfs_get_subrequest(struct netfs_io_subrequest *subreq)
 {
 	refcount_inc(&subreq->usage);
 }
@@ -147,7 +146,7 @@ static void __netfs_put_subrequest(struct netfs_io_subrequest *subreq,
 	trace_netfs_sreq(subreq, netfs_sreq_trace_free);
 	kfree(subreq);
 	netfs_stat_d(&netfs_n_rh_sreq);
-	netfs_put_read_request(rreq, was_async);
+	netfs_put_request(rreq, was_async);
 }
 
 /*
@@ -222,7 +221,7 @@ static void netfs_read_from_server(struct netfs_io_request *rreq,
 				   struct netfs_io_subrequest *subreq)
 {
 	netfs_stat(&netfs_n_rh_download);
-	rreq->netfs_ops->issue_op(subreq);
+	rreq->netfs_ops->issue_read(subreq);
 }
 
 /*
@@ -231,8 +230,8 @@ static void netfs_read_from_server(struct netfs_io_request *rreq,
 static void netfs_rreq_completed(struct netfs_io_request *rreq, bool was_async)
 {
 	trace_netfs_rreq(rreq, netfs_rreq_trace_done);
-	netfs_rreq_clear_subreqs(rreq, was_async);
-	netfs_put_read_request(rreq, was_async);
+	netfs_clear_subrequests(rreq, was_async);
+	netfs_put_request(rreq, was_async);
 }
 
 /*
@@ -312,7 +311,7 @@ static void netfs_rreq_do_write_to_cache(struct netfs_io_request *rreq)
 	atomic_inc(&rreq->nr_copy_ops);
 
 	list_for_each_entry_safe(subreq, p, &rreq->subrequests, rreq_link) {
-		if (!test_bit(NETFS_SREQ_WRITE_TO_CACHE, &subreq->flags)) {
+		if (!test_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags)) {
 			list_del_init(&subreq->rreq_link);
 			netfs_put_subrequest(subreq, false);
 		}
@@ -342,7 +341,7 @@ static void netfs_rreq_do_write_to_cache(struct netfs_io_request *rreq)
 
 		atomic_inc(&rreq->nr_copy_ops);
 		netfs_stat(&netfs_n_rh_write);
-		netfs_get_read_subrequest(subreq);
+		netfs_get_subrequest(subreq);
 		trace_netfs_sreq(subreq, netfs_sreq_trace_write);
 		cres->ops->write(cres, subreq->start, &iter,
 				 netfs_rreq_copy_terminated, subreq);
@@ -384,9 +383,9 @@ static void netfs_rreq_unlock(struct netfs_io_request *rreq)
 	XA_STATE(xas, &rreq->mapping->i_pages, start_page);
 
 	if (test_bit(NETFS_RREQ_FAILED, &rreq->flags)) {
-		__clear_bit(NETFS_RREQ_WRITE_TO_CACHE, &rreq->flags);
+		__clear_bit(NETFS_RREQ_COPY_TO_CACHE, &rreq->flags);
 		list_for_each_entry(subreq, &rreq->subrequests, rreq_link) {
-			__clear_bit(NETFS_SREQ_WRITE_TO_CACHE, &subreq->flags);
+			__clear_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags);
 		}
 	}
 
@@ -414,7 +413,7 @@ static void netfs_rreq_unlock(struct netfs_io_request *rreq)
 				pg_failed = true;
 				break;
 			}
-			if (test_bit(NETFS_SREQ_WRITE_TO_CACHE, &subreq->flags))
+			if (test_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags))
 				folio_start_fscache(folio);
 			pg_failed |= subreq_failed;
 			if (pgend < iopos + subreq->len)
@@ -459,13 +458,13 @@ static void netfs_rreq_unlock(struct netfs_io_request *rreq)
 static void netfs_rreq_short_read(struct netfs_io_request *rreq,
 				  struct netfs_io_subrequest *subreq)
 {
-	__clear_bit(NETFS_SREQ_SHORT_READ, &subreq->flags);
+	__clear_bit(NETFS_SREQ_SHORT_IO, &subreq->flags);
 	__set_bit(NETFS_SREQ_SEEK_DATA_READ, &subreq->flags);
 
 	netfs_stat(&netfs_n_rh_short_read);
 	trace_netfs_sreq(subreq, netfs_sreq_trace_resubmit_short);
 
-	netfs_get_read_subrequest(subreq);
+	netfs_get_subrequest(subreq);
 	atomic_inc(&rreq->nr_outstanding);
 	if (subreq->source == NETFS_READ_FROM_CACHE)
 		netfs_read_from_cache(rreq, subreq, NETFS_READ_HOLE_CLEAR);
@@ -499,10 +498,10 @@ static bool netfs_rreq_perform_resubmissions(struct netfs_io_request *rreq)
 			subreq->error = 0;
 			netfs_stat(&netfs_n_rh_download_instead);
 			trace_netfs_sreq(subreq, netfs_sreq_trace_download_instead);
-			netfs_get_read_subrequest(subreq);
+			netfs_get_subrequest(subreq);
 			atomic_inc(&rreq->nr_outstanding);
 			netfs_read_from_server(rreq, subreq);
-		} else if (test_bit(NETFS_SREQ_SHORT_READ, &subreq->flags)) {
+		} else if (test_bit(NETFS_SREQ_SHORT_IO, &subreq->flags)) {
 			netfs_rreq_short_read(rreq, subreq);
 		}
 	}
@@ -559,7 +558,7 @@ static void netfs_rreq_assess(struct netfs_io_request *rreq, bool was_async)
 	clear_bit_unlock(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
 	wake_up_bit(&rreq->flags, NETFS_RREQ_IN_PROGRESS);
 
-	if (test_bit(NETFS_RREQ_WRITE_TO_CACHE, &rreq->flags))
+	if (test_bit(NETFS_RREQ_COPY_TO_CACHE, &rreq->flags))
 		return netfs_rreq_write_to_cache(rreq);
 
 	netfs_rreq_completed(rreq, was_async);
@@ -648,8 +647,8 @@ void netfs_subreq_terminated(struct netfs_io_subrequest *subreq,
 
 complete:
 	__clear_bit(NETFS_SREQ_NO_PROGRESS, &subreq->flags);
-	if (test_bit(NETFS_SREQ_WRITE_TO_CACHE, &subreq->flags))
-		set_bit(NETFS_RREQ_WRITE_TO_CACHE, &rreq->flags);
+	if (test_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags))
+		set_bit(NETFS_RREQ_COPY_TO_CACHE, &rreq->flags);
 
 out:
 	trace_netfs_sreq(subreq, netfs_sreq_trace_terminated);
@@ -680,7 +679,7 @@ void netfs_subreq_terminated(struct netfs_io_subrequest *subreq,
 		__clear_bit(NETFS_SREQ_NO_PROGRESS, &subreq->flags);
 	}
 
-	__set_bit(NETFS_SREQ_SHORT_READ, &subreq->flags);
+	__set_bit(NETFS_SREQ_SHORT_IO, &subreq->flags);
 	set_bit(NETFS_RREQ_INCOMPLETE_IO, &rreq->flags);
 	goto out;
 
@@ -880,10 +879,10 @@ void netfs_readahead(struct readahead_control *ractl)
 	if (readahead_count(ractl) == 0)
 		return;
 
-	rreq = netfs_alloc_read_request(ractl->mapping, ractl->file,
-					readahead_pos(ractl),
-					readahead_length(ractl),
-					NETFS_READAHEAD);
+	rreq = netfs_alloc_request(ractl->mapping, ractl->file,
+				   readahead_pos(ractl),
+				   readahead_length(ractl),
+				   NETFS_READAHEAD);
 	if (!rreq)
 		return;
 
@@ -918,7 +917,7 @@ void netfs_readahead(struct readahead_control *ractl)
 	return;
 
 cleanup_free:
-	netfs_put_read_request(rreq, false);
+	netfs_put_request(rreq, false);
 	return;
 }
 EXPORT_SYMBOL(netfs_readahead);
@@ -948,8 +947,8 @@ int netfs_readpage(struct file *file, struct page *subpage)
 
 	_enter("%lx", folio_index(folio));
 
-	rreq = netfs_alloc_read_request(mapping, file, folio_file_pos(folio),
-					folio_size(folio), NETFS_READPAGE);
+	rreq = netfs_alloc_request(mapping, file, folio_file_pos(folio),
+				   folio_size(folio), NETFS_READPAGE);
 	if (!rreq)
 		goto nomem;
 
@@ -964,7 +963,7 @@ int netfs_readpage(struct file *file, struct page *subpage)
 	netfs_stat(&netfs_n_rh_readpage);
 	trace_netfs_read(rreq, rreq->start, rreq->len, netfs_read_trace_readpage);
 
-	netfs_get_read_request(rreq);
+	netfs_get_request(rreq);
 
 	atomic_set(&rreq->nr_outstanding, 1);
 	do {
@@ -978,7 +977,8 @@ int netfs_readpage(struct file *file, struct page *subpage)
 	 * process.
 	 */
 	do {
-		wait_var_event(&rreq->nr_outstanding, atomic_read(&rreq->nr_outstanding) == 1);
+		wait_var_event(&rreq->nr_outstanding,
+			       atomic_read(&rreq->nr_outstanding) == 1);
 		netfs_rreq_assess(rreq, false);
 	} while (test_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags));
 
@@ -988,7 +988,7 @@ int netfs_readpage(struct file *file, struct page *subpage)
 		ret = -EIO;
 	}
 out:
-	netfs_put_read_request(rreq, false);
+	netfs_put_request(rreq, false);
 	return ret;
 nomem:
 	folio_unlock(folio);
@@ -1124,8 +1124,8 @@ int netfs_write_begin(struct file *file, struct address_space *mapping,
 	}
 
 	ret = -ENOMEM;
-	rreq = netfs_alloc_read_request(mapping, file, folio_file_pos(folio),
-					folio_size(folio), NETFS_READ_FOR_WRITE);
+	rreq = netfs_alloc_request(mapping, file, folio_file_pos(folio),
+				   folio_size(folio), NETFS_READ_FOR_WRITE);
 	if (!rreq)
 		goto error;
 	rreq->start		= folio_file_pos(folio);
@@ -1147,7 +1147,7 @@ int netfs_write_begin(struct file *file, struct address_space *mapping,
 	 */
 	ractl._nr_pages = folio_nr_pages(folio);
 	netfs_rreq_expand(rreq, &ractl);
-	netfs_get_read_request(rreq);
+	netfs_get_request(rreq);
 
 	/* We hold the folio locks, so we can drop the references */
 	folio_get(folio);
@@ -1161,12 +1161,13 @@ int netfs_write_begin(struct file *file, struct address_space *mapping,
 
 	} while (rreq->submitted < rreq->len);
 
-	/* Keep nr_outstanding incremented so that the ref always belongs to us, and
-	 * the service code isn't punted off to a random thread pool to
+	/* Keep nr_outstanding incremented so that the ref always belongs to
+	 * us, and the service code isn't punted off to a random thread pool to
 	 * process.
 	 */
 	for (;;) {
-		wait_var_event(&rreq->nr_outstanding, atomic_read(&rreq->nr_outstanding) == 1);
+		wait_var_event(&rreq->nr_outstanding,
+			       atomic_read(&rreq->nr_outstanding) == 1);
 		netfs_rreq_assess(rreq, false);
 		if (!test_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags))
 			break;
@@ -1178,7 +1179,7 @@ int netfs_write_begin(struct file *file, struct address_space *mapping,
 		trace_netfs_failure(rreq, NULL, ret, netfs_fail_short_write_begin);
 		ret = -EIO;
 	}
-	netfs_put_read_request(rreq, false);
+	netfs_put_request(rreq, false);
 	if (ret < 0)
 		goto error;
 
@@ -1192,7 +1193,7 @@ int netfs_write_begin(struct file *file, struct address_space *mapping,
 	return 0;
 
 error_put:
-	netfs_put_read_request(rreq, false);
+	netfs_put_request(rreq, false);
 error:
 	folio_unlock(folio);
 	folio_put(folio);
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index a5434bc80e1c..8c33777c439e 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -141,7 +141,7 @@ struct netfs_cache_resources {
  * Descriptor for a single component subrequest.
  */
 struct netfs_io_subrequest {
-	struct netfs_io_request *rreq;	/* Supervising read request */
+	struct netfs_io_request *rreq;		/* Supervising I/O request */
 	struct list_head	rreq_link;	/* Link in rreq->subrequests */
 	loff_t			start;		/* Where to start the I/O */
 	size_t			len;		/* Size of the I/O */
@@ -149,46 +149,46 @@ struct netfs_io_subrequest {
 	refcount_t		usage;
 	short			error;		/* 0 or error that occurred */
 	unsigned short		debug_index;	/* Index in list (for debugging output) */
-	enum netfs_io_source	source;		/* Where to read from */
+	enum netfs_io_source	source;		/* Where to read from/write to */
 	unsigned long		flags;
-#define NETFS_SREQ_WRITE_TO_CACHE	0	/* Set if should write to cache */
+#define NETFS_SREQ_COPY_TO_CACHE	0	/* Set if should copy the data to the cache */
 #define NETFS_SREQ_CLEAR_TAIL		1	/* Set if the rest of the read should be cleared */
-#define NETFS_SREQ_SHORT_READ		2	/* Set if there was a short read from the cache */
+#define NETFS_SREQ_SHORT_IO		2	/* Set if the I/O was short */
 #define NETFS_SREQ_SEEK_DATA_READ	3	/* Set if ->read() should SEEK_DATA first */
 #define NETFS_SREQ_NO_PROGRESS		4	/* Set if we didn't manage to read any data */
 };
 
-enum netfs_read_origin {
+enum netfs_io_origin {
 	NETFS_READAHEAD,		/* This read was triggered by readahead */
 	NETFS_READPAGE,			/* This read is a synchronous read */
 	NETFS_READ_FOR_WRITE,		/* This read is to prepare a write */
 } __mode(byte);
 
 /*
- * Descriptor for a read helper request.  This is used to make multiple I/O
- * requests on a variety of sources and then stitch the result together.
+ * Descriptor for an I/O helper request.  This is used to make multiple I/O
+ * operations to a variety of data stores and then stitch the result together.
  */
 struct netfs_io_request {
 	struct work_struct	work;
 	struct inode		*inode;		/* The file being accessed */
 	struct address_space	*mapping;	/* The mapping being accessed */
 	struct netfs_cache_resources cache_resources;
-	struct list_head	subrequests;	/* Requests to fetch I/O from disk or net */
+	struct list_head	subrequests;	/* Contributory I/O operations */
 	void			*netfs_priv;	/* Private data for the netfs */
 	unsigned int		debug_id;
-	atomic_t		nr_outstanding;	/* Number of read ops in progress */
-	atomic_t		nr_copy_ops;	/* Number of write ops in progress */
+	atomic_t		nr_outstanding;	/* Number of ops in progress */
+	atomic_t		nr_copy_ops;	/* Number of copy-to-cache ops in progress */
 	size_t			submitted;	/* Amount submitted for I/O so far */
 	size_t			len;		/* Length of the request */
 	short			error;		/* 0 or error that occurred */
-	enum netfs_read_origin	origin;		/* Origin of the read */
+	enum netfs_io_origin	origin;		/* Origin of the I/O */
 	loff_t			i_size;		/* Size of the file */
 	loff_t			start;		/* Start position */
 	pgoff_t			no_unlock_folio; /* Don't unlock this folio after read */
 	refcount_t		usage;
 	unsigned long		flags;
 #define NETFS_RREQ_INCOMPLETE_IO	0	/* Some ioreqs terminated short or with error */
-#define NETFS_RREQ_WRITE_TO_CACHE	1	/* Need to write to the cache */
+#define NETFS_RREQ_COPY_TO_CACHE	1	/* Need to write to the cache */
 #define NETFS_RREQ_NO_UNLOCK_FOLIO	2	/* Don't unlock no_unlock_folio on completion */
 #define NETFS_RREQ_DONT_UNLOCK_FOLIOS	3	/* Don't unlock the folios on completion */
 #define NETFS_RREQ_FAILED		4	/* The request failed */
@@ -200,11 +200,11 @@ struct netfs_io_request {
  * Operations the network filesystem can/must provide to the helpers.
  */
 struct netfs_request_ops {
-	void (*init_rreq)(struct netfs_io_request *rreq, struct file *file);
+	void (*init_request)(struct netfs_io_request *rreq, struct file *file);
 	int (*begin_cache_operation)(struct netfs_io_request *rreq);
 	void (*expand_readahead)(struct netfs_io_request *rreq);
 	bool (*clamp_length)(struct netfs_io_subrequest *subreq);
-	void (*issue_op)(struct netfs_io_subrequest *subreq);
+	void (*issue_read)(struct netfs_io_subrequest *subreq);
 	bool (*is_still_valid)(struct netfs_io_request *rreq);
 	int (*check_write_begin)(struct file *file, loff_t pos, unsigned len,
 				 struct folio *folio, void **_fsdata);



^ permalink raw reply related	[flat|nested] 20+ messages in thread

* [PATCH 07/19] netfs: Split netfs_io_* object handling out
  2022-03-02 14:01 [PATCH 00/19] netfs: Prep for write helpers David Howells
                   ` (5 preceding siblings ...)
  2022-03-02 14:05 ` [PATCH 06/19] netfs: Finish off rename of netfs_read_request to netfs_io_request David Howells
@ 2022-03-02 14:05 ` David Howells
  2022-03-02 14:06 ` [PATCH 08/19] netfs: Adjust the netfs_rreq tracepoint slightly David Howells
                   ` (11 subsequent siblings)
  18 siblings, 0 replies; 20+ messages in thread
From: David Howells @ 2022-03-02 14:05 UTC (permalink / raw)
  To: linux-cachefs
  Cc: dhowells, Anna Schumaker, Steve French, Dominique Martinet,
	Jeff Layton, David Wysochanski, Ilya Dryomov, Jeffle Xu,
	Linus Torvalds, linux-afs, linux-nfs, linux-cifs, ceph-devel,
	v9fs-developer, linux-fsdevel, linux-kernel

Split netfs_io_* object handling out into a file that's going to contain
object allocation, get and put routines.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
---

 fs/netfs/Makefile      |    6 ++
 fs/netfs/internal.h    |   16 ++++++
 fs/netfs/objects.c     |  129 ++++++++++++++++++++++++++++++++++++++++++++++++
 fs/netfs/read_helper.c |  125 -----------------------------------------------
 4 files changed, 151 insertions(+), 125 deletions(-)
 create mode 100644 fs/netfs/objects.c

diff --git a/fs/netfs/Makefile b/fs/netfs/Makefile
index c15bfc966d96..939fd00a1fc9 100644
--- a/fs/netfs/Makefile
+++ b/fs/netfs/Makefile
@@ -1,5 +1,9 @@
 # SPDX-License-Identifier: GPL-2.0
 
-netfs-y := read_helper.o stats.o
+netfs-y := \
+	objects.o \
+	read_helper.o
+
+netfs-$(CONFIG_NETFS_STATS) += stats.o
 
 obj-$(CONFIG_NETFS_SUPPORT) := netfs.o
diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h
index 82ce5c4228e4..1f2ad9c9d103 100644
--- a/fs/netfs/internal.h
+++ b/fs/netfs/internal.h
@@ -15,11 +15,27 @@
 
 #define pr_fmt(fmt) "netfs: " fmt
 
+/*
+ * objects.c
+ */
+struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
+					     struct file *file,
+					     loff_t start, size_t len,
+					     enum netfs_io_origin origin);
+void netfs_get_request(struct netfs_io_request *rreq);
+void netfs_clear_subrequests(struct netfs_io_request *rreq, bool was_async);
+void netfs_put_request(struct netfs_io_request *rreq, bool was_async);
+struct netfs_io_subrequest *netfs_alloc_subrequest(struct netfs_io_request *rreq);
+void netfs_put_subrequest(struct netfs_io_subrequest *subreq, bool was_async);
+void netfs_get_subrequest(struct netfs_io_subrequest *subreq);
+
 /*
  * read_helper.c
  */
 extern unsigned int netfs_debug;
 
+void netfs_rreq_work(struct work_struct *work);
+
 /*
  * stats.c
  */
diff --git a/fs/netfs/objects.c b/fs/netfs/objects.c
new file mode 100644
index 000000000000..b212de11ebca
--- /dev/null
+++ b/fs/netfs/objects.c
@@ -0,0 +1,129 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Object lifetime handling and tracing.
+ *
+ * Copyright (C) 2022 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/slab.h>
+#include "internal.h"
+
+/*
+ * Allocate an I/O request and initialise it.
+ */
+struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
+					     struct file *file,
+					     loff_t start, size_t len,
+					     enum netfs_io_origin origin)
+{
+	static atomic_t debug_ids;
+	struct inode *inode = file ? file_inode(file) : mapping->host;
+	struct netfs_i_context *ctx = netfs_i_context(inode);
+	struct netfs_io_request *rreq;
+
+	rreq = kzalloc(sizeof(struct netfs_io_request), GFP_KERNEL);
+	if (rreq) {
+		rreq->start	= start;
+		rreq->len	= len;
+		rreq->mapping	= mapping;
+		rreq->inode	= inode;
+		rreq->origin	= origin;
+		rreq->netfs_ops	= ctx->ops;
+		rreq->i_size	= i_size_read(inode);
+		rreq->debug_id	= atomic_inc_return(&debug_ids);
+		INIT_LIST_HEAD(&rreq->subrequests);
+		INIT_WORK(&rreq->work, netfs_rreq_work);
+		refcount_set(&rreq->usage, 1);
+		__set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
+		if (ctx->ops->init_request)
+			ctx->ops->init_request(rreq, file);
+		netfs_stat(&netfs_n_rh_rreq);
+	}
+
+	return rreq;
+}
+
+void netfs_get_request(struct netfs_io_request *rreq)
+{
+	refcount_inc(&rreq->usage);
+}
+
+void netfs_clear_subrequests(struct netfs_io_request *rreq, bool was_async)
+{
+	struct netfs_io_subrequest *subreq;
+
+	while (!list_empty(&rreq->subrequests)) {
+		subreq = list_first_entry(&rreq->subrequests,
+					  struct netfs_io_subrequest, rreq_link);
+		list_del(&subreq->rreq_link);
+		netfs_put_subrequest(subreq, was_async);
+	}
+}
+
+static void netfs_free_request(struct work_struct *work)
+{
+	struct netfs_io_request *rreq =
+		container_of(work, struct netfs_io_request, work);
+	netfs_clear_subrequests(rreq, false);
+	if (rreq->netfs_priv)
+		rreq->netfs_ops->cleanup(rreq->mapping, rreq->netfs_priv);
+	trace_netfs_rreq(rreq, netfs_rreq_trace_free);
+	if (rreq->cache_resources.ops)
+		rreq->cache_resources.ops->end_operation(&rreq->cache_resources);
+	kfree(rreq);
+	netfs_stat_d(&netfs_n_rh_rreq);
+}
+
+void netfs_put_request(struct netfs_io_request *rreq, bool was_async)
+{
+	if (refcount_dec_and_test(&rreq->usage)) {
+		if (was_async) {
+			rreq->work.func = netfs_free_request;
+			if (!queue_work(system_unbound_wq, &rreq->work))
+				BUG();
+		} else {
+			netfs_free_request(&rreq->work);
+		}
+	}
+}
+
+/*
+ * Allocate and partially initialise an I/O request structure.
+ */
+struct netfs_io_subrequest *netfs_alloc_subrequest(struct netfs_io_request *rreq)
+{
+	struct netfs_io_subrequest *subreq;
+
+	subreq = kzalloc(sizeof(struct netfs_io_subrequest), GFP_KERNEL);
+	if (subreq) {
+		INIT_LIST_HEAD(&subreq->rreq_link);
+		refcount_set(&subreq->usage, 2);
+		subreq->rreq = rreq;
+		netfs_get_request(rreq);
+		netfs_stat(&netfs_n_rh_sreq);
+	}
+
+	return subreq;
+}
+
+void netfs_get_subrequest(struct netfs_io_subrequest *subreq)
+{
+	refcount_inc(&subreq->usage);
+}
+
+static void netfs_free_subrequest(struct netfs_io_subrequest *subreq,
+				  bool was_async)
+{
+	struct netfs_io_request *rreq = subreq->rreq;
+
+	trace_netfs_sreq(subreq, netfs_sreq_trace_free);
+	kfree(subreq);
+	netfs_stat_d(&netfs_n_rh_sreq);
+	netfs_put_request(rreq, was_async);
+}
+
+void netfs_put_subrequest(struct netfs_io_subrequest *subreq, bool was_async)
+{
+	if (refcount_dec_and_test(&subreq->usage))
+		netfs_free_subrequest(subreq, was_async);
+}
diff --git a/fs/netfs/read_helper.c b/fs/netfs/read_helper.c
index 74e510f9e11f..68616635c5ac 100644
--- a/fs/netfs/read_helper.c
+++ b/fs/netfs/read_helper.c
@@ -26,129 +26,6 @@ unsigned netfs_debug;
 module_param_named(debug, netfs_debug, uint, S_IWUSR | S_IRUGO);
 MODULE_PARM_DESC(netfs_debug, "Netfs support debugging mask");
 
-static void netfs_rreq_work(struct work_struct *);
-static void __netfs_put_subrequest(struct netfs_io_subrequest *, bool);
-
-static void netfs_put_subrequest(struct netfs_io_subrequest *subreq,
-				 bool was_async)
-{
-	if (refcount_dec_and_test(&subreq->usage))
-		__netfs_put_subrequest(subreq, was_async);
-}
-
-static struct netfs_io_request *netfs_alloc_request(
-	struct address_space *mapping,
-	struct file *file,
-	loff_t start, size_t len,
-	enum netfs_io_origin origin)
-{
-	static atomic_t debug_ids;
-	struct inode *inode = file ? file_inode(file) : mapping->host;
-	struct netfs_i_context *ctx = netfs_i_context(inode);
-	struct netfs_io_request *rreq;
-
-	rreq = kzalloc(sizeof(struct netfs_io_request), GFP_KERNEL);
-	if (rreq) {
-		rreq->start	= start;
-		rreq->len	= len;
-		rreq->mapping	= mapping;
-		rreq->inode	= inode;
-		rreq->origin	= origin;
-		rreq->netfs_ops	= ctx->ops;
-		rreq->i_size	= i_size_read(inode);
-		rreq->debug_id	= atomic_inc_return(&debug_ids);
-		INIT_LIST_HEAD(&rreq->subrequests);
-		INIT_WORK(&rreq->work, netfs_rreq_work);
-		refcount_set(&rreq->usage, 1);
-		__set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
-		if (ctx->ops->init_request)
-			ctx->ops->init_request(rreq, file);
-		netfs_stat(&netfs_n_rh_rreq);
-	}
-
-	return rreq;
-}
-
-static void netfs_get_request(struct netfs_io_request *rreq)
-{
-	refcount_inc(&rreq->usage);
-}
-
-static void netfs_clear_subrequests(struct netfs_io_request *rreq, bool was_async)
-{
-	struct netfs_io_subrequest *subreq;
-
-	while (!list_empty(&rreq->subrequests)) {
-		subreq = list_first_entry(&rreq->subrequests,
-					  struct netfs_io_subrequest, rreq_link);
-		list_del(&subreq->rreq_link);
-		netfs_put_subrequest(subreq, was_async);
-	}
-}
-
-static void netfs_free_request(struct work_struct *work)
-{
-	struct netfs_io_request *rreq =
-		container_of(work, struct netfs_io_request, work);
-	netfs_clear_subrequests(rreq, false);
-	if (rreq->netfs_priv)
-		rreq->netfs_ops->cleanup(rreq->mapping, rreq->netfs_priv);
-	trace_netfs_rreq(rreq, netfs_rreq_trace_free);
-	if (rreq->cache_resources.ops)
-		rreq->cache_resources.ops->end_operation(&rreq->cache_resources);
-	kfree(rreq);
-	netfs_stat_d(&netfs_n_rh_rreq);
-}
-
-static void netfs_put_request(struct netfs_io_request *rreq, bool was_async)
-{
-	if (refcount_dec_and_test(&rreq->usage)) {
-		if (was_async) {
-			rreq->work.func = netfs_free_request;
-			if (!queue_work(system_unbound_wq, &rreq->work))
-				BUG();
-		} else {
-			netfs_free_request(&rreq->work);
-		}
-	}
-}
-
-/*
- * Allocate and partially initialise an I/O request structure.
- */
-static struct netfs_io_subrequest *netfs_alloc_subrequest(
-	struct netfs_io_request *rreq)
-{
-	struct netfs_io_subrequest *subreq;
-
-	subreq = kzalloc(sizeof(struct netfs_io_subrequest), GFP_KERNEL);
-	if (subreq) {
-		INIT_LIST_HEAD(&subreq->rreq_link);
-		refcount_set(&subreq->usage, 2);
-		subreq->rreq = rreq;
-		netfs_get_request(rreq);
-		netfs_stat(&netfs_n_rh_sreq);
-	}
-
-	return subreq;
-}
-
-static void netfs_get_subrequest(struct netfs_io_subrequest *subreq)
-{
-	refcount_inc(&subreq->usage);
-}
-
-static void __netfs_put_subrequest(struct netfs_io_subrequest *subreq,
-				   bool was_async)
-{
-	struct netfs_io_request *rreq = subreq->rreq;
-
-	trace_netfs_sreq(subreq, netfs_sreq_trace_free);
-	kfree(subreq);
-	netfs_stat_d(&netfs_n_rh_sreq);
-	netfs_put_request(rreq, was_async);
-}
-
 /*
  * Clear the unread part of an I/O request.
  */
@@ -564,7 +441,7 @@ static void netfs_rreq_assess(struct netfs_io_request *rreq, bool was_async)
 	netfs_rreq_completed(rreq, was_async);
 }
 
-static void netfs_rreq_work(struct work_struct *work)
+void netfs_rreq_work(struct work_struct *work)
 {
 	struct netfs_io_request *rreq =
 		container_of(work, struct netfs_io_request, work);



^ permalink raw reply related	[flat|nested] 20+ messages in thread

* [PATCH 08/19] netfs: Adjust the netfs_rreq tracepoint slightly
  2022-03-02 14:01 [PATCH 00/19] netfs: Prep for write helpers David Howells
                   ` (6 preceding siblings ...)
  2022-03-02 14:05 ` [PATCH 07/19] netfs: Split netfs_io_* object handling out David Howells
@ 2022-03-02 14:06 ` David Howells
  2022-03-02 14:06 ` [PATCH 09/19] netfs: Trace refcounting on the netfs_io_request struct David Howells
                   ` (10 subsequent siblings)
  18 siblings, 0 replies; 20+ messages in thread
From: David Howells @ 2022-03-02 14:06 UTC (permalink / raw)
  To: linux-cachefs
  Cc: dhowells, Anna Schumaker, Steve French, Dominique Martinet,
	Jeff Layton, David Wysochanski, Ilya Dryomov, Jeffle Xu,
	Linus Torvalds, linux-afs, linux-nfs, linux-cifs, ceph-devel,
	v9fs-developer, linux-fsdevel, linux-kernel

Adjust the netfs_rreq tracepoint to include the origin of the request and
to increase the size of the "what trace" output strings by a character so
that "ENCRYPT" and "DECRYPT" will fit without abbreviation.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
---

 fs/netfs/read_helper.c       |    2 +-
 include/trace/events/netfs.h |   29 +++++++++++++++++++----------
 2 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/fs/netfs/read_helper.c b/fs/netfs/read_helper.c
index 68616635c5ac..5e0fdf9c9772 100644
--- a/fs/netfs/read_helper.c
+++ b/fs/netfs/read_helper.c
@@ -180,7 +180,7 @@ static void netfs_rreq_do_write_to_cache(struct netfs_io_request *rreq)
 	struct iov_iter iter;
 	int ret;
 
-	trace_netfs_rreq(rreq, netfs_rreq_trace_write);
+	trace_netfs_rreq(rreq, netfs_rreq_trace_copy);
 
 	/* We don't want terminating writes trying to wake us up whilst we're
 	 * still going through the list.
diff --git a/include/trace/events/netfs.h b/include/trace/events/netfs.h
index 2d0665b416bf..8330ae8fbc0a 100644
--- a/include/trace/events/netfs.h
+++ b/include/trace/events/netfs.h
@@ -21,14 +21,19 @@
 	EM(netfs_read_trace_readpage,		"READPAGE ")	\
 	E_(netfs_read_trace_write_begin,	"WRITEBEGN")
 
+#define netfs_rreq_origins					\
+	EM(NETFS_READAHEAD,			"RA")		\
+	EM(NETFS_READPAGE,			"RP")		\
+	E_(NETFS_READ_FOR_WRITE,		"RW")
+
 #define netfs_rreq_traces					\
-	EM(netfs_rreq_trace_assess,		"ASSESS")	\
-	EM(netfs_rreq_trace_done,		"DONE  ")	\
-	EM(netfs_rreq_trace_free,		"FREE  ")	\
-	EM(netfs_rreq_trace_resubmit,		"RESUBM")	\
-	EM(netfs_rreq_trace_unlock,		"UNLOCK")	\
-	EM(netfs_rreq_trace_unmark,		"UNMARK")	\
-	E_(netfs_rreq_trace_write,		"WRITE ")
+	EM(netfs_rreq_trace_assess,		"ASSESS ")	\
+	EM(netfs_rreq_trace_copy,		"COPY   ")	\
+	EM(netfs_rreq_trace_done,		"DONE   ")	\
+	EM(netfs_rreq_trace_free,		"FREE   ")	\
+	EM(netfs_rreq_trace_resubmit,		"RESUBMT")	\
+	EM(netfs_rreq_trace_unlock,		"UNLOCK ")	\
+	E_(netfs_rreq_trace_unmark,		"UNMARK ")
 
 #define netfs_sreq_sources					\
 	EM(NETFS_FILL_WITH_ZEROES,		"ZERO")		\
@@ -79,6 +84,7 @@ enum netfs_failure { netfs_failures } __mode(byte);
 #define E_(a, b) TRACE_DEFINE_ENUM(a);
 
 netfs_read_traces;
+netfs_rreq_origins;
 netfs_rreq_traces;
 netfs_sreq_sources;
 netfs_sreq_traces;
@@ -134,18 +140,21 @@ TRACE_EVENT(netfs_rreq,
 
 	    TP_STRUCT__entry(
 		    __field(unsigned int,		rreq		)
-		    __field(unsigned short,		flags		)
+		    __field(unsigned int,		flags		)
+		    __field(enum netfs_io_origin,	origin		)
 		    __field(enum netfs_rreq_trace,	what		)
 			     ),
 
 	    TP_fast_assign(
 		    __entry->rreq	= rreq->debug_id;
 		    __entry->flags	= rreq->flags;
+		    __entry->origin	= rreq->origin;
 		    __entry->what	= what;
 			   ),
 
-	    TP_printk("R=%08x %s f=%02x",
+	    TP_printk("R=%08x %s %s f=%02x",
 		      __entry->rreq,
+		      __print_symbolic(__entry->origin, netfs_rreq_origins),
 		      __print_symbolic(__entry->what, netfs_rreq_traces),
 		      __entry->flags)
 	    );
@@ -182,8 +191,8 @@ TRACE_EVENT(netfs_sreq,
 
 	    TP_printk("R=%08x[%u] %s %s f=%02x s=%llx %zx/%zx e=%d",
 		      __entry->rreq, __entry->index,
-		      __print_symbolic(__entry->what, netfs_sreq_traces),
 		      __print_symbolic(__entry->source, netfs_sreq_sources),
+		      __print_symbolic(__entry->what, netfs_sreq_traces),
 		      __entry->flags,
 		      __entry->start, __entry->transferred, __entry->len,
 		      __entry->error)



^ permalink raw reply related	[flat|nested] 20+ messages in thread

* [PATCH 09/19] netfs: Trace refcounting on the netfs_io_request struct
  2022-03-02 14:01 [PATCH 00/19] netfs: Prep for write helpers David Howells
                   ` (7 preceding siblings ...)
  2022-03-02 14:06 ` [PATCH 08/19] netfs: Adjust the netfs_rreq tracepoint slightly David Howells
@ 2022-03-02 14:06 ` David Howells
  2022-03-02 14:06 ` [PATCH 10/19] netfs: Trace refcounting on the netfs_io_subrequest struct David Howells
                   ` (9 subsequent siblings)
  18 siblings, 0 replies; 20+ messages in thread
From: David Howells @ 2022-03-02 14:06 UTC (permalink / raw)
  To: linux-cachefs
  Cc: dhowells, Anna Schumaker, Steve French, Dominique Martinet,
	Jeff Layton, David Wysochanski, Ilya Dryomov, Jeffle Xu,
	Linus Torvalds, linux-afs, linux-nfs, linux-cifs, ceph-devel,
	v9fs-developer, linux-fsdevel, linux-kernel

Add refcount tracing for the netfs_io_request structure.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
---

 fs/netfs/internal.h          |   11 +++++++++--
 fs/netfs/objects.c           |   24 +++++++++++++++++-------
 fs/netfs/read_helper.c       |   14 +++++++-------
 include/linux/netfs.h        |    2 +-
 include/trace/events/netfs.h |   35 +++++++++++++++++++++++++++++++++++
 5 files changed, 69 insertions(+), 17 deletions(-)

diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h
index 1f2ad9c9d103..b3877e276a3a 100644
--- a/fs/netfs/internal.h
+++ b/fs/netfs/internal.h
@@ -22,13 +22,20 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
 					     struct file *file,
 					     loff_t start, size_t len,
 					     enum netfs_io_origin origin);
-void netfs_get_request(struct netfs_io_request *rreq);
+void netfs_get_request(struct netfs_io_request *rreq, enum netfs_rreq_ref_trace what);
 void netfs_clear_subrequests(struct netfs_io_request *rreq, bool was_async);
-void netfs_put_request(struct netfs_io_request *rreq, bool was_async);
+void netfs_put_request(struct netfs_io_request *rreq, bool was_async,
+		       enum netfs_rreq_ref_trace what);
 struct netfs_io_subrequest *netfs_alloc_subrequest(struct netfs_io_request *rreq);
 void netfs_put_subrequest(struct netfs_io_subrequest *subreq, bool was_async);
 void netfs_get_subrequest(struct netfs_io_subrequest *subreq);
 
+static inline void netfs_see_request(struct netfs_io_request *rreq,
+				     enum netfs_rreq_ref_trace what)
+{
+	trace_netfs_rreq_ref(rreq->debug_id, refcount_read(&rreq->ref), what);
+}
+
 /*
  * read_helper.c
  */
diff --git a/fs/netfs/objects.c b/fs/netfs/objects.c
index b212de11ebca..57d53f1f6741 100644
--- a/fs/netfs/objects.c
+++ b/fs/netfs/objects.c
@@ -33,7 +33,7 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
 		rreq->debug_id	= atomic_inc_return(&debug_ids);
 		INIT_LIST_HEAD(&rreq->subrequests);
 		INIT_WORK(&rreq->work, netfs_rreq_work);
-		refcount_set(&rreq->usage, 1);
+		refcount_set(&rreq->ref, 1);
 		__set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
 		if (ctx->ops->init_request)
 			ctx->ops->init_request(rreq, file);
@@ -43,9 +43,12 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
 	return rreq;
 }
 
-void netfs_get_request(struct netfs_io_request *rreq)
+void netfs_get_request(struct netfs_io_request *rreq, enum netfs_rreq_ref_trace what)
 {
-	refcount_inc(&rreq->usage);
+	int r;
+
+	__refcount_inc(&rreq->ref, &r);
+	trace_netfs_rreq_ref(rreq->debug_id, r + 1, what);
 }
 
 void netfs_clear_subrequests(struct netfs_io_request *rreq, bool was_async)
@@ -74,9 +77,16 @@ static void netfs_free_request(struct work_struct *work)
 	netfs_stat_d(&netfs_n_rh_rreq);
 }
 
-void netfs_put_request(struct netfs_io_request *rreq, bool was_async)
+void netfs_put_request(struct netfs_io_request *rreq, bool was_async,
+		       enum netfs_rreq_ref_trace what)
 {
-	if (refcount_dec_and_test(&rreq->usage)) {
+	unsigned int debug_id = rreq->debug_id;
+	bool dead;
+	int r;
+
+	dead = __refcount_dec_and_test(&rreq->ref, &r);
+	trace_netfs_rreq_ref(debug_id, r - 1, what);
+	if (dead) {
 		if (was_async) {
 			rreq->work.func = netfs_free_request;
 			if (!queue_work(system_unbound_wq, &rreq->work))
@@ -99,7 +109,7 @@ struct netfs_io_subrequest *netfs_alloc_subrequest(struct netfs_io_request *rreq
 		INIT_LIST_HEAD(&subreq->rreq_link);
 		refcount_set(&subreq->usage, 2);
 		subreq->rreq = rreq;
-		netfs_get_request(rreq);
+		netfs_get_request(rreq, netfs_rreq_trace_get_subreq);
 		netfs_stat(&netfs_n_rh_sreq);
 	}
 
@@ -119,7 +129,7 @@ static void netfs_free_subrequest(struct netfs_io_subrequest *subreq,
 	trace_netfs_sreq(subreq, netfs_sreq_trace_free);
 	kfree(subreq);
 	netfs_stat_d(&netfs_n_rh_sreq);
-	netfs_put_request(rreq, was_async);
+	netfs_put_request(rreq, was_async, netfs_rreq_trace_put_subreq);
 }
 
 void netfs_put_subrequest(struct netfs_io_subrequest *subreq, bool was_async)
diff --git a/fs/netfs/read_helper.c b/fs/netfs/read_helper.c
index 5e0fdf9c9772..535b2cbde4c8 100644
--- a/fs/netfs/read_helper.c
+++ b/fs/netfs/read_helper.c
@@ -108,7 +108,7 @@ static void netfs_rreq_completed(struct netfs_io_request *rreq, bool was_async)
 {
 	trace_netfs_rreq(rreq, netfs_rreq_trace_done);
 	netfs_clear_subrequests(rreq, was_async);
-	netfs_put_request(rreq, was_async);
+	netfs_put_request(rreq, was_async, netfs_rreq_trace_put_complete);
 }
 
 /*
@@ -794,7 +794,7 @@ void netfs_readahead(struct readahead_control *ractl)
 	return;
 
 cleanup_free:
-	netfs_put_request(rreq, false);
+	netfs_put_request(rreq, false, netfs_rreq_trace_put_failed);
 	return;
 }
 EXPORT_SYMBOL(netfs_readahead);
@@ -840,7 +840,7 @@ int netfs_readpage(struct file *file, struct page *subpage)
 	netfs_stat(&netfs_n_rh_readpage);
 	trace_netfs_read(rreq, rreq->start, rreq->len, netfs_read_trace_readpage);
 
-	netfs_get_request(rreq);
+	netfs_get_request(rreq, netfs_rreq_trace_get_hold);
 
 	atomic_set(&rreq->nr_outstanding, 1);
 	do {
@@ -865,7 +865,7 @@ int netfs_readpage(struct file *file, struct page *subpage)
 		ret = -EIO;
 	}
 out:
-	netfs_put_request(rreq, false);
+	netfs_put_request(rreq, false, netfs_rreq_trace_put_hold);
 	return ret;
 nomem:
 	folio_unlock(folio);
@@ -1024,13 +1024,13 @@ int netfs_write_begin(struct file *file, struct address_space *mapping,
 	 */
 	ractl._nr_pages = folio_nr_pages(folio);
 	netfs_rreq_expand(rreq, &ractl);
-	netfs_get_request(rreq);
 
 	/* We hold the folio locks, so we can drop the references */
 	folio_get(folio);
 	while (readahead_folio(&ractl))
 		;
 
+	netfs_get_request(rreq, netfs_rreq_trace_get_hold);
 	atomic_set(&rreq->nr_outstanding, 1);
 	do {
 		if (!netfs_rreq_submit_slice(rreq, &debug_index))
@@ -1056,7 +1056,7 @@ int netfs_write_begin(struct file *file, struct address_space *mapping,
 		trace_netfs_failure(rreq, NULL, ret, netfs_fail_short_write_begin);
 		ret = -EIO;
 	}
-	netfs_put_request(rreq, false);
+	netfs_put_request(rreq, false, netfs_rreq_trace_put_hold);
 	if (ret < 0)
 		goto error;
 
@@ -1070,7 +1070,7 @@ int netfs_write_begin(struct file *file, struct address_space *mapping,
 	return 0;
 
 error_put:
-	netfs_put_request(rreq, false);
+	netfs_put_request(rreq, false, netfs_rreq_trace_put_failed);
 error:
 	folio_unlock(folio);
 	folio_put(folio);
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index 8c33777c439e..e5c049a25746 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -185,7 +185,7 @@ struct netfs_io_request {
 	loff_t			i_size;		/* Size of the file */
 	loff_t			start;		/* Start position */
 	pgoff_t			no_unlock_folio; /* Don't unlock this folio after read */
-	refcount_t		usage;
+	refcount_t		ref;
 	unsigned long		flags;
 #define NETFS_RREQ_INCOMPLETE_IO	0	/* Some ioreqs terminated short or with error */
 #define NETFS_RREQ_COPY_TO_CACHE	1	/* Need to write to the cache */
diff --git a/include/trace/events/netfs.h b/include/trace/events/netfs.h
index 8330ae8fbc0a..8c700e2bcd5c 100644
--- a/include/trace/events/netfs.h
+++ b/include/trace/events/netfs.h
@@ -60,6 +60,15 @@
 	EM(netfs_fail_short_write_begin,	"short-write-begin")	\
 	E_(netfs_fail_prepare_write,		"prep-write")
 
+#define netfs_rreq_ref_traces					\
+	EM(netfs_rreq_trace_get_hold,		"GET HOLD   ")	\
+	EM(netfs_rreq_trace_get_subreq,		"GET SUBREQ ")	\
+	EM(netfs_rreq_trace_put_complete,	"PUT COMPLT ")	\
+	EM(netfs_rreq_trace_put_failed,		"PUT FAILED ")	\
+	EM(netfs_rreq_trace_put_hold,		"PUT HOLD   ")	\
+	EM(netfs_rreq_trace_put_subreq,		"PUT SUBREQ ")	\
+	E_(netfs_rreq_trace_new,		"NEW        ")
+
 #ifndef __NETFS_DECLARE_TRACE_ENUMS_ONCE_ONLY
 #define __NETFS_DECLARE_TRACE_ENUMS_ONCE_ONLY
 
@@ -72,6 +81,7 @@ enum netfs_read_trace { netfs_read_traces } __mode(byte);
 enum netfs_rreq_trace { netfs_rreq_traces } __mode(byte);
 enum netfs_sreq_trace { netfs_sreq_traces } __mode(byte);
 enum netfs_failure { netfs_failures } __mode(byte);
+enum netfs_rreq_ref_trace { netfs_rreq_ref_traces } __mode(byte);
 
 #endif
 
@@ -89,6 +99,7 @@ netfs_rreq_traces;
 netfs_sreq_sources;
 netfs_sreq_traces;
 netfs_failures;
+netfs_rreq_ref_traces;
 
 /*
  * Now redefine the EM() and E_() macros to map the enums to the strings that
@@ -238,6 +249,30 @@ TRACE_EVENT(netfs_failure,
 		      __entry->error)
 	    );
 
+TRACE_EVENT(netfs_rreq_ref,
+	    TP_PROTO(unsigned int rreq_debug_id, int ref,
+		     enum netfs_rreq_ref_trace what),
+
+	    TP_ARGS(rreq_debug_id, ref, what),
+
+	    TP_STRUCT__entry(
+		    __field(unsigned int,		rreq		)
+		    __field(int,			ref		)
+		    __field(enum netfs_rreq_ref_trace,	what		)
+			     ),
+
+	    TP_fast_assign(
+		    __entry->rreq	= rreq_debug_id;
+		    __entry->ref	= ref;
+		    __entry->what	= what;
+			   ),
+
+	    TP_printk("W=%08x %s r=%u",
+		      __entry->rreq,
+		      __print_symbolic(__entry->what, netfs_rreq_ref_traces),
+		      __entry->ref)
+	    );
+
 #endif /* _TRACE_NETFS_H */
 
 /* This part must be outside protection */



^ permalink raw reply related	[flat|nested] 20+ messages in thread

* [PATCH 10/19] netfs: Trace refcounting on the netfs_io_subrequest struct
  2022-03-02 14:01 [PATCH 00/19] netfs: Prep for write helpers David Howells
                   ` (8 preceding siblings ...)
  2022-03-02 14:06 ` [PATCH 09/19] netfs: Trace refcounting on the netfs_io_request struct David Howells
@ 2022-03-02 14:06 ` David Howells
  2022-03-02 14:06 ` [PATCH 11/19] netfs: Adjust the netfs_failure tracepoint to indicate non-subreq lines David Howells
                   ` (8 subsequent siblings)
  18 siblings, 0 replies; 20+ messages in thread
From: David Howells @ 2022-03-02 14:06 UTC (permalink / raw)
  To: linux-cachefs
  Cc: dhowells, Anna Schumaker, Steve French, Dominique Martinet,
	Jeff Layton, David Wysochanski, Ilya Dryomov, Jeffle Xu,
	Linus Torvalds, linux-afs, linux-nfs, linux-cifs, ceph-devel,
	v9fs-developer, linux-fsdevel, linux-kernel

Add refcount tracing for the netfs_io_subrequest structure.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
---

 fs/netfs/internal.h          |    2 --
 fs/netfs/objects.c           |   26 ++++++++++++++++++++------
 fs/netfs/read_helper.c       |   20 +++++++++++---------
 include/linux/netfs.h        |    8 +++++++-
 include/trace/events/netfs.h |   40 ++++++++++++++++++++++++++++++++++++++++
 5 files changed, 78 insertions(+), 18 deletions(-)

diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h
index b3877e276a3a..ee2f64cde221 100644
--- a/fs/netfs/internal.h
+++ b/fs/netfs/internal.h
@@ -27,8 +27,6 @@ void netfs_clear_subrequests(struct netfs_io_request *rreq, bool was_async);
 void netfs_put_request(struct netfs_io_request *rreq, bool was_async,
 		       enum netfs_rreq_ref_trace what);
 struct netfs_io_subrequest *netfs_alloc_subrequest(struct netfs_io_request *rreq);
-void netfs_put_subrequest(struct netfs_io_subrequest *subreq, bool was_async);
-void netfs_get_subrequest(struct netfs_io_subrequest *subreq);
 
 static inline void netfs_see_request(struct netfs_io_request *rreq,
 				     enum netfs_rreq_ref_trace what)
diff --git a/fs/netfs/objects.c b/fs/netfs/objects.c
index 57d53f1f6741..c46d027c1692 100644
--- a/fs/netfs/objects.c
+++ b/fs/netfs/objects.c
@@ -59,7 +59,8 @@ void netfs_clear_subrequests(struct netfs_io_request *rreq, bool was_async)
 		subreq = list_first_entry(&rreq->subrequests,
 					  struct netfs_io_subrequest, rreq_link);
 		list_del(&subreq->rreq_link);
-		netfs_put_subrequest(subreq, was_async);
+		netfs_put_subrequest(subreq, was_async,
+				     netfs_sreq_trace_put_clear);
 	}
 }
 
@@ -107,7 +108,7 @@ struct netfs_io_subrequest *netfs_alloc_subrequest(struct netfs_io_request *rreq
 	subreq = kzalloc(sizeof(struct netfs_io_subrequest), GFP_KERNEL);
 	if (subreq) {
 		INIT_LIST_HEAD(&subreq->rreq_link);
-		refcount_set(&subreq->usage, 2);
+		refcount_set(&subreq->ref, 2);
 		subreq->rreq = rreq;
 		netfs_get_request(rreq, netfs_rreq_trace_get_subreq);
 		netfs_stat(&netfs_n_rh_sreq);
@@ -116,9 +117,14 @@ struct netfs_io_subrequest *netfs_alloc_subrequest(struct netfs_io_request *rreq
 	return subreq;
 }
 
-void netfs_get_subrequest(struct netfs_io_subrequest *subreq)
+void netfs_get_subrequest(struct netfs_io_subrequest *subreq,
+			  enum netfs_sreq_ref_trace what)
 {
-	refcount_inc(&subreq->usage);
+	int r;
+
+	__refcount_inc(&subreq->ref, &r);
+	trace_netfs_sreq_ref(subreq->rreq->debug_id, subreq->debug_index, r + 1,
+			     what);
 }
 
 static void netfs_free_subrequest(struct netfs_io_subrequest *subreq,
@@ -132,8 +138,16 @@ static void netfs_free_subrequest(struct netfs_io_subrequest *subreq,
 	netfs_put_request(rreq, was_async, netfs_rreq_trace_put_subreq);
 }
 
-void netfs_put_subrequest(struct netfs_io_subrequest *subreq, bool was_async)
+void netfs_put_subrequest(struct netfs_io_subrequest *subreq, bool was_async,
+			  enum netfs_sreq_ref_trace what)
 {
-	if (refcount_dec_and_test(&subreq->usage))
+	unsigned int debug_index = subreq->debug_index;
+	unsigned int debug_id = subreq->rreq->debug_id;
+	bool dead;
+	int r;
+
+	dead = __refcount_dec_and_test(&subreq->ref, &r);
+	trace_netfs_sreq_ref(debug_id, debug_index, r - 1, what);
+	if (dead)
 		netfs_free_subrequest(subreq, was_async);
 }
diff --git a/fs/netfs/read_helper.c b/fs/netfs/read_helper.c
index 535b2cbde4c8..c953a573b6b6 100644
--- a/fs/netfs/read_helper.c
+++ b/fs/netfs/read_helper.c
@@ -166,7 +166,7 @@ static void netfs_rreq_copy_terminated(void *priv, ssize_t transferred_or_error,
 	if (atomic_dec_and_test(&rreq->nr_copy_ops))
 		netfs_rreq_unmark_after_write(rreq, was_async);
 
-	netfs_put_subrequest(subreq, was_async);
+	netfs_put_subrequest(subreq, was_async, netfs_sreq_trace_put_terminated);
 }
 
 /*
@@ -190,7 +190,8 @@ static void netfs_rreq_do_write_to_cache(struct netfs_io_request *rreq)
 	list_for_each_entry_safe(subreq, p, &rreq->subrequests, rreq_link) {
 		if (!test_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags)) {
 			list_del_init(&subreq->rreq_link);
-			netfs_put_subrequest(subreq, false);
+			netfs_put_subrequest(subreq, false,
+					     netfs_sreq_trace_put_no_copy);
 		}
 	}
 
@@ -202,7 +203,8 @@ static void netfs_rreq_do_write_to_cache(struct netfs_io_request *rreq)
 				break;
 			subreq->len += next->len;
 			list_del_init(&next->rreq_link);
-			netfs_put_subrequest(next, false);
+			netfs_put_subrequest(next, false,
+					     netfs_sreq_trace_put_merged);
 		}
 
 		ret = cres->ops->prepare_write(cres, &subreq->start, &subreq->len,
@@ -218,7 +220,7 @@ static void netfs_rreq_do_write_to_cache(struct netfs_io_request *rreq)
 
 		atomic_inc(&rreq->nr_copy_ops);
 		netfs_stat(&netfs_n_rh_write);
-		netfs_get_subrequest(subreq);
+		netfs_get_subrequest(subreq, netfs_sreq_trace_get_copy_to_cache);
 		trace_netfs_sreq(subreq, netfs_sreq_trace_write);
 		cres->ops->write(cres, subreq->start, &iter,
 				 netfs_rreq_copy_terminated, subreq);
@@ -341,7 +343,7 @@ static void netfs_rreq_short_read(struct netfs_io_request *rreq,
 	netfs_stat(&netfs_n_rh_short_read);
 	trace_netfs_sreq(subreq, netfs_sreq_trace_resubmit_short);
 
-	netfs_get_subrequest(subreq);
+	netfs_get_subrequest(subreq, netfs_sreq_trace_get_short_read);
 	atomic_inc(&rreq->nr_outstanding);
 	if (subreq->source == NETFS_READ_FROM_CACHE)
 		netfs_read_from_cache(rreq, subreq, NETFS_READ_HOLE_CLEAR);
@@ -375,7 +377,7 @@ static bool netfs_rreq_perform_resubmissions(struct netfs_io_request *rreq)
 			subreq->error = 0;
 			netfs_stat(&netfs_n_rh_download_instead);
 			trace_netfs_sreq(subreq, netfs_sreq_trace_download_instead);
-			netfs_get_subrequest(subreq);
+			netfs_get_subrequest(subreq, netfs_sreq_trace_get_resubmit);
 			atomic_inc(&rreq->nr_outstanding);
 			netfs_read_from_server(rreq, subreq);
 		} else if (test_bit(NETFS_SREQ_SHORT_IO, &subreq->flags)) {
@@ -537,7 +539,7 @@ void netfs_subreq_terminated(struct netfs_io_subrequest *subreq,
 	else if (u == 1)
 		wake_up_var(&rreq->nr_outstanding);
 
-	netfs_put_subrequest(subreq, was_async);
+	netfs_put_subrequest(subreq, was_async, netfs_sreq_trace_put_terminated);
 	return;
 
 incomplete:
@@ -682,7 +684,7 @@ static bool netfs_rreq_submit_slice(struct netfs_io_request *rreq,
 
 subreq_failed:
 	rreq->error = subreq->error;
-	netfs_put_subrequest(subreq, false);
+	netfs_put_subrequest(subreq, false, netfs_sreq_trace_put_failed);
 	return false;
 }
 
@@ -1024,13 +1026,13 @@ int netfs_write_begin(struct file *file, struct address_space *mapping,
 	 */
 	ractl._nr_pages = folio_nr_pages(folio);
 	netfs_rreq_expand(rreq, &ractl);
+	netfs_get_request(rreq, netfs_rreq_trace_get_hold);
 
 	/* We hold the folio locks, so we can drop the references */
 	folio_get(folio);
 	while (readahead_folio(&ractl))
 		;
 
-	netfs_get_request(rreq, netfs_rreq_trace_get_hold);
 	atomic_set(&rreq->nr_outstanding, 1);
 	do {
 		if (!netfs_rreq_submit_slice(rreq, &debug_index))
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index e5c049a25746..725b8fb8e4bb 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -18,6 +18,8 @@
 #include <linux/fs.h>
 #include <linux/pagemap.h>
 
+enum netfs_sreq_ref_trace;
+
 /*
  * Overload PG_private_2 to give us PG_fscache - this is used to indicate that
  * a page is currently backed by a local disk cache
@@ -146,7 +148,7 @@ struct netfs_io_subrequest {
 	loff_t			start;		/* Where to start the I/O */
 	size_t			len;		/* Size of the I/O */
 	size_t			transferred;	/* Amount of data transferred */
-	refcount_t		usage;
+	refcount_t		ref;
 	short			error;		/* 0 or error that occurred */
 	unsigned short		debug_index;	/* Index in list (for debugging output) */
 	enum netfs_io_source	source;		/* Where to read from/write to */
@@ -277,6 +279,10 @@ extern int netfs_write_begin(struct file *, struct address_space *,
 			     void **);
 
 extern void netfs_subreq_terminated(struct netfs_io_subrequest *, ssize_t, bool);
+extern void netfs_get_subrequest(struct netfs_io_subrequest *subreq,
+				 enum netfs_sreq_ref_trace what);
+extern void netfs_put_subrequest(struct netfs_io_subrequest *subreq,
+				 bool was_async, enum netfs_sreq_ref_trace what);
 extern void netfs_stats_show(struct seq_file *);
 
 /**
diff --git a/include/trace/events/netfs.h b/include/trace/events/netfs.h
index 8c700e2bcd5c..507c5e612293 100644
--- a/include/trace/events/netfs.h
+++ b/include/trace/events/netfs.h
@@ -69,6 +69,17 @@
 	EM(netfs_rreq_trace_put_subreq,		"PUT SUBREQ ")	\
 	E_(netfs_rreq_trace_new,		"NEW        ")
 
+#define netfs_sreq_ref_traces					\
+	EM(netfs_sreq_trace_get_copy_to_cache,	"GET COPY2C ")	\
+	EM(netfs_sreq_trace_get_resubmit,	"GET RESUBMIT")	\
+	EM(netfs_sreq_trace_get_short_read,	"GET SHORTRD")	\
+	EM(netfs_sreq_trace_new,		"NEW        ")	\
+	EM(netfs_sreq_trace_put_clear,		"PUT CLEAR  ")	\
+	EM(netfs_sreq_trace_put_failed,		"PUT FAILED ")	\
+	EM(netfs_sreq_trace_put_merged,		"PUT MERGED ")	\
+	EM(netfs_sreq_trace_put_no_copy,	"PUT NO COPY")	\
+	E_(netfs_sreq_trace_put_terminated,	"PUT TERM   ")
+
 #ifndef __NETFS_DECLARE_TRACE_ENUMS_ONCE_ONLY
 #define __NETFS_DECLARE_TRACE_ENUMS_ONCE_ONLY
 
@@ -82,6 +93,7 @@ enum netfs_rreq_trace { netfs_rreq_traces } __mode(byte);
 enum netfs_sreq_trace { netfs_sreq_traces } __mode(byte);
 enum netfs_failure { netfs_failures } __mode(byte);
 enum netfs_rreq_ref_trace { netfs_rreq_ref_traces } __mode(byte);
+enum netfs_sreq_ref_trace { netfs_sreq_ref_traces } __mode(byte);
 
 #endif
 
@@ -100,6 +112,7 @@ netfs_sreq_sources;
 netfs_sreq_traces;
 netfs_failures;
 netfs_rreq_ref_traces;
+netfs_sreq_ref_traces;
 
 /*
  * Now redefine the EM() and E_() macros to map the enums to the strings that
@@ -273,6 +286,33 @@ TRACE_EVENT(netfs_rreq_ref,
 		      __entry->ref)
 	    );
 
+TRACE_EVENT(netfs_sreq_ref,
+	    TP_PROTO(unsigned int rreq_debug_id, unsigned int subreq_debug_index,
+		     int ref, enum netfs_sreq_ref_trace what),
+
+	    TP_ARGS(rreq_debug_id, subreq_debug_index, ref, what),
+
+	    TP_STRUCT__entry(
+		    __field(unsigned int,		rreq		)
+		    __field(unsigned int,		subreq		)
+		    __field(int,			ref		)
+		    __field(enum netfs_sreq_ref_trace,	what		)
+			     ),
+
+	    TP_fast_assign(
+		    __entry->rreq	= rreq_debug_id;
+		    __entry->subreq	= subreq_debug_index;
+		    __entry->ref	= ref;
+		    __entry->what	= what;
+			   ),
+
+	    TP_printk("W=%08x[%x] %s r=%u",
+		      __entry->rreq,
+		      __entry->subreq,
+		      __print_symbolic(__entry->what, netfs_sreq_ref_traces),
+		      __entry->ref)
+	    );
+
 #endif /* _TRACE_NETFS_H */
 
 /* This part must be outside protection */



^ permalink raw reply related	[flat|nested] 20+ messages in thread

* [PATCH 11/19] netfs: Adjust the netfs_failure tracepoint to indicate non-subreq lines
  2022-03-02 14:01 [PATCH 00/19] netfs: Prep for write helpers David Howells
                   ` (9 preceding siblings ...)
  2022-03-02 14:06 ` [PATCH 10/19] netfs: Trace refcounting on the netfs_io_subrequest struct David Howells
@ 2022-03-02 14:06 ` David Howells
  2022-03-02 14:07 ` [PATCH 12/19] netfs: Prepare to split read_helper.c David Howells
                   ` (7 subsequent siblings)
  18 siblings, 0 replies; 20+ messages in thread
From: David Howells @ 2022-03-02 14:06 UTC (permalink / raw)
  To: linux-cachefs
  Cc: dhowells, Anna Schumaker, Steve French, Dominique Martinet,
	Jeff Layton, David Wysochanski, Ilya Dryomov, Jeffle Xu,
	Linus Torvalds, linux-afs, linux-nfs, linux-cifs, ceph-devel,
	v9fs-developer, linux-fsdevel, linux-kernel

Adjust the netfs_failure tracepoint to indicate a subrequest number of -1
when it's a full-request failure unrelated to any particular subrequest,
such as a failure to encrypt its data buffer.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
---

 include/trace/events/netfs.h |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/trace/events/netfs.h b/include/trace/events/netfs.h
index 507c5e612293..685b07573394 100644
--- a/include/trace/events/netfs.h
+++ b/include/trace/events/netfs.h
@@ -231,7 +231,7 @@ TRACE_EVENT(netfs_failure,
 
 	    TP_STRUCT__entry(
 		    __field(unsigned int,		rreq		)
-		    __field(unsigned short,		index		)
+		    __field(short,			index		)
 		    __field(short,			error		)
 		    __field(unsigned short,		flags		)
 		    __field(enum netfs_io_source,	source		)
@@ -243,17 +243,17 @@ TRACE_EVENT(netfs_failure,
 
 	    TP_fast_assign(
 		    __entry->rreq	= rreq->debug_id;
-		    __entry->index	= sreq ? sreq->debug_index : 0;
+		    __entry->index	= sreq ? sreq->debug_index : -1;
 		    __entry->error	= error;
 		    __entry->flags	= sreq ? sreq->flags : 0;
 		    __entry->source	= sreq ? sreq->source : NETFS_INVALID_READ;
 		    __entry->what	= what;
-		    __entry->len	= sreq ? sreq->len : 0;
+		    __entry->len	= sreq ? sreq->len : rreq->len;
 		    __entry->transferred = sreq ? sreq->transferred : 0;
 		    __entry->start	= sreq ? sreq->start : 0;
 			   ),
 
-	    TP_printk("R=%08x[%u] %s f=%02x s=%llx %zx/%zx %s e=%d",
+	    TP_printk("R=%08x[%d] %s f=%02x s=%llx %zx/%zx %s e=%d",
 		      __entry->rreq, __entry->index,
 		      __print_symbolic(__entry->source, netfs_sreq_sources),
 		      __entry->flags,



^ permalink raw reply related	[flat|nested] 20+ messages in thread

* [PATCH 12/19] netfs: Prepare to split read_helper.c
  2022-03-02 14:01 [PATCH 00/19] netfs: Prep for write helpers David Howells
                   ` (10 preceding siblings ...)
  2022-03-02 14:06 ` [PATCH 11/19] netfs: Adjust the netfs_failure tracepoint to indicate non-subreq lines David Howells
@ 2022-03-02 14:07 ` David Howells
  2022-03-02 14:07 ` [PATCH 13/19] netfs: Add a function to consolidate beginning a read David Howells
                   ` (6 subsequent siblings)
  18 siblings, 0 replies; 20+ messages in thread
From: David Howells @ 2022-03-02 14:07 UTC (permalink / raw)
  To: linux-cachefs
  Cc: dhowells, Anna Schumaker, Steve French, Dominique Martinet,
	Jeff Layton, David Wysochanski, Ilya Dryomov, Jeffle Xu,
	Linus Torvalds, linux-afs, linux-nfs, linux-cifs, ceph-devel,
	v9fs-developer, linux-fsdevel, linux-kernel

Prepare to split read_helper.c by removing some 'static' markers and
declaring those functions in internal.h.

Rename netfs_rreq_unlock() to netfs_rreq_unlock_folios() to make it sound
less like it's dropping a lock on an netfs_io_request struct.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
---

 fs/netfs/internal.h    |    8 ++++++++
 fs/netfs/read_helper.c |   10 +++++-----
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h
index ee2f64cde221..3970528955be 100644
--- a/fs/netfs/internal.h
+++ b/fs/netfs/internal.h
@@ -15,6 +15,11 @@
 
 #define pr_fmt(fmt) "netfs: " fmt
 
+/*
+ * buffered_read.c
+ */
+void netfs_rreq_unlock_folios(struct netfs_io_request *rreq);
+
 /*
  * objects.c
  */
@@ -40,6 +45,9 @@ static inline void netfs_see_request(struct netfs_io_request *rreq,
 extern unsigned int netfs_debug;
 
 void netfs_rreq_work(struct work_struct *work);
+void netfs_rreq_assess(struct netfs_io_request *rreq, bool was_async);
+bool netfs_rreq_submit_slice(struct netfs_io_request *rreq,
+			     unsigned int *_debug_index);
 
 /*
  * stats.c
diff --git a/fs/netfs/read_helper.c b/fs/netfs/read_helper.c
index c953a573b6b6..e666f9cccc95 100644
--- a/fs/netfs/read_helper.c
+++ b/fs/netfs/read_helper.c
@@ -250,7 +250,7 @@ static void netfs_rreq_write_to_cache(struct netfs_io_request *rreq)
  * Unlock the folios in a read operation.  We need to set PG_fscache on any
  * folios we're going to write back before we unlock them.
  */
-static void netfs_rreq_unlock(struct netfs_io_request *rreq)
+void netfs_rreq_unlock_folios(struct netfs_io_request *rreq)
 {
 	struct netfs_io_subrequest *subreq;
 	struct folio *folio;
@@ -418,7 +418,7 @@ static void netfs_rreq_is_still_valid(struct netfs_io_request *rreq)
  * Note that we could be in an ordinary kernel thread, on a workqueue or in
  * softirq context at this point.  We inherit a ref from the caller.
  */
-static void netfs_rreq_assess(struct netfs_io_request *rreq, bool was_async)
+void netfs_rreq_assess(struct netfs_io_request *rreq, bool was_async)
 {
 	trace_netfs_rreq(rreq, netfs_rreq_trace_assess);
 
@@ -432,7 +432,7 @@ static void netfs_rreq_assess(struct netfs_io_request *rreq, bool was_async)
 		return;
 	}
 
-	netfs_rreq_unlock(rreq);
+	netfs_rreq_unlock_folios(rreq);
 
 	clear_bit_unlock(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
 	wake_up_bit(&rreq->flags, NETFS_RREQ_IN_PROGRESS);
@@ -632,8 +632,8 @@ netfs_rreq_prepare_read(struct netfs_io_request *rreq,
 /*
  * Slice off a piece of a read request and submit an I/O request for it.
  */
-static bool netfs_rreq_submit_slice(struct netfs_io_request *rreq,
-				    unsigned int *_debug_index)
+bool netfs_rreq_submit_slice(struct netfs_io_request *rreq,
+			     unsigned int *_debug_index)
 {
 	struct netfs_io_subrequest *subreq;
 	enum netfs_io_source source;



^ permalink raw reply related	[flat|nested] 20+ messages in thread

* [PATCH 13/19] netfs: Add a function to consolidate beginning a read
  2022-03-02 14:01 [PATCH 00/19] netfs: Prep for write helpers David Howells
                   ` (11 preceding siblings ...)
  2022-03-02 14:07 ` [PATCH 12/19] netfs: Prepare to split read_helper.c David Howells
@ 2022-03-02 14:07 ` David Howells
  2022-03-02 14:07 ` [PATCH 14/19] netfs: Split fs/netfs/read_helper.c David Howells
                   ` (5 subsequent siblings)
  18 siblings, 0 replies; 20+ messages in thread
From: David Howells @ 2022-03-02 14:07 UTC (permalink / raw)
  To: linux-cachefs
  Cc: dhowells, Anna Schumaker, Steve French, Dominique Martinet,
	Jeff Layton, David Wysochanski, Ilya Dryomov, Jeffle Xu,
	Linus Torvalds, linux-afs, linux-nfs, linux-cifs, ceph-devel,
	v9fs-developer, linux-fsdevel, linux-kernel

Add a function to do the steps needed to begin a read request, allowing this
code to be removed from several other functions and consolidated.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
---

 fs/netfs/internal.h          |    5 -
 fs/netfs/objects.c           |    2 -
 fs/netfs/read_helper.c       |  152 +++++++++++++++++++++---------------------
 include/trace/events/netfs.h |    5 +
 4 files changed, 81 insertions(+), 83 deletions(-)

diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h
index 3970528955be..7d8e83deaf81 100644
--- a/fs/netfs/internal.h
+++ b/fs/netfs/internal.h
@@ -44,10 +44,7 @@ static inline void netfs_see_request(struct netfs_io_request *rreq,
  */
 extern unsigned int netfs_debug;
 
-void netfs_rreq_work(struct work_struct *work);
-void netfs_rreq_assess(struct netfs_io_request *rreq, bool was_async);
-bool netfs_rreq_submit_slice(struct netfs_io_request *rreq,
-			     unsigned int *_debug_index);
+int netfs_begin_read(struct netfs_io_request *rreq, bool sync);
 
 /*
  * stats.c
diff --git a/fs/netfs/objects.c b/fs/netfs/objects.c
index c46d027c1692..8f99269c5344 100644
--- a/fs/netfs/objects.c
+++ b/fs/netfs/objects.c
@@ -32,7 +32,7 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
 		rreq->i_size	= i_size_read(inode);
 		rreq->debug_id	= atomic_inc_return(&debug_ids);
 		INIT_LIST_HEAD(&rreq->subrequests);
-		INIT_WORK(&rreq->work, netfs_rreq_work);
+		INIT_WORK(&rreq->work, NULL);
 		refcount_set(&rreq->ref, 1);
 		__set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
 		if (ctx->ops->init_request)
diff --git a/fs/netfs/read_helper.c b/fs/netfs/read_helper.c
index e666f9cccc95..df73e276decd 100644
--- a/fs/netfs/read_helper.c
+++ b/fs/netfs/read_helper.c
@@ -418,7 +418,7 @@ static void netfs_rreq_is_still_valid(struct netfs_io_request *rreq)
  * Note that we could be in an ordinary kernel thread, on a workqueue or in
  * softirq context at this point.  We inherit a ref from the caller.
  */
-void netfs_rreq_assess(struct netfs_io_request *rreq, bool was_async)
+static void netfs_rreq_assess(struct netfs_io_request *rreq, bool was_async)
 {
 	trace_netfs_rreq(rreq, netfs_rreq_trace_assess);
 
@@ -443,7 +443,7 @@ void netfs_rreq_assess(struct netfs_io_request *rreq, bool was_async)
 	netfs_rreq_completed(rreq, was_async);
 }
 
-void netfs_rreq_work(struct work_struct *work)
+static void netfs_rreq_work(struct work_struct *work)
 {
 	struct netfs_io_request *rreq =
 		container_of(work, struct netfs_io_request, work);
@@ -632,8 +632,8 @@ netfs_rreq_prepare_read(struct netfs_io_request *rreq,
 /*
  * Slice off a piece of a read request and submit an I/O request for it.
  */
-bool netfs_rreq_submit_slice(struct netfs_io_request *rreq,
-			     unsigned int *_debug_index)
+static bool netfs_rreq_submit_slice(struct netfs_io_request *rreq,
+				    unsigned int *_debug_index)
 {
 	struct netfs_io_subrequest *subreq;
 	enum netfs_io_source source;
@@ -688,6 +688,68 @@ bool netfs_rreq_submit_slice(struct netfs_io_request *rreq,
 	return false;
 }
 
+/*
+ * Begin the process of reading in a chunk of data, where that data may be
+ * stitched together from multiple sources, including multiple servers and the
+ * local cache.
+ */
+int netfs_begin_read(struct netfs_io_request *rreq, bool sync)
+{
+	unsigned int debug_index = 0;
+	int ret;
+
+	_enter("R=%x %llx-%llx",
+	       rreq->debug_id, rreq->start, rreq->start + rreq->len - 1);
+
+	if (rreq->len == 0) {
+		pr_err("Zero-sized read [R=%x]\n", rreq->debug_id);
+		netfs_put_request(rreq, false, netfs_rreq_trace_put_zero_len);
+		return -EIO;
+	}
+
+	rreq->work.func = netfs_rreq_work;
+
+	if (sync)
+		netfs_get_request(rreq, netfs_rreq_trace_get_hold);
+
+	/* Chop the read into slices according to what the cache and the netfs
+	 * want and submit each one.
+	 */
+	atomic_set(&rreq->nr_outstanding, 1);
+	do {
+		if (!netfs_rreq_submit_slice(rreq, &debug_index))
+			break;
+
+	} while (rreq->submitted < rreq->len);
+
+	if (sync) {
+		/* Keep nr_outstanding incremented so that the ref always belongs to
+		 * us, and the service code isn't punted off to a random thread pool to
+		 * process.
+		 */
+		for (;;) {
+			wait_var_event(&rreq->nr_outstanding,
+				       atomic_read(&rreq->nr_outstanding) == 1);
+			netfs_rreq_assess(rreq, false);
+			if (!test_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags))
+				break;
+			cond_resched();
+		}
+
+		ret = rreq->error;
+		if (ret == 0 && rreq->submitted < rreq->len) {
+			trace_netfs_failure(rreq, NULL, ret, netfs_fail_short_read);
+			ret = -EIO;
+		}
+		netfs_put_request(rreq, false, netfs_rreq_trace_put_hold);
+	} else {
+		/* If we decrement nr_outstanding to 0, the ref belongs to us. */
+		if (atomic_dec_and_test(&rreq->nr_outstanding))
+			netfs_rreq_assess(rreq, false);
+	}
+	return ret;
+}
+
 static void netfs_cache_expand_readahead(struct netfs_io_request *rreq,
 					 loff_t *_start, size_t *_len, loff_t i_size)
 {
@@ -750,7 +812,6 @@ void netfs_readahead(struct readahead_control *ractl)
 {
 	struct netfs_io_request *rreq;
 	struct netfs_i_context *ctx = netfs_i_context(ractl->mapping->host);
-	unsigned int debug_index = 0;
 	int ret;
 
 	_enter("%lx,%x", readahead_index(ractl), readahead_count(ractl));
@@ -777,22 +838,13 @@ void netfs_readahead(struct readahead_control *ractl)
 
 	netfs_rreq_expand(rreq, ractl);
 
-	atomic_set(&rreq->nr_outstanding, 1);
-	do {
-		if (!netfs_rreq_submit_slice(rreq, &debug_index))
-			break;
-
-	} while (rreq->submitted < rreq->len);
-
 	/* Drop the refs on the folios here rather than in the cache or
 	 * filesystem.  The locks will be dropped in netfs_rreq_unlock().
 	 */
 	while (readahead_folio(ractl))
 		;
 
-	/* If we decrement nr_outstanding to 0, the ref belongs to us. */
-	if (atomic_dec_and_test(&rreq->nr_outstanding))
-		netfs_rreq_assess(rreq, false);
+	netfs_begin_read(rreq, false);
 	return;
 
 cleanup_free:
@@ -821,8 +873,7 @@ int netfs_readpage(struct file *file, struct page *subpage)
 	struct address_space *mapping = folio_file_mapping(folio);
 	struct netfs_io_request *rreq;
 	struct netfs_i_context *ctx = netfs_i_context(mapping->host);
-	unsigned int debug_index = 0;
-	int ret;
+	int ret = -ENOMEM;
 
 	_enter("%lx", folio_index(folio));
 
@@ -833,45 +884,19 @@ int netfs_readpage(struct file *file, struct page *subpage)
 
 	if (ctx->ops->begin_cache_operation) {
 		ret = ctx->ops->begin_cache_operation(rreq);
-		if (ret == -ENOMEM || ret == -EINTR || ret == -ERESTARTSYS) {
-			folio_unlock(folio);
-			goto out;
-		}
+		if (ret == -ENOMEM || ret == -EINTR || ret == -ERESTARTSYS)
+			goto discard;
 	}
 
 	netfs_stat(&netfs_n_rh_readpage);
 	trace_netfs_read(rreq, rreq->start, rreq->len, netfs_read_trace_readpage);
+	return netfs_begin_read(rreq, true);
 
-	netfs_get_request(rreq, netfs_rreq_trace_get_hold);
-
-	atomic_set(&rreq->nr_outstanding, 1);
-	do {
-		if (!netfs_rreq_submit_slice(rreq, &debug_index))
-			break;
-
-	} while (rreq->submitted < rreq->len);
-
-	/* Keep nr_outstanding incremented so that the ref always belongs to us, and
-	 * the service code isn't punted off to a random thread pool to
-	 * process.
-	 */
-	do {
-		wait_var_event(&rreq->nr_outstanding,
-			       atomic_read(&rreq->nr_outstanding) == 1);
-		netfs_rreq_assess(rreq, false);
-	} while (test_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags));
-
-	ret = rreq->error;
-	if (ret == 0 && rreq->submitted < rreq->len) {
-		trace_netfs_failure(rreq, NULL, ret, netfs_fail_short_readpage);
-		ret = -EIO;
-	}
-out:
-	netfs_put_request(rreq, false, netfs_rreq_trace_put_hold);
-	return ret;
+discard:
+	netfs_put_request(rreq, false, netfs_rreq_trace_put_discard);
 nomem:
 	folio_unlock(folio);
-	return -ENOMEM;
+	return ret;
 }
 EXPORT_SYMBOL(netfs_readpage);
 
@@ -963,7 +988,7 @@ int netfs_write_begin(struct file *file, struct address_space *mapping,
 	struct netfs_io_request *rreq;
 	struct netfs_i_context *ctx = netfs_i_context(file_inode(file ));
 	struct folio *folio;
-	unsigned int debug_index = 0, fgp_flags;
+	unsigned int fgp_flags;
 	pgoff_t index = pos >> PAGE_SHIFT;
 	int ret;
 
@@ -1033,32 +1058,7 @@ int netfs_write_begin(struct file *file, struct address_space *mapping,
 	while (readahead_folio(&ractl))
 		;
 
-	atomic_set(&rreq->nr_outstanding, 1);
-	do {
-		if (!netfs_rreq_submit_slice(rreq, &debug_index))
-			break;
-
-	} while (rreq->submitted < rreq->len);
-
-	/* Keep nr_outstanding incremented so that the ref always belongs to
-	 * us, and the service code isn't punted off to a random thread pool to
-	 * process.
-	 */
-	for (;;) {
-		wait_var_event(&rreq->nr_outstanding,
-			       atomic_read(&rreq->nr_outstanding) == 1);
-		netfs_rreq_assess(rreq, false);
-		if (!test_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags))
-			break;
-		cond_resched();
-	}
-
-	ret = rreq->error;
-	if (ret == 0 && rreq->submitted < rreq->len) {
-		trace_netfs_failure(rreq, NULL, ret, netfs_fail_short_write_begin);
-		ret = -EIO;
-	}
-	netfs_put_request(rreq, false, netfs_rreq_trace_put_hold);
+	ret = netfs_begin_read(rreq, true);
 	if (ret < 0)
 		goto error;
 
diff --git a/include/trace/events/netfs.h b/include/trace/events/netfs.h
index 685b07573394..55501d044bbc 100644
--- a/include/trace/events/netfs.h
+++ b/include/trace/events/netfs.h
@@ -56,17 +56,18 @@
 	EM(netfs_fail_check_write_begin,	"check-write-begin")	\
 	EM(netfs_fail_copy_to_cache,		"copy-to-cache")	\
 	EM(netfs_fail_read,			"read")			\
-	EM(netfs_fail_short_readpage,		"short-readpage")	\
-	EM(netfs_fail_short_write_begin,	"short-write-begin")	\
+	EM(netfs_fail_short_read,		"short-read")		\
 	E_(netfs_fail_prepare_write,		"prep-write")
 
 #define netfs_rreq_ref_traces					\
 	EM(netfs_rreq_trace_get_hold,		"GET HOLD   ")	\
 	EM(netfs_rreq_trace_get_subreq,		"GET SUBREQ ")	\
 	EM(netfs_rreq_trace_put_complete,	"PUT COMPLT ")	\
+	EM(netfs_rreq_trace_put_discard,	"PUT DISCARD")	\
 	EM(netfs_rreq_trace_put_failed,		"PUT FAILED ")	\
 	EM(netfs_rreq_trace_put_hold,		"PUT HOLD   ")	\
 	EM(netfs_rreq_trace_put_subreq,		"PUT SUBREQ ")	\
+	EM(netfs_rreq_trace_put_zero_len,	"PUT ZEROLEN")	\
 	E_(netfs_rreq_trace_new,		"NEW        ")
 
 #define netfs_sreq_ref_traces					\



^ permalink raw reply related	[flat|nested] 20+ messages in thread

* [PATCH 14/19] netfs: Split fs/netfs/read_helper.c
  2022-03-02 14:01 [PATCH 00/19] netfs: Prep for write helpers David Howells
                   ` (12 preceding siblings ...)
  2022-03-02 14:07 ` [PATCH 13/19] netfs: Add a function to consolidate beginning a read David Howells
@ 2022-03-02 14:07 ` David Howells
  2022-03-02 14:07 ` [PATCH 15/19] netfs: Split some core bits out into their own file David Howells
                   ` (4 subsequent siblings)
  18 siblings, 0 replies; 20+ messages in thread
From: David Howells @ 2022-03-02 14:07 UTC (permalink / raw)
  To: linux-cachefs
  Cc: dhowells, Anna Schumaker, Steve French, Dominique Martinet,
	Jeff Layton, David Wysochanski, Ilya Dryomov, Jeffle Xu,
	Linus Torvalds, linux-afs, linux-nfs, linux-cifs, ceph-devel,
	v9fs-developer, linux-fsdevel, linux-kernel

Split fs/netfs/read_helper.c into two pieces, one to deal with buffered
writes and one to deal with the I/O mechanism.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
---

 fs/netfs/Makefile        |    1 
 fs/netfs/buffered_read.c |  426 ++++++++++++++++++++++++++++++++++++++++++++++
 fs/netfs/read_helper.c   |  416 ---------------------------------------------
 3 files changed, 427 insertions(+), 416 deletions(-)
 create mode 100644 fs/netfs/buffered_read.c

diff --git a/fs/netfs/Makefile b/fs/netfs/Makefile
index 939fd00a1fc9..0466159b8222 100644
--- a/fs/netfs/Makefile
+++ b/fs/netfs/Makefile
@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 
 netfs-y := \
+	buffered_read.o \
 	objects.o \
 	read_helper.o
 
diff --git a/fs/netfs/buffered_read.c b/fs/netfs/buffered_read.c
new file mode 100644
index 000000000000..343c0957ae27
--- /dev/null
+++ b/fs/netfs/buffered_read.c
@@ -0,0 +1,426 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Network filesystem high-level buffered read support.
+ *
+ * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/export.h>
+#include <linux/task_io_accounting_ops.h>
+#include "internal.h"
+
+/*
+ * Unlock the folios in a read operation.  We need to set PG_fscache on any
+ * folios we're going to write back before we unlock them.
+ */
+void netfs_rreq_unlock_folios(struct netfs_io_request *rreq)
+{
+	struct netfs_io_subrequest *subreq;
+	struct folio *folio;
+	unsigned int iopos, account = 0;
+	pgoff_t start_page = rreq->start / PAGE_SIZE;
+	pgoff_t last_page = ((rreq->start + rreq->len) / PAGE_SIZE) - 1;
+	bool subreq_failed = false;
+
+	XA_STATE(xas, &rreq->mapping->i_pages, start_page);
+
+	if (test_bit(NETFS_RREQ_FAILED, &rreq->flags)) {
+		__clear_bit(NETFS_RREQ_COPY_TO_CACHE, &rreq->flags);
+		list_for_each_entry(subreq, &rreq->subrequests, rreq_link) {
+			__clear_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags);
+		}
+	}
+
+	/* Walk through the pagecache and the I/O request lists simultaneously.
+	 * We may have a mixture of cached and uncached sections and we only
+	 * really want to write out the uncached sections.  This is slightly
+	 * complicated by the possibility that we might have huge pages with a
+	 * mixture inside.
+	 */
+	subreq = list_first_entry(&rreq->subrequests,
+				  struct netfs_io_subrequest, rreq_link);
+	iopos = 0;
+	subreq_failed = (subreq->error < 0);
+
+	trace_netfs_rreq(rreq, netfs_rreq_trace_unlock);
+
+	rcu_read_lock();
+	xas_for_each(&xas, folio, last_page) {
+		unsigned int pgpos = (folio_index(folio) - start_page) * PAGE_SIZE;
+		unsigned int pgend = pgpos + folio_size(folio);
+		bool pg_failed = false;
+
+		for (;;) {
+			if (!subreq) {
+				pg_failed = true;
+				break;
+			}
+			if (test_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags))
+				folio_start_fscache(folio);
+			pg_failed |= subreq_failed;
+			if (pgend < iopos + subreq->len)
+				break;
+
+			account += subreq->transferred;
+			iopos += subreq->len;
+			if (!list_is_last(&subreq->rreq_link, &rreq->subrequests)) {
+				subreq = list_next_entry(subreq, rreq_link);
+				subreq_failed = (subreq->error < 0);
+			} else {
+				subreq = NULL;
+				subreq_failed = false;
+			}
+			if (pgend == iopos)
+				break;
+		}
+
+		if (!pg_failed) {
+			flush_dcache_folio(folio);
+			folio_mark_uptodate(folio);
+		}
+
+		if (!test_bit(NETFS_RREQ_DONT_UNLOCK_FOLIOS, &rreq->flags)) {
+			if (folio_index(folio) == rreq->no_unlock_folio &&
+			    test_bit(NETFS_RREQ_NO_UNLOCK_FOLIO, &rreq->flags))
+				_debug("no unlock");
+			else
+				folio_unlock(folio);
+		}
+	}
+	rcu_read_unlock();
+
+	task_io_account_read(account);
+	if (rreq->netfs_ops->done)
+		rreq->netfs_ops->done(rreq);
+}
+
+static void netfs_cache_expand_readahead(struct netfs_io_request *rreq,
+					 loff_t *_start, size_t *_len, loff_t i_size)
+{
+	struct netfs_cache_resources *cres = &rreq->cache_resources;
+
+	if (cres->ops && cres->ops->expand_readahead)
+		cres->ops->expand_readahead(cres, _start, _len, i_size);
+}
+
+static void netfs_rreq_expand(struct netfs_io_request *rreq,
+			      struct readahead_control *ractl)
+{
+	/* Give the cache a chance to change the request parameters.  The
+	 * resultant request must contain the original region.
+	 */
+	netfs_cache_expand_readahead(rreq, &rreq->start, &rreq->len, rreq->i_size);
+
+	/* Give the netfs a chance to change the request parameters.  The
+	 * resultant request must contain the original region.
+	 */
+	if (rreq->netfs_ops->expand_readahead)
+		rreq->netfs_ops->expand_readahead(rreq);
+
+	/* Expand the request if the cache wants it to start earlier.  Note
+	 * that the expansion may get further extended if the VM wishes to
+	 * insert THPs and the preferred start and/or end wind up in the middle
+	 * of THPs.
+	 *
+	 * If this is the case, however, the THP size should be an integer
+	 * multiple of the cache granule size, so we get a whole number of
+	 * granules to deal with.
+	 */
+	if (rreq->start  != readahead_pos(ractl) ||
+	    rreq->len != readahead_length(ractl)) {
+		readahead_expand(ractl, rreq->start, rreq->len);
+		rreq->start  = readahead_pos(ractl);
+		rreq->len = readahead_length(ractl);
+
+		trace_netfs_read(rreq, readahead_pos(ractl), readahead_length(ractl),
+				 netfs_read_trace_expanded);
+	}
+}
+
+/**
+ * netfs_readahead - Helper to manage a read request
+ * @ractl: The description of the readahead request
+ *
+ * Fulfil a readahead request by drawing data from the cache if possible, or
+ * the netfs if not.  Space beyond the EOF is zero-filled.  Multiple I/O
+ * requests from different sources will get munged together.  If necessary, the
+ * readahead window can be expanded in either direction to a more convenient
+ * alighment for RPC efficiency or to make storage in the cache feasible.
+ *
+ * The calling netfs must initialise a netfs context contiguous to the vfs
+ * inode before calling this.
+ *
+ * This is usable whether or not caching is enabled.
+ */
+void netfs_readahead(struct readahead_control *ractl)
+{
+	struct netfs_io_request *rreq;
+	struct netfs_i_context *ctx = netfs_i_context(ractl->mapping->host);
+	int ret;
+
+	_enter("%lx,%x", readahead_index(ractl), readahead_count(ractl));
+
+	if (readahead_count(ractl) == 0)
+		return;
+
+	rreq = netfs_alloc_request(ractl->mapping, ractl->file,
+				   readahead_pos(ractl),
+				   readahead_length(ractl),
+				   NETFS_READAHEAD);
+	if (!rreq)
+		return;
+
+	if (ctx->ops->begin_cache_operation) {
+		ret = ctx->ops->begin_cache_operation(rreq);
+		if (ret == -ENOMEM || ret == -EINTR || ret == -ERESTARTSYS)
+			goto cleanup_free;
+	}
+
+	netfs_stat(&netfs_n_rh_readahead);
+	trace_netfs_read(rreq, readahead_pos(ractl), readahead_length(ractl),
+			 netfs_read_trace_readahead);
+
+	netfs_rreq_expand(rreq, ractl);
+
+	/* Drop the refs on the folios here rather than in the cache or
+	 * filesystem.  The locks will be dropped in netfs_rreq_unlock().
+	 */
+	while (readahead_folio(ractl))
+		;
+
+	netfs_begin_read(rreq, false);
+	return;
+
+cleanup_free:
+	netfs_put_request(rreq, false, netfs_rreq_trace_put_failed);
+	return;
+}
+EXPORT_SYMBOL(netfs_readahead);
+
+/**
+ * netfs_readpage - Helper to manage a readpage request
+ * @file: The file to read from
+ * @subpage: A subpage of the folio to read
+ *
+ * Fulfil a readpage request by drawing data from the cache if possible, or the
+ * netfs if not.  Space beyond the EOF is zero-filled.  Multiple I/O requests
+ * from different sources will get munged together.
+ *
+ * The calling netfs must initialise a netfs context contiguous to the vfs
+ * inode before calling this.
+ *
+ * This is usable whether or not caching is enabled.
+ */
+int netfs_readpage(struct file *file, struct page *subpage)
+{
+	struct folio *folio = page_folio(subpage);
+	struct address_space *mapping = folio_file_mapping(folio);
+	struct netfs_io_request *rreq;
+	struct netfs_i_context *ctx = netfs_i_context(mapping->host);
+	int ret = -ENOMEM;
+
+	_enter("%lx", folio_index(folio));
+
+	rreq = netfs_alloc_request(mapping, file, folio_file_pos(folio),
+				   folio_size(folio), NETFS_READPAGE);
+	if (!rreq)
+		goto nomem;
+
+	if (ctx->ops->begin_cache_operation) {
+		ret = ctx->ops->begin_cache_operation(rreq);
+		if (ret == -ENOMEM || ret == -EINTR || ret == -ERESTARTSYS)
+			goto discard;
+	}
+
+	netfs_stat(&netfs_n_rh_readpage);
+	trace_netfs_read(rreq, rreq->start, rreq->len, netfs_read_trace_readpage);
+	return netfs_begin_read(rreq, true);
+
+discard:
+	netfs_put_request(rreq, false, netfs_rreq_trace_put_discard);
+nomem:
+	folio_unlock(folio);
+	return ret;
+}
+EXPORT_SYMBOL(netfs_readpage);
+
+/*
+ * Prepare a folio for writing without reading first
+ * @folio: The folio being prepared
+ * @pos: starting position for the write
+ * @len: length of write
+ * @always_fill: T if the folio should always be completely filled/cleared
+ *
+ * In some cases, write_begin doesn't need to read at all:
+ * - full folio write
+ * - write that lies in a folio that is completely beyond EOF
+ * - write that covers the folio from start to EOF or beyond it
+ *
+ * If any of these criteria are met, then zero out the unwritten parts
+ * of the folio and return true. Otherwise, return false.
+ */
+static bool netfs_skip_folio_read(struct folio *folio, loff_t pos, size_t len,
+				 bool always_fill)
+{
+	struct inode *inode = folio_inode(folio);
+	loff_t i_size = i_size_read(inode);
+	size_t offset = offset_in_folio(folio, pos);
+	size_t plen = folio_size(folio);
+
+	if (unlikely(always_fill)) {
+		if (pos - offset + len <= i_size)
+			return false; /* Page entirely before EOF */
+		zero_user_segment(&folio->page, 0, plen);
+		folio_mark_uptodate(folio);
+		return true;
+	}
+
+	/* Full folio write */
+	if (offset == 0 && len >= plen)
+		return true;
+
+	/* Page entirely beyond the end of the file */
+	if (pos - offset >= i_size)
+		goto zero_out;
+
+	/* Write that covers from the start of the folio to EOF or beyond */
+	if (offset == 0 && (pos + len) >= i_size)
+		goto zero_out;
+
+	return false;
+zero_out:
+	zero_user_segments(&folio->page, 0, offset, offset + len, len);
+	return true;
+}
+
+/**
+ * netfs_write_begin - Helper to prepare for writing
+ * @file: The file to read from
+ * @mapping: The mapping to read from
+ * @pos: File position at which the write will begin
+ * @len: The length of the write (may extend beyond the end of the folio chosen)
+ * @aop_flags: AOP_* flags
+ * @_folio: Where to put the resultant folio
+ * @_fsdata: Place for the netfs to store a cookie
+ *
+ * Pre-read data for a write-begin request by drawing data from the cache if
+ * possible, or the netfs if not.  Space beyond the EOF is zero-filled.
+ * Multiple I/O requests from different sources will get munged together.  If
+ * necessary, the readahead window can be expanded in either direction to a
+ * more convenient alighment for RPC efficiency or to make storage in the cache
+ * feasible.
+ *
+ * The calling netfs must provide a table of operations, only one of which,
+ * issue_op, is mandatory.
+ *
+ * The check_write_begin() operation can be provided to check for and flush
+ * conflicting writes once the folio is grabbed and locked.  It is passed a
+ * pointer to the fsdata cookie that gets returned to the VM to be passed to
+ * write_end.  It is permitted to sleep.  It should return 0 if the request
+ * should go ahead; unlock the folio and return -EAGAIN to cause the folio to
+ * be regot; or return an error.
+ *
+ * The calling netfs must initialise a netfs context contiguous to the vfs
+ * inode before calling this.
+ *
+ * This is usable whether or not caching is enabled.
+ */
+int netfs_write_begin(struct file *file, struct address_space *mapping,
+		      loff_t pos, unsigned int len, unsigned int aop_flags,
+		      struct folio **_folio, void **_fsdata)
+{
+	struct netfs_io_request *rreq;
+	struct netfs_i_context *ctx = netfs_i_context(file_inode(file ));
+	struct folio *folio;
+	unsigned int fgp_flags;
+	pgoff_t index = pos >> PAGE_SHIFT;
+	int ret;
+
+	DEFINE_READAHEAD(ractl, file, NULL, mapping, index);
+
+retry:
+	fgp_flags = FGP_LOCK | FGP_WRITE | FGP_CREAT | FGP_STABLE;
+	if (aop_flags & AOP_FLAG_NOFS)
+		fgp_flags |= FGP_NOFS;
+	folio = __filemap_get_folio(mapping, index, fgp_flags,
+				    mapping_gfp_mask(mapping));
+	if (!folio)
+		return -ENOMEM;
+
+	if (ctx->ops->check_write_begin) {
+		/* Allow the netfs (eg. ceph) to flush conflicts. */
+		ret = ctx->ops->check_write_begin(file, pos, len, folio, _fsdata);
+		if (ret < 0) {
+			trace_netfs_failure(NULL, NULL, ret, netfs_fail_check_write_begin);
+			if (ret == -EAGAIN)
+				goto retry;
+			goto error;
+		}
+	}
+
+	if (folio_test_uptodate(folio))
+		goto have_folio;
+
+	/* If the page is beyond the EOF, we want to clear it - unless it's
+	 * within the cache granule containing the EOF, in which case we need
+	 * to preload the granule.
+	 */
+	if (!netfs_is_cache_enabled(ctx) &&
+	    netfs_skip_folio_read(folio, pos, len, false)) {
+		netfs_stat(&netfs_n_rh_write_zskip);
+		goto have_folio_no_wait;
+	}
+
+	ret = -ENOMEM;
+	rreq = netfs_alloc_request(mapping, file, folio_file_pos(folio),
+				   folio_size(folio), NETFS_READ_FOR_WRITE);
+	if (!rreq)
+		goto error;
+	rreq->start		= folio_file_pos(folio);
+	rreq->len		= folio_size(folio);
+	rreq->no_unlock_folio	= folio_index(folio);
+	__set_bit(NETFS_RREQ_NO_UNLOCK_FOLIO, &rreq->flags);
+
+	if (ctx->ops->begin_cache_operation) {
+		ret = ctx->ops->begin_cache_operation(rreq);
+		if (ret == -ENOMEM || ret == -EINTR || ret == -ERESTARTSYS)
+			goto error_put;
+	}
+
+	netfs_stat(&netfs_n_rh_write_begin);
+	trace_netfs_read(rreq, pos, len, netfs_read_trace_write_begin);
+
+	/* Expand the request to meet caching requirements and download
+	 * preferences.
+	 */
+	ractl._nr_pages = folio_nr_pages(folio);
+	netfs_rreq_expand(rreq, &ractl);
+	netfs_get_request(rreq, netfs_rreq_trace_get_hold);
+
+	/* We hold the folio locks, so we can drop the references */
+	folio_get(folio);
+	while (readahead_folio(&ractl))
+		;
+
+	ret = netfs_begin_read(rreq, true);
+	if (ret < 0)
+		goto error;
+
+have_folio:
+	ret = folio_wait_fscache_killable(folio);
+	if (ret < 0)
+		goto error;
+have_folio_no_wait:
+	*_folio = folio;
+	_leave(" = 0");
+	return 0;
+
+error_put:
+	netfs_put_request(rreq, false, netfs_rreq_trace_put_failed);
+error:
+	folio_unlock(folio);
+	folio_put(folio);
+	_leave(" = %d", ret);
+	return ret;
+}
+EXPORT_SYMBOL(netfs_write_begin);
diff --git a/fs/netfs/read_helper.c b/fs/netfs/read_helper.c
index df73e276decd..78843820d9f1 100644
--- a/fs/netfs/read_helper.c
+++ b/fs/netfs/read_helper.c
@@ -246,91 +246,6 @@ static void netfs_rreq_write_to_cache(struct netfs_io_request *rreq)
 		BUG();
 }
 
-/*
- * Unlock the folios in a read operation.  We need to set PG_fscache on any
- * folios we're going to write back before we unlock them.
- */
-void netfs_rreq_unlock_folios(struct netfs_io_request *rreq)
-{
-	struct netfs_io_subrequest *subreq;
-	struct folio *folio;
-	unsigned int iopos, account = 0;
-	pgoff_t start_page = rreq->start / PAGE_SIZE;
-	pgoff_t last_page = ((rreq->start + rreq->len) / PAGE_SIZE) - 1;
-	bool subreq_failed = false;
-
-	XA_STATE(xas, &rreq->mapping->i_pages, start_page);
-
-	if (test_bit(NETFS_RREQ_FAILED, &rreq->flags)) {
-		__clear_bit(NETFS_RREQ_COPY_TO_CACHE, &rreq->flags);
-		list_for_each_entry(subreq, &rreq->subrequests, rreq_link) {
-			__clear_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags);
-		}
-	}
-
-	/* Walk through the pagecache and the I/O request lists simultaneously.
-	 * We may have a mixture of cached and uncached sections and we only
-	 * really want to write out the uncached sections.  This is slightly
-	 * complicated by the possibility that we might have huge pages with a
-	 * mixture inside.
-	 */
-	subreq = list_first_entry(&rreq->subrequests,
-				  struct netfs_io_subrequest, rreq_link);
-	iopos = 0;
-	subreq_failed = (subreq->error < 0);
-
-	trace_netfs_rreq(rreq, netfs_rreq_trace_unlock);
-
-	rcu_read_lock();
-	xas_for_each(&xas, folio, last_page) {
-		unsigned int pgpos = (folio_index(folio) - start_page) * PAGE_SIZE;
-		unsigned int pgend = pgpos + folio_size(folio);
-		bool pg_failed = false;
-
-		for (;;) {
-			if (!subreq) {
-				pg_failed = true;
-				break;
-			}
-			if (test_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags))
-				folio_start_fscache(folio);
-			pg_failed |= subreq_failed;
-			if (pgend < iopos + subreq->len)
-				break;
-
-			account += subreq->transferred;
-			iopos += subreq->len;
-			if (!list_is_last(&subreq->rreq_link, &rreq->subrequests)) {
-				subreq = list_next_entry(subreq, rreq_link);
-				subreq_failed = (subreq->error < 0);
-			} else {
-				subreq = NULL;
-				subreq_failed = false;
-			}
-			if (pgend == iopos)
-				break;
-		}
-
-		if (!pg_failed) {
-			flush_dcache_folio(folio);
-			folio_mark_uptodate(folio);
-		}
-
-		if (!test_bit(NETFS_RREQ_DONT_UNLOCK_FOLIOS, &rreq->flags)) {
-			if (folio_index(folio) == rreq->no_unlock_folio &&
-			    test_bit(NETFS_RREQ_NO_UNLOCK_FOLIO, &rreq->flags))
-				_debug("no unlock");
-			else
-				folio_unlock(folio);
-		}
-	}
-	rcu_read_unlock();
-
-	task_io_account_read(account);
-	if (rreq->netfs_ops->done)
-		rreq->netfs_ops->done(rreq);
-}
-
 /*
  * Handle a short read.
  */
@@ -749,334 +664,3 @@ int netfs_begin_read(struct netfs_io_request *rreq, bool sync)
 	}
 	return ret;
 }
-
-static void netfs_cache_expand_readahead(struct netfs_io_request *rreq,
-					 loff_t *_start, size_t *_len, loff_t i_size)
-{
-	struct netfs_cache_resources *cres = &rreq->cache_resources;
-
-	if (cres->ops && cres->ops->expand_readahead)
-		cres->ops->expand_readahead(cres, _start, _len, i_size);
-}
-
-static void netfs_rreq_expand(struct netfs_io_request *rreq,
-			      struct readahead_control *ractl)
-{
-	/* Give the cache a chance to change the request parameters.  The
-	 * resultant request must contain the original region.
-	 */
-	netfs_cache_expand_readahead(rreq, &rreq->start, &rreq->len, rreq->i_size);
-
-	/* Give the netfs a chance to change the request parameters.  The
-	 * resultant request must contain the original region.
-	 */
-	if (rreq->netfs_ops->expand_readahead)
-		rreq->netfs_ops->expand_readahead(rreq);
-
-	/* Expand the request if the cache wants it to start earlier.  Note
-	 * that the expansion may get further extended if the VM wishes to
-	 * insert THPs and the preferred start and/or end wind up in the middle
-	 * of THPs.
-	 *
-	 * If this is the case, however, the THP size should be an integer
-	 * multiple of the cache granule size, so we get a whole number of
-	 * granules to deal with.
-	 */
-	if (rreq->start  != readahead_pos(ractl) ||
-	    rreq->len != readahead_length(ractl)) {
-		readahead_expand(ractl, rreq->start, rreq->len);
-		rreq->start  = readahead_pos(ractl);
-		rreq->len = readahead_length(ractl);
-
-		trace_netfs_read(rreq, readahead_pos(ractl), readahead_length(ractl),
-				 netfs_read_trace_expanded);
-	}
-}
-
-/**
- * netfs_readahead - Helper to manage a read request
- * @ractl: The description of the readahead request
- *
- * Fulfil a readahead request by drawing data from the cache if possible, or
- * the netfs if not.  Space beyond the EOF is zero-filled.  Multiple I/O
- * requests from different sources will get munged together.  If necessary, the
- * readahead window can be expanded in either direction to a more convenient
- * alighment for RPC efficiency or to make storage in the cache feasible.
- *
- * The calling netfs must initialise a netfs context contiguous to the vfs
- * inode before calling this.
- *
- * This is usable whether or not caching is enabled.
- */
-void netfs_readahead(struct readahead_control *ractl)
-{
-	struct netfs_io_request *rreq;
-	struct netfs_i_context *ctx = netfs_i_context(ractl->mapping->host);
-	int ret;
-
-	_enter("%lx,%x", readahead_index(ractl), readahead_count(ractl));
-
-	if (readahead_count(ractl) == 0)
-		return;
-
-	rreq = netfs_alloc_request(ractl->mapping, ractl->file,
-				   readahead_pos(ractl),
-				   readahead_length(ractl),
-				   NETFS_READAHEAD);
-	if (!rreq)
-		return;
-
-	if (ctx->ops->begin_cache_operation) {
-		ret = ctx->ops->begin_cache_operation(rreq);
-		if (ret == -ENOMEM || ret == -EINTR || ret == -ERESTARTSYS)
-			goto cleanup_free;
-	}
-
-	netfs_stat(&netfs_n_rh_readahead);
-	trace_netfs_read(rreq, readahead_pos(ractl), readahead_length(ractl),
-			 netfs_read_trace_readahead);
-
-	netfs_rreq_expand(rreq, ractl);
-
-	/* Drop the refs on the folios here rather than in the cache or
-	 * filesystem.  The locks will be dropped in netfs_rreq_unlock().
-	 */
-	while (readahead_folio(ractl))
-		;
-
-	netfs_begin_read(rreq, false);
-	return;
-
-cleanup_free:
-	netfs_put_request(rreq, false, netfs_rreq_trace_put_failed);
-	return;
-}
-EXPORT_SYMBOL(netfs_readahead);
-
-/**
- * netfs_readpage - Helper to manage a readpage request
- * @file: The file to read from
- * @subpage: A subpage of the folio to read
- *
- * Fulfil a readpage request by drawing data from the cache if possible, or the
- * netfs if not.  Space beyond the EOF is zero-filled.  Multiple I/O requests
- * from different sources will get munged together.
- *
- * The calling netfs must initialise a netfs context contiguous to the vfs
- * inode before calling this.
- *
- * This is usable whether or not caching is enabled.
- */
-int netfs_readpage(struct file *file, struct page *subpage)
-{
-	struct folio *folio = page_folio(subpage);
-	struct address_space *mapping = folio_file_mapping(folio);
-	struct netfs_io_request *rreq;
-	struct netfs_i_context *ctx = netfs_i_context(mapping->host);
-	int ret = -ENOMEM;
-
-	_enter("%lx", folio_index(folio));
-
-	rreq = netfs_alloc_request(mapping, file, folio_file_pos(folio),
-				   folio_size(folio), NETFS_READPAGE);
-	if (!rreq)
-		goto nomem;
-
-	if (ctx->ops->begin_cache_operation) {
-		ret = ctx->ops->begin_cache_operation(rreq);
-		if (ret == -ENOMEM || ret == -EINTR || ret == -ERESTARTSYS)
-			goto discard;
-	}
-
-	netfs_stat(&netfs_n_rh_readpage);
-	trace_netfs_read(rreq, rreq->start, rreq->len, netfs_read_trace_readpage);
-	return netfs_begin_read(rreq, true);
-
-discard:
-	netfs_put_request(rreq, false, netfs_rreq_trace_put_discard);
-nomem:
-	folio_unlock(folio);
-	return ret;
-}
-EXPORT_SYMBOL(netfs_readpage);
-
-/*
- * Prepare a folio for writing without reading first
- * @folio: The folio being prepared
- * @pos: starting position for the write
- * @len: length of write
- * @always_fill: T if the folio should always be completely filled/cleared
- *
- * In some cases, write_begin doesn't need to read at all:
- * - full folio write
- * - write that lies in a folio that is completely beyond EOF
- * - write that covers the folio from start to EOF or beyond it
- *
- * If any of these criteria are met, then zero out the unwritten parts
- * of the folio and return true. Otherwise, return false.
- */
-static bool netfs_skip_folio_read(struct folio *folio, loff_t pos, size_t len,
-				 bool always_fill)
-{
-	struct inode *inode = folio_inode(folio);
-	loff_t i_size = i_size_read(inode);
-	size_t offset = offset_in_folio(folio, pos);
-	size_t plen = folio_size(folio);
-
-	if (unlikely(always_fill)) {
-		if (pos - offset + len <= i_size)
-			return false; /* Page entirely before EOF */
-		zero_user_segment(&folio->page, 0, plen);
-		folio_mark_uptodate(folio);
-		return true;
-	}
-
-	/* Full folio write */
-	if (offset == 0 && len >= plen)
-		return true;
-
-	/* Page entirely beyond the end of the file */
-	if (pos - offset >= i_size)
-		goto zero_out;
-
-	/* Write that covers from the start of the folio to EOF or beyond */
-	if (offset == 0 && (pos + len) >= i_size)
-		goto zero_out;
-
-	return false;
-zero_out:
-	zero_user_segments(&folio->page, 0, offset, offset + len, len);
-	return true;
-}
-
-/**
- * netfs_write_begin - Helper to prepare for writing
- * @file: The file to read from
- * @mapping: The mapping to read from
- * @pos: File position at which the write will begin
- * @len: The length of the write (may extend beyond the end of the folio chosen)
- * @aop_flags: AOP_* flags
- * @_folio: Where to put the resultant folio
- * @_fsdata: Place for the netfs to store a cookie
- *
- * Pre-read data for a write-begin request by drawing data from the cache if
- * possible, or the netfs if not.  Space beyond the EOF is zero-filled.
- * Multiple I/O requests from different sources will get munged together.  If
- * necessary, the readahead window can be expanded in either direction to a
- * more convenient alighment for RPC efficiency or to make storage in the cache
- * feasible.
- *
- * The calling netfs must provide a table of operations, only one of which,
- * issue_op, is mandatory.
- *
- * The check_write_begin() operation can be provided to check for and flush
- * conflicting writes once the folio is grabbed and locked.  It is passed a
- * pointer to the fsdata cookie that gets returned to the VM to be passed to
- * write_end.  It is permitted to sleep.  It should return 0 if the request
- * should go ahead; unlock the folio and return -EAGAIN to cause the folio to
- * be regot; or return an error.
- *
- * The calling netfs must initialise a netfs context contiguous to the vfs
- * inode before calling this.
- *
- * This is usable whether or not caching is enabled.
- */
-int netfs_write_begin(struct file *file, struct address_space *mapping,
-		      loff_t pos, unsigned int len, unsigned int aop_flags,
-		      struct folio **_folio, void **_fsdata)
-{
-	struct netfs_io_request *rreq;
-	struct netfs_i_context *ctx = netfs_i_context(file_inode(file ));
-	struct folio *folio;
-	unsigned int fgp_flags;
-	pgoff_t index = pos >> PAGE_SHIFT;
-	int ret;
-
-	DEFINE_READAHEAD(ractl, file, NULL, mapping, index);
-
-retry:
-	fgp_flags = FGP_LOCK | FGP_WRITE | FGP_CREAT | FGP_STABLE;
-	if (aop_flags & AOP_FLAG_NOFS)
-		fgp_flags |= FGP_NOFS;
-	folio = __filemap_get_folio(mapping, index, fgp_flags,
-				    mapping_gfp_mask(mapping));
-	if (!folio)
-		return -ENOMEM;
-
-	if (ctx->ops->check_write_begin) {
-		/* Allow the netfs (eg. ceph) to flush conflicts. */
-		ret = ctx->ops->check_write_begin(file, pos, len, folio, _fsdata);
-		if (ret < 0) {
-			trace_netfs_failure(NULL, NULL, ret, netfs_fail_check_write_begin);
-			if (ret == -EAGAIN)
-				goto retry;
-			goto error;
-		}
-	}
-
-	if (folio_test_uptodate(folio))
-		goto have_folio;
-
-	/* If the page is beyond the EOF, we want to clear it - unless it's
-	 * within the cache granule containing the EOF, in which case we need
-	 * to preload the granule.
-	 */
-	if (!netfs_is_cache_enabled(ctx) &&
-	    netfs_skip_folio_read(folio, pos, len, false)) {
-		netfs_stat(&netfs_n_rh_write_zskip);
-		goto have_folio_no_wait;
-	}
-
-	ret = -ENOMEM;
-	rreq = netfs_alloc_request(mapping, file, folio_file_pos(folio),
-				   folio_size(folio), NETFS_READ_FOR_WRITE);
-	if (!rreq)
-		goto error;
-	rreq->start		= folio_file_pos(folio);
-	rreq->len		= folio_size(folio);
-	rreq->no_unlock_folio	= folio_index(folio);
-	__set_bit(NETFS_RREQ_NO_UNLOCK_FOLIO, &rreq->flags);
-
-	if (ctx->ops->begin_cache_operation) {
-		ret = ctx->ops->begin_cache_operation(rreq);
-		if (ret == -ENOMEM || ret == -EINTR || ret == -ERESTARTSYS)
-			goto error_put;
-	}
-
-	netfs_stat(&netfs_n_rh_write_begin);
-	trace_netfs_read(rreq, pos, len, netfs_read_trace_write_begin);
-
-	/* Expand the request to meet caching requirements and download
-	 * preferences.
-	 */
-	ractl._nr_pages = folio_nr_pages(folio);
-	netfs_rreq_expand(rreq, &ractl);
-	netfs_get_request(rreq, netfs_rreq_trace_get_hold);
-
-	/* We hold the folio locks, so we can drop the references */
-	folio_get(folio);
-	while (readahead_folio(&ractl))
-		;
-
-	ret = netfs_begin_read(rreq, true);
-	if (ret < 0)
-		goto error;
-
-have_folio:
-	ret = folio_wait_fscache_killable(folio);
-	if (ret < 0)
-		goto error;
-have_folio_no_wait:
-	*_folio = folio;
-	_leave(" = 0");
-	return 0;
-
-error_put:
-	netfs_put_request(rreq, false, netfs_rreq_trace_put_failed);
-error:
-	folio_unlock(folio);
-	folio_put(folio);
-	_leave(" = %d", ret);
-	return ret;
-}
-EXPORT_SYMBOL(netfs_write_begin);



^ permalink raw reply related	[flat|nested] 20+ messages in thread

* [PATCH 15/19] netfs: Split some core bits out into their own file
  2022-03-02 14:01 [PATCH 00/19] netfs: Prep for write helpers David Howells
                   ` (13 preceding siblings ...)
  2022-03-02 14:07 ` [PATCH 14/19] netfs: Split fs/netfs/read_helper.c David Howells
@ 2022-03-02 14:07 ` David Howells
  2022-03-02 14:08 ` [PATCH 16/19] netfs: Rename rename read_helper.c to io.c David Howells
                   ` (3 subsequent siblings)
  18 siblings, 0 replies; 20+ messages in thread
From: David Howells @ 2022-03-02 14:07 UTC (permalink / raw)
  To: linux-cachefs
  Cc: dhowells, Anna Schumaker, Steve French, Dominique Martinet,
	Jeff Layton, David Wysochanski, Ilya Dryomov, Jeffle Xu,
	Linus Torvalds, linux-afs, linux-nfs, linux-cifs, ceph-devel,
	v9fs-developer, linux-fsdevel, linux-kernel

Split some core bits out into their own file.  More bits will be added to
this file later.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
---

 fs/netfs/Makefile      |    1 +
 fs/netfs/internal.h    |    7 +++++--
 fs/netfs/main.c        |   20 ++++++++++++++++++++
 fs/netfs/read_helper.c |   10 ----------
 4 files changed, 26 insertions(+), 12 deletions(-)
 create mode 100644 fs/netfs/main.c

diff --git a/fs/netfs/Makefile b/fs/netfs/Makefile
index 0466159b8222..029657b6db63 100644
--- a/fs/netfs/Makefile
+++ b/fs/netfs/Makefile
@@ -2,6 +2,7 @@
 
 netfs-y := \
 	buffered_read.o \
+	main.o \
 	objects.o \
 	read_helper.o
 
diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h
index 7d8e83deaf81..f9dd64521fe6 100644
--- a/fs/netfs/internal.h
+++ b/fs/netfs/internal.h
@@ -20,6 +20,11 @@
  */
 void netfs_rreq_unlock_folios(struct netfs_io_request *rreq);
 
+/*
+ * main.c
+ */
+extern unsigned int netfs_debug;
+
 /*
  * objects.c
  */
@@ -42,8 +47,6 @@ static inline void netfs_see_request(struct netfs_io_request *rreq,
 /*
  * read_helper.c
  */
-extern unsigned int netfs_debug;
-
 int netfs_begin_read(struct netfs_io_request *rreq, bool sync);
 
 /*
diff --git a/fs/netfs/main.c b/fs/netfs/main.c
new file mode 100644
index 000000000000..068568702957
--- /dev/null
+++ b/fs/netfs/main.c
@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Miscellaneous bits for the netfs support library.
+ *
+ * Copyright (C) 2022 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/module.h>
+#include <linux/export.h>
+#include "internal.h"
+#define CREATE_TRACE_POINTS
+#include <trace/events/netfs.h>
+
+MODULE_DESCRIPTION("Network fs support");
+MODULE_AUTHOR("Red Hat, Inc.");
+MODULE_LICENSE("GPL");
+
+unsigned netfs_debug;
+module_param_named(debug, netfs_debug, uint, S_IWUSR | S_IRUGO);
+MODULE_PARM_DESC(netfs_debug, "Netfs support debugging mask");
diff --git a/fs/netfs/read_helper.c b/fs/netfs/read_helper.c
index 78843820d9f1..3db9356eb7c2 100644
--- a/fs/netfs/read_helper.c
+++ b/fs/netfs/read_helper.c
@@ -15,16 +15,6 @@
 #include <linux/sched/mm.h>
 #include <linux/task_io_accounting_ops.h>
 #include "internal.h"
-#define CREATE_TRACE_POINTS
-#include <trace/events/netfs.h>
-
-MODULE_DESCRIPTION("Network fs support");
-MODULE_AUTHOR("Red Hat, Inc.");
-MODULE_LICENSE("GPL");
-
-unsigned netfs_debug;
-module_param_named(debug, netfs_debug, uint, S_IWUSR | S_IRUGO);
-MODULE_PARM_DESC(netfs_debug, "Netfs support debugging mask");
 
 /*
  * Clear the unread part of an I/O request.



^ permalink raw reply related	[flat|nested] 20+ messages in thread

* [PATCH 16/19] netfs: Rename rename read_helper.c to io.c
  2022-03-02 14:01 [PATCH 00/19] netfs: Prep for write helpers David Howells
                   ` (14 preceding siblings ...)
  2022-03-02 14:07 ` [PATCH 15/19] netfs: Split some core bits out into their own file David Howells
@ 2022-03-02 14:08 ` David Howells
  2022-03-02 14:08 ` [PATCH 17/19] netfs: Change ->init_rreq() to return an error code David Howells
                   ` (2 subsequent siblings)
  18 siblings, 0 replies; 20+ messages in thread
From: David Howells @ 2022-03-02 14:08 UTC (permalink / raw)
  To: linux-cachefs
  Cc: dhowells, Anna Schumaker, Steve French, Dominique Martinet,
	Jeff Layton, David Wysochanski, Ilya Dryomov, Jeffle Xu,
	Linus Torvalds, linux-afs, linux-nfs, linux-cifs, ceph-devel,
	v9fs-developer, linux-fsdevel, linux-kernel

The read_helper.c file now only contains I/O functions, so rename the file
to io.c.  It will eventually get write-side I/O functions also.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
---

 fs/netfs/Makefile      |    4 
 fs/netfs/internal.h    |   10 -
 fs/netfs/io.c          |  656 ++++++++++++++++++++++++++++++++++++++++++++++++
 fs/netfs/read_helper.c |  656 ------------------------------------------------
 4 files changed, 663 insertions(+), 663 deletions(-)
 create mode 100644 fs/netfs/io.c
 delete mode 100644 fs/netfs/read_helper.c

diff --git a/fs/netfs/Makefile b/fs/netfs/Makefile
index 029657b6db63..f684c0cd1ec5 100644
--- a/fs/netfs/Makefile
+++ b/fs/netfs/Makefile
@@ -2,9 +2,9 @@
 
 netfs-y := \
 	buffered_read.o \
+	io.o \
 	main.o \
-	objects.o \
-	read_helper.o
+	objects.o
 
 netfs-$(CONFIG_NETFS_STATS) += stats.o
 
diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h
index f9dd64521fe6..e2c80b10bf4d 100644
--- a/fs/netfs/internal.h
+++ b/fs/netfs/internal.h
@@ -20,6 +20,11 @@
  */
 void netfs_rreq_unlock_folios(struct netfs_io_request *rreq);
 
+/*
+ * io.c
+ */
+int netfs_begin_read(struct netfs_io_request *rreq, bool sync);
+
 /*
  * main.c
  */
@@ -44,11 +49,6 @@ static inline void netfs_see_request(struct netfs_io_request *rreq,
 	trace_netfs_rreq_ref(rreq->debug_id, refcount_read(&rreq->ref), what);
 }
 
-/*
- * read_helper.c
- */
-int netfs_begin_read(struct netfs_io_request *rreq, bool sync);
-
 /*
  * stats.c
  */
diff --git a/fs/netfs/io.c b/fs/netfs/io.c
new file mode 100644
index 000000000000..3db9356eb7c2
--- /dev/null
+++ b/fs/netfs/io.c
@@ -0,0 +1,656 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Network filesystem high-level read support.
+ *
+ * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/module.h>
+#include <linux/export.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/slab.h>
+#include <linux/uio.h>
+#include <linux/sched/mm.h>
+#include <linux/task_io_accounting_ops.h>
+#include "internal.h"
+
+/*
+ * Clear the unread part of an I/O request.
+ */
+static void netfs_clear_unread(struct netfs_io_subrequest *subreq)
+{
+	struct iov_iter iter;
+
+	iov_iter_xarray(&iter, READ, &subreq->rreq->mapping->i_pages,
+			subreq->start + subreq->transferred,
+			subreq->len   - subreq->transferred);
+	iov_iter_zero(iov_iter_count(&iter), &iter);
+}
+
+static void netfs_cache_read_terminated(void *priv, ssize_t transferred_or_error,
+					bool was_async)
+{
+	struct netfs_io_subrequest *subreq = priv;
+
+	netfs_subreq_terminated(subreq, transferred_or_error, was_async);
+}
+
+/*
+ * Issue a read against the cache.
+ * - Eats the caller's ref on subreq.
+ */
+static void netfs_read_from_cache(struct netfs_io_request *rreq,
+				  struct netfs_io_subrequest *subreq,
+				  enum netfs_read_from_hole read_hole)
+{
+	struct netfs_cache_resources *cres = &rreq->cache_resources;
+	struct iov_iter iter;
+
+	netfs_stat(&netfs_n_rh_read);
+	iov_iter_xarray(&iter, READ, &rreq->mapping->i_pages,
+			subreq->start + subreq->transferred,
+			subreq->len   - subreq->transferred);
+
+	cres->ops->read(cres, subreq->start, &iter, read_hole,
+			netfs_cache_read_terminated, subreq);
+}
+
+/*
+ * Fill a subrequest region with zeroes.
+ */
+static void netfs_fill_with_zeroes(struct netfs_io_request *rreq,
+				   struct netfs_io_subrequest *subreq)
+{
+	netfs_stat(&netfs_n_rh_zero);
+	__set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags);
+	netfs_subreq_terminated(subreq, 0, false);
+}
+
+/*
+ * Ask the netfs to issue a read request to the server for us.
+ *
+ * The netfs is expected to read from subreq->pos + subreq->transferred to
+ * subreq->pos + subreq->len - 1.  It may not backtrack and write data into the
+ * buffer prior to the transferred point as it might clobber dirty data
+ * obtained from the cache.
+ *
+ * Alternatively, the netfs is allowed to indicate one of two things:
+ *
+ * - NETFS_SREQ_SHORT_READ: A short read - it will get called again to try and
+ *   make progress.
+ *
+ * - NETFS_SREQ_CLEAR_TAIL: A short read - the rest of the buffer will be
+ *   cleared.
+ */
+static void netfs_read_from_server(struct netfs_io_request *rreq,
+				   struct netfs_io_subrequest *subreq)
+{
+	netfs_stat(&netfs_n_rh_download);
+	rreq->netfs_ops->issue_read(subreq);
+}
+
+/*
+ * Release those waiting.
+ */
+static void netfs_rreq_completed(struct netfs_io_request *rreq, bool was_async)
+{
+	trace_netfs_rreq(rreq, netfs_rreq_trace_done);
+	netfs_clear_subrequests(rreq, was_async);
+	netfs_put_request(rreq, was_async, netfs_rreq_trace_put_complete);
+}
+
+/*
+ * Deal with the completion of writing the data to the cache.  We have to clear
+ * the PG_fscache bits on the folios involved and release the caller's ref.
+ *
+ * May be called in softirq mode and we inherit a ref from the caller.
+ */
+static void netfs_rreq_unmark_after_write(struct netfs_io_request *rreq,
+					  bool was_async)
+{
+	struct netfs_io_subrequest *subreq;
+	struct folio *folio;
+	pgoff_t unlocked = 0;
+	bool have_unlocked = false;
+
+	rcu_read_lock();
+
+	list_for_each_entry(subreq, &rreq->subrequests, rreq_link) {
+		XA_STATE(xas, &rreq->mapping->i_pages, subreq->start / PAGE_SIZE);
+
+		xas_for_each(&xas, folio, (subreq->start + subreq->len - 1) / PAGE_SIZE) {
+			/* We might have multiple writes from the same huge
+			 * folio, but we mustn't unlock a folio more than once.
+			 */
+			if (have_unlocked && folio_index(folio) <= unlocked)
+				continue;
+			unlocked = folio_index(folio);
+			folio_end_fscache(folio);
+			have_unlocked = true;
+		}
+	}
+
+	rcu_read_unlock();
+	netfs_rreq_completed(rreq, was_async);
+}
+
+static void netfs_rreq_copy_terminated(void *priv, ssize_t transferred_or_error,
+				       bool was_async)
+{
+	struct netfs_io_subrequest *subreq = priv;
+	struct netfs_io_request *rreq = subreq->rreq;
+
+	if (IS_ERR_VALUE(transferred_or_error)) {
+		netfs_stat(&netfs_n_rh_write_failed);
+		trace_netfs_failure(rreq, subreq, transferred_or_error,
+				    netfs_fail_copy_to_cache);
+	} else {
+		netfs_stat(&netfs_n_rh_write_done);
+	}
+
+	trace_netfs_sreq(subreq, netfs_sreq_trace_write_term);
+
+	/* If we decrement nr_copy_ops to 0, the ref belongs to us. */
+	if (atomic_dec_and_test(&rreq->nr_copy_ops))
+		netfs_rreq_unmark_after_write(rreq, was_async);
+
+	netfs_put_subrequest(subreq, was_async, netfs_sreq_trace_put_terminated);
+}
+
+/*
+ * Perform any outstanding writes to the cache.  We inherit a ref from the
+ * caller.
+ */
+static void netfs_rreq_do_write_to_cache(struct netfs_io_request *rreq)
+{
+	struct netfs_cache_resources *cres = &rreq->cache_resources;
+	struct netfs_io_subrequest *subreq, *next, *p;
+	struct iov_iter iter;
+	int ret;
+
+	trace_netfs_rreq(rreq, netfs_rreq_trace_copy);
+
+	/* We don't want terminating writes trying to wake us up whilst we're
+	 * still going through the list.
+	 */
+	atomic_inc(&rreq->nr_copy_ops);
+
+	list_for_each_entry_safe(subreq, p, &rreq->subrequests, rreq_link) {
+		if (!test_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags)) {
+			list_del_init(&subreq->rreq_link);
+			netfs_put_subrequest(subreq, false,
+					     netfs_sreq_trace_put_no_copy);
+		}
+	}
+
+	list_for_each_entry(subreq, &rreq->subrequests, rreq_link) {
+		/* Amalgamate adjacent writes */
+		while (!list_is_last(&subreq->rreq_link, &rreq->subrequests)) {
+			next = list_next_entry(subreq, rreq_link);
+			if (next->start != subreq->start + subreq->len)
+				break;
+			subreq->len += next->len;
+			list_del_init(&next->rreq_link);
+			netfs_put_subrequest(next, false,
+					     netfs_sreq_trace_put_merged);
+		}
+
+		ret = cres->ops->prepare_write(cres, &subreq->start, &subreq->len,
+					       rreq->i_size, true);
+		if (ret < 0) {
+			trace_netfs_failure(rreq, subreq, ret, netfs_fail_prepare_write);
+			trace_netfs_sreq(subreq, netfs_sreq_trace_write_skip);
+			continue;
+		}
+
+		iov_iter_xarray(&iter, WRITE, &rreq->mapping->i_pages,
+				subreq->start, subreq->len);
+
+		atomic_inc(&rreq->nr_copy_ops);
+		netfs_stat(&netfs_n_rh_write);
+		netfs_get_subrequest(subreq, netfs_sreq_trace_get_copy_to_cache);
+		trace_netfs_sreq(subreq, netfs_sreq_trace_write);
+		cres->ops->write(cres, subreq->start, &iter,
+				 netfs_rreq_copy_terminated, subreq);
+	}
+
+	/* If we decrement nr_copy_ops to 0, the usage ref belongs to us. */
+	if (atomic_dec_and_test(&rreq->nr_copy_ops))
+		netfs_rreq_unmark_after_write(rreq, false);
+}
+
+static void netfs_rreq_write_to_cache_work(struct work_struct *work)
+{
+	struct netfs_io_request *rreq =
+		container_of(work, struct netfs_io_request, work);
+
+	netfs_rreq_do_write_to_cache(rreq);
+}
+
+static void netfs_rreq_write_to_cache(struct netfs_io_request *rreq)
+{
+	rreq->work.func = netfs_rreq_write_to_cache_work;
+	if (!queue_work(system_unbound_wq, &rreq->work))
+		BUG();
+}
+
+/*
+ * Handle a short read.
+ */
+static void netfs_rreq_short_read(struct netfs_io_request *rreq,
+				  struct netfs_io_subrequest *subreq)
+{
+	__clear_bit(NETFS_SREQ_SHORT_IO, &subreq->flags);
+	__set_bit(NETFS_SREQ_SEEK_DATA_READ, &subreq->flags);
+
+	netfs_stat(&netfs_n_rh_short_read);
+	trace_netfs_sreq(subreq, netfs_sreq_trace_resubmit_short);
+
+	netfs_get_subrequest(subreq, netfs_sreq_trace_get_short_read);
+	atomic_inc(&rreq->nr_outstanding);
+	if (subreq->source == NETFS_READ_FROM_CACHE)
+		netfs_read_from_cache(rreq, subreq, NETFS_READ_HOLE_CLEAR);
+	else
+		netfs_read_from_server(rreq, subreq);
+}
+
+/*
+ * Resubmit any short or failed operations.  Returns true if we got the rreq
+ * ref back.
+ */
+static bool netfs_rreq_perform_resubmissions(struct netfs_io_request *rreq)
+{
+	struct netfs_io_subrequest *subreq;
+
+	WARN_ON(in_interrupt());
+
+	trace_netfs_rreq(rreq, netfs_rreq_trace_resubmit);
+
+	/* We don't want terminating submissions trying to wake us up whilst
+	 * we're still going through the list.
+	 */
+	atomic_inc(&rreq->nr_outstanding);
+
+	__clear_bit(NETFS_RREQ_INCOMPLETE_IO, &rreq->flags);
+	list_for_each_entry(subreq, &rreq->subrequests, rreq_link) {
+		if (subreq->error) {
+			if (subreq->source != NETFS_READ_FROM_CACHE)
+				break;
+			subreq->source = NETFS_DOWNLOAD_FROM_SERVER;
+			subreq->error = 0;
+			netfs_stat(&netfs_n_rh_download_instead);
+			trace_netfs_sreq(subreq, netfs_sreq_trace_download_instead);
+			netfs_get_subrequest(subreq, netfs_sreq_trace_get_resubmit);
+			atomic_inc(&rreq->nr_outstanding);
+			netfs_read_from_server(rreq, subreq);
+		} else if (test_bit(NETFS_SREQ_SHORT_IO, &subreq->flags)) {
+			netfs_rreq_short_read(rreq, subreq);
+		}
+	}
+
+	/* If we decrement nr_outstanding to 0, the usage ref belongs to us. */
+	if (atomic_dec_and_test(&rreq->nr_outstanding))
+		return true;
+
+	wake_up_var(&rreq->nr_outstanding);
+	return false;
+}
+
+/*
+ * Check to see if the data read is still valid.
+ */
+static void netfs_rreq_is_still_valid(struct netfs_io_request *rreq)
+{
+	struct netfs_io_subrequest *subreq;
+
+	if (!rreq->netfs_ops->is_still_valid ||
+	    rreq->netfs_ops->is_still_valid(rreq))
+		return;
+
+	list_for_each_entry(subreq, &rreq->subrequests, rreq_link) {
+		if (subreq->source == NETFS_READ_FROM_CACHE) {
+			subreq->error = -ESTALE;
+			__set_bit(NETFS_RREQ_INCOMPLETE_IO, &rreq->flags);
+		}
+	}
+}
+
+/*
+ * Assess the state of a read request and decide what to do next.
+ *
+ * Note that we could be in an ordinary kernel thread, on a workqueue or in
+ * softirq context at this point.  We inherit a ref from the caller.
+ */
+static void netfs_rreq_assess(struct netfs_io_request *rreq, bool was_async)
+{
+	trace_netfs_rreq(rreq, netfs_rreq_trace_assess);
+
+again:
+	netfs_rreq_is_still_valid(rreq);
+
+	if (!test_bit(NETFS_RREQ_FAILED, &rreq->flags) &&
+	    test_bit(NETFS_RREQ_INCOMPLETE_IO, &rreq->flags)) {
+		if (netfs_rreq_perform_resubmissions(rreq))
+			goto again;
+		return;
+	}
+
+	netfs_rreq_unlock_folios(rreq);
+
+	clear_bit_unlock(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
+	wake_up_bit(&rreq->flags, NETFS_RREQ_IN_PROGRESS);
+
+	if (test_bit(NETFS_RREQ_COPY_TO_CACHE, &rreq->flags))
+		return netfs_rreq_write_to_cache(rreq);
+
+	netfs_rreq_completed(rreq, was_async);
+}
+
+static void netfs_rreq_work(struct work_struct *work)
+{
+	struct netfs_io_request *rreq =
+		container_of(work, struct netfs_io_request, work);
+	netfs_rreq_assess(rreq, false);
+}
+
+/*
+ * Handle the completion of all outstanding I/O operations on a read request.
+ * We inherit a ref from the caller.
+ */
+static void netfs_rreq_terminated(struct netfs_io_request *rreq,
+				  bool was_async)
+{
+	if (test_bit(NETFS_RREQ_INCOMPLETE_IO, &rreq->flags) &&
+	    was_async) {
+		if (!queue_work(system_unbound_wq, &rreq->work))
+			BUG();
+	} else {
+		netfs_rreq_assess(rreq, was_async);
+	}
+}
+
+/**
+ * netfs_subreq_terminated - Note the termination of an I/O operation.
+ * @subreq: The I/O request that has terminated.
+ * @transferred_or_error: The amount of data transferred or an error code.
+ * @was_async: The termination was asynchronous
+ *
+ * This tells the read helper that a contributory I/O operation has terminated,
+ * one way or another, and that it should integrate the results.
+ *
+ * The caller indicates in @transferred_or_error the outcome of the operation,
+ * supplying a positive value to indicate the number of bytes transferred, 0 to
+ * indicate a failure to transfer anything that should be retried or a negative
+ * error code.  The helper will look after reissuing I/O operations as
+ * appropriate and writing downloaded data to the cache.
+ *
+ * If @was_async is true, the caller might be running in softirq or interrupt
+ * context and we can't sleep.
+ */
+void netfs_subreq_terminated(struct netfs_io_subrequest *subreq,
+			     ssize_t transferred_or_error,
+			     bool was_async)
+{
+	struct netfs_io_request *rreq = subreq->rreq;
+	int u;
+
+	_enter("[%u]{%llx,%lx},%zd",
+	       subreq->debug_index, subreq->start, subreq->flags,
+	       transferred_or_error);
+
+	switch (subreq->source) {
+	case NETFS_READ_FROM_CACHE:
+		netfs_stat(&netfs_n_rh_read_done);
+		break;
+	case NETFS_DOWNLOAD_FROM_SERVER:
+		netfs_stat(&netfs_n_rh_download_done);
+		break;
+	default:
+		break;
+	}
+
+	if (IS_ERR_VALUE(transferred_or_error)) {
+		subreq->error = transferred_or_error;
+		trace_netfs_failure(rreq, subreq, transferred_or_error,
+				    netfs_fail_read);
+		goto failed;
+	}
+
+	if (WARN(transferred_or_error > subreq->len - subreq->transferred,
+		 "Subreq overread: R%x[%x] %zd > %zu - %zu",
+		 rreq->debug_id, subreq->debug_index,
+		 transferred_or_error, subreq->len, subreq->transferred))
+		transferred_or_error = subreq->len - subreq->transferred;
+
+	subreq->error = 0;
+	subreq->transferred += transferred_or_error;
+	if (subreq->transferred < subreq->len)
+		goto incomplete;
+
+complete:
+	__clear_bit(NETFS_SREQ_NO_PROGRESS, &subreq->flags);
+	if (test_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags))
+		set_bit(NETFS_RREQ_COPY_TO_CACHE, &rreq->flags);
+
+out:
+	trace_netfs_sreq(subreq, netfs_sreq_trace_terminated);
+
+	/* If we decrement nr_outstanding to 0, the ref belongs to us. */
+	u = atomic_dec_return(&rreq->nr_outstanding);
+	if (u == 0)
+		netfs_rreq_terminated(rreq, was_async);
+	else if (u == 1)
+		wake_up_var(&rreq->nr_outstanding);
+
+	netfs_put_subrequest(subreq, was_async, netfs_sreq_trace_put_terminated);
+	return;
+
+incomplete:
+	if (test_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags)) {
+		netfs_clear_unread(subreq);
+		subreq->transferred = subreq->len;
+		goto complete;
+	}
+
+	if (transferred_or_error == 0) {
+		if (__test_and_set_bit(NETFS_SREQ_NO_PROGRESS, &subreq->flags)) {
+			subreq->error = -ENODATA;
+			goto failed;
+		}
+	} else {
+		__clear_bit(NETFS_SREQ_NO_PROGRESS, &subreq->flags);
+	}
+
+	__set_bit(NETFS_SREQ_SHORT_IO, &subreq->flags);
+	set_bit(NETFS_RREQ_INCOMPLETE_IO, &rreq->flags);
+	goto out;
+
+failed:
+	if (subreq->source == NETFS_READ_FROM_CACHE) {
+		netfs_stat(&netfs_n_rh_read_failed);
+		set_bit(NETFS_RREQ_INCOMPLETE_IO, &rreq->flags);
+	} else {
+		netfs_stat(&netfs_n_rh_download_failed);
+		set_bit(NETFS_RREQ_FAILED, &rreq->flags);
+		rreq->error = subreq->error;
+	}
+	goto out;
+}
+EXPORT_SYMBOL(netfs_subreq_terminated);
+
+static enum netfs_io_source netfs_cache_prepare_read(struct netfs_io_subrequest *subreq,
+						       loff_t i_size)
+{
+	struct netfs_io_request *rreq = subreq->rreq;
+	struct netfs_cache_resources *cres = &rreq->cache_resources;
+
+	if (cres->ops)
+		return cres->ops->prepare_read(subreq, i_size);
+	if (subreq->start >= rreq->i_size)
+		return NETFS_FILL_WITH_ZEROES;
+	return NETFS_DOWNLOAD_FROM_SERVER;
+}
+
+/*
+ * Work out what sort of subrequest the next one will be.
+ */
+static enum netfs_io_source
+netfs_rreq_prepare_read(struct netfs_io_request *rreq,
+			struct netfs_io_subrequest *subreq)
+{
+	enum netfs_io_source source;
+
+	_enter("%llx-%llx,%llx", subreq->start, subreq->start + subreq->len, rreq->i_size);
+
+	source = netfs_cache_prepare_read(subreq, rreq->i_size);
+	if (source == NETFS_INVALID_READ)
+		goto out;
+
+	if (source == NETFS_DOWNLOAD_FROM_SERVER) {
+		/* Call out to the netfs to let it shrink the request to fit
+		 * its own I/O sizes and boundaries.  If it shinks it here, it
+		 * will be called again to make simultaneous calls; if it wants
+		 * to make serial calls, it can indicate a short read and then
+		 * we will call it again.
+		 */
+		if (subreq->len > rreq->i_size - subreq->start)
+			subreq->len = rreq->i_size - subreq->start;
+
+		if (rreq->netfs_ops->clamp_length &&
+		    !rreq->netfs_ops->clamp_length(subreq)) {
+			source = NETFS_INVALID_READ;
+			goto out;
+		}
+	}
+
+	if (WARN_ON(subreq->len == 0))
+		source = NETFS_INVALID_READ;
+
+out:
+	subreq->source = source;
+	trace_netfs_sreq(subreq, netfs_sreq_trace_prepare);
+	return source;
+}
+
+/*
+ * Slice off a piece of a read request and submit an I/O request for it.
+ */
+static bool netfs_rreq_submit_slice(struct netfs_io_request *rreq,
+				    unsigned int *_debug_index)
+{
+	struct netfs_io_subrequest *subreq;
+	enum netfs_io_source source;
+
+	subreq = netfs_alloc_subrequest(rreq);
+	if (!subreq)
+		return false;
+
+	subreq->debug_index	= (*_debug_index)++;
+	subreq->start		= rreq->start + rreq->submitted;
+	subreq->len		= rreq->len   - rreq->submitted;
+
+	_debug("slice %llx,%zx,%zx", subreq->start, subreq->len, rreq->submitted);
+	list_add_tail(&subreq->rreq_link, &rreq->subrequests);
+
+	/* Call out to the cache to find out what it can do with the remaining
+	 * subset.  It tells us in subreq->flags what it decided should be done
+	 * and adjusts subreq->len down if the subset crosses a cache boundary.
+	 *
+	 * Then when we hand the subset, it can choose to take a subset of that
+	 * (the starts must coincide), in which case, we go around the loop
+	 * again and ask it to download the next piece.
+	 */
+	source = netfs_rreq_prepare_read(rreq, subreq);
+	if (source == NETFS_INVALID_READ)
+		goto subreq_failed;
+
+	atomic_inc(&rreq->nr_outstanding);
+
+	rreq->submitted += subreq->len;
+
+	trace_netfs_sreq(subreq, netfs_sreq_trace_submit);
+	switch (source) {
+	case NETFS_FILL_WITH_ZEROES:
+		netfs_fill_with_zeroes(rreq, subreq);
+		break;
+	case NETFS_DOWNLOAD_FROM_SERVER:
+		netfs_read_from_server(rreq, subreq);
+		break;
+	case NETFS_READ_FROM_CACHE:
+		netfs_read_from_cache(rreq, subreq, NETFS_READ_HOLE_IGNORE);
+		break;
+	default:
+		BUG();
+	}
+
+	return true;
+
+subreq_failed:
+	rreq->error = subreq->error;
+	netfs_put_subrequest(subreq, false, netfs_sreq_trace_put_failed);
+	return false;
+}
+
+/*
+ * Begin the process of reading in a chunk of data, where that data may be
+ * stitched together from multiple sources, including multiple servers and the
+ * local cache.
+ */
+int netfs_begin_read(struct netfs_io_request *rreq, bool sync)
+{
+	unsigned int debug_index = 0;
+	int ret;
+
+	_enter("R=%x %llx-%llx",
+	       rreq->debug_id, rreq->start, rreq->start + rreq->len - 1);
+
+	if (rreq->len == 0) {
+		pr_err("Zero-sized read [R=%x]\n", rreq->debug_id);
+		netfs_put_request(rreq, false, netfs_rreq_trace_put_zero_len);
+		return -EIO;
+	}
+
+	rreq->work.func = netfs_rreq_work;
+
+	if (sync)
+		netfs_get_request(rreq, netfs_rreq_trace_get_hold);
+
+	/* Chop the read into slices according to what the cache and the netfs
+	 * want and submit each one.
+	 */
+	atomic_set(&rreq->nr_outstanding, 1);
+	do {
+		if (!netfs_rreq_submit_slice(rreq, &debug_index))
+			break;
+
+	} while (rreq->submitted < rreq->len);
+
+	if (sync) {
+		/* Keep nr_outstanding incremented so that the ref always belongs to
+		 * us, and the service code isn't punted off to a random thread pool to
+		 * process.
+		 */
+		for (;;) {
+			wait_var_event(&rreq->nr_outstanding,
+				       atomic_read(&rreq->nr_outstanding) == 1);
+			netfs_rreq_assess(rreq, false);
+			if (!test_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags))
+				break;
+			cond_resched();
+		}
+
+		ret = rreq->error;
+		if (ret == 0 && rreq->submitted < rreq->len) {
+			trace_netfs_failure(rreq, NULL, ret, netfs_fail_short_read);
+			ret = -EIO;
+		}
+		netfs_put_request(rreq, false, netfs_rreq_trace_put_hold);
+	} else {
+		/* If we decrement nr_outstanding to 0, the ref belongs to us. */
+		if (atomic_dec_and_test(&rreq->nr_outstanding))
+			netfs_rreq_assess(rreq, false);
+	}
+	return ret;
+}
diff --git a/fs/netfs/read_helper.c b/fs/netfs/read_helper.c
deleted file mode 100644
index 3db9356eb7c2..000000000000
--- a/fs/netfs/read_helper.c
+++ /dev/null
@@ -1,656 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-or-later
-/* Network filesystem high-level read support.
- *
- * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved.
- * Written by David Howells (dhowells@redhat.com)
- */
-
-#include <linux/module.h>
-#include <linux/export.h>
-#include <linux/fs.h>
-#include <linux/mm.h>
-#include <linux/pagemap.h>
-#include <linux/slab.h>
-#include <linux/uio.h>
-#include <linux/sched/mm.h>
-#include <linux/task_io_accounting_ops.h>
-#include "internal.h"
-
-/*
- * Clear the unread part of an I/O request.
- */
-static void netfs_clear_unread(struct netfs_io_subrequest *subreq)
-{
-	struct iov_iter iter;
-
-	iov_iter_xarray(&iter, READ, &subreq->rreq->mapping->i_pages,
-			subreq->start + subreq->transferred,
-			subreq->len   - subreq->transferred);
-	iov_iter_zero(iov_iter_count(&iter), &iter);
-}
-
-static void netfs_cache_read_terminated(void *priv, ssize_t transferred_or_error,
-					bool was_async)
-{
-	struct netfs_io_subrequest *subreq = priv;
-
-	netfs_subreq_terminated(subreq, transferred_or_error, was_async);
-}
-
-/*
- * Issue a read against the cache.
- * - Eats the caller's ref on subreq.
- */
-static void netfs_read_from_cache(struct netfs_io_request *rreq,
-				  struct netfs_io_subrequest *subreq,
-				  enum netfs_read_from_hole read_hole)
-{
-	struct netfs_cache_resources *cres = &rreq->cache_resources;
-	struct iov_iter iter;
-
-	netfs_stat(&netfs_n_rh_read);
-	iov_iter_xarray(&iter, READ, &rreq->mapping->i_pages,
-			subreq->start + subreq->transferred,
-			subreq->len   - subreq->transferred);
-
-	cres->ops->read(cres, subreq->start, &iter, read_hole,
-			netfs_cache_read_terminated, subreq);
-}
-
-/*
- * Fill a subrequest region with zeroes.
- */
-static void netfs_fill_with_zeroes(struct netfs_io_request *rreq,
-				   struct netfs_io_subrequest *subreq)
-{
-	netfs_stat(&netfs_n_rh_zero);
-	__set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags);
-	netfs_subreq_terminated(subreq, 0, false);
-}
-
-/*
- * Ask the netfs to issue a read request to the server for us.
- *
- * The netfs is expected to read from subreq->pos + subreq->transferred to
- * subreq->pos + subreq->len - 1.  It may not backtrack and write data into the
- * buffer prior to the transferred point as it might clobber dirty data
- * obtained from the cache.
- *
- * Alternatively, the netfs is allowed to indicate one of two things:
- *
- * - NETFS_SREQ_SHORT_READ: A short read - it will get called again to try and
- *   make progress.
- *
- * - NETFS_SREQ_CLEAR_TAIL: A short read - the rest of the buffer will be
- *   cleared.
- */
-static void netfs_read_from_server(struct netfs_io_request *rreq,
-				   struct netfs_io_subrequest *subreq)
-{
-	netfs_stat(&netfs_n_rh_download);
-	rreq->netfs_ops->issue_read(subreq);
-}
-
-/*
- * Release those waiting.
- */
-static void netfs_rreq_completed(struct netfs_io_request *rreq, bool was_async)
-{
-	trace_netfs_rreq(rreq, netfs_rreq_trace_done);
-	netfs_clear_subrequests(rreq, was_async);
-	netfs_put_request(rreq, was_async, netfs_rreq_trace_put_complete);
-}
-
-/*
- * Deal with the completion of writing the data to the cache.  We have to clear
- * the PG_fscache bits on the folios involved and release the caller's ref.
- *
- * May be called in softirq mode and we inherit a ref from the caller.
- */
-static void netfs_rreq_unmark_after_write(struct netfs_io_request *rreq,
-					  bool was_async)
-{
-	struct netfs_io_subrequest *subreq;
-	struct folio *folio;
-	pgoff_t unlocked = 0;
-	bool have_unlocked = false;
-
-	rcu_read_lock();
-
-	list_for_each_entry(subreq, &rreq->subrequests, rreq_link) {
-		XA_STATE(xas, &rreq->mapping->i_pages, subreq->start / PAGE_SIZE);
-
-		xas_for_each(&xas, folio, (subreq->start + subreq->len - 1) / PAGE_SIZE) {
-			/* We might have multiple writes from the same huge
-			 * folio, but we mustn't unlock a folio more than once.
-			 */
-			if (have_unlocked && folio_index(folio) <= unlocked)
-				continue;
-			unlocked = folio_index(folio);
-			folio_end_fscache(folio);
-			have_unlocked = true;
-		}
-	}
-
-	rcu_read_unlock();
-	netfs_rreq_completed(rreq, was_async);
-}
-
-static void netfs_rreq_copy_terminated(void *priv, ssize_t transferred_or_error,
-				       bool was_async)
-{
-	struct netfs_io_subrequest *subreq = priv;
-	struct netfs_io_request *rreq = subreq->rreq;
-
-	if (IS_ERR_VALUE(transferred_or_error)) {
-		netfs_stat(&netfs_n_rh_write_failed);
-		trace_netfs_failure(rreq, subreq, transferred_or_error,
-				    netfs_fail_copy_to_cache);
-	} else {
-		netfs_stat(&netfs_n_rh_write_done);
-	}
-
-	trace_netfs_sreq(subreq, netfs_sreq_trace_write_term);
-
-	/* If we decrement nr_copy_ops to 0, the ref belongs to us. */
-	if (atomic_dec_and_test(&rreq->nr_copy_ops))
-		netfs_rreq_unmark_after_write(rreq, was_async);
-
-	netfs_put_subrequest(subreq, was_async, netfs_sreq_trace_put_terminated);
-}
-
-/*
- * Perform any outstanding writes to the cache.  We inherit a ref from the
- * caller.
- */
-static void netfs_rreq_do_write_to_cache(struct netfs_io_request *rreq)
-{
-	struct netfs_cache_resources *cres = &rreq->cache_resources;
-	struct netfs_io_subrequest *subreq, *next, *p;
-	struct iov_iter iter;
-	int ret;
-
-	trace_netfs_rreq(rreq, netfs_rreq_trace_copy);
-
-	/* We don't want terminating writes trying to wake us up whilst we're
-	 * still going through the list.
-	 */
-	atomic_inc(&rreq->nr_copy_ops);
-
-	list_for_each_entry_safe(subreq, p, &rreq->subrequests, rreq_link) {
-		if (!test_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags)) {
-			list_del_init(&subreq->rreq_link);
-			netfs_put_subrequest(subreq, false,
-					     netfs_sreq_trace_put_no_copy);
-		}
-	}
-
-	list_for_each_entry(subreq, &rreq->subrequests, rreq_link) {
-		/* Amalgamate adjacent writes */
-		while (!list_is_last(&subreq->rreq_link, &rreq->subrequests)) {
-			next = list_next_entry(subreq, rreq_link);
-			if (next->start != subreq->start + subreq->len)
-				break;
-			subreq->len += next->len;
-			list_del_init(&next->rreq_link);
-			netfs_put_subrequest(next, false,
-					     netfs_sreq_trace_put_merged);
-		}
-
-		ret = cres->ops->prepare_write(cres, &subreq->start, &subreq->len,
-					       rreq->i_size, true);
-		if (ret < 0) {
-			trace_netfs_failure(rreq, subreq, ret, netfs_fail_prepare_write);
-			trace_netfs_sreq(subreq, netfs_sreq_trace_write_skip);
-			continue;
-		}
-
-		iov_iter_xarray(&iter, WRITE, &rreq->mapping->i_pages,
-				subreq->start, subreq->len);
-
-		atomic_inc(&rreq->nr_copy_ops);
-		netfs_stat(&netfs_n_rh_write);
-		netfs_get_subrequest(subreq, netfs_sreq_trace_get_copy_to_cache);
-		trace_netfs_sreq(subreq, netfs_sreq_trace_write);
-		cres->ops->write(cres, subreq->start, &iter,
-				 netfs_rreq_copy_terminated, subreq);
-	}
-
-	/* If we decrement nr_copy_ops to 0, the usage ref belongs to us. */
-	if (atomic_dec_and_test(&rreq->nr_copy_ops))
-		netfs_rreq_unmark_after_write(rreq, false);
-}
-
-static void netfs_rreq_write_to_cache_work(struct work_struct *work)
-{
-	struct netfs_io_request *rreq =
-		container_of(work, struct netfs_io_request, work);
-
-	netfs_rreq_do_write_to_cache(rreq);
-}
-
-static void netfs_rreq_write_to_cache(struct netfs_io_request *rreq)
-{
-	rreq->work.func = netfs_rreq_write_to_cache_work;
-	if (!queue_work(system_unbound_wq, &rreq->work))
-		BUG();
-}
-
-/*
- * Handle a short read.
- */
-static void netfs_rreq_short_read(struct netfs_io_request *rreq,
-				  struct netfs_io_subrequest *subreq)
-{
-	__clear_bit(NETFS_SREQ_SHORT_IO, &subreq->flags);
-	__set_bit(NETFS_SREQ_SEEK_DATA_READ, &subreq->flags);
-
-	netfs_stat(&netfs_n_rh_short_read);
-	trace_netfs_sreq(subreq, netfs_sreq_trace_resubmit_short);
-
-	netfs_get_subrequest(subreq, netfs_sreq_trace_get_short_read);
-	atomic_inc(&rreq->nr_outstanding);
-	if (subreq->source == NETFS_READ_FROM_CACHE)
-		netfs_read_from_cache(rreq, subreq, NETFS_READ_HOLE_CLEAR);
-	else
-		netfs_read_from_server(rreq, subreq);
-}
-
-/*
- * Resubmit any short or failed operations.  Returns true if we got the rreq
- * ref back.
- */
-static bool netfs_rreq_perform_resubmissions(struct netfs_io_request *rreq)
-{
-	struct netfs_io_subrequest *subreq;
-
-	WARN_ON(in_interrupt());
-
-	trace_netfs_rreq(rreq, netfs_rreq_trace_resubmit);
-
-	/* We don't want terminating submissions trying to wake us up whilst
-	 * we're still going through the list.
-	 */
-	atomic_inc(&rreq->nr_outstanding);
-
-	__clear_bit(NETFS_RREQ_INCOMPLETE_IO, &rreq->flags);
-	list_for_each_entry(subreq, &rreq->subrequests, rreq_link) {
-		if (subreq->error) {
-			if (subreq->source != NETFS_READ_FROM_CACHE)
-				break;
-			subreq->source = NETFS_DOWNLOAD_FROM_SERVER;
-			subreq->error = 0;
-			netfs_stat(&netfs_n_rh_download_instead);
-			trace_netfs_sreq(subreq, netfs_sreq_trace_download_instead);
-			netfs_get_subrequest(subreq, netfs_sreq_trace_get_resubmit);
-			atomic_inc(&rreq->nr_outstanding);
-			netfs_read_from_server(rreq, subreq);
-		} else if (test_bit(NETFS_SREQ_SHORT_IO, &subreq->flags)) {
-			netfs_rreq_short_read(rreq, subreq);
-		}
-	}
-
-	/* If we decrement nr_outstanding to 0, the usage ref belongs to us. */
-	if (atomic_dec_and_test(&rreq->nr_outstanding))
-		return true;
-
-	wake_up_var(&rreq->nr_outstanding);
-	return false;
-}
-
-/*
- * Check to see if the data read is still valid.
- */
-static void netfs_rreq_is_still_valid(struct netfs_io_request *rreq)
-{
-	struct netfs_io_subrequest *subreq;
-
-	if (!rreq->netfs_ops->is_still_valid ||
-	    rreq->netfs_ops->is_still_valid(rreq))
-		return;
-
-	list_for_each_entry(subreq, &rreq->subrequests, rreq_link) {
-		if (subreq->source == NETFS_READ_FROM_CACHE) {
-			subreq->error = -ESTALE;
-			__set_bit(NETFS_RREQ_INCOMPLETE_IO, &rreq->flags);
-		}
-	}
-}
-
-/*
- * Assess the state of a read request and decide what to do next.
- *
- * Note that we could be in an ordinary kernel thread, on a workqueue or in
- * softirq context at this point.  We inherit a ref from the caller.
- */
-static void netfs_rreq_assess(struct netfs_io_request *rreq, bool was_async)
-{
-	trace_netfs_rreq(rreq, netfs_rreq_trace_assess);
-
-again:
-	netfs_rreq_is_still_valid(rreq);
-
-	if (!test_bit(NETFS_RREQ_FAILED, &rreq->flags) &&
-	    test_bit(NETFS_RREQ_INCOMPLETE_IO, &rreq->flags)) {
-		if (netfs_rreq_perform_resubmissions(rreq))
-			goto again;
-		return;
-	}
-
-	netfs_rreq_unlock_folios(rreq);
-
-	clear_bit_unlock(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
-	wake_up_bit(&rreq->flags, NETFS_RREQ_IN_PROGRESS);
-
-	if (test_bit(NETFS_RREQ_COPY_TO_CACHE, &rreq->flags))
-		return netfs_rreq_write_to_cache(rreq);
-
-	netfs_rreq_completed(rreq, was_async);
-}
-
-static void netfs_rreq_work(struct work_struct *work)
-{
-	struct netfs_io_request *rreq =
-		container_of(work, struct netfs_io_request, work);
-	netfs_rreq_assess(rreq, false);
-}
-
-/*
- * Handle the completion of all outstanding I/O operations on a read request.
- * We inherit a ref from the caller.
- */
-static void netfs_rreq_terminated(struct netfs_io_request *rreq,
-				  bool was_async)
-{
-	if (test_bit(NETFS_RREQ_INCOMPLETE_IO, &rreq->flags) &&
-	    was_async) {
-		if (!queue_work(system_unbound_wq, &rreq->work))
-			BUG();
-	} else {
-		netfs_rreq_assess(rreq, was_async);
-	}
-}
-
-/**
- * netfs_subreq_terminated - Note the termination of an I/O operation.
- * @subreq: The I/O request that has terminated.
- * @transferred_or_error: The amount of data transferred or an error code.
- * @was_async: The termination was asynchronous
- *
- * This tells the read helper that a contributory I/O operation has terminated,
- * one way or another, and that it should integrate the results.
- *
- * The caller indicates in @transferred_or_error the outcome of the operation,
- * supplying a positive value to indicate the number of bytes transferred, 0 to
- * indicate a failure to transfer anything that should be retried or a negative
- * error code.  The helper will look after reissuing I/O operations as
- * appropriate and writing downloaded data to the cache.
- *
- * If @was_async is true, the caller might be running in softirq or interrupt
- * context and we can't sleep.
- */
-void netfs_subreq_terminated(struct netfs_io_subrequest *subreq,
-			     ssize_t transferred_or_error,
-			     bool was_async)
-{
-	struct netfs_io_request *rreq = subreq->rreq;
-	int u;
-
-	_enter("[%u]{%llx,%lx},%zd",
-	       subreq->debug_index, subreq->start, subreq->flags,
-	       transferred_or_error);
-
-	switch (subreq->source) {
-	case NETFS_READ_FROM_CACHE:
-		netfs_stat(&netfs_n_rh_read_done);
-		break;
-	case NETFS_DOWNLOAD_FROM_SERVER:
-		netfs_stat(&netfs_n_rh_download_done);
-		break;
-	default:
-		break;
-	}
-
-	if (IS_ERR_VALUE(transferred_or_error)) {
-		subreq->error = transferred_or_error;
-		trace_netfs_failure(rreq, subreq, transferred_or_error,
-				    netfs_fail_read);
-		goto failed;
-	}
-
-	if (WARN(transferred_or_error > subreq->len - subreq->transferred,
-		 "Subreq overread: R%x[%x] %zd > %zu - %zu",
-		 rreq->debug_id, subreq->debug_index,
-		 transferred_or_error, subreq->len, subreq->transferred))
-		transferred_or_error = subreq->len - subreq->transferred;
-
-	subreq->error = 0;
-	subreq->transferred += transferred_or_error;
-	if (subreq->transferred < subreq->len)
-		goto incomplete;
-
-complete:
-	__clear_bit(NETFS_SREQ_NO_PROGRESS, &subreq->flags);
-	if (test_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags))
-		set_bit(NETFS_RREQ_COPY_TO_CACHE, &rreq->flags);
-
-out:
-	trace_netfs_sreq(subreq, netfs_sreq_trace_terminated);
-
-	/* If we decrement nr_outstanding to 0, the ref belongs to us. */
-	u = atomic_dec_return(&rreq->nr_outstanding);
-	if (u == 0)
-		netfs_rreq_terminated(rreq, was_async);
-	else if (u == 1)
-		wake_up_var(&rreq->nr_outstanding);
-
-	netfs_put_subrequest(subreq, was_async, netfs_sreq_trace_put_terminated);
-	return;
-
-incomplete:
-	if (test_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags)) {
-		netfs_clear_unread(subreq);
-		subreq->transferred = subreq->len;
-		goto complete;
-	}
-
-	if (transferred_or_error == 0) {
-		if (__test_and_set_bit(NETFS_SREQ_NO_PROGRESS, &subreq->flags)) {
-			subreq->error = -ENODATA;
-			goto failed;
-		}
-	} else {
-		__clear_bit(NETFS_SREQ_NO_PROGRESS, &subreq->flags);
-	}
-
-	__set_bit(NETFS_SREQ_SHORT_IO, &subreq->flags);
-	set_bit(NETFS_RREQ_INCOMPLETE_IO, &rreq->flags);
-	goto out;
-
-failed:
-	if (subreq->source == NETFS_READ_FROM_CACHE) {
-		netfs_stat(&netfs_n_rh_read_failed);
-		set_bit(NETFS_RREQ_INCOMPLETE_IO, &rreq->flags);
-	} else {
-		netfs_stat(&netfs_n_rh_download_failed);
-		set_bit(NETFS_RREQ_FAILED, &rreq->flags);
-		rreq->error = subreq->error;
-	}
-	goto out;
-}
-EXPORT_SYMBOL(netfs_subreq_terminated);
-
-static enum netfs_io_source netfs_cache_prepare_read(struct netfs_io_subrequest *subreq,
-						       loff_t i_size)
-{
-	struct netfs_io_request *rreq = subreq->rreq;
-	struct netfs_cache_resources *cres = &rreq->cache_resources;
-
-	if (cres->ops)
-		return cres->ops->prepare_read(subreq, i_size);
-	if (subreq->start >= rreq->i_size)
-		return NETFS_FILL_WITH_ZEROES;
-	return NETFS_DOWNLOAD_FROM_SERVER;
-}
-
-/*
- * Work out what sort of subrequest the next one will be.
- */
-static enum netfs_io_source
-netfs_rreq_prepare_read(struct netfs_io_request *rreq,
-			struct netfs_io_subrequest *subreq)
-{
-	enum netfs_io_source source;
-
-	_enter("%llx-%llx,%llx", subreq->start, subreq->start + subreq->len, rreq->i_size);
-
-	source = netfs_cache_prepare_read(subreq, rreq->i_size);
-	if (source == NETFS_INVALID_READ)
-		goto out;
-
-	if (source == NETFS_DOWNLOAD_FROM_SERVER) {
-		/* Call out to the netfs to let it shrink the request to fit
-		 * its own I/O sizes and boundaries.  If it shinks it here, it
-		 * will be called again to make simultaneous calls; if it wants
-		 * to make serial calls, it can indicate a short read and then
-		 * we will call it again.
-		 */
-		if (subreq->len > rreq->i_size - subreq->start)
-			subreq->len = rreq->i_size - subreq->start;
-
-		if (rreq->netfs_ops->clamp_length &&
-		    !rreq->netfs_ops->clamp_length(subreq)) {
-			source = NETFS_INVALID_READ;
-			goto out;
-		}
-	}
-
-	if (WARN_ON(subreq->len == 0))
-		source = NETFS_INVALID_READ;
-
-out:
-	subreq->source = source;
-	trace_netfs_sreq(subreq, netfs_sreq_trace_prepare);
-	return source;
-}
-
-/*
- * Slice off a piece of a read request and submit an I/O request for it.
- */
-static bool netfs_rreq_submit_slice(struct netfs_io_request *rreq,
-				    unsigned int *_debug_index)
-{
-	struct netfs_io_subrequest *subreq;
-	enum netfs_io_source source;
-
-	subreq = netfs_alloc_subrequest(rreq);
-	if (!subreq)
-		return false;
-
-	subreq->debug_index	= (*_debug_index)++;
-	subreq->start		= rreq->start + rreq->submitted;
-	subreq->len		= rreq->len   - rreq->submitted;
-
-	_debug("slice %llx,%zx,%zx", subreq->start, subreq->len, rreq->submitted);
-	list_add_tail(&subreq->rreq_link, &rreq->subrequests);
-
-	/* Call out to the cache to find out what it can do with the remaining
-	 * subset.  It tells us in subreq->flags what it decided should be done
-	 * and adjusts subreq->len down if the subset crosses a cache boundary.
-	 *
-	 * Then when we hand the subset, it can choose to take a subset of that
-	 * (the starts must coincide), in which case, we go around the loop
-	 * again and ask it to download the next piece.
-	 */
-	source = netfs_rreq_prepare_read(rreq, subreq);
-	if (source == NETFS_INVALID_READ)
-		goto subreq_failed;
-
-	atomic_inc(&rreq->nr_outstanding);
-
-	rreq->submitted += subreq->len;
-
-	trace_netfs_sreq(subreq, netfs_sreq_trace_submit);
-	switch (source) {
-	case NETFS_FILL_WITH_ZEROES:
-		netfs_fill_with_zeroes(rreq, subreq);
-		break;
-	case NETFS_DOWNLOAD_FROM_SERVER:
-		netfs_read_from_server(rreq, subreq);
-		break;
-	case NETFS_READ_FROM_CACHE:
-		netfs_read_from_cache(rreq, subreq, NETFS_READ_HOLE_IGNORE);
-		break;
-	default:
-		BUG();
-	}
-
-	return true;
-
-subreq_failed:
-	rreq->error = subreq->error;
-	netfs_put_subrequest(subreq, false, netfs_sreq_trace_put_failed);
-	return false;
-}
-
-/*
- * Begin the process of reading in a chunk of data, where that data may be
- * stitched together from multiple sources, including multiple servers and the
- * local cache.
- */
-int netfs_begin_read(struct netfs_io_request *rreq, bool sync)
-{
-	unsigned int debug_index = 0;
-	int ret;
-
-	_enter("R=%x %llx-%llx",
-	       rreq->debug_id, rreq->start, rreq->start + rreq->len - 1);
-
-	if (rreq->len == 0) {
-		pr_err("Zero-sized read [R=%x]\n", rreq->debug_id);
-		netfs_put_request(rreq, false, netfs_rreq_trace_put_zero_len);
-		return -EIO;
-	}
-
-	rreq->work.func = netfs_rreq_work;
-
-	if (sync)
-		netfs_get_request(rreq, netfs_rreq_trace_get_hold);
-
-	/* Chop the read into slices according to what the cache and the netfs
-	 * want and submit each one.
-	 */
-	atomic_set(&rreq->nr_outstanding, 1);
-	do {
-		if (!netfs_rreq_submit_slice(rreq, &debug_index))
-			break;
-
-	} while (rreq->submitted < rreq->len);
-
-	if (sync) {
-		/* Keep nr_outstanding incremented so that the ref always belongs to
-		 * us, and the service code isn't punted off to a random thread pool to
-		 * process.
-		 */
-		for (;;) {
-			wait_var_event(&rreq->nr_outstanding,
-				       atomic_read(&rreq->nr_outstanding) == 1);
-			netfs_rreq_assess(rreq, false);
-			if (!test_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags))
-				break;
-			cond_resched();
-		}
-
-		ret = rreq->error;
-		if (ret == 0 && rreq->submitted < rreq->len) {
-			trace_netfs_failure(rreq, NULL, ret, netfs_fail_short_read);
-			ret = -EIO;
-		}
-		netfs_put_request(rreq, false, netfs_rreq_trace_put_hold);
-	} else {
-		/* If we decrement nr_outstanding to 0, the ref belongs to us. */
-		if (atomic_dec_and_test(&rreq->nr_outstanding))
-			netfs_rreq_assess(rreq, false);
-	}
-	return ret;
-}



^ permalink raw reply related	[flat|nested] 20+ messages in thread

* [PATCH 17/19] netfs: Change ->init_rreq() to return an error code
  2022-03-02 14:01 [PATCH 00/19] netfs: Prep for write helpers David Howells
                   ` (15 preceding siblings ...)
  2022-03-02 14:08 ` [PATCH 16/19] netfs: Rename rename read_helper.c to io.c David Howells
@ 2022-03-02 14:08 ` David Howells
  2022-03-02 14:08 ` [PATCH 18/19] netfs: Keep track of the actual remote file size David Howells
  2022-03-02 14:09 ` [PATCH 19/19] afs: Maintain netfs_i_context::remote_i_size David Howells
  18 siblings, 0 replies; 20+ messages in thread
From: David Howells @ 2022-03-02 14:08 UTC (permalink / raw)
  To: linux-cachefs
  Cc: dhowells, Anna Schumaker, Steve French, Dominique Martinet,
	Jeff Layton, David Wysochanski, Ilya Dryomov, Jeffle Xu,
	Linus Torvalds, linux-afs, linux-nfs, linux-cifs, ceph-devel,
	v9fs-developer, linux-fsdevel, linux-kernel

Change the read-request initialisation function to return an error code so
that the network filesystem can return a failure (ENOMEM, for example).

This will also allow ceph to abort a ->readahead() op if the server refuses
to give it a cap allowing local caching from within the netfslib framework
(errors aren't passed back through ->readahead(), so returning, say,
-ENOBUFS will cause the op to be aborted).

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
---

 fs/9p/vfs_addr.c         |    3 ++-
 fs/afs/file.c            |    3 ++-
 fs/netfs/buffered_read.c |   15 +++++++++------
 fs/netfs/objects.c       |   40 ++++++++++++++++++++++++----------------
 include/linux/netfs.h    |    2 +-
 5 files changed, 38 insertions(+), 25 deletions(-)

diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
index 840111da1172..e50326d11e8f 100644
--- a/fs/9p/vfs_addr.c
+++ b/fs/9p/vfs_addr.c
@@ -56,12 +56,13 @@ static void v9fs_issue_read(struct netfs_io_subrequest *subreq)
  * @rreq: The read request
  * @file: The file being read from
  */
-static void v9fs_init_request(struct netfs_io_request *rreq, struct file *file)
+static int v9fs_init_request(struct netfs_io_request *rreq, struct file *file)
 {
 	struct p9_fid *fid = file->private_data;
 
 	refcount_inc(&fid->count);
 	rreq->netfs_priv = fid;
+	return 0;
 }
 
 /**
diff --git a/fs/afs/file.c b/fs/afs/file.c
index aef0fbbd834d..2b68b2070248 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -357,9 +357,10 @@ static int afs_symlink_readpage(struct file *file, struct page *page)
 	return ret;
 }
 
-static void afs_init_request(struct netfs_io_request *rreq, struct file *file)
+static int afs_init_request(struct netfs_io_request *rreq, struct file *file)
 {
 	rreq->netfs_priv = key_get(afs_file_key(file));
+	return 0;
 }
 
 static int afs_begin_cache_operation(struct netfs_io_request *rreq)
diff --git a/fs/netfs/buffered_read.c b/fs/netfs/buffered_read.c
index 343c0957ae27..64049e123185 100644
--- a/fs/netfs/buffered_read.c
+++ b/fs/netfs/buffered_read.c
@@ -167,7 +167,7 @@ void netfs_readahead(struct readahead_control *ractl)
 				   readahead_pos(ractl),
 				   readahead_length(ractl),
 				   NETFS_READAHEAD);
-	if (!rreq)
+	if (IS_ERR(rreq))
 		return;
 
 	if (ctx->ops->begin_cache_operation) {
@@ -223,8 +223,10 @@ int netfs_readpage(struct file *file, struct page *subpage)
 
 	rreq = netfs_alloc_request(mapping, file, folio_file_pos(folio),
 				   folio_size(folio), NETFS_READPAGE);
-	if (!rreq)
-		goto nomem;
+	if (IS_ERR(rreq)) {
+		ret = PTR_ERR(rreq);
+		goto alloc_error;
+	}
 
 	if (ctx->ops->begin_cache_operation) {
 		ret = ctx->ops->begin_cache_operation(rreq);
@@ -238,7 +240,7 @@ int netfs_readpage(struct file *file, struct page *subpage)
 
 discard:
 	netfs_put_request(rreq, false, netfs_rreq_trace_put_discard);
-nomem:
+alloc_error:
 	folio_unlock(folio);
 	return ret;
 }
@@ -371,11 +373,12 @@ int netfs_write_begin(struct file *file, struct address_space *mapping,
 		goto have_folio_no_wait;
 	}
 
-	ret = -ENOMEM;
 	rreq = netfs_alloc_request(mapping, file, folio_file_pos(folio),
 				   folio_size(folio), NETFS_READ_FOR_WRITE);
-	if (!rreq)
+	if (IS_ERR(rreq)) {
+		ret = PTR_ERR(rreq);
 		goto error;
+	}
 	rreq->start		= folio_file_pos(folio);
 	rreq->len		= folio_size(folio);
 	rreq->no_unlock_folio	= folio_index(folio);
diff --git a/fs/netfs/objects.c b/fs/netfs/objects.c
index 8f99269c5344..d8a07df03427 100644
--- a/fs/netfs/objects.c
+++ b/fs/netfs/objects.c
@@ -20,26 +20,34 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
 	struct inode *inode = file ? file_inode(file) : mapping->host;
 	struct netfs_i_context *ctx = netfs_i_context(inode);
 	struct netfs_io_request *rreq;
+	int ret;
 
 	rreq = kzalloc(sizeof(struct netfs_io_request), GFP_KERNEL);
-	if (rreq) {
-		rreq->start	= start;
-		rreq->len	= len;
-		rreq->mapping	= mapping;
-		rreq->inode	= inode;
-		rreq->origin	= origin;
-		rreq->netfs_ops	= ctx->ops;
-		rreq->i_size	= i_size_read(inode);
-		rreq->debug_id	= atomic_inc_return(&debug_ids);
-		INIT_LIST_HEAD(&rreq->subrequests);
-		INIT_WORK(&rreq->work, NULL);
-		refcount_set(&rreq->ref, 1);
-		__set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
-		if (ctx->ops->init_request)
-			ctx->ops->init_request(rreq, file);
-		netfs_stat(&netfs_n_rh_rreq);
+	if (!rreq)
+		return ERR_PTR(-ENOMEM);
+
+	rreq->start	= start;
+	rreq->len	= len;
+	rreq->mapping	= mapping;
+	rreq->inode	= inode;
+	rreq->origin	= origin;
+	rreq->netfs_ops	= ctx->ops;
+	rreq->i_size	= i_size_read(inode);
+	rreq->debug_id	= atomic_inc_return(&debug_ids);
+	INIT_LIST_HEAD(&rreq->subrequests);
+	INIT_WORK(&rreq->work, NULL);
+	refcount_set(&rreq->ref, 1);
+	__set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
+
+	if (ctx->ops->init_request) {
+		ret = ctx->ops->init_request(rreq, file);
+		if (ret < 0) {
+			kfree(rreq);
+			return ERR_PTR(ret);
+		}
 	}
 
+	netfs_stat(&netfs_n_rh_rreq);
 	return rreq;
 }
 
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index 725b8fb8e4bb..c925596c1bb3 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -202,7 +202,7 @@ struct netfs_io_request {
  * Operations the network filesystem can/must provide to the helpers.
  */
 struct netfs_request_ops {
-	void (*init_request)(struct netfs_io_request *rreq, struct file *file);
+	int (*init_request)(struct netfs_io_request *rreq, struct file *file);
 	int (*begin_cache_operation)(struct netfs_io_request *rreq);
 	void (*expand_readahead)(struct netfs_io_request *rreq);
 	bool (*clamp_length)(struct netfs_io_subrequest *subreq);



^ permalink raw reply related	[flat|nested] 20+ messages in thread

* [PATCH 18/19] netfs: Keep track of the actual remote file size
  2022-03-02 14:01 [PATCH 00/19] netfs: Prep for write helpers David Howells
                   ` (16 preceding siblings ...)
  2022-03-02 14:08 ` [PATCH 17/19] netfs: Change ->init_rreq() to return an error code David Howells
@ 2022-03-02 14:08 ` David Howells
  2022-03-02 14:09 ` [PATCH 19/19] afs: Maintain netfs_i_context::remote_i_size David Howells
  18 siblings, 0 replies; 20+ messages in thread
From: David Howells @ 2022-03-02 14:08 UTC (permalink / raw)
  To: linux-cachefs
  Cc: dhowells, Anna Schumaker, Steve French, Dominique Martinet,
	Jeff Layton, David Wysochanski, Ilya Dryomov, Jeffle Xu,
	Linus Torvalds, linux-afs, linux-nfs, linux-cifs, ceph-devel,
	v9fs-developer, linux-fsdevel, linux-kernel

Provide a place in which to keep track of the actual remote file size in
the netfs context.  This is needed because inode->i_size will be updated as
we buffer writes in the pagecache, but the server file size won't get
updated until we flush them back.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
---

 include/linux/netfs.h |   16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index c925596c1bb3..7049782b41f0 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -126,6 +126,7 @@ struct netfs_i_context {
 #if IS_ENABLED(CONFIG_FSCACHE)
 	struct fscache_cookie	*cache;
 #endif
+	loff_t			remote_i_size;	/* Size of the remote file */
 };
 
 /*
@@ -324,6 +325,21 @@ static inline void netfs_i_context_init(struct inode *inode,
 
 	memset(ctx, 0, sizeof(*ctx));
 	ctx->ops = ops;
+	ctx->remote_i_size = i_size_read(inode);
+}
+
+/**
+ * netfs_resize_file - Note that a file got resized
+ * @inode: The inode being resized
+ * @new_i_size: The new file size
+ *
+ * Inform the netfs lib that a file got resized so that it can adjust its state.
+ */
+static inline void netfs_resize_file(struct inode *inode, loff_t new_i_size)
+{
+	struct netfs_i_context *ctx = netfs_i_context(inode);
+
+	ctx->remote_i_size = new_i_size;
 }
 
 /**



^ permalink raw reply related	[flat|nested] 20+ messages in thread

* [PATCH 19/19] afs: Maintain netfs_i_context::remote_i_size
  2022-03-02 14:01 [PATCH 00/19] netfs: Prep for write helpers David Howells
                   ` (17 preceding siblings ...)
  2022-03-02 14:08 ` [PATCH 18/19] netfs: Keep track of the actual remote file size David Howells
@ 2022-03-02 14:09 ` David Howells
  18 siblings, 0 replies; 20+ messages in thread
From: David Howells @ 2022-03-02 14:09 UTC (permalink / raw)
  To: linux-cachefs
  Cc: linux-afs, dhowells, Anna Schumaker, Steve French,
	Dominique Martinet, Jeff Layton, David Wysochanski, Ilya Dryomov,
	Jeffle Xu, Linus Torvalds, linux-afs, linux-nfs, linux-cifs,
	ceph-devel, v9fs-developer, linux-fsdevel, linux-kernel

Make afs use netfslib's tracking for the server's idea of what the current
inode size is independently of inode->i_size.  We really want to use this
value when calculating the new vnode size when initiating a StoreData RPC
op rather than the size stat() presents to the user (ie. inode->i_size) as
the latter is affected by as-yet uncommitted writes.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
cc: linux-afs@lists.infradead.org
---

 fs/afs/inode.c |    1 +
 fs/afs/write.c |    7 +++----
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index 5b5e40197655..2fe402483ad5 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -246,6 +246,7 @@ static void afs_apply_status(struct afs_operation *op,
 		 * idea of what the size should be that's not the same as
 		 * what's on the server.
 		 */
+		vnode->netfs_ctx.remote_i_size = status->size;
 		if (change_size) {
 			afs_set_i_size(vnode, status->size);
 			inode->i_ctime = t;
diff --git a/fs/afs/write.c b/fs/afs/write.c
index e4b47f67a408..85c9056ba9fb 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -353,9 +353,10 @@ static const struct afs_operation_ops afs_store_data_operation = {
 static int afs_store_data(struct afs_vnode *vnode, struct iov_iter *iter, loff_t pos,
 			  bool laundering)
 {
+	struct netfs_i_context *ictx = &vnode->netfs_ctx;
 	struct afs_operation *op;
 	struct afs_wb_key *wbk = NULL;
-	loff_t size = iov_iter_count(iter), i_size;
+	loff_t size = iov_iter_count(iter);
 	int ret = -ENOKEY;
 
 	_enter("%s{%llx:%llu.%u},%llx,%llx",
@@ -377,15 +378,13 @@ static int afs_store_data(struct afs_vnode *vnode, struct iov_iter *iter, loff_t
 		return -ENOMEM;
 	}
 
-	i_size = i_size_read(&vnode->vfs_inode);
-
 	afs_op_set_vnode(op, 0, vnode);
 	op->file[0].dv_delta = 1;
 	op->file[0].modification = true;
 	op->store.write_iter = iter;
 	op->store.pos = pos;
 	op->store.size = size;
-	op->store.i_size = max(pos + size, i_size);
+	op->store.i_size = max(pos + size, ictx->remote_i_size);
 	op->store.laundering = laundering;
 	op->mtime = vnode->vfs_inode.i_mtime;
 	op->flags |= AFS_OPERATION_UNINTR;



^ permalink raw reply related	[flat|nested] 20+ messages in thread

end of thread, other threads:[~2022-03-02 14:10 UTC | newest]

Thread overview: 20+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-03-02 14:01 [PATCH 00/19] netfs: Prep for write helpers David Howells
2022-03-02 14:01 ` [PATCH 01/19] fscache: export fscache_end_operation() David Howells
2022-03-02 14:03 ` [PATCH 02/19] netfs: Generate enums from trace symbol mapping lists David Howells
2022-03-02 14:04 ` [PATCH 03/19] netfs: Add a netfs inode context David Howells
2022-03-02 14:04 ` [PATCH 04/19] netfs: Rename netfs_read_*request to netfs_io_*request David Howells
2022-03-02 14:04 ` [PATCH 05/19] netfs: Refactor arguments for netfs_alloc_read_request David Howells
2022-03-02 14:05 ` [PATCH 06/19] netfs: Finish off rename of netfs_read_request to netfs_io_request David Howells
2022-03-02 14:05 ` [PATCH 07/19] netfs: Split netfs_io_* object handling out David Howells
2022-03-02 14:06 ` [PATCH 08/19] netfs: Adjust the netfs_rreq tracepoint slightly David Howells
2022-03-02 14:06 ` [PATCH 09/19] netfs: Trace refcounting on the netfs_io_request struct David Howells
2022-03-02 14:06 ` [PATCH 10/19] netfs: Trace refcounting on the netfs_io_subrequest struct David Howells
2022-03-02 14:06 ` [PATCH 11/19] netfs: Adjust the netfs_failure tracepoint to indicate non-subreq lines David Howells
2022-03-02 14:07 ` [PATCH 12/19] netfs: Prepare to split read_helper.c David Howells
2022-03-02 14:07 ` [PATCH 13/19] netfs: Add a function to consolidate beginning a read David Howells
2022-03-02 14:07 ` [PATCH 14/19] netfs: Split fs/netfs/read_helper.c David Howells
2022-03-02 14:07 ` [PATCH 15/19] netfs: Split some core bits out into their own file David Howells
2022-03-02 14:08 ` [PATCH 16/19] netfs: Rename rename read_helper.c to io.c David Howells
2022-03-02 14:08 ` [PATCH 17/19] netfs: Change ->init_rreq() to return an error code David Howells
2022-03-02 14:08 ` [PATCH 18/19] netfs: Keep track of the actual remote file size David Howells
2022-03-02 14:09 ` [PATCH 19/19] afs: Maintain netfs_i_context::remote_i_size David Howells

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