* [PATCH v8 0/3] Convert NFS with fscache to the netfs API
@ 2022-09-22 13:58 Dave Wysochanski
2022-09-22 13:58 ` [PATCH v8 1/5] NFS: Rename readpage_async_filler to nfs_pageio_add_page Dave Wysochanski
` (5 more replies)
0 siblings, 6 replies; 8+ messages in thread
From: Dave Wysochanski @ 2022-09-22 13:58 UTC (permalink / raw)
To: Anna Schumaker, Trond Myklebust, David Howells
Cc: linux-nfs, linux-cachefs, Benjamin Maynard, Daire Byrne
This patchset converts NFS with fscache non-direct READ IO paths to
use the netfs API with a non-invasive approach. The existing NFS pgio
layer does not need extensive changes, and is the best way so far I've
found to address Trond's concerns about modifying the IO path [1] as
well as only enabling netfs when fscache is configured and enabled [2].
I have not attempted performance comparisions to address Chuck
Lever's concern [3] because we are not converting the non-fscache
enabled NFS IO paths to netfs.
The main patch to be reviewed is patch #3 which converts nfs_read_folio
and nfs_readahead. There are two main compatibility points with the
interface between the NFS READ IO path and netfs. First, NFS IO
interfaces are page based and netfs is request based (multiple page).
Thus, there's some accounting information collected to turn multiple
NFS READ RPC completions into a single netfs completion, and we have
to pass a pointer to this information through NFS pgio layer. Second,
the unlocking of pages of an NFS READ is handled inside netfs, which
requires a tiny bit of refactoring of the NFS read code.
Patch #4 removes the NFS fscache counters and also removes the "fsc:"
line from /proc/self/mountstats. I was not sure if we need to leave
that line in the mountstats file, and just leave the values at 0, or
we can remove it. For now I've removed it but if needed for ABI or
some other reason I can add back a "dummy" line with zeros.
In patch #5 I've removed the existing trace events because they no
longer have any meaning, and did not add any new ones since netfs
and fscache has many tracepoints. A future series may want to look
at some of the pgio layer tracepoints along with maybe one or two
related to NFS with fscache but for now it does not seem needed.
The patchset is based on 6.0-rc6 and has been pushed to github at:
https://github.com/DaveWysochanskiRH/kernel/commits/nfs-fscache-netfs
https://github.com/DaveWysochanskiRH/kernel/commit/b0467a2c39f3e8582660d073f9fa5c45ec2ca7f0
Changes since v7
================
- PATCH3: Free netfs memory if nfs_pageio_add_page() fails inside
nfs_netfs_issue_read()
- PATCH3: Clean up handling of READs completing with retryable and
non-retryable errors by removing unneeded nfs_netfs_read_done();
fixes oops in generic/303 with vers=4.2 and RHEL8 server due to
use-after-free of netfs structure
- PATCH3: Update patch header
- PATCH4 and PATCH5: new
Testing
=======
The patches are fairly stable as evidenced with xfstests generic with
various servers, both with and without fscache enabled, with no hangs
or crashes seen:
- hammerspace(pNFS flexfiles): NFS4.1, NFS4.2
- NetApp(pNFS filelayout): NFS3, NFS4.0, NFS4.1
- RHEL8: NFS3,NFS4.0,NFS4.2
The known issues are as follows:
1. Unit test setting rsize < readahead does not properly read from
fscache but re-reads data from the NFS server
* This will be fixed with another linux-cachefs [4] patch to resolve
"Stop read optimisation when folio removed from pagecache"
* Daire Byrne also verified the patch fixes his issue as well
2. "Cache volume key already in use" after xfstest runs
* xfstests (hammerspace with vers=4.2,fsc) shows the following on the
console after some tests:
"NFS: Cache volume key already in use (nfs,4.1,2,c50,cfe0100a,3,,,8000,100000,100000,bb8,ea60,7530,ea60,1)"
* This may be fixed with another patch [5] that is in progress
3. Daire Byrne reported a NULL pointer oops at cachefiles_prepare_write+0x28/0x90
* only reproduced on RHEL7.9 based NFS re-export server using fscache with upstream kernel plus
the previous patches
* may be a bug in netfs or cachefiles exposed by NFS patches
* harder to reproduce/debug but under investigation
[58710.346376] BUG: kernel NULL pointer dereference, address: 0000000000000008
[58710.371212] CPU: 12 PID: 9134 Comm: kworker/u129:0 Tainted: G E 6.0.0-2.dneg.x86_64 #1
...
[58710.389995] Workqueue: events_unbound netfs_rreq_write_to_cache_work [netfs]
[58710.397188] RIP: 0010:cachefiles_prepare_write+0x28/0x90 [cachefiles]
...
[58710.500316] Call Trace:
[58710.502894] <TASK>
[58710.505126] netfs_rreq_write_to_cache_work+0x11c/0x320 [netfs]
[58710.511201] process_one_work+0x217/0x3e0
[58710.515358] worker_thread+0x4a/0x3b0
[58710.519152] ? process_one_work+0x3e0/0x3e0
[58710.523467] kthread+0xd6/0x100
[58710.526740] ? kthread_complete_and_exit+0x20/0x20
[58710.531659] ret_from_fork+0x1f/0x30
References
==========
[1] https://lore.kernel.org/linux-nfs/9cfd5bc3cfc6abc2d3316b0387222e708d67f595.camel@hammerspace.com/
[2] https://lore.kernel.org/linux-nfs/da9200f1bded9b8b078a7aef227fd6b92eb028fb.camel@hammerspace.com/
[3] https://marc.info/?l=linux-nfs&m=160597917525083&w=4
[4] https://www.mail-archive.com/linux-cachefs@redhat.com/msg03043.html
[5] https://marc.info/?l=linux-nfs&m=165962662200679&w=4
Dave Wysochanski (5):
NFS: Rename readpage_async_filler to nfs_pageio_add_page
NFS: Configure support for netfs when NFS fscache is configured
NFS: Convert buffered read paths to use netfs when fscache is enabled
NFS: Remove all NFSIOS_FSCACHE counters due to conversion to netfs API
NFS: Remove fscache specific trace points and NFS_INO_FSCACHE bit
fs/nfs/Kconfig | 1 +
fs/nfs/delegation.c | 2 +-
fs/nfs/dir.c | 2 +-
fs/nfs/fscache.c | 242 ++++++++++++++++++++++---------------
fs/nfs/fscache.h | 111 +++++++++++------
fs/nfs/inode.c | 8 +-
fs/nfs/internal.h | 11 +-
fs/nfs/iostat.h | 17 ---
fs/nfs/nfstrace.h | 91 --------------
fs/nfs/pagelist.c | 12 ++
fs/nfs/pnfs.c | 12 +-
fs/nfs/read.c | 110 +++++++++--------
fs/nfs/super.c | 11 --
fs/nfs/write.c | 2 +-
include/linux/nfs_fs.h | 35 ++++--
include/linux/nfs_iostat.h | 12 --
include/linux/nfs_page.h | 3 +
include/linux/nfs_xdr.h | 3 +
18 files changed, 335 insertions(+), 350 deletions(-)
--
2.31.1
^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH v8 1/5] NFS: Rename readpage_async_filler to nfs_pageio_add_page
2022-09-22 13:58 [PATCH v8 0/3] Convert NFS with fscache to the netfs API Dave Wysochanski
@ 2022-09-22 13:58 ` Dave Wysochanski
2022-09-22 13:58 ` [PATCH v8 2/5] NFS: Configure support for netfs when NFS fscache is configured Dave Wysochanski
` (4 subsequent siblings)
5 siblings, 0 replies; 8+ messages in thread
From: Dave Wysochanski @ 2022-09-22 13:58 UTC (permalink / raw)
To: Anna Schumaker, Trond Myklebust, David Howells
Cc: linux-nfs, linux-cachefs, Benjamin Maynard, Daire Byrne
Rename readpage_async_filler to nfs_pageio_add_page to
better reflect what this function does (add a page to
the nfs_pageio_descriptor), and simplify arguments to
this function by removing struct nfs_readdesc.
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
---
fs/nfs/read.c | 60 +++++++++++++++++++++++++--------------------------
1 file changed, 30 insertions(+), 30 deletions(-)
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 8ae2c8d1219d..525e82ea9a9e 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -127,11 +127,6 @@ static void nfs_readpage_release(struct nfs_page *req, int error)
nfs_release_request(req);
}
-struct nfs_readdesc {
- struct nfs_pageio_descriptor pgio;
- struct nfs_open_context *ctx;
-};
-
static void nfs_page_group_set_uptodate(struct nfs_page *req)
{
if (nfs_page_group_sync_on_bit(req, PG_UPTODATE))
@@ -153,7 +148,8 @@ static void nfs_read_completion(struct nfs_pgio_header *hdr)
if (test_bit(NFS_IOHDR_EOF, &hdr->flags)) {
/* note: regions of the page not covered by a
- * request are zeroed in readpage_async_filler */
+ * request are zeroed in nfs_pageio_add_page
+ */
if (bytes > hdr->good_bytes) {
/* nothing in this request was good, so zero
* the full extent of the request */
@@ -281,8 +277,10 @@ static void nfs_readpage_result(struct rpc_task *task,
nfs_readpage_retry(task, hdr);
}
-static int
-readpage_async_filler(struct nfs_readdesc *desc, struct page *page)
+int
+nfs_pageio_add_page(struct nfs_pageio_descriptor *pgio,
+ struct nfs_open_context *ctx,
+ struct page *page)
{
struct inode *inode = page_file_mapping(page)->host;
unsigned int rsize = NFS_SERVER(inode)->rsize;
@@ -302,15 +300,15 @@ readpage_async_filler(struct nfs_readdesc *desc, struct page *page)
goto out_unlock;
}
- new = nfs_create_request(desc->ctx, page, 0, aligned_len);
+ new = nfs_create_request(ctx, page, 0, aligned_len);
if (IS_ERR(new))
goto out_error;
if (len < PAGE_SIZE)
zero_user_segment(page, len, PAGE_SIZE);
- if (!nfs_pageio_add_request(&desc->pgio, new)) {
+ if (!nfs_pageio_add_request(pgio, new)) {
nfs_list_remove_request(new);
- error = desc->pgio.pg_error;
+ error = pgio->pg_error;
nfs_readpage_release(new, error);
goto out;
}
@@ -332,7 +330,8 @@ readpage_async_filler(struct nfs_readdesc *desc, struct page *page)
int nfs_read_folio(struct file *file, struct folio *folio)
{
struct page *page = &folio->page;
- struct nfs_readdesc desc;
+ struct nfs_pageio_descriptor pgio;
+ struct nfs_open_context *ctx;
struct inode *inode = page_file_mapping(page)->host;
int ret;
@@ -358,29 +357,29 @@ int nfs_read_folio(struct file *file, struct folio *folio)
if (file == NULL) {
ret = -EBADF;
- desc.ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
- if (desc.ctx == NULL)
+ ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
+ if (ctx == NULL)
goto out_unlock;
} else
- desc.ctx = get_nfs_open_context(nfs_file_open_context(file));
+ ctx = get_nfs_open_context(nfs_file_open_context(file));
- xchg(&desc.ctx->error, 0);
- nfs_pageio_init_read(&desc.pgio, inode, false,
+ xchg(&ctx->error, 0);
+ nfs_pageio_init_read(&pgio, inode, false,
&nfs_async_read_completion_ops);
- ret = readpage_async_filler(&desc, page);
+ ret = nfs_pageio_add_page(&pgio, ctx, page);
if (ret)
goto out;
- nfs_pageio_complete_read(&desc.pgio);
- ret = desc.pgio.pg_error < 0 ? desc.pgio.pg_error : 0;
+ nfs_pageio_complete_read(&pgio);
+ ret = pgio.pg_error < 0 ? pgio.pg_error : 0;
if (!ret) {
ret = wait_on_page_locked_killable(page);
if (!PageUptodate(page) && !ret)
- ret = xchg(&desc.ctx->error, 0);
+ ret = xchg(&ctx->error, 0);
}
out:
- put_nfs_open_context(desc.ctx);
+ put_nfs_open_context(ctx);
trace_nfs_aop_readpage_done(inode, page, ret);
return ret;
out_unlock:
@@ -391,9 +390,10 @@ int nfs_read_folio(struct file *file, struct folio *folio)
void nfs_readahead(struct readahead_control *ractl)
{
+ struct nfs_pageio_descriptor pgio;
+ struct nfs_open_context *ctx;
unsigned int nr_pages = readahead_count(ractl);
struct file *file = ractl->file;
- struct nfs_readdesc desc;
struct inode *inode = ractl->mapping->host;
struct page *page;
int ret;
@@ -407,25 +407,25 @@ void nfs_readahead(struct readahead_control *ractl)
if (file == NULL) {
ret = -EBADF;
- desc.ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
- if (desc.ctx == NULL)
+ ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
+ if (ctx == NULL)
goto out;
} else
- desc.ctx = get_nfs_open_context(nfs_file_open_context(file));
+ ctx = get_nfs_open_context(nfs_file_open_context(file));
- nfs_pageio_init_read(&desc.pgio, inode, false,
+ nfs_pageio_init_read(&pgio, inode, false,
&nfs_async_read_completion_ops);
while ((page = readahead_page(ractl)) != NULL) {
- ret = readpage_async_filler(&desc, page);
+ ret = nfs_pageio_add_page(&pgio, ctx, page);
put_page(page);
if (ret)
break;
}
- nfs_pageio_complete_read(&desc.pgio);
+ nfs_pageio_complete_read(&pgio);
- put_nfs_open_context(desc.ctx);
+ put_nfs_open_context(ctx);
out:
trace_nfs_aop_readahead_done(inode, nr_pages, ret);
}
--
2.31.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH v8 2/5] NFS: Configure support for netfs when NFS fscache is configured
2022-09-22 13:58 [PATCH v8 0/3] Convert NFS with fscache to the netfs API Dave Wysochanski
2022-09-22 13:58 ` [PATCH v8 1/5] NFS: Rename readpage_async_filler to nfs_pageio_add_page Dave Wysochanski
@ 2022-09-22 13:58 ` Dave Wysochanski
2022-09-22 13:58 ` [PATCH v8 3/5] NFS: Convert buffered read paths to use netfs when fscache is enabled Dave Wysochanski
` (3 subsequent siblings)
5 siblings, 0 replies; 8+ messages in thread
From: Dave Wysochanski @ 2022-09-22 13:58 UTC (permalink / raw)
To: Anna Schumaker, Trond Myklebust, David Howells
Cc: linux-nfs, linux-cachefs, Benjamin Maynard, Daire Byrne
As first steps for support of the netfs library when NFS_FSCACHE is
configured, add NETFS_SUPPORT to Kconfig and add the required netfs_inode
into struct nfs_inode.
Using netfs requires we move the VFS inode structure to be stored
inside struct netfs_inode, along with the fscache_cookie.
Thus, create a new helper, VFS_I(), which is defined
differently depending on whether NFS_FSCACHE is configured.
In addition, use the netfs_inode() and netfs_i_cookie() helpers,
and remove our own helper, nfs_i_fscache().
Later patches will convert NFS fscache to fully use netfs.
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
---
fs/nfs/Kconfig | 1 +
fs/nfs/delegation.c | 2 +-
fs/nfs/dir.c | 2 +-
fs/nfs/fscache.c | 20 +++++++++-----------
fs/nfs/fscache.h | 15 ++++++---------
fs/nfs/inode.c | 6 +++---
fs/nfs/internal.h | 2 +-
fs/nfs/pnfs.c | 12 ++++++------
fs/nfs/write.c | 2 +-
include/linux/nfs_fs.h | 34 +++++++++++++++++++++++-----------
10 files changed, 52 insertions(+), 44 deletions(-)
diff --git a/fs/nfs/Kconfig b/fs/nfs/Kconfig
index 14a72224b657..8fbb6caf3481 100644
--- a/fs/nfs/Kconfig
+++ b/fs/nfs/Kconfig
@@ -171,6 +171,7 @@ config ROOT_NFS
config NFS_FSCACHE
bool "Provide NFS client caching support"
depends on NFS_FS=m && FSCACHE || NFS_FS=y && FSCACHE=y
+ select NETFS_SUPPORT
help
Say Y here if you want NFS data to be cached locally on disc through
the general filesystem cache manager
diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index 5c97cad741a7..b5c492d40367 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -306,7 +306,7 @@ nfs_start_delegation_return_locked(struct nfs_inode *nfsi)
}
spin_unlock(&delegation->lock);
if (ret)
- nfs_clear_verifier_delegated(&nfsi->vfs_inode);
+ nfs_clear_verifier_delegated(VFS_I(nfsi));
out:
return ret;
}
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 5d6c2ddc7ea6..b63c624cea6d 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -2799,7 +2799,7 @@ nfs_do_access_cache_scan(unsigned int nr_to_scan)
if (nr_to_scan-- == 0)
break;
- inode = &nfsi->vfs_inode;
+ inode = VFS_I(nfsi);
spin_lock(&inode->i_lock);
if (list_empty(&nfsi->access_cache_entry_lru))
goto remove_lru_entry;
diff --git a/fs/nfs/fscache.c b/fs/nfs/fscache.c
index e861d7bae305..a6fc1c8b6644 100644
--- a/fs/nfs/fscache.c
+++ b/fs/nfs/fscache.c
@@ -163,13 +163,14 @@ void nfs_fscache_init_inode(struct inode *inode)
struct nfs_server *nfss = NFS_SERVER(inode);
struct nfs_inode *nfsi = NFS_I(inode);
- nfsi->fscache = NULL;
+ netfs_inode(inode)->cache = NULL;
if (!(nfss->fscache && S_ISREG(inode->i_mode)))
return;
nfs_fscache_update_auxdata(&auxdata, inode);
- nfsi->fscache = fscache_acquire_cookie(NFS_SB(inode->i_sb)->fscache,
+ netfs_inode(inode)->cache = fscache_acquire_cookie(
+ nfss->fscache,
0,
nfsi->fh.data, /* index_key */
nfsi->fh.size,
@@ -183,11 +184,8 @@ void nfs_fscache_init_inode(struct inode *inode)
*/
void nfs_fscache_clear_inode(struct inode *inode)
{
- struct nfs_inode *nfsi = NFS_I(inode);
- struct fscache_cookie *cookie = nfs_i_fscache(inode);
-
- fscache_relinquish_cookie(cookie, false);
- nfsi->fscache = NULL;
+ fscache_relinquish_cookie(netfs_i_cookie(&NFS_I(inode)->netfs), false);
+ netfs_inode(inode)->cache = NULL;
}
/*
@@ -212,7 +210,7 @@ void nfs_fscache_clear_inode(struct inode *inode)
void nfs_fscache_open_file(struct inode *inode, struct file *filp)
{
struct nfs_fscache_inode_auxdata auxdata;
- struct fscache_cookie *cookie = nfs_i_fscache(inode);
+ struct fscache_cookie *cookie = netfs_i_cookie(&NFS_I(inode)->netfs);
bool open_for_write = inode_is_open_for_write(inode);
if (!fscache_cookie_valid(cookie))
@@ -230,7 +228,7 @@ EXPORT_SYMBOL_GPL(nfs_fscache_open_file);
void nfs_fscache_release_file(struct inode *inode, struct file *filp)
{
struct nfs_fscache_inode_auxdata auxdata;
- struct fscache_cookie *cookie = nfs_i_fscache(inode);
+ struct fscache_cookie *cookie = netfs_i_cookie(&NFS_I(inode)->netfs);
loff_t i_size = i_size_read(inode);
nfs_fscache_update_auxdata(&auxdata, inode);
@@ -243,7 +241,7 @@ void nfs_fscache_release_file(struct inode *inode, struct file *filp)
static int fscache_fallback_read_page(struct inode *inode, struct page *page)
{
struct netfs_cache_resources cres;
- struct fscache_cookie *cookie = nfs_i_fscache(inode);
+ struct fscache_cookie *cookie = netfs_i_cookie(&NFS_I(inode)->netfs);
struct iov_iter iter;
struct bio_vec bvec[1];
int ret;
@@ -271,7 +269,7 @@ static int fscache_fallback_write_page(struct inode *inode, struct page *page,
bool no_space_allocated_yet)
{
struct netfs_cache_resources cres;
- struct fscache_cookie *cookie = nfs_i_fscache(inode);
+ struct fscache_cookie *cookie = netfs_i_cookie(&NFS_I(inode)->netfs);
struct iov_iter iter;
struct bio_vec bvec[1];
loff_t start = page_offset(page);
diff --git a/fs/nfs/fscache.h b/fs/nfs/fscache.h
index 2a37af880978..38614ed8f951 100644
--- a/fs/nfs/fscache.h
+++ b/fs/nfs/fscache.h
@@ -54,7 +54,7 @@ static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp)
if (current_is_kswapd() || !(gfp & __GFP_FS))
return false;
folio_wait_fscache(folio);
- fscache_note_page_release(nfs_i_fscache(folio->mapping->host));
+ fscache_note_page_release(netfs_i_cookie(&NFS_I(folio->mapping->host)->netfs));
nfs_inc_fscache_stats(folio->mapping->host,
NFSIOS_FSCACHE_PAGES_UNCACHED);
}
@@ -66,7 +66,7 @@ static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp)
*/
static inline int nfs_fscache_read_page(struct inode *inode, struct page *page)
{
- if (nfs_i_fscache(inode))
+ if (netfs_inode(inode)->cache)
return __nfs_fscache_read_page(inode, page);
return -ENOBUFS;
}
@@ -78,7 +78,7 @@ static inline int nfs_fscache_read_page(struct inode *inode, struct page *page)
static inline void nfs_fscache_write_page(struct inode *inode,
struct page *page)
{
- if (nfs_i_fscache(inode))
+ if (netfs_inode(inode)->cache)
__nfs_fscache_write_page(inode, page);
}
@@ -101,13 +101,10 @@ static inline void nfs_fscache_update_auxdata(struct nfs_fscache_inode_auxdata *
static inline void nfs_fscache_invalidate(struct inode *inode, int flags)
{
struct nfs_fscache_inode_auxdata auxdata;
- struct nfs_inode *nfsi = NFS_I(inode);
+ struct fscache_cookie *cookie = netfs_i_cookie(&NFS_I(inode)->netfs);
- if (nfsi->fscache) {
- nfs_fscache_update_auxdata(&auxdata, inode);
- fscache_invalidate(nfsi->fscache, &auxdata,
- i_size_read(inode), flags);
- }
+ nfs_fscache_update_auxdata(&auxdata, inode);
+ fscache_invalidate(cookie, &auxdata, i_size_read(inode), flags);
}
/*
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index bea7c005119c..aa2aec785ab5 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1411,7 +1411,7 @@ int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping)
static bool nfs_file_has_writers(struct nfs_inode *nfsi)
{
- struct inode *inode = &nfsi->vfs_inode;
+ struct inode *inode = VFS_I(nfsi);
if (!S_ISREG(inode->i_mode))
return false;
@@ -2249,7 +2249,7 @@ struct inode *nfs_alloc_inode(struct super_block *sb)
#ifdef CONFIG_NFS_V4_2
nfsi->xattr_cache = NULL;
#endif
- return &nfsi->vfs_inode;
+ return VFS_I(nfsi);
}
EXPORT_SYMBOL_GPL(nfs_alloc_inode);
@@ -2273,7 +2273,7 @@ static void init_once(void *foo)
{
struct nfs_inode *nfsi = (struct nfs_inode *) foo;
- inode_init_once(&nfsi->vfs_inode);
+ inode_init_once(VFS_I(nfsi));
INIT_LIST_HEAD(&nfsi->open_files);
INIT_LIST_HEAD(&nfsi->access_cache_entry_lru);
INIT_LIST_HEAD(&nfsi->access_cache_inode_lru);
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 898dd95bc7a7..4d240ac4430f 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -355,7 +355,7 @@ nfs4_label_copy(struct nfs4_label *dst, struct nfs4_label *src)
static inline void nfs_zap_label_cache_locked(struct nfs_inode *nfsi)
{
- if (nfs_server_capable(&nfsi->vfs_inode, NFS_CAP_SECURITY_LABEL))
+ if (nfs_server_capable(VFS_I(nfsi), NFS_CAP_SECURITY_LABEL))
nfsi->cache_validity |= NFS_INO_INVALID_LABEL;
}
#else
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 2613b7e36eb9..035bf2eac2cf 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -763,19 +763,19 @@ static struct pnfs_layout_hdr *__pnfs_destroy_layout(struct nfs_inode *nfsi)
struct pnfs_layout_hdr *lo;
LIST_HEAD(tmp_list);
- spin_lock(&nfsi->vfs_inode.i_lock);
+ spin_lock(&VFS_I(nfsi)->i_lock);
lo = nfsi->layout;
if (lo) {
pnfs_get_layout_hdr(lo);
pnfs_mark_layout_stateid_invalid(lo, &tmp_list);
pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RO_FAILED);
pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RW_FAILED);
- spin_unlock(&nfsi->vfs_inode.i_lock);
+ spin_unlock(&VFS_I(nfsi)->i_lock);
pnfs_free_lseg_list(&tmp_list);
- nfs_commit_inode(&nfsi->vfs_inode, 0);
+ nfs_commit_inode(VFS_I(nfsi), 0);
pnfs_put_layout_hdr(lo);
} else
- spin_unlock(&nfsi->vfs_inode.i_lock);
+ spin_unlock(&VFS_I(nfsi)->i_lock);
return lo;
}
@@ -790,9 +790,9 @@ static bool pnfs_layout_removed(struct nfs_inode *nfsi,
{
bool ret;
- spin_lock(&nfsi->vfs_inode.i_lock);
+ spin_lock(&VFS_I(nfsi)->i_lock);
ret = nfsi->layout != lo;
- spin_unlock(&nfsi->vfs_inode.i_lock);
+ spin_unlock(&VFS_I(nfsi)->i_lock);
return ret;
}
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index f41d24b54fd1..911569022036 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -828,7 +828,7 @@ nfs_page_search_commits_for_head_request_locked(struct nfs_inode *nfsi,
{
struct nfs_page *freq, *t;
struct nfs_commit_info cinfo;
- struct inode *inode = &nfsi->vfs_inode;
+ struct inode *inode = VFS_I(nfsi);
nfs_init_cinfo_from_inode(&cinfo, inode);
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 7931fa472561..a1c402e26abf 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -31,6 +31,10 @@
#include <linux/sunrpc/auth.h>
#include <linux/sunrpc/clnt.h>
+#ifdef CONFIG_NFS_FSCACHE
+#include <linux/netfs.h>
+#endif
+
#include <linux/nfs.h>
#include <linux/nfs2.h>
#include <linux/nfs3.h>
@@ -204,9 +208,11 @@ struct nfs_inode {
__u64 write_io;
__u64 read_io;
#ifdef CONFIG_NFS_FSCACHE
- struct fscache_cookie *fscache;
-#endif
+ struct netfs_inode netfs; /* netfs context and VFS inode */
+#else
struct inode vfs_inode;
+#endif
+
#ifdef CONFIG_NFS_V4_2
struct nfs4_xattr_cache *xattr_cache;
@@ -281,10 +287,25 @@ struct nfs4_copy_state {
#define NFS_INO_LAYOUTSTATS (11) /* layoutstats inflight */
#define NFS_INO_ODIRECT (12) /* I/O setting is O_DIRECT */
+#ifdef CONFIG_NFS_FSCACHE
+static inline struct inode *VFS_I(struct nfs_inode *nfsi)
+{
+ return &nfsi->netfs.inode;
+}
+static inline struct nfs_inode *NFS_I(const struct inode *inode)
+{
+ return container_of(inode, struct nfs_inode, netfs.inode);
+}
+#else
+static inline struct inode *VFS_I(struct nfs_inode *nfsi)
+{
+ return &nfsi->vfs_inode;
+}
static inline struct nfs_inode *NFS_I(const struct inode *inode)
{
return container_of(inode, struct nfs_inode, vfs_inode);
}
+#endif
static inline struct nfs_server *NFS_SB(const struct super_block *s)
{
@@ -328,15 +349,6 @@ static inline int NFS_STALE(const struct inode *inode)
return test_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
}
-static inline struct fscache_cookie *nfs_i_fscache(struct inode *inode)
-{
-#ifdef CONFIG_NFS_FSCACHE
- return NFS_I(inode)->fscache;
-#else
- return NULL;
-#endif
-}
-
static inline __u64 NFS_FILEID(const struct inode *inode)
{
return NFS_I(inode)->fileid;
--
2.31.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH v8 3/5] NFS: Convert buffered read paths to use netfs when fscache is enabled
2022-09-22 13:58 [PATCH v8 0/3] Convert NFS with fscache to the netfs API Dave Wysochanski
2022-09-22 13:58 ` [PATCH v8 1/5] NFS: Rename readpage_async_filler to nfs_pageio_add_page Dave Wysochanski
2022-09-22 13:58 ` [PATCH v8 2/5] NFS: Configure support for netfs when NFS fscache is configured Dave Wysochanski
@ 2022-09-22 13:58 ` Dave Wysochanski
2022-09-28 10:07 ` Jeff Layton
2022-09-22 13:58 ` [PATCH v8 4/5] NFS: Remove all NFSIOS_FSCACHE counters due to conversion to netfs API Dave Wysochanski
` (2 subsequent siblings)
5 siblings, 1 reply; 8+ messages in thread
From: Dave Wysochanski @ 2022-09-22 13:58 UTC (permalink / raw)
To: Anna Schumaker, Trond Myklebust, David Howells
Cc: linux-nfs, linux-cachefs, Benjamin Maynard, Daire Byrne
Convert the NFS buffered read code paths to corresponding netfs APIs,
but only when fscache is configured and enabled.
The netfs API defines struct netfs_request_ops which must be filled
in by the network filesystem. For NFS, we only need to define 5 of
the functions, the main one being the issue_read() function.
The issue_read() function is called by the netfs layer when a read
cannot be fulfilled locally, and must be sent to the server (either
the cache is not active, or it is active but the data is not available).
Once the read from the server is complete, netfs requires a call to
netfs_subreq_terminated() which conveys either how many bytes were read
successfully, or an error. Note that issue_read() is called with a
structure, netfs_io_subrequest, which defines the IO requested, and
contains a start and a length (both in bytes), and assumes the underlying
netfs will return a either an error on the whole region, or the number
of bytes successfully read.
The NFS IO path is page based and the main APIs are the pgio APIs defined
in pagelist.c. For the pgio APIs, there is no way for the caller to
know how many RPCs will be sent and how the pages will be broken up
into underlying RPCs, each of which will have their own completion and
return code. In contrast, netfs is subrequest based, a single
subrequest may contain multiple pages, and a single subrequest is
initiated with issue_read() and terminated with netfs_subreq_terminated().
Thus, to utilze the netfs APIs, NFS needs some way to accommodate
the netfs API requirement on the single response to the whole
subrequest, while also minimizing disruptive changes to the NFS
pgio layer.
The approach taken with this patch is to allocate a small structure
for each nfs_netfs_issue_read() call, store the final error and number
of bytes successfully transferred in the structure, and update these values
as each RPC completes. The refcount on the structure is used as a marker
for the last RPC completion, is incremented in nfs_netfs_read_initiate(),
and decremented inside nfs_netfs_read_completion(), when a nfs_pgio_header
contains a valid pointer to the data. On the final put (which signals
the final outstanding RPC is complete) in nfs_netfs_read_completion(),
call netfs_subreq_terminated() with either the final error value (if
one or more READs complete with an error) or the number of bytes
successfully transferred (if all RPCs complete successfully). Note
that when all RPCs complete successfully, the number of bytes transferred
is capped to the length of the subrequest. Capping the transferred length
to the subrequest length prevents "Subreq overread" warnings from netfs.
This is due to the "aligned_len" in nfs_pageio_add_page(), and the
corner case where NFS requests a full page at the end of the file,
even when i_size reflects only a partial page (NFS overread).
Suggested-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
---
fs/nfs/fscache.c | 232 +++++++++++++++++++++++----------------
fs/nfs/fscache.h | 102 +++++++++++------
fs/nfs/inode.c | 2 +
fs/nfs/internal.h | 9 ++
fs/nfs/pagelist.c | 12 ++
fs/nfs/read.c | 50 ++++-----
include/linux/nfs_page.h | 3 +
include/linux/nfs_xdr.h | 3 +
8 files changed, 261 insertions(+), 152 deletions(-)
diff --git a/fs/nfs/fscache.c b/fs/nfs/fscache.c
index a6fc1c8b6644..58462f6579d6 100644
--- a/fs/nfs/fscache.c
+++ b/fs/nfs/fscache.c
@@ -15,6 +15,9 @@
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/iversion.h>
+#include <linux/xarray.h>
+#include <linux/fscache.h>
+#include <linux/netfs.h>
#include "internal.h"
#include "iostat.h"
@@ -184,7 +187,7 @@ void nfs_fscache_init_inode(struct inode *inode)
*/
void nfs_fscache_clear_inode(struct inode *inode)
{
- fscache_relinquish_cookie(netfs_i_cookie(&NFS_I(inode)->netfs), false);
+ fscache_relinquish_cookie(netfs_i_cookie(netfs_inode(inode)), false);
netfs_inode(inode)->cache = NULL;
}
@@ -210,7 +213,7 @@ void nfs_fscache_clear_inode(struct inode *inode)
void nfs_fscache_open_file(struct inode *inode, struct file *filp)
{
struct nfs_fscache_inode_auxdata auxdata;
- struct fscache_cookie *cookie = netfs_i_cookie(&NFS_I(inode)->netfs);
+ struct fscache_cookie *cookie = netfs_i_cookie(netfs_inode(inode));
bool open_for_write = inode_is_open_for_write(inode);
if (!fscache_cookie_valid(cookie))
@@ -228,119 +231,160 @@ EXPORT_SYMBOL_GPL(nfs_fscache_open_file);
void nfs_fscache_release_file(struct inode *inode, struct file *filp)
{
struct nfs_fscache_inode_auxdata auxdata;
- struct fscache_cookie *cookie = netfs_i_cookie(&NFS_I(inode)->netfs);
+ struct fscache_cookie *cookie = netfs_i_cookie(netfs_inode(inode));
loff_t i_size = i_size_read(inode);
nfs_fscache_update_auxdata(&auxdata, inode);
fscache_unuse_cookie(cookie, &auxdata, &i_size);
}
-/*
- * Fallback page reading interface.
- */
-static int fscache_fallback_read_page(struct inode *inode, struct page *page)
+int nfs_netfs_read_folio(struct file *file, struct folio *folio)
{
- struct netfs_cache_resources cres;
- struct fscache_cookie *cookie = netfs_i_cookie(&NFS_I(inode)->netfs);
- struct iov_iter iter;
- struct bio_vec bvec[1];
- int ret;
-
- memset(&cres, 0, sizeof(cres));
- bvec[0].bv_page = page;
- bvec[0].bv_offset = 0;
- bvec[0].bv_len = PAGE_SIZE;
- iov_iter_bvec(&iter, READ, bvec, ARRAY_SIZE(bvec), PAGE_SIZE);
-
- ret = fscache_begin_read_operation(&cres, cookie);
- if (ret < 0)
- return ret;
-
- ret = fscache_read(&cres, page_offset(page), &iter, NETFS_READ_HOLE_FAIL,
- NULL, NULL);
- fscache_end_operation(&cres);
- return ret;
+ if (!netfs_inode(folio_inode(folio))->cache)
+ return -ENOBUFS;
+
+ return netfs_read_folio(file, folio);
}
-/*
- * Fallback page writing interface.
- */
-static int fscache_fallback_write_page(struct inode *inode, struct page *page,
- bool no_space_allocated_yet)
+int nfs_netfs_readahead(struct readahead_control *ractl)
{
- struct netfs_cache_resources cres;
- struct fscache_cookie *cookie = netfs_i_cookie(&NFS_I(inode)->netfs);
- struct iov_iter iter;
- struct bio_vec bvec[1];
- loff_t start = page_offset(page);
- size_t len = PAGE_SIZE;
- int ret;
-
- memset(&cres, 0, sizeof(cres));
- bvec[0].bv_page = page;
- bvec[0].bv_offset = 0;
- bvec[0].bv_len = PAGE_SIZE;
- iov_iter_bvec(&iter, WRITE, bvec, ARRAY_SIZE(bvec), PAGE_SIZE);
-
- ret = fscache_begin_write_operation(&cres, cookie);
- if (ret < 0)
- return ret;
-
- ret = cres.ops->prepare_write(&cres, &start, &len, i_size_read(inode),
- no_space_allocated_yet);
- if (ret == 0)
- ret = fscache_write(&cres, page_offset(page), &iter, NULL, NULL);
- fscache_end_operation(&cres);
- return ret;
+ struct inode *inode = ractl->mapping->host;
+
+ if (!netfs_inode(inode)->cache)
+ return -ENOBUFS;
+
+ netfs_readahead(ractl);
+ return 0;
}
-/*
- * Retrieve a page from fscache
- */
-int __nfs_fscache_read_page(struct inode *inode, struct page *page)
+atomic_t nfs_netfs_debug_id;
+static int nfs_netfs_init_request(struct netfs_io_request *rreq, struct file *file)
{
- int ret;
+ rreq->netfs_priv = get_nfs_open_context(nfs_file_open_context(file));
+ rreq->debug_id = atomic_inc_return(&nfs_netfs_debug_id);
- trace_nfs_fscache_read_page(inode, page);
- if (PageChecked(page)) {
- ClearPageChecked(page);
- ret = 1;
- goto out;
- }
+ return 0;
+}
- ret = fscache_fallback_read_page(inode, page);
- if (ret < 0) {
- nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_FAIL);
- SetPageChecked(page);
- goto out;
- }
+static void nfs_netfs_free_request(struct netfs_io_request *rreq)
+{
+ put_nfs_open_context(rreq->netfs_priv);
+}
- /* Read completed synchronously */
- nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_OK);
- SetPageUptodate(page);
- ret = 0;
-out:
- trace_nfs_fscache_read_page_exit(inode, page, ret);
- return ret;
+static inline int nfs_netfs_begin_cache_operation(struct netfs_io_request *rreq)
+{
+ return fscache_begin_read_operation(&rreq->cache_resources,
+ netfs_i_cookie(netfs_inode(rreq->inode)));
}
-/*
- * Store a newly fetched page in fscache. We can be certain there's no page
- * stored in the cache as yet otherwise we would've read it from there.
- */
-void __nfs_fscache_write_page(struct inode *inode, struct page *page)
+static struct nfs_netfs_io_data *nfs_netfs_alloc(struct netfs_io_subrequest *sreq)
{
- int ret;
+ struct nfs_netfs_io_data *netfs;
+
+ netfs = kzalloc(sizeof(*netfs), GFP_KERNEL_ACCOUNT);
+ if (!netfs)
+ return NULL;
+ netfs->sreq = sreq;
+ refcount_set(&netfs->refcount, 1);
+ return netfs;
+}
- trace_nfs_fscache_write_page(inode, page);
+static bool nfs_netfs_clamp_length(struct netfs_io_subrequest *sreq)
+{
+ size_t rsize = NFS_SB(sreq->rreq->inode->i_sb)->rsize;
- ret = fscache_fallback_write_page(inode, page, true);
+ sreq->len = min(sreq->len, rsize);
+ return true;
+}
- if (ret != 0) {
- nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_WRITTEN_FAIL);
- nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_UNCACHED);
- } else {
- nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_WRITTEN_OK);
+static void nfs_netfs_issue_read(struct netfs_io_subrequest *sreq)
+{
+ struct nfs_netfs_io_data *netfs;
+ struct nfs_pageio_descriptor pgio;
+ struct inode *inode = sreq->rreq->inode;
+ struct nfs_open_context *ctx = sreq->rreq->netfs_priv;
+ struct page *page;
+ int err;
+ pgoff_t start = (sreq->start + sreq->transferred) >> PAGE_SHIFT;
+ pgoff_t last = ((sreq->start + sreq->len -
+ sreq->transferred - 1) >> PAGE_SHIFT);
+ XA_STATE(xas, &sreq->rreq->mapping->i_pages, start);
+
+ nfs_pageio_init_read(&pgio, inode, false,
+ &nfs_async_read_completion_ops);
+
+ netfs = nfs_netfs_alloc(sreq);
+ if (!netfs)
+ return netfs_subreq_terminated(sreq, -ENOMEM, false);
+
+ pgio.pg_netfs = netfs; /* used in completion */
+
+ xas_lock(&xas);
+ xas_for_each(&xas, page, last) {
+ /* nfs_pageio_add_page() may schedule() due to pNFS layout and other RPCs */
+ xas_pause(&xas);
+ xas_unlock(&xas);
+ err = nfs_pageio_add_page(&pgio, ctx, page);
+ if (err < 0) {
+ netfs->error = err;
+ goto out;
+ }
+ xas_lock(&xas);
}
- trace_nfs_fscache_write_page_exit(inode, page, ret);
+ xas_unlock(&xas);
+out:
+ nfs_pageio_complete_read(&pgio);
+ nfs_netfs_put(netfs);
+}
+
+void nfs_netfs_initiate_read(struct nfs_pgio_header *hdr)
+{
+ struct nfs_netfs_io_data *netfs = hdr->netfs;
+
+ if (!netfs)
+ return;
+
+ nfs_netfs_get(netfs);
+}
+
+void nfs_netfs_readpage_release(struct nfs_page *req)
+{
+ struct inode *inode = d_inode(nfs_req_openctx(req)->dentry);
+
+ /*
+ * If fscache is enabled, netfs will unlock pages.
+ */
+ if (netfs_inode(inode)->cache)
+ return;
+
+ unlock_page(req->wb_page);
}
+
+void nfs_netfs_read_completion(struct nfs_pgio_header *hdr)
+{
+ struct nfs_netfs_io_data *netfs = hdr->netfs;
+ struct netfs_io_subrequest *sreq;
+
+ if (!netfs)
+ return;
+
+ sreq = netfs->sreq;
+ if (test_bit(NFS_IOHDR_EOF, &hdr->flags))
+ __set_bit(NETFS_SREQ_CLEAR_TAIL, &sreq->flags);
+
+ if (hdr->error)
+ netfs->error = hdr->error;
+ else
+ atomic64_add(hdr->res.count, &netfs->transferred);
+
+ nfs_netfs_put(netfs);
+ hdr->netfs = NULL;
+}
+
+const struct netfs_request_ops nfs_netfs_ops = {
+ .init_request = nfs_netfs_init_request,
+ .free_request = nfs_netfs_free_request,
+ .begin_cache_operation = nfs_netfs_begin_cache_operation,
+ .issue_read = nfs_netfs_issue_read,
+ .clamp_length = nfs_netfs_clamp_length
+};
diff --git a/fs/nfs/fscache.h b/fs/nfs/fscache.h
index 38614ed8f951..8d9d916b3a86 100644
--- a/fs/nfs/fscache.h
+++ b/fs/nfs/fscache.h
@@ -34,6 +34,58 @@ struct nfs_fscache_inode_auxdata {
u64 change_attr;
};
+struct nfs_netfs_io_data {
+ /*
+ * NFS may split a netfs_io_subrequest into multiple RPCs, each
+ * with their own read completion. In netfs, we can only call
+ * netfs_subreq_terminated() once for each subrequest. Use the
+ * refcount here to double as a marker of the last RPC completion,
+ * and only call netfs via netfs_subreq_terminated() once.
+ */
+ refcount_t refcount;
+ struct netfs_io_subrequest *sreq;
+
+ /*
+ * Final disposition of the netfs_io_subrequest, sent in
+ * netfs_subreq_terminated()
+ */
+ atomic64_t transferred;
+ int error;
+};
+
+static inline void nfs_netfs_get(struct nfs_netfs_io_data *netfs)
+{
+ refcount_inc(&netfs->refcount);
+}
+
+static inline void nfs_netfs_put(struct nfs_netfs_io_data *netfs)
+{
+ ssize_t final_len;
+
+ /* Only the last RPC completion should call netfs_subreq_terminated() */
+ if (!refcount_dec_and_test(&netfs->refcount))
+ return;
+
+ /*
+ * The NFS pageio interface may read a complete page, even when netfs
+ * only asked for a partial page. Specifically, this may be seen when
+ * one thread is truncating a file while another one is reading the last
+ * page of the file.
+ * Correct the final length here to be no larger than the netfs subrequest
+ * length, and prevent netfs from complain throwing "Subreq overread".
+ */
+ final_len = min_t(s64, netfs->sreq->len, atomic64_read(&netfs->transferred));
+ netfs_subreq_terminated(netfs->sreq, netfs->error ?: final_len, false);
+ kfree(netfs);
+}
+static inline void nfs_netfs_inode_init(struct nfs_inode *nfsi)
+{
+ netfs_inode_init(&nfsi->netfs, &nfs_netfs_ops);
+}
+extern void nfs_netfs_initiate_read(struct nfs_pgio_header *hdr);
+extern void nfs_netfs_read_completion(struct nfs_pgio_header *hdr);
+extern void nfs_netfs_readpage_release(struct nfs_page *req);
+
/*
* fscache.c
*/
@@ -44,9 +96,8 @@ extern void nfs_fscache_init_inode(struct inode *);
extern void nfs_fscache_clear_inode(struct inode *);
extern void nfs_fscache_open_file(struct inode *, struct file *);
extern void nfs_fscache_release_file(struct inode *, struct file *);
-
-extern int __nfs_fscache_read_page(struct inode *, struct page *);
-extern void __nfs_fscache_write_page(struct inode *, struct page *);
+extern int nfs_netfs_readahead(struct readahead_control *ractl);
+extern int nfs_netfs_read_folio(struct file *file, struct folio *folio);
static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp)
{
@@ -54,34 +105,11 @@ static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp)
if (current_is_kswapd() || !(gfp & __GFP_FS))
return false;
folio_wait_fscache(folio);
- fscache_note_page_release(netfs_i_cookie(&NFS_I(folio->mapping->host)->netfs));
- nfs_inc_fscache_stats(folio->mapping->host,
- NFSIOS_FSCACHE_PAGES_UNCACHED);
}
+ fscache_note_page_release(netfs_i_cookie(&NFS_I(folio->mapping->host)->netfs));
return true;
}
-/*
- * Retrieve a page from an inode data storage object.
- */
-static inline int nfs_fscache_read_page(struct inode *inode, struct page *page)
-{
- if (netfs_inode(inode)->cache)
- return __nfs_fscache_read_page(inode, page);
- return -ENOBUFS;
-}
-
-/*
- * Store a page newly fetched from the server in an inode data storage object
- * in the cache.
- */
-static inline void nfs_fscache_write_page(struct inode *inode,
- struct page *page)
-{
- if (netfs_inode(inode)->cache)
- __nfs_fscache_write_page(inode, page);
-}
-
static inline void nfs_fscache_update_auxdata(struct nfs_fscache_inode_auxdata *auxdata,
struct inode *inode)
{
@@ -118,6 +146,13 @@ static inline const char *nfs_server_fscache_state(struct nfs_server *server)
}
#else /* CONFIG_NFS_FSCACHE */
+static inline void nfs_netfs_inode_init(struct nfs_inode *nfsi) {}
+static inline void nfs_netfs_initiate_read(struct nfs_pgio_header *hdr) {}
+static inline void nfs_netfs_read_completion(struct nfs_pgio_header *hdr) {}
+static inline void nfs_netfs_readpage_release(struct nfs_page *req)
+{
+ unlock_page(req->wb_page);
+}
static inline void nfs_fscache_release_super_cookie(struct super_block *sb) {}
static inline void nfs_fscache_init_inode(struct inode *inode) {}
@@ -125,16 +160,19 @@ static inline void nfs_fscache_clear_inode(struct inode *inode) {}
static inline void nfs_fscache_open_file(struct inode *inode,
struct file *filp) {}
static inline void nfs_fscache_release_file(struct inode *inode, struct file *file) {}
-
-static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp)
+static inline int nfs_netfs_readahead(struct readahead_control *ractl)
{
- return true; /* may release folio */
+ return -ENOBUFS;
}
-static inline int nfs_fscache_read_page(struct inode *inode, struct page *page)
+static inline int nfs_netfs_read_folio(struct file *file, struct folio *folio)
{
return -ENOBUFS;
}
-static inline void nfs_fscache_write_page(struct inode *inode, struct page *page) {}
+
+static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp)
+{
+ return true; /* may release folio */
+}
static inline void nfs_fscache_invalidate(struct inode *inode, int flags) {}
static inline const char *nfs_server_fscache_state(struct nfs_server *server)
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index aa2aec785ab5..b36a02b932e8 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -2249,6 +2249,8 @@ struct inode *nfs_alloc_inode(struct super_block *sb)
#ifdef CONFIG_NFS_V4_2
nfsi->xattr_cache = NULL;
#endif
+ nfs_netfs_inode_init(nfsi);
+
return VFS_I(nfsi);
}
EXPORT_SYMBOL_GPL(nfs_alloc_inode);
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 4d240ac4430f..e9c0e4abc954 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -453,6 +453,10 @@ extern void nfs_sb_deactive(struct super_block *sb);
extern int nfs_client_for_each_server(struct nfs_client *clp,
int (*fn)(struct nfs_server *, void *),
void *data);
+#ifdef CONFIG_NFS_FSCACHE
+extern const struct netfs_request_ops nfs_netfs_ops;
+#endif
+
/* io.c */
extern void nfs_start_io_read(struct inode *inode);
extern void nfs_end_io_read(struct inode *inode);
@@ -482,9 +486,14 @@ extern int nfs4_get_rootfh(struct nfs_server *server, struct nfs_fh *mntfh, bool
struct nfs_pgio_completion_ops;
/* read.c */
+extern const struct nfs_pgio_completion_ops nfs_async_read_completion_ops;
extern void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
struct inode *inode, bool force_mds,
const struct nfs_pgio_completion_ops *compl_ops);
+extern int nfs_pageio_add_page(struct nfs_pageio_descriptor *pgio,
+ struct nfs_open_context *ctx,
+ struct page *page);
+extern void nfs_pageio_complete_read(struct nfs_pageio_descriptor *pgio);
extern void nfs_read_prepare(struct rpc_task *task, void *calldata);
extern void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio);
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 317cedfa52bf..e28754476d1b 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -25,6 +25,7 @@
#include "internal.h"
#include "pnfs.h"
#include "nfstrace.h"
+#include "fscache.h"
#define NFSDBG_FACILITY NFSDBG_PAGECACHE
@@ -68,6 +69,10 @@ void nfs_pgheader_init(struct nfs_pageio_descriptor *desc,
hdr->good_bytes = mirror->pg_count;
hdr->io_completion = desc->pg_io_completion;
hdr->dreq = desc->pg_dreq;
+#ifdef CONFIG_NFS_FSCACHE
+ if (desc->pg_netfs)
+ hdr->netfs = desc->pg_netfs;
+#endif
hdr->release = release;
hdr->completion_ops = desc->pg_completion_ops;
if (hdr->completion_ops->init_hdr)
@@ -846,6 +851,9 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
desc->pg_lseg = NULL;
desc->pg_io_completion = NULL;
desc->pg_dreq = NULL;
+#ifdef CONFIG_NFS_FSCACHE
+ desc->pg_netfs = NULL;
+#endif
desc->pg_bsize = bsize;
desc->pg_mirror_count = 1;
@@ -940,6 +948,7 @@ int nfs_generic_pgio(struct nfs_pageio_descriptor *desc,
/* Set up the argument struct */
nfs_pgio_rpcsetup(hdr, mirror->pg_count, desc->pg_ioflags, &cinfo);
desc->pg_rpc_callops = &nfs_pgio_common_ops;
+
return 0;
}
EXPORT_SYMBOL_GPL(nfs_generic_pgio);
@@ -1360,6 +1369,9 @@ int nfs_pageio_resend(struct nfs_pageio_descriptor *desc,
desc->pg_io_completion = hdr->io_completion;
desc->pg_dreq = hdr->dreq;
+#ifdef CONFIG_NFS_FSCACHE
+ desc->pg_netfs = hdr->netfs;
+#endif
list_splice_init(&hdr->pages, &pages);
while (!list_empty(&pages)) {
struct nfs_page *req = nfs_list_entry(pages.next);
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 525e82ea9a9e..fdfebca017fc 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -30,7 +30,7 @@
#define NFSDBG_FACILITY NFSDBG_PAGECACHE
-static const struct nfs_pgio_completion_ops nfs_async_read_completion_ops;
+const struct nfs_pgio_completion_ops nfs_async_read_completion_ops;
static const struct nfs_rw_ops nfs_rw_read_ops;
static struct kmem_cache *nfs_rdata_cachep;
@@ -74,7 +74,7 @@ void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
}
EXPORT_SYMBOL_GPL(nfs_pageio_init_read);
-static void nfs_pageio_complete_read(struct nfs_pageio_descriptor *pgio)
+void nfs_pageio_complete_read(struct nfs_pageio_descriptor *pgio)
{
struct nfs_pgio_mirror *pgm;
unsigned long npages;
@@ -110,20 +110,13 @@ EXPORT_SYMBOL_GPL(nfs_pageio_reset_read_mds);
static void nfs_readpage_release(struct nfs_page *req, int error)
{
- struct inode *inode = d_inode(nfs_req_openctx(req)->dentry);
struct page *page = req->wb_page;
- dprintk("NFS: read done (%s/%llu %d@%lld)\n", inode->i_sb->s_id,
- (unsigned long long)NFS_FILEID(inode), req->wb_bytes,
- (long long)req_offset(req));
-
if (nfs_error_is_fatal_on_server(error) && error != -ETIMEDOUT)
SetPageError(page);
- if (nfs_page_group_sync_on_bit(req, PG_UNLOCKPAGE)) {
- if (PageUptodate(page))
- nfs_fscache_write_page(inode, page);
- unlock_page(page);
- }
+ if (nfs_page_group_sync_on_bit(req, PG_UNLOCKPAGE))
+ nfs_netfs_readpage_release(req);
+
nfs_release_request(req);
}
@@ -177,6 +170,8 @@ static void nfs_read_completion(struct nfs_pgio_header *hdr)
nfs_list_remove_request(req);
nfs_readpage_release(req, error);
}
+ nfs_netfs_read_completion(hdr);
+
out:
hdr->release(hdr);
}
@@ -187,6 +182,7 @@ static void nfs_initiate_read(struct nfs_pgio_header *hdr,
struct rpc_task_setup *task_setup_data, int how)
{
rpc_ops->read_setup(hdr, msg);
+ nfs_netfs_initiate_read(hdr);
trace_nfs_initiate_read(hdr);
}
@@ -202,7 +198,7 @@ nfs_async_read_error(struct list_head *head, int error)
}
}
-static const struct nfs_pgio_completion_ops nfs_async_read_completion_ops = {
+const struct nfs_pgio_completion_ops nfs_async_read_completion_ops = {
.error_cleanup = nfs_async_read_error,
.completion = nfs_read_completion,
};
@@ -294,12 +290,6 @@ nfs_pageio_add_page(struct nfs_pageio_descriptor *pgio,
aligned_len = min_t(unsigned int, ALIGN(len, rsize), PAGE_SIZE);
- if (!IS_SYNC(page->mapping->host)) {
- error = nfs_fscache_read_page(page->mapping->host, page);
- if (error == 0)
- goto out_unlock;
- }
-
new = nfs_create_request(ctx, page, 0, aligned_len);
if (IS_ERR(new))
goto out_error;
@@ -315,8 +305,6 @@ nfs_pageio_add_page(struct nfs_pageio_descriptor *pgio,
return 0;
out_error:
error = PTR_ERR(new);
-out_unlock:
- unlock_page(page);
out:
return error;
}
@@ -355,6 +343,10 @@ int nfs_read_folio(struct file *file, struct folio *folio)
if (NFS_STALE(inode))
goto out_unlock;
+ ret = nfs_netfs_read_folio(file, folio);
+ if (!ret)
+ goto out;
+
if (file == NULL) {
ret = -EBADF;
ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
@@ -368,8 +360,10 @@ int nfs_read_folio(struct file *file, struct folio *folio)
&nfs_async_read_completion_ops);
ret = nfs_pageio_add_page(&pgio, ctx, page);
- if (ret)
- goto out;
+ if (ret) {
+ put_nfs_open_context(ctx);
+ goto out_unlock;
+ }
nfs_pageio_complete_read(&pgio);
ret = pgio.pg_error < 0 ? pgio.pg_error : 0;
@@ -378,12 +372,12 @@ int nfs_read_folio(struct file *file, struct folio *folio)
if (!PageUptodate(page) && !ret)
ret = xchg(&ctx->error, 0);
}
-out:
put_nfs_open_context(ctx);
- trace_nfs_aop_readpage_done(inode, page, ret);
- return ret;
+ goto out;
+
out_unlock:
unlock_page(page);
+out:
trace_nfs_aop_readpage_done(inode, page, ret);
return ret;
}
@@ -405,6 +399,10 @@ void nfs_readahead(struct readahead_control *ractl)
if (NFS_STALE(inode))
goto out;
+ ret = nfs_netfs_readahead(ractl);
+ if (!ret)
+ goto out;
+
if (file == NULL) {
ret = -EBADF;
ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h
index ba7e2e4b0926..8eeb16d9bacd 100644
--- a/include/linux/nfs_page.h
+++ b/include/linux/nfs_page.h
@@ -101,6 +101,9 @@ struct nfs_pageio_descriptor {
struct pnfs_layout_segment *pg_lseg;
struct nfs_io_completion *pg_io_completion;
struct nfs_direct_req *pg_dreq;
+#ifdef CONFIG_NFS_FSCACHE
+ void *pg_netfs;
+#endif
unsigned int pg_bsize; /* default bsize for mirrors */
u32 pg_mirror_count;
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index e86cf6642d21..e196ef595908 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1619,6 +1619,9 @@ struct nfs_pgio_header {
const struct nfs_rw_ops *rw_ops;
struct nfs_io_completion *io_completion;
struct nfs_direct_req *dreq;
+#ifdef CONFIG_NFS_FSCACHE
+ void *netfs;
+#endif
int pnfs_error;
int error; /* merge with pnfs_error */
--
2.31.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH v8 4/5] NFS: Remove all NFSIOS_FSCACHE counters due to conversion to netfs API
2022-09-22 13:58 [PATCH v8 0/3] Convert NFS with fscache to the netfs API Dave Wysochanski
` (2 preceding siblings ...)
2022-09-22 13:58 ` [PATCH v8 3/5] NFS: Convert buffered read paths to use netfs when fscache is enabled Dave Wysochanski
@ 2022-09-22 13:58 ` Dave Wysochanski
2022-09-22 13:58 ` [PATCH v8 5/5] NFS: Remove fscache specific trace points and NFS_INO_FSCACHE bit Dave Wysochanski
2022-09-28 10:10 ` [PATCH v8 0/3] Convert NFS with fscache to the netfs API Jeff Layton
5 siblings, 0 replies; 8+ messages in thread
From: Dave Wysochanski @ 2022-09-22 13:58 UTC (permalink / raw)
To: Anna Schumaker, Trond Myklebust, David Howells
Cc: linux-nfs, linux-cachefs, Benjamin Maynard, Daire Byrne
The old NFSIOS_FSCACHE counters are no longer accurate or useful with
the conversion to the new netfs API. The new API does not have a page
based interface, and so the counters in nfs_stat_fscachecounters are
no longer obtainable. The new netfs the API has extensive statistics
inside /proc/fs/fscache/stats so we no longer need NFS specific fscache
stats.
Note this also removes the 'fsc:' line from /proc/self/mountstats so
it will be a user-visible change.
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
---
fs/nfs/iostat.h | 17 -----------------
fs/nfs/super.c | 11 -----------
include/linux/nfs_iostat.h | 12 ------------
3 files changed, 40 deletions(-)
diff --git a/fs/nfs/iostat.h b/fs/nfs/iostat.h
index 2ddaab1ac653..5aa776b5a3e7 100644
--- a/fs/nfs/iostat.h
+++ b/fs/nfs/iostat.h
@@ -17,9 +17,6 @@
struct nfs_iostats {
unsigned long long bytes[__NFSIOS_BYTESMAX];
-#ifdef CONFIG_NFS_FSCACHE
- unsigned long long fscache[__NFSIOS_FSCACHEMAX];
-#endif
unsigned long events[__NFSIOS_COUNTSMAX];
} ____cacheline_aligned;
@@ -49,20 +46,6 @@ static inline void nfs_add_stats(const struct inode *inode,
nfs_add_server_stats(NFS_SERVER(inode), stat, addend);
}
-#ifdef CONFIG_NFS_FSCACHE
-static inline void nfs_add_fscache_stats(struct inode *inode,
- enum nfs_stat_fscachecounters stat,
- long addend)
-{
- this_cpu_add(NFS_SERVER(inode)->io_stats->fscache[stat], addend);
-}
-static inline void nfs_inc_fscache_stats(struct inode *inode,
- enum nfs_stat_fscachecounters stat)
-{
- this_cpu_inc(NFS_SERVER(inode)->io_stats->fscache[stat]);
-}
-#endif
-
static inline struct nfs_iostats __percpu *nfs_alloc_iostats(void)
{
return alloc_percpu(struct nfs_iostats);
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index ee66ffdb985e..302148258ff1 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -692,10 +692,6 @@ int nfs_show_stats(struct seq_file *m, struct dentry *root)
totals.events[i] += stats->events[i];
for (i = 0; i < __NFSIOS_BYTESMAX; i++)
totals.bytes[i] += stats->bytes[i];
-#ifdef CONFIG_NFS_FSCACHE
- for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
- totals.fscache[i] += stats->fscache[i];
-#endif
preempt_enable();
}
@@ -706,13 +702,6 @@ int nfs_show_stats(struct seq_file *m, struct dentry *root)
seq_puts(m, "\n\tbytes:\t");
for (i = 0; i < __NFSIOS_BYTESMAX; i++)
seq_printf(m, "%Lu ", totals.bytes[i]);
-#ifdef CONFIG_NFS_FSCACHE
- if (nfss->options & NFS_OPTION_FSCACHE) {
- seq_puts(m, "\n\tfsc:\t");
- for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
- seq_printf(m, "%Lu ", totals.fscache[i]);
- }
-#endif
seq_putc(m, '\n');
rpc_clnt_show_stats(m, nfss->client);
diff --git a/include/linux/nfs_iostat.h b/include/linux/nfs_iostat.h
index 027874c36c88..8d946089d151 100644
--- a/include/linux/nfs_iostat.h
+++ b/include/linux/nfs_iostat.h
@@ -119,16 +119,4 @@ enum nfs_stat_eventcounters {
__NFSIOS_COUNTSMAX,
};
-/*
- * NFS local caching servicing counters
- */
-enum nfs_stat_fscachecounters {
- NFSIOS_FSCACHE_PAGES_READ_OK,
- NFSIOS_FSCACHE_PAGES_READ_FAIL,
- NFSIOS_FSCACHE_PAGES_WRITTEN_OK,
- NFSIOS_FSCACHE_PAGES_WRITTEN_FAIL,
- NFSIOS_FSCACHE_PAGES_UNCACHED,
- __NFSIOS_FSCACHEMAX,
-};
-
#endif /* _LINUX_NFS_IOSTAT */
--
2.31.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH v8 5/5] NFS: Remove fscache specific trace points and NFS_INO_FSCACHE bit
2022-09-22 13:58 [PATCH v8 0/3] Convert NFS with fscache to the netfs API Dave Wysochanski
` (3 preceding siblings ...)
2022-09-22 13:58 ` [PATCH v8 4/5] NFS: Remove all NFSIOS_FSCACHE counters due to conversion to netfs API Dave Wysochanski
@ 2022-09-22 13:58 ` Dave Wysochanski
2022-09-28 10:10 ` [PATCH v8 0/3] Convert NFS with fscache to the netfs API Jeff Layton
5 siblings, 0 replies; 8+ messages in thread
From: Dave Wysochanski @ 2022-09-22 13:58 UTC (permalink / raw)
To: Anna Schumaker, Trond Myklebust, David Howells
Cc: linux-nfs, linux-cachefs, Benjamin Maynard, Daire Byrne
The NFS specific trace points are no longer needed as tracing is well
covered by netfs and fscache.
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
---
fs/nfs/nfstrace.h | 91 ------------------------------------------
include/linux/nfs_fs.h | 1 -
2 files changed, 92 deletions(-)
diff --git a/fs/nfs/nfstrace.h b/fs/nfs/nfstrace.h
index 8c6cc58679ff..6b56abe49ec2 100644
--- a/fs/nfs/nfstrace.h
+++ b/fs/nfs/nfstrace.h
@@ -39,7 +39,6 @@
{ BIT(NFS_INO_STALE), "STALE" }, \
{ BIT(NFS_INO_ACL_LRU_SET), "ACL_LRU_SET" }, \
{ BIT(NFS_INO_INVALIDATING), "INVALIDATING" }, \
- { BIT(NFS_INO_FSCACHE), "FSCACHE" }, \
{ BIT(NFS_INO_LAYOUTCOMMIT), "NEED_LAYOUTCOMMIT" }, \
{ BIT(NFS_INO_LAYOUTCOMMITTING), "LAYOUTCOMMIT" }, \
{ BIT(NFS_INO_LAYOUTSTATS), "LAYOUTSTATS" }, \
@@ -1213,96 +1212,6 @@ TRACE_EVENT(nfs_readpage_short,
)
);
-DECLARE_EVENT_CLASS(nfs_fscache_page_event,
- TP_PROTO(
- const struct inode *inode,
- struct page *page
- ),
-
- TP_ARGS(inode, page),
-
- TP_STRUCT__entry(
- __field(dev_t, dev)
- __field(u32, fhandle)
- __field(u64, fileid)
- __field(loff_t, offset)
- ),
-
- TP_fast_assign(
- const struct nfs_inode *nfsi = NFS_I(inode);
- const struct nfs_fh *fh = &nfsi->fh;
-
- __entry->offset = page_index(page) << PAGE_SHIFT;
- __entry->dev = inode->i_sb->s_dev;
- __entry->fileid = nfsi->fileid;
- __entry->fhandle = nfs_fhandle_hash(fh);
- ),
-
- TP_printk(
- "fileid=%02x:%02x:%llu fhandle=0x%08x "
- "offset=%lld",
- MAJOR(__entry->dev), MINOR(__entry->dev),
- (unsigned long long)__entry->fileid,
- __entry->fhandle,
- (long long)__entry->offset
- )
-);
-DECLARE_EVENT_CLASS(nfs_fscache_page_event_done,
- TP_PROTO(
- const struct inode *inode,
- struct page *page,
- int error
- ),
-
- TP_ARGS(inode, page, error),
-
- TP_STRUCT__entry(
- __field(int, error)
- __field(dev_t, dev)
- __field(u32, fhandle)
- __field(u64, fileid)
- __field(loff_t, offset)
- ),
-
- TP_fast_assign(
- const struct nfs_inode *nfsi = NFS_I(inode);
- const struct nfs_fh *fh = &nfsi->fh;
-
- __entry->offset = page_index(page) << PAGE_SHIFT;
- __entry->dev = inode->i_sb->s_dev;
- __entry->fileid = nfsi->fileid;
- __entry->fhandle = nfs_fhandle_hash(fh);
- __entry->error = error;
- ),
-
- TP_printk(
- "fileid=%02x:%02x:%llu fhandle=0x%08x "
- "offset=%lld error=%d",
- MAJOR(__entry->dev), MINOR(__entry->dev),
- (unsigned long long)__entry->fileid,
- __entry->fhandle,
- (long long)__entry->offset, __entry->error
- )
-);
-#define DEFINE_NFS_FSCACHE_PAGE_EVENT(name) \
- DEFINE_EVENT(nfs_fscache_page_event, name, \
- TP_PROTO( \
- const struct inode *inode, \
- struct page *page \
- ), \
- TP_ARGS(inode, page))
-#define DEFINE_NFS_FSCACHE_PAGE_EVENT_DONE(name) \
- DEFINE_EVENT(nfs_fscache_page_event_done, name, \
- TP_PROTO( \
- const struct inode *inode, \
- struct page *page, \
- int error \
- ), \
- TP_ARGS(inode, page, error))
-DEFINE_NFS_FSCACHE_PAGE_EVENT(nfs_fscache_read_page);
-DEFINE_NFS_FSCACHE_PAGE_EVENT_DONE(nfs_fscache_read_page_exit);
-DEFINE_NFS_FSCACHE_PAGE_EVENT(nfs_fscache_write_page);
-DEFINE_NFS_FSCACHE_PAGE_EVENT_DONE(nfs_fscache_write_page_exit);
TRACE_EVENT(nfs_pgio_error,
TP_PROTO(
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index a1c402e26abf..0150a5673419 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -281,7 +281,6 @@ struct nfs4_copy_state {
#define NFS_INO_ACL_LRU_SET (2) /* Inode is on the LRU list */
#define NFS_INO_INVALIDATING (3) /* inode is being invalidated */
#define NFS_INO_PRESERVE_UNLINKED (4) /* preserve file if removed while open */
-#define NFS_INO_FSCACHE (5) /* inode can be cached by FS-Cache */
#define NFS_INO_LAYOUTCOMMIT (9) /* layoutcommit required */
#define NFS_INO_LAYOUTCOMMITTING (10) /* layoutcommit inflight */
#define NFS_INO_LAYOUTSTATS (11) /* layoutstats inflight */
--
2.31.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH v8 3/5] NFS: Convert buffered read paths to use netfs when fscache is enabled
2022-09-22 13:58 ` [PATCH v8 3/5] NFS: Convert buffered read paths to use netfs when fscache is enabled Dave Wysochanski
@ 2022-09-28 10:07 ` Jeff Layton
0 siblings, 0 replies; 8+ messages in thread
From: Jeff Layton @ 2022-09-28 10:07 UTC (permalink / raw)
To: Dave Wysochanski, Anna Schumaker, Trond Myklebust, David Howells
Cc: linux-nfs, linux-cachefs, Benjamin Maynard, Daire Byrne
On Thu, 2022-09-22 at 09:58 -0400, Dave Wysochanski wrote:
> Convert the NFS buffered read code paths to corresponding netfs APIs,
> but only when fscache is configured and enabled.
>
> The netfs API defines struct netfs_request_ops which must be filled
> in by the network filesystem. For NFS, we only need to define 5 of
> the functions, the main one being the issue_read() function.
> The issue_read() function is called by the netfs layer when a read
> cannot be fulfilled locally, and must be sent to the server (either
> the cache is not active, or it is active but the data is not available).
> Once the read from the server is complete, netfs requires a call to
> netfs_subreq_terminated() which conveys either how many bytes were read
> successfully, or an error. Note that issue_read() is called with a
> structure, netfs_io_subrequest, which defines the IO requested, and
> contains a start and a length (both in bytes), and assumes the underlying
> netfs will return a either an error on the whole region, or the number
> of bytes successfully read.
>
> The NFS IO path is page based and the main APIs are the pgio APIs defined
> in pagelist.c. For the pgio APIs, there is no way for the caller to
> know how many RPCs will be sent and how the pages will be broken up
> into underlying RPCs, each of which will have their own completion and
> return code. In contrast, netfs is subrequest based, a single
> subrequest may contain multiple pages, and a single subrequest is
> initiated with issue_read() and terminated with netfs_subreq_terminated().
> Thus, to utilze the netfs APIs, NFS needs some way to accommodate
> the netfs API requirement on the single response to the whole
> subrequest, while also minimizing disruptive changes to the NFS
> pgio layer.
>
> The approach taken with this patch is to allocate a small structure
> for each nfs_netfs_issue_read() call, store the final error and number
> of bytes successfully transferred in the structure, and update these values
> as each RPC completes. The refcount on the structure is used as a marker
> for the last RPC completion, is incremented in nfs_netfs_read_initiate(),
> and decremented inside nfs_netfs_read_completion(), when a nfs_pgio_header
> contains a valid pointer to the data. On the final put (which signals
> the final outstanding RPC is complete) in nfs_netfs_read_completion(),
> call netfs_subreq_terminated() with either the final error value (if
> one or more READs complete with an error) or the number of bytes
> successfully transferred (if all RPCs complete successfully). Note
> that when all RPCs complete successfully, the number of bytes transferred
> is capped to the length of the subrequest. Capping the transferred length
> to the subrequest length prevents "Subreq overread" warnings from netfs.
> This is due to the "aligned_len" in nfs_pageio_add_page(), and the
> corner case where NFS requests a full page at the end of the file,
> even when i_size reflects only a partial page (NFS overread).
>
> Suggested-by: Jeff Layton <jlayton@kernel.org>
> Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
> ---
> fs/nfs/fscache.c | 232 +++++++++++++++++++++++----------------
> fs/nfs/fscache.h | 102 +++++++++++------
> fs/nfs/inode.c | 2 +
> fs/nfs/internal.h | 9 ++
> fs/nfs/pagelist.c | 12 ++
> fs/nfs/read.c | 50 ++++-----
> include/linux/nfs_page.h | 3 +
> include/linux/nfs_xdr.h | 3 +
> 8 files changed, 261 insertions(+), 152 deletions(-)
>
> diff --git a/fs/nfs/fscache.c b/fs/nfs/fscache.c
> index a6fc1c8b6644..58462f6579d6 100644
> --- a/fs/nfs/fscache.c
> +++ b/fs/nfs/fscache.c
> @@ -15,6 +15,9 @@
> #include <linux/seq_file.h>
> #include <linux/slab.h>
> #include <linux/iversion.h>
> +#include <linux/xarray.h>
> +#include <linux/fscache.h>
> +#include <linux/netfs.h>
>
> #include "internal.h"
> #include "iostat.h"
> @@ -184,7 +187,7 @@ void nfs_fscache_init_inode(struct inode *inode)
> */
> void nfs_fscache_clear_inode(struct inode *inode)
> {
> - fscache_relinquish_cookie(netfs_i_cookie(&NFS_I(inode)->netfs), false);
> + fscache_relinquish_cookie(netfs_i_cookie(netfs_inode(inode)), false);
> netfs_inode(inode)->cache = NULL;
> }
>
> @@ -210,7 +213,7 @@ void nfs_fscache_clear_inode(struct inode *inode)
> void nfs_fscache_open_file(struct inode *inode, struct file *filp)
> {
> struct nfs_fscache_inode_auxdata auxdata;
> - struct fscache_cookie *cookie = netfs_i_cookie(&NFS_I(inode)->netfs);
> + struct fscache_cookie *cookie = netfs_i_cookie(netfs_inode(inode));
> bool open_for_write = inode_is_open_for_write(inode);
>
> if (!fscache_cookie_valid(cookie))
> @@ -228,119 +231,160 @@ EXPORT_SYMBOL_GPL(nfs_fscache_open_file);
> void nfs_fscache_release_file(struct inode *inode, struct file *filp)
> {
> struct nfs_fscache_inode_auxdata auxdata;
> - struct fscache_cookie *cookie = netfs_i_cookie(&NFS_I(inode)->netfs);
> + struct fscache_cookie *cookie = netfs_i_cookie(netfs_inode(inode));
> loff_t i_size = i_size_read(inode);
>
> nfs_fscache_update_auxdata(&auxdata, inode);
> fscache_unuse_cookie(cookie, &auxdata, &i_size);
> }
>
> -/*
> - * Fallback page reading interface.
> - */
> -static int fscache_fallback_read_page(struct inode *inode, struct page *page)
> +int nfs_netfs_read_folio(struct file *file, struct folio *folio)
> {
> - struct netfs_cache_resources cres;
> - struct fscache_cookie *cookie = netfs_i_cookie(&NFS_I(inode)->netfs);
> - struct iov_iter iter;
> - struct bio_vec bvec[1];
> - int ret;
> -
> - memset(&cres, 0, sizeof(cres));
> - bvec[0].bv_page = page;
> - bvec[0].bv_offset = 0;
> - bvec[0].bv_len = PAGE_SIZE;
> - iov_iter_bvec(&iter, READ, bvec, ARRAY_SIZE(bvec), PAGE_SIZE);
> -
> - ret = fscache_begin_read_operation(&cres, cookie);
> - if (ret < 0)
> - return ret;
> -
> - ret = fscache_read(&cres, page_offset(page), &iter, NETFS_READ_HOLE_FAIL,
> - NULL, NULL);
> - fscache_end_operation(&cres);
> - return ret;
> + if (!netfs_inode(folio_inode(folio))->cache)
> + return -ENOBUFS;
> +
> + return netfs_read_folio(file, folio);
> }
>
> -/*
> - * Fallback page writing interface.
> - */
> -static int fscache_fallback_write_page(struct inode *inode, struct page *page,
> - bool no_space_allocated_yet)
> +int nfs_netfs_readahead(struct readahead_control *ractl)
> {
> - struct netfs_cache_resources cres;
> - struct fscache_cookie *cookie = netfs_i_cookie(&NFS_I(inode)->netfs);
> - struct iov_iter iter;
> - struct bio_vec bvec[1];
> - loff_t start = page_offset(page);
> - size_t len = PAGE_SIZE;
> - int ret;
> -
> - memset(&cres, 0, sizeof(cres));
> - bvec[0].bv_page = page;
> - bvec[0].bv_offset = 0;
> - bvec[0].bv_len = PAGE_SIZE;
> - iov_iter_bvec(&iter, WRITE, bvec, ARRAY_SIZE(bvec), PAGE_SIZE);
> -
> - ret = fscache_begin_write_operation(&cres, cookie);
> - if (ret < 0)
> - return ret;
> -
> - ret = cres.ops->prepare_write(&cres, &start, &len, i_size_read(inode),
> - no_space_allocated_yet);
> - if (ret == 0)
> - ret = fscache_write(&cres, page_offset(page), &iter, NULL, NULL);
> - fscache_end_operation(&cres);
> - return ret;
> + struct inode *inode = ractl->mapping->host;
> +
> + if (!netfs_inode(inode)->cache)
> + return -ENOBUFS;
> +
> + netfs_readahead(ractl);
> + return 0;
> }
>
> -/*
> - * Retrieve a page from fscache
> - */
> -int __nfs_fscache_read_page(struct inode *inode, struct page *page)
> +atomic_t nfs_netfs_debug_id;
> +static int nfs_netfs_init_request(struct netfs_io_request *rreq, struct file *file)
> {
> - int ret;
> + rreq->netfs_priv = get_nfs_open_context(nfs_file_open_context(file));
> + rreq->debug_id = atomic_inc_return(&nfs_netfs_debug_id);
>
> - trace_nfs_fscache_read_page(inode, page);
> - if (PageChecked(page)) {
> - ClearPageChecked(page);
> - ret = 1;
> - goto out;
> - }
> + return 0;
> +}
>
> - ret = fscache_fallback_read_page(inode, page);
> - if (ret < 0) {
> - nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_FAIL);
> - SetPageChecked(page);
> - goto out;
> - }
> +static void nfs_netfs_free_request(struct netfs_io_request *rreq)
> +{
> + put_nfs_open_context(rreq->netfs_priv);
> +}
>
> - /* Read completed synchronously */
> - nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_OK);
> - SetPageUptodate(page);
> - ret = 0;
> -out:
> - trace_nfs_fscache_read_page_exit(inode, page, ret);
> - return ret;
> +static inline int nfs_netfs_begin_cache_operation(struct netfs_io_request *rreq)
> +{
> + return fscache_begin_read_operation(&rreq->cache_resources,
> + netfs_i_cookie(netfs_inode(rreq->inode)));
> }
>
> -/*
> - * Store a newly fetched page in fscache. We can be certain there's no page
> - * stored in the cache as yet otherwise we would've read it from there.
> - */
> -void __nfs_fscache_write_page(struct inode *inode, struct page *page)
> +static struct nfs_netfs_io_data *nfs_netfs_alloc(struct netfs_io_subrequest *sreq)
> {
> - int ret;
> + struct nfs_netfs_io_data *netfs;
> +
> + netfs = kzalloc(sizeof(*netfs), GFP_KERNEL_ACCOUNT);
> + if (!netfs)
> + return NULL;
> + netfs->sreq = sreq;
> + refcount_set(&netfs->refcount, 1);
> + return netfs;
> +}
>
> - trace_nfs_fscache_write_page(inode, page);
> +static bool nfs_netfs_clamp_length(struct netfs_io_subrequest *sreq)
> +{
> + size_t rsize = NFS_SB(sreq->rreq->inode->i_sb)->rsize;
>
> - ret = fscache_fallback_write_page(inode, page, true);
> + sreq->len = min(sreq->len, rsize);
> + return true;
> +}
>
> - if (ret != 0) {
> - nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_WRITTEN_FAIL);
> - nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_UNCACHED);
> - } else {
> - nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_WRITTEN_OK);
> +static void nfs_netfs_issue_read(struct netfs_io_subrequest *sreq)
> +{
> + struct nfs_netfs_io_data *netfs;
> + struct nfs_pageio_descriptor pgio;
> + struct inode *inode = sreq->rreq->inode;
> + struct nfs_open_context *ctx = sreq->rreq->netfs_priv;
> + struct page *page;
> + int err;
> + pgoff_t start = (sreq->start + sreq->transferred) >> PAGE_SHIFT;
> + pgoff_t last = ((sreq->start + sreq->len -
> + sreq->transferred - 1) >> PAGE_SHIFT);
> + XA_STATE(xas, &sreq->rreq->mapping->i_pages, start);
> +
> + nfs_pageio_init_read(&pgio, inode, false,
> + &nfs_async_read_completion_ops);
> +
> + netfs = nfs_netfs_alloc(sreq);
> + if (!netfs)
> + return netfs_subreq_terminated(sreq, -ENOMEM, false);
> +
> + pgio.pg_netfs = netfs; /* used in completion */
> +
> + xas_lock(&xas);
> + xas_for_each(&xas, page, last) {
> + /* nfs_pageio_add_page() may schedule() due to pNFS layout and other RPCs */
> + xas_pause(&xas);
> + xas_unlock(&xas);
> + err = nfs_pageio_add_page(&pgio, ctx, page);
> + if (err < 0) {
> + netfs->error = err;
> + goto out;
> + }
> + xas_lock(&xas);
> }
> - trace_nfs_fscache_write_page_exit(inode, page, ret);
> + xas_unlock(&xas);
> +out:
> + nfs_pageio_complete_read(&pgio);
> + nfs_netfs_put(netfs);
> +}
> +
> +void nfs_netfs_initiate_read(struct nfs_pgio_header *hdr)
> +{
> + struct nfs_netfs_io_data *netfs = hdr->netfs;
> +
> + if (!netfs)
> + return;
> +
> + nfs_netfs_get(netfs);
> +}
> +
> +void nfs_netfs_readpage_release(struct nfs_page *req)
> +{
> + struct inode *inode = d_inode(nfs_req_openctx(req)->dentry);
> +
> + /*
> + * If fscache is enabled, netfs will unlock pages.
> + */
> + if (netfs_inode(inode)->cache)
> + return;
> +
> + unlock_page(req->wb_page);
> }
> +
> +void nfs_netfs_read_completion(struct nfs_pgio_header *hdr)
> +{
> + struct nfs_netfs_io_data *netfs = hdr->netfs;
> + struct netfs_io_subrequest *sreq;
> +
> + if (!netfs)
> + return;
> +
> + sreq = netfs->sreq;
> + if (test_bit(NFS_IOHDR_EOF, &hdr->flags))
> + __set_bit(NETFS_SREQ_CLEAR_TAIL, &sreq->flags);
> +
> + if (hdr->error)
> + netfs->error = hdr->error;
> + else
> + atomic64_add(hdr->res.count, &netfs->transferred);
> +
> + nfs_netfs_put(netfs);
> + hdr->netfs = NULL;
> +}
> +
> +const struct netfs_request_ops nfs_netfs_ops = {
> + .init_request = nfs_netfs_init_request,
> + .free_request = nfs_netfs_free_request,
> + .begin_cache_operation = nfs_netfs_begin_cache_operation,
> + .issue_read = nfs_netfs_issue_read,
> + .clamp_length = nfs_netfs_clamp_length
> +};
> diff --git a/fs/nfs/fscache.h b/fs/nfs/fscache.h
> index 38614ed8f951..8d9d916b3a86 100644
> --- a/fs/nfs/fscache.h
> +++ b/fs/nfs/fscache.h
> @@ -34,6 +34,58 @@ struct nfs_fscache_inode_auxdata {
> u64 change_attr;
> };
>
> +struct nfs_netfs_io_data {
> + /*
> + * NFS may split a netfs_io_subrequest into multiple RPCs, each
> + * with their own read completion. In netfs, we can only call
> + * netfs_subreq_terminated() once for each subrequest. Use the
> + * refcount here to double as a marker of the last RPC completion,
> + * and only call netfs via netfs_subreq_terminated() once.
> + */
> + refcount_t refcount;
> + struct netfs_io_subrequest *sreq;
> +
> + /*
> + * Final disposition of the netfs_io_subrequest, sent in
> + * netfs_subreq_terminated()
> + */
> + atomic64_t transferred;
> + int error;
> +};
> +
> +static inline void nfs_netfs_get(struct nfs_netfs_io_data *netfs)
> +{
> + refcount_inc(&netfs->refcount);
> +}
> +
> +static inline void nfs_netfs_put(struct nfs_netfs_io_data *netfs)
> +{
> + ssize_t final_len;
> +
> + /* Only the last RPC completion should call netfs_subreq_terminated() */
> + if (!refcount_dec_and_test(&netfs->refcount))
> + return;
> +
> + /*
> + * The NFS pageio interface may read a complete page, even when netfs
> + * only asked for a partial page. Specifically, this may be seen when
> + * one thread is truncating a file while another one is reading the last
> + * page of the file.
> + * Correct the final length here to be no larger than the netfs subrequest
> + * length, and prevent netfs from complain throwing "Subreq overread".
> + */
> + final_len = min_t(s64, netfs->sreq->len, atomic64_read(&netfs->transferred));
> + netfs_subreq_terminated(netfs->sreq, netfs->error ?: final_len, false);
> + kfree(netfs);
> +}
> +static inline void nfs_netfs_inode_init(struct nfs_inode *nfsi)
> +{
> + netfs_inode_init(&nfsi->netfs, &nfs_netfs_ops);
> +}
> +extern void nfs_netfs_initiate_read(struct nfs_pgio_header *hdr);
> +extern void nfs_netfs_read_completion(struct nfs_pgio_header *hdr);
> +extern void nfs_netfs_readpage_release(struct nfs_page *req);
> +
> /*
> * fscache.c
> */
> @@ -44,9 +96,8 @@ extern void nfs_fscache_init_inode(struct inode *);
> extern void nfs_fscache_clear_inode(struct inode *);
> extern void nfs_fscache_open_file(struct inode *, struct file *);
> extern void nfs_fscache_release_file(struct inode *, struct file *);
> -
> -extern int __nfs_fscache_read_page(struct inode *, struct page *);
> -extern void __nfs_fscache_write_page(struct inode *, struct page *);
> +extern int nfs_netfs_readahead(struct readahead_control *ractl);
> +extern int nfs_netfs_read_folio(struct file *file, struct folio *folio);
>
> static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp)
> {
> @@ -54,34 +105,11 @@ static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp)
> if (current_is_kswapd() || !(gfp & __GFP_FS))
> return false;
> folio_wait_fscache(folio);
> - fscache_note_page_release(netfs_i_cookie(&NFS_I(folio->mapping->host)->netfs));
> - nfs_inc_fscache_stats(folio->mapping->host,
> - NFSIOS_FSCACHE_PAGES_UNCACHED);
> }
> + fscache_note_page_release(netfs_i_cookie(&NFS_I(folio->mapping->host)->netfs));
> return true;
> }
>
> -/*
> - * Retrieve a page from an inode data storage object.
> - */
> -static inline int nfs_fscache_read_page(struct inode *inode, struct page *page)
> -{
> - if (netfs_inode(inode)->cache)
> - return __nfs_fscache_read_page(inode, page);
> - return -ENOBUFS;
> -}
> -
> -/*
> - * Store a page newly fetched from the server in an inode data storage object
> - * in the cache.
> - */
> -static inline void nfs_fscache_write_page(struct inode *inode,
> - struct page *page)
> -{
> - if (netfs_inode(inode)->cache)
> - __nfs_fscache_write_page(inode, page);
> -}
> -
> static inline void nfs_fscache_update_auxdata(struct nfs_fscache_inode_auxdata *auxdata,
> struct inode *inode)
> {
> @@ -118,6 +146,13 @@ static inline const char *nfs_server_fscache_state(struct nfs_server *server)
> }
>
> #else /* CONFIG_NFS_FSCACHE */
> +static inline void nfs_netfs_inode_init(struct nfs_inode *nfsi) {}
> +static inline void nfs_netfs_initiate_read(struct nfs_pgio_header *hdr) {}
> +static inline void nfs_netfs_read_completion(struct nfs_pgio_header *hdr) {}
> +static inline void nfs_netfs_readpage_release(struct nfs_page *req)
> +{
> + unlock_page(req->wb_page);
> +}
> static inline void nfs_fscache_release_super_cookie(struct super_block *sb) {}
>
> static inline void nfs_fscache_init_inode(struct inode *inode) {}
> @@ -125,16 +160,19 @@ static inline void nfs_fscache_clear_inode(struct inode *inode) {}
> static inline void nfs_fscache_open_file(struct inode *inode,
> struct file *filp) {}
> static inline void nfs_fscache_release_file(struct inode *inode, struct file *file) {}
> -
> -static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp)
> +static inline int nfs_netfs_readahead(struct readahead_control *ractl)
> {
> - return true; /* may release folio */
> + return -ENOBUFS;
> }
> -static inline int nfs_fscache_read_page(struct inode *inode, struct page *page)
> +static inline int nfs_netfs_read_folio(struct file *file, struct folio *folio)
> {
> return -ENOBUFS;
> }
> -static inline void nfs_fscache_write_page(struct inode *inode, struct page *page) {}
> +
> +static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp)
> +{
> + return true; /* may release folio */
> +}
> static inline void nfs_fscache_invalidate(struct inode *inode, int flags) {}
>
> static inline const char *nfs_server_fscache_state(struct nfs_server *server)
> diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
> index aa2aec785ab5..b36a02b932e8 100644
> --- a/fs/nfs/inode.c
> +++ b/fs/nfs/inode.c
> @@ -2249,6 +2249,8 @@ struct inode *nfs_alloc_inode(struct super_block *sb)
> #ifdef CONFIG_NFS_V4_2
> nfsi->xattr_cache = NULL;
> #endif
> + nfs_netfs_inode_init(nfsi);
> +
> return VFS_I(nfsi);
> }
> EXPORT_SYMBOL_GPL(nfs_alloc_inode);
> diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
> index 4d240ac4430f..e9c0e4abc954 100644
> --- a/fs/nfs/internal.h
> +++ b/fs/nfs/internal.h
> @@ -453,6 +453,10 @@ extern void nfs_sb_deactive(struct super_block *sb);
> extern int nfs_client_for_each_server(struct nfs_client *clp,
> int (*fn)(struct nfs_server *, void *),
> void *data);
> +#ifdef CONFIG_NFS_FSCACHE
> +extern const struct netfs_request_ops nfs_netfs_ops;
> +#endif
> +
> /* io.c */
> extern void nfs_start_io_read(struct inode *inode);
> extern void nfs_end_io_read(struct inode *inode);
> @@ -482,9 +486,14 @@ extern int nfs4_get_rootfh(struct nfs_server *server, struct nfs_fh *mntfh, bool
>
> struct nfs_pgio_completion_ops;
> /* read.c */
> +extern const struct nfs_pgio_completion_ops nfs_async_read_completion_ops;
> extern void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
> struct inode *inode, bool force_mds,
> const struct nfs_pgio_completion_ops *compl_ops);
> +extern int nfs_pageio_add_page(struct nfs_pageio_descriptor *pgio,
> + struct nfs_open_context *ctx,
> + struct page *page);
> +extern void nfs_pageio_complete_read(struct nfs_pageio_descriptor *pgio);
> extern void nfs_read_prepare(struct rpc_task *task, void *calldata);
> extern void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio);
>
> diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
> index 317cedfa52bf..e28754476d1b 100644
> --- a/fs/nfs/pagelist.c
> +++ b/fs/nfs/pagelist.c
> @@ -25,6 +25,7 @@
> #include "internal.h"
> #include "pnfs.h"
> #include "nfstrace.h"
> +#include "fscache.h"
>
> #define NFSDBG_FACILITY NFSDBG_PAGECACHE
>
> @@ -68,6 +69,10 @@ void nfs_pgheader_init(struct nfs_pageio_descriptor *desc,
> hdr->good_bytes = mirror->pg_count;
> hdr->io_completion = desc->pg_io_completion;
> hdr->dreq = desc->pg_dreq;
> +#ifdef CONFIG_NFS_FSCACHE
> + if (desc->pg_netfs)
> + hdr->netfs = desc->pg_netfs;
> +#endif
> hdr->release = release;
> hdr->completion_ops = desc->pg_completion_ops;
> if (hdr->completion_ops->init_hdr)
> @@ -846,6 +851,9 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
> desc->pg_lseg = NULL;
> desc->pg_io_completion = NULL;
> desc->pg_dreq = NULL;
> +#ifdef CONFIG_NFS_FSCACHE
> + desc->pg_netfs = NULL;
> +#endif
> desc->pg_bsize = bsize;
>
> desc->pg_mirror_count = 1;
> @@ -940,6 +948,7 @@ int nfs_generic_pgio(struct nfs_pageio_descriptor *desc,
> /* Set up the argument struct */
> nfs_pgio_rpcsetup(hdr, mirror->pg_count, desc->pg_ioflags, &cinfo);
> desc->pg_rpc_callops = &nfs_pgio_common_ops;
> +
> return 0;
> }
> EXPORT_SYMBOL_GPL(nfs_generic_pgio);
> @@ -1360,6 +1369,9 @@ int nfs_pageio_resend(struct nfs_pageio_descriptor *desc,
>
> desc->pg_io_completion = hdr->io_completion;
> desc->pg_dreq = hdr->dreq;
> +#ifdef CONFIG_NFS_FSCACHE
> + desc->pg_netfs = hdr->netfs;
> +#endif
> list_splice_init(&hdr->pages, &pages);
> while (!list_empty(&pages)) {
> struct nfs_page *req = nfs_list_entry(pages.next);
> diff --git a/fs/nfs/read.c b/fs/nfs/read.c
> index 525e82ea9a9e..fdfebca017fc 100644
> --- a/fs/nfs/read.c
> +++ b/fs/nfs/read.c
> @@ -30,7 +30,7 @@
>
> #define NFSDBG_FACILITY NFSDBG_PAGECACHE
>
> -static const struct nfs_pgio_completion_ops nfs_async_read_completion_ops;
> +const struct nfs_pgio_completion_ops nfs_async_read_completion_ops;
> static const struct nfs_rw_ops nfs_rw_read_ops;
>
> static struct kmem_cache *nfs_rdata_cachep;
> @@ -74,7 +74,7 @@ void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
> }
> EXPORT_SYMBOL_GPL(nfs_pageio_init_read);
>
> -static void nfs_pageio_complete_read(struct nfs_pageio_descriptor *pgio)
> +void nfs_pageio_complete_read(struct nfs_pageio_descriptor *pgio)
> {
> struct nfs_pgio_mirror *pgm;
> unsigned long npages;
> @@ -110,20 +110,13 @@ EXPORT_SYMBOL_GPL(nfs_pageio_reset_read_mds);
>
> static void nfs_readpage_release(struct nfs_page *req, int error)
> {
> - struct inode *inode = d_inode(nfs_req_openctx(req)->dentry);
> struct page *page = req->wb_page;
>
> - dprintk("NFS: read done (%s/%llu %d@%lld)\n", inode->i_sb->s_id,
> - (unsigned long long)NFS_FILEID(inode), req->wb_bytes,
> - (long long)req_offset(req));
> -
> if (nfs_error_is_fatal_on_server(error) && error != -ETIMEDOUT)
> SetPageError(page);
> - if (nfs_page_group_sync_on_bit(req, PG_UNLOCKPAGE)) {
> - if (PageUptodate(page))
> - nfs_fscache_write_page(inode, page);
> - unlock_page(page);
> - }
> + if (nfs_page_group_sync_on_bit(req, PG_UNLOCKPAGE))
> + nfs_netfs_readpage_release(req);
> +
> nfs_release_request(req);
> }
>
> @@ -177,6 +170,8 @@ static void nfs_read_completion(struct nfs_pgio_header *hdr)
> nfs_list_remove_request(req);
> nfs_readpage_release(req, error);
> }
> + nfs_netfs_read_completion(hdr);
> +
> out:
> hdr->release(hdr);
> }
> @@ -187,6 +182,7 @@ static void nfs_initiate_read(struct nfs_pgio_header *hdr,
> struct rpc_task_setup *task_setup_data, int how)
> {
> rpc_ops->read_setup(hdr, msg);
> + nfs_netfs_initiate_read(hdr);
> trace_nfs_initiate_read(hdr);
> }
>
> @@ -202,7 +198,7 @@ nfs_async_read_error(struct list_head *head, int error)
> }
> }
>
> -static const struct nfs_pgio_completion_ops nfs_async_read_completion_ops = {
> +const struct nfs_pgio_completion_ops nfs_async_read_completion_ops = {
> .error_cleanup = nfs_async_read_error,
> .completion = nfs_read_completion,
> };
> @@ -294,12 +290,6 @@ nfs_pageio_add_page(struct nfs_pageio_descriptor *pgio,
>
> aligned_len = min_t(unsigned int, ALIGN(len, rsize), PAGE_SIZE);
>
> - if (!IS_SYNC(page->mapping->host)) {
> - error = nfs_fscache_read_page(page->mapping->host, page);
> - if (error == 0)
> - goto out_unlock;
> - }
> -
> new = nfs_create_request(ctx, page, 0, aligned_len);
> if (IS_ERR(new))
> goto out_error;
> @@ -315,8 +305,6 @@ nfs_pageio_add_page(struct nfs_pageio_descriptor *pgio,
> return 0;
> out_error:
> error = PTR_ERR(new);
> -out_unlock:
> - unlock_page(page);
> out:
> return error;
> }
> @@ -355,6 +343,10 @@ int nfs_read_folio(struct file *file, struct folio *folio)
> if (NFS_STALE(inode))
> goto out_unlock;
>
> + ret = nfs_netfs_read_folio(file, folio);
> + if (!ret)
> + goto out;
> +
> if (file == NULL) {
> ret = -EBADF;
> ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
> @@ -368,8 +360,10 @@ int nfs_read_folio(struct file *file, struct folio *folio)
> &nfs_async_read_completion_ops);
>
> ret = nfs_pageio_add_page(&pgio, ctx, page);
> - if (ret)
> - goto out;
> + if (ret) {
> + put_nfs_open_context(ctx);
> + goto out_unlock;
> + }
>
> nfs_pageio_complete_read(&pgio);
> ret = pgio.pg_error < 0 ? pgio.pg_error : 0;
> @@ -378,12 +372,12 @@ int nfs_read_folio(struct file *file, struct folio *folio)
> if (!PageUptodate(page) && !ret)
> ret = xchg(&ctx->error, 0);
> }
> -out:
> put_nfs_open_context(ctx);
> - trace_nfs_aop_readpage_done(inode, page, ret);
> - return ret;
> + goto out;
> +
> out_unlock:
> unlock_page(page);
> +out:
> trace_nfs_aop_readpage_done(inode, page, ret);
> return ret;
> }
> @@ -405,6 +399,10 @@ void nfs_readahead(struct readahead_control *ractl)
> if (NFS_STALE(inode))
> goto out;
>
> + ret = nfs_netfs_readahead(ractl);
> + if (!ret)
> + goto out;
> +
> if (file == NULL) {
> ret = -EBADF;
> ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
> diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h
> index ba7e2e4b0926..8eeb16d9bacd 100644
> --- a/include/linux/nfs_page.h
> +++ b/include/linux/nfs_page.h
> @@ -101,6 +101,9 @@ struct nfs_pageio_descriptor {
> struct pnfs_layout_segment *pg_lseg;
> struct nfs_io_completion *pg_io_completion;
> struct nfs_direct_req *pg_dreq;
> +#ifdef CONFIG_NFS_FSCACHE
> + void *pg_netfs;
> +#endif
> unsigned int pg_bsize; /* default bsize for mirrors */
>
> u32 pg_mirror_count;
> diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
> index e86cf6642d21..e196ef595908 100644
> --- a/include/linux/nfs_xdr.h
> +++ b/include/linux/nfs_xdr.h
> @@ -1619,6 +1619,9 @@ struct nfs_pgio_header {
> const struct nfs_rw_ops *rw_ops;
> struct nfs_io_completion *io_completion;
> struct nfs_direct_req *dreq;
> +#ifdef CONFIG_NFS_FSCACHE
> + void *netfs;
> +#endif
>
> int pnfs_error;
> int error; /* merge with pnfs_error */
Reviewed-by: Jeff Layton <jlayton@kernel.org>
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v8 0/3] Convert NFS with fscache to the netfs API
2022-09-22 13:58 [PATCH v8 0/3] Convert NFS with fscache to the netfs API Dave Wysochanski
` (4 preceding siblings ...)
2022-09-22 13:58 ` [PATCH v8 5/5] NFS: Remove fscache specific trace points and NFS_INO_FSCACHE bit Dave Wysochanski
@ 2022-09-28 10:10 ` Jeff Layton
5 siblings, 0 replies; 8+ messages in thread
From: Jeff Layton @ 2022-09-28 10:10 UTC (permalink / raw)
To: Dave Wysochanski, Anna Schumaker, Trond Myklebust, David Howells
Cc: linux-nfs, linux-cachefs, Benjamin Maynard, Daire Byrne
On Thu, 2022-09-22 at 09:58 -0400, Dave Wysochanski wrote:
> This patchset converts NFS with fscache non-direct READ IO paths to
> use the netfs API with a non-invasive approach. The existing NFS pgio
> layer does not need extensive changes, and is the best way so far I've
> found to address Trond's concerns about modifying the IO path [1] as
> well as only enabling netfs when fscache is configured and enabled [2].
> I have not attempted performance comparisions to address Chuck
> Lever's concern [3] because we are not converting the non-fscache
> enabled NFS IO paths to netfs.
>
> The main patch to be reviewed is patch #3 which converts nfs_read_folio
> and nfs_readahead. There are two main compatibility points with the
> interface between the NFS READ IO path and netfs. First, NFS IO
> interfaces are page based and netfs is request based (multiple page).
> Thus, there's some accounting information collected to turn multiple
> NFS READ RPC completions into a single netfs completion, and we have
> to pass a pointer to this information through NFS pgio layer. Second,
> the unlocking of pages of an NFS READ is handled inside netfs, which
> requires a tiny bit of refactoring of the NFS read code.
>
> Patch #4 removes the NFS fscache counters and also removes the "fsc:"
> line from /proc/self/mountstats. I was not sure if we need to leave
> that line in the mountstats file, and just leave the values at 0, or
> we can remove it. For now I've removed it but if needed for ABI or
> some other reason I can add back a "dummy" line with zeros.
>
> In patch #5 I've removed the existing trace events because they no
> longer have any meaning, and did not add any new ones since netfs
> and fscache has many tracepoints. A future series may want to look
> at some of the pgio layer tracepoints along with maybe one or two
> related to NFS with fscache but for now it does not seem needed.
>
> The patchset is based on 6.0-rc6 and has been pushed to github at:
> https://github.com/DaveWysochanskiRH/kernel/commits/nfs-fscache-netfs
> https://github.com/DaveWysochanskiRH/kernel/commit/b0467a2c39f3e8582660d073f9fa5c45ec2ca7f0
>
>
> Changes since v7
> ================
> - PATCH3: Free netfs memory if nfs_pageio_add_page() fails inside
> nfs_netfs_issue_read()
> - PATCH3: Clean up handling of READs completing with retryable and
> non-retryable errors by removing unneeded nfs_netfs_read_done();
> fixes oops in generic/303 with vers=4.2 and RHEL8 server due to
> use-after-free of netfs structure
> - PATCH3: Update patch header
> - PATCH4 and PATCH5: new
>
>
> Testing
> =======
> The patches are fairly stable as evidenced with xfstests generic with
> various servers, both with and without fscache enabled, with no hangs
> or crashes seen:
> - hammerspace(pNFS flexfiles): NFS4.1, NFS4.2
> - NetApp(pNFS filelayout): NFS3, NFS4.0, NFS4.1
> - RHEL8: NFS3,NFS4.0,NFS4.2
>
> The known issues are as follows:
>
> 1. Unit test setting rsize < readahead does not properly read from
> fscache but re-reads data from the NFS server
> * This will be fixed with another linux-cachefs [4] patch to resolve
> "Stop read optimisation when folio removed from pagecache"
> * Daire Byrne also verified the patch fixes his issue as well
>
> 2. "Cache volume key already in use" after xfstest runs
> * xfstests (hammerspace with vers=4.2,fsc) shows the following on the
> console after some tests:
> "NFS: Cache volume key already in use (nfs,4.1,2,c50,cfe0100a,3,,,8000,100000,100000,bb8,ea60,7530,ea60,1)"
> * This may be fixed with another patch [5] that is in progress
>
> 3. Daire Byrne reported a NULL pointer oops at cachefiles_prepare_write+0x28/0x90
> * only reproduced on RHEL7.9 based NFS re-export server using fscache with upstream kernel plus
> the previous patches
> * may be a bug in netfs or cachefiles exposed by NFS patches
> * harder to reproduce/debug but under investigation
>
> [58710.346376] BUG: kernel NULL pointer dereference, address: 0000000000000008
> [58710.371212] CPU: 12 PID: 9134 Comm: kworker/u129:0 Tainted: G E 6.0.0-2.dneg.x86_64 #1
> ...
> [58710.389995] Workqueue: events_unbound netfs_rreq_write_to_cache_work [netfs]
> [58710.397188] RIP: 0010:cachefiles_prepare_write+0x28/0x90 [cachefiles]
> ...
> [58710.500316] Call Trace:
> [58710.502894] <TASK>
> [58710.505126] netfs_rreq_write_to_cache_work+0x11c/0x320 [netfs]
> [58710.511201] process_one_work+0x217/0x3e0
> [58710.515358] worker_thread+0x4a/0x3b0
> [58710.519152] ? process_one_work+0x3e0/0x3e0
> [58710.523467] kthread+0xd6/0x100
> [58710.526740] ? kthread_complete_and_exit+0x20/0x20
> [58710.531659] ret_from_fork+0x1f/0x30
>
>
> References
> ==========
> [1] https://lore.kernel.org/linux-nfs/9cfd5bc3cfc6abc2d3316b0387222e708d67f595.camel@hammerspace.com/
> [2] https://lore.kernel.org/linux-nfs/da9200f1bded9b8b078a7aef227fd6b92eb028fb.camel@hammerspace.com/
> [3] https://marc.info/?l=linux-nfs&m=160597917525083&w=4
> [4] https://www.mail-archive.com/linux-cachefs@redhat.com/msg03043.html
> [5] https://marc.info/?l=linux-nfs&m=165962662200679&w=4
>
> Dave Wysochanski (5):
> NFS: Rename readpage_async_filler to nfs_pageio_add_page
> NFS: Configure support for netfs when NFS fscache is configured
> NFS: Convert buffered read paths to use netfs when fscache is enabled
> NFS: Remove all NFSIOS_FSCACHE counters due to conversion to netfs API
> NFS: Remove fscache specific trace points and NFS_INO_FSCACHE bit
>
> fs/nfs/Kconfig | 1 +
> fs/nfs/delegation.c | 2 +-
> fs/nfs/dir.c | 2 +-
> fs/nfs/fscache.c | 242 ++++++++++++++++++++++---------------
> fs/nfs/fscache.h | 111 +++++++++++------
> fs/nfs/inode.c | 8 +-
> fs/nfs/internal.h | 11 +-
> fs/nfs/iostat.h | 17 ---
> fs/nfs/nfstrace.h | 91 --------------
> fs/nfs/pagelist.c | 12 ++
> fs/nfs/pnfs.c | 12 +-
> fs/nfs/read.c | 110 +++++++++--------
> fs/nfs/super.c | 11 --
> fs/nfs/write.c | 2 +-
> include/linux/nfs_fs.h | 35 ++++--
> include/linux/nfs_iostat.h | 12 --
> include/linux/nfs_page.h | 3 +
> include/linux/nfs_xdr.h | 3 +
> 18 files changed, 335 insertions(+), 350 deletions(-)
>
Like seeing a net-negative diffstat!
I reviewed the 3rd patch and you can add my Reviewed-by: to the 4th and
5th patches as well.
Nice work, Dave!
--
Jeff Layton <jlayton@kernel.org>
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2022-09-28 10:10 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-09-22 13:58 [PATCH v8 0/3] Convert NFS with fscache to the netfs API Dave Wysochanski
2022-09-22 13:58 ` [PATCH v8 1/5] NFS: Rename readpage_async_filler to nfs_pageio_add_page Dave Wysochanski
2022-09-22 13:58 ` [PATCH v8 2/5] NFS: Configure support for netfs when NFS fscache is configured Dave Wysochanski
2022-09-22 13:58 ` [PATCH v8 3/5] NFS: Convert buffered read paths to use netfs when fscache is enabled Dave Wysochanski
2022-09-28 10:07 ` Jeff Layton
2022-09-22 13:58 ` [PATCH v8 4/5] NFS: Remove all NFSIOS_FSCACHE counters due to conversion to netfs API Dave Wysochanski
2022-09-22 13:58 ` [PATCH v8 5/5] NFS: Remove fscache specific trace points and NFS_INO_FSCACHE bit Dave Wysochanski
2022-09-28 10:10 ` [PATCH v8 0/3] Convert NFS with fscache to the netfs API Jeff Layton
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