[PATCH v3 0/6] ceph: convert to netfs helper library

[PATCH v3 0/6] ceph: convert to netfs helper library

[Jeff Layton]

This is the third posting of this patchset. The main differences between
this one and the last are some bugfixes, and cleanups:

- rebase onto David's latest fscache-netfs-lib set
- unify the netfs_read_request_ops into one struct
- fix inline_data handling in write_begin
- remove the now-unneeded i_fscache_gen field from ceph_inode_info
- rename gfp_flags to gfp in releasepage
- pass appropriate was_async flag to netfs_subreq_terminated

This set is currently sitting in the ceph-client/testing branch, so
it should get good testing coverage over the next few weeks via in
the teuthology lab.

Jeff Layton (6):
  ceph: disable old fscache readpage handling
  ceph: rework PageFsCache handling
  ceph: fix fscache invalidation
  ceph: convert readpage to fscache read helper
  ceph: plug write_begin into read helper
  ceph: convert ceph_readpages to ceph_readahead

 fs/ceph/Kconfig |   1 +
 fs/ceph/addr.c  | 541 +++++++++++++++++++-----------------------------
 fs/ceph/cache.c | 125 -----------
 fs/ceph/cache.h | 101 +++------
 fs/ceph/caps.c  |  10 +-
 fs/ceph/inode.c |   1 +
 fs/ceph/super.h |   2 +-
 7 files changed, 242 insertions(+), 539 deletions(-)

-- 
2.29.2

[PATCH v3 1/6] ceph: disable old fscache readpage handling

[Jeff Layton]

With the new netfs read helper functions, we won't need a lot of this
infrastructure as it handles the pagecache pages itself. Rip out the
read handling for now, and much of the old infrastructure that deals in
individual pages.

The cookie handling is mostly unchanged, however.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Cc: ceph-devel@vger.kernel.org
Cc: linux-cachefs@redhat.com
Cc: linux-fsdevel@vger.kernel.org
---
 fs/ceph/addr.c  |  31 +-----------
 fs/ceph/cache.c | 125 ------------------------------------------------
 fs/ceph/cache.h |  91 +----------------------------------
 fs/ceph/caps.c  |   9 ----
 fs/ceph/super.h |   1 -
 5 files changed, 3 insertions(+), 254 deletions(-)

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 26e66436f005..e267aa60c8b6 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -155,8 +155,6 @@ static void ceph_invalidatepage(struct page *page, unsigned int offset,
 		return;
 	}
 
-	ceph_invalidate_fscache_page(inode, page);
-
 	WARN_ON(!PageLocked(page));
 	if (!PagePrivate(page))
 		return;
@@ -175,10 +173,6 @@ static int ceph_releasepage(struct page *page, gfp_t g)
 	dout("%p releasepage %p idx %lu (%sdirty)\n", page->mapping->host,
 	     page, page->index, PageDirty(page) ? "" : "not ");
 
-	/* Can we release the page from the cache? */
-	if (!ceph_release_fscache_page(page, g))
-		return 0;
-
 	return !PagePrivate(page);
 }
 
@@ -213,10 +207,6 @@ static int ceph_do_readpage(struct file *filp, struct page *page)
 		return 0;
 	}
 
-	err = ceph_readpage_from_fscache(inode, page);
-	if (err == 0)
-		return -EINPROGRESS;
-
 	dout("readpage ino %llx.%llx file %p off %llu len %llu page %p index %lu\n",
 	     vino.ino, vino.snap, filp, off, len, page, page->index);
 	req = ceph_osdc_new_request(osdc, &ci->i_layout, vino, off, &len, 0, 1,
@@ -241,7 +231,6 @@ static int ceph_do_readpage(struct file *filp, struct page *page)
 	if (err == -ENOENT)
 		err = 0;
 	if (err < 0) {
-		ceph_fscache_readpage_cancel(inode, page);
 		if (err == -EBLOCKLISTED)
 			fsc->blocklisted = true;
 		goto out;
@@ -253,8 +242,6 @@ static int ceph_do_readpage(struct file *filp, struct page *page)
 		flush_dcache_page(page);
 
 	SetPageUptodate(page);
-	ceph_readpage_to_fscache(inode, page);
-
 out:
 	return err < 0 ? err : 0;
 }
@@ -294,10 +281,8 @@ static void finish_read(struct ceph_osd_request *req)
 	for (i = 0; i < num_pages; i++) {
 		struct page *page = osd_data->pages[i];
 
-		if (rc < 0 && rc != -ENOENT) {
-			ceph_fscache_readpage_cancel(inode, page);
+		if (rc < 0 && rc != -ENOENT)
 			goto unlock;
-		}
 		if (bytes < (int)PAGE_SIZE) {
 			/* zero (remainder of) page */
 			int s = bytes < 0 ? 0 : bytes;
@@ -307,7 +292,6 @@ static void finish_read(struct ceph_osd_request *req)
 		     page->index);
 		flush_dcache_page(page);
 		SetPageUptodate(page);
-		ceph_readpage_to_fscache(inode, page);
 unlock:
 		unlock_page(page);
 		put_page(page);
@@ -408,7 +392,6 @@ static int start_read(struct inode *inode, struct ceph_rw_context *rw_ctx,
 		     page->index);
 		if (add_to_page_cache_lru(page, &inode->i_data, page->index,
 					  GFP_KERNEL)) {
-			ceph_fscache_uncache_page(inode, page);
 			put_page(page);
 			dout("start_read %p add_to_page_cache failed %p\n",
 			     inode, page);
@@ -440,10 +423,8 @@ static int start_read(struct inode *inode, struct ceph_rw_context *rw_ctx,
 	return nr_pages;
 
 out_pages:
-	for (i = 0; i < nr_pages; ++i) {
-		ceph_fscache_readpage_cancel(inode, pages[i]);
+	for (i = 0; i < nr_pages; ++i)
 		unlock_page(pages[i]);
-	}
 	ceph_put_page_vector(pages, nr_pages, false);
 out_put:
 	ceph_osdc_put_request(req);
@@ -471,12 +452,6 @@ static int ceph_readpages(struct file *file, struct address_space *mapping,
 	if (ceph_inode(inode)->i_inline_version != CEPH_INLINE_NONE)
 		return -EINVAL;
 
-	rc = ceph_readpages_from_fscache(mapping->host, mapping, page_list,
-					 &nr_pages);
-
-	if (rc == 0)
-		goto out;
-
 	rw_ctx = ceph_find_rw_context(fi);
 	max = fsc->mount_options->rsize >> PAGE_SHIFT;
 	dout("readpages %p file %p ctx %p nr_pages %d max %d\n",
@@ -487,8 +462,6 @@ static int ceph_readpages(struct file *file, struct address_space *mapping,
 			goto out;
 	}
 out:
-	ceph_fscache_readpages_cancel(inode, page_list);
-
 	dout("readpages %p file %p ret %d\n", inode, file, rc);
 	return rc;
 }
diff --git a/fs/ceph/cache.c b/fs/ceph/cache.c
index 2f5cb6bc78e1..9cfadbb86568 100644
--- a/fs/ceph/cache.c
+++ b/fs/ceph/cache.c
@@ -173,7 +173,6 @@ void ceph_fscache_unregister_inode_cookie(struct ceph_inode_info* ci)
 
 	ci->fscache = NULL;
 
-	fscache_uncache_all_inode_pages(cookie, &ci->vfs_inode);
 	fscache_relinquish_cookie(cookie, &ci->i_vino, false);
 }
 
@@ -194,7 +193,6 @@ void ceph_fscache_file_set_cookie(struct inode *inode, struct file *filp)
 		dout("fscache_file_set_cookie %p %p disabling cache\n",
 		     inode, filp);
 		fscache_disable_cookie(ci->fscache, &ci->i_vino, false);
-		fscache_uncache_all_inode_pages(ci->fscache, inode);
 	} else {
 		fscache_enable_cookie(ci->fscache, &ci->i_vino, i_size_read(inode),
 				      ceph_fscache_can_enable, inode);
@@ -205,108 +203,6 @@ void ceph_fscache_file_set_cookie(struct inode *inode, struct file *filp)
 	}
 }
 
-static void ceph_readpage_from_fscache_complete(struct page *page, void *data, int error)
-{
-	if (!error)
-		SetPageUptodate(page);
-
-	unlock_page(page);
-}
-
-static inline bool cache_valid(struct ceph_inode_info *ci)
-{
-	return ci->i_fscache_gen == ci->i_rdcache_gen;
-}
-
-
-/* Atempt to read from the fscache,
- *
- * This function is called from the readpage_nounlock context. DO NOT attempt to
- * unlock the page here (or in the callback).
- */
-int ceph_readpage_from_fscache(struct inode *inode, struct page *page)
-{
-	struct ceph_inode_info *ci = ceph_inode(inode);
-	int ret;
-
-	if (!cache_valid(ci))
-		return -ENOBUFS;
-
-	ret = fscache_read_or_alloc_page(ci->fscache, page,
-					 ceph_readpage_from_fscache_complete, NULL,
-					 GFP_KERNEL);
-
-	switch (ret) {
-		case 0: /* Page found */
-			dout("page read submitted\n");
-			return 0;
-		case -ENOBUFS: /* Pages were not found, and can't be */
-		case -ENODATA: /* Pages were not found */
-			dout("page/inode not in cache\n");
-			return ret;
-		default:
-			dout("%s: unknown error ret = %i\n", __func__, ret);
-			return ret;
-	}
-}
-
-int ceph_readpages_from_fscache(struct inode *inode,
-				  struct address_space *mapping,
-				  struct list_head *pages,
-				  unsigned *nr_pages)
-{
-	struct ceph_inode_info *ci = ceph_inode(inode);
-	int ret;
-
-	if (!cache_valid(ci))
-		return -ENOBUFS;
-
-	ret = fscache_read_or_alloc_pages(ci->fscache, mapping, pages, nr_pages,
-					  ceph_readpage_from_fscache_complete,
-					  NULL, mapping_gfp_mask(mapping));
-
-	switch (ret) {
-		case 0: /* All pages found */
-			dout("all-page read submitted\n");
-			return 0;
-		case -ENOBUFS: /* Some pages were not found, and can't be */
-		case -ENODATA: /* some pages were not found */
-			dout("page/inode not in cache\n");
-			return ret;
-		default:
-			dout("%s: unknown error ret = %i\n", __func__, ret);
-			return ret;
-	}
-}
-
-void ceph_readpage_to_fscache(struct inode *inode, struct page *page)
-{
-	struct ceph_inode_info *ci = ceph_inode(inode);
-	int ret;
-
-	if (!PageFsCache(page))
-		return;
-
-	if (!cache_valid(ci))
-		return;
-
-	ret = fscache_write_page(ci->fscache, page, i_size_read(inode),
-				 GFP_KERNEL);
-	if (ret)
-		 fscache_uncache_page(ci->fscache, page);
-}
-
-void ceph_invalidate_fscache_page(struct inode* inode, struct page *page)
-{
-	struct ceph_inode_info *ci = ceph_inode(inode);
-
-	if (!PageFsCache(page))
-		return;
-
-	fscache_wait_on_page_write(ci->fscache, page);
-	fscache_uncache_page(ci->fscache, page);
-}
-
 void ceph_fscache_unregister_fs(struct ceph_fs_client* fsc)
 {
 	if (fscache_cookie_valid(fsc->fscache)) {
@@ -329,24 +225,3 @@ void ceph_fscache_unregister_fs(struct ceph_fs_client* fsc)
 	}
 	fsc->fscache = NULL;
 }
-
-/*
- * caller should hold CEPH_CAP_FILE_{RD,CACHE}
- */
-void ceph_fscache_revalidate_cookie(struct ceph_inode_info *ci)
-{
-	if (cache_valid(ci))
-		return;
-
-	/* resue i_truncate_mutex. There should be no pending
-	 * truncate while the caller holds CEPH_CAP_FILE_RD */
-	mutex_lock(&ci->i_truncate_mutex);
-	if (!cache_valid(ci)) {
-		if (fscache_check_consistency(ci->fscache, &ci->i_vino))
-			fscache_invalidate(ci->fscache);
-		spin_lock(&ci->i_ceph_lock);
-		ci->i_fscache_gen = ci->i_rdcache_gen;
-		spin_unlock(&ci->i_ceph_lock);
-	}
-	mutex_unlock(&ci->i_truncate_mutex);
-}
diff --git a/fs/ceph/cache.h b/fs/ceph/cache.h
index 89dbdd1eb14a..10c21317b62f 100644
--- a/fs/ceph/cache.h
+++ b/fs/ceph/cache.h
@@ -29,13 +29,10 @@ int ceph_readpages_from_fscache(struct inode *inode,
 				struct address_space *mapping,
 				struct list_head *pages,
 				unsigned *nr_pages);
-void ceph_readpage_to_fscache(struct inode *inode, struct page *page);
-void ceph_invalidate_fscache_page(struct inode* inode, struct page *page);
 
 static inline void ceph_fscache_inode_init(struct ceph_inode_info *ci)
 {
 	ci->fscache = NULL;
-	ci->i_fscache_gen = 0;
 }
 
 static inline void ceph_fscache_invalidate(struct inode *inode)
@@ -43,40 +40,6 @@ static inline void ceph_fscache_invalidate(struct inode *inode)
 	fscache_invalidate(ceph_inode(inode)->fscache);
 }
 
-static inline void ceph_fscache_uncache_page(struct inode *inode,
-					     struct page *page)
-{
-	struct ceph_inode_info *ci = ceph_inode(inode);
-	return fscache_uncache_page(ci->fscache, page);
-}
-
-static inline int ceph_release_fscache_page(struct page *page, gfp_t gfp)
-{
-	struct inode* inode = page->mapping->host;
-	struct ceph_inode_info *ci = ceph_inode(inode);
-	return fscache_maybe_release_page(ci->fscache, page, gfp);
-}
-
-static inline void ceph_fscache_readpage_cancel(struct inode *inode,
-						struct page *page)
-{
-	struct ceph_inode_info *ci = ceph_inode(inode);
-	if (fscache_cookie_valid(ci->fscache) && PageFsCache(page))
-		__fscache_uncache_page(ci->fscache, page);
-}
-
-static inline void ceph_fscache_readpages_cancel(struct inode *inode,
-						 struct list_head *pages)
-{
-	struct ceph_inode_info *ci = ceph_inode(inode);
-	return fscache_readpages_cancel(ci->fscache, pages);
-}
-
-static inline void ceph_disable_fscache_readpage(struct ceph_inode_info *ci)
-{
-	ci->i_fscache_gen = ci->i_rdcache_gen - 1;
-}
-
 #else
 
 static inline int ceph_fscache_register(void)
@@ -115,62 +78,10 @@ static inline void ceph_fscache_file_set_cookie(struct inode *inode,
 {
 }
 
-static inline void ceph_fscache_revalidate_cookie(struct ceph_inode_info *ci)
-{
-}
-
-static inline void ceph_fscache_uncache_page(struct inode *inode,
-					     struct page *pages)
-{
-}
-
-static inline int ceph_readpage_from_fscache(struct inode* inode,
-					     struct page *page)
-{
-	return -ENOBUFS;
-}
-
-static inline int ceph_readpages_from_fscache(struct inode *inode,
-					      struct address_space *mapping,
-					      struct list_head *pages,
-					      unsigned *nr_pages)
-{
-	return -ENOBUFS;
-}
-
-static inline void ceph_readpage_to_fscache(struct inode *inode,
-					    struct page *page)
-{
-}
-
 static inline void ceph_fscache_invalidate(struct inode *inode)
 {
 }
 
-static inline void ceph_invalidate_fscache_page(struct inode *inode,
-						struct page *page)
-{
-}
-
-static inline int ceph_release_fscache_page(struct page *page, gfp_t gfp)
-{
-	return 1;
-}
-
-static inline void ceph_fscache_readpage_cancel(struct inode *inode,
-						struct page *page)
-{
-}
-
-static inline void ceph_fscache_readpages_cancel(struct inode *inode,
-						 struct list_head *pages)
-{
-}
-
-static inline void ceph_disable_fscache_readpage(struct ceph_inode_info *ci)
-{
-}
-
 #endif
 
-#endif
+#endif /* _CEPH_CACHE_H */
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 570731c4d019..b256fc8c68d0 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -2730,10 +2730,6 @@ static int try_get_cap_refs(struct inode *inode, int need, int want,
 				*got = need | want;
 			else
 				*got = need;
-			if (S_ISREG(inode->i_mode) &&
-			    (need & CEPH_CAP_FILE_RD) &&
-			    !(*got & CEPH_CAP_FILE_CACHE))
-				ceph_disable_fscache_readpage(ci);
 			ceph_take_cap_refs(ci, *got, true);
 			ret = 1;
 		}
@@ -2983,11 +2979,6 @@ int ceph_get_caps(struct file *filp, int need, int want,
 		}
 		break;
 	}
-
-	if (S_ISREG(ci->vfs_inode.i_mode) &&
-	    (_got & CEPH_CAP_FILE_RD) && (_got & CEPH_CAP_FILE_CACHE))
-		ceph_fscache_revalidate_cookie(ci);
-
 	*got = _got;
 	return 0;
 }
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 13b02887b085..060c93df9b93 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -427,7 +427,6 @@ struct ceph_inode_info {
 
 #ifdef CONFIG_CEPH_FSCACHE
 	struct fscache_cookie *fscache;
-	u32 i_fscache_gen;
 #endif
 	errseq_t i_meta_err;
 
-- 
2.29.2

[PATCH v3 2/6] ceph: rework PageFsCache handling

[Jeff Layton]

With the new fscache API, the PageFsCache bit now indicates that the
page is being written to the cache and shouldn't be modified or released
until it's finished.

Change releasepage and invalidatepage to wait on that bit before
returning.

Also define FSCACHE_USE_NEW_IO_API so that we opt into the new fscache
API.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Cc: ceph-devel@vger.kernel.org
Cc: linux-cachefs@redhat.com
Cc: linux-fsdevel@vger.kernel.org
---
 fs/ceph/addr.c  | 9 ++++++++-
 fs/ceph/super.h | 1 +
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index e267aa60c8b6..3936ae3e8dcd 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -146,6 +146,8 @@ static void ceph_invalidatepage(struct page *page, unsigned int offset,
 	struct ceph_inode_info *ci;
 	struct ceph_snap_context *snapc = page_snap_context(page);
 
+	wait_on_page_fscache(page);
+
 	inode = page->mapping->host;
 	ci = ceph_inode(inode);
 
@@ -168,11 +170,16 @@ static void ceph_invalidatepage(struct page *page, unsigned int offset,
 	ClearPagePrivate(page);
 }
 
-static int ceph_releasepage(struct page *page, gfp_t g)
+static int ceph_releasepage(struct page *page, gfp_t gfp)
 {
 	dout("%p releasepage %p idx %lu (%sdirty)\n", page->mapping->host,
 	     page, page->index, PageDirty(page) ? "" : "not ");
 
+	if (PageFsCache(page)) {
+		if (!(gfp & __GFP_DIRECT_RECLAIM) || !(gfp & __GFP_FS))
+			return 0;
+		wait_on_page_fscache(page);
+	}
 	return !PagePrivate(page);
 }
 
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 060c93df9b93..2f7e769290c4 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -21,6 +21,7 @@
 #include <linux/ceph/libceph.h>
 
 #ifdef CONFIG_CEPH_FSCACHE
+#define FSCACHE_USE_NEW_IO_API
 #include <linux/fscache.h>
 #endif
 
-- 
2.29.2

[PATCH v3 3/6] ceph: fix fscache invalidation

[Jeff Layton]

Ensure that we invalidate the fscache whenever we invalidate the
pagecache.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Cc: ceph-devel@vger.kernel.org
Cc: linux-cachefs@redhat.com
Cc: linux-fsdevel@vger.kernel.org
---
 fs/ceph/caps.c  | 1 +
 fs/ceph/inode.c | 1 +
 2 files changed, 2 insertions(+)

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index b256fc8c68d0..e12e4cdefac1 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -1867,6 +1867,7 @@ static int try_nonblocking_invalidate(struct inode *inode)
 	u32 invalidating_gen = ci->i_rdcache_gen;
 
 	spin_unlock(&ci->i_ceph_lock);
+	ceph_fscache_invalidate(inode);
 	invalidate_mapping_pages(&inode->i_data, 0, -1);
 	spin_lock(&ci->i_ceph_lock);
 
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 5d20a620e96c..2d424b41a8b9 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -1863,6 +1863,7 @@ static void ceph_do_invalidate_pages(struct inode *inode)
 	orig_gen = ci->i_rdcache_gen;
 	spin_unlock(&ci->i_ceph_lock);
 
+	ceph_fscache_invalidate(inode);
 	if (invalidate_inode_pages2(inode->i_mapping) < 0) {
 		pr_err("invalidate_pages %p fails\n", inode);
 	}
-- 
2.29.2

[PATCH v3 4/6] ceph: convert readpage to fscache read helper

[Jeff Layton]

Have the ceph KConfig select NETFS_SUPPORT. Add a new netfs ops
structure and the operations for it. Convert ceph_readpage to use
the new netfs_readpage helper.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Cc: ceph-devel@vger.kernel.org
Cc: linux-cachefs@redhat.com
Cc: linux-fsdevel@vger.kernel.org
---
 fs/ceph/Kconfig |   1 +
 fs/ceph/addr.c  | 167 +++++++++++++++++++++++++++++++++++++++++++++---
 fs/ceph/cache.h |  36 +++++++++++
 3 files changed, 194 insertions(+), 10 deletions(-)

diff --git a/fs/ceph/Kconfig b/fs/ceph/Kconfig
index 471e40156065..94df854147d3 100644
--- a/fs/ceph/Kconfig
+++ b/fs/ceph/Kconfig
@@ -6,6 +6,7 @@ config CEPH_FS
 	select LIBCRC32C
 	select CRYPTO_AES
 	select CRYPTO
+	select NETFS_SUPPORT
 	default n
 	help
 	  Choose Y or M here to include support for mounting the
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 3936ae3e8dcd..fbfdf1296174 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -12,6 +12,7 @@
 #include <linux/signal.h>
 #include <linux/iversion.h>
 #include <linux/ktime.h>
+#include <linux/netfs.h>
 
 #include "super.h"
 #include "mds_client.h"
@@ -183,6 +184,162 @@ static int ceph_releasepage(struct page *page, gfp_t gfp)
 	return !PagePrivate(page);
 }
 
+static void ceph_netfs_expand_readahead(struct netfs_read_request *rreq)
+{
+	struct inode *inode = rreq->mapping->host;
+	struct ceph_inode_info *ci = ceph_inode(inode);
+	struct ceph_file_layout *lo = &ci->i_layout;
+	u32 blockoff;
+	u64 blockno;
+
+	/* Expand the start downward */
+	blockno = div_u64_rem(rreq->start, lo->stripe_unit, &blockoff);
+	rreq->start = blockno * lo->stripe_unit;
+	rreq->len += blockoff;
+
+	/* Now, round up the length to the next block */
+	rreq->len = roundup(rreq->len, lo->stripe_unit);
+}
+
+static bool ceph_netfs_clamp_length(struct netfs_read_subrequest *subreq)
+{
+	struct inode *inode = subreq->rreq->mapping->host;
+	struct ceph_inode_info *ci = ceph_inode(inode);
+	u64 objno, objoff;
+	u32 xlen;
+
+	/* Truncate the extent at the end of the current block */
+	ceph_calc_file_object_mapping(&ci->i_layout, subreq->start, subreq->len,
+				      &objno, &objoff, &xlen);
+	subreq->len = xlen;
+	return true;
+}
+
+static void finish_netfs_read(struct ceph_osd_request *req)
+{
+	struct ceph_fs_client *fsc = ceph_inode_to_client(req->r_inode);
+	struct ceph_osd_data *osd_data = osd_req_op_extent_osd_data(req, 0);
+	struct netfs_read_subrequest *subreq = req->r_priv;
+	int num_pages;
+	int err = req->r_result;
+
+	ceph_update_read_latency(&fsc->mdsc->metric, req->r_start_latency,
+				 req->r_end_latency, err);
+
+	dout("%s: result %d subreq->len=%zu i_size=%lld\n", __func__, req->r_result,
+	     subreq->len, i_size_read(req->r_inode));
+
+	/* no object means success but no data */
+	if (err == -ENOENT)
+		err = 0;
+	else if (err == -EBLOCKLISTED)
+		fsc->blocklisted = true;
+
+	if (err >= 0 && err < subreq->len)
+		__set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags);
+
+	netfs_subreq_terminated(subreq, err, true);
+
+	num_pages = calc_pages_for(osd_data->alignment, osd_data->length);
+	ceph_put_page_vector(osd_data->pages, num_pages, false);
+	iput(req->r_inode);
+}
+
+static void ceph_netfs_issue_op(struct netfs_read_subrequest *subreq)
+{
+	struct netfs_read_request *rreq = subreq->rreq;
+	struct inode *inode = rreq->mapping->host;
+	struct ceph_inode_info *ci = ceph_inode(inode);
+	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
+	struct ceph_osd_request *req;
+	struct ceph_vino vino = ceph_vino(inode);
+	struct iov_iter iter;
+	struct page **pages;
+	size_t page_off;
+	int err = 0;
+	u64 len = subreq->len;
+
+	req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout, vino, subreq->start, &len,
+			0, 1, CEPH_OSD_OP_READ,
+			CEPH_OSD_FLAG_READ | fsc->client->osdc.client->options->read_from_replica,
+			NULL, ci->i_truncate_seq, ci->i_truncate_size, false);
+	if (IS_ERR(req)) {
+		err = PTR_ERR(req);
+		req = NULL;
+		goto out;
+	}
+
+	dout("%s: pos=%llu orig_len=%zu len=%llu\n", __func__, subreq->start, subreq->len, len);
+	iov_iter_xarray(&iter, READ, &rreq->mapping->i_pages, subreq->start, len);
+	err = iov_iter_get_pages_alloc(&iter, &pages, len, &page_off);
+	if (err < 0) {
+		dout("%s: iov_ter_get_pages_alloc returned %d\n", __func__, err);
+		goto out;
+	}
+
+	/* should always give us a page-aligned read */
+	WARN_ON_ONCE(page_off);
+	len = err;
+
+	osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0, false, false);
+	req->r_callback = finish_netfs_read;
+	req->r_priv = subreq;
+	req->r_inode = inode;
+	ihold(inode);
+
+	err = ceph_osdc_start_request(req->r_osdc, req, false);
+	if (err)
+		iput(inode);
+out:
+	ceph_osdc_put_request(req);
+	if (err)
+		netfs_subreq_terminated(subreq, err, false);
+	dout("%s: result %d\n", __func__, err);
+}
+
+static void ceph_init_rreq(struct netfs_read_request *rreq, struct file *file)
+{
+}
+
+const struct netfs_read_request_ops ceph_netfs_read_ops = {
+	.init_rreq		= ceph_init_rreq,
+	.is_cache_enabled	= ceph_is_cache_enabled,
+	.begin_cache_operation	= ceph_begin_cache_operation,
+	.issue_op		= ceph_netfs_issue_op,
+	.expand_readahead	= ceph_netfs_expand_readahead,
+	.clamp_length		= ceph_netfs_clamp_length,
+};
+
+/* read a single page, without unlocking it. */
+static int ceph_readpage(struct file *file, struct page *page)
+{
+	struct inode *inode = file_inode(file);
+	struct ceph_inode_info *ci = ceph_inode(inode);
+	struct ceph_vino vino = ceph_vino(inode);
+	u64 off = page_offset(page);
+	u64 len = PAGE_SIZE;
+
+	if (ci->i_inline_version != CEPH_INLINE_NONE) {
+		/*
+		 * Uptodate inline data should have been added
+		 * into page cache while getting Fcr caps.
+		 */
+		if (off == 0) {
+			unlock_page(page);
+			return -EINVAL;
+		}
+		zero_user_segment(page, 0, PAGE_SIZE);
+		SetPageUptodate(page);
+		unlock_page(page);
+		return 0;
+	}
+
+	dout("readpage ino %llx.%llx file %p off %llu len %llu page %p index %lu\n",
+	     vino.ino, vino.snap, file, off, len, page, page->index);
+
+	return netfs_readpage(file, page, &ceph_netfs_read_ops, NULL);
+}
+
 /* read a single page, without unlocking it. */
 static int ceph_do_readpage(struct file *filp, struct page *page)
 {
@@ -253,16 +410,6 @@ static int ceph_do_readpage(struct file *filp, struct page *page)
 	return err < 0 ? err : 0;
 }
 
-static int ceph_readpage(struct file *filp, struct page *page)
-{
-	int r = ceph_do_readpage(filp, page);
-	if (r != -EINPROGRESS)
-		unlock_page(page);
-	else
-		r = 0;
-	return r;
-}
-
 /*
  * Finish an async read(ahead) op.
  */
diff --git a/fs/ceph/cache.h b/fs/ceph/cache.h
index 10c21317b62f..1409d6149281 100644
--- a/fs/ceph/cache.h
+++ b/fs/ceph/cache.h
@@ -9,6 +9,8 @@
 #ifndef _CEPH_CACHE_H
 #define _CEPH_CACHE_H
 
+#include <linux/netfs.h>
+
 #ifdef CONFIG_CEPH_FSCACHE
 
 extern struct fscache_netfs ceph_cache_netfs;
@@ -35,11 +37,31 @@ static inline void ceph_fscache_inode_init(struct ceph_inode_info *ci)
 	ci->fscache = NULL;
 }
 
+static inline struct fscache_cookie *ceph_fscache_cookie(struct ceph_inode_info *ci)
+{
+	return ci->fscache;
+}
+
 static inline void ceph_fscache_invalidate(struct inode *inode)
 {
 	fscache_invalidate(ceph_inode(inode)->fscache);
 }
 
+static inline bool ceph_is_cache_enabled(struct inode *inode)
+{
+	struct fscache_cookie *cookie = ceph_fscache_cookie(ceph_inode(inode));
+
+	if (!cookie)
+		return false;
+	return fscache_cookie_enabled(cookie);
+}
+
+static inline int ceph_begin_cache_operation(struct netfs_read_request *rreq)
+{
+	struct fscache_cookie *cookie = ceph_fscache_cookie(ceph_inode(rreq->inode));
+
+	return fscache_begin_read_operation(rreq, cookie);
+}
 #else
 
 static inline int ceph_fscache_register(void)
@@ -65,6 +87,11 @@ static inline void ceph_fscache_inode_init(struct ceph_inode_info *ci)
 {
 }
 
+static inline struct fscache_cookie *ceph_fscache_cookie(struct ceph_inode_info *ci)
+{
+	return NULL;
+}
+
 static inline void ceph_fscache_register_inode_cookie(struct inode *inode)
 {
 }
@@ -82,6 +109,15 @@ static inline void ceph_fscache_invalidate(struct inode *inode)
 {
 }
 
+static inline bool ceph_is_cache_enabled(struct inode *inode)
+{
+	return false;
+}
+
+static inline int ceph_begin_cache_operation(struct netfs_read_request *rreq)
+{
+	return -ENOBUFS;
+}
 #endif
 
 #endif /* _CEPH_CACHE_H */
-- 
2.29.2

[PATCH v3 5/6] ceph: plug write_begin into read helper

[Jeff Layton]

Convert ceph_write_begin to use the netfs_write_begin helper. Most of
the ops we need for it are already in place from the readpage conversion
but we do add a new check_write_begin op since ceph needs to be able to
vet whether there is an incompatible writeback already in flight before
reading in the page.

With this, we can also remove the old ceph_do_readpage helper.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Cc: ceph-devel@vger.kernel.org
Cc: linux-cachefs@redhat.com
Cc: linux-fsdevel@vger.kernel.org
---
 fs/ceph/addr.c | 186 +++++++++++++++----------------------------------
 1 file changed, 57 insertions(+), 129 deletions(-)

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index fbfdf1296174..84b6b43c399d 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -62,6 +62,9 @@
 	(CONGESTION_ON_THRESH(congestion_kb) -				\
 	 (CONGESTION_ON_THRESH(congestion_kb) >> 2))
 
+static int ceph_netfs_check_write_begin(struct file *file, loff_t pos, unsigned int len,
+					struct page *page, void **_fsdata);
+
 static inline struct ceph_snap_context *page_snap_context(struct page *page)
 {
 	if (PagePrivate(page))
@@ -308,6 +311,7 @@ const struct netfs_read_request_ops ceph_netfs_read_ops = {
 	.issue_op		= ceph_netfs_issue_op,
 	.expand_readahead	= ceph_netfs_expand_readahead,
 	.clamp_length		= ceph_netfs_clamp_length,
+	.check_write_begin	= ceph_netfs_check_write_begin,
 };
 
 /* read a single page, without unlocking it. */
@@ -340,76 +344,6 @@ static int ceph_readpage(struct file *file, struct page *page)
 	return netfs_readpage(file, page, &ceph_netfs_read_ops, NULL);
 }
 
-/* read a single page, without unlocking it. */
-static int ceph_do_readpage(struct file *filp, struct page *page)
-{
-	struct inode *inode = file_inode(filp);
-	struct ceph_inode_info *ci = ceph_inode(inode);
-	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
-	struct ceph_osd_client *osdc = &fsc->client->osdc;
-	struct ceph_osd_request *req;
-	struct ceph_vino vino = ceph_vino(inode);
-	int err = 0;
-	u64 off = page_offset(page);
-	u64 len = PAGE_SIZE;
-
-	if (off >= i_size_read(inode)) {
-		zero_user_segment(page, 0, PAGE_SIZE);
-		SetPageUptodate(page);
-		return 0;
-	}
-
-	if (ci->i_inline_version != CEPH_INLINE_NONE) {
-		/*
-		 * Uptodate inline data should have been added
-		 * into page cache while getting Fcr caps.
-		 */
-		if (off == 0)
-			return -EINVAL;
-		zero_user_segment(page, 0, PAGE_SIZE);
-		SetPageUptodate(page);
-		return 0;
-	}
-
-	dout("readpage ino %llx.%llx file %p off %llu len %llu page %p index %lu\n",
-	     vino.ino, vino.snap, filp, off, len, page, page->index);
-	req = ceph_osdc_new_request(osdc, &ci->i_layout, vino, off, &len, 0, 1,
-				    CEPH_OSD_OP_READ, CEPH_OSD_FLAG_READ, NULL,
-				    ci->i_truncate_seq, ci->i_truncate_size,
-				    false);
-	if (IS_ERR(req))
-		return PTR_ERR(req);
-
-	osd_req_op_extent_osd_data_pages(req, 0, &page, len, 0, false, false);
-
-	err = ceph_osdc_start_request(osdc, req, false);
-	if (!err)
-		err = ceph_osdc_wait_request(osdc, req);
-
-	ceph_update_read_latency(&fsc->mdsc->metric, req->r_start_latency,
-				 req->r_end_latency, err);
-
-	ceph_osdc_put_request(req);
-	dout("readpage result %d\n", err);
-
-	if (err == -ENOENT)
-		err = 0;
-	if (err < 0) {
-		if (err == -EBLOCKLISTED)
-			fsc->blocklisted = true;
-		goto out;
-	}
-	if (err < PAGE_SIZE)
-		/* zero fill remainder of page */
-		zero_user_segment(page, err, PAGE_SIZE);
-	else
-		flush_dcache_page(page);
-
-	SetPageUptodate(page);
-out:
-	return err < 0 ? err : 0;
-}
-
 /*
  * Finish an async read(ahead) op.
  */
@@ -1429,6 +1363,31 @@ ceph_find_incompatible(struct page *page)
 	return NULL;
 }
 
+static int ceph_netfs_check_write_begin(struct file *file, loff_t pos, unsigned int len,
+					struct page *page, void **_fsdata)
+{
+	struct inode *inode = file_inode(file);
+	struct ceph_inode_info *ci = ceph_inode(inode);
+	struct ceph_snap_context *snapc;
+
+	snapc = ceph_find_incompatible(page);
+	if (snapc) {
+		int r;
+
+		unlock_page(page);
+		put_page(page);
+		if (IS_ERR(snapc))
+			return PTR_ERR(snapc);
+
+		ceph_queue_writeback(inode);
+		r = wait_event_killable(ci->i_cap_wq,
+					context_is_writeable_or_written(inode, snapc));
+		ceph_put_snap_context(snapc);
+		return r == 0 ? -EAGAIN : r;
+	}
+	return 0;
+}
+
 /*
  * We are only allowed to write into/dirty the page if the page is
  * clean, or already dirty within the same snap context.
@@ -1439,75 +1398,47 @@ static int ceph_write_begin(struct file *file, struct address_space *mapping,
 {
 	struct inode *inode = file_inode(file);
 	struct ceph_inode_info *ci = ceph_inode(inode);
-	struct ceph_snap_context *snapc;
 	struct page *page = NULL;
 	pgoff_t index = pos >> PAGE_SHIFT;
-	int pos_in_page = pos & ~PAGE_MASK;
-	int r = 0;
-
-	dout("write_begin file %p inode %p page %p %d~%d\n", file, inode, page, (int)pos, (int)len);
+	int r;
 
-	for (;;) {
+	/*
+	 * Uninlining should have already been done and everything updated, EXCEPT
+	 * for inline_version sent to the MDS.
+	 */
+	if (ci->i_inline_version != CEPH_INLINE_NONE) {
 		page = grab_cache_page_write_begin(mapping, index, flags);
-		if (!page) {
-			r = -ENOMEM;
-			break;
-		}
-
-		snapc = ceph_find_incompatible(page);
-		if (snapc) {
-			if (IS_ERR(snapc)) {
-				r = PTR_ERR(snapc);
-				break;
-			}
-			unlock_page(page);
-			put_page(page);
-			page = NULL;
-			ceph_queue_writeback(inode);
-			r = wait_event_killable(ci->i_cap_wq,
-						context_is_writeable_or_written(inode, snapc));
-			ceph_put_snap_context(snapc);
-			if (r != 0)
-				break;
-			continue;
-		}
-
-		if (PageUptodate(page)) {
-			dout(" page %p already uptodate\n", page);
-			break;
-		}
+		if (!page)
+			return -ENOMEM;
 
 		/*
-		 * In some cases we don't need to read at all:
-		 * - full page write
-		 * - write that lies completely beyond EOF
-		 * - write that covers the the page from start to EOF or beyond it
+		 * The inline_version on a new inode is set to 1. If that's the
+		 * case, then the page is brand new and isn't yet Uptodate.
 		 */
-		if ((pos_in_page == 0 && len == PAGE_SIZE) ||
-		    (pos >= i_size_read(inode)) ||
-		    (pos_in_page == 0 && (pos + len) >= i_size_read(inode))) {
-			zero_user_segments(page, 0, pos_in_page,
-					   pos_in_page + len, PAGE_SIZE);
-			break;
+		r = 0;
+		if (index == 0 && ci->i_inline_version != 1) {
+			if (!PageUptodate(page)) {
+				WARN_ONCE(1, "ceph: write_begin called on still-inlined inode (inline_version %llu)!\n",
+					  ci->i_inline_version);
+				r = -EINVAL;
+			}
+			goto out;
 		}
-
-		/*
-		 * We need to read it. If we get back -EINPROGRESS, then the page was
-		 * handed off to fscache and it will be unlocked when the read completes.
-		 * Refind the page in that case so we can reacquire the page lock. Otherwise
-		 * we got a hard error or the read was completed synchronously.
-		 */
-		r = ceph_do_readpage(file, page);
-		if (r != -EINPROGRESS)
-			break;
+		zero_user_segment(page, 0, PAGE_SIZE);
+		SetPageUptodate(page);
+		goto out;
 	}
 
+	r = netfs_write_begin(file, inode->i_mapping, pos, len, 0, &page, NULL,
+			      &ceph_netfs_read_ops, NULL);
+out:
+	if (r == 0)
+		wait_on_page_fscache(page);
 	if (r < 0) {
-		if (page) {
-			unlock_page(page);
+		if (page)
 			put_page(page);
-		}
 	} else {
+		WARN_ON_ONCE(!PageLocked(page));
 		*pagep = page;
 	}
 	return r;
@@ -1680,9 +1611,6 @@ static vm_fault_t ceph_filemap_fault(struct vm_fault *vmf)
 	return ret;
 }
 
-/*
- * Reuse write_begin here for simplicity.
- */
 static vm_fault_t ceph_page_mkwrite(struct vm_fault *vmf)
 {
 	struct vm_area_struct *vma = vmf->vma;
-- 
2.29.2

[PATCH v3 6/6] ceph: convert ceph_readpages to ceph_readahead

[Jeff Layton]

Convert ceph_readpages to ceph_readahead and make it use
netfs_readahead. With this we can rip out a lot of the old
readpage/readpages infrastructure.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Cc: ceph-devel@vger.kernel.org
Cc: linux-cachefs@redhat.com
Cc: linux-fsdevel@vger.kernel.org
---
 fs/ceph/addr.c | 230 +++++++------------------------------------------
 1 file changed, 31 insertions(+), 199 deletions(-)

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 84b6b43c399d..b476133353ae 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -304,6 +304,16 @@ static void ceph_init_rreq(struct netfs_read_request *rreq, struct file *file)
 {
 }
 
+static void ceph_readahead_cleanup(struct address_space *mapping, void *priv)
+{
+	struct inode *inode = mapping->host;
+	struct ceph_inode_info *ci = ceph_inode(inode);
+	int got = (uintptr_t)priv;
+
+	if (got)
+		ceph_put_cap_refs(ci, got);
+}
+
 const struct netfs_read_request_ops ceph_netfs_read_ops = {
 	.init_rreq		= ceph_init_rreq,
 	.is_cache_enabled	= ceph_is_cache_enabled,
@@ -312,6 +322,7 @@ const struct netfs_read_request_ops ceph_netfs_read_ops = {
 	.expand_readahead	= ceph_netfs_expand_readahead,
 	.clamp_length		= ceph_netfs_clamp_length,
 	.check_write_begin	= ceph_netfs_check_write_begin,
+	.cleanup		= ceph_readahead_cleanup,
 };
 
 /* read a single page, without unlocking it. */
@@ -344,214 +355,35 @@ static int ceph_readpage(struct file *file, struct page *page)
 	return netfs_readpage(file, page, &ceph_netfs_read_ops, NULL);
 }
 
-/*
- * Finish an async read(ahead) op.
- */
-static void finish_read(struct ceph_osd_request *req)
+static void ceph_readahead(struct readahead_control *ractl)
 {
-	struct inode *inode = req->r_inode;
-	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
-	struct ceph_osd_data *osd_data;
-	int rc = req->r_result <= 0 ? req->r_result : 0;
-	int bytes = req->r_result >= 0 ? req->r_result : 0;
-	int num_pages;
-	int i;
-
-	dout("finish_read %p req %p rc %d bytes %d\n", inode, req, rc, bytes);
-	if (rc == -EBLOCKLISTED)
-		ceph_inode_to_client(inode)->blocklisted = true;
-
-	/* unlock all pages, zeroing any data we didn't read */
-	osd_data = osd_req_op_extent_osd_data(req, 0);
-	BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_PAGES);
-	num_pages = calc_pages_for((u64)osd_data->alignment,
-					(u64)osd_data->length);
-	for (i = 0; i < num_pages; i++) {
-		struct page *page = osd_data->pages[i];
-
-		if (rc < 0 && rc != -ENOENT)
-			goto unlock;
-		if (bytes < (int)PAGE_SIZE) {
-			/* zero (remainder of) page */
-			int s = bytes < 0 ? 0 : bytes;
-			zero_user_segment(page, s, PAGE_SIZE);
-		}
- 		dout("finish_read %p uptodate %p idx %lu\n", inode, page,
-		     page->index);
-		flush_dcache_page(page);
-		SetPageUptodate(page);
-unlock:
-		unlock_page(page);
-		put_page(page);
-		bytes -= PAGE_SIZE;
-	}
-
-	ceph_update_read_latency(&fsc->mdsc->metric, req->r_start_latency,
-				 req->r_end_latency, rc);
-
-	kfree(osd_data->pages);
-}
-
-/*
- * start an async read(ahead) operation.  return nr_pages we submitted
- * a read for on success, or negative error code.
- */
-static int start_read(struct inode *inode, struct ceph_rw_context *rw_ctx,
-		      struct list_head *page_list, int max)
-{
-	struct ceph_osd_client *osdc =
-		&ceph_inode_to_client(inode)->client->osdc;
-	struct ceph_inode_info *ci = ceph_inode(inode);
-	struct page *page = lru_to_page(page_list);
-	struct ceph_vino vino;
-	struct ceph_osd_request *req;
-	u64 off;
-	u64 len;
-	int i;
-	struct page **pages;
-	pgoff_t next_index;
-	int nr_pages = 0;
+	struct inode *inode = file_inode(ractl->file);
+	struct ceph_file_info *fi = ractl->file->private_data;
+	struct ceph_rw_context *rw_ctx;
 	int got = 0;
 	int ret = 0;
 
+	if (ceph_inode(inode)->i_inline_version != CEPH_INLINE_NONE)
+		return;
+
+	rw_ctx = ceph_find_rw_context(fi);
 	if (!rw_ctx) {
-		/* caller of readpages does not hold buffer and read caps
-		 * (fadvise, madvise and readahead cases) */
+		/*
+		 * readahead callers do not necessarily hold Fcb caps
+		 * (e.g. fadvise, madvise).
+		 */
 		int want = CEPH_CAP_FILE_CACHE;
-		ret = ceph_try_get_caps(inode, CEPH_CAP_FILE_RD, want,
-					true, &got);
-		if (ret < 0) {
+
+		ret = ceph_try_get_caps(inode, CEPH_CAP_FILE_RD, want, true, &got);
+		if (ret < 0)
 			dout("start_read %p, error getting cap\n", inode);
-		} else if (!(got & want)) {
+		else if (!(got & want))
 			dout("start_read %p, no cache cap\n", inode);
-			ret = 0;
-		}
-		if (ret <= 0) {
-			if (got)
-				ceph_put_cap_refs(ci, got);
-			while (!list_empty(page_list)) {
-				page = lru_to_page(page_list);
-				list_del(&page->lru);
-				put_page(page);
-			}
-			return ret;
-		}
-	}
-
-	off = (u64) page_offset(page);
 
-	/* count pages */
-	next_index = page->index;
-	list_for_each_entry_reverse(page, page_list, lru) {
-		if (page->index != next_index)
-			break;
-		nr_pages++;
-		next_index++;
-		if (max && nr_pages == max)
-			break;
-	}
-	len = nr_pages << PAGE_SHIFT;
-	dout("start_read %p nr_pages %d is %lld~%lld\n", inode, nr_pages,
-	     off, len);
-	vino = ceph_vino(inode);
-	req = ceph_osdc_new_request(osdc, &ci->i_layout, vino, off, &len,
-				    0, 1, CEPH_OSD_OP_READ,
-				    CEPH_OSD_FLAG_READ, NULL,
-				    ci->i_truncate_seq, ci->i_truncate_size,
-				    false);
-	if (IS_ERR(req)) {
-		ret = PTR_ERR(req);
-		goto out;
-	}
-
-	/* build page vector */
-	nr_pages = calc_pages_for(0, len);
-	pages = kmalloc_array(nr_pages, sizeof(*pages), GFP_KERNEL);
-	if (!pages) {
-		ret = -ENOMEM;
-		goto out_put;
-	}
-	for (i = 0; i < nr_pages; ++i) {
-		page = list_entry(page_list->prev, struct page, lru);
-		BUG_ON(PageLocked(page));
-		list_del(&page->lru);
-
- 		dout("start_read %p adding %p idx %lu\n", inode, page,
-		     page->index);
-		if (add_to_page_cache_lru(page, &inode->i_data, page->index,
-					  GFP_KERNEL)) {
-			put_page(page);
-			dout("start_read %p add_to_page_cache failed %p\n",
-			     inode, page);
-			nr_pages = i;
-			if (nr_pages > 0) {
-				len = nr_pages << PAGE_SHIFT;
-				osd_req_op_extent_update(req, 0, len);
-				break;
-			}
-			goto out_pages;
-		}
-		pages[i] = page;
-	}
-	osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0, false, false);
-	req->r_callback = finish_read;
-	req->r_inode = inode;
-
-	dout("start_read %p starting %p %lld~%lld\n", inode, req, off, len);
-	ret = ceph_osdc_start_request(osdc, req, false);
-	if (ret < 0)
-		goto out_pages;
-	ceph_osdc_put_request(req);
-
-	/* After adding locked pages to page cache, the inode holds cache cap.
-	 * So we can drop our cap refs. */
-	if (got)
-		ceph_put_cap_refs(ci, got);
-
-	return nr_pages;
-
-out_pages:
-	for (i = 0; i < nr_pages; ++i)
-		unlock_page(pages[i]);
-	ceph_put_page_vector(pages, nr_pages, false);
-out_put:
-	ceph_osdc_put_request(req);
-out:
-	if (got)
-		ceph_put_cap_refs(ci, got);
-	return ret;
-}
-
-
-/*
- * Read multiple pages.  Leave pages we don't read + unlock in page_list;
- * the caller (VM) cleans them up.
- */
-static int ceph_readpages(struct file *file, struct address_space *mapping,
-			  struct list_head *page_list, unsigned nr_pages)
-{
-	struct inode *inode = file_inode(file);
-	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
-	struct ceph_file_info *fi = file->private_data;
-	struct ceph_rw_context *rw_ctx;
-	int rc = 0;
-	int max = 0;
-
-	if (ceph_inode(inode)->i_inline_version != CEPH_INLINE_NONE)
-		return -EINVAL;
-
-	rw_ctx = ceph_find_rw_context(fi);
-	max = fsc->mount_options->rsize >> PAGE_SHIFT;
-	dout("readpages %p file %p ctx %p nr_pages %d max %d\n",
-	     inode, file, rw_ctx, nr_pages, max);
-	while (!list_empty(page_list)) {
-		rc = start_read(inode, rw_ctx, page_list, max);
-		if (rc < 0)
-			goto out;
+		if (ret <= 0)
+			return;
 	}
-out:
-	dout("readpages %p file %p ret %d\n", inode, file, rc);
-	return rc;
+	netfs_readahead(ractl, &ceph_netfs_read_ops, (void *)(uintptr_t)got);
 }
 
 struct ceph_writeback_ctl
@@ -1496,7 +1328,7 @@ static ssize_t ceph_direct_io(struct kiocb *iocb, struct iov_iter *iter)
 
 const struct address_space_operations ceph_aops = {
 	.readpage = ceph_readpage,
-	.readpages = ceph_readpages,
+	.readahead = ceph_readahead,
 	.writepage = ceph_writepage,
 	.writepages = ceph_writepages_start,
 	.write_begin = ceph_write_begin,
-- 
2.29.2

Re: [PATCH v3 0/6] ceph: convert to netfs helper library

[Xiubo Li]

On 2021/2/23 21:06, Jeff Layton wrote:
> This is the third posting of this patchset. The main differences between
> this one and the last are some bugfixes, and cleanups:
>
> - rebase onto David's latest fscache-netfs-lib set
> - unify the netfs_read_request_ops into one struct
> - fix inline_data handling in write_begin
> - remove the now-unneeded i_fscache_gen field from ceph_inode_info
> - rename gfp_flags to gfp in releasepage
> - pass appropriate was_async flag to netfs_subreq_terminated
>
> This set is currently sitting in the ceph-client/testing branch, so
> it should get good testing coverage over the next few weeks via in
> the teuthology lab.
>
> Jeff Layton (6):
>    ceph: disable old fscache readpage handling
>    ceph: rework PageFsCache handling
>    ceph: fix fscache invalidation
>    ceph: convert readpage to fscache read helper
>    ceph: plug write_begin into read helper
>    ceph: convert ceph_readpages to ceph_readahead
>
>   fs/ceph/Kconfig |   1 +
>   fs/ceph/addr.c  | 541 +++++++++++++++++++-----------------------------
>   fs/ceph/cache.c | 125 -----------
>   fs/ceph/cache.h | 101 +++------
>   fs/ceph/caps.c  |  10 +-
>   fs/ceph/inode.c |   1 +
>   fs/ceph/super.h |   2 +-
>   7 files changed, 242 insertions(+), 539 deletions(-)
>
This series LGTM.

Reviewed-by: Xiubo Li <xiubli@redhat.com>