[PATCH 0/7] Cifs and Ceph: Uncache single no-data page in readpage()

[PATCH 0/7] Cifs and Ceph: Uncache single no-data page in readpage()

[Li Wang]

Currently, the page allocated into fscache in readpage() 
for Cifs and Ceph does not be uncached if no data read due
to io error. This patch fixes this. fscache_readpages_cancel() 
is for this kind of job but taking list read * as input, so
a new routine take page * as input is introduced. 

Li Wang (7):
  Fscache: Introduce new API fscache_readpage_cancel()
  Fscache: Implement uncaching single no-data page
  Ceph: Introduce routine for uncaching single no-data page
  Ceph: Uncaching no-data page in readpage()
  Cifs: Introduce routine for uncaching single no-data page
  Cifs: Implement uncaching single no-data page
  Cifs: Uncaching no-data page in readpage()

 fs/ceph/addr.c          |    1 +
 fs/ceph/cache.h         |   13 +++++++++++++
 fs/cifs/file.c          |    4 +++-
 fs/cifs/fscache.c       |    7 +++++++
 fs/cifs/fscache.h       |   13 +++++++++++++
 fs/fscache/page.c       |    8 ++++++++
 include/linux/fscache.h |   11 +++++++++++
 7 files changed, 56 insertions(+), 1 deletion(-)

-- 
1.7.9.5

[PATCH 1/7] Fscache: Introduce new API fscache_readpage_cancel()

[Li Wang]

Introduce a new API fscache_readpage_cancel() for uncaching one single
no-data page from fscache.

Signed-off-by: Li Wang <liwang@ubuntukylin.com>
---
 include/linux/fscache.h |   11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/include/linux/fscache.h b/include/linux/fscache.h
index 115bb81..f1ed21f 100644
--- a/include/linux/fscache.h
+++ b/include/linux/fscache.h
@@ -245,6 +245,8 @@ extern bool __fscache_maybe_release_page(struct fscache_cookie *, struct page *,
 					 gfp_t);
 extern void __fscache_uncache_all_inode_pages(struct fscache_cookie *,
 					      struct inode *);
+extern void __fscache_readpage_cancel(struct fscache_cookie *cookie,
+				      struct page *page);
 extern void __fscache_readpages_cancel(struct fscache_cookie *cookie,
 				       struct list_head *pages);
 extern void __fscache_disable_cookie(struct fscache_cookie *, bool);
@@ -633,6 +635,15 @@ int fscache_alloc_page(struct fscache_cookie *cookie,
 		return -ENOBUFS;
 }
 
+static inline
+void fscache_readpage_cancel(struct fscache_cookie *cookie,
+			     struct page *page)
+{
+	if (fscache_cookie_valid(cookie))
+		__fscache_readpage_cancel(cookie, page);
+}
+
+
 /**
  * fscache_readpages_cancel - Cancel read/alloc on pages
  * @cookie: The cookie representing the inode's cache object.
-- 
1.7.9.5

[PATCH 2/7] Fscache: Implement uncaching single no-data page

[Li Wang]

Similar to the routine for multiple pages except
that it takes page * as input rather than list head *.

Signed-off-by: Li Wang <liwang@ubuntukylin.com>
---
 fs/fscache/page.c |    8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/fs/fscache/page.c b/fs/fscache/page.c
index 7f5c658..0c69f72 100644
--- a/fs/fscache/page.c
+++ b/fs/fscache/page.c
@@ -721,6 +721,14 @@ nobufs:
 }
 EXPORT_SYMBOL(__fscache_alloc_page);
 
+void __fscache_readpage_cancel(struct fscache_cookie *cookie,
+			       struct page *page)
+{
+	if (PageFsCache(page))
+		__fscache_uncache_page(cookie, page);
+}
+EXPORT_SYMBOL(__fscache_readpage_cancel);
+
 /*
  * Unmark pages allocate in the readahead code path (via:
  * fscache_readpages_or_alloc) after delegating to the base filesystem
-- 
1.7.9.5

[PATCH 3/7] Ceph: Introduce routine for uncaching single no-data page

[Li Wang]

Introduce a routine for uncaching single no-data page, typically
in readpage().

Signed-off-by: Li Wang <liwang@ubuntukylin.com>
---
 fs/ceph/cache.h |   13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/fs/ceph/cache.h b/fs/ceph/cache.h
index ba94940..eb0ec76 100644
--- a/fs/ceph/cache.h
+++ b/fs/ceph/cache.h
@@ -67,6 +67,14 @@ static inline int ceph_release_fscache_page(struct page *page, gfp_t gfp)
 	return fscache_maybe_release_page(ci->fscache, page, gfp);
 }
 
+
+static inline void cpeh_fscache_readpage_cancel(struct inode *inode,
+						struct page *page)
+{
+	struct ceph_inode_info *ci = ceph_inode(inode);
+	return fscache_readpage_cancel(ci->fscache, page);
+}
+
 static inline void ceph_fscache_readpages_cancel(struct inode *inode,
 						 struct list_head *pages)
 {
@@ -145,6 +153,11 @@ 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)
 {
-- 
1.7.9.5

[PATCH 4/7] Ceph: Uncaching no-data page in readpage()

[Li Wang]

Currently, if one page allocated into fscache in readpage(), however, with
no-data read, it is not uncached. This patch fixes this.

Signed-off-by: Li Wang <liwang@ubuntukylin.com>
---
 fs/ceph/addr.c |    1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 6df8bd4..be5f4b6 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -209,6 +209,7 @@ static int readpage_nounlock(struct file *filp, struct page *page)
 		err = 0;
 	if (err < 0) {
 		SetPageError(page);
+		ceph_fscache_readpage_cancel(inode, page);
 		goto out;
 	} else if (err < PAGE_CACHE_SIZE) {
 		/* zero fill remainder of page */
-- 
1.7.9.5

[PATCH 5/7] Cifs: Introduce routine for uncaching single no-data page

[Li Wang]

Introduce a routine for uncaching single no-data page, typically
in readpage().

Signed-off-by: Li Wang <liwang@ubuntukylin.com>
---
 fs/cifs/fscache.h |   13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/fs/cifs/fscache.h b/fs/cifs/fscache.h
index 24794b6..c712f42 100644
--- a/fs/cifs/fscache.h
+++ b/fs/cifs/fscache.h
@@ -54,6 +54,7 @@ extern int __cifs_readpages_from_fscache(struct inode *,
 					 struct address_space *,
 					 struct list_head *,
 					 unsigned *);
+extern void __cifs_fscache_readpage_cancel(struct inode *, struct page *);
 extern void __cifs_fscache_readpages_cancel(struct inode *, struct list_head *);
 
 extern void __cifs_readpage_to_fscache(struct inode *, struct page *);
@@ -92,6 +93,13 @@ static inline void cifs_readpage_to_fscache(struct inode *inode,
 		__cifs_readpage_to_fscache(inode, page);
 }
 
+static inline void cifs_fscache_readpage_cancel(struct inode *inode,
+						struct page *page)
+{
+	if (CIFS_I(inode)->fscache)
+		return __cifs_fscache_readpage_cancel(inode, page);
+}
+
 static inline void cifs_fscache_readpages_cancel(struct inode *inode,
 						 struct list_head *pages)
 {
@@ -139,6 +147,11 @@ static inline int cifs_readpages_from_fscache(struct inode *inode,
 static inline void cifs_readpage_to_fscache(struct inode *inode,
 			struct page *page) {}
 
+static inline void cifs_fscache_readpage_cancel(struct inode *inode,
+						struct page *page)
+{
+}
+
 static inline void cifs_fscache_readpages_cancel(struct inode *inode,
 						 struct list_head *pages)
 {
-- 
1.7.9.5

[PATCH 6/7] Cifs: Implement uncaching single no-data page

[Li Wang]

Implement the routine for uncaching single no-data page, typically
in readpage().

Signed-off-by: Li Wang <liwang@ubuntukylin.com>
---
 fs/cifs/fscache.c |    7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/fs/cifs/fscache.c b/fs/cifs/fscache.c
index 8d4b7bc..168f184 100644
--- a/fs/cifs/fscache.c
+++ b/fs/cifs/fscache.c
@@ -223,6 +223,13 @@ void __cifs_readpage_to_fscache(struct inode *inode, struct page *page)
 		fscache_uncache_page(CIFS_I(inode)->fscache, page);
 }
 
+void __cifs_fscache_readpage_cancel(struct inode *inode, struct page *page)
+{
+        cifs_dbg(FYI, "%s: (fsc: %p, i: %p)\n",
+                 __func__, CIFS_I(inode)->fscache, inode);
+        fscache_readpage_cancel(CIFS_I(inode)->fscache, page);
+}
+
 void __cifs_fscache_readpages_cancel(struct inode *inode, struct list_head *pages)
 {
 	cifs_dbg(FYI, "%s: (fsc: %p, i: %p)\n",
-- 
1.7.9.5

[PATCH 7/7] Cifs: Uncaching no-data page in readpage()

[Li Wang]

Currently, if one page allocated into fscache in readpage(), however, with
no-data read, it is not uncached. This patch fixes this.

Signed-off-by: Li Wang <liwang@ubuntukylin.com>
---
 fs/cifs/file.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 7ddddf2..153bc58 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -3406,8 +3406,10 @@ static int cifs_readpage_worker(struct file *file, struct page *page,
 
 	rc = cifs_read(file, read_data, PAGE_CACHE_SIZE, poffset);
 
-	if (rc < 0)
+	if (rc < 0) {
+		cifs_fscache_readpage_cancel(file_inode(file), page);
 		goto io_error;
+	}
 	else
 		cifs_dbg(FYI, "Bytes read %d\n", rc);
 
-- 
1.7.9.5

Re: [PATCH 0/7] Cifs and Ceph: Uncache single no-data page in readpage()

[Milosz Tanski]

Li,

I recommend you CC David Howells who maintains FSCache directly on your emails.

Thanks,
- Milosz

On Mon, Nov 11, 2013 at 10:27 AM, Li Wang <liwang@ubuntukylin.com> wrote:
> Currently, the page allocated into fscache in readpage()
> for Cifs and Ceph does not be uncached if no data read due
> to io error. This patch fixes this. fscache_readpages_cancel()
> is for this kind of job but taking list read * as input, so
> a new routine take page * as input is introduced.
>
> Li Wang (7):
>   Fscache: Introduce new API fscache_readpage_cancel()
>   Fscache: Implement uncaching single no-data page
>   Ceph: Introduce routine for uncaching single no-data page
>   Ceph: Uncaching no-data page in readpage()
>   Cifs: Introduce routine for uncaching single no-data page
>   Cifs: Implement uncaching single no-data page
>   Cifs: Uncaching no-data page in readpage()
>
>  fs/ceph/addr.c          |    1 +
>  fs/ceph/cache.h         |   13 +++++++++++++
>  fs/cifs/file.c          |    4 +++-
>  fs/cifs/fscache.c       |    7 +++++++
>  fs/cifs/fscache.h       |   13 +++++++++++++
>  fs/fscache/page.c       |    8 ++++++++
>  include/linux/fscache.h |   11 +++++++++++
>  7 files changed, 56 insertions(+), 1 deletion(-)
>
> --
> 1.7.9.5
>



-- 
Milosz Tanski
CTO
10 East 53rd Street, 37th floor
New York, NY 10022

p: 646-253-9055
e: milosz@adfin.com