From 54afa99057ee2ffd3df0f5e891298bbbb65ea63c Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 4 Sep 2013 17:10:39 +0000 Subject: [PATCH] CIFS: FS-Cache: Uncache unread pages in cifs_readpages() before freeing them In cifs_readpages(), we may decide we don't want to read a page after all - but the page may already have passed through fscache_read_or_alloc_pages() and thus have marks and reservations set. Thus we have to call fscache_readpages_cancel() or fscache_uncache_page() on the pages we're returning to clear the marks. NFS, AFS and 9P should be unaffected by this as they call read_cache_pages() which does the cleanup for you. Signed-off-by: David Howells Reviewed-by: Jeff Layton Signed-off-by: Steve French --- fs/cifs/file.c | 8 ++++++++ fs/cifs/fscache.c | 7 +++++++ fs/cifs/fscache.h | 13 +++++++++++++ 3 files changed, 28 insertions(+) diff --git a/fs/cifs/file.c b/fs/cifs/file.c index eb955b5..7ddddf2 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -3254,6 +3254,9 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, /* * Reads as many pages as possible from fscache. Returns -ENOBUFS * immediately if the cookie is negative + * + * After this point, every page in the list might have PG_fscache set, + * so we will need to clean that up off of every page we don't use. */ rc = cifs_readpages_from_fscache(mapping->host, mapping, page_list, &num_pages); @@ -3376,6 +3379,11 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, kref_put(&rdata->refcount, cifs_readdata_release); } + /* Any pages that have been shown to fscache but didn't get added to + * the pagecache must be uncached before they get returned to the + * allocator. + */ + cifs_fscache_readpages_cancel(mapping->host, page_list); return rc; } diff --git a/fs/cifs/fscache.c b/fs/cifs/fscache.c index 2f4bc5a..b3258f3 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_readpages_cancel(struct inode *inode, struct list_head *pages) +{ + cifs_dbg(FYI, "%s: (fsc: %p, i: %p)\n", + __func__, CIFS_I(inode)->fscache, inode); + fscache_readpages_cancel(CIFS_I(inode)->fscache, pages); +} + void __cifs_fscache_invalidate_page(struct page *page, struct inode *inode) { struct cifsInodeInfo *cifsi = CIFS_I(inode); diff --git a/fs/cifs/fscache.h b/fs/cifs/fscache.h index 6353932..24794b6 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_readpages_cancel(struct inode *, struct list_head *); extern void __cifs_readpage_to_fscache(struct inode *, struct page *); @@ -91,6 +92,13 @@ static inline void cifs_readpage_to_fscache(struct inode *inode, __cifs_readpage_to_fscache(inode, page); } +static inline void cifs_fscache_readpages_cancel(struct inode *inode, + struct list_head *pages) +{ + if (CIFS_I(inode)->fscache) + return __cifs_fscache_readpages_cancel(inode, pages); +} + #else /* CONFIG_CIFS_FSCACHE */ static inline int cifs_fscache_register(void) { return 0; } static inline void cifs_fscache_unregister(void) {} @@ -131,6 +139,11 @@ 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_readpages_cancel(struct inode *inode, + struct list_head *pages) +{ +} + #endif /* CONFIG_CIFS_FSCACHE */ #endif /* _CIFS_FSCACHE_H */ -- 2.7.4