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 <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>

1 files changed, 7 insertions, 0 deletions

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);