Commit 54afa990 authored by David Howells's avatar David Howells Committed by Steve French
Browse files

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: default avatarDavid Howells <dhowells@redhat.com>
Reviewed-by: default avatarJeff Layton <jlayton@redhat.com>
Signed-off-by: default avatarSteve French <smfrench@gmail.com>
parent 62d228b8

fs/cifs/file.c

+8 −0
Original line number Diff line number Diff line
@@ -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;

}

fs/cifs/fscache.c

+7 −0
Original line number Diff line number Diff line
@@ -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);

fs/cifs/fscache.h

+13 −0
Original line number Diff line number Diff line
@@ -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 */

CRA Git | Maintained and supported by SUSTech CRA and CCSE