Commit 99bff93c authored by David Howells's avatar David Howells
Browse files

netfs, mm: Add set/end/wait_on_page_fscache() aliases 



Add set/end/wait_on_page_fscache() as aliases of
set/end/wait_page_private_2().  These allow a page to marked with
PG_fscache, the flag to be removed and waiters woken and waiting for the
flag to be cleared.  A ref on the page is also taken and dropped.

[Linus suggested putting the fscache-themed functions into the
 caching-specific headers rather than pagemap.h[1]]

Changes:
v5:
- Mirror the changes to the core routines[2].

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Tested-by: default avatarJeff Layton <jlayton@kernel.org>
Tested-by: default avatarDave Wysochanski <dwysocha@redhat.com>
Tested-By: default avatarMarc Dionne <marc.dionne@auristor.com>
cc: Linus Torvalds <torvalds@linux-foundation.org>
cc: Matthew Wilcox <willy@infradead.org>
cc: linux-mm@kvack.org
cc: linux-cachefs@redhat.com
cc: linux-afs@lists.infradead.org
cc: linux-nfs@vger.kernel.org
cc: linux-cifs@vger.kernel.org
cc: ceph-devel@vger.kernel.org
cc: v9fs-developer@lists.sourceforge.net
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/1330473.1612974547@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/CAHk-=wjgA-74ddehziVk=XAEMTKswPu1Yw4uaro1R3ibs27ztw@mail.gmail.com/ [1]
Link: https://lore.kernel.org/r/161340393568.1303470.4997526899111310530.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/161539536093.286939.5076448803512118764.stgit@warthog.procyon.org.uk/ # v4
Link: https://lore.kernel.org/r/2499407.1616505440@warthog.procyon.org.uk/ [2]
Link: https://lore.kernel.org/r/161653793873.2770958.12157243390965814502.stgit@warthog.procyon.org.uk/ # v5
Link: https://lore.kernel.org/r/161789075327.6155.7432127924219092385.stgit@warthog.procyon.org.uk/ # v6
parent b533a83f

include/linux/netfs.h

+57 −0
Original line number Diff line number Diff line
@@ -26,4 +26,61 @@ 
#define TestSetPageFsCache(page)	TestSetPagePrivate2((page))

#define TestClearPageFsCache(page)	TestClearPagePrivate2((page))



/**

 * set_page_fscache - Set PG_fscache on a page and take a ref

 * @page: The page.

 *

 * Set the PG_fscache (PG_private_2) flag on a page and take the reference

 * needed for the VM to handle its lifetime correctly.  This sets the flag and

 * takes the reference unconditionally, so care must be taken not to set the

 * flag again if it's already set.

 */

static inline void set_page_fscache(struct page *page)

{

	set_page_private_2(page);

}



/**

 * end_page_fscache - Clear PG_fscache and release any waiters

 * @page: The page

 *

 * Clear the PG_fscache (PG_private_2) bit on a page and wake up any sleepers

 * waiting for this.  The page ref held for PG_private_2 being set is released.

 *

 * This is, for example, used when a netfs page is being written to a local

 * disk cache, thereby allowing writes to the cache for the same page to be

 * serialised.

 */

static inline void end_page_fscache(struct page *page)

{

	end_page_private_2(page);

}



/**

 * wait_on_page_fscache - Wait for PG_fscache to be cleared on a page

 * @page: The page to wait on

 *

 * Wait for PG_fscache (aka PG_private_2) to be cleared on a page.

 */

static inline void wait_on_page_fscache(struct page *page)

{

	wait_on_page_private_2(page);

}



/**

 * wait_on_page_fscache_killable - Wait for PG_fscache to be cleared on a page

 * @page: The page to wait on

 *

 * Wait for PG_fscache (aka PG_private_2) to be cleared on a page or until a

 * fatal signal is received by the calling task.

 *

 * Return:

 * - 0 if successful.

 * - -EINTR if a fatal signal was encountered.

 */

static inline int wait_on_page_fscache_killable(struct page *page)

{

	return wait_on_page_private_2_killable(page);

}



#endif /* _LINUX_NETFS_H */