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

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
......@@ -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 */
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