linux/include
Minchan Kim 97cecb5a25 mm: introduce delete_from_page_cache()
Presently we increase the page refcount in add_to_page_cache() but don't
decrease it in remove_from_page_cache().  Such asymmetry adds confusion,
requiring that callers notice it and a comment explaining why they release
a page reference.  It's not a good API.

A long time ago, Hugh tried it (http://lkml.org/lkml/2004/10/24/140) but
gave up because reiser4's drop_page() had to unlock the page between
removing it from page cache and doing the page_cache_release().  But now
the situation is changed.  I think at least things in current mainline
don't have any obstacles.  The problem is for out-of-mainline filesystems
- if they have done such things as reiser4, this patch could be a problem
but they will discover this at compile time since we remove
remove_from_page_cache().

This patch:

This function works as just wrapper remove_from_page_cache().  The
difference is that it decreases page references in itself.  So caller have
to make sure it has a page reference before calling.

This patch is ready for removing remove_from_page_cache().

Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Edward Shishkin <edward.shishkin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22 17:44:02 -07:00
..
acpi PM: Remove CONFIG_PM_OPS 2011-03-15 00:43:15 +01:00
asm-generic include/asm-generic/unistd.h: fix syncfs syscall number 2011-03-22 17:43:58 -07:00
crypto
drm Merge remote branch 'intel/drm-intel-next' of ../drm-next into drm-core-next 2011-03-14 14:15:13 +10:00
keys
linux mm: introduce delete_from_page_cache() 2011-03-22 17:44:02 -07:00
math-emu
media
mtd
net IPVS: Use global mutex in ip_vs_app.c 2011-03-21 20:39:24 -07:00
pcmcia
rdma
rxrpc
scsi Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6 2011-03-17 17:54:40 -07:00
sound Merge branch 'topic/misc' into for-linus 2011-03-18 07:39:08 +01:00
target
trace Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6 2011-03-18 10:46:37 -07:00
video fbdev: sh_mobile_lcdc: Add YUV framebuffer support 2011-03-16 17:27:10 +09:00
xen Merge branch 'stable/xen.pm.bug-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen 2011-03-17 18:37:42 -07:00
Kbuild