linux/fs/ubifs
Nick Piggin 54566b2c15 fs: symlink write_begin allocation context fix
With the write_begin/write_end aops, page_symlink was broken because it
could no longer pass a GFP_NOFS type mask into the point where the
allocations happened.  They are done in write_begin, which would always
assume that the filesystem can be entered from reclaim.  This bug could
cause filesystem deadlocks.

The funny thing with having a gfp_t mask there is that it doesn't really
allow the caller to arbitrarily tinker with the context in which it can be
called.  It couldn't ever be GFP_ATOMIC, for example, because it needs to
take the page lock.  The only thing any callers care about is __GFP_FS
anyway, so turn that into a single flag.

Add a new flag for write_begin, AOP_FLAG_NOFS.  Filesystems can now act on
this flag in their write_begin function.  Change __grab_cache_page to
accept a nofs argument as well, to honour that flag (while we're there,
change the name to grab_cache_page_write_begin which is more instructive
and does away with random leading underscores).

This is really a more flexible way to go in the end anyway -- if a
filesystem happens to want any extra allocations aside from the pagecache
ones in ints write_begin function, it may now use GFP_KERNEL (rather than
GFP_NOFS) for common case allocations (eg.  ocfs2_alloc_write_ctxt, for a
random example).

[kosaki.motohiro@jp.fujitsu.com: fix ubifs]
[kosaki.motohiro@jp.fujitsu.com: fix fuse]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: <stable@kernel.org>		[2.6.28.x]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ Cleaned up the calling convention: just pass in the AOP flags
  untouched to the grab_cache_page_write_begin() function.  That
  just simplifies everybody, and may even allow future expansion of the
  logic.   - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-04 13:33:20 -08:00
..
Kconfig UBIFS: include to compilation 2008-07-15 17:35:24 +03:00
Makefile UBIFS: include to compilation 2008-07-15 17:35:24 +03:00
budget.c Merge branch 'linux-next' of git://git.infradead.org/ubifs-2.6 2009-01-02 15:57:47 -08:00
commit.c UBIFS: separate debugging fields out 2008-12-03 13:14:33 +02:00
compress.c UBIFS: fix sparse warnings 2008-12-31 14:13:24 +02:00
debug.c UBIFS: print debugging messages properly 2008-12-31 14:13:25 +02:00
debug.h UBIFS: introduce LPT dump function 2008-12-03 13:14:34 +02:00
dir.c Merge branch 'master' into next 2008-12-04 17:16:36 +11:00
file.c fs: symlink write_begin allocation context fix 2009-01-04 13:33:20 -08:00
find.c UBIFS: remove unneeded unlikely() 2008-09-30 11:12:55 +03:00
gc.c UBIFS: improve garbage collection 2008-09-30 11:12:59 +03:00
io.c UBIFS: check data CRC when in error state 2008-09-30 11:12:57 +03:00
ioctl.c UBIFS: fix writing uncompressed files 2008-12-31 14:13:25 +02:00
journal.c UBIFS: fix writing uncompressed files 2008-12-31 14:13:25 +02:00
key.h UBIFS: avoid unnecessary checks 2008-12-03 13:14:11 +02:00
log.c UBIFS: increment commit number earlier 2008-08-13 11:27:47 +03:00
lprops.c UBIFS: various comment improvements and fixes 2008-12-23 12:23:08 +02:00
lpt.c UBIFS: use nicer 64-bit math 2008-12-23 12:23:40 +02:00
lpt_commit.c UBIFS: fix numerous spelling mistakes 2008-12-31 14:13:25 +02:00
master.c
misc.h UBIFS: inline one-line functions 2008-09-30 11:12:56 +03:00
orphan.c UBIFS: separate debugging fields out 2008-12-03 13:14:33 +02:00
recovery.c UBIFS: fix compilation warnings 2008-11-06 11:06:31 +02:00
replay.c UBIFS: restore budg_uncommitted_idx 2008-12-31 14:13:24 +02:00
sb.c UBIFS: use nicer 64-bit math 2008-12-23 12:23:40 +02:00
scan.c UBIFS: add no_chk_data_crc mount option 2008-09-30 11:12:56 +03:00
shrinker.c
super.c UBIFS: add more useful debugging prints 2008-12-31 14:13:25 +02:00
tnc.c UBIFS: fix checkpatch.pl warnings 2008-12-31 14:13:25 +02:00
tnc_commit.c UBIFS: re-calculate min_idx_size after the commit 2008-12-23 12:24:05 +02:00
tnc_misc.c UBIFS: correct key comparison 2008-09-30 11:12:57 +03:00
ubifs-media.h UBIFS: slight compression optimization 2008-12-03 13:13:50 +02:00
ubifs.h UBIFS: fix numerous spelling mistakes 2008-12-31 14:13:25 +02:00
xattr.c UBIFS: remove unneeded unlikely() 2008-09-30 11:12:55 +03:00