WSL2-Linux-Kernel/fs/gfs2
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
..
locking/dlm dlm: allow multiple lockspace creates 2008-08-28 11:49:15 -05:00
Kconfig [GFS2] No lock_nolock 2008-06-27 09:39:28 +01:00
Makefile [GFS2] No lock_nolock 2008-06-27 09:39:28 +01:00
acl.c [GFS2] fix GFP_KERNEL misuses 2008-04-10 09:55:26 +01:00
acl.h [GFS2] Remove gfs2_check_acl() 2006-11-30 10:37:32 -05:00
bmap.c [GFS2] fix gfs2 block allocation (cleaned up) 2008-06-24 19:02:28 +01:00
bmap.h [GFS2] Remove function gfs2_get_block 2008-01-25 08:08:25 +00:00
daemon.c [GFS2] Move gfs2_logd into log.c 2008-01-25 08:07:56 +00:00
daemon.h [GFS2] Move gfs2_logd into log.c 2008-01-25 08:07:56 +00:00
dir.c [GFS2] fix GFP_KERNEL misuses 2008-04-10 09:55:26 +01:00
dir.h [GFS2] Clean up inode number handling 2007-07-09 08:22:24 +01:00
eaops.c [GFS2] Remove unrequired code 2008-01-25 08:08:13 +00:00
eaops.h [GFS2] mark struct *_operations const 2007-10-10 08:55:03 +01:00
eattr.c [GFS2] fix GFP_KERNEL misuses 2008-04-10 09:55:26 +01:00
eattr.h [GFS2] gfs2 misc endianness annotations 2006-11-30 10:33:46 -05:00
gfs2.h [GFS2] Remove remote lock dropping code 2008-06-27 09:39:44 +01:00
glock.c GFS2: high time to take some time over atime 2008-09-18 13:53:59 +01:00
glock.h GFS2: high time to take some time over atime 2008-09-18 13:53:59 +01:00
glops.c [GFS2] Clean up the glock core 2008-06-27 09:39:22 +01:00
glops.h [GFS2] Make headers compile on their own 2006-09-05 10:39:21 -04:00
incore.h GFS2: Support for I/O barriers 2008-09-26 10:23:22 +01:00
inode.c CRED: Wrap task credential accesses in the GFS2 filesystem 2008-11-14 10:38:53 +11:00
inode.h GFS2: high time to take some time over atime 2008-09-18 13:53:59 +01:00
locking.c [GFS2] Fix ordering of args for list_add 2008-06-27 09:39:34 +01:00
log.c GFS2: Support for I/O barriers 2008-09-26 10:23:22 +01:00
log.h [GFS2] trivial sparse lock annotations 2008-06-27 09:39:31 +01:00
lops.c [GFS2] Plug an unlikely leak 2008-03-31 10:40:05 +01:00
lops.h [GFS2] Only do lo_incore_commit once 2008-03-31 10:39:54 +01:00
main.c SL*B: drop kmem cache argument from constructor 2008-07-26 12:00:07 -07:00
meta_io.c [GFS2] Clean up the glock core 2008-06-27 09:39:22 +01:00
meta_io.h [GFS2] Clean up the glock core 2008-06-27 09:39:22 +01:00
mount.c vfs: Use const for kernel parser table 2008-10-13 10:10:37 -07:00
mount.h [GFS2] Make headers compile on their own 2006-09-05 10:39:21 -04:00
ops_address.c fs: symlink write_begin allocation context fix 2009-01-04 13:33:20 -08:00
ops_address.h [GFS2] Remove function gfs2_get_block 2008-01-25 08:08:25 +00:00
ops_dentry.c [GFS2] Fix a page lock / glock deadlock 2008-03-31 10:41:12 +01:00
ops_dentry.h [GFS2] Make headers compile on their own 2006-09-05 10:39:21 -04:00
ops_export.c [PATCH] switch all filesystems over to d_obtain_alias 2008-10-23 05:13:01 -04:00
ops_file.c GFS2: high time to take some time over atime 2008-09-18 13:53:59 +01:00
ops_fstype.c GFS2: high time to take some time over atime 2008-09-18 13:53:59 +01:00
ops_fstype.h exportfs: make struct export_operations const 2007-10-22 08:13:21 -07:00
ops_inode.c [PATCH] make O_EXCL in nd->intent.flags visible in nd->flags 2008-10-23 05:12:56 -04:00
ops_inode.h [GFS2] remove gfs2_dev_iops 2008-03-31 10:41:20 +01:00
ops_super.c GFS2: high time to take some time over atime 2008-09-18 13:53:59 +01:00
ops_super.h [PATCH] Mark struct super_operations const 2007-02-12 09:48:47 -08:00
quota.c [GFS2] Fix GFS2's use of do_div() in its quota calculations 2008-07-11 14:35:01 +01:00
quota.h [GFS2] Streamline quota lock/check for no-quota case 2008-03-31 10:41:36 +01:00
recovery.c [GFS2] No lock_nolock 2008-06-27 09:39:28 +01:00
recovery.h [GFS2] split and annotate gfs2_log_head 2006-11-30 10:33:14 -05:00
rgrp.c [GFS2] Replace rgrp "recent list" with mru list 2008-07-10 15:54:12 +01:00
rgrp.h [GFS2] Add extent allocation to block allocator 2008-03-31 10:40:47 +01:00
super.c GFS2: Fix metafs mounts 2008-08-13 09:59:40 +01:00
super.h GFS2: Fix metafs mounts 2008-08-13 09:59:40 +01:00
sys.c GFS2: high time to take some time over atime 2008-09-18 13:53:59 +01:00
sys.h [GFS2] Make headers compile on their own 2006-09-05 10:39:21 -04:00
trans.c [GFS2] Update gfs2_trans_add_unrevoke to accept extents 2008-03-31 10:40:42 +01:00
trans.h [GFS2] Update gfs2_trans_add_unrevoke to accept extents 2008-03-31 10:40:42 +01:00
util.c [GFS2] Remove lm.[ch] and distribute content 2008-03-31 10:40:26 +01:00
util.h fs: replace remaining __FUNCTION__ occurrences 2008-04-30 08:29:54 -07:00