linux/fs/gfs2
Takashi Sato c4be0c1dc4 filesystem freeze: add error handling of write_super_lockfs/unlockfs
Currently, ext3 in mainline Linux doesn't have the freeze feature which
suspends write requests.  So, we cannot take a backup which keeps the
filesystem's consistency with the storage device's features (snapshot and
replication) while it is mounted.

In many case, a commercial filesystem (e.g.  VxFS) has the freeze feature
and it would be used to get the consistent backup.

If Linux's standard filesystem ext3 has the freeze feature, we can do it
without a commercial filesystem.

So I have implemented the ioctls of the freeze feature.
I think we can take the consistent backup with the following steps.
1. Freeze the filesystem with the freeze ioctl.
2. Separate the replication volume or create the snapshot
   with the storage device's feature.
3. Unfreeze the filesystem with the unfreeze ioctl.
4. Take the backup from the separated replication volume
   or the snapshot.

This patch:

VFS:
Changed the type of write_super_lockfs and unlockfs from "void"
to "int" so that they can return an error.
Rename write_super_lockfs and unlockfs of the super block operation
freeze_fs and unfreeze_fs to avoid a confusion.

ext3, ext4, xfs, gfs2, jfs:
Changed the type of write_super_lockfs and unlockfs from "void"
to "int" so that write_super_lockfs returns an error if needed,
and unlockfs always returns 0.

reiserfs:
Changed the type of write_super_lockfs and unlockfs from "void"
to "int" so that they always return 0 (success) to keep a current behavior.

Signed-off-by: Takashi Sato <t-sato@yk.jp.nec.com>
Signed-off-by: Masayuki Hamaguchi <m-hamaguchi@ys.jp.nec.com>
Cc: <xfs-masters@oss.sgi.com>
Cc: <linux-ext4@vger.kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Alasdair G Kergon <agk@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-09 16:54:42 -08:00
..
locking/dlm GFS2: Send useful information with uevent messages 2009-01-05 07:39:15 +00:00
acl.c GFS2: Move di_eattr into "proper" inode 2009-01-05 07:38:57 +00:00
acl.h [GFS2] Remove gfs2_check_acl() 2006-11-30 10:37:32 -05:00
bmap.c GFS2: Streamline alloc calculations for writes 2009-01-05 07:39:17 +00:00
bmap.h GFS2: Streamline alloc calculations for writes 2009-01-05 07:39:17 +00:00
dir.c GFS2: Banish struct gfs2_dinode_host 2009-01-05 07:38:59 +00:00
dir.h GFS2: Fix bug in gfs2_lock_fs_check_clean() 2009-01-05 07:39:11 +00:00
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: Banish struct gfs2_dinode_host 2009-01-05 07:38:59 +00:00
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: Use DEFINE_SPINLOCK 2009-01-05 07:45:02 +00:00
glock.h Revert "GFS2: Fix use-after-free bug on umount" 2009-01-05 07:39:18 +00:00
glops.c GFS2: Kill two daemons with one patch 2009-01-05 07:39:09 +00:00
glops.h [GFS2] Make headers compile on their own 2006-09-05 10:39:21 -04:00
incore.h GFS2: Kill two daemons with one patch 2009-01-05 07:39:09 +00:00
inode.c GFS2: Kill two daemons with one patch 2009-01-05 07:39:09 +00:00
inode.h GFS2: Banish struct gfs2_dinode_host 2009-01-05 07:38:59 +00:00
Kconfig GFS2: LSF and LBD are now one and the same 2009-01-07 08:57:35 +00:00
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 GFS2: Kill two daemons with one patch 2009-01-05 07:39:09 +00:00
Makefile GFS2: Kill two daemons with one patch 2009-01-05 07:39:09 +00:00
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 GFS2: Remove ancient, unused code 2009-01-05 07:39:13 +00:00
mount.h [GFS2] Make headers compile on their own 2006-09-05 10:39:21 -04:00
ops_address.c GFS2: Set GFP_NOFS when allocating page on write 2009-01-07 08:57:04 +00:00
ops_address.h [GFS2] Remove function gfs2_get_block 2008-01-25 08:08:25 +00:00
ops_dentry.c GFS2: Rationalise header files 2009-01-05 07:38:48 +00:00
ops_export.c GFS2: Banish struct gfs2_dinode_host 2009-01-05 07:38:59 +00:00
ops_file.c GFS2: Fix typo in gfs_page_mkwrite() 2009-01-07 08:58:28 +00:00
ops_fstype.c GFS2: Fix use-after-free bug on umount (try #2) 2009-01-05 07:39:19 +00:00
ops_inode.c GFS2: Banish struct gfs2_dinode_host 2009-01-05 07:38:59 +00:00
ops_super.c filesystem freeze: add error handling of write_super_lockfs/unlockfs 2009-01-09 16:54:42 -08:00
quota.c GFS2: Fix "truncate in progress" hang 2009-01-05 07:39:06 +00:00
quota.h GFS2: Move gfs2_recoverd into recovery.c 2009-01-05 07:39:07 +00:00
recovery.c GFS2: Move four functions from super.c 2009-01-05 07:39:12 +00:00
recovery.h GFS2: Move gfs2_recoverd into recovery.c 2009-01-05 07:39:07 +00:00
rgrp.c GFS2: Banish struct gfs2_rgrpd_host 2009-01-05 07:39:03 +00:00
rgrp.h [GFS2] Add extent allocation to block allocator 2008-03-31 10:40:47 +01:00
super.c Revert "GFS2: Fix use-after-free bug on umount" 2009-01-05 07:39:18 +00:00
super.h Revert "GFS2: Fix use-after-free bug on umount" 2009-01-05 07:39:18 +00:00
sys.c GFS2: Remove ancient, unused code 2009-01-05 07:39:13 +00:00
sys.h GFS2: Remove ancient, unused code 2009-01-05 07:39:13 +00:00
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: Clean up & move gfs2_quotad 2009-01-05 07:39:05 +00:00
util.h GFS2: Clean up & move gfs2_quotad 2009-01-05 07:39:05 +00:00