linux/fs/btrfs
Liu Bo cf7c1ef6e1 Btrfs: fix a bug of writting free space cache during balance
Here is the whole story:
1)
A free space cache consists of two parts:
o  free space cache inode, which is special becase it's stored in root tree.
o  free space info, which is stored as the above inode's file data.

But we only build up another new inode and does not flush its free space info
onto disk when we _clear and setup_ free space cache, and this ends up with
that the block group cache's cache_state remains DC_SETUP instead of DC_WRITTEN.

And holding DC_SETUP means that we will not truncate this free space cache inode,
which means the disk offset of its file extent will remain _unchanged_ at least
until next transaction finishes committing itself.

2)
We can set a block group readonly when we relocate the block group.

However,
if the readonly block group covers the disk offset where our free space cache
inode is going to write, it will force the free space cache inode into
cow_file_range() and it'll end up hitting a BUG_ON.

3)
Due to the above analysis, we fix this bug by adding the missing dirty flag.

4)
However, it's not over, there is still another case, nospace_cache.

With nospace_cache, we do not want to set dirty flag, instead we just truncate
free space cache inode and bail out with setting cache state DC_WRITTEN.

We can benifit from it since it saves us another 'pre-allocation' part which
usually costs a lot.

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-07-23 16:28:02 -04:00
..
acl.c Btrfs: cache no acl on new inodes 2012-05-30 10:23:27 -04:00
async-thread.c btrfs: return void in functions without error conditions 2012-03-22 01:45:34 +01:00
async-thread.h btrfs: return void in functions without error conditions 2012-03-22 01:45:34 +01:00
backref.c Btrfs: leave critical region in btrfs_find_all_roots as soon as possible 2012-06-27 16:34:39 +02:00
backref.h Btrfs: use the tree modification log for backref resolving 2012-05-30 15:17:34 +02:00
btrfs_inode.h Btrfs: kill root from btrfs_is_free_space_inode 2012-07-23 16:28:00 -04:00
check-integrity.c Btrfs: use rcu to protect device->name 2012-06-14 21:29:16 -04:00
check-integrity.h Btrfs: add optional integrity check code 2011-12-21 19:14:09 +01:00
compat.h
compression.c Merge branch 'for-linus-min' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs 2012-04-13 19:41:27 -07:00
compression.h btrfs: return void in functions without error conditions 2012-03-22 01:45:34 +01:00
ctree.c Btrfs: resolve tree mod log locking issue in btrfs_next_leaf 2012-06-27 16:34:40 +02:00
ctree.h Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs 2012-06-21 13:41:07 -07:00
delayed-inode.c Btrfs: flush delayed inodes if we're short on space 2012-07-23 15:41:40 -04:00
delayed-inode.h Btrfs: flush delayed inodes if we're short on space 2012-07-23 15:41:40 -04:00
delayed-ref.c Btrfs: use delayed ref sequence numbers for all fs-tree updates 2012-05-30 18:18:21 +02:00
delayed-ref.h Btrfs: use delayed ref sequence numbers for all fs-tree updates 2012-05-30 18:18:21 +02:00
dir-item.c btrfs: replace many BUG_ONs with proper error handling 2012-03-22 11:52:54 +01:00
disk-io.c Btrfs: avoid I/O repair BUG() from btree_read_extent_buffer_pages() 2012-07-23 16:27:59 -04:00
disk-io.h btrfs: Drop unused function btrfs_abort_devices() 2012-05-30 10:23:39 -04:00
export.c ->encode_fh() API change 2012-05-29 23:28:33 -04:00
export.h
extent_io.c Btrfs: hold a ref on the inode during writepages 2012-07-02 15:39:18 -04:00
extent_io.h Merge branch 'for-chris' of git://git.jan-o-sch.net/btrfs-unstable into for-linus 2012-05-31 16:49:53 -04:00
extent_map.c Btrfs: clean up code for merging extent maps 2011-08-01 14:30:50 -04:00
extent_map.h btrfs: fix structs where bitfields and spinlock/atomic share 8B word 2012-02-15 16:40:25 +01:00
extent-tree.c Btrfs: fix a bug of writting free space cache during balance 2012-07-23 16:28:02 -04:00
file-item.c Btrfs: kill root from btrfs_is_free_space_inode 2012-07-23 16:28:00 -04:00
file.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs 2012-07-05 13:06:25 -07:00
free-space-cache.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs 2012-07-05 13:06:25 -07:00
free-space-cache.h btrfs: remove all unused functions 2011-05-06 12:34:03 +02:00
hash.h Btrfs: remove crc32c.h and use libcrc32c directly. 2009-06-10 11:29:53 -04:00
inode-item.c Merge branch 'error-handling' into for-linus 2012-03-28 20:31:37 -04:00
inode-map.c Btrfs: show useful info in space reservation tracepoint 2012-03-29 09:57:44 -04:00
inode-map.h Btrfs: Support reading/writing on disk free ino cache 2011-04-25 16:46:11 +08:00
inode.c Btrfs: kill root from btrfs_is_free_space_inode 2012-07-23 16:28:00 -04:00
ioctl.c Btrfs: do not set subvolume flags in readonly mode 2012-07-23 16:27:58 -04:00
ioctl.h Btrfs: add DEVICE_READY ioctl 2012-07-23 16:27:42 -04:00
Kconfig Btrfs: add config option to enable btrfs integrity check 2011-12-21 19:14:16 +01:00
locking.c Btrfs: reduce calls to wake_up on uncontended locks 2012-07-23 15:36:18 -04:00
locking.h btrfs: return void in functions without error conditions 2012-03-22 01:45:34 +01:00
lzo.c btrfs: remove the second argument of k[un]map_atomic() 2012-03-20 21:48:21 +08:00
Makefile Merge branch 'integrity-check-patch-v2' of git://btrfs.giantdisaster.de/git/btrfs into integration 2012-01-16 15:27:58 -05:00
ordered-data.c Btrfs: call filemap_fdatawrite twice for compression 2012-06-14 21:30:54 -04:00
ordered-data.h Btrfs: finish ordered extents in their own thread 2012-05-30 10:23:33 -04:00
orphan.c btrfs: replace many BUG_ONs with proper error handling 2012-03-22 11:52:54 +01:00
print-tree.c Btrfs: read device stats on mount, write modified ones during commit 2012-05-30 10:23:41 -04:00
print-tree.h
rcu-string.h Btrfs: use rcu to protect device->name 2012-06-14 21:29:16 -04:00
reada.c Btrfs: set ioprio of scrub readahead to idle 2012-05-30 10:23:43 -04:00
relocation.c Btrfs: fix error handling in __add_reloc_root() 2012-07-23 16:27:53 -04:00
root-tree.c btrfs: replace many BUG_ONs with proper error handling 2012-03-22 11:52:54 +01:00
scrub.c Btrfs: use rcu to protect device->name 2012-06-14 21:29:16 -04:00
struct-funcs.c Btrfs: add the ability to cache a pointer into the eb 2012-03-26 17:04:23 -04:00
super.c Btrfs: add DEVICE_READY ioctl 2012-07-23 16:27:42 -04:00
sysfs.c btrfs: Remove unused sysfs code 2011-06-17 14:54:18 -04:00
transaction.c Btrfs: change how we indicate we're adding csums 2012-07-23 16:27:55 -04:00
transaction.h Btrfs: change how we indicate we're adding csums 2012-07-23 16:27:55 -04:00
tree-defrag.c btrfs: drop unused parameter from btrfs_release_path 2011-05-02 13:57:22 +02:00
tree-log.c Btrfs: return error of btrfs_update_inode() to caller 2012-07-23 16:27:54 -04:00
tree-log.h btrfs: return void in functions without error conditions 2012-03-22 01:45:34 +01:00
ulist.c Merge branch 'for-chris' of git://git.jan-o-sch.net/btrfs-unstable into for-linus 2012-05-31 16:49:53 -04:00
ulist.h Merge branch 'for-chris' of git://git.jan-o-sch.net/btrfs-unstable into for-linus 2012-05-31 16:49:53 -04:00
version.h
volumes.c Btrfs: add DEVICE_READY ioctl 2012-07-23 16:27:42 -04:00
volumes.h Btrfs: add DEVICE_READY ioctl 2012-07-23 16:27:42 -04:00
xattr.c Btrfs: use i_version instead of our own sequence 2012-05-30 10:23:27 -04:00
xattr.h fs/vfs/security: pass last path component to LSM on inode creation 2011-02-01 11:12:29 -05:00
zlib.c btrfs: remove the second argument of k[un]map_atomic() 2012-03-20 21:48:21 +08:00