Commit Graph

2334 Commits

Author SHA1 Message Date
Dmitry Monakhov
be5cd90dda ext4: optimize block allocation on grow indepth
It is reasonable to prepend newly created index to older one.

[ Dropped no longer used function parameter newext. -tytso ]

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-10-01 22:57:09 -04:00
Dmitry Monakhov
dfe076c106 ext4: get rid of code duplication
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-10-01 22:26:17 -04:00
Dmitry Monakhov
c5d311926d ext4: fix over-defensive complaint after journal abort
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-10-01 22:23:15 -04:00
Li Xi
bce92d566a ext4: fix return value of ext4_do_update_inode
When ext4_do_update_inode() gets error from ext4_inode_blocks_set(),
error number should be returned.

Signed-off-by: Li Xi <lixi@ddn.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
2014-10-01 22:11:06 -04:00
Jan Kara
d6320cbfc9 ext4: fix mmap data corruption when blocksize < pagesize
Use truncate_isize_extended() when hole is being created in a file so that
->page_mkwrite() will get called for the partial tail page if it is
mmaped (see the first patch in the series for details).

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
2014-10-01 21:49:46 -04:00
Theodore Ts'o
f6e63f9080 ext4: fold ext4_nojournal_sops into ext4_sops
There's no longer any need to have a separate set of super_operations
for nojournal mode.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-18 17:12:30 -04:00
Theodore Ts'o
bb04457658 ext4: support freezing ext2 (nojournal) file systems
Through an oversight, when we added nojournal support to ext4, we
didn't add support to allow file system freezing.  This is relatively
easy to add, so let's do it.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reported-by: Dexuan Cui <decui@microsoft.com>
2014-09-18 17:12:02 -04:00
Theodore Ts'o
bda3253043 ext4: fold ext4_sync_fs_nojournal() into ext4_sync_fs()
This allows us to eliminate duplicate code, and eventually allow us to
also fold ext4_sops and ext4_nojournal_sops together.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-18 16:12:37 -04:00
Jan Kara
279bf6d390 ext4: don't check quota format when there are no quota files
The check whether quota format is set even though there are no
quota files with journalled quota is pointless and it actually
makes it impossible to turn off journalled quotas (as there's
no way to unset journalled quota format). Just remove the check.

CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-18 01:12:15 -04:00
Dmitry Monakhov
844749764b ext4: explicitly inform user about orphan list cleanup
Production fs likely compiled/mounted w/o jbd debugging, so orphan
list clearing will be silent.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-16 14:52:03 -04:00
Darrick J. Wong
a0626e7595 ext4: check EA value offset when loading
When loading extended attributes, check each entry's value offset to
make sure it doesn't collide with the entries.

Without this check it is easy to crash the kernel by mounting a
malicious FS containing a file with an EA wherein e_value_offs = 0 and
e_value_size > 0 and then deleting the EA, which corrupts the name
list.

(See the f_ea_value_crash test's FS image in e2fsprogs for an example.)

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
2014-09-16 14:34:59 -04:00
Darrick J. Wong
684de57486 ext4: don't keep using page if inline conversion fails
If inline->extent conversion fails (most probably due to ENOSPC) and
we release the temporary page that we allocated to transfer the file
contents, don't keep using the page pointer after releasing the page.
This occasionally leads to complaints about evicting locked pages or
hangs when blocksize > pagesize, because it's possible for the page to
get reallocated elsewhere in the meantime.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Tao Ma <tm@tao.ma>
2014-09-11 11:45:12 -04:00
Darrick J. Wong
df4763bea5 ext4: validate external journal superblock checksum
If the external journal device has metadata_csum enabled, verify
that the superblock checksum matches the block before we try to
mount.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-11 11:44:36 -04:00
Darrick J. Wong
feb8c6d3dd jbd2: fix journal checksum feature flag handling
Clear all three journal checksum feature flags before turning on
whichever journal checksum options we want.  Rearrange the error
checking so that newer flags get complained about first.

Reported-by: TR Reardon <thomas_reardon@hotmail.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-11 11:38:21 -04:00
Lukas Czerner
c7f725435a ext4: provide separate operations for sysfs feature files
Currently sysfs feature files uses ext4_attr_ops as the file operations
to show/store data. However the feature files is not supposed to contain
any data at all, the sole existence of the file means that the module
support the feature. Moreover, none of the sysfs feature attributes
actually register show/store functions so that would not be a problem.

However if a sysfs feature attribute register a show or store function
we might be in trouble because the kobject in this case is _not_ embedded
in the ext4_sb_info structure as ext4_attr_show/store expect.

So just to be safe, provide separate empty sysfs_ops to use in
ext4_feat_ktype. This might safe us from potential problems in the
future. As a bonus we can "store" something more descriptive than
nothing in the files, so let it contain "enabled" to make it clear that
the feature is really present in the module.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-11 11:27:58 -04:00
Lukas Czerner
52c198c682 ext4: add sysfs entry showing whether the fs contains errors
Currently there is no easy way to tell that the mounted file system
contains errors other than checking for log messages, or reading the
information directly from superblock.

This patch adds new sysfs entries:

errors_count		(number of fs errors we encounter)
first_error_time	(unix timestamp for the first error we see)
last_error_time		(unix timestamp for the last error we see)

If the file system is not marked as containing errors then any of the
file will return 0. Otherwise it will contain valid information. More
details about the errors should as always be found in the logs.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-11 11:18:13 -04:00
Jan Kara
a2d4a646e6 ext4: don't use MAXQUOTAS value
MAXQUOTAS value defines maximum number of quota types VFS supports.
This isn't necessarily the number of types ext4 supports. Although
ext4 will support project quotas, use ext4 private definition for
consistency with other filesystems.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-11 11:15:15 -04:00
Gioh Kim
a8ac900b81 ext4: use non-movable memory for the ext4 superblock
Since the ext4 superblock is not released until the file system is
unmounted, allocate the buffer cache entry for the ext4 superblock out
of the non-moveable are to allow page migrations and thus CMA
allocations to more easily succeed if the CMA area is limited.

Signed-off-by: Gioh Kim <gioh.kim@lge.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
2014-09-04 22:36:15 -04:00
Theodore Ts'o
d26e2c4d72 ext4: renumber EXT4_EX_* flags to avoid flag aliasing problems
Suggested-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-04 18:09:29 -04:00
Theodore Ts'o
754cfed6bb ext4: drop the EXT4_STATE_DELALLOC_RESERVED flag
Having done a full regression test, we can now drop the
DELALLOC_RESERVED state flag.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
2014-09-04 18:08:22 -04:00
Theodore Ts'o
e3cf5d5d9a ext4: prepare to drop EXT4_STATE_DELALLOC_RESERVED
The EXT4_STATE_DELALLOC_RESERVED flag was originally implemented
because it was too hard to make sure the mballoc and get_block flags
could be reliably passed down through all of the codepaths that end up
calling ext4_mb_new_blocks().

Since then, we have mb_flags passed down through most of the code
paths, so getting rid of EXT4_STATE_DELALLOC_RESERVED isn't as tricky
as it used to.

This commit plumbs in the last of what is required, and then adds a
WARN_ON check to make sure we haven't missed anything.  If this passes
a full regression test run, we can then drop
EXT4_STATE_DELALLOC_RESERVED.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
2014-09-04 18:07:25 -04:00
Theodore Ts'o
a521100231 ext4: pass allocation_request struct to ext4_(alloc,splice)_branch
Instead of initializing the allocation_request structure in
ext4_alloc_branch(), set it up in ext4_ind_map_blocks(), and then pass
it to ext4_alloc_branch() and ext4_splice_branch().

This allows ext4_ind_map_blocks to pass flags in the allocation
request structure without having to add Yet Another argument to
ext4_alloc_branch().

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
2014-09-04 18:06:25 -04:00
Zheng Liu
eb68d0e2fc ext4: track extent status tree shrinker delay statictics
This commit adds some statictics in extent status tree shrinker.  The
purpose to add these is that we want to collect more details when we
encounter a stall caused by extent status tree shrinker.  Here we count
the following statictics:
  stats:
    the number of all objects on all extent status trees
    the number of reclaimable objects on lru list
    cache hits/misses
    the last sorted interval
    the number of inodes on lru list
  average:
    scan time for shrinking some objects
    the number of shrunk objects
  maximum:
    the inode that has max nr. of objects on lru list
    the maximum scan time for shrinking some objects

The output looks like below:
  $ cat /proc/fs/ext4/sda1/es_shrinker_info
  stats:
    28228 objects
    6341 reclaimable objects
    5281/631 cache hits/misses
    586 ms last sorted interval
    250 inodes on lru list
  average:
    153 us scan time
    128 shrunk objects
  maximum:
    255 inode (255 objects, 198 reclaimable)
    125723 us max scan time

If the lru list has never been sorted, the following line will not be
printed:
    586ms last sorted interval
If there is an empty lru list, the following lines also will not be
printed:
    250 inodes on lru list
  ...
  maximum:
    255 inode (255 objects, 198 reclaimable)
    0 us max scan time

Meanwhile in this commit a new trace point is defined to print some
details in __ext4_es_shrink().

Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-01 22:26:49 -04:00
Zheng Liu
e963bb1de4 ext4: improve extents status tree trace point
This commit improves the trace point of extents status tree.  We rename
trace_ext4_es_shrink_enter in ext4_es_count() because it is also used
in ext4_es_scan() and we can not identify them from the result.

Further this commit fixes a variable name in trace point in order to
keep consistency with others.

Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-01 22:22:13 -04:00
Seunghun Lee
d91bd2c1d7 ext4: fix comments about get_blocks
get_blocks is renamed to get_block.

Signed-off-by: Seunghun Lee <waydi1@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-01 22:15:30 -04:00
Darrick J. Wong
45f1a9c3f6 ext4: enable block_validity by default
Enable by default the block_validity feature, which checks for
collisions between newly allocated blocks and critical system
metadata.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-01 21:34:09 -04:00
Theodore Ts'o
ed8a1a766a ext4: rename ext4_ext_find_extent() to ext4_find_extent()
Make the function name less redundant.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-01 14:43:09 -04:00
Theodore Ts'o
3bdf14b4d7 ext4: reuse path object in ext4_move_extents()
Reuse the path object in ext4_move_extents() so we don't unnecessarily
free and reallocate it.

Also clean up the get_ext_path() wrapper so that it has the same
semantics of freeing the path object on error as ext4_ext_find_extent().

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-01 14:42:09 -04:00
Theodore Ts'o
ee4bd0d963 ext4: reuse path object in ext4_ext_shift_extents()
Now that the semantics of ext4_ext_find_extent() are much cleaner,
it's safe and more efficient to reuse the path object across the
multiple calls to ext4_ext_find_extent() in ext4_ext_shift_extents().

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-01 14:41:09 -04:00
Theodore Ts'o
10809df84a ext4: teach ext4_ext_find_extent() to realloc path if necessary
This adds additional safety in case for some reason we end reusing a
path structure which isn't big enough for current depth of the inode.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-01 14:40:09 -04:00
Theodore Ts'o
b7ea89ad0a ext4: allow a NULL argument to ext4_ext_drop_refs()
Teach ext4_ext_drop_refs() to accept a NULL argument, much like
kfree().  This allows us to drop a lot of checks to make sure path is
non-NULL before calling ext4_ext_drop_refs().

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-01 14:39:09 -04:00
Theodore Ts'o
523f431ccf ext4: call ext4_ext_drop_refs() from ext4_ext_find_extent()
In nearly all of the calls to ext4_ext_find_extent() where the caller
is trying to recycle the path object, ext4_ext_drop_refs() gets called
to release the buffer heads before the path object gets overwritten.
To simplify things for the callers, and to avoid the possibility of a
memory leak, make ext4_ext_find_extent() responsible for dropping the
buffers.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-01 14:38:09 -04:00
Theodore Ts'o
dfe5080939 ext4: drop EXT4_EX_NOFREE_ON_ERR from rest of extents handling code
Drop EXT4_EX_NOFREE_ON_ERR from ext4_ext_create_new_leaf(),
ext4_split_extent(), ext4_convert_unwritten_extents_endio().

This requires fixing all of their callers to potentially
ext4_ext_find_extent() to free the struct ext4_ext_path object in case
of an error, and there are interlocking dependencies all the way up to
ext4_ext_map_blocks(), ext4_swap_extents(), and
ext4_ext_remove_space().

Once this is done, we can drop the EXT4_EX_NOFREE_ON_ERR flag since it
is no longer necessary.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-01 14:37:09 -04:00
Theodore Ts'o
4f224b8b7b ext4: drop EXT4_EX_NOFREE_ON_ERR in convert_initialized_extent()
Transfer responsibility of freeing struct ext4_ext_path on error to
ext4_ext_find_extent().

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-01 14:36:09 -04:00
Theodore Ts'o
e8b83d9303 ext4: collapse ext4_convert_initialized_extents()
The function ext4_convert_initialized_extents() is only called by a
single function --- ext4_ext_convert_initalized_extents().  Inline the
code and get rid of the unnecessary bits in order to simplify the code.

Rename ext4_ext_convert_initalized_extents() to
convert_initalized_extents() since it's a static function that is
actually only used in a single caller, ext4_ext_map_blocks().

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-01 14:35:09 -04:00
Theodore Ts'o
705912ca95 ext4: teach ext4_ext_find_extent() to free path on error
Right now, there are a places where it is all to easy to leak memory
on an error path, via a usage like this:

	struct ext4_ext_path *path = NULL

	while (...) {
		...
		path = ext4_ext_find_extent(inode, block, path, 0);
		if (IS_ERR(path)) {
			/* oops, if path was non-NULL before the call to
			   ext4_ext_find_extent, we've leaked it!  :-(  */
			...
			return PTR_ERR(path);
		}
		...
	}

Unfortunately, there some code paths where we are doing the following
instead:

	path = ext4_ext_find_extent(inode, block, orig_path, 0);

and where it's important that we _not_ free orig_path in the case
where ext4_ext_find_extent() returns an error.

So change the function signature of ext4_ext_find_extent() so that it
takes a struct ext4_ext_path ** for its third argument, and by
default, on an error, it will free the struct ext4_ext_path, and then
zero out the struct ext4_ext_path * pointer.  In order to avoid
causing problems, we add a flag EXT4_EX_NOFREE_ON_ERR which causes
ext4_ext_find_extent() to use the original behavior of forcing the
caller to deal with freeing the original path pointer on the error
case.

The goal is to get rid of EXT4_EX_NOFREE_ON_ERR entirely, but this
allows for a gentle transition and makes the patches easier to verify.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-01 14:34:09 -04:00
Theodore Ts'o
bd30d702fc ext4: fix accidental flag aliasing in ext4_map_blocks flags
Commit b8a8684502 introduced an accidental flag aliasing between
EXT4_EX_NOCACHE and EXT4_GET_BLOCKS_CONVERT_UNWRITTEN.

Fortunately, this didn't introduce any untorward side effects --- we
got lucky.  Nevertheless, fix this and leave a warning to hopefully
avoid this from happening in the future.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-01 14:33:09 -04:00
Theodore Ts'o
713e8dde3e ext4: fix ZERO_RANGE bug hidden by flag aliasing
We accidently aliased EXT4_EX_NOCACHE and EXT4_GET_CONVERT_UNWRITTEN
falgs, which apparently was hiding a bug that was unmasked when this
flag aliasing issue was addressed (see the subsequent commit).  The
reproduction case was:

   fsx -N 10000 -l 500000 -r 4096 -t 4096 -w 4096 -Z -R -W /vdb/junk

... which would cause fsx to report corruption in the data file.

The fix we have is a bit of an overkill, but I'd much rather be
conservative for now, and we can optimize ZERO_RANGE_FL handling
later.  The fact that we need to zap the extent_status cache for the
inode is unfortunate, but correctness is far more important than
performance.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: Namjae Jeon <namjae.jeon@samsung.com>
2014-09-01 14:32:09 -04:00
Theodore Ts'o
19008f6dfa ext4: fix ext4_swap_extents() error handling
If ext4_ext_find_extent() returns an error, we have to clear path1 or
path2 or else we would end up trying to free an ERR_PTR, which would
be bad.

Also eliminate some redundant code and mark the error paths as unlikely()

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-08-31 15:03:14 -04:00
Dmitry Monakhov
fcf6b1b729 ext4: refactor ext4_move_extents code base
ext4_move_extents is too complex for review. It has duplicate almost
each function available in the rest of other codebase. It has useless
artificial restriction orig_offset == donor_offset. But in fact logic
of ext4_move_extents is very simple:

Iterate extents one by one (similar to ext4_fill_fiemap_extents)
   ->Iterate each page covered extent (similar to generic_perform_write)
     ->swap extents for covered by page (can be shared with IOC_MOVE_DATA)

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-08-30 23:52:19 -04:00
Dmitry Monakhov
f8fb4f4150 ext4: use ext4_ext_next_allocated_block instead of mext_next_extent
This allows us to make mext_next_extent static and potentially get rid
of it.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-08-30 23:50:56 -04:00
Dmitry Monakhov
ee124d2746 ext4: use ext4_update_i_disksize instead of opencoded ones
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-08-30 23:34:06 -04:00
Wang Shilong
52c826db6d ext4: remove a duplicate call in ext4_init_new_dir()
ext4_journal_get_write_access() has just been called in ext4_append()
calling it again here is duplicated.

Signed-off-by: Wang Shilong <wshilong@ddn.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-08-29 23:20:44 -04:00
Theodore Ts'o
f8b3b59d4d ext4: convert do_split() to use the ERR_PTR convention
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-08-29 20:52:18 -04:00
Theodore Ts'o
dd73b5d5cb ext4: convert dx_probe() to use the ERR_PTR convention
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-08-29 20:52:17 -04:00
Theodore Ts'o
1c2150283c ext4: convert ext4_bread() to use the ERR_PTR convention
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-08-29 20:52:15 -04:00
Theodore Ts'o
1056008226 ext4: convert ext4_getblk() to use the ERR_PTR convention
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-08-29 20:51:32 -04:00
Theodore Ts'o
537d8f9380 ext4: convert ext4_dx_find_entry() to use the ERR_PTR convention
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-08-29 20:49:51 -04:00
Darrick J. Wong
d80d448c6c ext4: fix same-dir rename when inline data directory overflows
When performing a same-directory rename, it's possible that adding or
setting the new directory entry will cause the directory to overflow
the inline data area, which causes the directory to be converted to an
extent-based directory.  Under this circumstance it is necessary to
re-read the directory when deleting the old dirent because the "old
directory" context still points to i_block in the inode table, which
is now an extent tree root!  The delete fails with an FS error, and
the subsequent fsck complains about incorrect link counts and
hardlinked directories.

Test case (originally found with flat_dir_test in the metadata_csum
test program):

# mkfs.ext4 -O inline_data /dev/sda
# mount /dev/sda /mnt
# mkdir /mnt/x
# touch /mnt/x/changelog.gz /mnt/x/copyright /mnt/x/README.Debian
# sync
# for i in /mnt/x/*; do mv $i $i.longer; done
# ls -la /mnt/x/
total 0
-rw-r--r-- 1 root root 0 Aug 25 12:03 changelog.gz.longer
-rw-r--r-- 1 root root 0 Aug 25 12:03 copyright
-rw-r--r-- 1 root root 0 Aug 25 12:03 copyright.longer
-rw-r--r-- 1 root root 0 Aug 25 12:03 README.Debian.longer

(Hey!  Why are there four files now??)

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
2014-08-28 22:22:29 -04:00
Darrick J. Wong
db9ee22036 jbd2: fix descriptor block size handling errors with journal_csum
It turns out that there are some serious problems with the on-disk
format of journal checksum v2.  The foremost is that the function to
calculate descriptor tag size returns sizes that are too big.  This
causes alignment issues on some architectures and is compounded by the
fact that some parts of jbd2 use the structure size (incorrectly) to
determine the presence of a 64bit journal instead of checking the
feature flags.

Therefore, introduce journal checksum v3, which enlarges the
descriptor block tag format to allow for full 32-bit checksums of
journal blocks, fix the journal tag function to return the correct
sizes, and fix the jbd2 recovery code to use feature flags to
determine 64bitness.

Add a few function helpers so we don't have to open-code quite so
many pieces.

Switching to a 16-byte block size was found to increase journal size
overhead by a maximum of 0.1%, to convert a 32-bit journal with no
checksumming to a 32-bit journal with checksum v3 enabled.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reported-by: TR Reardon <thomas_reardon@hotmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
2014-08-28 22:22:29 -04:00