Commit Graph

582 Commits

Author SHA1 Message Date
Jan Kara
cbd7584e6e ext4: fix block reservation for bigalloc filesystems
For bigalloc filesystems we have to check whether newly requested inode
block isn't already part of a cluster for which we already have delayed
allocation reservation. This check happens in ext4_ext_map_blocks() and
that function sets EXT4_MAP_FROM_CLUSTER if that's the case. However if
ext4_da_map_blocks() finds in extent cache information about the block,
we don't call into ext4_ext_map_blocks() and thus we always end up
getting new reservation even if the space for cluster is already
reserved. This results in overreservation and premature ENOSPC reports.

Fix the problem by checking for existing cluster reservation already in
ext4_da_map_blocks(). That simplifies the logic and actually allows us
to get rid of the EXT4_MAP_FROM_CLUSTER flag completely.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-11-25 11:41:49 -05:00
Eric Whitney
0756b908a3 ext4: fix end of region partial cluster handling
ext4_ext_remove_space() can incorrectly free a partial_cluster if
EAGAIN is encountered while truncating or punching.  Extent removal
should be retried in this case.

It also fails to free a partial cluster when the punched region begins
at the start of a file on that unaligned cluster and where the entire
file has not been punched.  Remove the requirement that all blocks in
the file must have been freed in order to free the partial cluster.

Signed-off-by: Eric Whitney <enwlinux@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-11-23 00:59:39 -05:00
Eric Whitney
345ee94748 ext4: miscellaneous partial cluster cleanups
Add some casts and rearrange a few statements for improved readability.
Some code can also be simplified and made more readable if we set
partial_cluster to 0 rather than to a negative value when we can tell
we've hit the left edge of the punched region.

Signed-off-by: Eric Whitney <enwlinux@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-11-23 00:59:39 -05:00
Eric Whitney
5bf4376065 ext4: fix end of leaf partial cluster handling
The fix in commit ad6599ab3a ("ext4: fix premature freeing of
partial clusters split across leaf blocks"), intended to avoid
dereferencing an invalid extent pointer when determining whether a
partial cluster should be freed, wasn't quite good enough.  Assure that
at least one extent remains at the start of the leaf once the hole has
been punched.  Otherwise, the pointer to the extent to the right of the
hole will be invalid and a partial cluster will be incorrectly freed.

Set partial_cluster to 0 when we can tell we've hit the left edge of
the punched region within the leaf.  This prevents incorrect freeing
of a partial cluster when ext4_ext_rm_leaf is called one last time
during extent tree traversal after the punched region has been removed.

Adjust comments to reflect code changes and a correction.  Remove a bit
of dead code.

Signed-off-by: Eric Whitney <enwlinux@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-11-23 00:58:11 -05:00
Eric Whitney
f4226d9ea4 ext4: fix partial cluster initialization
The partial_cluster variable is not always initialized correctly when
hole punching on bigalloc file systems.  Although commit c063449394
("ext4: fix partial cluster handling for bigalloc file systems")
addressed the case where the right edge of the punched region and the
next extent to its right were within the same leaf, it didn't handle
the case where the next extent to its right is in the next leaf.  This
causes xfstest generic/300 to fail.

Fix this by replacing the code in c0634493922 with a more general
solution that can continue the search for the first cluster to the
right of the punched region into the next leaf if present.  If found,
partial_cluster is initialized to this cluster's negative value.
There's no need to determine if that cluster is actually shared;  we
simply record it so its blocks won't be freed in the event it does
happen to be shared.

Also, minimize the burden on non-bigalloc file systems with some minor
code simplification.

Signed-off-by: Eric Whitney <enwlinux@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-11-23 00:55:42 -05:00
Jan Kara
ae9e9c6aee ext4: make ext4_ext_convert_to_initialized() return proper number of blocks
ext4_ext_convert_to_initialized() can return more blocks than are
actually allocated from map->m_lblk in case where initial part of the
on-disk extent is zeroed out. Luckily this doesn't have serious
consequences because the caller currently uses the return value
only to unmap metadata buffers. Anyway this is a data
corruption/exposure problem waiting to happen so fix it.

Coverity-id: 1226848
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-10-30 10:53:17 -04:00
Dmitry Monakhov
9aa5d32ba2 ext4: Replace open coded mdata csum feature to helper function
Besides the fact that this replacement improves code readability
it also protects from errors caused direct EXT4_S(sb)->s_es manipulation
which may result attempt to use uninitialized  csum machinery.

#Testcase_BEGIN
IMG=/dev/ram0
MNT=/mnt
mkfs.ext4 $IMG
mount $IMG $MNT
#Enable feature directly on disk, on mounted fs
tune2fs -O metadata_csum  $IMG
# Provoke metadata update, likey result in OOPS
touch $MNT/test
umount $MNT
#Testcase_END

# Replacement script
@@
expression E;
@@
- EXT4_HAS_RO_COMPAT_FEATURE(E, EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)
+ ext4_has_metadata_csum(E)

https://bugzilla.kernel.org/show_bug.cgi?id=82201

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
2014-10-13 03:36:16 -04:00
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
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
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
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
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
c174e6d697 ext4: fix transaction issues for ext4_fallocate and ext_zero_range
After commit f282ac19d8 we use different transactions for
preallocation and i_disksize update which result in complain from fsck
after power-failure.  spotted by generic/019. IMHO this is regression
because fs becomes inconsistent, even more 'e2fsck -p' will no longer
works (which drives admins go crazy) Same transaction requirement
applies ctime,mtime updates

testcase: xfstest generic/019

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
2014-08-27 18:40:00 -04:00
Dmitry Monakhov
69dc953640 ext4: fix incorect journal credits reservation in ext4_zero_range
Currently we reserve only 4 blocks but in worst case scenario
ext4_zero_partial_blocks() may want to zeroout and convert two
non adjacent blocks.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
2014-08-27 18:33:49 -04:00
Dmitry Monakhov
4631dbf677 ext4: move i_size,i_disksize update routines to helper function
Cc: stable@vger.kernel.org # needed for bug fix patches
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-08-23 17:48:28 -04:00
Namjae Jeon
ee98fa3a8b ext4: fix COLLAPSE RANGE test for bigalloc file systems
Blocks in collapse range should be collapsed per cluster unit when
bigalloc is enable. If bigalloc is not enable, EXT4_CLUSTER_SIZE will
be same with EXT4_BLOCK_SIZE.

With this bug fixed, patch enables COLLAPSE_RANGE for bigalloc, which
fixes a large number of xfstest failures which use fsx.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-07-29 10:45:31 -04:00
Dmitry Monakhov
29faed1638 ext4: use correct depth value
Inode's depth can be changed from here:
ext4_ext_try_to_merge() ->ext4_ext_try_to_merge_up()
We must use correct value.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
2014-07-27 22:30:29 -04:00
Dmitry Monakhov
4b1f166071 ext4: add i_data_sem sanity check
Each caller of ext4_ext_dirty must hold i_data_sem,
The only exception is migration code, let's make it convenient.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
2014-07-27 22:28:15 -04:00
Theodore Ts'o
71d4f7d032 ext4: remove metadata reservation checks
Commit 27dd438542 ("ext4: introduce reserved space") reserves 2% of
the file system space to make sure metadata allocations will always
succeed.  Given that, tracking the reservation of metadata blocks is
no longer necessary.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-07-15 06:02:38 -04:00
Namjae Jeon
e1ee60fd89 ext4: fix ZERO_RANGE test failure in data journalling
xfstests generic/091 is failing when mounting ext4 with data=journal.
I think that this regression is same problem that occurred prior to collapse
range issue. So ZERO RANGE also need to call ext4_force_commit as
collapse range.

Cc: stable@vger.kernel.org
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-05-27 12:48:55 -04:00
liang xie
5d60125530 ext4: add missing BUFFER_TRACE before ext4_journal_get_write_access
Make them more consistently

Signed-off-by: xieliang <xieliang@xiaomi.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-05-12 22:06:43 -04:00
Lukas Czerner
c8b459f492 ext4: remove unnecessary double parentheses
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-05-12 12:55:07 -04:00
Lukas Czerner
556615dcbf ext4: rename uninitialized extents to unwritten
Currently in ext4 there is quite a mess when it comes to naming
unwritten extents. Sometimes we call it uninitialized and sometimes we
refer to it as unwritten.

The right name for the extent which has been allocated but does not
contain any written data is _unwritten_. Other file systems are
using this name consistently, even the buffer head state refers to it as
unwritten. We need to fix this confusion in ext4.

This commit changes every reference to an uninitialized extent (meaning
allocated but unwritten) to unwritten extent. This includes comments,
function names and variable names. It even covers abbreviation of the
word uninitialized (such as uninit) and some misspellings.

This commit does not change any of the code paths at all. This has been
confirmed by comparing md5sums of the assembly code of each object file
after all the function names were stripped from it.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-04-20 23:45:47 -04:00
Lukas Czerner
090f32ee4e ext4: get rid of EXT4_MAP_UNINIT flag
Currently EXT4_MAP_UNINIT is used in dioread_nolock case to mark the
cases where we're using dioread_nolock and we're writing into either
unallocated, or unwritten extent, because we need to make sure that
any DIO write into that inode will wait for the extent conversion.

However EXT4_MAP_UNINIT is not only entirely misleading name but also
unnecessary because we can check for EXT4_MAP_UNWRITTEN in the
dioread_nolock case instead.

This commit removes EXT4_MAP_UNINIT flag.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-04-20 23:44:47 -04:00
Namjae Jeon
0a04b24853 ext4: disable COLLAPSE_RANGE for bigalloc
Once COLLAPSE RANGE is be disable for ext4 with bigalloc feature till finding
root-cause of problem. It will be enable with fixing that regression of
xfstest(generic 075 and 091) again.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>
Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-04-19 16:38:21 -04:00
Namjae Jeon
a8680e0d5e ext4: fix COLLAPSE_RANGE failure with 1KB block size
When formatting with 1KB or 2KB(not aligned with PAGE SIZE) block
size, xfstests generic/075 and 091 are failing. The offset supplied to
function truncate_pagecache_range is block size aligned. In this
function start offset is re-aligned to PAGE_SIZE by rounding_up to the
next page boundary.  Due to this rounding up, old data remains in the
page cache when blocksize is less than page size and start offset is
not aligned with page size.  In case of collapse range, we need to
align start offset to page size boundary by doing a round down
operation instead of round up.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-04-19 16:37:31 -04:00
Theodore Ts'o
86f1ca3889 ext4: use EINVAL if not a regular file in ext4_collapse_range()
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-04-18 11:52:11 -04:00
jon ernst
6c5e73d3a2 ext4: enforce we are operating on a regular file in ext4_zero_range()
Signed-off-by: Jon Ernst <jonernst07@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-04-18 11:50:35 -04:00
Lukas Czerner
6dd834effc ext4: fix extent merging in ext4_ext_shift_path_extents()
There is a bug in ext4_ext_shift_path_extents() where if we actually
manage to merge a extent we would skip shifting the next extent. This
will result in in one extent in the extent tree not being properly
shifted.

This is causing failure in various xfstests tests using fsx or fsstress
with collapse range support. It will also cause file system corruption
which looks something like:

 e2fsck 1.42.9 (4-Feb-2014)
 Pass 1: Checking inodes, blocks, and sizes
 Inode 20 has out of order extents
        (invalid logical block 3, physical block 492938, len 2)
 Clear? yes
 ...

when running e2fsck.

It's also very easily reproducible just by running fsx without any
parameters. I can usually hit the problem within a minute.

Fix it by increasing ex_start only if we're not merging the extent.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
2014-04-18 10:55:24 -04:00
Lukas Czerner
ef24f6c234 ext4: discard preallocations after removing space
Currently in ext4_collapse_range() and ext4_punch_hole() we're
discarding preallocation twice. Once before we attempt to do any changes
and second time after we're done with the changes.

While the second call to ext4_discard_preallocations() in
ext4_punch_hole() case is not needed, we need to discard preallocation
right after ext4_ext_remove_space() in collapse range case because in
the case we had to restart a transaction in the middle of removing space
we might have new preallocations created.

Remove unneeded ext4_discard_preallocations() ext4_punch_hole() and move
it to the better place in ext4_collapse_range()

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-04-18 10:50:23 -04:00
Lukas Czerner
9337d5d31a ext4: no need to truncate pagecache twice in collapse range
We're already calling truncate_pagecache() before we attempt to do any
actual job so there is not need to truncate pagecache once more using
truncate_setsize() after we're finished.

Remove truncate_setsize() and replace it just with i_size_write() note
that we're holding appropriate locks.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-04-18 10:48:25 -04:00
Lukas Czerner
2c1d23289b ext4: fix removing status extents in ext4_collapse_range()
Currently in ext4_collapse_range() when calling ext4_es_remove_extent() to
remove status extents we're passing (EXT_MAX_BLOCKS - punch_start - 1)
in order to remove all extents from start of the collapse range to the
end of the file. However this is wrong because we might miss the
possible extent covering the last block of the file.

Fix it by removing the -1.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
2014-04-18 10:43:21 -04:00
Lukas Czerner
1a66c7c3be ext4: use filemap_write_and_wait_range() correctly in collapse range
Currently we're passing -1 as lend argumnet for
filemap_write_and_wait_range() which is wrong since lend is signed type
so it would cause some confusion and we might not write_and_wait for the
entire range we're expecting to write.

Fix it by using LLONG_MAX instead.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-04-18 10:41:52 -04:00
Lukas Czerner
694c793fc1 ext4: use truncate_pagecache() in collapse range
We should be using truncate_pagecache() instead of
truncate_pagecache_range() in the collapse range because we're
truncating page cache from offset to the end of file.
truncate_pagecache() also get rid of the private COWed pages from the
range because we're going to shift the end of the file.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-04-18 10:21:15 -04:00
Dmitry Monakhov
a18ed359bd ext4: always check ext4_ext_find_extent result
Where are some places where logic guaranties us that extent we are
searching exits, but this may not be true due to on-disk data
corruption. If such corruption happens we must prevent possible
null pointer dereferences.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-04-13 15:41:13 -04:00
Dmitry Monakhov
8dc79ec4c0 ext4: fix error handling in ext4_ext_shift_extents
Fix error handling by adding some.  :-)

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-04-13 15:05:42 -04:00
Theodore Ts'o
40c406c74e ext4: COLLAPSE_RANGE only works on extent-based files
Unfortunately, we weren't checking to make sure of this the inode was
extent-based before attempt operate on it.  Hilarity ensues.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Namjae Jeon <namjae.jeon@samsung.com>
2014-04-12 22:53:53 -04:00
Zheng Liu
847c6c422a ext4: fix byte order problems introduced by the COLLAPSE_RANGE patches
This commit tries to fix some byte order issues that is found by sparse
check.

$ make M=fs/ext4 C=2 CF=-D__CHECK_ENDIAN__
...
  CHECK   fs/ext4/extents.c
fs/ext4/extents.c:5232:41: warning: restricted __le32 degrades to integer
fs/ext4/extents.c:5236:52: warning: bad assignment (-=) to restricted __le32
fs/ext4/extents.c:5258:45: warning: bad assignment (-=) to restricted __le32
fs/ext4/extents.c:5303:28: warning: restricted __le32 degrades to integer
fs/ext4/extents.c:5318:18: warning: incorrect type in assignment (different base types)
fs/ext4/extents.c:5318:18:    expected unsigned int [unsigned] [usertype] ex_start
fs/ext4/extents.c:5318:18:    got restricted __le32 [usertype] ee_block
fs/ext4/extents.c:5319:24: warning: restricted __le32 degrades to integer
fs/ext4/extents.c:5334:31: warning: incorrect type in assignment (different base types)
...

Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-04-12 12:45:55 -04:00
Lukas Czerner
0790b31b69 fs: disallow all fallocate operation on active swapfile
Currently some file system have IS_SWAPFILE check in their fallocate
implementations and some do not. However we should really prevent any
fallocate operation on swapfile so move the check to vfs and remove the
redundant checks from the file systems fallocate implementations.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-04-12 10:05:37 -04:00
Lukas Czerner
23fffa925e fs: move falloc collapse range check into the filesystem methods
Currently in do_fallocate in collapse range case we're checking
whether offset + len is not bigger than i_size.  However there is
nothing which would prevent i_size from changing so the check is
pointless.  It should be done in the file system itself and the file
system needs to make sure that i_size is not going to change.  The
i_size check for the other fallocate modes are also done in the
filesystems.

As it is now we can easily crash the kernel by having two processes
doing truncate and fallocate collapse range at the same time.  This
can be reproduced on ext4 and it is theoretically possible on xfs even
though I was not able to trigger it with this simple test.

This commit removes the check from do_fallocate and adds it to the
file system.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Acked-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2014-04-12 09:56:41 -04:00
Lukas Czerner
9ef06cec7c ext4: remove unnecessary check for APPEND and IMMUTABLE
All the checks IS_APPEND and IS_IMMUTABLE for the fallocate operation on
the inode are done in vfs. No need to do this again in ext4. Remove it.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-04-12 09:47:00 -04:00
Namjae Jeon
1ce01c4a19 ext4: fix COLLAPSE_RANGE test failure in data journalling mode
When mounting ext4 with data=journal option, xfstest shared/002 and
shared/004 are currently failing as checksum computed for testfile
does not match with the checksum computed in other journal modes.
In case of data=journal mode, a call to filemap_write_and_wait_range
will not flush anything to disk as buffers are not marked dirty in
write_end. In collapse range this call is followed by a call to
truncate_pagecache_range. Due to this, when checksum is computed,
a portion of file is re-read from disk which replace valid data with
NULL bytes and hence the reason for the difference in checksum.

Calling ext4_force_commit before filemap_write_and_wait_range solves
the issue as it will mark the buffers dirty during commit transaction
which can be later synced by a call to filemap_write_and_wait_range.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-04-10 22:58:20 -04:00
Eric Whitney
ad6599ab3a ext4: fix premature freeing of partial clusters split across leaf blocks
Xfstests generic/311 and shared/298 fail when run on a bigalloc file
system.  Kernel error messages produced during the tests report that
blocks to be freed are already on the to-be-freed list.  When e2fsck
is run at the end of the tests, it typically reports bad i_blocks and
bad free blocks counts.

The bug that causes these failures is located in ext4_ext_rm_leaf().
Code at the end of the function frees a partial cluster if it's not
shared with an extent remaining in the leaf.  However, if all the
extents in the leaf have been removed, the code dereferences an
invalid extent pointer (off the front of the leaf) when the check for
sharing is made.  This generally has the effect of unconditionally
freeing the partial cluster, which leads to the observed failures
when the partial cluster is shared with the last extent in the next
leaf.

Fix this by attempting to free the cluster only if extents remain in
the leaf.  Any remaining partial cluster will be freed if possible
when the next leaf is processed or when leaf removal is complete.

Signed-off-by: Eric Whitney <enwlinux@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
2014-04-01 19:49:30 -04:00
Lukas Czerner
e5b30416f3 ext4: remove unneeded test of ret variable
Currently in ext4_fallocate() and ext4_zero_range() we're testing ret
variable along with new_size. However in ext4_fallocate() we just tested
ret before and in ext4_zero_range() if will always be zero when we get
there so there is no need to test it in both cases.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-04-01 00:59:21 -04:00
Lukas Czerner
b8a8684502 ext4: Introduce FALLOC_FL_ZERO_RANGE flag for fallocate
Introduce new FALLOC_FL_ZERO_RANGE flag for fallocate. This has the same
functionality as xfs ioctl XFS_IOC_ZERO_RANGE.

It can be used to convert a range of file to zeros preferably without
issuing data IO. Blocks should be preallocated for the regions that span
holes in the file, and the entire range is preferable converted to
unwritten extents

This can be also used to preallocate blocks past EOF in the same way as
with fallocate. Flag FALLOC_FL_KEEP_SIZE which should cause the inode
size to remain the same.

Also add appropriate tracepoints.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-03-18 18:05:35 -04:00
Lukas Czerner
0e8b6879f3 ext4: refactor ext4_fallocate code
Move block allocation out of the ext4_fallocate into separate function
called ext4_alloc_file_blocks(). This will allow us to use the same
allocation code for other allocation operations such as zero range which
is commit in the next patch.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-03-18 18:03:51 -04:00
Lukas Czerner
f282ac19d8 ext4: Update inode i_size after the preallocation
Currently in ext4_fallocate we would update inode size, c_time and sync
the file with every partial allocation which is entirely unnecessary. It
is true that if the crash happens in the middle of truncate we might end
up with unchanged i size, or c_time which I do not think is really a
problem - it does not mean file system corruption in any way. Note that
xfs is doing things the same way e.g. update all of the mentioned after
the allocation is done.

This commit moves all the updates after the allocation is done. In
addition we also need to change m_time as not only inode has been change
bot also data regions might have changed (unwritten extents). However
m_time will be only updated when i_size changed.

Also we do not need to be paranoid about changing the c_time only if the
actual allocation have happened, we can change it even if we try to
allocate only to find out that there are already block allocated. It's
not really a big deal and it will save us some additional complexity.

Also use ext4_debug, instead of ext4_warning in #ifdef EXT4FS_DEBUG
section.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>-
--
v3: Do not remove the code to set EXT4_INODE_EOFBLOCKS flag

 fs/ext4/extents.c | 96 ++++++++++++++++++++++++-------------------------------
 1 file changed, 42 insertions(+), 54 deletions(-)
2014-03-18 17:44:35 -04:00
Eric Whitney
c063449394 ext4: fix partial cluster handling for bigalloc file systems
Commit 9cb00419fa, which enables hole punching for bigalloc file
systems, exposed a bug introduced by commit 6ae06ff51e in an earlier
release.  When run on a bigalloc file system, xfstests generic/013, 068,
075, 083, 091, 100, 112, 127, 263, 269, and 270 fail with e2fsck errors
or cause kernel error messages indicating that previously freed blocks
are being freed again.

The latter commit optimizes the selection of the starting extent in
ext4_ext_rm_leaf() when hole punching by beginning with the extent
supplied in the path argument rather than with the last extent in the
leaf node (as is still done when truncating).  However, the code in
rm_leaf that initially sets partial_cluster to track cluster sharing on
extent boundaries is only guaranteed to run if rm_leaf starts with the
last node in the leaf.  Consequently, partial_cluster is not correctly
initialized when hole punching, and a cluster on the boundary of a
punched region that should be retained may instead be deallocated.

Signed-off-by: Eric Whitney <enwlinux@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
2014-03-13 23:34:16 -04:00
Eric Whitney
31cf0f2c31 ext4: delete path dealloc code in ext4_ext_handle_uninitialized_extents
Code deallocating the extent path referenced by an argument to
ext4_ext_handle_uninitialized_extents was made redundant with identical
code in its one caller, ext4_ext_map_blocks, by commit 3779473246.
Allocating and deallocating the path in the same function also makes
the code clearer.

Signed-off-by: Eric Whitney <enwlinux@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-03-13 23:14:46 -04:00
Namjae Jeon
9eb79482a9 ext4: Add support FALLOC_FL_COLLAPSE_RANGE for fallocate
This patch implements fallocate's FALLOC_FL_COLLAPSE_RANGE for Ext4.
 
The semantics of this flag are following:
1) It collapses the range lying between offset and length by removing any data
   blocks which are present in this range and than updates all the logical
   offsets of extents beyond "offset + len" to nullify the hole created by
   removing blocks. In short, it does not leave a hole.
2) It should be used exclusively. No other fallocate flag in combination.
3) Offset and length supplied to fallocate should be fs block size aligned
   in case of xfs and ext4.
4) Collaspe range does not work beyond i_size.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>
Tested-by: Dongsu Park <dongsu.park@profitbricks.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-02-23 15:18:59 -05:00
Lukas Czerner
a633f5a319 ext4: translate fallocate mode bits to strings
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-02-22 06:18:17 -05:00
Darrick J. Wong
a9b8241594 ext4: merge uninitialized extents
Allow for merging uninitialized extents.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-02-20 21:17:35 -05:00
Eric Whitney
ce37c42919 ext4: fix error return from ext4_ext_handle_uninitialized_extents()
Commit 3779473246 breaks the return of error codes from
ext4_ext_handle_uninitialized_extents() in ext4_ext_map_blocks().  A
portion of the patch assigns that function's signed integer return
value to an unsigned int.  Consequently, negatively valued error codes
are lost and can be treated as a bogus allocated block count.

Signed-off-by: Eric Whitney <enwlinux@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
2014-02-19 18:52:39 -05:00
Eric Whitney
15cc176785 ext4: fix xfstest generic/299 block validity failures
Commit a115f749c1 (ext4: remove wait for unwritten extent conversion from
ext4_truncate) exposed a bug in ext4_ext_handle_uninitialized_extents().
It can be triggered by xfstest generic/299 when run on a test file
system created without a journal.  This test continuously fallocates and
truncates files to which random dio/aio writes are simultaneously
performed by a separate process.  The test completes successfully, but
if the test filesystem is mounted with the block_validity option, a
warning message stating that a logical block has been mapped to an
illegal physical block is posted in the kernel log.

The bug occurs when an extent is being converted to the written state
by ext4_end_io_dio() and ext4_ext_handle_uninitialized_extents()
discovers a mapping for an existing uninitialized extent. Although it
sets EXT4_MAP_MAPPED in map->m_flags, it fails to set map->m_pblk to
the discovered physical block number.  Because map->m_pblk is not
otherwise initialized or set by this function or its callers, its
uninitialized value is returned to ext4_map_blocks(), where it is
stored as a bogus mapping in the extent status tree.

Since map->m_pblk can accidentally contain illegal values that are
larger than the physical size of the file system,  calls to
check_block_validity() in ext4_map_blocks() that are enabled if the
block_validity mount option is used can fail, resulting in the logged
warning message.

Signed-off-by: Eric Whitney <enwlinux@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org  # 3.11+
2014-02-12 10:42:45 -05:00
Yongqiang Yang
9e740568bc ext4: fix a typo in extents.c
Signed-off-by: Yongqiang Yang <yangyongqiang01@baidu.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
2014-01-06 14:05:23 -05:00
Eric Whitney
d0abafac8c ext4: fix bigalloc regression
Commit f5a44db5d2 introduced a regression on filesystems created with
the bigalloc feature (cluster size > blocksize).  It causes xfstests
generic/006 and /013 to fail with an unexpected JBD2 failure and
transaction abort that leaves the test file system in a read only state.
Other xfstests run on bigalloc file systems are likely to fail as well.

The cause is the accidental use of a cluster mask where a cluster
offset was needed in ext4_ext_map_blocks().

Signed-off-by: Eric Whitney <enwlinux@gmail.com>
2014-01-06 14:00:23 -05:00
Theodore Ts'o
f5a44db5d2 ext4: add explicit casts when masking cluster sizes
The missing casts can cause the high 64-bits of the physical blocks to
be lost.  Set up new macros which allows us to make sure the right
thing happen, even if at some point we end up supporting larger
logical block numbers.

Thanks to the Emese Revfy and the PaX security team for reporting this
issue.

Reported-by: PaX Team <pageexec@freemail.hu>
Reported-by: Emese Revfy <re.emese@gmail.com>                                 
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
2013-12-20 09:29:35 -05:00
Eryu Guan
5946d08937 ext4: check for overlapping extents in ext4_valid_extent_entries()
A corrupted ext4 may have out of order leaf extents, i.e.

extent: lblk 0--1023, len 1024, pblk 9217, flags: LEAF UNINIT
extent: lblk 1000--2047, len 1024, pblk 10241, flags: LEAF UNINIT
             ^^^^ overlap with previous extent

Reading such extent could hit BUG_ON() in ext4_es_cache_extent().

	BUG_ON(end < lblk);

The problem is that __read_extent_tree_block() tries to cache holes as
well but assumes 'lblk' is greater than 'prev' and passes underflowed
length to ext4_es_cache_extent(). Fix it by checking for overlapping
extents in ext4_valid_extent_entries().

I hit this when fuzz testing ext4, and am able to reproduce it by
modifying the on-disk extent by hand.

Also add the check for (ee_block + len - 1) in ext4_valid_extent() to
make sure the value is not overflow.

Ran xfstests on patched ext4 and no regression.

Cc: Lukáš Czerner <lczerner@redhat.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
2013-12-03 21:22:21 -05:00
Eric Sandeen
f275411440 ext4: remove unreachable code after ext4_can_extents_be_merged()
Commit ec22ba8e ("ext4: disable merging of uninitialized extents")
ensured that if either extent under consideration is uninit, we
decline to merge, and ext4_can_extents_be_merged() returns false.

So there is no need for the caller to then test whether the
extent under consideration is unitialized; if it were, we
wouldn't have gotten that far.

The comments were also inaccurate; ext4_can_extents_be_merged()
no longer XORs the states, it fails if *either* is uninit.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
2013-11-07 22:22:08 -05:00
Eric Sandeen
da0169b3b9 ext4: remove unreachable code in ext4_can_extents_be_merged()
Commit ec22ba8e ("ext4: disable merging of uninitialized extents")
ensured that if either extent under consideration is uninit, we
decline to merge, and immediately return.

But right after that test, we test again for an uninit
extent; we can never hit this.  So just remove the impossible
test and associated variable.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
2013-11-04 09:58:26 -05:00
Zheng Liu
d7b2a00c2e ext4: isolate ext4_extents.h file
After applied the commit (4a092d73), we have reduced the number of
source files that need to #include ext4_extents.h.  But we can do
better.

This commit defines ext4_zeroout_es() in extents.c and move
EXT_MAX_BLOCKS into ext4.h in order not to include ext4_extents.h in
indirect.c and ioctl.c.  Meanwhile we just need to include this file in
extent_status.c when ES_AGGRESSIVE_TEST is defined.  Otherwise, this
commit removes a duplicated declaration in trace/events/ext4.h.

After applied this patch, we just need to include ext4_extents.h file
in {super,migrate,move_extents,extents}.c, and it is easy for us to
define a new extent disk layout.

Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-08-28 14:47:06 -04:00
Anatol Pomozov
70261f568f ext4: Fix misspellings using 'codespell' tool
Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-08-28 14:40:12 -04:00
Andi Shyti
27b1b22882 ext4: fix use of potentially uninitialized variables in debugging code
If ext_debugging is enabled and path[depth].p_ext is NULL, len
and lblock are printed non initialized

Signed-off-by: Andi Shyti <andi@etezian.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-08-28 14:00:00 -04:00
Jan Kara
7d7345322d ext4: fix warning in ext4_da_update_reserve_space()
reaim workfile.dbase test easily triggers warning in
ext4_da_update_reserve_space():

EXT4-fs warning (device ram0): ext4_da_update_reserve_space:365:
ino 12, allocated 1 with only 0 reserved metadata blocks (releasing 1
blocks with reserved 9 data blocks)

The problem is that (one of) tests creates file and then randomly writes
to it with O_SYNC. That results in writing back pages of the file in
random order so we create extents for written blocks say 0, 2, 4, 6, 8
- this last allocation also allocates new block for extents. Then we
writeout block 1 so we have extents 0-2, 4, 6, 8 and we release
indirect extent block because extents fit in the inode again. Then we
writeout block 10 and we need to allocate indirect extent block again
which triggers the warning because we don't have the reservation
anymore.

Fix the problem by giving back freed metadata blocks resulting from
extent merging into inode's reservation pool.

Signed-off-by: Jan Kara <jack@suse.cz>
2013-08-17 09:36:54 -04:00
Theodore Ts'o
7869a4a6c5 ext4: add support for extent pre-caching
Add a new fiemap flag which forces the all of the extents in an inode
to be cached in the extent_status tree.  This is critically important
when using AIO to a preallocated file, since if we need to read in
blocks from the extent tree, the io_submit(2) system call becomes
synchronous, and the AIO is no longer "A", which is bad.

In addition, for most files which have an external leaf tree block,
the cost of caching the information in the extent status tree will be
less than caching the entire 4k block in the buffer cache.  So it is
generally a win to keep the extent information cached.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-08-16 22:05:14 -04:00
Theodore Ts'o
107a7bd31a ext4: cache all of an extent tree's leaf block upon reading
When we read in an extent tree leaf block from disk, arrange to have
all of its entries cached.  In nearly all cases the in-memory
representation will be more compact than the on-disk representation in
the buffer cache, and it allows us to get the information without
having to traverse the extent tree for successive extents.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
2013-08-16 21:23:41 -04:00
Theodore Ts'o
c349179b48 ext4: print the block number of invalid extent tree blocks
When we find an invalid extent tree block, report the block number of
the bad block for debugging purposes.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
2013-08-16 21:21:41 -04:00
Theodore Ts'o
7d7ea89e75 ext4: refactor code to read the extent tree block
Refactor out the code needed to read the extent tree block into a
single read_extent_tree_block() function.  In addition to simplifying
the code, it also makes sure that we call the ext4_ext_load_extent
tracepoint whenever we need to read an extent tree block from disk.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
2013-08-16 21:20:41 -04:00
Theodore Ts'o
94eec0fc35 ext4: fix retry handling in ext4_ext_truncate()
We tested for ENOMEM instead of -ENOMEM.   Oops.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
2013-07-29 12:12:56 -04:00
Theodore Ts'o
63b999685c ext4: call ext4_es_lru_add() after handling cache miss
If there are no items in the extent status tree, ext4_es_lru_add() is
a no-op.  So it is not sufficient to call ext4_es_lru_add() before we
try to lookup an entry in the extent status tree.  We also need to
call it at the end of ext4_ext_map_blocks(), after items have been
added to the extent status tree.

This could lead to inodes with that have extent status trees but which
are not in the LRU list, which means they won't get considered for
eviction by the es_shrinker.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Zheng Liu <wenqing.lz@taobao.com>
Cc: stable@vger.kernel.org
2013-07-16 10:28:47 -04:00
Theodore Ts'o
76828c8826 ext4: yield during large unlinks
During large unlink operations on files with extents, we can use a lot
of CPU time.  This adds a cond_resched() call when starting to examine
the next level of a multi-level extent tree.  Multi-level extent trees
are rare in the first place, and this should rarely be executed.
    
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-07-15 12:27:47 -04:00
Theodore Ts'o
c8e15130e1 ext4: simplify calculation of blocks to free on error
In ext4_ext_map_blocks(), if we have successfully allocated the data
blocks, but then run into trouble inserting the extent into the extent
tree, most likely due to an ENOSPC condition, determine the arguments
to ext4_free_blocks() in a simpler way which is easier to prove to be
correct.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-07-15 00:09:37 -04:00
Theodore Ts'o
8acd5e9b12 ext4: fix error handling in ext4_ext_truncate()
Previously ext4_ext_truncate() was ignoring potential error returns
from ext4_es_remove_extent() and ext4_ext_remove_space().  This can
lead to the on-diks extent tree and the extent status tree cache
getting out of sync, which is particuarlly bad, and can lead to file
system corruption and potential data loss.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
2013-07-15 00:09:19 -04:00
Ashish Sangwan
6ae06ff51e ext4: optimize starting extent in ext4_ext_rm_leaf()
Both hole punch and truncate use ext4_ext_rm_leaf() for removing
blocks.  Currently we choose the last extent as the starting
point for removing blocks:

	ex = EXT_LAST_EXTENT(eh);

This is OK for truncate but for hole punch we can optimize the extent
selection as the path is already initialized.  We could use this
information to select proper starting extent.  The code change in this
patch will not affect truncate as for truncate path[depth].p_ext will
always be NULL.

Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-07-01 08:12:41 -04:00
Theodore Ts'o
21ddd568c1 ext4: translate flag bits to strings in tracepoints
Translate the bitfields used in various flags argument to strings to
make the tracepoint output more human-readable.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-07-01 08:12:40 -04:00
Ashish Sangwan
aeb2817a4e ext4: pass inode pointer instead of file pointer to punch hole
No need to pass file pointer when we can directly pass inode pointer.

Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-07-01 08:12:38 -04:00
Jie Liu
72dac95d44 ext4: return FIEMAP_EXTENT_UNKNOWN for delalloc extents
Return the FIEMAP_EXTENT_UNKNOWN flag as well except the
FIEMAP_EXTENT_DELALLOC because the data location of an
delayed allocation extent is unknown.

Signed-off-by: Jie Liu <jeff.liu@oracle.com>
2013-06-12 23:13:59 -04:00
Theodore Ts'o
981250ca89 ext4: don't use EXT4_FREE_BLOCKS_FORGET unnecessarily
Commit 18888cf088: "ext4: speed up truncate/unlink by not using
bforget() unless needed" removed the use of EXT4_FREE_BLOCKS_FORGET in
the most important codepath for file systems using extents, but a
similar optimization also can be done for file systems using indirect
blocks, and for the two special cases in the ext4 extents code.

Cc: Andrey Sidorov <qrxd43@motorola.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-12 11:48:29 -04:00
Jan Kara
6b523df4fb ext4: use transaction reservation for extent conversion in ext4_end_io
Later we would like to clear PageWriteback bit only after extent
conversion from unwritten to written extents is performed.  However it
is not possible to start a transaction after PageWriteback is set
because that violates lock ordering (and is easy to deadlock).  So we
have to reserve a transaction before locking pages and sending them
for IO and later we use the transaction for extent conversion from
ext4_end_io().

Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-04 13:21:11 -04:00
Jan Kara
fffb273997 ext4: better estimate credits needed for ext4_da_writepages()
We limit the number of blocks written in a single loop of
ext4_da_writepages() to 64 when inode uses indirect blocks.  That is
unnecessary as credit estimates for mapping logically continguous run
of blocks is rather low even for inode with indirect blocks.  So just
lift this limitation and properly calculate the number of necessary
credits.

This better credit estimate will also later allow us to always write
at least a single page in one iteration.

Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-04 13:01:11 -04:00
Jan Kara
a60697f411 ext4: fix data offset overflow in ext4_xattr_fiemap() on 32-bit archs
On 32-bit architectures with 32-bit sector_t computation of data offset
in ext4_xattr_fiemap() can overflow resulting in reporting bogus data
location. Fix the problem by typing block number to proper type before
shifting.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2013-05-31 19:38:56 -04:00
Lukas Czerner
d23142c627 ext4: make punch hole code path work with bigalloc
Currently punch hole is disabled in file systems with bigalloc
feature enabled. However the recent changes in punch hole patch should
make it easier to support punching holes on bigalloc enabled file
systems.

This commit changes partial_cluster handling in ext4_remove_blocks(),
ext4_ext_rm_leaf() and ext4_ext_remove_space(). Currently
partial_cluster is unsigned long long type and it makes sure that we
will free the partial cluster if all extents has been released from that
cluster. However it has been specifically designed only for truncate.

With punch hole we can be freeing just some extents in the cluster
leaving the rest untouched. So we have to make sure that we will notice
cluster which still has some extents. To do this I've changed
partial_cluster to be signed long long type. The only scenario where
this could be a problem is when cluster_size == block size, however in
that case there would not be any partial clusters so we're safe. For
bigger clusters the signed type is enough. Now we use the negative value
in partial_cluster to mark such cluster used, hence we know that we must
not free it even if all other extents has been freed from such cluster.

This scenario can be described in simple diagram:

|FFF...FF..FF.UUU|
 ^----------^
  punch hole

. - free space
| - cluster boundary
F - freed extent
U - used extent

Also update respective tracepoints to use signed long long type for
partial_cluster.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2013-05-27 23:33:35 -04:00
Lukas Czerner
61801325f7 ext4: update ext4_ext_remove_space trace point
Add "end" variable.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2013-05-27 23:32:35 -04:00
Lukas Czerner
78fb9cdf03 ext4: remove unused code from ext4_remove_blocks()
The "head removal" branch in the condition is never used in any code
path in ext4 since the function only caller ext4_ext_rm_leaf() will make
sure that the extent is properly split before removing blocks. Note that
there is a bug in this branch anyway.

This commit removes the unused code completely and makes use of
ext4_error() instead of printk if dubious range is provided.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2013-05-27 23:32:35 -04:00
Yan, Zheng
e30b5dca15 ext4: fix fio regression
We (Linux Kernel Performance project) found a regression introduced
by commit:

  f7fec032aa ext4: track all extent status in extent status tree

The commit causes about 20% performance decrease in fio random write
test. Profiler shows that rb_next() uses a lot of CPU time. The call
stack is:

  rb_next
  ext4_es_find_delayed_extent
  ext4_map_blocks
  _ext4_get_block
  ext4_get_block_write
  __blockdev_direct_IO
  ext4_direct_IO
  generic_file_direct_write
  __generic_file_aio_write
  ext4_file_write
  aio_rw_vect_retry
  aio_run_iocb
  do_io_submit
  sys_io_submit
  system_call_fastpath
  io_submit
  td_io_getevents
  io_u_queued_complete
  thread_main
  main
  __libc_start_main

The cause is that ext4_es_find_delayed_extent() doesn't have an
upper bound, it keeps searching until a delayed extent is found.
When there are a lots of non-delayed entries in the extent state
tree, ext4_es_find_delayed_extent() may uses a lot of CPU time.

Reported-by: LKP project <lkp@linux.intel.com>
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
2013-05-03 02:15:52 -04:00
Darrick J. Wong
2656497b26 ext4: mext_insert_extents should update extent block checksum
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-04-19 14:04:12 -04:00
Lukas Czerner
0d14b098ce ext4: move ext4_ind_migrate() into migrate.c
Move ext4_ind_migrate() into migrate.c file since it makes much more
sense and ext4_ext_migrate() is there as well.

Also fix tiny style problem - add spaces around "=" in "i=0".

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-04-10 23:32:52 -04:00
Dmitry Monakhov
0b65349ebc ext4: fix big-endian bug in extent migration code
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
2013-04-09 23:56:44 -04:00
Lukas Czerner
27dd438542 ext4: introduce reserved space
Currently in ENOSPC condition when writing into unwritten space, or
punching a hole, we might need to split the extent and grow extent tree.
However since we can not allocate any new metadata blocks we'll have to
zero out unwritten part of extent or punched out part of extent, or in
the worst case return ENOSPC even though use actually does not allocate
any space.

Also in delalloc path we do reserve metadata and data blocks for the
time we're going to write out, however metadata block reservation is
very tricky especially since we expect that logical connectivity implies
physical connectivity, however that might not be the case and hence we
might end up allocating more metadata blocks than previously reserved.
So in future, metadata reservation checks should be removed since we can
not assure that we do not under reserve.

And this is where reserved space comes into the picture. When mounting
the file system we slice off a little bit of the file system space (2%
or 4096 clusters, whichever is smaller) which can be then used for the
cases mentioned above to prevent costly zeroout, or unexpected ENOSPC.

The number of reserved clusters can be set via sysfs, however it can
never be bigger than number of free clusters in the file system.

Note that this patch fixes the failure of xfstest 274 as expected.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
2013-04-09 22:11:22 -04:00
Dmitry Monakhov
e8238f9a83 ext4: fix incorrect lock ordering for ext4_ind_migrate
existing locking ordering: journal-> i_data_sem, but
ext4_ind_migrate() grab locks in opposite order which may result in
deadlock.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-04-08 13:02:25 -04:00
Lukas Czerner
be8981be6b ext4: try to prepend extent to the existing one
Currently when inserting extent in ext4_ext_insert_extent() we would
only try to to see if we can append new extent to the found extent. If
we can not, then we proceed with adding new extent into the extent tree,
but then possibly merging it back again.

We can avoid this situation by trying to append and prepend new extent
to the existing ones. However since the new extent can be on either
sides of the existing extent, we have to pick the right extent to try to
append/prepend to.

This patch adds the conditions to pick the right extent to
append/prepend to and adds the actual prepending condition as well. This
will also eliminate the need to use "reserved" block for possibly
growing extent tree.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-04-03 23:33:28 -04:00
Lukas Czerner
bc2d9db48c ext4: Transfer initialized block to right neighbor if possible
Currently when converting extent to initialized we attempt to transfer
initialized block to the left neighbour if possible when certain
criteria are met. However we do not attempt to do the same for the
right neighbor.

This commit adds the possibility to transfer initialized block to the
right neighbour if:

1. We're not converting the whole extent
2. Both extents are stored in the same extent tree node
3. Right neighbor is initialized
4. Right neighbor is logically abutting the current one
5. Right neighbor is physically abutting the current one
6. Right neighbor would not overflow the length limit

This is basically the same logic as with transferring to the left. This
will gain us some performance benefits since it is faster than inserting
extent and then merging it.

It would also prevent some situation in delalloc patch when we might run
out of metadata reservation. This is due to the fact that we would
attempt to split the extent first (possibly allocating new metadata
block) even though we did not counted for that because it can (and will)
be merged again. This commit fix that scenario, because we no longer
need to split the extent in such case.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
2013-04-03 23:33:27 -04:00
Theodore Ts'o
996bb9fddd ext4: support simple conversion of extent-mapped inodes to use i_blocks
In order to make it simpler to test the code which support
i_blocks/indirect-mapped inodes, support the conversion of inodes
which are less than 12 blocks and which are contained in no more than
a single extent.

The primary intended use of this code is to converting freshly created
zero-length files and empty directories.

Note that the version of chattr in e2fsprogs 1.42.7 and earlier has a
check that prevents the clearing of the extent flag.  A simple patch
which allows "chattr -e <file>" to work will be checked into the
e2fsprogs git repository.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-04-03 22:04:52 -04:00
Theodore Ts'o
819c4920b7 ext4: refactor truncate code
Move common code in ext4_ind_truncate() and ext4_ext_truncate() into
ext4_truncate().  This saves over 60 lines of code.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-04-03 12:47:17 -04:00
Theodore Ts'o
26a4c0c6cc ext4: refactor punch hole code
Move common code in ext4_ind_punch_hole() and ext4_ext_punch_hole()
into ext4_punch_hole().  This saves over 150 lines of code.

This also fixes a potential bug when the punch_hole() code is racing
against indirect-to-extents or extents-to-indirect migation.  We are
currently using i_mutex to protect against changes to the inode flag;
specifically, the append-only, immutable, and extents inode flags.  So
we need to take i_mutex before deciding whether to use the
extents-specific or indirect-specific punch_hole code.

Also, there was a missing call to ext4_inode_block_unlocked_dio() in
the indirect punch codepath.  This was added in commit 02d262dffc
to block DIO readers racing against the punch operation in the
codepath for extent-mapped inodes, but it was missing for
indirect-block mapped inodes.  One of the advantages of refactoring
the code is that it makes such oversights much less likely.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-04-03 12:45:17 -04:00
Zheng Liu
8cde7ad17e ext4: fix big-endian bugs which could cause fs corruptions
When an extent was zeroed out, we forgot to do convert from cpu to le16.
It could make us hit a BUG_ON when we try to write dirty pages out.  So
fix it.

[ Also fix a bug found by Dmitry Monakhov where we were missing
  le32_to_cpu() calls in the new indirect punch hole code.

  There are a number of other big endian warnings found by static code
  analyzers, but we'll wait for the next merge window to fix them all
  up.  These fixes are designed to be Obviously Correct by code
  inspection, and easy to demonstrate that it won't make any
  difference (and hence, won't introduce any bugs) on little endian
  architectures such as x86.  --tytso ]

Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reported-by: CAI Qian <caiqian@redhat.com>
Reported-by: Christian Kujau <lists@nerdbynature.de>
Cc: Dmitry Monakhov <dmonakhov@openvz.org>
2013-04-03 12:37:17 -04:00
Linus Torvalds
d3c926264a Fix a number of regression and other bugs in ext4, most of which were
relatively obscure cornercases or races that were found using
 regression tests.
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Merge tag 'ext4_for_linue' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 fixes from Ted Ts'o:
 "Fix a number of regression and other bugs in ext4, most of which were
  relatively obscure cornercases or races that were found using
  regression tests."

* tag 'ext4_for_linue' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (21 commits)
  ext4: fix data=journal fast mount/umount hang
  ext4: fix ext4_evict_inode() racing against workqueue processing code
  ext4: fix memory leakage in mext_check_coverage
  ext4: use s_extent_max_zeroout_kb value as number of kb
  ext4: use atomic64_t for the per-flexbg free_clusters count
  jbd2: fix use after free in jbd2_journal_dirty_metadata()
  ext4: reserve metadata block for every delayed write
  ext4: update reserved space after the 'correction'
  ext4: do not use yield()
  ext4: remove unused variable in ext4_free_blocks()
  ext4: fix WARN_ON from ext4_releasepage()
  ext4: fix the wrong number of the allocated blocks in ext4_split_extent()
  ext4: update extent status tree after an extent is zeroed out
  ext4: fix wrong m_len value after unwritten extent conversion
  ext4: add self-testing infrastructure to do a sanity check
  ext4: avoid a potential overflow in ext4_es_can_be_merged()
  ext4: invalidate extent status tree during extent migration
  ext4: remove unnecessary wait for extent conversion in ext4_fallocate()
  ext4: add warning to ext4_convert_unwritten_extents_endio
  ext4: disable merging of uninitialized extents
  ...
2013-03-21 17:56:10 -07:00
Lukas Czerner
4f42f80a8f ext4: use s_extent_max_zeroout_kb value as number of kb
Currently when converting extent to initialized, we have to decide
whether to zeroout part/all of the uninitialized extent in order to
avoid extent tree growing rapidly.

The decision is made by comparing the size of the extent with the
configurable value s_extent_max_zeroout_kb which is in kibibytes units.

However when converting it to number of blocks we currently use it as it
was in bytes. This is obviously bug and it will result in ext4 _never_
zeroout extents, but rather always split and convert parts to
initialized while leaving the rest uninitialized in default setting.

Fix this by using s_extent_max_zeroout_kb as kibibytes.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
2013-03-12 12:40:04 -04:00
Lukas Czerner
232ec8720d ext4: update reserved space after the 'correction'
Currently in ext4_ext_map_blocks() in delayed allocation writeback
we would update the reservation and after that check whether we claimed
cluster outside of the range of the allocation and if so, we'll give the
block back to the reservation pool.

However this also means that if the number of reserved data block
dropped to zero before the correction, we would release all the metadata
reservation as well, however we might still need it because the we're
not done with the delayed allocation and there might be more blocks to
come. This will result in error messages such as:

EXT4-fs warning (device sdb): ext4_da_update_reserve_space:361: ino 12,
allocated 1 with only 0 reserved metadata blocks (releasing 1 blocks
with reserved 1 data blocks)

This will only happen on bigalloc file system and it can be easily
reproduced using fiemap-tester from xfstests like this:

./src/fiemap-tester -m DHDHDHDHD -S -p0 /mnt/test/file

Or using xfstests such as 225.

Fix this by doing the correction first and updating the reservation
after that so that we do not accidentally decrease
i_reserved_data_blocks to zero.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-03-10 22:46:30 -04:00
Zheng Liu
3a2256702e ext4: fix the wrong number of the allocated blocks in ext4_split_extent()
This commit fixes a wrong return value of the number of the allocated
blocks in ext4_split_extent.  When the length of blocks we want to
allocate is greater than the length of the current extent, we return a
wrong number.  Let's see what happens in the following case when we
call ext4_split_extent().

  map: [48, 72]
  ex:  [32, 64, u]

'ex' will be split into two parts:
  ex1: [32, 47, u]
  ex2: [48, 64, w]

'map->m_len' is returned from this function, and the value is 24.  But
the real length is 16.  So it should be fixed.

Meanwhile in this commit we use right length of the allocated blocks
when get_reserved_cluster_alloc in ext4_ext_handle_uninitialized_extents
is called.

Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Dmitry Monakhov <dmonakhov@openvz.org>
Cc: stable@vger.kernel.org
2013-03-10 21:20:23 -04:00
Zheng Liu
adb2355104 ext4: update extent status tree after an extent is zeroed out
When we try to split an extent, this extent could be zeroed out and mark
as initialized.  But we don't know this in ext4_map_blocks because it
only returns a length of allocated extent.  Meanwhile we will mark this
extent as uninitialized because we only check m_flags.

This commit update extent status tree when we try to split an unwritten
extent.  We don't need to worry about the status of this extent because
we always mark it as initialized.

Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Dmitry Monakhov <dmonakhov@openvz.org>
2013-03-10 21:13:05 -04:00
Zheng Liu
cdee78433c ext4: fix wrong m_len value after unwritten extent conversion
The ext4_ext_handle_uninitialized_extents() function was assuming the
return value of ext4_ext_map_blocks() is equal to map->m_len.  This
incorrect assumption was harmless until we started use status tree as
a extent cache because we need to update status tree according to
'm_len' value.

Meanwhile this commit marks EXT4_MAP_MAPPED flag after unwritten extent
conversion.  It shouldn't cause a bug because we update status tree
according to checking EXT4_MAP_UNWRITTEN flag.  But it should be fixed.

After applied this commit, the following error message from self-testing
infrastructure disappears.

    ...
    kernel: ES len assertation failed for inode: 230 retval 1 !=
    map->m_len 3 in ext4_map_blocks (allocation)
    ...

Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Dmitry Monakhov <dmonakhov@openvz.org>
2013-03-10 21:08:52 -04:00
Jan Kara
de99fcce1d ext4: remove unnecessary wait for extent conversion in ext4_fallocate()
Now that we don't merge uninitialized extents anymore,
ext4_fallocate() is free to operate on the inode while there are still
some extent conversions pending - it won't disturb them in any way.

Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
Reviewed-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-03-04 00:43:32 -05:00
Dmitry Monakhov
ff95ec22cd ext4: add warning to ext4_convert_unwritten_extents_endio
Splitting extents inside endio is a bad thing, but unfortunately it is
still possible.  In fact we are pretty close to the moment when all
related issues will be fixed.  Let's warn developer if it still the
case.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
2013-03-04 00:41:05 -05:00
Dmitry Monakhov
ec22ba8edb ext4: disable merging of uninitialized extents
Derived from Jan's patch:http://permalink.gmane.org/gmane.comp.file-systems.ext4/36470

Merging of uninitialized extents creates all sorts of interesting race
possibilities when writeback / DIO races with fallocate. Thus
ext4_convert_unwritten_extents_endio() has to deal with a case where
extent to be converted needs to be split out first. That isn't nice
for two reasons:

1) It may need allocation of extent tree block so ENOSPC is possible.
2) It complicates end_io handling code

So we disable merging of uninitialized extents which allows us to simplify
the code. Extents will get merged after they are converted to initialized
ones.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
2013-03-04 00:36:06 -05:00
Dmitry Monakhov
357b66fdc8 ext4: ext4_split_extent should take care of extent zeroout
When ext4_split_extent_at() ends up doing zeroout & conversion to
initialized instead of split & conversion, ext4_split_extent() gets
confused and can wrongly mark the extent back as uninitialized
resulting in end IO code getting confused from large unwritten extents
and may result in data loss.

The example of problematic behavior is:
			    lblk len              lblk len
  ext4_split_extent() (ex=[1000,30,uninit], map=[1010,10])
    ext4_split_extent_at() (split [1000,30,uninit] at 1020)
      ext4_ext_insert_extent() -> ENOSPC
      ext4_ext_zeroout()
	 -> extent [1000,30] is now initialized
    ext4_split_extent_at() (split [1000,30,init] at 1010,
			     MARK_UNINIT1 | MARK_UNINIT2)
      -> extent is split and parts marked as uninitialized

Fix the problem by rechecking extent type after the first
ext4_split_extent_at() returns. None of split_flags can not be applied
to initialized extent so this patch also add BUG_ON to prevent similar
issues in future.

TESTCASE: b8a55eb5ce

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
2013-03-04 00:34:34 -05:00
Linus Torvalds
d895cb1af1 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs pile (part one) from Al Viro:
 "Assorted stuff - cleaning namei.c up a bit, fixing ->d_name/->d_parent
  locking violations, etc.

  The most visible changes here are death of FS_REVAL_DOT (replaced with
  "has ->d_weak_revalidate()") and a new helper getting from struct file
  to inode.  Some bits of preparation to xattr method interface changes.

  Misc patches by various people sent this cycle *and* ocfs2 fixes from
  several cycles ago that should've been upstream right then.

  PS: the next vfs pile will be xattr stuff."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits)
  saner proc_get_inode() calling conventions
  proc: avoid extra pde_put() in proc_fill_super()
  fs: change return values from -EACCES to -EPERM
  fs/exec.c: make bprm_mm_init() static
  ocfs2/dlm: use GFP_ATOMIC inside a spin_lock
  ocfs2: fix possible use-after-free with AIO
  ocfs2: Fix oops in ocfs2_fast_symlink_readpage() code path
  get_empty_filp()/alloc_file() leave both ->f_pos and ->f_version zero
  target: writev() on single-element vector is pointless
  export kernel_write(), convert open-coded instances
  fs: encode_fh: return FILEID_INVALID if invalid fid_type
  kill f_vfsmnt
  vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op
  nfsd: handle vfs_getattr errors in acl protocol
  switch vfs_getattr() to struct path
  default SET_PERSONALITY() in linux/elf.h
  ceph: prepopulate inodes only when request is aborted
  d_hash_and_lookup(): export, switch open-coded instances
  9p: switch v9fs_set_create_acl() to inode+fid, do it before d_instantiate()
  9p: split dropping the acls from v9fs_set_create_acl()
  ...
2013-02-26 20:16:07 -08:00
Al Viro
496ad9aa8e new helper: file_inode(file)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-22 23:31:31 -05:00
Zheng Liu
69eb33dc24 ext4: remove single extent cache
Single extent cache could be removed because we have extent status tree
as a extent cache, and it would be better.

Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Jan kara <jack@suse.cz>
2013-02-18 00:31:07 -05:00
Zheng Liu
d100eef244 ext4: lookup block mapping in extent status tree
After tracking all extent status, we already have a extent cache in
memory.  Every time we want to lookup a block mapping, we can first
try to lookup it in extent status tree to avoid a potential disk I/O.

A new function called ext4_es_lookup_extent is defined to finish this
work.  When we try to lookup a block mapping, we always call
ext4_map_blocks and/or ext4_da_map_blocks.  So in these functions we
first try to lookup a block mapping in extent status tree.

A new flag EXT4_GET_BLOCKS_NO_PUT_HOLE is used in ext4_da_map_blocks
in order not to put a hole into extent status tree because this hole
will be converted to delayed extent in the tree immediately.

Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Jan kara <jack@suse.cz>
2013-02-18 00:29:59 -05:00
Zheng Liu
f7fec032aa ext4: track all extent status in extent status tree
By recording the phycisal block and status, extent status tree is able
to track the status of every extents.  When we call _map_blocks
functions to lookup an extent or create a new written/unwritten/delayed
extent, this extent will be inserted into extent status tree.

We don't load all extents from disk in alloc_inode() because it costs
too much memory, and if a file is opened and closed frequently it will
takes too much time to load all extent information.  So currently when
we create/lookup an extent, this extent will be inserted into extent
status tree.  Hence, the extent status tree may not comprehensively
contain all of the extents found in the file.

Here a condition we need to take care is that an extent might contains
unwritten and delayed status simultaneously because an extent is delayed
allocated and could be allocated by fallocate.  At this time we need to
keep delayed status because later we need to update delayed reservation
space using it.

Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Jan kara <jack@suse.cz>
2013-02-18 00:28:47 -05:00
Zheng Liu
a25a4e1a5d ext4: let ext4_ext_map_blocks return EXT4_MAP_UNWRITTEN flag
This commit lets ext4_ext_map_blocks return EXT4_MAP_UNWRITTEN flag
because in later commit ext4_map_blocks needs to use this flag to
determine the extent status.

Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
2013-02-18 00:28:04 -05:00
Zheng Liu
be401363ac ext4: rename and improbe ext4_es_find_extent()
This commit renames ext4_es_find_extent with ext4_es_find_delayed_extent
and improve this function.  First, we split input and output parameter.
Second, this function never return the first block of the next delayed
extent after 'es'.

Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Jan kara <jack@suse.cz>
2013-02-18 00:27:26 -05:00
Zheng Liu
06b0c88621 ext4: refine extent status tree
This commit refines the extent status tree code.

1) A prefix 'es_' is added to to the extent status tree structure
members.

2) Refactored es_remove_extent() so that __es_remove_extent() can be
used by es_insert_extent() to remove the old extent entry(-ies) before
inserting a new one.

3) Rename extent_status_end() to ext4_es_end()

4) ext4_es_can_be_merged() is define to check whether two extents can
be merged or not.

5) Update and clarified comments.

Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
2013-02-18 00:26:51 -05:00
Theodore Ts'o
9924a92a8c ext4: pass context information to jbd2__journal_start()
So we can better understand what bits of ext4 are responsible for
long-running jbd2 handles, use jbd2__journal_start() so we can pass
context information for logging purposes.

The recommended way for finding the longer-running handles is:

   T=/sys/kernel/debug/tracing
   EVENT=$T/events/jbd2/jbd2_handle_stats
   echo "interval > 5" > $EVENT/filter
   echo 1 > $EVENT/enable

   ./run-my-fs-benchmark

   cat $T/trace > /tmp/problem-handles

This will list handles that were active for longer than 20ms.  Having
longer-running handles is bad, because a commit started at the wrong
time could stall for those 20+ milliseconds, which could delay an
fsync() or an O_SYNC operation.  Here is an example line from the
trace file describing a handle which lived on for 311 jiffies, or over
1.2 seconds:

postmark-2917  [000] ....   196.435786: jbd2_handle_stats: dev 254,32 
   tid 570 type 2 line_no 2541 interval 311 sync 0 requested_blocks 1
   dirtied_blocks 0

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-02-08 21:59:22 -05:00
Lukas Czerner
b06acd38a4 ext4: remove explicit WARN_ON when ext4_map_blocks() fails
In two places we call WARN_ON() before we print out the debug message,
however we agreed that the WARN_ON() is unnecessary at those places so
remove them.

Also use ext4_warning() instead of ext4_msg() and printk().

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-01-28 21:21:12 -05:00
Zheng Liu
8bad6fc813 ext4: add punching hole support for non-extent-mapped files
This patch add supports for indirect file support punching hole.  It
is almost the same as ext4_ext_punch_hole.  First, we invalidate all
pages between this hole, and then we try to deallocate all blocks of
this hole.

A recursive function is used to handle deallocation of blocks.  In
this function, it iterates over the entries in inode's i_blocks or
indirect blocks, and try to free the block for each one of them.

After applying this patch, xfstest #255 will not pass w/o extent because
indirect-based file doesn't support unwritten extents.

Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-01-28 09:21:37 -05:00
Wang Shilong
aebf02430d ext4: use unlikely to improve the efficiency of the kernel
Because the function 'sb_getblk' seldomly fails to return NULL
value,it will be better to use 'unlikely' to optimize it.

Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-01-12 16:28:47 -05:00
Theodore Ts'o
860d21e2c5 ext4: return ENOMEM if sb_getblk() fails
The only reason for sb_getblk() failing is if it can't allocate the
buffer_head.  So ENOMEM is more appropriate than EIO.  In addition,
make sure that the file system is marked as being inconsistent if
sb_getblk() fails.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
2013-01-12 16:19:36 -05:00
Forrest Liu
c36575e663 ext4: fix extent tree corruption caused by hole punch
When depth of extent tree is greater than 1, logical start value of
interior node is not correctly updated in ext4_ext_rm_idx.

Signed-off-by: Forrest Liu <forrestl@synology.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Ashish Sangwan <ashishsangwan2@gmail.com>
Cc: stable@vger.kernel.org
2012-12-17 09:55:39 -05:00
Zhi Yong Wu
187fd030d8 ext4: remove unused variable from ext4_ext_in_cache()
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Reviewed-by: Zheng Liu <gnehzuil.liu@gmail.com>
2012-12-10 14:06:04 -05:00
Tao Ma
0c8d414f16 ext4: let fallocate handle inline data correctly
If we are punching hole in a file, we will return ENOTSUPP.
As for the fallocation of some extents, we will convert the
inline data to a normal extent based file first.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-10 14:06:03 -05:00
Tao Ma
941919856c ext4: let fiemap work with inline data
fiemap is used to find the disk layout of a file, as for inline data,
let us just pretend like a file with just one extent.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-10 14:06:02 -05:00
Tao Ma
f19d5870cb ext4: add normal write support for inline data
For a normal write case (not journalled write, not delayed
allocation), we write to the inline if the file is small and convert
it to an extent based file when the write is larger than the max
inline size.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-10 14:05:51 -05:00
Theodore Ts'o
4a092d7379 ext4: rationalize ext4_extents.h inclusion
Previously, ext4_extents.h was being included at the end of ext4.h,
which was bad for a number of reasons: (a) it was not being included
in the expected place, and (b) it caused the header to be included
multiple times.  There were #ifdef's to prevent this from causing any
problems, but it still was unnecessary.

By moving the function declarations that were in ext4_extents.h to
ext4.h, which is standard practice for where the function declarations
for the rest of ext4.h can be found, we can remove ext4_extents.h from
being included in ext4.h at all, and then we can only include
ext4_extents.h where it is needed in ext4's source files.

It should be possible to move a few more things into ext4.h, and
further reduce the number of source files that need to #include
ext4_extents.h, but that's a cleanup for another day.

Reported-by: Sachin Kamat <sachin.kamat@linaro.org>
Reported-by: Wei Yongjun <weiyj.lk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-11-28 13:03:30 -05:00
Lukas Czerner
06348679c9 ext4: simple cleanup in fiemap codepath
This commit is simple cleanup of fiemap codepath which has not been
included in previous commit to make the changes clearer. In this commit
we rename cbex variable to newex in ext4_fill_fiemap_extents() because
callback is no longer present

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-11-28 12:33:22 -05:00
Lukas Czerner
91dd8c1144 ext4: prevent race while walking extent tree for fiemap
Currently ext4_ext_walk_space() only takes i_data_sem for read when
searching for the extent at given block with ext4_ext_find_extent().
Then it drops the lock and the extent tree can be changed at will.
However later on we're searching for the 'next' extent, but the extent
tree might already have changed, so the information might not be
accurate.

In fact we can hit BUG_ON(end <= start) if the extent got inserted into
the tree after the one we found and before the block we were searching
for. This has been reproduced by running xfstests 225 in loop on s390x
architecture, but theoretically we could hit this on any other
architecture as well, but probably not as often.

Moreover the extent currently in delayed allocation might be allocated
after we search the extent tree and before we search extent status tree
delayed buffers resulting in those delayed buffers being completely
missed, even though completely written and allocated.

We fix all those problems in several steps:

 1. remove unnecessary callback indirection
 2. rename functions
        ext4_ext_walk_space -> ext4_fill_fiemap_extents
        ext4_ext_fiemap_cb -> ext4_find_delayed_extent
 3. move fiemap_fill_next_extent() into ext4_fill_fiemap_extents()
 4. hold the i_data_sem for:
        ext4_ext_find_extent()
        ext4_ext_next_allocated_block()
        ext4_find_delayed_extent()
 5. call fiemap_fill_next_extent after releasing the i_data_sem
 6. move path reinitialization into the critical section.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-11-28 12:32:26 -05:00
Zheng Liu
b3aff3e3f6 ext4: reimplement fiemap using extent status tree
Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: Allison Henderson <achender@linux.vnet.ibm.com>
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-11-08 21:57:37 -05:00
Zheng Liu
7d1b1fbc95 ext4: reimplement ext4_find_delay_alloc_range on extent status tree
Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: Allison Henderson <achender@linux.vnet.ibm.com>
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-11-08 21:57:35 -05:00
Zheng Liu
51865fda28 ext4: let ext4 maintain extent status tree
This patch lets ext4 maintain extent status tree.

Currently it only tracks delay extent status in extent status tree.  When a
delay allocation is issued, the related delay extent will be inserted into
extent status tree.  When a delay extent is written out or invalidated, it will
be removed from this tree.

Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: Allison Henderson <achender@linux.vnet.ibm.com>
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-11-08 21:57:32 -05:00
Zheng Liu
3779473246 ext4: fix missing call to trace_ext4_ext_map_blocks_exit
When ext4_ext_handle_uninitialized_extents(), we will directly return
from ext4_ext_map_blocks().  The trace point of
trace_ext4_ext_map_blocks_exit isn't called, and the user doesn't see
any result.  This patch tries to fix this problem.

Meanwhile in ext4_ext_handle_uninitialized_extents it returns errors
or the number of allocated blocks.  So 'ret' variable can be removed
due to previously modifications.

Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
2012-11-08 14:47:52 -05:00
Zheng Liu
19b303d8b5 ext4: print map->m_flags in trace_ext4_ext/ind_map_blocks_exit
When we use trace_ext4_ext/ind_map_blocks_exit, print the value of
map->m_flags in order that we can understand the extent's current
status.

Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-11-08 14:34:04 -05:00
Zheng Liu
b5645534ce ext4: print 'flags' in ext4_ext_handle_uninitialized_extents
In trace_ext4_ext_handle_uninitialized_extents we don't care about the
value of map->m_flags because this value is probably 0, and we prefer
to get the value of flags because we can know how to handle this
extent in this function.

Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-11-08 14:33:43 -05:00
Dmitry Monakhov
dee1f973ca ext4: race-condition protection for ext4_convert_unwritten_extents_endio
We assumed that at the time we call ext4_convert_unwritten_extents_endio()
extent in question is fully inside [map.m_lblk, map->m_len] because
it was already split during submission.  But this may not be true due to
a race between writeback vs fallocate.

If extent in question is larger than requested we will split it again.
Special precautions should being done if zeroout required because
[map.m_lblk, map->m_len] already contains valid data.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
2012-10-10 01:04:58 -04:00
Dmitry Monakhov
60d4616f3d ext4: serialize fallocate with ext4_convert_unwritten_extents
Fallocate should wait for pended ext4_convert_unwritten_extents()
otherwise following race may happen:

ftruncate( ,12288);
fallocate( ,0, 4096)
io_sibmit( ,0, 4096); /* Write to fallocated area, split extent if needed */
fallocate( ,0, 8192); /* Grow extent and broke assumption about extent */

Later kwork completion will do:
 ->ext4_convert_unwritten_extents (0, 4096)
   ->ext4_map_blocks(handle, inode, &map, EXT4_GET_BLOCKS_IO_CONVERT_EXT);
    ->ext4_ext_map_blocks() /* Will find new extent:  ex = [0,2] !!!!!! */
      ->ext4_ext_handle_uninitialized_extents()
        ->ext4_convert_unwritten_extents_endio()
        /* convert [0,2] extent to initialized, but only[0,1] was written */

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-10-05 11:32:02 -04:00
Dmitry Monakhov
c278531d39 ext4: fix ext4_flush_completed_IO wait semantics
BUG #1) All places where we call ext4_flush_completed_IO are broken
    because buffered io and DIO/AIO goes through three stages
    1) submitted io,
    2) completed io (in i_completed_io_list) conversion pended
    3) finished  io (conversion done)
    And by calling ext4_flush_completed_IO we will flush only
    requests which were in (2) stage, which is wrong because:
     1) punch_hole and truncate _must_ wait for all outstanding unwritten io
      regardless to it's state.
     2) fsync and nolock_dio_read should also wait because there is
        a time window between end_page_writeback() and ext4_add_complete_io()
        As result integrity fsync is broken in case of buffered write
        to fallocated region:
        fsync                                      blkdev_completion
	 ->filemap_write_and_wait_range
                                                   ->ext4_end_bio
                                                     ->end_page_writeback
          <-- filemap_write_and_wait_range return
	 ->ext4_flush_completed_IO
   	 sees empty i_completed_io_list but pended
   	 conversion still exist
                                                     ->ext4_add_complete_io

BUG #2) Race window becomes wider due to the 'ext4: completed_io
locking cleanup V4' patch series

This patch make following changes:
1) ext4_flush_completed_io() now first try to flush completed io and when
   wait for any outstanding unwritten io via ext4_unwritten_wait()
2) Rename function to more appropriate name.
3) Assert that all callers of ext4_flush_unwritten_io should hold i_mutex to
   prevent endless wait

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
2012-10-05 11:31:55 -04:00
Dmitry Monakhov
6f2080e644 ext4: fix ext_remove_space for punch_hole case
Inode is allowed to have empty leaf only if it this is blockless inode.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-09-30 23:03:50 -04:00
Dmitry Monakhov
02d262dffc ext4: punch_hole should wait for DIO writers
punch_hole is the place where we have to wait for all existing writers
(writeback, aio, dio), but currently we simply flush pended end_io request
which is not sufficient. Other issue is that punch_hole performed w/o i_mutex
held which obviously result in dangerous data corruption due to
write-after-free.

This patch performs following changes:
- Guard punch_hole with i_mutex
- Recheck inode flags under i_mutex
- Block all new dio readers in order to prevent information leak caused by
  read-after-free pattern.
- punch_hole now wait for all writers in flight
  NOTE: XXX write-after-free race is still possible because new dirty pages
  may appear due to mmap(), and currently there is no easy way to stop
  writeback while punch_hole is in progress.

[ Fixed error return from ext4_ext_punch_hole() to make sure that we
  release i_mutex before returning EPERM or ETXTBUSY -- Ted ]

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-09-30 23:03:42 -04:00
Dmitry Monakhov
28a535f9a0 ext4: completed_io locking cleanup
Current unwritten extent conversion state-machine is very fuzzy.
- For unknown reason it performs conversion under i_mutex. What for?
  My diagnosis:
  We already protect extent tree with i_data_sem, truncate and punch_hole
  should wait for DIO, so the only data we have to protect is end_io->flags
  modification, but only flush_completed_IO and end_io_work modified this
  flags and we can serialize them via i_completed_io_lock.

  Currently all these games with mutex_trylock result in the following deadlock
   truncate:                          kworker:
    ext4_setattr                       ext4_end_io_work
    mutex_lock(i_mutex)
    inode_dio_wait(inode)  ->BLOCK
                             DEADLOCK<- mutex_trylock()
                                        inode_dio_done()
  #TEST_CASE1_BEGIN
  MNT=/mnt_scrach
  unlink $MNT/file
  fallocate -l $((1024*1024*1024)) $MNT/file
  aio-stress -I 100000 -O -s 100m -n -t 1 -c 10 -o 2 -o 3 $MNT/file
  sleep 2
  truncate -s 0 $MNT/file
  #TEST_CASE1_END

Or use 286's xfstests https://github.com/dmonakhov/xfstests/blob/devel/286

This patch makes state machine simple and clean:

(1) xxx_end_io schedule final extent conversion simply by calling
    ext4_add_complete_io(), which append it to ei->i_completed_io_list
    NOTE1: because of (2A) work should be queued only if
    ->i_completed_io_list was empty, otherwise the work is scheduled already.

(2) ext4_flush_completed_IO is responsible for handling all pending
    end_io from ei->i_completed_io_list
    Flushing sequence consists of following stages:
    A) LOCKED: Atomically drain completed_io_list to local_list
    B) Perform extents conversion
    C) LOCKED: move converted io's to to_free list for final deletion
       	     This logic depends on context which we was called from.
    D) Final end_io context destruction
    NOTE1: i_mutex is no longer required because end_io->flags modification
    is protected by ei->ext4_complete_io_lock

Full list of changes:
- Move all completion end_io related routines to page-io.c in order to improve
  logic locality
- Move open coded logic from various xx_end_xx routines to ext4_add_complete_io()
- remove EXT4_IO_END_FSYNC
- Improve SMP scalability by removing useless i_mutex which does not
  protect io->flags anymore.
- Reduce lock contention on i_completed_io_lock by optimizing list walk.
- Rename ext4_end_io_nolock to end4_end_io and make it static
- Check flush completion status to ext4_ext_punch_hole(). Because it is
  not good idea to punch blocks from corrupted inode.

Changes since V3 (in request to Jan's comments):
  Fall back to active flush_completed_IO() approach in order to prevent
  performance issues with nolocked DIO reads.
Changes since V2:
  Fix use-after-free caused by race truncate vs end_io_work

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-09-29 00:14:55 -04:00
Dmitry Monakhov
82e5422911 ext4: fix unwritten counter leakage
ext4_set_io_unwritten_flag() will increment i_unwritten counter, so
once we mark end_io with EXT4_END_IO_UNWRITTEN we have to revert it back
on error path.

 - add missed error checks to prevent counter leakage
 - ext4_end_io_nolock() will clear EXT4_END_IO_UNWRITTEN flag to signal
   that conversion finished.
 - add BUG_ON to ext4_free_end_io() to prevent similar leakage in future.

Visible effect of this bug is that unaligned aio_stress may deadlock

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-09-28 23:36:25 -04:00
Dmitry Monakhov
f45ee3a1ea ext4: ext4_inode_info diet
Generic inode has unused i_private pointer which may be used as cur_aio_dio
storage.

TODO: If cur_aio_dio will be passed as an argument to get_block_t this allow
      to have concurent AIO_DIO requests.

Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-09-28 23:21:09 -04:00
Wei Yongjun
ba39ebb614 ext4: convert to use leXX_add_cpu()
Convert cpu_to_leXX(leXX_to_cpu(E1) + E2) to use leXX_add_cpu().

dpatch engine is used to auto generate this patch.
(https://github.com/weiyj/dpatch)

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-09-27 09:37:53 -04:00
Lukas Czerner
63fedaf1c2 ext4: remove unused function ext4_ext_check_cache
Remove unused function ext4_ext_check_cache() and merge the code back to
the ext4_ext_in_cache().

Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-09-26 21:09:06 -04:00
Andrey Sidorov
18888cf088 ext4: speed up truncate/unlink by not using bforget() unless needed
Do not iterate over data blocks scanning for bh's to forget as they're
never exist. This improves time taken by unlink / truncate syscall.
Tested by continuously truncating file that is being written by dd.
Another test is rm -rf of linux tree while tar unpacks it. With
ordered data mode condition unlikely(!tbh) was always met in
ext4_free_blocks. With journal data mode tbh was found only few times,
so optimisation is also possible.

Unlinking fallocated 60G file after doing sync && echo 3 >
/proc/sys/vm/drop_caches && time rm --help

X86 before (linux 3.6-rc4):
# time rm -f test1
real    0m2.710s
user    0m0.000s
sys     0m1.530s

X86 after:
# time rm -f test1
real    0m0.644s
user    0m0.003s
sys     0m0.060s

MIPS before (linux 2.6.37):
# time rm -f test1
real    0m 4.93s
user    0m 0.00s
sys     0m 4.61s

MIPS after:
# time rm -f test1
real    0m 0.16s
user    0m 0.00s
sys     0m 0.06s

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrey Sidorov <qrxd43@motorola.com>
2012-09-19 14:14:53 -04:00
Wang Sheng-Hui
30cb27d661 ext4: fix trivial typo in comment
Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-08-18 22:38:07 -04:00
Ashish Sangwan
e3d2e433e3 ext4: no need to add inode to orphan list during hole punch
While performing punch hole for an inode, i_disksize is not changed.
So, there is no need to add the inode to orphan list.

Signed-off-by: Ashish Sangwan <ashish.sangwan2@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@gmail.com>
Acked-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-08-18 22:29:46 -04:00
Zheng Liu
67a5da564f ext4: make the zero-out chunk size tunable
Currently in ext4 the length of zero-out chunk is set to 7 file system
blocks.  But if an inode has uninitailized extents from using
fallocate to preallocate space, and the workload issues many random
writes, this can cause a fragmented extent tree that will
unnecessarily grow the extent tree.

So create a new sysfs tunable, extent_max_zeroout_kb, which controls
the maximum size where blocks will be zeroed out instead of creating a
new uninitialized extent.  The default of this has been sent to 32kb.

CC: Zach Brown <zab@zabbo.net>
CC: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-08-17 09:54:17 -04:00
Theodore Ts'o
ecb94f5fdf ext4: collapse a single extent tree block into the inode if possible
If an inode has more than 4 extents, but then later some of the
extents are merged together, we can optimize the file system by moving
the extents up into the inode, and discarding the extent tree block.
This is important, because if there are a large number of inodes with
an external extent tree blocks where the contents could fit in the
inode, this can significantly increase the fsck time of the file
system.

Google-Bug-Id: 6801242

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-08-17 09:44:17 -04:00
Theodore Ts'o
89a4e48f84 ext4: fix kernel BUG on large-scale rm -rf commands
Commit 968dee7722: "ext4: fix hole punch failure when depth is greater
than 0" introduced a regression in v3.5.1/v3.6-rc1 which caused kernel
crashes when users ran run "rm -rf" on large directory hierarchy on
ext4 filesystems on RAID devices:

    BUG: unable to handle kernel NULL pointer dereference at 0000000000000028

    Process rm (pid: 18229, threadinfo ffff8801276bc000, task ffff880123631710)
    Call Trace:
     [<ffffffff81236483>] ? __ext4_handle_dirty_metadata+0x83/0x110
     [<ffffffff812353d3>] ext4_ext_truncate+0x193/0x1d0
     [<ffffffff8120a8cf>] ? ext4_mark_inode_dirty+0x7f/0x1f0
     [<ffffffff81207e05>] ext4_truncate+0xf5/0x100
     [<ffffffff8120cd51>] ext4_evict_inode+0x461/0x490
     [<ffffffff811a1312>] evict+0xa2/0x1a0
     [<ffffffff811a1513>] iput+0x103/0x1f0
     [<ffffffff81196d84>] do_unlinkat+0x154/0x1c0
     [<ffffffff8118cc3a>] ? sys_newfstatat+0x2a/0x40
     [<ffffffff81197b0b>] sys_unlinkat+0x1b/0x50
     [<ffffffff816135e9>] system_call_fastpath+0x16/0x1b
    Code: 8b 4d 20 0f b7 41 02 48 8d 04 40 48 8d 04 81 49 89 45 18 0f b7 49 02 48 83 c1 01 49 89 4d 00 e9 ae f8 ff ff 0f 1f 00 49 8b 45 28 <48> 8b 40 28 49 89 45 20 e9 85 f8 ff ff 0f 1f 80 00 00 00

    RIP  [<ffffffff81233164>] ext4_ext_remove_space+0xa34/0xdf0

This could be reproduced as follows:

The problem in commit 968dee7722 was that caused the variable 'i' to
be left uninitialized if the truncate required more space than was
available in the journal.  This resulted in the function
ext4_ext_truncate_extend_restart() returning -EAGAIN, which caused
ext4_ext_remove_space() to restart the truncate operation after
starting a new jbd2 handle.

Reported-by: Maciej Żenczykowski <maze@google.com>
Reported-by: Marti Raudsepp <marti@juffo.org>
Tested-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
2012-08-17 09:42:17 -04:00
Ashish Sangwan
968dee7722 ext4: fix hole punch failure when depth is greater than 0
Whether to continue removing extents or not is decided by the return
value of function ext4_ext_more_to_rm() which checks 2 conditions:
a) if there are no more indexes to process.
b) if the number of entries are decreased in the header of "depth -1".

In case of hole punch, if the last block to be removed is not part of
the last extent index than this index will not be deleted, hence the
number of valid entries in the extent header of "depth - 1" will
remain as it is and ext4_ext_more_to_rm will return 0 although the
required blocks are not yet removed.

This patch fixes the above mentioned problem as instead of removing
the extents from the end of file, it starts removing the blocks from
the particular extent from which removing blocks is actually required
and continue backward until done.

Signed-off-by: Ashish Sangwan <ashish.sangwan2@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@gmail.com>
Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Cc: stable@vger.kernel.org
2012-07-22 22:49:08 -04:00
HaiboLiu
e7bcf82304 ext4: fix out-of-date comments in extents.c
In this patch, ext4_ext_try_to_merge has been change to merge 
an extent both left and right.  So we need to update the comment
in here.

Signed-off-by: HaiboLiu <HaiboLiu6@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-07-09 16:29:28 -04:00
Zheng Liu
f4e95b3316 ext4: honor O_(D)SYNC semantic in ext4_fallocate()
Ext4 must make sure the transaction to be commited to the disk when
user opens a file with O_(D)SYNC flag and do a fallocate(2) call.

This problem had been reported by Christoph Hellwig in this thread:
http://www.spinics.net/lists/linux-btrfs/msg13621.html

Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-06-30 19:12:57 -04:00
Hugh Dickins
5e44f8c374 ext4: hole-punch use truncate_pagecache_range
When truncating a file, we unmap pages from userspace first, as that's
usually more efficient than relying, page by page, on the fallback in
truncate_inode_page() - particularly if the file is mapped many times.

Do the same when punching a hole: 3.4 added truncate_pagecache_range()
to do the unmap and trunc, so use it in ext4_ext_punch_hole(), instead
of calling truncate_inode_pages_range() directly.

Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-06-01 00:15:28 -04:00
Zheng Liu
4a3c3a5120 ext4: fix format flag in ext4_ext_binsearch_idx()
fix ext_debug format flag in ext4_ext_binsearch_idx().

Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-05-28 17:55:16 -04:00
Darrick J. Wong
7ac5990d5a ext4: verify and calculate checksums for extent tree blocks
Calculate and verify the checksum for each extent tree block.  The
checksum is located in the space immediately after the last possible
ext4_extent in the block.  The space is is typically the last 4-8
bytes in the block.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-04-29 18:37:10 -04:00
Darrick J. Wong
f84891289e ext4: create a new BH_Verified flag to avoid unnecessary metadata validation
Create a new BH_Verified flag to indicate that we've verified all the
data in a buffer_head for correctness.  This allows us to bypass
expensive verification steps when they are not necessary without
missing them when they are.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-04-29 18:21:10 -04:00
Linus Torvalds
592fe89806 Ext4 regression fixes for 3.4
This fixes a scalability problem reported by Andi Kleen and Tim Chen;
 they were quite secretive about the precise nature of their workload,
 but they later admitted that it only showed up when they were using a
 large sparse file, so the amount of data I/O that was needed was close
 to zero.  I'm not sure how realistic this is and it's only a
 regression if you consider changes made since 2.6.39 to be a
 "regression" vis-a-vis the policy regarding post-merge window bug
 fixes, but Linus agreed it was worth fixing, so I'm including it in
 this pull request.
 
 This also fixes the journalled quota mount options, which I
 accidentally broke while I was cleaning up the mount option handling.
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Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 regression fixes from Ted Ts'o:
 "This fixes a scalability problem reported by Andi Kleen and Tim Chen;
  they were quite secretive about the precise nature of their workload,
  but they later admitted that it only showed up when they were using a
  large sparse file, so the amount of data I/O that was needed was close
  to zero.

  I'm not sure how realistic this is and it's only a regression if you
  consider changes made since 2.6.39 to be a "regression" vis-a-vis the
  policy regarding post-merge window bug fixes, but Linus agreed it was
  worth fixing, so I'm including it in this pull request.

  This also fixes the journalled quota mount options, which I
  accidentally broke while I was cleaning up the mount option handling."

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix handling of journalled quota options
  ext4: address scalability issue by removing extent cache statistics
2012-04-17 13:30:34 -07:00
Theodore Ts'o
9cd70b347e ext4: address scalability issue by removing extent cache statistics
Andi Kleen and Tim Chen have reported that under certain circumstances
the extent cache statistics are causing scalability problems due to
cache line bounces.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
2012-04-16 12:16:20 -04:00
Al Viro
af1584f570 ext4: fix endianness breakage in ext4_split_extent_at()
->ee_len is __le16, so assigning cpu_to_le32() to it is going to do
Bad Things(tm) on big-endian hosts...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-04-13 10:12:08 -04:00
Lukas Czerner
afcff5d80a ext4: remove restrictive checks for EOFBLOCKS_FL
We are going to remove the EOFBLOCKS_FL flag in the future, so this is
the first part of the removal. We can not remove it entirely just now,
since the e2fsck is still checking for it and it might cause headache to
some people. Instead, remove the restrictive checks now and the rest
later, when the new e2fsck code is out and common enough.

This is also needed because punch hole already breaks the EOFBLOCKS_FL
semantics, so it might cause the some troubles. So simply remove it.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-03-21 21:47:55 -04:00
Theodore Ts'o
92b9781658 ext4: change some printk() calls to use ext4_msg() instead
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-03-19 23:41:49 -04:00
Lukas Czerner
dc1841d6cf ext4: give more helpful error message in ext4_ext_rm_leaf()
The error message produced by the ext4_ext_rm_leaf() when we are
removing blocks which accidentally ends up inside the existing extent,
is not very helpful, because we would like to also know which extent did
we collide with.

This commit changes the error message to get us also the information
about the extent we are colliding with.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-03-19 23:07:43 -04:00
Lukas Czerner
7877191c28 ext4: remove unused code from ext4_ext_map_blocks()
Since the commit 'Rewrite punch hole to use ext4_ext_remove_space()'
reworked the punch hole implementation to use ext4_ext_remove_space()
instead of ext4_ext_map_blocks(), we can remove the code which is no
longer needed from the ext4_ext_map_blocks().

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-03-19 23:05:43 -04:00
Lukas Czerner
5f95d21fb6 ext4: rewrite punch hole to use ext4_ext_remove_space()
This commit rewrites ext4 punch hole implementation to use
ext4_ext_remove_space() instead of its home gown way of doing this via
ext4_ext_map_blocks(). There are several reasons for changing this.

Firstly it is quite non obvious that punching hole needs to
ext4_ext_map_blocks() to punch a hole, especially given that this
function should map blocks, not unmap it. It also required a lot of new
code in ext4_ext_map_blocks().

Secondly the design of it is not very effective. The reason is that we
are trying to punch out blocks in ext4_ext_punch_hole() in opposite
direction than in ext4_ext_rm_leaf() which causes the ext4_ext_rm_leaf()
to iterate through the whole tree from the end to the start to find the
requested extent for every extent we are going to punch out.

And finally the current implementation does not use the existing code,
but bring a lot of new code, which is IMO unnecessary since there
already is some infrastructure we can use. Specifically
ext4_ext_remove_space().

This commit changes ext4_ext_remove_space() to accept 'end' parameter so
we can not only truncate to the end of file, but also remove the space
in the middle of the file (punch a hole). Moreover, because the last
block to punch out, might be in the middle of the extent, we have to
split the extent at 'end + 1' so ext4_ext_rm_leaf() can easily either
remove the whole fist part of split extent, or change its size.

ext4_ext_remove_space() is then used to actually remove the space
(extents) from within the hole, instead of ext4_ext_map_blocks().

Note that this also fix the issue with punch hole, where we would forget
to remove empty index blocks from the extent tree, resulting in double
free block error and file system corruption. This is simply because we
now use different code path, where this problem does not exist.

This has been tested with fsx running for several days and xfstests,
plus xfstest #251 with '-o discard' run on the loop image (which
converts discard requestes into punch hole to the backing file). All of
it on 1K and 4K file system block size.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-03-19 23:03:19 -04:00
Theodore Ts'o
31d4f3a2f3 ext4: check for zero length extent
Explicitly test for an extent whose length is zero, and flag that as a
corrupted extent.

This avoids a kernel BUG_ON assertion failure.

Tested: Without this patch, the file system image found in
tests/f_ext_zero_len/image.gz in the latest e2fsprogs sources causes a
kernel panic.  With this patch, an ext4 file system error is noted
instead, and the file system is marked as being corrupted.

https://bugzilla.kernel.org/show_bug.cgi?id=42859

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
2012-03-11 23:30:16 -04:00
Theodore Ts'o
ff9cb1c4ee Merge branch 'for_linus' into for_linus_merged
Conflicts:
	fs/ext4/ioctl.c
2012-01-10 11:54:07 -05:00
Linus Torvalds
ac69e09280 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  ext2/3/4: delete unneeded includes of module.h
  ext{3,4}: Fix potential race when setversion ioctl updates inode
  udf: Mark LVID buffer as uptodate before marking it dirty
  ext3: Don't warn from writepage when readonly inode is spotted after error
  jbd: Remove j_barrier mutex
  reiserfs: Force inode evictions before umount to avoid crash
  reiserfs: Fix quota mount option parsing
  udf: Treat symlink component of type 2 as /
  udf: Fix deadlock when converting file from in-ICB one to normal one
  udf: Cleanup calling convention of inode_getblk()
  ext2: Fix error handling on inode bitmap corruption
  ext3: Fix error handling on inode bitmap corruption
  ext3: replace ll_rw_block with other functions
  ext3: NULL dereference in ext3_evict_inode()
  jbd: clear revoked flag on buffers before a new transaction started
  ext3: call ext3_mark_recovery_complete() when recovery is really needed
2012-01-09 12:51:21 -08:00
Paul Gortmaker
302bf2f325 ext2/3/4: delete unneeded includes of module.h
Delete any instances of include module.h that were not strictly
required.  In the case of ext2, the declaration of MODULE_LICENSE
etc. were in inode.c but the module_init/exit were in super.c, so
relocate the MODULE_LICENCE/AUTHOR block to super.c which makes it
consistent with ext3 and ext4 at the same time.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2012-01-09 13:52:10 +01:00
Zheng Liu
88635ca277 ext4: add missing spaces to debugging printk's
Fix ext4_debug format in ext4_ext_handle_uninitialized_extents() and
ext4_end_io_dio().

Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-12-28 19:00:25 -05:00
Robin Dong
8c48f7e88e ext4: optimize ext4_find_delalloc_range() in nodelalloc mode
We found performance regression when using bigalloc with "nodelalloc"
(1MB cluster size):

1. mke2fs -C 1048576 -O ^has_journal,bigalloc /dev/sda
2. mount -o nodelalloc /dev/sda /test/
3. time dd if=/dev/zero of=/test/io bs=1048576 count=1024

The "dd" will cost about 2 seconds to finish, but if we mke2fs without
"bigalloc", "dd" will only cost less than 1 second.

The reason is: when using ext4 with "nodelalloc", it will call
ext4_find_delalloc_cluster() nearly everytime it call
ext4_ext_map_blocks(), and ext4_find_delalloc_range() will also scan
all pages in cluster because no buffer is "delayed".  A cluster has
256 pages (1MB cluster), so it will scan 256 * 256k pags when creating
a 1G file. That severely hurts the performance.

Therefore, we return immediately from ext4_find_delalloc_range() in
nodelalloc mode, since by definition there can't be any delalloc
pages.

Signed-off-by: Robin Dong <sanbai@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-12-18 23:05:43 -05:00
Curt Wohlgemuth
14d7f3efe9 ext4: remove unused local variable
In get_implied_cluster_alloc(), rr_cluster_end was being
defined and set, but was never used.  Removed this.

Signed-off-by: Curt Wohlgemuth <curtw@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-12-18 17:39:02 -05:00
Yongqiang Yang
5b5ffa49d4 ext4: remove a wrong BUG_ON in ext4_ext_convert_to_initialized
If a file is fallocated on a hole, map->m_lblk + map->m_len may be greater
than ee_block + ee_len.

Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
2011-12-13 22:13:42 -05:00
Paul Mackerras
b4611abfa9 ext4: Fix crash due to getting bogus eh_depth value on big-endian systems
Commit 1939dd84b3 ("ext4: cleanup ext4_ext_grow_indepth code") added a
reference to ext4_extent_header.eh_depth, but forget to pass the value
read through le16_to_cpu.  The result is a crash on big-endian
machines, such as this crash on a POWER7 server:

attempt to access beyond end of device
sda8: rw=0, want=776392648163376, limit=168558560
Unable to handle kernel paging request for data at address 0x6b6b6b6b6b6b6bcb
Faulting instruction address: 0xc0000000001f5f38
cpu 0x14: Vector: 300 (Data Access) at [c000001bd1aaecf0]
    pc: c0000000001f5f38: .__brelse+0x18/0x60
    lr: c0000000002e07a4: .ext4_ext_drop_refs+0x44/0x80
    sp: c000001bd1aaef70
   msr: 9000000000009032
   dar: 6b6b6b6b6b6b6bcb
 dsisr: 40000000
  current = 0xc000001bd15b8010
  paca    = 0xc00000000ffe4600
    pid   = 19911, comm = flush-8:0
enter ? for help
[c000001bd1aaeff0] c0000000002e07a4 .ext4_ext_drop_refs+0x44/0x80
[c000001bd1aaf090] c0000000002e0c58 .ext4_ext_find_extent+0x408/0x4c0
[c000001bd1aaf180] c0000000002e145c .ext4_ext_insert_extent+0x2bc/0x14c0
[c000001bd1aaf2c0] c0000000002e3fb8 .ext4_ext_map_blocks+0x628/0x1710
[c000001bd1aaf420] c0000000002b2974 .ext4_map_blocks+0x224/0x310
[c000001bd1aaf4d0] c0000000002b7f2c .mpage_da_map_and_submit+0xbc/0x490
[c000001bd1aaf5a0] c0000000002b8688 .write_cache_pages_da+0x2c8/0x430
[c000001bd1aaf720] c0000000002b8b28 .ext4_da_writepages+0x338/0x670
[c000001bd1aaf8d0] c000000000157280 .do_writepages+0x40/0x90
[c000001bd1aaf940] c0000000001ea830 .writeback_single_inode+0xe0/0x530
[c000001bd1aafa00] c0000000001eb680 .writeback_sb_inodes+0x210/0x300
[c000001bd1aafb20] c0000000001ebc84 .__writeback_inodes_wb+0xd4/0x140
[c000001bd1aafbe0] c0000000001ebfec .wb_writeback+0x2fc/0x3e0
[c000001bd1aafce0] c0000000001ed770 .wb_do_writeback+0x2f0/0x300
[c000001bd1aafdf0] c0000000001ed848 .bdi_writeback_thread+0xc8/0x340
[c000001bd1aafed0] c0000000000c5494 .kthread+0xb4/0xc0
[c000001bd1aaff90] c000000000021f48 .kernel_thread+0x54/0x70

This is due to getting ext_depth(inode) == 0x101 and therefore running
off the end of the path array in ext4_ext_drop_refs into following
unallocated structures.

This fixes it by adding the necessary le16_to_cpu.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-12-12 11:00:56 -05:00
Yongqiang Yang
bf52c6f7af ext4: let ext4_ext_rm_leaf work with EXT_DEBUG defined
The variable 'block' is removed by commit 750c9c47, so use the
replacement ex_ee_block instead.

Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-11-01 18:59:26 -04:00
Yongqiang Yang
32de675690 ext4: fix a syntax error in ext4_ext_insert_extent when debugging enabled
This patch fixes a syntax error which omits a comma. Besides this,
logical block number is unsigend 32 bits, so printk should use %u
instead %d.

Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-11-01 18:56:41 -04:00
Greg Harm
3c6fe77017 ext4: Don't normalize an falloc request if it can fit in 1 extent.
If an fallocate request fits in EXT_UNINIT_MAX_LEN, then set the
EXT4_GET_BLOCKS_NO_NORMALIZE flag. For larger fallocate requests,
let mballoc.c normalize the request.

This fixes a problem where large requests were being split into
non-contiguous extents due to commit 556b27abf7: ext4: do not
normalize block requests from fallocate.

Testing: 
*) Checked that 8.x MB falloc'ed files are still laid down next to
each other (contiguously).
*) Checked that the maximum size extent (127.9MB) is allocated as 1
extent.
*) Checked that a 1GB file is somewhat contiguous (often 5-6
non-contiguous extents now).
*) Checked that a 120MB file can still be falloc'ed even if there are
no single extents large enough to hold it.

Signed-off-by: Greg Harm <gharm@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-10-31 18:41:47 -04:00
Tao Ma
0edeb71dc9 ext4: Create helper function for EXT4_IO_END_UNWRITTEN and i_aiodio_unwritten
EXT4_IO_END_UNWRITTEN flag set and the increase of i_aiodio_unwritten
should be done simultaneously since ext4_end_io_nolock always clear
the flag and decrease the counter in the same time.

We have found some bugs that the flag is set while leaving
i_aiodio_unwritten unchanged(commit 32c80b32c0). So this patch just tries
to create a helper function to wrap them to avoid any future bug.
The idea is inspired by Eric.

Cc: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-10-31 17:30:44 -04:00
Yongqiang Yang
e7b319e397 ext4: trace punch_hole correctly in ext4_ext_map_blocks
When ext4_ext_map_blocks() is called by punch_hole, trace should
trace blocks punched out.

Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-10-29 09:39:51 -04:00
Yongqiang Yang
02dc62fba8 ext4: clean up AGGRESSIVE_TEST code
Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-10-29 09:29:11 -04:00
Yongqiang Yang
81fdbb4a8d ext4: move variables to their scope
Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-10-29 09:23:38 -04:00
Eric Gouriou
80e675f906 ext4: optimize memmmove lengths in extent/index insertions
ext4_ext_insert_extent() (respectively ext4_ext_insert_index())
was using EXT_MAX_EXTENT() (resp. EXT_MAX_INDEX()) to determine
how many entries needed to be moved beyond the insertion point.
In practice this means that (320 - I) * 24 bytes were memmove()'d
when I is the insertion point, rather than (#entries - I) * 24 bytes.

This patch uses EXT_LAST_EXTENT() (resp. EXT_LAST_INDEX()) instead
to only move existing entries. The code flow is also simplified
slightly to highlight similarities and reduce code duplication in
the insertion logic.

This patch reduces system CPU consumption by over 25% on a 4kB
synchronous append DIO write workload when used with the
pre-2.6.39 x86_64 memmove() implementation. With the much faster
2.6.39 memmove() implementation we still see a decrease in
system CPU usage between 2% and 7%.

Note that the ext_debug() output changes with this patch, splitting
some log information between entries. Users of the ext_debug() output
should note that the "move %d" units changed from reporting the number
of bytes moved to reporting the number of entries moved.

Signed-off-by: Eric Gouriou <egouriou@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-10-27 11:52:18 -04:00
Eric Gouriou
6f91bc5fda ext4: optimize ext4_ext_convert_to_initialized()
This patch introduces a fast path in ext4_ext_convert_to_initialized()
for the case when the conversion can be performed by transferring
the newly initialized blocks from the uninitialized extent into
an adjacent initialized extent. Doing so removes the expensive
invocations of memmove() which occur during extent insertion and
the subsequent merge.

In practice this should be the common case for clients performing
append writes into files pre-allocated via
fallocate(FALLOC_FL_KEEP_SIZE). In such a workload performed via
direct IO and when using a suboptimal implementation of memmove()
(x86_64 prior to the 2.6.39 rewrite), this patch reduces kernel CPU
consumption by 32%.

Two new trace points are added to ext4_ext_convert_to_initialized()
to offer visibility into its operations. No exit trace point has
been added due to the multiplicity of return points. This can be
revisited once the upstream cleanup is backported.

Signed-off-by: Eric Gouriou <egouriou@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-10-27 11:43:23 -04:00
Tao Ma
b3ff056908 ext4: don't check io->flag when setting EXT4_STATE_DIO_UNWRITTEN inode state
When we want to convert the unitialized extent in direct write, we can
either do it in ext4_end_io_nolock(AIO case) or in
ext4_ext_direct_IO(non AIO case) and EXT4_I(inode)->cur_aio_dio is a
guard for ext4_ext_map_blocks to find the right case.  In e9e3bcecf,
we mistakenly change it by:

-			if (io)
+			if (io && !(io->flag & EXT4_IO_END_UNWRITTEN)) {
 				io->flag = EXT4_IO_END_UNWRITTEN;
-			else
+				atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten);
+			} else
 				ext4_set_inode_state(inode,
 						     EXT4_STATE_DIO_UNWRITTEN);

So now if we map 2 blocks, and the first one set the
EXT_IO_END_UNWRITTEN, the 2nd mapping will set inode state because of
the check for the flag. This is wrong.

Cc: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-10-26 11:08:39 -04:00
Curt Wohlgemuth
6f8ff53726 ext4: handle NULL p_ext in ext4_ext_next_allocated_block()
In ext4_ext_next_allocated_block(), the path[depth] might
have a p_ext that is NULL -- see ext4_ext_binsearch().  In
such a case, dereferencing it will crash the machine.

This patch checks for p_ext == NULL in
ext4_ext_next_allocated_block() before dereferencinging it.

Tested using a hand-crafted an inode with eh_entries == 0 in
an extent block, verified that running FIEMAP on it crashes
without this patch, works fine with it.

Signed-off-by: Curt Wohlgemuth <curtw@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-10-26 04:38:59 -04:00
Dan Carpenter
f85b287a01 ext4: error handling fix in ext4_ext_convert_to_initialized()
When allocated is unsigned it breaks the error handling at the end
of the function when we call:
	allocated = ext4_split_extent(...);
	if (allocated < 0)
		err = allocated;

I've made it a signed int instead of unsigned.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-10-26 03:42:36 -04:00
Dmitry Monakhov
a4e5d88b1b ext4: update EOFBLOCKS flag on fallocate properly
EOFBLOCK_FL should be updated if called w/o FALLOCATE_FL_KEEP_SIZE
Currently it happens only if new extent was allocated.

TESTCASE:
fallocate test_file -n -l4096
fallocate test_file -l4096
Last fallocate cmd has updated size, but keept EOFBLOCK_FL set. And
fsck will complain about that.

Also remove ping pong in ext4_fallocate() in case of new extents,
where ext4_ext_map_blocks() clear EOFBLOCKS bit, and later
ext4_falloc_update_inode() restore it again.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-10-25 08:15:12 -04:00
Dmitry Monakhov
750c9c47a5 ext4: remove messy logic from ext4_ext_rm_leaf
- Both callers(truncate and punch_hole) already aligned left end point
  so we no longer need split logic here.
- Remove dead duplicated code.
- Call ext4_ext_dirty only after we have updated eh_entries, otherwise
  we'll loose entries update. Regression caused by d583fb87a3
  266'th testcase in xfstests (http://patchwork.ozlabs.org/patch/120872)

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-10-25 05:35:05 -04:00
Dmitry Monakhov
1939dd84b3 ext4: cleanup ext4_ext_grow_indepth code
Currently code make an impression what grow procedure is very complicated
and some mythical paths, blocks are involved. But in fact grow in depth
it relatively simple procedure:
 1) Just create new meta block and copy root data to that block.
 2) Convert root from extent to index if old depth == 0
 3) Update root block pointer

This patch does:
 - Reorganize code to make it more self explanatory
 - Do not pass path parameter to new_meta_block() in order to
   provoke allocation from inode's group because top-level block
   should site closer to it's inode, but not to leaf data block.

   [ This happens anyway, due to logic in mballoc; we should drop
     the path parameter from new_meta_block() entirely.  -- tytso ]

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-10-22 01:26:05 -04:00
H Hartley Sweeten
ee90d57e20 ext4: quiet sparse noise about plain integer as NULL pointer
The third parameter to ext4_free_blocks is a struct buffer_head *.  This
parameter should be NULL not 0.

This quiets the sparse noise:

warning: Using plain integer as NULL pointer

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-10-18 11:01:51 -04:00
Tao Ma
f472e02669 ext4: avoid stamping on other memories in ext4_ext_insert_index()
Add a sanity check to make sure ix hasn't gone beyond the valid bounds
of the extent block.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-10-17 10:13:46 -04:00