This patch fixes a second punch hole bug found by xfstests 127.
This bug happens because punch hole needs to flush the pages
of the hole to avoid race conditions. But if the end of the
hole is in the same page as i_size, the buffer heads beyond
i_size need to be unmapped and the page needs to be zeroed
after it is flushed.
To correct this, the new ext4_discard_partial_page_buffers
routine is used to zero and unmap the partial page
beyond i_size if the end of the hole appears in the same
page as i_size.
The code has also been optimized to set the end of the hole
to the page after i_size if the specified hole exceeds i_size,
and the code that flushes the pages has been simplified.
Signed-off-by: Allison Henderson <achender@linux.vnet.ibm.com>
This patch addresses a bug found by xfstests 75, 112, 127
when blocksize = 1k
This bug happens because the punch hole code only zeros
out non block aligned regions of the page. This means that if the
blocks are smaller than a page, then the block aligned regions of
the page inside the hole are left un-zeroed, and their buffer heads
are still mapped. This bug is corrected by using
ext4_discard_partial_page_buffers to properly zero the partial page
at the head and tail of the hole, and unmap the corresponding buffer
heads
This patch also addresses a bug reported by Lukas while working on a
new patch to add discard support for loop devices using punch hole.
The bug happened because of the first and last block number
needed to be cast to a larger data type before calculating the
byte offset, but since now we only need the byte offsets of the
pages, we no longer even need to be calculating the byte offsets
of the blocks. The code to do the block offset calculations is
removed in this patch.
Signed-off-by: Allison Henderson <achender@linux.vnet.ibm.com>
The logical block number in map.l_blk is a __u32, and so before we
shift it left, by the block size, we neeed cast it to a 64-bit size.
Otherwise i_size can be corrupted on an ENOSPC.
# df -T /mnt/mp1
Filesystem Type 1K-blocks Used Available Use% Mounted on
/dev/sda6 ext4 9843276 153056 9190200 2% /mnt/mp1
# fallocate -o 0 -l 2199023251456 /mnt/mp1/testfile
fallocate: /mnt/mp1/testfile: fallocate failed: No space left on device
# stat /mnt/mp1/testfile
File: `/mnt/mp1/testfile'
Size: 4293656576 Blocks: 19380440 IO Block: 4096 regular file
Device: 806h/2054d Inode: 12 Links: 1
Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root)
Access: 2011-07-25 13:01:31.414490496 +0900
Modify: 2011-07-25 13:01:31.414490496 +0900
Change: 2011-07-25 13:01:31.454490495 +0900
Signed-off-by: Utako Kusaka <u-kusaka@wm.jp.nec.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
--
fs/ext4/extents.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
The old function ext4_ext_rm_idx is used only for truncate case
because it just remove last index in extent-index-block. When punching
hole, it usually needed to remove "middle" index, therefore we must
move indexes which after it forward.
(I create a file with 1 depth extent tree and punch hole in the middle
of it, the last index in index-block strangly gone, so I find out this
bug)
Signed-off-by: Robin Dong <sanbai@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The debug message in ext4_ext_insert_extent before moving extent
is incorrect (the "from xx to xx").
Signed-off-by: Robin Dong <sanbai@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The argument "inode" in function ext4_ext_next_allocated_block looks useless,
so clean it.
Signed-off-by: Robin Dong <sanbai@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
If eh_entries is equal to (or greater than) eh_max, the operation of
inserting new extent_idx will make number of entries overflow.
So check eh_entries before inserting the new extent_idx.
Although there is no bug case according the code (function
ext4_ext_insert_index is called by ext4_ext_split and ext4_ext_split
is called only if the index block has free space), the right logic
should be "lookup the capacity before insertion".
Signed-off-by: Robin Dong <sanbai@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This patch avoids an extraneous lookup of the extent cache
in ext4_ext_map_blocks() when the flag
EXT4_GET_BLOCKS_PUNCH_OUT_EXT is absent.
The existing logic was performing the lookup but not making
use of the result. The patch simply reverses the order of evaluation
in the condition.
Since ext4_ext_in_cache() does not initialize newex on misses, bypassing
its invocation does not introduce any new issue in this regard.
Signed-off-by: Robin Dong <sanbai@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Reviewed-by: Eric Gouriou <egouriou@google.com>
This patch removes the extra parameter in ext4_ext_remove_space()
which is no longer needed.
Signed-off-by: Allison Henderson <achender@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This patch optimizes the punch hole operation by skipping the
tree walking code that is used by truncate. Since punch hole
is done through map blocks, the path to the extent is already
known in this function, so we do not need to look it up again.
Signed-off-by: Allison Henderson <achender@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Optimize ext4_ext_insert_extent() by avoiding
ext4_ext_next_leaf_block() when the result is not used/needed.
Signed-off-by: Robin Dong <sanbai@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
If eh->eh_entries is smaller than eh->eh_max, the routine will
go to the "repeat" and then go to "has_space" directlly ,
since argument "depth" and "eh" are not even changed.
Therefore, goto "has_space" directly and remove redundant "repeat" tag.
Signed-off-by: Robin Dong <sanbai@taobao.com>
Upon corrupted inode or disk failures, we may fail after we already
allocate some blocks from the inode or take some blocks from the
inode's preallocation list, but before we successfully insert the
corresponding extent to the extent tree. In this case, we should free
any allocated blocks and discard the inode's preallocated blocks
because the entries in the inode's preallocation list may be in an
inconsistent state.
Signed-off-by: Jiaying Zhang <jiayingz@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
The current implementation of ext4_free_blocks() always calls
dquot_free_block This looks quite sensible in the most cases: blocks
to be freed are associated with inode and were accounted in quota and
i_blocks some time ago.
However, there is a case when blocks to free were not accounted by the
time calling ext4_free_blocks() yet:
1. delalloc is on, write_begin pre-allocated some space in quota
2. write-back happens, ext4 allocates some blocks in ext4_ext_map_blocks()
3. then ext4_ext_map_blocks() gets an error (e.g. ENOSPC) from
ext4_ext_insert_extent() and calls ext4_free_blocks().
In this scenario, ext4_free_blocks() calls dquot_free_block() who, in
turn, decrements i_blocks for blocks which were not accounted yet (due
to delalloc) After clean umount, e2fsck reports something like:
> Inode 21, i_blocks is 5080, should be 5128. Fix<y>?
because i_blocks was erroneously decremented as explained above.
The patch fixes the problem by passing the new flag
EXT4_FREE_BLOCKS_NO_QUOT_UPDATE to ext4_free_blocks(), to request
that the dquot_free_block() call be skipped.
Signed-off-by: Maxim Patlasov <maxim.patlasov@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
I found that ext4_ext_find_goal() and ext4_find_near()
share the same code for returning a coloured start block
based on i_block_group.
We can refactor this into a common function so that they
don't diverge in the future.
Thanks to adilger for suggesting the new function name.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
In function ext4_ext_insert_index when eh_entries of curp is
bigger than eh_max, error messages will be printed out, but the content
is about logical and ei_block, that's incorret.
Signed-off-by: Robin Dong <sanbai@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Currently we are not marking the extent as the last one
(FIEMAP_EXTENT_LAST) if there is a hole at the end of the file. This is
because we just do not check for it right now and continue searching for
next extent. But at the point we hit the hole at the end of the file, it
is too late.
This commit adds check for the allocated block in subsequent extent and
if there is no more extents (block = EXT_MAX_BLOCKS) just flag the
current one as the last one.
This behaviour has been spotted unintentionally by 252 xfstest, when the
test hangs out, because of wrong loop condition. However on other
filesystems (like xfs) it will exit anyway, because we notice the last
extent flag and exit.
With this patch xfstest 252 does not hang anymore, ext4 fiemap
implementation still reports bad extent type in some cases, however
this seems to be different issue.
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Kazuya Mio reported that he was able to hit BUG_ON(next == lblock)
in ext4_ext_put_gap_in_cache() while creating a sparse file in extent
format and fill the tail of file up to its end. We will hit the BUG_ON
when we write the last block (2^32-1) into the sparse file.
The root cause of the problem lies in the fact that we specifically set
s_maxbytes so that block at s_maxbytes fit into on-disk extent format,
which is 32 bit long. However, we are not storing start and end block
number, but rather start block number and length in blocks. It means
that in order to cover extent from 0 to EXT_MAX_BLOCK we need
EXT_MAX_BLOCK+1 to fit into len (because we counting block 0 as well) -
and it does not.
The only way to fix it without changing the meaning of the struct
ext4_extent members is, as Kazuya Mio suggested, to lower s_maxbytes
by one fs block so we can cover the whole extent we can get by the
on-disk extent format.
Also in many places EXT_MAX_BLOCK is used as length instead of maximum
logical block number as the name suggests, it is all a bit messy. So
this commit renames it to EXT_MAX_BLOCKS and change its usage in some
places to actually be maximum number of blocks in the extent.
The bug which this commit fixes can be reproduced as follows:
dd if=/dev/zero of=/mnt/mp1/file bs=<blocksize> count=1 seek=$((2**32-2))
sync
dd if=/dev/zero of=/mnt/mp1/file bs=<blocksize> count=1 seek=$((2**32-1))
Reported-by: Kazuya Mio <k-mio@sx.jp.nec.com>
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Make ext4_ext_split() get extents to be moved by calculating in a statement
instead of counting in a loop.
Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Currently, an fallocate request of size slightly larger than a power of
2 is turned into two block requests, each a power of 2, with the extra
blocks pre-allocated for future use. When an application calls
fallocate, it already has an idea about how large the file may grow so
there is usually little benefit to reserve extra blocks on the
preallocation list. This reduces disk fragmentation.
Tested: fsstress. Also verified manually that fallocat'ed files are
contiguously laid out with this change (whereas without it they begin at
power-of-2 boundaries, leaving blocks in between). CPU usage of
fallocate is not appreciably higher. In a tight fallocate loop, CPU
usage hovers between 5%-8% with this change, and 5%-7% without it.
Using a simulated file system aging program which the file system to
70%, the percentage of free extents larger than 8MB (as measured by
e2freefrag) increased from 38.8% without this change, to 69.4% with
this change.
Signed-off-by: Vivek Haldar <haldar@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This patch adds new routines: "ext4_punch_hole" "ext4_ext_punch_hole"
and "ext4_ext_check_cache"
fallocate has been modified to call ext4_punch_hole when the punch hole
flag is passed. At the moment, we only support punching holes in
extents, so this routine is pretty much a wrapper for the ext4_ext_punch_hole
routine.
The ext4_ext_punch_hole routine first completes all outstanding writes
with the associated pages, and then releases them. The unblock
aligned data is zeroed, and all blocks in between are punched out.
The ext4_ext_check_cache routine is very similar to ext4_ext_in_cache
except it accepts a ext4_ext_cache parameter instead of a ext4_extent
parameter. This routine is used by ext4_ext_punch_hole to check and
see if a block in a hole that has been cached. The ext4_ext_cache
parameter is necessary because the members ext4_extent structure are
not large enough to hold a 32 bit value. The existing
ext4_ext_in_cache routine has become a wrapper to this new function.
[ext4 punch hole patch series 5/5 v7]
Signed-off-by: Allison Henderson <achender@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Mingming Cao <cmm@us.ibm.com>
This patch adds a new flag to ext4_map_blocks() that specifies the
given range of blocks should be punched out. Extents are first
converted to uninitialized extents before they are punched
out. Because punching a hole may require that the extent be split, it
is possible that the splitting may need more blocks than are
available. To deal with this, use of reserved blocks are enabled to
allow the split to proceed.
The routine then returns the number of blocks successfully
punched out.
[ext4 punch hole patch series 4/5 v7]
Signed-off-by: Allison Henderson <achender@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Mingming Cao <cmm@us.ibm.com>
This patch modifies the truncate routines to support hole punching
Below is a brief summary of the patches changes:
- Added end param to ext_ext4_rm_leaf
This function has been modified to accept an end parameter
which enables it to punch holes in leafs instead of just
truncating them.
- Implemented the "remove head" case in the ext_remove_blocks routine
This routine is used by ext_ext4_rm_leaf to remove the tail
of an extent during a truncate. The new ext_ext4_rm_leaf
routine will now also use it to remove the head of an extent in the
case that the hole covers a region of blocks at the beginning
of an extent.
- Added "end" param to ext4_ext_remove_space routine
This function has been modified to accept a stop parameter, which
is passed through to ext4_ext_rm_leaf.
[ext4 punch hole patch series 3/5 v6]
Signed-off-by: Allison Henderson <achender@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This patch adds an allocation request flag to the ext4_has_free_blocks
function which enables the use of reserved blocks. This will allow a
punch hole to proceed even if the disk is full. Punching a hole may
require additional blocks to first split the extents.
Because ext4_has_free_blocks is a low level function, the flag needs
to be passed down through several functions listed below:
ext4_ext_insert_extent
ext4_ext_create_new_leaf
ext4_ext_grow_indepth
ext4_ext_split
ext4_ext_new_meta_block
ext4_mb_new_blocks
ext4_claim_free_blocks
ext4_has_free_blocks
[ext4 punch hole patch series 1/5 v7]
Signed-off-by: Allison Henderson <achender@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Mingming Cao <cmm@us.ibm.com>
To get delayed-extent information, ext4_ext_fiemap_cb() looks up
pagecache, it thus collects information starting from a page's
head block.
If blocksize < pagesize, the beginning blocks of a page may lies
before the request range. So ext4_ext_fiemap_cb() should proceed
ignoring them, because they has been handled before. If no mapped
buffer in the range is found in the 1st page, we need to look up
the 2nd page, otherwise delayed-extents after a hole will be ignored.
Without this patch, xfstests 225 will hung on ext4 with 1K block.
Reported-by: Amir Goldstein <amir73il@users.sourceforge.net>
Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4_ext_truncate() should not invoke up_write(&EXT4_I(inode)->i_data_sem)
when ext4_orphan_add() returns an error, as it hasn't performed a
down_write() yet. This trivial patch fixes this by moving the up_write()
invocation above the out_stop label.
Signed-off-by: Eric Gouriou <egouriou@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The number of hits and misses for each filesystem is exposed in
/sys/fs/ext4/<dev>/extent_cache_{hits, misses}.
Tested: fsstress, manual checks.
Signed-off-by: Vivek Haldar <haldar@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This patch addresses bugs found while testing punch hole
with the fsx test. The patch corrects the number of blocks
that are zeroed out while splitting an extent, and also corrects
the return value to return the number of blocks split out, instead
of the number of blocks zeroed out.
This patch has been tested in addition to the following patches:
[Ext4 punch hole v7]
[XFS Tests Punch Hole 1/1 v2] Add Punch Hole Testing to FSX
The test ran successfully for 24 hours.
Signed-off-by: Allison Henderson <achender@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Add two functions: ext4_split_extent_at(), which splits an extent into
two extents at given logical block, and ext4_split_extent() which
splits an extent into three extents.
Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Tested-by: Allison Henderson <achender@linux.vnet.ibm.com>
1) Rename ext4_ext_try_to_merge() to ext4_ext_try_to_merge_right().
2) Add a new function ext4_ext_try_to_merge() which tries to merge
an extent both left and right.
3) Use the new function in ext4_ext_convert_unwritten_endio() and
ext4_ext_insert_extent().
Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Tested-by: Allison Henderson <achender@linux.vnet.ibm.com>
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (43 commits)
ext4: fix a BUG in mb_mark_used during trim.
ext4: unused variables cleanup in fs/ext4/extents.c
ext4: remove redundant set_buffer_mapped() in ext4_da_get_block_prep()
ext4: add more tracepoints and use dev_t in the trace buffer
ext4: don't kfree uninitialized s_group_info members
ext4: add missing space in printk's in __ext4_grp_locked_error()
ext4: add FITRIM to compat_ioctl.
ext4: handle errors in ext4_clear_blocks()
ext4: unify the ext4_handle_release_buffer() api
ext4: handle errors in ext4_rename
jbd2: add COW fields to struct jbd2_journal_handle
jbd2: add the b_cow_tid field to journal_head struct
ext4: Initialize fsync transaction ids in ext4_new_inode()
ext4: Use single thread to perform DIO unwritten convertion
ext4: optimize ext4_bio_write_page() when no extent conversion is needed
ext4: skip orphan cleanup if fs has unknown ROCOMPAT features
ext4: use the nblocks arg to ext4_truncate_restart_trans()
ext4: fix missing iput of root inode for some mount error paths
ext4: make FIEMAP and delayed allocation play well together
ext4: suppress verbose debugging information if malloc-debug is off
...
Fi up conflicts in fs/ext4/super.c due to workqueue changes
- Add more ext4 tracepoints.
- Change ext4 tracepoints to use dev_t field with MAJOR/MINOR macros
so that we can save 4 bytes in the ring buffer on some platforms.
- Add sync_mode to ext4_da_writepages, ext4_da_write_pages, and
ext4_da_writepages_result tracepoints. Also remove for_reclaim
field from ext4_da_writepages since it is usually not very useful.
Signed-off-by: Jiaying Zhang <jiayingz@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Fix the FIEMAP ioctl so that it returns all of the page ranges which
are still subject to delayed allocation. We were missing some cases
if the file was sparse.
Reported by Chris Mason <chris.mason@oracle.com>:
>We've had reports on btrfs that cp is giving us files full of zeros
>instead of actually copying them. It was tracked down to a bug with
>the btrfs fiemap implementation where it was returning holes for
>delalloc ranges.
>
>Newer versions of cp are trusting fiemap to tell it where the holes
>are, which does seem like a pretty neat trick.
>
>I decided to give xfs and ext4 a shot with a few tests cases too, xfs
>passed with all the ones btrfs was getting wrong, and ext4 got the basic
>delalloc case right.
>$ mkfs.ext4 /dev/xxx
>$ mount /dev/xxx /mnt
>$ dd if=/dev/zero of=/mnt/foo bs=1M count=1
>$ fiemap-test foo
>ext: 0 logical: [ 0.. 255] phys: 0.. 255
>flags: 0x007 tot: 256
>
>Horray! But once we throw a hole in, things go bad:
>$ mkfs.ext4 /dev/xxx
>$ mount /dev/xxx /mnt
>$ dd if=/dev/zero of=/mnt/foo bs=1M count=1 seek=1
>$ fiemap-test foo
>< no output >
>
>We've got a delalloc extent after the hole and ext4 fiemap didn't find
>it. If I run sync to kick the delalloc out:
>$sync
>$ fiemap-test foo
>ext: 0 logical: [ 256.. 511] phys: 34048.. 34303
>flags: 0x001 tot: 256
>
>fiemap-test is sitting in my /usr/local/bin, and I have no idea how it
>got there. It's full of pretty comments so I know it isn't mine, but
>you can grab it here:
>
>http://oss.oracle.com/~mason/fiemap-test.c
>
>xfsqa has a fiemap program too.
After Fix, test results are as follows:
ext: 0 logical: [ 256.. 511] phys: 0.. 255
flags: 0x007 tot: 256
ext: 0 logical: [ 256.. 511] phys: 33280.. 33535
flags: 0x001 tot: 256
$ mkfs.ext4 /dev/xxx
$ mount /dev/xxx /mnt
$ dd if=/dev/zero of=/mnt/foo bs=1M count=1 seek=1
$ sync
$ dd if=/dev/zero of=/mnt/foo bs=1M count=1 seek=3
$ dd if=/dev/zero of=/mnt/foo bs=1M count=1 seek=5
$ fiemap-test foo
ext: 0 logical: [ 256.. 511] phys: 33280.. 33535
flags: 0x000 tot: 256
ext: 1 logical: [ 768.. 1023] phys: 0.. 255
flags: 0x006 tot: 256
ext: 2 logical: [ 1280.. 1535] phys: 0.. 255
flags: 0x007 tot: 256
Tested-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This patch fixes the warning "Using plain integer as NULL pointer",
generated by sparse, by replacing the offending 0s with NULL.
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4 has a data corruption case when doing non-block-aligned
asynchronous direct IO into a sparse file, as demonstrated
by xfstest 240.
The root cause is that while ext4 preallocates space in the
hole, mappings of that space still look "new" and
dio_zero_block() will zero out the unwritten portions. When
more than one AIO thread is going, they both find this "new"
block and race to zero out their portion; this is uncoordinated
and causes data corruption.
Dave Chinner fixed this for xfs by simply serializing all
unaligned asynchronous direct IO. I've done the same here.
The difference is that we only wait on conversions, not all IO.
This is a very big hammer, and I'm not very pleased with
stuffing this into ext4_file_write(). But since ext4 is
DIO_LOCKING, we need to serialize it at this high level.
I tried to move this into ext4_ext_direct_IO, but by then
we have the i_mutex already, and we will wait on the
work queue to do conversions - which must also take the
i_mutex. So that won't work.
This was originally exposed by qemu-kvm installing to
a raw disk image with a normal sector-63 alignment. I've
tested a backport of this patch with qemu, and it does
avoid the corruption. It is also quite a lot slower
(14 min for package installs, vs. 8 min for well-aligned)
but I'll take slow correctness over fast corruption any day.
Mingming suggested that we can track outstanding
conversions, and wait on those so that non-sparse
files won't be affected, and I've implemented that here;
unaligned AIO to nonsparse files won't take a perf hit.
[tytso@mit.edu: Keep the mutex as a hashed array instead
of bloating the ext4 inode]
[tytso@mit.edu: Fix up namespace issues so that global
variables are protected with an "ext4_" prefix.]
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Currently all filesystems except XFS implement fallocate asynchronously,
while XFS forced a commit. Both of these are suboptimal - in case of O_SYNC
I/O we really want our allocation on disk, especially for the !KEEP_SIZE
case where we actually grow the file with user-visible zeroes. On the
other hand always commiting the transaction is a bad idea for fast-path
uses of fallocate like for example in recent Samba versions. Given
that block allocation is a data plane operation anyway change it from
an inode operation to a file operation so that we have the file structure
available that lets us check for O_SYNC.
This also includes moving the code around for a few of the filesystems,
and remove the already unnedded S_ISDIR checks given that we only wire
up fallocate for regular files.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Instead of various home grown checks that might need updates for new
flags just check for any bit outside the mask of the features supported
by the filesystem. This makes the check future proof for any newly
added flag.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (41 commits)
fs: add documentation on fallocate hole punching
Gfs2: fail if we try to use hole punch
Btrfs: fail if we try to use hole punch
Ext4: fail if we try to use hole punch
Ocfs2: handle hole punching via fallocate properly
XFS: handle hole punching via fallocate properly
fs: add hole punching to fallocate
vfs: pass struct file to do_truncate on O_TRUNC opens (try #2)
fix signedness mess in rw_verify_area() on 64bit architectures
fs: fix kernel-doc for dcache::prepend_path
fs: fix kernel-doc for dcache::d_validate
sanitize ecryptfs ->mount()
switch afs
move internal-only parts of ncpfs headers to fs/ncpfs
switch ncpfs
switch 9p
pass default dentry_operations to mount_pseudo()
switch hostfs
switch affs
switch configfs
...
Ext4 doesn't have the ability to punch holes yet, so make sure we return
EOPNOTSUPP if we try to use hole punching through fallocate. This support can
be added later. Thanks,
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Since check_eofblocks_fl() only uses the m_lblk portion of the map
structure, we may as well pass that directly, rather than passing the
entire map, which IMHO obfuscates what parameters check_eofblocks_fl()
cares about. Not a big deal, but seems tidier and less confusing, to
me.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Ted first found the bug when running 2.6.36 kernel with dioread_nolock
mount option that xfstests #13 complained about wrong file size during fsck.
However, the bug exists in the older kernels as well although it is
somehow harder to trigger.
The problem is that ext4_end_io_work() can happen after we have truncated an
inode to a smaller size. Then when ext4_end_io_work() calls
ext4_convert_unwritten_extents(), we may reallocate some blocks that have
been truncated, so the inode size becomes inconsistent with the allocated
blocks.
The following patch flushes the i_completed_io_list during truncate to reduce
the risk that some pending end_io requests are executed later and convert
already truncated blocks to initialized.
Note that although the fix helps reduce the problem a lot there may still
be a race window between vmtruncate() and ext4_end_io_work(). The fundamental
problem is that if vmtruncate() is called without either i_mutex or i_alloc_sem
held, it can race with an ongoing write request so that the io_end request is
processed later when the corresponding blocks have been truncated.
Ted and I have discussed the problem offline and we saw a few ways to fix
the race completely:
a) We guarantee that i_mutex lock and i_alloc_sem write lock are both hold
whenever vmtruncate() is called. The i_mutex lock prevents any new write
requests from entering writeback and the i_alloc_sem prevents the race
from ext4_page_mkwrite(). Currently we hold both locks if vmtruncate()
is called from do_truncate(), which is probably the most common case.
However, there are places where we may call vmtruncate() without holding
either i_mutex or i_alloc_sem. I would like to ask for other people's
opinions on what locks are expected to be held before calling vmtruncate().
There seems a disagreement among the callers of that function.
b) We change the ext4 write path so that we change the extent tree to contain
the newly allocated blocks and update i_size both at the same time --- when
the write of the data blocks is completed.
c) We add some additional locking to synchronize vmtruncate() and
ext4_end_io_work(). This approach may have performance implications so we
need to be careful.
All of the above proposals may require more substantial changes, so
we may consider to take the following patch as a bandaid.
Signed-off-by: Jiaying Zhang <jiayingz@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
We can encode the ec_type information by using ee_len == 0 to denote
EXT4_EXT_CACHE_NO, ee_start == 0 to denote EXT4_EXT_CACHE_GAP, and if
neither is true, then the cache type must be EXT4_EXT_CACHE_EXTENT.
This allows us to reduce the size of ext4_ext_inode by another 8
bytes. (ec_type is 4 bytes, plus another 4 bytes of padding)
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This fixes a number of places where we used sector_t instead of
ext4_lblk_t for logical blocks, which for ext4 are still 32-bit data
types. No point wasting space in the ext4_inode_info structure, and
requiring 64-bit arithmetic on 32-bit systems, when it isn't
necessary.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4_ext_find_goal() returns an ideal physical block number that the block
allocator tries to allocate first. However, if a required file offset is
smaller than the existing extent's one, ext4_ext_find_goal() returns
a wrong block number because it may overflow at
"block - le32_to_cpu(ex->ee_block)". This patch fixes the problem.
ext4_ext_find_goal() will also return a wrong block number in case
a file offset of the existing extent is too big. In this case,
the ideal physical block number is fixed in ext4_mb_initialize_context(),
so it's no problem.
reproduce:
# dd if=/dev/zero of=/mnt/mp1/tmp bs=127M count=1 oflag=sync
# dd if=/dev/zero of=/mnt/mp1/file bs=512K count=1 seek=1 oflag=sync
# filefrag -v /mnt/mp1/file
Filesystem type is: ef53
File size of /mnt/mp1/file is 1048576 (256 blocks, blocksize 4096)
ext logical physical expected length flags
0 128 67456 128 eof
/mnt/mp1/file: 2 extents found
# rm -rf /mnt/mp1/tmp
# echo $((512*4096)) > /sys/fs/ext4/loop0/mb_stream_req
# dd if=/dev/zero of=/mnt/mp1/file bs=512K count=1 oflag=sync conv=notrunc
result (linux-2.6.37-rc2 + ext4 patch queue):
# filefrag -v /mnt/mp1/file
Filesystem type is: ef53
File size of /mnt/mp1/file is 1048576 (256 blocks, blocksize 4096)
ext logical physical expected length flags
0 0 33280 128
1 128 67456 33407 128 eof
/mnt/mp1/file: 2 extents found
result(apply this patch):
# filefrag -v /mnt/mp1/file
Filesystem type is: ef53
File size of /mnt/mp1/file is 1048576 (256 blocks, blocksize 4096)
ext logical physical expected length flags
0 0 66560 128
1 128 67456 66687 128 eof
/mnt/mp1/file: 2 extents found
Signed-off-by: Kazuya Mio <k-mio@sx.jp.nec.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
When I compiled 2.6.36-rc3 kernel with EXT4FS_DEBUG definition, I got
the following compile error.
CC [M] fs/ext4/extents.o
fs/ext4/extents.c: In function 'ext4_fallocate':
fs/ext4/extents.c:3772: error: 'block' undeclared (first use in this function)
fs/ext4/extents.c:3772: error: (Each undeclared identifier is reported only once
fs/ext4/extents.c:3772: error: for each function it appears in.)
make[2]: *** [fs/ext4/extents.o] Error 1
The patch fixes this problem.
Signed-off-by: Kazuya Mio <k-mio@sx.jp.nec.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cleanup namespace leaks from fs/ext4 and the inline trivial functions
ext4_{ext,idx}_pblock() and ext4_{ext,idx}_store_pblock() since the
code size actually shrinks when we make these functions inline,
they're so trivial.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
These functions have no need to be exported beyond file context.
No functions needed to be moved for this commit; just some function
declarations changed to be static and removed from header files.
(A similar patch was submitted by Eric Sandeen, but I wanted to handle
code movement in separate patches to make sure code changes didn't
accidentally get dropped.)
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Call the block I/O layer directly instad of going through the buffer
layer. This should give us much better performance and scalability,
as well as lowering our CPU utilization when doing buffered writeback.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Change ext4_ext_zeroout to use sb_issue_zeroout instead of its
own approach to zero out extents.
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
It turns out we have several problems with how EOFBLOCKS_FL is
handled. First of all, there was a fencepost error where we were not
clearing the EOFBLOCKS_FL when fill in the last uninitialized block,
but rather when we allocate the next block _after_ the uninitalized
block. Secondly we were not testing to see if we needed to clear the
EOFBLOCKS_FL when writing to the file O_DIRECT or when were converting
an uninitialized block (which is the most common case).
Google-Bug-Id: 2928259
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (40 commits)
ext4: Adding error check after calling ext4_mb_regular_allocator()
ext4: Fix dirtying of journalled buffers in data=journal mode
ext4: re-inline ext4_rec_len_(to|from)_disk functions
jbd2: Remove t_handle_lock from start_this_handle()
jbd2: Change j_state_lock to be a rwlock_t
jbd2: Use atomic variables to avoid taking t_handle_lock in jbd2_journal_stop
ext4: Add mount options in superblock
ext4: force block allocation on quota_off
ext4: fix freeze deadlock under IO
ext4: drop inode from orphan list if ext4_delete_inode() fails
ext4: check to make make sure bd_dev is set before dereferencing it
jbd2: Make barrier messages less scary
ext4: don't print scary messages for allocation failures post-abort
ext4: fix EFBIG edge case when writing to large non-extent file
ext4: fix ext4_get_blocks references
ext4: Always journal quota file modifications
ext4: Fix potential memory leak in ext4_fill_super
ext4: Don't error out the fs if the user tries to make a file too big
ext4: allocate stripe-multiple IOs on stripe boundaries
ext4: move aio completion after unwritten extent conversion
...
Fix up conflicts in fs/ext4/inode.c as per Ted.
Fix up xfs conflicts as per earlier xfs merge.
No real bugs found, just removed some dead code.
Found by gcc 4.6's new warnings.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
If i_data_sem was internally dropped due to transaction restart, it is
necessary to restart path look-up because extents tree was possibly
modified by ext4_get_block().
https://bugzilla.kernel.org/show_bug.cgi?id=15827
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Acked-by: Jan Kara <jack@suse.cz>
Dimitry Monakhov discovered an edge case where it was possible for the
EXT4_EOFBLOCKS_FL flag could get cleared unnecessarily. This is true;
I have a test case that can be exercised via downloading and
decompressing the file:
wget ftp://ftp.kernel.org/pub/linux/kernel/people/tytso/ext4-testcases/eofblocks-fl-test-case.img.bz2
bunzip2 eofblocks-fl-test-case.img
dd if=/dev/zero of=eofblocks-fl-test-case.img bs=1k seek=17925 bs=1k count=1 conv=notrunc
However, triggering it in real life is highly unlikely since it
requires an extremely fragmented sparse file with a hole in exactly
the right place in the extent tree. (It actually took quite a bit of
work to generate this test case.) Still, it's nice to get even
extreme corner cases to be correct, so this patch makes sure that we
don't clear the EXT4_EOFBLOCKS_FL incorrectly even in this corner
case.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
If the EOFBLOCK_FL flag is set when it should not be and the inode is
zero length, then eh_entries is zero, and ex is NULL, so dereferencing
ex to print ex->ee_block causes a kernel OOPS in
ext4_ext_map_blocks().
On top of that, the error message which is printed isn't very helpful.
So we fix this by printing something more explanatory which doesn't
involve trying to print ex->ee_block.
Addresses-Google-Bug: #2655740
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
At several places we modify EXT4_I(inode)->i_flags without holding
i_mutex (ext4_do_update_inode, ...). These modifications are racy and
we can lose updates to i_flags. So convert handling of i_flags to use
bitops which are atomic.
https://bugzilla.kernel.org/show_bug.cgi?id=15792
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
EXT4_ERROR_INODE() tends to provide better error information and in a
more consistent format. Some errors were not even identifying the inode
or directory which was corrupted, which made them not very useful.
Addresses-Google-Bug: #2507977
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This saves a huge amount of stack space by avoiding unnecesary struct
buffer_head's from being allocated on the stack.
In addition, to make the code easier to understand, collapse and
refactor ext4_get_block(), ext4_get_block_write(),
noalloc_get_block_write(), into a single function.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Jack up ext4_get_blocks() and add a new function, ext4_map_blocks()
which uses a much smaller structure, struct ext4_map_blocks which is
20 bytes, as opposed to a struct buffer_head, which nearly 5 times
bigger on an x86_64 machine. By switching things to use
ext4_map_blocks(), we can save stack space by using ext4_map_blocks()
since we can avoid allocating a struct buffer_head on the stack.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Currently using posix_fallocate one can bypass an RLIMIT_FSIZE limit
and create a file larger than the limit. Add a check for that.
Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Signed-off-by: Amit Arora <aarora@in.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The extents code will sometimes zero out blocks and mark them as
initialized instead of splitting an extent into several smaller ones.
This optimization however, causes problems if the extent is beyond
i_size because fsck will complain if there are uninitialized blocks
after i_size as this can not be distinguished from an inode that has
an incorrect i_size field.
https://bugzilla.kernel.org/show_bug.cgi?id=15742
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
When EIO occurs after bio is submitted, there is no memory free
operation for bio, which results in memory leakage. And there is also
no check against bio_alloc() for bio.
Acked-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Jing Zhang <zj.barak@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Calls to ext4_get_inode_loc() returns with a reference to a buffer
head in iloc->bh. The callers of this function in ext4_write_inode()
when in no journal mode and in ext4_xattr_fiemap() don't release the
buffer head after using it.
Addresses-Google-Bug: #2548165
Signed-off-by: Curt Wohlgemuth <curtw@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
There are duplicate macro definitions of in_range() in mballoc.h and
balloc.c. This consolidates these two definitions into ext4.h, and
changes extents.c to use in_range() as well.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andreas Dilger <adilger@sun.com>
This is a cleanup and simplification patch which takes some open-coded
calculations to calculate the first block number of a group and
converts them to use the (already defined) ext4_group_first_block_no()
function.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andreas Dilger <adilger@sun.com>
Convert a bunch of BUG_ONs to emit a ext4_error() message and return
EIO. This is a first pass and most notably does _not_ cover
mballoc.c, which is a morass of void functions.
Signed-off-by: Frank Mayhar <fmayhar@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Allocate uninitialized extent before ext4 buffer write and
convert the extent to initialized after io completes.
The purpose is to make sure an extent can only be marked
initialized after it has been written with new data so
we can safely drop the i_mutex lock in ext4 DIO read without
exposing stale data. This helps to improve multi-thread DIO
read performance on high-speed disks.
Skip the nobh and data=journal mount cases to make things simple for now.
Signed-off-by: Jiaying Zhang <jiayingz@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit renames some of the direct I/O's block allocation flags,
variables, and functions introduced in Mingming's "Direct IO for holes
and fallocate" patches so that they can be used by ext4's buffered
write path as well. Also changed the related function comments
accordingly to cover both direct write and buffered write cases.
Signed-off-by: Jiaying Zhang <jiayingz@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
fallocate() may potentially instantiate blocks past EOF, depending
on the flags used when it is called.
e2fsck currently has a test for blocks past i_size, and it
sometimes trips up - noticeably on xfstests 013 which runs fsstress.
This patch from Jiayang does fix it up - it (along with
e2fsprogs updates and other patches recently from Aneesh) has
survived many fsstress runs in a row.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Jiaying Zhang <jiayingz@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4_fiemap() rounds the length of the requested range down to
blocksize, which is is not the true number of blocks that cover the
requested region. This problem is especially impressive if the user
requests only the first byte of a file: not a single extent will be
reported.
We fix this by calculating the last block of the region and then
subtract to find the number of blocks in the extents.
Signed-off-by: Leonard Michlmayr <leonard.michlmayr@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Just a pet peeve of mine; we had a mishash of calls with either __func__
or "function_name" and the latter tends to get out of sync.
I think it's easier to just hide the __func__ in a macro, and it'll
be consistent from then on.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
At several places we modify EXT4_I(inode)->i_state without holding
i_mutex (ext4_release_file, ext4_bmap, ext4_journalled_writepage,
ext4_do_update_inode, ...). These modifications are racy and we can
lose updates to i_state. So convert handling of i_state to use bitops
which are atomic.
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The "offset" member in ext4_io_end holds bytes, not blocks, so
ext4_lblk_t is wrong - and too small (u32).
This caused the async i/o writes to sparse files beyond 4GB to fail
when they wrapped around to 0.
Also fix up the type of arguments to ext4_convert_unwritten_extents(),
it gets ssize_t from ext4_end_aio_dio_nolock() and
ext4_ext_direct_IO().
Reported-by: Giel de Nijs <giel@vectorwise.com>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
We should update reserve space if it is delalloc buffer
and that is indicated by EXT4_GET_BLOCKS_DELALLOC_RESERVE flag.
So use EXT4_GET_BLOCKS_DELALLOC_RESERVE in place of
EXT4_GET_BLOCKS_UPDATE_RESERVE_SPACE
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
When we fallocate a region of the file which we had recently written,
and which is still in the page cache marked as delayed allocated blocks
we need to make sure we don't do the quota update on writepage path.
This is because the needed quota updated would have already be done
by fallocate.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
In the past, ext4_calc_metadata_amount(), and its sub-functions
ext4_ext_calc_metadata_amount() and ext4_indirect_calc_metadata_amount()
badly over-estimated the number of metadata blocks that might be
required for delayed allocation blocks. This didn't matter as much
when functions which managed the reserved metadata blocks were more
aggressive about dropping reserved metadata blocks as delayed
allocation blocks were written, but unfortunately they were too
aggressive. This was fixed in commit 0637c6f, but as a result the
over-estimation by ext4_calc_metadata_amount() would lead to reserving
2-3 times the number of pending delayed allocation blocks as
potentially required metadata blocks. So if there are 1 megabytes of
blocks which have been not yet been allocation, up to 3 megabytes of
space would get reserved out of the user's quota and from the file
system free space pool until all of the inode's data blocks have been
allocated.
This commit addresses this problem by much more accurately estimating
the number of metadata blocks that will be required. It will still
somewhat over-estimate the number of blocks needed, since it must make
a worst case estimate not knowing which physical blocks will be
needed, but it is much more accurate than before.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This fixes a bug (found by Curt Wohlgemuth) in which new blocks
returned from an extent created with ext4_ext_zeroout() can have dirty
metadata still associated with them.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Curt Wohlgemuth <curtw@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This patch fixes the Kernel BZ #14286. When the address of an extent
corresponding to a valid block is corrupted, a -EIO should be reported
instead of a BUG(). This situation should not normally not occur
except in the case of a corrupted filesystem. If however it does,
then the system should not panic directly but depending on the mount
time options appropriate action should be taken. If the mount options
so permit, the I/O should be gracefully aborted by returning a -EIO.
http://bugzilla.kernel.org/show_bug.cgi?id=14286
Signed-off-by: Surbhi Palande <surbhi.palande@canonical.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
We cannot rely on buffer dirty bits during fsync because pdflush can come
before fsync is called and clear dirty bits without forcing a transaction
commit. What we do is that we track which transaction has last changed
the inode and which transaction last changed allocation and force it to
disk on fsync.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Currently all quota block reservation macros contains hard-coded "2"
aka MAXQUOTAS value. This is no good because in some places it is not
obvious to understand what does this digit represent. Let's introduce
new macro with self descriptive name.
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Acked-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Add the facility for ext4_forget() to be called from
ext4_free_blocks(). This simplifies the code in a large number of
places, and centralizes most of the work of calling ext4_forget() into
a single place.
Also fix a bug in the extents migration code; it wasn't calling
ext4_forget() when releasing the indirect blocks during the
conversion. As a result, if the system cashed during or shortly after
the extents migration, and the released indirect blocks get reused as
data blocks, the journal replay would corrupt the data blocks. With
this new patch, fixing this bug was as simple as adding the
EXT4_FREE_BLOCKS_FORGET flags to the call to ext4_free_blocks().
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
When an inode gets unlinked, the functions ext4_clear_blocks() and
ext4_remove_blocks() call ext4_forget() for all the buffer heads
corresponding to the deleted inode's data blocks. If the inode is a
directory or a symlink, the is_metadata parameter must be non-zero so
ext4_forget() will revoke them via jbd2_journal_revoke(). Otherwise,
if these blocks are reused for a data file, and the system crashes
before a journal checkpoint, the journal replay could end up
corrupting these data blocks.
Thanks to Curt Wohlgemuth for pointing out potential problems in this
area.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
To prepare for a direct I/O write, we need to split the unwritten
extents before submitting the I/O. When no extents needed to be
split, ext4_split_unwritten_extents() was incorrectly returning 0
instead of the size of uninitialized extents. This bug caused the
wrong return value sent back to VFS code when it gets called from
async IO path, leading to an unnecessary fall back to buffered IO.
This bug also hid the fact that the check to see whether or not a
split would be necessary was incorrect; we can only skip splitting the
extent if the write completely covers the uninitialized extent.
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Allison Henderson
Utako Kusaka
Robin Dong
Robin Dong
Jiaying Zhang
Maxim Patlasov
Yongqiang Yang
Eric Sandeen
Lukas Czerner
Vivek Haldar
Eric Gouriou
Lucas De Marchi
Linus Torvalds
Sergey Senozhatsky
Peter Huewe
Paul Bolle
Jiri Kosina
Tao Ma
Christoph Hellwig
Josef Bacik
Theodore Ts'o
Kazuya Mio
Uwe Kleine-König
Andi Kleen
Dmitry Monakhov
Nikanth Karthikesan
Jing Zhang
Curt Wohlgemuth
Akinobu Mita
Frank Mayhar
Leonard Michlmayr
Aneesh Kumar K.V
Surbhi Palande
Jan Kara
Mingming