metadata_csum supersedes uninit_bg. Convert the ROCOMPAT uninit_bg
flag check to a helper function that covers both, and make the
checksum calculation algorithm use either crc16 or the metadata_csum
chosen algorithm depending on which flag is set. Print a warning if
we try to mount a filesystem with both feature flags set.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Calculate and verify the checksums of extended attribute blocks. This
only applies to separate EA blocks that are pointed to by
inode->i_file_acl (i.e. external EA blocks); the checksum lives in
the EA header.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Calculate and verify the checksums for directory leaf blocks
(i.e. blocks that only contain actual directory entries). The
checksum lives in what looks to be an unused directory entry with a 0
name_len at the end of the block. This scheme is not used for
internal htree nodes because the mechanism in place there only costs
one dx_entry, whereas the "empty" directory entry would cost two
dx_entries.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Calculate and verify the checksum for directory index tree (htree)
node blocks. The checksum is stored in the last 4 bytes of the htree
block and requires the dx_entry array to stop 1 dx_entry short of the
end of the block.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
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>
Compute and verify the checksum of the block bitmap; this checksum is
stored in the block group descriptor.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Compute and verify the checksum of the inode bitmap; the checkum is
stored in the block group descriptor.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This patch introduces to ext4 the ability to calculate and verify
inode checksums. This requires the use of a new ro compatibility flag
and some accompanying e2fsprogs patches to provide the relevant
features in tune2fs and e2fsck. The inode generation changes have
been integrated into this patch.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Calculate and verify the superblock checksum. Since the UUID and
block group number are embedded in each copy of the superblock, we
need only checksum the entire block. Refactor some of the code to
eliminate open-coding of the checksum update call.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Obtain a reference to the cryptoapi and crc32c if we mount a
filesystem with metadata checksumming enabled.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Record the type of checksum algorithm we're using for metadata in the
superblock, in case we ever want/need to change the algorithm.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Define flags and change structure definitions to allow checksumming of
ext4 metadata.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
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>
These are two low-risk bug fixes for ext4, fixing a compile warning
and a potential deadlock.
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Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 bug fixes from Ted Ts'o:
"These are two low-risk bug fixes for ext4, fixing a compile warning
and a potential deadlock."
* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
super.c: unused variable warning without CONFIG_QUOTA
jbd2: use GFP_NOFS for blkdev_issue_flush
sb info is only checked with quota support.
fs/ext4/super.c: In function ‘parse_options’:
fs/ext4/super.c:1600:23: warning: unused variable ‘sbi’ [-Wunused-variable]
Signed-off-by: Eldad Zack <eldad@fogrefinery.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
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
Commit 26092bf5 broke handling of journalled quota mount options by
trying to parse argument of every mount option as a number. Fix this
by dealing with the quota options before we call match_int().
Thanks to Jan Kara for discovering this regression.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
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
->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>
This reverts commit b43d17f319.
Dave Jones reports that it causes lockups on his laptop, and his debug
output showed a lot of processes hung waiting for page_writeback (or
more commonly - processes hung waiting for a lock that was held during
that writeback wait).
The page_writeback hint made Ted suggest that Dave look at this commit,
and Dave verified that reverting it makes his problems go away.
Ted says:
"That commit fixes a race which is seen when you write into fallocated
(and hence uninitialized) disk blocks under *very* heavy memory
pressure. Furthermore, although theoretically it could trigger under
normal direct I/O writes, it only seems to trigger if you are issuing
a huge number of AIO writes, such that a just-written page can get
evicted from memory, and then read back into memory, before the
workqueue has a chance to update the extent tree.
This race has been around for a little over a year, and no one noticed
until two months ago; it only happens under fairly exotic conditions,
and in fact even after trying very hard to create a simple repro under
lab conditions, we could only reproduce the problem and confirm the
fix on production servers running MySQL on very fast PCIe-attached
flash devices.
Given that Dave was able to hit this problem pretty quickly, if we
confirm that this commit is at fault, the only reasonable thing to do
is to revert it IMO."
Reported-and-tested-by: Dave Jones <davej@redhat.com>
Acked-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull nfsd changes from Bruce Fields:
Highlights:
- Benny Halevy and Tigran Mkrtchyan implemented some more 4.1 features,
moving us closer to a complete 4.1 implementation.
- Bernd Schubert fixed a long-standing problem with readdir cookies on
ext2/3/4.
- Jeff Layton performed a long-overdue overhaul of the server reboot
recovery code which will allow us to deprecate the current code (a
rather unusual user of the vfs), and give us some needed flexibility
for further improvements.
- Like the client, we now support numeric uid's and gid's in the
auth_sys case, allowing easier upgrades from NFSv2/v3 to v4.x.
Plus miscellaneous bugfixes and cleanup.
Thanks to everyone!
There are also some delegation fixes waiting on vfs review that I
suppose will have to wait for 3.5. With that done I think we'll finally
turn off the "EXPERIMENTAL" dependency for v4 (though that's mostly
symbolic as it's been on by default in distro's for a while).
And the list of 4.1 todo's should be achievable for 3.5 as well:
http://wiki.linux-nfs.org/wiki/index.php/Server_4.0_and_4.1_issues
though we may still want a bit more experience with it before turning it
on by default.
* 'for-3.4' of git://linux-nfs.org/~bfields/linux: (55 commits)
nfsd: only register cld pipe notifier when CONFIG_NFSD_V4 is enabled
nfsd4: use auth_unix unconditionally on backchannel
nfsd: fix NULL pointer dereference in cld_pipe_downcall
nfsd4: memory corruption in numeric_name_to_id()
sunrpc: skip portmap calls on sessions backchannel
nfsd4: allow numeric idmapping
nfsd: don't allow legacy client tracker init for anything but init_net
nfsd: add notifier to handle mount/unmount of rpc_pipefs sb
nfsd: add the infrastructure to handle the cld upcall
nfsd: add a header describing upcall to nfsdcld
nfsd: add a per-net-namespace struct for nfsd
sunrpc: create nfsd dir in rpc_pipefs
nfsd: add nfsd4_client_tracking_ops struct and a way to set it
nfsd: convert nfs4_client->cl_cb_flags to a generic flags field
NFSD: Fix nfs4_verifier memory alignment
NFSD: Fix warnings when NFSD_DEBUG is not defined
nfsd: vfs_llseek() with 32 or 64 bit offsets (hashes)
nfsd: rename 'int access' to 'int may_flags' in nfsd_open()
ext4: return 32/64-bit dir name hash according to usage type
fs: add new FMODE flags: FMODE_32bithash and FMODE_64bithash
...
The changes to export dirty_writeback_interval are from Artem's s_dirt
cleanup patch series. The same is true of the change to remove the
s_dirt helper functions which never got used by anyone in-tree. I've
run these changes by Al Viro, and am carrying them so that Artem can
more easily fix up the rest of the file systems during the next merge
window. (Originally we had hopped to remove the use of s_dirt from
ext4 during this merge window, but his patches had some bugs, so I
ultimately ended dropping them from the ext4 tree.)
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Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 updates for 3.4 from Ted Ts'o:
"Ext4 commits for 3.3 merge window; mostly cleanups and bug fixes
The changes to export dirty_writeback_interval are from Artem's s_dirt
cleanup patch series. The same is true of the change to remove the
s_dirt helper functions which never got used by anyone in-tree. I've
run these changes by Al Viro, and am carrying them so that Artem can
more easily fix up the rest of the file systems during the next merge
window. (Originally we had hopped to remove the use of s_dirt from
ext4 during this merge window, but his patches had some bugs, so I
ultimately ended dropping them from the ext4 tree.)"
* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (66 commits)
vfs: remove unused superblock helpers
mm: export dirty_writeback_interval
ext4: remove useless s_dirt assignment
ext4: write superblock only once on unmount
ext4: do not mark superblock as dirty unnecessarily
ext4: correct ext4_punch_hole return codes
ext4: remove restrictive checks for EOFBLOCKS_FL
ext4: always set then trimmed blocks count into len
ext4: fix trimmed block count accunting
ext4: fix start and len arguments handling in ext4_trim_fs()
ext4: update s_free_{inodes,blocks}_count during online resize
ext4: change some printk() calls to use ext4_msg() instead
ext4: avoid output message interleaving in ext4_error_<foo>()
ext4: remove trailing newlines from ext4_msg() and ext4_error() messages
ext4: add no_printk argument validation, fix fallout
ext4: remove redundant "EXT4-fs: " from uses of ext4_msg
ext4: give more helpful error message in ext4_ext_rm_leaf()
ext4: remove unused code from ext4_ext_map_blocks()
ext4: rewrite punch hole to use ext4_ext_remove_space()
jbd2: cleanup journal tail after transaction commit
...
Clean-up ext4 a tiny bit by removing useless s_dirt assignment in
'ext4_fill_super()' because a bit later we anyway call
'ext4_setup_super()' which writes the superblock to the media
unconditionally.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
In some rather rare cases it is possible that ext4 may the superblock
to the media twice. This patch makes sure this does not happen. This
should speed up unmounting in those cases.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Commit a0375156ca cleaned up superblock
dirtying handling, but missed one place. This patch does what was
intended: if we have the journal, then we update the superblock
through the journal rather than doing this directly.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4_punch_hole returns -ENOTSUPP but it should be using -EOPNOTSUPP
Signed-off-by: Allison Henderson <achender@linux.vnet.ibm.com>
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
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>
Currently if the range to trim is too small, for example on 1K fs
the request to trim the first block, then the 'range->len' is not set
reporting wrong number of discarded block to the caller.
Fix this by always setting the 'range->len' before we return. Note that
when there is a failure (-EINVAL) caller can not depend on 'range->len'
being set properly.
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Currently when there is not enough free blocks in the block group to
discard (grp->bb_free < minlen) the 'trimmed' is bumped up anyway with
the number of discarded blocks from the previous iteration. Fix this
by bumping up 'trimmed' only if the ext4_trim_all_free() was actually
run.
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The overflow can happen when we are calling get_group_no_and_offset()
which stores the group number in the ext4_grpblk_t type which is
actually int. However when the blocknr is big enough the group number
might be bigger than ext4_grpblk_t resulting in overflow. This will
most likely happen with FITRIM default argument len = ULLONG_MAX.
Fix this by using "end" variable instead of "start+len" as it is easier
to get right and specifically check that the end is not beyond the end
of the file system, so we are sure that the result of
get_group_no_and_offset() will not overflow. Otherwise truncate it to
the size of the file system.
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
When we're doing an online resize of an ext4 filesystem, we need to
update the free inode and block counts in the superblock so that fsck
doesn't complain.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Using KERN_CONT means that messages from multiple threads may be
interleaved. Avoid this by using a single printk call in
ext4_error_inode and ext4_error_file.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The functions ext4_msg() and ext4_error() already tack on a trailing
newline, so remove the unnecessary extra newline.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Add argument validation to debug functions.
Use ##__VA_ARGS__.
Fix format and argument mismatches.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4_msg adds "EXT4-fs: " to the messsage output.
Remove the redundant bits from uses.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
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>
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>
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>
Traditionally ext2/3/4 has returned a 32-bit hash value from llseek()
to appease NFSv2, which can only handle a 32-bit cookie for seekdir()
and telldir(). However, this causes problems if there are 32-bit hash
collisions, since the NFSv2 server can get stuck resending the same
entries from the directory repeatedly.
Allow ext4 to return a full 64-bit hash (both major and minor) for
telldir to decrease the chance of hash collisions. This still needs
integration on the NFS side.
Patch-updated-by: Bernd Schubert <bernd.schubert@itwm.fraunhofer.de>
(blame me if something is not correct)
Signed-off-by: Fan Yong <yong.fan@whamcloud.com>
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Signed-off-by: Bernd Schubert <bernd.schubert@itwm.fraunhofer.de>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
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
This should make it more clear what this structure is used
for, and how some of the (mutually exclusive) fields are
used to keep page cache references.
Signed-off-by: Curt Wohlgemuth <curtw@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
We can clear PageWriteback on each page when the IO
completes, but we can't release the references on the page
until we convert any uninitialized extents.
Without this patch, the use of the dioread_nolock mount
option can break buffered writes, because extents may
not be converted by the time a subsequent buffered read
comes in; if the page is not in the page cache, a read
will return zeros if the extent is still uninitialized.
I tested this with a (temporary) patch that adds a call
to msleep(1000) at the start of ext4_end_io_work(), to delay
processing of each DIO-unwritten work queue item. With this
msleep(), a simple workload of
fallocate
write
fadvise
read
will fail without this patch, succeeds with it.
Signed-off-by: Curt Wohlgemuth <curtw@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The following command line will leave the aio-stress process unkillable
on an ext4 file system (in my case, mounted on /mnt/test):
aio-stress -t 20 -s 10 -O -S -o 2 -I 1000 /mnt/test/aiostress.3561.4 /mnt/test/aiostress.3561.4.20 /mnt/test/aiostress.3561.4.19 /mnt/test/aiostress.3561.4.18 /mnt/test/aiostress.3561.4.17 /mnt/test/aiostress.3561.4.16 /mnt/test/aiostress.3561.4.15 /mnt/test/aiostress.3561.4.14 /mnt/test/aiostress.3561.4.13 /mnt/test/aiostress.3561.4.12 /mnt/test/aiostress.3561.4.11 /mnt/test/aiostress.3561.4.10 /mnt/test/aiostress.3561.4.9 /mnt/test/aiostress.3561.4.8 /mnt/test/aiostress.3561.4.7 /mnt/test/aiostress.3561.4.6 /mnt/test/aiostress.3561.4.5 /mnt/test/aiostress.3561.4.4 /mnt/test/aiostress.3561.4.3 /mnt/test/aiostress.3561.4.2
This is using the aio-stress program from the xfstests test suite.
That particular command line tells aio-stress to do random writes to
20 files from 20 threads (one thread per file). The files are NOT
preallocated, so you will get writes to random offsets within the
file, thus creating holes and extending i_size. It also opens the
file with O_DIRECT and O_SYNC.
On to the problem. When an I/O requires unwritten extent conversion,
it is queued onto the completed_io_list for the ext4 inode. Two code
paths will pull work items from this list. The first is the
ext4_end_io_work routine, and the second is ext4_flush_completed_IO,
which is called via the fsync path (and O_SYNC handling, as well).
There are two issues I've found in these code paths. First, if the
fsync path beats the work routine to a particular I/O, the work
routine will free the io_end structure! It does not take into account
the fact that the io_end may still be in use by the fsync path. I've
fixed this issue by adding yet another IO_END flag, indicating that
the io_end is being processed by the fsync path.
The second problem is that the work routine will make an assignment to
io->flag outside of the lock. I have witnessed this result in a hang
at umount. Moving the flag setting inside the lock resolved that
problem.
The problem was introduced by commit b82e384c7b ("ext4: optimize
locking for end_io extent conversion"), which first appeared in 3.2.
As such, the fix should be backported to that release (probably along
with the unwritten extent conversion race fix).
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
CC: stable@kernel.org
For extent-based files, you can perform DIO to holes, as mentioned in
the comments in ext4_ext_direct_IO. However, that function passes
DIO_SKIP_HOLES to __blockdev_direct_IO, which is *really* confusing to
the uninitiated reader. The key, here, is that the get_block function
passed in, ext4_get_block_write, completely ignores the create flag
that is passed to it (the create flag is passed in from the direct I/O
code, which uses the DIO_SKIP_HOLES flag to determine whether or not
it should be cleared).
This is a long-winded way of saying that the DIO_SKIP_HOLES flag is
ultimately ignored. So let's remove it.
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
No other file system allows ACL's and extended attributes to be
enabled or disabled via a mount option. So let's try to deprecate
these options from ext4.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Users who tried to use the ext4 file system driver is being used for
the ext2 or ext3 file systems (via the CONFIG_EXT4_USE_FOR_EXT23
option) could have failed mounts if their /etc/fstab contains options
recognized by ext2 or ext3 but which have since been removed in ext4.
So teach ext4 to recognize them and give a warning that the mount
option was removed.
Report: https://bbs.archlinux.org/profile.php?id=33804
Signed-off-by: Tom Gundersen <teg@jklm.no>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Thomas Baechler <thomas@archlinux.org>
Cc: Tobias Powalowski <tobias.powalowski@googlemail.com>
Cc: Dave Reisner <d@falconindy.com>
