This is for Red Hat bug 490026: EXT4 panic, list corruption in
ext4_mb_new_inode_pa
ext4_lock_group(sb, group) is supposed to protect this list for
each group, and a common code flow to remove an album is like
this:
ext4_get_group_no_and_offset(sb, pa->pa_pstart, &grp, NULL);
ext4_lock_group(sb, grp);
list_del(&pa->pa_group_list);
ext4_unlock_group(sb, grp);
so it's critical that we get the right group number back for
this prealloc context, to lock the right group (the one
associated with this pa) and prevent concurrent list manipulation.
however, ext4_mb_put_pa() passes in (pa->pa_pstart - 1) with a
comment, "-1 is to protect from crossing allocation group".
This makes sense for the group_pa, where pa_pstart is advanced
by the length which has been used (in ext4_mb_release_context()),
and when the entire length has been used, pa_pstart has been
advanced to the first block of the next group.
However, for inode_pa, pa_pstart is never advanced; it's just
set once to the first block in the group and not moved after
that. So in this case, if we subtract one in ext4_mb_put_pa(),
we are actually locking the *previous* group, and opening the
race with the other threads which do not subtract off the extra
block.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Add a mount option which allows the user to disable automatic
allocation of blocks whose allocation by delayed allocation when the
file was originally truncated or when the file is renamed over an
existing file. This feature is intended to save users from the
effects of naive application writers, but it reduces the effectiveness
of the delayed allocation code. This mount option disables this
safety feature, which may be desirable for prodcutions systems where
the risk of unclean shutdowns or unexpected system crashes is low.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Thiemo Nagel reported that:
# dd if=/dev/zero of=image.ext4 bs=1M count=2
# mkfs.ext4 -v -F -b 1024 -m 0 -g 512 -G 4 -I 128 -N 1 \
-O large_file,dir_index,flex_bg,extent,sparse_super image.ext4
# mount -o loop image.ext4 mnt/
# dd if=/dev/zero of=mnt/file
oopsed, with a BUG_ON in ext4_mb_normalize_request because
size == EXT4_BLOCKS_PER_GROUP
It appears to me (esp. after talking to Andreas) that the BUG_ON
is bogus; a request of exactly EXT4_BLOCKS_PER_GROUP should
be allowed, though larger sizes do indicate a problem.
Fix that an another (apparently rare) codepath with a similar check.
Reported-by: Thiemo Nagel <thiemo.nagel@ph.tum.de>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This is a short-term warning, and even printk_ratelimit() can result
in too much noise in system logs. So only print it once as a warning.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The ext4_ext_search_right() function is confusing; it uses a
"depth" variable which is 0 at the root and maximum at the leaves,
but the on-disk metadata uses a "depth" (actually eh_depth) which
is opposite: maximum at the root, and 0 at the leaves.
The ext4_ext_check_header() function is given a depth and checks
the header agaisnt that depth; it expects the on-disk semantics,
but we are giving it the opposite in the while loop in this
function. We should be giving it the on-disk notion of "depth"
which we can get from (p_depth - depth) - and if you look, the last
(more commonly hit) call to ext4_ext_check_header() does just this.
Sending in the wrong depth results in (incorrect) messages
about corruption:
EXT4-fs error (device sdb1): ext4_ext_search_right: bad header
in inode #2621457: unexpected eh_depth - magic f30a, entries 340,
max 340(0), depth 1(2)
http://bugzilla.kernel.org/show_bug.cgi?id=12821
Reported-by: David Dindorp <ddi@dubex.dk>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Instead of looping over all of the block groups in a flex group
summing their summary statistics, start tracking used_dirs in struct
flex_groups, and use struct flex_groups instead. This should save a
bit of CPU for mkdir-heavy workloads.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reduce pressure on the sb_bgl_lock family of locks by using atomic_t's
to track the number of free blocks and inodes in each flex_group.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Remove tuning knobs in /proc/fs/ext4/<dev/* since they have been
replaced by knobs in sysfs at /sys/fs/ext4/<dev>/*.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Add basic sysfs support so that information about the mounted
filesystem and various tuning parameters can be accessed via
/sys/fs/ext4/<dev>/*.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
I was seeing fsck errors on inode bitmaps after a 4 thread
dbench run on a 4 cpu machine:
Inode bitmap differences: -50736 -(50752--50753) etc...
I believe that this is because ext4_free_inode() uses atomic
bitops, and although ext4_new_inode() *used* to also use atomic
bitops for synchronization, commit
393418676a changed this to use
the sb_bgl_lock, so that we could also synchronize against
read_inode_bitmap and initialization of uninit inode tables.
However, that change left ext4_free_inode using atomic bitops,
which I think leaves no synchronization between setting &
unsetting bits in the inode table.
The below patch fixes it for me, although I wonder if we're
getting at all heavy-handed with this spinlock...
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Add a new superblock value which tracks the lifetime amount of writes
to the filesystem. This is useful in estimating the amount of wear on
solid state drives (SSD's) caused by writes to the filesystem.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
With delayed allocation we should not/cannot discard inode prealloc
space during file close. We would still have dirty pages for which we
haven't allocated blocks yet. With this fix after each get_blocks
request we check whether we have zero reserved blocks and if yes and
we don't have any writers on the file we discard inode prealloc space.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Running without a journal, I oopsed when I ran out of space,
because we called jbd2_journal_force_commit_nested() from
ext4_should_retry_alloc() without a journal.
This should take care of it, I think.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Commit c4be0c1d added error checking to ext4_freeze() when calling
ext4_commit_super(). Unfortunately the patch failed to remove the
original call to ext4_commit_super(), with the net result that when
freezing the filesystem, the superblock gets written twice, the first
time without error checking.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
When renaming a file such that a link to another inode is overwritten,
force any delay allocated blocks that to be allocated so that if the
filesystem is mounted with data=ordered, the data blocks will be
pushed out to disk along with the journal commit. Many application
programs expect this, so we do this to avoid zero length files if the
system crashes unexpectedly.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
When closing a file that had been previously truncated, force any
delay allocated blocks that to be allocated so that if the filesystem
is mounted with data=ordered, the data blocks will be pushed out to
disk along with the journal commit. Many application programs expect
this, so we do this to avoid zero length files if the system crashes
unexpectedly.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Add an ioctl which forces all of the delay allocated blocks to be
allocated. This also provides a function ext4_alloc_da_blocks() which
will be used by the following commits to force files to be fully
allocated to preserve application-expected ext3 behaviour.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The mpage_da_writepages() function is only used in one place, so
inline it to simplify the call stack and make the code easier to
understand.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Struct mpage_da_data and mpage_add_bh_to_extent() use a fake struct
buffer_head which is 104 bytes on an x86_64 system, but only use 24
bytes of the structure. On systems that use a spinlock for atomic_t,
the stack savings will be even greater.
It turns out that using a fake struct buffer_head doesn't even save
that much code, and it makes the code more confusing since it's not
used as a "real" buffer head. So just store pass b_size and b_state
in mpage_add_bh_to_extent(), and store b_size, b_state, and b_block_nr
in the mpage_da_data structure.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Make sure we validate extent details only when read from the disk.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Thiemo Nagel <thiemo.nagel@ph.tum.de>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This patch adds checks to validate the extent entries along with extent
headers, to avoid crashes caused by corrupt filesystems.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4_iget() returns -ESTALE if invoked on a deleted inode, in order to
report errors to NFS properly. However, in ext4_lookup(), this
-ESTALE can be propagated to userspace if the filesystem is corrupted
such that a directory entry references a deleted inode. This leads to
a misleading error message - "Stale NFS file handle" - and confusion
on the part of the admin.
The bug can be easily reproduced by creating a new filesystem, making
a link to an unused inode using debugfs, then mounting and attempting
to ls -l said link.
This patch thus changes ext4_lookup to return -EIO if it receives
-ESTALE from ext4_iget(), as ext4 does for other filesystem metadata
corruption; and also invokes the appropriate ext*_error functions when
this case is detected.
Signed-off-by: Bryan Donlan <bdonlan@gmail.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The find_group_flex() inode allocator is now only used if the
filesystem is mounted using the "oldalloc" mount option. It is
replaced with the original Orlov allocator that has been updated for
flex_bg filesystems (it should behave the same way if flex_bg is
disabled). The inode allocator now functions by taking into account
each flex_bg group, instead of each block group, when deciding whether
or not it's time to allocate a new directory into a fresh flex_bg.
The block allocator has also been changed so that the first block
group in each flex_bg is preferred for use for storing directory
blocks. This keeps directory blocks close together, which is good for
speeding up e2fsck since large directories are more likely to look
like this:
debugfs: stat /home/tytso/Maildir/cur
Inode: 1844562 Type: directory Mode: 0700 Flags: 0x81000
Generation: 1132745781 Version: 0x00000000:0000ad71
User: 15806 Group: 15806 Size: 1060864
File ACL: 0 Directory ACL: 0
Links: 2 Blockcount: 2072
Fragment: Address: 0 Number: 0 Size: 0
ctime: 0x499c0ff4:164961f4 -- Wed Feb 18 08:41:08 2009
atime: 0x499c0ff4:00000000 -- Wed Feb 18 08:41:08 2009
mtime: 0x49957f51:00000000 -- Fri Feb 13 09:10:25 2009
crtime: 0x499c0f57:00d51440 -- Wed Feb 18 08:38:31 2009
Size of extra inode fields: 28
BLOCKS:
(0):7348651, (1-258):7348654-7348911
TOTAL: 259
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Functions ext4_write_begin() and ext4_da_write_begin() call
grab_cache_page_write_begin() without AOP_FLAG_NOFS. Thus it
can happen that page reclaim is triggered in that function
and it recurses back into the filesystem (or some other filesystem).
But this can lead to various problems as a transaction is already
started at that point. Add the necessary flag.
http://bugzilla.kernel.org/show_bug.cgi?id=11688
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This is a workaround for find_group_flex() which badly needs to be
replaced. One of its problems (besides ignoring the Orlov algorithm)
is that it is a bit hyperactive about returning failure under
suspicious circumstances. This can lead to spurious ENOSPC failures
even when there are inodes still available.
Work around this for now by retrying the search using
find_group_other() if find_group_flex() returns -1. If
find_group_other() succeeds when find_group_flex() has failed, log a
warning message.
A better block/inode allocator that will fix this problem for real has
been queued up for the next merge window.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This was found through a code checker (http://repo.or.cz/w/smatch.git/).
It looks like you might be able to trigger the error by trying to migrate
a readonly file system.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
At the moment there are few restrictions on which flags may be set on
which inodes. Specifically DIRSYNC may only be set on directories and
IMMUTABLE and APPEND may not be set on links. Tighten that to disallow
TOPDIR being set on non-directories and only NODUMP and NOATIME to be set
on non-regular file, non-directories.
Introduces a flags masking function which masks flags based on mode and
use it during inode creation and when flags are set via the ioctl to
facilitate future consistency.
Signed-off-by: Duane Griffin <duaneg@dghda.com>
Acked-by: Andreas Dilger <adilger@sun.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
At present INDEX and EXTENTS are the only flags that new ext4 inodes do
NOT inherit from their parent. In addition prevent the flags DIRTY,
ECOMPR, IMAGIC, TOPDIR, HUGE_FILE and EXT_MIGRATE from being inherited.
List inheritable flags explicitly to prevent future flags from
accidentally being inherited.
This fixes the TOPDIR flag inheritance bug reported at
http://bugzilla.kernel.org/show_bug.cgi?id=9866.
Signed-off-by: Duane Griffin <duaneg@dghda.com>
Acked-by: Andreas Dilger <adilger@sun.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
As spotted by kmemtrace, struct ext4_sb_info is 17664 bytes on 64-bit
which makes it a very bad fit for SLAB allocators. The culprit of the
wasted memory is ->s_blockgroup_lock which can be as big as 16 KB when
NR_CPUS >= 32.
To fix that, allocate ->s_blockgroup_lock, which fits nicely in a order 2
page in the worst case, separately. This shinks down struct ext4_sb_info
enough to fit a 2 KB slab cache so now we allocate 16 KB + 2 KB instead of
32 KB saving 14 KB of memory.
Acked-by: Andreas Dilger <adilger@sun.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The rec_len field in the directory entry is 16 bits, so to encode
blocksizes larger than 64k becomes problematic. This patch allows us
to supprot block sizes up to 256k, by using the low 2 bits to extend
the range of rec_len to 2**18-1 (since valid rec_len sizes must be a
multiple of 4). We use the convention that a rec_len of 0 or 65535
means the filesystem block size, for compatibility with older kernels.
It's unlikely we'll see VM pages of up to 256k, but at some point we
might find that the Linux VM has been enhanced to support filesystem
block sizes > than the VM page size, at which point it might be useful
for some applications to allow very large filesystem block sizes.
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
With delayed allocation we lock the page in write_cache_pages() and
try to build an in memory extent of contiguous blocks. This is needed
so that we can get large contiguous blocks request. If range_cyclic
mode is enabled, write_cache_pages() will loop back to the 0 index if
no I/O has been done yet, and try to start writing from the beginning
of the range. That causes an attempt to take the page lock of lower
index page while holding the page lock of higher index page, which can
cause a dead lock with another writeback thread.
The solution is to implement the range_cyclic behavior in
ext4_da_writepages() instead.
http://bugzilla.kernel.org/show_bug.cgi?id=12579
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
When creating a new ext4_prealloc_space structure, we have to
initialize its list_head pointers before we add them to any prealloc
lists. Otherwise, with list debug enabled, we will get list
corruption warnings.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The rec_len field in the directory entry is 16 bits, so there was a
problem representing rec_len for filesystems with a 64k block size in
the case where the directory entry takes the entire 64k block.
Unfortunately, there were two schemes that were proposed; one where
all zeros meant 65536 and one where all ones (65535) meant 65536.
E2fsprogs used 0, whereas the kernel used 65535. Oops. Fortunately
this case happens extremely rarely, with the most common case being
the lost+found directory, created by mke2fs.
So we will be liberal in what we accept, and accept both encodings,
but we will continue to encode 65536 as 65535. This will require a
change in e2fsprogs, but with fortunately ext4 filesystems normally
have the dir_index feature enabled, which precludes having a
completely empty directory block.
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
If we race with commit code setting i_transaction to NULL, we could
possibly dereference it. Proper locking requires the journal pointer
(to access journal->j_list_lock), which we don't have. So we have to
change the prototype of the function so that filesystem passes us the
journal pointer. Also add a more detailed comment about why the
function jbd2_journal_begin_ordered_truncate() does what it does and
how it should be used.
Thanks to Dan Carpenter <error27@gmail.com> for pointing to the
suspitious code.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Acked-by: Joel Becker <joel.becker@oracle.com>
CC: linux-ext4@vger.kernel.org
CC: ocfs2-devel@oss.oracle.com
CC: mfasheh@suse.de
CC: Dan Carpenter <error27@gmail.com>
This undoes commit 14ce0cb411.
Since jbd2_journal_start_commit() is now fixed to return 1 when we
started a transaction commit, there's some transaction waiting to be
committed or there's a transaction already committing, we don't
need to call ext4_force_commit() in ext4_sync_fs(). Furthermore
ext4_force_commit() can unnecessarily create sync transaction which is
expensive so it's worthwhile to remove it when we can.
http://bugzilla.kernel.org/show_bug.cgi?id=12224
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Eric Sandeen <sandeen@redhat.com>
Cc: linux-ext4@vger.kernel.org
The static function ext4_group_used_meta_blocks() only has one caller,
who already has access to the block group's group descriptor. So it's
better to have ext4_init_block_bitmap() pass the group descriptor to
ext4_group_used_meta_blocks(), so it doesn't need to call
ext4_group_desc(). Previously this function did not check if
ext4_group_desc() returned NULL due to an error, potentially causing a
kernel OOPS report. This avoids the issue entirely.
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Remove some leftovers from when the old block allocator was removed
(c2ea3fde). ext4_sb_info is now a bit lighter. Also remove a dangling
read_block_bitmap() prototype.
Signed-off-by: Mike Snitzer <snitzer@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The code to support journal-less ext4 operation added a BUG to
ext4_bmap() which fired if there was no journal and the
EXT4_STATE_JDATA bit was set in the i_state field. This caused
running the filefrag program (which uses the FIMBAP ioctl) to trigger
a BUG().
The EXT4_STATE_JDATA bit is only used for ext4_bmap(), and it's
harmless for the bit to be set. We could add a check in
__ext4_journalled_writepage() and ext4_journalled_write_end() to only
set the EXT4_STATE_JDATA bit if the journal is present, but that adds
an extra test and jump instruction. It's easier to simply remove the
BUG check.
http://bugzilla.kernel.org/show_bug.cgi?id=12568
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
When bg_free_blocks_count was renamed to bg_free_blocks_count_lo in
560671a0, its uses under EXT4FS_DEBUG were not changed to the helper
ext4_free_blks_count.
Another commit, 498e5f24, also did not change everything needed under
EXT4FS_DEBUG, thus making it spill some warnings related to printing
format.
This commit fixes both issues and makes ext4 build again when
EXT4FS_DEBUG is enabled.
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Make sure all of the fields of the group descriptor are properly
initialized. Previously, we allowed bg_flags field to be contain
random garbage, which could trigger non-deterministic behavior,
including a kernel OOPS.
http://bugzilla.kernel.org/show_bug.cgi?id=12433
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
When trying to unlink a file with indirect blocks on a filesystem
without a journal, the "circular indirect block" sanity test was
getting falsely triggered.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Make sure the rec_len field in the '..' entry is sane, lest we overrun
the directory block and cause a kernel oops on a purposefully
corrupted filesystem.
Thanks to Sami Liedes for reporting this bug.
http://bugzilla.kernel.org/show_bug.cgi?id=12430
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
Directories are not allowed to be bigger than 2GB, so don't use
i_size_high for anything other than regular files. E2fsck should
complain about these inodes, but the simplest thing to do for the
kernel is to only use i_size_high for regular files.
This prevents an intentially corrupted filesystem from causing the
kernel to burn a huge amount of CPU and issuing error messages such
as:
EXT4-fs warning (device loop0): ext4_block_to_path: block 135090028 > max
Thanks to David Maciejak from Fortinet's FortiGuard Global Security
Research Team for reporting this issue.
http://bugzilla.kernel.org/show_bug.cgi?id=12375
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
Currently, ext3 in mainline Linux doesn't have the freeze feature which
suspends write requests. So, we cannot take a backup which keeps the
filesystem's consistency with the storage device's features (snapshot and
replication) while it is mounted.
In many case, a commercial filesystem (e.g. VxFS) has the freeze feature
and it would be used to get the consistent backup.
If Linux's standard filesystem ext3 has the freeze feature, we can do it
without a commercial filesystem.
So I have implemented the ioctls of the freeze feature.
I think we can take the consistent backup with the following steps.
1. Freeze the filesystem with the freeze ioctl.
2. Separate the replication volume or create the snapshot
with the storage device's feature.
3. Unfreeze the filesystem with the unfreeze ioctl.
4. Take the backup from the separated replication volume
or the snapshot.
This patch:
VFS:
Changed the type of write_super_lockfs and unlockfs from "void"
to "int" so that they can return an error.
Rename write_super_lockfs and unlockfs of the super block operation
freeze_fs and unfreeze_fs to avoid a confusion.
ext3, ext4, xfs, gfs2, jfs:
Changed the type of write_super_lockfs and unlockfs from "void"
to "int" so that write_super_lockfs returns an error if needed,
and unlockfs always returns 0.
reiserfs:
Changed the type of write_super_lockfs and unlockfs from "void"
to "int" so that they always return 0 (success) to keep a current behavior.
Signed-off-by: Takashi Sato <t-sato@yk.jp.nec.com>
Signed-off-by: Masayuki Hamaguchi <m-hamaguchi@ys.jp.nec.com>
Cc: <xfs-masters@oss.sgi.com>
Cc: <linux-ext4@vger.kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Alasdair G Kergon <agk@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (57 commits)
jbd2: Fix oops in jbd2_journal_init_inode() on corrupted fs
ext4: Remove "extents" mount option
block: Add Kconfig help which notes that ext4 needs CONFIG_LBD
ext4: Make printk's consistently prefixed with "EXT4-fs: "
ext4: Add sanity checks for the superblock before mounting the filesystem
ext4: Add mount option to set kjournald's I/O priority
jbd2: Submit writes to the journal using WRITE_SYNC
jbd2: Add pid and journal device name to the "kjournald2 starting" message
ext4: Add markers for better debuggability
ext4: Remove code to create the journal inode
ext4: provide function to release metadata pages under memory pressure
ext3: provide function to release metadata pages under memory pressure
add releasepage hooks to block devices which can be used by file systems
ext4: Fix s_dirty_blocks_counter if block allocation failed with nodelalloc
ext4: Init the complete page while building buddy cache
ext4: Don't allow new groups to be added during block allocation
ext4: mark the blocks/inode bitmap beyond end of group as used
ext4: Use new buffer_head flag to check uninit group bitmaps initialization
ext4: Fix the race between read_inode_bitmap() and ext4_new_inode()
ext4: code cleanup
...
When I review ocfs2 code, find there are 2 typos to "successfull". After
doing grep "successfull " in kernel tree, 22 typos found totally -- great
minds always think alike :)
This patch fixes all the similar typos. Thanks for Randy's ack and comments.
Signed-off-by: Coly Li <coyli@suse.de>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Roland Dreier <rolandd@cisco.com>
Cc: Jeremy Kerr <jk@ozlabs.org>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Vlad Yasevich <vladislav.yasevich@hp.com>
Cc: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For NR_CPUS >= 16 values, FBC_BATCH is 2*NR_CPUS
Considering more and more distros are using high NR_CPUS values, it makes
sense to use a more sensible value for FBC_BATCH, and get rid of NR_CPUS.
A sensible value is 2*num_online_cpus(), with a minimum value of 32 (This
minimum value helps branch prediction in __percpu_counter_add())
We already have a hotcpu notifier, so we can adjust FBC_BATCH dynamically.
We rename FBC_BATCH to percpu_counter_batch since its not a constant
anymore.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This mount option is largely superfluous, and in fact the way it was
implemented was buggy; if a filesystem which did not have the extents
feature flag was mounted -o extents, the filesystem would attempt to
create and use extents-based file even though the extents feature flag
was not eabled. The simplest thing to do is to nuke the mount option
entirely. It's not all that useful to force the non-creation of new
extent-based files if the filesystem can support it.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Previously, some were "ext4: ", and some were "EXT4: "; change them to
be consistent with most ext4 printk's, which is to use "EXT4-fs: ".
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This avoids insane superblock configurations that could lead to kernel
oops due to null pointer derefences.
http://bugzilla.kernel.org/show_bug.cgi?id=12371
Thanks to David Maciejak at Fortinet's FortiGuard Global Security
Research Team who discovered this bug independently (but at
approximately the same time) as Thiemo Nagel, who submitted the patch.
Signed-off-by: Thiemo Nagel <thiemo.nagel@ph.tum.de>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
With the write_begin/write_end aops, page_symlink was broken because it
could no longer pass a GFP_NOFS type mask into the point where the
allocations happened. They are done in write_begin, which would always
assume that the filesystem can be entered from reclaim. This bug could
cause filesystem deadlocks.
The funny thing with having a gfp_t mask there is that it doesn't really
allow the caller to arbitrarily tinker with the context in which it can be
called. It couldn't ever be GFP_ATOMIC, for example, because it needs to
take the page lock. The only thing any callers care about is __GFP_FS
anyway, so turn that into a single flag.
Add a new flag for write_begin, AOP_FLAG_NOFS. Filesystems can now act on
this flag in their write_begin function. Change __grab_cache_page to
accept a nofs argument as well, to honour that flag (while we're there,
change the name to grab_cache_page_write_begin which is more instructive
and does away with random leading underscores).
This is really a more flexible way to go in the end anyway -- if a
filesystem happens to want any extra allocations aside from the pagecache
ones in ints write_begin function, it may now use GFP_KERNEL (rather than
GFP_NOFS) for common case allocations (eg. ocfs2_alloc_write_ctxt, for a
random example).
[kosaki.motohiro@jp.fujitsu.com: fix ubifs]
[kosaki.motohiro@jp.fujitsu.com: fix fuse]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: <stable@kernel.org> [2.6.28.x]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ Cleaned up the calling convention: just pass in the AOP flags
untouched to the grab_cache_page_write_begin() function. That
just simplifies everybody, and may even allow future expansion of the
logic. - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As suggested by Andreas Dilger, introduce a bgl_lock_ptr() helper in
<linux/blockgroup_lock.h> and add separate sb_bgl_lock() helpers to
filesystem specific header files to break the hidden dependency to
struct ext[234]_sb_info.
Also, while at it, convert the macros to static inlines to try make up
for all the times I broke Andrew Morton's tree.
Acked-by: Andreas Dilger <adilger@sun.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This code has been obsolete in quite some time, since the supported
method for adding a journal inode is to use tune2fs (or to creating
new filesystem with a journal via mke2fs or mkfs.ext4).
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Pages in the page cache belonging to ext4 data files are released via
the ext4_releasepage() function specified in the ext4 inode's
address_space_ops. However, metadata blocks (such as indirect blocks,
directory blocks, etc) are managed via the block device
address_space_ops, and they can not be released by
try_to_free_buffers() if they have a journal head attached to them.
To address this, we supply a release_metadata function which calls
jbd2_journal_try_to_free_buffers() function to free the metadata, and
which is called by the block device's blkdev_releasepage() function.
Signed-off-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: linux-fsdevel@vger.kernel.org
With nodelalloc option we need to update the dirty block counter on
block allocation failure. This is needed because we increment the
dirty block counter early in the block allocation phase. Without
the patch s_dirty_blocks_counter goes wrong so that filesystem's
free blocks decreases incorrectly.
Tested-by: Akira Fujita <a-fujita@rs.jp.nec.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
We need to init the complete page during buddy cache init
by setting the contents to '1'. Otherwise we can see the
following errors after doing an online resize of the
filesystem:
EXT4-fs error (device sdb1): ext4_mb_mark_diskspace_used:
Allocating block 1040385 in system zone of 127 group
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
After we mark the blocks in the buddy cache as allocated,
we need to ensure that we don't reinit the buddy cache until
the block bitmap is updated. This commit achieves this by holding
the group_info alloc_semaphore till ext4_mb_release_context
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
We need to mark the block/inode bitmap beyond the end of the group
with '1'.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
For uninit block group, the on-disk bitmap is not initialized. That
implies we cannot depend on the uptodate flag on the bitmap
buffer_head to find bitmap validity. Use a new buffer_head flag which
would be set after we properly initialize the bitmap. This also
prevents (re-)initializing the uninit group bitmap every time we call
ext4_read_block_bitmap().
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
We need to make sure we update the inode bitmap and clear
EXT4_BG_INODE_UNINIT flag with sb_bgl_lock held, since
ext4_read_inode_bitmap() looks at EXT4_BG_INODE_UNINIT to decide
whether to initialize the inode bitmap each time it is called.
(introduced by commit c806e68f.)
ext4_read_inode_bitmap does:
spin_lock(sb_bgl_lock(EXT4_SB(sb), block_group));
if (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
ext4_init_inode_bitmap(sb, bh, block_group, desc);
and ext4_new_inode does
if (!ext4_set_bit_atomic(sb_bgl_lock(sbi, group),
ino, inode_bitmap_bh->b_data))
......
...
spin_lock(sb_bgl_lock(sbi, group));
gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
i.e., on allocation we update the bitmap then we take the sb_bgl_lock
and clear the EXT4_BG_INODE_UNINIT flag. What can happen is a
parallel ext4_read_inode_bitmap can zero out the bitmap in between
the above ext4_set_bit_atomic and spin_lock(sb_bg_lock..)
The race results in below user visible errors
EXT4-fs error (device sdb1): ext4_free_inode: bit already cleared for inode 168449
EXT4-fs warning (device sdb1): ext4_unlink: Deleting nonexistent file ...
EXT4-fs warning (device sdb1): ext4_rmdir: empty directory has too many links ...
# ls -al /mnt/tmp/f/p369/d3/d6/d39/db2/dee/d10f/d3f/l71
ls: /mnt/tmp/f/p369/d3/d6/d39/db2/dee/d10f/d3f/l71: Stale NFS file handle
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
Rename some variables. We also unlock locks in the reverse order we
acquired as a part of cleanup.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Rename the lower bits with suffix _lo and add helper
to access the values. Also rename bg_itable_unused_hi
to bg_pad as in e2fsprogs.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
We need to make sure we update the block bitmap and clear
EXT4_BG_BLOCK_UNINIT flag with sb_bgl_lock held, since
ext4_read_block_bitmap() looks at EXT4_BG_BLOCK_UNINIT to decide
whether to initialize the block bitmap each time it is called
(introduced by commit c806e68f), and this can race with block
allocations in ext4_mb_mark_diskspace_used().
ext4_read_block_bitmap does:
spin_lock(sb_bgl_lock(EXT4_SB(sb), block_group));
if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
ext4_init_block_bitmap(sb, bh, block_group, desc);
Now on the block allocation side we do
mb_set_bits(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group), bitmap_bh->b_data,
ac->ac_b_ex.fe_start, ac->ac_b_ex.fe_len);
....
spin_lock(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group));
if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
ie on allocation we update the bitmap then we take the sb_bgl_lock
and clear the EXT4_BG_BLOCK_UNINIT flag. What can happen is a
parallel ext4_read_block_bitmap can zero out the bitmap in between
the above mb_set_bits and spin_lock(sb_bg_lock..)
The race results in below user visible errors
EXT4-fs error (device sdb1): ext4_mb_release_inode_pa: free 100, pa_free 105
EXT4-fs error (device sdb1): mb_free_blocks: double-free of inode 0's block ..
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
The mballoc code likes to call ext4_error while it is holding locked
block groups. This can causes a scheduling in atomic context BUG. We
can't just unlock the block group and relock it after/if ext4_error
returns since that might result in race conditions in the case where
the filesystem is set to continue after finding errors.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Ensure fast symlink targets are NUL-terminated, even if corrupted
on-disk.
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: adilger@sun.com
Cc: linux-ext4@vger.kernel.org
Signed-off-by: Duane Griffin <duaneg@dghda.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
We have two seperate config entries for large devices/files. One
is CONFIG_LBD that guards just the devices, the other is CONFIG_LSF
that handles large files. This doesn't make a lot of sense, you typically
want both or none. So get rid of CONFIG_LSF and change CONFIG_LBD wording
to indicate that it covers both.
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Revert
commit e8ced39d5e
Author: Mingming Cao <cmm@us.ibm.com>
Date: Fri Jul 11 19:27:31 2008 -0400
percpu_counter: new function percpu_counter_sum_and_set
As described in
revert "percpu counter: clean up percpu_counter_sum_and_set()"
the new percpu_counter_sum_and_set() is racy against updates to the
cpu-local accumulators on other CPUs. Revert that change.
This means that ext4 will be slow again. But correct.
Reported-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mingming Cao <cmm@us.ibm.com>
Cc: <linux-ext4@vger.kernel.org>
Cc: <stable@kernel.org> [2.6.27.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Revert
commit 1f7c14c62c
Author: Mingming Cao <cmm@us.ibm.com>
Date: Thu Oct 9 12:50:59 2008 -0400
percpu counter: clean up percpu_counter_sum_and_set()
Before this patch we had the following:
percpu_counter_sum(): return the percpu_counter's value
percpu_counter_sum_and_set(): return the percpu_counter's value, copying
that value into the central value and zeroing the per-cpu counters before
returning.
After this patch, percpu_counter_sum_and_set() has gone, and
percpu_counter_sum() gets the old percpu_counter_sum_and_set()
functionality.
Problem is, as Eric points out, the old percpu_counter_sum_and_set()
functionality was racy and wrong. It zeroes out counters on "other" cpus,
without holding any locks which will prevent races agaist updates from
those other CPUS.
This patch reverts 1f7c14c62c. This means
that percpu_counter_sum_and_set() still has the race, but
percpu_counter_sum() does not.
Note that this is not a simple revert - ext4 has since started using
percpu_counter_sum() for its dirty_blocks counter as well.
Note that this revert patch changes percpu_counter_sum() semantics.
Before the patch, a call to percpu_counter_sum() will bring the counter's
central counter mostly up-to-date, so a following percpu_counter_read()
will return a close value.
After this patch, a call to percpu_counter_sum() will leave the counter's
central accumulator unaltered, so a subsequent call to
percpu_counter_read() can now return a significantly inaccurate result.
If there is any code in the tree which was introduced after
e8ced39d5e was merged, and which depends
upon the new percpu_counter_sum() semantics, that code will break.
Reported-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mingming Cao <cmm@us.ibm.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In ext4_mb_init_group(), if the filesystem block size is less than
PAGE_SIZE/2, the code tries to grab alloc_sem for multiple block
groups in a loop. We need to allow for this by using
down_write_nested() and passing in the loop index as a lock subclass
number. This works because no other code path needs to take multiple
alloc_sem's. Note that lockdep will fail for filesystem blocksize
smaller than to PAGE_SIZE/16k. (e.g., a 1k filesystem blocksize with
a 32k page size, or a 2k filesystem blocksize with a 64k blocksize,
etc.)
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
When we generate buddy cache (especially during resize) we need to
make sure we don't use the blocks freed but not yet comitted. This
makes sure we have the right value of free blocks count in the group
info and also in the bitmap. This also ensures the ordered mode
consistency
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
Conflicts:
security/keys/internal.h
security/keys/process_keys.c
security/keys/request_key.c
Fixed conflicts above by using the non 'tsk' versions.
Signed-off-by: James Morris <jmorris@namei.org>
Wrap access to task credentials so that they can be separated more easily from
the task_struct during the introduction of COW creds.
Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id().
Change some task->e?[ug]id to task_e?[ug]id(). In some places it makes more
sense to use RCU directly rather than a convenient wrapper; these will be
addressed by later patches.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: adilger@sun.com
Cc: linux-ext4@vger.kernel.org
Signed-off-by: James Morris <jmorris@namei.org>
When initializing an uninitialized block group in ext4_new_inode(),
its block group checksum must be re-calculated. This fixes a race
when several threads try to allocate a new inode in an UNINIT'd group.
There is some question whether we need to be initializing the block
bitmap in ext4_new_inode() at all, but for now, if we are going to
init the block group, let's eliminate the race.
Signed-off-by: Frederic Bohe <frederic.bohe@bull.net>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
We need to make sure we mark the buffer_heads as dirty and uptodate
so that block_write_full_page write them correctly.
This fixes mmap corruptions that can occur in low memory situations.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Move some of the forward declaration of the static functions
to mballoc.c where they are used. This enables us to include
mballoc.h in other .c files. Also correct the buddy cache
documentation.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The new groups added during resize are flagged as
need_init group. Make sure we properly initialize these
groups. When we have block size < page size and we are adding
new groups the page may still be marked uptodate even though
we haven't initialized the group. While forcing the init
of buddy cache we need to make sure other groups part of the
same page of buddy cache is not using the cache.
group_info->alloc_sem is added to ensure the same.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
cc: stable@kernel.org
With this change new blocks added during resize
are marked as free in the block bitmap and the
group is flagged with EXT4_GROUP_INFO_NEED_INIT_BIT
flag. This makes sure when mballoc tries to allocate
blocks from the new group we would reload the
buddy information using the bitmap present in the disk.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
* Change EXT4_HAS_*_FEATURE to return a boolean
* Add a function prototype for ext4_fiemap() in ext4.h
* Make ext4_ext_fiemap_cb() and ext4_xattr_fiemap() be static functions
* Add lock annotations to mb_free_blocks()
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This fixes a 2.6.27 regression which was introduced in commit a02908f1.
We weren't passing the chunk parameter down to the two subections,
ext4_indirect_trans_blocks() and ext4_ext_index_trans_blocks(), with
the result that massively overestimate the amount of credits needed by
ext4_da_writepages, especially in the non-extents case. This causes
failures especially on /boot partitions, which tend to be small and
non-extent using since GRUB doesn't handle extents.
This patch fixes the bug reported by Joseph Fannin at:
http://bugzilla.kernel.org/show_bug.cgi?id=11964
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Convert the unsigned longs that are most responsible for bloating the
stack usage on 64-bit systems.
Nearly all places in the ext3/4 code which uses "unsigned long" is
probably a bug, since on 32-bit systems a ulong a 32-bits, which means
we are wasting stack space on 64-bit systems.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Nearly all places in the ext3/4 code which uses "unsigned long" is
probably a bug, since on 32-bit systems a ulong a 32-bits, which means
we are wasting stack space on 64-bit systems.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The i_ext_generation was incremented, but never used. Remove it to
slim down the ext4_inode_info structure.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Add new mount options, min_batch_time and max_batch_time, which
controls how long the jbd2 layer should wait for additional filesystem
operations to get batched with a synchronous write transaction.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
We can call ext4_mb_check_limits even after successfully allocating
the requested blocks. In that case, make sure we don't overwrite
ac_status if it already has the status AC_STATUS_FOUND. This fixes
the lockdep warning:
=============================================
[ INFO: possible recursive locking detected ]
2.6.28-rc6-autokern1 #1
---------------------------------------------
fsstress/11948 is trying to acquire lock:
(&meta_group_info[i]->alloc_sem){----}, at: [<c04d9a49>] ext4_mb_load_buddy+0x9f/0x278
.....
stack backtrace:
.....
[<c04db974>] ext4_mb_regular_allocator+0xbb5/0xd44
.....
but task is already holding lock:
(&meta_group_info[i]->alloc_sem){----}, at: [<c04d9a49>] ext4_mb_load_buddy+0x9f/0x278
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
This removes annoying blank syslog entries emitted by ext4_error() or
ext4_warning(), since these functions add their own newline.
Signed-off-by: Nick Warne <nick@ukfsn.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
A few weeks ago I posted a patch for discussion that allowed ext4 to run
without a journal. Since that time I've integrated the excellent
comments from Andreas and fixed several serious bugs. We're currently
running with this patch and generating some performance numbers against
both ext2 (with backported reservations code) and ext4 with and without
a journal. It just so happens that running without a journal is
slightly faster for most everything.
We did
iozone -T -t 4 s 2g -r 256k -T -I -i0 -i1 -i2
which creates 4 threads, each of which create and do reads and writes on
a 2G file, with a buffer size of 256K, using O_DIRECT for all file opens
to bypass the page cache. Results:
ext2 ext4, default ext4, no journal
initial writes 13.0 MB/s 15.4 MB/s 15.7 MB/s
rewrites 13.1 MB/s 15.6 MB/s 15.9 MB/s
reads 15.2 MB/s 16.9 MB/s 17.2 MB/s
re-reads 15.3 MB/s 16.9 MB/s 17.2 MB/s
random readers 5.6 MB/s 5.6 MB/s 5.7 MB/s
random writers 5.1 MB/s 5.3 MB/s 5.4 MB/s
So it seems that, so far, this was a useful exercise.
Signed-off-by: Frank Mayhar <fmayhar@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
I chased the cause of following ext4 oops report which is tested on
ia64 box.
http://bugzilla.kernel.org/show_bug.cgi?id=12018
The cause is the size of s_mb_maxs array that is defined as "unsigned
short" in ext4_sb_info structure. If the file system's block size is
8k or greater, an unsigned short is not wide enough to contain the
value fs->blocksize << 3.
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Miao Xie <miaox@cn.fujitsu.com>
Cc: stable@kernel.org
The inode table has been zeroed in setup_new_group_blocks(). Mark it as
such in ext4_group_add(). Since we are currently clearing inode table
for the new block group, we should set the EXT4_BG_INODE_ZEROED flag.
If at some point in the future we don't immediately zero out the inode
table as part of the resize operation, then obviously we shouldn't do
this.
Signed-off-by: Solofo.Ramangalahy@bull.net
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Remove some completely unneeded code which which caused an ext4_error
to be generated when mounting a file system with only a single block
group.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
When iterating through the pages which have mapped buffer_heads, we
failed to update the b_state value. This results in allocating blocks
at logical offset 0.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
If the filesystem has errors, ext4_da_writepages() will return a *lot*
of errors, including lots and lots of stack dumps. While it's true
that we are dropping user data on the floor, which is unfortunate, the
stack dumps aren't helpful, and they tend to obscure the true original
root cause of the problem. So in the case where the filesystem has
aborted, return an EROFS right away.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The convenience function do_blk_alloc() is a static function with only
one caller, so fold it into ext4_new_meta_blocks() to simplify the
code and to make it easier to understand.
To save more stack space, if count is a null pointer in
ext4_new_meta_blocks() assume that caller wanted a single block (and
if there is an error, no blocks were allocated).
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
There were only two one callers of the function ext4_new_meta_block(),
which just a very simpler wrapper function around
ext4_new_meta_blocks(). Change those two functions to call
ext4_new_meta_blocks() directly, to save code and stack space usage.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
There was only one caller of the compatibility function
ext4_new_blocks(), in balloc.c's ext4_alloc_blocks(). Change it to
call ext4_mb_new_blocks() directly, and remove ext4_new_blocks()
altogether. This cleans up the code, by removing two extra functions
from the call chain, and hopefully saving some stack usage.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This fixes a gcc warning but it doesn't appear able to result in a
failure, since the primary way the loop is exited is the first
conditional in the for loop, and at least for a consistent filesystem,
the signed/unsigned should in practice never be exposed.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
In ext4_sync_fs, we only wait for a commit to finish if we started it,
but there may be one already in progress which will not be synced.
In the case of a data=ordered umount with pending long symlinks which
are delayed due to a long list of other I/O on the backing block
device, this causes the buffer associated with the long symlinks to
not be moved to the inode dirty list in the second phase of
fsync_super. Then, before they can be dirtied again, kjournald exits,
seeing the UMOUNT flag and the dirty pages are never written to the
backing block device, causing long symlink corruption and exposing new
or previously freed block data to userspace.
To ensure all commits are synced, we flush all journal commits now
when sync_fs'ing ext4.
Signed-off-by: Arthur Jones <ajones@riverbed.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Eric Sandeen <sandeen@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Use le16_to_cpu to read the s_reserved_gdt_blocks values
from super block.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
If we try to free a block which is already freed, the code was
returning without first unlocking the group.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The original ext3 hash algorithms assumed that variables of type char
were signed, as God and K&R intended. Unfortunately, this assumption
is not true on some architectures. Userspace support for marking
filesystems with non-native signed/unsigned chars was added two years
ago, but the kernel-side support was never added (until now).
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
fs/ext4/balloc.c:607: warning: format '%lld' expects type 'long long int', but argument 2 has type 's64'
fs/ext4/inode.c:1822: warning: format '%lld' expects type 'long long int', but argument 2 has type 's64'
fs/ext4/inode.c:1824: warning: format '%lld' expects type 'long long int', but argument 2 has type 's64'
Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
As reported by Eric Paris, the capable() check in ext4_has_free_blocks()
sometimes causes SELinux denials.
We can rearrange the logic so that we only try to use the root-reserved
blocks when necessary, and even then we can move the capable() test
to last, to avoid the check most of the time.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Mingming pointed out that ext4_claim_free_blocks & ext4_has_free_blocks
are largely cut & pasted; they can be collapsed/merged as follows.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Vegard Nossum reported a bug which accesses freed memory (found via
kmemcheck). When journal has been aborted, ext4_put_super() calls
ext4_abort() after freeing the journal_t object, and then ext4_abort()
accesses it. This patch fix it.
Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Fix a regression caused by commit d0156417, "ext4: fix ext4_dx_readdir
hash collision handling", where deleting files in a large directory
(requiring more than one getdents system call), results in some
filenames being returned twice. This was caused by a failure to
update info->curr_hash and info->curr_minor_hash, so that if the
directory had gotten modified since the last getdents() system call
(as would be the case if the user is running "rm -r" or "git clean"),
a directory entry would get returned twice to the userspace.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This patch fixes the bug reported by Markus Trippelsdorf at:
http://bugzilla.kernel.org/show_bug.cgi?id=11844
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Tested-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
[ All users removed in "switch all filesystems over to d_obtain_alias",
aka commit 440037287c ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/viro/bdev: (66 commits)
[PATCH] kill the rest of struct file propagation in block ioctls
[PATCH] get rid of struct file use in blkdev_ioctl() BLKBSZSET
[PATCH] get rid of blkdev_locked_ioctl()
[PATCH] get rid of blkdev_driver_ioctl()
[PATCH] sanitize blkdev_get() and friends
[PATCH] remember mode of reiserfs journal
[PATCH] propagate mode through swsusp_close()
[PATCH] propagate mode through open_bdev_excl/close_bdev_excl
[PATCH] pass fmode_t to blkdev_put()
[PATCH] kill the unused bsize on the send side of /dev/loop
[PATCH] trim file propagation in block/compat_ioctl.c
[PATCH] end of methods switch: remove the old ones
[PATCH] switch sr
[PATCH] switch sd
[PATCH] switch ide-scsi
[PATCH] switch tape_block
[PATCH] switch dcssblk
[PATCH] switch dasd
[PATCH] switch mtd_blkdevs
[PATCH] switch mmc
...
Use fs/*/Kconfig more, which is good because everything related to one
filesystem is in one place and fs/Kconfig is quite fat.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the HUGE_FILE feature flag is not set, don't allow the creation of
large files, instead of automatically enabling the feature flag.
Recent versions of mke2fs will set the HUGE_FILE flag automatically
anyway for ext4 filesystems.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The multiblock allocator needs to be able to release blocks (and issue
a blkdev discard request) when the transaction which freed those
blocks is committed. Previously this was done via a polling mechanism
when blocks are allocated or freed. A much better way of doing things
is to create a jbd2 callback function and attaching the list of blocks
to be freed directly to the transaction structure.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
There are some newlines missing in ext4_check_descriptors, which
cause the printk level to be printed out when the next printk call
is made:
[ 778.847265] EXT4-fs: ext4_check_descriptors: Block bitmap for group 0
not in group (block 1509949442)!<3>EXT4-fs: group descriptors corrupted!
[ 802.646630] EXT4-fs: ext4_check_descriptors: Inode bitmap for group 0
not in group (block 9043971)!<3>EXT4-fs: group descriptors corrupted!
Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The range_cyclic writeback mode uses the address_space writeback_index
as the start index for writeback. With delayed allocation we were
updating writeback_index wrongly resulting in highly fragmented file.
This patch reduces the number of extents reduced from 4000 to 27 for a
3GB file.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Let the block device know when unused blocks can be discarded, using
the new sb_issue_discard() interface.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
We need to make sure we don't reuse the data blocks released
during the transaction untill the transaction commits. We force
this mode only for ordered and journalled mode. Writeback mode
already don't provided data consistency.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
With this patch we track the block freed during a transaction using
red-black tree. We also make sure contiguous blocks freed are collected
in one node in the tree.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
During filesystem recovery we may be doing a truncate
which expects some of the mballoc data structures to
be initialized. So do ext4_mb_init before recovery.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
We should use kmem_cache_free to free memory allocated
via kmem_cache_alloc
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This is a much better version of a previous patch to make the parser
tables constant. Rather than changing the typedef, we put the "const" in
all the various places where its required, allowing the __initconst
exception for nfsroot which was the cause of the previous trouble.
This was posted for review some time ago and I believe its been in -mm
since then.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Alexander Viro <aviro@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/ext4/super.c: In function 'ext4_fill_super':
fs/ext4/super.c:2226: error: 'ext4_ui_proc_fops' undeclared (first use
in this function)
fs/ext4/super.c:2226: error: (Each undeclared identifier is reported
only once
fs/ext4/super.c:2226: error: for each function it appears in.)
Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
If the journal doesn't abort when it gets an IO error in file data
blocks, the file data corruption will spread silently. Because
most of applications and commands do buffered writes without fsync(),
they don't notice the IO error. It's scary for mission critical
systems. On the other hand, if the journal aborts whenever it gets
an IO error in file data blocks, the system will easily become
inoperable. So this patch introduces a filesystem option to
determine whether it aborts the journal or just call printk() when
it gets an IO error in file data.
If you mount an ext4 fs with data_err=abort option, it aborts on file
data write error. If you mount it with data_err=ignore, it doesn't
abort, just call printk(). data_err=ignore is the default.
Here is the corresponding patch of the ext3 version:
http://kerneltrap.org/mailarchive/linux-kernel/2008/9/9/3239374
Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
If the journal has aborted due to a checkpointing failure, we
have to keep the contents of the journal space. Otherwise, the
filesystem will lose uncheckpointed metadata completely and
become inconsistent. To avoid this, we need to keep needs_recovery
flag if checkpoint has failed.
With this patch, ext4_put_super() detects a checkpointing failure
from the return value of journal_destroy(), then it invokes
ext4_abort() to make the filesystem read only and keep
needs_recovery flag. Errors from jbd2_journal_flush() are also
handled by this patch in some places.
Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The ext4 filesystem is getting stable enough that it's time to drop
the "dev" prefix. Also remove the requirement for the TEST_FILESYS
flag.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
While reading code I noticed that ext4_put_super() dirties the
superblock bh twice. It is always done in ext4_commit_super()
too. Remove the redundant dirty operation.
Should be a nop semantically.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
ext4_ext_walk_space() was reinstated to be used for iterating over file
extents with a callback; it is used by the ext4 fiemap implementation.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: linux-ext4@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
ext4_xattr_set_handle() eventually ends up calling
ext4_mark_inode_dirty() which tries to expand the inode by shifting
the EAs. This leads to the xattr_sem being downed again and leading
to a deadlock.
This patch makes sure that if ext4_xattr_set_handle() is in the
call-chain, ext4_mark_inode_dirty() will not expand the inode.
Signed-off-by: Kalpak Shah <kalpak.shah@sun.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This debugging markers are designed to debug problems such as the
random filesystem latency problems reported by Arjan.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This fixes a bug which caused on-line resizing of filesystems with a
1k blocksize to fail. The root cause of this bug was the fact that if
an uninitalized bitmap block gets read in by userspace (which
e2fsprogs does try to avoid, but can happen when the blocksize is less
than the pagesize and an adjacent blocks is read into memory)
ext4_read_block_bitmap() was erroneously depending on the buffer
uptodate flag to decide whether it needed to initialize the bitmap
block in memory --- i.e., to set the standard set of blocks in use by
a block group (superblock, bitmaps, inode table, etc.). Essentially,
ext4_read_block_bitmap() assumed it was the only routine that might
try to read a block containing a block bitmap, which is simply not
true.
To fix this, ext4_read_block_bitmap() and ext4_read_inode_bitmap()
must always initialize uninitialized bitmap blocks. Once a block or
inode is allocated out of that bitmap, it will be marked as
initialized in the block group descriptor, so in general this won't
result any extra unnecessary work.
Signed-off-by: Frederic Bohe <frederic.bohe@bull.net>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
With modern hard drives, reading 64k takes roughly the same time as
reading a 4k block. So request readahead for adjacent inode table
blocks to reduce the time it takes when iterating over directories
(especially when doing this in htree sort order) in a cold cache case.
With this patch, the time it takes to run "git status" on a kernel
tree after flushing the caches via "echo 3 > /proc/sys/vm/drop_caches"
is reduced by 21%.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Previously mballoc created a separate set of functions for each proc
file. This combines the tunables into a single set of functions which
gets used for all of the per-superblock proc files, saving
approximately 2k of compiled object code.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
...and into the core setup/teardown code in fs/ext4/super.c so that
other parts of ext4 can define tuning parameters.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This is a port of a patch from Linus which fixes a 200+ byte stack
usage problem in ext4_get_parent().
It's more efficient to pass down only the actual parts of the dentry
that matter: the parent inode and the name, instead of allocating a
struct dentry on the stack.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
lg_prealloc_list seems to cry out for a per-cpu data structure; on a large
smp system I think this should be better. I've lightly tested this change
on a 4-cpu system.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Acked-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Pick an ioctl number for EXT4_IOC_MIGRATE that won't conflict with
other ext4 ioctl's. Since there haven't been any major userspace
users of this ioctl, we can afford to change this now, to avoid
potential problems later.
Also, reorder the ioctl numbers in ext4.h to avoid this sort of
mistake in the future.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This patch hooks the ext3 to ext4 migrate interface to
EXT4_IOC_SETFLAGS ioctl. The userspace interface is via chattr +e. We
only allow setting extent flags. Clearing extent flag (migrating from
ext4 to ext3) is not supported.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The migrate ioctl writes to the filsystem, so we need to elevate the
write count.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
If there group descriptors are corrupted we need unlock the block
group lock before returning from the function; else we will oops when
freeing a spinlock which is still being held.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Calculate the journal device name once and stash it away in the
journal_s structure. This avoids needing to call bdevname()
everywhere and reduces stack usage by not needing to allocate an
on-stack buffer. In addition, we eliminate the '/' that can appear in
device names (e.g. "cciss/c0d0p9" --- see kernel bugzilla #11321) that
can cause problems when creating proc directory names, and include the
inode number to support ocfs2 which creates multiple journals with
different inode numbers.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4 creates per-suberblock directory in /proc/ext4/ . Name used as
basis is taken from bdevname, which, surprise, can contain slash.
However, proc while allowing to use proc_create("a/b", parent) form of
PDE creation, assumes that parent/a was already created.
bdevname in question is 'cciss/c0d0p9', directory is not created and all
this stuff goes directly into /proc (which is real bug).
Warning comes when _second_ partition is mounted.
http://bugzilla.kernel.org/show_bug.cgi?id=11321
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This fixes a bug which prevented the newly created inodes after a
resize from being used on filesystems with flex_bg.
Signed-off-by: Frederic Bohe <frederic.bohe@bull.net>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Note: some people thinks this represents a security bug, since it
might make the system go away while it is printing a large number of
console messages, especially if a serial console is involved. Hence,
it has been assigned CVE-2008-3528, but it requires that the attacker
either has physical access to your machine to insert a USB disk with a
corrupted filesystem image (at which point why not just hit the power
button), or is otherwise able to convince the system administrator to
mount an arbitrary filesystem image (at which point why not just
include a setuid shell or world-writable hard disk device file or some
such). Me, I think they're just being silly. --tytso
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: linux-ext4@vger.kernel.org
Cc: Eugene Teo <eugeneteo@kernel.sg>
With delayed allocation we use i_data_sem to update i_disksize. We need
to update i_disksize only if the new size specified is greater than the
current value and we need to make sure we don't race with other
i_disksize update. With delayed allocation we will switch to the
write_begin function for non-delayed allocation if we are low on free
blocks. This means the write_begin function for non-delayed allocation
also needs to use the same locking.
We also need to check and update i_disksize even if the new size is less
that inode.i_size because of delayed allocation.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
For blocksize < pagesize we need to remove blocks that got allocated in
block_write_begin() if we fail with ENOSPC for later blocks.
block_write_begin() internally does this if it allocated pages locally.
This makes sure we don't have blocks outside inode.i_size during ENOSPC.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
When we truncate files, the meta-data blocks released are not reused
untill we commit the truncate transaction. That means delayed get_block
request will return ENOSPC even if we have free blocks left. Force a
journal commit and retry block allocation if we get ENOSPC with free
blocks left.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Make sure we don't add the inode to the journal handle until after the
block allocation, so that a journal commit will not include the inode in
case of block allocation failure.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
We run into ENOSPC error on nonmballoc ext4, even when there is free blocks
on the filesystem.
The patch includes two changes:
a) Set reservation to NULL if we trying to allocate near group_target_block
from the goal group if the free block in the group is less than windows.
This should give us a better chance to allocate near group_target_block.
This also ensures that if we are not allocating near group_target_block
then we don't trun off reservation. This should enable us to allocate
with reservation from other groups that have large free blocks count.
b) we don't need to check the window size if the block reservation is off.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This patch converts some usage of ext4_fsblk_t to s64. This is needed
so that some of the sign conversion works as expected in if loops.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The delayed allocation code allocates blocks during writepages(), which
can not handle block allocation failures. To deal with this, we switch
away from delayed allocation mode when we are running low on free
blocks. This also allows us to avoid needing to reserve a large number
of meta-data blocks in case all of the requested blocks are
discontiguous.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This patch adds dirty block accounting using percpu_counters. Delayed
allocation block reservation is now done by updating dirty block
counter. In a later patch we switch to non delalloc mode if the
filesystem free blocks is greater than 150% of total filesystem dirty
blocks
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao<cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
During block reservation if we don't have enough blocks left, retry
block reservation with smaller block counts. This makes sure we try
fallocate and DIO with smaller request size and don't fail early. The
delayed allocation reservation cannot try with smaller block count. So
retry block reservation to handle temporary disk full conditions. Also
print free blocks details if we fail block allocation during writepages.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
With delayed allocation we need to make sure block are reserved before
we attempt to allocate them. Otherwise we get block allocation failure
(ENOSPC) during writepages which cannot be handled. This would mean
silent data loss (We do a printk stating data will be lost). This patch
updates the DIO and fallocate code path to do block reservation before
block allocation. This is needed to make sure parallel DIO and fallocate
request doesn't take block out of delayed reserve space.
When free blocks count go below a threshold we switch to a slow patch
which looks at other CPU's accumulated percpu counter values.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
We are a bit agressive in invalidating all the pages. But
it is ok because we really don't know why the block allocation
failed and it is better to come of the writeback path
so that user can look for more info.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
percpu_counter_sum_and_set() and percpu_counter_sum() is the same except
the former updates the global counter after accounting. Since we are
taking the fbc->lock to calculate the precise value of the counter in
percpu_counter_sum() anyway, it should simply set fbc->count too, as the
percpu_counter_sum_and_set() does.
This patch merges these two interfaces into one.
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
For small file block allocations, mballoc uses per cpu prealloc
space. Use goal block when searching for the right prealloc
space. Also make sure ext4_da_writepages tries to write
all the pages for small files in single attempt
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The write_cache_pages() function uses the mapping->writeback_index as
the starting index to write out when range_cyclic is set. Properly
initialize writeback_index so that we start the writeout at index 0.
This was found when debugging the small file fragmentation on ext4.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Fix ext4_has_free_blocks() to return 0 when we don't have enough space.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Previous delalloc writepages implementation started a new transaction
outside of a loop which called get_block() to do the block allocation.
Since we didn't know exactly how many blocks would need to be allocated,
the estimated journal credits required was very conservative and caused
many issues.
With the reworked delayed allocation, a new transaction is created for
each get_block(), thus we don't need to guess how many credits for the
multiple chunk of allocation. We start every transaction with enough
credits for inserting a single exent. When estimate the credits for
indirect blocks to allocate a chunk of blocks, we need to know the
number of data blocks to allocate. We use the total number of reserved
delalloc datablocks; if that is too big, for non-extent files, we need
to limit the number of blocks to EXT4_MAX_TRANS_BLOCKS.
Code cleanup from Aneesh.
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Reviewed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
With the below changes we reserve credit needed to insert only one
extent resulting from a call to single get_block. This makes sure we
don't take too much journal credits during writeout. We also don't
limit the pages to write. That means we loop through the dirty pages
building largest possible contiguous block request. Then we issue a
single get_block request. We may get less block that we requested. If
so we would end up not mapping some of the buffer_heads. That means
those buffer_heads are still marked delay. Later in the writepage
callback via __mpage_writepage we redirty those pages.
We should also not limit/throttle wbc->nr_to_write in the filesystem
writepages callback. That cause wrong behaviour in
generic_sync_sb_inodes caused by wbc->nr_to_write being <= 0
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
DIO and fallocate credit calculation is different than writepage, as
they do start a new journal right for each call to ext4_get_blocks_wrap().
This patch uses the helper function in DIO and fallocate case, passing
a flag indicating that the modified data are contigous thus could account
less indirect/index blocks.
This patch also fixed the journal credit reservation for direct I/O
(DIO). Previously the estimated credits for DIO only was calculated for
non-extent files, which was not enough if the file is extent-based.
Also fixed was fallocate double-counting credits for modifying the the
superblock.
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This patch modified the writepage/write_begin credit calculation for
extent files, to use the credits caculation helper function.
The current calculation of how many index/leaf blocks should be
accounted is too conservetive, it always considered the worse case,
where the tree level is 5, and in the case of multiple chunk
allocations, it always assumed no blocks were dirtied in common across
the allocations. This path uses the accurate depth of the inode with
some extras to calculate the index blocks, and also less conservative in
the case of multiple allocation accounting.
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
When considering how many journal credits are needed for modifying a
chunk of data, we need to account for the super block, inode block,
quota blocks and xattr block, indirect/index blocks, also, group bitmap
and group descriptor blocks for new allocation (including data and
indirect/index blocks). There are many places in ext4 do the calculation
on their own and often missed one or two meta blocks, and often they
assume single block allocation, and did not considering the multile
chunk of allocation case.
This patch is trying to cleanup current journal credit code, provides
some common helper funtion to calculate the journal credits, to be used
for writepage, writepages, DIO, fallocate, migration, defrag, and for
both nonextent and extent files.
This patch modified the writepage/write_begin credit caculation for
nonextent files, to use the new helper function. It also fixed the
problem that writepage on nonextent files did not consider the case
blocksize <pagesize, thus could possibelly need multiple block
allocation in a single transaction.
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The find_group_flex() function starts with best_flex as the
parent_fbg_group, which happens to have 0 inodes free. Some of the
flex groups searched have free blocks and free inodes, but the
flex_freeb_ratio is < 10, so they're skipped. Then when a group is
compared to the current "best" flex group, it does not have more free
blocks than "best", so it is skipped as well.
This continues until no flex group with free inodes is found which has
a proper ratio or which has more free blocks than the "best" group,
and we're left with a "best" group that has 0 inodes free, and we
return -ENOSPC.
We fix this by changing the logic so that if the current "best" flex
group has no inodes free, and the current one does have room, it is
promoted to the next "best."
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
When trying to resize an ext4 fs and you run out of reserved gdt blocks,
you get an error that doesn't actually tell you what went wrong, it just
says that the gdb it picked is not correct, which is the case since you
don't have any reserved gdt blocks left. This patch adds a check to make
sure you have reserved gdt blocks to use, and if not prints out a more
relevant error.
Signed-off-by: Josef Bacik <jbacik@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Cc: Andreas Dilger <adilger@sun.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
In ext4_ext_truncate(), we should use the more generic
ext4_discard_reservations() call so we do the right thing when the
filesystem is mounted with the nomballoc option.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Mingming Cao <cmm@us.ibm.com>
This fixes a bug where readdir() would return a directory entry twice
if there was a hash collision in an hash tree indexed directory.
Signed-off-by: Eugene Dashevsky <eugene@ibrix.com>
Signed-off-by: Mike Snitzer <msnitzer@ibrix.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Ext4 will release the reserved blocks for delayed allocations when
inode is truncated/unlinked. If there is no reserved block at all, we
shouldn't need to do so. But current code still tries to release the
reserved blocks regardless whether the counters's value is 0.
Continue to do that causes the later calculation to go wrong and a
kernel BUG_ON() caught that. This doesn't happen for extent-based
files, as the calculation for 0 reserved blocks was right for extent
based file.
This patch fixed the kernel BUG() due to above reason. It adds checks
for 0 to avoid unnecessary release and fix calculation for non-extent
files.
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
We need to call ext4_discard_reservation() earlier in ext4_truncate(),
to avoid a BUG() in ext4_mb_return_to_preallocation(), which is called
(ultimately) by ext4_free_blocks(). So we must ditch the blocks on
i_prealloc_list before we start freeing the data blocks.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
When using fallocate the buffer_heads are marked unwritten and unmapped.
We need to map them in the writepages after a get_block. Otherwise we
split the uninit extents, but never write the content to disk.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: remove write-only variables from ext4_ordered_write_end
ext4: unexport jbd2_journal_update_superblock
ext4: Cleanup whitespace and other miscellaneous style issues
ext4: improve ext4_fill_flex_info() a bit
ext4: Cleanup the block reservation code path
ext4: don't assume extents can't cross block groups when truncating
ext4: Fix lack of credits BUG() when deleting a badly fragmented inode
ext4: Fix ext4_ext_journal_restart()
ext4: fix ext4_da_write_begin error path
jbd2: don't abort if flushing file data failed
ext4: don't read inode block if the buffer has a write error
ext4: Don't allow lg prealloc list to be grow large.
ext4: Convert the usage of NR_CPUS to nr_cpu_ids.
ext4: Improve error handling in mballoc
ext4: lock block groups when initializing
ext4: sync up block and inode bitmap reading functions
ext4: Allow read/only mounts with corrupted block group checksums
ext4: Fix data corruption when writing to prealloc area
The variables 'from' and 'to' are not used anywhere.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Acked-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* new helper: vfs_quota_on_path(); equivalent of vfs_quota_on() sans the
pathname resolution.
* callers of vfs_quota_on() that do their own pathname resolution and
checks based on it are switched to vfs_quota_on_path(); that way we
avoid the races.
* reiserfs leaked dentry/vfsmount references on several failure exits.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
When we read some part of a file through pagecache, if there is a
pagecache of corresponding index but this page is not uptodate, read IO
is issued and this page will be uptodate.
I think this is good for pagesize == blocksize environment but there is
room for improvement on pagesize != blocksize environment. Because in
this case a page can have multiple buffers and even if a page is not
uptodate, some buffers can be uptodate.
So I suggest that when all buffers which correspond to a part of a file
that we want to read are uptodate, use this pagecache and copy data from
this pagecache to user buffer even if a page is not uptodate. This can
reduce read IO and improve system throughput.
I wrote a benchmark program and got result number with this program.
This benchmark do:
1: mount and open a test file.
2: create a 512MB file.
3: close a file and umount.
4: mount and again open a test file.
5: pwrite randomly 300000 times on a test file. offset is aligned
by IO size(1024bytes).
6: measure time of preading randomly 100000 times on a test file.
The result was:
2.6.26
330 sec
2.6.26-patched
226 sec
Arch:i386
Filesystem:ext3
Blocksize:1024 bytes
Memory: 1GB
On ext3/4, a file is written through buffer/block. So random read/write
mixed workloads or random read after random write workloads are optimized
with this patch under pagesize != blocksize environment. This test result
showed this.
The benchmark program is as follows:
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <time.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mount.h>
#define LEN 1024
#define LOOP 1024*512 /* 512MB */
main(void)
{
unsigned long i, offset, filesize;
int fd;
char buf[LEN];
time_t t1, t2;
if (mount("/dev/sda1", "/root/test1/", "ext3", 0, 0) < 0) {
perror("cannot mount\n");
exit(1);
}
memset(buf, 0, LEN);
fd = open("/root/test1/testfile", O_CREAT|O_RDWR|O_TRUNC);
if (fd < 0) {
perror("cannot open file\n");
exit(1);
}
for (i = 0; i < LOOP; i++)
write(fd, buf, LEN);
close(fd);
if (umount("/root/test1/") < 0) {
perror("cannot umount\n");
exit(1);
}
if (mount("/dev/sda1", "/root/test1/", "ext3", 0, 0) < 0) {
perror("cannot mount\n");
exit(1);
}
fd = open("/root/test1/testfile", O_RDWR);
if (fd < 0) {
perror("cannot open file\n");
exit(1);
}
filesize = LEN * LOOP;
for (i = 0; i < 300000; i++){
offset = (random() % filesize) & (~(LEN - 1));
pwrite(fd, buf, LEN, offset);
}
printf("start test\n");
time(&t1);
for (i = 0; i < 100000; i++){
offset = (random() % filesize) & (~(LEN - 1));
pread(fd, buf, LEN, offset);
}
time(&t2);
printf("%ld sec\n", t2-t1);
close(fd);
if (umount("/root/test1/") < 0) {
perror("cannot umount\n");
exit(1);
}
}
Signed-off-by: Hisashi Hifumi <hifumi.hisashi@oss.ntt.co.jp>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jan Kara <jack@ucw.cz>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kill nameidata * argument; map the 3 bits in ->flags anybody cares
about to new MAY_... ones and pass with the mask.
* kill redundant gfs2_iop_permission()
* sanitize ecryptfs_permission()
* fix remaining places where ->permission() instances might barf on new
MAY_... found in mask.
The obvious next target in that direction is permission(9)
folded fix for nfs_permission() breakage from Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Kmem cache passed to constructor is only needed for constructors that are
themselves multiplexeres. Nobody uses this "feature", nor does anybody uses
passed kmem cache in non-trivial way, so pass only pointer to object.
Non-trivial places are:
arch/powerpc/mm/init_64.c
arch/powerpc/mm/hugetlbpage.c
This is flag day, yes.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Jon Tollefson <kniht@linux.vnet.ibm.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Matt Mackall <mpm@selenic.com>
[akpm@linux-foundation.org: fix arch/powerpc/mm/hugetlbpage.c]
[akpm@linux-foundation.org: fix mm/slab.c]
[akpm@linux-foundation.org: fix ubifs]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- use kzalloc() instead of kmalloc() + memset()
- improve a printk info
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The truncate patch should not use the i_allocated_meta_blocks
value. So add seperate functions to be used in the truncate
and alloc path. We also need to release the meta-data block
that we reserved for the blocks that we are truncating.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
With the FLEX_BG layout, there is no reason why extents can't cross
block groups, so make the truncate code reserve enough credits so we
don't BUG if we come across such an extent.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The extents codepath for ext4_truncate() requests journal transaction
credits in very small chunks, requesting only what is needed. This
means there may not be enough credits left on the transaction handle
after ext4_truncate() returns and then when ext4_delete_inode() tries
finish up its work, it may not have enough transaction credits,
causing a BUG() oops in the jbd2 core.
Also, reserve an extra 2 blocks when starting an ext4_delete_inode()
since we need to update the inode bitmap, as well as update the
orphaned inode linked list.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The ext4_ext_journal_restart() is a convenience function which checks
to see if the requested number of credits is present, and if so it
closes the current transaction and attaches the current handle to the
new transaction. Unfortunately, it wasn't proprely checking the
return value from ext4_journal_extend(), so it was starting a new
transaction when one was not necessary, and returning an error when
all that was necessary was to restart the handle with a new
transaction.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4_da_write_begin needs to call journal_stop before returning,
if the page allocation fails.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Acked-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
A transient I/O error can corrupt inode data. Here is the scenario:
(1) update inode_A at the block_B
(2) pdflush writes out new inode_A to the filesystem, but it results
in write I/O error, at this point, BH_Uptodate flag of the buffer
for block_B is cleared and BH_Write_EIO is set
(3) create new inode_C which located at block_B, and
__ext4_get_inode_loc() tries to read on-disk block_B because the
buffer is not uptodate
(4) if it can read on-disk block_B successfully, inode_A is
overwritten by old data
This patch makes __ext4_get_inode_loc() not read the inode block if the
buffer has BH_Write_EIO flag. In this case, the buffer should have the
latest information, so setting the uptodate flag to the buffer (this
avoids WARN_ON_ONCE() in mark_buffer_dirty().)
According to this change, we would need to test BH_Write_EIO flag for the
error checking. Currently nobody checks write I/O errors on metadata
buffers, but it will be done in other patches I'm working on.
Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: sugita <yumiko.sugita.yf@hitachi.com>
Cc: Satoshi OSHIMA <satoshi.oshima.fk@hitachi.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Jan Kara <jack@ucw.cz>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Currently, the locality group prealloc list is freed only when there
is a block allocation failure. This can result in large number of
entries in the preallocation list making ext4_mb_use_preallocated()
expensive.
To fix this, we convert the locality group prealloc list to a hash
list. The hash index is the order of number of blocks in the prealloc
space with a max order of 9. When adding prealloc space to the list we
make sure total entries for each order does not exceed 8. If it is
more than 8 we discard few entries and make sure the we have only <= 5
entries.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
NR_CPUS can be really large. We should be using nr_cpu_ids instead.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Don't call BUG_ON on file system failures. Instead use ext4_error and
also handle the continue case properly.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
I noticed when filling a 1T filesystem with 4 threads using the
fs_mark benchmark:
fs_mark -d /mnt/test -D 256 -n 100000 -t 4 -s 20480 -F -S 0
that I occasionally got checksum mismatch errors:
EXT4-fs error (device sdb): ext4_init_inode_bitmap: Checksum bad for group 6935
etc. I'd reliably get 4-5 of them during the run.
It appears that the problem is likely a race to init the bg's
when the uninit_bg feature is enabled.
With the patch below, which adds sb_bgl_locking around initialization,
I was able to complete several runs with no errors or warnings.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
ext4_read_block_bitmap and read_inode_bitmap do essentially
the same thing, and yet they are structured quite differently.
I came across this difference while looking at doing bg locking
during bg initialization.
This patch:
* removes unnecessary casts in the error messages
* renames read_inode_bitmap to ext4_read_inode_bitmap
* and more substantially, restructures the inode bitmap
reading function to be more like the block bitmap counterpart.
The change to the inode bitmap reader simplifies the locking
to be applied in the next patch.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
If the block group checksums are corrupted, still allow the mount to
succeed, so e2fsck can have a chance to try to fix things up. Add
code in the remount r/w path to make sure the block group checksums
are valid before allowing the filesystem to be remounted read/write.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Inserting an extent can cause a new entry in the already existing index
block. That doesn't increase the depth of the instead. Instead it adds a
new leaf block. Now with the new leaf block the path information
corresponding to the logical block should be fetched from the new block.
The old path will be pointing to the old leaf block.
We need to recalucate the path information on extent insert
even if depth doesn't change. Without this change, the extent merge
after converting an unwritten extent to initialized extent takes the wrong
extent and cause data corruption.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
We've talked for a while about getting rid of any feature-
setting from the kernel; this gets rid of the code which would
set the INCOMPAT_EXTENTS flag on the first file write when mounted
as ext4[dev].
With this patch, if the extents feature is not already set on disk,
then mounting as ext4 will fall back to noextents with a warning,
and if -o extents is explicitly requested, the mount will fail,
also with warning.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The block mapped inode format can address only blocks within 2**32. This
causes a number of issues, the biggest of which is that the block
allocator needs to be taught that certain inodes can not utilize block
numbers > 2**32. So until this is fixed, it is simplest to fail
mounting of file systems with more than 2**32 blocks if the -o noextents
option is given.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Enable delalloc by default to ensure it gets sufficient testing and
because it makes the filesystem much more efficient. Add a nodealalloc
option to disable delayed allocation, and update ext4_show_options to
show delayed allocation off if it is disabled.
If the data=journal mount option is used, disable delayed allocation
since the delalloc code doesn't support data=journal yet.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Right now i_blocks is not getting updated until the blocks are actually
allocaed on disk. This means with delayed allocation, right after files
are copied, "ls -sF" shoes the file as taking 0 blocks on disk. "du"
also shows the files taking zero space, which is highly confusing to the
user.
Since delayed allocation already keeps track of per-inode total
number of blocks that are subject to delayed allocation, this patch fix
this by using that to adjust the value returned by stat(2). When real
block allocation is done, the i_blocks will get updated. Since the
reserved blocks for delayed allocation will be decreased, this will be
keep value returned by stat(2) consistent.
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Ext4_da_write_end() used walk_page_buffers() with a callback function of
ext4_bh_unmapped_or_delay() to check if it extended the file size
without allocating any blocks (since in this case i_disksize needs to be
updated). However, this is didn't work proprely because the buffer head
has not been marked dirty yet --- this is done later in
block_commit_write() --- which caused ext4_bh_unmapped_or_delay() to
always return false.
In addition, walk_page_buffers() checks all of the buffer heads covering
the page, and the only buffer_head that should be checked is the one
covering the end of the write. Otherwise, given a 1k blocksize
filesystem and a 4k page size, the buffer head covering the first 1k
stripe of the file could be unmapped (because it was a sparse file), and
the second or third buffer_head covering that page could be mapped, and
using walk_page_buffers() would fail in this case since it would stop at
the first unmapped buffer_head and return true.
The core problem is that walk_page_buffers() was intended to do work in
a callback function, and a non-zero return value indicated a failure,
which termined the walk of the buffer heads covering the page. It was
not intended to be used with a boolean function, such as
ext4_bh_unmapped_or_delay().
Add addtional fix from Aneesh to protect i_disksize update rave with truncate.
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
It can happen that buffers are removed from the page before it gets
marked dirty and then is passed to writepage(). In writepage() we just
initialize the buffers and check whether they are mapped and non
delay. If they are mapped and non delay we write the page. Otherwise we
mark them dirty. With this change we don't do block allocation at all
in ext4_*_write_page.
writepage() can get called under many condition and with a locking order
of journal_start -> lock_page, we should not try to allocate blocks in
writepage() which get called after taking page lock. writepage() can
get called via shrink_page_list even with a journal handle which was
created for doing inode update. For example when doing
ext4_da_write_begin we create a journal handle with credit 1 expecting a
i_disksize update for the inode. But ext4_da_write_begin can cause
shrink_page_list via _grab_page_cache. So having a valid handle via
ext4_journal_current_handle is not a guarantee that we can use the
handle for block allocation in writepage, since we shouldn't be using
credits that had been reserved for other updates. That it could result
in we running out of credits when we update inodes.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This provides a new ordered mode implementation which gets rid of using
buffer heads to enforce the ordering between metadata change with the
related data chage. Instead, in the new ordering mode, it keeps track
of all of the inodes touched by each transaction on a list, and when
that transaction is committed, it flushes all of the dirty pages for
those inodes. In addition, the new ordered mode reverses the lock
ordering of the page lock and transaction lock, which provides easier
support for delayed allocation.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
With the reverse locking, we need to start a transation before taking
the page lock, so in ext4_da_writepages() we need to break the write-out
into chunks, and restart the journal for each chunck to ensure the
write-out fits in a single transaction.
Updated patch from Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
which fixes delalloc sync hang with journal lock inversion, and address
the performance regression issue.
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This patch does block reservation for delayed
allocation, to avoid ENOSPC later at page flush time.
Blocks(data and metadata) are reserved at da_write_begin()
time, the freeblocks counter is updated by then, and the number of
reserved blocks is store in per inode counter.
At the writepage time, the unused reserved meta blocks are returned
back. At unlink/truncate time, reserved blocks are properly released.
Updated fix from Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
to fix the oldallocator block reservation accounting with delalloc, added
lock to guard the counters and also fix the reservation for meta blocks.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Delayed allocation need to check free blocks at every write time.
percpu_counter_read_positive() is not quit accurate. delayed
allocation need a more accurate accounting, but using
percpu_counter_sum_positive() is frequently is quite expensive.
This patch added a new function to update center counter when sum
per-cpu counter, to increase the accurate rate for next
percpu_counter_read() and require less calling expensive
percpu_counter_sum().
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Updated with fixes from Mingming Cao <cmm@us.ibm.com> to unlock and
release the page from page cache if the delalloc write_begin failed, and
properly handle preallocated blocks. Also added a fix to clear
buffer_delay in block_write_full_page() after allocating a delayed
buffer.
Updated with fixes from Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
to update i_disksize properly and to add bmap support for delayed
allocation.
Updated with a fix from Valerie Clement <valerie.clement@bull.net> to
avoid filesystem corruption when the filesystem is mounted with the
delalloc option and blocksize < pagesize.
Signed-off-by: Alex Tomas <alex@clusterfs.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
This patch makes ext4 use inode-based implementation of data=ordered mode
in JBD2. It allows us to unify some data=ordered and data=writeback paths
(especially writepage since we don't have to start a transaction anymore)
and remove some buffer walking.
Updated fix from Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
to fix file system hang due to corrupt jinode values.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
We cannot call ext4_orphan_add() from under i_data_sem because that
causes a lock ordering violation between i_data_sem and and the
superblock lock.
Updated with Aneesh's locking order fix
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This changes are needed to support data=ordered mode handling via
inodes. This enables us to get rid of the journal heads and buffer
heads for data buffers in the ordered mode. With the changes, during
tranasaction commit we writeout the inode pages using the
writepages()/writepage(). That implies we take page lock during
transaction commit. This can cause a deadlock with the locking order
page_lock -> jbd2_journal_start, since the jbd2_journal_start can wait
for the journal_commit to happen and the journal_commit now needs to
take the page lock. To avoid this dead lock reverse the locking order.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
We would like to get notified when we are doing a write on mmap section.
This is needed with respect to preallocated area. We split the preallocated
area into initialzed extent and uninitialzed extent in the call back. This
let us handle ENOSPC better. Otherwise we get ENOSPC in the writepage and
that would result in data loss. The changes are also needed to handle ENOSPC
when writing to an mmap section of files with holes.
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Update group infos when updating a group's descriptor.
Add group infos when adding a group's descriptor.
Refresh cache pages used by mb_alloc when changes occur.
This will probably need modifications when META_BG resizing will be allowed.
Signed-off-by: Frederic Bohe <frederic.bohe@bull.net>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Use the BUFFER_FNS functions (set_buffer_foo) to set buffer
head state atomically instead of nonatomic __set_bit().
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Set sbi->s_journal to NULL after we call journal_destroy(). This
will be later needed because after journal_destroy() is called,
ext4_clear_inode() can still be called for some inodes (e.g. root
inode) and we'll need to detect there that journal doesn't exists
anymore.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
mballoc allocation missed check for blocks reserved for root users. Add
ext4_has_free_blocks() check before allocation. Also modified
ext4_has_free_blocks() to support multiple block allocation request.
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
To ensure that bits are truly on-disk after an fsync,
we should call blkdev_issue_flush if barriers are supported.
Inspired by an old thread on barriers, by reiserfs & xfs
which do the same, and by a patch SuSE ships with their kernel
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Move the code related to block allocation to a single function and add helper
funtions to differient allocation for data and meta data blocks
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
When mballoc is enabled, block allocation for old block-based
files are allocated using mballoc allocator instead of old
block-based allocator. The old ext3 block reservation is turned
off when mballoc is turned on.
However, the in-core preallocation is not enabled for block-based/
non-extent based file block allocation. This result in performance
regression, as now we don't have "reservation" ore in-core preallocation
to prevent interleaved fragmentation in multiple writes workload.
This patch fix this by enable per inode in-core preallocation
for non extent files when mballoc is used.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
When meta_bg feature is enabled and s_first_meta_bg != 0,
ext4_init_block_bitmap() miscalculates the number of block used by
the group descriptor table (0 or 1 for metablock block group)
This patch fixes this by using ext4_bg_num_gdb()
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Stephen Tweedie <sct@redhat.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Acked-by: Andreas Dilger <adilger@sun.com>
dx_root_limit() will had some dead code which forced it to always return
20, and dx_node_limit to always return 22 for debugging purposes.
Remove it.
Acked-by: Andreas Dilger <adilger@sun.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Fix ext4_ext_journal_restart() so it returns any errors reported by
ext4_journal_extend() and ext4_journal_restart().
Signed-off-by: Shen Feng <shen@cn.fujitsu.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
When pos=0 or depth, the fields of ext4_ext_path is are not
completely filled. This patch also removes some unnecessary code.
Signed-off-by: Shen Feng <shen@cn.fujitsu.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
When allocating unitialized space at the end of file which had been
preallocated with the FALLOC_FL_KEEP_SIZE option, the file size is not
updated at that time. But the later we are not updating the file size
when writing to that preallocated space.
These changes are for code correctness. This patch allows us to update
the i_disksize at the write_end() callback of filesystem properly.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Quota allocation is not removed when ext4_mb_new_blocks calls
kmem_cache_alloc failed. Also make sure the allocation context is freed
on the error path.
Signed-off-by: Shen Feng <shen@cn.fujitsu.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The previous sb_min_blocksize() has already set the block size.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This patch mostly controls the way inode are allocated in order to
make ialloc aware of flex_bg block group grouping. It achieves this
by bypassing the Orlov allocator when block group meta-data are packed
toghether through mke2fs. Since the impact on the block allocator is
minimal, this patch should have little or no effect on other block
allocation algorithms. By controlling the inode allocation, it can
basically control where the initial search for new block begins and
thus indirectly manipulate the block allocator.
This allocator favors data and meta-data locality so the disk will
gradually be filled from block group zero upward. This helps improve
performance by reducing seek time. Since the group of inode tables
within one flex_bg are treated as one giant inode table, uninitialized
block groups would not need to partially initialize as many inode
table as with Orlov which would help fsck time as the filesystem usage
goes up.
Signed-off-by: Jose R. Santos <jrs@us.ibm.com>
Signed-off-by: Valerie Clement <valerie.clement@bull.net>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The error processing of the return value of mb_free_blocks is meanless
because it only returns 0. This fix includes
- make mb_free_blocks return void
- remove the error processing part in callers
- unlock group before calling ext4_error in mb_free_blocks
Signed-off-by: Shen Feng <shen@cn.fujitsu.com>
Cc: Mingming Cao <cmm@us.ibm.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
When the directory fs/ext4 is not correctly created under proc, the entry
under this directory should not be created.
Signed-off-by: Shen Feng <shen@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
ext4_next_entry() is used by the debugging function dx_show_leaf(), so
it must be defined before that function.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Since this a non-static function, make it be ext4 specific to avoid
conflicts with potentially other filesystems.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
remove the definitions of macros XATTR_TRUSTED_PREFIX and XATTR_USER_PREFIX
since they are defined in linux/xattr.h
Signed-off-by: Shen Feng <shen@cn.fujitsu.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
