Commit Graph

21414 Commits

Author SHA1 Message Date
Linus Torvalds
3b71710f08 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ecryptfs/ecryptfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ecryptfs/ecryptfs-2.6:
  eCryptfs: Copy up lower inode attrs in getattr
  ecryptfs: read on a directory should return EISDIR if not supported
  eCryptfs: Handle NULL nameidata pointers
  eCryptfs: Revert "dont call lookup_one_len to avoid NULL nameidata"
2011-02-21 17:25:00 -08:00
Randy Dunlap
361821854b Docbook: add fs/eventfd.c and fix typos in it
Add fs/eventfd.c to filesystems docbook.
Make typo corrections in fs/eventfd.c.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-21 15:07:04 -08:00
Linus Torvalds
8bd89ca220 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  ceph: keep reference to parent inode on ceph_dentry
  ceph: queue cap_snaps once per realm
  libceph: fix socket write error handling
  libceph: fix socket read error handling
2011-02-21 15:01:38 -08:00
Linus Torvalds
b4f5c46245 Merge git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
  [CIFS] update cifs version
  cifs: Fix regression in LANMAN (LM) auth code
  cifs: fix handling of scopeid in cifs_convert_address
2011-02-21 14:57:39 -08:00
Steve French
eed9e8307e [CIFS] update cifs version
Update version to 1.71 so we can more easily spot modules with the last two fixes

Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-02-21 22:31:47 +00:00
Shirish Pargaonkar
5e640927a5 cifs: Fix regression in LANMAN (LM) auth code
LANMAN response length was changed to 16 bytes instead of 24 bytes.
Revert it back to 24 bytes.

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
CC: stable@kernel.org
Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-02-21 21:53:30 +00:00
Tyler Hicks
55f9cf6bba eCryptfs: Copy up lower inode attrs in getattr
The lower filesystem may do some type of inode revalidation during a
getattr call. eCryptfs should take advantage of that by copying the
lower inode attributes to the eCryptfs inode after a call to
vfs_getattr() on the lower inode.

I originally wrote this fix while working on eCryptfs on nfsv3 support,
but discovered it also fixed an eCryptfs on ext4 nanosecond timestamp
bug that was reported.

https://bugs.launchpad.net/bugs/613873

Cc: <stable@kernel.org>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-02-21 14:46:36 -06:00
Andy Whitcroft
323ef68faf ecryptfs: read on a directory should return EISDIR if not supported
read() calls against a file descriptor connected to a directory are
incorrectly returning EINVAL rather than EISDIR:

  [EISDIR]
    [XSI] [Option Start] The fildes argument refers to a directory and the
    implementation does not allow the directory to be read using read()
    or pread(). The readdir() function should be used instead. [Option End]

This occurs because we do not have a .read operation defined for
ecryptfs directories.  Connect this up to generic_read_dir().

BugLink: http://bugs.launchpad.net/bugs/719691
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-02-21 14:46:36 -06:00
Tyler Hicks
70b8902199 eCryptfs: Handle NULL nameidata pointers
Allow for NULL nameidata pointers in eCryptfs create, lookup, and
d_revalidate functions.

Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-02-21 14:45:57 -06:00
Yehuda Sadeh
97d79b403e ceph: keep reference to parent inode on ceph_dentry
When creating a new dentry we now hold a reference to the parent
inode in the ceph_dentry.  This is required due to the new RCU
changes from 949854d0, which set dentry->d_parent to NULL in d_kill before
calling the ->release() callback.  If/when that behavior is changed, we can
revert this hack.

Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
2011-02-19 19:59:14 -08:00
Linus Torvalds
bc3adfc670 Merge branch 'fixes-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
* 'fixes-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: make sure MAYDAY_INITIAL_TIMEOUT is at least 2 jiffies long
  workqueue, freezer: unify spelling of 'freeze' + 'able' to 'freezable'
  workqueue: wake up a worker when a rescuer is leaving a gcwq
2011-02-18 12:36:06 -08:00
Tyler Hicks
8787c7a3e0 eCryptfs: Revert "dont call lookup_one_len to avoid NULL nameidata"
This reverts commit 21edad3220 and commit
93c3fe40c2, which fixed a regression by
the former.

Al Viro pointed out bypassed dcache lookups in
ecryptfs_new_lower_dentry(), misuse of vfs_path_lookup() in
ecryptfs_lookup_one_lower() and a dislike of passing nameidata to the
lower filesystem.

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-02-17 20:30:29 -06:00
Timo Warns
fa7ea87a05 fs/partitions: Validate map_count in Mac partition tables
Validate number of blocks in map and remove redundant variable.

Signed-off-by: Timo Warns <warns@pre-sense.de>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-17 17:50:51 -08:00
Linus Torvalds
ee71508702 Merge branch 'for-2.6.38' of git://linux-nfs.org/~bfields/linux
* 'for-2.6.38' of git://linux-nfs.org/~bfields/linux:
  nfsd: correctly handle return value from nfsd_map_name_to_*
2011-02-16 21:53:41 -08:00
Jeff Layton
9616125611 cifs: fix handling of scopeid in cifs_convert_address
The code finds, the '%' sign in an ipv6 address and copies that to a
buffer allocated on the stack. It then ignores that buffer, and passes
'pct' to simple_strtoul(), which doesn't work right because we're
comparing 'endp' against a completely different string.

Fix it by passing the correct pointer. While we're at it, this is a
good candidate for conversion to strict_strtoul as well.

Cc: stable@kernel.org
Cc: David Howells <dhowells@redhat.com>
Reported-by: Björn JACKE <bj@sernet.de>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-02-17 05:35:33 +00:00
Chuck Ebbert
e51900f7d3 block: revert block_dev read-only check
This reverts commit 75f1dc0d07 ("block: check bdev_read_only() from
blkdev_get()").  That commit added stricter checking to make sure
devices that were being used read-only were actually opened in that
mode.

It turns out that the change breaks a bunch of kernel code that opens
block devices.  Affected systems include dm, md, and the loop device.
Because strict checking for read-only opens of block devices was not
done before this, the code that opens the devices was opening them
read-write even if they were being used read-only.  Auditing all that
code will take time, and new userspace packages for dm, mdadm, etc.
will also be required.

Signed-off-by: Chuck Ebbert <cebbert@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-16 16:48:13 -08:00
NeilBrown
47c85291d3 nfsd: correctly handle return value from nfsd_map_name_to_*
These functions return an nfs status, not a host_err.  So don't
try to convert  before returning.

This is a regression introduced by
3c726023402a2f3b28f49b9d90ebf9e71151157d; I fixed up two of the callers,
but missed these two.

Cc: stable@kernel.org
Reported-by: Herbert Poetzl <herbert@13thfloor.at>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-02-16 18:31:05 -05:00
Linus Torvalds
3abb17e82f vfs: fix BUG_ON() in fs/namei.c:1461
When Al moved the nameidata_dentry_drop_rcu_maybe() call into the
do_follow_link function in commit 844a391799 ("nothing in
do_follow_link() is going to see RCU"), he mistakenly left the

	BUG_ON(inode != path->dentry->d_inode);

behind.  Which would otherwise be ok, but that BUG_ON() really needs to
be _after_ dropping RCU, since the dentry isn't necessarily stable
otherwise.

So complete the code movement in that commit, and move the BUG_ON() into
do_follow_link() too.  This means that we need to pass in 'inode' as an
argument (just for this one use), but that's a small thing.  And
eventually we may be confident enough in our path lookup that we can
just remove the BUG_ON() and the unnecessary inode argument.

Reported-and-tested-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-16 08:56:55 -08:00
Tejun Heo
58a69cb47e workqueue, freezer: unify spelling of 'freeze' + 'able' to 'freezable'
There are two spellings in use for 'freeze' + 'able' - 'freezable' and
'freezeable'.  The former is the more prominent one.  The latter is
mostly used by workqueue and in a few other odd places.  Unify the
spelling to 'freezable'.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Dmitry Torokhov <dtor@mail.ru>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Alex Dubov <oakad@yahoo.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Steven Whitehouse <swhiteho@redhat.com>
2011-02-16 17:48:59 +01:00
Linus Torvalds
f60c153d50 Merge branch 'for-2.6.38' of git://linux-nfs.org/~bfields/linux
* 'for-2.6.38' of git://linux-nfs.org/~bfields/linux:
  nfsd: break lease on unlink due to rename
  nfsd4: acquire only one lease per file
  nfsd4: modify fi_delegations under recall_lock
  nfsd4: remove unused deleg dprintk's.
  nfsd4: split lease setting into separate function
  nfsd4: fix leak on allocation error
  nfsd4: add helper function for lease setup
  nfsd4: split up nfsd_break_deleg_cb
  NFSD: memory corruption due to writing beyond the stat array
  NFSD: use nfserr for status after decode_cb_op_status
  nfsd: don't leak dentry count on mnt_want_write failure
2011-02-15 12:06:38 -08:00
Linus Torvalds
055d219441 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  get rid of nameidata_dentry_drop_rcu() calling nameidata_drop_rcu()
  drop out of RCU in return_reval
  split do_revalidate() into RCU and non-RCU cases
  in do_lookup() split RCU and non-RCU cases of need_revalidate
  nothing in do_follow_link() is going to see RCU
2011-02-15 08:06:36 -08:00
Linus Torvalds
007a14af26 Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: check return value of alloc_extent_map()
  Btrfs - Fix memory leak in btrfs_init_new_device()
  btrfs: prevent heap corruption in btrfs_ioctl_space_info()
  Btrfs: Fix balance panic
  Btrfs: don't release pages when we can't clear the uptodate bits
  Btrfs: fix page->private races
2011-02-15 08:00:35 -08:00
Martin Schwidefsky
261cd298a8 s390: remove task_show_regs
task_show_regs used to be a debugging aid in the early bringup days
of Linux on s390. /proc/<pid>/status is a world readable file, it
is not a good idea to show the registers of a process. The only
correct fix is to remove task_show_regs.

Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-15 07:34:16 -08:00
Al Viro
4e924a4f53 get rid of nameidata_dentry_drop_rcu() calling nameidata_drop_rcu()
can't happen anymore and didn't work right anyway

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-02-15 02:26:54 -05:00
Al Viro
f60aef7ec6 drop out of RCU in return_reval
... thus killing the need to handle drop-from-RCU in d_revalidate()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-02-15 02:26:54 -05:00
Al Viro
f5e1c1c1af split do_revalidate() into RCU and non-RCU cases
fixing oopsen in lookup_one_len()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-02-15 02:26:54 -05:00
Al Viro
24643087e7 in do_lookup() split RCU and non-RCU cases of need_revalidate
and use unlikely() instead of gotos, for fsck sake...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-02-15 02:26:54 -05:00
Al Viro
844a391799 nothing in do_follow_link() is going to see RCU
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-02-15 02:26:53 -05:00
Tsutomu Itoh
c26a920373 Btrfs: check return value of alloc_extent_map()
I add the check on the return value of alloc_extent_map() to several places.
In addition, alloc_extent_map() returns only the address or NULL.
Therefore, check by IS_ERR() is unnecessary. So, I remove IS_ERR() checking.

Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-02-14 16:21:37 -05:00
Ilya Dryomov
67100f255d Btrfs - Fix memory leak in btrfs_init_new_device()
Memory allocated by calling kstrdup() should be freed.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-02-14 16:21:31 -05:00
Dan Rosenberg
51788b1bdd btrfs: prevent heap corruption in btrfs_ioctl_space_info()
Commit bf5fc093c5 refactored
btrfs_ioctl_space_info() and introduced several security issues.

space_args.space_slots is an unsigned 64-bit type controlled by a
possibly unprivileged caller.  The comparison as a signed int type
allows providing values that are treated as negative and cause the
subsequent allocation size calculation to wrap, or be truncated to 0.
By providing a size that's truncated to 0, kmalloc() will return
ZERO_SIZE_PTR.  It's also possible to provide a value smaller than the
slot count.  The subsequent loop ignores the allocation size when
copying data in, resulting in a heap overflow or write to ZERO_SIZE_PTR.

The fix changes the slot count type and comparison typecast to u64,
which prevents truncation or signedness errors, and also ensures that we
don't copy more data than we've allocated in the subsequent loop.  Note
that zero-size allocations are no longer possible since there is already
an explicit check for space_args.space_slots being 0 and truncation of
this value is no longer an issue.

Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Signed-off-by: Josef Bacik <josef@redhat.com>
Reviewed-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-02-14 16:04:23 -05:00
Yan, Zheng
6848ad6461 Btrfs: Fix balance panic
Mark the cloned backref_node as checked in clone_backref_node()

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-02-14 16:00:03 -05:00
Chris Mason
e3f24cc521 Btrfs: don't release pages when we can't clear the uptodate bits
Btrfs tracks uptodate state in an rbtree as well as in the
page bits.  This is supposed to enable us to use block sizes other than
the page size, but there are a few parts still missing before that
completely works.

But, our readpage routine trusts this additional range based tracking
of uptodateness, much in the same way the buffer head up to date bits
are trusted for the other filesystems.

The problem is that sometimes we need to allocate memory in order to
split records in the rbtree, even when we are just clearing bits.  This
can be difficult when our clearing function is called GFP_ATOMIC, which
can happen in the releasepage path.

So, what happens today looks like this:

releasepage called with GFP_ATOMIC
btrfs_releasepage calls clear_extent_bit
clear_extent_bit fails to allocate ram, leaving the up to date bit set
btrfs_releasepage returns success

The end result is the page being gone, but btrfs thinking the range is
up to date.   Later on if someone tries to read that same page, the
btrfs readpage code will return immediately thinking the page is already
up to date.

This commit fixes things to fail the releasepage when we can't clear the
extent state bits.  It covers both data pages and metadata tree blocks.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-02-14 13:04:01 -05:00
Chris Mason
eb14ab8ed2 Btrfs: fix page->private races
There is a race where btrfs_releasepage can drop the
page->private contents just as alloc_extent_buffer is setting
up pages for metadata.  Because of how the Btrfs page flags work,
this results in us skipping the crc on the page during IO.

This patch sovles the race by waiting until after the extent buffer
is inserted into the radix tree before it sets page private.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-02-14 13:03:52 -05:00
J. Bruce Fields
83f6b0c182 nfsd: break lease on unlink due to rename
4795bb37ef "nfsd: break lease on unlink,
link, and rename", only broke the lease on the file that was being
renamed, and didn't handle the case where the target path refers to an
already-existing file that will be unlinked by a rename--in that case
the target file should have any leases broken as well.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-02-14 10:35:19 -05:00
J. Bruce Fields
acfdf5c383 nfsd4: acquire only one lease per file
Instead of acquiring one lease each time another client opens a file,
nfsd can acquire just one lease to represent all of them, and reference
count it to determine when to release it.

This fixes a regression introduced by
c45821d263 "locks: eliminate fl_mylease
callback": after that patch, only the struct file * is used to determine
who owns a given lease.  But since we recently converted the server to
share a single struct file per open, if we acquire multiple leases on
the same file from nfsd, it then becomes impossible on unlocking a lease
to determine which of those leases (all of whom share the same struct
file *) we meant to remove.

Thanks to Takashi Iwai <tiwai@suse.de> for catching a bug in a previous
version of this patch.

Tested-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-02-14 10:35:19 -05:00
J. Bruce Fields
5d926e8c2f nfsd4: modify fi_delegations under recall_lock
Modify fi_delegations only under the recall_lock, allowing us to use
that list on lease breaks.

Also some trivial cleanup to simplify later changes.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-02-14 10:35:19 -05:00
J. Bruce Fields
65bc58f518 nfsd4: remove unused deleg dprintk's.
These aren't all that useful, and get in the way of the next steps.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-02-14 10:35:19 -05:00
J. Bruce Fields
edab9782b5 nfsd4: split lease setting into separate function
Splitting some code into a separate function which we'll be adding some
more to.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-02-14 10:35:18 -05:00
J. Bruce Fields
dd239cc05f nfsd4: fix leak on allocation error
Also share some common exit code.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-02-14 10:35:18 -05:00
J. Bruce Fields
22d38c4c10 nfsd4: add helper function for lease setup
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-02-14 10:35:18 -05:00
J. Bruce Fields
6b57d9c86d nfsd4: split up nfsd_break_deleg_cb
We'll be adding some more code here soon.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-02-14 10:35:18 -05:00
Konstantin Khorenko
3aa6e0aa8a NFSD: memory corruption due to writing beyond the stat array
If nfsd fails to find an exported via NFS file in the readahead cache, it
should increment corresponding nfsdstats counter (ra_depth[10]), but due to a
bug it may instead write to ra_depth[11], corrupting the following field.

In a kernel with NFSDv4 compiled in the corruption takes the form of an
increment of a counter of the number of NFSv4 operation 0's received; since
there is no operation 0, this is harmless.

In a kernel with NFSDv4 disabled it corrupts whatever happens to be in the
memory beyond nfsdstats.

Signed-off-by: Konstantin Khorenko <khorenko@openvz.org>
Cc: stable@kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-02-14 10:35:18 -05:00
Benny Halevy
0af3f814cc NFSD: use nfserr for status after decode_cb_op_status
Bugs introduced in 85a5648019
"NFSD: Update XDR decoders in NFSv4 callback client"

Cc: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-02-14 10:35:18 -05:00
J. Bruce Fields
541ce98c10 nfsd: don't leak dentry count on mnt_want_write failure
The exit cleanup isn't quite right here.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-02-14 10:31:08 -05:00
Linus Torvalds
c8e0b00ed1 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  jbd2: call __jbd2_log_start_commit with j_state_lock write locked
  ext4: serialize unaligned asynchronous DIO
  ext4: make grpinfo slab cache names static
  ext4: Fix data corruption with multi-block writepages support
  ext4: fix up ext4 error handling
  ext4: unregister features interface on module unload
  ext4: fix panic on module unload when stopping lazyinit thread
2011-02-12 09:10:24 -08:00
Theodore Ts'o
e447183180 jbd2: call __jbd2_log_start_commit with j_state_lock write locked
On an SMP ARM system running ext4, I've received a report that the
first J_ASSERT in jbd2_journal_commit_transaction has been triggering:

	J_ASSERT(journal->j_running_transaction != NULL);

While investigating possible causes for this problem, I noticed that
__jbd2_log_start_commit() is getting called with j_state_lock only
read-locked, in spite of the fact that it's possible for it might
j_commit_request.  Fix this by grabbing the necessary information so
we can test to see if we need to start a new transaction before
dropping the read lock, and then calling jbd2_log_start_commit() which
will grab the write lock.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-02-12 08:18:24 -05:00
Eric Sandeen
e9e3bcecf4 ext4: serialize unaligned asynchronous DIO
ext4 has a data corruption case when doing non-block-aligned
asynchronous direct IO into a sparse file, as demonstrated
by xfstest 240.

The root cause is that while ext4 preallocates space in the
hole, mappings of that space still look "new" and 
dio_zero_block() will zero out the unwritten portions.  When
more than one AIO thread is going, they both find this "new"
block and race to zero out their portion; this is uncoordinated
and causes data corruption.

Dave Chinner fixed this for xfs by simply serializing all
unaligned asynchronous direct IO.  I've done the same here.
The difference is that we only wait on conversions, not all IO.
This is a very big hammer, and I'm not very pleased with
stuffing this into ext4_file_write().  But since ext4 is
DIO_LOCKING, we need to serialize it at this high level.

I tried to move this into ext4_ext_direct_IO, but by then
we have the i_mutex already, and we will wait on the
work queue to do conversions - which must also take the
i_mutex.  So that won't work.

This was originally exposed by qemu-kvm installing to
a raw disk image with a normal sector-63 alignment.  I've
tested a backport of this patch with qemu, and it does
avoid the corruption.  It is also quite a lot slower
(14 min for package installs, vs. 8 min for well-aligned)
but I'll take slow correctness over fast corruption any day.

Mingming suggested that we can track outstanding
conversions, and wait on those so that non-sparse
files won't be affected, and I've implemented that here;
unaligned AIO to nonsparse files won't take a perf hit.

[tytso@mit.edu: Keep the mutex as a hashed array instead
 of bloating the ext4 inode]

[tytso@mit.edu: Fix up namespace issues so that global
 variables are protected with an "ext4_" prefix.]

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-02-12 08:17:34 -05:00
Eric Sandeen
2892c15ddd ext4: make grpinfo slab cache names static
In 2.6.37 I was running into oopses with repeated module
loads & unloads.  I tracked this down to:

fb1813f4 ext4: use dedicated slab caches for group_info structures

(this was in addition to the features advert unload problem)

The kstrdup & subsequent kfree of the cache name was causing
a double free.  In slub, at least, if I read it right it allocates
& frees the name itself, slab seems to do something different...
so in slub I think we were leaking -our- cachep->name, and double
freeing the one allocated by slub.

After getting lost in slab/slub/slob a bit, I just looked at other
sized-caches that get allocated.  jbd2, biovec, sgpool all do it
more or less the way jbd2 does.  Below patch follows the jbd2
method of dynamically allocating a cache at mount time from
a list of static names.

(This might also possibly fix a race creating the caches with
parallel mounts running).

[Folded in a fix from Dan Carpenter which fixed an off-by-one error in
the original patch]

Cc: stable@kernel.org
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-02-12 08:12:18 -05:00
Linus Torvalds
d40b0c3482 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/dlm
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/dlm:
  dlm: use single thread workqueues
2011-02-11 16:29:57 -08:00