Commit Graph

29397 Commits

Author SHA1 Message Date
Linus Torvalds 87726c334b Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull ext3 regression fix from Jan Kara:
 "Fix an ext3 regression introduced during 3.7 merge window.  It leads
  to deadlock if you stress the filesystem in the right way (luckily
  only if blocksize < pagesize)."

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  jbd: Fix lock ordering bug in journal_unmap_buffer()
2012-11-26 17:42:07 -08:00
Jan Kara 4eff96dd52 writeback: put unused inodes to LRU after writeback completion
Commit 169ebd9013 ("writeback: Avoid iput() from flusher thread")
removed iget-iput pair from inode writeback.  As a side effect, inodes
that are dirty during iput_final() call won't be ever added to inode LRU
(iput_final() doesn't add dirty inodes to LRU and later when the inode
is cleaned there's noone to add the inode there).  Thus inodes are
effectively unreclaimable until someone looks them up again.

The practical effect of this bug is limited by the fact that inodes are
pinned by a dentry for long enough that the inode gets cleaned.  But
still the bug can have nasty consequences leading up to OOM conditions
under certain circumstances.  Following can easily reproduce the
problem:

  for (( i = 0; i < 1000; i++ )); do
    mkdir $i
    for (( j = 0; j < 1000; j++ )); do
      touch $i/$j
      echo 2 > /proc/sys/vm/drop_caches
    done
  done

then one needs to run 'sync; ls -lR' to make inodes reclaimable again.

We fix the issue by inserting unused clean inodes into the LRU after
writeback finishes in inode_sync_complete().

Signed-off-by: Jan Kara <jack@suse.cz>
Reported-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: <stable@vger.kernel.org>		[3.5+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-11-26 17:41:24 -08:00
Stanislav Kinsbursky 05f564849d proc: check vma->vm_file before dereferencing
Commit 7b540d0646 ("proc_map_files_readdir(): don't bother with
grabbing files") switched proc_map_files_readdir() to use @f_mode
directly instead of grabbing @file reference, but same time the test for
@vm_file presence was lost leading to nil dereference.  The patch brings
the test back.

The all proc_map_files feature is CONFIG_CHECKPOINT_RESTORE wrapped
(which is set to 'n' by default) so the bug doesn't affect regular
kernels.

The regression is 3.7-rc1 only as far as I can tell.

[gorcunov@openvz.org: provided changelog]
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
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>
2012-11-26 17:41:24 -08:00
Josh Triplett 1f20dfdaed sysfs: Mark sysfs_attr_ns static
Nothing outside of fs/sysfs/file.c references this function, so mark it static.

Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-26 16:25:36 -08:00
Seiji Aguchi 755d4fe465 efi_pstore: Add a sequence counter to a variable name
[Issue]

Currently, a variable name, which identifies each entry, consists of type, id and ctime.
But if multiple events happens in a short time, a second/third event may fail to log because
efi_pstore can't distinguish each event with current variable name.

[Solution]

A reasonable way to identify all events precisely is introducing a sequence counter to
the variable name.

The sequence counter has already supported in a pstore layer with "oopscount".
So, this patch adds it to a variable name.
Also, it is passed to read/erase callbacks of platform drivers in accordance with
the modification of the variable name.

  <before applying this patch>
 a variable name of first event: dump-type0-1-12345678
 a variable name of second event: dump-type0-1-12345678

  type:0
  id:1
  ctime:12345678

 If multiple events happen in a short time, efi_pstore can't distinguish them because
 variable names are same among them.

  <after applying this patch>

 it can be distinguishable by adding a sequence counter as follows.

 a variable name of first event: dump-type0-1-1-12345678
 a variable name of Second event: dump-type0-1-2-12345678

  type:0
  id:1
  sequence counter: 1(first event), 2(second event)
  ctime:12345678

In case of a write callback executed in pstore_console_write(), "0" is added to
an argument of the write callback because it just logs all kernel messages and
doesn't need to care about multiple events.

Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Mike Waychison <mikew@google.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2012-11-26 16:07:44 -08:00
Seiji Aguchi a9efd39cd5 efi_pstore: Add ctime to argument of erase callback
[Issue]

Currently, a variable name, which is used to identify each log entry, consists of type,
id and ctime. But an erase callback does not use ctime.

If efi_pstore supported just one log, type and id were enough.
However, in case of supporting multiple logs, it doesn't work because
it can't distinguish each entry without ctime at erasing time.

 <Example>

 As you can see below, efi_pstore can't differentiate first event from second one without ctime.

 a variable name of first event: dump-type0-1-12345678
 a variable name of second event: dump-type0-1-23456789

  type:0
  id:1
  ctime:12345678, 23456789

[Solution]

This patch adds ctime to an argument of an erase callback.

It works across reboots because ctime of pstore means the date that the record was originally stored.
To do this, efi_pstore saves the ctime to variable name at writing time and passes it to pstore
at reading time.

Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Acked-by: Mike Waychison <mikew@google.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2012-11-26 16:02:12 -08:00
Dave Chinner 7c4cebe8e0 xfs: inode allocation should use unmapped buffers.
Inode buffers do not need to be mapped as inodes are read or written
directly from/to the pages underlying the buffer. This fixes a
regression introduced by commit 611c994 ("xfs: make XBF_MAPPED the
default behaviour").

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-26 16:01:31 -06:00
David S. Miller 24bc518a68 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/wireless/iwlwifi/pcie/tx.c

Minor iwlwifi conflict in TX queue disabling between 'net', which
removed a bogus warning, and 'net-next' which added some status
register poking code.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-25 12:49:17 -05:00
Linus Torvalds 35f95d228e Most important part of this is that it fixes a regression in Samsung
NAND chip detection, introduced by some rework which went into 3.7. The
 initial fix wasn't quite complete, so it's in two parts. In fact the
 first part is committed twice (Artem committed his own copy of the same
 patch) and I've merged Artem's tree into mine which already had that fix.
 
 I'd have recommitted that to make it somewhat cleaner, but figured by
 this point in the release cycle it was better to merge *exactly* the
 commits which have been in linux-next.
 
 If I'd recommitted, I'd also omit the sparse warning fix. But it's there,
 and it's harmless — just marking one function as 'static' in onenand code.
 
 This also includes a couple more fixes for stable: an AB-BA deadlock in
 JFFS2, and an invalid range check in slram.
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Merge tag 'for-linus-20121123' of git://git.infradead.org/mtd-2.6

Pull MTD fixes from David Woodhouse:
 "The most important part of this is that it fixes a regression in
  Samsung NAND chip detection, introduced by some rework which went into
  3.7.  The initial fix wasn't quite complete, so it's in two parts.  In
  fact the first part is committed twice (Artem committed his own copy
  of the same patch) and I've merged Artem's tree into mine which
  already had that fix.

  I'd have recommitted that to make it somewhat cleaner, but figured by
  this point in the release cycle it was better to merge *exactly* the
  commits which have been in linux-next.

  If I'd recommitted, I'd also omit the sparse warning fix.  But it's
  there, and it's harmless — just marking one function as 'static' in
  onenand code.

  This also includes a couple more fixes for stable: an AB-BA deadlock
  in JFFS2, and an invalid range check in slram."

* tag 'for-linus-20121123' of git://git.infradead.org/mtd-2.6:
  mtd: nand: fix Samsung SLC detection regression
  mtd: nand: fix Samsung SLC NAND identification regression
  jffs2: Fix lock acquisition order bug in jffs2_write_begin
  mtd: onenand: Make flexonenand_set_boundary static
  mtd: slram: invalid checking of absolute end address
  mtd: ofpart: Fix incorrect NULL check in parse_ofoldpart_partitions()
  mtd: nand: fix Samsung SLC NAND identification regression
2012-11-23 15:12:17 -10:00
Jan Kara 25389bb207 jbd: Fix lock ordering bug in journal_unmap_buffer()
Commit 09e05d48 introduced a wait for transaction commit into
journal_unmap_buffer() in the case we are truncating a buffer undergoing commit
in the page stradding i_size on a filesystem with blocksize < pagesize. Sadly
we forgot to drop buffer lock before waiting for transaction commit and thus
deadlock is possible when kjournald wants to lock the buffer.

Fix the problem by dropping the buffer lock before waiting for transaction
commit. Since we are still holding page lock (and that is OK), buffer cannot
disappear under us.

CC: stable@vger.kernel.org # Wherever commit 09e05d48 was taken
Signed-off-by: Jan Kara <jack@suse.cz>
2012-11-23 15:17:18 +01:00
Linus Torvalds ca6215dfc7 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull reiserfs and ext3 fixes from Jan Kara:
 "Fixes of reiserfs deadlocks when quotas are enabled (locking there was
  completely busted by BKL conversion) and also one small ext3 fix in
  the trim interface."

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  ext3: Avoid underflow of in ext3_trim_fs()
  reiserfs: Move quota calls out of write lock
  reiserfs: Protect reiserfs_quota_write() with write lock
  reiserfs: Protect reiserfs_quota_on() with write lock
  reiserfs: Fix lock ordering during remount
2012-11-20 18:48:25 -10:00
Christoph Hellwig 0e446be448 xfs: add CRC checks to the log
Implement CRCs for the log buffers.  We re-use a field in
struct xlog_rec_header that was used for a weak checksum of the
log buffer payload in debug builds before.

The new checksumming uses the crc32c checksum we will use elsewhere
in XFS, and also protects the record header and addition cycle data.

Due to this there are some interesting changes in xlog_sync, as we
need to do the cycle wrapping for the split buffer case much earlier,
as we would touch the buffer after generating the checksum otherwise.

The CRC calculation is always enabled, even for non-CRC filesystems,
as adding this CRC does not change the log format. On non-CRC
filesystems, only issue an alert if a CRC mismatch is found and
allow recovery to continue - this will act as an indicator that
log recovery problems are a result of log corruption. On CRC enabled
filesystems, however, log recovery will fail.

Note that existing debug kernels will write a simple checksum value
to the log, so the first time this is run on a filesystem taht was
last used on a debug kernel it will through CRC mismatch warning
errors. These can be ignored.

Initially based on a patch from Dave Chinner, then modified
significantly by Christoph Hellwig.  Modified again by Dave Chinner
to get to this version.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-19 20:18:41 -06:00
Christoph Hellwig bc02e8693d xfs: add CRC infrastructure
- add a mount feature bit for CRC enabled filesystems
 - add some helpers for generating and verifying the CRCs
 - add a copy_uuid helper

The checksumming helpers are loosely based on similar ones in sctp,
all other bits come from Dave Chinner.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-19 20:11:24 -06:00
Lukas Czerner ae49eeec78 ext3: Avoid underflow of in ext3_trim_fs()
Currently if len argument in ext3_trim_fs() is smaller than one block,
the 'end' variable underflow. Avoid that by returning EINVAL if len is
smaller than file system block.

Also remove useless unlikely().

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2012-11-19 21:36:12 +01:00
Jan Kara 7af1168693 reiserfs: Move quota calls out of write lock
Calls into highlevel quota code cannot happen under the write lock. These
calls take dqio_mutex which ranks above write lock. So drop write lock
before calling back into quota code.

CC: stable@vger.kernel.org # >= 3.0
Signed-off-by: Jan Kara <jack@suse.cz>
2012-11-19 21:34:33 +01:00
Jan Kara 361d94a338 reiserfs: Protect reiserfs_quota_write() with write lock
Calls into reiserfs journalling code and reiserfs_get_block() need to
be protected with write lock. We remove write lock around calls to high
level quota code in the next patch so these paths would suddently become
unprotected.

CC: stable@vger.kernel.org # >= 3.0
Signed-off-by: Jan Kara <jack@suse.cz>
2012-11-19 21:34:33 +01:00
Jan Kara b9e06ef2e8 reiserfs: Protect reiserfs_quota_on() with write lock
In reiserfs_quota_on() we do quite some work - for example unpacking
tail of a quota file. Thus we have to hold write lock until a moment
we call back into the quota code.

CC: stable@vger.kernel.org # >= 3.0
Signed-off-by: Jan Kara <jack@suse.cz>
2012-11-19 21:34:32 +01:00
Jan Kara 3bb3e1fc47 reiserfs: Fix lock ordering during remount
When remounting reiserfs dquot_suspend() or dquot_resume() can be called.
These functions take dqonoff_mutex which ranks above write lock so we have
to drop it before calling into quota code.

CC: stable@vger.kernel.org # >= 3.0
Signed-off-by: Jan Kara <jack@suse.cz>
2012-11-19 21:34:32 +01:00
Adam Buchbinder b3834be5c4 various: Fix spelling of "asynchronous" in comments.
"Asynchronous" is misspelled in some comments. No code changes.

Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-11-19 14:32:13 +01:00
Adam Buchbinder 48fc7f7e78 Fix misspellings of "whether" in comments.
"Whether" is misspelled in various comments across the tree; this
fixes them. No code changes.

Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-11-19 14:31:35 +01:00
Masanari Iida 02582e9bcc treewide: fix typo of "suport" in various comments and Kconfig
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-11-19 14:16:09 +01:00
Eric W. Biederman 73f7ef4359 sysctl: Pass useful parameters to sysctl permissions
- Current is implicitly avaiable so passing current->nsproxy isn't useful.
- The ctl_table_header is needed to find how the sysctl table is connected
  to the rest of sysctl.
- ctl_table_root is avaiable in the ctl_table_header so no need to it.

With these changes it becomes possible to write a version of
net_sysctl_permission that takes into account the network namespace of
the sysctl table, an important feature in extending the user namespace.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-18 20:30:55 -05:00
Al Viro 3587b1b097 fanotify: fix FAN_Q_OVERFLOW case of fanotify_read()
If the FAN_Q_OVERFLOW bit set in event->mask, the fanotify event
metadata will not contain a valid file descriptor, but
copy_event_to_user() didn't check for that, and unconditionally does a
fd_install() on the file descriptor.

Which in turn will cause a BUG_ON() in __fd_install().

Introduced by commit 352e3b2492 ("fanotify: sanitize failure exits in
copy_event_to_user()")

Mea culpa - missed that path ;-/

Reported-by: Alex Shi <lkml.alex@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-11-18 09:30:00 -10:00
Linus Torvalds 8d938105e4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc VFS fixes from Al Viro:
 "Remove a bogus BUG_ON() that can trigger spuriously + alpha bits of
  do_mount() constification I'd missed during the merge window."

This pull request came in a week ago, I missed it for some reason.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  kill bogus BUG_ON() in do_close_on_exec()
  missing const in alpha callers of do_mount()
2012-11-18 09:13:48 -10:00
Linus Torvalds d28d3730fd xfs: bugfixes for 3.7-rc7
- fix attr tree double split corruption
 - fix broken error handling in xfs_vm_writepage
 - drop buffer io reference when a bad bio is built
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Merge tag 'for-linus-v3.7-rc7' of git://oss.sgi.com/xfs/xfs

Pull xfs bugfixes from Ben Myers:

 - fix attr tree double split corruption

 - fix broken error handling in xfs_vm_writepage

 - drop buffer io reference when a bad bio is built

* tag 'for-linus-v3.7-rc7' of git://oss.sgi.com/xfs/xfs:
  xfs: drop buffer io reference when a bad bio is built
  xfs: fix broken error handling in xfs_vm_writepage
  xfs: fix attr tree double split corruption
2012-11-18 08:29:34 -10:00
Ingo Molnar ec05a2311c Merge branch 'sched/urgent' into sched/core
Merge in fixes before we queue up dependent bits, to avoid conflicts.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-11-18 09:34:44 +01:00
Dave Chinner d69043c42d xfs: drop buffer io reference when a bad bio is built
Error handling in xfs_buf_ioapply_map() does not handle IO reference
counts correctly. We increment the b_io_remaining count before
building the bio, but then fail to decrement it in the failure case.
This leads to the buffer never running IO completion and releasing
the reference that the IO holds, so at unmount we can leak the
buffer. This leak is captured by this assert failure during unmount:

XFS: Assertion failed: atomic_read(&pag->pag_ref) == 0, file: fs/xfs/xfs_mount.c, line: 273

This is not a new bug - the b_io_remaining accounting has had this
problem for a long, long time - it's just very hard to get a
zero length bio being built by this code...

Further, the buffer IO error can be overwritten on a multi-segment
buffer by subsequent bio completions for partial sections of the
buffer. Hence we should only set the buffer error status if the
buffer is not already carrying an error status. This ensures that a
partial IO error on a multi-segment buffer will not be lost. This
part of the problem is a regression, however.

cc: <stable@vger.kernel.org>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-17 09:36:57 -06:00
Dave Chinner 3daed8bc3e xfs: fix broken error handling in xfs_vm_writepage
When we shut down the filesystem, it might first be detected in
writeback when we are allocating a inode size transaction. This
happens after we have moved all the pages into the writeback state
and unlocked them. Unfortunately, if we fail to set up the
transaction we then abort writeback and try to invalidate the
current page. This then triggers are BUG() in block_invalidatepage()
because we are trying to invalidate an unlocked page.

Fixing this is a bit of a chicken and egg problem - we can't
allocate the transaction until we've clustered all the pages into
the IO and we know the size of it (i.e. whether the last block of
the IO is beyond the current EOF or not). However, we don't want to
hold pages locked for long periods of time, especially while we lock
other pages to cluster them into the write.

To fix this, we need to make a clear delineation in writeback where
errors can only be handled by IO completion processing. That is,
once we have marked a page for writeback and unlocked it, we have to
report errors via IO completion because we've already started the
IO. We may not have submitted any IO, but we've changed the page
state to indicate that it is under IO so we must now use the IO
completion path to report errors.

To do this, add an error field to xfs_submit_ioend() to pass it the
error that occurred during the building on the ioend chain. When
this is non-zero, mark each ioend with the error and call
xfs_finish_ioend() directly rather than building bios. This will
immediately push the ioends through completion processing with the
error that has occurred.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-17 09:35:42 -06:00
Dave Chinner 42e2976f13 xfs: fix attr tree double split corruption
In certain circumstances, a double split of an attribute tree is
needed to insert or replace an attribute. In rare situations, this
can go wrong, leaving the attribute tree corrupted. In this case,
the attr being replaced is the last attr in a leaf node, and the
replacement is larger so doesn't fit in the same leaf node.
When we have the initial condition of a node format attribute
btree with two leaves at index 1 and 2. Call them L1 and L2.  The
leaf L1 is completely full, there is not a single byte of free space
in it. L2 is mostly empty.  The attribute being replaced - call it X
- is the last attribute in L1.

The way an attribute replace is executed is that the replacement
attribute - call it Y - is first inserted into the tree, but has an
INCOMPLETE flag set on it so that list traversals ignore it. Once
this transaction is committed, a second transaction it run to
atomically mark Y as COMPLETE and X as INCOMPLETE, so that a
traversal will now find Y and skip X. Once that transaction is
committed, attribute X is then removed.

So, the initial condition is:

     +--------+     +--------+
     |   L1   |     |   L2   |
     | fwd: 2 |---->| fwd: 0 |
     | bwd: 0 |<----| bwd: 1 |
     | fsp: 0 |     | fsp: N |
     |--------|     |--------|
     | attr A |     | attr 1 |
     |--------|     |--------|
     | attr B |     | attr 2 |
     |--------|     |--------|
     ..........     ..........
     |--------|     |--------|
     | attr X |     | attr n |
     +--------+     +--------+

So now we go to replace X, and see that L1:fsp = 0 - it is full so
we can't insert Y in the same leaf. So we record the the location of
attribute X so we can track it for later use, then we split L1 into
L1 and L3 and reblance across the two leafs. We end with:

     +--------+     +--------+     +--------+
     |   L1   |     |   L3   |     |   L2   |
     | fwd: 3 |---->| fwd: 2 |---->| fwd: 0 |
     | bwd: 0 |<----| bwd: 1 |<----| bwd: 3 |
     | fsp: M |     | fsp: J |     | fsp: N |
     |--------|     |--------|     |--------|
     | attr A |     | attr X |     | attr 1 |
     |--------|     +--------+     |--------|
     | attr B |                    | attr 2 |
     |--------|                    |--------|
     ..........                    ..........
     |--------|                    |--------|
     | attr W |                    | attr n |
     +--------+                    +--------+

And we track that the original attribute is now at L3:0.

We then try to insert Y into L1 again, and find that there isn't
enough room because the new attribute is larger than the old one.
Hence we have to split again to make room for Y. We end up with
this:

     +--------+     +--------+     +--------+     +--------+
     |   L1   |     |   L4   |     |   L3   |     |   L2   |
     | fwd: 4 |---->| fwd: 3 |---->| fwd: 2 |---->| fwd: 0 |
     | bwd: 0 |<----| bwd: 1 |<----| bwd: 4 |<----| bwd: 3 |
     | fsp: M |     | fsp: J |     | fsp: J |     | fsp: N |
     |--------|     |--------|     |--------|     |--------|
     | attr A |     | attr Y |     | attr X |     | attr 1 |
     |--------|     + INCOMP +     +--------+     |--------|
     | attr B |     +--------+                    | attr 2 |
     |--------|                                   |--------|
     ..........                                   ..........
     |--------|                                   |--------|
     | attr W |                                   | attr n |
     +--------+                                   +--------+

And now we have the new (incomplete) attribute @ L4:0, and the
original attribute at L3:0. At this point, the first transaction is
committed, and we move to the flipping of the flags.

This is where we are supposed to end up with this:

     +--------+     +--------+     +--------+     +--------+
     |   L1   |     |   L4   |     |   L3   |     |   L2   |
     | fwd: 4 |---->| fwd: 3 |---->| fwd: 2 |---->| fwd: 0 |
     | bwd: 0 |<----| bwd: 1 |<----| bwd: 4 |<----| bwd: 3 |
     | fsp: M |     | fsp: J |     | fsp: J |     | fsp: N |
     |--------|     |--------|     |--------|     |--------|
     | attr A |     | attr Y |     | attr X |     | attr 1 |
     |--------|     +--------+     + INCOMP +     |--------|
     | attr B |                    +--------+     | attr 2 |
     |--------|                                   |--------|
     ..........                                   ..........
     |--------|                                   |--------|
     | attr W |                                   | attr n |
     +--------+                                   +--------+

But that doesn't happen properly - the attribute tracking indexes
are not pointing to the right locations. What we end up with is both
the old attribute to be removed pointing at L4:0 and the new
attribute at L4:1.  On a debug kernel, this assert fails like so:

XFS: Assertion failed: args->index2 < be16_to_cpu(leaf2->hdr.count), file: fs/xfs/xfs_attr_leaf.c, line: 2725

because the new attribute location does not exist. On a production
kernel, this goes unnoticed and the code proceeds ahead merrily and
removes L4 because it thinks that is the block that is no longer
needed. This leaves the hash index node pointing to entries
L1, L4 and L2, but only blocks L1, L3 and L2 to exist. Further, the
leaf level sibling list is L1 <-> L4 <-> L2, but L4 is now free
space, and so everything is busted. This corruption is caused by the
removal of the old attribute triggering a join - it joins everything
correctly but then frees the wrong block.

xfs_repair will report something like:

bad sibling back pointer for block 4 in attribute fork for inode 131
problem with attribute contents in inode 131
would clear attr fork
bad nblocks 8 for inode 131, would reset to 3
bad anextents 4 for inode 131, would reset to 0

The problem lies in the assignment of the old/new blocks for
tracking purposes when the double leaf split occurs. The first split
tries to place the new attribute inside the current leaf (i.e.
"inleaf == true") and moves the old attribute (X) to the new block.
This sets up the old block/index to L1:X, and newly allocated
block to L3:0. It then moves attr X to the new block and tries to
insert attr Y at the old index. That fails, so it splits again.

With the second split, the rebalance ends up placing the new attr in
the second new block - L4:0 - and this is where the code goes wrong.
What is does is it sets both the new and old block index to the
second new block. Hence it inserts attr Y at the right place (L4:0)
but overwrites the current location of the attr to replace that is
held in the new block index (currently L3:0). It over writes it with
L4:1 - the index we later assert fail on.

Hopefully this table will show this in a foramt that is a bit easier
to understand:

Split		old attr index		new attr index
		vanilla	patched		vanilla	patched
before 1st	L1:26	L1:26		N/A	N/A
after 1st	L3:0	L3:0		L1:26	L1:26
after 2nd	L4:0	L3:0		L4:1	L4:0
                ^^^^			^^^^
		wrong			wrong

The fix is surprisingly simple, for all this analysis - just stop
the rebalance on the out-of leaf case from overwriting the new attr
index - it's already correct for the double split case.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-17 09:34:13 -06:00
Greg Kroah-Hartman 1e619a1bf9 Merge 3.7-rc6 into tty-next 2012-11-16 18:26:00 -08:00
David Rientjes fa0cbbf145 mm, oom: reintroduce /proc/pid/oom_adj
This is mostly a revert of 01dc52ebdf ("oom: remove deprecated oom_adj")
from Davidlohr Bueso.

It reintroduces /proc/pid/oom_adj for backwards compatibility with earlier
kernels.  It simply scales the value linearly when /proc/pid/oom_score_adj
is written.

The major difference is that its scheduled removal is no longer included
in Documentation/feature-removal-schedule.txt.  We do warn users with a
single printk, though, to suggest the more powerful and supported
/proc/pid/oom_score_adj interface.

Reported-by: Artem S. Tashkinov <t.artem@lycos.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-11-16 10:15:35 -08:00
David Teigland da8c66638a dlm: fix lvb invalidation conditions
When a node is removed that held a PW/EX lock, the
existing master node should invalidate the lvb on the
resource due to the purged lock.

Previously, the existing master node was invalidating
the lvb if it found only NL/CR locks on the resource
during recovery for the removed node.  This could lead
to cases where it invalidated the lvb and shouldn't
have, or cases where it should have invalidated and
didn't.

When recovery selects a *new* master node for a
resource, and that new master finds only NL/CR locks
on the resource after lock recovery, it should
invalidate the lvb.  This case was handled correctly
(but was incorrectly applied to the existing master
case also.)

When a process exits while holding a PW/EX lock,
the lvb on the resource should be invalidated.
This was not happening.

The lvb contents and VALNOTVALID flag should be
recovered before granting locks in recovery so that
the recovered lvb state is provided in the callback.
The lvb was being recovered after the lock was granted.

Signed-off-by: David Teigland <teigland@redhat.com>
2012-11-16 11:20:42 -06:00
Dave Chinner 1813dd6405 xfs: convert buffer verifiers to an ops structure.
To separate the verifiers from iodone functions and associate read
and write verifiers at the same time, introduce a buffer verifier
operations structure to the xfs_buf.

This avoids the need for assigning the write verifier, clearing the
iodone function and re-running ioend processing in the read
verifier, and gets rid of the nasty "b_pre_io" name for the write
verifier function pointer. If we ever need to, it will also be
easier to add further content specific callbacks to a buffer with an
ops structure in place.

We also avoid needing to export verifier functions, instead we
can simply export the ops structures for those that are needed
outside the function they are defined in.

This patch also fixes a directory block readahead verifier issue
it exposed.

This patch also adds ops callbacks to the inode/alloc btree blocks
initialised by growfs. These will need more work before they will
work with CRCs.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Phil White <pwhite@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15 21:35:12 -06:00
Dave Chinner b0f539de9f xfs: connect up write verifiers to new buffers
Metadata buffers that are read from disk have write verifiers
already attached to them, but newly allocated buffers do not. Add
appropriate write verifiers to all new metadata buffers.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15 21:35:09 -06:00
Dave Chinner 612cfbfe17 xfs: add pre-write metadata buffer verifier callbacks
These verifiers are essentially the same code as the read verifiers,
but do not require ioend processing. Hence factor the read verifier
functions and add a new write verifier wrapper that is used as the
callback.

This is done as one large patch for all verifiers rather than one
patch per verifier as the change is largely mechanical. This
includes hooking up the write verifier via the read verifier
function.

Hooking up the write verifier for buffers obtained via
xfs_trans_get_buf() will be done in a separate patch as that touches
code in many different places rather than just the verifier
functions.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15 21:35:02 -06:00
Dave Chinner cfb0285222 xfs: add buffer pre-write callback
Add a callback to the buffer write path to enable verification of
the buffer and CRC calculation prior to issuing the write to the
underlying storage.

If the callback function detects some kind of failure or error
condition, it must mark the buffer with an error so that the caller
can take appropriate action. In the case of xfs_buf_ioapply(), a
corrupt metadta buffer willt rigger a shutdown of the filesystem,
because something is clearly wrong and we can't allow corrupt
metadata to be written to disk.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Phil White <pwhite@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15 21:35:00 -06:00
Dave Chinner da6958c873 xfs: Add verifiers to dir2 data readahead.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Phil White <pwhite@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15 21:34:57 -06:00
Dave Chinner d9392a4bb7 xfs: add xfs_da_node verification
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Phil White <pwhite@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15 21:34:55 -06:00
Dave Chinner ad14c33ac8 xfs: factor and verify attr leaf reads
Some reads are not converted yet because it isn't obvious ahead of
time what the format of the block is going to be. Need to determine
how to tell if the first block in the tree is a node or leaf format
block. That will be done in later patches.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Phil White <pwhite@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15 21:34:52 -06:00
Dave Chinner e6f7667c4e xfs: factor dir2 leaf read
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Phil White <pwhite@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15 21:34:48 -06:00
Dave Chinner e481357264 xfs: factor out dir2 data block reading
And add a verifier callback function while there.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Phil White <pwhite@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15 21:34:45 -06:00
Dave Chinner 2025207ca6 xfs: factor dir2 free block reading
Also factor out the updating of the free block when removing entries
from leaf blocks, and add a verifier callback for reads.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Phil White <pwhite@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15 21:34:43 -06:00
Dave Chinner 82025d7f79 xfs: verify dir2 block format buffers
Add a dir2 block format read verifier. To fully verify every block
when read, call xfs_dir2_data_check() on them. Change
xfs_dir2_data_check() to do runtime checking, convert ASSERT()
checks to XFS_WANT_CORRUPTED_RETURN(), which will trigger an ASSERT
failure on debug kernels, but on production kernels will dump an
error to dmesg and return EFSCORRUPTED to the caller.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Phil White <pwhite@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15 21:34:41 -06:00
Dave Chinner 20f7e9f372 xfs: factor dir2 block read operations
In preparation for verifying dir2 block format buffers, factor
the read operations out of the block operations (lookup, addname,
getdents) and some of the additional logic to make it easier to
understand an dmodify the code.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15 21:34:39 -06:00
Dave Chinner 4bb20a83a2 xfs: add verifier callback to directory read code
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Phil White <pwhite@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15 21:34:36 -06:00
Dave Chinner c631919870 xfs: verify dquot blocks as they are read from disk
Add a dquot buffer verify callback function and pass it into the
buffer read functions. This checks all the dquots in a buffer, but
cannot completely verify the dquot ids are correct. Also, errors
cannot be repaired, so an additional function is added to repair bad
dquots in the buffer if such an error is detected in a context where
repair is allowed.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Phil White <pwhite@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15 21:34:33 -06:00
Dave Chinner 3d3e6f64e2 xfs: verify btree blocks as they are read from disk
Add an btree block verify callback function and pass it into the
buffer read functions. Because each different btree block type
requires different verification, add a function to the ops structure
that is called from the generic code.

Also, propagate the verification callback functions through the
readahead functions, and into the external bmap and bulkstat inode
readahead code that uses the generic btree buffer read functions.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Phil White <pwhite@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15 21:34:31 -06:00
Dave Chinner af133e8606 xfs: verify inode buffers as they are read from disk
Add an inode buffer verify callback function and pass it into the
buffer read functions. Inodes are special in that the verbose checks
will be done when reading the inode, but we still need to sanity
check the buffer when that is first read. Always verify the magic
numbers in all inodes in the buffer, rather than jus ton debug
kernels.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Phil White <pwhite@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15 21:34:19 -06:00
Dave Chinner bb80c6d79a xfs: verify AGFL blocks as they are read from disk
Add an AGFL block verify callback function and pass it into the
buffer read functions.

While this commit adds verification code to the AGFL, it cannot be
used reliably until the CRC format change comes along as mkfs does
not initialise the full AGFL. Hence it can be full of garbage at the
first mount and will fail verification right now. CRC enabled
filesystems won't have this problem, so leave the code that has
already been written ifdef'd out until the proper time.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Phil White <pwhite@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15 21:34:14 -06:00
Dave Chinner 3702ce6ed7 xfs: verify AGI blocks as they are read from disk
Add an AGI block verify callback function and pass it into the
buffer read functions. Remove the now redundant verification code
that is currently in use.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15 21:34:12 -06:00
Dave Chinner 5d5f527d13 xfs: verify AGF blocks as they are read from disk
Add an AGF block verify callback function and pass it into the
buffer read functions. This replaces the existing verification that
is done after the read completes.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15 21:34:10 -06:00
Dave Chinner 98021821a5 xfs: verify superblocks as they are read from disk
Add a superblock verify callback function and pass it into the
buffer read functions. Remove the now redundant verification code
that is currently in use.

Adding verification shows that secondary superblocks never have
their "sb_inprogress" flag cleared by mkfs.xfs, so when validating
the secondary superblocks during a grow operation we have to avoid
checking this field. Even if we fix mkfs, we will still have to
ignore this field for verification purposes unless a version of mkfs
that does not have this bug was used.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Phil White <pwhite@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15 21:34:07 -06:00
Dave Chinner eab4e63368 xfs: uncached buffer reads need to return an error
With verification being done as an IO completion callback, different
errors can be returned from a read. Uncached reads only return a
buffer or NULL on failure, which means the verification error cannot
be returned to the caller.

Split the error handling for these reads into two - a failure to get
a buffer will still return NULL, but a read error will return a
referenced buffer with b_error set rather than NULL. The caller is
responsible for checking the error state of the buffer returned.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Phil White <pwhite@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15 21:34:05 -06:00
Dave Chinner c3f8fc73ac xfs: make buffer read verication an IO completion function
Add a verifier function callback capability to the buffer read
interfaces.  This will be used by the callers to supply a function
that verifies the contents of the buffer when it is read from disk.
This patch does not provide callback functions, but simply modifies
the interfaces to allow them to be called.

The reason for adding this to the read interfaces is that it is very
difficult to tell fom the outside is a buffer was just read from
disk or whether we just pulled it out of cache. Supplying a callbck
allows the buffer cache to use it's internal knowledge of the buffer
to execute it only when the buffer is read from disk.

It is intended that the verifier functions will mark the buffer with
an EFSCORRUPTED error when verification fails. This allows the
reading context to distinguish a verification error from an IO
error, and potentially take further actions on the buffer (e.g.
attempt repair) based on the error reported.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Phil White <pwhite@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15 21:34:02 -06:00
Yan Hong 7dd2517c39 fs/debugsfs: remove unnecessary inode->i_private initialization
inode->i_private is promised to be NULL on allocation, no need to set it
explicitly.

Signed-off-by: Yan Hong <clouds.yan@gmail.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-15 17:46:42 -08:00
Linus Torvalds ce95a36bb9 Two patches which fix a problem reported by several people in the past,
but only fixed now because no one gave enough material for debugging.
 
 Anyway, these fix the problem that sometimes after a power cut the
 file-system is not mountable with the following symptom:
 
 	grab_empty_leb: could not find an empty LEB
 
 The fixes make the file-system mountable again.
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Merge tag 'upstream-3.7-rc6' of git://git.infradead.org/linux-ubifs

Pull UBIFS fixes from Artem Bityutskiy:
 "Two patches which fix a problem reported by several people in the
  past, but only fixed now because no one gave enough material for
  debugging.

  Anyway, these fix the problem that sometimes after a power cut the
  file-system is not mountable with the following symptom:

	grab_empty_leb: could not find an empty LEB

  The fixes make the file-system mountable again."

* tag 'upstream-3.7-rc6' of git://git.infradead.org/linux-ubifs:
  UBIFS: fix mounting problems after power cuts
  UBIFS: introduce categorized lprops counter
2012-11-15 11:28:43 -08:00
Colin Ian King 70a6f46d7b pstore: Fix NULL pointer dereference in console writes
Passing a NULL id causes a NULL pointer deference in writers such as
erst_writer and efi_pstore_write because they expect to update this id.
Pass a dummy id instead.

This avoids a cascade of oopses caused when the initial
pstore_console_write passes a null which in turn causes writes to the
console causing further oopses in subsequent pstore_console_write calls.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
2012-11-14 18:30:21 -08:00
Dave Chinner fb59581404 xfs: remove xfs_flushinval_pages
It's just a simple wrapper around VFS functionality, and is actually
bugging in that it doesn't remove mappings before invalidating the
page cache. Remove it and replace it with the correct VFS
functionality.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Andrew Dahl <adahl@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-14 15:15:08 -06:00
Dave Chinner 4bc1ea6b8d xfs: remove xfs_flush_pages
It is a complex wrapper around VFS functions, but there are VFS
functions that provide exactly the same functionality. Call the VFS
functions directly and remove the unnecessary indirection and
complexity.

We don't need to care about clearing the XFS_ITRUNCATED flag, as
that is done during .writepages. Hence is cleared by the VFS
writeback path if there is anything to write back during the flush.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Andrew Dahl <adahl@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-14 15:12:45 -06:00
Dave Chinner 95eacf0f71 xfs: remove xfs_wait_on_pages()
It's just a simple wrapper around a VFS function that is only called
by another function in xfs_fs_subr.c. Remove it and call the VFS
function directly.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Andrew Dahl <adahl@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-14 15:12:20 -06:00
Andrew Dahl d6638ae244 xfs: reverse the check on XFS_IOC_ZERO_RANGE
Reversing the check on XFS_IOC_ZERO_RANGE.

Range should be zeroed if the start is less than or equal to the end.

Signed-off-by: Andrew Dahl <adahl@sgi.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-14 15:11:52 -06:00
Dave Chinner f5b8911b67 xfs: remove xfs_tosspages
It's a buggy, unnecessary wrapper that is duplicating
truncate_pagecache_range().

When replacing the call in xfs_change_file_space(), also ensure that
the length being allocated/freed is always positive before making
any changes. These checks are done in the lower extent manipulation
functions, too, but we need to do them before any page cache
operations.

Reported-by: Andrew Dahl <adahl@sgi.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-By: Andrew Dahl <adahl@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-14 15:11:19 -06:00
Greg Kroah-Hartman 54d5f88f25 Merge v3.7-rc5 into tty-next
This pulls in the 3.7-rc5 fixes into tty-next to make it easier to test.
2012-11-14 12:30:12 -08:00
Dave Chinner de497688da xfs: make growfs initialise the AGFL header
For verification purposes, AGFLs need to be initialised to a known
set of values. For upcoming CRC changes, they are also headers that
need to be initialised. Currently, growfs does neither for the AGFLs
- it ignores them completely. Add initialisation of the AGFL to be
full of invalid block numbers (NULLAGBLOCK) to put the
infrastructure in place needed for CRC support.

Includes a comment clarification from Jeff Liu.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by Rich Johnston <rjohnston@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-13 16:40:59 -06:00
Dave Chinner fd23683c3b xfs: growfs: use uncached buffers for new headers
When writing the new AG headers to disk, we can't attach write
verifiers because they have a dependency on the struct xfs-perag
being attached to the buffer to be fully initialised and growfs
can't fully initialise them until later in the process.

The simplest way to avoid this problem is to use uncached buffers
for writing the new headers. These buffers don't have the xfs-perag
attached to them, so it's simple to detect in the write verifier and
be able to skip the checks that need the xfs-perag.

This enables us to attach the appropriate buffer ops to the buffer
and hence calculate CRCs on the way to disk. IT also means that the
buffer is torn down immediately, and so the first access to the AG
headers will re-read the header from disk and perform full
verification of the buffer. This way we also can catch corruptions
due to problems that went undetected in growfs.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by Rich Johnston <rjohnston@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-13 16:40:43 -06:00
Dave Chinner b64f3a390d xfs: use btree block initialisation functions in growfs
Factor xfs_btree_init_block() to be independent of the btree cursor,
and use the function to initialise btree blocks in the growfs code.
This makes adding support for different format btree blocks simple.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by Rich Johnston <rjohnston@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-13 16:40:27 -06:00
Dave Chinner ee73259b40 xfs: add more attribute tree trace points.
Added when debugging recent attribute tree problems to more finely
trace code execution through the maze of twisty passages that makes
up the attr code.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-13 14:47:00 -06:00
Dave Chinner 37eb17e604 xfs: drop buffer io reference when a bad bio is built
Error handling in xfs_buf_ioapply_map() does not handle IO reference
counts correctly. We increment the b_io_remaining count before
building the bio, but then fail to decrement it in the failure case.
This leads to the buffer never running IO completion and releasing
the reference that the IO holds, so at unmount we can leak the
buffer. This leak is captured by this assert failure during unmount:

XFS: Assertion failed: atomic_read(&pag->pag_ref) == 0, file: fs/xfs/xfs_mount.c, line: 273

This is not a new bug - the b_io_remaining accounting has had this
problem for a long, long time - it's just very hard to get a
zero length bio being built by this code...

Further, the buffer IO error can be overwritten on a multi-segment
buffer by subsequent bio completions for partial sections of the
buffer. Hence we should only set the buffer error status if the
buffer is not already carrying an error status. This ensures that a
partial IO error on a multi-segment buffer will not be lost. This
part of the problem is a regression, however.

cc: <stable@vger.kernel.org>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-13 14:45:57 -06:00
Dave Chinner 7bf7f35219 xfs: fix broken error handling in xfs_vm_writepage
When we shut down the filesystem, it might first be detected in
writeback when we are allocating a inode size transaction. This
happens after we have moved all the pages into the writeback state
and unlocked them. Unfortunately, if we fail to set up the
transaction we then abort writeback and try to invalidate the
current page. This then triggers are BUG() in block_invalidatepage()
because we are trying to invalidate an unlocked page.

Fixing this is a bit of a chicken and egg problem - we can't
allocate the transaction until we've clustered all the pages into
the IO and we know the size of it (i.e. whether the last block of
the IO is beyond the current EOF or not). However, we don't want to
hold pages locked for long periods of time, especially while we lock
other pages to cluster them into the write.

To fix this, we need to make a clear delineation in writeback where
errors can only be handled by IO completion processing. That is,
once we have marked a page for writeback and unlocked it, we have to
report errors via IO completion because we've already started the
IO. We may not have submitted any IO, but we've changed the page
state to indicate that it is under IO so we must now use the IO
completion path to report errors.

To do this, add an error field to xfs_submit_ioend() to pass it the
error that occurred during the building on the ioend chain. When
this is non-zero, mark each ioend with the error and call
xfs_finish_ioend() directly rather than building bios. This will
immediately push the ioends through completion processing with the
error that has occurred.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-13 14:45:45 -06:00
Dave Chinner 07428d7f0c xfs: fix attr tree double split corruption
In certain circumstances, a double split of an attribute tree is
needed to insert or replace an attribute. In rare situations, this
can go wrong, leaving the attribute tree corrupted. In this case,
the attr being replaced is the last attr in a leaf node, and the
replacement is larger so doesn't fit in the same leaf node.
When we have the initial condition of a node format attribute
btree with two leaves at index 1 and 2. Call them L1 and L2.  The
leaf L1 is completely full, there is not a single byte of free space
in it. L2 is mostly empty.  The attribute being replaced - call it X
- is the last attribute in L1.

The way an attribute replace is executed is that the replacement
attribute - call it Y - is first inserted into the tree, but has an
INCOMPLETE flag set on it so that list traversals ignore it. Once
this transaction is committed, a second transaction it run to
atomically mark Y as COMPLETE and X as INCOMPLETE, so that a
traversal will now find Y and skip X. Once that transaction is
committed, attribute X is then removed.

So, the initial condition is:

     +--------+     +--------+
     |   L1   |     |   L2   |
     | fwd: 2 |---->| fwd: 0 |
     | bwd: 0 |<----| bwd: 1 |
     | fsp: 0 |     | fsp: N |
     |--------|     |--------|
     | attr A |     | attr 1 |
     |--------|     |--------|
     | attr B |     | attr 2 |
     |--------|     |--------|
     ..........     ..........
     |--------|     |--------|
     | attr X |     | attr n |
     +--------+     +--------+


So now we go to replace X, and see that L1:fsp = 0 - it is full so
we can't insert Y in the same leaf. So we record the the location of
attribute X so we can track it for later use, then we split L1 into
L1 and L3 and reblance across the two leafs. We end with:


     +--------+     +--------+     +--------+
     |   L1   |     |   L3   |     |   L2   |
     | fwd: 3 |---->| fwd: 2 |---->| fwd: 0 |
     | bwd: 0 |<----| bwd: 1 |<----| bwd: 3 |
     | fsp: M |     | fsp: J |     | fsp: N |
     |--------|     |--------|     |--------|
     | attr A |     | attr X |     | attr 1 |
     |--------|     +--------+     |--------|
     | attr B |                    | attr 2 |
     |--------|                    |--------|
     ..........                    ..........
     |--------|                    |--------|
     | attr W |                    | attr n |
     +--------+                    +--------+


And we track that the original attribute is now at L3:0.

We then try to insert Y into L1 again, and find that there isn't
enough room because the new attribute is larger than the old one.
Hence we have to split again to make room for Y. We end up with
this:


     +--------+     +--------+     +--------+     +--------+
     |   L1   |     |   L4   |     |   L3   |     |   L2   |
     | fwd: 4 |---->| fwd: 3 |---->| fwd: 2 |---->| fwd: 0 |
     | bwd: 0 |<----| bwd: 1 |<----| bwd: 4 |<----| bwd: 3 |
     | fsp: M |     | fsp: J |     | fsp: J |     | fsp: N |
     |--------|     |--------|     |--------|     |--------|
     | attr A |     | attr Y |     | attr X |     | attr 1 |
     |--------|     + INCOMP +     +--------+     |--------|
     | attr B |     +--------+                    | attr 2 |
     |--------|                                   |--------|
     ..........                                   ..........
     |--------|                                   |--------|
     | attr W |                                   | attr n |
     +--------+                                   +--------+

And now we have the new (incomplete) attribute @ L4:0, and the
original attribute at L3:0. At this point, the first transaction is
committed, and we move to the flipping of the flags.

This is where we are supposed to end up with this:

     +--------+     +--------+     +--------+     +--------+
     |   L1   |     |   L4   |     |   L3   |     |   L2   |
     | fwd: 4 |---->| fwd: 3 |---->| fwd: 2 |---->| fwd: 0 |
     | bwd: 0 |<----| bwd: 1 |<----| bwd: 4 |<----| bwd: 3 |
     | fsp: M |     | fsp: J |     | fsp: J |     | fsp: N |
     |--------|     |--------|     |--------|     |--------|
     | attr A |     | attr Y |     | attr X |     | attr 1 |
     |--------|     +--------+     + INCOMP +     |--------|
     | attr B |                    +--------+     | attr 2 |
     |--------|                                   |--------|
     ..........                                   ..........
     |--------|                                   |--------|
     | attr W |                                   | attr n |
     +--------+                                   +--------+

But that doesn't happen properly - the attribute tracking indexes
are not pointing to the right locations. What we end up with is both
the old attribute to be removed pointing at L4:0 and the new
attribute at L4:1.  On a debug kernel, this assert fails like so:

XFS: Assertion failed: args->index2 < be16_to_cpu(leaf2->hdr.count), file: fs/xfs/xfs_attr_leaf.c, line: 2725

because the new attribute location does not exist. On a production
kernel, this goes unnoticed and the code proceeds ahead merrily and
removes L4 because it thinks that is the block that is no longer
needed. This leaves the hash index node pointing to entries
L1, L4 and L2, but only blocks L1, L3 and L2 to exist. Further, the
leaf level sibling list is L1 <-> L4 <-> L2, but L4 is now free
space, and so everything is busted. This corruption is caused by the
removal of the old attribute triggering a join - it joins everything
correctly but then frees the wrong block.

xfs_repair will report something like:

bad sibling back pointer for block 4 in attribute fork for inode 131
problem with attribute contents in inode 131
would clear attr fork
bad nblocks 8 for inode 131, would reset to 3
bad anextents 4 for inode 131, would reset to 0

The problem lies in the assignment of the old/new blocks for
tracking purposes when the double leaf split occurs. The first split
tries to place the new attribute inside the current leaf (i.e.
"inleaf == true") and moves the old attribute (X) to the new block.
This sets up the old block/index to L1:X, and newly allocated
block to L3:0. It then moves attr X to the new block and tries to
insert attr Y at the old index. That fails, so it splits again.

With the second split, the rebalance ends up placing the new attr in
the second new block - L4:0 - and this is where the code goes wrong.
What is does is it sets both the new and old block index to the
second new block. Hence it inserts attr Y at the right place (L4:0)
but overwrites the current location of the attr to replace that is
held in the new block index (currently L3:0). It over writes it with
L4:1 - the index we later assert fail on.

Hopefully this table will show this in a foramt that is a bit easier
to understand:

Split		old attr index		new attr index
		vanilla	patched		vanilla	patched
before 1st	L1:26	L1:26		N/A	N/A
after 1st	L3:0	L3:0		L1:26	L1:26
after 2nd	L4:0	L3:0		L4:1	L4:0
                ^^^^			^^^^
		wrong			wrong

The fix is surprisingly simple, for all this analysis - just stop
the rebalance on the out-of leaf case from overwriting the new attr
index - it's already correct for the double split case.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-13 14:45:29 -06:00
Al Viro 5a8477660d kill bogus BUG_ON() in do_close_on_exec()
It can be legitimately triggered via procfs access.  Now, at least
2 of 3 of get_files_struct() callers in procfs are useless, but
when and if we get rid of those we can always add WARN_ON() here.
BUG_ON() at that spot is simply wrong.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-11-12 01:19:02 -05:00
Linus Torvalds affd9a8dbc Merge branch 'for-linus' of git://git.samba.org/sfrench/cifs-2.6
Pull cifs fixes from Jeff Layton.

* 'for-linus' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: Do not lookup hashed negative dentry in cifs_atomic_open
  cifs: fix potential buffer overrun in cifs.idmap handling code
2012-11-10 06:59:35 +01:00
Thomas Betker 5ffd3412ae jffs2: Fix lock acquisition order bug in jffs2_write_begin
jffs2_write_begin() first acquires the page lock, then f->sem. This
causes an AB-BA deadlock with jffs2_garbage_collect_live(), which first
acquires f->sem, then the page lock:

jffs2_garbage_collect_live
    mutex_lock(&f->sem)                         (A)
    jffs2_garbage_collect_dnode
        jffs2_gc_fetch_page
            read_cache_page_async
                do_read_cache_page
                    lock_page(page)             (B)

jffs2_write_begin
    grab_cache_page_write_begin
        find_lock_page
            lock_page(page)                     (B)
    mutex_lock(&f->sem)                         (A)

We fix this by restructuring jffs2_write_begin() to take f->sem before
the page lock. However, we make sure that f->sem is not held when
calling jffs2_reserve_space(), as this is not permitted by the locking
rules.

The deadlock above was observed multiple times on an SoC with a dual
ARMv7 (Cortex-A9), running the long-term 3.4.11 kernel; it occurred
when using scp to copy files from a host system to the ARM target
system. The fix was heavily tested on the same target system.

Cc: stable@vger.kernel.org
Signed-off-by: Thomas Betker <thomas.betker@rohde-schwarz.com>
Acked-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2012-11-09 17:02:50 +02:00
Linus Torvalds ce6d841e9c Merge branch 'akpm' (Fixes from Andrew)
Merge misc fixes from Andrew Morton:
 "Five fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (5 patches)
  h8300: add missing L1_CACHE_SHIFT
  mm: bugfix: set current->reclaim_state to NULL while returning from kswapd()
  fanotify: fix missing break
  revert "epoll: support for disabling items, and a self-test app"
  checkpatch: improve network block comment style checking
2012-11-09 06:53:02 +01:00
Linus Torvalds a601e63717 xfs: bugfixes for 3.7-rc5
- fix for large transactions spanning multiple iclog buffers
 - zero the allocation_args structure on the stack before using it
   to determine whether to use a worker for allocation
 - move allocation stack switch to xfs_bmapi_allocate in order
   to prevent deadlock on AGF buffers
 - growfs no longer reads in garbage for new secondary superblocks
 - silence a build warning
 - ensure that invalid buffers never get written to disk while on
   free list
 - don't vmap inode cluster buffers during free
 - fix buffer shutdown reference count mismatch
 - fix reading of wrapped log data
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Merge tag 'for-linus-v3.7-rc5' of git://oss.sgi.com/xfs/xfs

Pull xfs bugfixes from Ben Myers:

 - fix for large transactions spanning multiple iclog buffers

 - zero the allocation_args structure on the stack before using it to
   determine whether to use a worker for allocation
 - move allocation stack switch to xfs_bmapi_allocate in order to
   prevent deadlock on AGF buffers

 - growfs no longer reads in garbage for new secondary superblocks

 - silence a build warning

 - ensure that invalid buffers never get written to disk while on free
   list

 - don't vmap inode cluster buffers during free

 - fix buffer shutdown reference count mismatch

 - fix reading of wrapped log data

* tag 'for-linus-v3.7-rc5' of git://oss.sgi.com/xfs/xfs:
  xfs: fix reading of wrapped log data
  xfs: fix buffer shudown reference count mismatch
  xfs: don't vmap inode cluster buffers during free
  xfs: invalidate allocbt blocks moved to the free list
  xfs: silence uninitialised f.file warning.
  xfs: growfs: don't read garbage for new secondary superblocks
  xfs: move allocation stack switch up to xfs_bmapi_allocate
  xfs: introduce XFS_BMAPI_STACK_SWITCH
  xfs: zero allocation_args on the kernel stack
  xfs: only update the last_sync_lsn when a transaction completes
2012-11-09 06:42:51 +01:00
Eric Paris 848561d368 fanotify: fix missing break
Anders Blomdell noted in 2010 that Fanotify lost events and provided a
test case.  Eric Paris confirmed it was a bug and posted a fix to the
list

  https://groups.google.com/forum/?fromgroups=#!topic/linux.kernel/RrJfTfyW2BE

but never applied it.  Repeated attempts over time to actually get him
to apply it have never had a reply from anyone who has raised it

So apply it anyway

Signed-off-by: Alan Cox <alan@linux.intel.com>
Reported-by: Anders Blomdell <anders.blomdell@control.lth.se>
Cc: Eric Paris <eparis@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-11-09 06:41:47 +01:00
Andrew Morton a80a6b85b4 revert "epoll: support for disabling items, and a self-test app"
Revert commit 03a7beb55b ("epoll: support for disabling items, and a
self-test app") pending resolution of the issues identified by Michael
Kerrisk, copied below.

We'll revisit this for 3.8.

: I've taken a look at this patch as it currently stands in 3.7-rc1, and
: done a bit of testing. (By the way, the test program
: tools/testing/selftests/epoll/test_epoll.c does not compile...)
:
: There are one or two places where the behavior seems a little strange,
: so I have a question or two at the end of this mail. But other than
: that, I want to check my understanding so that the interface can be
: correctly documented.
:
: Just to go though my understanding, the problem is the following
: scenario in a multithreaded application:
:
: 1. Multiple threads are performing epoll_wait() operations,
:    and maintaining a user-space cache that contains information
:    corresponding to each file descriptor being monitored by
:    epoll_wait().
:
: 2. At some point, a thread wants to delete (EPOLL_CTL_DEL)
:    a file descriptor from the epoll interest list, and
:    delete the corresponding record from the user-space cache.
:
: 3. The problem with (2) is that some other thread may have
:    previously done an epoll_wait() that retrieved information
:    about the fd in question, and may be in the middle of using
:    information in the cache that relates to that fd. Thus,
:    there is a potential race.
:
: 4. The race can't solved purely in user space, because doing
:    so would require applying a mutex across the epoll_wait()
:    call, which would of course blow thread concurrency.
:
: Right?
:
: Your solution is the EPOLL_CTL_DISABLE operation. I want to
: confirm my understanding about how to use this flag, since
: the description that has accompanied the patches so far
: has been a bit sparse
:
: 0. In the scenario you're concerned about, deleting a file
:    descriptor means (safely) doing the following:
:    (a) Deleting the file descriptor from the epoll interest list
:        using EPOLL_CTL_DEL
:    (b) Deleting the corresponding record in the user-space cache
:
: 1. It's only meaningful to use this EPOLL_CTL_DISABLE in
:    conjunction with EPOLLONESHOT.
:
: 2. Using EPOLL_CTL_DISABLE without using EPOLLONESHOT in
:    conjunction is a logical error.
:
: 3. The correct way to code multithreaded applications using
:    EPOLL_CTL_DISABLE and EPOLLONESHOT is as follows:
:
:    a. All EPOLL_CTL_ADD and EPOLL_CTL_MOD operations should
:       should EPOLLONESHOT.
:
:    b. When a thread wants to delete a file descriptor, it
:       should do the following:
:
:       [1] Call epoll_ctl(EPOLL_CTL_DISABLE)
:       [2] If the return status from epoll_ctl(EPOLL_CTL_DISABLE)
:           was zero, then the file descriptor can be safely
:           deleted by the thread that made this call.
:       [3] If the epoll_ctl(EPOLL_CTL_DISABLE) fails with EBUSY,
:           then the descriptor is in use. In this case, the calling
:           thread should set a flag in the user-space cache to
:           indicate that the thread that is using the descriptor
:           should perform the deletion operation.
:
: Is all of the above correct?
:
: The implementation depends on checking on whether
: (events & ~EP_PRIVATE_BITS) == 0
: This replies on the fact that EPOLL_CTL_AD and EPOLL_CTL_MOD always
: set EPOLLHUP and EPOLLERR in the 'events' mask, and EPOLLONESHOT
: causes those flags (as well as all others in ~EP_PRIVATE_BITS) to be
: cleared.
:
: A corollary to the previous paragraph is that using EPOLL_CTL_DISABLE
: is only useful in conjunction with EPOLLONESHOT. However, as things
: stand, one can use EPOLL_CTL_DISABLE on a file descriptor that does
: not have EPOLLONESHOT set in 'events' This results in the following
: (slightly surprising) behavior:
:
: (a) The first call to epoll_ctl(EPOLL_CTL_DISABLE) returns 0
:     (the indicator that the file descriptor can be safely deleted).
: (b) The next call to epoll_ctl(EPOLL_CTL_DISABLE) fails with EBUSY.
:
: This doesn't seem particularly useful, and in fact is probably an
: indication that the user made a logic error: they should only be using
: epoll_ctl(EPOLL_CTL_DISABLE) on a file descriptor for which
: EPOLLONESHOT was set in 'events'. If that is correct, then would it
: not make sense to return an error to user space for this case?

Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: "Paton J. Lewis" <palewis@adobe.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-11-09 06:41:46 +01:00
Brian Foster 579b62faa5 xfs: add background scanning to clear eofblocks inodes
Create a new mount workqueue and delayed_work to enable background
scanning and freeing of eofblocks inodes. The scanner kicks in once
speculative preallocation occurs and stops requeueing itself when
no eofblocks inodes exist.

The scan interval is based on the new
'speculative_prealloc_lifetime' tunable (default to 5m). The
background scanner performs unfiltered, best effort scans (which
skips inodes under lock contention or with a dirty cache mapping).

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08 15:34:59 -06:00
Brian Foster 00ca79a04b xfs: add minimum file size filtering to eofblocks scan
Support minimum file size filtering in the eofblocks scan. The
caller must set the XFS_EOF_FLAGS_MINFILESIZE flags bit and minimum
file size value in bytes.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08 15:32:29 -06:00
Brian Foster 1b5560488d xfs: support multiple inode id filtering in eofblocks scan
Enhance the eofblocks scan code to filter based on multiply specified
inode id values. When multiple inode id values are specified, only
inodes that match all id values are selected.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08 15:31:13 -06:00
Brian Foster 3e3f9f5863 xfs: add inode id filtering to eofblocks scan
Support inode ID filtering in the eofblocks scan. The caller must
set the associated XFS_EOF_FLAGS_*ID bit and ID field.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08 15:29:14 -06:00
Brian Foster 8ca149de80 xfs: add XFS_IOC_FREE_EOFBLOCKS ioctl
The XFS_IOC_FREE_EOFBLOCKS ioctl allows users to invoke an EOFBLOCKS
scan. The xfs_eofblocks structure is defined to support the command
parameters (scan mode).

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08 15:27:49 -06:00
Brian Foster 41176a68e3 xfs: create function to scan and clear EOFBLOCKS inodes
xfs_inodes_free_eofblocks() implements scanning functionality for
EOFBLOCKS inodes. It uses the AG iterator to walk the tagged inodes
and free post-EOF blocks via the xfs_inode_free_eofblocks() execute
function. The scan can be invoked in best-effort mode or wait
(force) mode.

A best-effort scan (default) handles all inodes that do not have a
dirty cache and we successfully acquire the io lock via trylock. In
wait mode, we continue to cycle through an AG until all inodes are
handled.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08 15:25:40 -06:00
Brian Foster 40165e2761 xfs: make xfs_free_eofblocks() non-static, return EAGAIN on trylock failure
Turn xfs_free_eofblocks() into a non-static function, return EAGAIN to
indicate trylock failure and make sure this error is not propagated in
xfs_release().

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08 15:24:26 -06:00
Brian Foster 72b53efa4a xfs: create helper to check whether to free eofblocks on inode
This check is used in multiple places to determine whether we
should check for (and potentially free) post EOF blocks on an
inode. Add a helper to consolidate the check.

Note that when we remove an inode from the cache (xfs_inactive()),
we are required to trim post-EOF blocks even if the inode is marked
preallocated or append-only to maintain correct space accounting.
The 'force' parameter to xfs_can_free_eofblocks() specifies whether
we should ignore the prealloc/append-only status of the inode.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08 15:22:34 -06:00
Brian Foster a454f7428f xfs: support a tag-based inode_ag_iterator
Genericize xfs_inode_ag_walk() to support an optional radix tree tag
and args argument for the execute function. Create a new wrapper
called xfs_inode_ag_iterator_tag() that performs a tag based walk
of perag's and inodes.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08 15:20:38 -06:00
Brian Foster 27b5286792 xfs: add EOFBLOCKS inode tagging/untagging
Add the XFS_ICI_EOFBLOCKS_TAG inode tag to identify inodes with
speculatively preallocated blocks beyond EOF. An inode is tagged
when speculative preallocation occurs and untagged either via
truncate down or when post-EOF blocks are freed via release or
reclaim.

The tag management is intentionally not aggressive to prefer
simplicity over the complexity of handling all the corner cases
under which post-EOF blocks could be freed (i.e., forward
truncation, fallocate, write error conditions, etc.). This means
that a tagged inode may or may not have post-EOF blocks after a
period of time. The tag is eventually cleared when the inode is
released or reclaimed.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08 14:20:44 -06:00
Dave Chinner 6ce377afd1 xfs: fix reading of wrapped log data
Commit 4439647 ("xfs: reset buffer pointers before freeing them") in
3.0-rc1 introduced a regression when recovering log buffers that
wrapped around the end of log. The second part of the log buffer at
the start of the physical log was being read into the header buffer
rather than the data buffer, and hence recovery was seeing garbage
in the data buffer when it got to the region of the log buffer that
was incorrectly read.

Cc: <stable@vger.kernel.org> # 3.0.x, 3.2.x, 3.4.x 3.6.x
Reported-by: Torsten Kaiser <just.for.lkml@googlemail.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08 11:10:51 -06:00
Dave Chinner 03b1293eda xfs: fix buffer shudown reference count mismatch
When we shut down the filesystem, we have to unpin and free all the
buffers currently active in the CIL. To do this we unpin and remove
them in one operation as a result of a failed iclogbuf write. For
buffers, we do this removal via a simultated IO completion of after
marking the buffer stale.

At the time we do this, we have two references to the buffer - the
active LRU reference and the buf log item.  The LRU reference is
removed by marking the buffer stale, and the active CIL reference is
by the xfs_buf_iodone() callback that is run by
xfs_buf_do_callbacks() during ioend processing (via the bp->b_iodone
callback).

However, ioend processing requires one more reference - that of the
IO that it is completing. We don't have this reference, so we free
the buffer prematurely and use it after it is freed. For buffers
marked with XBF_ASYNC, this leads to assert failures in
xfs_buf_rele() on debug kernels because the b_hold count is zero.

Fix this by making sure we take the necessary IO reference before
starting IO completion processing on the stale buffer, and set the
XBF_ASYNC flag to ensure that IO completion processing removes all
the active references from the buffer to ensure it is fully torn
down.

Cc: <stable@vger.kernel.org>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08 11:10:35 -06:00
Dave Chinner 4b62acfe99 xfs: don't vmap inode cluster buffers during free
Inode buffers do not need to be mapped as inodes are read or written
directly from/to the pages underlying the buffer. This fixes a
regression introduced by commit 611c994 ("xfs: make XBF_MAPPED the
default behaviour").

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08 11:10:18 -06:00
Dave Chinner ca250b1b3d xfs: invalidate allocbt blocks moved to the free list
When we free a block from the alloc btree tree, we move it to the
freelist held in the AGFL and mark it busy in the busy extent tree.
This typically happens when we merge btree blocks.

Once the transaction is committed and checkpointed, the block can
remain on the free list for an indefinite amount of time.  Now, this
isn't the end of the world at this point - if the free list is
shortened, the buffer is invalidated in the transaction that moves
it back to free space. If the buffer is allocated as metadata from
the free list, then all the modifications getted logged, and we have
no issues, either. And if it gets allocated as userdata direct from
the freelist, it gets invalidated and so will never get written.

However, during the time it sits on the free list, pressure on the
log can cause the AIL to be pushed and the buffer that covers the
block gets pushed for write. IOWs, we end up writing a freed
metadata block to disk. Again, this isn't the end of the world
because we know from the above we are only writing to free space.

The problem, however, is for validation callbacks. If the block was
on old btree root block, then the level of the block is going to be
higher than the current tree root, and so will fail validation.
There may be other inconsistencies in the block as well, and
currently we don't care because the block is in free space. Shutting
down the filesystem because a freed block doesn't pass write
validation, OTOH, is rather unfriendly.

So, make sure we always invalidate buffers as they move from the
free space trees to the free list so that we guarantee they never
get written to disk while on the free list.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Phil White <pwhite@sgi.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08 11:09:44 -06:00
Dave Chinner 1e7acbb7bc xfs: silence uninitialised f.file warning.
Uninitialised variable build warning introduced by 2903ff0 ("switch
simple cases of fget_light to fdget"), gcc is not smart enough to
work out that the variable is not used uninitialised, and the commit
removed the initialisation at declaration that the old variable had.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08 11:09:17 -06:00
Dave Chinner eaef854335 xfs: growfs: don't read garbage for new secondary superblocks
When updating new secondary superblocks in a growfs operation, the
superblock buffer is read from the newly grown region of the
underlying device. This is not guaranteed to be zero, so violates
the underlying assumption that the unused parts of superblocks are
zero filled. Get a new buffer for these secondary superblocks to
ensure that the unused regions are zero filled correctly.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08 11:08:57 -06:00
Dave Chinner 1f3c785c3a xfs: move allocation stack switch up to xfs_bmapi_allocate
Switching stacks are xfs_alloc_vextent can cause deadlocks when we
run out of worker threads on the allocation workqueue. This can
occur because xfs_bmap_btalloc can make multiple calls to
xfs_alloc_vextent() and even if xfs_alloc_vextent() fails it can
return with the AGF locked in the current allocation transaction.

If we then need to make another allocation, and all the allocation
worker contexts are exhausted because the are blocked waiting for
the AGF lock, holder of the AGF cannot get it's xfs-alloc_vextent
work completed to release the AGF.  Hence allocation effectively
deadlocks.

To avoid this, move the stack switch one layer up to
xfs_bmapi_allocate() so that all of the allocation attempts in a
single switched stack transaction occur in a single worker context.
This avoids the problem of an allocation being blocked waiting for
a worker thread whilst holding the AGF.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08 11:08:46 -06:00
Dave Chinner 326c03555b xfs: introduce XFS_BMAPI_STACK_SWITCH
Certain allocation paths through xfs_bmapi_write() are in situations
where we have limited stack available. These are almost always in
the buffered IO writeback path when convertion delayed allocation
extents to real extents.

The current stack switch occurs for userdata allocations, which
means we also do stack switches for preallocation, direct IO and
unwritten extent conversion, even those these call chains have never
been implicated in a stack overrun.

Hence, let's target just the single stack overun offended for stack
switches. To do that, introduce a XFS_BMAPI_STACK_SWITCH flag that
the caller can pass xfs_bmapi_write() to indicate it should switch
stacks if it needs to do allocation.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08 11:08:27 -06:00
Mark Tinguely 408cc4e97a xfs: zero allocation_args on the kernel stack
Zero the kernel stack space that makes up the xfs_alloc_arg structures.

Signed-off-by: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08 11:08:10 -06:00
Dave Chinner 7e9620f21d xfs: only update the last_sync_lsn when a transaction completes
The log write code stamps each iclog with the current tail LSN in
the iclog header so that recovery knows where to find the tail of
thelog once it has found the head. Normally this is taken from the
first item on the AIL - the log item that corresponds to the oldest
active item in the log.

The problem is that when the AIL is empty, the tail lsn is dervied
from the the l_last_sync_lsn, which is the LSN of the last iclog to
be written to the log. In most cases this doesn't happen, because
the AIL is rarely empty on an active filesystem. However, when it
does, it opens up an interesting case when the transaction being
committed to the iclog spans multiple iclogs.

That is, the first iclog is stamped with the l_last_sync_lsn, and IO
is issued. Then the next iclog is setup, the changes copied into the
iclog (takes some time), and then the l_last_sync_lsn is stamped
into the header and IO is issued. This is still the same
transaction, so the tail lsn of both iclogs must be the same for log
recovery to find the entire transaction to be able to replay it.

The problem arises in that the iclog buffer IO completion updates
the l_last_sync_lsn with it's own LSN. Therefore, If the first iclog
completes it's IO before the second iclog is filled and has the tail
lsn stamped in it, it will stamp the LSN of the first iclog into
it's tail lsn field. If the system fails at this point, log recovery
will not see a complete transaction, so the transaction will no be
replayed.

The fix is simple - the l_last_sync_lsn is updated when a iclog
buffer IO completes, and this is incorrect. The l_last_sync_lsn
shoul dbe updated when a transaction is completed by a iclog buffer
IO. That is, only iclog buffers that have transaction commit
callbacks attached to them should update the l_last_sync_lsn. This
means that the last_sync_lsn will only move forward when a commit
record it written, not in the middle of a large transaction that is
rolling through multiple iclog buffers.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08 11:07:38 -06:00
Eric Sandeen 69a58a43f7 xfs: report projid32bit feature in geometry call
When xfs gained the projid32bit feature, it was never added to
the FSGEOMETRY ioctl feature flags, so it's not queryable without
this patch.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-07 15:27:27 -06:00
Dave Chinner 009507b052 xfs: fix reading of wrapped log data
Commit 4439647 ("xfs: reset buffer pointers before freeing them") in
3.0-rc1 introduced a regression when recovering log buffers that
wrapped around the end of log. The second part of the log buffer at
the start of the physical log was being read into the header buffer
rather than the data buffer, and hence recovery was seeing garbage
in the data buffer when it got to the region of the log buffer that
was incorrectly read.

Cc: <stable@vger.kernel.org> # 3.0.x, 3.2.x, 3.4.x 3.6.x
Reported-by: Torsten Kaiser <just.for.lkml@googlemail.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-07 15:27:17 -06:00
Dave Chinner 137fff09b7 xfs: fix buffer shudown reference count mismatch
When we shut down the filesystem, we have to unpin and free all the
buffers currently active in the CIL. To do this we unpin and remove
them in one operation as a result of a failed iclogbuf write. For
buffers, we do this removal via a simultated IO completion of after
marking the buffer stale.

At the time we do this, we have two references to the buffer - the
active LRU reference and the buf log item.  The LRU reference is
removed by marking the buffer stale, and the active CIL reference is
by the xfs_buf_iodone() callback that is run by
xfs_buf_do_callbacks() during ioend processing (via the bp->b_iodone
callback).

However, ioend processing requires one more reference - that of the
IO that it is completing. We don't have this reference, so we free
the buffer prematurely and use it after it is freed. For buffers
marked with XBF_ASYNC, this leads to assert failures in
xfs_buf_rele() on debug kernels because the b_hold count is zero.

Fix this by making sure we take the necessary IO reference before
starting IO completion processing on the stale buffer, and set the
XBF_ASYNC flag to ensure that IO completion processing removes all
the active references from the buffer to ensure it is fully torn
down.

Cc: <stable@vger.kernel.org>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-07 15:26:53 -06:00
Dave Chinner b6aff29f3a xfs: don't vmap inode cluster buffers during free
Inode buffers do not need to be mapped as inodes are read or written
directly from/to the pages underlying the buffer. This fixes a
regression introduced by commit 611c994 ("xfs: make XBF_MAPPED the
default behaviour").

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-07 14:15:48 -06:00
Dave Chinner 4c05f9ad4d xfs: invalidate allocbt blocks moved to the free list
When we free a block from the alloc btree tree, we move it to the
freelist held in the AGFL and mark it busy in the busy extent tree.
This typically happens when we merge btree blocks.

Once the transaction is committed and checkpointed, the block can
remain on the free list for an indefinite amount of time.  Now, this
isn't the end of the world at this point - if the free list is
shortened, the buffer is invalidated in the transaction that moves
it back to free space. If the buffer is allocated as metadata from
the free list, then all the modifications getted logged, and we have
no issues, either. And if it gets allocated as userdata direct from
the freelist, it gets invalidated and so will never get written.

However, during the time it sits on the free list, pressure on the
log can cause the AIL to be pushed and the buffer that covers the
block gets pushed for write. IOWs, we end up writing a freed
metadata block to disk. Again, this isn't the end of the world
because we know from the above we are only writing to free space.

The problem, however, is for validation callbacks. If the block was
on old btree root block, then the level of the block is going to be
higher than the current tree root, and so will fail validation.
There may be other inconsistencies in the block as well, and
currently we don't care because the block is in free space. Shutting
down the filesystem because a freed block doesn't pass write
validation, OTOH, is rather unfriendly.

So, make sure we always invalidate buffers as they move from the
free space trees to the free list so that we guarantee they never
get written to disk while on the free list.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Phil White <pwhite@sgi.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-07 14:13:30 -06:00
Linus Torvalds 0e4a43ed08 Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-fixes
Pull gfs2 fixes from Steven Whitehouse:
 "Here are a number of GFS2 bug fixes.  There are three from Andy Price
  which fix various issues spotted by automated code analysis.  There
  are two from Lukas Czerner fixing my mistaken assumptions as to how
  FITRIM should work.  Finally Ben Marzinski has fixed a bug relating to
  mmap and atime and also a bug relating to a locking issue in the
  transaction code."

* git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-fixes:
  GFS2: Test bufdata with buffer locked and gfs2_log_lock held
  GFS2: Don't call file_accessed() with a shared glock
  GFS2: Fix FITRIM argument handling
  GFS2: Require user to provide argument for FITRIM
  GFS2: Clean up some unused assignments
  GFS2: Fix possible null pointer deref in gfs2_rs_alloc
  GFS2: Fix an unchecked error from gfs2_rs_alloc
2012-11-07 13:38:56 +01:00
Benjamin Marzinski 96e5d1d3ad GFS2: Test bufdata with buffer locked and gfs2_log_lock held
In gfs2_trans_add_bh(), gfs2 was testing if a there was a bd attached to the
buffer without having the gfs2_log_lock held. It was then assuming it would
stay attached for the rest of the function. However, without either the log
lock being held of the buffer locked, __gfs2_ail_flush() could detach bd at any
time.  This patch moves the locking before the test.  If there isn't a bd
already attached, gfs2 can safely allocate one and attach it before locking.
There is no way that the newly allocated bd could be on the ail list,
and thus no way for __gfs2_ail_flush() to detach it.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-11-07 09:43:03 +00:00
Benjamin Marzinski 3d1626889a GFS2: Don't call file_accessed() with a shared glock
file_accessed() was being called by gfs2_mmap() with a shared glock. If it
needed to update the atime, it was crashing because it dirtied the inode in
gfs2_dirty_inode() without holding an exclusive lock. gfs2_dirty_inode()
checked if the caller was already holding a glock, but it didn't make sure that
the glock was in the exclusive state. Now, instead of calling file_accessed()
while holding the shared lock in gfs2_mmap(), file_accessed() is called after
grabbing and releasing the glock to update the inode.  If file_accessed() needs
to update the atime, it will grab an exclusive lock in gfs2_dirty_inode().

gfs2_dirty_inode() now also checks to make sure that if the calling process has
already locked the glock, it has an exclusive lock.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-11-07 09:42:49 +00:00
Lukas Czerner 076f0faa76 GFS2: Fix FITRIM argument handling
Currently implementation in gfs2 uses FITRIM arguments as it were in
file system blocks units which is wrong. The FITRIM arguments
(fstrim_range.start, fstrim_range.len and fstrim_range.minlen) are
actually in bytes.

Moreover, check for start argument beyond the end of file system, len
argument being smaller than file system block and minlen argument being
bigger than biggest resource group were missing.

This commit converts the code to convert FITRIM argument to file system
blocks and also adds appropriate checks mentioned above.

All the problems were recognised by xfstests 251 and 260.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-11-07 09:41:58 +00:00
Lukas Czerner 3a238adefb GFS2: Require user to provide argument for FITRIM
When the fstrim_range argument is not provided by user in FITRIM ioctl
we should just return EFAULT and not promoting bad behaviour by filling
the structure in kernel. Let the user deal with it.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-11-07 09:41:37 +00:00
Andrew Price 73738a77f4 GFS2: Clean up some unused assignments
Cleans up two cases where variables were assigned values but then never
used again.

Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-11-07 09:41:07 +00:00
Andrew Price cd0ed19fb6 GFS2: Fix possible null pointer deref in gfs2_rs_alloc
Despite the return value from kmem_cache_zalloc() being checked, the
error wasn't being returned until after a possible null pointer
dereference. This patch returns the error immediately, allowing the
removal of the error variable.

Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-11-07 09:40:39 +00:00
Andrew Price aaaf68c562 GFS2: Fix an unchecked error from gfs2_rs_alloc
Check the return value of gfs2_rs_alloc(ip) and avoid a possible null
pointer dereference.

Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-11-07 09:40:05 +00:00
Sachin Prabhu 3798f47aa2 cifs: Do not lookup hashed negative dentry in cifs_atomic_open
We do not need to lookup a hashed negative directory since we have
already revalidated it before and have found it to be fine.

This also prevents a crash in cifs_lookup() when it attempts to rehash
the already hashed negative lookup dentry.

The patch has been tested using the reproducer at
https://bugzilla.redhat.com/show_bug.cgi?id=867344#c28

Cc: <stable@kernel.org> # 3.6.x
Reported-by: Vit Zahradka <vit.zahradka@tiscali.cz>
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
2012-11-05 06:45:54 -05:00
Jeff Layton 36960e440c cifs: fix potential buffer overrun in cifs.idmap handling code
The userspace cifs.idmap program generally works with the wbclient libs
to generate binary SIDs in userspace. That program defines the struct
that holds these values as having a max of 15 subauthorities. The kernel
idmapping code however limits that value to 5.

When the kernel copies those values around though, it doesn't sanity
check the num_subauths value handed back from userspace or from the
server. It's possible therefore for userspace to hand us back a bogus
num_subauths value (or one that's valid, but greater than 5) that could
cause the kernel to walk off the end of the cifs_sid->sub_auths array.

Fix this by defining a new routine for copying sids and using that in
all of the places that copy it. If we end up with a sid that's longer
than expected then this approach will just lop off the "extra" subauths,
but that's basically what the code does today already. Better approaches
might be to fix this code to reject SIDs with >5 subauths, or fix it
to handle the subauths array dynamically.

At the same time, change the kernel to check the length of the data
returned by userspace. If it's shorter than struct cifs_sid, reject it
and return -EIO. If that happens we'll end up with fields that are
basically uninitialized.

Long term, it might make sense to redefine cifs_sid using a flexarray at
the end, to allow for variable-length subauth lists, and teach the code
to handle the case where the subauths array being passed in from
userspace is shorter than 5 elements.

Note too, that I don't consider this a security issue since you'd need
a compromised cifs.idmap program. If you have that, you can do all sorts
of nefarious stuff. Still, this is probably reasonable for stable.

Cc: stable@kernel.org
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
2012-11-03 09:37:28 -04:00
Weston Andros Adamson 998f40b550 NFS4: nfs4_opendata_access should return errno
Return errno - not an NFS4ERR_. This worked because NFS4ERR_ACCESS == EACCES.

Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-11-02 18:51:54 -04:00
Carlos Maiolino cd856db69c xfs: Update inode alloc comments
I found some out of date comments while studying the inode allocation
code, so I believe it's worth to have these comments updated.

It basically rewrites the comment regarding to "call_again" variable,
which is not used anymore, but instead, callers of xfs_ialloc() decides
if it needs to be called again relying only if ialloc_context is NULL or
not.

Also did some small changes in another comment that I thought to be
pertinent to the current behaviour of these functions and some alignment
on both comments.

Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-02 17:13:12 -05:00
Dave Chinner 531c3bdc86 xfs: silence uninitialised f.file warning.
Uninitialised variable build warning introduced by 2903ff0 ("switch
simple cases of fget_light to fdget"), gcc is not smart enough to
work out that the variable is not used uninitialised, and the commit
removed the initialisation at declaration that the old variable had.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-02 16:18:45 -05:00
Dave Chinner 1375cb65e8 xfs: growfs: don't read garbage for new secondary superblocks
When updating new secondary superblocks in a growfs operation, the
superblock buffer is read from the newly grown region of the
underlying device. This is not guaranteed to be zero, so violates
the underlying assumption that the unused parts of superblocks are
zero filled. Get a new buffer for these secondary superblocks to
ensure that the unused regions are zero filled correctly.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-02 15:42:35 -05:00
Kees Cook a3de56bdb9 fs/dlm: remove CONFIG_EXPERIMENTAL
This config item has not carried much meaning for a while now and is
almost always enabled by default. As agreed during the Linux kernel
summit, remove it.

CC: Christine Caulfield <ccaulfie@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Teigland <teigland@redhat.com>
2012-11-01 15:27:24 -05:00
Wei Yongjun eeee2b5fe1 dlm: remove unused variable in *dlm_lowcomms_get_buffer()
The variable users is initialized but never used
otherwise, so remove the unused variable.

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

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: David Teigland <teigland@redhat.com>
2012-11-01 15:27:13 -05:00
Trond Myklebust f9b1ef5f06 NFSv4: Initialise the NFSv4.1 slot table highest_used_slotid correctly
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-11-01 12:02:03 -04:00
Masanari Iida 926ccfef82 Btrfs: Fix printk and variable name
Correct spelling typo in btrfs.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-11-01 09:48:04 +01:00
Weston Andros Adamson 324d003b0c NFS: add nfs_sb_deactive_async to avoid deadlock
Use nfs_sb_deactive_async instead of nfs_sb_deactive when in a workqueue
context.  This avoids a deadlock where rpc_shutdown_client loops forever
in a workqueue kworker context, trying to kill all RPC tasks associated with
the client, while one or more of these tasks have already been assigned to the
same kworker (and will never run rpc_exit_task).

This approach is needed because RPC tasks that have already been assigned
to a kworker by queue_work cannot be canceled, as explained in the comment
for workqueue.c:insert_wq_barrier.

Signed-off-by: Weston Andros Adamson <dros@netapp.com>
[Trond: add module_get/put.]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-10-31 16:26:26 -04:00
Ben Hutchings 97a5486826 nfs: Show original device name verbatim in /proc/*/mount{s,info}
Since commit c7f404b ('vfs: new superblock methods to override
/proc/*/mount{s,info}'), nfs_path() is used to generate the mounted
device name reported back to userland.

nfs_path() always generates a trailing slash when the given dentry is
the root of an NFS mount, but userland may expect the original device
name to be returned verbatim (as it used to be).  Make this
canonicalisation optional and change the callers accordingly.

[jrnieder@gmail.com: use flag instead of bool argument]
Reported-and-tested-by: Chris Hiestand <chiestand@salk.edu>
Reference: http://bugs.debian.org/669314
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: <stable@vger.kernel.org> # v2.6.39+
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-10-31 16:26:26 -04:00
Scott Mayhew acce94e68a nfsv3: Make v3 mounts fail with ETIMEDOUTs instead EIO on mountd timeouts
In very busy v3 environment, rpc.mountd can respond to the NULL
procedure but not the MNT procedure in a timely manner causing
the MNT procedure to time out. The problem is the mount system
call returns EIO which causes the mount to fail, instead of
ETIMEDOUT, which would cause the mount to be retried.

This patch sets the RPC_TASK_SOFT|RPC_TASK_TIMEOUT flags to
the rpc_call_sync() call in nfs_mount() which causes
ETIMEDOUT to be returned on timed out connections.

Signed-off-by: Steve Dickson <steved@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org
2012-10-31 16:26:25 -04:00
Yanchuan Nian 7175fe9015 nfs: Check whether a layout pointer is NULL before free it
The new layout pointer in pnfs_find_alloc_layout() may be NULL because of
out of memory. we must do some check work, otherwise pnfs_free_layout_hdr()
will go wrong because it can not deal with a NULL pointer.

Signed-off-by: Yanchuan Nian <ycnian@gmail.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-10-31 16:26:25 -04:00
NeilBrown 8d96b10639 NFS: fix bug in legacy DNS resolver.
The DNS resolver's use of the sunrpc cache involves a 'ttl' number
(relative) rather that a timeout (absolute).  This confused me when
I wrote
  commit c5b29f885a
     "sunrpc: use seconds since boot in expiry cache"

and I managed to break it.  The effect is that any TTL is interpreted
as 0, and nothing useful gets into the cache.

This patch removes the use of get_expiry() - which really expects an
expiry time - and uses get_uint() instead, treating the int correctly
as a ttl.

This fixes a regression that has been present since 2.6.37, causing
certain NFS accesses in certain environments to incorrectly fail.

Reported-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Chuck Lever <chuck.lever@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-10-31 16:25:59 -04:00
Trond Myklebust 2b1bc308f4 NFSv4: nfs4_locku_done must release the sequence id
If the state recovery machinery is triggered by the call to
nfs4_async_handle_error() then we can deadlock.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org
2012-10-31 15:10:04 -04:00
Trond Myklebust 2240a9e2d0 NFSv4.1: We must release the sequence id when we fail to get a session slot
If we do not release the sequence id in cases where we fail to get a
session slot, then we can deadlock if we hit a recovery scenario.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org
2012-10-31 15:08:18 -04:00
Bryan Schumaker 399f11c3d8 NFS: Wait for session recovery to finish before returning
Currently, we will schedule session recovery and then return to the
caller of nfs4_handle_exception.  This works for most cases, but causes
a hang on the following test case:

	Client				Server
	------				------
	Open file over NFS v4.1
	Write to file
					Expire client
	Try to lock file

The server will return NFS4ERR_BADSESSION, prompting the client to
schedule recovery.  However, the client will continue placing lock
attempts and the open recovery never seems to be scheduled.  The
simplest solution is to wait for session recovery to run before retrying
the lock.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org
2012-10-31 13:13:28 -04:00
Al Viro 08f05c4974 Return the right error value when dup[23]() newfd argument is too large
Jack Lin reports that the error return from dup3() for the RLIMIT_NOFILE
case changed incorrectly after 3.6.

The culprit is commit f33ff9927f ("take rlimit check to callers of
expand_files()") which when it moved the "return -EMFILE" out to the
caller, didn't notice that the dup3() had special code to turn the
EMFILE return into EBADF.

The replace_fd() helper that got added later then inherited the bug too.

Reported-by: Jack Lin <linliangjie@huawei.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[ Noted more bugs, wrote proper changelog, fixed up typos - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-30 21:27:28 -07:00
Linus Torvalds 8c673cbc76 This fixes the root cause of the ext4 data corruption bug which raised
a ruckus on LWN, Phoronix, and Slashdot.  This bug only showed up when
 non-standard mount options (journal_async_commit and/or
 journal_checksum) were enabled, and when the file system was not
 cleanly unmounted, but the root cause was the inode bitmap
 modifications was not being properly journaled.  This could
 potentially lead to minor file system corruptions (pass 5 complaints
 with the inode allocation bitmap) after an unclean shutdown under the
 wrong/unlucky workloads, but it turned into major failure if the
 journal_checksum and/or jouaral_async_commit  was enabled.
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Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 bugfix from Ted Ts'o:
 "This fixes the root cause of the ext4 data corruption bug which raised
  a ruckus on LWN, Phoronix, and Slashdot.

  This bug only showed up when non-standard mount options
  (journal_async_commit and/or journal_checksum) were enabled, and when
  the file system was not cleanly unmounted, but the root cause was the
  inode bitmap modifications was not being properly journaled.

  This could potentially lead to minor file system corruptions (pass 5
  complaints with the inode allocation bitmap) after an unclean shutdown
  under the wrong/unlucky workloads, but it turned into major failure if
  the journal_checksum and/or jouaral_async_commit was enabled."

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix unjournaled inode bitmap modification
2012-10-30 15:35:16 -07:00
Linus Torvalds 4476c0eead Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block driver update from Jens Axboe:
 "Distilled down variant, the rest will pass over to 3.8.  I pulled it
  into the for-linus branch I had waiting for a pull request as well, in
  case you are wondering why there are new entries in here too.  This
  also got rid of two reverts and the ones of the mtip32xx patches that
  went in later in the 3.6 cycle, so the series looks a bit cleaner."

* 'for-linus' of git://git.kernel.dk/linux-block:
  loop: Make explicit loop device destruction lazy
  mtip32xx:Added appropriate timeout value for secure erase
  xen/blkback: Change xen_vbd's flush_support and discard_secure to have type unsigned int, rather than bool
  cciss: select CONFIG_CHECK_SIGNATURE
  cciss: remove unneeded memset()
  xen/blkback: use kmem_cache_zalloc instead of kmem_cache_alloc/memset
  pktcdvd: update MAINTAINERS
  floppy: remove dr, reuse drive on do_floppy_init
  floppy: use common function to check if floppies can be registered
  floppy: properly handle failure on add_disk loop
  floppy: do put_disk on current dr if blk_init_queue fails
  floppy: don't call alloc_ordered_workqueue inside the alloc_disk loop
  xen/blkback: Fix compile warning
  block: Add blk_rq_pos(rq) to sort rq when plushing
  drivers/block: remove CONFIG_EXPERIMENTAL
  block: remove CONFIG_EXPERIMENTAL
  vfs: fix: don't increase bio_slab_max if krealloc() fails
  blkcg: stop iteration early if root_rl is the only request list
  blkcg: Fix use-after-free of q->root_blkg and q->root_rl.blkg
2012-10-30 15:34:09 -07:00
Mike Galbraith 5258f386ea sched/autogroup: Fix crash on reboot when autogroup is disabled
Due to these two commits:

  8323f26ce3 sched: Fix race in task_group()
  800d4d30c8 sched, autogroup: Stop going ahead if autogroup is disabled

... autogroup scheduling's dynamic knobs are wrecked.

With both patches applied, all you have to do to crash a box is
disable autogroup during boot up, then reboot.. boom, NULL pointer
dereference due to 800d4d30 not allowing autogroup to move things,
and 8323f26ce making that the only way to switch runqueues.

Remove most of the (dysfunctional) knobs and turn the remaining
sched_autogroup_enabled knob readonly.

If the user fiddles with cgroups hereafter, once tasks
are moved, autogroup won't mess with them again unless
they call setsid().

No knobs, no glitz, nada, just a cute little thing folks can
turn on if they don't want to muck about with cgroups and/or
systemd.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Cc: Xiaotian Feng <xtfeng@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Xiaotian Feng <dannyfeng@tencent.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: <stable@vger.kernel.org> # v3.6
Link: http://lkml.kernel.org/r/1351451963.4999.8.camel@maggy.simpson.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-10-30 10:26:04 +01:00
Liu Bo 52b1de91ea btrfs: unpin_extent_cache: fix the typo and unnecessary arguements
- unpint->unpin
- prealloc is no more used

Signed-off-by: Liu Bo <liub.liubo@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-10-30 10:18:50 +01:00
Greg Kroah-Hartman ca364d8388 Merge 3.7-rc3 into tty-next
This merges the tty changes in 3.7-rc3 into tty-next

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-29 09:00:57 -07:00
Linus Torvalds 35fd3dc58d Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client
Pull Ceph fixes form Sage Weil:
 "There are two fixes in the messenger code, one that can trigger a NULL
  dereference, and one that error in refcounting (extra put).  There is
  also a trivial fix that in the fs client code that is triggered by NFS
  reexport."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  ceph: fix dentry reference leak in encode_fh()
  libceph: avoid NULL kref_put when osd reset races with alloc_msg
  rbd: reset BACKOFF if unable to re-queue
2012-10-29 08:49:25 -07:00
David Zafman 52eb5a900a ceph: fix dentry reference leak in encode_fh()
Call to d_find_alias() needs a corresponding dput()

This fixes http://tracker.newdream.net/issues/3271

Signed-off-by: David Zafman <david.zafman@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2012-10-29 08:17:10 -07:00
Eric Sandeen ffb5387e85 ext4: fix unjournaled inode bitmap modification
commit 119c0d4460 changed
ext4_new_inode() such that the inode bitmap was being modified
outside a transaction, which could lead to corruption, and was
discovered when journal_checksum found a bad checksum in the
journal during log replay.

Nix ran into this when using the journal_async_commit mount
option, which enables journal checksumming.  The ensuing
journal replay failures due to the bad checksums led to
filesystem corruption reported as the now infamous
"Apparent serious progressive ext4 data corruption bug"

[ Changed by tytso to only call ext4_journal_get_write_access() only
  when we're fairly certain that we're going to allocate the inode. ]

I've tested this by mounting with journal_checksum and
running fsstress then dropping power; I've also tested by
hacking DM to create snapshots w/o first quiescing, which
allows me to test journal replay repeatedly w/o actually
power-cycling the box.  Without the patch I hit a journal
checksum error every time.  With this fix it survives
many iterations.

Reported-by: Nix <nix@esperi.org.uk>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
2012-10-28 22:24:57 -04:00
Mikulas Patocka 1a25b1c4ce Lock splice_read and splice_write functions
Functions generic_file_splice_read and generic_file_splice_write access
the pagecache directly. For block devices these functions must be locked
so that block size is not changed while they are in progress.

This patch is an additional fix for commit b87570f5d3 ("Fix a crash
when block device is read and block size is changed at the same time")
that locked aio_read, aio_write and mmap against block size change.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-28 10:59:37 -07:00
Linus Torvalds 64b1cbaa10 Power management and ACPI fixes for 3.7-rc3
* Fix for a memory leak in acpi_bind_one() from Jesper Juhl.
 
 * Fix for an error code path memory leak in pm_genpd_attach_cpuidle()
   from Jonghwan Choi.
 
 * Fix for smp_processor_id() usage in preemptible code in powernow-k8 from
   Andreas Herrmann.
 
 * Fix for a suspend-related memory leak in cpufreq stats from Xiaobing Tu.
 
 * Freezer fix for failure to clear PF_NOFREEZE along with PF_KTHREAD
   in flush_old_exec() from Oleg Nesterov.
 
 * acpi_processor_notify() fix from Alan Cox.
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Merge tag 'pm+acpi-for-3.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management and ACPI fixes from Rafael J Wysocki:

 - Fix for a memory leak in acpi_bind_one() from Jesper Juhl.

 - Fix for an error code path memory leak in pm_genpd_attach_cpuidle()
   from Jonghwan Choi.

 - Fix for smp_processor_id() usage in preemptible code in powernow-k8
   from Andreas Herrmann.

 - Fix for a suspend-related memory leak in cpufreq stats from Xiaobing
   Tu.

 - Freezer fix for failure to clear PF_NOFREEZE along with PF_KTHREAD in
   flush_old_exec() from Oleg Nesterov.

 - acpi_processor_notify() fix from Alan Cox.

* tag 'pm+acpi-for-3.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI: missing break
  freezer: exec should clear PF_NOFREEZE along with PF_KTHREAD
  Fix memory leak in cpufreq stats.
  cpufreq / powernow-k8: Remove usage of smp_processor_id() in preemptible code
  PM / Domains: Fix memory leak on error path in pm_genpd_attach_cpuidle
  ACPI: Fix memory leak in acpi_bind_one()
2012-10-26 14:23:35 -07:00
Linus Torvalds 299650cad6 Driver core fixes for 3.7-rc3
Here are a number of firmware core fixes for 3.7, and some other minor fixes.
 And some documentation updates thrown in for good measure.
 
 All have been in the linux-next tree for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core fixes from Greg Kroah-Hartman:
 "Here are a number of firmware core fixes for 3.7, and some other minor
  fixes.  And some documentation updates thrown in for good measure.

  All have been in the linux-next tree for a while.

  Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"

* tag 'driver-core-3.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  Documentation:Chinese translation of Documentation/arm64/memory.txt
  Documentation:Chinese translation of Documentation/arm64/booting.txt
  Documentation:Chinese translation of Documentation/IRQ.txt
  firmware loader: document kernel direct loading
  sysfs: sysfs_pathname/sysfs_add_one: Use strlcat() instead of strcat()
  dynamic_debug: Remove unnecessary __used
  firmware loader: sync firmware cache by async_synchronize_full_domain
  firmware loader: let direct loading back on 'firmware_buf'
  firmware loader: fix one reqeust_firmware race
  firmware loader: cancel uncache work before caching firmware
2012-10-26 10:24:51 -07:00
Linus Torvalds 561ec64ae6 VFS: don't do protected {sym,hard}links by default
In commit 800179c9b8 ("This adds symlink and hardlink restrictions to
the Linux VFS"), the new link protections were enabled by default, in
the hope that no actual application would care, despite it being
technically against legacy UNIX (and documented POSIX) behavior.

However, it does turn out to break some applications.  It's rare, and
it's unfortunate, but it's unacceptable to break existing systems, so
we'll have to default to legacy behavior.

In particular, it has broken the way AFD distributes files, see

  http://www.dwd.de/AFD/

along with some legacy scripts.

Distributions can end up setting this at initrd time or in system
scripts: if you have security problems due to link attacks during your
early boot sequence, you have bigger problems than some kernel sysctl
setting. Do:

	echo 1 > /proc/sys/fs/protected_symlinks
	echo 1 > /proc/sys/fs/protected_hardlinks

to re-enable the link protections.

Alternatively, we may at some point introduce a kernel config option
that sets these kinds of "more secure but not traditional" behavioural
options automatically.

Reported-by: Nick Bowler <nbowler@elliptictech.com>
Reported-by: Holger Kiehl <Holger.Kiehl@dwd.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org # v3.6
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-26 10:05:07 -07:00
Linus Torvalds f48d42773b Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
 "This has our series of fixes for the next rc.  The biggest batch is
  from Jan Schmidt, fixing up some problems in our subvolume quota code
  and fixing btrfs send/receive to work with the new extended inode
  refs."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: do not bug when we fail to commit the transaction
  Btrfs: fix memory leak when cloning root's node
  Btrfs: Use btrfs_update_inode_fallback when creating a snapshot
  Btrfs: Send: preserve ownership (uid and gid) also for symlinks.
  Btrfs: fix deadlock caused by the nested chunk allocation
  btrfs: Return EINVAL when length to trim is less than FSB
  Btrfs: fix memory leak in btrfs_quota_enable()
  Btrfs: send correct rdev and mode in btrfs-send
  Btrfs: extended inode refs support for send mechanism
  Btrfs: Fix wrong error handling code
  Fix a sign bug causing invalid memory access in the ino_paths ioctl.
  Btrfs: comment for loop in tree_mod_log_insert_move
  Btrfs: fix extent buffer reference for tree mod log roots
  Btrfs: determine level of old roots
  Btrfs: tree mod log's old roots could still be part of the tree
  Btrfs: fix a tree mod logging issue for root replacement operations
  Btrfs: don't put removals from push_node_left into tree mod log twice
2012-10-26 09:34:04 -07:00
Artem Bityutskiy a28ad42a4a UBIFS: fix mounting problems after power cuts
This is a bugfix for a problem with the following symptoms:

1. A power cut happens
2. After reboot, we try to mount UBIFS
3. Mount fails with "No space left on device" error message

UBIFS complains like this:

UBIFS error (pid 28225): grab_empty_leb: could not find an empty LEB

The root cause of this problem is that when we mount, not all LEBs are
categorized. Only those which were read are. However, the
'ubifs_find_free_leb_for_idx()' function assumes that all LEBs were
categorized and 'c->freeable_cnt' is valid, which is a false assumption.

This patch fixes the problem by teaching 'ubifs_find_free_leb_for_idx()'
to always fall back to LPT scanning if no freeable LEBs were found.

This problem was reported by few people in the past, but Brent Taylor
was able to reproduce it and send me a flash image which cannot be mounted,
which made it easy to hunt the bug. Kudos to Brent.

Reported-by: Brent Taylor <motobud@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: stable@vger.kernel.org
2012-10-26 16:26:44 +03:00
Artem Bityutskiy 98a1eebda3 UBIFS: introduce categorized lprops counter
This commit is a preparation for a subsequent bugfix. We introduce a
counter for categorized lprops.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: stable@vger.kernel.org
2012-10-26 16:00:26 +03:00
Linus Torvalds fec4fba6e4 NFS bugfixes for Linux 3.7
- Fix the NFSv2/v3 kernel statd protocol, which broke due to net namespace
   related changes.
 - Fix a number of races in the SUNRPC TCP disconnect/reconnect code.
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Merge tag 'nfs-for-3.7-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS bugfixes from Trond Myklebust:

 - Fix the NFSv2/v3 kernel statd protocol, which broke due to net
   namespace related changes.

 - Fix a number of races in the SUNRPC TCP disconnect/reconnect code.

* tag 'nfs-for-3.7-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  LOCKD: Clear ln->nsm_clnt only when ln->nsm_users is zero
  LOCKD: fix races in nsm_client_get
  SUNRPC: Get rid of the xs_error_report socket callback
  SUNRPC: Prevent races in xs_abort_connection()
  Revert "SUNRPC: Ensure we close the socket on EPIPE errors too..."
  SUNRPC: Clear the connect flag when socket state is TCP_CLOSE_WAIT
2012-10-25 19:26:16 -07:00
Kees Cook 1217650336 fs/compat_ioctl.c: VIDEO_SET_SPU_PALETTE missing error check
The compat ioctl for VIDEO_SET_SPU_PALETTE was missing an error check
while converting ioctl arguments.  This could lead to leaking kernel
stack contents into userspace.

Patch extracted from existing fix in grsecurity.

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: David Miller <davem@davemloft.net>
Cc: Brad Spengler <spender@grsecurity.net>
Cc: PaX Team <pageexec@freemail.hu>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-25 14:37:53 -07:00
Oleg Nesterov b40a79591c freezer: exec should clear PF_NOFREEZE along with PF_KTHREAD
flush_old_exec() clears PF_KTHREAD but forgets about PF_NOFREEZE.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-10-25 22:28:12 +02:00
Josef Bacik c37b2b6269 Btrfs: do not bug when we fail to commit the transaction
We BUG if we fail to commit the transaction when creating a snapshot, which
is just obnoxious.  Remove the BUG_ON().  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-10-25 15:59:57 -04:00
Liu Bo 7bfdcf7fba Btrfs: fix memory leak when cloning root's node
After cloning root's node, we forgot to dec the src's ref
which can lead to a memory leak.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-10-25 15:55:21 -04:00
Chris Mason c657c3ef1a Merge branch 'for-chris-fixed' of git://git.jan-o-sch.net/btrfs-unstable 2012-10-25 15:53:10 -04:00