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29177 Commits

Author SHA1 Message Date
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
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
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
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
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
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
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
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