Since commit c7f404b4 ('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: NChris Hiestand <chiestand@salk.edu>
Reference: http://bugs.debian.org/669314Signed-off-by: NBen Hutchings <ben@decadent.org.uk>
Cc: <stable@vger.kernel.org> # v2.6.39+
Signed-off-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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: NSteve Dickson <steved@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org

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: NYanchuan Nian <ycnian@gmail.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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 c5b29f88
     "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: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NChuck Lever <chuck.lever@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If the state recovery machinery is triggered by the call to
nfs4_async_handle_error() then we can deadlock.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org

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: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org

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: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org

Jack Lin reports that the error return from dup3() for the RLIMIT_NOFILE
case changed incorrectly after 3.6.

The culprit is commit f33ff992 ("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: NJack Lin <linliangjie@huawei.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
[ Noted more bugs, wrote proper changelog, fixed up typos - Linus ]
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Call to d_find_alias() needs a corresponding dput()

This fixes http://tracker.newdream.net/issues/3271Signed-off-by: NDavid Zafman <david.zafman@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>

commit 119c0d44 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: NNix <nix@esperi.org.uk>
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org

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 b87570f5 ("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: NMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In commit 800179c9 ("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: NNick Bowler <nbowler@elliptictech.com>
Reported-by: NHolger 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: NLinus Torvalds <torvalds@linux-foundation.org>

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: NKees 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: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

flush_old_exec() clears PF_KTHREAD but forgets about PF_NOFREEZE.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NTejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

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: NJosef Bacik <jbacik@fusionio.com>

After cloning root's node, we forgot to dec the src's ref
which can lead to a memory leak.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

On a really full file system I was getting ENOSPC back from
btrfs_update_inode when trying to update the parent inode when creating a
snapshot.  Just use the fallback method so we can update the inode and not
have to worry about having a delayed ref.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

This patch also requires a change in the user-space part of "receive".
We need to use "lchown" instead of "chown". We will do this in the
following patch.
Signed-off-by: NAlex Lyakas <alex.btrfs@zadarastorage.com>

 	if (S_ISREG(sctx->cur_inode_mode)) {

Steps to reproduce:
 # mkfs.btrfs -m raid1 <disk1> <disk2>
 # btrfstune -S 1 <disk1>
 # mount <disk1> <mnt>
 # btrfs device add <disk3> <disk4> <mnt>
 # mount -o remount,rw <mnt>
 # dd if=/dev/zero of=<mnt>/tmpfile bs=1M count=1
 Deadlock happened.

It is because of the nested chunk allocation. When we wrote the data
into the filesystem, we would allocate the data chunk because there was
no data chunk in the filesystem. At the end of the data chunk allocation,
we should insert the metadata of the data chunk into the extent tree, but
there was no raid1 chunk, so we tried to lock the chunk allocation mutex to
allocate the new chunk, but we had held the mutex, the deadlock happened.

By rights, we would allocate the raid1 chunk when we added the second device
because the profile of the seed filesystem is raid1 and we had two devices.
But we didn't do that in fact. It is because the last step of the first device
insertion didn't commit the transaction. So when we added the second device,
we didn't cow the tree, and just inserted the relative metadata into the leaves
which were generated by the first device insertion, and its profile was dup.

So, I fix this problem by commiting the transaction at the end of the first
device insertion.
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>

Currently if len argument in btrfs_ioctl_fitrim() is smaller than
one FSB we will continue and finally return 0 bytes discarded.
However if the length to discard is smaller then file system block
we should really return EINVAL.
Signed-off-by: NLukas Czerner <lczerner@redhat.com>

We should free quota_root before returning from the error
handling code.
Signed-off-by: NTsutomu Itoh <t-itoh@jp.fujitsu.com>

When sending a device file, the stream was missing the mode. Also the
rdev was encoded wrongly.
Signed-off-by: NArne Jansen <sensille@gmx.net>

This adds support for the new extended inode refs to btrfs send.
Signed-off-by: NJan Schmidt <list.btrfs@jan-o-sch.net>

gcc says "warning: comparison of unsigned expression >= 0 is always
true" because i is an unsigned long. And gcc is right this time.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>

To see the problem, create many hardlinks to the same file (120 should do it),
then look up paths by inode with:

  ls -i
  btrfs inspect inode-resolve -v $ino /mnt/btrfs

I noticed the memory layout of the fspath->val data had some irregularities
(some unnecessary gaps that stop appearing about halfway),
so I'm not sure there aren't any bugs left in it.

The warning check for duplicate sysfs entries can cause a buffer overflow
when printing the warning, as strcat() doesn't check buffer sizes.
Use strlcat() instead.

Since strlcat() doesn't return a pointer to the passed buffer, unlike
strcat(), I had to convert the nested concatenation in sysfs_add_one() to
an admittedly more obscure comma operator construct, to avoid emitting code
for the concatenation if CONFIG_BUG is disabled.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Cc: stable@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The current code is clearing it in all cases _except_ when zero.
Reported-by: NStanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org

Commit e9406db2 (lockd: per-net
NSM client creation and destruction helpers introduced) contains
a nasty race on initialisation of the per-net NSM client because
it doesn't check whether or not the client is set after grabbing
the nsm_create_mutex.
Reported-by: NNix <nix@esperi.org.uk>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org

Emphasis the way tree_mod_log_insert_move avoids adding
MOD_LOG_KEY_REMOVE_WHILE_MOVING operations, depending on the direction of
the move operation.
Signed-off-by: NJan Schmidt <list.btrfs@jan-o-sch.net>

In get_old_root we grab a lock on the extent buffer before we obtain a
reference on that buffer. That order is changed now.
Signed-off-by: NJan Schmidt <list.btrfs@jan-o-sch.net>

In btrfs_find_all_roots' termination condition, we compare the level of the
old buffer we got from btrfs_search_old_slot to the level of the current
root node. We'd better compare it to the level of the rewinded root node.
Signed-off-by: NJan Schmidt <list.btrfs@jan-o-sch.net>

Tree mod log treated old root buffers as always empty buffers when starting
the rewind operations. However, the old root may still be part of the
current tree at a lower level, with still some valid entries.
Signed-off-by: NJan Schmidt <list.btrfs@jan-o-sch.net>

Avoid the implicit free by tree_mod_log_set_root_pointer, which is wrong in
two places. Where needed, we call tree_mod_log_free_eb explicitly now.
Signed-off-by: NJan Schmidt <list.btrfs@jan-o-sch.net>

Independant of the check (push_items < src_items) tree_mod_log_eb_copy did
log the removal of the old data entries from the source buffer. Therefore,
we must not call tree_mod_log_eb_move if the check evaluates to true, as
that would log the removal twice, finally resulting in (rewinded) buffers
with wrong values for header_nritems.
Signed-off-by: NJan Schmidt <list.btrfs@jan-o-sch.net>

Currently if len argument in ext4_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: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org

Without the patch, bio_slab_max, representing bio_slabs capacity, is increased before krealloc() of bio_slabs. If krealloc() fails, bio_slab_max is too high. Fix that by only updating bio_slab_max if krealloc() is successful.
Signed-off-by: NAnna Leuschner <anna.m.leuschner@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

In certain cases (for example when a cdev structure is embedded into
another object whose lifetime is controlled by a separate kobject) it is
beneficial to tie lifetime of another object to the lifetime of
character device so that related object is not freed until after
char_dev object is freed.

To achieve this let's pin kobject's parent when doing cdev_add() and
unpin when last reference to cdev structure is being released.
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In mke2fs, we only checksum the whole bitmap block and it is right.
While in the kernel, we use EXT4_BLOCKS_PER_GROUP to indicate the
size of the checksumed bitmap which is wrong when we enable bigalloc.
The right size should be EXT4_CLUSTERS_PER_GROUP and this patch fixes
it.

Also as every caller of ext4_block_bitmap_csum_set and
ext4_block_bitmap_csum_verify pass in EXT4_BLOCKS_PER_GROUP(sb)/8,
we'd better removes this parameter and sets it in the function itself.
Signed-off-by: NTao Ma <boyu.mt@taobao.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: NLukas Czerner <lczerner@redhat.com>
Cc: stable@vger.kernel.org

  /proc/<pid>/numa_maps scans vma and show mempolicy under
  mmap_sem. It sometimes accesses task->mempolicy which can
  be freed without mmap_sem and numa_maps can show some
  garbage while scanning.

This patch tries to take reference count of task->mempolicy at reading
numa_maps before calling get_vma_policy(). By this, task->mempolicy
will not be freed until numa_maps reaches its end.

V2->v3
  -  updated comments to be more verbose.
  -  removed task_lock() in numa_maps code.
V1->V2
  -  access task->mempolicy only once and remember it.  Becase kernel/exit.c
     can overwrite it.
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 38f38657 ("xattr: extract simple_xattr code from tmpfs") moved
some code from tmpfs but introduced a subtle bug along the way.

If the name passed to simple_xattr_remove() does not exist in the list of
xattrs, then it is possible to call kfree(new_xattr) when new_xattr is
actually initialized to itself on the stack via uninitialized_var().

This causes a BUG() since the memory was not allocated via the slab
allocator and was not bypassed through to the page allocator because it
was too large.

Initialize the local variable to NULL so the kfree() never takes place.
Reported-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Acked-by: NHugh Dickins <hughd@google.com>
Acked-by: NAristeu Rozanski <aris@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>