linux-stable.git/fs, branch v3.16.4

ext4: avoid trying to kfree an ERR_PTR pointer

2014-10-05T20:41:12+00:00

commit a9cfcd63e8d206ce4235c355d857c4fbdf0f4587 upstream.

Thanks to Dan Carpenter for extending smatch to find bugs like this.
(This was found using a development version of smatch.)

Fixes: 36de928641ee48b2078d3fe9514242aaa2f92013
Reported-by: Dan Carpenter 
Signed-off-by: Greg Kroah-Hartman

ext4: propagate errors up to ext4_find_entry()'s callers

2014-10-05T20:41:12+00:00

commit 36de928641ee48b2078d3fe9514242aaa2f92013 upstream.

If we run into some kind of error, such as ENOMEM, while calling
ext4_getblk() or ext4_dx_find_entry(), we need to make sure this error
gets propagated up to ext4_find_entry() and then to its callers.  This
way, transient errors such as ENOMEM can get propagated to the VFS.
This is important so that the system calls return the appropriate
error, and also so that in the case of ext4_lookup(), we return an
error instead of a NULL inode, since that will result in a negative
dentry cache entry that will stick around long past the OOM condition
which caused a transient ENOMEM error.

Google-Bug-Id: #17142205

Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

aio: block exit_aio() until all context requests are completed

2014-10-05T20:41:12+00:00

commit 6098b45b32e6baeacc04790773ced9340601d511 upstream.

It seems that exit_aio() also needs to wait for all iocbs to complete (like
io_destroy), but we missed the wait step in current implemention, so fix
it in the same way as we did in io_destroy.

Signed-off-by: Gu Zheng 
Signed-off-by: Benjamin LaHaise 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

Fix nasty 32-bit overflow bug in buffer i/o code.

2014-10-05T20:41:09+00:00

commit f2d5a94436cc7cc0221b9a81bba2276a25187dd3 upstream.

On 32-bit architectures, the legacy buffer_head functions are not always
handling the sector number with the proper 64-bit types, and will thus
fail on 4TB+ disks.

Any code that uses __getblk() (and thus bread(), breadahead(),
sb_bread(), sb_breadahead(), sb_getblk()), and calls it using a 64-bit
block on a 32-bit arch (where "long" is 32-bit) causes an inifinite loop
in __getblk_slow() with an infinite stream of errors logged to dmesg
like this:

  __find_get_block_slow() failed. block=6740375944, b_blocknr=2445408648
  b_state=0x00000020, b_size=512
  device sda1 blocksize: 512

Note how in hex block is 0x191C1F988 and b_blocknr is 0x91C1F988 i.e. the
top 32-bits are missing (in this case the 0x1 at the top).

This is because grow_dev_page() is broken and has a 32-bit overflow due
to shifting the page index value (a pgoff_t - which is just 32 bits on
32-bit architectures) left-shifted as the block number.  But the top
bits to get lost as the pgoff_t is not type cast to sector_t / 64-bit
before the shift.

This patch fixes this issue by type casting "index" to sector_t before
doing the left shift.

Note this is not a theoretical bug but has been seen in the field on a
4TiB hard drive with logical sector size 512 bytes.

This patch has been verified to fix the infinite loop problem on 3.17-rc5
kernel using a 4TB disk image mounted using "-o loop".  Without this patch
doing a "find /nt" where /nt is an NTFS volume causes the inifinite loop
100% reproducibly whilst with the patch it works fine as expected.

Signed-off-by: Anton Altaparmakov 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

GFS2: fix d_splice_alias() misuses

2014-10-05T20:41:08+00:00

commit cfb2f9d5c921e38b0f12bb26fed10b877664444d upstream.

Callers of d_splice_alias(dentry, inode) don't need iput(), neither
on success nor on failure.  Either the reference to inode is stored
in a previously negative dentry, or it's dropped.  In either case
inode reference the caller used to hold is consumed.

__gfs2_lookup() does iput() in case when d_splice_alias() has failed.
Double iput() if we ever hit that.  And gfs2_create_inode() ends up
not only with double iput(), but with link count dropped to zero - on
an inode it has just found in directory.

Signed-off-by: Al Viro 
Signed-off-by: Steven Whitehouse 
Signed-off-by: Greg Kroah-Hartman

don't bugger nd->seq on set_root_rcu() from follow_dotdot_rcu()

2014-10-05T20:41:08+00:00

commit 7bd88377d482e1eae3c5329b12e33cfd664fa6a9 upstream.

return the value instead, and have path_init() do the assignment.  Broken by
"vfs: Fix absolute RCU path walk failures due to uninitialized seq number",
which was Cc-stable with 2.6.38+ as destination.  This one should go where
it went.

To avoid dummy value returned in case when root is already set (it would do
no harm, actually, since the only caller that doesn't ignore the return value
is guaranteed to have nd->root *not* set, but it's more obvious that way),
lift the check into callers.  And do the same to set_root(), to keep them
in sync.

Signed-off-by: Al Viro 
Signed-off-by: Greg Kroah-Hartman

fs/cachefiles: add missing \n to kerror conversions

2014-10-05T20:41:07+00:00

commit 6ff66ac77aeaa9c13db28784e1c50c027a1f487b upstream.

Commit 0227d6abb378 ("fs/cachefiles: replace kerror by pr_err") didn't
include newline featuring in original kerror definition

Signed-off-by: Fabian Frederick 
Reported-by: David Howells 
Acked-by: David Howells 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

ocfs2/dlm: do not get resource spinlock if lockres is new

2014-10-05T20:41:07+00:00

commit 5760a97c7143c208fa3a8f8cad0ed7dd672ebd28 upstream.

There is a deadlock case which reported by Guozhonghua:
  https://oss.oracle.com/pipermail/ocfs2-devel/2014-September/010079.html

This case is caused by &res->spinlock and &dlm->master_lock
misordering in different threads.

It was introduced by commit 8d400b81cc83 ("ocfs2/dlm: Clean up refmap
helpers").  Since lockres is new, it doesn't not require the
&res->spinlock.  So remove it.

Fixes: 8d400b81cc83 ("ocfs2/dlm: Clean up refmap helpers")
Signed-off-by: Joseph Qi 
Reviewed-by: joyce.xue 
Reported-by: Guozhonghua 
Cc: Joel Becker 
Cc: Mark Fasheh 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

nilfs2: fix data loss with mmap()

2014-10-05T20:41:07+00:00

commit 56d7acc792c0d98f38f22058671ee715ff197023 upstream.

This bug leads to reproducible silent data loss, despite the use of
msync(), sync() and a clean unmount of the file system.  It is easily
reproducible with the following script:

  ----------------[BEGIN SCRIPT]--------------------
  mkfs.nilfs2 -f /dev/sdb
  mount /dev/sdb /mnt

  dd if=/dev/zero bs=1M count=30 of=/mnt/testfile

  umount /mnt
  mount /dev/sdb /mnt
  CHECKSUM_BEFORE="$(md5sum /mnt/testfile)"

  /root/mmaptest/mmaptest /mnt/testfile 30 10 5

  sync
  CHECKSUM_AFTER="$(md5sum /mnt/testfile)"
  umount /mnt
  mount /dev/sdb /mnt
  CHECKSUM_AFTER_REMOUNT="$(md5sum /mnt/testfile)"
  umount /mnt

  echo "BEFORE MMAP:\t$CHECKSUM_BEFORE"
  echo "AFTER MMAP:\t$CHECKSUM_AFTER"
  echo "AFTER REMOUNT:\t$CHECKSUM_AFTER_REMOUNT"
  ----------------[END SCRIPT]--------------------

The mmaptest tool looks something like this (very simplified, with
error checking removed):

  ----------------[BEGIN mmaptest]--------------------
  data = mmap(NULL, file_size - file_offset, PROT_READ | PROT_WRITE,
              MAP_SHARED, fd, file_offset);

  for (i = 0; i < write_count; ++i) {
        memcpy(data + i * 4096, buf, sizeof(buf));
        msync(data, file_size - file_offset, MS_SYNC))
  }
  ----------------[END mmaptest]--------------------

The output of the script looks something like this:

  BEFORE MMAP:    281ed1d5ae50e8419f9b978aab16de83  /mnt/testfile
  AFTER MMAP:     6604a1c31f10780331a6850371b3a313  /mnt/testfile
  AFTER REMOUNT:  281ed1d5ae50e8419f9b978aab16de83  /mnt/testfile

So it is clear, that the changes done using mmap() do not survive a
remount.  This can be reproduced a 100% of the time.  The problem was
introduced in commit 136e8770cd5d ("nilfs2: fix issue of
nilfs_set_page_dirty() for page at EOF boundary").

If the page was read with mpage_readpage() or mpage_readpages() for
example, then it has no buffers attached to it.  In that case
page_has_buffers(page) in nilfs_set_page_dirty() will be false.
Therefore nilfs_set_file_dirty() is never called and the pages are never
collected and never written to disk.

This patch fixes the problem by also calling nilfs_set_file_dirty() if the
page has no buffers attached to it.

[akpm@linux-foundation.org: s/PAGE_SHIFT/PAGE_CACHE_SHIFT/]
Signed-off-by: Andreas Rohner 
Tested-by: Andreas Rohner 
Signed-off-by: Ryusuke Konishi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

fs/notify: don't show f_handle if exportfs_encode_inode_fh failed

2014-10-05T20:41:07+00:00

commit 7e8824816bda16bb11ff5ff1e1212d642e57b0b3 upstream.

Currently we handle only ENOSPC.  In case of other errors the file_handle
variable isn't filled properly and we will show a part of stack.

Signed-off-by: Andrey Vagin 
Acked-by: Cyrill Gorcunov 
Cc: Alexander Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman