Move kernel-doc notation to immediately before its function to eliminate
kernel-doc warnings introduced by commit db14fc3a ("vfs: add
d_walk()")

  Warning(fs/dcache.c:1343): No description found for parameter 'data'
  Warning(fs/dcache.c:1343): No description found for parameter 'dentry'
  Warning(fs/dcache.c:1343): Excess function parameter 'parent' description in 'check_mount'
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Cc: Miklos Szeredi <mszeredi@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add @path parameter to fix kernel-doc warning.
Also fix a spello/typo.

  Warning(fs/namei.c:2304): No description found for parameter 'path'
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We can't be holding tree locks while we try to start a transaction, we will
deadlock.  Thanks,
Reported-by: NSage Weil <sage@inktank.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Commit c4fe2448 ("sparc: fix PCI device proc file mmap(2)") added
proc_reg_get_unmapped_area in proc_reg_file_ops and
proc_reg_file_ops_no_compat, by which now mmap always returns EIO if
get_unmapped_area method is not defined for the target procfs file,
which causes regression of mmap on /proc/vmcore.

To address this issue, like get_unmapped_area(), call default
current->mm->get_unmapped_area on MMU-present architectures if
pde->proc_fops->get_unmapped_area, i.e.  the one in actual file
operation in the procfs file, is not defined.
Reported-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NHATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Tested-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently, proc_reg_get_unmapped_area truncates upper 32-bit of the
mapped virtual address returned from get_unmapped_area method in
pde->proc_fops due to the variable rv of signed integer on x86_64.  This
is too small to have vitual address of unsigned long on x86_64 since on
x86_64, signed integer is of 4 bytes while unsigned long is of 8 bytes.
To fix this issue, use unsigned long instead.

Fixes a regression added in commit c4fe2448 ("sparc: fix PCI device
proc file mmap(2)").
Signed-off-by: NHATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Tested-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Buffer allocation has a very crude indefinite loop around waking the
flusher threads and performing global NOFS direct reclaim because it can
not handle allocation failures.

The most immediate problem with this is that the allocation may fail due
to a memory cgroup limit, where flushers + direct reclaim might not make
any progress towards resolving the situation at all.  Because unlike the
global case, a memory cgroup may not have any cache at all, only
anonymous pages but no swap.  This situation will lead to a reclaim
livelock with insane IO from waking the flushers and thrashing unrelated
filesystem cache in a tight loop.

Use __GFP_NOFAIL allocations for buffers for now.  This makes sure that
any looping happens in the page allocator, which knows how to
orchestrate kswapd, direct reclaim, and the flushers sensibly.  It also
allows memory cgroups to detect allocations that can't handle failure
and will allow them to ultimately bypass the limit if reclaim can not
make progress.
Reported-by: NazurIt <azurit@pobox.sk>
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If a page we are inspecting is in swap we may occasionally report it as
having soft dirty bit (even if it is clean).  The pte_soft_dirty helper
should be called on present pte only.
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

d_tmpfile() already swallowed the inode ref.
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Cc: stable@vger.kernel.org
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Functions that walk the ntstatus_to_dos_map[] array could
run off the end. For example, ntstatus_to_dos() loops
while ntstatus_to_dos_map[].ntstatus is not 0. Granted,
this is mostly theoretical, but could be used as a DOS attack
if the error code in the SMB header is bogus.

[Might consider adding to stable, as this patch is low risk - Steve]
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NTim Gardner <tim.gardner@canonical.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

Olga reported that file descriptors opened with O_PATH do not work with
fstatfs(), found during further development of ksh93's thread support.

There is no reason to not allow O_PATH file descriptors here (fstatfs is
very much a path operation), so use "fdget_raw()".  See commit
55815f70 ("vfs: make O_PATH file descriptors usable for 'fstat()'")
for a very similar issue reported for fstat() by the same team.
Reported-and-tested-by: Nольга крыжановская <olga.kryzhanovska@gmail.com>
Acked-by: NAl Viro <viro@zeniv.linux.org.uk>
Cc: stable@kernel.org	# O_PATH introduced in 3.0+
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If we take the 2nd retry path in ext4_expand_extra_isize_ea, we
potentionally return from the function without having freed these
allocations.  If we don't do the return, we over-write the previous
allocation pointers, so we leak either way.

Spotted with Coverity.

[ Fixed by tytso to set is and bs to NULL after freeing these
  pointers, in case in the retry loop we later end up triggering an
  error causing a jump to cleanup, at which point we could have a double
  free bug. -- Ted ]
Signed-off-by: NDave Jones <davej@fedoraproject.org>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: NEric Sandeen <sandeen@redhat.com>
Cc: stable@vger.kernel.org

When doing space balance and subvolume destroy at the same time, we met
the following oops:

kernel BUG at fs/btrfs/relocation.c:2247!
RIP: 0010: [<ffffffffa04cec16>] prepare_to_merge+0x154/0x1f0 [btrfs]
Call Trace:
 [<ffffffffa04b5ab7>] relocate_block_group+0x466/0x4e6 [btrfs]
 [<ffffffffa04b5c7a>] btrfs_relocate_block_group+0x143/0x275 [btrfs]
 [<ffffffffa0495c56>] btrfs_relocate_chunk.isra.27+0x5c/0x5a2 [btrfs]
 [<ffffffffa0459871>] ? btrfs_item_key_to_cpu+0x15/0x31 [btrfs]
 [<ffffffffa048b46a>] ? btrfs_get_token_64+0x7e/0xcd [btrfs]
 [<ffffffffa04a3467>] ? btrfs_tree_read_unlock_blocking+0xb2/0xb7 [btrfs]
 [<ffffffffa049907d>] btrfs_balance+0x9c7/0xb6f [btrfs]
 [<ffffffffa049ef84>] btrfs_ioctl_balance+0x234/0x2ac [btrfs]
 [<ffffffffa04a1e8e>] btrfs_ioctl+0xd87/0x1ef9 [btrfs]
 [<ffffffff81122f53>] ? path_openat+0x234/0x4db
 [<ffffffff813c3b78>] ? __do_page_fault+0x31d/0x391
 [<ffffffff810f8ab6>] ? vma_link+0x74/0x94
 [<ffffffff811250f5>] vfs_ioctl+0x1d/0x39
 [<ffffffff811258c8>] do_vfs_ioctl+0x32d/0x3e2
 [<ffffffff811259d4>] SyS_ioctl+0x57/0x83
 [<ffffffff813c3bfa>] ? do_page_fault+0xe/0x10
 [<ffffffff813c73c2>] system_call_fastpath+0x16/0x1b

It is because we returned the error number if the reference of the root was 0
when doing space relocation. It was not right here, because though the root
was dead(refs == 0), but the space it held still need be relocated, or we
could not remove the block group. So in this case, we should return the root
no matter it is dead or not.
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Now we don't drop all the deleted snapshots/subvolumes before the space
balance. It means we have to relocate the space which is held by the dead
snapshots/subvolumes. So we must into them into fs radix tree, or we would
forget to commit the change of them when doing transaction commit, and it
would corrupt the metadata.
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Liu fixed part of this problem and unfortunately I steered him in slightly the
wrong direction and so didn't completely fix the problem.  The problem is we
limit the size of the delalloc range we are looking for to max bytes and then we
try to lock that range.  If we fail to lock the pages in that range we will
shrink the max bytes to a single page and re loop.  However if our first page is
inside of the delalloc range then we will end up limiting the end of the range
to a period before our first page.  This is illustrated below

[0 -------- delalloc range --------- 256mb]
                                  [page]

So find_delalloc_range will return with delalloc_start as 0 and end as 128mb,
and then we will notice that delalloc_start < *start and adjust it up, but not
adjust delalloc_end up, so things go sideways.  To fix this we need to not limit
the max bytes in find_delalloc_range, but in find_lock_delalloc_range and that
way we don't end up with this confusion.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

btrfs_rename was using the root of the old dir instead of the root of the new
dir when checking for a hash collision, so if you tried to move a file into a
subvol it would freak out because it would see the file you are trying to move
in its current root.  This fixes the bug where this would fail

btrfs subvol create test1
btrfs subvol create test2
mv test1 test2.

Thanks to Chris Murphy for catching this,

Cc: stable@vger.kernel.org
Reported-by: NChris Murphy <lists@colorremedies.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

This allows users to use LANMAN authentication on servers which support
unencapsulated authentication.

The patch fixes a regression where users using plaintext authentication
were no longer able to do so because of changed bought in by patch
3f618223

https://bugzilla.redhat.com/show_bug.cgi?id=1011621Reported-by: NPanos Kavalagios <Panagiotis.Kavalagios@eurodyn.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSachin Prabhu <sprabhu@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

When connecting to SMB2/3 shares, maximum file size is set to non-LFS maximum in superblock. This is due to cap_large_files bit being different for SMB1 and SMB2/3 (where it is just an internal flag that is not negotiated and the SMB1 one corresponds to multichannel capability, so maybe LFS works correctly if server sends 0x08 flag) while capabilities are checked always for the SMB1 bit in cifs_read_super().

The patch fixes this by checking for the correct bit according to the protocol version.

CC: Stable <stable@kernel.org>
Signed-off-by: NJan Klos <honza.klos@gmail.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

Do not send SMB2 Logoff command when reconnecting, the way smb1
code base works.

Also, no need to wait for a credit for an echo command when one is already
in flight.

Without these changes, umount command hangs if the server is unresponsive
e.g. hibernating.
Signed-off-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>
Acked-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <smfrench@us.ibm.com>

Windows 8 and later can create NFS symlinks (within reparse points)
which we were assuming were normal NTFS symlinks and thus reporting
corrupt paths for.  Add check for reparse points to make sure that
they really are normal symlinks before we try to parse the pathname.

We also should not be parsing other types of reparse points (DFS
junctions etc) as if they were a  symlink so return EOPNOTSUPP
on those.  Also fix endian errors (we were not parsing symlink
lengths as little endian).

This fixes commit d244bf2d
which implemented follow link for non-Unix CIFS mounts

CC: Stable <stable@kernel.org>
Reviewed-by: NAndrew Bartlett <abartlet@samba.org>
Signed-off-by: NSteve French <smfrench@gmail.com>

When btrfs creates a bioset, we must also allocate the integrity data pool.
Otherwise btrfs will crash when it tries to submit a bio to a checksumming
disk:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
 IP: [<ffffffff8111e28a>] mempool_alloc+0x4a/0x150
 PGD 2305e4067 PUD 23063d067 PMD 0
 Oops: 0000 [#1] PREEMPT SMP
 Modules linked in: btrfs scsi_debug xfs ext4 jbd2 ext3 jbd mbcache
sch_fq_codel eeprom lpc_ich mfd_core nfsd exportfs auth_rpcgss af_packet
raid6_pq xor zlib_deflate libcrc32c [last unloaded: scsi_debug]
 CPU: 1 PID: 4486 Comm: mount Not tainted 3.12.0-rc1-mcsum #2
 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
 task: ffff8802451c9720 ti: ffff880230698000 task.ti: ffff880230698000
 RIP: 0010:[<ffffffff8111e28a>]  [<ffffffff8111e28a>] mempool_alloc+0x4a/0x150
 RSP: 0018:ffff880230699688  EFLAGS: 00010286
 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 00000000005f8445
 RDX: 0000000000000001 RSI: 0000000000000010 RDI: 0000000000000000
 RBP: ffff8802306996f8 R08: 0000000000011200 R09: 0000000000000008
 R10: 0000000000000020 R11: ffff88009d6e8000 R12: 0000000000011210
 R13: 0000000000000030 R14: ffff8802306996b8 R15: ffff8802451c9720
 FS:  00007f25b8a16800(0000) GS:ffff88024fc80000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
 CR2: 0000000000000018 CR3: 0000000230576000 CR4: 00000000000007e0
 Stack:
  ffff8802451c9720 0000000000000002 ffffffff81a97100 0000000000281250
  ffffffff81a96480 ffff88024fc99150 ffff880228d18200 0000000000000000
  0000000000000000 0000000000000040 ffff880230e8c2e8 ffff8802459dc900
 Call Trace:
  [<ffffffff811b2208>] bio_integrity_alloc+0x48/0x1b0
  [<ffffffff811b26fc>] bio_integrity_prep+0xac/0x360
  [<ffffffff8111e298>] ? mempool_alloc+0x58/0x150
  [<ffffffffa03e8041>] ? alloc_extent_state+0x31/0x110 [btrfs]
  [<ffffffff81241579>] blk_queue_bio+0x1c9/0x460
  [<ffffffff8123e58a>] generic_make_request+0xca/0x100
  [<ffffffff8123e639>] submit_bio+0x79/0x160
  [<ffffffffa03f865e>] btrfs_map_bio+0x48e/0x5b0 [btrfs]
  [<ffffffffa03c821a>] btree_submit_bio_hook+0xda/0x110 [btrfs]
  [<ffffffffa03e7eba>] submit_one_bio+0x6a/0xa0 [btrfs]
  [<ffffffffa03ef450>] read_extent_buffer_pages+0x250/0x310 [btrfs]
  [<ffffffff8125eef6>] ? __radix_tree_preload+0x66/0xf0
  [<ffffffff8125f1c5>] ? radix_tree_insert+0x95/0x260
  [<ffffffffa03c66f6>] btree_read_extent_buffer_pages.constprop.128+0xb6/0x120
[btrfs]
  [<ffffffffa03c8c1a>] read_tree_block+0x3a/0x60 [btrfs]
  [<ffffffffa03caefd>] open_ctree+0x139d/0x2030 [btrfs]
  [<ffffffffa03a282a>] btrfs_mount+0x53a/0x7d0 [btrfs]
  [<ffffffff8113ab0b>] ? pcpu_alloc+0x8eb/0x9f0
  [<ffffffff81167305>] ? __kmalloc_track_caller+0x35/0x1e0
  [<ffffffff81176ba0>] mount_fs+0x20/0xd0
  [<ffffffff81191096>] vfs_kern_mount+0x76/0x120
  [<ffffffff81193320>] do_mount+0x200/0xa40
  [<ffffffff81135cdb>] ? strndup_user+0x5b/0x80
  [<ffffffff81193bf0>] SyS_mount+0x90/0xe0
  [<ffffffff8156d31d>] system_call_fastpath+0x1a/0x1f
 Code: 4c 8d 75 a8 4c 89 6d e8 45 89 e0 4c 8d 6f 30 48 89 5d d8 41 83 e0 af 48
89 fb 49 83 c6 18 4c 89 7d f8 65 4c 8b 3c 25 c0 b8 00 00 <48> 8b 73 18 44 89 c7
44 89 45 98 ff 53 20 48 85 c0 48 89 c2 74
 RIP  [<ffffffff8111e28a>] mempool_alloc+0x4a/0x150
  RSP <ffff880230699688>
 CR2: 0000000000000018
 ---[ end trace 7a96042017ed21e2 ]---
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

free_device rcu callback, scheduled from btrfs_rm_dev_replace_srcdev,
can be processed before btrfs_scratch_superblock is called, which would
result in a use-after-free on btrfs_device contents.  Fix this by
zeroing the superblock before the rcu callback is registered.

Cc: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

The current implementation of worker threads in Btrfs has races in
worker stopping code, which cause all kinds of panics and lockups when
running btrfs/011 xfstest in a loop.  The problem is that
btrfs_stop_workers is unsynchronized with respect to check_idle_worker,
check_busy_worker and __btrfs_start_workers.

E.g., check_idle_worker race flow:

       btrfs_stop_workers():            check_idle_worker(aworker):
- grabs the lock
- splices the idle list into the
  working list
- removes the first worker from the
  working list
- releases the lock to wait for
  its kthread's completion
                                  - grabs the lock
                                  - if aworker is on the working list,
                                    moves aworker from the working list
                                    to the idle list
                                  - releases the lock
- grabs the lock
- puts the worker
- removes the second worker from the
  working list
                              ......
        btrfs_stop_workers returns, aworker is on the idle list
                 FS is umounted, memory is freed
                              ......
              aworker is waken up, fireworks ensue

With this applied, I wasn't able to trigger the problem in 48 hours,
whereas previously I could reliably reproduce at least one of these
races within an hour.
Reported-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

The crash[1] is found by xfstests/generic/208 with "-o compress",
it's not reproduced everytime, but it does panic.

The bug is quite interesting, it's actually introduced by a recent commit
(573aecaf,
Btrfs: actually limit the size of delalloc range).

Btrfs implements delay allocation, so during writeback, we
(1) get a page A and lock it
(2) search the state tree for delalloc bytes and lock all pages within the range
(3) process the delalloc range, including find disk space and create
    ordered extent and so on.
(4) submit the page A.

It runs well in normal cases, but if we're in a racy case, eg.
buffered compressed writes and aio-dio writes,
sometimes we may fail to lock all pages in the 'delalloc' range,
in which case, we need to fall back to search the state tree again with
a smaller range limit(max_bytes = PAGE_CACHE_SIZE - offset).

The mentioned commit has a side effect, that is, in the fallback case,
we can find delalloc bytes before the index of the page we already have locked,
so we're in the case of (delalloc_end <= *start) and return with (found > 0).

This ends with not locking delalloc pages but making ->writepage still
process them, and the crash happens.

This fixes it by just thinking that we find nothing and returning to caller
as the caller knows how to deal with it properly.

[1]:
------------[ cut here ]------------
kernel BUG at mm/page-writeback.c:2170!
[...]
CPU: 2 PID: 11755 Comm: btrfs-delalloc- Tainted: G           O 3.11.0+ #8
[...]
RIP: 0010:[<ffffffff810f5093>]  [<ffffffff810f5093>] clear_page_dirty_for_io+0x1e/0x83
[...]
[ 4934.248731] Stack:
[ 4934.248731]  ffff8801477e5dc8 ffffea00049b9f00 ffff8801869f9ce8 ffffffffa02b841a
[ 4934.248731]  0000000000000000 0000000000000000 0000000000000fff 0000000000000620
[ 4934.248731]  ffff88018db59c78 ffffea0005da8d40 ffffffffa02ff860 00000001810016c0
[ 4934.248731] Call Trace:
[ 4934.248731]  [<ffffffffa02b841a>] extent_range_clear_dirty_for_io+0xcf/0xf5 [btrfs]
[ 4934.248731]  [<ffffffffa02a8889>] compress_file_range+0x1dc/0x4cb [btrfs]
[ 4934.248731]  [<ffffffff8104f7af>] ? detach_if_pending+0x22/0x4b
[ 4934.248731]  [<ffffffffa02a8bad>] async_cow_start+0x35/0x53 [btrfs]
[ 4934.248731]  [<ffffffffa02c694b>] worker_loop+0x14b/0x48c [btrfs]
[ 4934.248731]  [<ffffffffa02c6800>] ? btrfs_queue_worker+0x25c/0x25c [btrfs]
[ 4934.248731]  [<ffffffff810608f5>] kthread+0x8d/0x95
[ 4934.248731]  [<ffffffff81060868>] ? kthread_freezable_should_stop+0x43/0x43
[ 4934.248731]  [<ffffffff814fe09c>] ret_from_fork+0x7c/0xb0
[ 4934.248731]  [<ffffffff81060868>] ? kthread_freezable_should_stop+0x43/0x43
[ 4934.248731] Code: ff 85 c0 0f 94 c0 0f b6 c0 59 5b 5d c3 0f 1f 44 00 00 55 48 89 e5 41 54 53 48 89 fb e8 2c de 00 00 49 89 c4 48 8b 03 a8 01 75 02 <0f> 0b 4d 85 e4 74 52 49 8b 84 24 80 00 00 00 f6 40 20 01 75 44
[ 4934.248731] RIP  [<ffffffff810f5093>] clear_page_dirty_for_io+0x1e/0x83
[ 4934.248731]  RSP <ffff8801869f9c48>
[ 4934.280307] ---[ end trace 36f06d3f8750236a ]---
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

If we crash with a log, remount and recover that log, and then crash before we
can commit another transaction we will get transid verify errors on the next
mount.  This is because we were not zero'ing out the log when we committed the
transaction after recovery.  This is ok as long as we commit another transaction
at some point in the future, but if you abort or something else goes wrong you
can end up in this weird state because the recovery stuff says that the tree log
should have a generation+1 of the super generation, which won't be the case of
the transaction that was started for recovery.  Fix this by removing the check
and _always_ zero out the log portion of the super when we commit a transaction.
This fixes the transid verify issues I was seeing with my force errors tests.
Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

This fixes a build failure caused by calling the free() function which
does not exist in the Linux kernel.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

(cherry picked from commit aaaae980)

Free the memory in error path of xlog_recover_add_to_trans().
Normally this memory is freed in recovery pass2, but is leaked
in the error path.
Signed-off-by: NMark Tinguely <tinguely@sgi.com>
Reviewed-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

(cherry picked from commit 519ccb81)

The determination of whether a directory entry contains a dtype
field originally was dependent on the filesystem having CRCs
enabled. This meant that the format for dtype beign enabled could be
determined by checking the directory block magic number rather than
doing a feature bit check. This was useful in that it meant that we
didn't need to pass a struct xfs_mount around to functions that
were already supplied with a directory block header.

Unfortunately, the introduction of dtype fields into the v4
structure via a feature bit meant this "use the directory block
magic number" method of discriminating the dirent entry sizes is
broken. Hence we need to convert the places that use magic number
checks to use feature bit checks so that they work correctly and not
by chance.

The current code works on v4 filesystems only because the dirent
size roundup covers the extra byte needed by the dtype field in the
places where this problem occurs.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

(cherry picked from commit 367993e7)

Michael Semon reported that xfs/299 generated this lockdep warning:

=============================================
[ INFO: possible recursive locking detected ]
3.12.0-rc2+ #2 Not tainted
---------------------------------------------
touch/21072 is trying to acquire lock:
 (&xfs_dquot_other_class){+.+...}, at: [<c12902fb>] xfs_trans_dqlockedjoin+0x57/0x64

but task is already holding lock:
 (&xfs_dquot_other_class){+.+...}, at: [<c12902fb>] xfs_trans_dqlockedjoin+0x57/0x64

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&xfs_dquot_other_class);
  lock(&xfs_dquot_other_class);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

7 locks held by touch/21072:
 #0:  (sb_writers#10){++++.+}, at: [<c11185b6>] mnt_want_write+0x1e/0x3e
 #1:  (&type->i_mutex_dir_key#4){+.+.+.}, at: [<c11078ee>] do_last+0x245/0xe40
 #2:  (sb_internal#2){++++.+}, at: [<c122c9e0>] xfs_trans_alloc+0x1f/0x35
 #3:  (&(&ip->i_lock)->mr_lock/1){+.+...}, at: [<c126cd1b>] xfs_ilock+0x100/0x1f1
 #4:  (&(&ip->i_lock)->mr_lock){++++-.}, at: [<c126cf52>] xfs_ilock_nowait+0x105/0x22f
 #5:  (&dqp->q_qlock){+.+...}, at: [<c12902fb>] xfs_trans_dqlockedjoin+0x57/0x64
 #6:  (&xfs_dquot_other_class){+.+...}, at: [<c12902fb>] xfs_trans_dqlockedjoin+0x57/0x64

The lockdep annotation for dquot lock nesting only understands
locking for user and "other" dquots, not user, group and quota
dquots. Fix the annotations to match the locking heirarchy we now
have.
Reported-by: NMichael L. Semon <mlsemon35@gmail.com>
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

(cherry picked from commit f112a049)

Freeing ->s_{inode,dentry}_lru in deactivate_locked_super() is wrong;
the right place is destroy_super().  As it is, we leak them if sget()
decides that new superblock it has allocated (and never shown to
anybody) isn't needed and should be freed.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

fuse_access() is never called in RCU walk, only on the final component of
access(2) and chdir(2)...
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>

Doing dput(parent) is not valid in RCU walk mode.  In RCU mode it would
probably be okay to update the parent flags, but it's actually not
necessary most of the time...

So only set the FUSE_I_ADVISE_RDPLUS flag on the parent when the entry was
recently initialized by READDIRPLUS.

This is achieved by setting FUSE_I_INIT_RDPLUS on entries added by
READDIRPLUS and only dropping out of RCU mode if this flag is set.
FUSE_I_INIT_RDPLUS is cleared once the FUSE_I_ADVISE_RDPLUS flag is set in
the parent.
Reported-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Cc: stable@vger.kernel.org

If revalidate finds an invalid dentry in RCU walk mode, let the VFS deal
with it instead of calling check_submounts_and_drop() which is not prepared
for being called from RCU walk.
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Cc: stable@vger.kernel.org

Many NILFS2 users were reported about strange file system corruption
(for example):

   NILFS: bad btree node (blocknr=185027): level = 0, flags = 0x0, nchildren = 768
   NILFS error (device sda4): nilfs_bmap_last_key: broken bmap (inode number=11540)

But such error messages are consequence of file system's issue that takes
place more earlier.  Fortunately, Jerome Poulin <jeromepoulin@gmail.com>
and Anton Eliasson <devel@antoneliasson.se> were reported about another
issue not so recently.  These reports describe the issue with segctor
thread's crash:

  BUG: unable to handle kernel paging request at 0000000000004c83
  IP: nilfs_end_page_io+0x12/0xd0 [nilfs2]

  Call Trace:
   nilfs_segctor_do_construct+0xf25/0x1b20 [nilfs2]
   nilfs_segctor_construct+0x17b/0x290 [nilfs2]
   nilfs_segctor_thread+0x122/0x3b0 [nilfs2]
   kthread+0xc0/0xd0
   ret_from_fork+0x7c/0xb0

These two issues have one reason.  This reason can raise third issue
too.  Third issue results in hanging of segctor thread with eating of
100% CPU.

REPRODUCING PATH:

One of the possible way or the issue reproducing was described by
Jermoe me Poulin <jeromepoulin@gmail.com>:

1. init S to get to single user mode.
2. sysrq+E to make sure only my shell is running
3. start network-manager to get my wifi connection up
4. login as root and launch "screen"
5. cd /boot/log/nilfs which is a ext3 mount point and can log when NILFS dies.
6. lscp | xz -9e > lscp.txt.xz
7. mount my snapshot using mount -o cp=3360839,ro /dev/vgUbuntu/root /mnt/nilfs
8. start a screen to dump /proc/kmsg to text file since rsyslog is killed
9. start a screen and launch strace -f -o find-cat.log -t find
/mnt/nilfs -type f -exec cat {} > /dev/null \;
10. start a screen and launch strace -f -o apt-get.log -t apt-get update
11. launch the last command again as it did not crash the first time
12. apt-get crashes
13. ps aux > ps-aux-crashed.log
13. sysrq+W
14. sysrq+E  wait for everything to terminate
15. sysrq+SUSB

Simplified way of the issue reproducing is starting kernel compilation
task and "apt-get update" in parallel.

REPRODUCIBILITY:

The issue is reproduced not stable [60% - 80%].  It is very important to
have proper environment for the issue reproducing.  The critical
conditions for successful reproducing:

(1) It should have big modified file by mmap() way.

(2) This file should have the count of dirty blocks are greater that
    several segments in size (for example, two or three) from time to time
    during processing.

(3) It should be intensive background activity of files modification
    in another thread.

INVESTIGATION:

First of all, it is possible to see that the reason of crash is not valid
page address:

  NILFS [nilfs_segctor_complete_write]:2100 bh->b_count 0, bh->b_blocknr 13895680, bh->b_size 13897727, bh->b_page 0000000000001a82
  NILFS [nilfs_segctor_complete_write]:2101 segbuf->sb_segnum 6783

Moreover, value of b_page (0x1a82) is 6786.  This value looks like segment
number.  And b_blocknr with b_size values look like block numbers.  So,
buffer_head's pointer points on not proper address value.

Detailed investigation of the issue is discovered such picture:

  [-----------------------------SEGMENT 6783-------------------------------]
  NILFS [nilfs_segctor_do_construct]:2310 nilfs_segctor_begin_construction
  NILFS [nilfs_segctor_do_construct]:2321 nilfs_segctor_collect
  NILFS [nilfs_segctor_do_construct]:2336 nilfs_segctor_assign
  NILFS [nilfs_segctor_do_construct]:2367 nilfs_segctor_update_segusage
  NILFS [nilfs_segctor_do_construct]:2371 nilfs_segctor_prepare_write
  NILFS [nilfs_segctor_do_construct]:2376 nilfs_add_checksums_on_logs
  NILFS [nilfs_segctor_do_construct]:2381 nilfs_segctor_write
  NILFS [nilfs_segbuf_submit_bio]:464 bio->bi_sector 111149024, segbuf->sb_segnum 6783

  [-----------------------------SEGMENT 6784-------------------------------]
  NILFS [nilfs_segctor_do_construct]:2310 nilfs_segctor_begin_construction
  NILFS [nilfs_segctor_do_construct]:2321 nilfs_segctor_collect
  NILFS [nilfs_lookup_dirty_data_buffers]:782 bh->b_count 1, bh->b_page ffffea000709b000, page->index 0, i_ino 1033103, i_size 25165824
  NILFS [nilfs_lookup_dirty_data_buffers]:783 bh->b_assoc_buffers.next ffff8802174a6798, bh->b_assoc_buffers.prev ffff880221cffee8
  NILFS [nilfs_segctor_do_construct]:2336 nilfs_segctor_assign
  NILFS [nilfs_segctor_do_construct]:2367 nilfs_segctor_update_segusage
  NILFS [nilfs_segctor_do_construct]:2371 nilfs_segctor_prepare_write
  NILFS [nilfs_segctor_do_construct]:2376 nilfs_add_checksums_on_logs
  NILFS [nilfs_segctor_do_construct]:2381 nilfs_segctor_write
  NILFS [nilfs_segbuf_submit_bh]:575 bh->b_count 1, bh->b_page ffffea000709b000, page->index 0, i_ino 1033103, i_size 25165824
  NILFS [nilfs_segbuf_submit_bh]:576 segbuf->sb_segnum 6784
  NILFS [nilfs_segbuf_submit_bh]:577 bh->b_assoc_buffers.next ffff880218a0d5f8, bh->b_assoc_buffers.prev ffff880218bcdf50
  NILFS [nilfs_segbuf_submit_bio]:464 bio->bi_sector 111150080, segbuf->sb_segnum 6784, segbuf->sb_nbio 0
  [----------] ditto
  NILFS [nilfs_segbuf_submit_bio]:464 bio->bi_sector 111164416, segbuf->sb_segnum 6784, segbuf->sb_nbio 15

  [-----------------------------SEGMENT 6785-------------------------------]
  NILFS [nilfs_segctor_do_construct]:2310 nilfs_segctor_begin_construction
  NILFS [nilfs_segctor_do_construct]:2321 nilfs_segctor_collect
  NILFS [nilfs_lookup_dirty_data_buffers]:782 bh->b_count 2, bh->b_page ffffea000709b000, page->index 0, i_ino 1033103, i_size 25165824
  NILFS [nilfs_lookup_dirty_data_buffers]:783 bh->b_assoc_buffers.next ffff880219277e80, bh->b_assoc_buffers.prev ffff880221cffc88
  NILFS [nilfs_segctor_do_construct]:2367 nilfs_segctor_update_segusage
  NILFS [nilfs_segctor_do_construct]:2371 nilfs_segctor_prepare_write
  NILFS [nilfs_segctor_do_construct]:2376 nilfs_add_checksums_on_logs
  NILFS [nilfs_segctor_do_construct]:2381 nilfs_segctor_write
  NILFS [nilfs_segbuf_submit_bh]:575 bh->b_count 2, bh->b_page ffffea000709b000, page->index 0, i_ino 1033103, i_size 25165824
  NILFS [nilfs_segbuf_submit_bh]:576 segbuf->sb_segnum 6785
  NILFS [nilfs_segbuf_submit_bh]:577 bh->b_assoc_buffers.next ffff880218a0d5f8, bh->b_assoc_buffers.prev ffff880222cc7ee8
  NILFS [nilfs_segbuf_submit_bio]:464 bio->bi_sector 111165440, segbuf->sb_segnum 6785, segbuf->sb_nbio 0
  [----------] ditto
  NILFS [nilfs_segbuf_submit_bio]:464 bio->bi_sector 111177728, segbuf->sb_segnum 6785, segbuf->sb_nbio 12

  NILFS [nilfs_segctor_do_construct]:2399 nilfs_segctor_wait
  NILFS [nilfs_segbuf_wait]:676 segbuf->sb_segnum 6783
  NILFS [nilfs_segbuf_wait]:676 segbuf->sb_segnum 6784
  NILFS [nilfs_segbuf_wait]:676 segbuf->sb_segnum 6785

  NILFS [nilfs_segctor_complete_write]:2100 bh->b_count 0, bh->b_blocknr 13895680, bh->b_size 13897727, bh->b_page 0000000000001a82

  BUG: unable to handle kernel paging request at 0000000000001a82
  IP: [<ffffffffa024d0f2>] nilfs_end_page_io+0x12/0xd0 [nilfs2]

Usually, for every segment we collect dirty files in list.  Then, dirty
blocks are gathered for every dirty file, prepared for write and
submitted by means of nilfs_segbuf_submit_bh() call.  Finally, it takes
place complete write phase after calling nilfs_end_bio_write() on the
block layer.  Buffers/pages are marked as not dirty on final phase and
processed files removed from the list of dirty files.

It is possible to see that we had three prepare_write and submit_bio
phases before segbuf_wait and complete_write phase.  Moreover, segments
compete between each other for dirty blocks because on every iteration
of segments processing dirty buffer_heads are added in several lists of
payload_buffers:

  [SEGMENT 6784]: bh->b_assoc_buffers.next ffff880218a0d5f8, bh->b_assoc_buffers.prev ffff880218bcdf50
  [SEGMENT 6785]: bh->b_assoc_buffers.next ffff880218a0d5f8, bh->b_assoc_buffers.prev ffff880222cc7ee8

The next pointer is the same but prev pointer has changed.  It means
that buffer_head has next pointer from one list but prev pointer from
another.  Such modification can be made several times.  And, finally, it
can be resulted in various issues: (1) segctor hanging, (2) segctor
crashing, (3) file system metadata corruption.

FIX:
This patch adds:

(1) setting of BH_Async_Write flag in nilfs_segctor_prepare_write()
    for every proccessed dirty block;

(2) checking of BH_Async_Write flag in
    nilfs_lookup_dirty_data_buffers() and
    nilfs_lookup_dirty_node_buffers();

(3) clearing of BH_Async_Write flag in nilfs_segctor_complete_write(),
    nilfs_abort_logs(), nilfs_forget_buffer(), nilfs_clear_dirty_page().
Reported-by: NJerome Poulin <jeromepoulin@gmail.com>
Reported-by: NAnton Eliasson <devel@antoneliasson.se>
Cc: Paul Fertser <fercerpav@gmail.com>
Cc: ARAI Shun-ichi <hermes@ceres.dti.ne.jp>
Cc: Piotr Szymaniak <szarpaj@grubelek.pl>
Cc: Juan Barry Manuel Canham <Linux@riotingpacifist.net>
Cc: Zahid Chowdhury <zahid.chowdhury@starsolutions.com>
Cc: Elmer Zhang <freeboy6716@gmail.com>
Cc: Kenneth Langga <klangga@gmail.com>
Signed-off-by: NVyacheslav Dubeyko <slava@dubeyko.com>
Acked-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A high setting of max_map_count, and a process core-dumping with a large
enough vm_map_count could result in an NT_FILE note not being written,
and the kernel crashing immediately later because it has assumed
otherwise.

Reproduction of the oops-causing bug described here:

    https://lkml.org/lkml/2013/8/30/50

Rge ussue originated in commit 2aa362c4 ("coredump: extend core dump
note section to contain file names of mapped file") from Oct 4, 2012.

This patch make that section optional in that case.  fill_files_note()
should signify the error, and also let the info struct in
elf_core_dump() be zero-initialized so that we can check for the
optionally written note.

[akpm@linux-foundation.org: avoid abusing E2BIG, remove a couple of not-really-needed local variables]
[akpm@linux-foundation.org: fix sparse warning]
Signed-off-by: NDan Aloni <alonid@stratoscale.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Denys Vlasenko <vda.linux@googlemail.com>
Reported-by: NMartin MOKREJS <mmokrejs@gmail.com>
Tested-by: NMartin MOKREJS <mmokrejs@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Superblock lock was replaced with (un)lock_super() removal, but left
uninitialized for Seventh Edition UNIX filesystem in the following commit (3.7):
c07cb01c sysv: drop lock/unlock super
Signed-off-by: NLubomir Rintel <lkundrak@v3.sk>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

The previous patch introduces a compile warning by not assigning an initial
value to the "flavor" variable.  This could only be a problem if the server
returns a supported secflavor list of length zero, but it's better to
fix this before it's ever hit.
Signed-off-by: NAnna Schumaker <bjschuma@netapp.com>
Acked-by: NWeston Andros Adamson <dros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Call nfs4_lookup_root_sec for each flavor returned by SECINFO_NO_NAME until
one works.

One example of a situation this fixes:

 - server configured for krb5
 - server principal somehow gets deleted from KDC
 - server still thinking krb is good, sends krb5 as first entry in
    SECINFO_NO_NAME response
 - client tries krb5, but this fails without even sending an RPC because
    gssd's requests to the KDC can't find the server's principal
Signed-off-by: NWeston Andros Adamson <dros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We need to ensure that the initialisation of the data server nfs_client
structure in nfs4_ds_connect is correctly ordered w.r.t. the read of
ds->ds_clp in nfs4_fl_prepare_ds.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>