Direct decompression into the page cache.  If we fall back
to using an intermediate buffer (because we cannot grab all the
page cache pages) and we get a decompress fail, we forgot to
release the pages.
Reported-by: NRoman Peniaev <r.peniaev@gmail.com>
Signed-off-by: NPhillip Lougher <phillip@squashfs.org.uk>

Fix static checker complaint that stream is not checked in
squashfs_decompressor_destroy().
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NPhillip Lougher <phillip@squashfs.org.uk>
Reviewed-by: NMinchan Kim <minchan@kernel.org>

This introduces an implementation of squashfs_readpage_block()
that directly decompresses into the page cache.

This uses the previously added page handler abstraction to push
down the necessary kmap_atomic/kunmap_atomic operations on the
page cache buffers into the decompressors.  This enables
direct copying into the page cache without using the slow
kmap/kunmap calls.

The code detects when multiple threads are racing in
squashfs_readpage() to decompress the same block, and avoids
this regression by falling back to using an intermediate
buffer.

This patch enhances the performance of Squashfs significantly
when multiple processes are accessing the filesystem simultaneously
because it not only reduces memcopying, but it more importantly
eliminates the lock contention on the intermediate buffer.

Using single-thread decompression.

        dd if=file1 of=/dev/null bs=4096 &
        dd if=file2 of=/dev/null bs=4096 &
        dd if=file3 of=/dev/null bs=4096 &
        dd if=file4 of=/dev/null bs=4096

Before:

629145600 bytes (629 MB) copied, 45.8046 s, 13.7 MB/s

After:

629145600 bytes (629 MB) copied, 9.29414 s, 67.7 MB/s
Signed-off-by: NPhillip Lougher <phillip@squashfs.org.uk>
Reviewed-by: NMinchan Kim <minchan@kernel.org>

Restructure squashfs_readpage() splitting it into separate
functions for datablocks, fragments and sparse blocks.

Move the memcpying (from squashfs cache entry) implementation of
squashfs_readpage_block into file_cache.c

This allows different implementations to be supported.
Signed-off-by: NPhillip Lougher <phillip@squashfs.org.uk>
Reviewed-by: NMinchan Kim <minchan@kernel.org>

Further generalise the decompressors by adding a page handler
abstraction.  This adds helpers to allow the decompressors
to access and process the output buffers in an implementation
independant manner.

This allows different types of output buffer to be passed
to the decompressors, with the implementation specific
aspects handled at decompression time, but without the
knowledge being held in the decompressor wrapper code.

This will allow the decompressors to handle Squashfs
cache buffers, and page cache pages.

This patch adds the abstraction and an implementation for
the caches.
Signed-off-by: NPhillip Lougher <phillip@squashfs.org.uk>
Reviewed-by: NMinchan Kim <minchan@kernel.org>

Add a multi-threaded decompression implementation which uses
percpu variables.

Using percpu variables has advantages and disadvantages over
implementations which do not use percpu variables.

Advantages:
  * the nature of percpu variables ensures decompression is
    load-balanced across the multiple cores.
  * simplicity.

Disadvantages: it limits decompression to one thread per core.
Signed-off-by: NPhillip Lougher <phillip@squashfs.org.uk>

Now squashfs have used for only one stream buffer for decompression
so it hurts parallel read performance so this patch supports
multiple decompressor to enhance performance parallel I/O.

Four 1G file dd read on KVM machine which has 2 CPU and 4G memory.

dd if=test/test1.dat of=/dev/null &
dd if=test/test2.dat of=/dev/null &
dd if=test/test3.dat of=/dev/null &
dd if=test/test4.dat of=/dev/null &

old : 1m39s -> new : 9s

* From v1
  * Change comp_strm with decomp_strm - Phillip
  * Change/add comments - Phillip
Signed-off-by: NMinchan Kim <minchan@kernel.org>
Signed-off-by: NPhillip Lougher <phillip@squashfs.org.uk>

The decompressor interface and code was written from
the point of view of single-threaded operation.  In doing
so it mixed a lot of single-threaded implementation specific
aspects into the decompressor code and elsewhere which makes it
difficult to seamlessly support multiple different decompressor
implementations.

This patch does the following:

1.  It removes compressor_options parsing from the decompressor
    init() function.  This allows the decompressor init() function
    to be dynamically called to instantiate multiple decompressors,
    without the compressor options needing to be read and parsed each
    time.

2.  It moves threading and all sleeping operations out of the
    decompressors.  In doing so, it makes the decompressors
    non-blocking wrappers which only deal with interfacing with
    the decompressor implementation.

3. It splits decompressor.[ch] into decompressor generic functions
   in decompressor.[ch], and moves the single threaded
   decompressor implementation into decompressor_single.c.

The result of this patch is Squashfs should now be able to
support multiple decompressors by adding new decompressor_xxx.c
files with specialised implementations of the functions in
decompressor_single.c
Signed-off-by: NPhillip Lougher <phillip@squashfs.org.uk>
Reviewed-by: NMinchan Kim <minchan@kernel.org>

This issue was first pointed out by Jiaxing Wang several months ago, but no
further comments:
https://lkml.org/lkml/2013/6/29/41

As we know pread() does not change f_pos, so after pread(), file->f_pos
and m->read_pos become different. And seq_lseek() does not update file->f_pos
if offset equals to m->read_pos, so after pread() and seq_lseek()(lseek to
m->read_pos), then a subsequent read may read from a wrong position, the
following program produces the problem:

    char str1[32] = { 0 };
    char str2[32] = { 0 };
    int poffset = 10;
    int count = 20;

    /*open any seq file*/
    int fd = open("/proc/modules", O_RDONLY);

    pread(fd, str1, count, poffset);
    printf("pread:%s\n", str1);

    /*seek to where m->read_pos is*/
    lseek(fd, poffset+count, SEEK_SET);

    /*supposed to read from poffset+count, but this read from position 0*/
    read(fd, str2, count);
    printf("read:%s\n", str2);

out put:
pread:
 ck_netbios_ns 12665
read:
 nf_conntrack_netbios

/proc/modules:
nf_conntrack_netbios_ns 12665 0 - Live 0xffffffffa038b000
nf_conntrack_broadcast 12589 1 nf_conntrack_netbios_ns, Live 0xffffffffa0386000

So we always update file->f_pos to offset in seq_lseek() to fix this issue.
Signed-off-by: NJiaxing Wang <hello.wjx@gmail.com>
Signed-off-by: NGu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Shifting page->index on 32 bit systems was overflowing, causing
data corruption of > 4GB files. Fix this by casting it first.

https://launchpad.net/bugs/1243636Signed-off-by: NColin Ian King <colin.king@canonical.com>
Reported-by: NLars Duesing <lars.duesing@camelotsweb.de>
Cc: stable@vger.kernel.org # v3.11+
Signed-off-by: NTyler Hicks <tyhicks@canonical.com>

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>

Background: nfsd v[23] had throughput regression since delayed fput
went in; every read or write ends up doing fput() and we get a pair
of extra context switches out of that (plus quite a bit of work
in queue_work itselfi, apparently).  Use of schedule_delayed_work()
gives it a chance to accumulate a bit before we do __fput() on all
of them.  I'm not too happy about that solution, but... on at least
one real-world setup it reverts about 10% throughput loss we got from
switch to delayed fput.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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>

In 'decrypt_pki_encrypted_session_key' function:

Initializes 'payload' pointer and releases it on exit.
Signed-off-by: NGeyslan G. Bem <geyslan@gmail.com>
Signed-off-by: NTyler Hicks <tyhicks@canonical.com>
Cc: stable@vger.kernel.org # v2.6.28+

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)