linux-stable.git/fs, branch v5.7.7

NFSv4 fix CLOSE not waiting for direct IO compeletion

2020-06-30T19:36:30+00:00

commit d03727b248d0dae6199569a8d7b629a681154633 upstream.

Figuring out the root case for the REMOVE/CLOSE race and
suggesting the solution was done by Neil Brown.

Currently what happens is that direct IO calls hold a reference
on the open context which is decremented as an asynchronous task
in the nfs_direct_complete(). Before reference is decremented,
control is returned to the application which is free to close the
file. When close is being processed, it decrements its reference
on the open_context but since directIO still holds one, it doesn't
sent a close on the wire. It returns control to the application
which is free to do other operations. For instance, it can delete a
file. Direct IO is finally releasing its reference and triggering
an asynchronous close. Which races with the REMOVE. On the server,
REMOVE can be processed before the CLOSE, failing the REMOVE with
EACCES as the file is still opened.

Signed-off-by: Olga Kornievskaia 
Suggested-by: Neil Brown 
CC: stable@vger.kernel.org
Signed-off-by: Anna Schumaker 
Signed-off-by: Greg Kroah-Hartman

pNFS/flexfiles: Fix list corruption if the mirror count changes

2020-06-30T19:36:30+00:00

commit 8b04013737341442ed914b336cde866b902664ae upstream.

If the mirror count changes in the new layout we pick up inside
ff_layout_pg_init_write(), then we can end up adding the
request to the wrong mirror and corrupting the mirror->pg_list.

Fixes: d600ad1f2bdb ("NFS41: pop some layoutget errors to application")
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust 
Signed-off-by: Anna Schumaker 
Signed-off-by: Greg Kroah-Hartman

ocfs2: fix panic on nfs server over ocfs2

2020-06-30T19:36:25+00:00

commit e5a15e17a78d58f933d17cafedfcf7486a29f5b4 upstream.

The following kernel panic was captured when running nfs server over
ocfs2, at that time ocfs2_test_inode_bit() was checking whether one
inode locating at "blkno" 5 was valid, that is ocfs2 root inode, its
"suballoc_slot" was OCFS2_INVALID_SLOT(65535) and it was allocted from
//global_inode_alloc, but here it wrongly assumed that it was got from per
slot inode alloctor which would cause array overflow and trigger kernel
panic.

  BUG: unable to handle kernel paging request at 0000000000001088
  IP: [] _raw_spin_lock+0x18/0xf0
  PGD 1e06ba067 PUD 1e9e7d067 PMD 0
  Oops: 0002 [#1] SMP
  CPU: 6 PID: 24873 Comm: nfsd Not tainted 4.1.12-124.36.1.el6uek.x86_64 #2
  Hardware name: Huawei CH121 V3/IT11SGCA1, BIOS 3.87 02/02/2018
  RIP: _raw_spin_lock+0x18/0xf0
  RSP: e02b:ffff88005ae97908  EFLAGS: 00010206
  RAX: ffff88005ae98000 RBX: 0000000000001088 RCX: 0000000000000000
  RDX: 0000000000020000 RSI: 0000000000000009 RDI: 0000000000001088
  RBP: ffff88005ae97928 R08: 0000000000000000 R09: ffff880212878e00
  R10: 0000000000007ff0 R11: 0000000000000000 R12: 0000000000001088
  R13: ffff8800063c0aa8 R14: ffff8800650c27d0 R15: 000000000000ffff
  FS:  0000000000000000(0000) GS:ffff880218180000(0000) knlGS:ffff880218180000
  CS:  e033 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000001088 CR3: 00000002033d0000 CR4: 0000000000042660
  Call Trace:
    igrab+0x1e/0x60
    ocfs2_get_system_file_inode+0x63/0x3a0 [ocfs2]
    ocfs2_test_inode_bit+0x328/0xa00 [ocfs2]
    ocfs2_get_parent+0xba/0x3e0 [ocfs2]
    reconnect_path+0xb5/0x300
    exportfs_decode_fh+0xf6/0x2b0
    fh_verify+0x350/0x660 [nfsd]
    nfsd4_putfh+0x4d/0x60 [nfsd]
    nfsd4_proc_compound+0x3d3/0x6f0 [nfsd]
    nfsd_dispatch+0xe0/0x290 [nfsd]
    svc_process_common+0x412/0x6a0 [sunrpc]
    svc_process+0x123/0x210 [sunrpc]
    nfsd+0xff/0x170 [nfsd]
    kthread+0xcb/0xf0
    ret_from_fork+0x61/0x90
  Code: 83 c2 02 0f b7 f2 e8 18 dc 91 ff 66 90 eb bf 0f 1f 40 00 55 48 89 e5 41 56 41 55 41 54 53 0f 1f 44 00 00 48 89 fb ba 00 00 02 00  0f c1 17 89 d0 45 31 e4 45 31 ed c1 e8 10 66 39 d0 41 89 c6
  RIP   _raw_spin_lock+0x18/0xf0
  CR2: 0000000000001088
  ---[ end trace 7264463cd1aac8f9 ]---
  Kernel panic - not syncing: Fatal exception

Link: http://lkml.kernel.org/r/20200616183829.87211-4-junxiao.bi@oracle.com
Signed-off-by: Junxiao Bi 
Reviewed-by: Joseph Qi 
Cc: Changwei Ge 
Cc: Gang He 
Cc: Joel Becker 
Cc: Jun Piao 
Cc: Mark Fasheh 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

ocfs2: fix value of OCFS2_INVALID_SLOT

2020-06-30T19:36:25+00:00

commit 9277f8334ffc719fe922d776444d6e4e884dbf30 upstream.

In the ocfs2 disk layout, slot number is 16 bits, but in ocfs2
implementation, slot number is 32 bits.  Usually this will not cause any
issue, because slot number is converted from u16 to u32, but
OCFS2_INVALID_SLOT was defined as -1, when an invalid slot number from
disk was obtained, its value was (u16)-1, and it was converted to u32.
Then the following checking in get_local_system_inode will be always
skipped:

 static struct inode **get_local_system_inode(struct ocfs2_super *osb,
                                               int type,
                                               u32 slot)
 {
 	BUG_ON(slot == OCFS2_INVALID_SLOT);
	...
 }

Link: http://lkml.kernel.org/r/20200616183829.87211-5-junxiao.bi@oracle.com
Signed-off-by: Junxiao Bi 
Reviewed-by: Joseph Qi 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Changwei Ge 
Cc: Gang He 
Cc: Jun Piao 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

ocfs2: load global_inode_alloc

2020-06-30T19:36:24+00:00

commit 7569d3c754e452769a5747eeeba488179e38a5da upstream.

Set global_inode_alloc as OCFS2_FIRST_ONLINE_SYSTEM_INODE, that will
make it load during mount.  It can be used to test whether some
global/system inodes are valid.  One use case is that nfsd will test
whether root inode is valid.

Link: http://lkml.kernel.org/r/20200616183829.87211-3-junxiao.bi@oracle.com
Signed-off-by: Junxiao Bi 
Reviewed-by: Joseph Qi 
Cc: Changwei Ge 
Cc: Gang He 
Cc: Joel Becker 
Cc: Jun Piao 
Cc: Mark Fasheh 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

ocfs2: avoid inode removal while nfsd is accessing it

2020-06-30T19:36:24+00:00

commit 4cd9973f9ff69e37dd0ba2bd6e6423f8179c329a upstream.

Patch series "ocfs2: fix nfsd over ocfs2 issues", v2.

This is a series of patches to fix issues on nfsd over ocfs2.  patch 1
is to avoid inode removed while nfsd access it patch 2 & 3 is to fix a
panic issue.

This patch (of 4):

When nfsd is getting file dentry using handle or parent dentry of some
dentry, one cluster lock is used to avoid inode removed from other node,
but it still could be removed from local node, so use a rw lock to avoid
this.

Link: http://lkml.kernel.org/r/20200616183829.87211-1-junxiao.bi@oracle.com
Link: http://lkml.kernel.org/r/20200616183829.87211-2-junxiao.bi@oracle.com
Signed-off-by: Junxiao Bi 
Reviewed-by: Joseph Qi 
Cc: Changwei Ge 
Cc: Gang He 
Cc: Joel Becker 
Cc: Jun Piao 
Cc: Mark Fasheh 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

btrfs: fix RWF_NOWAIT write not failling when we need to cow

2020-06-30T19:36:23+00:00

commit 260a63395f90f67d6ab89e4266af9e3dc34a77e9 upstream.

If we attempt to do a RWF_NOWAIT write against a file range for which we
can only do NOCOW for a part of it, due to the existence of holes or
shared extents for example, we proceed with the write as if it were
possible to NOCOW the whole range.

Example:

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt

  $ touch /mnt/sdj/bar
  $ chattr +C /mnt/sdj/bar

  $ xfs_io -d -c "pwrite -S 0xab -b 256K 0 256K" /mnt/bar
  wrote 262144/262144 bytes at offset 0
  256 KiB, 1 ops; 0.0003 sec (694.444 MiB/sec and 2777.7778 ops/sec)

  $ xfs_io -c "fpunch 64K 64K" /mnt/bar
  $ sync

  $ xfs_io -d -c "pwrite -N -V 1 -b 128K -S 0xfe 0 128K" /mnt/bar
  wrote 131072/131072 bytes at offset 0
  128 KiB, 1 ops; 0.0007 sec (160.051 MiB/sec and 1280.4097 ops/sec)

This last write should fail with -EAGAIN since the file range from 64K to
128K is a hole. On xfs it fails, as expected, but on ext4 it currently
succeeds because apparently it is expensive to check if there are extents
allocated for the whole range, but I'll check with the ext4 people.

Fix the issue by checking if check_can_nocow() returns a number of
NOCOW'able bytes smaller then the requested number of bytes, and if it
does return -EAGAIN.

Fixes: edf064e7c6fec3 ("btrfs: nowait aio support")
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Filipe Manana 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba 
Signed-off-by: Greg Kroah-Hartman

btrfs: fix failure of RWF_NOWAIT write into prealloc extent beyond eof

2020-06-30T19:36:23+00:00

commit 4b1946284dd6641afdb9457101056d9e6ee6204c upstream.

If we attempt to write to prealloc extent located after eof using a
RWF_NOWAIT write, we always fail with -EAGAIN.

We do actually check if we have an allocated extent for the write at
the start of btrfs_file_write_iter() through a call to check_can_nocow(),
but later when we go into the actual direct IO write path we simply
return -EAGAIN if the write starts at or beyond EOF.

Trivial to reproduce:

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt

  $ touch /mnt/foo
  $ chattr +C /mnt/foo

  $ xfs_io -d -c "pwrite -S 0xab 0 64K" /mnt/foo
  wrote 65536/65536 bytes at offset 0
  64 KiB, 16 ops; 0.0004 sec (135.575 MiB/sec and 34707.1584 ops/sec)

  $ xfs_io -c "falloc -k 64K 1M" /mnt/foo

  $ xfs_io -d -c "pwrite -N -V 1 -S 0xfe -b 64K 64K 64K" /mnt/foo
  pwrite: Resource temporarily unavailable

On xfs and ext4 the write succeeds, as expected.

Fix this by removing the wrong check at btrfs_direct_IO().

Fixes: edf064e7c6fec3 ("btrfs: nowait aio support")
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Filipe Manana 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba 
Signed-off-by: Greg Kroah-Hartman

btrfs: fix hang on snapshot creation after RWF_NOWAIT write

2020-06-30T19:36:23+00:00

commit f2cb2f39ccc30fa13d3ac078d461031a63960e5b upstream.

If we do a successful RWF_NOWAIT write we end up locking the snapshot lock
of the inode, through a call to check_can_nocow(), but we never unlock it.

This means the next attempt to create a snapshot on the subvolume will
hang forever.

Trivial reproducer:

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt

  $ touch /mnt/foobar
  $ chattr +C /mnt/foobar
  $ xfs_io -d -c "pwrite -S 0xab 0 64K" /mnt/foobar
  $ xfs_io -d -c "pwrite -N -V 1 -S 0xfe 0 64K" /mnt/foobar

  $ btrfs subvolume snapshot -r /mnt /mnt/snap
    --> hangs

Fix this by unlocking the snapshot lock if check_can_nocow() returned
success.

Fixes: edf064e7c6fec3 ("btrfs: nowait aio support")
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Filipe Manana 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba 
Signed-off-by: Greg Kroah-Hartman

btrfs: check if a log root exists before locking the log_mutex on unlink

2020-06-30T19:36:23+00:00

commit e7a79811d0db136dc2d336b56d54cf1b774ce972 upstream.

This brings back an optimization that commit e678934cbe5f02 ("btrfs:
Remove unnecessary check from join_running_log_trans") removed, but in
a different form. So it's almost equivalent to a revert.

That commit removed an optimization where we avoid locking a root's
log_mutex when there is no log tree created in the current transaction.
The affected code path is triggered through unlink operations.

That commit was based on the assumption that the optimization was not
necessary because we used to have the following checks when the patch
was authored:

  int btrfs_del_dir_entries_in_log(...)
  {
        (...)
        if (dir->logged_trans < trans->transid)
            return 0;

        ret = join_running_log_trans(root);
        (...)
   }

   int btrfs_del_inode_ref_in_log(...)
   {
        (...)
        if (inode->logged_trans < trans->transid)
            return 0;

        ret = join_running_log_trans(root);
        (...)
   }

However before that patch was merged, another patch was merged first which
replaced those checks because they were buggy.

That other patch corresponds to commit 803f0f64d17769 ("Btrfs: fix fsync
not persisting dentry deletions due to inode evictions"). The assumption
that if the logged_trans field of an inode had a smaller value then the
current transaction's generation (transid) meant that the inode was not
logged in the current transaction was only correct if the inode was not
evicted and reloaded in the current transaction. So the corresponding bug
fix changed those checks and replaced them with the following helper
function:

  static bool inode_logged(struct btrfs_trans_handle *trans,
                           struct btrfs_inode *inode)
  {
        if (inode->logged_trans == trans->transid)
                return true;

        if (inode->last_trans == trans->transid &&
            test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags) &&
            !test_bit(BTRFS_FS_LOG_RECOVERING, &trans->fs_info->flags))
                return true;

        return false;
  }

So if we have a subvolume without a log tree in the current transaction
(because we had no fsyncs), every time we unlink an inode we can end up
trying to lock the log_mutex of the root through join_running_log_trans()
twice, once for the inode being unlinked (by btrfs_del_inode_ref_in_log())
and once for the parent directory (with btrfs_del_dir_entries_in_log()).

This means if we have several unlink operations happening in parallel for
inodes in the same subvolume, and the those inodes and/or their parent
inode were changed in the current transaction, we end up having a lot of
contention on the log_mutex.

The test robots from intel reported a -30.7% performance regression for
a REAIM test after commit e678934cbe5f02 ("btrfs: Remove unnecessary check
from join_running_log_trans").

So just bring back the optimization to join_running_log_trans() where we
check first if a log root exists before trying to lock the log_mutex. This
is done by checking for a bit that is set on the root when a log tree is
created and removed when a log tree is freed (at transaction commit time).

Commit e678934cbe5f02 ("btrfs: Remove unnecessary check from
join_running_log_trans") was merged in the 5.4 merge window while commit
803f0f64d17769 ("Btrfs: fix fsync not persisting dentry deletions due to
inode evictions") was merged in the 5.3 merge window. But the first
commit was actually authored before the second commit (May 23 2019 vs
June 19 2019).

Reported-by: kernel test robot 
Link: https://lore.kernel.org/lkml/20200611090233.GL12456@shao2-debian/
Fixes: e678934cbe5f02 ("btrfs: Remove unnecessary check from join_running_log_trans")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Josef Bacik 
Signed-off-by: Filipe Manana 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba 
Signed-off-by: Greg Kroah-Hartman