61702 Commits

Author SHA1 Message Date
Josef Bacik
e4e024e89c btrfs: fix setting last_trans for reloc roots
[ Upstream commit aec7db3b13a07d515c15ada752a7287a44a79ea0 ]

I made a mistake with my previous fix, I assumed that we didn't need to
mess with the reloc roots once we were out of the part of relocation where
we are actually moving the extents.

The subtle thing that I missed is that btrfs_init_reloc_root() also
updates the last_trans for the reloc root when we do
btrfs_record_root_in_trans() for the corresponding fs_root.  I've added a
comment to make sure future me doesn't make this mistake again.

This showed up as a WARN_ON() in btrfs_copy_root() because our
last_trans didn't == the current transid.  This could happen if we
snapshotted a fs root with a reloc root after we set
rc->create_reloc_tree = 0, but before we actually merge the reloc root.

Worth mentioning that the regression produced the following warning
when running snapshot creation and balance in parallel:

  BTRFS info (device sdc): relocating block group 30408704 flags metadata|dup
  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 12823 at fs/btrfs/ctree.c:191 btrfs_copy_root+0x26f/0x430 [btrfs]
  CPU: 0 PID: 12823 Comm: btrfs Tainted: G        W 5.6.0-rc7-btrfs-next-58 #1
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
  RIP: 0010:btrfs_copy_root+0x26f/0x430 [btrfs]
  RSP: 0018:ffffb96e044279b8 EFLAGS: 00010202
  RAX: 0000000000000009 RBX: ffff9da70bf61000 RCX: ffffb96e04427a48
  RDX: ffff9da733a770c8 RSI: ffff9da70bf61000 RDI: ffff9da694163818
  RBP: ffff9da733a770c8 R08: fffffffffffffff8 R09: 0000000000000002
  R10: ffffb96e044279a0 R11: 0000000000000000 R12: ffff9da694163818
  R13: fffffffffffffff8 R14: ffff9da6d2512000 R15: ffff9da714cdac00
  FS:  00007fdeacf328c0(0000) GS:ffff9da735e00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 000055a2a5b8a118 CR3: 00000001eed78002 CR4: 00000000003606f0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   ? create_reloc_root+0x49/0x2b0 [btrfs]
   ? kmem_cache_alloc_trace+0xe5/0x200
   create_reloc_root+0x8b/0x2b0 [btrfs]
   btrfs_reloc_post_snapshot+0x96/0x5b0 [btrfs]
   create_pending_snapshot+0x610/0x1010 [btrfs]
   create_pending_snapshots+0xa8/0xd0 [btrfs]
   btrfs_commit_transaction+0x4c7/0xc50 [btrfs]
   ? btrfs_mksubvol+0x3cd/0x560 [btrfs]
   btrfs_mksubvol+0x455/0x560 [btrfs]
   __btrfs_ioctl_snap_create+0x15f/0x190 [btrfs]
   btrfs_ioctl_snap_create_v2+0xa4/0xf0 [btrfs]
   ? mem_cgroup_commit_charge+0x6e/0x540
   btrfs_ioctl+0x12d8/0x3760 [btrfs]
   ? do_raw_spin_unlock+0x49/0xc0
   ? _raw_spin_unlock+0x29/0x40
   ? __handle_mm_fault+0x11b3/0x14b0
   ? ksys_ioctl+0x92/0xb0
   ksys_ioctl+0x92/0xb0
   ? trace_hardirqs_off_thunk+0x1a/0x1c
   __x64_sys_ioctl+0x16/0x20
   do_syscall_64+0x5c/0x280
   entry_SYSCALL_64_after_hwframe+0x49/0xbe
  RIP: 0033:0x7fdeabd3bdd7

Fixes: 2abc726ab4b8 ("btrfs: do not init a reloc root if we aren't relocating")
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:55 +02:00
Trond Myklebust
24c56b6fe0 NFS: Fix races nfs_page_group_destroy() vs nfs_destroy_unlinked_subrequests()
[ Upstream commit 08ca8b21f760c0ed5034a5c122092eec22ccf8f4 ]

When a subrequest is being detached from the subgroup, we want to
ensure that it is not holding the group lock, or in the process
of waiting for the group lock.

Fixes: 5b2b5187fa85 ("NFS: Fix nfs_page_group_destroy() and nfs_lock_and_join_requests() race cases")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:52 +02:00
Liu Song
af574e78e7 ubifs: Fix out-of-bounds memory access caused by abnormal value of node_len
[ Upstream commit acc5af3efa303d5f36cc8c0f61716161f6ca1384 ]

In “ubifs_check_node”, when the value of "node_len" is abnormal,
the code will goto label of "out_len" for execution. Then, in the
following "ubifs_dump_node", if inode type is "UBIFS_DATA_NODE",
in "print_hex_dump", an out-of-bounds access may occur due to the
wrong "ch->len".

Therefore, when the value of "node_len" is abnormal, data length
should to be adjusted to a reasonable safe range. At this time,
structured data is not credible, so dump the corrupted data directly
for analysis.

Signed-off-by: Liu Song <liu.song11@zte.com.cn>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:51 +02:00
Zhihao Cheng
49bc26b765 ubifs: ubifs_add_orphan: Fix a memory leak bug
[ Upstream commit 927cc5cec35f01fe4f8af0ba80830a90b0533983 ]

Memory leak occurs when files with extended attributes are added to
orphan list.

Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Fixes: 988bec41318f3fa897e2f8 ("ubifs: orphan: Handle xattrs like files")
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:51 +02:00
Zhihao Cheng
17bc3bff02 ubifs: ubifs_jnl_write_inode: Fix a memory leak bug
[ Upstream commit 81423c78551654953d746250f1721300b470be0e ]

When inodes with extended attributes are evicted, xent is not freed in one
exit branch.

Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Fixes: 9ca2d732644484488db3112 ("ubifs: Limit number of xattrs per inode")
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:51 +02:00
Darrick J. Wong
f812e43e72 xfs: prohibit fs freezing when using empty transactions
[ Upstream commit 27fb5a72f50aa770dd38b0478c07acacef97e3e7 ]

I noticed that fsfreeze can take a very long time to freeze an XFS if
there happens to be a GETFSMAP caller running in the background.  I also
happened to notice the following in dmesg:

------------[ cut here ]------------
WARNING: CPU: 2 PID: 43492 at fs/xfs/xfs_super.c:853 xfs_quiesce_attr+0x83/0x90 [xfs]
Modules linked in: xfs libcrc32c ip6t_REJECT nf_reject_ipv6 ipt_REJECT nf_reject_ipv4 ip_set_hash_ip ip_set_hash_net xt_tcpudp xt_set ip_set_hash_mac ip_set nfnetlink ip6table_filter ip6_tables bfq iptable_filter sch_fq_codel ip_tables x_tables nfsv4 af_packet [last unloaded: xfs]
CPU: 2 PID: 43492 Comm: xfs_io Not tainted 5.6.0-rc4-djw #rc4
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.10.2-1ubuntu1 04/01/2014
RIP: 0010:xfs_quiesce_attr+0x83/0x90 [xfs]
Code: 7c 07 00 00 85 c0 75 22 48 89 df 5b e9 96 c1 00 00 48 c7 c6 b0 2d 38 a0 48 89 df e8 57 64 ff ff 8b 83 7c 07 00 00 85 c0 74 de <0f> 0b 48 89 df 5b e9 72 c1 00 00 66 90 0f 1f 44 00 00 41 55 41 54
RSP: 0018:ffffc900030f3e28 EFLAGS: 00010202
RAX: 0000000000000001 RBX: ffff88802ac54000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff81e4a6f0 RDI: 00000000ffffffff
RBP: ffff88807859f070 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000010 R12: 0000000000000000
R13: ffff88807859f388 R14: ffff88807859f4b8 R15: ffff88807859f5e8
FS:  00007fad1c6c0fc0(0000) GS:ffff88807e000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0c7d237000 CR3: 0000000077f01003 CR4: 00000000001606a0
Call Trace:
 xfs_fs_freeze+0x25/0x40 [xfs]
 freeze_super+0xc8/0x180
 do_vfs_ioctl+0x70b/0x750
 ? __fget_files+0x135/0x210
 ksys_ioctl+0x3a/0xb0
 __x64_sys_ioctl+0x16/0x20
 do_syscall_64+0x50/0x1a0
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

These two things appear to be related.  The assertion trips when another
thread initiates a fsmap request (which uses an empty transaction) after
the freezer waited for m_active_trans to hit zero but before the the
freezer executes the WARN_ON just prior to calling xfs_log_quiesce.

The lengthy delays in freezing happen because the freezer calls
xfs_wait_buftarg to clean out the buffer lru list.  Meanwhile, the
GETFSMAP caller is continuing to grab and release buffers, which means
that it can take a very long time for the buffer lru list to empty out.

We fix both of these races by calling sb_start_write to obtain freeze
protection while using empty transactions for GETFSMAP and for metadata
scrubbing.  The other two users occur during mount, during which time we
cannot fs freeze.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:49 +02:00
Bernd Edlinger
ba7eb0e48e proc: io_accounting: Use new infrastructure to fix deadlocks in execve
[ Upstream commit 76518d3798855242817e8a8ed76b2d72f4415624 ]

This changes do_io_accounting to use the new exec_update_mutex
instead of cred_guard_mutex.

This fixes possible deadlocks when the trace is accessing
/proc/$pid/io for instance.

This should be safe, as the credentials are only used for reading.

Signed-off-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:48 +02:00
Bernd Edlinger
4301db49e5 proc: Use new infrastructure to fix deadlocks in execve
[ Upstream commit 2db9dbf71bf98d02a0bf33e798e5bfd2a9944696 ]

This changes lock_trace to use the new exec_update_mutex
instead of cred_guard_mutex.

This fixes possible deadlocks when the trace is accessing
/proc/$pid/stack for instance.

This should be safe, as the credentials are only used for reading,
and task->mm is updated on execve under the new exec_update_mutex.

Signed-off-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:48 +02:00
Eric W. Biederman
b796d94921 exec: Add exec_update_mutex to replace cred_guard_mutex
[ Upstream commit eea9673250db4e854e9998ef9da6d4584857f0ea ]

The cred_guard_mutex is problematic as it is held over possibly
indefinite waits for userspace.  The possible indefinite waits for
userspace that I have identified are: The cred_guard_mutex is held in
PTRACE_EVENT_EXIT waiting for the tracer.  The cred_guard_mutex is
held over "put_user(0, tsk->clear_child_tid)" in exit_mm().  The
cred_guard_mutex is held over "get_user(futex_offset, ...")  in
exit_robust_list.  The cred_guard_mutex held over copy_strings.

The functions get_user and put_user can trigger a page fault which can
potentially wait indefinitely in the case of userfaultfd or if
userspace implements part of the page fault path.

In any of those cases the userspace process that the kernel is waiting
for might make a different system call that winds up taking the
cred_guard_mutex and result in deadlock.

Holding a mutex over any of those possibly indefinite waits for
userspace does not appear necessary.  Add exec_update_mutex that will
just cover updating the process during exec where the permissions and
the objects pointed to by the task struct may be out of sync.

The plan is to switch the users of cred_guard_mutex to
exec_update_mutex one by one.  This lets us move forward while still
being careful and not introducing any regressions.

Link: https://lore.kernel.org/lkml/20160921152946.GA24210@dhcp22.suse.cz/
Link: https://lore.kernel.org/lkml/AM6PR03MB5170B06F3A2B75EFB98D071AE4E60@AM6PR03MB5170.eurprd03.prod.outlook.com/
Link: https://lore.kernel.org/linux-fsdevel/20161102181806.GB1112@redhat.com/
Link: https://lore.kernel.org/lkml/20160923095031.GA14923@redhat.com/
Link: https://lore.kernel.org/lkml/20170213141452.GA30203@redhat.com/
Ref: 45c1a159b85b ("Add PTRACE_O_TRACEVFORKDONE and PTRACE_O_TRACEEXIT facilities.")
Ref: 456f17cd1a28 ("[PATCH] user-vm-unlock-2.5.31-A2")
Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:47 +02:00
Josef Bacik
5dc170aee1 btrfs: free the reloc_control in a consistent way
[ Upstream commit 1a0afa0ecfc4dbc8d7583d03cafd3f68f781df0c ]

If we have an error while processing the reloc roots we could leak roots
that were added to rc->reloc_roots before we hit the error.  We could
have also not removed the reloc tree mapping from our rb_tree, so clean
up any remaining nodes in the reloc root rb_tree.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ use rbtree_postorder_for_each_entry_safe ]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:45 +02:00
Josef Bacik
c88596d593 btrfs: do not init a reloc root if we aren't relocating
[ Upstream commit 2abc726ab4b83db774e315c660ab8da21477092f ]

We previously were checking if the root had a dead root before accessing
root->reloc_root in order to avoid a use-after-free type bug.  However
this scenario happens after we've unset the reloc control, so we would
have been saved if we'd simply checked for fs_info->reloc_control.  At
this point during relocation we no longer need to be creating new reloc
roots, so simply move this check above the reloc_root checks to avoid
any future races and confusion.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:45 +02:00
Trond Myklebust
0300cda500 nfsd: Don't add locks to closed or closing open stateids
[ Upstream commit a451b12311aa8c96c6f6e01c783a86995dc3ec6b ]

In NFSv4, the lock stateids are tied to the lockowner, and the open stateid,
so that the action of closing the file also results in either an automatic
loss of the locks, or an error of the form NFS4ERR_LOCKS_HELD.

In practice this means we must not add new locks to the open stateid
after the close process has been invoked. In fact doing so, can result
in the following panic:

 kernel BUG at lib/list_debug.c:51!
 invalid opcode: 0000 [#1] SMP NOPTI
 CPU: 2 PID: 1085 Comm: nfsd Not tainted 5.6.0-rc3+ #2
 Hardware name: VMware, Inc. VMware7,1/440BX Desktop Reference Platform, BIOS VMW71.00V.14410784.B64.1908150010 08/15/2019
 RIP: 0010:__list_del_entry_valid.cold+0x31/0x55
 Code: 1a 3d 9b e8 74 10 c2 ff 0f 0b 48 c7 c7 f0 1a 3d 9b e8 66 10 c2 ff 0f 0b 48 89 f2 48 89 fe 48 c7 c7 b0 1a 3d 9b e8 52 10 c2 ff <0f> 0b 48 89 fe 4c 89 c2 48 c7 c7 78 1a 3d 9b e8 3e 10 c2 ff 0f 0b
 RSP: 0018:ffffb296c1d47d90 EFLAGS: 00010246
 RAX: 0000000000000054 RBX: ffff8ba032456ec8 RCX: 0000000000000000
 RDX: 0000000000000000 RSI: ffff8ba039e99cc8 RDI: ffff8ba039e99cc8
 RBP: ffff8ba032456e60 R08: 0000000000000781 R09: 0000000000000003
 R10: 0000000000000000 R11: 0000000000000001 R12: ffff8ba009a4abe0
 R13: ffff8ba032456e8c R14: 0000000000000000 R15: ffff8ba00adb01d8
 FS:  0000000000000000(0000) GS:ffff8ba039e80000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007fb213f0b008 CR3: 00000001347de006 CR4: 00000000003606e0
 Call Trace:
  release_lock_stateid+0x2b/0x80 [nfsd]
  nfsd4_free_stateid+0x1e9/0x210 [nfsd]
  nfsd4_proc_compound+0x414/0x700 [nfsd]
  ? nfs4svc_decode_compoundargs+0x407/0x4c0 [nfsd]
  nfsd_dispatch+0xc1/0x200 [nfsd]
  svc_process_common+0x476/0x6f0 [sunrpc]
  ? svc_sock_secure_port+0x12/0x30 [sunrpc]
  ? svc_recv+0x313/0x9c0 [sunrpc]
  ? nfsd_svc+0x2d0/0x2d0 [nfsd]
  svc_process+0xd4/0x110 [sunrpc]
  nfsd+0xe3/0x140 [nfsd]
  kthread+0xf9/0x130
  ? nfsd_destroy+0x50/0x50 [nfsd]
  ? kthread_park+0x90/0x90
  ret_from_fork+0x1f/0x40

The fix is to ensure that lock creation tests for whether or not the
open stateid is unhashed, and to fail if that is the case.

Fixes: 659aefb68eca ("nfsd: Ensure we don't recognise lock stateids after freeing them")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:43 +02:00
Dmitry Monakhov
be4ff3a49c ext4: mark block bitmap corrupted when found instead of BUGON
[ Upstream commit eb5760863fc28feab28b567ddcda7e667e638da0 ]

We already has similar code in ext4_mb_complex_scan_group(), but
ext4_mb_simple_scan_group() still affected.

Other reports: https://www.spinics.net/lists/linux-ext4/msg60231.html

Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Dmitry Monakhov <dmonakhov@gmail.com>
Link: https://lore.kernel.org/r/20200310150156.641-1-dmonakhov@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:42 +02:00
Darrick J. Wong
152875a0f0 xfs: mark dir corrupt when lookup-by-hash fails
[ Upstream commit 2e107cf869eecc770e3f630060bb4e5f547d0fd8 ]

In xchk_dir_actor, we attempt to validate the directory hash structures
by performing a directory entry lookup by (hashed) name.  If the lookup
returns ENOENT, that means that the hash information is corrupt.  The
_process_error functions don't catch this, so we have to add that
explicitly.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:42 +02:00
Darrick J. Wong
cb72c9f842 xfs: don't ever return a stale pointer from __xfs_dir3_free_read
[ Upstream commit 1cb5deb5bc095c070c09a4540c45f9c9ba24be43 ]

If we decide that a directory free block is corrupt, we must take care
not to leak a buffer pointer to the caller.  After xfs_trans_brelse
returns, the buffer can be freed or reused, which means that we have to
set *bpp back to NULL.

Callers are supposed to notice the nonzero return value and not use the
buffer pointer, but we should code more defensively, even if all current
callers handle this situation correctly.

Fixes: de14c5f541e7 ("xfs: verify free block header fields")
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:42 +02:00
Qiujun Huang
26005b604c ext4: fix a data race at inode->i_disksize
[ Upstream commit dce8e237100f60c28cc66effb526ba65a01d8cb3 ]

KCSAN find inode->i_disksize could be accessed concurrently.

BUG: KCSAN: data-race in ext4_mark_iloc_dirty / ext4_write_end

write (marked) to 0xffff8b8932f40090 of 8 bytes by task 66792 on cpu 0:
 ext4_write_end+0x53f/0x5b0
 ext4_da_write_end+0x237/0x510
 generic_perform_write+0x1c4/0x2a0
 ext4_buffered_write_iter+0x13a/0x210
 ext4_file_write_iter+0xe2/0x9b0
 new_sync_write+0x29c/0x3a0
 __vfs_write+0x92/0xa0
 vfs_write+0xfc/0x2a0
 ksys_write+0xe8/0x140
 __x64_sys_write+0x4c/0x60
 do_syscall_64+0x8a/0x2a0
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8b8932f40090 of 8 bytes by task 14414 on cpu 1:
 ext4_mark_iloc_dirty+0x716/0x1190
 ext4_mark_inode_dirty+0xc9/0x360
 ext4_convert_unwritten_extents+0x1bc/0x2a0
 ext4_convert_unwritten_io_end_vec+0xc5/0x150
 ext4_put_io_end+0x82/0x130
 ext4_writepages+0xae7/0x16f0
 do_writepages+0x64/0x120
 __writeback_single_inode+0x7d/0x650
 writeback_sb_inodes+0x3a4/0x860
 __writeback_inodes_wb+0xc4/0x150
 wb_writeback+0x43f/0x510
 wb_workfn+0x3b2/0x8a0
 process_one_work+0x39b/0x7e0
 worker_thread+0x88/0x650
 kthread+0x1d4/0x1f0
 ret_from_fork+0x35/0x40

The plain read is outside of inode->i_data_sem critical section
which results in a data race. Fix it by adding READ_ONCE().

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Link: https://lore.kernel.org/r/1582556566-3909-1-git-send-email-hqjagain@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:39 +02:00
Trond Myklebust
1f483c3ef0 nfsd: Fix a perf warning
[ Upstream commit a9ceb060b3cf37987b6162223575eaf4f4e0fc36 ]

perf does not know how to deal with a __builtin_bswap32() call, and
complains. All other functions just store the xid etc in host endian
form, so let's do that in the tracepoint for nfsd_file_acquire too.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:31 +02:00
Jeff Layton
379deeac55 ceph: ensure we have a new cap before continuing in fill_inode
[ Upstream commit 9a6bed4fe0c8bf57785cbc4db9f86086cb9b193d ]

If the caller passes in a NULL cap_reservation, and we can't allocate
one then ensure that we fail gracefully.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:29 +02:00
Trond Myklebust
fed639f7e1 nfsd: Fix a soft lockup race in nfsd_file_mark_find_or_create()
[ Upstream commit 90d2f1da832fd23290ef0c0d964d97501e5e8553 ]

If nfsd_file_mark_find_or_create() keeps winning the race for the
nfsd_file_fsnotify_group->mark_mutex against nfsd_file_mark_put()
then it can soft lock up, since fsnotify_add_inode_mark() ends
up always finding an existing entry.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:28 +02:00
Qu Wenruo
d64f6dfdf4 btrfs: tree-checker: Check leaf chunk item size
[ Upstream commit f6d2a5c263afca84646cf3300dc13061bedbd99e ]

Inspired by btrfs-progs github issue #208, where chunk item in chunk
tree has invalid num_stripes (0).

Although that can already be caught by current btrfs_check_chunk_valid(),
that function doesn't really check item size as it needs to handle chunk
item in super block sys_chunk_array().

This patch will add two extra checks for chunk items in chunk tree:

- Basic chunk item size
  If the item is smaller than btrfs_chunk (which already contains one
  stripe), exit right now as reading num_stripes may even go beyond
  eb boundary.

- Item size check against num_stripes
  If item size doesn't match with calculated chunk size, then either the
  item size or the num_stripes is corrupted. Error out anyway.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:28 +02:00
Darrick J. Wong
b56212ddca xfs: fix log reservation overflows when allocating large rt extents
[ Upstream commit b1de6fc7520fe12949c070af0e8c0e4044cd3420 ]

Omar Sandoval reported that a 4G fallocate on the realtime device causes
filesystem shutdowns due to a log reservation overflow that happens when
we log the rtbitmap updates.  Factor rtbitmap/rtsummary updates into the
the tr_write and tr_itruncate log reservation calculation.

"The following reproducer results in a transaction log overrun warning
for me:

    mkfs.xfs -f -r rtdev=/dev/vdc -d rtinherit=1 -m reflink=0 /dev/vdb
    mount -o rtdev=/dev/vdc /dev/vdb /mnt
    fallocate -l 4G /mnt/foo

Reported-by: Omar Sandoval <osandov@osandov.com>
Tested-by: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:24 +02:00
Omar Sandoval
6a74132bee xfs: fix realtime file data space leak
[ Upstream commit 0c4da70c83d41a8461fdf50a3f7b292ecb04e378 ]

Realtime files in XFS allocate extents in rextsize units. However, the
written/unwritten state of those extents is still tracked in blocksize
units. Therefore, a realtime file can be split up into written and
unwritten extents that are not necessarily aligned to the realtime
extent size. __xfs_bunmapi() has some logic to handle these various
corner cases. Consider how it handles the following case:

1. The last extent is unwritten.
2. The last extent is smaller than the realtime extent size.
3. startblock of the last extent is not aligned to the realtime extent
   size, but startblock + blockcount is.

In this case, __xfs_bunmapi() calls xfs_bmap_add_extent_unwritten_real()
to set the second-to-last extent to unwritten. This should merge the
last and second-to-last extents, so __xfs_bunmapi() moves on to the
second-to-last extent.

However, if the size of the last and second-to-last extents combined is
greater than MAXEXTLEN, xfs_bmap_add_extent_unwritten_real() does not
merge the two extents. When that happens, __xfs_bunmapi() skips past the
last extent without unmapping it, thus leaking the space.

Fix it by only unwriting the minimum amount needed to align the last
extent to the realtime extent size, which is guaranteed to merge with
the last extent.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:22 +02:00
Jaegeuk Kim
273589e82c f2fs: stop GC when the victim becomes fully valid
[ Upstream commit 803e74be04b32f7785742dcabfc62116718fbb06 ]

We must stop GC, once the segment becomes fully valid. Otherwise, it can
produce another dirty segments by moving valid blocks in the segment partially.

Ramon hit no free segment panic sometimes and saw this case happens when
validating reliable file pinning feature.

Signed-off-by: Ramon Pantin <pantin@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:21 +02:00
Pavel Shilovsky
84b15c4e15 CIFS: Properly process SMB3 lease breaks
[ Upstream commit 9bd4540836684013aaad6070a65d6fcdd9006625 ]

Currenly we doesn't assume that a server may break a lease
from RWH to RW which causes us setting a wrong lease state
on a file and thus mistakenly flushing data and byte-range
locks and purging cached data on the client. This leads to
performance degradation because subsequent IOs go directly
to the server.

Fix this by propagating new lease state and epoch values
to the oplock break handler through cifsFileInfo structure
and removing the use of cifsInodeInfo flags for that. It
allows to avoid some races of several lease/oplock breaks
using those flags in parallel.

Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:21 +02:00
Markus Elfring
2005c32ec9 CIFS: Use common error handling code in smb2_ioctl_query_info()
[ Upstream commit 2b1116bbe898aefdf584838448c6869f69851e0f ]

Move the same error code assignments so that such exception handling
can be better reused at the end of this function.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:21 +02:00
Bob Peterson
714dbaf2f8 gfs2: clean up iopen glock mess in gfs2_create_inode
[ Upstream commit 2c47c1be51fbded1f7baa2ceaed90f97932f79be ]

Before this patch, gfs2_create_inode had a use-after-free for the
iopen glock in some error paths because it did this:

	gfs2_glock_put(io_gl);
fail_gunlock2:
	if (io_gl)
		clear_bit(GLF_INODE_CREATING, &io_gl->gl_flags);

In some cases, the io_gl was used for create and only had one
reference, so the glock might be freed before the clear_bit().
This patch tries to straighten it out by only jumping to the
error paths where iopen is properly set, and moving the
gfs2_glock_put after the clear_bit.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:20 +02:00
Brian Foster
be45bce4ad xfs: fix attr leaf header freemap.size underflow
[ Upstream commit 2a2b5932db67586bacc560cc065d62faece5b996 ]

The leaf format xattr addition helper xfs_attr3_leaf_add_work()
adjusts the block freemap in a couple places. The first update drops
the size of the freemap that the caller had already selected to
place the xattr name/value data. Before the function returns, it
also checks whether the entries array has encroached on a freemap
range by virtue of the new entry addition. This is necessary because
the entries array grows from the start of the block (but end of the
block header) towards the end of the block while the name/value data
grows from the end of the block in the opposite direction. If the
associated freemap is already empty, however, size is zero and the
subtraction underflows the field and causes corruption.

This is reproduced rarely by generic/070. The observed behavior is
that a smaller sized freemap is aligned to the end of the entries
list, several subsequent xattr additions land in larger freemaps and
the entries list expands into the smaller freemap until it is fully
consumed and then underflows. Note that it is not otherwise a
corruption for the entries array to consume an empty freemap because
the nameval list (i.e. the firstused pointer in the xattr header)
starts beyond the end of the corrupted freemap.

Update the freemap size modification to account for the fact that
the freemap entry can be empty and thus stale.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:19 +02:00
Al Viro
424388f0c5 fix dget_parent() fastpath race
[ Upstream commit e84009336711d2bba885fc9cea66348ddfce3758 ]

We are overoptimistic about taking the fast path there; seeing
the same value in ->d_parent after having grabbed a reference
to that parent does *not* mean that it has remained our parent
all along.

That wouldn't be a big deal (in the end it is our parent and
we have grabbed the reference we are about to return), but...
the situation with barriers is messed up.

We might have hit the following sequence:

d is a dentry of /tmp/a/b
CPU1:					CPU2:
parent = d->d_parent (i.e. dentry of /tmp/a)
					rename /tmp/a/b to /tmp/b
					rmdir /tmp/a, making its dentry negative
grab reference to parent,
end up with cached parent->d_inode (NULL)
					mkdir /tmp/a, rename /tmp/b to /tmp/a/b
recheck d->d_parent, which is back to original
decide that everything's fine and return the reference we'd got.

The trouble is, caller (on CPU1) will observe dget_parent()
returning an apparently negative dentry.  It actually is positive,
but CPU1 has stale ->d_inode cached.

Use d->d_seq to see if it has been moved instead of rechecking ->d_parent.
NOTE: we are *NOT* going to retry on any kind of ->d_seq mismatch;
we just go into the slow path in such case.  We don't wait for ->d_seq
to become even either - again, if we are racing with renames, we
can bloody well go to slow path anyway.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:19 +02:00
Jaegeuk Kim
5eb67d3843 f2fs: avoid kernel panic on corruption test
[ Upstream commit bc005a4d5347da68e690f78d365d8927c87dc85a ]

xfstests/generic/475 complains kernel warn/panic while testing corrupted disk.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:16 +02:00
Andreas Gruenbacher
5657f17bcd iomap: Fix overflow in iomap_page_mkwrite
[ Upstream commit add66fcbd3fbe5aa0dd4dddfa23e119c12989a27 ]

On architectures where loff_t is wider than pgoff_t, the expression
((page->index + 1) << PAGE_SHIFT) can overflow.  Rewrite to use the page
offset, which we already compute here anyway.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:15 +02:00
Dave Chinner
36f11775da xfs: properly serialise fallocate against AIO+DIO
[ Upstream commit 249bd9087a5264d2b8a974081870e2e27671b4dc ]

AIO+DIO can extend the file size on IO completion, and it holds
no inode locks while the IO is in flight. Therefore, a race
condition exists in file size updates if we do something like this:

aio-thread			fallocate-thread

lock inode
submit IO beyond inode->i_size
unlock inode
.....
				lock inode
				break layouts
				if (off + len > inode->i_size)
					new_size = off + len
				.....
				inode_dio_wait()
				<blocks>
.....
completes
inode->i_size updated
inode_dio_done()
....
				<wakes>
				<does stuff no long beyond EOF>
				if (new_size)
					xfs_vn_setattr(inode, new_size)

Yup, that attempt to extend the file size in the fallocate code
turns into a truncate - it removes the whatever the aio write
allocated and put to disk, and reduced the inode size back down to
where the fallocate operation ends.

Fundamentally, xfs_file_fallocate()  not compatible with racing
AIO+DIO completions, so we need to move the inode_dio_wait() call
up to where the lock the inode and break the layouts.

Secondly, storing the inode size and then using it unchecked without
holding the ILOCK is not safe; we can only do such a thing if we've
locked out and drained all IO and other modification operations,
which we don't do initially in xfs_file_fallocate.

It should be noted that some of the fallocate operations are
compound operations - they are made up of multiple manipulations
that may zero data, and so we may need to flush and invalidate the
file multiple times during an operation. However, we only need to
lock out IO and other space manipulation operations once, as that
lockout is maintained until the entire fallocate operation has been
completed.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:14 +02:00
Dave Chinner
8c355ed619 xfs: fix inode fork extent count overflow
[ Upstream commit 3f8a4f1d876d3e3e49e50b0396eaffcc4ba71b08 ]

[commit message is verbose for discussion purposes - will trim it
down later. Some questions about implementation details at the end.]

Zorro Lang recently ran a new test to stress single inode extent
counts now that they are no longer limited by memory allocation.
The test was simply:

# xfs_io -f -c "falloc 0 40t" /mnt/scratch/big-file
# ~/src/xfstests-dev/punch-alternating /mnt/scratch/big-file

This test uncovered a problem where the hole punching operation
appeared to finish with no error, but apparently only created 268M
extents instead of the 10 billion it was supposed to.

Further, trying to punch out extents that should have been present
resulted in success, but no change in the extent count. It looked
like a silent failure.

While running the test and observing the behaviour in real time,
I observed the extent coutn growing at ~2M extents/minute, and saw
this after about an hour:

# xfs_io -f -c "stat" /mnt/scratch/big-file |grep next ; \
> sleep 60 ; \
> xfs_io -f -c "stat" /mnt/scratch/big-file |grep next
fsxattr.nextents = 127657993
fsxattr.nextents = 129683339
#

And a few minutes later this:

# xfs_io -f -c "stat" /mnt/scratch/big-file |grep next
fsxattr.nextents = 4177861124
#

Ah, what? Where did that 4 billion extra extents suddenly come from?

Stop the workload, unmount, mount:

# xfs_io -f -c "stat" /mnt/scratch/big-file |grep next
fsxattr.nextents = 166044375
#

And it's back at the expected number. i.e. the extent count is
correct on disk, but it's screwed up in memory. I loaded up the
extent list, and immediately:

# xfs_io -f -c "stat" /mnt/scratch/big-file |grep next
fsxattr.nextents = 4192576215
#

It's bad again. So, where does that number come from?
xfs_fill_fsxattr():

                if (ip->i_df.if_flags & XFS_IFEXTENTS)
                        fa->fsx_nextents = xfs_iext_count(&ip->i_df);
                else
                        fa->fsx_nextents = ip->i_d.di_nextents;

And that's the behaviour I just saw in a nutshell. The on disk count
is correct, but once the tree is loaded into memory, it goes whacky.
Clearly there's something wrong with xfs_iext_count():

inline xfs_extnum_t xfs_iext_count(struct xfs_ifork *ifp)
{
        return ifp->if_bytes / sizeof(struct xfs_iext_rec);
}

Simple enough, but 134M extents is 2**27, and that's right about
where things went wrong. A struct xfs_iext_rec is 16 bytes in size,
which means 2**27 * 2**4 = 2**31 and we're right on target for an
integer overflow. And, sure enough:

struct xfs_ifork {
        int                     if_bytes;       /* bytes in if_u1 */
....

Once we get 2**27 extents in a file, we overflow if_bytes and the
in-core extent count goes wrong. And when we reach 2**28 extents,
if_bytes wraps back to zero and things really start to go wrong
there. This is where the silent failure comes from - only the first
2**28 extents can be looked up directly due to the overflow, all the
extents above this index wrap back to somewhere in the first 2**28
extents. Hence with a regular pattern, trying to punch a hole in the
range that didn't have holes mapped to a hole in the first 2**28
extents and so "succeeded" without changing anything. Hence "silent
failure"...

Fix this by converting if_bytes to a int64_t and converting all the
index variables and size calculations to use int64_t types to avoid
overflows in future. Signed integers are still used to enable easy
detection of extent count underflows. This enables scalability of
extent counts to the limits of the on-disk format - MAXEXTNUM
(2**31) extents.

Current testing is at over 500M extents and still going:

fsxattr.nextents = 517310478

Reported-by: Zorro Lang <zlang@redhat.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:13 +02:00
Gabriel Krisman Bertazi
78d48322dd f2fs: Return EOF on unaligned end of file DIO read
[ Upstream commit 20d0a107fb35f37578b919f62bd474d6d358d579 ]

Reading past end of file returns EOF for aligned reads but -EINVAL for
unaligned reads on f2fs.  While documentation is not strict about this
corner case, most filesystem returns EOF on this case, like iomap
filesystems.  This patch consolidates the behavior for f2fs, by making
it return EOF(0).

it can be verified by a read loop on a file that does a partial read
before EOF (A file that doesn't end at an aligned address).  The
following code fails on an unaligned file on f2fs, but not on
btrfs, ext4, and xfs.

  while (done < total) {
    ssize_t delta = pread(fd, buf + done, total - done, off + done);
    if (!delta)
      break;
    ...
  }

It is arguable whether filesystems should actually return EOF or
-EINVAL, but since iomap filesystems support it, and so does the
original DIO code, it seems reasonable to consolidate on that.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-23 12:40:38 +02:00
Sahitya Tummala
e34313d1b7 f2fs: fix indefinite loop scanning for free nid
[ Upstream commit e2cab031ba7b5003cd12185b3ef38f1a75e3dae8 ]

If the sbi->ckpt->next_free_nid is not NAT block aligned and if there
are free nids in that NAT block between the start of the block and
next_free_nid, then those free nids will not be scanned in scan_nat_page().
This results into mismatch between nm_i->available_nids and the sum of
nm_i->free_nid_count of all NAT blocks scanned. And nm_i->available_nids
will always be greater than the sum of free nids in all the blocks.
Under this condition, if we use all the currently scanned free nids,
then it will loop forever in f2fs_alloc_nid() as nm_i->available_nids
is still not zero but nm_i->free_nid_count of that partially scanned
NAT block is zero.

Fix this to align the nm_i->next_scan_nid to the first nid of the
corresponding NAT block.

Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-23 12:40:37 +02:00
Ronnie Sahlberg
5dda8b9b6a cifs: fix DFS mount with cifsacl/modefromsid
[ Upstream commit 01ec372cef1e5afa4ab843bbaf88a6fcb64dc14c ]

RHBZ: 1871246

If during cifs_lookup()/get_inode_info() we encounter a DFS link
and we use the cifsacl or modefromsid mount options we must suppress
any -EREMOTE errors that triggers or else we will not be able to follow
the DFS link and automount the target.

This fixes an issue with modefromsid/cifsacl where these mountoptions
would break DFS and we would no longer be able to access the share.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-23 12:40:36 +02:00
Chuck Lever
7b8fb2a4d3 NFS: Zero-stateid SETATTR should first return delegation
[ Upstream commit 644c9f40cf71969f29add32f32349e71d4995c0b ]

If a write delegation isn't available, the Linux NFS client uses
a zero-stateid when performing a SETATTR.

NFSv4.0 provides no mechanism for an NFS server to match such a
request to a particular client. It recalls all delegations for that
file, even delegations held by the client issuing the request. If
that client happens to hold a read delegation, the server will
recall it immediately, resulting in an NFS4ERR_DELAY/CB_RECALL/
DELEGRETURN sequence.

Optimize out this pipeline bubble by having the client return any
delegations it may hold on a file before it issues a
SETATTR(zero-stateid) on that file.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-23 12:40:36 +02:00
Olga Kornievskaia
db081ee4d8 NFSv4.1 handle ERR_DELAY error reclaiming locking state on delegation recall
[ Upstream commit 3d7a9520f0c3e6a68b6de8c5812fc8b6d7a52626 ]

A client should be able to handle getting an ERR_DELAY error
while doing a LOCK call to reclaim state due to delegation being
recalled. This is a transient error that can happen due to server
moving its volumes and invalidating its file location cache and
upon reference to it during the LOCK call needing to do an
expensive lookup (leading to an ERR_DELAY error on a PUTFH).

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-23 12:40:34 +02:00
Bob Peterson
29dd419f56 gfs2: initialize transaction tr_ailX_lists earlier
commit cbcc89b630447ec7836aa2b9242d9bb1725f5a61 upstream.

Since transactions may be freed shortly after they're created, before
a log_flush occurs, we need to initialize their ail1 and ail2 lists
earlier. Before this patch, the ail1 list was initialized in gfs2_log_flush().
This moves the initialization to the point when the transaction is first
created.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Salvatore Bonaccorso <carnil@debian.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-23 12:40:33 +02:00
Vladis Dronov
323159acb2 debugfs: Fix module state check condition
commit e3b9fc7eec55e6fdc8beeed18f2ed207086341e2 upstream.

The '#ifdef MODULE' check in the original commit does not work as intended.
The code under the check is not built at all if CONFIG_DEBUG_FS=y. Fix this
by using a correct check.

Fixes: 275678e7a9be ("debugfs: Check module state before warning in {full/open}_proxy_open()")
Signed-off-by: Vladis Dronov <vdronov@redhat.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200811150129.53343-1-vdronov@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-17 13:47:55 +02:00
Filipe Manana
b85c64a716 btrfs: fix wrong address when faulting in pages in the search ioctl
commit 1c78544eaa4660096aeb6a57ec82b42cdb3bfe5a upstream.

When faulting in the pages for the user supplied buffer for the search
ioctl, we are passing only the base address of the buffer to the function
fault_in_pages_writeable(). This means that after the first iteration of
the while loop that searches for leaves, when we have a non-zero offset,
stored in 'sk_offset', we try to fault in a wrong page range.

So fix this by adding the offset in 'sk_offset' to the base address of the
user supplied buffer when calling fault_in_pages_writeable().

Several users have reported that the applications compsize and bees have
started to operate incorrectly since commit a48b73eca4ceb9 ("btrfs: fix
potential deadlock in the search ioctl") was added to stable trees, and
these applications make heavy use of the search ioctls. This fixes their
issues.

Link: https://lore.kernel.org/linux-btrfs/632b888d-a3c3-b085-cdf5-f9bb61017d92@lechevalier.se/
Link: https://github.com/kilobyte/compsize/issues/34
Fixes: a48b73eca4ceb9 ("btrfs: fix potential deadlock in the search ioctl")
CC: stable@vger.kernel.org # 4.4+
Tested-by: A L <mail@lechevalier.se>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-17 13:47:52 +02:00
Josef Bacik
524f3f3030 btrfs: fix lockdep splat in add_missing_dev
commit fccc0007b8dc952c6bc0805cdf842eb8ea06a639 upstream.

Nikolay reported a lockdep splat in generic/476 that I could reproduce
with btrfs/187.

  ======================================================
  WARNING: possible circular locking dependency detected
  5.9.0-rc2+ #1 Tainted: G        W
  ------------------------------------------------------
  kswapd0/100 is trying to acquire lock:
  ffff9e8ef38b6268 (&delayed_node->mutex){+.+.}-{3:3}, at: __btrfs_release_delayed_node.part.0+0x3f/0x330

  but task is already holding lock:
  ffffffffa9d74700 (fs_reclaim){+.+.}-{0:0}, at: __fs_reclaim_acquire+0x5/0x30

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #2 (fs_reclaim){+.+.}-{0:0}:
	 fs_reclaim_acquire+0x65/0x80
	 slab_pre_alloc_hook.constprop.0+0x20/0x200
	 kmem_cache_alloc_trace+0x3a/0x1a0
	 btrfs_alloc_device+0x43/0x210
	 add_missing_dev+0x20/0x90
	 read_one_chunk+0x301/0x430
	 btrfs_read_sys_array+0x17b/0x1b0
	 open_ctree+0xa62/0x1896
	 btrfs_mount_root.cold+0x12/0xea
	 legacy_get_tree+0x30/0x50
	 vfs_get_tree+0x28/0xc0
	 vfs_kern_mount.part.0+0x71/0xb0
	 btrfs_mount+0x10d/0x379
	 legacy_get_tree+0x30/0x50
	 vfs_get_tree+0x28/0xc0
	 path_mount+0x434/0xc00
	 __x64_sys_mount+0xe3/0x120
	 do_syscall_64+0x33/0x40
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #1 (&fs_info->chunk_mutex){+.+.}-{3:3}:
	 __mutex_lock+0x7e/0x7e0
	 btrfs_chunk_alloc+0x125/0x3a0
	 find_free_extent+0xdf6/0x1210
	 btrfs_reserve_extent+0xb3/0x1b0
	 btrfs_alloc_tree_block+0xb0/0x310
	 alloc_tree_block_no_bg_flush+0x4a/0x60
	 __btrfs_cow_block+0x11a/0x530
	 btrfs_cow_block+0x104/0x220
	 btrfs_search_slot+0x52e/0x9d0
	 btrfs_lookup_inode+0x2a/0x8f
	 __btrfs_update_delayed_inode+0x80/0x240
	 btrfs_commit_inode_delayed_inode+0x119/0x120
	 btrfs_evict_inode+0x357/0x500
	 evict+0xcf/0x1f0
	 vfs_rmdir.part.0+0x149/0x160
	 do_rmdir+0x136/0x1a0
	 do_syscall_64+0x33/0x40
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #0 (&delayed_node->mutex){+.+.}-{3:3}:
	 __lock_acquire+0x1184/0x1fa0
	 lock_acquire+0xa4/0x3d0
	 __mutex_lock+0x7e/0x7e0
	 __btrfs_release_delayed_node.part.0+0x3f/0x330
	 btrfs_evict_inode+0x24c/0x500
	 evict+0xcf/0x1f0
	 dispose_list+0x48/0x70
	 prune_icache_sb+0x44/0x50
	 super_cache_scan+0x161/0x1e0
	 do_shrink_slab+0x178/0x3c0
	 shrink_slab+0x17c/0x290
	 shrink_node+0x2b2/0x6d0
	 balance_pgdat+0x30a/0x670
	 kswapd+0x213/0x4c0
	 kthread+0x138/0x160
	 ret_from_fork+0x1f/0x30

  other info that might help us debug this:

  Chain exists of:
    &delayed_node->mutex --> &fs_info->chunk_mutex --> fs_reclaim

   Possible unsafe locking scenario:

	 CPU0                    CPU1
	 ----                    ----
    lock(fs_reclaim);
				 lock(&fs_info->chunk_mutex);
				 lock(fs_reclaim);
    lock(&delayed_node->mutex);

   *** DEADLOCK ***

  3 locks held by kswapd0/100:
   #0: ffffffffa9d74700 (fs_reclaim){+.+.}-{0:0}, at: __fs_reclaim_acquire+0x5/0x30
   #1: ffffffffa9d65c50 (shrinker_rwsem){++++}-{3:3}, at: shrink_slab+0x115/0x290
   #2: ffff9e8e9da260e0 (&type->s_umount_key#48){++++}-{3:3}, at: super_cache_scan+0x38/0x1e0

  stack backtrace:
  CPU: 1 PID: 100 Comm: kswapd0 Tainted: G        W         5.9.0-rc2+ #1
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
  Call Trace:
   dump_stack+0x92/0xc8
   check_noncircular+0x12d/0x150
   __lock_acquire+0x1184/0x1fa0
   lock_acquire+0xa4/0x3d0
   ? __btrfs_release_delayed_node.part.0+0x3f/0x330
   __mutex_lock+0x7e/0x7e0
   ? __btrfs_release_delayed_node.part.0+0x3f/0x330
   ? __btrfs_release_delayed_node.part.0+0x3f/0x330
   ? lock_acquire+0xa4/0x3d0
   ? btrfs_evict_inode+0x11e/0x500
   ? find_held_lock+0x2b/0x80
   __btrfs_release_delayed_node.part.0+0x3f/0x330
   btrfs_evict_inode+0x24c/0x500
   evict+0xcf/0x1f0
   dispose_list+0x48/0x70
   prune_icache_sb+0x44/0x50
   super_cache_scan+0x161/0x1e0
   do_shrink_slab+0x178/0x3c0
   shrink_slab+0x17c/0x290
   shrink_node+0x2b2/0x6d0
   balance_pgdat+0x30a/0x670
   kswapd+0x213/0x4c0
   ? _raw_spin_unlock_irqrestore+0x46/0x60
   ? add_wait_queue_exclusive+0x70/0x70
   ? balance_pgdat+0x670/0x670
   kthread+0x138/0x160
   ? kthread_create_worker_on_cpu+0x40/0x40
   ret_from_fork+0x1f/0x30

This is because we are holding the chunk_mutex when we call
btrfs_alloc_device, which does a GFP_KERNEL allocation.  We don't want
to switch that to a GFP_NOFS lock because this is the only place where
it matters.  So instead use memalloc_nofs_save() around the allocation
in order to avoid the lockdep splat.

Reported-by: Nikolay Borisov <nborisov@suse.com>
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-17 13:47:51 +02:00
Qu Wenruo
1aaceffa5a btrfs: require only sector size alignment for parent eb bytenr
commit ea57788eb76dc81f6003245427356a1dcd0ac524 upstream.

[BUG]
A completely sane converted fs will cause kernel warning at balance
time:

  [ 1557.188633] BTRFS info (device sda7): relocating block group 8162107392 flags data
  [ 1563.358078] BTRFS info (device sda7): found 11722 extents
  [ 1563.358277] BTRFS info (device sda7): leaf 7989321728 gen 95 total ptrs 213 free space 3458 owner 2
  [ 1563.358280] 	item 0 key (7984947200 169 0) itemoff 16250 itemsize 33
  [ 1563.358281] 		extent refs 1 gen 90 flags 2
  [ 1563.358282] 		ref#0: tree block backref root 4
  [ 1563.358285] 	item 1 key (7985602560 169 0) itemoff 16217 itemsize 33
  [ 1563.358286] 		extent refs 1 gen 93 flags 258
  [ 1563.358287] 		ref#0: shared block backref parent 7985602560
  [ 1563.358288] 			(parent 7985602560 is NOT ALIGNED to nodesize 16384)
  [ 1563.358290] 	item 2 key (7985635328 169 0) itemoff 16184 itemsize 33
  ...
  [ 1563.358995] BTRFS error (device sda7): eb 7989321728 invalid extent inline ref type 182
  [ 1563.358996] ------------[ cut here ]------------
  [ 1563.359005] WARNING: CPU: 14 PID: 2930 at 0xffffffff9f231766

Then with transaction abort, and obviously failed to balance the fs.

[CAUSE]
That mentioned inline ref type 182 is completely sane, it's
BTRFS_SHARED_BLOCK_REF_KEY, it's some extra check making kernel to
believe it's invalid.

Commit 64ecdb647ddb ("Btrfs: add one more sanity check for shared ref
type") introduced extra checks for backref type.

One of the requirement is, parent bytenr must be aligned to node size,
which is not correct.

One example is like this:

0	1G  1G+4K		2G 2G+4K
	|   |///////////////////|//|  <- A chunk starts at 1G+4K
            |   |	<- A tree block get reserved at bytenr 1G+4K

Then we have a valid tree block at bytenr 1G+4K, but not aligned to
nodesize (16K).

Such chunk is not ideal, but current kernel can handle it pretty well.
We may warn about such tree block in the future, but should not reject
them.

[FIX]
Change the alignment requirement from node size alignment to sector size
alignment.

Also, to make our lives a little easier, also output @iref when
btrfs_get_extent_inline_ref_type() failed, so we can locate the item
easier.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=205475
Fixes: 64ecdb647ddb ("Btrfs: add one more sanity check for shared ref type")
CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
[ update comments and messages ]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-17 13:47:51 +02:00
Darrick J. Wong
41ac2e8a6a xfs: initialize the shortform attr header padding entry
[ Upstream commit 125eac243806e021f33a1fdea3687eccbb9f7636 ]

Don't leak kernel memory contents into the shortform attr fork.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-17 13:47:46 +02:00
Brian Foster
e91f2ec0bf xfs: fix off-by-one in inode alloc block reservation calculation
[ Upstream commit 657f101930bc6c5b41bd7d6c22565c4302a80d33 ]

The inode chunk allocation transaction reserves inobt_maxlevels-1
blocks to accommodate a full split of the inode btree. A full split
requires an allocation for every existing level and a new root
block, which means inobt_maxlevels is the worst case block
requirement for a transaction that inserts to the inobt. This can
lead to a transaction block reservation overrun when tmpfile
creation allocates an inode chunk and expands the inobt to its
maximum depth. This problem has been observed in conjunction with
overlayfs, which makes frequent use of tmpfiles internally.

The existing reservation code goes back as far as the Linux git repo
history (v2.6.12). It was likely never observed as a problem because
the traditional file/directory creation transactions also include
worst case block reservation for directory modifications, which most
likely is able to make up for a single block deficiency in the inode
allocation portion of the calculation. tmpfile support is relatively
more recent (v3.15), less heavily used, and only includes the inode
allocation block reservation as tmpfiles aren't linked into the
directory tree on creation.

Fix up the inode alloc block reservation macro and a couple of the
block allocator minleft parameters that enforce an allocation to
leave enough free blocks in the AG for a full inobt split.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-17 13:47:46 +02:00
Max Staudt
b6e4827c04 affs: fix basic permission bits to actually work
commit d3a84a8d0dde4e26bc084b36ffcbdc5932ac85e2 upstream.

The basic permission bits (protection bits in AmigaOS) have been broken
in Linux' AFFS - it would only set bits, but never delete them.
Also, contrary to the documentation, the Archived bit was not handled.

Let's fix this for good, and set the bits such that Linux and classic
AmigaOS can coexist in the most peaceful manner.

Also, update the documentation to represent the current state of things.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Max Staudt <max@enpas.org>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-09 19:12:34 +02:00
Josef Bacik
4254a4f798 btrfs: fix potential deadlock in the search ioctl
[ Upstream commit a48b73eca4ceb9b8a4b97f290a065335dbcd8a04 ]

With the conversion of the tree locks to rwsem I got the following
lockdep splat:

  ======================================================
  WARNING: possible circular locking dependency detected
  5.8.0-rc7-00165-g04ec4da5f45f-dirty #922 Not tainted
  ------------------------------------------------------
  compsize/11122 is trying to acquire lock:
  ffff889fabca8768 (&mm->mmap_lock#2){++++}-{3:3}, at: __might_fault+0x3e/0x90

  but task is already holding lock:
  ffff889fe720fe40 (btrfs-fs-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x39/0x180

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #2 (btrfs-fs-00){++++}-{3:3}:
	 down_write_nested+0x3b/0x70
	 __btrfs_tree_lock+0x24/0x120
	 btrfs_search_slot+0x756/0x990
	 btrfs_lookup_inode+0x3a/0xb4
	 __btrfs_update_delayed_inode+0x93/0x270
	 btrfs_async_run_delayed_root+0x168/0x230
	 btrfs_work_helper+0xd4/0x570
	 process_one_work+0x2ad/0x5f0
	 worker_thread+0x3a/0x3d0
	 kthread+0x133/0x150
	 ret_from_fork+0x1f/0x30

  -> #1 (&delayed_node->mutex){+.+.}-{3:3}:
	 __mutex_lock+0x9f/0x930
	 btrfs_delayed_update_inode+0x50/0x440
	 btrfs_update_inode+0x8a/0xf0
	 btrfs_dirty_inode+0x5b/0xd0
	 touch_atime+0xa1/0xd0
	 btrfs_file_mmap+0x3f/0x60
	 mmap_region+0x3a4/0x640
	 do_mmap+0x376/0x580
	 vm_mmap_pgoff+0xd5/0x120
	 ksys_mmap_pgoff+0x193/0x230
	 do_syscall_64+0x50/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #0 (&mm->mmap_lock#2){++++}-{3:3}:
	 __lock_acquire+0x1272/0x2310
	 lock_acquire+0x9e/0x360
	 __might_fault+0x68/0x90
	 _copy_to_user+0x1e/0x80
	 copy_to_sk.isra.32+0x121/0x300
	 search_ioctl+0x106/0x200
	 btrfs_ioctl_tree_search_v2+0x7b/0xf0
	 btrfs_ioctl+0x106f/0x30a0
	 ksys_ioctl+0x83/0xc0
	 __x64_sys_ioctl+0x16/0x20
	 do_syscall_64+0x50/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  other info that might help us debug this:

  Chain exists of:
    &mm->mmap_lock#2 --> &delayed_node->mutex --> btrfs-fs-00

   Possible unsafe locking scenario:

	 CPU0                    CPU1
	 ----                    ----
    lock(btrfs-fs-00);
				 lock(&delayed_node->mutex);
				 lock(btrfs-fs-00);
    lock(&mm->mmap_lock#2);

   *** DEADLOCK ***

  1 lock held by compsize/11122:
   #0: ffff889fe720fe40 (btrfs-fs-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x39/0x180

  stack backtrace:
  CPU: 17 PID: 11122 Comm: compsize Kdump: loaded Not tainted 5.8.0-rc7-00165-g04ec4da5f45f-dirty #922
  Hardware name: Quanta Tioga Pass Single Side 01-0030993006/Tioga Pass Single Side, BIOS F08_3A18 12/20/2018
  Call Trace:
   dump_stack+0x78/0xa0
   check_noncircular+0x165/0x180
   __lock_acquire+0x1272/0x2310
   lock_acquire+0x9e/0x360
   ? __might_fault+0x3e/0x90
   ? find_held_lock+0x72/0x90
   __might_fault+0x68/0x90
   ? __might_fault+0x3e/0x90
   _copy_to_user+0x1e/0x80
   copy_to_sk.isra.32+0x121/0x300
   ? btrfs_search_forward+0x2a6/0x360
   search_ioctl+0x106/0x200
   btrfs_ioctl_tree_search_v2+0x7b/0xf0
   btrfs_ioctl+0x106f/0x30a0
   ? __do_sys_newfstat+0x5a/0x70
   ? ksys_ioctl+0x83/0xc0
   ksys_ioctl+0x83/0xc0
   __x64_sys_ioctl+0x16/0x20
   do_syscall_64+0x50/0x90
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

The problem is we're doing a copy_to_user() while holding tree locks,
which can deadlock if we have to do a page fault for the copy_to_user().
This exists even without my locking changes, so it needs to be fixed.
Rework the search ioctl to do the pre-fault and then
copy_to_user_nofault for the copying.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-09 19:12:31 +02:00
Qu Wenruo
df0c47585c btrfs: tree-checker: fix the error message for transid error
commit f96d6960abbc52e26ad124e69e6815283d3e1674 upstream.

The error message for inode transid is the same as for inode generation,
which makes us unable to detect the real problem.

Reported-by: Tyler Richmond <t.d.richmond@gmail.com>
Fixes: 496245cac57e ("btrfs: tree-checker: Verify inode item")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-09 19:12:31 +02:00
Josef Bacik
650275310f btrfs: set the lockdep class for log tree extent buffers
commit d3beaa253fd6fa40b8b18a216398e6e5376a9d21 upstream.

These are special extent buffers that get rewound in order to lookup
the state of the tree at a specific point in time.  As such they do not
go through the normal initialization paths that set their lockdep class,
so handle them appropriately when they are created and before they are
locked.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-09 19:12:31 +02:00
Josef Bacik
7e0ffb0d9d btrfs: set the correct lockdep class for new nodes
commit ad24466588ab7d7c879053c5afd919b0c555fec0 upstream.

When flipping over to the rw_semaphore I noticed I'd get a lockdep splat
in replace_path(), which is weird because we're swapping the reloc root
with the actual target root.  Turns out this is because we're using the
root->root_key.objectid as the root id for the newly allocated tree
block when setting the lockdep class, however we need to be using the
actual owner of this new block, which is saved in owner.

The affected path is through btrfs_copy_root as all other callers of
btrfs_alloc_tree_block (which calls init_new_buffer) have root_objectid
== root->root_key.objectid .

CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-09 19:12:31 +02:00
Josef Bacik
c37cc199da btrfs: allocate scrub workqueues outside of locks
commit e89c4a9c8e6ce3a84cab4f342687d3fbbb1234eb upstream.

I got the following lockdep splat while testing:

  ======================================================
  WARNING: possible circular locking dependency detected
  5.8.0-rc7-00172-g021118712e59 #932 Not tainted
  ------------------------------------------------------
  btrfs/229626 is trying to acquire lock:
  ffffffff828513f0 (cpu_hotplug_lock){++++}-{0:0}, at: alloc_workqueue+0x378/0x450

  but task is already holding lock:
  ffff889dd3889518 (&fs_info->scrub_lock){+.+.}-{3:3}, at: btrfs_scrub_dev+0x11c/0x630

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #7 (&fs_info->scrub_lock){+.+.}-{3:3}:
	 __mutex_lock+0x9f/0x930
	 btrfs_scrub_dev+0x11c/0x630
	 btrfs_dev_replace_by_ioctl.cold.21+0x10a/0x1d4
	 btrfs_ioctl+0x2799/0x30a0
	 ksys_ioctl+0x83/0xc0
	 __x64_sys_ioctl+0x16/0x20
	 do_syscall_64+0x50/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #6 (&fs_devs->device_list_mutex){+.+.}-{3:3}:
	 __mutex_lock+0x9f/0x930
	 btrfs_run_dev_stats+0x49/0x480
	 commit_cowonly_roots+0xb5/0x2a0
	 btrfs_commit_transaction+0x516/0xa60
	 sync_filesystem+0x6b/0x90
	 generic_shutdown_super+0x22/0x100
	 kill_anon_super+0xe/0x30
	 btrfs_kill_super+0x12/0x20
	 deactivate_locked_super+0x29/0x60
	 cleanup_mnt+0xb8/0x140
	 task_work_run+0x6d/0xb0
	 __prepare_exit_to_usermode+0x1cc/0x1e0
	 do_syscall_64+0x5c/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #5 (&fs_info->tree_log_mutex){+.+.}-{3:3}:
	 __mutex_lock+0x9f/0x930
	 btrfs_commit_transaction+0x4bb/0xa60
	 sync_filesystem+0x6b/0x90
	 generic_shutdown_super+0x22/0x100
	 kill_anon_super+0xe/0x30
	 btrfs_kill_super+0x12/0x20
	 deactivate_locked_super+0x29/0x60
	 cleanup_mnt+0xb8/0x140
	 task_work_run+0x6d/0xb0
	 __prepare_exit_to_usermode+0x1cc/0x1e0
	 do_syscall_64+0x5c/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #4 (&fs_info->reloc_mutex){+.+.}-{3:3}:
	 __mutex_lock+0x9f/0x930
	 btrfs_record_root_in_trans+0x43/0x70
	 start_transaction+0xd1/0x5d0
	 btrfs_dirty_inode+0x42/0xd0
	 touch_atime+0xa1/0xd0
	 btrfs_file_mmap+0x3f/0x60
	 mmap_region+0x3a4/0x640
	 do_mmap+0x376/0x580
	 vm_mmap_pgoff+0xd5/0x120
	 ksys_mmap_pgoff+0x193/0x230
	 do_syscall_64+0x50/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #3 (&mm->mmap_lock#2){++++}-{3:3}:
	 __might_fault+0x68/0x90
	 _copy_to_user+0x1e/0x80
	 perf_read+0x141/0x2c0
	 vfs_read+0xad/0x1b0
	 ksys_read+0x5f/0xe0
	 do_syscall_64+0x50/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #2 (&cpuctx_mutex){+.+.}-{3:3}:
	 __mutex_lock+0x9f/0x930
	 perf_event_init_cpu+0x88/0x150
	 perf_event_init+0x1db/0x20b
	 start_kernel+0x3ae/0x53c
	 secondary_startup_64+0xa4/0xb0

  -> #1 (pmus_lock){+.+.}-{3:3}:
	 __mutex_lock+0x9f/0x930
	 perf_event_init_cpu+0x4f/0x150
	 cpuhp_invoke_callback+0xb1/0x900
	 _cpu_up.constprop.26+0x9f/0x130
	 cpu_up+0x7b/0xc0
	 bringup_nonboot_cpus+0x4f/0x60
	 smp_init+0x26/0x71
	 kernel_init_freeable+0x110/0x258
	 kernel_init+0xa/0x103
	 ret_from_fork+0x1f/0x30

  -> #0 (cpu_hotplug_lock){++++}-{0:0}:
	 __lock_acquire+0x1272/0x2310
	 lock_acquire+0x9e/0x360
	 cpus_read_lock+0x39/0xb0
	 alloc_workqueue+0x378/0x450
	 __btrfs_alloc_workqueue+0x15d/0x200
	 btrfs_alloc_workqueue+0x51/0x160
	 scrub_workers_get+0x5a/0x170
	 btrfs_scrub_dev+0x18c/0x630
	 btrfs_dev_replace_by_ioctl.cold.21+0x10a/0x1d4
	 btrfs_ioctl+0x2799/0x30a0
	 ksys_ioctl+0x83/0xc0
	 __x64_sys_ioctl+0x16/0x20
	 do_syscall_64+0x50/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  other info that might help us debug this:

  Chain exists of:
    cpu_hotplug_lock --> &fs_devs->device_list_mutex --> &fs_info->scrub_lock

   Possible unsafe locking scenario:

	 CPU0                    CPU1
	 ----                    ----
    lock(&fs_info->scrub_lock);
				 lock(&fs_devs->device_list_mutex);
				 lock(&fs_info->scrub_lock);
    lock(cpu_hotplug_lock);

   *** DEADLOCK ***

  2 locks held by btrfs/229626:
   #0: ffff88bfe8bb86e0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: btrfs_scrub_dev+0xbd/0x630
   #1: ffff889dd3889518 (&fs_info->scrub_lock){+.+.}-{3:3}, at: btrfs_scrub_dev+0x11c/0x630

  stack backtrace:
  CPU: 15 PID: 229626 Comm: btrfs Kdump: loaded Not tainted 5.8.0-rc7-00172-g021118712e59 #932
  Hardware name: Quanta Tioga Pass Single Side 01-0030993006/Tioga Pass Single Side, BIOS F08_3A18 12/20/2018
  Call Trace:
   dump_stack+0x78/0xa0
   check_noncircular+0x165/0x180
   __lock_acquire+0x1272/0x2310
   lock_acquire+0x9e/0x360
   ? alloc_workqueue+0x378/0x450
   cpus_read_lock+0x39/0xb0
   ? alloc_workqueue+0x378/0x450
   alloc_workqueue+0x378/0x450
   ? rcu_read_lock_sched_held+0x52/0x80
   __btrfs_alloc_workqueue+0x15d/0x200
   btrfs_alloc_workqueue+0x51/0x160
   scrub_workers_get+0x5a/0x170
   btrfs_scrub_dev+0x18c/0x630
   ? start_transaction+0xd1/0x5d0
   btrfs_dev_replace_by_ioctl.cold.21+0x10a/0x1d4
   btrfs_ioctl+0x2799/0x30a0
   ? do_sigaction+0x102/0x250
   ? lockdep_hardirqs_on_prepare+0xca/0x160
   ? _raw_spin_unlock_irq+0x24/0x30
   ? trace_hardirqs_on+0x1c/0xe0
   ? _raw_spin_unlock_irq+0x24/0x30
   ? do_sigaction+0x102/0x250
   ? ksys_ioctl+0x83/0xc0
   ksys_ioctl+0x83/0xc0
   __x64_sys_ioctl+0x16/0x20
   do_syscall_64+0x50/0x90
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

This happens because we're allocating the scrub workqueues under the
scrub and device list mutex, which brings in a whole host of other
dependencies.

Because the work queue allocation is done with GFP_KERNEL, it can
trigger reclaim, which can lead to a transaction commit, which in turns
needs the device_list_mutex, it can lead to a deadlock. A different
problem for which this fix is a solution.

Fix this by moving the actual allocation outside of the
scrub lock, and then only take the lock once we're ready to actually
assign them to the fs_info.  We'll now have to cleanup the workqueues in
a few more places, so I've added a helper to do the refcount dance to
safely free the workqueues.

CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-09 19:12:31 +02:00