Commit Graph

841908 Commits

Author SHA1 Message Date
Qu Wenruo
07301df7d2 btrfs: trim: Check the range passed into to prevent overflow
Normally the range->len is set to default value (U64_MAX), but when it's
not default value, we should check if the range overflows.

And if it overflows, return -EINVAL before doing anything.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-08-07 16:42:39 +02:00
Filipe Manana
d7cd4dd907 Btrfs: fix sysfs warning and missing raid sysfs directories
In the 5.3 merge window, commit 7c7e301406 ("btrfs: sysfs: Replace
default_attrs in ktypes with groups"), we started using the member
"defaults_groups" for the kobject type "btrfs_raid_ktype". That leads
to a series of warnings when running some test cases of fstests, such
as btrfs/027, btrfs/124 and btrfs/176. The traces produced by those
warnings are like the following:

  [116648.059212] kernfs: can not remove 'total_bytes', no directory
  [116648.060112] WARNING: CPU: 3 PID: 28500 at fs/kernfs/dir.c:1504 kernfs_remove_by_name_ns+0x75/0x80
  (...)
  [116648.066482] CPU: 3 PID: 28500 Comm: umount Tainted: G        W         5.3.0-rc3-btrfs-next-54 #1
  (...)
  [116648.069376] RIP: 0010:kernfs_remove_by_name_ns+0x75/0x80
  (...)
  [116648.072385] RSP: 0018:ffffabfd0090bd08 EFLAGS: 00010282
  [116648.073437] RAX: 0000000000000000 RBX: ffffffffc0c11998 RCX: 0000000000000000
  [116648.074201] RDX: ffff9fff603a7a00 RSI: ffff9fff603978a8 RDI: ffff9fff603978a8
  [116648.074956] RBP: ffffffffc0b9ca2f R08: 0000000000000000 R09: 0000000000000001
  [116648.075708] R10: ffff9ffe1f72e1c0 R11: 0000000000000000 R12: ffffffffc0b94120
  [116648.076434] R13: ffffffffb3d9b4e0 R14: 0000000000000000 R15: dead000000000100
  [116648.077143] FS:  00007f9cdc78a2c0(0000) GS:ffff9fff60380000(0000) knlGS:0000000000000000
  [116648.077852] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [116648.078546] CR2: 00007f9fc4747ab4 CR3: 00000005c7832003 CR4: 00000000003606e0
  [116648.079235] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  [116648.079907] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  [116648.080585] Call Trace:
  [116648.081262]  remove_files+0x31/0x70
  [116648.081929]  sysfs_remove_group+0x38/0x80
  [116648.082596]  sysfs_remove_groups+0x34/0x70
  [116648.083258]  kobject_del+0x20/0x60
  [116648.083933]  btrfs_free_block_groups+0x405/0x430 [btrfs]
  [116648.084608]  close_ctree+0x19a/0x380 [btrfs]
  [116648.085278]  generic_shutdown_super+0x6c/0x110
  [116648.085951]  kill_anon_super+0xe/0x30
  [116648.086621]  btrfs_kill_super+0x12/0xa0 [btrfs]
  [116648.087289]  deactivate_locked_super+0x3a/0x70
  [116648.087956]  cleanup_mnt+0xb4/0x160
  [116648.088620]  task_work_run+0x7e/0xc0
  [116648.089285]  exit_to_usermode_loop+0xfa/0x100
  [116648.089933]  do_syscall_64+0x1cb/0x220
  [116648.090567]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  [116648.091197] RIP: 0033:0x7f9cdc073b37
  (...)
  [116648.100046] ---[ end trace 22e24db328ccadf8 ]---
  [116648.100618] ------------[ cut here ]------------
  [116648.101175] kernfs: can not remove 'used_bytes', no directory
  [116648.101731] WARNING: CPU: 3 PID: 28500 at fs/kernfs/dir.c:1504 kernfs_remove_by_name_ns+0x75/0x80
  (...)
  [116648.105649] CPU: 3 PID: 28500 Comm: umount Tainted: G        W         5.3.0-rc3-btrfs-next-54 #1
  (...)
  [116648.107461] RIP: 0010:kernfs_remove_by_name_ns+0x75/0x80
  (...)
  [116648.109336] RSP: 0018:ffffabfd0090bd08 EFLAGS: 00010282
  [116648.109979] RAX: 0000000000000000 RBX: ffffffffc0c119a0 RCX: 0000000000000000
  [116648.110625] RDX: ffff9fff603a7a00 RSI: ffff9fff603978a8 RDI: ffff9fff603978a8
  [116648.111283] RBP: ffffffffc0b9ca41 R08: 0000000000000000 R09: 0000000000000001
  [116648.111940] R10: ffff9ffe1f72e1c0 R11: 0000000000000000 R12: ffffffffc0b94120
  [116648.112603] R13: ffffffffb3d9b4e0 R14: 0000000000000000 R15: dead000000000100
  [116648.113268] FS:  00007f9cdc78a2c0(0000) GS:ffff9fff60380000(0000) knlGS:0000000000000000
  [116648.113939] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [116648.114607] CR2: 00007f9fc4747ab4 CR3: 00000005c7832003 CR4: 00000000003606e0
  [116648.115286] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  [116648.115966] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  [116648.116649] Call Trace:
  [116648.117326]  remove_files+0x31/0x70
  [116648.117997]  sysfs_remove_group+0x38/0x80
  [116648.118671]  sysfs_remove_groups+0x34/0x70
  [116648.119342]  kobject_del+0x20/0x60
  [116648.120022]  btrfs_free_block_groups+0x405/0x430 [btrfs]
  [116648.120707]  close_ctree+0x19a/0x380 [btrfs]
  [116648.121396]  generic_shutdown_super+0x6c/0x110
  [116648.122057]  kill_anon_super+0xe/0x30
  [116648.122702]  btrfs_kill_super+0x12/0xa0 [btrfs]
  [116648.123335]  deactivate_locked_super+0x3a/0x70
  [116648.123961]  cleanup_mnt+0xb4/0x160
  [116648.124586]  task_work_run+0x7e/0xc0
  [116648.125210]  exit_to_usermode_loop+0xfa/0x100
  [116648.125830]  do_syscall_64+0x1cb/0x220
  [116648.126463]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  [116648.127080] RIP: 0033:0x7f9cdc073b37
  (...)
  [116648.135923] ---[ end trace 22e24db328ccadf9 ]---

These happen because, during the unmount path, we call kobject_del() for
raid kobjects that are not fully initialized, meaning that we set their
ktype (as btrfs_raid_ktype) through link_block_group() but we didn't set
their parent kobject, which is done through btrfs_add_raid_kobjects().

We have this split raid kobject setup since commit 75cb379d26
("btrfs: defer adding raid type kobject until after chunk relocation") in
order to avoid triggering reclaim during contextes where we can not
(either we are holding a transaction handle or some lock required by
the transaction commit path), so that we do the calls to kobject_add(),
which triggers GFP_KERNEL allocations, through btrfs_add_raid_kobjects()
in contextes where it is safe to trigger reclaim. That change expected
that a new raid kobject can only be created either when mounting the
filesystem or after raid profile conversion through the relocation path.
However, we can have new raid kobject created in other two cases at least:

1) During device replace (or scrub) after adding a device a to the
   filesystem. The replace procedure (and scrub) do calls to
   btrfs_inc_block_group_ro() which can allocate a new block group
   with a new raid profile (because we now have more devices). This
   can be triggered by test cases btrfs/027 and btrfs/176.

2) During a degraded mount trough any write path. This can be triggered
   by test case btrfs/124.

Fixing this by adding extra calls to btrfs_add_raid_kobjects(), not only
makes things more complex and fragile, can also introduce deadlocks with
reclaim the following way:

1) Calling btrfs_add_raid_kobjects() at btrfs_inc_block_group_ro() or
   anywhere in the replace/scrub path will cause a deadlock with reclaim
   because if reclaim happens and a transaction commit is triggered,
   the transaction commit path will block at btrfs_scrub_pause().

2) During degraded mounts it is essentially impossible to figure out where
   to add extra calls to btrfs_add_raid_kobjects(), because allocation of
   a block group with a new raid profile can happen anywhere, which means
   we can't safely figure out which contextes are safe for reclaim, as
   we can either hold a transaction handle or some lock needed by the
   transaction commit path.

So it is too complex and error prone to have this split setup of raid
kobjects. So fix the issue by consolidating the setup of the kobjects in a
single place, at link_block_group(), and setup a nofs context there in
order to prevent reclaim being triggered by the memory allocations done
through the call chain of kobject_add().

Besides fixing the sysfs warnings during kobject_del(), this also ensures
the sysfs directories for the new raid profiles end up created and visible
to users (a bug that existed before the 5.3 commit 7c7e301406
("btrfs: sysfs: Replace default_attrs in ktypes with groups")).

Fixes: 75cb379d26 ("btrfs: defer adding raid type kobject until after chunk relocation")
Fixes: 7c7e301406 ("btrfs: sysfs: Replace default_attrs in ktypes with groups")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-08-07 16:25:44 +02:00
Filipe Manana
a6d155d2e3 Btrfs: fix deadlock between fiemap and transaction commits
The fiemap handler locks a file range that can have unflushed delalloc,
and after locking the range, it tries to attach to a running transaction.
If the running transaction started its commit, that is, it is in state
TRANS_STATE_COMMIT_START, and either the filesystem was mounted with the
flushoncommit option or the transaction is creating a snapshot for the
subvolume that contains the file that fiemap is operating on, we end up
deadlocking. This happens because fiemap is blocked on the transaction,
waiting for it to complete, and the transaction is waiting for the flushed
dealloc to complete, which requires locking the file range that the fiemap
task already locked. The following stack traces serve as an example of
when this deadlock happens:

  (...)
  [404571.515510] Workqueue: btrfs-endio-write btrfs_endio_write_helper [btrfs]
  [404571.515956] Call Trace:
  [404571.516360]  ? __schedule+0x3ae/0x7b0
  [404571.516730]  schedule+0x3a/0xb0
  [404571.517104]  lock_extent_bits+0x1ec/0x2a0 [btrfs]
  [404571.517465]  ? remove_wait_queue+0x60/0x60
  [404571.517832]  btrfs_finish_ordered_io+0x292/0x800 [btrfs]
  [404571.518202]  normal_work_helper+0xea/0x530 [btrfs]
  [404571.518566]  process_one_work+0x21e/0x5c0
  [404571.518990]  worker_thread+0x4f/0x3b0
  [404571.519413]  ? process_one_work+0x5c0/0x5c0
  [404571.519829]  kthread+0x103/0x140
  [404571.520191]  ? kthread_create_worker_on_cpu+0x70/0x70
  [404571.520565]  ret_from_fork+0x3a/0x50
  [404571.520915] kworker/u8:6    D    0 31651      2 0x80004000
  [404571.521290] Workqueue: btrfs-flush_delalloc btrfs_flush_delalloc_helper [btrfs]
  (...)
  [404571.537000] fsstress        D    0 13117  13115 0x00004000
  [404571.537263] Call Trace:
  [404571.537524]  ? __schedule+0x3ae/0x7b0
  [404571.537788]  schedule+0x3a/0xb0
  [404571.538066]  wait_current_trans+0xc8/0x100 [btrfs]
  [404571.538349]  ? remove_wait_queue+0x60/0x60
  [404571.538680]  start_transaction+0x33c/0x500 [btrfs]
  [404571.539076]  btrfs_check_shared+0xa3/0x1f0 [btrfs]
  [404571.539513]  ? extent_fiemap+0x2ce/0x650 [btrfs]
  [404571.539866]  extent_fiemap+0x2ce/0x650 [btrfs]
  [404571.540170]  do_vfs_ioctl+0x526/0x6f0
  [404571.540436]  ksys_ioctl+0x70/0x80
  [404571.540734]  __x64_sys_ioctl+0x16/0x20
  [404571.540997]  do_syscall_64+0x60/0x1d0
  [404571.541279]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  (...)
  [404571.543729] btrfs           D    0 14210  14208 0x00004000
  [404571.544023] Call Trace:
  [404571.544275]  ? __schedule+0x3ae/0x7b0
  [404571.544526]  ? wait_for_completion+0x112/0x1a0
  [404571.544795]  schedule+0x3a/0xb0
  [404571.545064]  schedule_timeout+0x1ff/0x390
  [404571.545351]  ? lock_acquire+0xa6/0x190
  [404571.545638]  ? wait_for_completion+0x49/0x1a0
  [404571.545890]  ? wait_for_completion+0x112/0x1a0
  [404571.546228]  wait_for_completion+0x131/0x1a0
  [404571.546503]  ? wake_up_q+0x70/0x70
  [404571.546775]  btrfs_wait_ordered_extents+0x27c/0x400 [btrfs]
  [404571.547159]  btrfs_commit_transaction+0x3b0/0xae0 [btrfs]
  [404571.547449]  ? btrfs_mksubvol+0x4a4/0x640 [btrfs]
  [404571.547703]  ? remove_wait_queue+0x60/0x60
  [404571.547969]  btrfs_mksubvol+0x605/0x640 [btrfs]
  [404571.548226]  ? __sb_start_write+0xd4/0x1c0
  [404571.548512]  ? mnt_want_write_file+0x24/0x50
  [404571.548789]  btrfs_ioctl_snap_create_transid+0x169/0x1a0 [btrfs]
  [404571.549048]  btrfs_ioctl_snap_create_v2+0x11d/0x170 [btrfs]
  [404571.549307]  btrfs_ioctl+0x133f/0x3150 [btrfs]
  [404571.549549]  ? mem_cgroup_charge_statistics+0x4c/0xd0
  [404571.549792]  ? mem_cgroup_commit_charge+0x84/0x4b0
  [404571.550064]  ? __handle_mm_fault+0xe3e/0x11f0
  [404571.550306]  ? do_raw_spin_unlock+0x49/0xc0
  [404571.550608]  ? _raw_spin_unlock+0x24/0x30
  [404571.550976]  ? __handle_mm_fault+0xedf/0x11f0
  [404571.551319]  ? do_vfs_ioctl+0xa2/0x6f0
  [404571.551659]  ? btrfs_ioctl_get_supported_features+0x30/0x30 [btrfs]
  [404571.552087]  do_vfs_ioctl+0xa2/0x6f0
  [404571.552355]  ksys_ioctl+0x70/0x80
  [404571.552621]  __x64_sys_ioctl+0x16/0x20
  [404571.552864]  do_syscall_64+0x60/0x1d0
  [404571.553104]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  (...)

If we were joining the transaction instead of attaching to it, we would
not risk a deadlock because a join only blocks if the transaction is in a
state greater then or equals to TRANS_STATE_COMMIT_DOING, and the delalloc
flush performed by a transaction is done before it reaches that state,
when it is in the state TRANS_STATE_COMMIT_START. However a transaction
join is intended for use cases where we do modify the filesystem, and
fiemap only needs to peek at delayed references from the current
transaction in order to determine if extents are shared, and, besides
that, when there is no current transaction or when it blocks to wait for
a current committing transaction to complete, it creates a new transaction
without reserving any space. Such unnecessary transactions, besides doing
unnecessary IO, can cause transaction aborts (-ENOSPC) and unnecessary
rotation of the precious backup roots.

So fix this by adding a new transaction join variant, named join_nostart,
which behaves like the regular join, but it does not create a transaction
when none currently exists or after waiting for a committing transaction
to complete.

Fixes: 03628cdbc6 ("Btrfs: do not start a transaction during fiemap")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-30 18:25:12 +02:00
Filipe Manana
cb2d3daddb Btrfs: fix race leading to fs corruption after transaction abort
When one transaction is finishing its commit, it is possible for another
transaction to start and enter its initial commit phase as well. If the
first ends up getting aborted, we have a small time window where the second
transaction commit does not notice that the previous transaction aborted
and ends up committing, writing a superblock that points to btrees that
reference extent buffers (nodes and leafs) that were not persisted to disk.
The consequence is that after mounting the filesystem again, we will be
unable to load some btree nodes/leafs, either because the content on disk
is either garbage (or just zeroes) or corresponds to the old content of a
previouly COWed or deleted node/leaf, resulting in the well known error
messages "parent transid verify failed on ...".
The following sequence diagram illustrates how this can happen.

        CPU 1                                           CPU 2

 <at transaction N>

 btrfs_commit_transaction()
   (...)
   --> sets transaction state to
       TRANS_STATE_UNBLOCKED
   --> sets fs_info->running_transaction
       to NULL

                                                    (...)
                                                    btrfs_start_transaction()
                                                      start_transaction()
                                                        wait_current_trans()
                                                          --> returns immediately
                                                              because
                                                              fs_info->running_transaction
                                                              is NULL
                                                        join_transaction()
                                                          --> creates transaction N + 1
                                                          --> sets
                                                              fs_info->running_transaction
                                                              to transaction N + 1
                                                          --> adds transaction N + 1 to
                                                              the fs_info->trans_list list
                                                        --> returns transaction handle
                                                            pointing to the new
                                                            transaction N + 1
                                                    (...)

                                                    btrfs_sync_file()
                                                      btrfs_start_transaction()
                                                        --> returns handle to
                                                            transaction N + 1
                                                      (...)

   btrfs_write_and_wait_transaction()
     --> writeback of some extent
         buffer fails, returns an
	 error
   btrfs_handle_fs_error()
     --> sets BTRFS_FS_STATE_ERROR in
         fs_info->fs_state
   --> jumps to label "scrub_continue"
   cleanup_transaction()
     btrfs_abort_transaction(N)
       --> sets BTRFS_FS_STATE_TRANS_ABORTED
           flag in fs_info->fs_state
       --> sets aborted field in the
           transaction and transaction
	   handle structures, for
           transaction N only
     --> removes transaction from the
         list fs_info->trans_list
                                                      btrfs_commit_transaction(N + 1)
                                                        --> transaction N + 1 was not
							    aborted, so it proceeds
                                                        (...)
                                                        --> sets the transaction's state
                                                            to TRANS_STATE_COMMIT_START
                                                        --> does not find the previous
                                                            transaction (N) in the
                                                            fs_info->trans_list, so it
                                                            doesn't know that transaction
                                                            was aborted, and the commit
                                                            of transaction N + 1 proceeds
                                                        (...)
                                                        --> sets transaction N + 1 state
                                                            to TRANS_STATE_UNBLOCKED
                                                        btrfs_write_and_wait_transaction()
                                                          --> succeeds writing all extent
                                                              buffers created in the
                                                              transaction N + 1
                                                        write_all_supers()
                                                           --> succeeds
                                                           --> we now have a superblock on
                                                               disk that points to trees
                                                               that refer to at least one
                                                               extent buffer that was
                                                               never persisted

So fix this by updating the transaction commit path to check if the flag
BTRFS_FS_STATE_TRANS_ABORTED is set on fs_info->fs_state if after setting
the transaction to the TRANS_STATE_COMMIT_START we do not find any previous
transaction in the fs_info->trans_list. If the flag is set, just fail the
transaction commit with -EROFS, as we do in other places. The exact error
code for the previous transaction abort was already logged and reported.

Fixes: 49b25e0540 ("btrfs: enhance transaction abort infrastructure")
CC: stable@vger.kernel.org # 4.4+
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>
2019-07-30 18:25:12 +02:00
Filipe Manana
b4f9a1a87a Btrfs: fix incremental send failure after deduplication
When doing an incremental send operation we can fail if we previously did
deduplication operations against a file that exists in both snapshots. In
that case we will fail the send operation with -EIO and print a message
to dmesg/syslog like the following:

  BTRFS error (device sdc): Send: inconsistent snapshot, found updated \
  extent for inode 257 without updated inode item, send root is 258, \
  parent root is 257

This requires that we deduplicate to the same file in both snapshots for
the same amount of times on each snapshot. The issue happens because a
deduplication only updates the iversion of an inode and does not update
any other field of the inode, therefore if we deduplicate the file on
each snapshot for the same amount of time, the inode will have the same
iversion value (stored as the "sequence" field on the inode item) on both
snapshots, therefore it will be seen as unchanged between in the send
snapshot while there are new/updated/deleted extent items when comparing
to the parent snapshot. This makes the send operation return -EIO and
print an error message.

Example reproducer:

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

  # Create our first file. The first half of the file has several 64Kb
  # extents while the second half as a single 512Kb extent.
  $ xfs_io -f -s -c "pwrite -S 0xb8 -b 64K 0 512K" /mnt/foo
  $ xfs_io -c "pwrite -S 0xb8 512K 512K" /mnt/foo

  # Create the base snapshot and the parent send stream from it.
  $ btrfs subvolume snapshot -r /mnt /mnt/mysnap1
  $ btrfs send -f /tmp/1.snap /mnt/mysnap1

  # Create our second file, that has exactly the same data as the first
  # file.
  $ xfs_io -f -c "pwrite -S 0xb8 0 1M" /mnt/bar

  # Create the second snapshot, used for the incremental send, before
  # doing the file deduplication.
  $ btrfs subvolume snapshot -r /mnt /mnt/mysnap2

  # Now before creating the incremental send stream:
  #
  # 1) Deduplicate into a subrange of file foo in snapshot mysnap1. This
  #    will drop several extent items and add a new one, also updating
  #    the inode's iversion (sequence field in inode item) by 1, but not
  #    any other field of the inode;
  #
  # 2) Deduplicate into a different subrange of file foo in snapshot
  #    mysnap2. This will replace an extent item with a new one, also
  #    updating the inode's iversion by 1 but not any other field of the
  #    inode.
  #
  # After these two deduplication operations, the inode items, for file
  # foo, are identical in both snapshots, but we have different extent
  # items for this inode in both snapshots. We want to check this doesn't
  # cause send to fail with an error or produce an incorrect stream.

  $ xfs_io -r -c "dedupe /mnt/bar 0 0 512K" /mnt/mysnap1/foo
  $ xfs_io -r -c "dedupe /mnt/bar 512K 512K 512K" /mnt/mysnap2/foo

  # Create the incremental send stream.
  $ btrfs send -p /mnt/mysnap1 -f /tmp/2.snap /mnt/mysnap2
  ERROR: send ioctl failed with -5: Input/output error

This issue started happening back in 2015 when deduplication was updated
to not update the inode's ctime and mtime and update only the iversion.
Back then we would hit a BUG_ON() in send, but later in 2016 send was
updated to return -EIO and print the error message instead of doing the
BUG_ON().

A test case for fstests follows soon.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203933
Fixes: 1c919a5e13 ("btrfs: don't update mtime/ctime on deduped inodes")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-30 18:25:11 +02:00
Naohiro Aota
a3b46b86ca btrfs: fix extent_state leak in btrfs_lock_and_flush_ordered_range
btrfs_lock_and_flush_ordered_range() loads given "*cached_state" into
cachedp, which, in general, is NULL. Then, lock_extent_bits() updates
"cachedp", but it never goes backs to the caller. Thus the caller still
see its "cached_state" to be NULL and never free the state allocated
under btrfs_lock_and_flush_ordered_range(). As a result, we will
see massive state leak with e.g. fstests btrfs/005. Fix this bug by
properly handling the pointers.

Fixes: bd80d94efb ("btrfs: Always use a cached extent_state in btrfs_lock_and_flush_ordered_range")
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-26 12:21:22 +02:00
Nikolay Borisov
6e7ca09b58 btrfs: Fix deadlock caused by missing memory barrier
Commit 06297d8cef ("btrfs: switch extent_buffer blocking_writers from
atomic to int") changed the type of blocking_writers but forgot to
adjust relevant code in btrfs_tree_unlock by converting the
smp_mb__after_atomic to smp_mb.  This opened up the possibility of a
deadlock due to re-ordering of setting blocking_writers and
checking/waking up the waiter. This particular lockup is explained in a
comment above waitqueue_active() function.

Fix it by converting the memory barrier to a full smp_mb, accounting
for the fact that blocking_writers is a simple integer.

Fixes: 06297d8cef ("btrfs: switch extent_buffer blocking_writers from atomic to int")
Tested-by: Johannes Thumshirn <jthumshirn@suse.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-25 17:34:08 +02:00
Johannes Thumshirn
373c3b80e4 btrfs: don't leak extent_map in btrfs_get_io_geometry()
btrfs_get_io_geometry() calls btrfs_get_chunk_map() to acquire a reference
on a extent_map, but on normal operation it does not drop this reference
anymore.

This leads to excessive kmemleak reports.

Always call free_extent_map(), not just in the error case.

Fixes: 5f1411265e ("btrfs: Introduce btrfs_io_geometry infrastructure")
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-17 17:03:36 +02:00
Johannes Thumshirn
bfcea1c661 btrfs: free checksum hash on in close_ctree
fs_info::csum_hash gets initialized in btrfs_init_csum_hash() which is
called by open_ctree().

But it only gets freed if open_ctree() fails, not on normal operation.

This leads to a memory leak like the following found by kmemleak:
unreferenced object 0xffff888132cb8720 (size 96):

  comm "mount", pid 450, jiffies 4294912436 (age 17.584s)
  hex dump (first 32 bytes):
    04 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<000000000c9643d4>] crypto_create_tfm+0x2d/0xd0
    [<00000000ae577f68>] crypto_alloc_tfm+0x4b/0xb0
    [<000000002b5cdf30>] open_ctree+0xb84/0x2060 [btrfs]
    [<0000000043204297>] btrfs_mount_root+0x552/0x640 [btrfs]
    [<00000000c99b10ea>] legacy_get_tree+0x22/0x40
    [<0000000071a6495f>] vfs_get_tree+0x1f/0xc0
    [<00000000f180080e>] fc_mount+0x9/0x30
    [<000000009e36cebd>] vfs_kern_mount.part.11+0x6a/0x80
    [<0000000004594c05>] btrfs_mount+0x174/0x910 [btrfs]
    [<00000000c99b10ea>] legacy_get_tree+0x22/0x40
    [<0000000071a6495f>] vfs_get_tree+0x1f/0xc0
    [<00000000b86e92c5>] do_mount+0x6b0/0x940
    [<0000000097464494>] ksys_mount+0x7b/0xd0
    [<0000000057213c80>] __x64_sys_mount+0x1c/0x20
    [<00000000cb689b5e>] do_syscall_64+0x43/0x130
    [<000000002194e289>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

Free fs_info::csum_hash in close_ctree() to avoid the memory leak.

Fixes: 6d97c6e31b ("btrfs: add boilerplate code for directly including the crypto framework")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-17 17:03:33 +02:00
YueHaibing
314c4cd6d9 btrfs: Fix build error while LIBCRC32C is module
If CONFIG_BTRFS_FS is y and CONFIG_LIBCRC32C is m,
building fails:

  fs/btrfs/super.o: In function `btrfs_mount_root':
  super.c:(.text+0xb7f9): undefined reference to `crc32c_impl'
  fs/btrfs/super.o: In function `init_btrfs_fs':
  super.c:(.init.text+0x3465): undefined reference to `crc32c_impl'
  fs/btrfs/extent-tree.o: In function `hash_extent_data_ref':
  extent-tree.c:(.text+0xe60): undefined reference to `crc32c'
  extent-tree.c:(.text+0xe78): undefined reference to `crc32c'
  extent-tree.c:(.text+0xe8b): undefined reference to `crc32c'
  fs/btrfs/dir-item.o: In function `btrfs_insert_xattr_item':
  dir-item.c:(.text+0x291): undefined reference to `crc32c'
  fs/btrfs/dir-item.o: In function `btrfs_insert_dir_item':
  dir-item.c:(.text+0x429): undefined reference to `crc32c'

Select LIBCRC32C to fix it.

Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: d5178578bc ("btrfs: directly call into crypto framework for checksumming")
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-17 17:03:30 +02:00
Qu Wenruo
42c16da6d6 btrfs: inode: Don't compress if NODATASUM or NODATACOW set
As btrfs(5) specified:

	Note
	If nodatacow or nodatasum are enabled, compression is disabled.

If NODATASUM or NODATACOW set, we should not compress the extent.

Normally NODATACOW is detected properly in run_delalloc_range() so
compression won't happen for NODATACOW.

However for NODATASUM we don't have any check, and it can cause
compressed extent without csum pretty easily, just by:
  mkfs.btrfs -f $dev
  mount $dev $mnt -o nodatasum
  touch $mnt/foobar
  mount -o remount,datasum,compress $mnt
  xfs_io -f -c "pwrite 0 128K" $mnt/foobar

And in fact, we have a bug report about corrupted compressed extent
without proper data checksum so even RAID1 can't recover the corruption.
(https://bugzilla.kernel.org/show_bug.cgi?id=199707)

Running compression without proper checksum could cause more damage when
corruption happens, as compressed data could make the whole extent
unreadable, so there is no need to allow compression for
NODATACSUM.

The fix will refactor the inode compression check into two parts:

- inode_can_compress()
  As the hard requirement, checked at btrfs_run_delalloc_range(), so no
  compression will happen for NODATASUM inode at all.

- inode_need_compress()
  As the soft requirement, checked at btrfs_run_delalloc_range() and
  compress_file_range().

Reported-by: James Harvey <jamespharvey20@gmail.com>
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-17 17:03:28 +02:00
Colin Ian King
e02d48eaae btrfs: fix memory leak of path on error return path
Currently if the allocation of roots or tmp_ulist fails the error handling
does not free up the allocation of path causing a memory leak. Fix this and
other similar leaks by moving the call of btrfs_free_path from label out
to label out_free_ulist.

Kudos to David Sterba for spotting the issue in my original fix and suggesting
the correct way to fix the leak and Anand Jain for spotting a double free
issue.

Addresses-Coverity: ("Resource leak")
Fixes: 5911c8fe05 ("btrfs: fiemap: preallocate ulists for btrfs_check_shared")
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-05 18:47:57 +02:00
Josef Bacik
28a32d2b1a btrfs: move the subvolume reservation stuff out of extent-tree.c
This is just two functions, put it in root-tree.c since it involves root
items.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-04 17:26:18 +02:00
Josef Bacik
867363429d btrfs: migrate the delalloc space stuff to it's own home
We have code for data and metadata reservations for delalloc.  There's
quite a bit of code here, and it's used in a lot of places so I've
separated it out to it's own file.  inode.c and file.c are already
pretty large, and this code is complicated enough to live in its own
space.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-04 17:26:17 +02:00
Josef Bacik
fb6dea2660 btrfs: migrate btrfs_trans_release_chunk_metadata
Move this into transaction.c with the rest of the transaction related
code.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-04 17:26:17 +02:00
Josef Bacik
6ef03debdb btrfs: migrate the delayed refs rsv code
These belong with the delayed refs related code, not in extent-tree.c.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-04 17:26:17 +02:00
Goldwyn Rodrigues
9978059be8 btrfs: Evaluate io_tree in find_lock_delalloc_range()
Simplification.  No point passing the tree variable when it can be
evaluated from inode. The tests now use the io_tree from btrfs_inode as
opposed to creating one.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-04 17:26:17 +02:00
Josef Bacik
67f9c2209e btrfs: migrate the global_block_rsv helpers to block-rsv.c
These helpers belong in block-rsv.c

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:55 +02:00
Josef Bacik
550fa228ee btrfs: migrate the block-rsv code to block-rsv.c
This moves everything out of extent-tree.c to block-rsv.c.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:54 +02:00
Josef Bacik
424a47805a btrfs: stop using block_rsv_release_bytes everywhere
block_rsv_release_bytes() is the internal to the block_rsv code, and
shouldn't be called directly by anything else.  Switch all users to the
exported helpers.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:54 +02:00
Josef Bacik
fcec36224f btrfs: cleanup the target logic in __btrfs_block_rsv_release
This works for all callers already, but if we wanted to use the helper
for the global_block_rsv it would end up trying to refill itself.  Fix
the logic to be able to be used no matter which block rsv is passed in
to this helper.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:54 +02:00
Josef Bacik
fed14b323d btrfs: export __btrfs_block_rsv_release
The delalloc reserve stuff calls this directly because it cares about
the qgroup accounting stuff, so export it so we can move it around.  Fix
btrfs_block_rsv_release() to just be a static inline since it just calls
__btrfs_block_rsv_release() with NULL for the qgroup stuff.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:54 +02:00
Josef Bacik
0b50174ad5 btrfs: export btrfs_block_rsv_add_bytes
This is used in a few places, we need to make sure it's exported so we
can move it around.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:54 +02:00
Josef Bacik
d12ffdd1aa btrfs: move btrfs_block_rsv definitions into it's own header
Prep work for separating out all of the block_rsv related code into its
own file.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:53 +02:00
Goldwyn Rodrigues
9b4851bc48 btrfs: Simplify update of space_info in __reserve_metadata_bytes()
We don't need an if-else-if chain where we can use a simple OR since
both conditions are performing the same action. The short-circuit for OR
will ensure that if the first condition is true, can_overcommit() is not
called.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:53 +02:00
Josef Bacik
83d731a5b2 btrfs: unexport can_overcommit
Now that we've moved all of the users to space-info.c, unexport it and
name it back to can_overcommit.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:53 +02:00
Josef Bacik
0d9764f6d0 btrfs: move reserve_metadata_bytes and supporting code to space-info.c
This moves all of the metadata reservation code into space-info.c.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:53 +02:00
Josef Bacik
5da6afeb32 btrfs: move dump_space_info to space-info.c
We'll need this exported so we can use it in all the various was we need
to use it.  This is prep work to move reserve_metadata_bytes.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:53 +02:00
Josef Bacik
c2a67a76ec btrfs: export block_rsv_use_bytes
We are going to need this to move the metadata reservation stuff to
space_info.c.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:53 +02:00
Josef Bacik
b338b013e1 btrfs: move btrfs_space_info_add_*_bytes to space-info.c
Now that we've moved all the pre-requisite stuff, move these two
functions.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:52 +02:00
Josef Bacik
bb96c4e574 btrfs: move the space info update macro to space-info.h
Also rename it to btrfs_space_info_update_* so it's clear what we're
updating.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:52 +02:00
Josef Bacik
41783ef24d btrfs: move and export can_overcommit
This is the first piece of moving the space reservation code to
space-info.c

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:52 +02:00
Josef Bacik
280c290881 btrfs: move the space_info handling code to space-info.c
These are the basic init and lookup functions and some helper functions,
fairly straightforward before the bad stuff starts.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:52 +02:00
Josef Bacik
d44b72aa12 btrfs: export space_info_add_*_bytes
Prep work for consolidating all of the space_info code into one file.
We need to export these so multiple files can use them.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:52 +02:00
Josef Bacik
fc471cb0c8 btrfs: rename do_chunk_alloc to btrfs_chunk_alloc
Really we just need the enum, but as we break more things up it'll help
to have this external to extent-tree.c.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:51 +02:00
Josef Bacik
8719aaae8d btrfs: move space_info to space-info.h
Migrate the struct definition and the one helper that's in ctree.h into
space-info.h

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:51 +02:00
David Sterba
e749af443f btrfs: lift bio_set_dev from bio allocation helpers
The block device is passed around for the only purpose to set it in new
bios. Move the assignment one level up. This is a preparatory patch for
further bdev cleanups.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:51 +02:00
David Sterba
e1ea2beee2 btrfs: use raid_attr for minimum stripe count in btrfs_calc_avail_data_space
Minimum stripe count matches the minimum devices required for a given
profile. The open coded assignments match the raid_attr table.

What's changed here is the meaning for RAID5/6. Previously their
min_stripes would be 1, while newly it's devs_min. This however shold be
the same as before because it's not possible to create filesystem on
fewer devices than the raid_attr table allows.

There's no adjustment regarding the parity stripes (like
calc_data_stripes does), because we're interested in overall space that
would fit on the devices.

Missing devices make no difference for the whole calculation, we have
the size stored in the structures.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:51 +02:00
David Sterba
4f080f5711 btrfs: use raid_attr to adjust minimal stripe size in btrfs_calc_avail_data_space
Special case for DUP can be replaced by lookup to the attribute table,
where the dev_stripes is the right coefficient.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:51 +02:00
David Sterba
f262fa8de6 btrfs: drop default value assignments in enums
A few more instances whre we don't need to specify the values as long as
they are the same that enum assigns automatically. All of the enums are
in-memory only and nothing relies on the exact values.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:50 +02:00
David Sterba
2792237d0c btrfs: use common helpers for extent IO state insertion messages
Print the error messages using the helpers that also print the
filesystem identification.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:50 +02:00
Josef Bacik
63611e738a btrfs: run delayed iput at unlink time
We have been seeing issues in production where a cleaner script will end
up unlinking a bunch of files that have pending iputs.  This means they
will get their final iput's run at btrfs-cleaner time and thus are not
throttled, which impacts the workload.

Since we are unlinking these files we can just drop the delayed iput at
unlink time.  We are already holding a reference to the inode so this
will not be the final iput and thus is completely safe to do at this
point.  Doing this means we are more likely to be doing the final iput
at unlink time, and thus will get the IO charged to the caller and get
throttled appropriately without affecting the main workload.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:50 +02:00
Filipe Manana
179006688a Btrfs: add missing inode version, ctime and mtime updates when punching hole
If the range for which we are punching a hole covers only part of a page,
we end up updating the inode item but we skip the update of the inode's
iversion, mtime and ctime. Fix that by ensuring we update those properties
of the inode.

A patch for fstests test case generic/059 that tests this as been sent
along with this fix.

Fixes: 2aaa665581 ("Btrfs: add hole punching")
Fixes: e8c1c76e80 ("Btrfs: add missing inode update when punching hole")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:50 +02:00
Filipe Manana
803f0f64d1 Btrfs: fix fsync not persisting dentry deletions due to inode evictions
In order to avoid searches on a log tree when unlinking an inode, we check
if the inode being unlinked was logged in the current transaction, as well
as the inode of its parent directory. When any of the inodes are logged,
we proceed to delete directory items and inode reference items from the
log, to ensure that if a subsequent fsync of only the inode being unlinked
or only of the parent directory when the other is not fsync'ed as well,
does not result in the entry still existing after a power failure.

That check however is not reliable when one of the inodes involved (the
one being unlinked or its parent directory's inode) is evicted, since the
logged_trans field is transient, that is, it is not stored on disk, so it
is lost when the inode is evicted and loaded into memory again (which is
set to zero on load). As a consequence the checks currently being done by
btrfs_del_dir_entries_in_log() and btrfs_del_inode_ref_in_log() always
return true if the inode was evicted before, regardless of the inode
having been logged or not before (and in the current transaction), this
results in the dentry being unlinked still existing after a log replay
if after the unlink operation only one of the inodes involved is fsync'ed.

Example:

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

  $ mkdir /mnt/dir
  $ touch /mnt/dir/foo
  $ xfs_io -c fsync /mnt/dir/foo

  # Keep an open file descriptor on our directory while we evict inodes.
  # We just want to evict the file's inode, the directory's inode must not
  # be evicted.
  $ ( cd /mnt/dir; while true; do :; done ) &
  $ pid=$!

  # Wait a bit to give time to background process to chdir to our test
  # directory.
  $ sleep 0.5

  # Trigger eviction of the file's inode.
  $ echo 2 > /proc/sys/vm/drop_caches

  # Unlink our file and fsync the parent directory. After a power failure
  # we don't expect to see the file anymore, since we fsync'ed the parent
  # directory.
  $ rm -f $SCRATCH_MNT/dir/foo
  $ xfs_io -c fsync /mnt/dir

  <power failure>

  $ mount /dev/sdb /mnt
  $ ls /mnt/dir
  foo
  $
   --> file still there, unlink not persisted despite explicit fsync on dir

Fix this by checking if the inode has the full_sync bit set in its runtime
flags as well, since that bit is set everytime an inode is loaded from
disk, or for other less common cases such as after a shrinking truncate
or failure to allocate extent maps for holes, and gets cleared after the
first fsync. Also consider the inode as possibly logged only if it was
last modified in the current transaction (besides having the full_fsync
flag set).

Fixes: 3a5f1d458a ("Btrfs: Optimize btree walking while logging inodes")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:50 +02:00
Nikolay Borisov
89b798ad1b btrfs: Use btrfs_get_io_geometry appropriately
Presently btrfs_map_block is used not only to do everything necessary to
map a bio to the underlying allocation profile but it's also used to
identify how much data could be written based on btrfs' stripe logic
without actually submitting anything. This is achieved by passing NULL
for 'bbio_ret' parameter.

This patch refactors all callers that require just the mapping length
by switching them to using btrfs_io_geometry instead of calling
btrfs_map_block with a special NULL value for 'bbio_ret'. No functional
change.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:50 +02:00
Nikolay Borisov
5f1411265e btrfs: Introduce btrfs_io_geometry infrastructure
Add a structure that holds various parameters for IO calculations and a
helper that fills the values. This will help further refactoring and
reduction of functions that in some way open-coded the calculations.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:49 +02:00
David Sterba
c9d713d5b5 btrfs: improve messages when updating feature flags
Currently the messages printed after setting an incompat feature are
cryptis, we can easily make it better as the textual description is
passed to the helpers. Old:

  setting 128 feature flag

updated:

  setting incompat feature flag for RAID56 (0x80)

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:49 +02:00
Arnd Bergmann
6c64460cdc btrfs: shut up bogus -Wmaybe-uninitialized warning
gcc sometimes can't determine whether a variable has been initialized
when both the initialization and the use are conditional:

fs/btrfs/props.c: In function 'inherit_props':
fs/btrfs/props.c:389:4: error: 'num_bytes' may be used uninitialized in this function [-Werror=maybe-uninitialized]
    btrfs_block_rsv_release(fs_info, trans->block_rsv,

This code is fine. Unfortunately, I cannot think of a good way to
rephrase it in a way that makes gcc understand this, so I add a bogus
initialization the way one should not.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: David Sterba <dsterba@suse.com>
[ gcc 8 and 9 don't emit the warning ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:49 +02:00
Filipe Manana
9e967495e0 Btrfs: prevent send failures and crashes due to concurrent relocation
Send always operates on read-only trees and always expected that while it
is in progress, nothing changes in those trees. Due to that expectation
and the fact that send is a read-only operation, it operates on commit
roots and does not hold transaction handles. However relocation can COW
nodes and leafs from read-only trees, which can cause unexpected failures
and crashes (hitting BUG_ONs). while send using a node/leaf, it gets
COWed, the transaction used to COW it is committed, a new transaction
starts, the extent previously used for that node/leaf gets allocated,
possibly for another tree, and the respective extent buffer' content
changes while send is still using it. When this happens send normally
fails with EIO being returned to user space and messages like the
following are found in dmesg/syslog:

  [ 3408.699121] BTRFS error (device sdc): parent transid verify failed on 58703872 wanted 250 found 253
  [ 3441.523123] BTRFS error (device sdc): did not find backref in send_root. inode=63211, offset=0, disk_byte=5222825984 found extent=5222825984

Other times, less often, we hit a BUG_ON() because an extent buffer that
send is using used to be a node, and while send is still using it, it
got COWed and got reused as a leaf while send is still using, producing
the following trace:

 [ 3478.466280] ------------[ cut here ]------------
 [ 3478.466282] kernel BUG at fs/btrfs/ctree.c:1806!
 [ 3478.466965] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC PTI
 [ 3478.467635] CPU: 0 PID: 2165 Comm: btrfs Not tainted 5.0.0-btrfs-next-46 #1
 [ 3478.468311] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014
 [ 3478.469681] RIP: 0010:read_node_slot+0x122/0x130 [btrfs]
 (...)
 [ 3478.471758] RSP: 0018:ffffa437826bfaa0 EFLAGS: 00010246
 [ 3478.472457] RAX: ffff961416ed7000 RBX: 000000000000003d RCX: 0000000000000002
 [ 3478.473151] RDX: 000000000000003d RSI: ffff96141e387408 RDI: ffff961599b30000
 [ 3478.473837] RBP: ffffa437826bfb8e R08: 0000000000000001 R09: ffffa437826bfb8e
 [ 3478.474515] R10: ffffa437826bfa70 R11: 0000000000000000 R12: ffff9614385c8708
 [ 3478.475186] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 [ 3478.475840] FS:  00007f8e0e9cc8c0(0000) GS:ffff9615b6a00000(0000) knlGS:0000000000000000
 [ 3478.476489] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [ 3478.477127] CR2: 00007f98b67a056e CR3: 0000000005df6005 CR4: 00000000003606f0
 [ 3478.477762] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 [ 3478.478385] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 [ 3478.479003] Call Trace:
 [ 3478.479600]  ? do_raw_spin_unlock+0x49/0xc0
 [ 3478.480202]  tree_advance+0x173/0x1d0 [btrfs]
 [ 3478.480810]  btrfs_compare_trees+0x30c/0x690 [btrfs]
 [ 3478.481388]  ? process_extent+0x1280/0x1280 [btrfs]
 [ 3478.481954]  btrfs_ioctl_send+0x1037/0x1270 [btrfs]
 [ 3478.482510]  _btrfs_ioctl_send+0x80/0x110 [btrfs]
 [ 3478.483062]  btrfs_ioctl+0x13fe/0x3120 [btrfs]
 [ 3478.483581]  ? rq_clock_task+0x2e/0x60
 [ 3478.484086]  ? wake_up_new_task+0x1f3/0x370
 [ 3478.484582]  ? do_vfs_ioctl+0xa2/0x6f0
 [ 3478.485075]  ? btrfs_ioctl_get_supported_features+0x30/0x30 [btrfs]
 [ 3478.485552]  do_vfs_ioctl+0xa2/0x6f0
 [ 3478.486016]  ? __fget+0x113/0x200
 [ 3478.486467]  ksys_ioctl+0x70/0x80
 [ 3478.486911]  __x64_sys_ioctl+0x16/0x20
 [ 3478.487337]  do_syscall_64+0x60/0x1b0
 [ 3478.487751]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
 [ 3478.488159] RIP: 0033:0x7f8e0d7d4dd7
 (...)
 [ 3478.489349] RSP: 002b:00007ffcf6fb4908 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
 [ 3478.489742] RAX: ffffffffffffffda RBX: 0000000000000105 RCX: 00007f8e0d7d4dd7
 [ 3478.490142] RDX: 00007ffcf6fb4990 RSI: 0000000040489426 RDI: 0000000000000005
 [ 3478.490548] RBP: 0000000000000005 R08: 00007f8e0d6f3700 R09: 00007f8e0d6f3700
 [ 3478.490953] R10: 00007f8e0d6f39d0 R11: 0000000000000202 R12: 0000000000000005
 [ 3478.491343] R13: 00005624e0780020 R14: 0000000000000000 R15: 0000000000000001
 (...)
 [ 3478.493352] ---[ end trace d5f537302be4f8c8 ]---

Another possibility, much less likely to happen, is that send will not
fail but the contents of the stream it produces may not be correct.

To avoid this, do not allow send and relocation (balance) to run in
parallel. In the long term the goal is to allow for both to be able to
run concurrently without any problems, but that will take a significant
effort in development and testing.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:49 +02:00
David Sterba
71a9c4885e btrfs: document BTRFS_MAX_MIRRORS
The real meaning of that constant is not clear from the context due to
the target device inclusion.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:49 +02:00