Commit Graph

7495 Commits

Author SHA1 Message Date
Josef Bacik
51f39f27a1 btrfs: wait on ordered extents on abort cleanup
commit 74d5d229b1 upstream.

If we flip read-only before we initiate writeback on all dirty pages for
ordered extents we've created then we'll have ordered extents left over
on umount, which results in all sorts of bad things happening.  Fix this
by making sure we wait on ordered extents if we have to do the aborted
transaction cleanup stuff.

generic/475 can produce this warning:

 [ 8531.177332] WARNING: CPU: 2 PID: 11997 at fs/btrfs/disk-io.c:3856 btrfs_free_fs_root+0x95/0xa0 [btrfs]
 [ 8531.183282] CPU: 2 PID: 11997 Comm: umount Tainted: G        W 5.0.0-rc1-default+ #394
 [ 8531.185164] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),BIOS rel-1.11.2-0-gf9626cc-prebuilt.qemu-project.org 04/01/2014
 [ 8531.187851] RIP: 0010:btrfs_free_fs_root+0x95/0xa0 [btrfs]
 [ 8531.193082] RSP: 0018:ffffb1ab86163d98 EFLAGS: 00010286
 [ 8531.194198] RAX: ffff9f3449494d18 RBX: ffff9f34a2695000 RCX:0000000000000000
 [ 8531.195629] RDX: 0000000000000002 RSI: 0000000000000001 RDI:0000000000000000
 [ 8531.197315] RBP: ffff9f344e930000 R08: 0000000000000001 R09:0000000000000000
 [ 8531.199095] R10: 0000000000000000 R11: ffff9f34494d4ff8 R12:ffffb1ab86163dc0
 [ 8531.200870] R13: ffff9f344e9300b0 R14: ffffb1ab86163db8 R15:0000000000000000
 [ 8531.202707] FS:  00007fc68e949fc0(0000) GS:ffff9f34bd800000(0000)knlGS:0000000000000000
 [ 8531.204851] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [ 8531.205942] CR2: 00007ffde8114dd8 CR3: 000000002dfbd000 CR4:00000000000006e0
 [ 8531.207516] Call Trace:
 [ 8531.208175]  btrfs_free_fs_roots+0xdb/0x170 [btrfs]
 [ 8531.210209]  ? wait_for_completion+0x5b/0x190
 [ 8531.211303]  close_ctree+0x157/0x350 [btrfs]
 [ 8531.212412]  generic_shutdown_super+0x64/0x100
 [ 8531.213485]  kill_anon_super+0x14/0x30
 [ 8531.214430]  btrfs_kill_super+0x12/0xa0 [btrfs]
 [ 8531.215539]  deactivate_locked_super+0x29/0x60
 [ 8531.216633]  cleanup_mnt+0x3b/0x70
 [ 8531.217497]  task_work_run+0x98/0xc0
 [ 8531.218397]  exit_to_usermode_loop+0x83/0x90
 [ 8531.219324]  do_syscall_64+0x15b/0x180
 [ 8531.220192]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
 [ 8531.221286] RIP: 0033:0x7fc68e5e4d07
 [ 8531.225621] RSP: 002b:00007ffde8116608 EFLAGS: 00000246 ORIG_RAX:00000000000000a6
 [ 8531.227512] RAX: 0000000000000000 RBX: 00005580c2175970 RCX:00007fc68e5e4d07
 [ 8531.229098] RDX: 0000000000000001 RSI: 0000000000000000 RDI:00005580c2175b80
 [ 8531.230730] RBP: 0000000000000000 R08: 00005580c2175ba0 R09:00007ffde8114e80
 [ 8531.232269] R10: 0000000000000000 R11: 0000000000000246 R12:00005580c2175b80
 [ 8531.233839] R13: 00007fc68eac61c4 R14: 00005580c2175a68 R15:0000000000000000

Leaving a tree in the rb-tree:

3853 void btrfs_free_fs_root(struct btrfs_root *root)
3854 {
3855         iput(root->ino_cache_inode);
3856         WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));

CC: stable@vger.kernel.org
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
[ add stacktrace ]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-22 21:09:51 +01:00
David Sterba
480c6fb23e Revert "btrfs: balance dirty metadata pages in btrfs_finish_ordered_io"
commit 77b7aad195 upstream.

This reverts commit e73e81b6d0.

This patch causes a few problems:

- adds latency to btrfs_finish_ordered_io
- as btrfs_finish_ordered_io is used for free space cache, generating
  more work from btrfs_btree_balance_dirty_nodelay could end up in the
  same workque, effectively deadlocking

12260 kworker/u96:16+btrfs-freespace-write D
[<0>] balance_dirty_pages+0x6e6/0x7ad
[<0>] balance_dirty_pages_ratelimited+0x6bb/0xa90
[<0>] btrfs_finish_ordered_io+0x3da/0x770
[<0>] normal_work_helper+0x1c5/0x5a0
[<0>] process_one_work+0x1ee/0x5a0
[<0>] worker_thread+0x46/0x3d0
[<0>] kthread+0xf5/0x130
[<0>] ret_from_fork+0x24/0x30
[<0>] 0xffffffffffffffff

Transaction commit will wait on the freespace cache:

838 btrfs-transacti D
[<0>] btrfs_start_ordered_extent+0x154/0x1e0
[<0>] btrfs_wait_ordered_range+0xbd/0x110
[<0>] __btrfs_wait_cache_io+0x49/0x1a0
[<0>] btrfs_write_dirty_block_groups+0x10b/0x3b0
[<0>] commit_cowonly_roots+0x215/0x2b0
[<0>] btrfs_commit_transaction+0x37e/0x910
[<0>] transaction_kthread+0x14d/0x180
[<0>] kthread+0xf5/0x130
[<0>] ret_from_fork+0x24/0x30
[<0>] 0xffffffffffffffff

And then writepages ends up waiting on transaction commit:

9520 kworker/u96:13+flush-btrfs-1 D
[<0>] wait_current_trans+0xac/0xe0
[<0>] start_transaction+0x21b/0x4b0
[<0>] cow_file_range_inline+0x10b/0x6b0
[<0>] cow_file_range.isra.69+0x329/0x4a0
[<0>] run_delalloc_range+0x105/0x3c0
[<0>] writepage_delalloc+0x119/0x180
[<0>] __extent_writepage+0x10c/0x390
[<0>] extent_write_cache_pages+0x26f/0x3d0
[<0>] extent_writepages+0x4f/0x80
[<0>] do_writepages+0x17/0x60
[<0>] __writeback_single_inode+0x59/0x690
[<0>] writeback_sb_inodes+0x291/0x4e0
[<0>] __writeback_inodes_wb+0x87/0xb0
[<0>] wb_writeback+0x3bb/0x500
[<0>] wb_workfn+0x40d/0x610
[<0>] process_one_work+0x1ee/0x5a0
[<0>] worker_thread+0x1e0/0x3d0
[<0>] kthread+0xf5/0x130
[<0>] ret_from_fork+0x24/0x30
[<0>] 0xffffffffffffffff

Eventually, we have every process in the system waiting on
balance_dirty_pages(), and nobody is able to make progress on page
writeback.

The original patch tried to fix an OOM condition, that happened on 4.4 but no
success reproducing that on later kernels (4.19 and 4.20). This is more likely
a problem in OOM itself.

Link: https://lore.kernel.org/linux-btrfs/20180528054821.9092-1-ethanlien@synology.com/
Reported-by: Chris Mason <clm@fb.com>
CC: stable@vger.kernel.org # 4.18+
CC: ethanlien <ethanlien@synology.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-22 21:09:51 +01:00
Filipe Manana
90caba63c2 Btrfs: use nofs context when initializing security xattrs to avoid deadlock
commit 827aa18e7b upstream.

When initializing the security xattrs, we are holding a transaction handle
therefore we need to use a GFP_NOFS context in order to avoid a deadlock
with reclaim in case it's triggered.

Fixes: 39a27ec100 ("btrfs: use GFP_KERNEL for xattr and acl allocations")
Reviewed-by: Nikolay Borisov <nborisov@suse.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>
2019-01-16 22:03:27 +01:00
Filipe Manana
d27994b2b2 Btrfs: fix deadlock when enabling quotas due to concurrent snapshot creation
commit 9a6f209e36 upstream.

If the quota enable and snapshot creation ioctls are called concurrently
we can get into a deadlock where the task enabling quotas will deadlock
on the fs_info->qgroup_ioctl_lock mutex because it attempts to lock it
twice, or the task creating a snapshot tries to commit the transaction
while the task enabling quota waits for the former task to commit the
transaction while holding the mutex. The following time diagrams show how
both cases happen.

First scenario:

           CPU 0                                    CPU 1

 btrfs_ioctl()
  btrfs_ioctl_quota_ctl()
   btrfs_quota_enable()
    mutex_lock(fs_info->qgroup_ioctl_lock)
    btrfs_start_transaction()

                                             btrfs_ioctl()
                                              btrfs_ioctl_snap_create_v2
                                               create_snapshot()
                                                --> adds snapshot to the
                                                    list pending_snapshots
                                                    of the current
                                                    transaction

    btrfs_commit_transaction()
     create_pending_snapshots()
       create_pending_snapshot()
        qgroup_account_snapshot()
         btrfs_qgroup_inherit()
	   mutex_lock(fs_info->qgroup_ioctl_lock)
	    --> deadlock, mutex already locked
	        by this task at
		btrfs_quota_enable()

Second scenario:

           CPU 0                                    CPU 1

 btrfs_ioctl()
  btrfs_ioctl_quota_ctl()
   btrfs_quota_enable()
    mutex_lock(fs_info->qgroup_ioctl_lock)
    btrfs_start_transaction()

                                             btrfs_ioctl()
                                              btrfs_ioctl_snap_create_v2
                                               create_snapshot()
                                                --> adds snapshot to the
                                                    list pending_snapshots
                                                    of the current
                                                    transaction

                                                btrfs_commit_transaction()
                                                 --> waits for task at
                                                     CPU 0 to release
                                                     its transaction
                                                     handle

    btrfs_commit_transaction()
     --> sees another task started
         the transaction commit first
     --> releases its transaction
         handle
     --> waits for the transaction
         commit to be completed by
         the task at CPU 1

                                                 create_pending_snapshot()
                                                  qgroup_account_snapshot()
                                                   btrfs_qgroup_inherit()
                                                    mutex_lock(fs_info->qgroup_ioctl_lock)
                                                     --> deadlock, task at CPU 0
                                                         has the mutex locked but
                                                         it is waiting for us to
                                                         finish the transaction
                                                         commit

So fix this by setting the quota enabled flag in fs_info after committing
the transaction at btrfs_quota_enable(). This ends up serializing quota
enable and snapshot creation as if the snapshot creation happened just
before the quota enable request. The quota rescan task, scheduled after
committing the transaction in btrfs_quote_enable(), will do the accounting.

Fixes: 6426c7ad69 ("btrfs: qgroup: Fix qgroup accounting when creating snapshot")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:03:27 +01:00
Filipe Manana
50ab57b23d Btrfs: fix access to available allocation bits when starting balance
commit 5a8067c0d1 upstream.

The available allocation bits members from struct btrfs_fs_info are
protected by a sequence lock, and when starting balance we access them
incorrectly in two different ways:

1) In the read sequence lock loop at btrfs_balance() we use the values we
   read from fs_info->avail_*_alloc_bits and we can immediately do actions
   that have side effects and can not be undone (printing a message and
   jumping to a label). This is wrong because a retry might be needed, so
   our actions must not have side effects and must be repeatable as long
   as read_seqretry() returns a non-zero value. In other words, we were
   essentially ignoring the sequence lock;

2) Right below the read sequence lock loop, we were reading the values
   from avail_metadata_alloc_bits and avail_data_alloc_bits without any
   protection from concurrent writers, that is, reading them outside of
   the read sequence lock critical section.

So fix this by making sure we only read the available allocation bits
while in a read sequence lock critical section and that what we do in the
critical section is repeatable (has nothing that can not be undone) so
that any eventual retry that is needed is handled properly.

Fixes: de98ced9e7 ("Btrfs: use seqlock to protect fs_info->avail_{data, metadata, system}_alloc_bits")
Fixes: 1450612797 ("btrfs: fix a bogus warning when converting only data or metadata")
Reviewed-by: Nikolay Borisov <nborisov@suse.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>
2019-01-16 22:03:27 +01:00
Filipe Manana
99f2b1929b Btrfs: fix deadlock when using free space tree due to block group creation
commit a6d8654d88 upstream.

When modifying the free space tree we can end up COWing one of its extent
buffers which in turn might result in allocating a new chunk, which in
turn can result in flushing (finish creation) of pending block groups. If
that happens we can deadlock because creating a pending block group needs
to update the free space tree, and if any of the updates tries to modify
the same extent buffer that we are COWing, we end up in a deadlock since
we try to write lock twice the same extent buffer.

So fix this by skipping pending block group creation if we are COWing an
extent buffer from the free space tree. This is a case missed by commit
5ce555578e ("Btrfs: fix deadlock when writing out free space caches").

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202173
Fixes: 5ce555578e ("Btrfs: fix deadlock when writing out free space caches")
CC: stable@vger.kernel.org # 4.18+
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>
2019-01-16 22:03:20 +01:00
Filipe Manana
aa63f2854f Btrfs: send, fix race with transaction commits that create snapshots
commit be6821f82c upstream.

If we create a snapshot of a snapshot currently being used by a send
operation, we can end up with send failing unexpectedly (returning
-ENOENT error to user space for example). The following diagram shows
how this happens.

            CPU 1                                   CPU2                                CPU3

 btrfs_ioctl_send()
  (...)
                                     create_snapshot()
                                      -> creates snapshot of a
                                         root used by the send
                                         task
                                      btrfs_commit_transaction()
                                       create_pending_snapshot()
  __get_inode_info()
   btrfs_search_slot()
    btrfs_search_slot_get_root()
     down_read commit_root_sem

     get reference on eb of the
     commit root
      -> eb with bytenr == X

     up_read commit_root_sem

                                        btrfs_cow_block(root node)
                                         btrfs_free_tree_block()
                                          -> creates delayed ref to
                                             free the extent

                                       btrfs_run_delayed_refs()
                                        -> runs the delayed ref,
                                           adds extent to
                                           fs_info->pinned_extents

                                       btrfs_finish_extent_commit()
                                        unpin_extent_range()
                                         -> marks extent as free
                                            in the free space cache

                                      transaction commit finishes

                                                                       btrfs_start_transaction()
                                                                        (...)
                                                                        btrfs_cow_block()
                                                                         btrfs_alloc_tree_block()
                                                                          btrfs_reserve_extent()
                                                                           -> allocates extent at
                                                                              bytenr == X
                                                                          btrfs_init_new_buffer(bytenr X)
                                                                           btrfs_find_create_tree_block()
                                                                            alloc_extent_buffer(bytenr X)
                                                                             find_extent_buffer(bytenr X)
                                                                              -> returns existing eb,
                                                                                 which the send task got

                                                                        (...)
                                                                         -> modifies content of the
                                                                            eb with bytenr == X

    -> uses an eb that now
       belongs to some other
       tree and no more matches
       the commit root of the
       snapshot, resuts will be
       unpredictable

The consequences of this race can be various, and can lead to searches in
the commit root performed by the send task failing unexpectedly (unable to
find inode items, returning -ENOENT to user space, for example) or not
failing because an inode item with the same number was added to the tree
that reused the metadata extent, in which case send can behave incorrectly
in the worst case or just fail later for some reason.

Fix this by performing a copy of the commit root's extent buffer when doing
a search in the context of a send operation.

CC: stable@vger.kernel.org # 4.4.x: 1fc28d8e2e: Btrfs: move get root out of btrfs_search_slot to a helper
CC: stable@vger.kernel.org # 4.4.x: f9ddfd0592: Btrfs: remove unused check of skip_locking
CC: stable@vger.kernel.org # 4.4.x
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-09 17:46:00 +01:00
Josef Bacik
4f68016148 btrfs: run delayed items before dropping the snapshot
commit 0568e82dbe upstream.

With my delayed refs patches in place we started seeing a large amount
of aborts in __btrfs_free_extent:

 BTRFS error (device sdb1): unable to find ref byte nr 91947008 parent 0 root 35964  owner 1 offset 0
 Call Trace:
  ? btrfs_merge_delayed_refs+0xaf/0x340
  __btrfs_run_delayed_refs+0x6ea/0xfc0
  ? btrfs_set_path_blocking+0x31/0x60
  btrfs_run_delayed_refs+0xeb/0x180
  btrfs_commit_transaction+0x179/0x7f0
  ? btrfs_check_space_for_delayed_refs+0x30/0x50
  ? should_end_transaction.isra.19+0xe/0x40
  btrfs_drop_snapshot+0x41c/0x7c0
  btrfs_clean_one_deleted_snapshot+0xb5/0xd0
  cleaner_kthread+0xf6/0x120
  kthread+0xf8/0x130
  ? btree_invalidatepage+0x90/0x90
  ? kthread_bind+0x10/0x10
  ret_from_fork+0x35/0x40

This was because btrfs_drop_snapshot depends on the root not being
modified while it's dropping the snapshot.  It will unlock the root node
(and really every node) as it walks down the tree, only to re-lock it
when it needs to do something.  This is a problem because if we modify
the tree we could cow a block in our path, which frees our reference to
that block.  Then once we get back to that shared block we'll free our
reference to it again, and get ENOENT when trying to lookup our extent
reference to that block in __btrfs_free_extent.

This is ultimately happening because we have delayed items left to be
processed for our deleted snapshot _after_ all of the inodes are closed
for the snapshot.  We only run the delayed inode item if we're deleting
the inode, and even then we do not run the delayed insertions or delayed
removals.  These can be run at any point after our final inode does its
last iput, which is what triggers the snapshot deletion.  We can end up
with the snapshot deletion happening and then have the delayed items run
on that file system, resulting in the above problem.

This problem has existed forever, however my patches made it much easier
to hit as I wake up the cleaner much more often to deal with delayed
iputs, which made us more likely to start the snapshot dropping work
before the transaction commits, which is when the delayed items would
generally be run.  Before, generally speaking, we would run the delayed
items, commit the transaction, and wakeup the cleaner thread to start
deleting snapshots, which means we were less likely to hit this problem.
You could still hit it if you had multiple snapshots to be deleted and
ended up with lots of delayed items, but it was definitely harder.

Fix for now by simply running all the delayed items before starting to
drop the snapshot.  We could make this smarter in the future by making
the delayed items per-root, and then simply drop any delayed items for
roots that we are going to delete.  But for now just a quick and easy
solution is the safest.

CC: stable@vger.kernel.org # 4.4+
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-09 17:46:00 +01:00
Filipe Manana
7f6d0d312e Btrfs: fix fsync of files with multiple hard links in new directories
commit 41bd606769 upstream.

The log tree has a long standing problem that when a file is fsync'ed we
only check for new ancestors, created in the current transaction, by
following only the hard link for which the fsync was issued. We follow the
ancestors using the VFS' dget_parent() API. This means that if we create a
new link for a file in a directory that is new (or in an any other new
ancestor directory) and then fsync the file using an old hard link, we end
up not logging the new ancestor, and on log replay that new hard link and
ancestor do not exist. In some cases, involving renames, the file will not
exist at all.

Example:

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

  mkdir /mnt/A
  touch /mnt/foo
  ln /mnt/foo /mnt/A/bar
  xfs_io -c fsync /mnt/foo

  <power failure>

In this example after log replay only the hard link named 'foo' exists
and directory A does not exist, which is unexpected. In other major linux
filesystems, such as ext4, xfs and f2fs for example, both hard links exist
and so does directory A after mounting again the filesystem.

Checking if any new ancestors are new and need to be logged was added in
2009 by commit 12fcfd22fe ("Btrfs: tree logging unlink/rename fixes"),
however only for the ancestors of the hard link (dentry) for which the
fsync was issued, instead of checking for all ancestors for all of the
inode's hard links.

So fix this by tracking the id of the last transaction where a hard link
was created for an inode and then on fsync fallback to a full transaction
commit when an inode has more than one hard link and at least one new hard
link was created in the current transaction. This is the simplest solution
since this is not a common use case (adding frequently hard links for
which there's an ancestor created in the current transaction and then
fsync the file). In case it ever becomes a common use case, a solution
that consists of iterating the fs/subvol btree for each hard link and
check if any ancestor is new, could be implemented.

This solves many unexpected scenarios reported by Jayashree Mohan and
Vijay Chidambaram, and for which there is a new test case for fstests
under review.

Fixes: 12fcfd22fe ("Btrfs: tree logging unlink/rename fixes")
CC: stable@vger.kernel.org # 4.4+
Reported-by: Vijay Chidambaram <vvijay03@gmail.com>
Reported-by: Jayashree Mohan <jayashree2912@gmail.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-09 17:46:00 +01:00
Lu Fengqi
878b83a007 btrfs: skip file_extent generation check for free_space_inode in run_delalloc_nocow
commit 27a7ff554e upstream.

The test case btrfs/001 with inode_cache mount option will encounter the
following warning:

  WARNING: CPU: 1 PID: 23700 at fs/btrfs/inode.c:956 cow_file_range.isra.19+0x32b/0x430 [btrfs]
  CPU: 1 PID: 23700 Comm: btrfs Kdump: loaded Tainted: G        W  O      4.20.0-rc4-custom+ #30
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
  RIP: 0010:cow_file_range.isra.19+0x32b/0x430 [btrfs]
  Call Trace:
   ? free_extent_buffer+0x46/0x90 [btrfs]
   run_delalloc_nocow+0x455/0x900 [btrfs]
   btrfs_run_delalloc_range+0x1a7/0x360 [btrfs]
   writepage_delalloc+0xf9/0x150 [btrfs]
   __extent_writepage+0x125/0x3e0 [btrfs]
   extent_write_cache_pages+0x1b6/0x3e0 [btrfs]
   ? __wake_up_common_lock+0x63/0xc0
   extent_writepages+0x50/0x80 [btrfs]
   do_writepages+0x41/0xd0
   ? __filemap_fdatawrite_range+0x9e/0xf0
   __filemap_fdatawrite_range+0xbe/0xf0
   btrfs_fdatawrite_range+0x1b/0x50 [btrfs]
   __btrfs_write_out_cache+0x42c/0x480 [btrfs]
   btrfs_write_out_ino_cache+0x84/0xd0 [btrfs]
   btrfs_save_ino_cache+0x551/0x660 [btrfs]
   commit_fs_roots+0xc5/0x190 [btrfs]
   btrfs_commit_transaction+0x2bf/0x8d0 [btrfs]
   btrfs_mksubvol+0x48d/0x4d0 [btrfs]
   btrfs_ioctl_snap_create_transid+0x170/0x180 [btrfs]
   btrfs_ioctl_snap_create_v2+0x124/0x180 [btrfs]
   btrfs_ioctl+0x123f/0x3030 [btrfs]

The file extent generation of the free space inode is equal to the last
snapshot of the file root, so the inode will be passed to cow_file_rage.
But the inode was created and its extents were preallocated in
btrfs_save_ino_cache, there are no cow copies on disk.

The preallocated extent is not yet in the extent tree, and
btrfs_cross_ref_exist will ignore the -ENOENT returned by
check_committed_ref, so we can directly write the inode to the disk.

Fixes: 78d4295b1e ("btrfs: lift some btrfs_cross_ref_exist checks in nocow path")
CC: stable@vger.kernel.org # 4.18+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-09 17:46:00 +01:00
Filipe Manana
78dcdf6632 Btrfs: fix deadlock with memory reclaim during scrub
commit a5fb114291 upstream.

When a transaction commit starts, it attempts to pause scrub and it blocks
until the scrub is paused. So while the transaction is blocked waiting for
scrub to pause, we can not do memory allocation with GFP_KERNEL from scrub,
otherwise we risk getting into a deadlock with reclaim.

Checking for scrub pause requests is done early at the beginning of the
while loop of scrub_stripe() and later in the loop, scrub_extent() and
scrub_raid56_parity() are called, which in turn call scrub_pages() and
scrub_pages_for_parity() respectively. These last two functions do memory
allocations using GFP_KERNEL. Same problem could happen while scrubbing
the super blocks, since it calls scrub_pages().

We also can not have any of the worker tasks, created by the scrub task,
doing GFP_KERNEL allocations, because before pausing, the scrub task waits
for all the worker tasks to complete (also done at scrub_stripe()).

So make sure GFP_NOFS is used for the memory allocations because at any
time a scrub pause request can happen from another task that started to
commit a transaction.

Fixes: 58c4e17384 ("btrfs: scrub: use GFP_KERNEL on the submission path")
CC: stable@vger.kernel.org # 4.6+
Reviewed-by: Nikolay Borisov <nborisov@suse.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>
2019-01-09 17:45:59 +01:00
Anand Jain
63ac0af609 btrfs: dev-replace: go back to suspend state if another EXCL_OP is running
commit 05c49e6bc1 upstream.

In a secnario where balance and replace co-exists as below,

  - start balance
  - pause balance
  - start replace
  - reboot

and when system restarts, balance resumes first. Then the replace is
attempted to restart but will fail as the EXCL_OP lock is already held
by the balance. If so place the replace state back to
BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED state.

Fixes: 010a47bde9 ("btrfs: add proper safety check before resuming dev-replace")
CC: stable@vger.kernel.org # 4.18+
Signed-off-by: Anand Jain <anand.jain@oracle.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>
2019-01-09 17:45:59 +01:00
Anand Jain
658e75a7f0 btrfs: dev-replace: go back to suspended state if target device is missing
commit 0d228ece59 upstream.

At the time of forced unmount we place the running replace to
BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED state, so when the system comes
back and expect the target device is missing.

Then let the replace state continue to be in
BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED state instead of
BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED as there isn't any matching scrub
running as part of replace.

Fixes: e93c89c1aa ("Btrfs: add new sources for device replace code")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Anand Jain <anand.jain@oracle.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>
2019-01-09 17:45:59 +01:00
Linus Torvalds
d089709045 Merge tag 'for-4.20-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fix from David Sterba:
 "A patch in 4.19 introduced a sanity check that was too strict and a
  filesystem cannot be mounted.

  This happens for filesystems with more than 10 devices and has been
  reported by a few users so we need the fix to propagate to stable"

* tag 'for-4.20-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: tree-checker: Don't check max block group size as current max chunk size limit is unreliable
2018-12-05 09:58:17 -08:00
Qu Wenruo
10950929e9 btrfs: tree-checker: Don't check max block group size as current max chunk size limit is unreliable
[BUG]
A completely valid btrfs will refuse to mount, with error message like:
  BTRFS critical (device sdb2): corrupt leaf: root=2 block=239681536 slot=172 \
    bg_start=12018974720 bg_len=10888413184, invalid block group size, \
    have 10888413184 expect (0, 10737418240]

This has been reported several times as the 4.19 kernel is now being
used. The filesystem refuses to mount, but is otherwise ok and booting
4.18 is a workaround.

Btrfs check returns no error, and all kernels used on this fs is later
than 2011, which should all have the 10G size limit commit.

[CAUSE]
For a 12 devices btrfs, we could allocate a chunk larger than 10G due to
stripe stripe bump up.

__btrfs_alloc_chunk()
|- max_stripe_size = 1G
|- max_chunk_size = 10G
|- data_stripe = 11
|- if (1G * 11 > 10G) {
       stripe_size = 976128930;
       stripe_size = round_up(976128930, SZ_16M) = 989855744

However the final stripe_size (989855744) * 11 = 10888413184, which is
still larger than 10G.

[FIX]
For the comprehensive check, we need to do the full check at chunk read
time, and rely on bg <-> chunk mapping to do the check.

We could just skip the length check for now.

Fixes: fce466eab7 ("btrfs: tree-checker: Verify block_group_item")
Cc: stable@vger.kernel.org # v4.19+
Reported-by: Wang Yugui <wangyugui@e16-tech.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-04 15:05:30 +01:00
Linus Torvalds
121b018f8c Merge tag 'for-4.20-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
 "Some of these bugs are being hit during testing so we'd like to get
  them merged, otherwise there are usual stability fixes for stable
  trees"

* tag 'for-4.20-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: relocation: set trans to be NULL after ending transaction
  Btrfs: fix race between enabling quotas and subvolume creation
  Btrfs: send, fix infinite loop due to directory rename dependencies
  Btrfs: ensure path name is null terminated at btrfs_control_ioctl
  Btrfs: fix rare chances for data loss when doing a fast fsync
  btrfs: Always try all copies when reading extent buffers
2018-11-28 08:38:20 -08:00
Pan Bian
42a657f576 btrfs: relocation: set trans to be NULL after ending transaction
The function relocate_block_group calls btrfs_end_transaction to release
trans when update_backref_cache returns 1, and then continues the loop
body. If btrfs_block_rsv_refill fails this time, it will jump out the
loop and the freed trans will be accessed. This may result in a
use-after-free bug. The patch assigns NULL to trans after trans is
released so that it will not be accessed.

Fixes: 0647bf564f ("Btrfs: improve forever loop when doing balance relocation")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Pan Bian <bianpan2016@163.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-11-23 13:47:46 +01:00
Filipe Manana
552f0329c7 Btrfs: fix race between enabling quotas and subvolume creation
We have a race between enabling quotas end subvolume creation that cause
subvolume creation to fail with -EINVAL, and the following diagram shows
how it happens:

              CPU 0                                          CPU 1

 btrfs_ioctl()
  btrfs_ioctl_quota_ctl()
   btrfs_quota_enable()
    mutex_lock(fs_info->qgroup_ioctl_lock)

                                                  btrfs_ioctl()
                                                   create_subvol()
                                                    btrfs_qgroup_inherit()
                                                     -> save fs_info->quota_root
                                                        into quota_root
                                                     -> stores a NULL value
                                                     -> tries to lock the mutex
                                                        qgroup_ioctl_lock
                                                        -> blocks waiting for
                                                           the task at CPU0

   -> sets BTRFS_FS_QUOTA_ENABLED in fs_info
   -> sets quota_root in fs_info->quota_root
      (non-NULL value)

   mutex_unlock(fs_info->qgroup_ioctl_lock)

                                                     -> checks quota enabled
                                                        flag is set
                                                     -> returns -EINVAL because
                                                        fs_info->quota_root was
                                                        NULL before it acquired
                                                        the mutex
                                                        qgroup_ioctl_lock
                                                   -> ioctl returns -EINVAL

Returning -EINVAL to user space will be confusing if all the arguments
passed to the subvolume creation ioctl were valid.

Fix it by grabbing the value from fs_info->quota_root after acquiring
the mutex.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-11-22 18:59:59 +01:00
Robbie Ko
a4390aee72 Btrfs: send, fix infinite loop due to directory rename dependencies
When doing an incremental send, due to the need of delaying directory move
(rename) operations we can end up in infinite loop at
apply_children_dir_moves().

An example scenario that triggers this problem is described below, where
directory names correspond to the numbers of their respective inodes.

Parent snapshot:

 .
 |--- 261/
       |--- 271/
             |--- 266/
                   |--- 259/
                   |--- 260/
                   |     |--- 267
                   |
                   |--- 264/
                   |     |--- 258/
                   |           |--- 257/
                   |
                   |--- 265/
                   |--- 268/
                   |--- 269/
                   |     |--- 262/
                   |
                   |--- 270/
                   |--- 272/
                   |     |--- 263/
                   |     |--- 275/
                   |
                   |--- 274/
                         |--- 273/

Send snapshot:

 .
 |-- 275/
      |-- 274/
           |-- 273/
                |-- 262/
                     |-- 269/
                          |-- 258/
                               |-- 271/
                                    |-- 268/
                                         |-- 267/
                                              |-- 270/
                                                   |-- 259/
                                                   |    |-- 265/
                                                   |
                                                   |-- 272/
                                                        |-- 257/
                                                             |-- 260/
                                                             |-- 264/
                                                                  |-- 263/
                                                                       |-- 261/
                                                                            |-- 266/

When processing inode 257 we delay its move (rename) operation because its
new parent in the send snapshot, inode 272, was not yet processed. Then
when processing inode 272, we delay the move operation for that inode
because inode 274 is its ancestor in the send snapshot. Finally we delay
the move operation for inode 274 when processing it because inode 275 is
its new parent in the send snapshot and was not yet moved.

When finishing processing inode 275, we start to do the move operations
that were previously delayed (at apply_children_dir_moves()), resulting in
the following iterations:

1) We issue the move operation for inode 274;

2) Because inode 262 depended on the move operation of inode 274 (it was
   delayed because 274 is its ancestor in the send snapshot), we issue the
   move operation for inode 262;

3) We issue the move operation for inode 272, because it was delayed by
   inode 274 too (ancestor of 272 in the send snapshot);

4) We issue the move operation for inode 269 (it was delayed by 262);

5) We issue the move operation for inode 257 (it was delayed by 272);

6) We issue the move operation for inode 260 (it was delayed by 272);

7) We issue the move operation for inode 258 (it was delayed by 269);

8) We issue the move operation for inode 264 (it was delayed by 257);

9) We issue the move operation for inode 271 (it was delayed by 258);

10) We issue the move operation for inode 263 (it was delayed by 264);

11) We issue the move operation for inode 268 (it was delayed by 271);

12) We verify if we can issue the move operation for inode 270 (it was
    delayed by 271). We detect a path loop in the current state, because
    inode 267 needs to be moved first before we can issue the move
    operation for inode 270. So we delay again the move operation for
    inode 270, this time we will attempt to do it after inode 267 is
    moved;

13) We issue the move operation for inode 261 (it was delayed by 263);

14) We verify if we can issue the move operation for inode 266 (it was
    delayed by 263). We detect a path loop in the current state, because
    inode 270 needs to be moved first before we can issue the move
    operation for inode 266. So we delay again the move operation for
    inode 266, this time we will attempt to do it after inode 270 is
    moved (its move operation was delayed in step 12);

15) We issue the move operation for inode 267 (it was delayed by 268);

16) We verify if we can issue the move operation for inode 266 (it was
    delayed by 270). We detect a path loop in the current state, because
    inode 270 needs to be moved first before we can issue the move
    operation for inode 266. So we delay again the move operation for
    inode 266, this time we will attempt to do it after inode 270 is
    moved (its move operation was delayed in step 12). So here we added
    again the same delayed move operation that we added in step 14;

17) We attempt again to see if we can issue the move operation for inode
    266, and as in step 16, we realize we can not due to a path loop in
    the current state due to a dependency on inode 270. Again we delay
    inode's 266 rename to happen after inode's 270 move operation, adding
    the same dependency to the empty stack that we did in steps 14 and 16.
    The next iteration will pick the same move dependency on the stack
    (the only entry) and realize again there is still a path loop and then
    again the same dependency to the stack, over and over, resulting in
    an infinite loop.

So fix this by preventing adding the same move dependency entries to the
stack by removing each pending move record from the red black tree of
pending moves. This way the next call to get_pending_dir_moves() will
not return anything for the current parent inode.

A test case for fstests, with this reproducer, follows soon.

Signed-off-by: Robbie Ko <robbieko@synology.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
[Wrote changelog with example and more clear explanation]
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-11-21 17:03:50 +01:00
Filipe Manana
f505754fd6 Btrfs: ensure path name is null terminated at btrfs_control_ioctl
We were using the path name received from user space without checking that
it is null terminated. While btrfs-progs is well behaved and does proper
validation and null termination, someone could call the ioctl and pass
a non-null terminated patch, leading to buffer overrun problems in the
kernel.  The ioctl is protected by CAP_SYS_ADMIN.

So just set the last byte of the path to a null character, similar to what
we do in other ioctls (add/remove/resize device, snapshot creation, etc).

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-11-14 18:26:20 +01:00
Filipe Manana
aab15e8ec2 Btrfs: fix rare chances for data loss when doing a fast fsync
After the simplification of the fast fsync patch done recently by commit
b5e6c3e170 ("btrfs: always wait on ordered extents at fsync time") and
commit e7175a6927 ("btrfs: remove the wait ordered logic in the
log_one_extent path"), we got a very short time window where we can get
extents logged without writeback completing first or extents logged
without logging the respective data checksums. Both issues can only happen
when doing a non-full (fast) fsync.

As soon as we enter btrfs_sync_file() we trigger writeback, then lock the
inode and then wait for the writeback to complete before starting to log
the inode. However before we acquire the inode's lock and after we started
writeback, it's possible that more writes happened and dirtied more pages.
If that happened and those pages get writeback triggered while we are
logging the inode (for example, the VM subsystem triggering it due to
memory pressure, or another concurrent fsync), we end up seeing the
respective extent maps in the inode's list of modified extents and will
log matching file extent items without waiting for the respective
ordered extents to complete, meaning that either of the following will
happen:

1) We log an extent after its writeback finishes but before its checksums
   are added to the csum tree, leading to -EIO errors when attempting to
   read the extent after a log replay.

2) We log an extent before its writeback finishes.
   Therefore after the log replay we will have a file extent item pointing
   to an unwritten extent (and without the respective data checksums as
   well).

This could not happen before the fast fsync patch simplification, because
for any extent we found in the list of modified extents, we would wait for
its respective ordered extent to finish writeback or collect its checksums
for logging if it did not complete yet.

Fix this by triggering writeback again after acquiring the inode's lock
and before waiting for ordered extents to complete.

Fixes: e7175a6927 ("btrfs: remove the wait ordered logic in the log_one_extent path")
Fixes: b5e6c3e170 ("btrfs: always wait on ordered extents at fsync time")
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-11-13 13:49:43 +01:00
Nikolay Borisov
f8397d69da btrfs: Always try all copies when reading extent buffers
When a metadata read is served the endio routine btree_readpage_end_io_hook
is called which eventually runs the tree-checker. If tree-checker fails
to validate the read eb then it sets EXTENT_BUFFER_CORRUPT flag. This
leads to btree_read_extent_buffer_pages wrongly assuming that all
available copies of this extent buffer are wrong and failing prematurely.
Fix this modify btree_read_extent_buffer_pages to read all copies of
the data.

This failure was exhibitted in xfstests btrfs/124 which would
spuriously fail its balance operations. The reason was that when balance
was run following re-introduction of the missing raid1 disk
__btrfs_map_block would map the read request to stripe 0, which
corresponded to devid 2 (the disk which is being removed in the test):

    item 2 key (FIRST_CHUNK_TREE CHUNK_ITEM 3553624064) itemoff 15975 itemsize 112
	length 1073741824 owner 2 stripe_len 65536 type DATA|RAID1
	io_align 65536 io_width 65536 sector_size 4096
	num_stripes 2 sub_stripes 1
		stripe 0 devid 2 offset 2156920832
		dev_uuid 8466c350-ed0c-4c3b-b17d-6379b445d5c8
		stripe 1 devid 1 offset 3553624064
		dev_uuid 1265d8db-5596-477e-af03-df08eb38d2ca

This caused read requests for a checksum item that to be routed to the
stale disk which triggered the aforementioned logic involving
EXTENT_BUFFER_CORRUPT flag. This then triggered cascading failures of
the balance operation.

Fixes: a826d6dcb3 ("Btrfs: check items for correctness as we search")
CC: stable@vger.kernel.org # 4.4+
Suggested-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-11-13 01:55:52 +01:00
Linus Torvalds
63a42e1a5c Merge tag 'for-4.20-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
 "Several fixes to recent release (4.19, fixes tagged for stable) and
  other fixes"

* tag 'for-4.20-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Btrfs: fix missing delayed iputs on unmount
  Btrfs: fix data corruption due to cloning of eof block
  Btrfs: fix infinite loop on inode eviction after deduplication of eof block
  Btrfs: fix deadlock on tree root leaf when finding free extent
  btrfs: avoid link error with CONFIG_NO_AUTO_INLINE
  btrfs: tree-checker: Fix misleading group system information
  Btrfs: fix missing data checksums after a ranged fsync (msync)
  btrfs: fix pinned underflow after transaction aborted
  Btrfs: fix cur_offset in the error case for nocow
2018-11-11 16:54:38 -06:00
Omar Sandoval
d6fd0ae25c Btrfs: fix missing delayed iputs on unmount
There's a race between close_ctree() and cleaner_kthread().
close_ctree() sets btrfs_fs_closing(), and the cleaner stops when it
sees it set, but this is racy; the cleaner might have already checked
the bit and could be cleaning stuff. In particular, if it deletes unused
block groups, it will create delayed iputs for the free space cache
inodes. As of "btrfs: don't run delayed_iputs in commit", we're no
longer running delayed iputs after a commit. Therefore, if the cleaner
creates more delayed iputs after delayed iputs are run in
btrfs_commit_super(), we will leak inodes on unmount and get a busy
inode crash from the VFS.

Fix it by parking the cleaner before we actually close anything. Then,
any remaining delayed iputs will always be handled in
btrfs_commit_super(). This also ensures that the commit in close_ctree()
is really the last commit, so we can get rid of the commit in
cleaner_kthread().

The fstest/generic/475 followed by 476 can trigger a crash that
manifests as a slab corruption caused by accessing the freed kthread
structure by a wake up function. Sample trace:

[ 5657.077612] BUG: unable to handle kernel NULL pointer dereference at 00000000000000cc
[ 5657.079432] PGD 1c57a067 P4D 1c57a067 PUD da10067 PMD 0
[ 5657.080661] Oops: 0000 [#1] PREEMPT SMP
[ 5657.081592] CPU: 1 PID: 5157 Comm: fsstress Tainted: G        W         4.19.0-rc8-default+ #323
[ 5657.083703] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626cc-prebuilt.qemu-project.org 04/01/2014
[ 5657.086577] RIP: 0010:shrink_page_list+0x2f9/0xe90
[ 5657.091937] RSP: 0018:ffffb5c745c8f728 EFLAGS: 00010287
[ 5657.092953] RAX: 0000000000000074 RBX: ffffb5c745c8f830 RCX: 0000000000000000
[ 5657.094590] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff9a8747fdf3d0
[ 5657.095987] RBP: ffffb5c745c8f9e0 R08: 0000000000000000 R09: 0000000000000000
[ 5657.097159] R10: ffff9a8747fdf5e8 R11: 0000000000000000 R12: ffffb5c745c8f788
[ 5657.098513] R13: ffff9a877f6ff2c0 R14: ffff9a877f6ff2c8 R15: dead000000000200
[ 5657.099689] FS:  00007f948d853b80(0000) GS:ffff9a877d600000(0000) knlGS:0000000000000000
[ 5657.101032] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 5657.101953] CR2: 00000000000000cc CR3: 00000000684bd000 CR4: 00000000000006e0
[ 5657.103159] Call Trace:
[ 5657.103776]  shrink_inactive_list+0x194/0x410
[ 5657.104671]  shrink_node_memcg.constprop.84+0x39a/0x6a0
[ 5657.105750]  shrink_node+0x62/0x1c0
[ 5657.106529]  try_to_free_pages+0x1a4/0x500
[ 5657.107408]  __alloc_pages_slowpath+0x2c9/0xb20
[ 5657.108418]  __alloc_pages_nodemask+0x268/0x2b0
[ 5657.109348]  kmalloc_large_node+0x37/0x90
[ 5657.110205]  __kmalloc_node+0x236/0x310
[ 5657.111014]  kvmalloc_node+0x3e/0x70

Fixes: 30928e9baa ("btrfs: don't run delayed_iputs in commit")
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add trace ]
Signed-off-by: David Sterba <dsterba@suse.com>
2018-11-07 20:17:45 +01:00
Filipe Manana
ac765f83f1 Btrfs: fix data corruption due to cloning of eof block
We currently allow cloning a range from a file which includes the last
block of the file even if the file's size is not aligned to the block
size. This is fine and useful when the destination file has the same size,
but when it does not and the range ends somewhere in the middle of the
destination file, it leads to corruption because the bytes between the EOF
and the end of the block have undefined data (when there is support for
discard/trimming they have a value of 0x00).

Example:

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

 $ export foo_size=$((256 * 1024 + 100))
 $ xfs_io -f -c "pwrite -S 0x3c 0 $foo_size" /mnt/foo
 $ xfs_io -f -c "pwrite -S 0xb5 0 1M" /mnt/bar

 $ xfs_io -c "reflink /mnt/foo 0 512K $foo_size" /mnt/bar

 $ od -A d -t x1 /mnt/bar
 0000000 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5
 *
 0524288 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c
 *
 0786528 3c 3c 3c 3c 00 00 00 00 00 00 00 00 00 00 00 00
 0786544 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 *
 0790528 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5
 *
 1048576

The bytes in the range from 786532 (512Kb + 256Kb + 100 bytes) to 790527
(512Kb + 256Kb + 4Kb - 1) got corrupted, having now a value of 0x00 instead
of 0xb5.

This is similar to the problem we had for deduplication that got recently
fixed by commit de02b9f6bb ("Btrfs: fix data corruption when
deduplicating between different files").

Fix this by not allowing such operations to be performed and return the
errno -EINVAL to user space. This is what XFS is doing as well at the VFS
level. This change however now makes us return -EINVAL instead of
-EOPNOTSUPP for cases where the source range maps to an inline extent and
the destination range's end is smaller then the destination file's size,
since the detection of inline extents is done during the actual process of
dropping file extent items (at __btrfs_drop_extents()). Returning the
-EINVAL error is done early on and solely based on the input parameters
(offsets and length) and destination file's size. This makes us consistent
with XFS and anyone else supporting cloning since this case is now checked
at a higher level in the VFS and is where the -EINVAL will be returned
from starting with kernel 4.20 (the VFS changed was introduced in 4.20-rc1
by commit 07d19dc9fb ("vfs: avoid problematic remapping requests into
partial EOF block"). So this change is more geared towards stable kernels,
as it's unlikely the new VFS checks get removed intentionally.

A test case for fstests follows soon, as well as an update to filter
existing tests that expect -EOPNOTSUPP to accept -EINVAL as well.

CC: <stable@vger.kernel.org> # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-11-06 16:42:41 +01:00
Filipe Manana
11023d3f5f Btrfs: fix infinite loop on inode eviction after deduplication of eof block
If we attempt to deduplicate the last block of a file A into the middle of
a file B, and file A's size is not a multiple of the block size, we end
rounding the deduplication length to 0 bytes, to avoid the data corruption
issue fixed by commit de02b9f6bb ("Btrfs: fix data corruption when
deduplicating between different files"). However a length of zero will
cause the insertion of an extent state with a start value greater (by 1)
then the end value, leading to a corrupt extent state that will trigger a
warning and cause chaos such as an infinite loop during inode eviction.
Example trace:

 [96049.833585] ------------[ cut here ]------------
 [96049.833714] WARNING: CPU: 0 PID: 24448 at fs/btrfs/extent_io.c:436 insert_state+0x101/0x120 [btrfs]
 [96049.833767] CPU: 0 PID: 24448 Comm: xfs_io Not tainted 4.19.0-rc7-btrfs-next-39 #1
 [96049.833768] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014
 [96049.833780] RIP: 0010:insert_state+0x101/0x120 [btrfs]
 [96049.833783] RSP: 0018:ffffafd2c3707af0 EFLAGS: 00010282
 [96049.833785] RAX: 0000000000000000 RBX: 000000000004dfff RCX: 0000000000000006
 [96049.833786] RDX: 0000000000000007 RSI: ffff99045c143230 RDI: ffff99047b2168a0
 [96049.833787] RBP: ffff990457851cd0 R08: 0000000000000001 R09: 0000000000000000
 [96049.833787] R10: ffffafd2c3707ab8 R11: 0000000000000000 R12: ffff9903b93b12c8
 [96049.833788] R13: 000000000004e000 R14: ffffafd2c3707b80 R15: ffffafd2c3707b78
 [96049.833790] FS:  00007f5c14e7d700(0000) GS:ffff99047b200000(0000) knlGS:0000000000000000
 [96049.833791] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [96049.833792] CR2: 00007f5c146abff8 CR3: 0000000115f4c004 CR4: 00000000003606f0
 [96049.833795] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 [96049.833796] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 [96049.833796] Call Trace:
 [96049.833809]  __set_extent_bit+0x46c/0x6a0 [btrfs]
 [96049.833823]  lock_extent_bits+0x6b/0x210 [btrfs]
 [96049.833831]  ? _raw_spin_unlock+0x24/0x30
 [96049.833841]  ? test_range_bit+0xdf/0x130 [btrfs]
 [96049.833853]  lock_extent_range+0x8e/0x150 [btrfs]
 [96049.833864]  btrfs_double_extent_lock+0x78/0xb0 [btrfs]
 [96049.833875]  btrfs_extent_same_range+0x14e/0x550 [btrfs]
 [96049.833885]  ? rcu_read_lock_sched_held+0x3f/0x70
 [96049.833890]  ? __kmalloc_node+0x2b0/0x2f0
 [96049.833899]  ? btrfs_dedupe_file_range+0x19a/0x280 [btrfs]
 [96049.833909]  btrfs_dedupe_file_range+0x270/0x280 [btrfs]
 [96049.833916]  vfs_dedupe_file_range_one+0xd9/0xe0
 [96049.833919]  vfs_dedupe_file_range+0x131/0x1b0
 [96049.833924]  do_vfs_ioctl+0x272/0x6e0
 [96049.833927]  ? __fget+0x113/0x200
 [96049.833931]  ksys_ioctl+0x70/0x80
 [96049.833933]  __x64_sys_ioctl+0x16/0x20
 [96049.833937]  do_syscall_64+0x60/0x1b0
 [96049.833939]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
 [96049.833941] RIP: 0033:0x7f5c1478ddd7
 [96049.833943] RSP: 002b:00007ffe15b196a8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
 [96049.833945] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5c1478ddd7
 [96049.833946] RDX: 00005625ece322d0 RSI: 00000000c0189436 RDI: 0000000000000004
 [96049.833947] RBP: 0000000000000000 R08: 00007f5c14a46f48 R09: 0000000000000040
 [96049.833948] R10: 0000000000000541 R11: 0000000000000202 R12: 0000000000000000
 [96049.833949] R13: 0000000000000000 R14: 0000000000000004 R15: 00005625ece322d0
 [96049.833954] irq event stamp: 6196
 [96049.833956] hardirqs last  enabled at (6195): [<ffffffff91b00663>] console_unlock+0x503/0x640
 [96049.833958] hardirqs last disabled at (6196): [<ffffffff91a037dd>] trace_hardirqs_off_thunk+0x1a/0x1c
 [96049.833959] softirqs last  enabled at (6114): [<ffffffff92600370>] __do_softirq+0x370/0x421
 [96049.833964] softirqs last disabled at (6095): [<ffffffff91a8dd4d>] irq_exit+0xcd/0xe0
 [96049.833965] ---[ end trace db7b05f01b7fa10c ]---
 [96049.935816] R13: 0000000000000000 R14: 00005562e5259240 R15: 00007ffff092b910
 [96049.935822] irq event stamp: 6584
 [96049.935823] hardirqs last  enabled at (6583): [<ffffffff91b00663>] console_unlock+0x503/0x640
 [96049.935825] hardirqs last disabled at (6584): [<ffffffff91a037dd>] trace_hardirqs_off_thunk+0x1a/0x1c
 [96049.935827] softirqs last  enabled at (6328): [<ffffffff92600370>] __do_softirq+0x370/0x421
 [96049.935828] softirqs last disabled at (6313): [<ffffffff91a8dd4d>] irq_exit+0xcd/0xe0
 [96049.935829] ---[ end trace db7b05f01b7fa123 ]---
 [96049.935840] ------------[ cut here ]------------
 [96049.936065] WARNING: CPU: 1 PID: 24463 at fs/btrfs/extent_io.c:436 insert_state+0x101/0x120 [btrfs]
 [96049.936107] CPU: 1 PID: 24463 Comm: umount Tainted: G        W         4.19.0-rc7-btrfs-next-39 #1
 [96049.936108] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014
 [96049.936117] RIP: 0010:insert_state+0x101/0x120 [btrfs]
 [96049.936119] RSP: 0018:ffffafd2c3637bc0 EFLAGS: 00010282
 [96049.936120] RAX: 0000000000000000 RBX: 000000000004dfff RCX: 0000000000000006
 [96049.936121] RDX: 0000000000000007 RSI: ffff990445cf88e0 RDI: ffff99047b2968a0
 [96049.936122] RBP: ffff990457851cd0 R08: 0000000000000001 R09: 0000000000000000
 [96049.936123] R10: ffffafd2c3637b88 R11: 0000000000000000 R12: ffff9904574301e8
 [96049.936124] R13: 000000000004e000 R14: ffffafd2c3637c50 R15: ffffafd2c3637c48
 [96049.936125] FS:  00007fe4b87e72c0(0000) GS:ffff99047b280000(0000) knlGS:0000000000000000
 [96049.936126] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [96049.936128] CR2: 00005562e52618d8 CR3: 00000001151c8005 CR4: 00000000003606e0
 [96049.936129] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 [96049.936131] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 [96049.936131] Call Trace:
 [96049.936141]  __set_extent_bit+0x46c/0x6a0 [btrfs]
 [96049.936154]  lock_extent_bits+0x6b/0x210 [btrfs]
 [96049.936167]  btrfs_evict_inode+0x1e1/0x5a0 [btrfs]
 [96049.936172]  evict+0xbf/0x1c0
 [96049.936174]  dispose_list+0x51/0x80
 [96049.936176]  evict_inodes+0x193/0x1c0
 [96049.936180]  generic_shutdown_super+0x3f/0x110
 [96049.936182]  kill_anon_super+0xe/0x30
 [96049.936189]  btrfs_kill_super+0x13/0x100 [btrfs]
 [96049.936191]  deactivate_locked_super+0x3a/0x70
 [96049.936193]  cleanup_mnt+0x3b/0x80
 [96049.936195]  task_work_run+0x93/0xc0
 [96049.936198]  exit_to_usermode_loop+0xfa/0x100
 [96049.936201]  do_syscall_64+0x17f/0x1b0
 [96049.936202]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
 [96049.936204] RIP: 0033:0x7fe4b80cfb37
 [96049.936206] RSP: 002b:00007ffff092b688 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
 [96049.936207] RAX: 0000000000000000 RBX: 00005562e5259060 RCX: 00007fe4b80cfb37
 [96049.936208] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 00005562e525faa0
 [96049.936209] RBP: 00005562e525faa0 R08: 00005562e525f770 R09: 0000000000000015
 [96049.936210] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007fe4b85d1e64
 [96049.936211] R13: 0000000000000000 R14: 00005562e5259240 R15: 00007ffff092b910
 [96049.936211] R13: 0000000000000000 R14: 00005562e5259240 R15: 00007ffff092b910
 [96049.936216] irq event stamp: 6616
 [96049.936219] hardirqs last  enabled at (6615): [<ffffffff91b00663>] console_unlock+0x503/0x640
 [96049.936219] hardirqs last disabled at (6616): [<ffffffff91a037dd>] trace_hardirqs_off_thunk+0x1a/0x1c
 [96049.936222] softirqs last  enabled at (6328): [<ffffffff92600370>] __do_softirq+0x370/0x421
 [96049.936222] softirqs last disabled at (6313): [<ffffffff91a8dd4d>] irq_exit+0xcd/0xe0
 [96049.936223] ---[ end trace db7b05f01b7fa124 ]---

The second stack trace, from inode eviction, is repeated forever due to
the infinite loop during eviction.

This is the same type of problem fixed way back in 2015 by commit
113e828386 ("Btrfs: fix inode eviction infinite loop after extent_same
ioctl") and commit ccccf3d672 ("Btrfs: fix inode eviction infinite loop
after cloning into it").

So fix this by returning immediately if the deduplication range length
gets rounded down to 0 bytes, as there is nothing that needs to be done in
such case.

Example reproducer:

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

 $ xfs_io -f -c "pwrite -S 0xe6 0 100" /mnt/foo
 $ xfs_io -f -c "pwrite -S 0xe6 0 1M" /mnt/bar

 # Unmount the filesystem and mount it again so that we start without any
 # extent state records when we ask for the deduplication.
 $ umount /mnt
 $ mount /dev/sdb /mnt

 $ xfs_io -c "dedupe /mnt/foo 0 500K 100" /mnt/bar

 # This unmount triggers the infinite loop.
 $ umount /mnt

A test case for fstests will follow soon.

Fixes: de02b9f6bb ("Btrfs: fix data corruption when deduplicating between different files")
CC: <stable@vger.kernel.org> # 4.19+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-11-06 16:42:37 +01:00
Filipe Manana
4222ea7100 Btrfs: fix deadlock on tree root leaf when finding free extent
When we are writing out a free space cache, during the transaction commit
phase, we can end up in a deadlock which results in a stack trace like the
following:

 schedule+0x28/0x80
 btrfs_tree_read_lock+0x8e/0x120 [btrfs]
 ? finish_wait+0x80/0x80
 btrfs_read_lock_root_node+0x2f/0x40 [btrfs]
 btrfs_search_slot+0xf6/0x9f0 [btrfs]
 ? evict_refill_and_join+0xd0/0xd0 [btrfs]
 ? inode_insert5+0x119/0x190
 btrfs_lookup_inode+0x3a/0xc0 [btrfs]
 ? kmem_cache_alloc+0x166/0x1d0
 btrfs_iget+0x113/0x690 [btrfs]
 __lookup_free_space_inode+0xd8/0x150 [btrfs]
 lookup_free_space_inode+0x5b/0xb0 [btrfs]
 load_free_space_cache+0x7c/0x170 [btrfs]
 ? cache_block_group+0x72/0x3b0 [btrfs]
 cache_block_group+0x1b3/0x3b0 [btrfs]
 ? finish_wait+0x80/0x80
 find_free_extent+0x799/0x1010 [btrfs]
 btrfs_reserve_extent+0x9b/0x180 [btrfs]
 btrfs_alloc_tree_block+0x1b3/0x4f0 [btrfs]
 __btrfs_cow_block+0x11d/0x500 [btrfs]
 btrfs_cow_block+0xdc/0x180 [btrfs]
 btrfs_search_slot+0x3bd/0x9f0 [btrfs]
 btrfs_lookup_inode+0x3a/0xc0 [btrfs]
 ? kmem_cache_alloc+0x166/0x1d0
 btrfs_update_inode_item+0x46/0x100 [btrfs]
 cache_save_setup+0xe4/0x3a0 [btrfs]
 btrfs_start_dirty_block_groups+0x1be/0x480 [btrfs]
 btrfs_commit_transaction+0xcb/0x8b0 [btrfs]

At cache_save_setup() we need to update the inode item of a block group's
cache which is located in the tree root (fs_info->tree_root), which means
that it may result in COWing a leaf from that tree. If that happens we
need to find a free metadata extent and while looking for one, if we find
a block group which was not cached yet we attempt to load its cache by
calling cache_block_group(). However this function will try to load the
inode of the free space cache, which requires finding the matching inode
item in the tree root - if that inode item is located in the same leaf as
the inode item of the space cache we are updating at cache_save_setup(),
we end up in a deadlock, since we try to obtain a read lock on the same
extent buffer that we previously write locked.

So fix this by using the tree root's commit root when searching for a
block group's free space cache inode item when we are attempting to load
a free space cache. This is safe since block groups once loaded stay in
memory forever, as well as their caches, so after they are first loaded
we will never need to read their inode items again. For new block groups,
once they are created they get their ->cached field set to
BTRFS_CACHE_FINISHED meaning we will not need to read their inode item.

Reported-by: Andrew Nelson <andrew.s.nelson@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/CAPTELenq9x5KOWuQ+fa7h1r3nsJG8vyiTH8+ifjURc_duHh2Wg@mail.gmail.com/
Fixes: 9d66e233c7 ("Btrfs: load free space cache if it exists")
Tested-by: Andrew Nelson <andrew.s.nelson@gmail.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-11-06 16:42:32 +01:00
Arnd Bergmann
7e17916b35 btrfs: avoid link error with CONFIG_NO_AUTO_INLINE
Note: this patch fixes a problem in a feature outside of btrfs ("kernel
hacking: add a config option to disable compiler auto-inlining") and is
applied ahead of time due to cross-subsystem dependencies.

On 32-bit ARM with gcc-8, I see a link error with the addition of the
CONFIG_NO_AUTO_INLINE option:

fs/btrfs/super.o: In function `btrfs_statfs':
super.c:(.text+0x67b8): undefined reference to `__aeabi_uldivmod'
super.c:(.text+0x67fc): undefined reference to `__aeabi_uldivmod'
super.c:(.text+0x6858): undefined reference to `__aeabi_uldivmod'
super.c:(.text+0x6920): undefined reference to `__aeabi_uldivmod'
super.c:(.text+0x693c): undefined reference to `__aeabi_uldivmod'
fs/btrfs/super.o:super.c:(.text+0x6958): more undefined references to `__aeabi_uldivmod' follow

So far this is the only file that shows the behavior, so I'd propose
to just work around it by marking the functions as 'static inline'
that normally get inlined here.

The reference to __aeabi_uldivmod comes from a div_u64() which has an
optimization for a constant division that uses a straight '/' operator
when the result should be known to the compiler. My interpretation is
that as we turn off inlining, gcc still expects the result to be constant
but fails to use that constant value.

Link: https://lkml.kernel.org/r/20181103153941.1881966-1-arnd@arndb.de
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Changbin Du <changbin.du@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
[ add the note ]
Signed-off-by: David Sterba <dsterba@suse.com>
2018-11-06 16:42:08 +01:00
Shaokun Zhang
761333f2f5 btrfs: tree-checker: Fix misleading group system information
block_group_err shows the group system as a decimal value with a '0x'
prefix, which is somewhat misleading.

Fix it to print hexadecimal, as was intended.

Fixes: fce466eab7 ("btrfs: tree-checker: Verify block_group_item")
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-11-06 16:41:53 +01:00
Filipe Manana
008c6753f7 Btrfs: fix missing data checksums after a ranged fsync (msync)
Recently we got a massive simplification for fsync, where for the fast
path we no longer log new extents while their respective ordered extents
are still running.

However that simplification introduced a subtle regression for the case
where we use a ranged fsync (msync). Consider the following example:

               CPU 0                                    CPU 1

                                            mmap write to range [2Mb, 4Mb[
  mmap write to range [512Kb, 1Mb[
  msync range [512K, 1Mb[
    --> triggers fast fsync
        (BTRFS_INODE_NEEDS_FULL_SYNC
         not set)
    --> creates extent map A for this
        range and adds it to list of
        modified extents
    --> starts ordered extent A for
        this range
    --> waits for it to complete

                                            writeback triggered for range
                                            [2Mb, 4Mb[
                                              --> create extent map B and
                                                  adds it to the list of
                                                  modified extents
                                              --> creates ordered extent B

    --> start looking for and logging
        modified extents
    --> logs extent maps A and B
    --> finds checksums for extent A
        in the csum tree, but not for
        extent B
  fsync (msync) finishes

                                              --> ordered extent B
                                                  finishes and its
                                                  checksums are added
                                                  to the csum tree

                                <power cut>

After replaying the log, we have the extent covering the range [2Mb, 4Mb[
but do not have the data checksum items covering that file range.

This happens because at the very beginning of an fsync (btrfs_sync_file())
we start and wait for IO in the given range [512Kb, 1Mb[ and therefore
wait for any ordered extents in that range to complete before we start
logging the extents. However if right before we start logging the extent
in our range [512Kb, 1Mb[, writeback is started for any other dirty range,
such as the range [2Mb, 4Mb[ due to memory pressure or a concurrent fsync
or msync (btrfs_sync_file() starts writeback before acquiring the inode's
lock), an ordered extent is created for that other range and a new extent
map is created to represent that range and added to the inode's list of
modified extents.

That means that we will see that other extent in that list when collecting
extents for logging (done at btrfs_log_changed_extents()) and log the
extent before the respective ordered extent finishes - namely before the
checksum items are added to the checksums tree, which is where
log_extent_csums() looks for the checksums, therefore making us log an
extent without logging its checksums. Before that massive simplification
of fsync, this wasn't a problem because besides looking for checkums in
the checksums tree, we also looked for them in any ordered extent still
running.

The consequence of data checksums missing for a file range is that users
attempting to read the affected file range will get -EIO errors and dmesg
reports the following:

 [10188.358136] BTRFS info (device sdc): no csum found for inode 297 start 57344
 [10188.359278] BTRFS warning (device sdc): csum failed root 5 ino 297 off 57344 csum 0x98f94189 expected csum 0x00000000 mirror 1

So fix this by skipping extents outside of our logging range at
btrfs_log_changed_extents() and leaving them on the list of modified
extents so that any subsequent ranged fsync may collect them if needed.
Also, if we find a hole extent outside of the range still log it, just
to prevent having gaps between extent items after replaying the log,
otherwise fsck will complain when we are not using the NO_HOLES feature
(fstest btrfs/056 triggers such case).

Fixes: e7175a6927 ("btrfs: remove the wait ordered logic in the log_one_extent path")
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-11-06 16:41:40 +01:00
Lu Fengqi
fcd5e74288 btrfs: fix pinned underflow after transaction aborted
When running generic/475, we may get the following warning in dmesg:

[ 6902.102154] WARNING: CPU: 3 PID: 18013 at fs/btrfs/extent-tree.c:9776 btrfs_free_block_groups+0x2af/0x3b0 [btrfs]
[ 6902.109160] CPU: 3 PID: 18013 Comm: umount Tainted: G        W  O      4.19.0-rc8+ #8
[ 6902.110971] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
[ 6902.112857] RIP: 0010:btrfs_free_block_groups+0x2af/0x3b0 [btrfs]
[ 6902.118921] RSP: 0018:ffffc9000459bdb0 EFLAGS: 00010286
[ 6902.120315] RAX: ffff880175050bb0 RBX: ffff8801124a8000 RCX: 0000000000170007
[ 6902.121969] RDX: 0000000000000002 RSI: 0000000000170007 RDI: ffffffff8125fb74
[ 6902.123716] RBP: ffff880175055d10 R08: 0000000000000000 R09: 0000000000000000
[ 6902.125417] R10: 0000000000000000 R11: 0000000000000000 R12: ffff880175055d88
[ 6902.127129] R13: ffff880175050bb0 R14: 0000000000000000 R15: dead000000000100
[ 6902.129060] FS:  00007f4507223780(0000) GS:ffff88017ba00000(0000) knlGS:0000000000000000
[ 6902.130996] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 6902.132558] CR2: 00005623599cac78 CR3: 000000014b700001 CR4: 00000000003606e0
[ 6902.134270] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 6902.135981] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 6902.137836] Call Trace:
[ 6902.138939]  close_ctree+0x171/0x330 [btrfs]
[ 6902.140181]  ? kthread_stop+0x146/0x1f0
[ 6902.141277]  generic_shutdown_super+0x6c/0x100
[ 6902.142517]  kill_anon_super+0x14/0x30
[ 6902.143554]  btrfs_kill_super+0x13/0x100 [btrfs]
[ 6902.144790]  deactivate_locked_super+0x2f/0x70
[ 6902.146014]  cleanup_mnt+0x3b/0x70
[ 6902.147020]  task_work_run+0x9e/0xd0
[ 6902.148036]  do_syscall_64+0x470/0x600
[ 6902.149142]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[ 6902.150375]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 6902.151640] RIP: 0033:0x7f45077a6a7b
[ 6902.157324] RSP: 002b:00007ffd589f3e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
[ 6902.159187] RAX: 0000000000000000 RBX: 000055e8eec732b0 RCX: 00007f45077a6a7b
[ 6902.160834] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 000055e8eec73490
[ 6902.162526] RBP: 0000000000000000 R08: 000055e8eec734b0 R09: 00007ffd589f26c0
[ 6902.164141] R10: 0000000000000000 R11: 0000000000000246 R12: 000055e8eec73490
[ 6902.165815] R13: 00007f4507ac61a4 R14: 0000000000000000 R15: 00007ffd589f40d8
[ 6902.167553] irq event stamp: 0
[ 6902.168998] hardirqs last  enabled at (0): [<0000000000000000>]           (null)
[ 6902.170731] hardirqs last disabled at (0): [<ffffffff810cd810>] copy_process.part.55+0x3b0/0x1f00
[ 6902.172773] softirqs last  enabled at (0): [<ffffffff810cd810>] copy_process.part.55+0x3b0/0x1f00
[ 6902.174671] softirqs last disabled at (0): [<0000000000000000>]           (null)
[ 6902.176407] ---[ end trace 463138c2986b275c ]---
[ 6902.177636] BTRFS info (device dm-3): space_info 4 has 273465344 free, is not full
[ 6902.179453] BTRFS info (device dm-3): space_info total=276824064, used=4685824, pinned=18446744073708158976, reserved=0, may_use=0, readonly=65536

In the above line there's "pinned=18446744073708158976" which is an
unsigned u64 value of -1392640, an obvious underflow.

When transaction_kthread is running cleanup_transaction(), another
fsstress is running btrfs_commit_transaction(). The
btrfs_finish_extent_commit() may get the same range as
btrfs_destroy_pinned_extent() got, which causes the pinned underflow.

Fixes: d4b450cd4b ("Btrfs: fix race between transaction commit and empty block group removal")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-11-06 16:41:34 +01:00
Robbie Ko
506481b20e Btrfs: fix cur_offset in the error case for nocow
When the cow_file_range fails, the related resources are unlocked
according to the range [start..end), so the unlock cannot be repeated in
run_delalloc_nocow.

In some cases (e.g. cur_offset <= end && cow_start != -1), cur_offset is
not updated correctly, so move the cur_offset update before
cow_file_range.

  kernel BUG at mm/page-writeback.c:2663!
  Internal error: Oops - BUG: 0 [#1] SMP
  CPU: 3 PID: 31525 Comm: kworker/u8:7 Tainted: P O
  Hardware name: Realtek_RTD1296 (DT)
  Workqueue: writeback wb_workfn (flush-btrfs-1)
  task: ffffffc076db3380 ti: ffffffc02e9ac000 task.ti: ffffffc02e9ac000
  PC is at clear_page_dirty_for_io+0x1bc/0x1e8
  LR is at clear_page_dirty_for_io+0x14/0x1e8
  pc : [<ffffffc00033c91c>] lr : [<ffffffc00033c774>] pstate: 40000145
  sp : ffffffc02e9af4f0
  Process kworker/u8:7 (pid: 31525, stack limit = 0xffffffc02e9ac020)
  Call trace:
  [<ffffffc00033c91c>] clear_page_dirty_for_io+0x1bc/0x1e8
  [<ffffffbffc514674>] extent_clear_unlock_delalloc+0x1e4/0x210 [btrfs]
  [<ffffffbffc4fb168>] run_delalloc_nocow+0x3b8/0x948 [btrfs]
  [<ffffffbffc4fb948>] run_delalloc_range+0x250/0x3a8 [btrfs]
  [<ffffffbffc514c0c>] writepage_delalloc.isra.21+0xbc/0x1d8 [btrfs]
  [<ffffffbffc516048>] __extent_writepage+0xe8/0x248 [btrfs]
  [<ffffffbffc51630c>] extent_write_cache_pages.isra.17+0x164/0x378 [btrfs]
  [<ffffffbffc5185a8>] extent_writepages+0x48/0x68 [btrfs]
  [<ffffffbffc4f5828>] btrfs_writepages+0x20/0x30 [btrfs]
  [<ffffffc00033d758>] do_writepages+0x30/0x88
  [<ffffffc0003ba0f4>] __writeback_single_inode+0x34/0x198
  [<ffffffc0003ba6c4>] writeback_sb_inodes+0x184/0x3c0
  [<ffffffc0003ba96c>] __writeback_inodes_wb+0x6c/0xc0
  [<ffffffc0003bac20>] wb_writeback+0x1b8/0x1c0
  [<ffffffc0003bb0f0>] wb_workfn+0x150/0x250
  [<ffffffc0002b0014>] process_one_work+0x1dc/0x388
  [<ffffffc0002b02f0>] worker_thread+0x130/0x500
  [<ffffffc0002b6344>] kthread+0x10c/0x110
  [<ffffffc000284590>] ret_from_fork+0x10/0x40
  Code: d503201f a9025bb5 a90363b7 f90023b9 (d4210000)

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Robbie Ko <robbieko@synology.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-11-06 16:41:04 +01:00
Linus Torvalds
c2aa1a444c Merge tag 'xfs-4.20-merge-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull vfs dedup fixes from Dave Chinner:
 "This reworks the vfs data cloning infrastructure.

  We discovered many issues with these interfaces late in the 4.19 cycle
  - the worst of them (data corruption, setuid stripping) were fixed for
  XFS in 4.19-rc8, but a larger rework of the infrastructure fixing all
  the problems was needed. That rework is the contents of this pull
  request.

  Rework the vfs_clone_file_range and vfs_dedupe_file_range
  infrastructure to use a common .remap_file_range method and supply
  generic bounds and sanity checking functions that are shared with the
  data write path. The current VFS infrastructure has problems with
  rlimit, LFS file sizes, file time stamps, maximum filesystem file
  sizes, stripping setuid bits, etc and so they are addressed in these
  commits.

  We also introduce the ability for the ->remap_file_range methods to
  return short clones so that clones for vfs_copy_file_range() don't get
  rejected if the entire range can't be cloned. It also allows
  filesystems to sliently skip deduplication of partial EOF blocks if
  they are not capable of doing so without requiring errors to be thrown
  to userspace.

  Existing filesystems are converted to user the new remap_file_range
  method, and both XFS and ocfs2 are modified to make use of the new
  generic checking infrastructure"

* tag 'xfs-4.20-merge-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (28 commits)
  xfs: remove [cm]time update from reflink calls
  xfs: remove xfs_reflink_remap_range
  xfs: remove redundant remap partial EOF block checks
  xfs: support returning partial reflink results
  xfs: clean up xfs_reflink_remap_blocks call site
  xfs: fix pagecache truncation prior to reflink
  ocfs2: remove ocfs2_reflink_remap_range
  ocfs2: support partial clone range and dedupe range
  ocfs2: fix pagecache truncation prior to reflink
  ocfs2: truncate page cache for clone destination file before remapping
  vfs: clean up generic_remap_file_range_prep return value
  vfs: hide file range comparison function
  vfs: enable remap callers that can handle short operations
  vfs: plumb remap flags through the vfs dedupe functions
  vfs: plumb remap flags through the vfs clone functions
  vfs: make remap_file_range functions take and return bytes completed
  vfs: remap helper should update destination inode metadata
  vfs: pass remap flags to generic_remap_checks
  vfs: pass remap flags to generic_remap_file_range_prep
  vfs: combine the clone and dedupe into a single remap_file_range
  ...
2018-11-02 09:33:08 -07:00
Linus Torvalds
85b5d4bcab Merge tag 'for-4.20-part2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull more btrfs updates from David Sterba:
 "This contains a few minor updates and fixes that were under testing or
  arrived shortly after the merge window freeze, mostly stable material"

* tag 'for-4.20-part2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Btrfs: fix use-after-free when dumping free space
  Btrfs: fix use-after-free during inode eviction
  btrfs: move the dio_sem higher up the callchain
  btrfs: don't run delayed_iputs in commit
  btrfs: fix insert_reserved error handling
  btrfs: only free reserved extent if we didn't insert it
  btrfs: don't use ctl->free_space for max_extent_size
  btrfs: set max_extent_size properly
  btrfs: reset max_extent_size properly
  MAINTAINERS: update my email address for btrfs
  btrfs: delayed-ref: extract find_first_ref_head from find_ref_head
  Btrfs: fix deadlock when writing out free space caches
  Btrfs: fix assertion on fsync of regular file when using no-holes feature
  Btrfs: fix null pointer dereference on compressed write path error
2018-10-30 08:27:13 -07:00
Darrick J. Wong
42ec3d4c02 vfs: make remap_file_range functions take and return bytes completed
Change the remap_file_range functions to take a number of bytes to
operate upon and return the number of bytes they operated on.  This is a
requirement for allowing fs implementations to return short clone/dedupe
results to the user, which will enable us to obey resource limits in a
graceful manner.

A subsequent patch will enable copy_file_range to signal to the
->clone_file_range implementation that it can handle a short length,
which will be returned in the function's return value.  For now the
short return is not implemented anywhere so the behavior won't change --
either copy_file_range manages to clone the entire range or it tries an
alternative.

Neither clone ioctl can take advantage of this, alas.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-30 10:41:49 +11:00
Darrick J. Wong
2e5dfc99f2 vfs: combine the clone and dedupe into a single remap_file_range
Combine the clone_file_range and dedupe_file_range operations into a
single remap_file_range file operation dispatch since they're
fundamentally the same operation.  The differences between the two can
be made in the prep functions.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-30 10:41:21 +11:00
Linus Torvalds
dad4f140ed Merge branch 'xarray' of git://git.infradead.org/users/willy/linux-dax
Pull XArray conversion from Matthew Wilcox:
 "The XArray provides an improved interface to the radix tree data
  structure, providing locking as part of the API, specifying GFP flags
  at allocation time, eliminating preloading, less re-walking the tree,
  more efficient iterations and not exposing RCU-protected pointers to
  its users.

  This patch set

   1. Introduces the XArray implementation

   2. Converts the pagecache to use it

   3. Converts memremap to use it

  The page cache is the most complex and important user of the radix
  tree, so converting it was most important. Converting the memremap
  code removes the only other user of the multiorder code, which allows
  us to remove the radix tree code that supported it.

  I have 40+ followup patches to convert many other users of the radix
  tree over to the XArray, but I'd like to get this part in first. The
  other conversions haven't been in linux-next and aren't suitable for
  applying yet, but you can see them in the xarray-conv branch if you're
  interested"

* 'xarray' of git://git.infradead.org/users/willy/linux-dax: (90 commits)
  radix tree: Remove multiorder support
  radix tree test: Convert multiorder tests to XArray
  radix tree tests: Convert item_delete_rcu to XArray
  radix tree tests: Convert item_kill_tree to XArray
  radix tree tests: Move item_insert_order
  radix tree test suite: Remove multiorder benchmarking
  radix tree test suite: Remove __item_insert
  memremap: Convert to XArray
  xarray: Add range store functionality
  xarray: Move multiorder_check to in-kernel tests
  xarray: Move multiorder_shrink to kernel tests
  xarray: Move multiorder account test in-kernel
  radix tree test suite: Convert iteration test to XArray
  radix tree test suite: Convert tag_tagged_items to XArray
  radix tree: Remove radix_tree_clear_tags
  radix tree: Remove radix_tree_maybe_preload_order
  radix tree: Remove split/join code
  radix tree: Remove radix_tree_update_node_t
  page cache: Finish XArray conversion
  dax: Convert page fault handlers to XArray
  ...
2018-10-28 11:35:40 -07:00
Linus Torvalds
4ba9628fe5 Merge branch 'work.lookup' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more ->lookup() cleanups from Al Viro:
 "Some ->lookup() instances are still overcomplicating the life
  for themselves, open-coding the stuff that would be handled by
  d_splice_alias() just fine.

  Simplify a couple of such cases caught this cycle and document
  d_splice_alias() intended use"

* 'work.lookup' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  Document d_splice_alias() calling conventions for ->lookup() users.
  simplify btrfs_lookup()
  clean erofs_lookup()
2018-10-25 12:55:31 -07:00
Filipe Manana
9084cb6a24 Btrfs: fix use-after-free when dumping free space
We were iterating a block group's free space cache rbtree without locking
first the lock that protects it (the free_space_ctl->free_space_offset
rbtree is protected by the free_space_ctl->tree_lock spinlock).

KASAN reported an use-after-free problem when iterating such a rbtree due
to a concurrent rbtree delete:

[ 9520.359168] ==================================================================
[ 9520.359656] BUG: KASAN: use-after-free in rb_next+0x13/0x90
[ 9520.359949] Read of size 8 at addr ffff8800b7ada500 by task btrfs-transacti/1721
[ 9520.360357]
[ 9520.360530] CPU: 4 PID: 1721 Comm: btrfs-transacti Tainted: G             L    4.19.0-rc8-nbor #555
[ 9520.360990] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 9520.362682] Call Trace:
[ 9520.362887]  dump_stack+0xa4/0xf5
[ 9520.363146]  print_address_description+0x78/0x280
[ 9520.363412]  kasan_report+0x263/0x390
[ 9520.363650]  ? rb_next+0x13/0x90
[ 9520.363873]  __asan_load8+0x54/0x90
[ 9520.364102]  rb_next+0x13/0x90
[ 9520.364380]  btrfs_dump_free_space+0x146/0x160 [btrfs]
[ 9520.364697]  dump_space_info+0x2cd/0x310 [btrfs]
[ 9520.364997]  btrfs_reserve_extent+0x1ee/0x1f0 [btrfs]
[ 9520.365310]  __btrfs_prealloc_file_range+0x1cc/0x620 [btrfs]
[ 9520.365646]  ? btrfs_update_time+0x180/0x180 [btrfs]
[ 9520.365923]  ? _raw_spin_unlock+0x27/0x40
[ 9520.366204]  ? btrfs_alloc_data_chunk_ondemand+0x2c0/0x5c0 [btrfs]
[ 9520.366549]  btrfs_prealloc_file_range_trans+0x23/0x30 [btrfs]
[ 9520.366880]  cache_save_setup+0x42e/0x580 [btrfs]
[ 9520.367220]  ? btrfs_check_data_free_space+0xd0/0xd0 [btrfs]
[ 9520.367518]  ? lock_downgrade+0x2f0/0x2f0
[ 9520.367799]  ? btrfs_write_dirty_block_groups+0x11f/0x6e0 [btrfs]
[ 9520.368104]  ? kasan_check_read+0x11/0x20
[ 9520.368349]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.368638]  btrfs_write_dirty_block_groups+0x2af/0x6e0 [btrfs]
[ 9520.368978]  ? btrfs_start_dirty_block_groups+0x870/0x870 [btrfs]
[ 9520.369282]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.369534]  ? _raw_spin_unlock+0x27/0x40
[ 9520.369811]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.370137]  commit_cowonly_roots+0x4b9/0x610 [btrfs]
[ 9520.370560]  ? commit_fs_roots+0x350/0x350 [btrfs]
[ 9520.370926]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.371285]  btrfs_commit_transaction+0x5e5/0x10e0 [btrfs]
[ 9520.371612]  ? btrfs_apply_pending_changes+0x90/0x90 [btrfs]
[ 9520.371943]  ? start_transaction+0x168/0x6c0 [btrfs]
[ 9520.372257]  transaction_kthread+0x21c/0x240 [btrfs]
[ 9520.372537]  kthread+0x1d2/0x1f0
[ 9520.372793]  ? btrfs_cleanup_transaction+0xb50/0xb50 [btrfs]
[ 9520.373090]  ? kthread_park+0xb0/0xb0
[ 9520.373329]  ret_from_fork+0x3a/0x50
[ 9520.373567]
[ 9520.373738] Allocated by task 1804:
[ 9520.373974]  kasan_kmalloc+0xff/0x180
[ 9520.374208]  kasan_slab_alloc+0x11/0x20
[ 9520.374447]  kmem_cache_alloc+0xfc/0x2d0
[ 9520.374731]  __btrfs_add_free_space+0x40/0x580 [btrfs]
[ 9520.375044]  unpin_extent_range+0x4f7/0x7a0 [btrfs]
[ 9520.375383]  btrfs_finish_extent_commit+0x15f/0x4d0 [btrfs]
[ 9520.375707]  btrfs_commit_transaction+0xb06/0x10e0 [btrfs]
[ 9520.376027]  btrfs_alloc_data_chunk_ondemand+0x237/0x5c0 [btrfs]
[ 9520.376365]  btrfs_check_data_free_space+0x81/0xd0 [btrfs]
[ 9520.376689]  btrfs_delalloc_reserve_space+0x25/0x80 [btrfs]
[ 9520.377018]  btrfs_direct_IO+0x42e/0x6d0 [btrfs]
[ 9520.377284]  generic_file_direct_write+0x11e/0x220
[ 9520.377587]  btrfs_file_write_iter+0x472/0xac0 [btrfs]
[ 9520.377875]  aio_write+0x25c/0x360
[ 9520.378106]  io_submit_one+0xaa0/0xdc0
[ 9520.378343]  __se_sys_io_submit+0xfa/0x2f0
[ 9520.378589]  __x64_sys_io_submit+0x43/0x50
[ 9520.378840]  do_syscall_64+0x7d/0x240
[ 9520.379081]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 9520.379387]
[ 9520.379557] Freed by task 1802:
[ 9520.379782]  __kasan_slab_free+0x173/0x260
[ 9520.380028]  kasan_slab_free+0xe/0x10
[ 9520.380262]  kmem_cache_free+0xc1/0x2c0
[ 9520.380544]  btrfs_find_space_for_alloc+0x4cd/0x4e0 [btrfs]
[ 9520.380866]  find_free_extent+0xa99/0x17e0 [btrfs]
[ 9520.381166]  btrfs_reserve_extent+0xd5/0x1f0 [btrfs]
[ 9520.381474]  btrfs_get_blocks_direct+0x60b/0xbd0 [btrfs]
[ 9520.381761]  __blockdev_direct_IO+0x10ee/0x58a1
[ 9520.382059]  btrfs_direct_IO+0x25a/0x6d0 [btrfs]
[ 9520.382321]  generic_file_direct_write+0x11e/0x220
[ 9520.382623]  btrfs_file_write_iter+0x472/0xac0 [btrfs]
[ 9520.382904]  aio_write+0x25c/0x360
[ 9520.383172]  io_submit_one+0xaa0/0xdc0
[ 9520.383416]  __se_sys_io_submit+0xfa/0x2f0
[ 9520.383678]  __x64_sys_io_submit+0x43/0x50
[ 9520.383927]  do_syscall_64+0x7d/0x240
[ 9520.384165]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 9520.384439]
[ 9520.384610] The buggy address belongs to the object at ffff8800b7ada500
                which belongs to the cache btrfs_free_space of size 72
[ 9520.385175] The buggy address is located 0 bytes inside of
                72-byte region [ffff8800b7ada500, ffff8800b7ada548)
[ 9520.385691] The buggy address belongs to the page:
[ 9520.385957] page:ffffea0002deb680 count:1 mapcount:0 mapping:ffff880108a1d700 index:0x0 compound_mapcount: 0
[ 9520.388030] flags: 0x8100(slab|head)
[ 9520.388281] raw: 0000000000008100 ffffea0002deb608 ffffea0002728808 ffff880108a1d700
[ 9520.388722] raw: 0000000000000000 0000000000130013 00000001ffffffff 0000000000000000
[ 9520.389169] page dumped because: kasan: bad access detected
[ 9520.389473]
[ 9520.389658] Memory state around the buggy address:
[ 9520.389943]  ffff8800b7ada400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.390368]  ffff8800b7ada480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.390796] >ffff8800b7ada500: fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc
[ 9520.391223]                    ^
[ 9520.391461]  ffff8800b7ada580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.391885]  ffff8800b7ada600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.392313] ==================================================================
[ 9520.392772] BTRFS critical (device vdc): entry offset 2258497536, bytes 131072, bitmap no
[ 9520.393247] BUG: unable to handle kernel NULL pointer dereference at 0000000000000011
[ 9520.393705] PGD 800000010dbab067 P4D 800000010dbab067 PUD 107551067 PMD 0
[ 9520.394059] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[ 9520.394378] CPU: 4 PID: 1721 Comm: btrfs-transacti Tainted: G    B        L    4.19.0-rc8-nbor #555
[ 9520.394858] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 9520.395350] RIP: 0010:rb_next+0x3c/0x90
[ 9520.396461] RSP: 0018:ffff8801074ff780 EFLAGS: 00010292
[ 9520.396762] RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81b5ac4c
[ 9520.397115] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000011
[ 9520.397468] RBP: ffff8801074ff7a0 R08: ffffed0021d64ccc R09: ffffed0021d64ccc
[ 9520.397821] R10: 0000000000000001 R11: ffffed0021d64ccb R12: ffff8800b91e0000
[ 9520.398188] R13: ffff8800a3ceba48 R14: ffff8800b627bf80 R15: 0000000000020000
[ 9520.398555] FS:  0000000000000000(0000) GS:ffff88010eb00000(0000) knlGS:0000000000000000
[ 9520.399007] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9520.399335] CR2: 0000000000000011 CR3: 0000000106b52000 CR4: 00000000000006a0
[ 9520.399679] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 9520.400023] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 9520.400400] Call Trace:
[ 9520.400648]  btrfs_dump_free_space+0x146/0x160 [btrfs]
[ 9520.400974]  dump_space_info+0x2cd/0x310 [btrfs]
[ 9520.401287]  btrfs_reserve_extent+0x1ee/0x1f0 [btrfs]
[ 9520.401609]  __btrfs_prealloc_file_range+0x1cc/0x620 [btrfs]
[ 9520.401952]  ? btrfs_update_time+0x180/0x180 [btrfs]
[ 9520.402232]  ? _raw_spin_unlock+0x27/0x40
[ 9520.402522]  ? btrfs_alloc_data_chunk_ondemand+0x2c0/0x5c0 [btrfs]
[ 9520.402882]  btrfs_prealloc_file_range_trans+0x23/0x30 [btrfs]
[ 9520.403261]  cache_save_setup+0x42e/0x580 [btrfs]
[ 9520.403570]  ? btrfs_check_data_free_space+0xd0/0xd0 [btrfs]
[ 9520.403871]  ? lock_downgrade+0x2f0/0x2f0
[ 9520.404161]  ? btrfs_write_dirty_block_groups+0x11f/0x6e0 [btrfs]
[ 9520.404481]  ? kasan_check_read+0x11/0x20
[ 9520.404732]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.405026]  btrfs_write_dirty_block_groups+0x2af/0x6e0 [btrfs]
[ 9520.405375]  ? btrfs_start_dirty_block_groups+0x870/0x870 [btrfs]
[ 9520.405694]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.405958]  ? _raw_spin_unlock+0x27/0x40
[ 9520.406243]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.406574]  commit_cowonly_roots+0x4b9/0x610 [btrfs]
[ 9520.406899]  ? commit_fs_roots+0x350/0x350 [btrfs]
[ 9520.407253]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.407589]  btrfs_commit_transaction+0x5e5/0x10e0 [btrfs]
[ 9520.407925]  ? btrfs_apply_pending_changes+0x90/0x90 [btrfs]
[ 9520.408262]  ? start_transaction+0x168/0x6c0 [btrfs]
[ 9520.408582]  transaction_kthread+0x21c/0x240 [btrfs]
[ 9520.408870]  kthread+0x1d2/0x1f0
[ 9520.409138]  ? btrfs_cleanup_transaction+0xb50/0xb50 [btrfs]
[ 9520.409440]  ? kthread_park+0xb0/0xb0
[ 9520.409682]  ret_from_fork+0x3a/0x50
[ 9520.410508] Dumping ftrace buffer:
[ 9520.410764]    (ftrace buffer empty)
[ 9520.411007] CR2: 0000000000000011
[ 9520.411297] ---[ end trace 01a0863445cf360a ]---
[ 9520.411568] RIP: 0010:rb_next+0x3c/0x90
[ 9520.412644] RSP: 0018:ffff8801074ff780 EFLAGS: 00010292
[ 9520.412932] RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81b5ac4c
[ 9520.413274] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000011
[ 9520.413616] RBP: ffff8801074ff7a0 R08: ffffed0021d64ccc R09: ffffed0021d64ccc
[ 9520.414007] R10: 0000000000000001 R11: ffffed0021d64ccb R12: ffff8800b91e0000
[ 9520.414349] R13: ffff8800a3ceba48 R14: ffff8800b627bf80 R15: 0000000000020000
[ 9520.416074] FS:  0000000000000000(0000) GS:ffff88010eb00000(0000) knlGS:0000000000000000
[ 9520.416536] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9520.416848] CR2: 0000000000000011 CR3: 0000000106b52000 CR4: 00000000000006a0
[ 9520.418477] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 9520.418846] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 9520.419204] Kernel panic - not syncing: Fatal exception
[ 9520.419666] Dumping ftrace buffer:
[ 9520.419930]    (ftrace buffer empty)
[ 9520.420168] Kernel Offset: disabled
[ 9520.420406] ---[ end Kernel panic - not syncing: Fatal exception ]---

Fix this by acquiring the respective lock before iterating the rbtree.

Reported-by: Nikolay Borisov <nborisov@suse.com>
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-22 20:31:22 +02:00
Matthew Wilcox
0a943c65e7 btrfs: Convert page cache to XArray
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Acked-by: David Sterba <dsterba@suse.com>
2018-10-21 10:46:41 -04:00
Matthew Wilcox
10bbd23585 pagevec: Use xa_mark_t
Removes sparse warnings.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-10-21 10:46:39 -04:00
Filipe Manana
421f0922a2 Btrfs: fix use-after-free during inode eviction
At inode.c:evict_inode_truncate_pages(), when we iterate over the
inode's extent states, we access an extent state record's "state" field
after we unlocked the inode's io tree lock. This can lead to a
use-after-free issue because after we unlock the io tree that extent
state record might have been freed due to being merged into another
adjacent extent state record (a previous inflight bio for a read
operation finished in the meanwhile which unlocked a range in the io
tree and cause a merge of extent state records, as explained in the
comment before the while loop added in commit 6ca0709756 ("Btrfs: fix
hang during inode eviction due to concurrent readahead")).

Fix this by keeping a copy of the extent state's flags in a local
variable and using it after unlocking the io tree.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=201189
Fixes: b9d0b38928 ("btrfs: Add handler for invalidate page")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-19 12:25:33 +02:00
Josef Bacik
c495144bc6 btrfs: move the dio_sem higher up the callchain
We're getting a lockdep splat because we take the dio_sem under the
log_mutex.  What we really need is to protect fsync() from logging an
extent map for an extent we never waited on higher up, so just guard the
whole thing with dio_sem.

======================================================
WARNING: possible circular locking dependency detected
4.18.0-rc4-xfstests-00025-g5de5edbaf1d4 #411 Not tainted
------------------------------------------------------
aio-dio-invalid/30928 is trying to acquire lock:
0000000092621cfd (&mm->mmap_sem){++++}, at: get_user_pages_unlocked+0x5a/0x1e0

but task is already holding lock:
00000000cefe6b35 (&ei->dio_sem){++++}, at: btrfs_direct_IO+0x3be/0x400

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #5 (&ei->dio_sem){++++}:
       lock_acquire+0xbd/0x220
       down_write+0x51/0xb0
       btrfs_log_changed_extents+0x80/0xa40
       btrfs_log_inode+0xbaf/0x1000
       btrfs_log_inode_parent+0x26f/0xa80
       btrfs_log_dentry_safe+0x50/0x70
       btrfs_sync_file+0x357/0x540
       do_fsync+0x38/0x60
       __ia32_sys_fdatasync+0x12/0x20
       do_fast_syscall_32+0x9a/0x2f0
       entry_SYSENTER_compat+0x84/0x96

-> #4 (&ei->log_mutex){+.+.}:
       lock_acquire+0xbd/0x220
       __mutex_lock+0x86/0xa10
       btrfs_record_unlink_dir+0x2a/0xa0
       btrfs_unlink+0x5a/0xc0
       vfs_unlink+0xb1/0x1a0
       do_unlinkat+0x264/0x2b0
       do_fast_syscall_32+0x9a/0x2f0
       entry_SYSENTER_compat+0x84/0x96

-> #3 (sb_internal#2){.+.+}:
       lock_acquire+0xbd/0x220
       __sb_start_write+0x14d/0x230
       start_transaction+0x3e6/0x590
       btrfs_evict_inode+0x475/0x640
       evict+0xbf/0x1b0
       btrfs_run_delayed_iputs+0x6c/0x90
       cleaner_kthread+0x124/0x1a0
       kthread+0x106/0x140
       ret_from_fork+0x3a/0x50

-> #2 (&fs_info->cleaner_delayed_iput_mutex){+.+.}:
       lock_acquire+0xbd/0x220
       __mutex_lock+0x86/0xa10
       btrfs_alloc_data_chunk_ondemand+0x197/0x530
       btrfs_check_data_free_space+0x4c/0x90
       btrfs_delalloc_reserve_space+0x20/0x60
       btrfs_page_mkwrite+0x87/0x520
       do_page_mkwrite+0x31/0xa0
       __handle_mm_fault+0x799/0xb00
       handle_mm_fault+0x7c/0xe0
       __do_page_fault+0x1d3/0x4a0
       async_page_fault+0x1e/0x30

-> #1 (sb_pagefaults){.+.+}:
       lock_acquire+0xbd/0x220
       __sb_start_write+0x14d/0x230
       btrfs_page_mkwrite+0x6a/0x520
       do_page_mkwrite+0x31/0xa0
       __handle_mm_fault+0x799/0xb00
       handle_mm_fault+0x7c/0xe0
       __do_page_fault+0x1d3/0x4a0
       async_page_fault+0x1e/0x30

-> #0 (&mm->mmap_sem){++++}:
       __lock_acquire+0x42e/0x7a0
       lock_acquire+0xbd/0x220
       down_read+0x48/0xb0
       get_user_pages_unlocked+0x5a/0x1e0
       get_user_pages_fast+0xa4/0x150
       iov_iter_get_pages+0xc3/0x340
       do_direct_IO+0xf93/0x1d70
       __blockdev_direct_IO+0x32d/0x1c20
       btrfs_direct_IO+0x227/0x400
       generic_file_direct_write+0xcf/0x180
       btrfs_file_write_iter+0x308/0x58c
       aio_write+0xf8/0x1d0
       io_submit_one+0x3a9/0x620
       __ia32_compat_sys_io_submit+0xb2/0x270
       do_int80_syscall_32+0x5b/0x1a0
       entry_INT80_compat+0x88/0xa0

other info that might help us debug this:

Chain exists of:
  &mm->mmap_sem --> &ei->log_mutex --> &ei->dio_sem

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ei->dio_sem);
                               lock(&ei->log_mutex);
                               lock(&ei->dio_sem);
  lock(&mm->mmap_sem);

 *** DEADLOCK ***

1 lock held by aio-dio-invalid/30928:
 #0: 00000000cefe6b35 (&ei->dio_sem){++++}, at: btrfs_direct_IO+0x3be/0x400

stack backtrace:
CPU: 0 PID: 30928 Comm: aio-dio-invalid Not tainted 4.18.0-rc4-xfstests-00025-g5de5edbaf1d4 #411
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014
Call Trace:
 dump_stack+0x7c/0xbb
 print_circular_bug.isra.37+0x297/0x2a4
 check_prev_add.constprop.45+0x781/0x7a0
 ? __lock_acquire+0x42e/0x7a0
 validate_chain.isra.41+0x7f0/0xb00
 __lock_acquire+0x42e/0x7a0
 lock_acquire+0xbd/0x220
 ? get_user_pages_unlocked+0x5a/0x1e0
 down_read+0x48/0xb0
 ? get_user_pages_unlocked+0x5a/0x1e0
 get_user_pages_unlocked+0x5a/0x1e0
 get_user_pages_fast+0xa4/0x150
 iov_iter_get_pages+0xc3/0x340
 do_direct_IO+0xf93/0x1d70
 ? __alloc_workqueue_key+0x358/0x490
 ? __blockdev_direct_IO+0x14b/0x1c20
 __blockdev_direct_IO+0x32d/0x1c20
 ? btrfs_run_delalloc_work+0x40/0x40
 ? can_nocow_extent+0x490/0x490
 ? kvm_clock_read+0x1f/0x30
 ? can_nocow_extent+0x490/0x490
 ? btrfs_run_delalloc_work+0x40/0x40
 btrfs_direct_IO+0x227/0x400
 ? btrfs_run_delalloc_work+0x40/0x40
 generic_file_direct_write+0xcf/0x180
 btrfs_file_write_iter+0x308/0x58c
 aio_write+0xf8/0x1d0
 ? kvm_clock_read+0x1f/0x30
 ? __might_fault+0x3e/0x90
 io_submit_one+0x3a9/0x620
 ? io_submit_one+0xe5/0x620
 __ia32_compat_sys_io_submit+0xb2/0x270
 do_int80_syscall_32+0x5b/0x1a0
 entry_INT80_compat+0x88/0xa0

CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-19 12:20:04 +02:00
Josef Bacik
30928e9baa btrfs: don't run delayed_iputs in commit
This could result in a really bad case where we do something like

evict
  evict_refill_and_join
    btrfs_commit_transaction
      btrfs_run_delayed_iputs
        evict
          evict_refill_and_join
            btrfs_commit_transaction
... forever

We have plenty of other places where we run delayed iputs that are much
safer, let those do the work.

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>
2018-10-19 12:20:03 +02:00
Josef Bacik
80ee54bfe8 btrfs: fix insert_reserved error handling
We were not handling the reserved byte accounting properly for data
references.  Metadata was fine, if it errored out the error paths would
free the bytes_reserved count and pin the extent, but it even missed one
of the error cases.  So instead move this handling up into
run_one_delayed_ref so we are sure that both cases are properly cleaned
up in case of a transaction abort.

CC: stable@vger.kernel.org # 4.18+
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>
2018-10-19 12:20:03 +02:00
Josef Bacik
49940bdd57 btrfs: only free reserved extent if we didn't insert it
When we insert the file extent once the ordered extent completes we free
the reserved extent reservation as it'll have been migrated to the
bytes_used counter.  However if we error out after this step we'll still
clear the reserved extent reservation, resulting in a negative
accounting of the reserved bytes for the block group and space info.
Fix this by only doing the free if we didn't successfully insert a file
extent for this extent.

CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-19 12:20:03 +02:00
Josef Bacik
fb5c39d7a8 btrfs: don't use ctl->free_space for max_extent_size
max_extent_size is supposed to be the largest contiguous range for the
space info, and ctl->free_space is the total free space in the block
group.  We need to keep track of these separately and _only_ use the
max_free_space if we don't have a max_extent_size, as that means our
original request was too large to search any of the block groups for and
therefore wouldn't have a max_extent_size set.

CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-19 12:20:03 +02:00
Josef Bacik
ad22cf6ea4 btrfs: set max_extent_size properly
We can't use entry->bytes if our entry is a bitmap entry, we need to use
entry->max_extent_size in that case.  Fix up all the logic to make this
consistent.

CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-19 12:20:03 +02:00
Josef Bacik
21a94f7acf btrfs: reset max_extent_size properly
If we use up our block group before allocating a new one we'll easily
get a max_extent_size that's set really really low, which will result in
a lot of fragmentation.  We need to make sure we're resetting the
max_extent_size when we add a new chunk or add new space.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-19 12:20:03 +02:00
Lu Fengqi
0a9df0df17 btrfs: delayed-ref: extract find_first_ref_head from find_ref_head
The find_ref_head shouldn't return the first entry even if no exact match
is found. So move the hidden behavior to higher level.

Besides, remove the useless local variables in the btrfs_select_ref_head.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
[ reformat comment ]
Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-17 19:21:00 +02:00