Commit graph

5230 commits

Author SHA1 Message Date
Nikolay Borisov
986543fcf5 btrfs: Ensure replaced device doesn't have pending chunk allocation
commit debd1c065d2037919a7da67baf55cc683fee09f0 upstream.

Recent FITRIM work, namely bbbf7243d62d ("btrfs: combine device update
operations during transaction commit") combined the way certain
operations are recoded in a transaction. As a result an ASSERT was added
in dev_replace_finish to ensure the new code works correctly.
Unfortunately I got reports that it's possible to trigger the assert,
meaning that during a device replace it's possible to have an unfinished
chunk allocation on the source device.

This is supposed to be prevented by the fact that a transaction is
committed before finishing the replace oepration and alter acquiring the
chunk mutex. This is not sufficient since by the time the transaction is
committed and the chunk mutex acquired it's possible to allocate a chunk
depending on the workload being executed on the replaced device. This
bug has been present ever since device replace was introduced but there
was never code which checks for it.

The correct way to fix is to ensure that there is no pending device
modification operation when the chunk mutex is acquire and if there is
repeat transaction commit. Unfortunately it's not possible to just
exclude the source device from btrfs_fs_devices::dev_alloc_list since
this causes ENOSPC to be hit in transaction commit.

Fixing that in another way would need to add special cases to handle the
last writes and forbid new ones. The looped transaction fix is more
obvious, and can be easily backported. The runtime of dev-replace is
long so there's no noticeable delay caused by that.

Reported-by: David Sterba <dsterba@suse.com>
Fixes: 391cd9df81 ("Btrfs: fix unprotected alloc list insertion during the finishing procedure of replace")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Nikolay Borisov <nborisov@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>
2019-07-10 09:56:44 +02:00
Naohiro Aota
d38cac353b btrfs: start readahead also in seed devices
commit c4e0540d0ad49c8ceab06cceed1de27c4fe29f6e upstream.

Currently, btrfs does not consult seed devices to start readahead. As a
result, if readahead zone is added to the seed devices, btrfs_reada_wait()
indefinitely wait for the reada_ctl to finish.

You can reproduce the hung by modifying btrfs/163 to have larger initial
file size (e.g. xfs_io pwrite 4M instead of current 256K).

Fixes: 7414a03fbf ("btrfs: initial readahead code and prototypes")
Cc: stable@vger.kernel.org # 3.2+: ce7791ffee1e: Btrfs: fix race between readahead and device replace/removal
Cc: stable@vger.kernel.org # 3.2+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-10 09:56:33 +02:00
Filipe Manana
95c8238695 Btrfs: fix race between readahead and device replace/removal
commit ce7791ffee1e1ee9f97193b817c7dd1fa6746aad upstream.

The list of devices is protected by the device_list_mutex and the device
replace code, in its finishing phase correctly takes that mutex before
removing the source device from that list. However the readahead code was
iterating that list without acquiring the respective mutex leading to
crashes later on due to invalid memory accesses:

[125671.831036] general protection fault: 0000 [#1] PREEMPT SMP
[125671.832129] Modules linked in: btrfs dm_flakey dm_mod crc32c_generic xor raid6_pq acpi_cpufreq tpm_tis tpm ppdev evdev parport_pc psmouse sg parport
processor ser
[125671.834973] CPU: 10 PID: 19603 Comm: kworker/u32:19 Tainted: G        W       4.6.0-rc7-btrfs-next-29+ #1
[125671.834973] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014
[125671.834973] Workqueue: btrfs-readahead btrfs_readahead_helper [btrfs]
[125671.834973] task: ffff8801ac520540 ti: ffff8801ac918000 task.ti: ffff8801ac918000
[125671.834973] RIP: 0010:[<ffffffff81270479>]  [<ffffffff81270479>] __radix_tree_lookup+0x6a/0x105
[125671.834973] RSP: 0018:ffff8801ac91bc28  EFLAGS: 00010206
[125671.834973] RAX: 0000000000000000 RBX: 6b6b6b6b6b6b6b6a RCX: 0000000000000000
[125671.834973] RDX: 0000000000000000 RSI: 00000000000c1bff RDI: ffff88002ebd62a8
[125671.834973] RBP: ffff8801ac91bc70 R08: 0000000000000001 R09: 0000000000000000
[125671.834973] R10: ffff8801ac91bc70 R11: 0000000000000000 R12: ffff88002ebd62a8
[125671.834973] R13: 0000000000000000 R14: 0000000000000000 R15: 00000000000c1bff
[125671.834973] FS:  0000000000000000(0000) GS:ffff88023fd40000(0000) knlGS:0000000000000000
[125671.834973] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[125671.834973] CR2: 000000000073cae4 CR3: 00000000b7723000 CR4: 00000000000006e0
[125671.834973] Stack:
[125671.834973]  0000000000000000 ffff8801422d5600 ffff8802286bbc00 0000000000000000
[125671.834973]  0000000000000001 ffff8802286bbc00 00000000000c1bff 0000000000000000
[125671.834973]  ffff88002e639eb8 ffff8801ac91bc80 ffffffff81270541 ffff8801ac91bcb0
[125671.834973] Call Trace:
[125671.834973]  [<ffffffff81270541>] radix_tree_lookup+0xd/0xf
[125671.834973]  [<ffffffffa04ae6a6>] reada_peer_zones_set_lock+0x3e/0x60 [btrfs]
[125671.834973]  [<ffffffffa04ae8b9>] reada_pick_zone+0x29/0x103 [btrfs]
[125671.834973]  [<ffffffffa04af42f>] reada_start_machine_worker+0x129/0x2d3 [btrfs]
[125671.834973]  [<ffffffffa04880be>] btrfs_scrubparity_helper+0x185/0x3aa [btrfs]
[125671.834973]  [<ffffffffa0488341>] btrfs_readahead_helper+0xe/0x10 [btrfs]
[125671.834973]  [<ffffffff81069691>] process_one_work+0x271/0x4e9
[125671.834973]  [<ffffffff81069dda>] worker_thread+0x1eb/0x2c9
[125671.834973]  [<ffffffff81069bef>] ? rescuer_thread+0x2b3/0x2b3
[125671.834973]  [<ffffffff8106f403>] kthread+0xd4/0xdc
[125671.834973]  [<ffffffff8149e242>] ret_from_fork+0x22/0x40
[125671.834973]  [<ffffffff8106f32f>] ? kthread_stop+0x286/0x286

So fix this by taking the device_list_mutex in the readahead code. We
can't use here the lighter approach of using a rcu_read_lock() and
rcu_read_unlock() pair together with a list_for_each_entry_rcu() call
because we end up doing calls to sleeping functions (kzalloc()) in the
respective code path.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-10 09:56:33 +02:00
Filipe Manana
494447b90d Btrfs: fix race updating log root item during fsync
commit 06989c799f04810f6876900d4760c0edda369cf7 upstream.

When syncing the log, the final phase of a fsync operation, we need to
either create a log root's item or update the existing item in the log
tree of log roots, and that depends on the current value of the log
root's log_transid - if it's 1 we need to create the log root item,
otherwise it must exist already and we update it. Since there is no
synchronization between updating the log_transid and checking it for
deciding whether the log root's item needs to be created or updated, we
end up with a tiny race window that results in attempts to update the
item to fail because the item was not yet created:

              CPU 1                                    CPU 2

  btrfs_sync_log()

    lock root->log_mutex

    set log root's log_transid to 1

    unlock root->log_mutex

                                               btrfs_sync_log()

                                                 lock root->log_mutex

                                                 sets log root's
                                                 log_transid to 2

                                                 unlock root->log_mutex

    update_log_root()

      sees log root's log_transid
      with a value of 2

        calls btrfs_update_root(),
        which fails with -EUCLEAN
        and causes transaction abort

Until recently the race lead to a BUG_ON at btrfs_update_root(), but after
the recent commit 7ac1e464c4d47 ("btrfs: Don't panic when we can't find a
root key") we just abort the current transaction.

A sample trace of the BUG_ON() on a SLE12 kernel:

  ------------[ cut here ]------------
  kernel BUG at ../fs/btrfs/root-tree.c:157!
  Oops: Exception in kernel mode, sig: 5 [#1]
  SMP NR_CPUS=2048 NUMA pSeries
  (...)
  Supported: Yes, External
  CPU: 78 PID: 76303 Comm: rtas_errd Tainted: G                 X 4.4.156-94.57-default #1
  task: c00000ffa906d010 ti: c00000ff42b08000 task.ti: c00000ff42b08000
  NIP: d000000036ae5cdc LR: d000000036ae5cd8 CTR: 0000000000000000
  REGS: c00000ff42b0b860 TRAP: 0700   Tainted: G                 X  (4.4.156-94.57-default)
  MSR: 8000000002029033 <SF,VEC,EE,ME,IR,DR,RI,LE>  CR: 22444484  XER: 20000000
  CFAR: d000000036aba66c SOFTE: 1
  GPR00: d000000036ae5cd8 c00000ff42b0bae0 d000000036bda220 0000000000000054
  GPR04: 0000000000000001 0000000000000000 c00007ffff8d37c8 0000000000000000
  GPR08: c000000000e19c00 0000000000000000 0000000000000000 3736343438312079
  GPR12: 3930373337303434 c000000007a3a800 00000000007fffff 0000000000000023
  GPR16: c00000ffa9d26028 c00000ffa9d261f8 0000000000000010 c00000ffa9d2ab28
  GPR20: c00000ff42b0bc48 0000000000000001 c00000ff9f0d9888 0000000000000001
  GPR24: c00000ffa9d26000 c00000ffa9d261e8 c00000ffa9d2a800 c00000ff9f0d9888
  GPR28: c00000ffa9d26028 c00000ffa9d2aa98 0000000000000001 c00000ffa98f5b20
  NIP [d000000036ae5cdc] btrfs_update_root+0x25c/0x4e0 [btrfs]
  LR [d000000036ae5cd8] btrfs_update_root+0x258/0x4e0 [btrfs]
  Call Trace:
  [c00000ff42b0bae0] [d000000036ae5cd8] btrfs_update_root+0x258/0x4e0 [btrfs] (unreliable)
  [c00000ff42b0bba0] [d000000036b53610] btrfs_sync_log+0x2d0/0xc60 [btrfs]
  [c00000ff42b0bce0] [d000000036b1785c] btrfs_sync_file+0x44c/0x4e0 [btrfs]
  [c00000ff42b0bd80] [c00000000032e300] vfs_fsync_range+0x70/0x120
  [c00000ff42b0bdd0] [c00000000032e44c] do_fsync+0x5c/0xb0
  [c00000ff42b0be10] [c00000000032e8dc] SyS_fdatasync+0x2c/0x40
  [c00000ff42b0be30] [c000000000009488] system_call+0x3c/0x100
  Instruction dump:
  7f43d378 4bffebb9 60000000 88d90008 3d220000 e8b90000 3b390009 e87a01f0
  e8898e08 e8f90000 4bfd48e5 60000000 <0fe00000> e95b0060 39200004 394a0ea0
  ---[ end trace 8f2dc8f919cabab8 ]---

So fix this by doing the check of log_transid and updating or creating the
log root's item while holding the root's log_mutex.

Fixes: 7237f18336 ("Btrfs: fix tree logs parallel sync")
CC: stable@vger.kernel.org # 4.4+
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>
2019-06-11 12:24:09 +02:00
Tobin C. Harding
5c9a20390c btrfs: sysfs: don't leak memory when failing add fsid
commit e32773357d5cc271b1d23550b3ed026eb5c2a468 upstream.

A failed call to kobject_init_and_add() must be followed by a call to
kobject_put().  Currently in the error path when adding fs_devices we
are missing this call.  This could be fixed by calling
btrfs_sysfs_remove_fsid() if btrfs_sysfs_add_fsid() returns an error or
by adding a call to kobject_put() directly in btrfs_sysfs_add_fsid().
Here we choose the second option because it prevents the slightly
unusual error path handling requirements of kobject from leaking out
into btrfs functions.

Add a call to kobject_put() in the error path of kobject_add_and_init().
This causes the release method to be called if kobject_init_and_add()
fails.  open_tree() is the function that calls btrfs_sysfs_add_fsid()
and the error code in this function is already written with the
assumption that the release method is called during the error path of
open_tree() (as seen by the call to btrfs_sysfs_remove_fsid() under the
fail_fsdev_sysfs label).

Cc: stable@vger.kernel.org # v4.4+
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-11 12:23:52 +02:00
Filipe Manana
0fa88718cd Btrfs: fix race between ranged fsync and writeback of adjacent ranges
commit 0c713cbab6200b0ab6473b50435e450a6e1de85d upstream.

When we do a full fsync (the bit BTRFS_INODE_NEEDS_FULL_SYNC is set in the
inode) that happens to be ranged, which happens during a msync() or writes
for files opened with O_SYNC for example, we can end up with a corrupt log,
due to different file extent items representing ranges that overlap with
each other, or hit some assertion failures.

When doing a ranged fsync we only flush delalloc and wait for ordered
exents within that range. If while we are logging items from our inode
ordered extents for adjacent ranges complete, we end up in a race that can
make us insert the file extent items that overlap with others we logged
previously and the assertion failures.

For example, if tree-log.c:copy_items() receives a leaf that has the
following file extents items, all with a length of 4K and therefore there
is an implicit hole in the range 68K to 72K - 1:

  (257 EXTENT_ITEM 64K), (257 EXTENT_ITEM 72K), (257 EXTENT_ITEM 76K), ...

It copies them to the log tree. However due to the need to detect implicit
holes, it may release the path, in order to look at the previous leaf to
detect an implicit hole, and then later it will search again in the tree
for the first file extent item key, with the goal of locking again the
leaf (which might have changed due to concurrent changes to other inodes).

However when it locks again the leaf containing the first key, the key
corresponding to the extent at offset 72K may not be there anymore since
there is an ordered extent for that range that is finishing (that is,
somewhere in the middle of btrfs_finish_ordered_io()), and it just
removed the file extent item but has not yet replaced it with a new file
extent item, so the part of copy_items() that does hole detection will
decide that there is a hole in the range starting from 68K to 76K - 1,
and therefore insert a file extent item to represent that hole, having
a key offset of 68K. After that we now have a log tree with 2 different
extent items that have overlapping ranges:

 1) The file extent item copied before copy_items() released the path,
    which has a key offset of 72K and a length of 4K, representing the
    file range 72K to 76K - 1.

 2) And a file extent item representing a hole that has a key offset of
    68K and a length of 8K, representing the range 68K to 76K - 1. This
    item was inserted after releasing the path, and overlaps with the
    extent item inserted before.

The overlapping extent items can cause all sorts of unpredictable and
incorrect behaviour, either when replayed or if a fast (non full) fsync
happens later, which can trigger a BUG_ON() when calling
btrfs_set_item_key_safe() through __btrfs_drop_extents(), producing a
trace like the following:

  [61666.783269] ------------[ cut here ]------------
  [61666.783943] kernel BUG at fs/btrfs/ctree.c:3182!
  [61666.784644] invalid opcode: 0000 [#1] PREEMPT SMP
  (...)
  [61666.786253] task: ffff880117b88c40 task.stack: ffffc90008168000
  [61666.786253] RIP: 0010:btrfs_set_item_key_safe+0x7c/0xd2 [btrfs]
  [61666.786253] RSP: 0018:ffffc9000816b958 EFLAGS: 00010246
  [61666.786253] RAX: 0000000000000000 RBX: 000000000000000f RCX: 0000000000030000
  [61666.786253] RDX: 0000000000000000 RSI: ffffc9000816ba4f RDI: ffffc9000816b937
  [61666.786253] RBP: ffffc9000816b998 R08: ffff88011dae2428 R09: 0000000000001000
  [61666.786253] R10: 0000160000000000 R11: 6db6db6db6db6db7 R12: ffff88011dae2418
  [61666.786253] R13: ffffc9000816ba4f R14: ffff8801e10c4118 R15: ffff8801e715c000
  [61666.786253] FS:  00007f6060a18700(0000) GS:ffff88023f5c0000(0000) knlGS:0000000000000000
  [61666.786253] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [61666.786253] CR2: 00007f6060a28000 CR3: 0000000213e69000 CR4: 00000000000006e0
  [61666.786253] Call Trace:
  [61666.786253]  __btrfs_drop_extents+0x5e3/0xaad [btrfs]
  [61666.786253]  ? time_hardirqs_on+0x9/0x14
  [61666.786253]  btrfs_log_changed_extents+0x294/0x4e0 [btrfs]
  [61666.786253]  ? release_extent_buffer+0x38/0xb4 [btrfs]
  [61666.786253]  btrfs_log_inode+0xb6e/0xcdc [btrfs]
  [61666.786253]  ? lock_acquire+0x131/0x1c5
  [61666.786253]  ? btrfs_log_inode_parent+0xee/0x659 [btrfs]
  [61666.786253]  ? arch_local_irq_save+0x9/0xc
  [61666.786253]  ? btrfs_log_inode_parent+0x1f5/0x659 [btrfs]
  [61666.786253]  btrfs_log_inode_parent+0x223/0x659 [btrfs]
  [61666.786253]  ? arch_local_irq_save+0x9/0xc
  [61666.786253]  ? lockref_get_not_zero+0x2c/0x34
  [61666.786253]  ? rcu_read_unlock+0x3e/0x5d
  [61666.786253]  btrfs_log_dentry_safe+0x60/0x7b [btrfs]
  [61666.786253]  btrfs_sync_file+0x317/0x42c [btrfs]
  [61666.786253]  vfs_fsync_range+0x8c/0x9e
  [61666.786253]  SyS_msync+0x13c/0x1c9
  [61666.786253]  entry_SYSCALL_64_fastpath+0x18/0xad

A sample of a corrupt log tree leaf with overlapping extents I got from
running btrfs/072:

      item 14 key (295 108 200704) itemoff 2599 itemsize 53
              extent data disk bytenr 0 nr 0
              extent data offset 0 nr 458752 ram 458752
      item 15 key (295 108 659456) itemoff 2546 itemsize 53
              extent data disk bytenr 4343541760 nr 770048
              extent data offset 606208 nr 163840 ram 770048
      item 16 key (295 108 663552) itemoff 2493 itemsize 53
              extent data disk bytenr 4343541760 nr 770048
              extent data offset 610304 nr 155648 ram 770048
      item 17 key (295 108 819200) itemoff 2440 itemsize 53
              extent data disk bytenr 4334788608 nr 4096
              extent data offset 0 nr 4096 ram 4096

The file extent item at offset 659456 (item 15) ends at offset 823296
(659456 + 163840) while the next file extent item (item 16) starts at
offset 663552.

Another different problem that the race can trigger is a failure in the
assertions at tree-log.c:copy_items(), which expect that the first file
extent item key we found before releasing the path exists after we have
released path and that the last key we found before releasing the path
also exists after releasing the path:

  $ cat -n fs/btrfs/tree-log.c
  4080          if (need_find_last_extent) {
  4081                  /* btrfs_prev_leaf could return 1 without releasing the path */
  4082                  btrfs_release_path(src_path);
  4083                  ret = btrfs_search_slot(NULL, inode->root, &first_key,
  4084                                  src_path, 0, 0);
  4085                  if (ret < 0)
  4086                          return ret;
  4087                  ASSERT(ret == 0);
  (...)
  4103                  if (i >= btrfs_header_nritems(src_path->nodes[0])) {
  4104                          ret = btrfs_next_leaf(inode->root, src_path);
  4105                          if (ret < 0)
  4106                                  return ret;
  4107                          ASSERT(ret == 0);
  4108                          src = src_path->nodes[0];
  4109                          i = 0;
  4110                          need_find_last_extent = true;
  4111                  }
  (...)

The second assertion implicitly expects that the last key before the path
release still exists, because the surrounding while loop only stops after
we have found that key. When this assertion fails it produces a stack like
this:

  [139590.037075] assertion failed: ret == 0, file: fs/btrfs/tree-log.c, line: 4107
  [139590.037406] ------------[ cut here ]------------
  [139590.037707] kernel BUG at fs/btrfs/ctree.h:3546!
  [139590.038034] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC PTI
  [139590.038340] CPU: 1 PID: 31841 Comm: fsstress Tainted: G        W         5.0.0-btrfs-next-46 #1
  (...)
  [139590.039354] RIP: 0010:assfail.constprop.24+0x18/0x1a [btrfs]
  (...)
  [139590.040397] RSP: 0018:ffffa27f48f2b9b0 EFLAGS: 00010282
  [139590.040730] RAX: 0000000000000041 RBX: ffff897c635d92c8 RCX: 0000000000000000
  [139590.041105] RDX: 0000000000000000 RSI: ffff897d36a96868 RDI: ffff897d36a96868
  [139590.041470] RBP: ffff897d1b9a0708 R08: 0000000000000000 R09: 0000000000000000
  [139590.041815] R10: 0000000000000008 R11: 0000000000000000 R12: 0000000000000013
  [139590.042159] R13: 0000000000000227 R14: ffff897cffcbba88 R15: 0000000000000001
  [139590.042501] FS:  00007f2efc8dee80(0000) GS:ffff897d36a80000(0000) knlGS:0000000000000000
  [139590.042847] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [139590.043199] CR2: 00007f8c064935e0 CR3: 0000000232252002 CR4: 00000000003606e0
  [139590.043547] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  [139590.043899] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  [139590.044250] Call Trace:
  [139590.044631]  copy_items+0xa3f/0x1000 [btrfs]
  [139590.045009]  ? generic_bin_search.constprop.32+0x61/0x200 [btrfs]
  [139590.045396]  btrfs_log_inode+0x7b3/0xd70 [btrfs]
  [139590.045773]  btrfs_log_inode_parent+0x2b3/0xce0 [btrfs]
  [139590.046143]  ? do_raw_spin_unlock+0x49/0xc0
  [139590.046510]  btrfs_log_dentry_safe+0x4a/0x70 [btrfs]
  [139590.046872]  btrfs_sync_file+0x3b6/0x440 [btrfs]
  [139590.047243]  btrfs_file_write_iter+0x45b/0x5c0 [btrfs]
  [139590.047592]  __vfs_write+0x129/0x1c0
  [139590.047932]  vfs_write+0xc2/0x1b0
  [139590.048270]  ksys_write+0x55/0xc0
  [139590.048608]  do_syscall_64+0x60/0x1b0
  [139590.048946]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  [139590.049287] RIP: 0033:0x7f2efc4be190
  (...)
  [139590.050342] RSP: 002b:00007ffe743243a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
  [139590.050701] RAX: ffffffffffffffda RBX: 0000000000008d58 RCX: 00007f2efc4be190
  [139590.051067] RDX: 0000000000008d58 RSI: 00005567eca0f370 RDI: 0000000000000003
  [139590.051459] RBP: 0000000000000024 R08: 0000000000000003 R09: 0000000000008d60
  [139590.051863] R10: 0000000000000078 R11: 0000000000000246 R12: 0000000000000003
  [139590.052252] R13: 00000000003d3507 R14: 00005567eca0f370 R15: 0000000000000000
  (...)
  [139590.055128] ---[ end trace 193f35d0215cdeeb ]---

So fix this race between a full ranged fsync and writeback of adjacent
ranges by flushing all delalloc and waiting for all ordered extents to
complete before logging the inode. This is the simplest way to solve the
problem because currently the full fsync path does not deal with ranges
at all (it assumes a full range from 0 to LLONG_MAX) and it always needs
to look at adjacent ranges for hole detection. For use cases of ranged
fsyncs this can make a few fsyncs slower but on the other hand it can
make some following fsyncs to other ranges do less work or no need to do
anything at all. A full fsync is rare anyway and happens only once after
loading/creating an inode and once after less common operations such as a
shrinking truncate.

This is an issue that exists for a long time, and was often triggered by
generic/127, because it does mmap'ed writes and msync (which triggers a
ranged fsync). Adding support for the tree checker to detect overlapping
extents (next patch in the series) and trigger a WARN() when such cases
are found, and then calling btrfs_check_leaf_full() at the end of
btrfs_insert_file_extent() made the issue much easier to detect. Running
btrfs/072 with that change to the tree checker and making fsstress open
files always with O_SYNC made it much easier to trigger the issue (as
triggering it with generic/127 is very rare).

CC: stable@vger.kernel.org # 3.16+
Reviewed-by: Josef Bacik <josef@toxicpanda.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>
2019-06-11 12:23:52 +02:00
Nikolay Borisov
7d64186e79 btrfs: Honour FITRIM range constraints during free space trim
commit c2d1b3aae33605a61cbab445d8ae1c708ccd2698 upstream.

Up until now trimming the freespace was done irrespective of what the
arguments of the FITRIM ioctl were. For example fstrim's -o/-l arguments
will be entirely ignored. Fix it by correctly handling those paramter.
This requires breaking if the found freespace extent is after the end of
the passed range as well as completing trim after trimming
fstrim_range::len bytes.

Fixes: 499f377f49 ("btrfs: iterate over unused chunk space in FITRIM")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Nikolay Borisov <nborisov@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>
2019-06-11 12:23:50 +02:00
Filipe Manana
686e4352e3 Btrfs: do not start a transaction at iterate_extent_inodes()
commit bfc61c36260ca990937539cd648ede3cd749bc10 upstream.

When finding out which inodes have references on a particular extent, done
by backref.c:iterate_extent_inodes(), from the BTRFS_IOC_LOGICAL_INO (both
v1 and v2) ioctl and from scrub we use the transaction join API to grab a
reference on the currently running transaction, since in order to give
accurate results we need to inspect the delayed references of the currently
running transaction.

However, if there is currently no running transaction, the join operation
will create a new transaction. This is inefficient as the transaction will
eventually be committed, doing unnecessary IO and introducing a potential
point of failure that will lead to a transaction abort due to -ENOSPC, as
recently reported [1].

That's because the join, creates the transaction but does not reserve any
space, so when attempting to update the root item of the root passed to
btrfs_join_transaction(), during the transaction commit, we can end up
failling with -ENOSPC. Users of a join operation are supposed to actually
do some filesystem changes and reserve space by some means, which is not
the case of iterate_extent_inodes(), it is a read-only operation for all
contextes from which it is called.

The reported [1] -ENOSPC failure stack trace is the following:

 heisenberg kernel: ------------[ cut here ]------------
 heisenberg kernel: BTRFS: Transaction aborted (error -28)
 heisenberg kernel: WARNING: CPU: 0 PID: 7137 at fs/btrfs/root-tree.c:136 btrfs_update_root+0x22b/0x320 [btrfs]
(...)
 heisenberg kernel: CPU: 0 PID: 7137 Comm: btrfs-transacti Not tainted 4.19.0-4-amd64 #1 Debian 4.19.28-2
 heisenberg kernel: Hardware name: FUJITSU LIFEBOOK U757/FJNB2A5, BIOS Version 1.21 03/19/2018
 heisenberg kernel: RIP: 0010:btrfs_update_root+0x22b/0x320 [btrfs]
(...)
 heisenberg kernel: RSP: 0018:ffffb5448828bd40 EFLAGS: 00010286
 heisenberg kernel: RAX: 0000000000000000 RBX: ffff8ed56bccef50 RCX: 0000000000000006
 heisenberg kernel: RDX: 0000000000000007 RSI: 0000000000000092 RDI: ffff8ed6bda166a0
 heisenberg kernel: RBP: 00000000ffffffe4 R08: 00000000000003df R09: 0000000000000007
 heisenberg kernel: R10: 0000000000000000 R11: 0000000000000001 R12: ffff8ed63396a078
 heisenberg kernel: R13: ffff8ed092d7c800 R14: ffff8ed64f5db028 R15: ffff8ed6bd03d068
 heisenberg kernel: FS:  0000000000000000(0000) GS:ffff8ed6bda00000(0000) knlGS:0000000000000000
 heisenberg kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 heisenberg kernel: CR2: 00007f46f75f8000 CR3: 0000000310a0a002 CR4: 00000000003606f0
 heisenberg kernel: DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 heisenberg kernel: DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 heisenberg kernel: Call Trace:
 heisenberg kernel:  commit_fs_roots+0x166/0x1d0 [btrfs]
 heisenberg kernel:  ? _cond_resched+0x15/0x30
 heisenberg kernel:  ? btrfs_run_delayed_refs+0xac/0x180 [btrfs]
 heisenberg kernel:  btrfs_commit_transaction+0x2bd/0x870 [btrfs]
 heisenberg kernel:  ? start_transaction+0x9d/0x3f0 [btrfs]
 heisenberg kernel:  transaction_kthread+0x147/0x180 [btrfs]
 heisenberg kernel:  ? btrfs_cleanup_transaction+0x530/0x530 [btrfs]
 heisenberg kernel:  kthread+0x112/0x130
 heisenberg kernel:  ? kthread_bind+0x30/0x30
 heisenberg kernel:  ret_from_fork+0x35/0x40
 heisenberg kernel: ---[ end trace 05de912e30e012d9 ]---

So fix that by using the attach API, which does not create a transaction
when there is currently no running transaction.

[1] https://lore.kernel.org/linux-btrfs/b2a668d7124f1d3e410367f587926f622b3f03a4.camel@scientia.net/

Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
CC: stable@vger.kernel.org # 4.4+
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>
2019-06-11 12:23:38 +02:00
Andrea Righi
61bde5e5af btrfs: raid56: properly unmap parity page in finish_parity_scrub()
commit 3897b6f0a859288c22fb793fad11ec2327e60fcd upstream.

Parity page is incorrectly unmapped in finish_parity_scrub(), triggering
a reference counter bug on i386, i.e.:

 [ 157.662401] kernel BUG at mm/highmem.c:349!
 [ 157.666725] invalid opcode: 0000 [#1] SMP PTI

The reason is that kunmap(p_page) was completely left out, so we never
did an unmap for the p_page and the loop unmapping the rbio page was
iterating over the wrong number of stripes: unmapping should be done
with nr_data instead of rbio->real_stripes.

Test case to reproduce the bug:

 - create a raid5 btrfs filesystem:
   # mkfs.btrfs -m raid5 -d raid5 /dev/sdb /dev/sdc /dev/sdd /dev/sde

 - mount it:
   # mount /dev/sdb /mnt

 - run btrfs scrub in a loop:
   # while :; do btrfs scrub start -BR /mnt; done

BugLink: https://bugs.launchpad.net/bugs/1812845
Fixes: 5a6ac9eacb ("Btrfs, raid56: support parity scrub on raid56")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Andrea Righi <andrea.righi@canonical.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>
2019-04-03 06:23:26 +02:00
Josef Bacik
a23f00416a btrfs: remove WARN_ON in log_dir_items
commit 2cc8334270e281815c3850c3adea363c51f21e0d upstream.

When Filipe added the recursive directory logging stuff in
2f2ff0ee5e ("Btrfs: fix metadata inconsistencies after directory
fsync") he specifically didn't take the directory i_mutex for the
children directories that we need to log because of lockdep.  This is
generally fine, but can lead to this WARN_ON() tripping if we happen to
run delayed deletion's in between our first search and our second search
of dir_item/dir_indexes for this directory.  We expect this to happen,
so the WARN_ON() isn't necessary.  Drop the WARN_ON() and add a comment
so we know why this case can happen.

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>
2019-04-03 06:23:26 +02:00
Filipe Manana
efe908169f Btrfs: fix corruption reading shared and compressed extents after hole punching
commit 8e928218780e2f1cf2f5891c7575e8f0b284fcce upstream.

In the past we had data corruption when reading compressed extents that
are shared within the same file and they are consecutive, this got fixed
by commit 005efedf2c ("Btrfs: fix read corruption of compressed and
shared extents") and by commit 808f80b467 ("Btrfs: update fix for read
corruption of compressed and shared extents"). However there was a case
that was missing in those fixes, which is when the shared and compressed
extents are referenced with a non-zero offset. The following shell script
creates a reproducer for this issue:

  #!/bin/bash

  mkfs.btrfs -f /dev/sdc &> /dev/null
  mount -o compress /dev/sdc /mnt/sdc

  # Create a file with 3 consecutive compressed extents, each has an
  # uncompressed size of 128Kb and a compressed size of 4Kb.
  for ((i = 1; i <= 3; i++)); do
      head -c 4096 /dev/zero
      for ((j = 1; j <= 31; j++)); do
          head -c 4096 /dev/zero | tr '\0' "\377"
      done
  done > /mnt/sdc/foobar
  sync

  echo "Digest after file creation:   $(md5sum /mnt/sdc/foobar)"

  # Clone the first extent into offsets 128K and 256K.
  xfs_io -c "reflink /mnt/sdc/foobar 0 128K 128K" /mnt/sdc/foobar
  xfs_io -c "reflink /mnt/sdc/foobar 0 256K 128K" /mnt/sdc/foobar
  sync

  echo "Digest after cloning:         $(md5sum /mnt/sdc/foobar)"

  # Punch holes into the regions that are already full of zeroes.
  xfs_io -c "fpunch 0 4K" /mnt/sdc/foobar
  xfs_io -c "fpunch 128K 4K" /mnt/sdc/foobar
  xfs_io -c "fpunch 256K 4K" /mnt/sdc/foobar
  sync

  echo "Digest after hole punching:   $(md5sum /mnt/sdc/foobar)"

  echo "Dropping page cache..."
  sysctl -q vm.drop_caches=1
  echo "Digest after hole punching:   $(md5sum /mnt/sdc/foobar)"

  umount /dev/sdc

When running the script we get the following output:

  Digest after file creation:   5a0888d80d7ab1fd31c229f83a3bbcc8  /mnt/sdc/foobar
  linked 131072/131072 bytes at offset 131072
  128 KiB, 1 ops; 0.0033 sec (36.960 MiB/sec and 295.6830 ops/sec)
  linked 131072/131072 bytes at offset 262144
  128 KiB, 1 ops; 0.0015 sec (78.567 MiB/sec and 628.5355 ops/sec)
  Digest after cloning:         5a0888d80d7ab1fd31c229f83a3bbcc8  /mnt/sdc/foobar
  Digest after hole punching:   5a0888d80d7ab1fd31c229f83a3bbcc8  /mnt/sdc/foobar
  Dropping page cache...
  Digest after hole punching:   fba694ae8664ed0c2e9ff8937e7f1484  /mnt/sdc/foobar

This happens because after reading all the pages of the extent in the
range from 128K to 256K for example, we read the hole at offset 256K
and then when reading the page at offset 260K we don't submit the
existing bio, which is responsible for filling all the page in the
range 128K to 256K only, therefore adding the pages from range 260K
to 384K to the existing bio and submitting it after iterating over the
entire range. Once the bio completes, the uncompressed data fills only
the pages in the range 128K to 256K because there's no more data read
from disk, leaving the pages in the range 260K to 384K unfilled. It is
just a slightly different variant of what was solved by commit
005efedf2c ("Btrfs: fix read corruption of compressed and shared
extents").

Fix this by forcing a bio submit, during readpages(), whenever we find a
compressed extent map for a page that is different from the extent map
for the previous page or has a different starting offset (in case it's
the same compressed extent), instead of the extent map's original start
offset.

A test case for fstests follows soon.

Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Fixes: 808f80b467 ("Btrfs: update fix for read corruption of compressed and shared extents")
Fixes: 005efedf2c ("Btrfs: fix read corruption of compressed and shared extents")
Cc: stable@vger.kernel.org # 4.3+
Tested-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
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>
2019-03-23 08:44:36 +01:00
Johannes Thumshirn
eb4763b1bb btrfs: ensure that a DUP or RAID1 block group has exactly two stripes
commit 349ae63f40638a28c6fce52e8447c2d14b84cc0c upstream.

We recently had a customer issue with a corrupted filesystem. When
trying to mount this image btrfs panicked with a division by zero in
calc_stripe_length().

The corrupt chunk had a 'num_stripes' value of 1. calc_stripe_length()
takes this value and divides it by the number of copies the RAID profile
is expected to have to calculate the amount of data stripes. As a DUP
profile is expected to have 2 copies this division resulted in 1/2 = 0.
Later then the 'data_stripes' variable is used as a divisor in the
stripe length calculation which results in a division by 0 and thus a
kernel panic.

When encountering a filesystem with a DUP block group and a
'num_stripes' value unequal to 2, refuse mounting as the image is
corrupted and will lead to unexpected behaviour.

Code inspection showed a RAID1 block group has the same issues.

Fixes: e06cd3dd7cea ("Btrfs: add validadtion checks for chunk loading")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-23 08:44:36 +01:00
Josef Bacik
bc42c4f338 btrfs: wait on ordered extents on abort cleanup
commit 74d5d229b1bf60f93bff244b2dfc0eb21ec32a07 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>
2019-01-26 09:42:50 +01:00
Shaokun Zhang
09527e390e btrfs: tree-checker: Fix misleading group system information
commit 761333f2f50ccc887aa9957ae829300262c0d15b upstream.

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: fce466eab7ac6 ("btrfs: tree-checker: Verify block_group_item")
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>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:10 +01:00
Qu Wenruo
40f2dd6106 btrfs: tree-checker: Check level for leaves and nodes
commit f556faa46eb4e96d0d0772e74ecf66781e132f72 upstream.

Although we have tree level check at tree read runtime, it's completely
based on its parent level.
We still need to do accurate level check to avoid invalid tree blocks
sneak into kernel space.

The check itself is simple, for leaf its level should always be 0.
For nodes its level should be in range [1, BTRFS_MAX_LEVEL - 1].

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Su Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[bwh: Backported to 4.4:
 - Pass root instead of fs_info to generic_err()
 - Adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:10 +01:00
Qu Wenruo
98620167ed btrfs: Verify that every chunk has corresponding block group at mount time
commit 7ef49515fa6727cb4b6f2f5b0ffbc5fc20a9f8c6 upstream.

If a crafted image has missing block group items, it could cause
unexpected behavior and breaks the assumption of 1:1 chunk<->block group
mapping.

Although we have the block group -> chunk mapping check, we still need
chunk -> block group mapping check.

This patch will do extra check to ensure each chunk has its
corresponding block group.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=199847
Reported-by: Xu Wen <wen.xu@gatech.edu>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Gu Jinxiang <gujx@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[bwh: Backported to 4.4: adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:09 +01:00
Qu Wenruo
ee5e37a267 btrfs: Check that each block group has corresponding chunk at mount time
commit 514c7dca85a0bf40be984dab0b477403a6db901f upstream.

A crafted btrfs image with incorrect chunk<->block group mapping will
trigger a lot of unexpected things as the mapping is essential.

Although the problem can be caught by block group item checker
added in "btrfs: tree-checker: Verify block_group_item", it's still not
sufficient.  A sufficiently valid block group item can pass the check
added by the mentioned patch but could fail to match the existing chunk.

This patch will add extra block group -> chunk mapping check, to ensure
we have a completely matching (start, len, flags) chunk for each block
group at mount time.

Here we reuse the original helper find_first_block_group(), which is
already doing the basic bg -> chunk checks, adding further checks of the
start/len and type flags.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=199837
Reported-by: Xu Wen <wen.xu@gatech.edu>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Su Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[bwh: Backported to 4.4: Use root->fs_info instead of fs_info]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:09 +01:00
Gu Jinxiang
50962a7b48 btrfs: validate type when reading a chunk
commit 315409b0098fb2651d86553f0436b70502b29bb2 upstream.

Reported in https://bugzilla.kernel.org/show_bug.cgi?id=199839, with an
image that has an invalid chunk type but does not return an error.

Add chunk type check in btrfs_check_chunk_valid, to detect the wrong
type combinations.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=199839
Reported-by: Xu Wen <wen.xu@gatech.edu>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Gu Jinxiang <gujx@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[bwh: Backported to 4.4: Use root->fs_info instead of fs_info]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:09 +01:00
Qu Wenruo
42d2638204 btrfs: tree-checker: Detect invalid and empty essential trees
commit ba480dd4db9f1798541eb2d1c423fc95feee8d36 upstream.

A crafted image has empty root tree block, which will later cause NULL
pointer dereference.

The following trees should never be empty:
1) Tree root
   Must contain at least root items for extent tree, device tree and fs
   tree

2) Chunk tree
   Or we can't even bootstrap as it contains the mapping.

3) Fs tree
   At least inode item for top level inode (.).

4) Device tree
   Dev extents for chunks

5) Extent tree
   Must have corresponding extent for each chunk.

If any of them is empty, we are sure the fs is corrupted and no need to
mount it.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=199847
Reported-by: Xu Wen <wen.xu@gatech.edu>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Tested-by: Gu Jinxiang <gujx@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[bwh: Backported to 4.4: Pass root instead of fs_info to generic_err()]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:09 +01:00
Qu Wenruo
ae94efaf2b btrfs: tree-checker: Verify block_group_item
commit fce466eab7ac6baa9d2dcd88abcf945be3d4a089 upstream.

A crafted image with invalid block group items could make free space cache
code to cause panic.

We could detect such invalid block group item by checking:
1) Item size
   Known fixed value.
2) Block group size (key.offset)
   We have an upper limit on block group item (10G)
3) Chunk objectid
   Known fixed value.
4) Type
   Only 4 valid type values, DATA, METADATA, SYSTEM and DATA|METADATA.
   No more than 1 bit set for profile type.
5) Used space
   No more than the block group size.

This should allow btrfs to detect and refuse to mount the crafted image.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=199849
Reported-by: Xu Wen <wen.xu@gatech.edu>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Gu Jinxiang <gujx@cn.fujitsu.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Gu Jinxiang <gujx@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[bwh: Backported to 4.4:
 - In check_leaf_item(), pass root->fs_info to check_block_group_item()
 - Include <linux/sizes.h> (in ctree.h, to match upstream)
 - Adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:09 +01:00
David Sterba
5b84bbce60 btrfs: tree-check: reduce stack consumption in check_dir_item
commit e2683fc9d219430f5b78889b50cde7f40efeba7b upstream.

I've noticed that the updated item checker stack consumption increased
dramatically in 542f5385e20cf97447 ("btrfs: tree-checker: Add checker
for dir item")

tree-checker.c:check_leaf                    +552 (176 -> 728)

The array is 255 bytes long, dynamic allocation would slow down the
sanity checks so it's more reasonable to keep it on-stack. Moving the
variable to the scope of use reduces the stack usage again

tree-checker.c:check_leaf                    -264 (728 -> 464)

Reviewed-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:09 +01:00
Arnd Bergmann
047ac3914e btrfs: tree-checker: use %zu format string for size_t
commit 7cfad65297bfe0aa2996cd72d21c898aa84436d9 upstream.

The return value of sizeof() is of type size_t, so we must print it
using the %z format modifier rather than %l to avoid this warning
on some architectures:

fs/btrfs/tree-checker.c: In function 'check_dir_item':
fs/btrfs/tree-checker.c:273:50: error: format '%lu' expects argument of type 'long unsigned int', but argument 5 has type 'u32' {aka 'unsigned int'} [-Werror=format=]

Fixes: 005887f2e3e0 ("btrfs: tree-checker: Add checker for dir item")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:09 +01:00
Qu Wenruo
a8f4164922 btrfs: tree-checker: Add checker for dir item
commit ad7b0368f33cffe67fecd302028915926e50ef7e upstream.

Add checker for dir item, for key types DIR_ITEM, DIR_INDEX and
XATTR_ITEM.

This checker does comprehensive checks for:

1) dir_item header and its data size
   Against item boundary and maximum name/xattr length.
   This part is mostly the same as old verify_dir_item().

2) dir_type
   Against maximum file types, and against key type.
   Since XATTR key should only have FT_XATTR dir item, and normal dir
   item type should not have XATTR key.

   The check between key->type and dir_type is newly introduced by this
   patch.

3) name hash
   For XATTR and DIR_ITEM key, key->offset is name hash (crc32c).
   Check the hash of the name against the key to ensure it's correct.

   The name hash check is only found in btrfs-progs before this patch.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Su Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[bwh: Backported to 4.4: BTRFS_MAX_XATTR_SIZE() takes a root instead of an
 fs_info, and yields a value of type size_t instead of unsigned int]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:09 +01:00
Qu Wenruo
7782b38595 btrfs: tree-checker: Fix false panic for sanity test
commit 69fc6cbbac542c349b3d350d10f6e394c253c81d upstream.

[BUG]
If we run btrfs with CONFIG_BTRFS_FS_RUN_SANITY_TESTS=y, it will
instantly cause kernel panic like:

------
...
assertion failed: 0, file: fs/btrfs/disk-io.c, line: 3853
...
Call Trace:
 btrfs_mark_buffer_dirty+0x187/0x1f0 [btrfs]
 setup_items_for_insert+0x385/0x650 [btrfs]
 __btrfs_drop_extents+0x129a/0x1870 [btrfs]
...
-----

[Cause]
Btrfs will call btrfs_check_leaf() in btrfs_mark_buffer_dirty() to check
if the leaf is valid with CONFIG_BTRFS_FS_RUN_SANITY_TESTS=y.

However quite some btrfs_mark_buffer_dirty() callers(*) don't really
initialize its item data but only initialize its item pointers, leaving
item data uninitialized.

This makes tree-checker catch uninitialized data as error, causing
such panic.

*: These callers include but not limited to
setup_items_for_insert()
btrfs_split_item()
btrfs_expand_item()

[Fix]
Add a new parameter @check_item_data to btrfs_check_leaf().
With @check_item_data set to false, item data check will be skipped and
fallback to old btrfs_check_leaf() behavior.

So we can still get early warning if we screw up item pointers, and
avoid false panic.

Cc: Filipe Manana <fdmanana@gmail.com>
Reported-by: Lakshmipathi.G <lakshmipathi.g@gmail.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[bwh: Backported to 4.4: adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:08 +01:00
Qu Wenruo
b3b3eaf729 btrfs: tree-checker: Enhance btrfs_check_node output
commit bba4f29896c986c4cec17bc0f19f2ce644fceae1 upstream.

Use inline function to replace macro since we don't need
stringification.
(Macro still exists until all callers get updated)

And add more info about the error, and replace EIO with EUCLEAN.

For nr_items error, report if it's too large or too small, and output
the valid value range.

For node block pointer, added a new alignment checker.

For key order, also output the next key to make the problem more
obvious.

Signed-off-by: Qu Wenruo <quwenruo.btrfs@gmx.com>
[ wording adjustments, unindented long strings ]
Signed-off-by: David Sterba <dsterba@suse.com>
[bwh: Backported to 4.4:
 - Use root->sectorsize instead of root->fs_info->sectorsize
 - BTRFS_NODEPTRS_PER_BLOCK() takes a root instead of an fs_info, and yields
   a value of type size_t instead of unsigned int]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:08 +01:00
Qu Wenruo
e74422ec14 btrfs: Move leaf and node validation checker to tree-checker.c
commit 557ea5dd003d371536f6b4e8f7c8209a2b6fd4e3 upstream.

It's no doubt the comprehensive tree block checker will become larger,
so moving them into their own files is quite reasonable.

Signed-off-by: Qu Wenruo <quwenruo.btrfs@gmx.com>
[ wording adjustments ]
Signed-off-by: David Sterba <dsterba@suse.com>
[bwh: Backported to 4.4:
 - The moved code is slightly different
 - Adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:08 +01:00
Qu Wenruo
68c23d0974 btrfs: Add checker for EXTENT_CSUM
commit 4b865cab96fe2a30ed512cf667b354bd291b3b0a upstream.

EXTENT_CSUM checker is a relatively easy one, only needs to check:

1) Objectid
   Fixed to BTRFS_EXTENT_CSUM_OBJECTID

2) Key offset alignment
   Must be aligned to sectorsize

3) Item size alignedment
   Must be aligned to csum size

Signed-off-by: Qu Wenruo <quwenruo.btrfs@gmx.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[bwh: Backported to 4.4: Use root->sectorsize instead of
 root->fs_info->sectorsize]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:08 +01:00
Qu Wenruo
56ab82441c btrfs: Add sanity check for EXTENT_DATA when reading out leaf
commit 40c3c40947324d9f40bf47830c92c59a9bbadf4a upstream.

Add extra checks for item with EXTENT_DATA type.  This checks the
following thing:

0) Key offset
   All key offsets must be aligned to sectorsize.
   Inline extent must have 0 for key offset.

1) Item size
   Uncompressed inline file extent size must match item size.
   (Compressed inline file extent has no information about its on-disk size.)
   Regular/preallocated file extent size must be a fixed value.

2) Every member of regular file extent item
   Including alignment for bytenr and offset, possible value for
   compression/encryption/type.

3) Type/compression/encode must be one of the valid values.

This should be the most comprehensive and strict check in the context
of btrfs_item for EXTENT_DATA.

Signed-off-by: Qu Wenruo <quwenruo.btrfs@gmx.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ switch to BTRFS_FILE_EXTENT_TYPES, similar to what
  BTRFS_COMPRESS_TYPES does ]
Signed-off-by: David Sterba <dsterba@suse.com>
[bwh: Backported to 4.4:
 - Use root->sectorsize instead of root->fs_info->sectorsize
 - Adjust filename]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:08 +01:00
Qu Wenruo
dc7a1fbccd btrfs: Check if item pointer overlaps with the item itself
commit 7f43d4affb2a254d421ab20b0cf65ac2569909fb upstream.

Function check_leaf() checks if any item pointer points outside of the
leaf, but it doesn't check if the pointer overlaps with the item itself.

Normally only the last item may be the victim, but adding such check is
never a bad idea anyway.

Signed-off-by: Qu Wenruo <quwenruo.btrfs@gmx.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:08 +01:00
Qu Wenruo
4583bc2c64 btrfs: Refactor check_leaf function for later expansion
commit c3267bbaa9cae09b62960eafe33ad19196803285 upstream.

Current check_leaf() function does a good job checking key order and
item offset/size.

However it only checks from slot 0 to the last but one slot, this is
good but makes later expansion hard.

So this refactoring iterates from slot 0 to the last slot.
For key comparison, it uses a key with all 0 as initial key, so all
valid keys should be larger than that.

And for item size/offset checks, it compares current item end with
previous item offset.
For slot 0, use leaf end as a special case.

This makes later item/key offset checks and item size checks easier to
be implemented.

Also, makes check_leaf() to return -EUCLEAN other than -EIO to indicate
error.

Signed-off-by: Qu Wenruo <quwenruo.btrfs@gmx.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[bwh: Backported to 4.4:
 - BTRFS_LEAF_DATA_SIZE() takes a root rather than an fs_info
 - Adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:08 +01:00
Jeff Mahoney
31c986aa7e btrfs: struct-funcs, constify readers
commit 1cbb1f454e5321e47fc1e6b233066c7ccc979d15 upstream.

We have reader helpers for most of the on-disk structures that use
an extent_buffer and pointer as offset into the buffer that are
read-only.  We should mark them as const and, in turn, allow consumers
of these interfaces to mark the buffers const as well.

No impact on code, but serves as documentation that a buffer is intended
not to be modified.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:07 +01:00
Filipe Manana
89643604a8 Btrfs: fix emptiness check for dirtied extent buffers at check_leaf()
commit f177d73949bf758542ca15a1c1945bd2e802cc65 upstream.

We can not simply use the owner field from an extent buffer's header to
get the id of the respective tree when the extent buffer is from a
relocation tree. When we create the root for a relocation tree we leave
(on purpose) the owner field with the same value as the subvolume's tree
root (we do this at ctree.c:btrfs_copy_root()). So we must ignore extent
buffers from relocation trees, which have the BTRFS_HEADER_FLAG_RELOC
flag set, because otherwise we will always consider the extent buffer
as not being the root of the tree (the root of original subvolume tree
is always different from the root of the respective relocation tree).

This lead to assertion failures when running with the integrity checker
enabled (CONFIG_BTRFS_FS_CHECK_INTEGRITY=y) such as the following:

[  643.393409] BTRFS critical (device sdg): corrupt leaf, non-root leaf's nritems is 0: block=38506496, root=260, slot=0
[  643.397609] BTRFS info (device sdg): leaf 38506496 total ptrs 0 free space 3995
[  643.407075] assertion failed: 0, file: fs/btrfs/disk-io.c, line: 4078
[  643.408425] ------------[ cut here ]------------
[  643.409112] kernel BUG at fs/btrfs/ctree.h:3419!
[  643.409773] invalid opcode: 0000 [#1] PREEMPT SMP
[  643.410447] Modules linked in: dm_flakey dm_mod crc32c_generic btrfs xor raid6_pq ppdev psmouse acpi_cpufreq parport_pc evdev parport tpm_tis tpm_tis_core pcspkr serio_raw i2c_piix4 sg tpm i2c_core button processor loop autofs4 ext4 crc16 jbd2 mbcache sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring scsi_mod virtio e1000 floppy
[  643.414356] CPU: 11 PID: 32726 Comm: btrfs Not tainted 4.8.0-rc8-btrfs-next-35+ #1
[  643.414356] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014
[  643.414356] task: ffff880145e95b00 task.stack: ffff88014826c000
[  643.414356] RIP: 0010:[<ffffffffa0352759>]  [<ffffffffa0352759>] assfail.constprop.41+0x1c/0x1e [btrfs]
[  643.414356] RSP: 0018:ffff88014826fa28  EFLAGS: 00010292
[  643.414356] RAX: 0000000000000039 RBX: ffff88014e2d7c38 RCX: 0000000000000001
[  643.414356] RDX: ffff88023f4d2f58 RSI: ffffffff81806c63 RDI: 00000000ffffffff
[  643.414356] RBP: ffff88014826fa28 R08: 0000000000000001 R09: 0000000000000000
[  643.414356] R10: ffff88014826f918 R11: ffffffff82f3c5ed R12: ffff880172910000
[  643.414356] R13: ffff880233992230 R14: ffff8801a68a3310 R15: fffffffffffffff8
[  643.414356] FS:  00007f9ca305e8c0(0000) GS:ffff88023f4c0000(0000) knlGS:0000000000000000
[  643.414356] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  643.414356] CR2: 00007f9ca3071000 CR3: 000000015d01b000 CR4: 00000000000006e0
[  643.414356] Stack:
[  643.414356]  ffff88014826fa50 ffffffffa02d655a 000000000000000a ffff88014e2d7c38
[  643.414356]  0000000000000000 ffff88014826faa8 ffffffffa02b72f3 ffff88014826fab8
[  643.414356]  00ffffffa03228e4 0000000000000000 0000000000000000 ffff8801bbd4e000
[  643.414356] Call Trace:
[  643.414356]  [<ffffffffa02d655a>] btrfs_mark_buffer_dirty+0xdf/0xe5 [btrfs]
[  643.414356]  [<ffffffffa02b72f3>] btrfs_copy_root+0x18a/0x1d1 [btrfs]
[  643.414356]  [<ffffffffa0322921>] create_reloc_root+0x72/0x1ba [btrfs]
[  643.414356]  [<ffffffffa03267c2>] btrfs_init_reloc_root+0x7b/0xa7 [btrfs]
[  643.414356]  [<ffffffffa02d9e44>] record_root_in_trans+0xdf/0xed [btrfs]
[  643.414356]  [<ffffffffa02db04e>] btrfs_record_root_in_trans+0x50/0x6a [btrfs]
[  643.414356]  [<ffffffffa030ad2b>] create_subvol+0x472/0x773 [btrfs]
[  643.414356]  [<ffffffffa030b406>] btrfs_mksubvol+0x3da/0x463 [btrfs]
[  643.414356]  [<ffffffffa030b406>] ? btrfs_mksubvol+0x3da/0x463 [btrfs]
[  643.414356]  [<ffffffff810781ac>] ? preempt_count_add+0x65/0x68
[  643.414356]  [<ffffffff811a6e97>] ? __mnt_want_write+0x62/0x77
[  643.414356]  [<ffffffffa030b55d>] btrfs_ioctl_snap_create_transid+0xce/0x187 [btrfs]
[  643.414356]  [<ffffffffa030b67d>] btrfs_ioctl_snap_create+0x67/0x81 [btrfs]
[  643.414356]  [<ffffffffa030ecfd>] btrfs_ioctl+0x508/0x20dd [btrfs]
[  643.414356]  [<ffffffff81293e39>] ? __this_cpu_preempt_check+0x13/0x15
[  643.414356]  [<ffffffff81155eca>] ? handle_mm_fault+0x976/0x9ab
[  643.414356]  [<ffffffff81091300>] ? arch_local_irq_save+0x9/0xc
[  643.414356]  [<ffffffff8119a2b0>] vfs_ioctl+0x18/0x34
[  643.414356]  [<ffffffff8119a8e8>] do_vfs_ioctl+0x581/0x600
[  643.414356]  [<ffffffff814b9552>] ? entry_SYSCALL_64_fastpath+0x5/0xa8
[  643.414356]  [<ffffffff81093fe9>] ? trace_hardirqs_on_caller+0x17b/0x197
[  643.414356]  [<ffffffff8119a9be>] SyS_ioctl+0x57/0x79
[  643.414356]  [<ffffffff814b9565>] entry_SYSCALL_64_fastpath+0x18/0xa8
[  643.414356]  [<ffffffff81091b08>] ? trace_hardirqs_off_caller+0x3f/0xaa
[  643.414356] Code: 89 83 88 00 00 00 31 c0 5b 41 5c 41 5d 5d c3 55 89 f1 48 c7 c2 98 bc 35 a0 48 89 fe 48 c7 c7 05 be 35 a0 48 89 e5 e8 13 46 dd e0 <0f> 0b 55 89 f1 48 c7 c2 9f d3 35 a0 48 89 fe 48 c7 c7 7a d5 35
[  643.414356] RIP  [<ffffffffa0352759>] assfail.constprop.41+0x1c/0x1e [btrfs]
[  643.414356]  RSP <ffff88014826fa28>
[  643.468267] ---[ end trace 6a1b3fb1a9d7d6e3 ]---

This can be easily reproduced by running xfstests with the integrity
checker enabled.

Fixes: 1ba98d086fe3 (Btrfs: detect corruption when non-root leaf has zero item)
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:07 +01:00
Liu Bo
452042d27b Btrfs: memset to avoid stale content in btree leaf
commit 851cd173f06045816528176001cf82948282029c upstream.

This is an additional patch to
"Btrfs: memset to avoid stale content in btree node block".

This uses memset to initialize the unused space in a leaf to avoid
potential stale content, which may be incurred by pushing items
between sibling leaves.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:07 +01:00
Liu Bo
79ddacdf1d Btrfs: kill BUG_ON in run_delayed_tree_ref
commit 02794222c4132ac003e7281fb71f4ec1645ffc87 upstream.

In a corrupted btrfs image, we can come across this BUG_ON and
get an unreponsive system, but if we return errors instead,
its caller can handle everything gracefully by aborting the current
transaction.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:07 +01:00
Liu Bo
d6719cf116 Btrfs: improve check_node to avoid reading corrupted nodes
commit 6b722c1747d533ac6d4df110dc8233db46918b65 upstream.

We need to check items in a node to make sure that we're reading
a valid one, otherwise we could get various crashes while processing
delayed_refs.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:07 +01:00
Liu Bo
731b866795 Btrfs: memset to avoid stale content in btree node block
commit 3eb548ee3a8042d95ad81be254e67a5222c24e03 upstream.

During updating btree, we could push items between sibling
nodes/leaves, for leaves data sections starts reversely from
the end of the block while for nodes we only have key pairs
which are stored one by one from the start of the block.

So we could do try to push key pairs from one node to the next
node right in the tree, and after that, we update the node's
nritems to reflect the correct end while leaving the stale
content in the node.  One may intentionally corrupt the fs
image and access the stale content by bumping the nritems and
causes various crashes.

This takes the in-memory @nritems as the correct one and
gets to memset the unused part of a btree node.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:07 +01:00
Liu Bo
4b522570f9 Btrfs: fix BUG_ON in btrfs_mark_buffer_dirty
commit ef85b25e982b5bba1530b936e283ef129f02ab9d upstream.

This can only happen with CONFIG_BTRFS_FS_CHECK_INTEGRITY=y.

Commit 1ba98d0 ("Btrfs: detect corruption when non-root leaf has zero item")
assumes that a leaf is its root when leaf->bytenr == btrfs_root_bytenr(root),
however, we should not use btrfs_root_bytenr(root) since it's mainly got
updated during committing transaction.  So the check can fail when doing
COW on this leaf while it is a root.

This changes to use "if (leaf == btrfs_root_node(root))" instead, just like
how we check whether leaf is a root in __btrfs_cow_block().

Fixes: 1ba98d086fe3 (Btrfs: detect corruption when non-root leaf has zero item)
Reported-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:07 +01:00
Liu Bo
1ef3ecf373 Btrfs: check btree node's nritems
commit 053ab70f0604224c7893b43f9d9d5efa283580d6 upstream.

When btree node (level = 1) has nritems which equals to zero,
we can end up with panic due to insert_ptr()'s

BUG_ON(slot > nritems);

where slot is 1 and nritems is 0, as copy_for_split() calls
insert_ptr(.., path->slots[1] + 1, ...);

A invalid value results in the whole mess, this adds the check
for btree's node nritems so that we stop reading block when
when something is wrong.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:07 +01:00
Liu Bo
dc059e58af Btrfs: detect corruption when non-root leaf has zero item
commit 1ba98d086fe3a14d6a31f2f66dbab70c45d00f63 upstream.

Right now we treat leaf which has zero item as a valid one
because we could have an empty tree, that is, a root that is
also a leaf without any item, however, in the same case but
when the leaf is not a root, we can end up with hitting the
BUG_ON(1) in btrfs_extend_item() called by
setup_inline_extent_backref().

This makes us check the situation as a corruption if leaf is
not its own root.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:06 +01:00
Josef Bacik
4bf414d2ff Btrfs: fix em leak in find_first_block_group
commit 187ee58c62c1d0d238d3dc4835869d33e1869906 upstream.

We need to call free_extent_map() on the em we look up.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:06 +01:00
Liu Bo
a155ec9322 Btrfs: check inconsistence between chunk and block group
commit 6fb37b756acce6d6e045f79c3764206033f617b4 upstream.

With btrfs-corrupt-block, one can drop one chunk item and mounting
will end up with a panic in btrfs_full_stripe_len().

This doesn't not remove the BUG_ON, but instead checks it a bit
earlier when we find the block group item.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:06 +01:00
Liu Bo
41fbc64930 Btrfs: add validadtion checks for chunk loading
commit e06cd3dd7cea50e87663a88acdfdb7ac1c53a5ca upstream.

To prevent fuzzed filesystem images from panic the whole system,
we need various validation checks to refuse to mount such an image
if btrfs finds any invalid value during loading chunks, including
both sys_array and regular chunks.

Note that these checks may not be sufficient to cover all corner cases,
feel free to add more checks.

Reported-by: Vegard Nossum <vegard.nossum@oracle.com>
Reported-by: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:06 +01:00
Qu Wenruo
66b8c06f93 btrfs: Enhance chunk validation check
commit f04b772bfc17f502703794f4d100d12155c1a1a9 upstream.

Enhance chunk validation:
1) Num_stripes
   We already have such check but it's only in super block sys chunk
   array.
   Now check all on-disk chunks.

2) Chunk logical
   It should be aligned to sector size.
   This behavior should be *DOUBLE CHECKED* for 64K sector size like
   PPC64 or AArch64.
   Maybe we can found some hidden bugs.

3) Chunk length
   Same as chunk logical, should be aligned to sector size.

4) Stripe length
   It should be power of 2.

5) Chunk type
   Any bit out of TYPE_MAS | PROFILE_MASK is invalid.

With all these much restrict rules, several fuzzed image reported in
mail list should no longer cause kernel panic.

Reported-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:06 +01:00
Jeff Mahoney
67405a1e78 btrfs: cleanup, stop casting for extent_map->lookup everywhere
commit 95617d69326ce386c95e33db7aeb832b45ee9f8f upstream.

Overloading extent_map->bdev to struct map_lookup * might have started out
as a means to an end, but it's a pattern that's used all over the place
now. Let's get rid of the casting and just add a union instead.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-16 22:16:06 +01:00
Robbie Ko
44b0243956 Btrfs: send, fix infinite loop due to directory rename dependencies
[ Upstream commit a4390aee72713d9e73f1132bcdeb17d72fbbf974 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-12-17 21:55:10 +01:00
Filipe Manana
f43cae2c89 Btrfs: fix use-after-free when dumping free space
commit 9084cb6a24bf5838a665af92ded1af8363f9e563 upstream.

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>
Cc: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-13 09:21:32 +01:00
Nikolay Borisov
8732a2f41c btrfs: Always try all copies when reading extent buffers
commit f8397d69daef06d358430d3054662fb597e37c00 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-13 09:21:32 +01:00
Josef Bacik
fed44f079c btrfs: release metadata before running delayed refs
We want to release the unused reservation we have since it refills the
delayed refs reserve, which will make everything go smoother when
running the delayed refs if we're short on our reservation.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-12-13 09:21:27 +01:00
Filipe Manana
e3fc2151d7 Btrfs: ensure path name is null terminated at btrfs_control_ioctl
commit f505754fd6599230371cb01b9332754ddc104be1 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-13 09:21:26 +01:00
Qu Wenruo
522ac5232a btrfs: Ensure btrfs_trim_fs can trim the whole filesystem
commit 6ba9fc8e628becf0e3ec94083450d089b0dec5f5 upstream.

[BUG]
fstrim on some btrfs only trims the unallocated space, not trimming any
space in existing block groups.

[CAUSE]
Before fstrim_range passed to btrfs_trim_fs(), it gets truncated to
range [0, super->total_bytes).  So later btrfs_trim_fs() will only be
able to trim block groups in range [0, super->total_bytes).

While for btrfs, any bytenr aligned to sectorsize is valid, since btrfs
uses its logical address space, there is nothing limiting the location
where we put block groups.

For filesystem with frequent balance, it's quite easy to relocate all
block groups and bytenr of block groups will start beyond
super->total_bytes.

In that case, btrfs will not trim existing block groups.

[FIX]
Just remove the truncation in btrfs_ioctl_fitrim(), so btrfs_trim_fs()
can get the unmodified range, which is normally set to [0, U64_MAX].

Reported-by: Chris Murphy <lists@colorremedies.com>
Fixes: f4c697e640 ("btrfs: return EINVAL if start > total_bytes in fitrim ioctl")
CC: <stable@vger.kernel.org> # v4.4+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@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>
2018-12-01 09:46:41 +01:00