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724521 commits

Author SHA1 Message Date
Edmund Nadolski 18bf591ba9 btrfs: add missing initialization in btrfs_check_shared
This patch addresses an issue that causes fiemap to falsely
report a shared extent.  The test case is as follows:

xfs_io -f -d -c "pwrite -b 16k 0 64k" -c "fiemap -v" /media/scratch/file5
sync
xfs_io  -c "fiemap -v" /media/scratch/file5

which gives the resulting output:

wrote 65536/65536 bytes at offset 0
64 KiB, 4 ops; 0.0000 sec (121.359 MiB/sec and 7766.9903 ops/sec)
/media/scratch/file5:
 EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
   0: [0..127]:        24576..24703       128 0x2001
/media/scratch/file5:
 EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
   0: [0..127]:        24576..24703       128   0x1

This is because btrfs_check_shared calls find_parent_nodes
repeatedly in a loop, passing a share_check struct to report
the count of shared extent. But btrfs_check_shared does not
re-initialize the count value to zero for subsequent calls
from the loop, resulting in a false share count value. This
is a regressive behavior from 4.13.

With proper re-initialization the test result is as follows:

wrote 65536/65536 bytes at offset 0
64 KiB, 4 ops; 0.0000 sec (110.035 MiB/sec and 7042.2535 ops/sec)
/media/scratch/file5:
 EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
   0: [0..127]:        24576..24703       128   0x1
/media/scratch/file5:
 EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
   0: [0..127]:        24576..24703       128   0x1

which corrects the regression.

Fixes: 3ec4d3238a ("btrfs: allow backref search checks for shared extents")
Signed-off-by: Edmund Nadolski <enadolski@suse.com>
[ add text from cover letter to changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-14 22:26:46 +01:00
Dmitriy Gorokh 047fdea634 btrfs: Fix NULL pointer exception in find_bio_stripe
On detaching of a disk which is a part of a RAID6 filesystem, the
following kernel OOPS may happen:

[63122.680461] BTRFS error (device sdo): bdev /dev/sdo errs: wr 0, rd 0, flush 1, corrupt 0, gen 0
[63122.719584] BTRFS warning (device sdo): lost page write due to IO error on /dev/sdo
[63122.719587] BTRFS error (device sdo): bdev /dev/sdo errs: wr 1, rd 0, flush 1, corrupt 0, gen 0
[63122.803516] BTRFS warning (device sdo): lost page write due to IO error on /dev/sdo
[63122.803519] BTRFS error (device sdo): bdev /dev/sdo errs: wr 2, rd 0, flush 1, corrupt 0, gen 0
[63122.863902] BTRFS critical (device sdo): fatal error on device /dev/sdo
[63122.935338] BUG: unable to handle kernel NULL pointer dereference at 0000000000000080
[63122.946554] IP: fail_bio_stripe+0x58/0xa0 [btrfs]
[63122.958185] PGD 9ecda067 P4D 9ecda067 PUD b2b37067 PMD 0
[63122.971202] Oops: 0000 [#1] SMP
[63123.006760] CPU: 0 PID: 3979 Comm: kworker/u8:9 Tainted: G W 4.14.2-16-scst34x+ #8
[63123.007091] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[63123.007402] Workqueue: btrfs-worker btrfs_worker_helper [btrfs]
[63123.007595] task: ffff880036ea4040 task.stack: ffffc90006384000
[63123.007796] RIP: 0010:fail_bio_stripe+0x58/0xa0 [btrfs]
[63123.007968] RSP: 0018:ffffc90006387ad8 EFLAGS: 00010287
[63123.008140] RAX: 0000000000000002 RBX: ffff88004beaa0b8 RCX: ffff8800b2bd5690
[63123.008359] RDX: 0000000000000000 RSI: ffff88007bb43500 RDI: ffff88004beaa000
[63123.008621] RBP: ffffc90006387ae8 R08: 0000000099100000 R09: ffff8800b2bd5600
[63123.008840] R10: 0000000000000004 R11: 0000000000010000 R12: ffff88007bb43500
[63123.009059] R13: 00000000fffffffb R14: ffff880036fc5180 R15: 0000000000000004
[63123.009278] FS: 0000000000000000(0000) GS:ffff8800b7000000(0000) knlGS:0000000000000000
[63123.009564] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[63123.009748] CR2: 0000000000000080 CR3: 00000000b0866000 CR4: 00000000000406f0
[63123.009969] Call Trace:
[63123.010085] raid_write_end_io+0x7e/0x80 [btrfs]
[63123.010251] bio_endio+0xa1/0x120
[63123.010378] generic_make_request+0x218/0x270
[63123.010921] submit_bio+0x66/0x130
[63123.011073] finish_rmw+0x3fc/0x5b0 [btrfs]
[63123.011245] full_stripe_write+0x96/0xc0 [btrfs]
[63123.011428] raid56_parity_write+0x117/0x170 [btrfs]
[63123.011604] btrfs_map_bio+0x2ec/0x320 [btrfs]
[63123.011759] ? ___cache_free+0x1c5/0x300
[63123.011909] __btrfs_submit_bio_done+0x26/0x50 [btrfs]
[63123.012087] run_one_async_done+0x9c/0xc0 [btrfs]
[63123.012257] normal_work_helper+0x19e/0x300 [btrfs]
[63123.012429] btrfs_worker_helper+0x12/0x20 [btrfs]
[63123.012656] process_one_work+0x14d/0x350
[63123.012888] worker_thread+0x4d/0x3a0
[63123.013026] ? _raw_spin_unlock_irqrestore+0x15/0x20
[63123.013192] kthread+0x109/0x140
[63123.013315] ? process_scheduled_works+0x40/0x40
[63123.013472] ? kthread_stop+0x110/0x110
[63123.013610] ret_from_fork+0x25/0x30
[63123.014469] RIP: fail_bio_stripe+0x58/0xa0 [btrfs] RSP: ffffc90006387ad8
[63123.014678] CR2: 0000000000000080
[63123.016590] ---[ end trace a295ea7259c17880 ]—

This is reproducible in a cycle, where a series of writes is followed by
SCSI device delete command. The test may take up to few minutes.

Fixes: 74d46992e0 ("block: replace bi_bdev with a gendisk pointer and partitions index")
[ no signed-off-by provided ]
Author: Dmitriy Gorokh <Dmitriy.Gorokh@wdc.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>
2018-03-14 22:26:35 +01:00
Filipe Manana 1f250e929a Btrfs: fix log replay failure after unlink and link combination
If we have a file with 2 (or more) hard links in the same directory,
remove one of the hard links, create a new file (or link an existing file)
in the same directory with the name of the removed hard link, and then
finally fsync the new file, we end up with a log that fails to replay,
causing a mount failure.

Example:

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

  $ mkdir /mnt/testdir
  $ touch /mnt/testdir/foo
  $ ln /mnt/testdir/foo /mnt/testdir/bar

  $ sync

  $ unlink /mnt/testdir/bar
  $ touch /mnt/testdir/bar
  $ xfs_io -c "fsync" /mnt/testdir/bar

  <power failure>

  $ mount /dev/sdb /mnt
  mount: mount(2) failed: /mnt: No such file or directory

When replaying the log, for that example, we also see the following in
dmesg/syslog:

  [71813.671307] BTRFS info (device dm-0): failed to delete reference to bar, inode 258 parent 257
  [71813.674204] ------------[ cut here ]------------
  [71813.675694] BTRFS: Transaction aborted (error -2)
  [71813.677236] WARNING: CPU: 1 PID: 13231 at fs/btrfs/inode.c:4128 __btrfs_unlink_inode+0x17b/0x355 [btrfs]
  [71813.679669] Modules linked in: btrfs xfs f2fs dm_flakey dm_mod dax ghash_clmulni_intel ppdev pcbc aesni_intel aes_x86_64 crypto_simd cryptd glue_helper evdev psmouse i2c_piix4 parport_pc i2c_core pcspkr sg serio_raw parport button sunrpc loop autofs4 ext4 crc16 mbcache jbd2 zstd_decompress zstd_compress xxhash raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod ata_generic sd_mod virtio_scsi ata_piix libata virtio_pci virtio_ring crc32c_intel floppy virtio e1000 scsi_mod [last unloaded: btrfs]
  [71813.679669] CPU: 1 PID: 13231 Comm: mount Tainted: G        W        4.15.0-rc9-btrfs-next-56+ #1
  [71813.679669] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014
  [71813.679669] RIP: 0010:__btrfs_unlink_inode+0x17b/0x355 [btrfs]
  [71813.679669] RSP: 0018:ffffc90001cef738 EFLAGS: 00010286
  [71813.679669] RAX: 0000000000000025 RBX: ffff880217ce4708 RCX: 0000000000000001
  [71813.679669] RDX: 0000000000000000 RSI: ffffffff81c14bae RDI: 00000000ffffffff
  [71813.679669] RBP: ffffc90001cef7c0 R08: 0000000000000001 R09: 0000000000000001
  [71813.679669] R10: ffffc90001cef5e0 R11: ffffffff8343f007 R12: ffff880217d474c8
  [71813.679669] R13: 00000000fffffffe R14: ffff88021ccf1548 R15: 0000000000000101
  [71813.679669] FS:  00007f7cee84c480(0000) GS:ffff88023fc80000(0000) knlGS:0000000000000000
  [71813.679669] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [71813.679669] CR2: 00007f7cedc1abf9 CR3: 00000002354b4003 CR4: 00000000001606e0
  [71813.679669] Call Trace:
  [71813.679669]  btrfs_unlink_inode+0x17/0x41 [btrfs]
  [71813.679669]  drop_one_dir_item+0xfa/0x131 [btrfs]
  [71813.679669]  add_inode_ref+0x71e/0x851 [btrfs]
  [71813.679669]  ? __lock_is_held+0x39/0x71
  [71813.679669]  ? replay_one_buffer+0x53/0x53a [btrfs]
  [71813.679669]  replay_one_buffer+0x4a4/0x53a [btrfs]
  [71813.679669]  ? rcu_read_unlock+0x3a/0x57
  [71813.679669]  ? __lock_is_held+0x39/0x71
  [71813.679669]  walk_up_log_tree+0x101/0x1d2 [btrfs]
  [71813.679669]  walk_log_tree+0xad/0x188 [btrfs]
  [71813.679669]  btrfs_recover_log_trees+0x1fa/0x31e [btrfs]
  [71813.679669]  ? replay_one_extent+0x544/0x544 [btrfs]
  [71813.679669]  open_ctree+0x1cf6/0x2209 [btrfs]
  [71813.679669]  btrfs_mount_root+0x368/0x482 [btrfs]
  [71813.679669]  ? trace_hardirqs_on_caller+0x14c/0x1a6
  [71813.679669]  ? __lockdep_init_map+0x176/0x1c2
  [71813.679669]  ? mount_fs+0x64/0x10b
  [71813.679669]  mount_fs+0x64/0x10b
  [71813.679669]  vfs_kern_mount+0x68/0xce
  [71813.679669]  btrfs_mount+0x13e/0x772 [btrfs]
  [71813.679669]  ? trace_hardirqs_on_caller+0x14c/0x1a6
  [71813.679669]  ? __lockdep_init_map+0x176/0x1c2
  [71813.679669]  ? mount_fs+0x64/0x10b
  [71813.679669]  mount_fs+0x64/0x10b
  [71813.679669]  vfs_kern_mount+0x68/0xce
  [71813.679669]  do_mount+0x6e5/0x973
  [71813.679669]  ? memdup_user+0x3e/0x5c
  [71813.679669]  SyS_mount+0x72/0x98
  [71813.679669]  entry_SYSCALL_64_fastpath+0x1e/0x8b
  [71813.679669] RIP: 0033:0x7f7cedf150ba
  [71813.679669] RSP: 002b:00007ffca71da688 EFLAGS: 00000206
  [71813.679669] Code: 7f a0 e8 51 0c fd ff 48 8b 43 50 f0 0f ba a8 30 2c 00 00 02 72 17 41 83 fd fb 74 11 44 89 ee 48 c7 c7 7d 11 7f a0 e8 38 f5 8d e0 <0f> ff 44 89 e9 ba 20 10 00 00 eb 4d 48 8b 4d b0 48 8b 75 88 4c
  [71813.679669] ---[ end trace 83bd473fc5b4663b ]---
  [71813.854764] BTRFS: error (device dm-0) in __btrfs_unlink_inode:4128: errno=-2 No such entry
  [71813.886994] BTRFS: error (device dm-0) in btrfs_replay_log:2307: errno=-2 No such entry (Failed to recover log tree)
  [71813.903357] BTRFS error (device dm-0): cleaner transaction attach returned -30
  [71814.128078] BTRFS error (device dm-0): open_ctree failed

This happens because the log has inode reference items for both inode 258
(the first file we created) and inode 259 (the second file created), and
when processing the reference item for inode 258, we replace the
corresponding item in the subvolume tree (which has two names, "foo" and
"bar") witht he one in the log (which only has one name, "foo") without
removing the corresponding dir index keys from the parent directory.
Later, when processing the inode reference item for inode 259, which has
a name of "bar" associated to it, we notice that dir index entries exist
for that name and for a different inode, so we attempt to unlink that
name, which fails because the inode reference item for inode 258 no longer
has the name "bar" associated to it, making a call to btrfs_unlink_inode()
fail with a -ENOENT error.

Fix this by unlinking all the names in an inode reference item from a
subvolume tree that are not present in the inode reference item found in
the log tree, before overwriting it with the item from the log tree.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-01 16:18:40 +01:00
Filipe Manana 9a6509c4da Btrfs: fix log replay failure after linking special file and fsync
If in the same transaction we rename a special file (fifo, character/block
device or symbolic link), create a hard link for it having its old name
then sync the log, we will end up with a log that can not be replayed and
at when attempting to replay it, an EEXIST error is returned and mounting
the filesystem fails. Example scenario:

  $ mkfs.btrfs -f /dev/sdc
  $ mount /dev/sdc /mnt
  $ mkdir /mnt/testdir
  $ mkfifo /mnt/testdir/foo
  # Make sure everything done so far is durably persisted.
  $ sync

  # Create some unrelated file and fsync it, this is just to create a log
  # tree. The file must be in the same directory as our special file.
  $ touch /mnt/testdir/f1
  $ xfs_io -c "fsync" /mnt/testdir/f1

  # Rename our special file and then create a hard link with its old name.
  $ mv /mnt/testdir/foo /mnt/testdir/bar
  $ ln /mnt/testdir/bar /mnt/testdir/foo

  # Create some other unrelated file and fsync it, this is just to persist
  # the log tree which was modified by the previous rename and link
  # operations. Alternatively we could have modified file f1 and fsync it.
  $ touch /mnt/f2
  $ xfs_io -c "fsync" /mnt/f2

  <power failure>

  $ mount /dev/sdc /mnt
  mount: mount /dev/sdc on /mnt failed: File exists

This happens because when both the log tree and the subvolume's tree have
an entry in the directory "testdir" with the same name, that is, there
is one key (258 INODE_REF 257) in the subvolume tree and another one in
the log tree (where 258 is the inode number of our special file and 257
is the inode for directory "testdir"). Only the data of those two keys
differs, in the subvolume tree the index field for inode reference has
a value of 3 while the log tree it has a value of 5. Because the same key
exists in both trees, but have different index, the log replay fails with
an -EEXIST error when attempting to replay the inode reference from the
log tree.

Fix this by setting the last_unlink_trans field of the inode (our special
file) to the current transaction id when a hard link is created, as this
forces logging the parent directory inode, solving the conflict at log
replay time.

A new generic test case for fstests was also submitted.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-01 16:18:34 +01:00
Filipe Manana d4dfc0f4d3 Btrfs: send, fix issuing write op when processing hole in no data mode
When doing an incremental send of a filesystem with the no-holes feature
enabled, we end up issuing a write operation when using the no data mode
send flag, instead of issuing an update extent operation. Fix this by
issuing the update extent operation instead.

Trivial reproducer:

  $ mkfs.btrfs -f -O no-holes /dev/sdc
  $ mkfs.btrfs -f /dev/sdd
  $ mount /dev/sdc /mnt/sdc
  $ mount /dev/sdd /mnt/sdd

  $ xfs_io -f -c "pwrite -S 0xab 0 32K" /mnt/sdc/foobar
  $ btrfs subvolume snapshot -r /mnt/sdc /mnt/sdc/snap1

  $ xfs_io -c "fpunch 8K 8K" /mnt/sdc/foobar
  $ btrfs subvolume snapshot -r /mnt/sdc /mnt/sdc/snap2

  $ btrfs send /mnt/sdc/snap1 | btrfs receive /mnt/sdd
  $ btrfs send --no-data -p /mnt/sdc/snap1 /mnt/sdc/snap2 \
       | btrfs receive -vv /mnt/sdd

Before this change the output of the second receive command is:

  receiving snapshot snap2 uuid=f6922049-8c22-e544-9ff9-fc6755918447...
  utimes
  write foobar, offset 8192, len 8192
  utimes foobar
  BTRFS_IOC_SET_RECEIVED_SUBVOL uuid=f6922049-8c22-e544-9ff9-...

After this change it is:

  receiving snapshot snap2 uuid=564d36a3-ebc8-7343-aec9-bf6fda278e64...
  utimes
  update_extent foobar: offset=8192, len=8192
  utimes foobar
  BTRFS_IOC_SET_RECEIVED_SUBVOL uuid=564d36a3-ebc8-7343-aec9-bf6fda278e64...

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-01 16:18:07 +01:00
Anand Jain 3c181c12c4 btrfs: use proper endianness accessors for super_copy
The fs_info::super_copy is a byte copy of the on-disk structure and all
members must use the accessor macros/functions to obtain the right
value.  This was missing in update_super_roots and in sysfs readers.

Moving between opposite endianness hosts will report bogus numbers in
sysfs, and mount may fail as the root will not be restored correctly. If
the filesystem is always used on a same endian host, this will not be a
problem.

Fix this by using the btrfs_set_super...() functions to set
fs_info::super_copy values, and for the sysfs, use the cached
fs_info::nodesize/sectorsize values.

CC: stable@vger.kernel.org
Fixes: df93589a17 ("btrfs: export more from FS_INFO to sysfs")
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-01 16:17:27 +01:00
Hans van Kranenburg 92e222df7b btrfs: alloc_chunk: fix DUP stripe size handling
In case of using DUP, we search for enough unallocated disk space on a
device to hold two stripes.

The devices_info[ndevs-1].max_avail that holds the amount of unallocated
space found is directly assigned to stripe_size, while it's actually
twice the stripe size.

Later on in the code, an unconditional division of stripe_size by
dev_stripes corrects the value, but in the meantime there's a check to
see if the stripe_size does not exceed max_chunk_size. Since during this
check stripe_size is twice the amount as intended, the check will reduce
the stripe_size to max_chunk_size if the actual correct to be used
stripe_size is more than half the amount of max_chunk_size.

The unconditional division later tries to correct stripe_size, but will
actually make sure we can't allocate more than half the max_chunk_size.

Fix this by moving the division by dev_stripes before the max chunk size
check, so it always contains the right value, instead of putting a duct
tape division in further on to get it fixed again.

Since in all other cases than DUP, dev_stripes is 1, this change only
affects DUP.

Other attempts in the past were made to fix this:
* 37db63a400 "Btrfs: fix max chunk size check in chunk allocator" tried
to fix the same problem, but still resulted in part of the code acting
on a wrongly doubled stripe_size value.
* 86db25785a "Btrfs: fix max chunk size on raid5/6" unintentionally
broke this fix again.

The real problem was already introduced with the rest of the code in
73c5de0051.

The user visible result however will be that the max chunk size for DUP
will suddenly double, while it's actually acting according to the limits
in the code again like it was 5 years ago.

Reported-by: Naohiro Aota <naohiro.aota@wdc.com>
Link: https://www.spinics.net/lists/linux-btrfs/msg69752.html
Fixes: 73c5de0051 ("btrfs: quasi-round-robin for chunk allocation")
Fixes: 86db25785a ("Btrfs: fix max chunk size on raid5/6")
Signed-off-by: Hans van Kranenburg <hans.van.kranenburg@mendix.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update comment ]
Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-01 16:16:47 +01:00
Nikolay Borisov 765f3cebff btrfs: Handle btrfs_set_extent_delalloc failure in relocate_file_extent_cluster
Essentially duplicate the error handling from the above block which
handles the !PageUptodate(page) case and additionally clear
EXTENT_BOUNDARY.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-01 16:16:12 +01:00
Nikolay Borisov ac01f26a27 btrfs: handle failure of add_pending_csums
add_pending_csums was added as part of the new data=ordered
implementation in e6dcd2dc9c ("Btrfs: New data=ordered
implementation"). Even back then it called the btrfs_csum_file_blocks
which can fail but it never bothered handling the failure. In ENOMEM
situation this could lead to the filesystem failing to write the
checksums for a particular extent and not detect this. On read this
could lead to the filesystem erroring out due to crc mismatch. Fix it by
propagating failure from add_pending_csums and handling them.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-01 16:16:00 +01:00
Jeff Mahoney a8fd1f7174 btrfs: use kvzalloc to allocate btrfs_fs_info
The srcu_struct in btrfs_fs_info scales in size with NR_CPUS.  On
kernels built with NR_CPUS=8192, this can result in kmalloc failures
that prevent mounting.

There is work in progress to try to resolve this for every user of
srcu_struct but using kvzalloc will work around the failures until
that is complete.

As an example with NR_CPUS=512 on x86_64: the overall size of
subvol_srcu is 3460 bytes, fs_info is 6496.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-01 16:15:36 +01:00
Nikolay Borisov fd649f10c3 btrfs: Fix use-after-free when cleaning up fs_devs with a single stale device
Commit 4fde46f0cc ("Btrfs: free the stale device") introduced
btrfs_free_stale_device which iterates the device lists for all
registered btrfs filesystems and deletes those devices which aren't
mounted. In a btrfs_devices structure has only 1 device attached to it
and it is unused then btrfs_free_stale_devices will proceed to also free
the btrfs_fs_devices struct itself. Currently this leads to a use after
free since list_for_each_entry will try to perform a check on the
already freed memory to see if it has to terminate the loop.

The fix is to use 'break' when we know we are freeing the current
fs_devs.

Fixes: 4fde46f0cc ("Btrfs: free the stale device")
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-02-05 17:15:14 +01:00
Filipe Manana 627e08738e Btrfs: fix null pointer dereference when replacing missing device
When we are replacing a missing device we mount the filesystem with the
degraded mode option in which case we are allowed to have a btrfs device
structure without a backing device member (its bdev member is NULL) and
therefore we can't dereference that member. Commit 38b5f68e98
("btrfs: drop btrfs_device::can_discard to query directly") started to
dereference that member when discarding extents, resulting in a null
pointer dereference:

 [ 3145.322257] BTRFS warning (device sdf): devid 2 uuid 4d922414-58eb-4880-8fed-9c3840f6c5d5 is missing
 [ 3145.364116] BTRFS info (device sdf): dev_replace from <missing disk> (devid 2) to /dev/sdg started
 [ 3145.413489] BUG: unable to handle kernel NULL pointer dereference at 00000000000000e0
 [ 3145.415085] IP: btrfs_discard_extent+0x6a/0xf8 [btrfs]
 [ 3145.415085] PGD 0 P4D 0
 [ 3145.415085] Oops: 0000 [#1] PREEMPT SMP PTI
 [ 3145.415085] Modules linked in: ppdev ghash_clmulni_intel pcbc aesni_intel aes_x86_64 crypto_simd cryptd glue_helper evdev psmouse parport_pc serio_raw i2c_piix4 i2
 [ 3145.415085] CPU: 0 PID: 11989 Comm: btrfs Tainted: G        W        4.15.0-rc9-btrfs-next-55+ #1
 [ 3145.415085] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014
 [ 3145.415085] RIP: 0010:btrfs_discard_extent+0x6a/0xf8 [btrfs]
 [ 3145.415085] RSP: 0018:ffffc90004813c60 EFLAGS: 00010293
 [ 3145.415085] RAX: ffff88020d39cc00 RBX: ffff88020c4ea2a0 RCX: 0000000000000002
 [ 3145.415085] RDX: 0000000000000000 RSI: ffff88020c4ea240 RDI: 0000000000000000
 [ 3145.415085] RBP: 0000000000000000 R08: 0000000000004000 R09: 0000000000000000
 [ 3145.415085] R10: ffffc90004813ae8 R11: 0000000000000000 R12: 0000000000000000
 [ 3145.415085] R13: ffff88020c418000 R14: 0000000000000000 R15: 0000000000000000
 [ 3145.415085] FS:  00007f565681f8c0(0000) GS:ffff88023fc00000(0000) knlGS:0000000000000000
 [ 3145.415085] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [ 3145.415085] CR2: 00000000000000e0 CR3: 000000020d208006 CR4: 00000000001606f0
 [ 3145.415085] Call Trace:
 [ 3145.415085]  btrfs_finish_extent_commit+0x9a/0x1be [btrfs]
 [ 3145.415085]  btrfs_commit_transaction+0x649/0x7a0 [btrfs]
 [ 3145.415085]  ? start_transaction+0x2b0/0x3b3 [btrfs]
 [ 3145.415085]  btrfs_dev_replace_start+0x274/0x30c [btrfs]
 [ 3145.415085]  btrfs_dev_replace_by_ioctl+0x45/0x59 [btrfs]
 [ 3145.415085]  btrfs_ioctl+0x1a91/0x1d62 [btrfs]
 [ 3145.415085]  ? lock_acquire+0x16a/0x1af
 [ 3145.415085]  ? vfs_ioctl+0x1b/0x28
 [ 3145.415085]  ? trace_hardirqs_on_caller+0x14c/0x1a6
 [ 3145.415085]  vfs_ioctl+0x1b/0x28
 [ 3145.415085]  do_vfs_ioctl+0x5a9/0x5e0
 [ 3145.415085]  ? _raw_spin_unlock_irq+0x34/0x46
 [ 3145.415085]  ? entry_SYSCALL_64_fastpath+0x5/0x8b
 [ 3145.415085]  ? trace_hardirqs_on_caller+0x14c/0x1a6
 [ 3145.415085]  SyS_ioctl+0x52/0x76
 [ 3145.415085]  entry_SYSCALL_64_fastpath+0x1e/0x8b
 [ 3145.415085] RIP: 0033:0x7f56558b3c47
 [ 3145.415085] RSP: 002b:00007ffdcfac4c58 EFLAGS: 00000202
 [ 3145.415085] Code: be 02 00 00 00 4c 89 ef e8 b9 e7 03 00 85 c0 89 c5 75 75 48 8b 44 24 08 45 31 f6 48 8d 58 60 eb 52 48 8b 03 48 8b b8 a0 00 00 00 <48> 8b 87 e0 00
 [ 3145.415085] RIP: btrfs_discard_extent+0x6a/0xf8 [btrfs] RSP: ffffc90004813c60
 [ 3145.415085] CR2: 00000000000000e0
 [ 3145.458185] ---[ end trace 06302e7ac31902bf ]---

This is trivially reproduced by running the test btrfs/027 from fstests
like this:

  $ MOUNT_OPTIONS="-o discard" ./check btrfs/027

Fix this by skipping devices without a backing device before attempting
to discard.

Fixes: 38b5f68e98 ("btrfs: drop btrfs_device::can_discard to query directly")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-02-02 16:25:44 +01:00
Zygo Blaxell c8195a7b1a btrfs: remove spurious WARN_ON(ref->count < 0) in find_parent_nodes
Until v4.14, this warning was very infrequent:

	WARNING: CPU: 3 PID: 18172 at fs/btrfs/backref.c:1391 find_parent_nodes+0xc41/0x14e0
	Modules linked in: [...]
	CPU: 3 PID: 18172 Comm: bees Tainted: G      D W    L  4.11.9-zb64+ #1
	Hardware name: System manufacturer System Product Name/M5A78L-M/USB3, BIOS 2101    12/02/2014
	Call Trace:
	 dump_stack+0x85/0xc2
	 __warn+0xd1/0xf0
	 warn_slowpath_null+0x1d/0x20
	 find_parent_nodes+0xc41/0x14e0
	 __btrfs_find_all_roots+0xad/0x120
	 ? extent_same_check_offsets+0x70/0x70
	 iterate_extent_inodes+0x168/0x300
	 iterate_inodes_from_logical+0x87/0xb0
	 ? iterate_inodes_from_logical+0x87/0xb0
	 ? extent_same_check_offsets+0x70/0x70
	 btrfs_ioctl+0x8ac/0x2820
	 ? lock_acquire+0xc2/0x200
	 do_vfs_ioctl+0x91/0x700
	 ? __fget+0x112/0x200
	 SyS_ioctl+0x79/0x90
	 entry_SYSCALL_64_fastpath+0x23/0xc6
	 ? trace_hardirqs_off_caller+0x1f/0x140

Starting with v4.14 (specifically 86d5f99442 ("btrfs: convert prelimary
reference tracking to use rbtrees")) the WARN_ON occurs three orders of
magnitude more frequently--almost once per second while running workloads
like bees.

Replace the WARN_ON() with a comment rationale for its removal.
The rationale is paraphrased from an explanation by Edmund Nadolski
<enadolski@suse.de> on the linux-btrfs mailing list.

Fixes: 8da6d5815c ("Btrfs: added btrfs_find_all_roots()")
Signed-off-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Reviewed-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-02-02 16:25:33 +01:00
Nikolay Borisov 952bd3db0d btrfs: Ignore errors from btrfs_qgroup_trace_extent_post
Running generic/019 with qgroups on the scratch device enabled is almost
guaranteed to trigger the BUG_ON in btrfs_free_tree_block. It's supposed
to trigger only on -ENOMEM, in reality, however, it's possible to get
-EIO from btrfs_qgroup_trace_extent_post. This function just finds the
roots of the extent being tracked and sets the qrecord->old_roots list.
If this operation fails nothing critical happens except the quota
accounting can be considered wrong. In such case just set the
INCONSISTENT flag for the quota and print a warning, rather than killing
off the system. Additionally, it's possible to trigger a BUG_ON in
btrfs_truncate_inode_items as well.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
[ error message adjustments ]
Signed-off-by: David Sterba <dsterba@suse.com>
2018-02-02 16:25:14 +01:00
Liu Bo 900c998168 Btrfs: fix unexpected -EEXIST when creating new inode
The highest objectid, which is assigned to new inode, is decided at
the time of initializing fs roots.  However, in cases where log replay
gets processed, the btree which fs root owns might be changed, so we
have to search it again for the highest objectid, otherwise creating
new inode would end up with -EEXIST.

cc: <stable@vger.kernel.org> v4.4-rc6+
Fixes: f32e48e925 ("Btrfs: Initialize btrfs_root->highest_objectid when loading tree root and subvolume roots")
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-02-02 16:24:53 +01:00
Liu Bo 1a932ef4e4 Btrfs: fix use-after-free on root->orphan_block_rsv
I got these from running generic/475,

WARNING: CPU: 0 PID: 26384 at fs/btrfs/inode.c:3326 btrfs_orphan_commit_root+0x1ac/0x2b0 [btrfs]
BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
IP: btrfs_block_rsv_release+0x1c/0x70 [btrfs]
Call Trace:
  btrfs_orphan_release_metadata+0x9f/0x200 [btrfs]
  btrfs_orphan_del+0x10d/0x170 [btrfs]
  btrfs_setattr+0x500/0x640 [btrfs]
  notify_change+0x7ae/0x870
  do_truncate+0xca/0x130
  vfs_truncate+0x2ee/0x3d0
  do_sys_truncate+0xaf/0xf0
  SyS_truncate+0xe/0x10
  entry_SYSCALL_64_fastpath+0x1f/0x96

The race is between btrfs_orphan_commit_root and btrfs_orphan_del,
        t1                                        t2
btrfs_orphan_commit_root                     btrfs_orphan_del
   spin_lock
   check (&root->orphan_inodes)
   root->orphan_block_rsv = NULL;
   spin_unlock
                                             atomic_dec(&root->orphan_inodes);
                                             access root->orphan_block_rsv

Accessing root->orphan_block_rsv must be done before decreasing
root->orphan_inodes.

cc: <stable@vger.kernel.org> v3.12+
Fixes: 703c88e035 ("Btrfs: fix tracking of orphan inode count")
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-02-02 16:24:40 +01:00
Liu Bo e8f1bc1493 Btrfs: fix btrfs_evict_inode to handle abnormal inodes correctly
This regression is introduced in
commit 3d48d9810d ("btrfs: Handle uninitialised inode eviction").

There are two problems,

a) it is ->destroy_inode() that does the final free on inode, not
   ->evict_inode(),
b) clear_inode() must be called before ->evict_inode() returns.

This could end up hitting BUG_ON(inode->i_state != (I_FREEING | I_CLEAR));
in evict() because I_CLEAR is set in clear_inode().

Fixes: commit 3d48d9810d ("btrfs: Handle uninitialised inode eviction")
Cc: <stable@vger.kernel.org> # v4.7-rc6+
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-02-02 16:24:35 +01:00
Liu Bo 55237a5f24 Btrfs: fix extent state leak from tree log
It's possible that btrfs_sync_log() bails out after one of the two
btrfs_write_marked_extents() which convert extent state's state bit into
EXTENT_NEED_WAIT from EXTENT_DIRTY/EXTENT_NEW, however only EXTENT_DIRTY
and EXTENT_NEW are searched by free_log_tree() so that those extent states
with EXTENT_NEED_WAIT lead to memory leak.

cc: <stable@vger.kernel.org>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-02-02 16:24:30 +01:00
Liu Bo 1846430c24 Btrfs: fix crash due to not cleaning up tree log block's dirty bits
In cases that the whole fs flips into readonly status due to failures in
critical sections, then log tree's blocks are still dirty, and this leads
to a crash during umount time, the crash is about use-after-free,

umount
 -> close_ctree
    -> stop workers
    -> iput(btree_inode)
       -> iput_final
          -> write_inode_now
	     -> ...
	       -> queue job on stop'd workers

cc: <stable@vger.kernel.org> v3.12+
Fixes: 681ae50917 ("Btrfs: cleanup reserved space when freeing tree log on error")
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-02-02 16:24:24 +01:00
Liu Bo e89166990f Btrfs: fix deadlock in run_delalloc_nocow
@cur_offset is not set back to what it should be (@cow_start) if
btrfs_next_leaf() returns something wrong, and the range [cow_start,
cur_offset) remains locked forever.

cc: <stable@vger.kernel.org>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-02-02 16:24:19 +01:00
Anand Jain 3acbcbfc8f btrfs: drop devid as device_list_add() arg
As struct btrfs_disk_super is being passed, so it can get devid
the same way its parent does.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-29 19:31:16 +01:00
Anand Jain e124ece53e btrfs: get device pointer from device_list_add()
Instead of pointer to btrfs_fs_devices as an arg in device_list_add()
better to get pointer to btrfs_device as return value, then we have
both, pointer to btrfs_device and btrfs_fs_devices. btrfs_device is
needed to handle reappearing missing device.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-29 19:31:15 +01:00
Anand Jain f2788d2f76 btrfs: set the total_devices in device_list_add()
There is no other parent for device_list_add() except for
btrfs_scan_one_device(), which would set btrfs_fs_devices::total_devices
if device_list_add is successful and this can be done with in
device_list_add() itself.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 20:25:56 +01:00
Anand Jain 327f18cc7f btrfs: move pr_info into device_list_add
Commit 60999ca4b4 ("btrfs: make device scan less noisy")
adds return value 1 to device_list_add(), so that parent function can
call pr_info only when new device is added. Move the pr_info() part
into device_list_add() so that this function can be kept simple.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 20:25:54 +01:00
Anand Jain d8367db30a btrfs: make btrfs_free_stale_devices() to match the path
The btrfs_free_stale_devices() is updated to match for the given device
path and delete it. (It searches for only unmounted list of devices.)
Also drop the comment about different path being used for the same
device, since now we will have cli to clean any device that's not a
concern any more.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 20:25:52 +01:00
Anand Jain 0d34097f66 btrfs: rename btrfs_free_stale_devices() arg to skip_dev
No functional changes.
Rename btrfs_free_stale_devices() arg to skip_dev, so that it
reflects what that arg for.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 20:25:50 +01:00
Anand Jain 522f1b45e4 btrfs: make btrfs_free_stale_devices() argument optional
This updates btrfs_free_stale_devices() helper function to delete all
unmouted devices, when arg is NULL.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 20:25:48 +01:00
Anand Jain 38cf665d33 btrfs: make btrfs_free_stale_device() to iterate all stales
Let the list iterator iterate further and find other stale
devices and delete it. This is in preparation to add support
for user land request-able stale devices cleanup. Also rename
btrfs_free_stale_device() to btrfs_free_stale_devices().

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 20:25:47 +01:00
Anand Jain a848b3e547 btrfs: no need to check for btrfs_fs_devices::seeding
There is no need to check for btrfs_fs_devices::seeding when we
have checked for btrfs_fs_devices::opened, because we can't sprout
without its seed FS being opened.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 20:25:44 +01:00
Nikolay Borisov b03ebd992f btrfs: Use IS_ALIGNED in btrfs_truncate_block instead of opencoding it
No functional changes, just makes the code more readable

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:22 +01:00
Liu Bo 5f4791f4a6 Btrfs: noinline merge_extent_mapping
In order to debug subtle bugs around merge_extent_mapping(), perf probe
can be used to check the arguments, but sometimes merge_extent_mapping()
got inlined by compiler and couldn't be probed.

This is adding noinline attribute to merge_extent_mapping().

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:22 +01:00
Liu Bo 9a7e10e7ba Btrfs: add WARN_ONCE to detect unexpected error from merge_extent_mapping
This is a subtle case, so in order to understand the problem, it'd be good
to know the content of existing and em when any error occurs.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:22 +01:00
Liu Bo cd77f4f836 Btrfs: extent map selftest: dio write vs dio read
This test case simulates the racy situation of dio write vs dio read,
and see if btrfs_get_extent() would return -EEXIST.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:22 +01:00
Liu Bo fd87526fad Btrfs: extent map selftest: buffered write vs dio read
This test case simulates the racy situation of buffered write vs dio
read, and see if btrfs_get_extent() would return -EEXIST.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:22 +01:00
Liu Bo 72b28077a2 Btrfs: add extent map selftests
We've observed that btrfs_get_extent() and merge_extent_mapping() could
return -EEXIST in several cases, and they are caused by some racy
condition, e.g dio read vs dio write, which makes the problem very tricky
to reproduce.

This adds extent map selftests in order to simulate those racy situations.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
[ minor string adjustments ]
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:22 +01:00
Liu Bo c04e61b5e4 Btrfs: move extent map specific code to extent_map.c
These helpers are extent map specific, move them to extent_map.c.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:22 +01:00
Liu Bo 7b4df058b0 Btrfs: add helper for em merge logic
This is a prepare work for the following extent map selftest, which
runs tests against em merge logic.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:21 +01:00
Liu Bo 18e83ac75b Btrfs: fix unexpected EEXIST from btrfs_get_extent
This fixes a corner case that is caused by a race of dio write vs dio
read/write.

Here is how the race could happen.

Suppose that no extent map has been loaded into memory yet.
There is a file extent [0, 32K), two jobs are running concurrently
against it, t1 is doing dio write to [8K, 32K) and t2 is doing dio
read from [0, 4K) or [4K, 8K).

t1 goes ahead of t2 and splits em [0, 32K) to em [0K, 8K) and [8K 32K).

------------------------------------------------------
             t1                                t2
      btrfs_get_blocks_direct()         btrfs_get_blocks_direct()
       -> btrfs_get_extent()              -> btrfs_get_extent()
           -> lookup_extent_mapping()
           -> add_extent_mapping()            -> lookup_extent_mapping()
              # load [0, 32K)
       -> btrfs_new_extent_direct()
           -> btrfs_drop_extent_cache()
              # split [0, 32K) and
	      # drop [8K, 32K)
           -> add_extent_mapping()
              # add [8K, 32K)
                                              -> add_extent_mapping()
                                                 # handle -EEXIST when adding
                                                 # [0, 32K)
------------------------------------------------------
About how t2(dio read/write) runs into -EEXIST:

a) add_extent_mapping() gets -EEXIST for adding em [0, 32k),

b) search_extent_mapping() then returns [0, 8k) as the existing em,
   even though start == existing->start, em is [0, 32k) so that
   extent_map_end(em) > extent_map_end(existing), i.e. 32k > 8k,

c) then it goes thru merge_extent_mapping() which tries to add a [8k, 8k)
   (with a length 0) and returns -EEXIST as [8k, 32k) is already in tree,

d) so btrfs_get_extent() ends up returning -EEXIST to dio read/write,
   which is confusing applications.

Here I conclude all the possible situations,
1) start < existing->start

            +-----------+em+-----------+
+--prev---+ |     +-------------+      |
|         | |     |             |      |
+---------+ +     +---+existing++      ++
                +
                |
                +
             start

2) start == existing->start

      +------------em------------+
      |     +-------------+      |
      |     |             |      |
      +     +----existing-+      +
            |
            |
            +
         start

3) start > existing->start && start < (existing->start + existing->len)

      +------------em------------+
      |     +-------------+      |
      |     |             |      |
      +     +----existing-+      +
               |
               |
               +
             start

4) start >= (existing->start + existing->len)

+-----------+em+-----------+
|     +-------------+      | +--next---+
|     |             |      | |         |
+     +---+existing++      + +---------+
                      +
                      |
                      +
                   start

As we can see, it turns out that if start is within existing em (front
inclusive), then the existing em should be returned as is, otherwise,
we try our best to merge candidate em with sibling ems to form a
larger em (in order to reduce the total number of em).

Reported-by: David Vallender <david.vallender@landmark.co.uk>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:21 +01:00
Liu Bo a520a7e0b5 Btrfs: fix incorrect block_len in merge_extent_mapping
%block_len could be checked on deciding if two em are mergeable.

merge_extent_mapping() has only added the front pad if the front part
of em gets truncated, but it's possible that the end part gets
truncated.

For both compressed extent and inline extent, em->block_len is not
adjusted accordingly, and for regular extent, em->block_len always
equals to em->len, hence this sets em->block_len with em->len.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:21 +01:00
Matthew Wilcox 3cbf26da5e btrfs: Remove unused readahead spinlock
The reada_lock in struct btrfs_device was only initialised, and not
actually used.  That's good because there's another lock also called
reada_lock in the btrfs_fs_info that was quite heavily used.  Remove
this one.

Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:21 +01:00
Liu Bo 7583d8d088 Btrfs: raid56: fix race between merge_bio and rbio_orig_end_io
Before rbio_orig_end_io() goes to free rbio, rbio may get merged with
more bios from other rbios and rbio->bio_list becomes non-empty,
in that case, these newly merged bios don't end properly.

Once unlock_stripe() is done, rbio->bio_list will not be updated any
more and we can call bio_endio() on all queued bios.

It should only happen in error-out cases, the normal path of recover
and full stripe write have already set RBIO_RMW_LOCKED_BIT to disable
merge before doing IO, so rbio_orig_end_io() called by them doesn't
have the above issue.

Reported-by: Jérôme Carretero <cJ-ko@zougloub.eu>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:21 +01:00
Liu Bo 44ac474def Btrfs: do not cache rbio pages if using raid6 recover
Since raid6 recover tries all possible combinations of failed stripes,

- when raid6 rebuild algorithm is used, i.e. raid6_datap_recov() and
  raid6_2data_recov(), it may change the in-memory content of failed
  stripes, if such a raid bio is cached, a later raid write rmw or recover
  can steal @stripe_pages from it instead of reading from disks, such that
  it carries the wrong content to do write rmw or recovery and ends up
  with corruption or recovery failures.

- when raid5 rebuild algorithm is used, i.e. xor, raid bio can be cached
  because the only failed stripe which contains @rbio->bio_pages gets
  modified, others remain the same so that their in-memory content is
  consistent with their on-disk content.

This adds a check to skip caching rbio if using raid6 recover.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:21 +01:00
Liu Bo 0198e5b707 Btrfs: raid56: iterate raid56 internal bio with bio_for_each_segment_all
Bio iterated by set_bio_pages_uptodate() is raid56 internal one, so it
will never be a BIO_CLONED bio, and since this is called by end_io
functions, bio->bi_iter.bi_size is zero, we mustn't use
bio_for_each_segment() as that is a no-op if bi_size is zero.

Fixes: 6592e58c6b ("Btrfs: fix write corruption due to bio cloning on raid5/6")
Cc: <stable@vger.kernel.org> # v4.12-rc6+
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:21 +01:00
Su Yue df6703e15c btrfs: correct wrong comment about magic number of index_cnt
There is no function named btrfs_get_inode_index_count.
Explanation for magic number index_cnt=2 in btrfs_new_inode() is
actually located in btrfs_set_inode_index_count().

So replace 'btrfs_get_inode_index_count' in the comment by
'btrfs_set_inode_index_count'.

Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:21 +01:00
Nikolay Borisov d2560ebd23 btrfs: Make btrfs_inode_rsv_release static
It's not used outside of extent-tree so there is no reason to not be
static.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:21 +01:00
Anand Jain 1c94da9dd9 btrfs: cleanup btrfs_free_stale_device() usage
We call btrfs_free_stale_device() only when we alloc a new struct
btrfs_device (ret=1), so move it closer to where we alloc the new
device. Also drop the comments.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:21 +01:00
David Sterba e2683fc9d2 btrfs: tree-check: reduce stack consumption in check_dir_item
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>
2018-01-22 16:08:21 +01:00
Xiongfeng Wang 6670d4c2d9 btrfs: use correct string length in DEV_INFO ioctl
gcc-8 reports:

fs/btrfs/ioctl.c: In function 'btrfs_ioctl':
./include/linux/string.h:245:9: warning: '__builtin_strncpy' specified
bound 1024 equals destination size [-Wstringop-truncation]

We need one less byte or call strlcpy() to make it a nul-terminated
string. This is done on the next line anyway, but we want to avoid the
warning.

Signed-off-by: Xiongfeng Wang <xiongfeng.wang@linaro.org>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:21 +01:00
Anand Jain 6f794e3c5c btrfs: fail mount when sb flag is not in BTRFS_SUPER_FLAG_SUPP
It appears from the original commit [1] that there isn't any design
specific reason not to fail the mount instead of just warning. This
patch will change it to fail.

[1]
 commit 319e4d0661
    btrfs: Enhance super validation check

Fixes: 319e4d0661 ("btrfs: Enhance super validation check")
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:21 +01:00
Anand Jain 98820a7e24 btrfs: add support for SUPER_FLAG_CHANGING_FSID
The UUID change by btrfstune sets SUPER_FLAG_CHANGING_FSID and resets it
only when changing fsid is complete. Its not a good idea to mount the
device anything in between, reading metadata blocks would fail with UUID
mismatch.

This patch doesn't add SUPER_FLAG_CHANGING_FSID into
BTRFS_SUPER_FLAG_SUPP list, so mount will fail (along with the fix in
the next patch) when SUPER_FLAG_CHANGING_FSID is set.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:21 +01:00