Commit Graph

1254 Commits

Author SHA1 Message Date
Josef Bacik
867363429d btrfs: migrate the delalloc space stuff to it's own home
We have code for data and metadata reservations for delalloc.  There's
quite a bit of code here, and it's used in a lot of places so I've
separated it out to it's own file.  inode.c and file.c are already
pretty large, and this code is complicated enough to live in its own
space.

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

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

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-04 17:26:17 +02:00
Josef Bacik
d12ffdd1aa btrfs: move btrfs_block_rsv definitions into it's own header
Prep work for separating out all of the block_rsv related code into its
own file.

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

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:53 +02:00
Josef Bacik
fc471cb0c8 btrfs: rename do_chunk_alloc to btrfs_chunk_alloc
Really we just need the enum, but as we break more things up it'll help
to have this external to extent-tree.c.

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

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:51 +02:00
David Sterba
c9d713d5b5 btrfs: improve messages when updating feature flags
Currently the messages printed after setting an incompat feature are
cryptis, we can easily make it better as the textual description is
passed to the helpers. Old:

  setting 128 feature flag

updated:

  setting incompat feature flag for RAID56 (0x80)

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

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

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

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

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

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

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

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:49 +02:00
David Sterba
6f8e4fd430 btrfs: use file:line format for assertion report
The filename:line format is commonly understood by editors and can be
copy&pasted more easily than the current format.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:02 +02:00
Johannes Thumshirn
6d97c6e31b btrfs: add boilerplate code for directly including the crypto framework
Add boilerplate code for directly including the crypto framework.  This
helps us flipping the switch for new algorithms.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:01 +02:00
Johannes Thumshirn
1e25a2e3ca btrfs: don't assume ordered sums to be 4 bytes
BTRFS has the implicit assumption that a checksum in btrfs_orderd_sums
is 4 bytes. While this is true for CRC32C, it is not for any other
checksum.

Change the data type to be a byte array and adjust loop index
calculation accordingly.

This includes moving the adjustment of 'index' by 'ins_size' in
btrfs_csum_file_blocks() before dividing 'ins_size' by the checksum
size, because before this patch the 'sums' member of 'struct
btrfs_ordered_sum' was 4 Bytes in size and afterwards it is only one
byte.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:00 +02:00
Johannes Thumshirn
65019df8c3 btrfs: resurrect btrfs_crc32c()
Commit 9678c54388 ("btrfs: Remove custom crc32c init code") removed
the btrfs_crc32c() function, because it was a duplicate of the crc32c()
library function we already have in the kernel.

Resurrect it as a shim wrapper over crc32c() to make following
transformations of the checksumming code in btrfs easier.

Also provide a btrfs_crc32_final() to ease following transformations.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:00 +02:00
David Sterba
c8bf1b6703 btrfs: remove mapping tree structures indirection
fs_info::mapping_tree is the physical<->logical mapping tree and uses
the same underlying structure as extents, but is embedded to another
structure. There are no other members and this indirection is useless.
No functional change.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:56 +02:00
David Sterba
9b4e675a99 btrfs: detect fast implementation of crc32c on all architectures
Currently, there's only check for fast crc32c implementation on X86,
based on the CPU flags. This is used to decide if checksumming should be
offloaded to worker threads or can be calculated by the caller.

As there are more architectures that implement a faster version of
crc32c (ARM, SPARC, s390, MIPS, PowerPC), also there are specialized hw
cards.

The detection is based on driver name, all generic C implementations
contain 'generic', while the specialized versions do not. Alternatively
the priority could be used, but this is not currently provided by the
crypto API.

The flag is set per-filesystem at mount time and used for the offloading
decisions.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:53 +02:00
Linus Torvalds
9f2e3a53f7 for-5.2-tag
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAlzQM7MACgkQxWXV+ddt
 WDvrVw/+K0AElSuEfDFWd9HBqRAPlGaEP71xCGGle1tkzuY0DJVIBRZ72q8UR0YP
 7yke7DU0oqXekGype83eTJUjDSLoOXrlVoQ+VqBdFteDk0W4BCG6Nw+N+wYBF7An
 gXRXlGFaYzb2CqqjG92FbtkfxBzISR0XBCQBUN9CBqHNDu1EUQSbnTBkmTMN8MYh
 PCoo37S6e5fR36uB/rOKbGNBJjsZEEg/2G6DprP52+eiQWV2h0avEUJrvv6xC4so
 97QNgUNuuiUmyurqcYHdlaflZwIhuf5nQeNeu/UvMZmmRnBHPhSP7YPM7f7FftwA
 y0d0p+AiEAO0he8nGFb5C6Avs4vuv1u65o1NbF5fqnmAyt+KXWem3LeG6etsXgU8
 +eITgprJD3sNBMDLbLoA+wlhTps+w9tukVF5Zp2a8KgQLMMEyAYqUDWmSHvnO2Me
 RCNPZLzeGXETgKun0WuMtl/CX2iBDnc0Kq5O6ks2ORl2TH6bg5lgEIwr6HP/Ewoy
 w8twsmCOltrxiIptqyQHYD+kvNwqMVV9LSOQ8+EjbYd6BHsfjHjKObOBkhmJ7iqz
 4MAIcZU++F9DLRv92H1kUYVNhAMCdXkEIWyxhZPwN1lUi5k9AhknY3FbheNc7ldl
 LNPIgRxamWCq9oBmzfOcJ3eFOBtNN02fgA1GTXGd1/AgAilEep8=
 =fEkD
 -----END PGP SIGNATURE-----

Merge tag 'for-5.2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs updates from David Sterba:
 "This time the majority of changes are cleanups, though there's still a
  number of changes of user interest.

  User visible changes:

   - better read time and write checks to catch errors early and before
     writing data to disk (to catch potential memory corruption on data
     that get checksummed)

   - qgroups + metadata relocation: last speed up patch int the series
     to address the slowness, there should be no overhead comparing
     balance with and without qgroups

   - FIEMAP ioctl does not start a transaction unnecessarily, this can
     result in a speed up and less blocking due to IO

   - LOGICAL_INO (v1, v2) does not start transaction unnecessarily, this
     can speed up the mentioned ioctl and scrub as well

   - fsync on files with many (but not too many) hardlinks is faster,
     finer decision if the links should be fsynced individually or
     completely

   - send tries harder to find ranges to clone

   - trim/discard will skip unallocated chunks that haven't been touched
     since the last mount

  Fixes:

   - send flushes delayed allocation before start, otherwise it could
     miss some changes in case of a very recent rw->ro switch of a
     subvolume

   - fix fallocate with qgroups that could lead to space accounting
     underflow, reported as a warning

   - trim/discard ioctl honours the requested range

   - starting send and dedupe on a subvolume at the same time will let
     only one of them succeed, this is to prevent changes that send
     could miss due to dedupe; both operations are restartable

  Core changes:

   - more tree-checker validations, errors reported by fuzzing tools:
      - device item
      - inode item
      - block group profiles

   - tracepoints for extent buffer locking

   - async cow preallocates memory to avoid errors happening too deep in
     the call chain

   - metadata reservations for delalloc reworked to better adapt in
     many-writers/low-space scenarios

   - improved space flushing logic for intense DIO vs buffered workloads

   - lots of cleanups
      - removed unused struct members
      - redundant argument removal
      - properties and xattrs
      - extent buffer locking
      - selftests
      - use common file type conversions
      - many-argument functions reduction"

* tag 'for-5.2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (227 commits)
  btrfs: Use kvmalloc for allocating compressed path context
  btrfs: Factor out common extent locking code in submit_compressed_extents
  btrfs: Set io_tree only once in submit_compressed_extents
  btrfs: Replace clear_extent_bit with unlock_extent
  btrfs: Make compress_file_range take only struct async_chunk
  btrfs: Remove fs_info from struct async_chunk
  btrfs: Rename async_cow to async_chunk
  btrfs: Preallocate chunks in cow_file_range_async
  btrfs: reserve delalloc metadata differently
  btrfs: track DIO bytes in flight
  btrfs: merge calls of btrfs_setxattr and btrfs_setxattr_trans in btrfs_set_prop
  btrfs: delete unused function btrfs_set_prop_trans
  btrfs: start transaction in xattr_handler_set_prop
  btrfs: drop local copy of inode i_mode
  btrfs: drop old_fsflags in btrfs_ioctl_setflags
  btrfs: modify local copy of btrfs_inode flags
  btrfs: drop useless inode i_flags copy and restore
  btrfs: start transaction in btrfs_ioctl_setflags()
  btrfs: export btrfs_set_prop
  btrfs: refactor btrfs_set_props to validate externally
  ...
2019-05-07 11:34:19 -07:00
Al Viro
26602cab41 btrfs: use ->free_inode()
a lot of stuff remains in ->destroy_inode()

Acked-by: David Sterba <dsterba@suse.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-05-01 22:43:26 -04:00
Josef Bacik
4297ff84dc btrfs: track DIO bytes in flight
When diagnosing a slowdown of generic/224 I noticed we were not doing
anything when calling into shrink_delalloc().  This is because all
writes in 224 are O_DIRECT, not delalloc, and thus our delalloc_bytes
counter is 0, which short circuits most of the work inside of
shrink_delalloc().  However O_DIRECT writes still consume metadata
resources and generate ordered extents, which we can still wait on.

Fix this by tracking outstanding DIO write bytes, and use this as well
as the delalloc bytes counter to decide if we need to lookup and wait on
any ordered extents.  If we have more DIO writes than delalloc bytes
we'll go ahead and wait on any ordered extents regardless of our flush
state as flushing delalloc is likely to not gain us anything.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
[ use dio instead of odirect in identifiers ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:25:37 +02:00
Filipe Manana
62d54f3a7f Btrfs: fix race between send and deduplication that lead to failures and crashes
Send operates on read only trees and expects them to never change while it
is using them. This is part of its initial design, and this expection is
due to two different reasons:

1) When it was introduced, no operations were allowed to modifiy read-only
   subvolumes/snapshots (including defrag for example).

2) It keeps send from having an impact on other filesystem operations.
   Namely send does not need to keep locks on the trees nor needs to hold on
   to transaction handles and delay transaction commits. This ends up being
   a consequence of the former reason.

However the deduplication feature was introduced later (on September 2013,
while send was introduced in July 2012) and it allowed for deduplication
with destination files that belong to read-only trees (subvolumes and
snapshots).

That means that having a send operation (either full or incremental) running
in parallel with a deduplication that has the destination inode in one of
the trees used by the send operation, can result in tree nodes and leaves
getting freed and reused while send is using them. This problem is similar
to the problem solved for the root nodes getting freed and reused when a
snapshot is made against one tree that is currenly being used by a send
operation, fixed in commits [1] and [2]. These commits explain in detail
how the problem happens and the explanation is valid for any node or leaf
that is not the root of a tree as well. This problem was also discussed
and explained recently in a thread [3].

The problem is very easy to reproduce when using send with large trees
(snapshots) and just a few concurrent deduplication operations that target
files in the trees used by send. A stress test case is being sent for
fstests that triggers the issue easily. The most common error to hit is
the send ioctl return -EIO with the following messages in dmesg/syslog:

 [1631617.204075] BTRFS error (device sdc): did not find backref in send_root. inode=63292, offset=0, disk_byte=5228134400 found extent=5228134400
 [1631633.251754] BTRFS error (device sdc): parent transid verify failed on 32243712 wanted 24 found 27

The first one is very easy to hit while the second one happens much less
frequently, except for very large trees (in that test case, snapshots
with 100000 files having large xattrs to get deep and wide trees).
Less frequently, at least one BUG_ON can be hit:

 [1631742.130080] ------------[ cut here ]------------
 [1631742.130625] kernel BUG at fs/btrfs/ctree.c:1806!
 [1631742.131188] invalid opcode: 0000 [#6] SMP DEBUG_PAGEALLOC PTI
 [1631742.131726] CPU: 1 PID: 13394 Comm: btrfs Tainted: G    B D W         5.0.0-rc8-btrfs-next-45 #1
 [1631742.132265] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014
 [1631742.133399] RIP: 0010:read_node_slot+0x122/0x130 [btrfs]
 (...)
 [1631742.135061] RSP: 0018:ffffb530021ebaa0 EFLAGS: 00010246
 [1631742.135615] RAX: ffff93ac8912e000 RBX: 000000000000009d RCX: 0000000000000002
 [1631742.136173] RDX: 000000000000009d RSI: ffff93ac564b0d08 RDI: ffff93ad5b48c000
 [1631742.136759] RBP: ffffb530021ebb7d R08: 0000000000000001 R09: ffffb530021ebb7d
 [1631742.137324] R10: ffffb530021eba70 R11: 0000000000000000 R12: ffff93ac87d0a708
 [1631742.137900] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001
 [1631742.138455] FS:  00007f4cdb1528c0(0000) GS:ffff93ad76a80000(0000) knlGS:0000000000000000
 [1631742.139010] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [1631742.139568] CR2: 00007f5acb3d0420 CR3: 000000012be3e006 CR4: 00000000003606e0
 [1631742.140131] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 [1631742.140719] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 [1631742.141272] Call Trace:
 [1631742.141826]  ? do_raw_spin_unlock+0x49/0xc0
 [1631742.142390]  tree_advance+0x173/0x1d0 [btrfs]
 [1631742.142948]  btrfs_compare_trees+0x268/0x690 [btrfs]
 [1631742.143533]  ? process_extent+0x1070/0x1070 [btrfs]
 [1631742.144088]  btrfs_ioctl_send+0x1037/0x1270 [btrfs]
 [1631742.144645]  _btrfs_ioctl_send+0x80/0x110 [btrfs]
 [1631742.145161]  ? trace_sched_stick_numa+0xe0/0xe0
 [1631742.145685]  btrfs_ioctl+0x13fe/0x3120 [btrfs]
 [1631742.146179]  ? account_entity_enqueue+0xd3/0x100
 [1631742.146662]  ? reweight_entity+0x154/0x1a0
 [1631742.147135]  ? update_curr+0x20/0x2a0
 [1631742.147593]  ? check_preempt_wakeup+0x103/0x250
 [1631742.148053]  ? do_vfs_ioctl+0xa2/0x6f0
 [1631742.148510]  ? btrfs_ioctl_get_supported_features+0x30/0x30 [btrfs]
 [1631742.148942]  do_vfs_ioctl+0xa2/0x6f0
 [1631742.149361]  ? __fget+0x113/0x200
 [1631742.149767]  ksys_ioctl+0x70/0x80
 [1631742.150159]  __x64_sys_ioctl+0x16/0x20
 [1631742.150543]  do_syscall_64+0x60/0x1b0
 [1631742.150931]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
 [1631742.151326] RIP: 0033:0x7f4cd9f5add7
 (...)
 [1631742.152509] RSP: 002b:00007ffe91017708 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
 [1631742.152892] RAX: ffffffffffffffda RBX: 0000000000000105 RCX: 00007f4cd9f5add7
 [1631742.153268] RDX: 00007ffe91017790 RSI: 0000000040489426 RDI: 0000000000000007
 [1631742.153633] RBP: 0000000000000007 R08: 00007f4cd9e79700 R09: 00007f4cd9e79700
 [1631742.153999] R10: 00007f4cd9e799d0 R11: 0000000000000202 R12: 0000000000000003
 [1631742.154365] R13: 0000555dfae53020 R14: 0000000000000000 R15: 0000000000000001
 (...)
 [1631742.156696] ---[ end trace 5dac9f96dcc3fd6b ]---

That BUG_ON happens because while send is using a node, that node is COWed
by a concurrent deduplication, gets freed and gets reused as a leaf (because
a transaction commit happened in between), so when it attempts to read a
slot from the extent buffer, at ctree.c:read_node_slot(), the extent buffer
contents were wiped out and it now matches a leaf (which can even belong to
some other tree now), hitting the BUG_ON(level == 0).

Fix this concurrency issue by not allowing send and deduplication to run
in parallel if both operate on the same readonly trees, returning EAGAIN
to user space and logging an exlicit warning in dmesg/syslog.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=be6821f82c3cc36e026f5afd10249988852b35ea
[2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=6f2f0b394b54e2b159ef969a0b5274e9bbf82ff2
[3] https://lore.kernel.org/linux-btrfs/CAL3q7H7iqSEEyFaEtpRZw3cp613y+4k2Q8b4W7mweR3tZA05bQ@mail.gmail.com/

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>
2019-04-29 19:02:52 +02:00
David Sterba
f5c8daa5b2 btrfs: remove unused parameter fs_info from btrfs_set_disk_extent_flags
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:51 +02:00
David Sterba
c71dd88007 btrfs: remove unused parameter fs_info from btrfs_extend_item
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:50 +02:00
David Sterba
78ac4f9e5a btrfs: remove unused parameter fs_info from btrfs_truncate_item
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:50 +02:00
Qu Wenruo
ffd4bb2a19 btrfs: extent-tree: Use btrfs_ref to refactor btrfs_free_extent()
Similar to btrfs_inc_extent_ref(), use btrfs_ref to replace the long
parameter list and the confusing @owner parameter.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:49 +02:00
Qu Wenruo
82fa113fcc btrfs: extent-tree: Use btrfs_ref to refactor btrfs_inc_extent_ref()
Use the new btrfs_ref structure and replace parameter list to clean up
the usage of owner and level to distinguish the extent types.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:49 +02:00
David Sterba
163e97ee0d btrfs: get fs_info from device in btrfs_scrub_cancel_dev
We can read fs_info from the device and can drop it from the parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:47 +02:00
Filipe Manana
32b593bfcb Btrfs: remove no longer used function to run delayed refs asynchronously
It used to be called from only two places (truncate path and releasing a
transaction handle), but commits 28bad21257 ("btrfs: fix truncate
throttling") and db2462a6ad ("btrfs: don't run delayed refs in the end
transaction logic") removed their calls to this function, so it's not used
anymore. Just remove it and all its helpers.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:45 +02:00
David Sterba
5742d15fa7 btrfs: get fs_info from trans in btrfs_write_dirty_block_groups
We can read fs_info from the transaction and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:40 +02:00
David Sterba
bbebb3e0ba btrfs: get fs_info from trans in btrfs_setup_space_cache
We can read fs_info from the transaction and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:40 +02:00
Nikolay Borisov
e74e3993bc btrfs: Factor out in_range macro
This is used in more than one places so let's factor it out in ctree.h.
No functional changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:37 +02:00
Jeff Mahoney
1c11b63eff btrfs: replace pending/pinned chunks lists with io tree
The pending chunks list contains chunks that are allocated in the
current transaction but haven't been created yet. The pinned chunks
list contains chunks that are being released in the current transaction.
Both describe chunks that are not reflected on disk as in use but are
unavailable just the same.

The pending chunks list is anchored by the transaction handle, which
means that we need to hold a reference to a transaction when working
with the list.

The way we use them is by iterating over both lists to perform
comparisons on the stripes they describe for each device. This is
backwards and requires that we keep a transaction handle open while
we're trimming.

This patchset adds an extent_io_tree to btrfs_device that maintains
the allocation state of the device.  Extents are set dirty when
chunks are first allocated -- when the extent maps are added to the
mapping tree. They're cleared when last removed -- when the extent
maps are removed from the mapping tree. This matches the lifespan
of the pending and pinned chunks list and allows us to do trims
on unallocated space safely without pinning the transaction for what
may be a lengthy operation. We can also use this io tree to mark
which chunks have already been trimmed so we don't repeat the operation.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:37 +02:00
Qu Wenruo
496245cac5 btrfs: tree-checker: Verify inode item
There is a report in kernel bugzilla about mismatch file type in dir
item and inode item.

This inspires us to check inode mode in inode item.

This patch will check the following members:

- inode key objectid
  Should be ROOT_DIR_DIR or [256, (u64)-256] or FREE_INO.

- inode key offset
  Should be 0

- inode item generation
- inode item transid
  No newer than sb generation + 1.
  The +1 is for log tree.

- inode item mode
  No unknown bits.
  No invalid S_IF* bit.
  NOTE: S_IFMT check is not enough, need to check every know type.

- inode item nlink
  Dir should have no more link than 1.

- inode item flags

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:32 +02:00
David Sterba
90b1377daa btrfs: qgroup: remove obsolete fs_info members
The commit fcebe4562d ("Btrfs: rework qgroup accounting") reworked
qgroups and added some new structures. Another rework of qgroup
mechanics e69bcee376 ("btrfs: qgroup: Cleanup the old
ref_node-oriented mechanism.") stopped using them and left uncleaned.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:31 +02:00
David Sterba
e902baac65 btrfs: get fs_info from eb in btrfs_leaf_free_space
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:30 +02:00
David Sterba
bcdc428cfe btrfs: get fs_info from eb in btrfs_exclude_logged_extents
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:30 +02:00
David Sterba
8f881e8c18 btrfs: get fs_info from eb in leaf_data_end
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:30 +02:00
Qu Wenruo
80fbc341dc btrfs: Make btrfs_(set|clear)_header_flag return void
From the introduction of btrfs_(set|clear)_header_flag, there is no
usage of its return value.  So just make it return void.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:22 +02:00
Linus Torvalds
92825b0298 for-5.1-part2-tag
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAlyHwgcACgkQxWXV+ddt
 WDvfFQ//VBO8Rnz0+V4XbxaIaz25EbCjR4cBuXwwXyl8HPJMZBvBPqW0LVXtV0eP
 SwK0A5qiWqaXgWNpByD43AvgizZuWF/9SvxebaCKTjSK5t9TuXpR27vJNnHJf0L0
 o4DeMXlgd8yE8yZstQo7UnLWfNU69v6Pi3Zbar/7IIJ0sVVCPMMoGoARZDlQ+w0M
 wwppi04+a6bnAUbqpnWiL0a8++WX6gqP7MovqLRgf/up4cmzmDFoV7b/7pbvZxNv
 LrKQBmJZQq44bW4TXMzhpkrIGyzrrUQuBhpbYJus9yZYqS6Owkzl5AQpdzo9reg2
 V35xOkOZbXxqdOTGY0he9Z6wxJL+ocfryfRyA2hE4gXbCAnfFqIRyFicpTXuXxwg
 RBan8VLB+1iC7j9djX/sP/uCH3tsPgN4WnjdZgnkUOkUhTuvpPw/A9bp6Uqfjr6g
 JU0o/TlCC8npaveUQsuNbqyVYgPk58d9by12HsSW7UaA8ENyHz62+zoiv9jX/uZY
 Tl4t2L+MKxEcsd0KEKEQpV+0hV56GtYcIZIqJTe9WFmPBHmEH3PCHDx4A5LrYveO
 hC+hGAnX9xWK4XIr8T3ck1tsnxNApD25pmKSivadUiVJqOrPpJFyZb3aztcKcx4Y
 sDbZdOV7XHq6ACrIhLoxpYWQc27v1FqrWVqsF51wo07I3meUVaA=
 =u4Kf
 -----END PGP SIGNATURE-----

Merge tag 'for-5.1-part2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "Correctness and a deadlock fixes"

* tag 'for-5.1-part2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: zstd: ensure reclaim timer is properly cleaned up
  btrfs: move ulist allocation out of transaction in quota enable
  btrfs: save drop_progress if we drop refs at all
  btrfs: check for refs on snapshot delete resume
  Btrfs: fix deadlock between clone/dedupe and rename
  Btrfs: fix corruption reading shared and compressed extents after hole punching
2019-03-12 14:53:57 -07:00
Linus Torvalds
b5dd0c658c Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton:

 - some of the rest of MM

 - various misc things

 - dynamic-debug updates

 - checkpatch

 - some epoll speedups

 - autofs

 - rapidio

 - lib/, lib/lzo/ updates

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (83 commits)
  samples/mic/mpssd/mpssd.h: remove duplicate header
  kernel/fork.c: remove duplicated include
  include/linux/relay.h: fix percpu annotation in struct rchan
  arch/nios2/mm/fault.c: remove duplicate include
  unicore32: stop printing the virtual memory layout
  MAINTAINERS: fix GTA02 entry and mark as orphan
  mm: create the new vm_fault_t type
  arm, s390, unicore32: remove oneliner wrappers for memblock_alloc()
  arch: simplify several early memory allocations
  openrisc: simplify pte_alloc_one_kernel()
  sh: prefer memblock APIs returning virtual address
  microblaze: prefer memblock API returning virtual address
  powerpc: prefer memblock APIs returning virtual address
  lib/lzo: separate lzo-rle from lzo
  lib/lzo: implement run-length encoding
  lib/lzo: fast 8-byte copy on arm64
  lib/lzo: 64-bit CTZ on arm64
  lib/lzo: tidy-up ifdefs
  ipc/sem.c: replace kvmalloc/memset with kvzalloc and use struct_size
  ipc: annotate implicit fall through
  ...
2019-03-07 19:25:37 -08:00
Rasmus Villemoes
afe1a715e8 btrfs: implement btrfs_debug* in terms of helper macro
First, the btrfs_debug macros open-code (one possible definition of)
DYNAMIC_DEBUG_BRANCH, so they don't benefit from the CONFIG_JUMP_LABEL
optimization.

Second, a planned change of struct _ddebug (to reduce its size on 64 bit
machines) requires that all descriptors in a translation unit use
distinct identifiers.

Using the new _dynamic_func_call_no_desc helper macro from
dynamic_debug.h takes care of both of these.  No functional change.

Link: http://lkml.kernel.org/r/20190212214150.4807-12-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: David Sterba <dsterba@suse.com>
Acked-by: Jason Baron <jbaron@akamai.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-07 18:32:00 -08:00
Josef Bacik
78c52d9eb6 btrfs: check for refs on snapshot delete resume
There's a bug in snapshot deletion where we won't update the
drop_progress key if we're in the UPDATE_BACKREF stage.  This is a
problem because we could drop refs for blocks we know don't belong to
ours.  If we crash or umount at the right time we could experience
messages such as the following when snapshot deletion resumes

 BTRFS error (device dm-3): unable to find ref byte nr 66797568 parent 0 root 258  owner 1 offset 0
 ------------[ cut here ]------------
 WARNING: CPU: 3 PID: 16052 at fs/btrfs/extent-tree.c:7108 __btrfs_free_extent.isra.78+0x62c/0xb30 [btrfs]
 CPU: 3 PID: 16052 Comm: umount Tainted: G        W  OE     5.0.0-rc4+ #147
 Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./890FX Deluxe5, BIOS P1.40 05/03/2011
 RIP: 0010:__btrfs_free_extent.isra.78+0x62c/0xb30 [btrfs]
 RSP: 0018:ffffc90005cd7b18 EFLAGS: 00010286
 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000
 RDX: ffff88842fade680 RSI: ffff88842fad6b18 RDI: ffff88842fad6b18
 RBP: ffffc90005cd7bc8 R08: 0000000000000000 R09: 0000000000000001
 R10: 0000000000000001 R11: ffffffff822696b8 R12: 0000000003fb4000
 R13: 0000000000000001 R14: 0000000000000102 R15: ffff88819c9d67e0
 FS:  00007f08bb138fc0(0000) GS:ffff88842fac0000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007f8f5d861ea0 CR3: 00000003e99fe000 CR4: 00000000000006e0
 Call Trace:
 ? _raw_spin_unlock+0x27/0x40
 ? btrfs_merge_delayed_refs+0x356/0x3e0 [btrfs]
 __btrfs_run_delayed_refs+0x75a/0x13c0 [btrfs]
 ? join_transaction+0x2b/0x460 [btrfs]
 btrfs_run_delayed_refs+0xf3/0x1c0 [btrfs]
 btrfs_commit_transaction+0x52/0xa50 [btrfs]
 ? start_transaction+0xa6/0x510 [btrfs]
 btrfs_sync_fs+0x79/0x1c0 [btrfs]
 sync_filesystem+0x70/0x90
 generic_shutdown_super+0x27/0x120
 kill_anon_super+0x12/0x30
 btrfs_kill_super+0x16/0xa0 [btrfs]
 deactivate_locked_super+0x43/0x70
 deactivate_super+0x40/0x60
 cleanup_mnt+0x3f/0x80
 __cleanup_mnt+0x12/0x20
 task_work_run+0x8b/0xc0
 exit_to_usermode_loop+0xce/0xd0
 do_syscall_64+0x20b/0x210
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

To fix this simply mark dead roots we read from disk as DEAD and then
set the walk_control->restarted flag so we know we have a restarted
deletion.  From here whenever we try to drop refs for blocks we check to
verify our ref is set on them, and if it is not we skip it.  Once we
find a ref that is set we unset walk_control->restarted since the tree
should be in a normal state from then on, and any problems we run into
from there are different issues.  I tested this with an existing broken
fs and my reproducer that creates a broken fs and it fixed both file
systems.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-27 14:08:47 +01:00
David Sterba
0ea8207626 btrfs: scrub: remove unused nocow worker pointer
The member btrfs_fs_info::scrub_nocow_workers is unused since the nocow
optimization was removed from scrub in 9bebe665c3 ("btrfs: scrub:
Remove unused copy_nocow_pages and its callchain").

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:38 +01:00
David Sterba
c835294274 btrfs: scrub: add assertions for worker pointers
The scrub worker pointers are not NULL iff the scrub is running, so
reset them back once the last reference is dropped. Add assertions to
the initial phase of scrub to verify that.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:38 +01:00
Anand Jain
ff09c4ca59 btrfs: scrub: convert scrub_workers_refcnt to refcount_t
Use the refcount_t for fs_info::scrub_workers_refcnt instead of int so
we get the extra checks. All reference changes are still done under
scrub_lock.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:38 +01:00
Josef Bacik
450114fc0d btrfs: don't use global reserve for chunk allocation
We've done this forever because of the voodoo around knowing how much
space we have.  However, we have better ways of doing this now, and on
normal file systems we'll easily have a global reserve of 512MiB, and
since metadata chunks are usually 1GiB that means we'll allocate
metadata chunks more readily.  Instead use the actual used amount when
determining if we need to allocate a chunk or not.

This has a side effect for mixed block group fs'es where we are no
longer allocating enough chunks for the data/metadata requirements.  To
deal with this add a ALLOC_CHUNK_FORCE step to the flushing state
machine.  This will only get used if we've already made a full loop
through the flushing machinery and tried committing the transaction.

If we have then we can try and force a chunk allocation since we likely
need it to make progress.  This resolves issues I was seeing with
the mixed bg tests in xfstests without the new flushing state.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
[ merged with patch "add ALLOC_CHUNK_FORCE to the flushing code" ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:34 +01:00
Josef Bacik
034f784d7c btrfs: replace cleaner_delayed_iput_mutex with a waitqueue
The throttle path doesn't take cleaner_delayed_iput_mutex, which means
we could think we're done flushing iputs in the data space reservation
path when we could have a throttler doing an iput.  There's no real
reason to serialize the delayed iput flushing, so instead of taking the
cleaner_delayed_iput_mutex whenever we flush the delayed iputs just
replace it with an atomic counter and a waitqueue.  This removes the
short (or long depending on how big the inode is) window where we think
there are no more pending iputs when there really are some.

The waiting is killable as it could be indirectly called from user
operations like fallocate or zero-range. Such call sites should handle
the error but otherwise it's not necessary. Eg. flush_space just needs
to attempt to make space by waiting on iputs.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
[ add killable comment and changelog parts ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:29 +01:00
Anders Roxell
2eec5f0042 btrfs: let the assertion expression compile in all configs
A compiler warning (in a patch in development) pointed to a variable
that was used only inside and ASSERT:

  u64 root_objectid = root->root_key.objectid;
  ASSERT(root_objectid == ...);

  fs/btrfs/relocation.c: In function ‘insert_dirty_subv’:
  fs/btrfs/relocation.c:2138:6: warning: unused variable ‘root_objectid’ [-Wunused-variable]
    u64 root_objectid = root->root_key.objectid;
	^~~~~~~~~~~~~

When CONFIG_BRTFS_ASSERT isn't enabled, variable root_objectid isn't used.

Rework the assertion helper by adding a runtime check instead of the
'#ifdef CONFIG_BTRFS_ASSERT #else ...", so the compiler sees the
condition being passed into an inline function after preprocessing.

Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:28 +01:00
Qu Wenruo
370a11b811 btrfs: qgroup: Introduce per-root swapped blocks infrastructure
To allow delayed subtree swap rescan, btrfs needs to record per-root
information about which tree blocks get swapped.  This patch introduces
the required infrastructure.

The designed workflow will be:

1) Record the subtree root block that gets swapped.

   During subtree swap:
   O = Old tree blocks
   N = New tree blocks
         reloc tree                         subvolume tree X
            Root                               Root
           /    \                             /    \
         NA     OB                          OA      OB
       /  |     |  \                      /  |      |  \
     NC  ND     OE  OF                   OC  OD     OE  OF

  In this case, NA and OA are going to be swapped, record (NA, OA) into
  subvolume tree X.

2) After subtree swap.
         reloc tree                         subvolume tree X
            Root                               Root
           /    \                             /    \
         OA     OB                          NA      OB
       /  |     |  \                      /  |      |  \
     OC  OD     OE  OF                   NC  ND     OE  OF

3a) COW happens for OB
    If we are going to COW tree block OB, we check OB's bytenr against
    tree X's swapped_blocks structure.
    If it doesn't fit any, nothing will happen.

3b) COW happens for NA
    Check NA's bytenr against tree X's swapped_blocks, and get a hit.
    Then we do subtree scan on both subtrees OA and NA.
    Resulting 6 tree blocks to be scanned (OA, OC, OD, NA, NC, ND).

    Then no matter what we do to subvolume tree X, qgroup numbers will
    still be correct.
    Then NA's record gets removed from X's swapped_blocks.

4)  Transaction commit
    Any record in X's swapped_blocks gets removed, since there is no
    modification to swapped subtrees, no need to trigger heavy qgroup
    subtree rescan for them.

This will introduce 128 bytes overhead for each btrfs_root even qgroup
is not enabled. This is to reduce memory allocations and potential
failures.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:26 +01:00
Qu Wenruo
d2311e6985 btrfs: relocation: Delay reloc tree deletion after merge_reloc_roots
Relocation code will drop btrfs_root::reloc_root as soon as
merge_reloc_root() finishes.

However later qgroup code will need to access btrfs_root::reloc_root
after merge_reloc_root() for delayed subtree rescan.

So alter the timming of resetting btrfs_root:::reloc_root, make it
happens after transaction commit.

With this patch, we will introduce a new btrfs_root::state,
BTRFS_ROOT_DEAD_RELOC_TREE, to info part of btrfs_root::reloc_tree user
that although btrfs_root::reloc_tree is still non-NULL, but still it's
not used any more.

The lifespan of btrfs_root::reloc tree will become:
          Old behavior            |              New
------------------------------------------------------------------------
btrfs_init_reloc_root()      ---  | btrfs_init_reloc_root()      ---
  set reloc_root              |   |   set reloc_root              |
                              |   |                               |
                              |   |                               |
merge_reloc_root()            |   | merge_reloc_root()            |
|- btrfs_update_reloc_root() ---  | |- btrfs_update_reloc_root() -+-
     clear btrfs_root::reloc_root |      set ROOT_DEAD_RELOC_TREE |
                                  |      record root into dirty   |
                                  |      roots rbtree             |
                                  |                               |
                                  | reloc_block_group() Or        |
                                  | btrfs_recover_relocation()    |
                                  | | After transaction commit    |
                                  | |- clean_dirty_subvols()     ---
                                  |     clear btrfs_root::reloc_root

During ROOT_DEAD_RELOC_TREE set lifespan, the only user of
btrfs_root::reloc_tree should be qgroup.

Since reloc root needs a longer life-span, this patch will also delay
btrfs_drop_snapshot() call.
Now btrfs_drop_snapshot() is called in clean_dirty_subvols().

This patch will increase the size of btrfs_root by 16 bytes.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:25 +01:00
Nikolay Borisov
4ab47a8d9c btrfs: Remove unused arguments from btrfs_get_extent_fiemap
This function is a simple wrapper over btrfs_get_extent that returns
either:

a) A real extent in the passed range or
b) Adjusted extent based on whether delalloc bytes are found backing up
   a hole.

To support these semantics it doesn't need the page/pg_offset/create
arguments which are passed to btrfs_get_extent in case an extent is to
be created. So simplify the function by removing the unused arguments.
No functional changes.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:17 +01:00