Commit Graph

15 Commits

Author SHA1 Message Date
Johannes Thumshirn 6b613cc97f btrfs: reschedule when cloning lots of extents
We have several occurrences of a soft lockup from fstest's generic/175
testcase, which look more or less like this one:

  watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [xfs_io:10030]
  Kernel panic - not syncing: softlockup: hung tasks
  CPU: 0 PID: 10030 Comm: xfs_io Tainted: G             L    5.9.0-rc5+ #768
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4-rebuilt.opensuse.org 04/01/2014
  Call Trace:
   <IRQ>
   dump_stack+0x77/0xa0
   panic+0xfa/0x2cb
   watchdog_timer_fn.cold+0x85/0xa5
   ? lockup_detector_update_enable+0x50/0x50
   __hrtimer_run_queues+0x99/0x4c0
   ? recalibrate_cpu_khz+0x10/0x10
   hrtimer_run_queues+0x9f/0xb0
   update_process_times+0x28/0x80
   tick_handle_periodic+0x1b/0x60
   __sysvec_apic_timer_interrupt+0x76/0x210
   asm_call_on_stack+0x12/0x20
   </IRQ>
   sysvec_apic_timer_interrupt+0x7f/0x90
   asm_sysvec_apic_timer_interrupt+0x12/0x20
  RIP: 0010:btrfs_tree_unlock+0x91/0x1a0 [btrfs]
  RSP: 0018:ffffc90007123a58 EFLAGS: 00000282
  RAX: ffff8881cea2fbe0 RBX: ffff8881cea2fbe0 RCX: 0000000000000000
  RDX: ffff8881d23fd200 RSI: ffffffff82045220 RDI: ffff8881cea2fba0
  RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000032
  R10: 0000160000000000 R11: 0000000000001000 R12: 0000000000001000
  R13: ffff8882357fd5b0 R14: ffff88816fa76e70 R15: ffff8881cea2fad0
   ? btrfs_tree_unlock+0x15b/0x1a0 [btrfs]
   btrfs_release_path+0x67/0x80 [btrfs]
   btrfs_insert_replace_extent+0x177/0x2c0 [btrfs]
   btrfs_replace_file_extents+0x472/0x7c0 [btrfs]
   btrfs_clone+0x9ba/0xbd0 [btrfs]
   btrfs_clone_files.isra.0+0xeb/0x140 [btrfs]
   ? file_update_time+0xcd/0x120
   btrfs_remap_file_range+0x322/0x3b0 [btrfs]
   do_clone_file_range+0xb7/0x1e0
   vfs_clone_file_range+0x30/0xa0
   ioctl_file_clone+0x8a/0xc0
   do_vfs_ioctl+0x5b2/0x6f0
   __x64_sys_ioctl+0x37/0xa0
   do_syscall_64+0x33/0x40
   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  RIP: 0033:0x7f87977fc247
  RSP: 002b:00007ffd51a2f6d8 EFLAGS: 00000206 ORIG_RAX: 0000000000000010
  RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f87977fc247
  RDX: 00007ffd51a2f710 RSI: 000000004020940d RDI: 0000000000000003
  RBP: 0000000000000004 R08: 00007ffd51a79080 R09: 0000000000000000
  R10: 00005621f11352f2 R11: 0000000000000206 R12: 0000000000000000
  R13: 0000000000000000 R14: 00005621f128b958 R15: 0000000080000000
  Kernel Offset: disabled
  ---[ end Kernel panic - not syncing: softlockup: hung tasks ]---

All of these lockup reports have the call chain btrfs_clone_files() ->
btrfs_clone() in common. btrfs_clone_files() calls btrfs_clone() with
both source and destination extents locked and loops over the source
extent to create the clones.

Conditionally reschedule in the btrfs_clone() loop, to give some time back
to other processes.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-10-07 12:13:22 +02:00
Filipe Manana 306bfec02b btrfs: rename btrfs_punch_hole_range() to a more generic name
The function btrfs_punch_hole_range() is now used to replace all the file
extents in a given file range with an extent described in the given struct
btrfs_replace_extent_info argument. This extent can either be an existing
extent that is being cloned or it can be a new extent (namely a prealloc
extent). When that argument is NULL it only punches a hole (drops all the
existing extents) in the file range.

So rename the function to btrfs_replace_file_extents().

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-10-07 12:13:17 +02:00
Filipe Manana bf385648fa btrfs: rename struct btrfs_clone_extent_info to a more generic name
Now that we can use btrfs_clone_extent_info to convey information for a
new prealloc extent as well, and not just for existing extents that are
being cloned, rename it to btrfs_replace_extent_info, which reflects the
fact that this is now more generic and it is used to replace all existing
extents in a file range with the extent described by the structure.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-10-07 12:13:16 +02:00
Filipe Manana fb870f6cdd btrfs: remove item_size member of struct btrfs_clone_extent_info
The value of item_size of struct btrfs_clone_extent_info is always set to
the size of a non-inline file extent item, and in fact the infrastructure
that uses this structure (btrfs_punch_hole_range()) does not work with
inline file extents at all (and it is not supposed to).

So just remove that field from the structure and use directly
sizeof(struct btrfs_file_extent_item) instead. Also assert that the
file extent type is not inline at btrfs_insert_clone_extent().

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-10-07 12:13:16 +02:00
Filipe Manana 8fccebfa53 btrfs: fix metadata reservation for fallocate that leads to transaction aborts
When doing an fallocate(), specially a zero range operation, we assume
that reserving 3 units of metadata space is enough, that at most we touch
one leaf in subvolume/fs tree for removing existing file extent items and
inserting a new file extent item. This assumption is generally true for
most common use cases. However when we end up needing to remove file extent
items from multiple leaves, we can end up failing with -ENOSPC and abort
the current transaction, turning the filesystem to RO mode. When this
happens a stack trace like the following is dumped in dmesg/syslog:

[ 1500.620934] ------------[ cut here ]------------
[ 1500.620938] BTRFS: Transaction aborted (error -28)
[ 1500.620973] WARNING: CPU: 2 PID: 30807 at fs/btrfs/inode.c:9724 __btrfs_prealloc_file_range+0x512/0x570 [btrfs]
[ 1500.620974] Modules linked in: btrfs intel_rapl_msr intel_rapl_common kvm_intel (...)
[ 1500.621010] CPU: 2 PID: 30807 Comm: xfs_io Tainted: G        W         5.9.0-rc3-btrfs-next-67 #1
[ 1500.621012] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
[ 1500.621023] RIP: 0010:__btrfs_prealloc_file_range+0x512/0x570 [btrfs]
[ 1500.621026] Code: 8b 40 50 f0 48 (...)
[ 1500.621028] RSP: 0018:ffffb05fc8803ca0 EFLAGS: 00010286
[ 1500.621030] RAX: 0000000000000000 RBX: ffff9608af276488 RCX: 0000000000000000
[ 1500.621032] RDX: 0000000000000001 RSI: 0000000000000027 RDI: 00000000ffffffff
[ 1500.621033] RBP: ffffb05fc8803d90 R08: 0000000000000001 R09: 0000000000000001
[ 1500.621035] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000003200000
[ 1500.621037] R13: 00000000ffffffe4 R14: ffff9608af275fe8 R15: ffff9608af275f60
[ 1500.621039] FS:  00007fb5b2368ec0(0000) GS:ffff9608b6600000(0000) knlGS:0000000000000000
[ 1500.621041] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1500.621043] CR2: 00007fb5b2366fb8 CR3: 0000000202d38005 CR4: 00000000003706e0
[ 1500.621046] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1500.621047] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 1500.621049] Call Trace:
[ 1500.621076]  btrfs_prealloc_file_range+0x10/0x20 [btrfs]
[ 1500.621087]  btrfs_fallocate+0xccd/0x1280 [btrfs]
[ 1500.621108]  vfs_fallocate+0x14d/0x290
[ 1500.621112]  ksys_fallocate+0x3a/0x70
[ 1500.621117]  __x64_sys_fallocate+0x1a/0x20
[ 1500.621120]  do_syscall_64+0x33/0x80
[ 1500.621123]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1500.621126] RIP: 0033:0x7fb5b248c477
[ 1500.621128] Code: 89 7c 24 08 (...)
[ 1500.621130] RSP: 002b:00007ffc7bee9060 EFLAGS: 00000293 ORIG_RAX: 000000000000011d
[ 1500.621132] RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fb5b248c477
[ 1500.621134] RDX: 0000000000000000 RSI: 0000000000000010 RDI: 0000000000000003
[ 1500.621136] RBP: 0000557718faafd0 R08: 0000000000000000 R09: 0000000000000000
[ 1500.621137] R10: 0000000003200000 R11: 0000000000000293 R12: 0000000000000010
[ 1500.621139] R13: 0000557718faafb0 R14: 0000557718faa480 R15: 0000000000000003
[ 1500.621151] irq event stamp: 1026217
[ 1500.621154] hardirqs last  enabled at (1026223): [<ffffffffba965570>] console_unlock+0x500/0x5c0
[ 1500.621156] hardirqs last disabled at (1026228): [<ffffffffba9654c7>] console_unlock+0x457/0x5c0
[ 1500.621159] softirqs last  enabled at (1022486): [<ffffffffbb6003dc>] __do_softirq+0x3dc/0x606
[ 1500.621161] softirqs last disabled at (1022477): [<ffffffffbb4010b2>] asm_call_on_stack+0x12/0x20
[ 1500.621162] ---[ end trace 2955b08408d8b9d4 ]---
[ 1500.621167] BTRFS: error (device sdj) in __btrfs_prealloc_file_range:9724: errno=-28 No space left

When we use fallocate() internally, for reserving an extent for a space
cache, inode cache or relocation, we can't hit this problem since either
there aren't any file extent items to remove from the subvolume tree or
there is at most one.

When using plain fallocate() it's very unlikely, since that would require
having many file extent items representing holes for the target range and
crossing multiple leafs - we attempt to increase the range (merge) of such
file extent items when punching holes, so at most we end up with 2 file
extent items for holes at leaf boundaries.

However when using the zero range operation of fallocate() for a large
range (100+ MiB for example) that's fairly easy to trigger. The following
example reproducer triggers the issue:

  $ cat reproducer.sh
  #!/bin/bash

  umount /dev/sdj &> /dev/null
  mkfs.btrfs -f -n 16384 -O ^no-holes /dev/sdj > /dev/null
  mount /dev/sdj /mnt/sdj

  # Create a 100M file with many file extent items. Punch a hole every 8K
  # just to speedup the file creation - we could do 4K sequential writes
  # followed by fsync (or O_SYNC) as well, but that takes a lot of time.
  file_size=$((100 * 1024 * 1024))
  xfs_io -f -c "pwrite -S 0xab -b 10M 0 $file_size" /mnt/sdj/foobar
  for ((i = 0; i < $file_size; i += 8192)); do
      xfs_io -c "fpunch $i 4096" /mnt/sdj/foobar
  done

  # Force a transaction commit, so the zero range operation will be forced
  # to COW all metadata extents it need to touch.
  sync

  xfs_io -c "fzero 0 $file_size" /mnt/sdj/foobar

  umount /mnt/sdj

  $ ./reproducer.sh
  wrote 104857600/104857600 bytes at offset 0
  100 MiB, 10 ops; 0.0669 sec (1.458 GiB/sec and 149.3117 ops/sec)
  fallocate: No space left on device

  $ dmesg
  <shows the same stack trace pasted before>

To fix this use the existing infrastructure that hole punching and
extent cloning use for replacing a file range with another extent. This
deals with doing the removal of file extent items and inserting the new
one using an incremental approach, reserving more space when needed and
always ensuring we don't leave an implicit hole in the range in case
we need to do multiple iterations and a crash happens between iterations.

A test case for fstests will follow up soon.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-10-07 12:13:16 +02:00
Nikolay Borisov 998acfe8ff btrfs: make copy_inline_to_page take btrfs_inode
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-10-07 12:12:19 +02:00
Nikolay Borisov 6fee248d2b btrfs: convert btrfs_inode_sectorsize to take btrfs_inode
It's counterintuitive to have a function named btrfs_inode_xxx which
takes a generic inode. Also move the function to btrfs_inode.h so that
it has access to the definition of struct btrfs_inode.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-10-07 12:12:18 +02:00
Filipe Manana 3ebac17ce5 btrfs: reduce contention on log trees when logging checksums
The possibility of extents being shared (through clone and deduplication
operations) requires special care when logging data checksums, to avoid
having a log tree with different checksum items that cover ranges which
overlap (which resulted in missing checksums after replaying a log tree).
Such problems were fixed in the past by the following commits:

commit 40e046acbd ("Btrfs: fix missing data checksums after replaying a
                      log tree")

commit e289f03ea7 ("btrfs: fix corrupt log due to concurrent fsync of
                      inodes with shared extents")

Test case generic/588 exercises the scenario solved by the first commit
(purely sequential and deterministic) while test case generic/457 often
triggered the case fixed by the second commit (not deterministic, requires
specific timings under concurrency).

The problems were addressed by deleting, from the log tree, any existing
checksums before logging the new ones. And also by doing the deletion and
logging of the cheksums while locking the checksum range in an extent io
tree (root->log_csum_range), to deal with the case where we have concurrent
fsyncs against files with shared extents.

That however causes more contention on the leaves of a log tree where we
store checksums (and all the nodes in the paths leading to them), even
when we do not have shared extents, or all the shared extents were created
by past transactions. It also adds a bit of contention on the spin lock of
the log_csums_range extent io tree of the log root.

This change adds a 'last_reflink_trans' field to the inode to keep track
of the last transaction where a new extent was shared between inodes
(through clone and deduplication operations). It is updated for both the
source and destination inodes of reflink operations whenever a new extent
(created in the current transaction) becomes shared by the inodes. This
field is kept in memory only, not persisted in the inode item, similar
to other existing fields (last_unlink_trans, logged_trans).

When logging checksums for an extent, if the value of 'last_reflink_trans'
is smaller then the current transaction's generation/id, we skip locking
the extent range and deletion of checksums from the log tree, since we
know we do not have new shared extents. This reduces contention on the
log tree's leaves where checksums are stored.

The following script, which uses fio, was used to measure the impact of
this change:

  $ cat test-fsync.sh
  #!/bin/bash

  DEV=/dev/sdk
  MNT=/mnt/sdk
  MOUNT_OPTIONS="-o ssd"
  MKFS_OPTIONS="-d single -m single"

  if [ $# -ne 3 ]; then
      echo "Use $0 NUM_JOBS FILE_SIZE FSYNC_FREQ"
      exit 1
  fi

  NUM_JOBS=$1
  FILE_SIZE=$2
  FSYNC_FREQ=$3

  cat <<EOF > /tmp/fio-job.ini
  [writers]
  rw=write
  fsync=$FSYNC_FREQ
  fallocate=none
  group_reporting=1
  direct=0
  bs=64k
  ioengine=sync
  size=$FILE_SIZE
  directory=$MNT
  numjobs=$NUM_JOBS
  EOF

  echo "Using config:"
  echo
  cat /tmp/fio-job.ini
  echo

  mkfs.btrfs -f $MKFS_OPTIONS $DEV
  mount $MOUNT_OPTIONS $DEV $MNT
  fio /tmp/fio-job.ini
  umount $MNT

The tests were performed for different numbers of jobs, file sizes and
fsync frequency. A qemu VM using kvm was used, with 8 cores (the host has
12 cores, with cpu governance set to performance mode on all cores), 16GiB
of ram (the host has 64GiB) and using a NVMe device directly (without an
intermediary filesystem in the host). While running the tests, the host
was not used for anything else, to avoid disturbing the tests.

The obtained results were the following (the last line of fio's output was
pasted). Starting with 16 jobs is where a significant difference is
observable in this particular setup and hardware (differences highlighted
below). The very small differences for tests with less than 16 jobs are
possibly just noise and random.

    **** 1 job, file size 1G, fsync frequency 1 ****

before this change:

WRITE: bw=23.8MiB/s (24.9MB/s), 23.8MiB/s-23.8MiB/s (24.9MB/s-24.9MB/s), io=1024MiB (1074MB), run=43075-43075msec

after this change:

WRITE: bw=24.4MiB/s (25.6MB/s), 24.4MiB/s-24.4MiB/s (25.6MB/s-25.6MB/s), io=1024MiB (1074MB), run=41938-41938msec

    **** 2 jobs, file size 1G, fsync frequency 1 ****

before this change:

WRITE: bw=37.7MiB/s (39.5MB/s), 37.7MiB/s-37.7MiB/s (39.5MB/s-39.5MB/s), io=2048MiB (2147MB), run=54351-54351msec

after this change:

WRITE: bw=37.7MiB/s (39.5MB/s), 37.6MiB/s-37.6MiB/s (39.5MB/s-39.5MB/s), io=2048MiB (2147MB), run=54428-54428msec

    **** 4 jobs, file size 1G, fsync frequency 1 ****

before this change:

WRITE: bw=67.5MiB/s (70.8MB/s), 67.5MiB/s-67.5MiB/s (70.8MB/s-70.8MB/s), io=4096MiB (4295MB), run=60669-60669msec

after this change:

WRITE: bw=68.6MiB/s (71.0MB/s), 68.6MiB/s-68.6MiB/s (71.0MB/s-71.0MB/s), io=4096MiB (4295MB), run=59678-59678msec

    **** 8 jobs, file size 1G, fsync frequency 1 ****

before this change:

WRITE: bw=128MiB/s (134MB/s), 128MiB/s-128MiB/s (134MB/s-134MB/s), io=8192MiB (8590MB), run=64048-64048msec

after this change:

WRITE: bw=129MiB/s (135MB/s), 129MiB/s-129MiB/s (135MB/s-135MB/s), io=8192MiB (8590MB), run=63405-63405msec

    **** 16 jobs, file size 1G, fsync frequency 1 ****

before this change:

WRITE: bw=78.5MiB/s (82.3MB/s), 78.5MiB/s-78.5MiB/s (82.3MB/s-82.3MB/s), io=16.0GiB (17.2GB), run=208676-208676msec

after this change:

WRITE: bw=110MiB/s (115MB/s), 110MiB/s-110MiB/s (115MB/s-115MB/s), io=16.0GiB (17.2GB), run=149295-149295msec
(+40.1% throughput, -28.5% runtime)

    **** 32 jobs, file size 1G, fsync frequency 1 ****

before this change:

WRITE: bw=58.8MiB/s (61.7MB/s), 58.8MiB/s-58.8MiB/s (61.7MB/s-61.7MB/s), io=32.0GiB (34.4GB), run=557134-557134msec

after this change:

WRITE: bw=76.1MiB/s (79.8MB/s), 76.1MiB/s-76.1MiB/s (79.8MB/s-79.8MB/s), io=32.0GiB (34.4GB), run=430550-430550msec
(+29.4% throughput, -22.7% runtime)

    **** 64 jobs, file size 512M, fsync frequency 1 ****

before this change:

WRITE: bw=65.8MiB/s (68.0MB/s), 65.8MiB/s-65.8MiB/s (68.0MB/s-68.0MB/s), io=32.0GiB (34.4GB), run=498055-498055msec

after this change:

WRITE: bw=85.1MiB/s (89.2MB/s), 85.1MiB/s-85.1MiB/s (89.2MB/s-89.2MB/s), io=32.0GiB (34.4GB), run=385116-385116msec
(+29.3% throughput, -22.7% runtime)

    **** 128 jobs, file size 256M, fsync frequency 1 ****

before this change:

WRITE: bw=54.7MiB/s (57.3MB/s), 54.7MiB/s-54.7MiB/s (57.3MB/s-57.3MB/s), io=32.0GiB (34.4GB), run=599373-599373msec

after this change:

WRITE: bw=121MiB/s (126MB/s), 121MiB/s-121MiB/s (126MB/s-126MB/s), io=32.0GiB (34.4GB), run=271907-271907msec
(+121.2% throughput, -54.6% runtime)

    **** 256 jobs, file size 256M, fsync frequency 1 ****

before this change:

WRITE: bw=69.2MiB/s (72.5MB/s), 69.2MiB/s-69.2MiB/s (72.5MB/s-72.5MB/s), io=64.0GiB (68.7GB), run=947536-947536msec

after this change:

WRITE: bw=121MiB/s (127MB/s), 121MiB/s-121MiB/s (127MB/s-127MB/s), io=64.0GiB (68.7GB), run=541916-541916msec
(+74.9% throughput, -42.8% runtime)

    **** 512 jobs, file size 128M, fsync frequency 1 ****

before this change:

WRITE: bw=85.4MiB/s (89.5MB/s), 85.4MiB/s-85.4MiB/s (89.5MB/s-89.5MB/s), io=64.0GiB (68.7GB), run=767734-767734msec

after this change:

WRITE: bw=141MiB/s (147MB/s), 141MiB/s-141MiB/s (147MB/s-147MB/s), io=64.0GiB (68.7GB), run=466022-466022msec
(+65.1% throughput, -39.3% runtime)

    **** 1024 jobs, file size 128M, fsync frequency 1 ****

before this change:

WRITE: bw=115MiB/s (120MB/s), 115MiB/s-115MiB/s (120MB/s-120MB/s), io=128GiB (137GB), run=1143775-1143775msec

after this change:

WRITE: bw=171MiB/s (180MB/s), 171MiB/s-171MiB/s (180MB/s-180MB/s), io=128GiB (137GB), run=764843-764843msec
(+48.7% throughput, -33.1% runtime)

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-07-27 12:55:45 +02:00
Nikolay Borisov e5b7231e20 btrfs: make btrfs_delalloc_reserve_space take btrfs_inode
All of its children take btrfs_inode so bubble up this requirement to
btrfs_delalloc_reserve_space's interface and stop calling BTRFS_I
internally.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-07-27 12:55:36 +02:00
Nikolay Borisov 86d52921a2 btrfs: make btrfs_delalloc_release_space take btrfs_inode
It needs btrfs_inode so take it as a parameter directly.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-07-27 12:55:36 +02:00
Nikolay Borisov c2566f2289 btrfs: make btrfs_set_extent_delalloc take btrfs_inode
Preparation to make btrfs_dirty_pages take btrfs_inode as parameter.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-07-27 12:55:35 +02:00
Filipe Manana 4fdb688c70 btrfs: fix lost i_size update after cloning inline extent
When not using the NO_HOLES feature we were not marking the destination's
file range as written after cloning an inline extent into it. This can
lead to a data loss if the current destination file size is smaller than
the source file's size.

Example:

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

  $ echo "hello world" > /mnt/foo
  $ cp --reflink=always /mnt/foo /mnt/bar
  $ rm -f /mnt/foo
  $ umount /mnt

  $ mount /mnt/sdc /mnt
  $ cat /mnt/bar
  $
  $ stat -c %s /mnt/bar
  0

  # -> the file is empty, since we deleted foo, the data lost is forever

Fix that by calling btrfs_inode_set_file_extent_range() after cloning an
inline extent.

A test case for fstests will follow soon.

Link: https://lore.kernel.org/linux-btrfs/20200404193846.GA432065@latitude/
Reported-by: Johannes Hirte <johannes.hirte@datenkhaos.de>
Fixes: 9ddc959e80 ("btrfs: use the file extent tree infrastructure")
Tested-by: Johannes Hirte <johannes.hirte@datenkhaos.de>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-04-08 19:10:34 +02:00
Filipe Manana 05a5a7621c Btrfs: implement full reflink support for inline extents
There are a few cases where we don't allow cloning an inline extent into
the destination inode, returning -EOPNOTSUPP to user space. This was done
to prevent several types of file corruption and because it's not very
straightforward to deal with these cases, as they can't rely on simply
copying the inline extent between leaves. Such cases require copying the
inline extent's data into the respective page of the destination inode.

Not supporting these cases makes it harder and more cumbersome to write
applications/libraries that work on any filesystem with reflink support,
since all these cases for which btrfs fails with -EOPNOTSUPP work just
fine on xfs for example. These unsupported cases are also not documented
anywhere and explaining which exact cases fail require a bit of too
technical understanding of btrfs's internal (inline extents and when and
where can they exist in a file), so it's not really user friendly.

Also some test cases from fstests that use fsx, such as generic/522 for
example, can sporadically fail because they trigger one of these cases,
and fsx expects all operations to succeed.

This change adds supports for cloning all these cases by copying the
inline extent's data into the respective page of the destination inode.

With this change test case btrfs/112 from fstests fails because it
expects some clone operations to fail, so it will be updated. Also a
new test case that exercises all these previously unsupported cases
will be added to fstests.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:54 +01:00
Filipe Manana a61e1e0df9 Btrfs: simplify inline extent handling when doing reflinks
We can not reflink parts of an inline extent, we must always reflink the
whole inline extent. We know that inline extents always start at file
offset 0 and that can never represent an amount of data larger then the
filesystem's sector size (both compressed and uncompressed). We also have
had the constraints that reflink operations must have a start offset that
is aligned to the sector size and an end offset that is also aligned or
it ends the inode's i_size, so there's no way for user space to be able
to do a reflink operation that will refer to only a part of an inline
extent.

Initially there was a bug in the inlining code that could allow compressed
inline extents that encoded more than 1 page, but that was fixed in 2008
by commit 70b99e6959 ("Btrfs: Compression corner fixes") since that
was problematic.

So remove all the extent cloning code that deals with the possibility
of cloning only partial inline extents.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:54 +01:00
Filipe Manana 6a17738100 Btrfs: move all reflink implementation code into its own file
The reflink code is quite large and has been living in ioctl.c since ever.
It has grown over the years after many bug fixes and improvements, and
since I'm planning on making some further improvements on it, it's time
to get it better organized by moving into its own file, reflink.c
(similar to what xfs does for example).

This change only moves the code out of ioctl.c into the new file, it
doesn't do any other change.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:54 +01:00