Commit graph

1,447,411 commits

Author SHA1 Message Date
Filipe Manana
f754acce0f btrfs: update comment for BTRFS_RESERVE_NO_FLUSH
The comment is incomplete as BTRFS_RESERVE_NO_FLUSH is used for more
reasons than currently holding a transaction handle open. Update the
comment with all the other reasons and give some details.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-04-07 18:55:53 +02:00
Filipe Manana
40f2b11c1b btrfs: don't allow log trees to consume global reserve or overcommit metadata
For a fsync we never reserve space in advance, we just start a transaction
without reserving space and we use an empty block reserve for a log tree.
We reserve space as we need while updating a log tree, we end up in
btrfs_use_block_rsv() when reserving space for the allocation of a log
tree extent buffer and we attempt first to reserve without flushing,
and if that fails we attempt to consume from the global reserve or
overcommit metadata. This makes us consume space that may be the last
resort for a transaction commit to succeed, therefore increasing the
chances for a transaction abort with -ENOSPC.

So make btrfs_use_block_rsv() fail if we can't reserve metadata space for
a log tree extent buffer allocation without flushing, making the fsync
fallback to a transaction commit and avoid using critical space that could
be the only resort for a transaction commit to succeed when we are in a
critical space situation.

Reviewed-by: Leo Martins <loemra.dev@gmail.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-04-07 18:55:53 +02:00
Filipe Manana
574d93fc62 btrfs: be less aggressive with metadata overcommit when we can do full flushing
Over the years we often get reports of some -ENOSPC failure while updating
metadata that leads to a transaction abort. I have seen this happen for
filesystems of all sizes and with workloads that are very user/customer
specific and unable to reproduce, but Aleksandar recently reported a
simple way to reproduce this with a 1G filesystem and using the bonnie++
benchmark tool. The following test script reproduces the failure:

    $ cat test.sh
    #!/bin/bash

    # Create and use a 1G null block device, memory backed, otherwise
    # the test takes a very long time.
    modprobe null_blk nr_devices="0"
    null_dev="/sys/kernel/config/nullb/nullb0"
    mkdir "$null_dev"
    size=$((1 * 1024)) # in MB
    echo 2 > "$null_dev/submit_queues"
    echo "$size" > "$null_dev/size"
    echo 1 > "$null_dev/memory_backed"
    echo 1 > "$null_dev/discard"
    echo 1 > "$null_dev/power"

    DEV=/dev/nullb0
    MNT=/mnt/nullb0

    mkfs.btrfs -f $DEV
    mount $DEV $MNT

    mkdir $MNT/test/
    bonnie++ -d $MNT/test/ -m BTRFS -u 0 -s 256M -r 128M -b

    umount $MNT

    echo 0 > "$null_dev/power"
    rmdir "$null_dev"

When running this bonnie++ fails in the phase where it deletes test
directories and files:

    $ ./test.sh
    (...)
    Using uid:0, gid:0.
    Writing a byte at a time...done
    Writing intelligently...done
    Rewriting...done
    Reading a byte at a time...done
    Reading intelligently...done
    start 'em...done...done...done...done...done...
    Create files in sequential order...done.
    Stat files in sequential order...done.
    Delete files in sequential order...done.
    Create files in random order...done.
    Stat files in random order...done.
    Delete files in random order...Can't sync directory, turning off dir-sync.
    Can't delete file 9Bq7sr0000000338
    Cleaning up test directory after error.
    Bonnie: drastic I/O error (rmdir): Read-only file system

And in the syslog/dmesg we can see the following transaction abort trace:

    [161915.501506] BTRFS warning (device nullb0): Skipping commit of aborted transaction.
    [161915.502983] ------------[ cut here ]------------
    [161915.503832] BTRFS: Transaction aborted (error -28)
    [161915.504748] WARNING: fs/btrfs/transaction.c:2045 at btrfs_commit_transaction+0xa21/0xd30 [btrfs], CPU#11: bonnie++/3377975
    [161915.506786] Modules linked in: btrfs dm_zero dm_snapshot (...)
    [161915.518759] CPU: 11 UID: 0 PID: 3377975 Comm: bonnie++ Tainted: G        W           6.19.0-rc7-btrfs-next-224+ #4 PREEMPT(full)
    [161915.520857] Tainted: [W]=WARN
    [161915.521405] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-0-gea1b7a073390-prebuilt.qemu.org 04/01/2014
    [161915.523414] RIP: 0010:btrfs_commit_transaction+0xa24/0xd30 [btrfs]
    [161915.524630] Code: 48 8b 7c 24 (...)
    [161915.526982] RSP: 0018:ffffd3fe8206fda8 EFLAGS: 00010292
    [161915.527707] RAX: 0000000000000002 RBX: ffff8f4886d3c000 RCX: 0000000000000000
    [161915.528723] RDX: 0000000002040001 RSI: 00000000ffffffe4 RDI: ffffffffc088f780
    [161915.529691] RBP: ffff8f4f5adae7e0 R08: 0000000000000000 R09: ffffd3fe8206fb90
    [161915.530842] R10: ffff8f4f9c1fffa8 R11: 0000000000000003 R12: 00000000ffffffe4
    [161915.532027] R13: ffff8f4ef2cf2400 R14: ffff8f4f5adae708 R15: ffff8f4f62d18000
    [161915.533229] FS:  00007ff93112a780(0000) GS:ffff8f4ff63ee000(0000) knlGS:0000000000000000
    [161915.534611] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    [161915.535575] CR2: 00005571b3072000 CR3: 0000000176080005 CR4: 0000000000370ef0
    [161915.536758] Call Trace:
    [161915.537185]  <TASK>
    [161915.537575]  btrfs_sync_file+0x431/0x530 [btrfs]
    [161915.538473]  do_fsync+0x39/0x80
    [161915.539042]  __x64_sys_fsync+0xf/0x20
    [161915.539750]  do_syscall_64+0x50/0xf20
    [161915.540396]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
    [161915.541301] RIP: 0033:0x7ff930ca49ee
    [161915.541904] Code: 08 0f 85 f5 (...)
    [161915.544830] RSP: 002b:00007ffd94291f38 EFLAGS: 00000246 ORIG_RAX: 000000000000004a
    [161915.546152] RAX: ffffffffffffffda RBX: 00007ff93112a780 RCX: 00007ff930ca49ee
    [161915.547263] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
    [161915.548383] RBP: 0000000000000dab R08: 0000000000000000 R09: 0000000000000000
    [161915.549853] R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd94291fb0
    [161915.551196] R13: 00007ffd94292350 R14: 0000000000000001 R15: 00007ffd94292340
    [161915.552161]  </TASK>
    [161915.552457] ---[ end trace 0000000000000000 ]---
    [161915.553232] BTRFS info (device nullb0 state A): dumping space info:
    [161915.553236] BTRFS info (device nullb0 state A): space_info DATA (sub-group id 0) has 12582912 free, is not full
    [161915.553239] BTRFS info (device nullb0 state A): space_info total=12582912, used=0, pinned=0, reserved=0, may_use=0, readonly=0 zone_unusable=0
    [161915.553243] BTRFS info (device nullb0 state A): space_info METADATA (sub-group id 0) has -5767168 free, is full
    [161915.553245] BTRFS info (device nullb0 state A): space_info total=53673984, used=6635520, pinned=46956544, reserved=16384, may_use=5767168, readonly=65536 zone_unusable=0
    [161915.553251] BTRFS info (device nullb0 state A): space_info SYSTEM (sub-group id 0) has 8355840 free, is not full
    [161915.553254] BTRFS info (device nullb0 state A): space_info total=8388608, used=16384, pinned=16384, reserved=0, may_use=0, readonly=0 zone_unusable=0
    [161915.553257] BTRFS info (device nullb0 state A): global_block_rsv: size 5767168 reserved 5767168
    [161915.553261] BTRFS info (device nullb0 state A): trans_block_rsv: size 0 reserved 0
    [161915.553263] BTRFS info (device nullb0 state A): chunk_block_rsv: size 0 reserved 0
    [161915.553265] BTRFS info (device nullb0 state A): remap_block_rsv: size 0 reserved 0
    [161915.553268] BTRFS info (device nullb0 state A): delayed_block_rsv: size 0 reserved 0
    [161915.553270] BTRFS info (device nullb0 state A): delayed_refs_rsv: size 0 reserved 0
    [161915.553272] BTRFS: error (device nullb0 state A) in cleanup_transaction:2045: errno=-28 No space left
    [161915.554463] BTRFS info (device nullb0 state EA): forced readonly

The problem is that we allow for a very aggressive metadata overcommit,
about 1/8th of the currently available space, even when the task
attempting the reservation allows for full flushing. Over time this allows
more and more tasks to overcommit without getting a transaction commit to
release pinned extents, joining the same transaction and eventually lead
to the transaction abort when attempting some tree update, as the extent
allocator is not able to find any available metadata extent and it's not
able to allocate a new metadata block group either (not enough unallocated
space for that).

Fix this by allowing the overcommit to be up to 1/64th of the available
(unallocated) space instead and for that limit to apply to both types of
full flushing, BTRFS_RESERVE_FLUSH_ALL and BTRFS_RESERVE_FLUSH_ALL_STEAL.
This way we get more frequent transaction commits to release pinned
extents in case our caller is in a context where full flushing is allowed.

Note that the space infos dump in the dmesg/syslog right after the
transaction abort give the wrong idea that we have plenty of unallocated
space when the abort happened. During the bonnie++ workload we had a
metadata chunk allocation attempt and it failed with -ENOSPC because at
that time we had a bunch of data block groups allocated, which then became
empty and got deleted by the cleaner kthread after the metadata chunk
allocation failed with -ENOSPC and before the transaction abort happened
and dumped the space infos.

The custom tracing (some trace_printk() calls spread in strategic places)
used to check that:

  mount-1793735 [011] ...1. 28877.261096: btrfs_add_bg_to_space_info: added bg offset 13631488 length 8388608 flags 1 to space_info->flags 1 total_bytes 8388608 bytes_used 0 bytes_may_use 0
  mount-1793735 [011] ...1. 28877.261098: btrfs_add_bg_to_space_info: added bg offset 22020096 length 8388608 flags 34 to space_info->flags 2 total_bytes 8388608 bytes_used 16384 bytes_may_use 0
  mount-1793735 [011] ...1. 28877.261100: btrfs_add_bg_to_space_info: added bg offset 30408704 length 53673984 flags 36 to space_info->flags 4 total_bytes 53673984 bytes_used 131072 bytes_may_use 0

These are from loading the block groups created by mkfs during mount.

Then when bonnie++ starts doing its thing:

  kworker/u48:5-1792004 [011] ..... 28886.122050: btrfs_create_chunk: gather_device_info 1 ctl->dev_extent_min = 65536 dev_extent_want 1073741824
  kworker/u48:5-1792004 [011] ..... 28886.122053: btrfs_create_chunk: gather_device_info 2 ctl->dev_extent_min = 65536 dev_extent_want 1073741824 max_avail 927596544
  kworker/u48:5-1792004 [011] ..... 28886.122055: btrfs_make_block_group: make bg offset 84082688 size 117440512 type 1
  kworker/u48:5-1792004 [011] ...1. 28886.122064: btrfs_add_bg_to_space_info: added bg offset 84082688 length 117440512 flags 1 to space_info->flags 1 total_bytes 125829120 bytes_used 0 bytes_may_use 5251072

First allocation of a data block group of 112M.

  kworker/u48:5-1792004 [011] ..... 28886.192408: btrfs_create_chunk: gather_device_info 1 ctl->dev_extent_min = 65536 dev_extent_want 1073741824
  kworker/u48:5-1792004 [011] ..... 28886.192413: btrfs_create_chunk: gather_device_info 2 ctl->dev_extent_min = 65536 dev_extent_want 1073741824 max_avail 810156032
  kworker/u48:5-1792004 [011] ..... 28886.192415: btrfs_make_block_group: make bg offset 201523200 size 117440512 type 1
  kworker/u48:5-1792004 [011] ...1. 28886.192425: btrfs_add_bg_to_space_info: added bg offset 201523200 length 117440512 flags 1 to space_info->flags 1 total_bytes 243269632 bytes_used 0 bytes_may_use 122691584

Another 112M data block group allocated.

  kworker/u48:5-1792004 [011] ..... 28886.260935: btrfs_create_chunk: gather_device_info 1 ctl->dev_extent_min = 65536 dev_extent_want 1073741824
  kworker/u48:5-1792004 [011] ..... 28886.260941: btrfs_create_chunk: gather_device_info 2 ctl->dev_extent_min = 65536 dev_extent_want 1073741824 max_avail 692715520
  kworker/u48:5-1792004 [011] ..... 28886.260943: btrfs_make_block_group: make bg offset 318963712 size 117440512 type 1
  kworker/u48:5-1792004 [011] ...1. 28886.260954: btrfs_add_bg_to_space_info: added bg offset 318963712 length 117440512 flags 1 to space_info->flags 1 total_bytes 360710144 bytes_used 0 bytes_may_use 240132096

Yet another one.

  bonnie++-1793755 [010] ..... 28886.280407: btrfs_create_chunk: gather_device_info 1 ctl->dev_extent_min = 65536 dev_extent_want 1073741824
  bonnie++-1793755 [010] ..... 28886.280412: btrfs_create_chunk: gather_device_info 2 ctl->dev_extent_min = 65536 dev_extent_want 1073741824 max_avail 575275008
  bonnie++-1793755 [010] ..... 28886.280414: btrfs_make_block_group: make bg offset 436404224 size 117440512 type 1
  bonnie++-1793755 [010] ...1. 28886.280419: btrfs_add_bg_to_space_info: added bg offset 436404224 length 117440512 flags 1 to space_info->flags 1 total_bytes 478150656 bytes_used 0 bytes_may_use 268435456

One more.

  kworker/u48:5-1792004 [011] ..... 28886.566233: btrfs_create_chunk: gather_device_info 1 ctl->dev_extent_min = 65536 dev_extent_want 1073741824
  kworker/u48:5-1792004 [011] ..... 28886.566238: btrfs_create_chunk: gather_device_info 2 ctl->dev_extent_min = 65536 dev_extent_want 1073741824 max_avail 457834496
  kworker/u48:5-1792004 [011] ..... 28886.566241: btrfs_make_block_group: make bg offset 553844736 size 117440512 type 1
  kworker/u48:5-1792004 [011] ...1. 28886.566250: btrfs_add_bg_to_space_info: added bg offset 553844736 length 117440512 flags 1 to space_info->flags 1 total_bytes 595591168 bytes_used 268435456 bytes_may_use 209723392

Another one.

  bonnie++-1793755 [009] ..... 28886.613446: btrfs_create_chunk: gather_device_info 1 ctl->dev_extent_min = 65536 dev_extent_want 1073741824
  bonnie++-1793755 [009] ..... 28886.613451: btrfs_create_chunk: gather_device_info 2 ctl->dev_extent_min = 65536 dev_extent_want 1073741824 max_avail 340393984
  bonnie++-1793755 [009] ..... 28886.613453: btrfs_make_block_group: make bg offset 671285248 size 117440512 type 1
  bonnie++-1793755 [009] ...1. 28886.613458: btrfs_add_bg_to_space_info: added bg offset 671285248 length 117440512 flags 1 to space_info->flags 1 total_bytes 713031680 bytes_used 268435456 bytes_may_use 2 68435456

Another one.

  bonnie++-1793755 [009] ..... 28886.674953: btrfs_create_chunk: gather_device_info 1 ctl->dev_extent_min = 65536 dev_extent_want 1073741824
  bonnie++-1793755 [009] ..... 28886.674957: btrfs_create_chunk: gather_device_info 2 ctl->dev_extent_min = 65536 dev_extent_want 1073741824 max_avail 222953472
  bonnie++-1793755 [009] ..... 28886.674959: btrfs_make_block_group: make bg offset 788725760 size 117440512 type 1
  bonnie++-1793755 [009] ...1. 28886.674963: btrfs_add_bg_to_space_info: added bg offset 788725760 length 117440512 flags 1 to space_info->flags 1 total_bytes 830472192 bytes_used 268435456 bytes_may_use 1 34217728

Another one.

  bonnie++-1793755 [009] ..... 28886.674981: btrfs_create_chunk: gather_device_info 1 ctl->dev_extent_min = 65536 dev_extent_want 1073741824
  bonnie++-1793755 [009] ..... 28886.674982: btrfs_create_chunk: gather_device_info 2 ctl->dev_extent_min = 65536 dev_extent_want 1073741824 max_avail 105512960
  bonnie++-1793755 [009] ..... 28886.674983: btrfs_make_block_group: make bg offset 906166272 size 105512960 type 1
  bonnie++-1793755 [009] ...1. 28886.674984: btrfs_add_bg_to_space_info: added bg offset 906166272 length 105512960 flags 1 to space_info->flags 1 total_bytes 935985152 bytes_used 268435456 bytes_may_use 67108864

Another one, but a bit smaller (~100.6M) since we now have less space.

  bonnie++-1793758 [009] ..... 28891.962096: btrfs_create_chunk: gather_device_info 1 ctl->dev_extent_min = 65536 dev_extent_want 1073741824
  bonnie++-1793758 [009] ..... 28891.962103: btrfs_create_chunk: gather_device_info 2 ctl->dev_extent_min = 65536 dev_extent_want 1073741824 max_avail 12582912
  bonnie++-1793758 [009] ..... 28891.962105: btrfs_make_block_group: make bg offset 1011679232 size 12582912 type 1
  bonnie++-1793758 [009] ...1. 28891.962114: btrfs_add_bg_to_space_info: added bg offset 1011679232 length 12582912 flags 1 to space_info->flags 1 total_bytes 948568064 bytes_used 268435456 bytes_may_use 8192

Another one, this one even smaller (12M).

  kworker/u48:5-1792004 [011] ..... 28892.112802: btrfs_chunk_alloc: enter first metadata chunk alloc attempt
  kworker/u48:5-1792004 [011] ..... 28892.112805: btrfs_create_chunk: gather_device_info 1 ctl->dev_extent_min = 131072 dev_extent_want 536870912
  kworker/u48:5-1792004 [011] ..... 28892.112806: btrfs_create_chunk: gather_device_info 2 ctl->dev_extent_min = 131072 dev_extent_want 536870912 max_avail 0

536870912 is 512M, the standard 256M metadata chunk size times 2 because
of the DUP profile for metadata.
'max_avail' is what find_free_dev_extent() returns to us in
gather_device_info().

As a result, gather_device_info() sets ctl->ndevs to 0, making
decide_stripe_size() fail with -ENOSPC, and therefore metadata chunk
allocation fails while we are attempting to run delayed items during
the transaction commit.

  kworker/u48:5-1792004 [011] ..... 28892.112807: btrfs_create_chunk: decide_stripe_size fail -ENOSPC

In the syslog/dmesg pasted above, which happened after the transaction was
aborted, the space info dumps did not account for all these data block
groups that were allocated during bonnie++'s workload. And that is because
after the metadata chunk allocation failed with -ENOSPC and before the
transaction abort happened, most of the data block groups had become empty
and got deleted by by the cleaner kthread - when the abort happened, we
had bonnie++ in the middle of deleting the files it created.

But dumping the space infos right after the metadata chunk allocation fails
by adding a call to btrfs_dump_space_info_for_trans_abort() in
decide_stripe_size() when it returns -ENOSPC, we get:

  [29972.409295] BTRFS info (device nullb0): dumping space info:
  [29972.409300] BTRFS info (device nullb0): space_info DATA (sub-group id 0) has 673341440 free, is not full
  [29972.409303] BTRFS info (device nullb0): space_info total=948568064, used=0, pinned=275226624, reserved=0, may_use=0, readonly=0 zone_unusable=0
  [29972.409305] BTRFS info (device nullb0): space_info METADATA (sub-group id 0) has 3915776 free, is not full
  [29972.409306] BTRFS info (device nullb0): space_info total=53673984, used=163840, pinned=42827776, reserved=147456, may_use=6553600, readonly=65536 zone_unusable=0
  [29972.409308] BTRFS info (device nullb0): space_info SYSTEM (sub-group id 0) has 7979008 free, is not full
  [29972.409310] BTRFS info (device nullb0): space_info total=8388608, used=16384, pinned=0, reserved=0, may_use=393216, readonly=0 zone_unusable=0
  [29972.409311] BTRFS info (device nullb0): global_block_rsv: size 5767168 reserved 5767168
  [29972.409313] BTRFS info (device nullb0): trans_block_rsv: size 0 reserved 0
  [29972.409314] BTRFS info (device nullb0): chunk_block_rsv: size 393216 reserved 393216
  [29972.409315] BTRFS info (device nullb0): remap_block_rsv: size 0 reserved 0
  [29972.409316] BTRFS info (device nullb0): delayed_block_rsv: size 0 reserved 0

So here we see there's ~904.6M of data space, ~51.2M of metadata space and
8M of system space, making a total of 963.8M.

Reported-by: Aleksandar Gerasimovski <Aleksandar.Gerasimovski@belden.com>
Link: https://lore.kernel.org/linux-btrfs/SA1PR18MB56922F690C5EC2D85371408B998FA@SA1PR18MB5692.namprd18.prod.outlook.com/
Link: https://lore.kernel.org/linux-btrfs/CAL3q7H61vZ3_+eqJ1A9po2WcgNJJjUu9MJQoYB2oDSAAecHaug@mail.gmail.com/
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-04-07 18:55:53 +02:00
Qu Wenruo
2672a26a75 btrfs: use per-profile available space in calc_available_free_space()
For the following disk layout, can_overcommit() can cause false
confidence in available space:

  devid 1 unallocated:	1GiB
  devid 2 unallocated:	50GiB
  metadata type:	RAID1

As can_overcommit() simply uses unallocated space with factor to
calculate the allocatable metadata chunk size, resulting 25.5GiB
available space.

But in reality we can only allocate one 1GiB RAID1 chunk, the remaining
49GiB on devid 2 will never be utilized to fulfill a RAID1 chunk.

This leads to various ENOSPC related transaction abort and flips the fs
read-only.

Now use per-profile available space in calc_available_free_space(), and
only when that failed we fall back to the old factor based estimation.

And for zoned devices or for the very low chance of temporary memory
allocation failure, we will still fallback to factor based estimation.
But I hope in reality it's very rare.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-04-07 18:55:53 +02:00
Qu Wenruo
c84053d9f7 btrfs: update per-profile available estimation
This involves the following timing:

- Chunk allocation
- Chunk removal
- After Mount
- New device
- Device removal
- Device shrink
- Device enlarge

And since the function btrfs_update_per_profile_avail() will not return
an error, this won't cause new error handling path.

Although when btrfs_update_per_profile_avail() failed (only ENOSPC
possible) it will mark the per-profile available estimation as
unreliable, so later btrfs_get_per_profile_avail() will return false and
require the caller to have a fallback solution.

The function btrfs_update_per_profile_avail() will be executed with
chunk_mutex hold, thus it will slightly slow down those involved
functions, but not a lot.

As all the core workload is just various u64 calculations inside a loop,
without any tree search, the overhead should be acceptable even for all
supported 9 profiles.

For 4 disks (which exercises all 9 profiles), the execution time of that
function will still be less than 10 us.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-04-07 18:55:53 +02:00
Qu Wenruo
52fead5eb8 btrfs: introduce the device layout aware per-profile available space
[BUG]
There is a long known bug that if metadata is using RAID1 on two disks
with unbalanced sizes, there is a very high chance to hit ENOSPC related
transaction abort.

[CAUSE]
The root cause is in the available space estimation code:

- Factor based calculation
  Just use all unallocated space, divide by the profile factor
  One obvious user is can_overcommit().

This can not handle the following example:

  devid 1 unallocated:	1GiB
  devid 2 unallocated:	50GiB
  metadata type:	RAID1

If using factor based estimation, we can use (1GiB + 50GiB) / 2 = 25.5GiB
free space for metadata.
Thus we can continue allocating metadata (over-commit) way beyond the
1GiB limit.

But this estimation is completely wrong, in reality we can only allocate
one single 1GiB RAID1 block group, thus if we continue over-commit, at
one time we will hit ENOSPC at some critical path and flips the fs
read-only.

[SOLUTION]
This patch will introduce per-profile available space estimation,
which can provide chunk-allocator like behavior to give a (mostly)
accurate result, with under-estimate corner cases.

There are some differences between the estimation and real chunk
allocator:

- No consideration on hole size
  It's fine for most cases, as all data/metadata strips are in 1GiB size
  thus there should not be any hole wasting much space.

  And chunk allocator is able to use smaller stripes when there is
  really no other choice.

  Although in theory this means it can lead to some over-estimation, it
  should not cause too much hassle in the real world.

  The other benefit of such behavior is, we avoid dev-extent tree search
  completely, thus the overhead is very small.

- No true balance for certain cases
  If we have 3 disks RAID1, and each device has 2GiB unallocated space,
  we can load balance the chunk allocation so that we can allocate 3GiB
  RAID1 chunks, and that's what chunk allocator will do.

  But this current estimation code is using the largest available space
  to do a single allocation. Meaning the estimation will be 2GiB, thus
  under estimate.

  Such under estimation is fine and after the first chunk allocation, the
  estimation will be updated and still give a correct 2GiB
  estimation.
  So this only means the estimation will be a little conservative, which
  is safer for call sites like metadata over-commit check.

With that facility, for above 1GiB + 50GiB case, it will give a RAID1
estimation of 1GiB, instead of the incorrect 25.5GiB.

Or for a more complex example:
  devid 1 unallocated:	1T
  devid 2 unallocated:  1T
  devid 3 unallocated:	10T

We will get an array of:
  RAID10:	2T
  RAID1:	2T
  RAID1C3:	1T
  RAID1C4:	0  (not enough devices)
  DUP:		6T
  RAID0:	3T
  SINGLE:	12T
  RAID5:	2T
  RAID6:	1T

[IMPLEMENTATION]
And for the each profile , we go chunk allocator level calculation:
The pseudo code looks like:

  clear_virtual_used_space_of_all_rw_devices();
  do {
  	/*
  	 * The same as chunk allocator, despite used space,
  	 * we also take virtual used space into consideration.
  	 */
  	sort_device_with_virtual_free_space();

  	/*
  	 * Unlike chunk allocator, we don't need to bother hole/stripe
  	 * size, so we use the smallest device to make sure we can
  	 * allocated as many stripes as regular chunk allocator
  	 */
  	stripe_size = device_with_smallest_free->avail_space;
	stripe_size = min(stripe_size, to_alloc / ndevs);

  	/*
  	 * Allocate a virtual chunk, allocated virtual chunk will
  	 * increase virtual used space, allow next iteration to
  	 * properly emulate chunk allocator behavior.
  	 */
  	ret = alloc_virtual_chunk(stripe_size, &allocated_size);
  	if (ret == 0)
  		avail += allocated_size;
  } while (ret == 0)

This minimal available space based calculation is not perfect, but the
important part is, the estimation is never exceeding the real available
space.

This patch just introduces the infrastructure, no hooks are executed
yet.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-04-07 18:55:53 +02:00
Jiasheng Jiang
08ef56661f btrfs: zoned: remove redundant space_info lock and variable in do_allocation_zoned()
In do_allocation_zoned(), the code acquires space_info->lock before
block_group->lock. However, the critical section does not access or
modify any members of the space_info structure. Thus, the lock is
redundant as it provides no necessary synchronization here.

This change simplifies the locking logic and aligns the function with
other zoned paths, such as __btrfs_add_free_space_zoned(), which only
rely on block_group->lock. Since the 'space_info' local variable is
no longer used after removing the lock calls, it is also removed.

Removing this unnecessary lock reduces contention on the global
space_info lock, improving concurrency in the zoned allocation path.

Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: Jiasheng Jiang <jiashengjiangcool@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-04-07 18:55:52 +02:00
Filipe Manana
6141abb7f1 btrfs: move min sys chunk array size check to validate_sys_chunk_array()
We check the minimum size of the sys chunk array in btrfs_validate_super()
but we have a better place for that, the helper validate_sys_chunk_array()
which we use for every other sys chunk array check. So move it there, also
converting the return error from -EINVAL to -EUCLEAN, which is a better
fit and also consistent with the other checks.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-04-07 18:55:52 +02:00
Filipe Manana
f3da62571b btrfs: remove duplicate system chunk array max size overflow check
We check it twice, once in validate_sys_chunk_array() and then again in
its caller, btrfs_validate_super(), right after it calls
validate_sys_chunk_array(). So remove the duplicated check from
btrfs_validate_super().

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-04-07 18:55:52 +02:00
Filipe Manana
c4d30088fa btrfs: pass boolean literals as the last argument to inc_block_group_ro()
The last argument of inc_block_group_ro() is defined as a boolean, but
every caller is passing an integer literal, 0 or 1 for false and true
respectively. While this is not incorrect, as 0 and 1 are converted to
false and true, it's less readable and somewhat awkward since the
argument is defined as boolean. Replace 0 and 1 with false and true.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-04-07 18:55:52 +02:00
Naohiro Aota
1ba19a6ea9 btrfs: tests: zoned: add tests cases for zoned code
Add a test function for the zoned code, for now it tests
btrfs_load_block_group_by_raid_type() with various test cases. The
load_zone_info_tests[] array defines the test cases.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-04-07 18:55:52 +02:00
Günther Noack
3457a5ccac
landlock: Document fallocate(2) as another truncation corner case
Reinforce the already stated policy that LANDLOCK_ACCESS_FS_TRUNCATE should
always go hand in hand with LANDLOCK_ACCESS_FS_WRITE_FILE, as their
meanings and enforcement overlap in counterintuitive ways.

On many common file systems, fallocate(2) offers a way to shorten files as
long as the file is opened for writing, side-stepping the
LANDLOCK_ACCESS_FS_TRUNCATE right.

Assisted-by: Gemini-CLI:gemini-3.1
Signed-off-by: Günther Noack <gnoack@google.com>
Link: https://lore.kernel.org/r/20260401150911.1038072-1-gnoack@google.com
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-04-07 18:51:11 +02:00
Günther Noack
d1b2ab221d
landlock: Document FS access right for pathname UNIX sockets
Add LANDLOCK_ACCESS_FS_RESOLVE_UNIX to the example code, and explain it
in the section about previous limitations.  The bulk of the interesting
flag documentation lives in the kernel header and is included in the
Sphinx rendering.

Cc: Justin Suess <utilityemal77@gmail.com>
Cc: Mickaël Salaün <mic@digikod.net>
Signed-off-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20260327164838.38231-13-gnoack3000@gmail.com
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-04-07 18:51:11 +02:00
Günther Noack
dc75f89046
selftests/landlock: Simplify ruleset creation and enforcement in fs_test
* Add enforce_fs() for defining and enforcing a ruleset in one step
* In some places, dropped "ASSERT_LE(0, fd)" checks after
  create_ruleset() call -- create_ruleset() already checks that.
* In some places, rename "file_fd" to "fd" if it is not needed to
  disambiguate any more.

Signed-off-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20260327164838.38231-12-gnoack3000@gmail.com
[mic: Tweak subjet]
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-04-07 18:51:10 +02:00
Günther Noack
f433fd3fa2
selftests/landlock: Check that coredump sockets stay unrestricted
Even when a process is restricted with the new
LANDLOCK_ACCESS_FS_RESOLVE_UNIX right, the kernel can continue writing
its coredump to the configured coredump socket.

In the test, we create a local server and rewire the system to write
coredumps into it.  We then create a child process within a Landlock
domain where LANDLOCK_ACCESS_FS_RESOLVE_UNIX is restricted and make
the process crash.  The test uses SO_PEERCRED to check that the
connecting client process is the expected one.

Includes a fix by Mickaël Salaün for setting the EUID to 0 (see [1]).

Link[1]: https://lore.kernel.org/all/20260218.ohth8theu8Yi@digikod.net/
Suggested-by: Mickaël Salaün <mic@digikod.net>
Signed-off-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20260327164838.38231-11-gnoack3000@gmail.com
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-04-07 18:51:10 +02:00
Günther Noack
0f42f5be0b
selftests/landlock: Audit test for LANDLOCK_ACCESS_FS_RESOLVE_UNIX
Add an audit test to check that Landlock denials from
LANDLOCK_ACCESS_FS_RESOLVE_UNIX result in audit logs in the expected
format.  (There is one audit test for each filesystem access right, so
we should add one for LANDLOCK_ACCESS_FS_RESOLVE_UNIX as well.)

Signed-off-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20260327164838.38231-10-gnoack3000@gmail.com
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-04-07 18:51:09 +02:00
Günther Noack
9da41c65c9
selftests/landlock: Test LANDLOCK_ACCESS_FS_RESOLVE_UNIX
* Extract common helpers from an existing IOCTL test that
  also uses pathname unix(7) sockets.
* These tests use the common scoped domains fixture which is also used
  in other Landlock scoping tests and which was used in Tingmao Wang's
  earlier patch set in [1].

These tests exercise the cross product of the following scenarios:

* Stream connect(), Datagram connect(), Datagram sendmsg() and
  Seqpacket connect().
* Child-to-parent and parent-to-child communication
* The Landlock policy configuration as listed in the scoped_domains
  fixture.
  * In the default variant, Landlock domains are only placed where
    prescribed in the fixture.
  * In the "ALL_DOMAINS" variant, Landlock domains are also placed in
    the places where the fixture says to omit them, but with a
    LANDLOCK_RULE_PATH_BENEATH that allows connection.

Cc: Justin Suess <utilityemal77@gmail.com>
Cc: Tingmao Wang <m@maowtm.org>
Cc: Mickaël Salaün <mic@digikod.net>
Link[1]: https://lore.kernel.org/all/53b9883648225d5a08e82d2636ab0b4fda003bc9.1767115163.git.m@maowtm.org/
Signed-off-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20260327164838.38231-9-gnoack3000@gmail.com
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-04-07 18:51:09 +02:00
Günther Noack
db8201a3fa
selftests/landlock: Replace access_fs_16 with ACCESS_ALL in fs_test
The access_fs_16 variable was originally intended to stay frozen at 16
access rights so that audit tests would not need updating when new
access rights are added.  Now that we have 17 access rights, the name
is confusing.

Replace all uses of access_fs_16 with ACCESS_ALL and delete the
variable.

Suggested-by: Mickaël Salaün <mic@digikod.net>
Signed-off-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20260327164838.38231-8-gnoack3000@gmail.com
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-04-07 18:51:08 +02:00
Günther Noack
a92cb5d7c6
samples/landlock: Add support for named UNIX domain socket restrictions
The access right for UNIX domain socket lookups is grouped with the
read-write rights in the sample tool.  Rationale: In the general case,
any operations are possible through a UNIX domain socket, including
data-mutating operations.

Cc: Justin Suess <utilityemal77@gmail.com>
Cc: Mickaël Salaün <mic@digikod.net>
Signed-off-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20260327164838.38231-7-gnoack3000@gmail.com
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-04-07 18:51:07 +02:00
Günther Noack
a46e32db1f
landlock: Clarify BUILD_BUG_ON check in scoping logic
The BUILD_BUG_ON check in domain_is_scoped() and
unmask_scoped_access() should check that the loop that counts down
client_layer finishes.  We therefore check that the numbers
LANDLOCK_MAX_NUM_LAYERS-1 and -1 are both representable by that
integer.  If they are representable, the numbers in between are
representable too, and the loop finishes.

Signed-off-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20260327164838.38231-6-gnoack3000@gmail.com
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-04-07 18:51:07 +02:00
Günther Noack
ae97330d1b
landlock: Control pathname UNIX domain socket resolution by path
* Add a new access right LANDLOCK_ACCESS_FS_RESOLVE_UNIX, which
  controls the lookup operations for named UNIX domain sockets.  The
  resolution happens during connect() and sendmsg() (depending on
  socket type).
* Change access_mask_t from u16 to u32 (see below)
* Hook into the path lookup in unix_find_bsd() in af_unix.c, using a
  LSM hook.  Make policy decisions based on the new access rights
* Increment the Landlock ABI version.
* Minor test adaptations to keep the tests working.
* Document the design rationale for scoped access rights,
  and cross-reference it from the header documentation.

With this access right, access is granted if either of the following
conditions is met:

* The target socket's filesystem path was allow-listed using a
  LANDLOCK_RULE_PATH_BENEATH rule, *or*:
* The target socket was created in the same Landlock domain in which
  LANDLOCK_ACCESS_FS_RESOLVE_UNIX was restricted.

In case of a denial, connect() and sendmsg() return EACCES, which is
the same error as it is returned if the user does not have the write
bit in the traditional UNIX file system permissions of that file.

The access_mask_t type grows from u16 to u32 to make space for the new
access right.  This also doubles the size of struct layer_access_masks
from 32 byte to 64 byte.  To avoid memory layout inconsistencies between
architectures (especially m68k), pack and align struct access_masks [2].

Document the (possible future) interaction between scoped flags and
other access rights in struct landlock_ruleset_attr, and summarize the
rationale, as discussed in code review leading up to [3].

This feature was created with substantial discussion and input from
Justin Suess, Tingmao Wang and Mickaël Salaün.

Cc: Tingmao Wang <m@maowtm.org>
Cc: Justin Suess <utilityemal77@gmail.com>
Cc: Kuniyuki Iwashima <kuniyu@google.com>
Suggested-by: Jann Horn <jannh@google.com>
Link[1]: https://github.com/landlock-lsm/linux/issues/36
Link[2]: https://lore.kernel.org/all/20260401.Re1Eesu1Yaij@digikod.net/
Link[3]: https://lore.kernel.org/all/20260205.8531e4005118@gnoack.org/
Signed-off-by: Günther Noack <gnoack3000@gmail.com>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20260327164838.38231-5-gnoack3000@gmail.com
[mic: Fix kernel-doc formatting, pack and align access_masks]
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-04-07 18:51:06 +02:00
Günther Noack
1c4fe87364
landlock: Use mem_is_zero() in is_layer_masks_allowed()
This is equivalent, but expresses the intent a bit clearer.

Signed-off-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20260327164838.38231-3-gnoack3000@gmail.com
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-04-07 18:51:06 +02:00
Justin Suess
eb25e202b3
lsm: Add LSM hook security_unix_find
Add an LSM hook security_unix_find.

This hook is called to check the path of a named UNIX socket before a
connection is initiated. The peer socket may be inspected as well.

Why existing hooks are unsuitable:

Existing socket hooks, security_unix_stream_connect(),
security_unix_may_send(), and security_socket_connect() don't provide
TOCTOU-free / namespace independent access to the paths of sockets.

(1) We cannot resolve the path from the struct sockaddr in existing hooks.
This requires another path lookup. A change in the path between the
two lookups will cause a TOCTOU bug.

(2) We cannot use the struct path from the listening socket, because it
may be bound to a path in a different namespace than the caller,
resulting in a path that cannot be referenced at policy creation time.

Consumers of the hook wishing to reference @other are responsible
for acquiring the unix_state_lock and checking for the SOCK_DEAD flag
therein, ensuring the socket hasn't died since lookup.

Cc: Günther Noack <gnoack3000@gmail.com>
Cc: Tingmao Wang <m@maowtm.org>
Cc: Mickaël Salaün <mic@digikod.net>
Cc: Paul Moore <paul@paul-moore.com>
Signed-off-by: Justin Suess <utilityemal77@gmail.com>
Signed-off-by: Günther Noack <gnoack3000@gmail.com>
Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Link: https://lore.kernel.org/r/20260327164838.38231-2-gnoack3000@gmail.com
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-04-07 18:51:05 +02:00
Mickaël Salaün
64617ec033
landlock: Fix kernel-doc warning for pointer-to-array parameters
The insert_rule() and create_rule() functions take a
pointer-to-flexible-array parameter declared as:

  const struct landlock_layer (*const layers)[]

The kernel-doc parser cannot handle a qualifier between * and the
parameter name in this syntax, producing spurious "Invalid param" and
"not described" warnings.

Remove the const qualifier of the "layers" argument to avoid this
parsing issue.

Cc: Günther Noack <gnoack@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Reviewed-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20260310172004.1839864-1-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-04-07 18:51:05 +02:00
Mickaël Salaün
aba1de96e8
landlock: Fix formatting in tsync.c
Fix comment formatting in tsync.c to fit in 80 columns.

Cc: Günther Noack <gnoack@google.com>
Reviewed-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20260304193134.250495-4-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-04-07 18:51:04 +02:00
Mickaël Salaün
fa20aeb95d
landlock: Improve kernel-doc "Return:" section consistency
The canonical kernel-doc form is "Return:" (singular, without trailing
"s").  Normalize all existing "Returns:" occurrences across the Landlock
source tree to the canonical form.

Also fix capitalization for consistency.  Balance descriptions to
describe all possible returned values.

Consolidate bullet-point return descriptions into inline text for
functions with simple two-value or three-value returns for consistency.

Cc: Günther Noack <gnoack@google.com>
Reviewed-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20260304193134.250495-3-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-04-07 18:51:04 +02:00
Mickaël Salaün
e89dea254d
landlock: Add missing kernel-doc "Return:" sections
The kernel-doc -Wreturn check warns about functions with documentation
comments that lack a "Return:" section.  Add "Return:" documentation to
all functions missing it so that kernel-doc -Wreturn passes cleanly.

Convert existing function descriptions into a formal "Return:" section.
Also fix the inaccurate return documentation for
landlock_merge_ruleset() which claimed to return @parent directly, and
document the previously missing ERR_PTR() error return path.  Document
the ABI version and errata return paths for landlock_create_ruleset()
which were previously only implied by the prose.

Cc: Günther Noack <gnoack@google.com>
Reviewed-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20260304193134.250495-2-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-04-07 18:51:03 +02:00
Mickaël Salaün
a060ac0b8c
selftests/landlock: Fix format warning for __u64 in net_test
On architectures where __u64 is unsigned long (e.g. powerpc64), using
%llx to format a __u64 triggers a -Wformat warning because %llx expects
unsigned long long.  Cast the argument to unsigned long long.

Cc: Günther Noack <gnoack@google.com>
Cc: stable@vger.kernel.org
Fixes: a549d055a2 ("selftests/landlock: Add network tests")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/r/202604020206.62zgOTeP-lkp@intel.com/
Reviewed-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20260402192608.1458252-6-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-04-07 18:51:03 +02:00
Mickaël Salaün
07c2572a87
selftests/landlock: Skip stale records in audit_match_record()
Domain deallocation records are emitted asynchronously from kworker
threads (via free_ruleset_work()).  Stale deallocation records from a
previous test can arrive during the current test's deallocation read
loop and be picked up by audit_match_record() instead of the expected
record, causing a domain ID mismatch.  The audit.layers test (which
creates 16 nested domains) is particularly vulnerable because it reads
16 deallocation records in sequence, providing a large window for stale
records to interleave.

The same issue affects audit_flags.signal, where deallocation records
from a previous test (audit.layers) can leak into the next test and be
picked up by audit_match_record() instead of the expected record.

Fix this by continuing to read records when the type matches but the
content pattern does not.  Stale records are silently consumed, and the
loop only stops when both type and pattern match (or the socket times
out with -EAGAIN).

Additionally, extend matches_log_domain_deallocated() with an
expected_domain_id parameter.  When set, the regex pattern includes the
specific domain ID as a literal hex value, so that deallocation records
for a different domain do not match the pattern at all.  This handles
the case where the stale record has the same denial count as the
expected one (e.g. both have denials=1), which the type+pattern loop
alone cannot distinguish.  Callers that already know the expected domain
ID (from a prior denial or allocation record) now pass it to filter
precisely.

When expected_domain_id is set, matches_log_domain_deallocated() also
temporarily increases the socket timeout to audit_tv_dom_drop (1 second)
to wait for the asynchronous kworker deallocation, and restores
audit_tv_default afterward.  This removes the need for callers to manage
the timeout switch manually.

Cc: Günther Noack <gnoack@google.com>
Cc: stable@vger.kernel.org
Fixes: 6a500b2297 ("selftests/landlock: Add tests for audit flags and domain IDs")
Link: https://lore.kernel.org/r/20260402192608.1458252-5-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-04-07 18:51:02 +02:00
Mickaël Salaün
3647a4977f
selftests/landlock: Drain stale audit records on init
Non-audit Landlock tests generate audit records as side effects when
audit_enabled is non-zero (e.g. from boot configuration).  These records
accumulate in the kernel audit backlog while no audit daemon socket is
open.  When the next test opens a new netlink socket and registers as
the audit daemon, the stale backlog is delivered, causing baseline
record count checks to fail spuriously.

Fix this by draining all pending records in audit_init() right after
setting the receive timeout.  The 1-usec SO_RCVTIMEO causes audit_recv()
to return -EAGAIN once the backlog is empty, naturally terminating the
drain loop.

Domain deallocation records are emitted asynchronously from a work
queue, so they may still arrive after the drain.  Remove records.domain
== 0 checks that are not preceded by audit_match_record() calls, which
would otherwise consume stale records before the count.  Document this
constraint above audit_count_records().

Increasing the drain timeout to catch in-flight deallocation records was
considered but rejected: a longer timeout adds latency to every
audit_init() call even when no stale record is pending, and any fixed
timeout is still not guaranteed to catch all records under load.
Removing the unprotected checks is simpler and avoids the spurious
failures.

Cc: Günther Noack <gnoack@google.com>
Cc: stable@vger.kernel.org
Fixes: 6a500b2297 ("selftests/landlock: Add tests for audit flags and domain IDs")
Reviewed-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20260402192608.1458252-4-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-04-07 18:51:01 +02:00
Mickaël Salaün
9143d79033
selftests/landlock: Fix socket file descriptor leaks in audit helpers
audit_init() opens a netlink socket and configures it, but leaks the
file descriptor if audit_set_status() or setsockopt() fails.  Fix this
by jumping to an error path that closes the socket before returning.

Apply the same fix to audit_init_with_exe_filter(), which leaks the file
descriptor from audit_init() if audit_init_filter_exe() or
audit_filter_exe() fails, and to audit_cleanup(), which leaks it if
audit_init_filter_exe() fails in FIXTURE_TEARDOWN_PARENT().

Cc: Günther Noack <gnoack@google.com>
Cc: stable@vger.kernel.org
Fixes: 6a500b2297 ("selftests/landlock: Add tests for audit flags and domain IDs")
Reviewed-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20260402192608.1458252-3-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-04-07 18:51:01 +02:00
Mickaël Salaün
b566f7a4f0
selftests/landlock: Fix snprintf truncation checks in audit helpers
snprintf() returns the number of characters that would have been
written, excluding the terminating NUL byte.  When the output is
truncated, this return value equals or exceeds the buffer size.  Fix
matches_log_domain_allocated() and matches_log_domain_deallocated() to
detect truncation with ">=" instead of ">".

Cc: Günther Noack <gnoack@google.com>
Cc: stable@vger.kernel.org
Fixes: 6a500b2297 ("selftests/landlock: Add tests for audit flags and domain IDs")
Reviewed-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20260402192608.1458252-2-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-04-07 18:51:00 +02:00
Mickaël Salaün
e75e38055b
landlock: Allow TSYNC with LOG_SUBDOMAINS_OFF and fd=-1
LANDLOCK_RESTRICT_SELF_TSYNC does not allow
LANDLOCK_RESTRICT_SELF_LOG_SUBDOMAINS_OFF with ruleset_fd=-1, preventing
a multithreaded process from atomically propagating subdomain log muting
to all threads without creating a domain layer.  Relax the fd=-1
condition to accept TSYNC alongside LOG_SUBDOMAINS_OFF, and update the
documentation accordingly.

Add flag validation tests for all TSYNC combinations with ruleset_fd=-1,
and audit tests verifying both transition directions: muting via TSYNC
(logged to not logged) and override via TSYNC (not logged to logged).

Cc: Günther Noack <gnoack@google.com>
Cc: stable@vger.kernel.org
Fixes: 42fc7e6543 ("landlock: Multithreading support for landlock_restrict_self()")
Reviewed-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20260407164107.2012589-2-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-04-07 18:51:00 +02:00
Mickaël Salaün
874c8f8382
landlock: Fix LOG_SUBDOMAINS_OFF inheritance across fork()
hook_cred_transfer() only copies the Landlock security blob when the
source credential has a domain.  This is inconsistent with
landlock_restrict_self() which can set LOG_SUBDOMAINS_OFF on a
credential without creating a domain (via the ruleset_fd=-1 path): the
field is committed but not preserved across fork() because the child's
prepare_creds() calls hook_cred_transfer() which skips the copy when
domain is NULL.

This breaks the documented use case where a process mutes subdomain logs
before forking sandboxed children: the children lose the muting and
their domains produce unexpected audit records.

Fix this by unconditionally copying the Landlock credential blob.

Cc: Günther Noack <gnoack@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: stable@vger.kernel.org
Fixes: ead9079f75 ("landlock: Add LANDLOCK_RESTRICT_SELF_LOG_SUBDOMAINS_OFF")
Reviewed-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20260407164107.2012589-1-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-04-07 18:50:56 +02:00
Raju Rangoju
705355a82b
MAINTAINERS: Update AMD SPI driver maintainers
Due to additional responsibilities, Raju Rangoju will no longer be
supporting AMD SPI driver. Maintenance will be handled by Krishnamoorthi
going forward.

Cc: Krishnamoorthi M <krishnamoorthi.m@amd.com>
Signed-off-by: Raju Rangoju <Raju.Rangoju@amd.com>
Link: https://patch.msgid.link/20260406091042.4065767-1-Raju.Rangoju@amd.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2026-04-07 17:45:37 +01:00
Pengpeng Hou
a6cd43fe9b
fs/ntfs3: terminate the cached volume label after UTF-8 conversion
ntfs_fill_super() loads the on-disk volume label with utf16s_to_utf8s()
and stores the result in sbi->volume.label. The converted label is later
exposed through ntfs3_label_show() using %s, but utf16s_to_utf8s() only
returns the number of bytes written and does not add a trailing NUL.

If the converted label fills the entire fixed buffer,
ntfs3_label_show() can read past the end of sbi->volume.label while
looking for a terminator.

Terminate the cached label explicitly after a successful conversion and
clamp the exact-full case to the last byte of the buffer.

Fixes: 82cae269cf ("fs/ntfs3: Add initialization of super block")
Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-04-07 18:43:40 +02:00
Zhan Xusheng
d1062683bf
fs/ntfs3: fix potential double iput on d_make_root() failure
d_make_root() consumes the reference to the passed inode: it either
attaches it to the newly created dentry on success, or drops it via
iput() on failure.

In the error path, the code currently does:
    sb->s_root = d_make_root(inode);
    if (!sb->s_root)
        goto put_inode_out;

which leads to a second iput(inode) in put_inode_out. This results in
a double iput and may trigger a use-after-free if the inode gets freed
after the first iput().

Fix this by jumping directly to the common cleanup path, avoiding the
extra iput(inode).

Signed-off-by: Zhan Xusheng <zhanxusheng@xiaomi.com>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-04-07 18:43:39 +02:00
Tobias Gaertner
984a415f01
ntfs3: fix integer overflow in run_unpack() volume boundary check
The volume boundary check `lcn + len > sbi->used.bitmap.nbits` uses raw
addition which can wrap around for large lcn and len values, bypassing
the validation.  Use check_add_overflow() as is already done for the
adjacent prev_lcn + dlcn and vcn64 + len checks added by commit
3ac37e1003 ("ntfs3: Fix integer overflow in run_unpack()").

Found by fuzzing with a source-patched harness (LibAFL + QEMU).

Fixes: 82cae269cf ("fs/ntfs3: Add initialization of super block")
Cc: stable@vger.kernel.org
Signed-off-by: Tobias Gaertner <tob.gaertner@me.com>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-04-07 18:43:39 +02:00
Tobias Gaertner
b62567bca4
ntfs3: add buffer boundary checks to run_unpack()
run_unpack() checks `run_buf < run_last` at the top of the while loop
but then reads size_size and offset_size bytes via run_unpack_s64()
without verifying they fit within the remaining buffer.  A crafted NTFS
image with truncated run data in an MFT attribute triggers an OOB heap
read of up to 15 bytes when the filesystem is mounted.

Add boundary checks before each run_unpack_s64() call to ensure the
declared field size does not exceed the remaining buffer.

Found by fuzzing with a source-patched harness (LibAFL + QEMU).

Fixes: 82cae269cf ("fs/ntfs3: Add initialization of super block")
Cc: stable@vger.kernel.org
Signed-off-by: Tobias Gaertner <tob.gaertner@me.com>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-04-07 18:43:38 +02:00
Konstantin Komarov
6d979b6428
ntfs3: fix mount failure on volumes with fragmented MFT bitmap
When the $MFT's $BITMAP attribute is fragmented across multiple MFT
records (base record + extent records), ntfs_fill_super() fails with
-ENOENT during wnd_init() because the MFT bitmap's run list only
contains runs from the base MFT record.

The issue is that wnd_init() (which calls wnd_rescan()) is invoked
before ni_load_all_mi(), so the extent MFT records containing
additional $BITMAP runs have not been loaded yet. When wnd_rescan()
tries to look up a VCN beyond the base record's runs, run_lookup_entry()
fails and returns -ENOENT.

This affects NTFS volumes with a large or heavily fragmented MFT, which
is common on long-used Windows systems where the MFT bitmap's run list
doesn't fit in the base MFT record and spills into extent records.

Fix this by:
1. Moving ni_load_all_mi() before wnd_init() so all extent records
   are available.
2. After ni_load_all_mi(), iterating through the attribute list to
   find any $BITMAP extent attributes and unpacking their runs into
   sbi->mft.bitmap.run before wnd_init() is called.

Tested on a 664GB NTFS volume with 86 MFT bitmap runs spanning
records 0 (VCN 0-105) and 17 (VCN 106-165). Before the fix, mount
fails with -ENOENT. After the fix, mount succeeds and all read/write
operations work correctly. Stress-tested with 8 test categories
(large file integrity, 10K small files, copy, move, delete/recreate
cycles, concurrent writes, deep directories, overwrite persistence).

Signed-off-by: Ruslan Elishev <relishev@gmail.com>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-04-07 18:43:37 +02:00
Zhan Xusheng
bb82fe0872
fs/ntfs3: fix $LXDEV xattr lookup
Use correct xattr name ("$LXDEV") and buffer size when calling
ntfs_get_ea(), otherwise the attribute may not be read.

Signed-off-by: Zhan Xusheng <zhanxusheng@xiaomi.com>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-04-07 18:43:36 +02:00
0xkato
859d777646
ntfs3: fix OOB write in attr_wof_frame_info()
In attr_wof_frame_info(), the offset-table read range for a nonresident
WofCompressedData stream is:

    u64 from = vbo[i] & ~(u64)(PAGE_SIZE - 1);
    u64 to   = min(from + PAGE_SIZE, wof_size);
    ...
    ntfs_read_run(sbi, run, addr, from, to - from);

A crafted image sets WofCompressedData.nres.data_size to 0xfff while the
file is large enough to request frame 1024 (offset 0x400000). This gives
from=0x1000, to=0xfff. The unsigned (to - from) wraps to 0xffffffffffffffff
and ntfs_read_write_run() overflows the single-page offs_folio via memcpy.

Triggered by pread() on a mounted NTFS image. Depending on adjacent
memory layout at the time of the overflow, KASAN reports this as
slab-out-of-bounds, use-after-free, or slab-use-after-free all at
ntfs_read_write_run(). Secondary corruption/panic paths were also observed.

Reject the read when the offset-table page is outside the stream.

Signed-off-by: 0xkato <0xkkato@gmail.com>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-04-07 18:43:27 +02:00
Claudio Imbrenda
3ffe5eb4a5 KVM: s390: vsie: Fix races with partial gmap invalidations
Introduce a new boolean flag, used for shadow gmaps, to keep track of
whether the gmap has been invalidated, either partially or totally.

Use the new flag to check whether shadow gmap invalidations happened
during shadowing. In such cases, abort whatever was going on, return
-EAGAIN and let the caller try again.

Fixes: 19d6c5b804 ("KVM: s390: vsie: Fix unshadowing while shadowing")
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Message-ID: <20260407161721.247044-1-imbrenda@linux.ibm.com>
2026-04-07 18:20:58 +02:00
Shawn Lin
f3ddb8a9a9 PCI: dw-rockchip: Add pcie_ltssm_state_transition tracepoint support
Rockchip platforms provide a 64x4 bytes debug FIFO to trace the LTSSM
transition and data rate change history. These will be useful for debugging
issues such as link failure, etc.

Hence, expose these information over pcie_ltssm_state_transition
tracepoint.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
[mani: commit log]
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Anand Moon <linux.amoon@gmail.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://patch.msgid.link/1774403912-210670-4-git-send-email-shawn.lin@rock-chips.com
2026-04-07 11:12:09 -05:00
Janne Grunau
d08082a872 dt-bindings: arm: cpus: Add Apple M3 CPU core compatibles
Add "apple,everest" compatible for the M3 performance core and
"apple,sawtooth" for the M3 efficiency CPU core. These CPU cores are
found on Apple Silicon SoCs M3 and M3 Pro, Max and Ultra.

Signed-off-by: Janne Grunau <j@jannau.net>
Link: https://patch.msgid.link/20260320-apple-m3-initial-devicetrees-v1-1-5842e1e393a8@jannau.net
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
2026-04-07 11:06:27 -05:00
Krzysztof Kozlowski
afc7e8f9bf dt-bindings: display: lt8912b: Drop redundant endpoint properties
The "endpoint" node references video-interfaces.yaml schema with
"unevaluatedProperties: false" which means that all properties from
referenced schema apply.  Listing some of them with ": true" is simply
redundant and does not make this code easier to read.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Link: https://patch.msgid.link/20260316134606.57070-2-krzysztof.kozlowski@oss.qualcomm.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
2026-04-07 10:58:51 -05:00
Thomas Zimmermann
98e5b6d069 fbcon: Put font-rotation state into separate struct
Move all temporary state of the font-rotation code into the struct
rotated in struct fbcon_par. Protect it with the Kconfig symbol
CONFIG_FRAMEBUFFER_CONSOLE_ROTATION. Avoids mixing it up with fbcon's
regular state.

v2:
- fix typos

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Helge Deller <deller@gmx.de>
2026-04-07 17:38:07 +02:00
Thomas Zimmermann
6903bd6920 fbcon: Fill cursor mask in helper function
Fbcon creates a cursor shape on the fly from the user-configured
settings. The logic to create a glyph with the cursor's bitmap mask
is duplicated in four places. In the cases that involve console
rotation, the implementation further rotates the cursor glyph for
displaying.

Consolidate all cursor-mask creation in a single helper. Update the
callers accordingly. For console rotation, use the glyph helpers to
rotate the created cursor glyph to the correct orientation.

v2:
- fix sparse truncated-bits warning

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Helge Deller <deller@gmx.de>
2026-04-07 17:38:07 +02:00
Thomas Zimmermann
cfa72955a0 lib/fonts: Implement font rotation
Move the core of fbcon's font-rotation code to the font library as
the new helper font_data_rotate(). The code can rotate in steps of
90°. For completeness, it also copies the glyph data for multiples
of 360°.

Bring back the memset optimization. A memset to 0 again clears the
whole glyph output buffer. Then use the internal rotation helpers on
the cleared output. Fbcon's original implementation worked like this,
but lost it during refactoring.

Replace fbcon's font-rotation code with the new implementations.
All that's left to do for fbcon is to maintain its internal fbcon
state.

v2:
- fix typos

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Helge Deller <deller@gmx.de>
2026-04-07 17:38:07 +02:00
Thomas Zimmermann
a30e9e6b01 lib/fonts: Refactor glyph-rotation helpers
Change the signatures of the glyph-rotation helpers to match their
public interfaces. Drop the inline qualifier.

Rename several variables to better match their meaning. Especially
rename variables to bit_pitch (or a variant thereof) if they store
a pitch value in bits per scanline. The original code is fairly
confusing about this. Move the calculation of the bit pitch into the
new helper font_glyph_bit_pitch().

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Helge Deller <deller@gmx.de>
2026-04-07 17:38:07 +02:00