Commit Graph

3218 Commits

Author SHA1 Message Date
Kent Overstreet
5197728f81 bcachefs: fix bch2_save_backtrace()
Missed a call in the previous fix.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-02-25 15:45:36 -05:00
Kent Overstreet
c4333eb541 bcachefs: Fix check_snapshot() memcpy
check_snapshot() copies the bch_snapshot to a temporary to easily handle
older versions that don't have all the fields of the current version,
but it lacked a min() to correctly handle keys newer and larger than the
current version.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-02-24 20:47:47 -05:00
Kent Overstreet
097471f9e4 bcachefs: Fix bch2_journal_flush_device_pins()
If a journal write errored, the list of devices it was written to could
be empty - we're not supposed to mark an empty replicas list.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-02-24 20:46:48 -05:00
Brian Foster
b58b1b883b bcachefs: fix iov_iter count underflow on sub-block dio read
bch2_direct_IO_read() checks the request offset and size for sector
alignment and then falls through to a couple calculations to shrink
the size of the request based on the inode size. The problem is that
these checks round up to the fs block size, which runs the risk of
underflowing iter->count if the block size happens to be large
enough. This is triggered by fstest generic/361 with a 4k block
size, which subsequently leads to a crash. To avoid this crash,
check that the shorten length doesn't exceed the overall length of
the iter.

Fixes:
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Su Yue <glass.su@suse.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-02-24 20:45:24 -05:00
Kent Overstreet
204f45140f bcachefs: Fix BTREE_ITER_FILTER_SNAPSHOTS on inodes btree
If we're in FILTER_SNAPSHOTS mode and we start scanning a range of the
keyspace where no keys are visible in the current snapshot, we have a
problem - we'll scan for a very long time before scanning terminates.

Awhile back, this was fixed for most cases with peek_upto() (and
assertions that enforce that it's being used).

But the fix missed the fact that the inodes btree is different - every
key offset is in a different snapshot tree, not just the inode field.

Fixes:
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-02-24 20:41:46 -05:00
Kent Overstreet
04fee68dd9 bcachefs: Kill __GFP_NOFAIL in buffered read path
Recently, we fixed our __GFP_NOFAIL usage in the readahead path, but the
easy one in read_single_folio() (where wa can return an error) was
missed - oops.

Fixes:
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-02-24 20:41:42 -05:00
Kent Overstreet
1f626223a0 bcachefs: fix backpointer_to_text() when dev does not exist
Fixes:
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-02-24 20:41:37 -05:00
Kent Overstreet
816054f40a bcachefs: Fix missing va_end()
Fixes: https://lore.kernel.org/linux-bcachefs/202402131603.E953E2CF@keescook/T/#u
Reported-by: coverity scan
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-02-13 21:59:27 -05:00
Kent Overstreet
2eeccee86d bcachefs: Fix check_version_upgrade()
When also downgrading, check_version_upgrade() could pick a new version
greater than the latest supported version.

Fixes:
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-02-13 21:58:37 -05:00
Kent Overstreet
4e07447503 bcachefs: Clamp replicas_required to replicas
This prevents going emergency read only when the user has specified
replicas_required > replicas.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-02-13 20:33:38 -05:00
Kent Overstreet
04eb57930e bcachefs: fix missing endiannes conversion in sb_members
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-02-10 17:37:34 -05:00
Su Yue
7dcfb87af9 bcachefs: fix kmemleak in __bch2_read_super error handling path
During xfstest tests, there are some kmemleak reports e.g. generic/051 with
if USE_KMEMLEAK=yes:

====================================================================
EXPERIMENTAL kmemleak reported some memory leaks!  Due to the way kmemleak
works, the leak might be from an earlier test, or something totally unrelated.
unreferenced object 0xffff9ef905aaf778 (size 8):
  comm "mount.bcachefs", pid 169844, jiffies 4295281209 (age 87.040s)
  hex dump (first 8 bytes):
    a5 cc cc cc cc cc cc cc                          ........
  backtrace:
    [<ffffffff87fd9a43>] __kmem_cache_alloc_node+0x1f3/0x2c0
    [<ffffffff87f49b66>] kmalloc_trace+0x26/0xb0
    [<ffffffffc0a3fefe>] __bch2_read_super+0xfe/0x4e0 [bcachefs]
    [<ffffffffc0a3ad22>] bch2_fs_open+0x262/0x1710 [bcachefs]
    [<ffffffffc09c9e24>] bch2_mount+0x4c4/0x640 [bcachefs]
    [<ffffffff88080c90>] legacy_get_tree+0x30/0x60
    [<ffffffff8802c748>] vfs_get_tree+0x28/0xf0
    [<ffffffff88061fe5>] path_mount+0x475/0xb60
    [<ffffffff880627e5>] __x64_sys_mount+0x105/0x140
    [<ffffffff88932642>] do_syscall_64+0x42/0xf0
    [<ffffffff88a000e6>] entry_SYSCALL_64_after_hwframe+0x6e/0x76
unreferenced object 0xffff9ef96cdc4fc0 (size 32):
  comm "mount.bcachefs", pid 169844, jiffies 4295281209 (age 87.040s)
  hex dump (first 32 bytes):
    2f 64 65 76 2f 6d 61 70 70 65 72 2f 74 65 73 74  /dev/mapper/test
    2d 31 00 cc cc cc cc cc cc cc cc cc cc cc cc cc  -1..............
  backtrace:
    [<ffffffff87fd9a43>] __kmem_cache_alloc_node+0x1f3/0x2c0
    [<ffffffff87f4a081>] __kmalloc_node_track_caller+0x51/0x150
    [<ffffffff87f3adc2>] kstrdup+0x32/0x60
    [<ffffffffc0a3ff1a>] __bch2_read_super+0x11a/0x4e0 [bcachefs]
    [<ffffffffc0a3ad22>] bch2_fs_open+0x262/0x1710 [bcachefs]
    [<ffffffffc09c9e24>] bch2_mount+0x4c4/0x640 [bcachefs]
    [<ffffffff88080c90>] legacy_get_tree+0x30/0x60
    [<ffffffff8802c748>] vfs_get_tree+0x28/0xf0
    [<ffffffff88061fe5>] path_mount+0x475/0xb60
    [<ffffffff880627e5>] __x64_sys_mount+0x105/0x140
    [<ffffffff88932642>] do_syscall_64+0x42/0xf0
    [<ffffffff88a000e6>] entry_SYSCALL_64_after_hwframe+0x6e/0x76
====================================================================

The leak happens if bdev_open_by_path() failed to open a block device
then it goes label 'out' directly without call of bch2_free_super().

Fix it by going to label 'err' instead of 'out' if bdev_open_by_path()
fails.

Signed-off-by: Su Yue <glass.su@suse.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-02-10 17:37:34 -05:00
Kent Overstreet
1a1c93e7f8 bcachefs: Fix missing bch2_err_class() calls
We aren't supposed to be leaking our private error codes outside of
fs/bcachefs/.

Fixes:
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-02-10 17:37:32 -05:00
Kent Overstreet
7b508b323b bcachefs: time_stats: Check for last_event == 0 when updating freq stats
This fixes spurious outliers in the frequency stats.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-02-05 01:16:31 -05:00
Mathias Krause
dd839f31d7 bcachefs: install fd later to avoid race with close
Calling fd_install() makes a file reachable for userland, including the
possibility to close the file descriptor, which leads to calling its
'release' hook. If that happens before the code had a chance to bump the
reference of the newly created task struct, the release callback will
call put_task_struct() too early, leading to the premature destruction
of the kernel thread.

Avoid that race by calling fd_install() later, after all the setup is
done.

Fixes: 1c6fdbd8f2 ("bcachefs: Initial commit")
Signed-off-by: Mathias Krause <minipli@grsecurity.net>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-02-05 01:16:15 -05:00
Guoyu Ou
6bb3f7f4c3 bcachefs: unlock parent dir if entry is not found in subvolume deletion
Parent dir is locked by user_path_locked_at() before validating the
required dentry. It should be unlocked if we can not perform the
deletion.

This fixes the problem:

$ bcachefs subvolume delete not-exist-entry
BCH_IOCTL_SUBVOLUME_DESTROY ioctl error: No such file or directory
$ bcachefs subvolume delete not-exist-entry

the second will stuck because the parent dir is locked in the previous
deletion.

Signed-off-by: Guoyu Ou <benogy@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-28 21:41:09 -05:00
Helge Deller
eba38cc757 bcachefs: Fix build on parisc by avoiding __multi3()
The gcc compiler on paric does support the __int128 type, although the
architecture does not have native 128-bit support.

The effect is, that the bcachefs u128_square() function will pull in the
libgcc __multi3() helper, which breaks the kernel build when bcachefs is
built as module since this function isn't currently exported in
arch/parisc/kernel/parisc_ksyms.c.
The build failure can be seen in the latest debian kernel build at:
https://buildd.debian.org/status/fetch.php?pkg=linux&arch=hppa&ver=6.7.1-1%7Eexp1&stamp=1706132569&raw=0

We prefer to not export that symbol, so fall back to the optional 64-bit
implementation provided by bcachefs and thus avoid usage of __multi3().

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-28 21:29:23 -05:00
Kent Overstreet
d2fda304bb bcachefs: __lookup_dirent() works in snapshot, not subvol
Add a new helper, bch2_hash_lookup_in_snapshot(), for when we're not
operating in a subvolume and already have a snapshot ID, and then use it
in lookup_lostfound() -> __lookup_dirent().

This is a bugfix - lookup_lostfound() doesn't take a subvolume ID, we
were passing a nonsense subvolume ID before, and don't have one to pass
since we may be operating in an interior snapshot node that doesn't have
a subvolume ID.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-25 20:02:11 -05:00
Kent Overstreet
096386a5bc bcachefs: discard path uses unlock_long()
Some (bad) devices can have really terrible discard latency; we don't
want them blocking memory reclaim and causing warnings.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-24 17:27:46 -05:00
Christoph Hellwig
3e44f325f6 bcachefs: fix incorrect usage of REQ_OP_FLUSH
REQ_OP_FLUSH is only for internal use in the blk-mq and request based
drivers. File systems and other block layer consumers must use
REQ_OP_WRITE | REQ_PREFLUSH as documented in
Documentation/block/writeback_cache_control.rst.

While REQ_OP_FLUSH appears to work for blk-mq drivers it does not
get the proper flush state machine handling, and completely fails
for any bio based drivers, including all the stacking drivers.  The
block layer will also get a check in 6.8 to reject this use case
entirely.

[Note: completely untested, but as this never got fixed since the
original bug report in November:

   https://bugzilla.kernel.org/show_bug.cgi?id=218184

and the the discussion in December:

    https://lore.kernel.org/all/20231221053016.72cqcfg46vxwohcj@moria.home.lan/T/

this seems to be best way to force it]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-22 12:37:51 -05:00
Kent Overstreet
612e1110d6 bcachefs: Add gfp flags param to bch2_prt_task_backtrace()
Fixes: e6a2566f7a ("bcachefs: Better journal tracepoints")
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Reported-by: smatch
2024-01-22 12:37:51 -05:00
Linus Torvalds
35a4474b5c More bcachefs updates for 6.7-rc1
- assorted prep work for disk space accounting rewrite
  - BTREE_TRIGGER_ATOMIC: after combining our trigger callbacks, this
    makes our trigger context more explicit
  - A few fixes to avoid excessive transaction restarts on multithreaded
    workloads: fstests (in addition to ktest tests) are now checking
    slowpath counters, and that's shaking out a few bugs
  - Assorted tracepoint improvements
  - Starting to break up bcachefs_format.h and move on disk types so
    they're with the code they belong to; this will make room to start
    documenting the on disk format better.
  - A few minor fixes
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Merge tag 'bcachefs-2024-01-21' of https://evilpiepirate.org/git/bcachefs

Pull more bcachefs updates from Kent Overstreet:
 "Some fixes, Some refactoring, some minor features:

   - Assorted prep work for disk space accounting rewrite

   - BTREE_TRIGGER_ATOMIC: after combining our trigger callbacks, this
     makes our trigger context more explicit

   - A few fixes to avoid excessive transaction restarts on
     multithreaded workloads: fstests (in addition to ktest tests) are
     now checking slowpath counters, and that's shaking out a few bugs

   - Assorted tracepoint improvements

   - Starting to break up bcachefs_format.h and move on disk types so
     they're with the code they belong to; this will make room to start
     documenting the on disk format better.

   - A few minor fixes"

* tag 'bcachefs-2024-01-21' of https://evilpiepirate.org/git/bcachefs: (46 commits)
  bcachefs: Improve inode_to_text()
  bcachefs: logged_ops_format.h
  bcachefs: reflink_format.h
  bcachefs; extents_format.h
  bcachefs: ec_format.h
  bcachefs: subvolume_format.h
  bcachefs: snapshot_format.h
  bcachefs: alloc_background_format.h
  bcachefs: xattr_format.h
  bcachefs: dirent_format.h
  bcachefs: inode_format.h
  bcachefs; quota_format.h
  bcachefs: sb-counters_format.h
  bcachefs: counters.c -> sb-counters.c
  bcachefs: comment bch_subvolume
  bcachefs: bch_snapshot::btime
  bcachefs: add missing __GFP_NOWARN
  bcachefs: opts->compression can now also be applied in the background
  bcachefs: Prep work for variable size btree node buffers
  bcachefs: grab s_umount only if snapshotting
  ...
2024-01-21 14:01:12 -08:00
Kent Overstreet
249f441f83 bcachefs: Improve inode_to_text()
Add line breaks - inode_to_text() is now much easier to read.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21 13:27:11 -05:00
Kent Overstreet
d826cc57c5 bcachefs: logged_ops_format.h
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21 13:27:11 -05:00
Kent Overstreet
8d52ba60c4 bcachefs: reflink_format.h
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21 13:27:11 -05:00
Kent Overstreet
b2fa1b633b bcachefs; extents_format.h
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21 13:27:11 -05:00
Kent Overstreet
0560eb9abf bcachefs: ec_format.h
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21 13:27:11 -05:00
Kent Overstreet
c6c4ff6507 bcachefs: subvolume_format.h
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21 13:27:11 -05:00
Kent Overstreet
8fed323b14 bcachefs: snapshot_format.h
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21 13:27:10 -05:00
Kent Overstreet
d455179fce bcachefs: alloc_background_format.h
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21 13:27:10 -05:00
Kent Overstreet
72e0801049 bcachefs: xattr_format.h
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21 13:27:10 -05:00
Kent Overstreet
7ffc4daa5f bcachefs: dirent_format.h
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21 13:27:10 -05:00
Kent Overstreet
b36425da71 bcachefs: inode_format.h
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21 13:27:10 -05:00
Kent Overstreet
82de6207fb bcachefs; quota_format.h
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21 13:27:10 -05:00
Kent Overstreet
43314801a4 bcachefs: sb-counters_format.h
bcachefs_format.h has gotten too big; let's do some organizing.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21 13:27:10 -05:00
Kent Overstreet
3a58dfbc46 bcachefs: counters.c -> sb-counters.c
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21 13:27:10 -05:00
Kent Overstreet
12207f49ef bcachefs: comment bch_subvolume
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21 13:27:10 -05:00
Kent Overstreet
d32088f2f2 bcachefs: bch_snapshot::btime
Add a field to bch_snapshot for creation time; this will be important
when we start exposing the snapshot tree to userspace.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21 13:27:10 -05:00
Kent Overstreet
7be0208fc9 bcachefs: add missing __GFP_NOWARN
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21 13:27:10 -05:00
Kent Overstreet
d7e77f53e9 bcachefs: opts->compression can now also be applied in the background
The "apply this compression method in the background" paths now use the
compression option if background_compression is not set; this means that
setting or changing the compression option will cause existing data to
be compressed accordingly in the background.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21 13:27:10 -05:00
Kent Overstreet
ec4edd7b9d bcachefs: Prep work for variable size btree node buffers
bcachefs btree nodes are big - typically 256k - and btree roots are
pinned in memory. As we're now up to 18 btrees, we now have significant
memory overhead in mostly empty btree roots.

And in the future we're going to start enforcing that certain btree node
boundaries exist, to solve lock contention issues - analagous to XFS's
AGIs.

Thus, we need to start allocating smaller btree node buffers when we
can. This patch changes code that refers to the filesystem constant
c->opts.btree_node_size to refer to the btree node buffer size -
btree_buf_bytes() - where appropriate.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21 13:27:10 -05:00
Su Yue
2acc59dd88 bcachefs: grab s_umount only if snapshotting
When I was testing mongodb over bcachefs with compression,
there is a lockdep warning when snapshotting mongodb data volume.

$ cat test.sh
prog=bcachefs

$prog subvolume create /mnt/data
$prog subvolume create /mnt/data/snapshots

while true;do
    $prog subvolume snapshot /mnt/data /mnt/data/snapshots/$(date +%s)
    sleep 1s
done

$ cat /etc/mongodb.conf
systemLog:
  destination: file
  logAppend: true
  path: /mnt/data/mongod.log

storage:
  dbPath: /mnt/data/

lockdep reports:
[ 3437.452330] ======================================================
[ 3437.452750] WARNING: possible circular locking dependency detected
[ 3437.453168] 6.7.0-rc7-custom+ #85 Tainted: G            E
[ 3437.453562] ------------------------------------------------------
[ 3437.453981] bcachefs/35533 is trying to acquire lock:
[ 3437.454325] ffffa0a02b2b1418 (sb_writers#10){.+.+}-{0:0}, at: filename_create+0x62/0x190
[ 3437.454875]
               but task is already holding lock:
[ 3437.455268] ffffa0a02b2b10e0 (&type->s_umount_key#48){.+.+}-{3:3}, at: bch2_fs_file_ioctl+0x232/0xc90 [bcachefs]
[ 3437.456009]
               which lock already depends on the new lock.

[ 3437.456553]
               the existing dependency chain (in reverse order) is:
[ 3437.457054]
               -> #3 (&type->s_umount_key#48){.+.+}-{3:3}:
[ 3437.457507]        down_read+0x3e/0x170
[ 3437.457772]        bch2_fs_file_ioctl+0x232/0xc90 [bcachefs]
[ 3437.458206]        __x64_sys_ioctl+0x93/0xd0
[ 3437.458498]        do_syscall_64+0x42/0xf0
[ 3437.458779]        entry_SYSCALL_64_after_hwframe+0x6e/0x76
[ 3437.459155]
               -> #2 (&c->snapshot_create_lock){++++}-{3:3}:
[ 3437.459615]        down_read+0x3e/0x170
[ 3437.459878]        bch2_truncate+0x82/0x110 [bcachefs]
[ 3437.460276]        bchfs_truncate+0x254/0x3c0 [bcachefs]
[ 3437.460686]        notify_change+0x1f1/0x4a0
[ 3437.461283]        do_truncate+0x7f/0xd0
[ 3437.461555]        path_openat+0xa57/0xce0
[ 3437.461836]        do_filp_open+0xb4/0x160
[ 3437.462116]        do_sys_openat2+0x91/0xc0
[ 3437.462402]        __x64_sys_openat+0x53/0xa0
[ 3437.462701]        do_syscall_64+0x42/0xf0
[ 3437.462982]        entry_SYSCALL_64_after_hwframe+0x6e/0x76
[ 3437.463359]
               -> #1 (&sb->s_type->i_mutex_key#15){+.+.}-{3:3}:
[ 3437.463843]        down_write+0x3b/0xc0
[ 3437.464223]        bch2_write_iter+0x5b/0xcc0 [bcachefs]
[ 3437.464493]        vfs_write+0x21b/0x4c0
[ 3437.464653]        ksys_write+0x69/0xf0
[ 3437.464839]        do_syscall_64+0x42/0xf0
[ 3437.465009]        entry_SYSCALL_64_after_hwframe+0x6e/0x76
[ 3437.465231]
               -> #0 (sb_writers#10){.+.+}-{0:0}:
[ 3437.465471]        __lock_acquire+0x1455/0x21b0
[ 3437.465656]        lock_acquire+0xc6/0x2b0
[ 3437.465822]        mnt_want_write+0x46/0x1a0
[ 3437.465996]        filename_create+0x62/0x190
[ 3437.466175]        user_path_create+0x2d/0x50
[ 3437.466352]        bch2_fs_file_ioctl+0x2ec/0xc90 [bcachefs]
[ 3437.466617]        __x64_sys_ioctl+0x93/0xd0
[ 3437.466791]        do_syscall_64+0x42/0xf0
[ 3437.466957]        entry_SYSCALL_64_after_hwframe+0x6e/0x76
[ 3437.467180]
               other info that might help us debug this:

[ 3437.469670] 2 locks held by bcachefs/35533:
               other info that might help us debug this:

[ 3437.467507] Chain exists of:
                 sb_writers#10 --> &c->snapshot_create_lock --> &type->s_umount_key#48

[ 3437.467979]  Possible unsafe locking scenario:

[ 3437.468223]        CPU0                    CPU1
[ 3437.468405]        ----                    ----
[ 3437.468585]   rlock(&type->s_umount_key#48);
[ 3437.468758]                                lock(&c->snapshot_create_lock);
[ 3437.469030]                                lock(&type->s_umount_key#48);
[ 3437.469291]   rlock(sb_writers#10);
[ 3437.469434]
                *** DEADLOCK ***

[ 3437.469670] 2 locks held by bcachefs/35533:
[ 3437.469838]  #0: ffffa0a02ce00a88 (&c->snapshot_create_lock){++++}-{3:3}, at: bch2_fs_file_ioctl+0x1e3/0xc90 [bcachefs]
[ 3437.470294]  #1: ffffa0a02b2b10e0 (&type->s_umount_key#48){.+.+}-{3:3}, at: bch2_fs_file_ioctl+0x232/0xc90 [bcachefs]
[ 3437.470744]
               stack backtrace:
[ 3437.470922] CPU: 7 PID: 35533 Comm: bcachefs Kdump: loaded Tainted: G            E      6.7.0-rc7-custom+ #85
[ 3437.471313] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014
[ 3437.471694] Call Trace:
[ 3437.471795]  <TASK>
[ 3437.471884]  dump_stack_lvl+0x57/0x90
[ 3437.472035]  check_noncircular+0x132/0x150
[ 3437.472202]  __lock_acquire+0x1455/0x21b0
[ 3437.472369]  lock_acquire+0xc6/0x2b0
[ 3437.472518]  ? filename_create+0x62/0x190
[ 3437.472683]  ? lock_is_held_type+0x97/0x110
[ 3437.472856]  mnt_want_write+0x46/0x1a0
[ 3437.473025]  ? filename_create+0x62/0x190
[ 3437.473204]  filename_create+0x62/0x190
[ 3437.473380]  user_path_create+0x2d/0x50
[ 3437.473555]  bch2_fs_file_ioctl+0x2ec/0xc90 [bcachefs]
[ 3437.473819]  ? lock_acquire+0xc6/0x2b0
[ 3437.474002]  ? __fget_files+0x2a/0x190
[ 3437.474195]  ? __fget_files+0xbc/0x190
[ 3437.474380]  ? lock_release+0xc5/0x270
[ 3437.474567]  ? __x64_sys_ioctl+0x93/0xd0
[ 3437.474764]  ? __pfx_bch2_fs_file_ioctl+0x10/0x10 [bcachefs]
[ 3437.475090]  __x64_sys_ioctl+0x93/0xd0
[ 3437.475277]  do_syscall_64+0x42/0xf0
[ 3437.475454]  entry_SYSCALL_64_after_hwframe+0x6e/0x76
[ 3437.475691] RIP: 0033:0x7f2743c313af
======================================================

In __bch2_ioctl_subvolume_create(), we grab s_umount unconditionally
and unlock it at the end of the function. There is a comment
"why do we need this lock?" about the lock coming from
commit 42d237320e ("bcachefs: Snapshot creation, deletion")
The reason is that __bch2_ioctl_subvolume_create() calls
sync_inodes_sb() which enforce locked s_umount to writeback all dirty
nodes before doing snapshot works.

Fix it by read locking s_umount for snapshotting only and unlocking
s_umount after sync_inodes_sb().

Signed-off-by: Su Yue <glass.su@suse.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21 13:27:10 -05:00
Su Yue
369acf97d6 bcachefs: kvfree bch_fs::snapshots in bch2_fs_snapshots_exit
bch_fs::snapshots is allocated by kvzalloc in __snapshot_t_mut.
It should be freed by kvfree not kfree.
Or umount will triger:

[  406.829178 ] BUG: unable to handle page fault for address: ffffe7b487148008
[  406.830676 ] #PF: supervisor read access in kernel mode
[  406.831643 ] #PF: error_code(0x0000) - not-present page
[  406.832487 ] PGD 0 P4D 0
[  406.832898 ] Oops: 0000 [#1] PREEMPT SMP PTI
[  406.833512 ] CPU: 2 PID: 1754 Comm: umount Kdump: loaded Tainted: G           OE      6.7.0-rc7-custom+ #90
[  406.834746 ] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014
[  406.835796 ] RIP: 0010:kfree+0x62/0x140
[  406.836197 ] Code: 80 48 01 d8 0f 82 e9 00 00 00 48 c7 c2 00 00 00 80 48 2b 15 78 9f 1f 01 48 01 d0 48 c1 e8 0c 48 c1 e0 06 48 03 05 56 9f 1f 01 <48> 8b 50 08 48 89 c7 f6 c2 01 0f 85 b0 00 00 00 66 90 48 8b 07 f6
[  406.837810 ] RSP: 0018:ffffb9d641607e48 EFLAGS: 00010286
[  406.838213 ] RAX: ffffe7b487148000 RBX: ffffb9d645200000 RCX: ffffb9d641607dc4
[  406.838738 ] RDX: 000065bb00000000 RSI: ffffffffc0d88b84 RDI: ffffb9d645200000
[  406.839217 ] RBP: ffff9a4625d00068 R08: 0000000000000001 R09: 0000000000000001
[  406.839650 ] R10: 0000000000000001 R11: 000000000000001f R12: ffff9a4625d4da80
[  406.840055 ] R13: ffff9a4625d00000 R14: ffffffffc0e2eb20 R15: 0000000000000000
[  406.840451 ] FS:  00007f0a264ffb80(0000) GS:ffff9a4e2d500000(0000) knlGS:0000000000000000
[  406.840851 ] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  406.841125 ] CR2: ffffe7b487148008 CR3: 000000018c4d2000 CR4: 00000000000006f0
[  406.841464 ] Call Trace:
[  406.841583 ]  <TASK>
[  406.841682 ]  ? __die+0x1f/0x70
[  406.841828 ]  ? page_fault_oops+0x159/0x470
[  406.842014 ]  ? fixup_exception+0x22/0x310
[  406.842198 ]  ? exc_page_fault+0x1ed/0x200
[  406.842382 ]  ? asm_exc_page_fault+0x22/0x30
[  406.842574 ]  ? bch2_fs_release+0x54/0x280 [bcachefs]
[  406.842842 ]  ? kfree+0x62/0x140
[  406.842988 ]  ? kfree+0x104/0x140
[  406.843138 ]  bch2_fs_release+0x54/0x280 [bcachefs]
[  406.843390 ]  kobject_put+0xb7/0x170
[  406.843552 ]  deactivate_locked_super+0x2f/0xa0
[  406.843756 ]  cleanup_mnt+0xba/0x150
[  406.843917 ]  task_work_run+0x59/0xa0
[  406.844083 ]  exit_to_user_mode_prepare+0x197/0x1a0
[  406.844302 ]  syscall_exit_to_user_mode+0x16/0x40
[  406.844510 ]  do_syscall_64+0x4e/0xf0
[  406.844675 ]  entry_SYSCALL_64_after_hwframe+0x6e/0x76
[  406.844907 ] RIP: 0033:0x7f0a2664e4fb

Signed-off-by: Su Yue <glass.su@suse.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21 13:27:10 -05:00
Kent Overstreet
00fff4dd58 bcachefs: bios must be 512 byte algined
Fixes: 023f9ac9f7 bcachefs: Delete dio read alignment check
Reported-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21 13:27:10 -05:00
Colin Ian King
aead3428e8 bcachefs: remove redundant variable tmp
The variable tmp is being assigned a value but it isn't being
read afterwards. The assignment is redundant and so tmp can be
removed.

Cleans up clang scan build warning:
warning: Although the value stored to 'ret' is used in the enclosing
expression, the value is never actually read from 'ret'
[deadcode.DeadStores]

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21 13:27:10 -05:00
Kent Overstreet
b97de45365 bcachefs: Improve trace_trans_restart_relock
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21 13:27:10 -05:00
Kent Overstreet
46bf2e9cc7 bcachefs: Fix excess transaction restarts in __bchfs_fallocate()
drop_locks_do() should not be used in a fastpath without first trying
the do in nonblocking mode - the unlock and relock will cause excessive
transaction restarts and potentially livelocking with other threads that
are contending for the same locks.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21 13:27:10 -05:00
Kent Overstreet
1a5039041b bcachefs: extents_to_bp_state
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21 13:27:10 -05:00
Kent Overstreet
ba96d36ca5 bcachefs: bkey_and_val_eq()
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21 13:27:09 -05:00
Kent Overstreet
e6a2566f7a bcachefs: Better journal tracepoints
Factor out bch2_journal_bufs_to_text(), and use it in the
journal_entry_full() tracepoint; when we can't get a journal reservation
we need to know the outstanding journal entry sizes to know if the
problem is due to excessive flushing.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21 13:27:09 -05:00