Commit Graph

45 Commits

Author SHA1 Message Date
Kent Overstreet
112d21fd1a bcachefs: switch to rhashtable for vfs inodes hash
the standard vfs inode hash table suffers from painful lock contention -
this is long overdue

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-09-09 09:41:47 -04:00
Kent Overstreet
6575b8c987 bcachefs: Fix locking in bch2_ioc_setlabel()
Fixes: 7a254053a5 ("bcachefs: support FS_IOC_SETFSLABEL")
Reported-by: syzbot+7e9efdfec27fbde0141d@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-08-22 02:07:23 -04:00
Hongbo Li
7a254053a5 bcachefs: support FS_IOC_SETFSLABEL
Implement support for FS_IOC_SETFSLABEL ioctl to set filesystem
label.

Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-07-14 19:00:15 -04:00
Hongbo Li
81bce3cf2b bcachefs: support get fs label
Implement support for FS_IOC_GETFSLABEL ioctl to read filesystem
label.

Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-07-14 19:00:15 -04:00
Hongbo Li
8a4ef7e28a bcachefs: implement FS_IOC_GETVERSION to support lsattr
In this patch we add the FS_IOC_GETVERSION ioctl for getting
i_generation from inode, after that, users can list file's
generation number by using "lsattr".

Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-07-14 19:00:14 -04:00
Kent Overstreet
504794067f bcachefs: Replace bare EEXIST with private error codes
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-06-21 10:17:07 -04:00
Kent Overstreet
e0cb5722e1 bcachefs: Fix snapshot_create_lock lock ordering
======================================================
WARNING: possible circular locking dependency detected
6.10.0-rc2-ktest-00018-gebd1d148b278 #144 Not tainted
------------------------------------------------------
fio/1345 is trying to acquire lock:
ffff88813e200ab8 (&c->snapshot_create_lock){++++}-{3:3}, at: bch2_truncate+0x76/0xf0

but task is already holding lock:
ffff888105a1fa38 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: do_truncate+0x7b/0xc0

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #2 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}:
       down_write+0x3d/0xd0
       bch2_write_iter+0x1c0/0x10f0
       vfs_write+0x24a/0x560
       __x64_sys_pwrite64+0x77/0xb0
       x64_sys_call+0x17e5/0x1ab0
       do_syscall_64+0x68/0x130
       entry_SYSCALL_64_after_hwframe+0x4b/0x53

-> #1 (sb_writers#10){.+.+}-{0:0}:
       mnt_want_write+0x4a/0x1d0
       filename_create+0x69/0x1a0
       user_path_create+0x38/0x50
       bch2_fs_file_ioctl+0x315/0xbf0
       __x64_sys_ioctl+0x297/0xaf0
       x64_sys_call+0x10cb/0x1ab0
       do_syscall_64+0x68/0x130
       entry_SYSCALL_64_after_hwframe+0x4b/0x53

-> #0 (&c->snapshot_create_lock){++++}-{3:3}:
       __lock_acquire+0x1445/0x25b0
       lock_acquire+0xbd/0x2b0
       down_read+0x40/0x180
       bch2_truncate+0x76/0xf0
       bchfs_truncate+0x240/0x3f0
       bch2_setattr+0x7b/0xb0
       notify_change+0x322/0x4b0
       do_truncate+0x8b/0xc0
       do_ftruncate+0x110/0x270
       __x64_sys_ftruncate+0x43/0x80
       x64_sys_call+0x1373/0x1ab0
       do_syscall_64+0x68/0x130
       entry_SYSCALL_64_after_hwframe+0x4b/0x53

other info that might help us debug this:

Chain exists of:
  &c->snapshot_create_lock --> sb_writers#10 --> &sb->s_type->i_mutex_key#13

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&sb->s_type->i_mutex_key#13);
                               lock(sb_writers#10);
                               lock(&sb->s_type->i_mutex_key#13);
  rlock(&c->snapshot_create_lock);

 *** DEADLOCK ***

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-06-10 13:17:16 -04:00
Youling Tang
75a53a0a23 bcachefs: Correct the FS_IOC_GETFLAGS to FS_IOC32_GETFLAGS in bch2_compat_fs_ioctl()
It should be FS_IOC32_GETFLAGS instead of FS_IOC_GETFLAGS in
compat ioctl.

Signed-off-by: Youling Tang <tangyouling@kylinos.cn>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-05-08 17:29:21 -04:00
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
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
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
Linus Torvalds
f16ab99c2e fix buggered locking in bch2_ioctl_subvolume_destroy()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Merge tag 'pull-bcachefs-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull bcachefs locking fix from Al Viro:
 "Fix broken locking in bch2_ioctl_subvolume_destroy()"

* tag 'pull-bcachefs-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  bch2_ioctl_subvolume_destroy(): fix locking
  new helper: user_path_locked_at()
2024-01-12 18:04:01 -08:00
Linus Torvalds
999a36b52b bcachefs updates for 6.8:
- btree write buffer rewrite: instead of adding keys to the btree write
    buffer at transaction commit time, we know journal them with a
    different journal entry type and copy them from the journal to the
    write buffer just prior to journal write.
 
    This reduces the number of atomic operations on shared cachelines
    in the transaction commit path and is a signicant performance
    improvement on some workloads: multithreaded 4k random writes went
    from ~650k iops to ~850k iops.
 
  - Bring back optimistic spinning for six locks: the new implementation
    doesn't use osq locks; instead we add to the lock waitlist as normal,
    and then spin on the lock_acquired bit in the waitlist entry, _not_
    the lock itself.
 
  - BCH_IOCTL_DEV_USAGE_V2, which allows for new data types
  - BCH_IOCTL_OFFLINE_FSCK, which runs the kernel implementation of fsck
    but without mounting: useful for transparently using the kernel
    version of fsck from 'bcachefs fsck' when the kernel version is a
    better match for the on disk filesystem.
 
  - BCH_IOCTL_ONLINE_FSCK: online fsck. Not all passes are supported yet,
    but the passes that are supported are fully featured - errors may be
    corrected as normal.
 
    The new ioctls use the new 'thread_with_file' abstraction for kicking
    off a kthread that's tied to a file descriptor returned to userspace
    via the ioctl.
 
  - btree_paths within a btree_trans are now dynamically growable,
    instead of being limited to 64. This is important for the
    check_directory_structure phase of fsck, and also fixes some issues
    we were having with btree path overflow in the reflink btree.
 
  - Trigger refactoring; prep work for the upcoming disk space accounting
    rewrite
 
  - Numerous bugfixes :)
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Merge tag 'bcachefs-2024-01-10' of https://evilpiepirate.org/git/bcachefs

Pull bcachefs updates from Kent Overstreet:

 - btree write buffer rewrite: instead of adding keys to the btree write
   buffer at transaction commit time, we now journal them with a
   different journal entry type and copy them from the journal to the
   write buffer just prior to journal write.

   This reduces the number of atomic operations on shared cachelines in
   the transaction commit path and is a signicant performance
   improvement on some workloads: multithreaded 4k random writes went
   from ~650k iops to ~850k iops.

 - Bring back optimistic spinning for six locks: the new implementation
   doesn't use osq locks; instead we add to the lock waitlist as normal,
   and then spin on the lock_acquired bit in the waitlist entry, _not_
   the lock itself.

 - New ioctls:

    - BCH_IOCTL_DEV_USAGE_V2, which allows for new data types

    - BCH_IOCTL_OFFLINE_FSCK, which runs the kernel implementation of
      fsck but without mounting: useful for transparently using the
      kernel version of fsck from 'bcachefs fsck' when the kernel
      version is a better match for the on disk filesystem.

    - BCH_IOCTL_ONLINE_FSCK: online fsck. Not all passes are supported
      yet, but the passes that are supported are fully featured - errors
      may be corrected as normal.

   The new ioctls use the new 'thread_with_file' abstraction for kicking
   off a kthread that's tied to a file descriptor returned to userspace
   via the ioctl.

 - btree_paths within a btree_trans are now dynamically growable,
   instead of being limited to 64. This is important for the
   check_directory_structure phase of fsck, and also fixes some issues
   we were having with btree path overflow in the reflink btree.

 - Trigger refactoring; prep work for the upcoming disk space accounting
   rewrite

 - Numerous bugfixes :)

* tag 'bcachefs-2024-01-10' of https://evilpiepirate.org/git/bcachefs: (226 commits)
  bcachefs: eytzinger0_find() search should be const
  bcachefs: move "ptrs not changing" optimization to bch2_trigger_extent()
  bcachefs: fix simulateously upgrading & downgrading
  bcachefs: Restart recovery passes more reliably
  bcachefs: bch2_dump_bset() doesn't choke on u64s == 0
  bcachefs: improve checksum error messages
  bcachefs: improve validate_bset_keys()
  bcachefs: print sb magic when relevant
  bcachefs: __bch2_sb_field_to_text()
  bcachefs: %pg is banished
  bcachefs: Improve would_deadlock trace event
  bcachefs: fsck_err()s don't need to manually check c->sb.version anymore
  bcachefs: Upgrades now specify errors to fix, like downgrades
  bcachefs: no thread_with_file in userspace
  bcachefs: Don't autofix errors we can't fix
  bcachefs: add missing bch2_latency_acct() call
  bcachefs: increase max_active on io_complete_wq
  bcachefs: add time_stats for btree_node_read_done()
  bcachefs: don't clear accessed bit in btree node fill
  bcachefs: Add an option to control btree node prefetching
  ...
2024-01-10 16:34:17 -08:00
Linus Torvalds
3f6984e730 vfs-6.8.super
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Merge tag 'vfs-6.8.super' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull vfs super updates from Christian Brauner:
 "This contains the super work for this cycle including the long-awaited
  series by Jan to make it possible to prevent writing to mounted block
  devices:

   - Writing to mounted devices is dangerous and can lead to filesystem
     corruption as well as crashes. Furthermore syzbot comes with more
     and more involved examples how to corrupt block device under a
     mounted filesystem leading to kernel crashes and reports we can do
     nothing about. Add tracking of writers to each block device and a
     kernel cmdline argument which controls whether other writeable
     opens to block devices open with BLK_OPEN_RESTRICT_WRITES flag are
     allowed.

     Note that this effectively only prevents modification of the
     particular block device's page cache by other writers. The actual
     device content can still be modified by other means - e.g. by
     issuing direct scsi commands, by doing writes through devices lower
     in the storage stack (e.g. in case loop devices, DM, or MD are
     involved) etc. But blocking direct modifications of the block
     device page cache is enough to give filesystems a chance to perform
     data validation when loading data from the underlying storage and
     thus prevent kernel crashes.

     Syzbot can use this cmdline argument option to avoid uninteresting
     crashes. Also users whose userspace setup does not need writing to
     mounted block devices can set this option for hardening. We expect
     that this will be interesting to quite a few workloads.

     Btrfs is currently opted out of this because they still haven't
     merged patches we require for this to work from three kernel
     releases ago.

   - Reimplement block device freezing and thawing as holder operations
     on the block device.

     This allows us to extend block device freezing to all devices
     associated with a superblock and not just the main device. It also
     allows us to remove get_active_super() and thus another function
     that scans the global list of superblocks.

     Freezing via additional block devices only works if the filesystem
     chooses to use @fs_holder_ops for these additional devices as well.
     That currently only includes ext4 and xfs.

     Earlier releases switched get_tree_bdev() and mount_bdev() to use
     @fs_holder_ops. The remaining nilfs2 open-coded version of
     mount_bdev() has been converted to rely on @fs_holder_ops as well.
     So block device freezing for the main block device will continue to
     work as before.

     There should be no regressions in functionality. The only special
     case is btrfs where block device freezing for the main block device
     never worked because sb->s_bdev isn't set. Block device freezing
     for btrfs can be fixed once they can switch to @fs_holder_ops but
     that can happen whenever they're ready"

* tag 'vfs-6.8.super' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (27 commits)
  block: Fix a memory leak in bdev_open_by_dev()
  super: don't bother with WARN_ON_ONCE()
  super: massage wait event mechanism
  ext4: Block writes to journal device
  xfs: Block writes to log device
  fs: Block writes to mounted block devices
  btrfs: Do not restrict writes to btrfs devices
  block: Add config option to not allow writing to mounted devices
  block: Remove blkdev_get_by_*() functions
  bcachefs: Convert to bdev_open_by_path()
  fs: handle freezing from multiple devices
  fs: remove dead check
  nilfs2: simplify device handling
  fs: streamline thaw_super_locked
  ext4: simplify device handling
  xfs: simplify device handling
  fs: simplify setup_bdev_super() calls
  blkdev: comment fs_holder_ops
  porting: document block device freeze and thaw changes
  fs: remove unused helper
  ...
2024-01-08 10:43:51 -08:00
Brian Foster
d9e14a4eb9 bcachefs: remove sb lock and flags update on explicit shutdown
bcachefs grabs s_umount and sets SB_RDONLY when the fs is shutdown
via the ioctl() interface. This has a couple issues related to
interactions between shutdown and freeze:

1. The flags == FSOP_GOING_FLAGS_DEFAULT case is a deadlock vector
   because freeze_bdev() calls into freeze_super(), which also
   acquires s_umount.

2. If an explicit shutdown occurs while the sb is frozen, SB_RDONLY
   alters the thaw path as if the sb was read-only at freeze time.
   This effectively leaks the frozen state and leaves the sb frozen
   indefinitely.

The usage of SB_RDONLY here goes back to the initial bcachefs commit
and AFAICT is simply historical behavior. This behavior is unique to
bcachefs relative to the handful of other filesystems that support
the shutdown ioctl(). Typically, SB_RDONLY is reserved for the
proper remount path, which itself is restricted from modifying
frozen superblocks in reconfigure_super(). Drop the unnecessary sb
lock and flags update bch2_ioc_goingdown() to address both of these
issues.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:40 -05:00
Kent Overstreet
0d72ab35a9 bcachefs: make RO snapshots actually RO
Add checks to all the VFS paths for "are we in a RO snapshot?".

Note - we don't check this when setting inode options via our xattr
interface, since those generally only affect data placement, not
contents of data.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Reported-by: "Carl E. Thompson" <list-bcachefs@carlthompson.net>
2024-01-01 11:47:07 -05:00
Kent Overstreet
7aebaabfed bcachefs: Fix creating snapshot with implict source
When creating a snapshot without specifying the source subvolume, we use
the subvolume containing the new snapshot.

Previously, this worked if the directory containing the new snapshot was
the subvolume root - but we were using the incorrect helper, and got a
subvolume ID of 0 when the parent directory wasn't the root of the
subvolume, causing an emergency read-only.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-12-06 00:21:30 -05:00
Christian Brauner
982c3b3058
bdev: rename freeze and thaw helpers
We have bdev_mark_dead() etc and we're going to move block device
freezing to holder ops in the next patch. Make the naming consistent:

* freeze_bdev() -> bdev_freeze()
* thaw_bdev()   -> bdev_thaw()

Also document the return code.

Link: https://lore.kernel.org/r/20231024-vfs-super-freeze-v2-2-599c19f4faac@kernel.org
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-11-18 14:59:23 +01:00
Al Viro
bbe6a7c899 bch2_ioctl_subvolume_destroy(): fix locking
make it use user_path_locked_at() to get the normal directory protection
for modifications, as well as stable ->d_parent and ->d_name in victim

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2023-11-15 22:47:58 -05:00
Kent Overstreet
103ffe9aaf bcachefs: x-macro-ify inode flags enum
This lets us use bch2_prt_bitflags to print them out.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-11-05 13:12:18 -05:00
Kent Overstreet
37fad9497f bcachefs: snapshot_create_lock
Add a new lock for snapshot creation - this addresses a few races with
logged operations and snapshot deletion.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:10:16 -04:00
Dan Carpenter
1f12900ab5 bcachefs: fs-ioctl: Fix copy_to_user() error code
The copy_to_user() function returns the number of bytes that it wasn't
able to copy but we want to return -EFAULT to the user.

Fixes: e0750d947352 ("bcachefs: Initial commit")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:10:14 -04:00
Joshua Ashton
791236b85c bcachefs: Add btree_trans* to inode_set_fn
This will be used when we need to re-hash a directory tree when setting
flags.

It is not possible to have concurrent btree_trans on a thread.

Signed-off-by: Joshua Ashton <joshua@froggi.es>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:10:10 -04:00
Kent Overstreet
e47a390aa5 bcachefs: Convert -ENOENT to private error codes
As with previous conversions, replace -ENOENT uses with more informative
private error codes.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:10:03 -04:00
Kent Overstreet
e1e7ecafe6 bcachefs: Improve error handling in bch2_ioctl_subvolume_destroy()
Pure style fixes

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:57 -04:00
Kent Overstreet
65ff2d3a7a bcachefs: Support FS_XFLAG_PROJINHERIT
We already have support for the flag's semantics: inode options are
inherited by children if they were explicitly set on the parent. This
patch just maps the FS_XFLAG_PROJINHERIT flag to the "this option was
epxlicitly set" bit.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:43 -04:00
Kent Overstreet
5c1ef830f6 bcachefs: Errcodes can now subtype standard error codes
The next patch is going to be adding private error codes for all the
places we return -ENOSPC.

Additionally, this patch updates return paths at all module boundaries
to call bch2_err_class(), to return the standard error code.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:40 -04:00
Kent Overstreet
2027875bd8 bcachefs: Add BCH_SUBVOLUME_UNLINKED
Snapshot deletion needs to become a multi step process, where we unlink,
then tear down the page cache, then delete the subvolume - the deleting
flag is equivalent to an inode with i_nlink = 0.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:15 -04:00
Kent Overstreet
521b806769 bcachefs: Delete dentry when deleting snapshots
This fixes a bug where subsequently doing creates with the same name
fails.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:14 -04:00
Kent Overstreet
42d237320e bcachefs: Snapshot creation, deletion
This is the final patch in the patch series implementing snapshots.
This patch implements two new ioctls that work like creation and
deletion of directories, but fancier.

 - BCH_IOCTL_SUBVOLUME_CREATE, for creating new subvolumes and snaphots
 - BCH_IOCTL_SUBVOLUME_DESTROY, for deleting subvolumes and snapshots

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:13 -04:00
Kent Overstreet
6fed42bb77 bcachefs: Plumb through subvolume id
To implement snapshots, we need every filesystem btree operation (every
btree operation without a subvolume) to start by looking up the
subvolume and getting the current snapshot ID, with
bch2_subvolume_get_snapshot() - then, that snapshot ID is used for doing
btree lookups in BTREE_ITER_FILTER_SNAPSHOTS mode.

This patch adds those bch2_subvolume_get_snapshot() calls, and also
switches to passing around a subvol_inum instead of just an inode
number.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:12 -04:00
Kent Overstreet
284ae18c1d bcachefs: Add subvolume to ei_inode_info
Filesystem operations generally operate within a subvolume: at the start
of every btree transaction we'll be looking up (and locking) the
subvolume to get the current snapshot ID, which we then use for our
other btree lookups in BTREE_ITER_FILTER_SNAPSHOTS mode.

But inodes don't record what subvolume they're in - they can't, because
if they did we'd have to update every single inode within a subvolume
when taking a snapshot in order to keep that field up to date. So it
needs to be tracked in memory, based on how we got to that inode.

Hence this patch adds a subvolume field to ei_inode_info, and switches
to iget5() so we can index by it in the inode hash table.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:12 -04:00
Kent Overstreet
4495cbed56 bcachefs: Improve FS_IOC_GOINGDOWN ioctl
We weren't interpreting the flags argument at all.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
2023-10-22 17:09:04 -04:00
Kent Overstreet
07bca3bd1e bcachefs: Kill ei_str_hash
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:55 -04:00
Kent Overstreet
7af0cec307 bcachefs: Some project id fixes
Inode options that are accessible via the xattr interface are stored
with a +1 bias, so that a value of 0 means unset. We weren't handling
this consistently.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:44 -04:00
Kent Overstreet
9638574229 bcachefs: Factor out fs-common.c
This refactoring makes the code easier to understand by separating the
bcachefs btree transactional code from the linux VFS code - but more
importantly, it's also to share code with the fuse port.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:28 -04:00
Kent Overstreet
168f4c5fb3 bcachefs: Improve bch2_lock_inodes()
Can now be used for the two different types of locks we have so far

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:23 -04:00
Kent Overstreet
619f5bee86 bcachefs: some improvements to startup messages and options
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:21 -04:00
Kent Overstreet
e19e57f8a1 bcachefs: fix new reinherit_attrs ioctl
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:14 -04:00
Kent Overstreet
2fab25cdd7 bcachefs: more project quota fixes
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:14 -04:00
Kent Overstreet
8095708fce bcachefs: bch2_ioc_reinherit_attrs()
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:13 -04:00
Kent Overstreet
721d4ad8eb bcachefs: Add flags to indicate if inode opts were inherited or explicitly set
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:13 -04:00
Kent Overstreet
0f5254aa98 bcachefs: bch2_fs_quota_transfer
improve quota transfer locking & make ei_qid usage more consistent

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:13 -04:00
Kent Overstreet
2ea9004864 bcachefs: Fix mtime/ctime updates
Also make inode flags consistent with how the rest of the inode is
updated

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:07 -04:00
Kent Overstreet
1c6fdbd8f2 bcachefs: Initial commit
Initially forked from drivers/md/bcache, bcachefs is a new copy-on-write
filesystem with every feature you could possibly want.

Website: https://bcachefs.org

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:07 -04:00