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>

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>

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>

Fixes:
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

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>

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>

This prevents going emergency read only when the user has specified
replicas_required > replicas.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

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>

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>

This fixes spurious outliers in the frequency stats.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

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: 1c6fdbd8 ("bcachefs: Initial commit")
Signed-off-by: Mathias Krause <minipli@grsecurity.net>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

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>

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>

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>

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>

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>

Fixes: e6a2566f ("bcachefs: Better journal tracepoints")
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Reported-by: smatch

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
  ...

Pull timer updates from Thomas Gleixner:
 "Updates for time and clocksources:

   - A fix for the idle and iowait time accounting vs CPU hotplug.

     The time is reset on CPU hotplug which makes the accumulated
     systemwide time jump backwards.

   - Assorted fixes and improvements for clocksource/event drivers"

* tag 'timers-core-2024-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tick-sched: Fix idle and iowait sleeptime accounting vs CPU hotplug
  clocksource/drivers/ep93xx: Fix error handling during probe
  clocksource/drivers/cadence-ttc: Fix some kernel-doc warnings
  clocksource/drivers/timer-ti-dm: Fix make W=n kerneldoc warnings
  clocksource/timer-riscv: Add riscv_clock_shutdown callback
  dt-bindings: timer: Add StarFive JH8100 clint
  dt-bindings: timer: thead,c900-aclint-mtimer: separate mtime and mtimecmp regs

Pull powerpc fixes from Aneesh Kumar:

 - Increase default stack size to 32KB for Book3S

Thanks to Michael Ellerman.

* tag 'powerpc-6.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64s: Increase default stack size to 32KB

Add line breaks - inode_to_text() is now much easier to read.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bcachefs_format.h has gotten too big; let's do some organizing.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

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>

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

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>