Fix a shutdown WARNING in bch2_dev_free caused by active write I/O
references (ca->io_ref[WRITE]) on a device being freed.
The problem occurs when:
- The filesystem is marked read-only (BCH_FS_rw clear in c->flags).
- A subsequent operation (e.g., error handling for device removal)
incorrectly tries to grant write references back to a device.
- During final shutdown, the read-only flag causes the system to skip
stopping write I/O references (bch2_dev_io_ref_stop(ca, WRITE)).
- The leftover active write reference triggers the WARN_ON in
bch2_dev_free.
Prevent this by checking if the filesystem is read-only before
attempting to grant write references to a device in the problematic
code path. Ensure consistency between the filesystem state flag
and the device I/O reference state during shutdown.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
As with the other algorithms, bcachefs does not access xxhash through
the crypto API. So there is no need to use a module softdep to ensure
that it is loaded.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Just use the ChaCha20 and Poly1305 libraries instead of the clunky
crypto API. This is much simpler. It is also slightly faster, since
the libraries provide more direct access to the same
architecture-optimized ChaCha20 and Poly1305 code.
I've tested that existing encrypted bcachefs filesystems can be continue
to be accessed with this patch applied.
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We now have separate per device io_refs for read and write access.
This fixes a device removal bug where the discard workers were still
running while we're removing alloc info for that device.
It's also a bit of hardening; we no longer allow writes to devices that
are read-only.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
state_lock guards against devices coming or leaving, changing state, or
the filesystem changing between ro <-> rw.
But it's not necessary for running recovery passes, and holding it
blocks asynchronous events that would cause us to go RO or kick out
devices.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
There's no reason for this not to be world readable - it provides the
currently supported on disk format version.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We're hitting some issues with uninitialized struct padding, flagged by
kmsan.
They appear to be falso positives, otherwise bch2_accounting_validate()
would have flagged them as "junk at end". But for now, we'll need to
initialize disk_accounting_pos with memset().
This adds a new helper, bch2_disk_accounting_mod2(), that initializes a
disk_accounting_pos and does the accounting mod all at once - so overall
things actually get slightly more ergonomic.
BCH_DISK_ACCOUNTING_replicas keys are left for now; KMSAN isn't warning
about them and they're a bit special.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Device options now use the common code for sysfs, and can superblock
fields (in a struct bch_member).
This replaces BCH_DEV_OPT_SETTERS(), which was weird and easy to miss.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Just use sha256() instead of the clunky crypto API. This is much
simpler.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Since bcachefs does not access crc32c and crc64 through the crypto API,
there is no need to use module softdeps to ensure they are loaded.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We can't use the standard fs_holder_ops because they're meant for single
device filesystems - fs_bdev_mark_dead() in particular - and they assume
that the blk_holder is the super_block, which also doesn't work for a
multi device filesystem.
These generally follow the standard fs_holder_ops; the
locking/refcounting is a bit simplified because c->ro_ref suffices, and
bch2_fs_bdev_mark_dead() is not necessarily shutting down the entire
filesystem.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Note that we open block devices before we allocate bch_fs, but once
attached to a filesystem they will be closed before the bch_fs is torn
down - so stashing a pointer without a refcount looks incorrect but it's
not.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This patch implements support for case-insensitive file name lookups
in bcachefs.
The implementation uses the same UTF-8 lowering and normalization that
ext4 and f2fs is using.
More information is provided in Documentation/bcachefs/casefolding.rst
Compatibility notes:
This uses the new versioning scheme for incompatible features where an
incompatible feature is tied to a version number: the superblock says
"we may use incompat features up to x" and "incompat features up to x
are in use", disallowing mounting by previous versions.
Additionally, and old style incompat feature bit is used, so that
kernels without utf8 casefolding support know if casefolding
specifically is in use and they're allowed to mount.
Signed-off-by: Joshua Ashton <joshua@froggi.es>
Cc: André Almeida <andrealmeid@igalia.com>
Cc: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
In the previous commit b3d82c2f27, code was added to prevent journal sequence
overflow. Among them, the code added to journal_entry_open() uses the
bch2_fs_fatal_err_on() function to handle errors.
However, __journal_res_get() , which calls journal_entry_open() , calls
journal_entry_open() while holding journal->lock , but bch2_fs_fatal_err_on()
internally tries to acquire journal->lock , which results in a deadlock.
So we need to add a locked helper to handle fatal errors even when the
journal->lock is held.
Fixes: b3d82c2f27 ("bcachefs: Guard against journal seq overflow")
Signed-off-by: Jeongjun Park <aha310510@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Persistent cursors for inode allocation.
A free inodes btree would add substantial overhead to inode allocation
and freeing - a "next num to allocate" cursor is always going to be
faster.
We just need it to be persistent, to avoid scanning the inodes btree
from the start on startup.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We can't hold mark_lock while calling fsck_err() - that's a deadlock,
mark_lock is meant to be a leaf node lock.
It's also unnecessary for gc_bucket() and bucket_gen(); rcu suffices
since the bucket_gens array describes its size, and we can't race with
device removal or resize during gc/fsck since that takes state lock.
Reported-by: syzbot+38641fcbda1aaffefdd4@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
The early-early allocation path, bch2_bucket_alloc_new_fs(), is no
longer needed - and inconsistencies around new_fs_bucket_idx have been a
frequent source of bugs.
Reported-by: syzbot+592425844580a6598410@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
The journal_keys array can't be substantially modified after we go RW,
because lookups need to be able to check it locklessly - thus we're
limited on what we can do when a key in the journal has been
overwritten.
This is a problem when there's many overwrites to skip over for peek()
operations. To fix this, add tracking of ranges of overwrites: we create
a range entry when there's more than one contiguous whiteout.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
The journal replay keys mechanism can only be used for updates in early
recovery, when still single threaded.
Add some asserts to make sure we never accidentally use it elsewhere.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Recovery can rewind in certain situations - when we discover we need to
run a pass that doesn't normally run.
This can happen from another thread for btree node read errors, so we
need a bit of locking.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
There are a several statements with two following semicolons, replace
these with just one semicolon.
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
The write buffer needs to be specifically flushed when going RO: keys in
the journal that haven't yet been moved to the write buffer don't have a
journal pin yet.
This fixes numerous syzbot bugs, all with symptoms of still doing writes
after we've got RO.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Using commit_do() to call alloc_sectors_start_trans() breaks when we're
randomly injecting transaction restarts - the restart in the commit
causes us to leak the lock that alloc_sectorS_start_trans() takes.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
sysfs warns if we're removing a symlink from a directory that's no
longer in sysfs; this is triggered by fstests generic/730, which
simulates hot removal of a block device.
This patch is however not a correct fix, since checking
kobj->state_in_sysfs on a kobj owned by another subsystem is racy.
A better fix would be to add the appropriate check to
sysfs_remove_link() - and sysfs_create_link() as well.
But kobject_add_internal()/kobject_del() do not as of today have locking
that would support that.
Note that the block/holder.c code appears to be subject to this race as
well.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
32 bits won't overflow any time soon, but size_t is the correct type for
counting objects in memory.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
the standard vfs inode hash table suffers from painful lock contention -
this is long overdue
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Verify that the in-memory accounting verifies the on-disk accounting
after a clean shutdown.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Rewrite fsck/gc for the new accounting scheme.
This adds a second set of in-memory accounting counters for gc to use;
like with other parts of gc we run all trigger in TRIGGER_GC mode, then
compare what we calculated to existing in-memory accounting at the end.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Main part of the disk accounting rewrite.
This is a wholesale rewrite of the existing disk space accounting, which
relies on percepu counters that are sharded by journal buffer, and
rolled up and added to each journal write.
With the new scheme, every set of counters is a distinct key in the
accounting btree; this fixes scaling limitations of the old scheme,
where counters took up space in each journal entry and required multiple
percpu counters.
Now, in memory accounting requires a single set of percpu counters - not
multiple for each in flight journal buffer - and in the future we'll
probably also have counters that don't use in memory percpu counters,
they're not strictly required.
An accounting update is now a normal btree update, using the btree write
buffer path. At transaction commit time, we apply accounting updates to
the in memory counters, which are percpu counters indexed in an
eytzinger tree by the accounting key.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
The output of mount options such as "metadata_target" in `/proc/mounts`
uses the full path to the device.
mount(8) from util-linux uses the output from `/proc/mounts` to pass
existing mount options when performing a remount, so bcachefs should
accept as input the same form that it prints as output.
Without this change:
$ mount -t bcachefs -o metadata_target=vdb /dev/vdb /mnt
$ strace mount -o remount /mnt
...
fsconfig(4, FSCONFIG_SET_STRING, "metadata_target", "/dev/vdb", 0) = -1 EINVAL (Invalid argument)
...
Signed-off-by: Thomas Bertschinger <tahbertschinger@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
On a new filesystem or device we have to allocate the journal with a
bump allocator, because allocation info isn't ready yet - but when
hot-adding a device that doesn't have a journal, we don't want to use
that path.
Reported-by: syzbot+24a867cb90d8315cccff@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
There's no reason for discards to be single threaded across all devices;
this will improve performance on multi device setups.
Additionally, making them per-device simplifies the refcounting on
bch_dev->io_ref; we now hold it for the duration that the discard path
is running, which fixes a race between the discard path and device
removal.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
btree_iter_init() needs to happen before key_cache_init(), to initialize
btree_trans_barrier
Reported-by: syzbot+3cca837c2183f8f6fcaf@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Split the workqueues for btree read completions and btree write
submissions; we don't want concurrency control on btree read
completions, but we do want concurrency control on write submissions,
else blocking in submit_bio() will cause a ton of kworkers to be
allocated.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
the btree key cache uses the srcu struct created/destroyed by
btree_iter.c; btree_iter needs to be exited last.
Reported-by: syzbot+3af9daea347788b15213@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This is needed for the next patch - the write submit path has to be able
to allocate a replica bio even when we weren't able to get a ref on the
device.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We can't strictly guarantee that no pointers refer to nonexistent
devices - we attempt to, but we need to be safe when the filesystem is
corrupt.
Therefore, change device_add to try to pick a slot that's never been
used, or the slot that's been unused the longest.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Now explicitly allocate and free the buckets_nouse bitmap - this is
going to be used for online fsck.
To go RW when we haven't check allocations, we'll do a much slimmed down
version that just initializes the buckets_nouse bitmaps.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Since btree_ptr_v2, we no longer require the journal seq blacklist table
for skipping blacklisted bsets (btree node entries); the pointer to a
given node indicates how much data is present.
Therefore there's no longer any need for journal seq blacklist gc to
walk the btree - we can prune entries older than journal last_seq.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This is a nice cleanup - and we've also been having problems with
kthread creation in the mount path.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Combine iter/update/trigger/str_hash flags into a single enum, and
x-macroize them for a to_text() function later.
These flags are all for a specific iter/key/update context, so it makes
sense to group them together - iter/update/trigger flags were already
given distinct bits, this cleans up and unifies that handling.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Consolidate mark_superblock() and trans_mark_superblock(), like we did
with the other trigger paths.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
The bucket_gens array is a single array allocation (one byte per
bucket), and kernel allocations are still limited to INT_MAX.
Check this limit to avoid failing the bucket_gens array allocation.
Reported-by: syzbot+b29f436493184ea42e2b@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
bch2_dev_lookup() is supposed to take a ref on the device it returns, but
for_each_member_device() takes refs as it iterates,
for_each_member_device_rcu() does not.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
If a btree root or interior btree node goes bad, we're going to lose a
lot of data, unless we can recover the nodes that it pointed to by
scanning.
Fortunately btree node headers are fully self describing, and
additionally the magic number is xored with the filesytem UUID, so we
can do so safely.
This implements the scanning - next patch will rework topology repair to
make use of the found nodes.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This adds opts.recovery_pass_limit, and redoes -o norecovery to make use
of it; this fixes some issues with -o norecovery so it can be safely
used for data recovery.
Norecovery means "don't do journal replay"; it's an important data
recovery tool when we're getting stuck in journal replay.
When using it this way we need to make sure we don't free journal keys
after startup, so we continue to overlay them: thus it needs to imply
retain_recovery_info, as well as nochanges.
recovery_pass_limit is an explicit option for telling recovery to exit
after a specific recovery pass; this is a much cleaner way of
implementing -o norecovery, as well as being a useful debug feature in
its own right.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This makes bch_sb_field_ext more consistent with the rest of -o
nochanges - we don't want to be varying other codepaths based on -o
nochanges, since it's used for testing in dry run mode; also fixes some
potential null ptr derefs.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Currently, struct time_stats has the optional ability to quantize the
information that it collects. This is /probably/ useful for callers who
want to see quantized information, but it more than doubles the size of
the structure from 224 bytes to 464. For users who don't care about
that (e.g. upcoming xfs patches) and want to avoid wasting 240 bytes per
counter, split the two into separate pieces.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
- eliminate the dependency on printbufs, so that we can lift
thread_with_file for use in xfs
- add a nonblocking parameter to stdio_redirect_printf(), and either
block if the buffer is full or drop it on the floor - don't buffer
infinitely
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Most bcachefs workqueues are used for completions, and should be
WQ_HIGHPRI - this helps reduce queuing delays, we want to complete
quickly once we can no longer signal backpressure by blocking.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This adds an option to disable kicking out devices when splitbrain is
detected - it seems there's some issues with splitbrain detection and
we're kicking out devices erronously.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
There is a null-ptr-deref issue reported by kasan:
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
Call Trace:
<TASK>
bch2_fs_alloc+0x1092/0x2170 [bcachefs]
bch2_fs_open+0x683/0xe10 [bcachefs]
...
When initializing the name of bch_fs, it needs to dynamically alloc memory
to meet the length of the name. However, when name allocation failed, it
will cause a null-ptr-deref access exception in subsequent string copy.
Fix this issue by checking if name allocation is successful.
Fixes: 401ec4db63 ("bcachefs: Printbuf rework")
Signed-off-by: Li Zetao <lizetao1@huawei.com>
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>
- 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
...
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>
strlcpy() reads the entire source buffer first. This read may exceed
the destination size limit. This is both inefficient and can lead
to linear read overflows if a source string is not NUL-terminated[1].
Additionally, it returns the size of the source string, not the
resulting size of the destination string. In an effort to remove strlcpy()
completely[2], replace strlcpy() here with strscpy().
Nothing checks the return value here, so a direct replacement with
strspy() is possible.
Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [1]
Link: https://github.com/KSPP/linux/issues/89 [2]
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Brian Foster <bfoster@redhat.com>
Cc: <linux-bcachefs@vger.kernel.org>
Link: https://lore.kernel.org/r/20240110235438.work.385-kees@kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
this definitely should _not_ be 1, and we don't actually want any
concurrency limiting at all here - btree node read completions are
getting blocked behind btree node write submissions.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Use the new bch_member->seq, sb->write_time fields to detect split brain
and kick out devices when necessary.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
nochanges means "we cannot issue writes at all"; it's possible to go
into a pseudo read-write mode where we pin dirty metadata in memory,
which is used for fsck in dry run mode and doing journal replay on a
read only mount, but we do not want to allow an actual read-write mount
in nochanges mode.
But we do always want to allow early read-write, during recovery - this
patch clarifies that.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
