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>
Previosuly, the transaction commit path would have to add keys to the
btree write buffer as a separate operation, requiring additional global
synchronization.
This patch introduces a new journal entry type, which indicates that the
keys need to be copied into the btree write buffer prior to being
written out. We switch the journal entry type back to
JSET_ENTRY_btree_keys prior to write, so this is not an on disk format
change.
Flushing the btree write buffer may require pulling keys out of journal
entries yet to be written, and quiescing outstanding journal
reservations; we previously added journal->buf_lock for synchronization
with the journal write path.
We also can't put strict bounds on the number of keys in the journal
destined for the write buffer, which means we might overflow the size of
the preallocated buffer and have to reallocate - this introduces a
potentially fatal memory allocation failure. This is something we'll
have to watch for, if it becomes an issue in practice we can do
additional mitigation.
The transaction commit path no longer has to explicitly check if the
write buffer is full and wait on flushing; this is another performance
optimization. Instead, when the btree write buffer is close to full we
change the journal watermark, so that only reservations for journal
reclaim are allowed.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This adds a new ioctl for running fsck on a mounted, in use filesystem.
This reuses the fsck_thread code from the previous patch for running
fsck on an offline, unmounted filesystem, so that log messages for the
fsck thread are redirected to userspace.
Only one running fsck instance is allowed at a time; a new semaphore
(since the lock will be taken by one thread and released by another) is
added for this.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Upcoming patches are going to add two new ioctls for running fsck in the
kernel, but pretending that we're running our normal userspace fsck.
This patch adds some plumbing for redirecting our normal log messages
away from the dmesg log to a thread_with_file file descriptor - via a
struct log_output, which will be consumed by the fsck f_op's read method.
The new ioctls will allow for running fsck in the kernel against an
offline filesystem (without mounting it), and an online filesystem. For
an offline filesystem we need a way to pass in a pointer to the
log_output, which is done via a new hidden opts.h option.
For online fsck, we can set c->output directly, but only want to
redirect log messages from the thread running fsck - hence the new
c->output_filter method.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Add a new refcount for async ops that don't necessarily need the fs to
be RW, with similar lifetime/rules otherwise as c->writes.
To be used by online fsck.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Now we can print out filesystem flags in sysfs, useful for debugging
various "what's my filesystem doing" issues.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This introduces a new helper for connecting time_stats to state changes,
i.e. when taking journal reservations is blocked for some reason.
We use this to track separately the different reasons the journal might
be blocked - i.e. space in the journal full, or the journal pin fifo
full.
Also do some cleanup and improvements on the time stats code.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Also log time waiting for c->writes references to be dropped; this will
help in debugging why unmounts are taking longer than they should.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We need to help modprobe load architecture specific modules so we don't
fall back to generic software implementations, this should help
performance when building as a module.
Signed-off-by: Daniel Hill <daniel@gluo.nz>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
When bch2_fs_alloc() gets an error before calling
bch2_fs_btree_iter_init(), bch2_fs_btree_iter_exit() makes an invalid
memory access because btree_trans_list is uninitialized.
Signed-off-by: Thomas Bertschinger <tahbertschinger@gmail.com>
Fixes: 6bd68ec266 ("bcachefs: Heap allocate btree_trans")
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
The btree iterator code overlays keys from the journal until journal
replay is finished; since we're now starting copygc/rebalance etc.
before replay is finished, this is multithreaded access and thus needs
refcounting.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This fixes a bug where copygc would occasionally race with going
read-write and die, thinking we were read only, because it couldn't take
a ref on c->writes.
It's not necessary for copygc (or rebalance, or copygc) to take write
refs; they could run with BCH_TRANS_COMMIT_nocheck_rw, but this is an
easier fix that making sure that flag is passed correctly everywhere.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Add a new superblock section to keep counts of errors seen since
filesystem creation: we'll be addingcounters for every distinct fsck
error.
The new superblock section has entries of the for [ id, count,
time_of_last_error ]; this is intended to let us see what errors are
occuring - and getting fixed - via show-super output.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We now track IO errors per device since filesystem creation.
IO error counts can be viewed in sysfs, or with the 'bcachefs
show-super' command.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This fixes a use after free - mi is dangling after the resize call.
Additionally, resizing the device's member info section was useless - we
were attempting to preallocate the space required before adding it to
the filesystem superblock, but there's other sections that we should
have been preallocating as well for that to work.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We're going to be using bch2_target_to_text() ->
bch2_disk_path_to_text() from bch2_bkey_ptrs_to_text() and
bch2_bkey_ptrs_invalid(), which can be called in any context.
This patch adds the actual label to bch_disk_group_cpu so that it can be
used by bch2_disk_path_to_text, and splits out bch2_disk_path_to_text()
into two variants - like the previous patch, one for when we have a
running filesystem and another for when we only have a superblock.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We can't mark device superblocks or allocate journal on a device that
isn't online.
That means we may need to do this on every mount, because we may have
formatted a new filesystem and then done the first mount
(bch2_fs_initialize()) in degraded mode.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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>
Instead of using token pasting to generate methods for each superblock
section, just make the type a parameter to bch2_sb_field_get().
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
bch2_dev_resize() was never updated for the allocator rewrite with
persistent freelists, and it wasn't noticed because the tests weren't
running fsck - oops.
Fix this by running bch2_dev_freespace_init() for the new buckets.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
members_v2 has dynamically resizable entries so that we can extend
bch_member. The members can no longer be accessed with simple array
indexing Instead members_v2_get is used to find a member's exact
location within the array and returns a copy of that member.
Alternatively member_v2_get_mut retrieves a mutable point to a member.
Signed-off-by: Hunter Shaffer <huntershaffer182456@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Prep work for introducing bch_sb_field_members_v2 - introduce new
helpers that will check for members_v2 if it exists, otherwise using v1
Signed-off-by: Hunter Shaffer <huntershaffer182456@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
- assert in shutdown path that no nocow locks are held
- check for overflow when taking nocow locks
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
There is a typo here where it uses ";" instead of "?:". The result is
that bch2_fs_fs_io_direct_init() is called unconditionally and the errors
from it are not checked.
Fixes: 0060c68159fc ("bcachefs: Split up fs-io.[ch]")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Remove a redundant call to bch2_free_super().
This is harmless because bch2_free_super() has a memset() at its end. So
a second call would only lead to from kfree(NULL).
Remove the redundant call and only rely on the error handling path.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
If __bch2_dev_attach_bdev() fails, bch2_dev_free() is called twice.
Once here and another time in the error handling path.
This leads to several use-after-free.
Remove the redundant call and only rely on the error handling path.
Fixes: 6a44735653d4 ("bcachefs: Improved superblock-related error messages")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
modpost produces the following warning:
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/bcachefs/bcachefs.o
Add a module description for bcachefs.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We're using more stack than we'd like in a number of functions, and
btree_trans is the biggest object that we stack allocate.
But we have to do a heap allocatation to initialize it anyways, so
there's no real downside to heap allocating the entire thing.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Add a new btree for long running logged operations - i.e. for logging
operations that we can't do within a single btree transaction, so that
they can be resumed if we crash.
Keys in the logged operations btree will represent operations in
progress, with the state of the operation stored in the value.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
More reorganization, this splits up io.c into
- io_read.c
- io_misc.c - fallocate, fpunch, truncate
- io_write.c
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
In the bch2_fs_alloc() error path we call bch2_fs_free() without setting
BCH_FS_STOPPING - this is fine.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Commit c2d5ff36065a4 ("bcachefs: Start journal reclaim thread
earlier") tweaked reclaim thread management to start a bit earlier
in the mount sequence by moving the start call from
__bch2_fs_read_write() to bch2_fs_journal_start(). This has the side
effect of never starting the reclaim thread on a ro->rw transition,
which can be observed by monitoring reclaim behavior via the
journal_reclaim tracepoints. I.e. once an fs has remounted ro->rw,
we only ever rely on direct reclaim from that point forward.
Since bch2_journal_reclaim_start() properly handles the case where
the reclaim thread has already been created, restore the start call
in the read-write helper. This allows the reclaim thread to start
early when appropriate and also exit/restart on remounts or freeze
cycles. In the latter case it may be possible to simply allow the
task to freeze rather than destroy it, but for now just fix the
immediate bug.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
In the bch2_mount() error path, we were calling
deactivate_locked_super(), which calls ->kill_sb(), which in our case
was calling bch2_fs_free() without __bch2_fs_stop().
This changes bch2_mount() to just call bch2_fs_stop() directly.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
subvolume.c has gotten a bit large, this splits out a separate file just
for managing snapshot trees - BTREE_ID_snapshots.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Split out a new file from recovery.c for managing the list of keys we
read from the journal: before journal replay finishes the btree iterator
code needs to be able to iterate over and return keys from the journal
as well, so there's a fair bit of code here.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
fs-io.c is too big - time for some reorganization
- fs-dio.c: direct io
- fs-pagecache.c: pagecache data structures (bch_folio), utility code
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Awhile back, we changed bkey_format generation to ensure that the packed
representation could never represent fields larger than the unpacked
representation.
This was to ensure that bkey_packed_successor() always gave a sensible
result, but in the current code bkey_packed_successor() is only used in
a debug assertion - not for anything important.
This kills the requirement that we've gotten rid of those weird bkey
formats, and instead changes the assertion to check if we're dealing
with an old weird bkey format.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
With "bcachefs: Snapshot depth, skiplist fields", we now can't run data
move operations until after bch2_check_snapshots() is complete.
Ideally we'd have the copygc (and rebalance) threads wait until
c->curr_recovery_pass has advanced, but the waitlist handling is tricky
- so for now, move starting copygc back to read_write_late().
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Now that we have distinct error codes for different memory allocation
failures, the early init log messages are no longer needed.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
- endianness fixes
- mark some things static
- fix a few __percpu annotations
- fix silent enum conversions
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We need to allow filesystems with metadata from newer versions to be
mountable and usable by older versions.
This patch enables us to roll out new btrees without a new major version
number; we can now handle btree roots for unknown btree types.
The unknown btree roots will be retained, and fsck (including
backpointers) will check them, the same as other btree types.
We add a dynamic array for the extra, unknown btree roots, in addition
to the fixed size btree root array, and add new helpers for looking up
btree roots.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
A crash immediately after device removal can result in an
unmountable filesystem due to recovery failure. The following
command reliably reproduces on a multi-device fs:
bcachefs device remove <dev> && xfs_io -xc shutdown <mnt>
The post-crash mount fails with an error similar to the following,
reported by fsck:
invalid journal entry dev_usage at offset 7994/8034 seq 12: bad dev, fixing
This refers to a device usage entry in the journal that refers to
the index of the just removed device. Recovery considers this an
invalid entry and fails to proceed.
Device usage entries are added to journal buffer writes via
bch_journal_write() -> bch2_journal_super_entries_add_common(),
which means any journal buffer write has content that refers to
member devices at the time of the journal write.
The device remove sequence already removes metadata references to
the device being removed. It then flushes any pins that refer to the
device, clears replica entries, removes the in-memory device object
and lastly updates the superblock to reflect that the device is no
longer present. The problem is that any journal writes that occur
during this sequence will include a dev usage entry so long as the
device is present. To avoid this problem, we can flush the journal
once more after the device entry is removed from the in-core
structures, but before the superblock is updated to fully remove the
device on-disk.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This fixes a null ptr deref in bch2_free_pending_node_rewrites() when
the list head wasn't initialized.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
As with previous conversions, replace -ENOENT uses with more informative
private error codes.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
If a device has keys in the bucket_gens btree associated with its
buckets and is removed from a bcachefs volume, fsck will complain
about the presence of keys associated with an invalid device index.
A repair removes the associated keys and restores correctness.
Update bch2_dev_remove_alloc() to remove device related keys at
device removal time to avoid the problem.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Like in the recovery, and device add, we have to check if devices don't
have the freespace btree initialized - this was missed in the device hot
add path.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
A workqueue resource deadlock has been observed when running fsck
on a filesystem with a full/stuck journal. fsck is not currently
able to repair the fs due to fairly rapid emergency shutdown, but
rather than exit gracefully the fsck process hangs during the
shutdown sequence. Fortunately this is easily recoverable from
userspace, but the root cause involves code shared between the
kernel and userspace and so should be addressed.
The deadlock scenario involves the main task in the bch2_fs_stop()
-> bch2_fs_read_only() path waiting on write references to drain
with the fs state lock held. A bch2_read_only_work() workqueue task
is scheduled on the system_long_wq, blocked on the state lock.
Finally, various other write ref holding workqueue tasks are
scheduled to run on the same workqueue and must complete in order to
release references that the initial task is waiting on.
To avoid this problem, we can split the dependent workqueue tasks
across different workqueues. It's a bit of a waste to create a
dedicated wq for the read-only worker, but there are several tasks
throughout the fs that follow the pattern of acquiring a write
reference and then scheduling to the system wq. Use a local wq
for such tasks to break the subtle dependency between these and the
read-only worker.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This fixes a bug in bch2_evict_subvolume_inodes(): d_mark_dontcache()
doesn't handle the case where i_count is already 0, we need to grab and
put the inode in order for it to be dropped.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This implements a new shutdown path for erasure coding, which is needed
for the upcoming BCH_WRITE_WAIT_FOR_EC write path.
The process is:
- Cancel new stripes being built up
- Close out/cancel open buckets on write points or the partial list
that are for stripes
- Shutdown rebalance/copygc
- Then wait for in flight new stripes to finish
With BCH_WRITE_WAIT_FOR_EC, move ops will be waiting on stripes to fill
up before they complete; the new ec shutdown path is needed for shutting
down copygc/rebalance without deadlocking.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This also adds bch2_write_op_to_text(): now we can see outstand moves,
useful for debugging shutdown with the upcoming BCH_WRITE_WAIT_FOR_EC
and likely for other things in the future.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This adds private error codes for most (but not all) of our ENOMEM uses,
which makes it easier to track down assorted allocation failures.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Now that we have much more efficient updates to the LRU btree, this
patch adds a new LRU that indexes buckets by fragmentation.
This means copygc no longer has to scan every bucket to find buckets
that need to be evacuated.
Changes:
- A new field in bch_alloc_v4, fragmentation_lru - this corresponds to
the bucket's position in the fragmentation LRU. We add a new field
for this instead of calculating it as needed because we may make the
fragmentation LRU optional; this field indicates whether a bucket is
on the fragmentation LRU.
Also, zoned devices will introduce variable bucket sizes; explicitly
recording the LRU position will be safer for them.
- A new copygc path for using the fragmentation LRU instead of
scanning every bucket and building up an in-memory heap.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This improves the nocow lock table so that hash table entries have
multiple locks, and locks specify which bucket they're for - i.e. we can
now resolve hash collisions.
This is important because the allocator has to skip buckets that are
locked in the nocow lock table, and previously hash collisions would
cause it to spuriously skip unlocked buckets.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
With the new backpointer based copygc we don't need an explicit copygc
reserve, we're always evacuating buckets one at a time - so this is no
longer needed, and in fact removing it fixes a deadlock in
bch2_dev_allocator_remove().
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This patch adds backpointers: we now have a reverse index from device
and offset on that device (specifically, offset within a bucket) back to
btree nodes and (non cached) data extents.
The first 40 backpointers within a bucket are stored in the alloc key;
after that backpointers spill over to the next backpointers btree. This
is to help avoid performance regressions from additional btree updates
on large streaming workloads.
This patch adds all the code for creating, checking and repairing
backpointers. The next patch in the series is going to use backpointers
for copygc - finally getting rid of the need to scan all extents to do
copygc.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This adds a new method of doing btree updates - a straight write buffer,
implemented as a flat fixed size array.
This is only useful when we don't need to read from the btree in order
to do the update, and when reading is infrequent - perfect for the LRU
btree.
This will make LRU btree updates fast enough that we'll be able to use
it for persistently indexing buckets by fragmentation, which will be a
massive boost to copygc performance.
Changes:
- A new btree_insert_type enum, for btree_insert_entries. Specifies
btree, btree key cache, or btree write buffer.
- bch2_trans_update_buffered(): updates via the btree write buffer
don't need a btree path, so we need a new update path.
- Transaction commit path changes:
The update to the btree write buffer both mutates global, and can
fail if there isn't currently room. Therefore we do all write buffer
updates in the transaction all at once, and also if it fails we have
to revert filesystem usage counter changes.
If there isn't room we flush the write buffer in the transaction
commit error path and retry.
- A new persistent option, for specifying the number of entries in the
write buffer.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
In the distant past, it wasn't possible to start copygc until after
journal replay had finished. Now, the btree iterator code overlays keys
from the journal, so there's no reason not to start it earlier - and it
solves a rare deadlock.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This adds a debug mode where we split up the c->writes refcount into
distinct refcounts for every codepath that takes a reference, and adds
sysfs code to print the value of each ref.
This will make it easier to debug shutdown hangs due to refcount leaks.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We shouldn't be overloading standard error codes now that we have
provisions for bcachefs-specific errorcodes: this patch converts super.c
and super-io.c to per error site errcodes, with a bit of cleanup.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
On startup, we need to ensure the first journal entry written is a flush
write: after a clean shutdown we generally don't read the journal, which
means we might be overwriting whatever was there previously, and there
must always be at least one flush entry in the journal or recovery will
fail.
Found by fstests generic/388.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
checkpatch.pl gives lots of warnings that we don't want - suggested
ignore list:
ASSIGN_IN_IF
UNSPECIFIED_INT - bcachefs coding style prefers single token type names
NEW_TYPEDEFS - typedefs are occasionally good
FUNCTION_ARGUMENTS - we prefer to look at functions in .c files
(hopefully with docbook documentation), not .h
file prototypes
MULTISTATEMENT_MACRO_USE_DO_WHILE
- we have _many_ x-macros and other macros where
we can't do this
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We need counters to be initialized before initializing shrinkers - the
shrinker callbacks will update those counters. This fixes a segfault in
userspace.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Continuing the saga of introducing private dedicated error codes for
each error path, this patch converts ENOSPC to error codes that are
subtypes of ENOSPC. We've recently had a test failure where we got
-ENOSPC where we shouldn't have, and didn't have enough information to
tell where it came from, so this patch will solve that problem.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Device labels are represented as pointers in the member info section: we
need to get and then set the label for it to be kept correctly.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Like bch2_do_discards(), we should check if this needs to be done when
going rw.
Also, add some sysfs code for debugging bucket invalidation.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
This converts bcachefs to the modern printbuf interface/implementation,
synced with the version to be submitted upstream.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This adds a new superblock field for persisting counters
and adds a sysfs interface in counters/ exposing these counters.
The superblock field is ignored by older versions letting us avoid
an on disk version bump.
Each sysfs file outputs a counter that tracks since filesystem
creation and a counter for the current mount session.
Signed-off-by: Daniel Hill <daniel@gluo.nz>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We're seeing occasional firings of the assertion in the key cache
shutdown code that nr_dirty == 0, which means we must sometimes be doing
transaction commits after we've gone read only.
Cleanups & changes:
- BCH_FS_ALLOC_CLEAN renamed to BCH_FS_CLEAN_SHUTDOWN
- new helper bch2_btree_interior_updates_flush(), which returns true if
it had to wait
- bch2_btree_flush_writes() now also returns true if there were btree
writes in flight
- __bch2_fs_read_only now checks if btree writes were in flight in the
shutdown loop: btree write completion does a transaction update, to
update the pointer in the parent node
- assert that !BCH_FS_CLEAN_SHUTDOWN in __bch2_trans_commit
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
- We weren't clearing the LRU btree
- bch2_alloc_read() runs before bch2_check_alloc_key() deletes alloc
keys for devices/buckets that don't exists, so it needs to check for
that
- bch2_check_lrus() needs to check that buckets exists
- improve some error messages
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
We need to ensure that work structs in bch_fs always get initialized -
otherwise an error in filesystem initialization can pop a warning in the
workqueue code when we try to cancel a work struct that wasn't
initialized.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Previously, the journal read path used a linked list for storing the
journal entries we read from disk. But there's been a bug that's been
causing journal_flush_delay to incorrectly be set to 0, leading to far
more journal entries than is normal being written out, which then means
filesystems are no longer able to start due to the O(n^2) behaviour of
inserting into/searching that linked list.
Fix this by switching to a radix tree.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Previously, we were missing accounting for buckets in need_gc_gens and
need_discard states. This matters because buckets in those states need
other btree operations done before they can be used, so they can't be
conuted when checking current number of free buckets against the
allocation watermark.
Also, we weren't directly counting free buckets at all. Now, data type 0
== BCH_DATA_free, and free buckets are counted; this means we can get
rid of the separate (poorly defined) count of unavailable buckets.
This is a new on disk format version, with upgrade and fsck required for
the accounting changes.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
- Move checks for whether the device & bucket are valid from the
.key_invalid method to bch2_check_alloc_key(). This is because
.key_invalid() is called on keys that may no longer exist (post
journal replay), which is a problem when removing/resizing devices.
- We weren't checking the need_discard btree to ensure that every set
bucket has a corresponding alloc key. This refactors the code for
checking the freespace btree, so that it now checks both.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
In the old allocator code, buckets would be discarded just prior to
being used - this made sense in bcache where we were discarding buckets
just after invalidating the cached data they contain, but in a
filesystem where we typically have more free space we want to be
discarding buckets when they become empty.
This patch implements the new behaviour - it checks the need_discard
btree for buckets awaiting discards, and then clears the appropriate
bit in the alloc btree, which moves the buckets to the freespace btree.
Additionally, discards are now enabled by default.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Now that we have new persistent data structures for the allocator, this
patch converts the allocator to use them.
Now, foreground bucket allocation uses the freespace btree to find
buckets to allocate, instead of popping buckets off the freelist.
The background allocator threads are no longer needed and are deleted,
as well as the allocator freelists. Now we only need background tasks
for invalidating buckets containing cached data (when we are low on
empty buckets), and for issuing discards.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This adds two new btrees for the upcoming allocator rewrite: an extents
btree of free buckets, and a btree for buckets awaiting discards.
We also add a new trigger for alloc keys to keep the new btrees up to
date, and a compatibility path to initialize them on existing
filesystems.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
In the write path, after the write to the block device(s) complete we
have to punt to process context to do the btree update.
Instead of using the work item embedded in op->cl, this patch switches
to a per write-point work item. This helps with two different issues:
- lock contention: btree updates to the same writepoint will (usually)
be updating the same alloc keys
- context switch overhead: when we're bottlenecked on btree updates,
having a thread (running out of a work item) checking the write point
for completed ops is cheaper than queueing up a new work item and
waking up a kworker.
In an arbitrary benchmark, 4k random writes with fio running inside a
VM, this patch resulted in a 10% improvement in total iops.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Now we've got strings for metadata versions - this changes
bch2_sb_to_text() and our mount log message to use it.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
