This helped with discovering some filesystem corruption fsck has having
trouble with: the str_hash type had gotten flipped on one snapshot's
version of an inode.
All versions of a given inode number have the same hash seed and hash
type, since lookups will be done with a single hash/seed and type and
see dirents/xattrs from multiple snapshots.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This adds mount options for specifying recovery passes to run, or
exclude; the immediate need for this is that backpointers fsck is having
trouble completing, so we need a way to skip it.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Limit these messages to once every 2 minutes to avoid spamming logs;
with multiple devices the output can be quite significant.
Also, up the default timeout to 30 seconds from 10 seconds.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
fsck passes read_only as a mount option, and it's required for
nochanges, which it also uses.
Usually read_only is handled by the VFS, but we need to be able to
handle it too; we just don't want to print it out twice, so mark it as a
hidden option.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This updates bcachefs to use the new mount API:
- Update the file_system_type to use the new init_fs_context()
function.
- Define the new fs_context_operations functions.
- No longer register bch2_mount() and bch2_remount(); these are now
called via the new fs_context functions.
- Define a new helper type, bch2_opts_parse that includes a struct
bch_opts and additionally a printbuf used to save options that can't
be parsed until after the FS is opened. This enables us to parse as
many options as possible prior to opening the filesystem while saving
those options that need the open FS for later parsing.
Signed-off-by: Thomas Bertschinger <tahbertschinger@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Mount options that take the name of a device that may be part of a
filesystem, for example "metadata_target", cannot be validated until
after the filesystem has been opened. However, an attempt to parse those
options may be made prior to the filesystem being opened.
This change adds a printbuf parameter to bch2_parse_mount_opts() which
will be used to save those mount options, when they are supplied prior
to the FS being opened, so that they can be parsed later.
This functionality is not currently needed, but will be used after
bcachefs starts using the new mount API to parse mount options. This is
because using the new mount API, we will process mount options prior to
opening the FS, but the new API doesn't provide a convenient way to
"replay" mount option parsing. So we save these options ourselves to
accomplish this.
This change also splits out the code to parse a single option into
bch2_parse_one_mount_opt(), which will be useful when using the new
mount API which deals with a single mount option at a time.
Signed-off-by: Thomas Bertschinger <tahbertschinger@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
When "read_only" is exposed as a mount option, it is redundant with the
standard option "ro" and gives users multiple ways to specify that a
bcachefs filesystem should be mounted read-only. This presents the risk
of having inconsistent options specified.
This can be seen when remounting a read-only filesystem in read-write
mode, using mount(8) from util-linux. Because mount(8) parses the
existing mount options from `/proc/mounts` and applies them when
remounting, it can end up applying both "read_only" and "rw":
$ mount img -o ro /mnt
$ strace mount -o remount,rw /mnt
...
fsconfig(4, FSCONFIG_SET_FLAG, "read_only", NULL, 0) = 0
fsconfig(4, FSCONFIG_SET_FLAG, "rw", NULL, 0) = 0
...
Making "read_only" no longer a mount option means this edge case cannot
occur.
Fixes: 62719cf33c ("bcachefs: Fix nochanges/read_only interaction")
Signed-off-by: Thomas Bertschinger <tahbertschinger@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
i.e. the start of automatic self healing:
If errors=continue or fix_safe, we now automatically fix simple errors
without user intervention.
New error action option: fix_safe
This replaces the existing errors=ro option, which gets a new slot, i.e.
existing errors=ro users now get errors=fix_safe.
This is currently only enabled for a limited set of errors - initially
just disk accounting; errors we would never not want to fix, and we
don't want to require user intervention (i.e. to make sure a bug report
gets filed).
Errors will still be counted in the superblock, so we (developers) will
still know they've been occuring if a bug report gets filed (as bug
reports typically include the errors superblock section).
Eventually we'll be enabling this for a much wider set of errors, after
we've done thorough error injection testing.
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>
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>
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>
Various phases of fsck involve checking references from one btree to
another: this means doing a sequential scan of one btree, and then
mostly random access into the second.
This is particularly painful for checking extents <-> backpointers; we
can prefetch btree node access on the sequential scan, but not on the
random access portion, and this is particularly painful on spinning
rust, where we'd like to keep the pipeline fairly full of btree node
reads so that the elevator can reduce seeking.
This patch implements prefetching and pinning of the portion of the
btree that we'll be doing random access to. We already calculate how
much of the random access btree will fit in memory so it's a fairly
straightforward change.
This will put more pressure on system memory usage, so we introduce a
new option, fsck_memory_usage_percent, which is the percentage of total
system ram that fsck is allowed to pin.
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>
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>
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>
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>
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>
Since compression options now include compression level, proper
validation is a bit more involved.
This adds bch2_compression_opt_valid(), and plumbs it around
appropriately.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Since we can run with unknown btree IDs, we can't directly index btree
IDs into fixed size arrays.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This allows including a compression level when specifying a compression
type, e.g.
compression=zstd:15
Values from 1 through 15 indicate compression levels, 0 or unspecified
indicates the default.
For LZ4, values 3-15 specify that the HC algorithm should be used.
Note that for compatibility, extents themselves only include the
compression type, not the compression level. This means that specifying
the same compression algorithm but different compression levels for the
compression and background_compression options will have no effect.
XXX: perhaps we could add a warning for this
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Before, it was parsed as a bool but internally it was really an enum:
this lets us pass in all the possible values.
But we special case the option parsing: no supplied value is parsed as
FSCK_FIX_yes, to match the previous behaviour.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
The version_upgrade parameter is now an enum, not a bool, and it's
persistent in the superblock:
- compatible (default): upgrade to the latest compatible version
- incompatible: upgrade to latest incompatible version
- none
Currently all upgrades are incompatible upgrades, but the next release
will introduce major:minor versions.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This adds an option for completely disabling nocow mode, including the
locking in the data move path.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This adds support for nocow mode, where we do writes in-place when
possible. Patch components:
- New boolean filesystem and inode option, nocow: note that when nocow
is enabled, data checksumming and compression are implicitly disabled
- To prevent in-place writes from racing with data moves
(data_update.c) or bucket reuse (i.e. a bucket being reused and
re-allocated while a nocow write is in flight, we have a new locking
mechanism.
Buckets can be locked for either data update or data move, using a
fixed size hash table of two_state_shared locks. We don't have any
chaining, meaning updates and moves to different buckets that hash to
the same lock will wait unnecessarily - we'll want to watch for this
becoming an issue.
- The allocator path also needs to check for in-place writes in flight
to a given bucket before giving it out: thus we add another counter
to bucket_alloc_state so we can track this.
- Fsync now may need to issue cache flushes to block devices instead of
flushing the journal. We add a device bitmask to bch_inode_info,
ei_devs_need_flush, which tracks devices that need to have flushes
issued - note that this will lead to unnecessary flushes when other
codepaths have already issued flushes, we may want to replace this with
a sequence number.
- New nocow write path: look up extents, and if they're writable write
to them - otherwise fall back to the normal COW write path.
XXX: switch to sequence numbers instead of bitmask for devs needing
journal flush
XXX: ei_quota_lock being a mutex means bch2_nocow_write_done() needs to
run in process context - see if we can improve this
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>
This improves io_opts() and makes it a non-inline function - it's big
enough that it probably shouldn't be.
Also, bch_io_opts no longer needs fields for whether options are
defined, so we can slim it down a bit.
We'd like to stop passing around the full bch_io_opts, but that'll be
tricky because of bch2_rebalance_add_key().
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
It turns out the *_defined entries of bch_io_opts are only used in one
place - in the xattr get path - and there we immediately convert to a
bch_opts struct, which also has the *_defined entries.
This patch changes bch2_inode_opts_to_opts() to go directly from
bch_inode_unpacked to bch_opts, which is a minor simplification and will
also let us slim down struct bch_io_opts in another patch.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Sometimes we see IO errors due to O_DIRECT alignment issues - having an
option to use buffered IO will be helpful.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
-o verbose is very useful, and we're starting to use it more for runtime
debug statements - making it possible to enable at runtime is a no
brainer.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
This adds a new option, move_bytes_in_flight, for configuring the amount
of IO in flight by copygc/rebalance - users with many devices in their
filesystem will want to increase this.
In the future we should be smarter about this, but this is an easy
improvement.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Rust FFI lacks support for unnamed structs and unions. The space
saved in bch_option is not enough to be significant.
Signed-off-by: Brett Holman <bholman.devel@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
