This adds a new ioctl for running fsck on a list of devices.
Normally, if we wish to use the kernel's implementation of fsck we'd run
it at mount time with -o fsck. This ioctl lets us run fsck without
mounting, so that userspace bcachefs-tools can transparently switch to
the kernel's implementation of fsck when appropriate - primarily if the
kernel version of bcachefs better matches the filesystem on disk.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Add a new helper for running online recovery passes - i.e. online fsck.
This is a subset of our normal recovery passes, and does not - for now -
use or follow c->curr_recovery_pass.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Online fsck is coming, and many of our recovery/fsck passes are already
safe to run while the filesystem is in use - mark which ones.
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>
Abstract out a new helper from the data job code, for connecting a
kthread to a file descriptor.
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>
single_device.merge_torture_flakey is, very rarely, finding a btree node
that doesn't match the key that points to it: this patch improves the
error message to print out more fields from the btree node header, so
that we can see what else does or does not match the key.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
When investigating transient failures of generic/441 on bcachefs, it
was determined that the cause of the failure was a combination of
unconditional emergency shutdown and racing between background
journal activity and the test switchover from a working device
mapper table to an error injecting table.
Part of the reason for this sequence of events is that bcachefs
aggressively flushes as much as possible during fsync(), regardless
of errors. While this is reasonable behavior, it is technically
unnecessary because once an error is returned from fsync(), the
caller cannot make any assumptions about the resilience of data.
Tweak the bch2_fsync() logic to return an error on failure of any of
the steps involved in the flush. Note that this change alone does
not prevent generic/441 failure, but in combination with a test
tweak to avoid racing during the dm-error table switchover it avoids
the unnecessary shutdowns and allows the test to pass reliably on
bcachefs.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Remove obsolete comment about zstd, since approach changed during
development of commit bbc3a46065
Signed-off-by: Richard Davies <richard@arachsys.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
bcachefs grabs s_umount and sets SB_RDONLY when the fs is shutdown
via the ioctl() interface. This has a couple issues related to
interactions between shutdown and freeze:
1. The flags == FSOP_GOING_FLAGS_DEFAULT case is a deadlock vector
because freeze_bdev() calls into freeze_super(), which also
acquires s_umount.
2. If an explicit shutdown occurs while the sb is frozen, SB_RDONLY
alters the thaw path as if the sb was read-only at freeze time.
This effectively leaks the frozen state and leaves the sb frozen
indefinitely.
The usage of SB_RDONLY here goes back to the initial bcachefs commit
and AFAICT is simply historical behavior. This behavior is unique to
bcachefs relative to the handful of other filesystems that support
the shutdown ioctl(). Typically, SB_RDONLY is reserved for the
proper remount path, which itself is restricted from modifying
frozen superblocks in reconfigure_super(). Drop the unnecessary sb
lock and flags update bch2_ioc_goingdown() to address both of these
issues.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
backpointers fsck now always runs in rw mode - the btree is being
modified while it runs, by e.g. copygc, rebalance, the discard worker,
the invalidate worker.
We could find a missing backpointer, flush the btree write buffer, and
then on the next iteration find a new key at the exact same position -
which will most likely need another write buffer flush.
Hence, we have to check for an exact match on last_flushed, not just the
pos.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Co-developed-by: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Daniel Hill <daniel@gluo.nz>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Fake flexible arrays (zero-length and one-element arrays) are
deprecated, and should be replaced by flexible-array members.
So, replace zero-length arrays with flexible-array members
in multiple structures.
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
In the CI, we're seeing tests failing due to excessive would_deadlock
transaction restarts - the tracepoint now includes the lock cycle that
occured.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Minor refactoring - improved naming, and move the responsibility for
flush_lock to the caller instead of having it be shared.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
__bch2_btree_write_buffer_flush() now assumes a write ref is already
held (as called by the transaction commit path); and the wrappers
bch2_write_buffer_flush() and flush_sync() take an explicit write ref.
This means internally the write buffer code can always use
BTREE_INSERT_NOCHECK_RW, instead of in the previous code passing flags
around and hoping the NOCHECK_RW flag was always carried around
correctly.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
- add a tracepoint for write_buffer_flush_sync; this is expensive
- fix the write_buffer_flush_slowpath tracepoint
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 code was somewhat convoluted - because originally bch2_lru_set()
could modify the LRU index if there was a collision.
That's no longer the case, so the "create LRU entry" path has no reason
to update the alloc key, so we can separate the handling of the two fsck
errors.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Add a tracepoint for rebalance, printing out
- the target option
- the compression option
- the key being rebalanced
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Break it out by compression type, and include average extent size.
Also, format into a nice table.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This counter is redundant; it's simply the sum of BCH_DATA_stripe and
BCH_DATA_parity buckets.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This introduces bch2_bucket_sectors() and bch2_bucket_sectors_dirty(),
prep work for separately accounting stripe sectors.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
BCH_IOCTL_DEV_USAGE mistakenly put the per-data-type array in struct
bch_ioctl_dev_usage; since ioctl numbers encode the size of the arg,
that means adding new data types breaks the ioctl.
This adds a new version that includes the number of data types as a
parameter: the old version is fixed at 10 so as to not break when adding
new types.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
osq lock maintainers don't want it to be used outside of kernel/locking/
- but, we can do better.
Since we have lock handoff signalled via waitlist entries, there's no
reason for optimistic spinning to have to look at the lock at all -
aside from checking lock-owner; we can just spin looking at our waitlist
entry.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
bcachefs's six locks need kvm_guest, via
ower_on_cpu() -> vcpu_is_preempted() -> is_kvm_guest()
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Cc: linuxppc-dev@lists.ozlabs.org
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
