The smp_rmb() guarantees that reads from reservations.counter
occur before accessing cur_entry_u64s. It's paired with the
atomic64_try_cmpxchg in journal_entry_open.
Signed-off-by: Alan Huang <mmpgouride@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Convert these to standard error codes, which means we can pass them
outside the journal code, they're easier to pass to tracepoints, etc.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
the discard option is special, because it's both a filesystem and a
device option.
When set at the filesytsem level, it's supposed to propagate to (if set
persistently via sysfs) or override (if non persistently as a mount
option) the devices - that now works correctly.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Other options can normally be set at runtime via sysfs, no reason for
this one not to be as well - it just doesn't support the degraded flags
argument this way, that requires the ioctl.
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>
Previously, device options had their superblock option field listed
separately, which was weird and easy to miss when defining options.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
atomic64_read(&j->seq) - j->seq_write_started == JOURNAL_STATE_BUF_NR is
the condition in journal_entry_open where we return JOURNAL_ERR_max_open,
so journal_cur_seq(j) - seq == JOURNAL_STATE_BUF_NR means that the buf
corresponding to seq has started to write.
Signed-off-by: Alan Huang <mmpgouride@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Rebalance requires a not_extents iterator.
This wasn't hit before because all_snapshots disableds is_extents on
snapshots btrees - but has no effect on the reflink btree.
Reported-by: Maël Kerbiriou <mael.kerbiriou@free.fr>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This was missed - but it needs to be correct for the superblock recovery
tool that scans the start and end of the device for backup superblocks:
we don't want to pick up superblocks that belong to a different
partition that starts at a different offset.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Minor refactoring, so that bch2_sb_validate() can be used in the new
userspace superblock recovery tool.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
If we can't mount because of an incompatibility, print what's supported
and unsupported - to help solve PEBKAC issues.
Reported-by: Roland Vet <vet.roland@protonmail.com>
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>
This fixes another "rebalance spinning and doing no work" issue;
rebalance was reading extents it wanted to move, but then failing in
bch2_write() -> bch2_alloc_sectors_start() due to being unable to
allocate sufficient replicas.
This was triggered by a user playing with the durability settings, the
foreground device was an NVME device with durability=2, and originally
he'd set the background device to durability=2 as well, but changed it
back to 1 (the default) after seeing IO errors.
That meant that with replicas=2, we want to move data off the NVME
device which satisfies that constraint, but with a single durability=1
device on the background target there's no way to move the extent to
that target while satisfiying the "required replicas" constraint.
The solution for now is for bch2_data_update_init() to check for this,
and return an error - before kicking off the read.
bch2_data_update_init() already had two different checks for "will we be
able to write this extent", with partially duplicated code, so this
patch combines and improves that logic.
Additionally, we now always bail out and return an error if there's
insufficient space on the destination target. Previously, we only did
this for BCH_WRITE_alloc_nowait moves, because it might be the case that
copygc just needs to free up space on the destination target.
But we really shouldn't kick off a move if the destination is full, we
can't currently distinguish between "really full" and "just need to wait
for copygc", and if we are going to wait on copygc it'd be better to do
that before kicking off the move.
This will additionally fix "rebalance spinning" issues caused by a
filesystem that has more data than can fit in background_target - which
is a valid scenario, since we don't exclude foreground/cache devices
when calculating filesystem capacity.
Reported-by: Maël Kerbiriou <mael.kerbiriou@free.fr>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Next patch will be checking if the extent we're reading from matches the
IO failure we saw before marking the failure.
For this to work, __bch2_read() needs to take the same transaction
context that bch2_rbio_retry() uses to do that check.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Read flags are codepath dependent and change as they're passed around,
while the fields in rbio._state are mostly fixed properties of that
particular object.
Losing track of BCH_READ_data_update would be bad, and previously it was
not obvious if it was always correctly set in the rbio, so this is a
safety cleanup.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
It's possible for checksum errors to be transient - e.g. flakey
controller or cable, thus we need additional retries (besides retrying
from different replicas) before we can definitely return an error.
This is particularly important for the next patch, which will allow the
data move path to move extents with checksum errors - we don't want to
accidentally introduce bitrot due to a transient error!
- bch2_bkey_pick_read_device() is substantially reworked, and
bch2_dev_io_failures is expanded to record more information about the
type of failure (i.e. number of checksum errors).
It now returns an error code that describes more precisely the reason
for the failure - checksum error, io error, or offline device, instead
of the previous generic "insufficient devices". This is important for
the next patches that add poisoning, as we only want to poison extents
when we've got real checksum errors (or perhaps IO errors?) - not
because a device was offline.
- Add a new option and superblock field for the number of checksum
retries.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Users have been asking for this, and now that errors are returned to the
top level read retry path - we can.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Next patch will be adding an additional retry loop for checksum errors,
so that we can rule out transient errors before marking an extent as
poisoned.
Prerequisite to this is returning errors to bch2_rbio_retry(); this will
also let us add a "successful retry" message.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Now that the read path uses proper error codes, we can get rid of the
weird rbio->hole signalling to the move path that the read didn't
happen.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
When we do a read to a buffer that's mapped into userspace, it's
possible to get a spurious checksum error if userspace was modified the
buffer at the same time.
When we retry those, they have to be bounced before we know definitively
whether we're reading corrupt data.
But the retry path propagates read flags differently, so needs special
handling.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kill the READ_ERR/READ_RETRY/READ_RETRY_AVOID enums, and add standard
error codes that describe precisely which error occured.
This is going to be used for the data move path, to move but poison
extents with checksum errors.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
dm-flakey is busted, and this is simpler anyways - this lets us test the
checksum error retry ptahs
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
These are commonly needed when debugging, and saves from having to ask
users to dig.
Also, rebalance_status now includes pending rebalance work.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We're improving our handling of write errors - we shouldn't write
degraded data just because a write failed once, we should retry it (on
other devices, if possible).
But for this to work, we need to kick devices out when they're only
returning errors - otherwise those retries will loop infinitely.
This adds a configurable timeout - if writes are failing for too long,
we'll set that device read-only.
In the future we should also implement more tracking and another knob
for an "allowed error rate", so that we can kick out drives that are
acting "unhealthy".
Another thing we'll want is a mechanism (likely in userspace) for
bringing a device back in after a transient error - perhaps a cable was
jiggled, or there was a controller reset.
After transient errors we also need a mechanism to walk (from the
journal) recent btree updates that weren't flushed to that device and
treat them as "degraded", since unflushed data may well not have been
written. Out of scope for this patch, but becoming relevant.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Previously, we woudn't try to read at all from a failed device - that
doesn't make much sense, the device may be unhealthy (perhaps taking
longer than it should to service reads), but if it's our only option we
should still try to read from it.
Now, bch2_bkey_pick_read_device() will pick failed devices only if there
are no non-failed replicas to read from.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
The next patch implementing freezing will change bch2_dev_get_ioref() to
sleep if a device is currently frozen.
Add an annotation and fix the journal code accordingly.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This was completely fubar; it's now simplified a bit as well.
Note that for_each_online_member() takes and releases io_refs as it
iterates, so we need to release that if we break.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
