Add async objs list for
- promote_op
- bch_read_bio
- btree_read_bio
- btree_write_bio
This gets us introspection on in-flight async ops, and because under the
hood it uses fast_lists (percpu slot buffer on top of a radix tree),
it'll be fast enough to enable in production.
This will be very helpful for debugging "something got stuck" issues,
which have been cropping up from time to time (in the CI, especially
with folio writeback).
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
There's something going on with the data move path; log the original key
being moved for debugging.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Add a new data op to walk all data and metadata in a filesystem,
checking if it can be read successfully, and on error repairing from
another copy if possible.
- New helper: bch2_dev_idx_is_online(), so that we can bail out and
report to userspace when we're unable to scrub because the device is
offline
- data_update_opts, which controls the data move path, now understands
scrub: data is only read, not written. The read path is responsible
for rewriting on read error, as with other reads.
- scrub_pred skips data extents that don't have checksums
- bch_ioctl_data has a new scrub member, which has a data_types field
for data types to check - i.e. all data types, or only metadata.
- Add new entries to bch_move_stats so that we can report numbers for
corrected and uncorrected errors
- Add a new enum to bch_ioctl_data_event for explicitly reporting
completion and return code (i.e. device offline)
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Add a new helper for bch2_moving_ctxt_to_text(), which may be used to
debug if moving_ios are getting stuck.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We had a bug report where the data update path was creating an extent
that failed to validate because it had too many pointers; almost all of
them were cached.
To fix this, we have:
- want_cached_ptr(), a new helper that checks if we even want a cached
pointer (is on appropriate target, device is readable).
- bch2_extent_set_ptr_cached() now only sets a pointer cached if we want
it.
- bch2_extent_normalize_by_opts() now ensures that we only have a single
cached pointer that we want.
While working on this, it was noticed that this doesn't work well with
reflinked data and per-file options. Another patch series is coming that
plumbs through additional io path options through bch_extent_rebalance,
with improved option handling.
Reported-by: Reed Riley <reed@riley.engineer>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Previously, there was a bug where if an extent had greater durability
than required (because we needed to move a durability=1 pointer and
ended up putting it on a durability 2 device), we would submit a write
for replicas=2 - the durability of the pointer being rewritten - instead
of the number of replicas required to bring it back up to the
data_replicas option.
This, plus the allocation path sometimes allocating on a greater
durability device than requested, meant that extents could continue
having more and more replicas added as they were being rewritten.
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>
The recent nocow locking rework introduced a deadlock in the data move
path: the new nocow locking scheme uses a hash table with a fixed size
array for chaining, meaning on hash collision we may have to wait for
other locks to be released before we can lock a bucket.
And since the data move path needs to submit writes from the same thread
that's taking nocow locks and submitting reads, this introduces a
deadlock.
This shouldn't happen often in practice, but since the data move path
can keep large numbers of IOs in flight simultaneously, it's something
we have to handle.
This patch makes move_ctxt_wait_event() available to
bch2_data_update_init() and uses it when appropriate, which is our
normal solution to this kind of thing.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
The data update path requires special support for unwritten extents - we
still need to be able to move them, but there's no need to read or write
anything.
This patch adds a new error code to tell bch2_move_extent() that we're
short circuiting the read, and adds bch2_update_unwritten_extent() to
create a reservation then call __bch2_data_update_index_update().
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Cached pointers are generally dropped, not moved: this led to an
assertion firing in the data update path when there were no new replicas
being written.
This path adds a data_options field for pointers to be dropped, and
tweaks move_extent() to check if we're only dropping pointers, not
writing new ones, before kicking off a data update operation.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This patch significantly cleans up and simplifies the data_update
interface. Instead of only being able to specify a single pointer by
device to rewrite, we're now able to specify any or all of the pointers
in the original extent to be rewrited, as a bitmask.
data_cmd is no more: the various pred functions now just return true if
the extent should be moved/updated. All the data_update path does is
rewrite existing replicas, or add new ones.
This fixes a bug where with background compression on replicated
filesystems, where rebalance -> data_update would incorrectly drop the
wrong old replica, and keep trying to recompress an extent pointer and
each time failing to drop the right replica. Oops.
Now, the data update path doesn't look at the io options to decide which
pointers to keep and which to drop - it only goes off of the
data_update_options passed to it.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
This is the start of reorganizing the data IO paths. The plan is to also
break apart io.c into data_read.c and data_write.c, and migrate_write
will be renamed to the data_update path.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
