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>
- bch2_extent_merge checks unwritten bit
- read path returns 0s for unwritten extents without actually reading
- reflink path skips over unwritten extents
- bch2_bkey_ptrs_invalid() checks for extents with both written and
unwritten extents, and non-normal extents (stripes, btree ptrs) with
unwritten ptrs
- fiemap checks for unwritten extents and returns
FIEMAP_EXTENT_UNWRITTEN
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Provide inline versions of some allocation functions
- bch2_alloc_sectors_done_inlined()
- bch2_alloc_sectors_append_ptrs_inlined()
and use them in the core IO path.
Also, inline bch2_extent_update_i_size_sectors() and
bch2_bkey_append_ptr().
In the core write path, function call overhead matters - every function
call is a jump to a new location and a potential cache miss.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This patch introduces
- bpos_eq()
- bpos_lt()
- bpos_le()
- bpos_gt()
- bpos_ge()
and equivalent replacements for bkey_cmp().
Looking at the generated assembly these could probably be improved
further, but we already see a significant code size improvement with
this patch.
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 adds a new parameter to .key_invalid() methods for whether the key
is being read or written; the idea being that methods can do more
aggressive checks when a key is newly created and being written, when we
wouldn't want to delete the key because of those checks.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
This replaces the switch statements in bch2_mark_key(),
bch2_trans_mark_key() with new bkey methods - prep work for the next
patch, which fixes BTREE_TRIGGER_WANTS_OLD_AND_NEW.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
When force-removing a device, we were silently dropping extents that we
no longer had pointers for - we should have been switching them to
KEY_TYPE_error, so that reads for data that was lost return errors.
This patch adds the logic for switching a key to KEY_TYPE_error to
bch2_bkey_drop_ptr(), and improves the logic somewhat.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
To implement snapshots, we need every filesystem btree operation (every
btree operation without a subvolume) to start by looking up the
subvolume and getting the current snapshot ID, with
bch2_subvolume_get_snapshot() - then, that snapshot ID is used for doing
btree lookups in BTREE_ITER_FILTER_SNAPSHOTS mode.
This patch adds those bch2_subvolume_get_snapshot() calls, and also
switches to passing around a subvol_inum instead of just an inode
number.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
- We no longer mark subsets of extents, they're marked like regular
keys now - which means we can drop the offset & sectors arguments
to trigger functions
- Drop other arguments that are no longer needed anymore in various
places - fs_usage
- Drop the logic for handling extents in bch2_mark_update() that isn't
needed anymore, to match bch2_trans_mark_update()
- Better logic for hanlding the BTREE_ITER_CACHED_NOFILL case, where we
don't have an old key to mark
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
This patch simplifies the key merging code by getting rid of partial
merges - it's simpler and saner if we just don't merge extents when
they'd overflow k->size.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
bch2_check_fix_ptrs() is awkward, we need to find a way to improve it.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
With snapshots, we're going to need to differentiate between comparisons
that should and shouldn't include the snapshot field. bpos_cmp is now
the comparison function that does include the snapshot field, used by
core btree code.
Upper level filesystem code generally does _not_ want to compare against
the snapshot field - that code wants keys to compare as equal even when
one of them is in an ancestor snapshot.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
It was using the method for btree_ptr_v1, but that wasn't checking all
the fields.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This code used to be used for running some assertions on alloc info at
runtime, but it long predates fsck and hasn't been good for much in
ages - we can delete it now.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
More repair code, now that we can repair extents during initial gc.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Originally, we'd check for -ENOSPC when getting a disk reservation
whenever the new extent took up more space on disk than the old extent.
Erasure coding screwed this up, because with erasure coding writes are
initially replicated, and then in the background the extra replicas are
dropped when the stripe is created. This means that with erasure coding
enabled, writes will always take up more space on disk than the data
they're overwriting - but, according to posix, overwrites aren't
supposed to return ENOSPC.
So, in this patch we fudge things: if the new extent has more replicas
than the _effective_ replicas of the old extent, or if the old extent is
compressed and the new one isn't, we check for ENOSPC when getting the
disk reservation - otherwise, we don't.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
When inline data extents were added, reflink was forgotten about - we
need indirect inline data extents for reflink + inline data to work
correctly.
This patch adds them, and a new feature bit that's flipped when they're
used.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Previously, BTREE_ID_INODES was special - inodes were indexed by the
inode field, which meant the offset field of struct bpos wasn't used,
which led to special cases in e.g. the btree iterator code.
Now, inodes in the inodes btree are indexed by the offset field.
Also: prevously min_key was special for extents btrees, min_key for
extents would equal max_key for the previous node. Now, min_key =
bkey_successor() of the previous node, same as non extent btrees.
This means we can completely get rid of
btree_type_sucessor/predecessor.
Also make some improvements to the metadata IO validate/compat code.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Add a new btree ptr type which contains the sequence number (random 64
bit cookie, actually) for that btree node - this lets us verify that
when we read in a btree node it really is the btree node we wanted.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
bch2_ptr_swab was never updated when the code for generic keys with
pointers was added - it assumed the entire val was only used for
pointers.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This fixes the background_compression option: wihout some way of marking
data as incompressible, rebalance will keep rewriting incompressible
data over and over.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This should be private to btree_update_leaf.c, and we might end up
removing it.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This implements extents that have their data inline, in the value,
instead of the bkey value being pointers to the data - and the read and
write paths are updated to read from these new extent types and write
them out, when the write size is small enough.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This changes bch2_cut_front and bch2_cut_back so that they're able to
shorten the size of the value, and it also changes the extent update
path to update the accounting in the btree node when this happens.
When the size of the value is shortened, they zero out the space that's
no longer used, so it's interpreted as noops (as implemented in the last
patch).
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This make the disk accounting code saner, and it's not clear why we'd
ever want the same data to be in multiple stripes simultaneously.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
.key_debugcheck no longer needs to take a pointer to the btree node
Also, try to make sure wherever we're inserting or modifying keys in the
btree.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This was spotted when the move_extent() path tried to allocate a bio for
a reflink_p extent, but adding pages to the bio failed because we
overflowed bi_max_vecs. Oops.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
With reflink, various code now has to handle both KEY_TYPE_extent
or KEY_TYPE_reflink_v - so, convert it to be generic across all keys
with pointers.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
this lets us get rid of a lot of extra switch statements - in a lot of
places we dispatch on the btree node type, and then the key type, so
this is a nice cleanup across a lot of code.
Also improve the on disk format versioning stuff.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
