Previously, partial overwrites of existing extents were handled
implicitly by the btree code; when reading in a btree node, we'd do a
mergesort of the different bsets and detect and fix partially
overlapping extents during that mergesort.
That approach won't work with snapshots: this changes extents to work
like regular keys as far as the btree code is concerned, where a 0 size
KEY_TYPE_deleted whiteout will completely overwrite an existing extent.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This was causing a bug with transaction iterators overflowing; now, if
triggers have to be reexecuted we always return -EINTR and retry from
the start of the transaction.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
BTREE_INSERT_ATOMIC should really be the default mode, and there's not
that much code that doesn't need it - so this is prep work for getting
rid of the flag.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
It needs to be called when we get -EINTR due to e.g. lock restart - this
fixes a transaction iterators overflow bug.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
More prep work for snapshots: extents will soon be using
KEY_TYPE_deleted for whiteouts, with 0 size. But we wen't be able to
keep these whiteouts with the rest of the extents in the btree node, due
to sorting invariants breaking.
We can deal with this by immediately moving the new whiteouts to the
unwritten whiteouts area - this just means those whiteouts won't be
sorted, so we need new code to sort them prior to merging them with the
rest of the keys to be written.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
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>
The main optimization here is that if we let
bch2_replicas_delta_list_apply() fail, we can completely skip calling
bch2_bkey_replicas_marked_locked().
And assorted other small optimizations.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
The btree_trans struct needs to memoize/cache btree iterators, so that
on transaction restart we don't have to completely redo btree lookups,
and so that we can do them all at once in the correct order when the
transaction had to restart to avoid a deadlock.
This switches the btree iterator lookups to work based on iterator
position, instead of trying to match them up based on the stack trace.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Call bch2_btree_iter_verify from bch2_btree_node_iter_fix(); also verify
in btree_iter_peek_uptodate() that iter->k matches what's in the btree.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Any time we're modifying what's in the btree, iterators potentially have
to be updated - this one was exposed by the reflink code.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Also, move other update path checks to where they actually check all the
updates (after triggers have run)
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Where unlink_on_commit is used, on unsuccessfull commit we're likely
retrying the whole update and were going to be using the same iterators
again.
The management of multiple iterators needs to be gone over a fair bit
more at some point...
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Transactional triggers meant that when we failed to get a journal
reservation, then bailed out into the error path to block on a journal
reservation, the second blocking call into the journal code was asking
for less space, which is not what we want.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This is prep work for the btree key cache: btree iterators will point to
either struct btree, or a new struct bkey_cached.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
