bcache: FUA fixes

Journal writes need to be marked FUA, not just REQ_FLUSH. And btree node
writes have... weird ordering requirements.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
This commit is contained in:
Kent Overstreet 2013-06-26 17:25:38 -07:00 committed by Kent Overstreet
parent cecd628d9a
commit e49c7c374e
3 changed files with 35 additions and 5 deletions

View file

@ -328,10 +328,25 @@ static void do_btree_node_write(struct btree *b)
b->bio->bi_end_io = btree_node_write_endio;
b->bio->bi_private = &b->io.cl;
b->bio->bi_rw = REQ_META|WRITE_SYNC;
b->bio->bi_size = set_blocks(i, b->c) * block_bytes(b->c);
b->bio->bi_rw = REQ_META|WRITE_SYNC|REQ_FUA;
b->bio->bi_size = set_blocks(i, b->c) * block_bytes(b->c);
bch_bio_map(b->bio, i);
/*
* If we're appending to a leaf node, we don't technically need FUA -
* this write just needs to be persisted before the next journal write,
* which will be marked FLUSH|FUA.
*
* Similarly if we're writing a new btree root - the pointer is going to
* be in the next journal entry.
*
* But if we're writing a new btree node (that isn't a root) or
* appending to a non leaf btree node, we need either FUA or a flush
* when we write the parent with the new pointer. FUA is cheaper than a
* flush, and writes appending to leaf nodes aren't blocking anything so
* just make all btree node writes FUA to keep things sane.
*/
bkey_copy(&k.key, &b->key);
SET_PTR_OFFSET(&k.key, 0, PTR_OFFSET(&k.key, 0) + bset_offset(b, i));
@ -2092,6 +2107,9 @@ int bch_btree_insert(struct btree_op *op, struct cache_set *c)
void bch_btree_set_root(struct btree *b)
{
unsigned i;
struct closure cl;
closure_init_stack(&cl);
trace_bcache_btree_set_root(b);
@ -2107,7 +2125,8 @@ void bch_btree_set_root(struct btree *b)
b->c->root = b;
__bkey_put(b->c, &b->key);
bch_journal_meta(b->c, NULL);
bch_journal_meta(b->c, &cl);
closure_sync(&cl);
}
/* Cache lookup */

View file

@ -620,7 +620,7 @@ static void journal_write_unlocked(struct closure *cl)
bio_reset(bio);
bio->bi_sector = PTR_OFFSET(k, i);
bio->bi_bdev = ca->bdev;
bio->bi_rw = REQ_WRITE|REQ_SYNC|REQ_META|REQ_FLUSH;
bio->bi_rw = REQ_WRITE|REQ_SYNC|REQ_META|REQ_FLUSH|REQ_FUA;
bio->bi_size = sectors << 9;
bio->bi_end_io = journal_write_endio;

View file

@ -1035,8 +1035,19 @@ static void request_write(struct cached_dev *dc, struct search *s)
closure_bio_submit(bio, cl, s->d);
} else {
s->op.cache_bio = bio;
bch_writeback_add(dc);
if (s->op.flush_journal) {
/* Also need to send a flush to the backing device */
s->op.cache_bio = bio_clone_bioset(bio, GFP_NOIO,
dc->disk.bio_split);
bio->bi_size = 0;
bio->bi_vcnt = 0;
closure_bio_submit(bio, cl, s->d);
} else {
s->op.cache_bio = bio;
}
}
out:
closure_call(&s->op.cl, bch_insert_data, NULL, cl);