diff options
author | Kent Overstreet <kent.overstreet@gmail.com> | 2015-11-30 02:47:01 (GMT) |
---|---|---|
committer | Jens Axboe <axboe@fb.com> | 2015-12-31 03:23:16 (GMT) |
commit | 627ccd20b4ad3ba836472468208e2ac4dfadbf03 (patch) | |
tree | a784e113c005e53ba3d86f27c3f9a0c59bd55de6 /drivers/md/bcache | |
parent | 8d16ce540c94c9d366eb36fc91b7154d92d6397b (diff) | |
download | linux-627ccd20b4ad3ba836472468208e2ac4dfadbf03.tar.xz |
bcache: Change refill_dirty() to always scan entire disk if necessary
Previously, it would only scan the entire disk if it was starting from
the very start of the disk - i.e. if the previous scan got to the end.
This was broken by refill_full_stripes(), which updates last_scanned so
that refill_dirty was never triggering the searched_from_start path.
But if we change refill_dirty() to always scan the entire disk if
necessary, regardless of what last_scanned was, the code gets cleaner
and we fix that bug too.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'drivers/md/bcache')
-rw-r--r-- | drivers/md/bcache/writeback.c | 37 |
1 files changed, 30 insertions, 7 deletions
diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c index b23f88d..b9346cd 100644 --- a/drivers/md/bcache/writeback.c +++ b/drivers/md/bcache/writeback.c @@ -323,6 +323,10 @@ void bcache_dev_sectors_dirty_add(struct cache_set *c, unsigned inode, static bool dirty_pred(struct keybuf *buf, struct bkey *k) { + struct cached_dev *dc = container_of(buf, struct cached_dev, writeback_keys); + + BUG_ON(KEY_INODE(k) != dc->disk.id); + return KEY_DIRTY(k); } @@ -372,11 +376,24 @@ next: } } +/* + * Returns true if we scanned the entire disk + */ static bool refill_dirty(struct cached_dev *dc) { struct keybuf *buf = &dc->writeback_keys; + struct bkey start = KEY(dc->disk.id, 0, 0); struct bkey end = KEY(dc->disk.id, MAX_KEY_OFFSET, 0); - bool searched_from_start = false; + struct bkey start_pos; + + /* + * make sure keybuf pos is inside the range for this disk - at bringup + * we might not be attached yet so this disk's inode nr isn't + * initialized then + */ + if (bkey_cmp(&buf->last_scanned, &start) < 0 || + bkey_cmp(&buf->last_scanned, &end) > 0) + buf->last_scanned = start; if (dc->partial_stripes_expensive) { refill_full_stripes(dc); @@ -384,14 +401,20 @@ static bool refill_dirty(struct cached_dev *dc) return false; } - if (bkey_cmp(&buf->last_scanned, &end) >= 0) { - buf->last_scanned = KEY(dc->disk.id, 0, 0); - searched_from_start = true; - } - + start_pos = buf->last_scanned; bch_refill_keybuf(dc->disk.c, buf, &end, dirty_pred); - return bkey_cmp(&buf->last_scanned, &end) >= 0 && searched_from_start; + if (bkey_cmp(&buf->last_scanned, &end) < 0) + return false; + + /* + * If we get to the end start scanning again from the beginning, and + * only scan up to where we initially started scanning from: + */ + buf->last_scanned = start; + bch_refill_keybuf(dc->disk.c, buf, &start_pos, dirty_pred); + + return bkey_cmp(&buf->last_scanned, &start_pos) >= 0; } static int bch_writeback_thread(void *arg) |