diff options
| -rw-r--r-- | drivers/md/dm-bufio.c | 73 |
1 files changed, 58 insertions, 15 deletions
diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c index 9588b864d311..5227e079a6e3 100644 --- a/drivers/md/dm-bufio.c +++ b/drivers/md/dm-bufio.c @@ -145,6 +145,7 @@ struct dm_buffer { unsigned long state; unsigned long last_accessed; struct dm_bufio_client *c; + struct list_head write_list; struct bio bio; struct bio_vec bio_vec[DM_BUFIO_INLINE_VECS]; }; @@ -630,7 +631,8 @@ static int do_io_schedule(void *word) * - Submit our write and don't wait on it. We set B_WRITING indicating * that there is a write in progress. */ -static void __write_dirty_buffer(struct dm_buffer *b) +static void __write_dirty_buffer(struct dm_buffer *b, + struct list_head *write_list) { if (!test_bit(B_DIRTY, &b->state)) return; @@ -639,7 +641,24 @@ static void __write_dirty_buffer(struct dm_buffer *b) wait_on_bit_lock(&b->state, B_WRITING, do_io_schedule, TASK_UNINTERRUPTIBLE); - submit_io(b, WRITE, b->block, write_endio); + if (!write_list) + submit_io(b, WRITE, b->block, write_endio); + else + list_add_tail(&b->write_list, write_list); +} + +static void __flush_write_list(struct list_head *write_list) +{ + struct blk_plug plug; + blk_start_plug(&plug); + while (!list_empty(write_list)) { + struct dm_buffer *b = + list_entry(write_list->next, struct dm_buffer, write_list); + list_del(&b->write_list); + submit_io(b, WRITE, b->block, write_endio); + dm_bufio_cond_resched(); + } + blk_finish_plug(&plug); } /* @@ -655,7 +674,7 @@ static void __make_buffer_clean(struct dm_buffer *b) return; wait_on_bit(&b->state, B_READING, do_io_schedule, TASK_UNINTERRUPTIBLE); - __write_dirty_buffer(b); + __write_dirty_buffer(b, NULL); wait_on_bit(&b->state, B_WRITING, do_io_schedule, TASK_UNINTERRUPTIBLE); } @@ -802,7 +821,8 @@ static void __free_buffer_wake(struct dm_buffer *b) wake_up(&c->free_buffer_wait); } -static void __write_dirty_buffers_async(struct dm_bufio_client *c, int no_wait) +static void __write_dirty_buffers_async(struct dm_bufio_client *c, int no_wait, + struct list_head *write_list) { struct dm_buffer *b, *tmp; @@ -818,7 +838,7 @@ static void __write_dirty_buffers_async(struct dm_bufio_client *c, int no_wait) if (no_wait && test_bit(B_WRITING, &b->state)) return; - __write_dirty_buffer(b); + __write_dirty_buffer(b, write_list); dm_bufio_cond_resched(); } } @@ -853,7 +873,8 @@ static void __get_memory_limit(struct dm_bufio_client *c, * If we are over threshold_buffers, start freeing buffers. * If we're over "limit_buffers", block until we get under the limit. */ -static void __check_watermark(struct dm_bufio_client *c) +static void __check_watermark(struct dm_bufio_client *c, + struct list_head *write_list) { unsigned long threshold_buffers, limit_buffers; @@ -872,7 +893,7 @@ static void __check_watermark(struct dm_bufio_client *c) } if (c->n_buffers[LIST_DIRTY] > threshold_buffers) - __write_dirty_buffers_async(c, 1); + __write_dirty_buffers_async(c, 1, write_list); } /* @@ -897,7 +918,8 @@ static struct dm_buffer *__find(struct dm_bufio_client *c, sector_t block) *--------------------------------------------------------------*/ static struct dm_buffer *__bufio_new(struct dm_bufio_client *c, sector_t block, - enum new_flag nf, int *need_submit) + enum new_flag nf, int *need_submit, + struct list_head *write_list) { struct dm_buffer *b, *new_b = NULL; @@ -924,7 +946,7 @@ static struct dm_buffer *__bufio_new(struct dm_bufio_client *c, sector_t block, goto found_buffer; } - __check_watermark(c); + __check_watermark(c, write_list); b = new_b; b->hold_count = 1; @@ -992,10 +1014,14 @@ static void *new_read(struct dm_bufio_client *c, sector_t block, int need_submit; struct dm_buffer *b; + LIST_HEAD(write_list); + dm_bufio_lock(c); - b = __bufio_new(c, block, nf, &need_submit); + b = __bufio_new(c, block, nf, &need_submit, &write_list); dm_bufio_unlock(c); + __flush_write_list(&write_list); + if (!b) return b; @@ -1047,6 +1073,8 @@ void dm_bufio_prefetch(struct dm_bufio_client *c, { struct blk_plug plug; + LIST_HEAD(write_list); + BUG_ON(dm_bufio_in_request()); blk_start_plug(&plug); @@ -1055,7 +1083,15 @@ void dm_bufio_prefetch(struct dm_bufio_client *c, for (; n_blocks--; block++) { int need_submit; struct dm_buffer *b; - b = __bufio_new(c, block, NF_PREFETCH, &need_submit); + b = __bufio_new(c, block, NF_PREFETCH, &need_submit, + &write_list); + if (unlikely(!list_empty(&write_list))) { + dm_bufio_unlock(c); + blk_finish_plug(&plug); + __flush_write_list(&write_list); + blk_start_plug(&plug); + dm_bufio_lock(c); + } if (unlikely(b != NULL)) { dm_bufio_unlock(c); @@ -1069,7 +1105,6 @@ void dm_bufio_prefetch(struct dm_bufio_client *c, goto flush_plug; dm_bufio_lock(c); } - } dm_bufio_unlock(c); @@ -1126,11 +1161,14 @@ EXPORT_SYMBOL_GPL(dm_bufio_mark_buffer_dirty); void dm_bufio_write_dirty_buffers_async(struct dm_bufio_client *c) { + LIST_HEAD(write_list); + BUG_ON(dm_bufio_in_request()); dm_bufio_lock(c); - __write_dirty_buffers_async(c, 0); + __write_dirty_buffers_async(c, 0, &write_list); dm_bufio_unlock(c); + __flush_write_list(&write_list); } EXPORT_SYMBOL_GPL(dm_bufio_write_dirty_buffers_async); @@ -1147,8 +1185,13 @@ int dm_bufio_write_dirty_buffers(struct dm_bufio_client *c) unsigned long buffers_processed = 0; struct dm_buffer *b, *tmp; + LIST_HEAD(write_list); + + dm_bufio_lock(c); + __write_dirty_buffers_async(c, 0, &write_list); + dm_bufio_unlock(c); + __flush_write_list(&write_list); dm_bufio_lock(c); - __write_dirty_buffers_async(c, 0); again: list_for_each_entry_safe_reverse(b, tmp, &c->lru[LIST_DIRTY], lru_list) { @@ -1274,7 +1317,7 @@ retry: BUG_ON(!b->hold_count); BUG_ON(test_bit(B_READING, &b->state)); - __write_dirty_buffer(b); + __write_dirty_buffer(b, NULL); if (b->hold_count == 1) { wait_on_bit(&b->state, B_WRITING, do_io_schedule, TASK_UNINTERRUPTIBLE); 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