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| author | NeilBrown <neilb@suse.com> | 2017-03-10 09:00:47 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2017-03-12 01:31:37 +0300 |
| commit | f5fe1b51905df7cfe4fdfd85c5fb7bc5b71a094f (patch) | |
| tree | fbc336ee9d7ca18f8bfd81a8b54e99efd0555241 /block/blk-core.c | |
| parent | 84c37c168c0e49a412d7021cda3183a72adac0d0 (diff) | |
| download | linux-f5fe1b51905df7cfe4fdfd85c5fb7bc5b71a094f.tar.xz | |
blk: Ensure users for current->bio_list can see the full list.
Commit 79bd99596b73 ("blk: improve order of bio handling in generic_make_request()")
changed current->bio_list so that it did not contain *all* of the
queued bios, but only those submitted by the currently running
make_request_fn.
There are two places which walk the list and requeue selected bios,
and others that check if the list is empty. These are no longer
correct.
So redefine current->bio_list to point to an array of two lists, which
contain all queued bios, and adjust various code to test or walk both
lists.
Signed-off-by: NeilBrown <neilb@suse.com>
Fixes: 79bd99596b73 ("blk: improve order of bio handling in generic_make_request()")
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block/blk-core.c')
| -rw-r--r-- | block/blk-core.c | 30 |
1 files changed, 18 insertions, 12 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index 0eeb99ef654f..d772c221cc17 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1973,7 +1973,14 @@ end_io: */ blk_qc_t generic_make_request(struct bio *bio) { - struct bio_list bio_list_on_stack; + /* + * bio_list_on_stack[0] contains bios submitted by the current + * make_request_fn. + * bio_list_on_stack[1] contains bios that were submitted before + * the current make_request_fn, but that haven't been processed + * yet. + */ + struct bio_list bio_list_on_stack[2]; blk_qc_t ret = BLK_QC_T_NONE; if (!generic_make_request_checks(bio)) @@ -1990,7 +1997,7 @@ blk_qc_t generic_make_request(struct bio *bio) * should be added at the tail */ if (current->bio_list) { - bio_list_add(current->bio_list, bio); + bio_list_add(¤t->bio_list[0], bio); goto out; } @@ -2009,18 +2016,17 @@ blk_qc_t generic_make_request(struct bio *bio) * bio_list, and call into ->make_request() again. */ BUG_ON(bio->bi_next); - bio_list_init(&bio_list_on_stack); - current->bio_list = &bio_list_on_stack; + bio_list_init(&bio_list_on_stack[0]); + current->bio_list = bio_list_on_stack; do { struct request_queue *q = bdev_get_queue(bio->bi_bdev); if (likely(blk_queue_enter(q, false) == 0)) { - struct bio_list hold; struct bio_list lower, same; /* Create a fresh bio_list for all subordinate requests */ - hold = bio_list_on_stack; - bio_list_init(&bio_list_on_stack); + bio_list_on_stack[1] = bio_list_on_stack[0]; + bio_list_init(&bio_list_on_stack[0]); ret = q->make_request_fn(q, bio); blk_queue_exit(q); @@ -2030,19 +2036,19 @@ blk_qc_t generic_make_request(struct bio *bio) */ bio_list_init(&lower); bio_list_init(&same); - while ((bio = bio_list_pop(&bio_list_on_stack)) != NULL) + while ((bio = bio_list_pop(&bio_list_on_stack[0])) != NULL) if (q == bdev_get_queue(bio->bi_bdev)) bio_list_add(&same, bio); else bio_list_add(&lower, bio); /* now assemble so we handle the lowest level first */ - bio_list_merge(&bio_list_on_stack, &lower); - bio_list_merge(&bio_list_on_stack, &same); - bio_list_merge(&bio_list_on_stack, &hold); + bio_list_merge(&bio_list_on_stack[0], &lower); + bio_list_merge(&bio_list_on_stack[0], &same); + bio_list_merge(&bio_list_on_stack[0], &bio_list_on_stack[1]); } else { bio_io_error(bio); } - bio = bio_list_pop(current->bio_list); + bio = bio_list_pop(&bio_list_on_stack[0]); } while (bio); current->bio_list = NULL; /* deactivate */ |