From bddd87c7e622ea681c665049027ed84cdcafcb09 Mon Sep 17 00:00:00 2001 From: Akinobu Mita Date: Tue, 23 Feb 2010 08:55:42 +0100 Subject: [PATCH] blk-core: use BIO list management functions Now that the bio list management stuff is generic, convert generic_make_request to use bio lists instead of its own private bio list implementation. Signed-off-by: Akinobu Mita Cc: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-core.c | 31 ++++++++++++++----------------- include/linux/sched.h | 4 ++-- 2 files changed, 16 insertions(+), 19 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 718897e6d37f..44b6d691728d 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1490,9 +1490,9 @@ end_io: /* * We only want one ->make_request_fn to be active at a time, * else stack usage with stacked devices could be a problem. - * So use current->bio_{list,tail} to keep a list of requests + * So use current->bio_list to keep a list of requests * submited by a make_request_fn function. - * current->bio_tail is also used as a flag to say if + * current->bio_list is also used as a flag to say if * generic_make_request is currently active in this task or not. * If it is NULL, then no make_request is active. If it is non-NULL, * then a make_request is active, and new requests should be added @@ -1500,11 +1500,11 @@ end_io: */ void generic_make_request(struct bio *bio) { - if (current->bio_tail) { + struct bio_list bio_list_on_stack; + + if (current->bio_list) { /* make_request is active */ - *(current->bio_tail) = bio; - bio->bi_next = NULL; - current->bio_tail = &bio->bi_next; + bio_list_add(current->bio_list, bio); return; } /* following loop may be a bit non-obvious, and so deserves some @@ -1512,30 +1512,27 @@ void generic_make_request(struct bio *bio) * Before entering the loop, bio->bi_next is NULL (as all callers * ensure that) so we have a list with a single bio. * We pretend that we have just taken it off a longer list, so - * we assign bio_list to the next (which is NULL) and bio_tail - * to &bio_list, thus initialising the bio_list of new bios to be + * we assign bio_list to a pointer to the bio_list_on_stack, + * thus initialising the bio_list of new bios to be * added. __generic_make_request may indeed add some more bios * through a recursive call to generic_make_request. If it * did, we find a non-NULL value in bio_list and re-enter the loop * from the top. In this case we really did just take the bio - * of the top of the list (no pretending) and so fixup bio_list and - * bio_tail or bi_next, and call into __generic_make_request again. + * of the top of the list (no pretending) and so remove it from + * bio_list, and call into __generic_make_request again. * * The loop was structured like this to make only one call to * __generic_make_request (which is important as it is large and * inlined) and to keep the structure simple. */ BUG_ON(bio->bi_next); + bio_list_init(&bio_list_on_stack); + current->bio_list = &bio_list_on_stack; do { - current->bio_list = bio->bi_next; - if (bio->bi_next == NULL) - current->bio_tail = ¤t->bio_list; - else - bio->bi_next = NULL; __generic_make_request(bio); - bio = current->bio_list; + bio = bio_list_pop(current->bio_list); } while (bio); - current->bio_tail = NULL; /* deactivate */ + current->bio_list = NULL; /* deactivate */ } EXPORT_SYMBOL(generic_make_request); diff --git a/include/linux/sched.h b/include/linux/sched.h index 78efe7c485ac..7eb82975e1ee 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -97,7 +97,7 @@ struct sched_param { struct exec_domain; struct futex_pi_state; struct robust_list_head; -struct bio; +struct bio_list; struct fs_struct; struct bts_context; struct perf_event_context; @@ -1466,7 +1466,7 @@ struct task_struct { void *journal_info; /* stacked block device info */ - struct bio *bio_list, **bio_tail; + struct bio_list *bio_list; /* VM state */ struct reclaim_state *reclaim_state; -- 2.20.1