diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index 4519a7c0098c..713a96237a80 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #include #include @@ -60,7 +61,7 @@ struct dm_crypt_io { int error; sector_t sector; - struct list_head list; + struct rb_node rb_node; } CRYPTO_MINALIGN_ATTR; struct dm_crypt_request { @@ -134,7 +135,7 @@ struct crypt_config { struct task_struct *write_thread; wait_queue_head_t write_thread_wait; - struct list_head write_thread_list; + struct rb_root write_tree; char *cipher; char *cipher_string; @@ -1169,11 +1170,15 @@ static void kcryptd_io_write(struct dm_crypt_io *io) generic_make_request(clone); } +#define crypt_io_from_node(node) rb_entry((node), struct dm_crypt_io, rb_node) + static int dmcrypt_write(void *data) { struct crypt_config *cc = data; + struct dm_crypt_io *io; + while (1) { - struct list_head local_list; + struct rb_root write_tree; struct blk_plug plug; DECLARE_WAITQUEUE(wait, current); @@ -1181,7 +1186,7 @@ static int dmcrypt_write(void *data) spin_lock_irq(&cc->write_thread_wait.lock); continue_locked: - if (!list_empty(&cc->write_thread_list)) + if (!RB_EMPTY_ROOT(&cc->write_tree)) goto pop_from_list; __set_current_state(TASK_INTERRUPTIBLE); @@ -1203,20 +1208,22 @@ continue_locked: goto continue_locked; pop_from_list: - local_list = cc->write_thread_list; - local_list.next->prev = &local_list; - local_list.prev->next = &local_list; - INIT_LIST_HEAD(&cc->write_thread_list); - + write_tree = cc->write_tree; + cc->write_tree = RB_ROOT; spin_unlock_irq(&cc->write_thread_wait.lock); + BUG_ON(rb_parent(write_tree.rb_node)); + + /* + * Note: we cannot walk the tree here with rb_next because + * the structures may be freed when kcryptd_io_write is called. + */ blk_start_plug(&plug); do { - struct dm_crypt_io *io = container_of(local_list.next, - struct dm_crypt_io, list); - list_del(&io->list); + io = crypt_io_from_node(rb_first(&write_tree)); + rb_erase(&io->rb_node, &write_tree); kcryptd_io_write(io); - } while (!list_empty(&local_list)); + } while (!RB_EMPTY_ROOT(&write_tree)); blk_finish_plug(&plug); } return 0; @@ -1227,6 +1234,8 @@ static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async) struct bio *clone = io->ctx.bio_out; struct crypt_config *cc = io->cc; unsigned long flags; + sector_t sector; + struct rb_node **rbp, *parent; if (unlikely(io->error < 0)) { crypt_free_buffer_pages(cc, clone); @@ -1246,7 +1255,19 @@ static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async) } spin_lock_irqsave(&cc->write_thread_wait.lock, flags); - list_add_tail(&io->list, &cc->write_thread_list); + rbp = &cc->write_tree.rb_node; + parent = NULL; + sector = io->sector; + while (*rbp) { + parent = *rbp; + if (sector < crypt_io_from_node(parent)->sector) + rbp = &(*rbp)->rb_left; + else + rbp = &(*rbp)->rb_right; + } + rb_link_node(&io->rb_node, parent, rbp); + rb_insert_color(&io->rb_node, &cc->write_tree); + wake_up_locked(&cc->write_thread_wait); spin_unlock_irqrestore(&cc->write_thread_wait.lock, flags); } @@ -1836,7 +1857,7 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) } init_waitqueue_head(&cc->write_thread_wait); - INIT_LIST_HEAD(&cc->write_thread_list); + cc->write_tree = RB_ROOT; cc->write_thread = kthread_create(dmcrypt_write, cc, "dmcrypt_write"); if (IS_ERR(cc->write_thread)) {