diff options
| author | OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> | 2006-04-18 09:45:18 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@suse.de> | 2006-04-18 09:45:18 +0200 |
| commit | dbecf3ab40b5a6cc4499543778cd9f9682c0abad (patch) | |
| tree | 56dcd8c30835472b54017e1cb5fd852386ee9e49 /block/cfq-iosched.c | |
| parent | [PATCH 1/2] iosched: fix typo and barrier() (diff) | |
| download | linux-dbecf3ab40b5a6cc4499543778cd9f9682c0abad.tar.xz linux-dbecf3ab40b5a6cc4499543778cd9f9682c0abad.zip | |
[PATCH 2/2] cfq: fix cic's rbtree traversal
When queue dies, we set cic->key=NULL as dead mark. So, when we
traverse a rbtree, we must check whether it's still valid key. if it
was invalidated, drop it, then restart the traversal from top.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Jens Axboe <axboe@suse.de>
Diffstat (limited to 'block/cfq-iosched.c')
| -rw-r--r-- | block/cfq-iosched.c | 33 |
1 files changed, 27 insertions, 6 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 01820b1094e9..246feae16c60 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -1472,15 +1472,31 @@ out: return cfqq; } +static void +cfq_drop_dead_cic(struct io_context *ioc, struct cfq_io_context *cic) +{ + read_lock(&cfq_exit_lock); + rb_erase(&cic->rb_node, &ioc->cic_root); + read_unlock(&cfq_exit_lock); + kmem_cache_free(cfq_ioc_pool, cic); + atomic_dec(&ioc_count); +} + static struct cfq_io_context * cfq_cic_rb_lookup(struct cfq_data *cfqd, struct io_context *ioc) { - struct rb_node *n = ioc->cic_root.rb_node; + struct rb_node *n; struct cfq_io_context *cic; void *key = cfqd; +restart: + n = ioc->cic_root.rb_node; while (n) { cic = rb_entry(n, struct cfq_io_context, rb_node); + if (unlikely(!cic->key)) { + cfq_drop_dead_cic(ioc, cic); + goto restart; + } if (key < cic->key) n = n->rb_left; @@ -1497,20 +1513,24 @@ static inline void cfq_cic_link(struct cfq_data *cfqd, struct io_context *ioc, struct cfq_io_context *cic) { - struct rb_node **p = &ioc->cic_root.rb_node; - struct rb_node *parent = NULL; + struct rb_node **p; + struct rb_node *parent; struct cfq_io_context *__cic; - read_lock(&cfq_exit_lock); - cic->ioc = ioc; cic->key = cfqd; ioc->set_ioprio = cfq_ioc_set_ioprio; - +restart: + parent = NULL; + p = &ioc->cic_root.rb_node; while (*p) { parent = *p; __cic = rb_entry(parent, struct cfq_io_context, rb_node); + if (unlikely(!__cic->key)) { + cfq_drop_dead_cic(ioc, cic); + goto restart; + } if (cic->key < __cic->key) p = &(*p)->rb_left; @@ -1520,6 +1540,7 @@ cfq_cic_link(struct cfq_data *cfqd, struct io_context *ioc, BUG(); } + read_lock(&cfq_exit_lock); rb_link_node(&cic->rb_node, parent, p); rb_insert_color(&cic->rb_node, &ioc->cic_root); list_add(&cic->queue_list, &cfqd->cic_list); |