From 6f325a13442d4e4a6c93d06d8e6deff79b6540b1 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 18 Mar 2006 14:58:37 -0500 Subject: [PATCH] fix cfq_get_queue()/ioprio_set(2) races Signed-off-by: Al Viro --- block/cfq-iosched.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 3cd985bece3a..2949920df45d 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -296,6 +296,7 @@ CFQ_CRQ_FNS(is_sync); static struct cfq_queue *cfq_find_cfq_hash(struct cfq_data *, unsigned int, unsigned short); static void cfq_dispatch_insert(request_queue_t *, struct cfq_rq *); static void cfq_put_cfqd(struct cfq_data *cfqd); +static struct cfq_queue *cfq_get_queue(struct cfq_data *cfqd, unsigned int key, struct task_struct *tsk, gfp_t gfp_mask); #define process_sync(tsk) ((tsk)->flags & PF_SYNCWRITE) @@ -1365,8 +1366,13 @@ static inline void changed_ioprio(struct cfq_io_context *cic) spin_lock(cfqd->queue->queue_lock); cfqq = cic->cfqq[ASYNC]; if (cfqq) { - cfq_mark_cfqq_prio_changed(cfqq); - cfq_init_prio_data(cfqq); + struct cfq_queue *new_cfqq; + new_cfqq = cfq_get_queue(cfqd, CFQ_KEY_ASYNC, + cic->ioc->task, GFP_ATOMIC); + if (new_cfqq) { + cic->cfqq[ASYNC] = new_cfqq; + cfq_put_queue(cfqq); + } } cfqq = cic->cfqq[SYNC]; if (cfqq) { @@ -1399,13 +1405,15 @@ static int cfq_ioc_set_ioprio(struct io_context *ioc, unsigned int ioprio) } static struct cfq_queue * -cfq_get_queue(struct cfq_data *cfqd, unsigned int key, unsigned short ioprio, +cfq_get_queue(struct cfq_data *cfqd, unsigned int key, struct task_struct *tsk, gfp_t gfp_mask) { const int hashval = hash_long(key, CFQ_QHASH_SHIFT); struct cfq_queue *cfqq, *new_cfqq = NULL; + unsigned short ioprio; retry: + ioprio = tsk->ioprio; cfqq = __cfq_find_cfq_hash(cfqd, key, ioprio, hashval); if (!cfqq) { @@ -1982,7 +1990,7 @@ cfq_set_request(request_queue_t *q, struct request *rq, struct bio *bio, goto queue_fail; if (!cic->cfqq[is_sync]) { - cfqq = cfq_get_queue(cfqd, key, tsk->ioprio, gfp_mask); + cfqq = cfq_get_queue(cfqd, key, tsk, gfp_mask); if (!cfqq) goto queue_fail; -- cgit v1.2.3-59-g8ed1b