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| author | Eric Dumazet <edumazet@google.com> | 2012-05-31 13:39:05 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2012-05-31 13:39:05 +0200 |
| commit | 3c9c708c9fc967e389f85bc735e4c1f65d67334e (patch) | |
| tree | 946eeefd4599bb1adafd87ad8f46d52382935001 /block | |
| parent | b77874c9699522540e65aa4291e37a7e43533bf3 (diff) | |
| download | lwn-3c9c708c9fc967e389f85bc735e4c1f65d67334e.tar.gz lwn-3c9c708c9fc967e389f85bc735e4c1f65d67334e.zip | |
block: avoid infinite loop in get_task_io_context()
Calling get_task_io_context() on a exiting task which isn't %current can
loop forever. This triggers at boot time on my dev machine.
BUG: soft lockup - CPU#3 stuck for 22s ! [mountall.1603]
Fix this by making create_task_io_context() returns -EBUSY in this case
to break the loop.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-ioc.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/block/blk-ioc.c b/block/blk-ioc.c index 1e2d53b04858..893b8007c657 100644 --- a/block/blk-ioc.c +++ b/block/blk-ioc.c @@ -235,6 +235,7 @@ void ioc_clear_queue(struct request_queue *q) int create_task_io_context(struct task_struct *task, gfp_t gfp_flags, int node) { struct io_context *ioc; + int ret; ioc = kmem_cache_alloc_node(iocontext_cachep, gfp_flags | __GFP_ZERO, node); @@ -262,9 +263,12 @@ int create_task_io_context(struct task_struct *task, gfp_t gfp_flags, int node) task->io_context = ioc; else kmem_cache_free(iocontext_cachep, ioc); + + ret = task->io_context ? 0 : -EBUSY; + task_unlock(task); - return 0; + return ret; } /** |