search for: atomic_flags

This patch should fix the bug reported in https://lkml.org/lkml/2014/9/11/249. Test is still pending. David Hildenbrand (1): blk-mq: Avoid race condition with uninitialized requests block/blk-mq.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) -- 1.8.5.5

This patch should fix the bug reported in https://lkml.org/lkml/2014/9/11/249. Test is still pending. David Hildenbrand (1): blk-mq: Avoid race condition with uninitialized requests block/blk-mq.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) -- 1.8.5.5

On 09/18/2014 11:04 AM, David Hildenbrand wrote: > This patch should fix the bug reported in https://lkml.org/lkml/2014/9/11/249. > > We have to initialize at least the atomic_flags and the cmd_flags when > allocating storage for the requests. > > Otherwise blk_mq_timeout_check() might dereference uninitialized pointers when > racing with the creation of a request. > > Also move the reset of cmd_flags for the initializing code to the point where a > requ...

On 09/18/2014 11:04 AM, David Hildenbrand wrote: > This patch should fix the bug reported in https://lkml.org/lkml/2014/9/11/249. > > We have to initialize at least the atomic_flags and the cmd_flags when > allocating storage for the requests. > > Otherwise blk_mq_timeout_check() might dereference uninitialized pointers when > racing with the creation of a request. > > Also move the reset of cmd_flags for the initializing code to the point where a > requ...

This patch should fix the bug reported in https://lkml.org/lkml/2014/9/11/249. We have to initialize at least the atomic_flags and the cmd_flags when allocating storage for the requests. Otherwise blk_mq_timeout_check() might dereference uninitialized pointers when racing with the creation of a request. Also move the reset of cmd_flags for the initializing code to the point where a request is freed. So we will never end...

...r enough to check if hw_ctx/tag_sets are > fully initialized if you mean all requests have been used one time. > > On Wed, Sep 17, 2014 at 10:11 PM, David Hildenbrand > > I was playing with a simple patch that just sets cmd_flags and action_flags to > > What is action_flags? atomic_flags, sorry :) Otherwise e.g. REQ_ATOM_STARTED could already be set due to the randomness. I am not sure if this is really necessary, or if it is completely shielded by the tag-handling code, but seemed to be clean for me to do it (and I remember it not being set within blk_mq_rq_ctx_init). > >...

...r enough to check if hw_ctx/tag_sets are > fully initialized if you mean all requests have been used one time. > > On Wed, Sep 17, 2014 at 10:11 PM, David Hildenbrand > > I was playing with a simple patch that just sets cmd_flags and action_flags to > > What is action_flags? atomic_flags, sorry :) Otherwise e.g. REQ_ATOM_STARTED could already be set due to the randomness. I am not sure if this is really necessary, or if it is completely shielded by the tag-handling code, but seemed to be clean for me to do it (and I remember it not being set within blk_mq_rq_ctx_init). > >...

----- Original Message ----- > From: "Ben via llvm-dev Craig" <llvm-dev at lists.llvm.org> > To: llvm-dev at lists.llvm.org > Sent: Thursday, January 28, 2016 9:41:06 AM > Subject: Re: [llvm-dev] Adding sanity to the Atomics implementation > > > I don't have much of substance to add, but I will say that I like the > proposal (I too prefer Alternative

On 2014-09-17 07:52, Ming Lei wrote: > On Wed, 17 Sep 2014 14:00:34 +0200 > David Hildenbrand <dahi at linux.vnet.ibm.com> wrote: > >>>>>> Does anyone have an idea? >>>>>> The request itself is completely filled with cc >>>>> >>>>> That is very weird, the 'rq' is got from hctx->tags, and rq should be

On 2014-09-17 07:52, Ming Lei wrote: > On Wed, 17 Sep 2014 14:00:34 +0200 > David Hildenbrand <dahi at linux.vnet.ibm.com> wrote: > >>>>>> Does anyone have an idea? >>>>>> The request itself is completely filled with cc >>>>> >>>>> That is very weird, the 'rq' is got from hctx->tags, and rq should be

I don't have much of substance to add, but I will say that I like the proposal (I too prefer Alternative A). When adding C11 atomic support for hexagon, I found it surprising that support for the __sync_* was implemented completely differently than the C11 atomics. On 1/27/2016 1:55 PM, James Knight via llvm-dev wrote: > Right now, the atomics implementation in clang is a bit of a

..._add_timer(struct request *req) { - struct request_queue *q = req->q; + struct request_queue *q = req->queue_ctx->queue; unsigned long expiry; if (!q->rq_timed_out_fn) return; BUG_ON(!list_empty(&req->timeout_list)); BUG_ON(test_bit(REQ_ATOM_COMPLETE, &req->atomic_flags)); /* * Some LLDs, like scsi, peek at the timeout to prevent a * command from being retried forever. */ if (!req->timeout) req->timeout = q->rq_timeout; req->deadline = jiffies + req->timeout; - list_add_tail(&req->timeout_list, &q->timeout_list);...

..._add_timer(struct request *req) { - struct request_queue *q = req->q; + struct request_queue *q = req->queue_ctx->queue; unsigned long expiry; if (!q->rq_timed_out_fn) return; BUG_ON(!list_empty(&req->timeout_list)); BUG_ON(test_bit(REQ_ATOM_COMPLETE, &req->atomic_flags)); /* * Some LLDs, like scsi, peek at the timeout to prevent a * command from being retried forever. */ if (!req->timeout) req->timeout = q->rq_timeout; req->deadline = jiffies + req->timeout; - list_add_tail(&req->timeout_list, &q->timeout_list);...