| Message ID | 20190725020500.4317-1-ming.lei@redhat.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | block/scsi/dm-rq: fix leak of request private data in dm-mpath | expand |
On Thu, Jul 25, 2019 at 10:04:58AM +0800, Ming Lei wrote: > Hi, > > When one request is dispatched to LLD via dm-rq, if the result is > BLK_STS_*RESOURCE, dm-rq will free the request. However, LLD may allocate > private data for this request, so this way will cause memory leak. > > Add .cleanup_rq() callback and implement it in SCSI for fixing the issue, > since SCSI is the only driver which allocates private requst data in > .queue_rq() path. > > Another use case of this callback is to free the request and re-submit > bios during cpu hotplug when the hctx is dead, see the following link: > > https://lore.kernel.org/linux-block/f122e8f2-5ede-2d83-9ca0-bc713ce66d01@huawei.com/T/#t > > V4: > - add more commit log on the new .cleanup_rq callback, as suggested > by Mike > > V3: > - run .cleanup_rq() from dm-rq because this issue is dm-rq specific, > and even in future it should be still very unusual to free request > in this way. If we call .cleanup_rq() in generic rq free code(fast > path), cost will be introduced unnecessarily, also we have to > consider related race. > > V2: > - run .cleanup_rq() in blk_mq_free_request(), as suggested by Mike > > > > Ming Lei (2): > blk-mq: add callback of .cleanup_rq > scsi: implement .cleanup_rq callback > > drivers/md/dm-rq.c | 1 + > drivers/scsi/scsi_lib.c | 13 +++++++++++++ > include/linux/blk-mq.h | 13 +++++++++++++ > 3 files changed, 27 insertions(+) > > Cc: Ewan D. Milne <emilne@redhat.com> > Cc: Bart Van Assche <bvanassche@acm.org> > Cc: Hannes Reinecke <hare@suse.com> > Cc: Christoph Hellwig <hch@lst.de> > Cc: Mike Snitzer <snitzer@redhat.com> > Cc: dm-devel@redhat.com > Cc: <stable@vger.kernel.org> > Fixes: 396eaf21ee17 ("blk-mq: improve DM's blk-mq IO merging via blk_insert_cloned_request feedback") Hello Jens & guys, Ping on this fix. Thanks, Ming -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel
On Tue, Jul 30, 2019 at 08:43:59AM +0800, Ming Lei wrote: > On Thu, Jul 25, 2019 at 10:04:58AM +0800, Ming Lei wrote: > > Hi, > > > > When one request is dispatched to LLD via dm-rq, if the result is > > BLK_STS_*RESOURCE, dm-rq will free the request. However, LLD may allocate > > private data for this request, so this way will cause memory leak. > > > > Add .cleanup_rq() callback and implement it in SCSI for fixing the issue, > > since SCSI is the only driver which allocates private requst data in > > .queue_rq() path. > > > > Another use case of this callback is to free the request and re-submit > > bios during cpu hotplug when the hctx is dead, see the following link: > > > > https://lore.kernel.org/linux-block/f122e8f2-5ede-2d83-9ca0-bc713ce66d01@huawei.com/T/#t > > > > V4: > > - add more commit log on the new .cleanup_rq callback, as suggested > > by Mike > > > > V3: > > - run .cleanup_rq() from dm-rq because this issue is dm-rq specific, > > and even in future it should be still very unusual to free request > > in this way. If we call .cleanup_rq() in generic rq free code(fast > > path), cost will be introduced unnecessarily, also we have to > > consider related race. > > > > V2: > > - run .cleanup_rq() in blk_mq_free_request(), as suggested by Mike > > > > > > > > Ming Lei (2): > > blk-mq: add callback of .cleanup_rq > > scsi: implement .cleanup_rq callback > > > > drivers/md/dm-rq.c | 1 + > > drivers/scsi/scsi_lib.c | 13 +++++++++++++ > > include/linux/blk-mq.h | 13 +++++++++++++ > > 3 files changed, 27 insertions(+) > > > > Cc: Ewan D. Milne <emilne@redhat.com> > > Cc: Bart Van Assche <bvanassche@acm.org> > > Cc: Hannes Reinecke <hare@suse.com> > > Cc: Christoph Hellwig <hch@lst.de> > > Cc: Mike Snitzer <snitzer@redhat.com> > > Cc: dm-devel@redhat.com > > Cc: <stable@vger.kernel.org> > > Fixes: 396eaf21ee17 ("blk-mq: improve DM's blk-mq IO merging via blk_insert_cloned_request feedback") > > Hello Jens & guys, > > Ping on this fix. Hi Jens, Could you make the patcheset merged for 5.4? And it has been verified that big memory leak issue can be fixed by this patchset. thanks, Ming -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel
On 7/24/19 7:04 PM, Ming Lei wrote: > Hi, > > When one request is dispatched to LLD via dm-rq, if the result is > BLK_STS_*RESOURCE, dm-rq will free the request. However, LLD may allocate > private data for this request, so this way will cause memory leak. > > Add .cleanup_rq() callback and implement it in SCSI for fixing the issue, > since SCSI is the only driver which allocates private requst data in > .queue_rq() path. > > Another use case of this callback is to free the request and re-submit > bios during cpu hotplug when the hctx is dead, see the following link: > > https://lore.kernel.org/linux-block/f122e8f2-5ede-2d83-9ca0-bc713ce66d01@huawei.com/T/#t Applied for 5.4, thanks.
Hi, When one request is dispatched to LLD via dm-rq, if the result is BLK_STS_*RESOURCE, dm-rq will free the request. However, LLD may allocate private data for this request, so this way will cause memory leak. Add .cleanup_rq() callback and implement it in SCSI for fixing the issue, since SCSI is the only driver which allocates private requst data in .queue_rq() path. Another use case of this callback is to free the request and re-submit bios during cpu hotplug when the hctx is dead, see the following link: https://lore.kernel.org/linux-block/f122e8f2-5ede-2d83-9ca0-bc713ce66d01@huawei.com/T/#t V4: - add more commit log on the new .cleanup_rq callback, as suggested by Mike V3: - run .cleanup_rq() from dm-rq because this issue is dm-rq specific, and even in future it should be still very unusual to free request in this way. If we call .cleanup_rq() in generic rq free code(fast path), cost will be introduced unnecessarily, also we have to consider related race. V2: - run .cleanup_rq() in blk_mq_free_request(), as suggested by Mike Ming Lei (2): blk-mq: add callback of .cleanup_rq scsi: implement .cleanup_rq callback drivers/md/dm-rq.c | 1 + drivers/scsi/scsi_lib.c | 13 +++++++++++++ include/linux/blk-mq.h | 13 +++++++++++++ 3 files changed, 27 insertions(+) Cc: Ewan D. Milne <emilne@redhat.com> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Hannes Reinecke <hare@suse.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Mike Snitzer <snitzer@redhat.com> Cc: dm-devel@redhat.com Cc: <stable@vger.kernel.org> Fixes: 396eaf21ee17 ("blk-mq: improve DM's blk-mq IO merging via blk_insert_cloned_request feedback")