user/sven/linux.git/block, branch v4.14.149

blk-mq: move cancel of requeue_work to the front of blk_exit_queue

2019-10-05T10:47:37Z

[ Upstream commit e26cc08265dda37d2acc8394604f220ef412299d ] blk_exit_queue will free elevator_data, while blk_mq_requeue_work will access it. Move cancel of requeue_work to the front of blk_exit_queue to avoid use-after-free. blk_exit_queue blk_mq_requeue_work __elevator_exit blk_mq_run_hw_queues blk_mq_exit_sched blk_mq_run_hw_queue dd_exit_queue blk_mq_hctx_has_pending kfree(elevator_data) blk_mq_sched_has_work dd_has_work Fixes: fbc2a15e3433 ("blk-mq: move cancel of requeue_work into blk_mq_release") Cc: stable@vger.kernel.org Reviewed-by: Ming Lei Signed-off-by: zhengbin Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block/bio-integrity: fix a memory leak bug

2019-07-31T05:28:55Z

[ Upstream commit e7bf90e5afe3aa1d1282c1635a49e17a32c4ecec ] In bio_integrity_prep(), a kernel buffer is allocated through kmalloc() to hold integrity metadata. Later on, the buffer will be attached to the bio structure through bio_integrity_add_page(), which returns the number of bytes of integrity metadata attached. Due to unexpected situations, bio_integrity_add_page() may return 0. As a result, bio_integrity_prep() needs to be terminated with 'false' returned to indicate this error. However, the allocated kernel buffer is not freed on this execution path, leading to a memory leak. To fix this issue, free the allocated buffer before returning from bio_integrity_prep(). Reviewed-by: Ming Lei Acked-by: Martin K. Petersen Signed-off-by: Wenwen Wang Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block, bfq: NULL out the bic when it's no longer valid

2019-07-21T07:04:30Z

commit dbc3117d4ca9e17819ac73501e914b8422686750 upstream. In reboot tests on several devices we were seeing a "use after free" when slub_debug or KASAN was enabled. The kernel complained about: Unable to handle kernel paging request at virtual address 6b6b6c2b ...which is a classic sign of use after free under slub_debug. The stack crawl in kgdb looked like: 0 test_bit (addr=, nr=) 1 bfq_bfqq_busy (bfqq=) 2 bfq_select_queue (bfqd=) 3 __bfq_dispatch_request (hctx=) 4 bfq_dispatch_request (hctx=) 5 0xc056ef00 in blk_mq_do_dispatch_sched (hctx=0xed249440) 6 0xc056f728 in blk_mq_sched_dispatch_requests (hctx=0xed249440) 7 0xc0568d24 in __blk_mq_run_hw_queue (hctx=0xed249440) 8 0xc0568d94 in blk_mq_run_work_fn (work=) 9 0xc024c5c4 in process_one_work (worker=0xec6d4640, work=0xed249480) 10 0xc024cff4 in worker_thread (__worker=0xec6d4640) Digging in kgdb, it could be found that, though bfqq looked fine, bfqq->bic had been freed. Through further digging, I postulated that perhaps it is illegal to access a "bic" (AKA an "icq") after bfq_exit_icq() had been called because the "bic" can be freed at some point in time after this call is made. I confirmed that there certainly were cases where the exact crashing code path would access the "bic" after bfq_exit_icq() had been called. Sspecifically I set the "bfqq->bic" to (void *)0x7 and saw that the bic was 0x7 at the time of the crash. To understand a bit more about why this crash was fairly uncommon (I saw it only once in a few hundred reboots), you can see that much of the time bfq_exit_icq_fbqq() fully frees the bfqq and thus it can't access the ->bic anymore. The only case it doesn't is if bfq_put_queue() sees a reference still held. However, even in the case when bfqq isn't freed, the crash is still rare. Why? I tracked what happened to the "bic" after the exit routine. It doesn't get freed right away. Rather, put_io_context_active() eventually called put_io_context() which queued up freeing on a workqueue. The freeing then actually happened later than that through call_rcu(). Despite all these delays, some extra debugging showed that all the hoops could be jumped through in time and the memory could be freed causing the original crash. Phew! To make a long story short, assuming it truly is illegal to access an icq after the "exit_icq" callback is finished, this patch is needed. Cc: stable@vger.kernel.org Reviewed-by: Paolo Valente Signed-off-by: Douglas Anderson Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

block: bio_iov_iter_get_pages: pin more pages for multi-segment IOs

2019-07-03T11:15:58Z

[ Upstream commit 17d51b10d7773e4618bcac64648f30f12d4078fb ] bio_iov_iter_get_pages() currently only adds pages for the next non-zero segment from the iov_iter to the bio. That's suboptimal for callers, which typically try to pin as many pages as fit into the bio. This patch converts the current bio_iov_iter_get_pages() into a static helper, and introduces a new helper that allocates as many pages as 1) fit into the bio, 2) are present in the iov_iter, 3) and can be pinned by MM. Error is returned only if zero pages could be pinned. Because of 3), a zero return value doesn't necessarily mean all pages have been pinned. Callers that have to pin every page in the iov_iter must still call this function in a loop (this is currently the case). This change matters most for __blkdev_direct_IO_simple(), which calls bio_iov_iter_get_pages() only once. If it obtains less pages than requested, it returns a "short write" or "short read", and __generic_file_write_iter() falls back to buffered writes, which may lead to data corruption. Fixes: 72ecad22d9f1 ("block: support a full bio worth of IO for simplified bdev direct-io") Reviewed-by: Christoph Hellwig Signed-off-by: Martin Wilck Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block: add a lower-level bio_add_page interface

2019-07-03T11:15:58Z

[ Upstream commit 0aa69fd32a5f766e997ca8ab4723c5a1146efa8b ] For the upcoming removal of buffer heads in XFS we need to keep track of the number of outstanding writeback requests per page. For this we need to know if bio_add_page merged a region with the previous bvec or not. Instead of adding additional arguments this refactors bio_add_page to be implemented using three lower level helpers which users like XFS can use directly if they care about the merge decisions. Signed-off-by: Christoph Hellwig Reviewed-by: Jens Axboe Reviewed-by: Ming Lei Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong Signed-off-by: Sasha Levin

block, bfq: increase idling for weight-raised queues

2019-06-15T09:54:58Z

[ Upstream commit 778c02a236a8728bb992de10ed1f12c0be5b7b0e ] If a sync bfq_queue has a higher weight than some other queue, and remains temporarily empty while in service, then, to preserve the bandwidth share of the queue, it is necessary to plug I/O dispatching until a new request arrives for the queue. In addition, a timeout needs to be set, to avoid waiting for ever if the process associated with the queue has actually finished its I/O. Even with the above timeout, the device is however not fed with new I/O for a while, if the process has finished its I/O. If this happens often, then throughput drops and latencies grow. For this reason, the timeout is kept rather low: 8 ms is the current default. Unfortunately, such a low value may cause, on the opposite end, a violation of bandwidth guarantees for a process that happens to issue new I/O too late. The higher the system load, the higher the probability that this happens to some process. This is a problem in scenarios where service guarantees matter more than throughput. One important case are weight-raised queues, which need to be granted a very high fraction of the bandwidth. To address this issue, this commit lower-bounds the plugging timeout for weight-raised queues to 20 ms. This simple change provides relevant benefits. For example, on a PLEXTOR PX-256M5S, with which gnome-terminal starts in 0.6 seconds if there is no other I/O in progress, the same applications starts in - 0.8 seconds, instead of 1.2 seconds, if ten files are being read sequentially in parallel - 1 second, instead of 2 seconds, if, in parallel, five files are being read sequentially, and five more files are being written sequentially Tested-by: Holger Hoffstätte Tested-by: Oleksandr Natalenko Signed-off-by: Paolo Valente Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

blk-mq: move cancel of requeue_work into blk_mq_release

2019-06-15T09:54:54Z

[ Upstream commit fbc2a15e3433058582e5635aabe48a3011a644a8 ] With holding queue's kobject refcount, it is safe for driver to schedule requeue. However, blk_mq_kick_requeue_list() may be called after blk_sync_queue() is done because of concurrent requeue activities, then requeue work may not be completed when freeing queue, and kernel oops is triggered. So moving the cancel of requeue_work into blk_mq_release() for avoiding race between requeue and freeing queue. Cc: Dongli Zhang Cc: James Smart Cc: Bart Van Assche Cc: linux-scsi@vger.kernel.org, Cc: Martin K . Petersen , Cc: Christoph Hellwig , Cc: James E . J . Bottomley , Reviewed-by: Bart Van Assche Reviewed-by: Johannes Thumshirn Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig Tested-by: James Smart Signed-off-by: Ming Lei Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block: sed-opal: fix IOC_OPAL_ENABLE_DISABLE_MBR

2019-05-31T13:47:29Z

[ Upstream commit 78bf47353b0041865564deeed257a54f047c2fdc ] The implementation of IOC_OPAL_ENABLE_DISABLE_MBR handled the value opal_mbr_data.enable_disable incorrectly: enable_disable is expected to be one of OPAL_MBR_ENABLE(0) or OPAL_MBR_DISABLE(1). enable_disable was passed directly to set_mbr_done and set_mbr_enable_disable where is was interpreted as either OPAL_TRUE(1) or OPAL_FALSE(0). The end result was that calling IOC_OPAL_ENABLE_DISABLE_MBR with OPAL_MBR_ENABLE actually disabled the shadow MBR and vice versa. This patch adds correct conversion from OPAL_MBR_DISABLE/ENABLE to OPAL_FALSE/TRUE. The change affects existing programs using IOC_OPAL_ENABLE_DISABLE_MBR but this is typically used only once when setting up an Opal drive. Acked-by: Jon Derrick Reviewed-by: Christoph Hellwig Reviewed-by: Scott Bauer Signed-off-by: David Kozub Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block: do not leak memory in bio_copy_user_iov()

2019-04-17T06:37:53Z

commit a3761c3c91209b58b6f33bf69dd8bb8ec0c9d925 upstream. When bio_add_pc_page() fails in bio_copy_user_iov() we should free the page we just allocated otherwise we are leaking it. Cc: linux-block@vger.kernel.org Cc: Linus Torvalds Cc: stable@vger.kernel.org Reviewed-by: Chaitanya Kulkarni Signed-off-by: Jérôme Glisse Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

blk-mq: fix a hung issue when fsync

2019-02-20T09:20:44Z

[ Upstream commit 85bd6e61f34dffa8ec2dc75ff3c02ee7b2f1cbce ] Florian reported a io hung issue when fsync(). It should be triggered by following race condition. data + post flush a flush blk_flush_complete_seq case REQ_FSEQ_DATA blk_flush_queue_rq issued to driver blk_mq_dispatch_rq_list try to issue a flush req failed due to NON-NCQ command .queue_rq return BLK_STS_DEV_RESOURCE request completion req->end_io // doesn't check RESTART mq_flush_data_end_io case REQ_FSEQ_POSTFLUSH blk_kick_flush do nothing because previous flush has not been completed blk_mq_run_hw_queue insert rq to hctx->dispatch due to RESTART is still set, do nothing To fix this, replace the blk_mq_run_hw_queue in mq_flush_data_end_io with blk_mq_sched_restart to check and clear the RESTART flag. Fixes: bd166ef1 (blk-mq-sched: add framework for MQ capable IO schedulers) Reported-by: Florian Stecker Tested-by: Florian Stecker Signed-off-by: Jianchao Wang Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin