- 28 Aug, 2020 15 commits
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Keith Busch authored
The kernel requires a power of two for boundaries because that's the only way it can efficiently split commands that cross them. A controller, however, may report a non-power of two boundary. The driver had been rounding the controller's value to one the kernel can use, but splitting on the wrong boundary provides no benefit on the device side, and incurs additional submission overhead from non-optimal splits. Don't provide any boundary hint if the controller's value can't be used and log a warning when first scanning a disk's unreported IO boundary. Since the chunk sector logic has grown, move it to a separate function. Cc: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by:
Keith Busch <kbusch@kernel.org> Reviewed-by:
Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by:
Sagi Grimberg <sagi@grimberg.me>
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Keith Busch authored
If the driver has to unbind from the controller for an early failure before the subsystem has been set up, there won't be a subsystem holding the controller's instance, so the controller needs to free its own instance in this case. Fixes: 733e4b69 ("nvme: Assign subsys instance from first ctrl") Signed-off-by:
Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Reviewed-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
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Christophe JAILLET authored
The way 'spin_lock()' and 'spin_lock_irqsave()' are used is not consistent in this function. Use 'spin_lock_irqsave()' also here, as there is no guarantee that interruptions are disabled at that point, according to surrounding code. Fixes: a97ec51b ("nvmet_fc: Rework target side abort handling") Signed-off-by:
Christophe JAILLET <christophe.jaillet@wanadoo.fr> Reviewed-by:
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Sagi Grimberg authored
PCIe controllers do not have fabric opts, verify they exist before showing ctrl_loss_tmo or reconnect_delay attributes. Fixes: 764075fd ("nvme: expose reconnect_delay and ctrl_loss_tmo via sysfs") Reported-by:
Tobias Markus <tobias@markus-regensburg.de> Reviewed-by:
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Sagi Grimberg authored
If the controller becomes unresponsive in the middle of a reset, we will hang because we are waiting for the freeze to complete, but that cannot happen since we have commands that are inflight holding the q_usage_counter, and we can't blindly fail requests that times out. So give a timeout and if we cannot wait for queue freeze before unfreezing, fail and have the error handling take care how to proceed (either schedule a reconnect of remove the controller). Reviewed-by:
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Sagi Grimberg authored
When a request times out in a LIVE state, we simply trigger error recovery and let the error recovery handle the request cancellation, however when a request times out in a non LIVE state, we make sure to complete it immediately as it might block controller setup or teardown and prevent forward progress. However tearing down the entire set of I/O and admin queues causes freeze/unfreeze imbalance (q->mq_freeze_depth) because and is really an overkill to what we actually need, which is to just fence controller teardown that may be running, stop the queue, and cancel the request if it is not already completed. Now that we have the controller teardown_lock, we can safely serialize request cancellation. This addresses a hang caused by calling extra queue freeze on controller namespaces, causing unfreeze to not complete correctly. Reviewed-by:
James Smart <james.smart@broadcom.com> Signed-off-by:
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Sagi Grimberg authored
In the timeout handler we may need to complete a request because the request that timed out may be an I/O that is a part of a serial sequence of controller teardown or initialization. In order to complete the request, we need to fence any other context that may compete with us and complete the request that is timing out. In this case, we could have a potential double completion in case a hard-irq or a different competing context triggered error recovery and is running inflight request cancellation concurrently with the timeout handler. Protect using a ctrl teardown_lock to serialize contexts that may complete a cancelled request due to error recovery or a reset. Reviewed-by:
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Sagi Grimberg authored
If the controller becomes unresponsive in the middle of a reset, we will hang because we are waiting for the freeze to complete, but that cannot happen since we have commands that are inflight holding the q_usage_counter, and we can't blindly fail requests that times out. So give a timeout and if we cannot wait for queue freeze before unfreezing, fail and have the error handling take care how to proceed (either schedule a reconnect of remove the controller). Signed-off-by: -
Sagi Grimberg authored
When a request times out in a LIVE state, we simply trigger error recovery and let the error recovery handle the request cancellation, however when a request times out in a non LIVE state, we make sure to complete it immediately as it might block controller setup or teardown and prevent forward progress. However tearing down the entire set of I/O and admin queues causes freeze/unfreeze imbalance (q->mq_freeze_depth) because and is really an overkill to what we actually need, which is to just fence controller teardown that may be running, stop the queue, and cancel the request if it is not already completed. Now that we have the controller teardown_lock, we can safely serialize request cancellation. This addresses a hang caused by calling extra queue freeze on controller namespaces, causing unfreeze to not complete correctly. Signed-off-by: -
Sagi Grimberg authored
In the timeout handler we may need to complete a request because the request that timed out may be an I/O that is a part of a serial sequence of controller teardown or initialization. In order to complete the request, we need to fence any other context that may compete with us and complete the request that is timing out. In this case, we could have a potential double completion in case a hard-irq or a different competing context triggered error recovery and is running inflight request cancellation concurrently with the timeout handler. Protect using a ctrl teardown_lock to serialize contexts that may complete a cancelled request due to error recovery or a reset. Signed-off-by: -
Sagi Grimberg authored
Users can detect if the wait has completed or not and take appropriate actions based on this information (e.g. weather to continue initialization or rather fail and schedule another initialization attempt). Reviewed-by:
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Sagi Grimberg authored
NVME_CTRL_NEW should never see any I/O, because in order to start initialization it has to transition to NVME_CTRL_CONNECTING and from there it will never return to this state. Reviewed-by:
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Ziye Yang authored
When handling commands without in-capsule data, we assign the ttag assuming we already have the queue commands array allocated (based on the queue size information in the connect data payload). However if the connect itself did not send the connect data in-capsule we have yet to allocate the queue commands,and we will assign a bogus ttag and suffer a NULL dereference when we receive the corresponding h2cdata pdu. Fix this by checking if we already allocated commands before dereferencing it when handling h2cdata, if we didn't, its for sure a connect and we should use the preallocated connect command. Signed-off-by:
Ziye Yang <ziye.yang@intel.com> Signed-off-by:
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https://git.kernel.org/pub/scm/linux/kernel/git/song/mdJens Axboe authored
Pull MD fix from Song. * 'md-fixes' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md: md/raid5: make sure stripe_size as power of two
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Yufen Yu authored
Commit 3b5408b9 ("md/raid5: support config stripe_size by sysfs entry") make stripe_size as a configurable value. It just requires stripe_size as multiple of 4KB. In fact, we should make sure stripe_size as power of two. Otherwise, stripe_shift which is the result of ilog2 can not represent the real stripe_size. Then, stripe_hash() and stripe_hash_locks_hash() may get unexpected value. Fixes: 3b5408b9 ("md/raid5: support config stripe_size by sysfs entry") Signed-off-by:
Yufen Yu <yuyufen@huawei.com> Signed-off-by:
Song Liu <songliubraving@fb.com>
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- 26 Aug, 2020 2 commits
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Martijn Coenen authored
The device size calculation was done before processing the loop configuration, which meant that the we set the size on the underlying block device incorrectly in case lo_offset/lo_sizelimit were set in the configuration. Delay computing the size until we've setup the device parameters correctly. Fixes: 3448914e("loop: Add LOOP_CONFIGURE ioctl") Reported-by:
Lennart Poettering <mzxreary@0pointer.de> Tested-by:
Yang Xu <xuyang2018.jy@cn.fujitsu.com> Signed-off-by:
Martijn Coenen <maco@android.com> Signed-off-by:
Jens Axboe <axboe@kernel.dk>
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Hou Pu authored
If we configured io timeout of nbd0 to 100s. Later after we finished using it, we configured nbd0 again and set the io timeout to 0. We expect it would timeout after 30 seconds and keep retry. But in fact we could not change the timeout when we set it to 0. the timeout is still the original 100s. So change the timeout to default 30s when we set it to zero. It also behaves same as commit 2da22da5 ("nbd: fix zero cmd timeout handling v2"). It becomes more important if we were reconfigure a nbd device and the io timeout it set to zero. Because it could take 30s to detect the new socket and thus io could be completed more quickly compared to 100s. Signed-off-by:
Hou Pu <houpu@bytedance.com> Reviewed-by:
Josef Bacik <josef@toxicpanda.com> Signed-off-by:
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- 21 Aug, 2020 23 commits
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Hou Pu authored
REQ_FUA should be checked using rq->cmd_flags instead of req_op(). Fixes: deb78b41 ("nullb: emulate cache") Signed-off-by:
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Amit Engel authored
Based on nvme spec, when keep alive timeout is set to zero the keep-alive timer should be disabled. Signed-off-by:
Amit Engel <amit.engel@dell.com> Signed-off-by:
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Chao Leng authored
If a command send through nvme-multipath failed on a dying queue, resend it on another path. Signed-off-by:
Chao Leng <lengchao@huawei.com> [hch: rebased on top of the completion refactoring] Signed-off-by:
Mike Snitzer <snitzer@redhat.com> Signed-off-by:
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Christoph Hellwig authored
Check the SCT sub-field for a path related status instead of enumerating invididual status code. As of NVMe 1.4 this adds "Internal Path Error" and "Controller Pathing Error" to the list, but it also future proofs for additional status codes added to the category. Suggested-by:
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Christoph Hellwig authored
Lift all the code to decide the dispostition of a completed command from nvme_complete_rq and nvme_failover_req into a new helper, which returns an emum of the potential actions. nvme_complete_rq then just switches on those and calls the proper helper for the action. Signed-off-by:
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Christoph Hellwig authored
nvme_end_request is a bit misnamed, as it wraps around the blk_mq_complete_* API. It's semantics also are non-trivial, so give it a more descriptive name and add a comment explaining the semantics. Signed-off-by:
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Keith Busch authored
Zoned block devices reuse the chunk_sectors queue limit to define zone boundaries. If a such a device happens to also report an optimal boundary, do not use that to define the chunk_sectors as that may intermittently interfere with io splitting and zone size queries. Signed-off-by:
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Christoph Hellwig authored
All operations are based on the controller, not the host page size. Switch the dma pool to use the controller page size as well to avoid massive overallocations on large page size systems. Signed-off-by:
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John Garry authored
Recently nvme_dev.q_depth was changed from an int to u16 type. This falls over for the queue depth calculation in nvme_pci_enable(), where NVME_CAP_MQES(dev->ctrl.cap) + 1 may overflow as a u16, as NVME_CAP_MQES() is a 16b number also. That happens for me, and this is the result: root@ubuntu:/home/john# [148.272996] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010 Mem abort info: ESR = 0x96000004 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000004 CM = 0, WnR = 0 user pgtable: 4k pages, 48-bit VAs, pgdp=00000a27bf3c9000 [0000000000000010] pgd=0000000000000000, p4d=0000000000000000 Internal error: Oops: 96000004 [#1] PREEMPT SMP Modules linked in: nvme nvme_core CPU: 56 PID: 256 Comm: kworker/u195:0 Not tainted 5.8.0-next-20200812 #27 Hardware name: Huawei D06 /D06, BIOS Hisilicon D06 UEFI RC0 - V1.16.01 03/15/2019 Workqueue: nvme-reset-wq nvme_reset_work [nvme] pstate: 80c00009 (Nzcv daif +PAN +UAO BTYPE=--) pc : __sg_alloc_table_from_pages+0xec/0x238 lr : __sg_alloc_table_from_pages+0xc8/0x238 sp : ffff800013ccbad0 x29: ffff800013ccbad0 x28: ffff0a27b3d380a8 x27: 0000000000000000 x26: 0000000000002dc2 x25: 0000000000000dc0 x24: 0000000000000000 x23: 0000000000000000 x22: ffff800013ccbbe8 x21: 0000000000000010 x20: 0000000000000000 x19: 00000000fffff000 x18: ffffffffffffffff x17: 00000000000000c0 x16: fffffe289eaf6380 x15: ffff800011b59948 x14: ffff002bc8fe98f8 x13: ff00000000000000 x12: ffff8000114ca000 x11: 0000000000000000 x10: ffffffffffffffff x9 : ffffffffffffffc0 x8 : ffff0a27b5f9b6a0 x7 : 0000000000000000 x6 : 0000000000000001 x5 : ffff0a27b5f9b680 x4 : 0000000000000000 x3 : ffff0a27b5f9b680 x2 : 0000000000000000 x1 : 0000000000000001 x0 : 0000000000000000 Call trace: __sg_alloc_table_from_pages+0xec/0x238 sg_alloc_table_from_pages+0x18/0x28 iommu_dma_alloc+0x474/0x678 dma_alloc_attrs+0xd8/0xf0 nvme_alloc_queue+0x114/0x160 [nvme] nvme_reset_work+0xb34/0x14b4 [nvme] process_one_work+0x1e8/0x360 worker_thread+0x44/0x478 kthread+0x150/0x158 ret_from_fork+0x10/0x34 Code: f94002c3 6b01017f 540007c2 11000486 (f8645aa5) ---[ end trace 89bb2b72d59bf925 ]--- Fix by making onto a u32. Also use u32 for nvme_dev.q_depth, as we assign this value from nvme_dev.q_depth, and nvme_dev.q_depth will possibly hold 65536 - this avoids the same crash as above. Fixes: 61f3b896 ("nvme-pci: use unsigned for io queue depth") Signed-off-by:
John Garry <john.garry@huawei.com> Reviewed-by:
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Logan Gunthorpe authored
When locking the ctrl->lock spinlock IRQs need to be disabled to avoid a dead lock. The new spin_lock() calls recently added produce the following lockdep warning when running the blktest nvme/003: ================================ WARNING: inconsistent lock state -------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. ksoftirqd/2/22 [HC0[0]:SC1[1]:HE0:SE0] takes: ffff888276a8c4c0 (&ctrl->lock){+.?.}-{2:2}, at: nvme_keep_alive_end_io+0x50/0xc0 {SOFTIRQ-ON-W} state was registered at: lock_acquire+0x164/0x500 _raw_spin_lock+0x28/0x40 nvme_get_effects_log+0x37/0x1c0 nvme_init_identify+0x9e4/0x14f0 nvme_reset_work+0xadd/0x2360 process_one_work+0x66b/0xb70 worker_thread+0x6e/0x6c0 kthread+0x1e7/0x210 ret_from_fork+0x22/0x30 irq event stamp: 1449221 hardirqs last enabled at (1449220): [<ffffffff81c58e69>] ktime_get+0xf9/0x140 hardirqs last disabled at (1449221): [<ffffffff83129665>] _raw_spin_lock_irqsave+0x25/0x60 softirqs last enabled at (1449210): [<ffffffff83400447>] __do_softirq+0x447/0x595 softirqs last disabled at (1449215): [<ffffffff81b489b5>] run_ksoftirqd+0x35/0x50 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&ctrl->lock); <Interrupt> lock(&ctrl->lock); *** DEADLOCK *** no locks held by ksoftirqd/2/22. stack backtrace: CPU: 2 PID: 22 Comm: ksoftirqd/2 Not tainted 5.8.0-rc4-eid-vmlocalyes-dbg-00157-g7236657c #1450 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.12.0-1 04/01/2014 Call Trace: dump_stack+0xc8/0x11a print_usage_bug.cold.63+0x235/0x23e mark_lock+0xa9c/0xcf0 __lock_acquire+0xd9a/0x2b50 lock_acquire+0x164/0x500 _raw_spin_lock_irqsave+0x40/0x60 nvme_keep_alive_end_io+0x50/0xc0 blk_mq_end_request+0x158/0x210 nvme_complete_rq+0x146/0x500 nvme_loop_complete_rq+0x26/0x30 [nvme_loop] blk_done_softirq+0x187/0x1e0 __do_softirq+0x118/0x595 run_ksoftirqd+0x35/0x50 smpboot_thread_fn+0x1d3/0x310 kthread+0x1e7/0x210 ret_from_fork+0x22/0x30 Fixes: be93e87e ("nvme: support for multiple Command Sets Supported and Effects log pages") Signed-off-by:Logan Gunthorpe <logang@deltatee.com> Reviewed-by:
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Chaitanya Kulkarni authored
Instead of calling blk_put_request() which calls blk_mq_free_request(), call blk_mq_free_request() directly for NVMeOF passthru. This is to mainly avoid an extra function call in the completion path nvmet_passthru_req_done(). Signed-off-by:
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Chaitanya Kulkarni authored
In the existing NVMeOF Passthru core command handling on failure of nvme_alloc_request() it errors out with rq value set to NULL. In the error handling path it calls blk_put_request() without checking if rq is set to NULL or not which produces following Oops:- [ 1457.346861] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 1457.347838] #PF: supervisor read access in kernel mode [ 1457.348464] #PF: error_code(0x0000) - not-present page [ 1457.349085] PGD 0 P4D 0 [ 1457.349402] Oops: 0000 [#1] SMP NOPTI [ 1457.349851] CPU: 18 PID: 10782 Comm: kworker/18:2 Tainted: G OE 5.8.0-rc4nvme-5.9+ #35 [ 1457.350951] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e3214 [ 1457.352347] Workqueue: events nvme_loop_execute_work [nvme_loop] [ 1457.353062] RIP: 0010:blk_mq_free_request+0xe/0x110 [ 1457.353651] Code: 3f ff ff ff 83 f8 01 75 0d 4c 89 e7 e8 1b db ff ff e9 2d ff ff ff 0f 0b eb ef 66 8 [ 1457.355975] RSP: 0018:ffffc900035b7de0 EFLAGS: 00010282 [ 1457.356636] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000002 [ 1457.357526] RDX: ffffffffa060bd05 RSI: 0000000000000000 RDI: 0000000000000000 [ 1457.358416] RBP: 0000000000000037 R08: 0000000000000000 R09: 0000000000000000 [ 1457.359317] R10: 0000000000000000 R11: 000000000000006d R12: 0000000000000000 [ 1457.360424] R13: ffff8887ffa68600 R14: 0000000000000000 R15: ffff8888150564c8 [ 1457.361322] FS: 0000000000000000(0000) GS:ffff888814600000(0000) knlGS:0000000000000000 [ 1457.362337] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1457.363058] CR2: 0000000000000000 CR3: 000000081c0ac000 CR4: 00000000003406e0 [ 1457.363973] Call Trace: [ 1457.364296] nvmet_passthru_execute_cmd+0x150/0x2c0 [nvmet] [ 1457.364990] process_one_work+0x24e/0x5a0 [ 1457.365493] ? __schedule+0x353/0x840 [ 1457.365957] worker_thread+0x3c/0x380 [ 1457.366426] ? process_one_work+0x5a0/0x5a0 [ 1457.366948] kthread+0x135/0x150 [ 1457.367362] ? kthread_create_on_node+0x60/0x60 [ 1457.367934] ret_from_fork+0x22/0x30 [ 1457.368388] Modules linked in: nvme_loop(OE) nvmet(OE) nvme_fabrics(OE) null_blk nvme(OE) nvme_corer [ 1457.368414] ata_piix crc32c_intel virtio_pci libata virtio_ring serio_raw t10_pi virtio floppy dm_] [ 1457.380849] CR2: 0000000000000000 [ 1457.381288] ---[ end trace c6cab61bfd1f68fd ]--- [ 1457.381861] RIP: 0010:blk_mq_free_request+0xe/0x110 [ 1457.382469] Code: 3f ff ff ff 83 f8 01 75 0d 4c 89 e7 e8 1b db ff ff e9 2d ff ff ff 0f 0b eb ef 66 8 [ 1457.384749] RSP: 0018:ffffc900035b7de0 EFLAGS: 00010282 [ 1457.385393] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000002 [ 1457.386264] RDX: ffffffffa060bd05 RSI: 0000000000000000 RDI: 0000000000000000 [ 1457.387142] RBP: 0000000000000037 R08: 0000000000000000 R09: 0000000000000000 [ 1457.388029] R10: 0000000000000000 R11: 000000000000006d R12: 0000000000000000 [ 1457.388914] R13: ffff8887ffa68600 R14: 0000000000000000 R15: ffff8888150564c8 [ 1457.389798] FS: 0000000000000000(0000) GS:ffff888814600000(0000) knlGS:0000000000000000 [ 1457.390796] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1457.391508] CR2: 0000000000000000 CR3: 000000081c0ac000 CR4: 00000000003406e0 [ 1457.392525] Kernel panic - not syncing: Fatal exception [ 1457.394138] Kernel Offset: disabled [ 1457.394677] ---[ end Kernel panic - not syncing: Fatal exception ]--- We fix this Oops by adding a new goto label out_put_req and reordering the blk_put_request call to avoid calling blk_put_request() with rq value is set to NULL. Here we also update the rest of the code accordingly. Fixes: 06b7164dfdc0 ("nvmet: add passthru code to process commands") Signed-off-by: -
Chaitanya Kulkarni authored
In the current implementation before submitting the passthru cmd we may come across error e.g. getting ns from passthru controller, allocating a request from passthru controller, etc. For all the failure cases it only uses single goto label fail_out. In the target code, we follow the pattern to have a separate label for each error out the case when setting up multiple things before the actual action. This patch follows the same pattern and renames generic fail_out label to out_put_ns and updates the error out cases in the nvmet_passthru_execute_cmd() where it is needed. Signed-off-by:
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Martin Wilck authored
If we find an optimized path, we quit the loop immediately. Thus we can use just one variable for the next path, slighly simplifying the code. Signed-off-by:
Martin Wilck <mwilck@suse.com> Reviewed-by:
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Martin Wilck authored
If there's only one usable, non-optimized path, nvme_round_robin_path() returns NULL, which is wrong. Fix it by falling back to "old", like in the single optimized path case. Also, if the active path isn't changed, there's no need to re-assign the pointer. Fixes: 3f6e3246 ("nvme-multipath: fix logic for non-optimized paths") Signed-off-by:
Martin George <marting@netapp.com> Reviewed-by:
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Tianjia Zhang authored
On an error exit path, a negative error code should be returned instead of a positive return value. Fixes: e399441d ("nvme-fabrics: Add host support for FC transport") Cc: James Smart <jsmart2021@gmail.com> Signed-off-by:
Tianjia Zhang <tianjia.zhang@linux.alibaba.com> Reviewed-by:
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Logan Gunthorpe authored
Any command with a non-SGL flag set (like fuse flags) should be rejected. Fixes: c1fef73f ("nvmet: add passthru code to process commands") Signed-off-by:
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Sagi Grimberg authored
We forgot to free new_model_number Fixes: 013b7ebe ("nvmet: make ctrl model configurable") Reviewed-by:
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Yufen Yu authored
Normally, blkcg_iolatency_exit() will free related memory in iolatency when cleanup queue. But if blk_throtl_init() return error and queue init fail, blkcg_iolatency_exit() will not do that for us. Then it cause memory leak. Fixes: d7067512 ("block: introduce blk-iolatency io controller") Signed-off-by:
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Geert Uytterhoeven authored
The various <linux/blk*.h> header files are part of the Block Layer. Add them to the corresponding section in the MAINTAINERS file, so scripts/get_maintainer.pl will pick them up. Signed-off-by:
Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by:
Bart Van Assche <bvanassche@acm.org> Signed-off-by:
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Keith Busch authored
A previous commit aligning splits to physical block sizes inadvertently modified one return case such that that it now returns 0 length splits when the number of sectors doesn't exceed the physical offset. This later hits a BUG in bio_split(). Restore the previous working behavior. Fixes: 9cc5169c ("block: Improve physical block alignment of split bios") Reported-by:
Eric Deal <eric.deal@wdc.com> Signed-off-by:
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Ming Lei authored
c616cbee ("blk-mq: punt failed direct issue to dispatch list") supposed to add request which has been through ->queue_rq() to the hw queue dispatch list, however it adds request running out of budget or driver tag to hw queue too. This way basically bypasses request merge, and causes too many request dispatched to LLD, and system% is unnecessary increased. Fixes this issue by adding request not through ->queue_rq into sw/scheduler queue, and this way is safe because no ->queue_rq is called on this request yet. High %system can be observed on Azure storvsc device, and even soft lock is observed. This patch reduces %system during heavy sequential IO, meantime decreases soft lockup risk. Fixes: c616cbee ("blk-mq: punt failed direct issue to dispatch list") Signed-off-by:
Ming Lei <ming.lei@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Mike Snitzer <snitzer@redhat.com> Signed-off-by:
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Nathan Chancellor authored
Clang warns: drivers/block/rnbd/rnbd-srv.c:150:6: warning: variable 'err' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] if (IS_ERR(bio)) { ^~~~~~~~~~~ drivers/block/rnbd/rnbd-srv.c:177:9: note: uninitialized use occurs here return err; ^~~ drivers/block/rnbd/rnbd-srv.c:150:2: note: remove the 'if' if its condition is always false if (IS_ERR(bio)) { ^~~~~~~~~~~~~~~~~~ drivers/block/rnbd/rnbd-srv.c:126:9: note: initialize the variable 'err' to silence this warning int err; ^ = 0 1 warning generated. err is indeed uninitialized when this statement is taken. Ensure that it is assigned the error value of bio before jumping to the error handling label. Fixes: 735d77d4 ("rnbd: remove rnbd_dev_submit_io") Reported-by:Brooke Basile <brookebasile@gmail.com> Signed-off-by:
Nathan Chancellor <natechancellor@gmail.com> Acked-by:
Jack Wang <jinpu.wang@cloud.ionos.com> Link: https://github.com/ClangBuiltLinux/linux/issues/1134Signed-off-by:
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