kernel/linux.git/drivers/nvme/host/fc.c, branch linux-5.9.y

nvme-fc: fail new connections to a deleted host or remote port

2020-09-22T15:49:55+00:00

The lldd may have made calls to delete a remote port or local port and the delete is in progress when the cli then attempts to create a new controller. Currently, this proceeds without error although it can't be very successful. Fix this by validating that both the host port and remote port are present when a new controller is to be created. Signed-off-by: James Smart Reviewed-by: Himanshu Madhani Signed-off-by: Christoph Hellwig

nvme-fc: cancel async events before freeing event struct

2020-09-08T17:46:29+00:00

Cancel async event work in case async event has been queued up, and nvme_fc_submit_async_event() runs after event has been freed. Signed-off-by: David Milburn Reviewed-by: Keith Busch Reviewed-by: Sagi Grimberg Signed-off-by: Christoph Hellwig

nvme: rename and document nvme_end_request

2020-08-21T23:14:28+00:00

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: Christoph Hellwig Reviewed-by: Sagi Grimberg Reviewed-by: Mike Snitzer Signed-off-by: Sagi Grimberg Signed-off-by: Jens Axboe

nvme-fc: Fix wrong return value in __nvme_fc_init_request()

2020-08-21T23:14:27+00:00

On an error exit path, a negative error code should be returned instead of a positive return value. Fixes: e399441de9115 ("nvme-fabrics: Add host support for FC transport") Cc: James Smart Signed-off-by: Tianjia Zhang Reviewed-by: Chaitanya Kulkarni Reviewed-by: Christoph Hellwig Signed-off-by: Sagi Grimberg Signed-off-by: Jens Axboe

nvme-fc: set max_segments to lldd max value

2020-07-29T05:45:20+00:00

Currently the FC transport is set max_hw_sectors based on the lldds max sgl segment count. However, the block queue max segments is set based on the controller's max_segments count, which the transport does not set. As such, the lldd is receiving sgl lists that are exceeding its max segment count. Set the controller max segment count and derive max_hw_sectors from the max segment count. Signed-off-by: James Smart Reviewed-by: Max Gurtovoy Reviewed-by: Himanshu Madhani Reviewed-by: Ewan D. Milne Signed-off-by: Christoph Hellwig

nvme: fix deadlock in disconnect during scan_work and/or ana_work

2020-07-29T05:45:19+00:00

A deadlock happens in the following scenario with multipath: 1) scan_work(nvme0) detects a new nsid while nvme0 is an optimized path to it, path nvme1 happens to be inaccessible. 2) Before scan_work is complete nvme0 disconnect is initiated nvme_delete_ctrl_sync() sets nvme0 state to NVME_CTRL_DELETING 3) scan_work(1) attempts to submit IO, but nvme_path_is_optimized() observes nvme0 is not LIVE. Since nvme1 is a possible path IO is requeued and scan_work hangs. -- Workqueue: nvme-wq nvme_scan_work [nvme_core] kernel: Call Trace: kernel: __schedule+0x2b9/0x6c0 kernel: schedule+0x42/0xb0 kernel: io_schedule+0x16/0x40 kernel: do_read_cache_page+0x438/0x830 kernel: read_cache_page+0x12/0x20 kernel: read_dev_sector+0x27/0xc0 kernel: read_lba+0xc1/0x220 kernel: efi_partition+0x1e6/0x708 kernel: check_partition+0x154/0x244 kernel: rescan_partitions+0xae/0x280 kernel: __blkdev_get+0x40f/0x560 kernel: blkdev_get+0x3d/0x140 kernel: __device_add_disk+0x388/0x480 kernel: device_add_disk+0x13/0x20 kernel: nvme_mpath_set_live+0x119/0x140 [nvme_core] kernel: nvme_update_ns_ana_state+0x5c/0x60 [nvme_core] kernel: nvme_set_ns_ana_state+0x1e/0x30 [nvme_core] kernel: nvme_parse_ana_log+0xa1/0x180 [nvme_core] kernel: nvme_mpath_add_disk+0x47/0x90 [nvme_core] kernel: nvme_validate_ns+0x396/0x940 [nvme_core] kernel: nvme_scan_work+0x24f/0x380 [nvme_core] kernel: process_one_work+0x1db/0x380 kernel: worker_thread+0x249/0x400 kernel: kthread+0x104/0x140 -- 4) Delete also hangs in flush_work(ctrl->scan_work) from nvme_remove_namespaces(). Similiarly a deadlock with ana_work may happen: if ana_work has started and calls nvme_mpath_set_live and device_add_disk, it will trigger I/O. When we trigger disconnect I/O will block because our accessible (optimized) path is disconnecting, but the alternate path is inaccessible, so I/O blocks. Then disconnect tries to flush the ana_work and hangs. [ 605.550896] Workqueue: nvme-wq nvme_ana_work [nvme_core] [ 605.552087] Call Trace: [ 605.552683] __schedule+0x2b9/0x6c0 [ 605.553507] schedule+0x42/0xb0 [ 605.554201] io_schedule+0x16/0x40 [ 605.555012] do_read_cache_page+0x438/0x830 [ 605.556925] read_cache_page+0x12/0x20 [ 605.557757] read_dev_sector+0x27/0xc0 [ 605.558587] amiga_partition+0x4d/0x4c5 [ 605.561278] check_partition+0x154/0x244 [ 605.562138] rescan_partitions+0xae/0x280 [ 605.563076] __blkdev_get+0x40f/0x560 [ 605.563830] blkdev_get+0x3d/0x140 [ 605.564500] __device_add_disk+0x388/0x480 [ 605.565316] device_add_disk+0x13/0x20 [ 605.566070] nvme_mpath_set_live+0x5e/0x130 [nvme_core] [ 605.567114] nvme_update_ns_ana_state+0x2c/0x30 [nvme_core] [ 605.568197] nvme_update_ana_state+0xca/0xe0 [nvme_core] [ 605.569360] nvme_parse_ana_log+0xa1/0x180 [nvme_core] [ 605.571385] nvme_read_ana_log+0x76/0x100 [nvme_core] [ 605.572376] nvme_ana_work+0x15/0x20 [nvme_core] [ 605.573330] process_one_work+0x1db/0x380 [ 605.574144] worker_thread+0x4d/0x400 [ 605.574896] kthread+0x104/0x140 [ 605.577205] ret_from_fork+0x35/0x40 [ 605.577955] INFO: task nvme:14044 blocked for more than 120 seconds. [ 605.579239] Tainted: G OE 5.3.5-050305-generic #201910071830 [ 605.580712] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 605.582320] nvme D 0 14044 14043 0x00000000 [ 605.583424] Call Trace: [ 605.583935] __schedule+0x2b9/0x6c0 [ 605.584625] schedule+0x42/0xb0 [ 605.585290] schedule_timeout+0x203/0x2f0 [ 605.588493] wait_for_completion+0xb1/0x120 [ 605.590066] __flush_work+0x123/0x1d0 [ 605.591758] __cancel_work_timer+0x10e/0x190 [ 605.593542] cancel_work_sync+0x10/0x20 [ 605.594347] nvme_mpath_stop+0x2f/0x40 [nvme_core] [ 605.595328] nvme_stop_ctrl+0x12/0x50 [nvme_core] [ 605.596262] nvme_do_delete_ctrl+0x3f/0x90 [nvme_core] [ 605.597333] nvme_sysfs_delete+0x5c/0x70 [nvme_core] [ 605.598320] dev_attr_store+0x17/0x30 Fix this by introducing a new state: NVME_CTRL_DELETE_NOIO, which will indicate the phase of controller deletion where I/O cannot be allowed to access the namespace. NVME_CTRL_DELETING still allows mpath I/O to be issued to the bottom device, and only after we flush the ana_work and scan_work (after nvme_stop_ctrl and nvme_prep_remove_namespaces) we change the state to NVME_CTRL_DELETING_NOIO. Also we prevent ana_work from re-firing by aborting early if we are not LIVE, so we should be safe here. In addition, change the transport drivers to follow the updated state machine. Fixes: 0d0b660f214d ("nvme: add ANA support") Reported-by: Anton Eidelman Signed-off-by: Sagi Grimberg Signed-off-by: Christoph Hellwig

nvme: use blk_mq_complete_request_remote to avoid an indirect function call

2020-06-24T15:15:57+00:00

Use the new blk_mq_complete_request_remote helper to avoid an indirect function call in the completion fast path. Reviewed-by: Daniel Wagner Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

nvme-fc: don't call nvme_cleanup_cmd() for AENs

2020-06-11T15:10:05+00:00

Asynchronous event notifications do not have an associated request. When fcp_io() fails we unconditionally call nvme_cleanup_cmd() which leads to a crash. Fixes: 16686f3a6c3c ("nvme: move common call to nvme_cleanup_cmd to core layer") Signed-off-by: Daniel Wagner Reviewed-by: Himanshu Madhani Reviewed-by: Hannes Reinecke Reviewed-by: James Smart Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

nvme: replace zero-length array with flexible-array

2020-05-27T05:12:37+00:00

The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] sizeof(flexible-array-member) triggers a warning because flexible array members have incomplete type[1]. There are some instances of code in which the sizeof operator is being incorrectly/erroneously applied to zero-length arrays and the result is zero. Such instances may be hiding some bugs. So, this work (flexible-array member conversions) will also help to get completely rid of those sorts of issues. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva Signed-off-by: Christoph Hellwig

nvme-fc: print proper nvme-fc devloss_tmo value

2020-05-27T05:12:37+00:00

The nvme-fc devloss_tmo is computed as the min of either the ctrl_loss_tmo (max_retries * reconnect_delay) or the remote port's devloss_tmo. But what gets printed as the nvme-fc devloss_tmo in nvme_fc_reconnect_or_delete() is always the remote port's devloss_tmo value. So correct this by printing the min value instead. Signed-off-by: Martin George Reviewed-by: James Smart Signed-off-by: Christoph Hellwig