BMC/Intel-BMC/linux.git/drivers/nvme/target/core.c, branch dev-5.8

nvmet: fail outstanding host posted AEN req

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

In function nvmet_async_event_process() we only process AENs iff there is an open slot on the ctrl->async_event_cmds[] && aen event list posted by the target is not empty. This keeps host posted AEN outstanding if target generated AEN list is empty. We do cleanup the target generated entries from the aen list in nvmet_ctrl_free()-> nvmet_async_events_free() but we don't process AEN posted by the host. This leads to following problem :- When processing admin sq at the time of nvmet_sq_destroy() holds an extra percpu reference(atomic value = 1), so in the following code path after switching to atomic rcu, release function (nvmet_sq_free()) is not getting called which blocks the sq->free_done in nvmet_sq_destroy() :- nvmet_sq_destroy() percpu_ref_kill_and_confirm() - __percpu_ref_switch_mode() -- __percpu_ref_switch_to_atomic() --- call_rcu() -> percpu_ref_switch_to_atomic_rcu() ---- /* calls switch callback */ - percpu_ref_put() -- percpu_ref_put_many(ref, 1) --- else if (unlikely(atomic_long_sub_and_test(nr, &ref->count))) ---- ref->release(ref); <---- Not called. This results in indefinite hang:- void nvmet_sq_destroy(struct nvmet_sq *sq) ... if (ctrl && ctrl->sqs && ctrl->sqs[0] == sq) { nvmet_async_events_process(ctrl, status); percpu_ref_put(&sq->ref); } percpu_ref_kill_and_confirm(&sq->ref, nvmet_confirm_sq); wait_for_completion(&sq->confirm_done); wait_for_completion(&sq->free_done); <-- Hang here Which breaks the further disconnect sequence. This problem seems to be introduced after commit 64f5e9cdd711b ("nvmet: fix memory leak when removing namespaces and controllers concurrently"). This patch processes ctrl->async_event_cmds[] in the admin sq destroy() context irrespetive of aen_list. Also we get rid of the controller's aen_list processing in the nvmet_sq_destroy() context and just ignore ctrl->aen_list. This results in nvmet_async_events_process() being called from workqueue context so we adjust the code accordingly. Fixes: 64f5e9cdd711 ("nvmet: fix memory leak when removing namespaces and controllers concurrently ") Signed-off-by: Chaitanya Kulkarni Reviewed-by: Sagi Grimberg Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

nvmet: cleanups the loop in nvmet_async_events_process

2020-05-27T05:12:40+00:00

Based-on-a-patch-by: Christoph Hellwig Tested-by: Yi Zhang Signed-off-by: David Milburn Signed-off-by: Christoph Hellwig

nvmet: fix memory leak when removing namespaces and controllers concurrently

2020-05-27T05:12:40+00:00

When removing a namespace, we add an NS_CHANGE async event, however if the controller admin queue is removed after the event was added but not yet processed, we won't free the aens, resulting in the below memory leak [1]. Fix that by moving nvmet_async_event_free to the final controller release after it is detached from subsys->ctrls ensuring no async events are added, and modify it to simply remove all pending aens. -- $ cat /sys/kernel/debug/kmemleak unreferenced object 0xffff888c1af2c000 (size 32): comm "nvmetcli", pid 5164, jiffies 4295220864 (age 6829.924s) hex dump (first 32 bytes): 28 01 82 3b 8b 88 ff ff 28 01 82 3b 8b 88 ff ff (..;....(..;.... 02 00 04 65 76 65 6e 74 5f 66 69 6c 65 00 00 00 ...event_file... backtrace: [<00000000217ae580>] nvmet_add_async_event+0x57/0x290 [nvmet] [<0000000012aa2ea9>] nvmet_ns_changed+0x206/0x300 [nvmet] [<00000000bb3fd52e>] nvmet_ns_disable+0x367/0x4f0 [nvmet] [<00000000e91ca9ec>] nvmet_ns_free+0x15/0x180 [nvmet] [<00000000a15deb52>] config_item_release+0xf1/0x1c0 [<000000007e148432>] configfs_rmdir+0x555/0x7c0 [<00000000f4506ea6>] vfs_rmdir+0x142/0x3c0 [<0000000000acaaf0>] do_rmdir+0x2b2/0x340 [<0000000034d1aa52>] do_syscall_64+0xa5/0x4d0 [<00000000211f13bc>] entry_SYSCALL_64_after_hwframe+0x6a/0xdf Fixes: a07b4970f464 ("nvmet: add a generic NVMe target") Reported-by: David Milburn Signed-off-by: Sagi Grimberg Tested-by: David Milburn Signed-off-by: Christoph Hellwig

nvmet: add metadata support for block devices

2020-05-27T05:12:40+00:00

Allocate the metadata SGL buffers and set metadata fields for the request. Then create a block IO request for the metadata from the protection SG list. Signed-off-by: Israel Rukshin Signed-off-by: Max Gurtovoy Signed-off-by: Christoph Hellwig

nvmet: add metadata/T10-PI support

2020-05-27T05:12:40+00:00

Expose the namespace metadata format when PI is enabled. The user needs to enable the capability per subsystem and per port. The other metadata properties are taken from the namespace/bdev. Usage example: echo 1 > /config/nvmet/subsystems/${NAME}/attr_pi_enable echo 1 > /config/nvmet/ports/${PORT_NUM}/param_pi_enable Signed-off-by: Israel Rukshin Signed-off-by: Max Gurtovoy Reviewed-by: James Smart Signed-off-by: Christoph Hellwig

nvmet: rename nvmet_check_data_len to nvmet_check_transfer_len

2020-05-27T05:12:39+00:00

The function doesn't check only the data length, because the transfer length includes also the metadata length in some cases. This is preparation for adding metadata (T10-PI) support. Signed-off-by: Israel Rukshin Signed-off-by: Max Gurtovoy Reviewed-by: Sagi Grimberg Reviewed-by: Martin K. Petersen Reviewed-by: James Smart Signed-off-by: Christoph Hellwig

nvmet: generate AEN for ns revalidate size change

2020-05-27T05:12:38+00:00

The newly added function nvmet_ns_revalidate() does update the ns size in the identify namespace in-core target data structure when host issues id-ns command. This can lead to host having inconsistencies between size of the namespace present in the id-ns command result and size of the corresponding block device until host scans the namespaces explicitly. To avoid this scenario generate AEN if old size is not same as the new one in nvmet_ns_revalidate(). This will allow automatic AEN generation when host calls id-ns command and also allows target to install userspace rules so that it can trigger nvmet_ns_revalidate() (using configfs interface with the help of next patch) resulting in appropriate AEN generation when underlying namespace size change is detected. Signed-off-by: Chaitanya Kulkarni Reviewed-by: Sagi Grimberg Signed-off-by: Christoph Hellwig

nvmet: add helper to revalidate bdev and file ns

2020-05-27T05:12:38+00:00

This patch adds a wrapper helper to indicate size change in the bdev & file-backed namespace when revalidating ns. This helper is needed in order to minimize code repetition in the next patch for configfs.c and existing admin-cmd.c. Signed-off-by: Chaitanya Kulkarni Reviewed-by: Sagi Grimberg Signed-off-by: Christoph Hellwig

nvmet: add async event tracing support

2020-05-27T05:12:38+00:00

This adds a new tracepoint for the target to trace async event. This is helpful in debugging and comparing host and target side async events especially when host is connected to different targets on different machines and now that we rely on userspace components to generate AEN. Signed-off-by: Chaitanya Kulkarni Reviewed-by: Christoph Hellwig Reviewed-by: Sagi Grimberg Signed-off-by: Christoph Hellwig

nvmet: make ctrl model configurable

2020-03-04T17:09:08+00:00

This patch adds a new target subsys attribute which allows user to optionally specify model name which then used in the nvmet_execute_identify_ctrl() to fill up the nvme_id_ctrl structure. The default value for the model is set to "Linux" for backward compatibility. Reviewed-by: Christoph Hellwig Reviewed-by: Sagi Grimberg Signed-off-by: Mark Ruijter [chaitanya.kulkarni@wdc.com *Use macro for default model, coding style fixes. *Use RCU for accessing model in for configfs and in nvmet_execute_identify_ctrl(). ] Signed-off-by: Chaitanya Kulkarni Signed-off-by: Keith Busch