linux.git/block, branch v4.13.13 Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git bio_copy_user_iov(): don't ignore ->iov_offset 2017-10-18T07:38:31+00:00 Al Viro viro@zeniv.linux.org.uk 2017-09-24T14:21:15+00:00 9f3bb57753d26ef4c491cd17d0670c3dcbb5528c commit 1cfd0ddd82232804e03f3023f6a58b50dfef0574 upstream. Since "block: support large requests in blk_rq_map_user_iov" we started to call it with partially drained iter; that works fine on the write side, but reads create a copy of iter for completion time. And that needs to take the possibility of ->iov_iter != 0 into account... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 1cfd0ddd82232804e03f3023f6a58b50dfef0574 upstream.

Since "block: support large requests in blk_rq_map_user_iov" we
started to call it with partially drained iter; that works fine
on the write side, but reads create a copy of iter for completion
time.  And that needs to take the possibility of ->iov_iter != 0
into account...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
more bio_map_user_iov() leak fixes 2017-10-18T07:38:31+00:00 Al Viro viro@zeniv.linux.org.uk 2017-09-23T19:51:23+00:00 02fb540228593ed28ac19040d403996f907ff6a7 commit 2b04e8f6bbb196cab4b232af0f8d48ff2c7a8058 upstream. we need to take care of failure exit as well - pages already in bio should be dropped by analogue of bio_unmap_pages(), since their refcounts had been bumped only once per reference in bio. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 2b04e8f6bbb196cab4b232af0f8d48ff2c7a8058 upstream.

we need to take care of failure exit as well - pages already
in bio should be dropped by analogue of bio_unmap_pages(),
since their refcounts had been bumped only once per reference
in bio.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fix unbalanced page refcounting in bio_map_user_iov 2017-10-18T07:38:31+00:00 Vitaly Mayatskikh v.mayatskih@gmail.com 2017-09-22T05:18:39+00:00 ffe1d63bc4570ee980a59996667c296c5be7252e commit 95d78c28b5a85bacbc29b8dba7c04babb9b0d467 upstream. bio_map_user_iov and bio_unmap_user do unbalanced pages refcounting if IO vector has small consecutive buffers belonging to the same page. bio_add_pc_page merges them into one, but the page reference is never dropped. Signed-off-by: Vitaly Mayatskikh <v.mayatskih@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 95d78c28b5a85bacbc29b8dba7c04babb9b0d467 upstream.

bio_map_user_iov and bio_unmap_user do unbalanced pages refcounting if
IO vector has small consecutive buffers belonging to the same page.
bio_add_pc_page merges them into one, but the page reference is never
dropped.

Signed-off-by: Vitaly Mayatskikh <v.mayatskih@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bsg-lib: fix use-after-free under memory-pressure 2017-10-12T09:56:19+00:00 Benjamin Block bblock@linux.vnet.ibm.com 2017-10-03T10:48:37+00:00 233538248fe6b0752847afc0ccbb96f9fcd283b6 commit eab40cf336065e8d765e006b81ff48c5c114b365 upstream. When under memory-pressure it is possible that the mempool which backs the 'struct request_queue' will make use of up to BLKDEV_MIN_RQ count emergency buffers - in case it can't get a regular allocation. These buffers are preallocated and once they are also used, they are re-supplied with old finished requests from the same request_queue (see mempool_free()). The bug is, when re-supplying the emergency pool, the old requests are not again ran through the callback mempool_t->alloc(), and thus also not through the callback bsg_init_rq(). Thus we skip initialization, and while the sense-buffer still should be good, scsi_request->cmd might have become to be an invalid pointer in the meantime. When the request is initialized in bsg.c, and the user's CDB is larger than BLK_MAX_CDB, bsg will replace it with a custom allocated buffer, which is freed when the user's command is finished, thus it dangles afterwards. When next a command is sent by the user that has a smaller/similar CDB as BLK_MAX_CDB, bsg will assume that scsi_request->cmd is backed by scsi_request->__cmd, will not make a custom allocation, and write into undefined memory. Fix this by splitting bsg_init_rq() into two functions: - bsg_init_rq() is changed to only do the allocation of the sense-buffer, which is used to back the bsg job's reply buffer. This pointer should never change during the lifetime of a scsi_request, so it doesn't need re-initialization. - bsg_initialize_rq() is a new function that makes use of 'struct request_queue's initialize_rq_fn callback (which was introduced in v4.12). This is always called before the request is given out via blk_get_request(). This function does the remaining initialization that was previously done in bsg_init_rq(), and will also do it when the request is taken from the emergency-pool of the backing mempool. Fixes: 50b4d485528d ("bsg-lib: fix kernel panic resulting from missing allocation of reply-buffer") Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Benjamin Block <bblock@linux.vnet.ibm.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit eab40cf336065e8d765e006b81ff48c5c114b365 upstream.

When under memory-pressure it is possible that the mempool which backs
the 'struct request_queue' will make use of up to BLKDEV_MIN_RQ count
emergency buffers - in case it can't get a regular allocation. These
buffers are preallocated and once they are also used, they are
re-supplied with old finished requests from the same request_queue (see
mempool_free()).

The bug is, when re-supplying the emergency pool, the old requests are
not again ran through the callback mempool_t->alloc(), and thus also not
through the callback bsg_init_rq(). Thus we skip initialization, and
while the sense-buffer still should be good, scsi_request->cmd might
have become to be an invalid pointer in the meantime. When the request
is initialized in bsg.c, and the user's CDB is larger than BLK_MAX_CDB,
bsg will replace it with a custom allocated buffer, which is freed when
the user's command is finished, thus it dangles afterwards. When next a
command is sent by the user that has a smaller/similar CDB as
BLK_MAX_CDB, bsg will assume that scsi_request->cmd is backed by
scsi_request->__cmd, will not make a custom allocation, and write into
undefined memory.

Fix this by splitting bsg_init_rq() into two functions:
 - bsg_init_rq() is changed to only do the allocation of the
   sense-buffer, which is used to back the bsg job's reply buffer. This
   pointer should never change during the lifetime of a scsi_request, so
   it doesn't need re-initialization.
 - bsg_initialize_rq() is a new function that makes use of
   'struct request_queue's initialize_rq_fn callback (which was
   introduced in v4.12). This is always called before the request is
   given out via blk_get_request(). This function does the remaining
   initialization that was previously done in bsg_init_rq(), and will
   also do it when the request is taken from the emergency-pool of the
   backing mempool.

Fixes: 50b4d485528d ("bsg-lib: fix kernel panic resulting from missing allocation of reply-buffer")
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bsg-lib: don't free job in bsg_prepare_job 2017-10-05T07:47:31+00:00 Christoph Hellwig hch@lst.de 2017-09-07T11:54:35+00:00 0ea30c797c6f6f2e1606ab8960387a88e68f6fe4 commit f507b54dccfd8000c517d740bc45f20c74532d18 upstream. The job structure is allocated as part of the request, so we should not free it in the error path of bsg_prepare_job. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit f507b54dccfd8000c517d740bc45f20c74532d18 upstream.

The job structure is allocated as part of the request, so we should not
free it in the error path of bsg_prepare_job.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
block: directly insert blk-mq request from blk_insert_cloned_request() 2017-09-27T12:43:15+00:00 Jens Axboe axboe@kernel.dk 2017-09-11T22:43:57+00:00 9fae18e7b39d0a40fd1280c8ea495e8b2e062db2 commit 157f377beb710e84bd8bc7a3c4475c0674ebebd7 upstream. A NULL pointer crash was reported for the case of having the BFQ IO scheduler attached to the underlying blk-mq paths of a DM multipath device. The crash occured in blk_mq_sched_insert_request()'s call to e->type->ops.mq.insert_requests(). Paolo Valente correctly summarized why the crash occured with: "the call chain (dm_mq_queue_rq -> map_request -> setup_clone -> blk_rq_prep_clone) creates a cloned request without invoking e->type->ops.mq.prepare_request for the target elevator e. The cloned request is therefore not initialized for the scheduler, but it is however inserted into the scheduler by blk_mq_sched_insert_request." All said, a request-based DM multipath device's IO scheduler should be the only one used -- when the original requests are issued to the underlying paths as cloned requests they are inserted directly in the underlying dispatch queue(s) rather than through an additional elevator. But commit bd166ef18 ("blk-mq-sched: add framework for MQ capable IO schedulers") switched blk_insert_cloned_request() from using blk_mq_insert_request() to blk_mq_sched_insert_request(). Which incorrectly added elevator machinery into a call chain that isn't supposed to have any. To fix this introduce a blk-mq private blk_mq_request_bypass_insert() that blk_insert_cloned_request() calls to insert the request without involving any elevator that may be attached to the cloned request's request_queue. Fixes: bd166ef183c2 ("blk-mq-sched: add framework for MQ capable IO schedulers") Reported-by: Bart Van Assche <Bart.VanAssche@wdc.com> Tested-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 157f377beb710e84bd8bc7a3c4475c0674ebebd7 upstream.

A NULL pointer crash was reported for the case of having the BFQ IO
scheduler attached to the underlying blk-mq paths of a DM multipath
device.  The crash occured in blk_mq_sched_insert_request()'s call to
e->type->ops.mq.insert_requests().

Paolo Valente correctly summarized why the crash occured with:
"the call chain (dm_mq_queue_rq -> map_request -> setup_clone ->
blk_rq_prep_clone) creates a cloned request without invoking
e->type->ops.mq.prepare_request for the target elevator e.  The cloned
request is therefore not initialized for the scheduler, but it is
however inserted into the scheduler by blk_mq_sched_insert_request."

All said, a request-based DM multipath device's IO scheduler should be
the only one used -- when the original requests are issued to the
underlying paths as cloned requests they are inserted directly in the
underlying dispatch queue(s) rather than through an additional elevator.

But commit bd166ef18 ("blk-mq-sched: add framework for MQ capable IO
schedulers") switched blk_insert_cloned_request() from using
blk_mq_insert_request() to blk_mq_sched_insert_request().  Which
incorrectly added elevator machinery into a call chain that isn't
supposed to have any.

To fix this introduce a blk-mq private blk_mq_request_bypass_insert()
that blk_insert_cloned_request() calls to insert the request without
involving any elevator that may be attached to the cloned request's
request_queue.

Fixes: bd166ef183c2 ("blk-mq-sched: add framework for MQ capable IO schedulers")
Reported-by: Bart Van Assche <Bart.VanAssche@wdc.com>
Tested-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
block: Relax a check in blk_start_queue() 2017-09-27T12:43:15+00:00 Bart Van Assche bart.vanassche@wdc.com 2017-08-17T20:12:44+00:00 200bac0172924b6a525013a899441dcdbe30fe70 commit 4ddd56b003f251091a67c15ae3fe4a5c5c5e390a upstream. Calling blk_start_queue() from interrupt context with the queue lock held and without disabling IRQs, as the skd driver does, is safe. This patch avoids that loading the skd driver triggers the following warning: WARNING: CPU: 11 PID: 1348 at block/blk-core.c:283 blk_start_queue+0x84/0xa0 RIP: 0010:blk_start_queue+0x84/0xa0 Call Trace: skd_unquiesce_dev+0x12a/0x1d0 [skd] skd_complete_internal+0x1e7/0x5a0 [skd] skd_complete_other+0xc2/0xd0 [skd] skd_isr_completion_posted.isra.30+0x2a5/0x470 [skd] skd_isr+0x14f/0x180 [skd] irq_forced_thread_fn+0x2a/0x70 irq_thread+0x144/0x1a0 kthread+0x125/0x140 ret_from_fork+0x2a/0x40 Fixes: commit a038e2536472 ("[PATCH] blk_start_queue() must be called with irq disabled - add warning") Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Andrew Morton <akpm@osdl.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.de> Cc: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 4ddd56b003f251091a67c15ae3fe4a5c5c5e390a upstream.

Calling blk_start_queue() from interrupt context with the queue
lock held and without disabling IRQs, as the skd driver does, is
safe. This patch avoids that loading the skd driver triggers the
following warning:

WARNING: CPU: 11 PID: 1348 at block/blk-core.c:283 blk_start_queue+0x84/0xa0
RIP: 0010:blk_start_queue+0x84/0xa0
Call Trace:
 skd_unquiesce_dev+0x12a/0x1d0 [skd]
 skd_complete_internal+0x1e7/0x5a0 [skd]
 skd_complete_other+0xc2/0xd0 [skd]
 skd_isr_completion_posted.isra.30+0x2a5/0x470 [skd]
 skd_isr+0x14f/0x180 [skd]
 irq_forced_thread_fn+0x2a/0x70
 irq_thread+0x144/0x1a0
 kthread+0x125/0x140
 ret_from_fork+0x2a/0x40

Fixes: commit a038e2536472 ("[PATCH] blk_start_queue() must be called with irq disabled - add warning")
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Andrew Morton <akpm@osdl.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
blk-mq-debugfs: Add names for recently added flags 2017-08-25T14:07:44+00:00 Bart Van Assche bart.vanassche@wdc.com 2017-08-18T22:52:54+00:00 22d538213ec4fa65b08b1edbf610066d8aab7bbb The symbolic constants QUEUE_FLAG_SCSI_PASSTHROUGH, QUEUE_FLAG_QUIESCED and REQ_NOWAIT are missing from blk-mq-debugfs.c. Add these to blk-mq-debugfs.c such that these appear as names in debugfs instead of as numbers. Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Cc: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> 
The symbolic constants QUEUE_FLAG_SCSI_PASSTHROUGH, QUEUE_FLAG_QUIESCED
and REQ_NOWAIT are missing from blk-mq-debugfs.c. Add these to
blk-mq-debugfs.c such that these appear as names in debugfs instead of
as numbers.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
bsg-lib: fix kernel panic resulting from missing allocation of reply-buffer 2017-08-24T14:22:10+00:00 Benjamin Block bblock@linux.vnet.ibm.com 2017-08-23T23:57:56+00:00 50b4d485528d1dbe0bd249f2073140e3444f4a7b Since we split the scsi_request out of struct request bsg fails to provide a reply-buffer for the drivers. This was done via the pointer for sense-data, that is not preallocated anymore. Failing to allocate/assign it results in illegal dereferences because LLDs use this pointer unquestioned. An example panic on s390x, using the zFCP driver, looks like this (I had debugging on, otherwise NULL-pointer dereferences wouldn't even panic on s390x): Unable to handle kernel pointer dereference in virtual kernel address space Failing address: 6b6b6b6b6b6b6000 TEID: 6b6b6b6b6b6b6403 Fault in home space mode while using kernel ASCE. AS:0000000001590007 R3:0000000000000024 Oops: 0038 ilc:2 [#1] PREEMPT SMP DEBUG_PAGEALLOC Modules linked in: <Long List> CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.12.0-bsg-regression+ #3 Hardware name: IBM 2964 N96 702 (z/VM 6.4.0) task: 0000000065cb0100 task.stack: 0000000065cb4000 Krnl PSW : 0704e00180000000 000003ff801e4156 (zfcp_fc_ct_els_job_handler+0x16/0x58 [zfcp]) R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3 Krnl GPRS: 0000000000000001 000000005fa9d0d0 000000005fa9d078 0000000000e16866 000003ff00000290 6b6b6b6b6b6b6b6b 0000000059f78f00 000000000000000f 00000000593a0958 00000000593a0958 0000000060d88800 000000005ddd4c38 0000000058b50100 07000000659cba08 000003ff801e8556 00000000659cb9a8 Krnl Code: 000003ff801e4146: e31020500004 lg %r1,80(%r2) 000003ff801e414c: 58402040 l %r4,64(%r2) #000003ff801e4150: e35020200004 lg %r5,32(%r2) >000003ff801e4156: 50405004 st %r4,4(%r5) 000003ff801e415a: e54c50080000 mvhi 8(%r5),0 000003ff801e4160: e33010280012 lt %r3,40(%r1) 000003ff801e4166: a718fffb lhi %r1,-5 000003ff801e416a: 1803 lr %r0,%r3 Call Trace: ([<000003ff801e8556>] zfcp_fsf_req_complete+0x726/0x768 [zfcp]) [<000003ff801ea82a>] zfcp_fsf_reqid_check+0x102/0x180 [zfcp] [<000003ff801eb980>] zfcp_qdio_int_resp+0x230/0x278 [zfcp] [<00000000009b91b6>] qdio_kick_handler+0x2ae/0x2c8 [<00000000009b9e3e>] __tiqdio_inbound_processing+0x406/0xc10 [<00000000001684c2>] tasklet_action+0x15a/0x1d8 [<0000000000bd28ec>] __do_softirq+0x3ec/0x848 [<00000000001675a4>] irq_exit+0x74/0xf8 [<000000000010dd6a>] do_IRQ+0xba/0xf0 [<0000000000bd19e8>] io_int_handler+0x104/0x2d4 [<00000000001033b6>] enabled_wait+0xb6/0x188 ([<000000000010339e>] enabled_wait+0x9e/0x188) [<000000000010396a>] arch_cpu_idle+0x32/0x50 [<0000000000bd0112>] default_idle_call+0x52/0x68 [<00000000001cd0fa>] do_idle+0x102/0x188 [<00000000001cd41e>] cpu_startup_entry+0x3e/0x48 [<0000000000118c64>] smp_start_secondary+0x11c/0x130 [<0000000000bd2016>] restart_int_handler+0x62/0x78 [<0000000000000000>] (null) INFO: lockdep is turned off. Last Breaking-Event-Address: [<000003ff801e41d6>] zfcp_fc_ct_job_handler+0x3e/0x48 [zfcp] Kernel panic - not syncing: Fatal exception in interrupt This patch moves bsg-lib to allocate and setup struct bsg_job ahead of time, including the allocation of a buffer for the reply-data. This means, struct bsg_job is not allocated separately anymore, but as part of struct request allocation - similar to struct scsi_cmd. Reflect this in the function names that used to handle creation/destruction of struct bsg_job. Reported-by: Steffen Maier <maier@linux.vnet.ibm.com> Suggested-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Benjamin Block <bblock@linux.vnet.ibm.com> Fixes: 82ed4db499b8 ("block: split scsi_request out of struct request") Cc: <stable@vger.kernel.org> #4.11+ Signed-off-by: Jens Axboe <axboe@kernel.dk> 
Since we split the scsi_request out of struct request bsg fails to
provide a reply-buffer for the drivers. This was done via the pointer
for sense-data, that is not preallocated anymore.

Failing to allocate/assign it results in illegal dereferences because
LLDs use this pointer unquestioned.

An example panic on s390x, using the zFCP driver, looks like this (I had
debugging on, otherwise NULL-pointer dereferences wouldn't even panic on
s390x):

Unable to handle kernel pointer dereference in virtual kernel address space
Failing address: 6b6b6b6b6b6b6000 TEID: 6b6b6b6b6b6b6403
Fault in home space mode while using kernel ASCE.
AS:0000000001590007 R3:0000000000000024
Oops: 0038 ilc:2 [#1] PREEMPT SMP DEBUG_PAGEALLOC
Modules linked in: <Long List>
CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.12.0-bsg-regression+ #3
Hardware name: IBM 2964 N96 702 (z/VM 6.4.0)
task: 0000000065cb0100 task.stack: 0000000065cb4000
Krnl PSW : 0704e00180000000 000003ff801e4156 (zfcp_fc_ct_els_job_handler+0x16/0x58 [zfcp])
           R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3
Krnl GPRS: 0000000000000001 000000005fa9d0d0 000000005fa9d078 0000000000e16866
           000003ff00000290 6b6b6b6b6b6b6b6b 0000000059f78f00 000000000000000f
           00000000593a0958 00000000593a0958 0000000060d88800 000000005ddd4c38
           0000000058b50100 07000000659cba08 000003ff801e8556 00000000659cb9a8
Krnl Code: 000003ff801e4146: e31020500004        lg      %r1,80(%r2)
           000003ff801e414c: 58402040           l       %r4,64(%r2)
          #000003ff801e4150: e35020200004       lg      %r5,32(%r2)
          >000003ff801e4156: 50405004           st      %r4,4(%r5)
           000003ff801e415a: e54c50080000       mvhi    8(%r5),0
           000003ff801e4160: e33010280012       lt      %r3,40(%r1)
           000003ff801e4166: a718fffb           lhi     %r1,-5
           000003ff801e416a: 1803               lr      %r0,%r3
Call Trace:
([<000003ff801e8556>] zfcp_fsf_req_complete+0x726/0x768 [zfcp])
 [<000003ff801ea82a>] zfcp_fsf_reqid_check+0x102/0x180 [zfcp]
 [<000003ff801eb980>] zfcp_qdio_int_resp+0x230/0x278 [zfcp]
 [<00000000009b91b6>] qdio_kick_handler+0x2ae/0x2c8
 [<00000000009b9e3e>] __tiqdio_inbound_processing+0x406/0xc10
 [<00000000001684c2>] tasklet_action+0x15a/0x1d8
 [<0000000000bd28ec>] __do_softirq+0x3ec/0x848
 [<00000000001675a4>] irq_exit+0x74/0xf8
 [<000000000010dd6a>] do_IRQ+0xba/0xf0
 [<0000000000bd19e8>] io_int_handler+0x104/0x2d4
 [<00000000001033b6>] enabled_wait+0xb6/0x188
([<000000000010339e>] enabled_wait+0x9e/0x188)
 [<000000000010396a>] arch_cpu_idle+0x32/0x50
 [<0000000000bd0112>] default_idle_call+0x52/0x68
 [<00000000001cd0fa>] do_idle+0x102/0x188
 [<00000000001cd41e>] cpu_startup_entry+0x3e/0x48
 [<0000000000118c64>] smp_start_secondary+0x11c/0x130
 [<0000000000bd2016>] restart_int_handler+0x62/0x78
 [<0000000000000000>]           (null)
INFO: lockdep is turned off.
Last Breaking-Event-Address:
 [<000003ff801e41d6>] zfcp_fc_ct_job_handler+0x3e/0x48 [zfcp]

Kernel panic - not syncing: Fatal exception in interrupt

This patch moves bsg-lib to allocate and setup struct bsg_job ahead of
time, including the allocation of a buffer for the reply-data.

This means, struct bsg_job is not allocated separately anymore, but as part
of struct request allocation - similar to struct scsi_cmd. Reflect this in
the function names that used to handle creation/destruction of struct
bsg_job.

Reported-by: Steffen Maier <maier@linux.vnet.ibm.com>
Suggested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Fixes: 82ed4db499b8 ("block: split scsi_request out of struct request")
Cc: <stable@vger.kernel.org> #4.11+
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blk-throttle: cap discard request size 2017-08-23T21:56:33+00:00 Shaohua Li shli@fb.com 2017-08-18T23:08:13+00:00 ea0ea2bc6dd8923d86a0fa98743dbeed98645486 discard request usually is very big and easily use all bandwidth budget of a cgroup. discard request size doesn't really mean the size of data written, so it doesn't make sense to account it into bandwidth budget. Jens pointed out treating the size 0 doesn't make sense too, because discard request does have cost. But it's not easy to find the actual cost. This patch simply makes the size one sector. Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> 
discard request usually is very big and easily use all bandwidth budget
of a cgroup. discard request size doesn't really mean the size of data
written, so it doesn't make sense to account it into bandwidth budget.
Jens pointed out treating the size 0 doesn't make sense too, because
discard request does have cost. But it's not easy to find the actual
cost. This patch simply makes the size one sector.

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>