talos-obmc-linux/include/linux/bsg-lib.h, branch dev-4.13-fsi

bsg-lib: fix kernel panic resulting from missing allocation of reply-buffer

2017-08-24T14:22:10+00:00

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: 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 Suggested-by: Christoph Hellwig Reviewed-by: Christoph Hellwig Signed-off-by: Benjamin Block Fixes: 82ed4db499b8 ("block: split scsi_request out of struct request") Cc: #4.11+ Signed-off-by: Jens Axboe

block/bsg: move queue creation into bsg_setup_queue

2017-01-27T22:08:35+00:00

Simply the boilerplate code needed for bsg nodes a bit. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe

scsi: fc: move FC transport's bsg code to bsg-lib

2016-11-18T01:15:26+00:00

Now that all conversions are done, move the FibreChannel bsg code over to the bsg library. This patch is derived from work done by Mike Christie in 2011 [1] but only the iscsi parts got merged back then. [1] http://marc.info/?l=linux-scsi&m=131149780921009&w=2 Signed-off-by: Johannes Thumshirn Reviewed-by: Hannes Reinecke Signed-off-by: Martin K. Petersen

block: add bsg_job_put() and bsg_job_get()

2016-11-18T01:15:26+00:00

Add bsg_job_put() and bsg_job_get() so don't need to export bsg_destroy_job() any more. Signed-off-by: Johannes Thumshirn Reviewed-by: Hannes Reinecke Signed-off-by: Martin K. Petersen

scsi: fc: use bsg_softirq_done

2016-11-18T01:15:26+00:00

bsg_softirq_done() and fc_bsg_softirq_done() are copies of each other, so ditch the fc specific one. Signed-off-by: Johannes Thumshirn Reviewed-by: Hannes Reinecke Signed-off-by: Martin K. Petersen

scsi: fc: Use bsg_destroy_job

2016-11-18T01:15:25+00:00

fc_destroy_bsgjob() and bsg_destroy_job() are now 1:1 copies, so use the latter. As bsg_destroy_job() comes from bsg-lib we need to select it in Kconfig once CONFOG_SCSI_FC_ATTRS is active. Signed-off-by: Johannes Thumshirn Reviewed-by: Hannes Reinecke Signed-off-by: Martin K. Petersen

block: add reference counting for struct bsg_job

2016-11-18T01:15:25+00:00

Add reference counting to 'struct bsg_job' so we can implement a reuqest timeout handler for bsg_jobs, which is needed for Fibre Channel. Signed-off-by: Johannes Thumshirn Reviewed-by: Hannes Reinecke Signed-off-by: Martin K. Petersen

bsg: Remove unused function bsg_goose_queue()

2012-12-06T13:33:02+00:00

The function bsg_goose_queue() does not have any in-tree callers, so let's remove it. Signed-off-by: Bart Van Assche Acked-by: Tejun Heo Signed-off-by: Jens Axboe

block: drop custom queue draining used by scsi_transport_{iscsi|fc}

2012-06-25T09:53:48+00:00

iscsi_remove_host() uses bsg_remove_queue() which implements custom queue draining. fc_bsg_remove() open-codes mostly identical logic. The draining logic isn't correct in that blk_stop_queue() doesn't prevent new requests from being queued - it just stops processing, so nothing prevents new requests to be queued after the logic determines that the queue is drained. blk_cleanup_queue() now implements proper queue draining and these custom draining logics aren't necessary. Drop them and use bsg_unregister_queue() + blk_cleanup_queue() instead. Signed-off-by: Tejun Heo Reviewed-by: Mike Christie Acked-by: Vivek Goyal Cc: James Bottomley Cc: James Smart Signed-off-by: Jens Axboe

block: add bsg helper library

2011-07-31T20:05:09+00:00

This moves the FC classes bsg code to the block layer and makes it a lib so that other classes like iscsi and SAS can use it. It is helpful because working with the request queue, bios, creating scatterlists, etc are a pain that the LLD does not have to worry about with normal IOs and should not have to worry about for bsg requests. Signed-off-by: Mike Christie Signed-off-by: Jens Axboe