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| author | Bart Van Assche <bart.vanassche@sandisk.com> | 2015-03-04 10:31:47 +0100 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2015-04-22 08:58:38 +0200 |
| commit | b71eafb8217c2006b45a4a056b0421870d16a6c4 (patch) | |
| tree | 5e31c9759e19d1491f03ea3101241af45c20af70 /include/linux | |
| parent | 708d0b8820cbf11df7a7dc2003c950c733bad2b6 (diff) | |
| download | lwn-b71eafb8217c2006b45a4a056b0421870d16a6c4.tar.gz lwn-b71eafb8217c2006b45a4a056b0421870d16a6c4.zip | |
Defer processing of REQ_PREEMPT requests for blocked devices
commit bba0bdd7ad4713d82338bcd9b72d57e9335a664b upstream.
SCSI transport drivers and SCSI LLDs block a SCSI device if the
transport layer is not operational. This means that in this state
no requests should be processed, even if the REQ_PREEMPT flag has
been set. This patch avoids that a rescan shortly after a cable
pull sporadically triggers the following kernel oops:
BUG: unable to handle kernel paging request at ffffc9001a6bc084
IP: [<ffffffffa04e08f2>] mlx4_ib_post_send+0xd2/0xb30 [mlx4_ib]
Process rescan-scsi-bus (pid: 9241, threadinfo ffff88053484a000, task ffff880534aae100)
Call Trace:
[<ffffffffa0718135>] srp_post_send+0x65/0x70 [ib_srp]
[<ffffffffa071b9df>] srp_queuecommand+0x1cf/0x3e0 [ib_srp]
[<ffffffffa0001ff1>] scsi_dispatch_cmd+0x101/0x280 [scsi_mod]
[<ffffffffa0009ad1>] scsi_request_fn+0x411/0x4d0 [scsi_mod]
[<ffffffff81223b37>] __blk_run_queue+0x27/0x30
[<ffffffff8122a8d2>] blk_execute_rq_nowait+0x82/0x110
[<ffffffff8122a9c2>] blk_execute_rq+0x62/0xf0
[<ffffffffa000b0e8>] scsi_execute+0xe8/0x190 [scsi_mod]
[<ffffffffa000b2f3>] scsi_execute_req+0xa3/0x130 [scsi_mod]
[<ffffffffa000c1aa>] scsi_probe_lun+0x17a/0x450 [scsi_mod]
[<ffffffffa000ce86>] scsi_probe_and_add_lun+0x156/0x480 [scsi_mod]
[<ffffffffa000dc2f>] __scsi_scan_target+0xdf/0x1f0 [scsi_mod]
[<ffffffffa000dfa3>] scsi_scan_host_selected+0x183/0x1c0 [scsi_mod]
[<ffffffffa000edfb>] scsi_scan+0xdb/0xe0 [scsi_mod]
[<ffffffffa000ee13>] store_scan+0x13/0x20 [scsi_mod]
[<ffffffff811c8d9b>] sysfs_write_file+0xcb/0x160
[<ffffffff811589de>] vfs_write+0xce/0x140
[<ffffffff81158b53>] sys_write+0x53/0xa0
[<ffffffff81464592>] system_call_fastpath+0x16/0x1b
[<00007f611c9d9300>] 0x7f611c9d92ff
Reported-by: Max Gurtuvoy <maxg@mellanox.com>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/blk_types.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index fa1abeb45b76..49c48dda162d 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -170,7 +170,9 @@ enum rq_flag_bits { __REQ_ELVPRIV, /* elevator private data attached */ __REQ_FAILED, /* set if the request failed */ __REQ_QUIET, /* don't worry about errors */ - __REQ_PREEMPT, /* set for "ide_preempt" requests */ + __REQ_PREEMPT, /* set for "ide_preempt" requests and also + for requests for which the SCSI "quiesce" + state must be ignored. */ __REQ_ALLOCED, /* request came from our alloc pool */ __REQ_COPY_USER, /* contains copies of user pages */ __REQ_FLUSH_SEQ, /* request for flush sequence */ |