linux/block
Keith Mannthey 08bafc0341 block: Supress Buffer I/O errors when SCSI REQ_QUIET flag set
Allow the scsi request REQ_QUIET flag to be propagated to the buffer
file system layer. The basic ideas is to pass the flag from the scsi
request to the bio (block IO) and then to the buffer layer.  The buffer
layer can then suppress needless printks.

This patch declutters the kernel log by removed the 40-50 (per lun)
buffer io error messages seen during a boot in my multipath setup . It
is a good chance any real errors will be missed in the "noise" it the
logs without this patch.

During boot I see blocks of messages like
"
__ratelimit: 211 callbacks suppressed
Buffer I/O error on device sdm, logical block 5242879
Buffer I/O error on device sdm, logical block 5242879
Buffer I/O error on device sdm, logical block 5242847
Buffer I/O error on device sdm, logical block 1
Buffer I/O error on device sdm, logical block 5242878
Buffer I/O error on device sdm, logical block 5242879
Buffer I/O error on device sdm, logical block 5242879
Buffer I/O error on device sdm, logical block 5242879
Buffer I/O error on device sdm, logical block 5242879
Buffer I/O error on device sdm, logical block 5242872
"
in my logs.

My disk environment is multipath fiber channel using the SCSI_DH_RDAC
code and multipathd.  This topology includes an "active" and "ghost"
path for each lun. IO's to the "ghost" path will never complete and the
SCSI layer, via the scsi device handler rdac code, quick returns the IOs
to theses paths and sets the REQ_QUIET scsi flag to suppress the scsi
layer messages.

 I am wanting to extend the QUIET behavior to include the buffer file
system layer to deal with these errors as well. I have been running this
patch for a while now on several boxes without issue.  A few runs of
bonnie++ show no noticeable difference in performance in my setup.

Thanks for John Stultz for the quiet_error finalization.

Submitted-by:  Keith Mannthey <kmannth@us.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29 08:28:44 +01:00
..
as-iosched.c block: as/cfq ssd idle check update 2008-10-09 08:56:19 +02:00
blk-barrier.c block: internal dequeue shouldn't start timer 2008-12-03 12:41:26 +01:00
blk-core.c block: Supress Buffer I/O errors when SCSI REQ_QUIET flag set 2008-12-29 08:28:44 +01:00
blk-exec.c Add some block/ source files to the kernel-api docbook. Fix kernel-doc notation in them as needed. Fix changed function parameter names. Fix typos/spellos. In comments, change REQ_SPECIAL to REQ_TYPE_SPECIAL and REQ_BLOCK_PC to REQ_TYPE_BLOCK_PC. 2008-10-09 08:56:03 +02:00
blk-integrity.c block: Switch blk_integrity_compare from bdev to gendisk 2008-10-09 08:56:21 +02:00
blk-ioc.c cfq-iosched: fix RCU race in the cfq io_context destructor handling 2008-05-07 09:28:57 +02:00
blk-map.c When block layer fails to map iov, it calls bio_unmap_user to undo 2008-12-03 12:41:20 +01:00
blk-merge.c block: remove unused ll_new_mergeable() 2008-11-06 08:41:55 +01:00
blk-settings.c block: fix setting of max_segment_size and seg_boundary mask 2008-12-03 12:55:55 +01:00
blk-softirq.c block: add fault injection mechanism for faking request timeouts 2008-10-09 08:56:17 +02:00
blk-sysfs.c block: don't take lock on changing ra_pages 2008-12-29 08:28:43 +01:00
blk-tag.c block/blk-tag.c: cleanup kernel-doc 2008-12-29 08:28:43 +01:00
blk-timeout.c block: leave the request timeout timer running even on an empty list 2008-12-29 08:28:42 +01:00
blk.h block: remove __generic_unplug_device() from exports 2008-10-17 14:03:08 +02:00
blktrace.c blktrace: port to tracepoints 2008-11-26 12:13:34 +01:00
bsg.c Enforce a minimum SG_IO timeout 2008-12-05 14:49:18 -08:00
cfq-iosched.c block: as/cfq ssd idle check update 2008-10-09 08:56:19 +02:00
cmd-filter.c [PATCH] introduce fmode_t, do annotations 2008-10-21 07:47:06 -04:00
compat_ioctl.c block: don't take lock on changing ra_pages 2008-12-29 08:28:43 +01:00
deadline-iosched.c deadline-iosched: non-functional fixes 2008-10-09 08:56:03 +02:00
elevator.c Merge branches 'tracing/ftrace', 'tracing/function-graph-tracer' and 'tracing/urgent' into tracing/core 2008-12-05 14:45:22 +01:00
genhd.c block: set disk->node_id before it's being used 2008-12-03 12:41:20 +01:00
ioctl.c block: don't take lock on changing ra_pages 2008-12-29 08:28:43 +01:00
Kconfig blktrace: port to tracepoints 2008-11-26 12:13:34 +01:00
Kconfig.iosched update I/O sched Kconfig help texts - CFQ is now default, not AS. 2007-02-17 20:08:22 +01:00
Makefile block: unify request timeout handling 2008-10-09 08:56:13 +02:00
noop-iosched.c block: let elv_register() return void 2007-12-18 08:29:28 +01:00
scsi_ioctl.c scsi-ioctl: use clock_t <> jiffies 2008-12-29 08:28:42 +01:00