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| author | Dave Wysochanski <dwysocha@redhat.com> | 2007-10-19 22:47:53 +0100 |
|---|---|---|
| committer | Alasdair G Kergon <agk@redhat.com> | 2007-10-20 02:01:18 +0100 |
| commit | c9e45581ad530cc1ca4b5d4add44a5b625234ada (patch) | |
| tree | 3d5ddc7762e9c3d3da78f8c4d98047f3f108dd98 /drivers/md/dm-hw-handler.h | |
| parent | 636d5786c45414fd8e48f2a2325be072274fdba4 (diff) | |
| download | op-kernel-dev-c9e45581ad530cc1ca4b5d4add44a5b625234ada.zip op-kernel-dev-c9e45581ad530cc1ca4b5d4add44a5b625234ada.tar.gz | |
dm mpath: add retry pg init
This patch allows a failed path group initialisation command to be retried.
It adds a generic MP_RETRY flag and a "pg_init_retries" feature to
device-mapper multipath which limits the number of retries.
1. A hw handler sends a path initialization command to the storage and
the command completes with an error code indicating the command
should be retried.
2. The hardware handler calls dm_pg_init_complete() with MP_RETRY
set in err_flags to ask the dm multipath core to retry.
3. If the retry limit has not been exceeded, pg_init() is retried.
Otherwise fail_path() is called.
If you are using the userspace multipath-tools or device-mapper-multipath
package, you can set pg_init_retries in the 'device' section of your
/etc/multipath.conf file. For example:
features "2 pg_init_retries 7"
The number of PG retries attempted is reported in the 'dmsetup status' output.
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Acked-by: Mike Christie <michaelc@cs.wisc.edu>
Acked-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Diffstat (limited to 'drivers/md/dm-hw-handler.h')
| -rw-r--r-- | drivers/md/dm-hw-handler.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/md/dm-hw-handler.h b/drivers/md/dm-hw-handler.h index e0832e6..46809dc 100644 --- a/drivers/md/dm-hw-handler.h +++ b/drivers/md/dm-hw-handler.h @@ -58,5 +58,6 @@ unsigned dm_scsi_err_handler(struct hw_handler *hwh, struct bio *bio); #define MP_FAIL_PATH 1 #define MP_BYPASS_PG 2 #define MP_ERROR_IO 4 /* Don't retry this I/O */ +#define MP_RETRY 8 #endif |
