linux/drivers/scsi/device_handler, branch v3.5

[SCSI] scsi_dh_alua: Optimize the STPG command

2012-04-23T18:28:18Z

This patch optimizes the set target port group(STPG) command. During our testing, we found that it is not optimal to send stpg command every time the path group switch happens. This patch uses PREF (preferred target port) bit with combination of flags passed by multipath user level tool to optimize this behaviour. If PREF bit is set then it issues a STPG command, otherwise it will let implicit transfer take place. By default there is no change in the behaviour. User tool needs to pass the parameter to make this change take effect. Patch has been tested on NetApp E series storage. Signed-off-by: Babu Moger Reviewed-by: Hannes Reinecke Signed-off-by: James Bottomley

[SCSI] scsi_dh_alua: Store the PREF bit from RTPG

2012-04-23T18:28:13Z

PREF bit indicates preferred target port group for accessing a logical unit. This bit is used to optimize the STPG command handling. Signed-off-by: Babu Moger Reviewed-by: Hannes Reinecke Signed-off-by: James Bottomley

[SCSI] scsi_dh_alua: Inroduce the set_params interface scsi_dh_alua handler

2012-04-23T18:28:07Z

Handler expects only one parameter to set the flag ALUA_OPTIMIZE_STPG. This flag is used to optimize the STPG behaviour. There is no change in behaviour by default. For example, to set the flag pass the following parameters from multipath.conf hardware_handler "2 alua 1" Signed-off-by: Babu Moger Reviewed-by: Hannes Reinecke Signed-off-by: James Bottomley

[SCSI] scsi_dh_rdac: Fix for unbalanced reference count

2012-02-22T18:15:19Z

This patch fixes an unbalanced refcount issue. Elevating the lock for both kref_put and also for controller node deletion. Previously, controller deletion was protected but the not the kref_put. This was causing the other thread to pick up the controller structure which was already kref'd zero. This was causing the following WARN_ON and also sometimes panic. WARNING: at lib/kref.c:43 kref_get+0x2d/0x30() (Not tainted) Hardware name: IBM System x3655 -[7985AC1]- Modules linked in: fuse scsi_dh_rdac autofs4 nfs lockd fscache nfs_acl auth_rpcgss sunrpc 8021q garp stp llc ipv6 ib_srp(U) scsi_transport_srp scsi_tgt ib_cm(U) ib_sa(U) ib_uverbs(U) ib_umad(U) mlx4_ib(U) mlx4_core(U) ib_mthca(U) ib_mad(U) ib_core(U) dm_mirror dm_region_hash dm_log dm_round_robin dm_multipath uinput bnx2 ses enclosure sg ibmpex ibmaem ipmi_msghandler serio_raw k8temp hwmon amd64_edac_mod edac_core edac_mce_amd shpchp i2c_piix4 ext4 mbcache jbd2 sr_mod cdrom sd_mod crc_t10dif sata_svw pata_acpi ata_generic pata_serverworks aacraid radeon ttm drm_kms_helper drm i2c_algo_bit i2c_core dm_mod [last unloaded: freq_table] Pid: 13735, comm: srp_daemon Not tainted 2.6.32-71.el6.x86_64 #1 Call Trace: [] warn_slowpath_common+0x87/0xc0 [] warn_slowpath_null+0x1a/0x20 [] kref_get+0x2d/0x30 [] rdac_bus_attach+0x459/0x580 [scsi_dh_rdac] [] scsi_dh_handler_attach+0x2a/0x80 [] scsi_dh_notifier+0x9b/0xa0 [] notifier_call_chain+0x55/0x80 [] __blocking_notifier_call_chain+0x5a/0x80 [] blocking_notifier_call_chain+0x16/0x20 [] device_add+0x515/0x640 [] ? attribute_container_device_trigger+0xc4/0xe0 [] scsi_sysfs_add_sdev+0x89/0x2c0 [] scsi_probe_and_add_lun+0xea6/0xed0 [] ? scsi_alloc_target+0x292/0x2d0 [] __scsi_scan_target+0x121/0x750 [] ? sysfs_create_file+0x26/0x30 [] ? device_create_file+0x19/0x20 [] ? attribute_container_add_attrs+0x78/0x90 [] ? klist_next+0x4c/0xf0 [] ? transport_configure+0x0/0x20 [] ? attribute_container_device_trigger+0xc4/0xe0 [] scsi_scan_target+0xd0/0xe0 [] srp_create_target+0x75a/0x890 [ib_srp] [] dev_attr_store+0x20/0x30 [] sysfs_write_file+0xe5/0x170 [] vfs_write+0xb8/0x1a0 [] ? audit_syscall_entry+0x272/0x2a0 [] sys_write+0x51/0x90 [] system_call_fastpath+0x16/0x1b Signed-off-by: Babu Moger Acked-by: Mike Snitzer Signed-off-by: James Bottomley

[SCSI] scsi_dh_alua: Retry the check-condition in case Mode Parameters Changed

2012-01-10T23:01:24Z

This patch adds a check-condition in scsi_dh_alua handler for a retry. Sometimes, I have seen attach failing due to this check-condition with following error messages on NetApp E series storage. Dec 7 15:31:01 nilgiris kernel: [102979.696673] scsi 3:0:2:9: alua: port group 00 rel port 01 Dec 7 15:31:01 nilgiris kernel: [102979.697082] scsi 3:0:2:9: alua: rtpg failed with 8000002 Dec 7 15:31:01 nilgiris kernel: [102979.697086] scsi 3:0:2:9: alua: rtpg sense code 06/2a/01 Dec 7 15:31:01 nilgiris kernel: [102979.697088] scsi 3:0:2:9: alua: not attached Signed-off-by: Babu Moger Signed-off-by: James Bottomley

[SCSI] scsi_dh_rdac: Fix error path

2012-01-10T23:01:18Z

If create_singlethread_workqueue() failes, rdac_init should fail too. Signed-off-by: Richard Weinberger Acked-by: "Moger, Babu" Signed-off-by: James Bottomley

[SCSI] scsi_dh: code cleanup and remove the references to scsi_dev_info

2011-12-15T06:55:00Z

All the handlers have now implemented the match function so We don't need to use scsi_dev_info any more for matching purposes. Signed-off-by: Babu Moger Acked-by: Hannes Reinecke Signed-off-by: James Bottomley

[SCSI] scsi_dh_rdac: Adding the match function for rdac device handler

2011-12-15T06:55:00Z

This patch introduces the match function for rdac device handler. Without this, sometimes handler attach fails during the device_add. Included check for TPGS bit before proceeding further. The match function was introduced by commit 6c3633d08acf514e2e89aa95d2346ce9d64d719a Signed-off-by: Babu Moger Acked-by: Hannes Reinecke Signed-off-by: James Bottomley

[SCSI] scsi_dh_hp_sw: Adding the match function for hp_sw device handler

2011-12-15T06:55:00Z

This patch introduces the match function for hp_sw device handler. Included the check for TPGS bit before proceeding further per Hannes comment. The match function was introduced by commit 6c3633d08acf514e2e89aa95d2346ce9d64d719a Signed-off-by: Babu Moger Acked-by: Hannes Reinecke Signed-off-by: James Bottomley

[SCSI] scsi_dh_emc: Add a match function for emc device handler

2011-12-15T06:55:00Z

This patch introduces the match function for emc device handler. Included check for TPGS bit before proceeding further. The match function was introduced by commit 6c3633d08acf514e2e89aa95d2346ce9d64d719a Signed-off-by: Babu Moger Acked-by: Hannes Reinecke Signed-off-by: James Bottomley