Greetings All, This patch changes core_scsi3_pr_seq_non_holder() to allow 'Registrants only' reservations to allow multiple writers from the reservation holder, and all registered I_T Nexuses. Previously, only 'All Registrants' reservations where allowed to to have multiple writers because each registration in a 'All Registrants' reservation is considered the reservation holder. This patch allows an I_T nexus to write who is NOT the reservation holder, but does have a valid registration. These patches are made against lio-core-2.6.git/master and tested on v2.6.29 x86 32-bit HVM using sg_persist from sg3_utils. The lio-core-2.6.git tree can be found at: http://git.kernel.org/?p=linux/kernel/git/nab/lio-core-2.6.git;a=summary Here is what it looks like from the initiator side with /dev/sde and /dev/sdf representing the same IBLOCK exported storage object across two different I_T nexuses: [3:0:0:0] disk iqn.2003-01.org.linux-iscsi.target.i686:sn.cff3eedbd2fd,t,0x1 /dev/sde [4:0:0:0] disk iqn.2003-01.org.linux-iscsi.target.i686:sn.e475ed6fcdd0,t,0x1 /dev/sdf *) Register and and create a 'Write Exclusive, Registrants Only' reservation for /dev/sde initiator# sg_persist --out --register-ignore --param-sark=0x1234abcd -Y -v /dev/sde inquiry cdb: 12 00 00 00 24 00 LIO-ORG IBLOCK 3.0 Peripheral device type: disk Persistent Reservation Out cmd: 5f 06 00 00 00 00 00 00 18 00 PR out: command (Register and ignore existing key) successful initiator# sg_persist --out --reserve --param-rk=0x1234abcd --prout-type=5 -v /dev/sde inquiry cdb: 12 00 00 00 24 00 LIO-ORG IBLOCK 3.0 Peripheral device type: disk Persistent Reservation Out cmd: 5f 01 05 00 00 00 00 00 18 00 PR out: command (Reserve) successful *) Attempt write on a unregistered I_T nexus (fails with RESERVATION CONFLICT): initiator# dd if=/dev/zero of=/dev/sdf bs=2048 count=1 1+0 records in 1+0 records out 2048 bytes (2.0 kB) copied, 4.4217e-05 seconds, 46.3 MB/s [ 1160.287946] sd 4:0:0:0: reservation conflict [ 1160.287971] sd 4:0:0:0: [sdf] Result: hostbyte=DID_OK driverbyte=DRIVER_OK,SUGGEST_OK [ 1160.287989] end_request: I/O error, dev sdf, sector 0 [ 1160.288115] Buffer I/O error on device sdf, logical block 0 [ 1160.288183] lost page write due to I/O error on sdf *) Create a registration on /dev/sdf, while /dev/sde is still holding the reservation. initiator# sg_persist --out --register-ignore --param-sark=0x4567ffff -Y -v /dev/sdf inquiry cdb: 12 00 00 00 24 00 LIO-ORG IBLOCK 3.0 Peripheral device type: disk Persistent Reservation Out cmd: 5f 06 00 00 00 00 00 00 18 00 PR out: command (Register and ignore existing key) successful *) A Write now succeeds after /dev/sdf has been registered successfully. initiator# dd if=/dev/zero of=/dev/sdf bs=2048 count=1 1+0 records in 1+0 records out 2048 bytes (2.0 kB) copied, 3.9031e-05 seconds, 52.5 MB/s *) From the Target side: SPC-3 PR [iSCSI] Service Action: REGISTER_AND_IGNORE_EXISTING_KEY Initiator Node: iqn.1993-08.org.debian:01:2dadf92d0ef SPC-3 PR [iSCSI] for ALL TCM Subsystem iblock Object Target Port(s) SPC-3 PR [iSCSI] SA Res Key: 0x000000001234abcd PRgeneration: 0x00000000 SPC-3 PR [iSCSI] Service Action: RESERVE created new reservation holder TYPE: Write Exclusive Access, Registrants Only ALL_TG_PT: 1 SPC-3 PR [iSCSI] RESERVE Node: iqn.1993-08.org.debian:01:2dadf92d0ef WRITE Conflict for unregistered nexus iqn.1993-08.org.debian:01:2dadf92d0ef CDB: 0x2a to Write Exclusive Access, Registrants Only reservation SPC-3 PR [iSCSI] Service Action: REGISTER_AND_IGNORE_EXISTING_KEY Initiator Node: iqn.1993-08.org.debian:01:2dadf92d0ef SPC-3 PR [iSCSI] for ALL TCM Subsystem iblock Object Target Port(s) SPC-3 PR [iSCSI] SA Res Key: 0x000000004567ffff PRgeneration: 0x00000001 Signed-off-by: Nicholas A. Bellinger <nab@xxxxxxxxxxxxxxx> --- drivers/lio-core/target_core_pr.c | 28 +++++++++++++++------------- 1 files changed, 15 insertions(+), 13 deletions(-) diff --git a/drivers/lio-core/target_core_pr.c b/drivers/lio-core/target_core_pr.c index 9fe6da5..63e19ad 100644 --- a/drivers/lio-core/target_core_pr.c +++ b/drivers/lio-core/target_core_pr.c @@ -181,7 +181,7 @@ static int core_scsi3_pr_seq_non_holder( se_lun_t *se_lun = SE_LUN(cmd); int other_cdb = 0; int registered_nexus = 0, ret = 1; /* Conflict by default */ - int all_reg = 0; /* ALL_REG */ + int all_reg = 0, reg_only = 0; /* ALL_REG, REG_ONLY */ int we = 0; /* Write Exclusive */ int legacy = 0; /* Act like a legacy device and return * RESERVATION CONFLICT on some CDBs */ @@ -205,6 +205,7 @@ static int core_scsi3_pr_seq_non_holder( /* * Some commands are only allowed for registered I_T Nexuses. */ + reg_only = 1; if (se_deve->deve_flags & DEF_PR_REGISTERED) registered_nexus = 1; break; @@ -349,21 +350,17 @@ static int core_scsi3_pr_seq_non_holder( * Check if write exclusive initiator ports *NOT* holding the * WRITE_EXCLUSIVE_* reservation. */ - if (we) { + if ((we) && !(registered_nexus)) { if ((cmd->data_direction == SE_DIRECTION_WRITE) || (cmd->data_direction == SE_DIRECTION_BIDI)) { /* * Conflict for write exclusive */ - printk(KERN_INFO "WRITE Conflict for %sregistered nexus" + printk(KERN_INFO "%s Conflict for unregistered nexus" " %s CDB: 0x%02x to %s reservation\n", - (registered_nexus) ? "" : "un", + transport_dump_cmd_direction(cmd), se_sess->se_node_acl->initiatorname, cdb[0], core_scsi3_pr_dump_type(pr_reg_type)); - if (cdb[0] == PERSISTENT_RESERVE_OUT) - printk(KERN_INFO "WRITE Conflict was" - " PERSISTENT_RESERVE_OUT, Service" - " Action: 0x%02x\n", cdb[1] & 0x1f); return 1; } else { /* @@ -385,20 +382,25 @@ static int core_scsi3_pr_seq_non_holder( #endif return 0; } - } else if (all_reg) { + } else if ((reg_only) || (all_reg)) { if (registered_nexus) { /* - * For PR_*_ALL_REG reservation, treat all registered - * nexuses as the reservation holder. + * For PR_*_REG_ONLY and PR_*_ALL_REG reservations, + * allow commands from registered nexuses. */ +#if 0 printk(KERN_INFO "Allowing implict CDB: 0x%02x for %s" " reservation\n", cdb[0], core_scsi3_pr_dump_type(pr_reg_type)); +#endif return 0; } } - printk(KERN_INFO "Conflict for CDB: 0x%2x for %s reservation\n", - cdb[0], core_scsi3_pr_dump_type(pr_reg_type)); + printk(KERN_INFO "%s Conflict for %sregistered nexus %s CDB: 0x%2x" + " for %s reservation\n", transport_dump_cmd_direction(cmd), + (registered_nexus) ? "" : "un", + se_sess->se_node_acl->initiatorname, cdb[0], + core_scsi3_pr_dump_type(pr_reg_type)); return 1; /* Conflict by default */ } -- 1.5.4.1 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
