From f4a93bcda74edfe6977dcf296ed8c86119638871 Mon Sep 17 00:00:00 2001 From: Mike Miller Date: Mon, 4 Aug 2008 11:54:53 +0200 Subject: [PATCH] cciss: change the way we notify scsi midlayer of tape drives This patch changes way we notify the scsi layer that something has changed on the SCSI tape side of the driver. The user can now just tell the driver to rescan a particular controller rather than having to know the SCSI nexus to echo into the SCSI mid-layer. Signed-off-by: Stephen M. Cameron Signed-off-by: Mike Miller Signed-off-by: Jens Axboe --- Documentation/cciss.txt | 21 ++--- drivers/block/cciss_scsi.c | 157 ++++++++++++++++++++++++++++--------- 2 files changed, 124 insertions(+), 54 deletions(-) diff --git a/Documentation/cciss.txt b/Documentation/cciss.txt index 63e59b8847..8244c6442f 100644 --- a/Documentation/cciss.txt +++ b/Documentation/cciss.txt @@ -112,27 +112,18 @@ Hot plug support for SCSI tape drives Hot plugging of SCSI tape drives is supported, with some caveats. The cciss driver must be informed that changes to the SCSI bus -have been made, in addition to and prior to informing the SCSI -mid layer. This may be done via the /proc filesystem. For example: +have been made. This may be done via the /proc filesystem. +For example: echo "rescan" > /proc/scsi/cciss0/1 -This causes the adapter to query the adapter about changes to the -physical SCSI buses and/or fibre channel arbitrated loop and the +This causes the driver to query the adapter about changes to the +physical SCSI buses and/or fibre channel arbitrated loop and the driver to make note of any new or removed sequential access devices or medium changers. The driver will output messages indicating what devices have been added or removed and the controller, bus, target and -lun used to address the device. Once this is done, the SCSI mid layer -can be informed of changes to the virtual SCSI bus which the driver -presents to it in the usual way. For example: - - echo scsi add-single-device 3 2 1 0 > /proc/scsi/scsi - -to add a device on controller 3, bus 2, target 1, lun 0. Note that -the driver makes an effort to preserve the devices positions -in the virtual SCSI bus, so if you are only moving tape drives -around on the same adapter and not adding or removing tape drives -from the adapter, informing the SCSI mid layer may not be necessary. +lun used to address the device. It then notifies the SCSI mid layer +of these changes. Note that the naming convention of the /proc filesystem entries contains a number in addition to the driver name. (E.g. "cciss0" diff --git a/drivers/block/cciss_scsi.c b/drivers/block/cciss_scsi.c index e4bf9a11ca..c673ff1412 100644 --- a/drivers/block/cciss_scsi.c +++ b/drivers/block/cciss_scsi.c @@ -358,10 +358,15 @@ find_bus_target_lun(int ctlr, int *bus, int *target, int *lun) } return (!found); } +struct scsi2map { + char scsi3addr[8]; + int bus, target, lun; +}; static int cciss_scsi_add_entry(int ctlr, int hostno, - unsigned char *scsi3addr, int devtype) + unsigned char *scsi3addr, int devtype, + struct scsi2map *added, int *nadded) { /* assumes hba[ctlr]->scsi_ctlr->lock is held */ int n = ccissscsi[ctlr].ndevices; @@ -375,6 +380,12 @@ cciss_scsi_add_entry(int ctlr, int hostno, sd = &ccissscsi[ctlr].dev[n]; if (find_bus_target_lun(ctlr, &sd->bus, &sd->target, &sd->lun) != 0) return -1; + + added[*nadded].bus = sd->bus; + added[*nadded].target = sd->target; + added[*nadded].lun = sd->lun; + (*nadded)++; + memcpy(&sd->scsi3addr[0], scsi3addr, 8); sd->devtype = devtype; ccissscsi[ctlr].ndevices++; @@ -390,7 +401,8 @@ cciss_scsi_add_entry(int ctlr, int hostno, } static void -cciss_scsi_remove_entry(int ctlr, int hostno, int entry) +cciss_scsi_remove_entry(int ctlr, int hostno, int entry, + struct scsi2map *removed, int *nremoved) { /* assumes hba[ctlr]->scsi_ctlr->lock is held */ int i; @@ -398,6 +410,10 @@ cciss_scsi_remove_entry(int ctlr, int hostno, int entry) if (entry < 0 || entry >= CCISS_MAX_SCSI_DEVS_PER_HBA) return; sd = ccissscsi[ctlr].dev[entry]; + removed[*nremoved].bus = sd.bus; + removed[*nremoved].target = sd.target; + removed[*nremoved].lun = sd.lun; + (*nremoved)++; for (i=entry;iscsi_ctlr)->scsi_host; + /* find any devices in ccissscsi[] that are not in sd[] and remove them from ccissscsi[] */ i = 0; + nremoved = 0; + nadded = 0; while(idevtype), hostno, csd->bus, csd->target, csd->lun); */ - cciss_scsi_remove_entry(ctlr, hostno, i); - /* note, i not incremented */ + cciss_scsi_remove_entry(ctlr, hostno, i, + removed, &nremoved); + /* remove ^^^, hence i not incremented */ } else if (found == 1) { /* device is different kind */ changes++; @@ -464,8 +521,15 @@ adjust_cciss_scsi_table(int ctlr, int hostno, "(device type now %s).\n", ctlr, hostno, csd->bus, csd->target, csd->lun, scsi_device_type(csd->devtype)); + cciss_scsi_remove_entry(ctlr, hostno, i, + removed, &nremoved); + /* remove ^^^, hence i not incremented */ + if (cciss_scsi_add_entry(ctlr, hostno, + &sd[j].scsi3addr[0], sd[j].devtype, + added, &nadded) != 0) + /* we just removed one, so add can't fail. */ + BUG(); csd->devtype = sd[j].devtype; - i++; /* so just move along. */ } else /* device is same as it ever was, */ i++; /* so just move along. */ } @@ -489,7 +553,9 @@ adjust_cciss_scsi_table(int ctlr, int hostno, if (!found) { changes++; if (cciss_scsi_add_entry(ctlr, hostno, - &sd[i].scsi3addr[0], sd[i].devtype) != 0) + + &sd[i].scsi3addr[0], sd[i].devtype, + added, &nadded) != 0) break; } else if (found == 1) { /* should never happen... */ @@ -501,9 +567,50 @@ adjust_cciss_scsi_table(int ctlr, int hostno, } CPQ_TAPE_UNLOCK(ctlr, flags); - if (!changes) - printk("cciss%d: No device changes detected.\n", ctlr); + /* Don't notify scsi mid layer of any changes the first time through */ + /* (or if there are no changes) scsi_scan_host will do it later the */ + /* first time through. */ + if (hostno == -1 || !changes) + goto free_and_out; + + /* Notify scsi mid layer of any removed devices */ + for (i = 0; i < nremoved; i++) { + struct scsi_device *sdev = + scsi_device_lookup(sh, removed[i].bus, + removed[i].target, removed[i].lun); + if (sdev != NULL) { + scsi_remove_device(sdev); + scsi_device_put(sdev); + } else { + /* We don't expect to get here. */ + /* future cmds to this device will get selection */ + /* timeout as if the device was gone. */ + printk(KERN_WARNING "cciss%d: didn't find " + "c%db%dt%dl%d\n for removal.", + ctlr, hostno, removed[i].bus, + removed[i].target, removed[i].lun); + } + } + + /* Notify scsi mid layer of any added devices */ + for (i = 0; i < nadded; i++) { + int rc; + rc = scsi_add_device(sh, added[i].bus, + added[i].target, added[i].lun); + if (rc == 0) + continue; + printk(KERN_WARNING "cciss%d: scsi_add_device " + "c%db%dt%dl%d failed, device not added.\n", + ctlr, hostno, + added[i].bus, added[i].target, added[i].lun); + /* now we have to remove it from ccissscsi, */ + /* since it didn't get added to scsi mid layer */ + fixup_botched_add(ctlr, added[i].scsi3addr); + } +free_and_out: + kfree(added); + kfree(removed); return 0; } @@ -1354,32 +1461,6 @@ cciss_unregister_scsi(int ctlr) kfree(sa); } -static int -cciss_register_scsi(int ctlr) -{ - unsigned long flags; - - CPQ_TAPE_LOCK(ctlr, flags); - - /* Since this is really a block driver, the SCSI core may not be - initialized at init time, in which case, calling scsi_register_host - would hang. Instead, we do it later, via /proc filesystem - and rc scripts, when we know SCSI core is good to go. */ - - /* Only register if SCSI devices are detected. */ - if (ccissscsi[ctlr].ndevices != 0) { - ((struct cciss_scsi_adapter_data_t *) - hba[ctlr]->scsi_ctlr)->registered = 1; - CPQ_TAPE_UNLOCK(ctlr, flags); - return cciss_scsi_detect(ctlr); - } - CPQ_TAPE_UNLOCK(ctlr, flags); - printk(KERN_INFO - "cciss%d: No appropriate SCSI device detected, " - "SCSI subsystem not engaged.\n", ctlr); - return 0; -} - static int cciss_engage_scsi(int ctlr) { @@ -1391,15 +1472,15 @@ cciss_engage_scsi(int ctlr) sa = (struct cciss_scsi_adapter_data_t *) hba[ctlr]->scsi_ctlr; stk = &sa->cmd_stack; - if (((struct cciss_scsi_adapter_data_t *) - hba[ctlr]->scsi_ctlr)->registered) { + if (sa->registered) { printk("cciss%d: SCSI subsystem already engaged.\n", ctlr); spin_unlock_irqrestore(CCISS_LOCK(ctlr), flags); return ENXIO; } + sa->registered = 1; spin_unlock_irqrestore(CCISS_LOCK(ctlr), flags); cciss_update_non_disk_devices(ctlr, -1); - cciss_register_scsi(ctlr); + cciss_scsi_detect(ctlr); return 0; } @@ -1493,7 +1574,5 @@ static int cciss_eh_abort_handler(struct scsi_cmnd *scsicmd) /* If no tape support, then these become defined out of existence */ #define cciss_scsi_setup(cntl_num) -#define cciss_unregister_scsi(ctlr) -#define cciss_register_scsi(ctlr) #endif /* CONFIG_CISS_SCSI_TAPE */ -- 2.39.5