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authorTejun Heo <htejun@gmail.com>2007-07-16 01:29:40 -0400
committerJeff Garzik <jeff@garzik.org>2007-07-20 08:26:25 -0400
commit1ae463171cc1b1ea6dad7bcb298e96c073e7373e (patch)
treec3d62562c9be8c855f7238785ea9c9348f1e56f1 /drivers/ata
parentf1545154a5c96590b1992aac8ee1e2c445e301ed (diff)
libata: improve SCSI scan failure handling
SCSI scan may fail due to memory allocation failure even if EH is not in progress. Due to use of GFP_ATOMIC in SCSI scan path, allocation failure isn't too rare especially while probing multiple devices at once which is the case when a bunch of devices are connected to PMP. This patch moves SCSI scan failure detetion logic from ata_scsi_hotplug() to ata_scsi_scan_host() and implement synchronous scan behavior. The synchronous path sleeps briefly and repeats SCSI scan if some devices aren't attached properly. It contains robust retry loop to minimize the chance of device misdetection during boot and falls back to async retry if everything fails. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
Diffstat (limited to 'drivers/ata')
-rw-r--r--drivers/ata/libata-core.c2
-rw-r--r--drivers/ata/libata-scsi.c63
-rw-r--r--drivers/ata/libata.h2
3 files changed, 49 insertions, 18 deletions
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 05922e9f4fad..35b621293831 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -6453,7 +6453,7 @@ int ata_host_register(struct ata_host *host, struct scsi_host_template *sht)
6453 for (i = 0; i < host->n_ports; i++) { 6453 for (i = 0; i < host->n_ports; i++) {
6454 struct ata_port *ap = host->ports[i]; 6454 struct ata_port *ap = host->ports[i];
6455 6455
6456 ata_scsi_scan_host(ap); 6456 ata_scsi_scan_host(ap, 1);
6457 } 6457 }
6458 6458
6459 return 0; 6459 return 0;
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index cfde22da07ac..12ac0b511f79 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -2947,17 +2947,22 @@ int ata_scsi_add_hosts(struct ata_host *host, struct scsi_host_template *sht)
2947 return rc; 2947 return rc;
2948} 2948}
2949 2949
2950void ata_scsi_scan_host(struct ata_port *ap) 2950void ata_scsi_scan_host(struct ata_port *ap, int sync)
2951{ 2951{
2952 int tries = 5;
2953 struct ata_device *last_failed_dev = NULL;
2954 struct ata_device *dev;
2952 unsigned int i; 2955 unsigned int i;
2953 2956
2954 if (ap->flags & ATA_FLAG_DISABLED) 2957 if (ap->flags & ATA_FLAG_DISABLED)
2955 return; 2958 return;
2956 2959
2960 repeat:
2957 for (i = 0; i < ATA_MAX_DEVICES; i++) { 2961 for (i = 0; i < ATA_MAX_DEVICES; i++) {
2958 struct ata_device *dev = &ap->device[i];
2959 struct scsi_device *sdev; 2962 struct scsi_device *sdev;
2960 2963
2964 dev = &ap->device[i];
2965
2961 if (!ata_dev_enabled(dev) || dev->sdev) 2966 if (!ata_dev_enabled(dev) || dev->sdev)
2962 continue; 2967 continue;
2963 2968
@@ -2967,6 +2972,45 @@ void ata_scsi_scan_host(struct ata_port *ap)
2967 scsi_device_put(sdev); 2972 scsi_device_put(sdev);
2968 } 2973 }
2969 } 2974 }
2975
2976 /* If we scanned while EH was in progress or allocation
2977 * failure occurred, scan would have failed silently. Check
2978 * whether all devices are attached.
2979 */
2980 for (i = 0; i < ATA_MAX_DEVICES; i++) {
2981 dev = &ap->device[i];
2982 if (ata_dev_enabled(dev) && !dev->sdev)
2983 break;
2984 }
2985 if (i == ATA_MAX_DEVICES)
2986 return;
2987
2988 /* we're missing some SCSI devices */
2989 if (sync) {
2990 /* If caller requested synchrnous scan && we've made
2991 * any progress, sleep briefly and repeat.
2992 */
2993 if (dev != last_failed_dev) {
2994 msleep(100);
2995 last_failed_dev = dev;
2996 goto repeat;
2997 }
2998
2999 /* We might be failing to detect boot device, give it
3000 * a few more chances.
3001 */
3002 if (--tries) {
3003 msleep(100);
3004 goto repeat;
3005 }
3006
3007 ata_port_printk(ap, KERN_ERR, "WARNING: synchronous SCSI scan "
3008 "failed without making any progress,\n"
3009 " switching to async\n");
3010 }
3011
3012 queue_delayed_work(ata_aux_wq, &ap->hotplug_task,
3013 round_jiffies_relative(HZ));
2970} 3014}
2971 3015
2972/** 3016/**
@@ -3093,20 +3137,7 @@ void ata_scsi_hotplug(struct work_struct *work)
3093 } 3137 }
3094 3138
3095 /* scan for new ones */ 3139 /* scan for new ones */
3096 ata_scsi_scan_host(ap); 3140 ata_scsi_scan_host(ap, 0);
3097
3098 /* If we scanned while EH was in progress, scan would have
3099 * failed silently. Requeue if there are enabled but
3100 * unattached devices.
3101 */
3102 for (i = 0; i < ATA_MAX_DEVICES; i++) {
3103 struct ata_device *dev = &ap->device[i];
3104 if (ata_dev_enabled(dev) && !dev->sdev) {
3105 queue_delayed_work(ata_aux_wq, &ap->hotplug_task,
3106 round_jiffies_relative(HZ));
3107 break;
3108 }
3109 }
3110 3141
3111 DPRINTK("EXIT\n"); 3142 DPRINTK("EXIT\n");
3112} 3143}
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index ba17fc5f2e99..48836b22ce2f 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -112,7 +112,7 @@ static inline int ata_acpi_on_devcfg(struct ata_device *adev) { return 0; }
112/* libata-scsi.c */ 112/* libata-scsi.c */
113extern int ata_scsi_add_hosts(struct ata_host *host, 113extern int ata_scsi_add_hosts(struct ata_host *host,
114 struct scsi_host_template *sht); 114 struct scsi_host_template *sht);
115extern void ata_scsi_scan_host(struct ata_port *ap); 115extern void ata_scsi_scan_host(struct ata_port *ap, int sync);
116extern int ata_scsi_offline_dev(struct ata_device *dev); 116extern int ata_scsi_offline_dev(struct ata_device *dev);
117extern void ata_scsi_hotplug(struct work_struct *work); 117extern void ata_scsi_hotplug(struct work_struct *work);
118extern unsigned int ata_scsiop_inq_std(struct ata_scsi_args *args, u8 *rbuf, 118extern unsigned int ata_scsiop_inq_std(struct ata_scsi_args *args, u8 *rbuf,