Hi all,
as discussed in San Jose here is a patch to resurrect sdevs which are
in state SDEV_CANCEL / SDEV_DEL.
I've updated sdev handling functions to be better aligned with the state
machine; we now have:
scsi_remove_device(): Same as before; transitioning into SDEV_CANCEL.
Initiate the device removal.
scsi_destroy_device(): Transition into SDEV_DEL; just initiate
the final device_put(). Device will be deleted properly once
the refcount drops to zero.
scsi_configure_device(): Transistion into SDEV_RUNNING.
If scsi_configure_device() succeeds it has to be added to
sysfs with scsi_sysfs_add_sdev(). If it fails the sdev
should be deleted with scsi_destroy_device().
scsi_resurrect_device(): Wrapper around scsi_configure_device.
Transition a deleted device into SDEV_RUNNING.
If it fails the device is in SDEV_DEL.
I've gone through the scanning mechanism and hopefully got it done properly.
I tried to ensure that after the scanning the sdevs are either in
SDEV_RUNNING or SDEV_DEL.
Patch apprears to work properly, but I haven't been running any stress tests
on it. Ie those cases which the patch is trying to solve :-)
Comments etc. welcome.
Cheers,
Hannes
--
Dr. Hannes Reinecke hare@xxxxxxx
SuSE Linux Products GmbH S390 & zSeries
Maxfeldstra�e 5 +49 911 74053 688
90409 N�rnberg http://www.suse.de
diff --git a/block/elevator.c b/block/elevator.c
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
diff --git a/drivers/block/DAC960.c b/drivers/block/DAC960.c
diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
diff --git a/drivers/block/cpqarray.c b/drivers/block/cpqarray.c
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
diff --git a/drivers/block/sx8.c b/drivers/block/sx8.c
diff --git a/drivers/block/ub.c b/drivers/block/ub.c
diff --git a/drivers/block/viodasd.c b/drivers/block/viodasd.c
diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
diff --git a/drivers/message/i2o/i2o_block.c b/drivers/message/i2o/i2o_block.c
diff --git a/drivers/mmc/mmc_block.c b/drivers/mmc/mmc_block.c
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
diff --git a/drivers/s390/char/tape_block.c b/drivers/s390/char/tape_block.c
diff --git a/drivers/scsi/ide-scsi.c b/drivers/scsi/ide-scsi.c
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index b8f0cab..73d0469 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -297,8 +297,7 @@ static struct scsi_device *scsi_alloc_sd
return sdev;
out_device_destroy:
- transport_destroy_device(&sdev->sdev_gendev);
- put_device(&sdev->sdev_gendev);
+ scsi_destroy_device(sdev);
out:
if (display_failure_msg)
printk(ALLOC_FAILURE_MSG, __FUNCTION__);
@@ -697,6 +696,8 @@ static int scsi_probe_lun(struct scsi_de
static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,
int *bflags, int async)
{
+ int ret;
+
/*
* XXX do not save the inquiry, since it can change underneath us,
* save just vendor/model/rev.
@@ -846,10 +847,6 @@ static int scsi_add_lun(struct scsi_devi
if (*bflags & BLIST_USE_10_BYTE_MS)
sdev->use_10_for_ms = 1;
- /* set the device running here so that slave configure
- * may do I/O */
- scsi_device_set_state(sdev, SDEV_RUNNING);
-
if (*bflags & BLIST_MS_192_BYTES_FOR_3F)
sdev->use_192_bytes_for_3f = 1;
@@ -859,21 +856,18 @@ static int scsi_add_lun(struct scsi_devi
if (*bflags & BLIST_RETRY_HWERROR)
sdev->retry_hwerror = 1;
- transport_configure_device(&sdev->sdev_gendev);
-
- if (sdev->host->hostt->slave_configure) {
- int ret = sdev->host->hostt->slave_configure(sdev);
- if (ret) {
- /*
- * if LLDD reports slave not present, don't clutter
- * console with alloc failure messages
- */
- if (ret != -ENXIO) {
- sdev_printk(KERN_ERR, sdev,
- "failed to configure device\n");
- }
- return SCSI_SCAN_NO_RESPONSE;
+ ret = scsi_configure_device(sdev);
+ if (ret) {
+ /*
+ * if LLDD reports slave not present, don't clutter
+ * console with alloc failure messages
+ */
+ if (ret != -ENXIO) {
+ sdev_printk(KERN_ERR, sdev,
+ "failed to configure device\n");
}
+ scsi_destroy_device(sdev);
+ return SCSI_SCAN_NO_RESPONSE;
}
/*
@@ -887,15 +881,6 @@ static int scsi_add_lun(struct scsi_devi
return SCSI_SCAN_LUN_PRESENT;
}
-static inline void scsi_destroy_sdev(struct scsi_device *sdev)
-{
- scsi_device_set_state(sdev, SDEV_DEL);
- if (sdev->host->hostt->slave_destroy)
- sdev->host->hostt->slave_destroy(sdev);
- transport_destroy_device(&sdev->sdev_gendev);
- put_device(&sdev->sdev_gendev);
-}
-
#ifdef CONFIG_SCSI_LOGGING
/**
* scsi_inq_str - print INQUIRY data from min to max index,
@@ -957,6 +942,10 @@ static int scsi_probe_and_add_lun(struct
*/
sdev = scsi_device_lookup_by_target(starget, lun);
if (sdev) {
+ if (scsi_resurrect_device(sdev)) {
+ scsi_device_put(sdev);
+ return SCSI_SCAN_NO_RESPONSE;
+ }
if (rescan || sdev->sdev_state != SDEV_CREATED) {
SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
"scsi scan: device exists on %s\n",
@@ -1067,11 +1056,12 @@ static int scsi_probe_and_add_lun(struct
*sdevp = sdev;
} else {
__scsi_remove_device(sdev);
+ scsi_destroy_device(sdev);
res = SCSI_SCAN_NO_RESPONSE;
}
}
} else
- scsi_destroy_sdev(sdev);
+ scsi_destroy_device(sdev);
out:
return res;
}
@@ -1273,6 +1263,9 @@ static int scsi_report_lun_scan(struct s
return 0;
if (scsi_device_get(sdev))
return 0;
+ } else if (scsi_resurrect_device(sdev)) {
+ scsi_device_put(sdev);
+ return 0;
}
sprintf(devname, "host %d channel %d id %d",
@@ -1425,7 +1418,7 @@ static int scsi_report_lun_scan(struct s
/*
* the sdev we used didn't appear in the report luns scan
*/
- scsi_destroy_sdev(sdev);
+ scsi_destroy_device(sdev);
return ret;
}
@@ -1628,8 +1621,11 @@ static void scsi_sysfs_add_devices(struc
{
struct scsi_device *sdev;
shost_for_each_device(sdev, shost) {
- if (scsi_sysfs_add_sdev(sdev) != 0)
- scsi_destroy_sdev(sdev);
+ /*
+ * scsi_sysfs_add_sdev will clean up on failure,
+ * no need to do it here.
+ */
+ scsi_sysfs_add_sdev(sdev);
}
}
@@ -1776,6 +1772,7 @@ void scsi_forget_host(struct Scsi_Host *
continue;
spin_unlock_irqrestore(shost->host_lock, flags);
__scsi_remove_device(sdev);
+ scsi_destroy_device(sdev);
goto restart;
}
spin_unlock_irqrestore(shost->host_lock, flags);
@@ -1843,7 +1840,7 @@ void scsi_free_host_dev(struct scsi_devi
{
BUG_ON(sdev->id != sdev->host->this_id);
- scsi_destroy_sdev(sdev);
+ scsi_destroy_device(sdev);
}
EXPORT_SYMBOL(scsi_free_host_dev);
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index 259c90c..e4d0c97 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -230,6 +230,10 @@ static void scsi_device_dev_release_user
parent = sdev->sdev_gendev.parent;
starget = to_scsi_target(parent);
+ if (sdev->host->hostt->slave_destroy)
+ sdev->host->hostt->slave_destroy(sdev);
+ transport_destroy_device(&sdev->sdev_gendev);
+
spin_lock_irqsave(sdev->host->host_lock, flags);
starget->reap_ref++;
list_del(&sdev->siblings);
@@ -681,14 +685,17 @@ int scsi_sysfs_add_sdev(struct scsi_devi
error = device_add(&sdev->sdev_gendev);
if (error) {
- put_device(sdev->sdev_gendev.parent);
printk(KERN_INFO "error 1\n");
+ scsi_device_set_state(sdev, SDEV_CANCEL);
+ put_device(sdev->sdev_gendev.parent);
return error;
}
error = class_device_add(&sdev->sdev_classdev);
if (error) {
printk(KERN_INFO "error 2\n");
- goto clean_device;
+ scsi_device_set_state(sdev, SDEV_CANCEL);
+ device_del(&sdev->sdev_gendev);
+ goto out_error;
}
/* take a reference for the sdev_classdev; this is
@@ -700,7 +707,7 @@ int scsi_sysfs_add_sdev(struct scsi_devi
sdev->host->hostt->sdev_attrs[i]);
if (error) {
__scsi_remove_device(sdev);
- goto out;
+ goto out_error;
}
}
}
@@ -714,25 +721,76 @@ int scsi_sysfs_add_sdev(struct scsi_devi
error = device_create_file(&sdev->sdev_gendev, attr);
if (error) {
__scsi_remove_device(sdev);
- goto out;
+ goto out_error;
}
}
}
transport_add_device(&sdev->sdev_gendev);
- out:
- return error;
- clean_device:
- scsi_device_set_state(sdev, SDEV_CANCEL);
+ return error;
- device_del(&sdev->sdev_gendev);
- transport_destroy_device(&sdev->sdev_gendev);
- put_device(&sdev->sdev_gendev);
+ out_error:
+ scsi_destroy_device(sdev);
return error;
}
+int scsi_resurrect_device(struct scsi_device *sdev)
+{
+ int ret = 0;
+
+ /* Device is active, return */
+ if (sdev->sdev_state == SDEV_RUNNING || sdev->sdev_state == SDEV_CREATED)
+ return 0;
+
+ /*
+ * Set the device to SDEV_CANCEL to start resurrection
+ */
+ if (scsi_device_set_state(sdev, SDEV_CANCEL) != 0)
+ return -ENXIO;
+
+ ret = scsi_configure_device(sdev);
+ if (ret) {
+ scsi_destroy_device(sdev);
+ return ret;
+ }
+
+ /*
+ * Ok, the device is now all set up, we can
+ * register it and tell the rest of the kernel
+ * about it.
+ */
+ return scsi_sysfs_add_sdev(sdev);
+}
+
+int scsi_configure_device(struct scsi_device *sdev)
+{
+ /* set the device running here so that slave configure
+ * may do I/O */
+ if (scsi_device_set_state(sdev, SDEV_RUNNING) != 0)
+ return -ENXIO;
+
+ transport_configure_device(&sdev->sdev_gendev);
+
+ if (sdev->host->hostt->slave_configure) {
+ int ret = sdev->host->hostt->slave_configure(sdev);
+ if (ret) {
+ /*
+ * if LLDD reports slave not present, don't clutter
+ * console with alloc failure messages
+ */
+ if (ret != -ENXIO) {
+ sdev_printk(KERN_ERR, sdev,
+ "failed to configure device\n");
+ }
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
void __scsi_remove_device(struct scsi_device *sdev)
{
struct device *dev = &sdev->sdev_gendev;
@@ -743,11 +801,6 @@ void __scsi_remove_device(struct scsi_de
class_device_unregister(&sdev->sdev_classdev);
transport_remove_device(dev);
device_del(dev);
- scsi_device_set_state(sdev, SDEV_DEL);
- if (sdev->host->hostt->slave_destroy)
- sdev->host->hostt->slave_destroy(sdev);
- transport_destroy_device(dev);
- put_device(dev);
}
/**
@@ -760,6 +813,7 @@ void scsi_remove_device(struct scsi_devi
mutex_lock(&shost->scan_mutex);
__scsi_remove_device(sdev);
+ scsi_destroy_device(sdev);
mutex_unlock(&shost->scan_mutex);
}
EXPORT_SYMBOL(scsi_remove_device);
diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index ebf31b1..af127aa 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -202,6 +202,8 @@ extern struct scsi_device *__scsi_add_de
uint, uint, uint, void *hostdata);
extern int scsi_add_device(struct Scsi_Host *host, uint channel,
uint target, uint lun);
+extern int scsi_configure_device(struct scsi_device *);
+extern int scsi_resurrect_device(struct scsi_device *);
extern void scsi_remove_device(struct scsi_device *);
extern int scsi_device_cancel(struct scsi_device *, int);
@@ -316,6 +318,12 @@ static inline unsigned int sdev_id(struc
#define scmd_id(scmd) sdev_id((scmd)->device)
#define scmd_channel(scmd) sdev_channel((scmd)->device)
+static inline void scsi_destroy_device(struct scsi_device *sdev)
+{
+ scsi_device_set_state(sdev, SDEV_DEL);
+ put_device(&sdev->sdev_gendev);
+}
+
static inline int scsi_device_online(struct scsi_device *sdev)
{
return sdev->sdev_state != SDEV_OFFLINE;
