Commit 6f4267e3 authored by James Bottomley's avatar James Bottomley

[SCSI] Update the SCSI state model to allow blocking in the created state

Brian King <brking@linux.vnet.ibm.com> reported that fibre channel
devices can oops during scanning if their ports block (because the
device goes from CREATED -> BLOCK -> RUNNING rather than CREATED ->
BLOCK -> CREATED).

Fix this by adding a new state: CREATED_BLOCK which can only transition
back to CREATED and disallow the CREATED -> BLOCK transition.  Now both
the created and blocked states that the mid-layer recognises can include
CREATED_BLOCK.
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent 0f1d87a2
......@@ -1251,6 +1251,7 @@ int scsi_prep_state_check(struct scsi_device *sdev, struct request *req)
break;
case SDEV_QUIESCE:
case SDEV_BLOCK:
case SDEV_CREATED_BLOCK:
/*
* If the devices is blocked we defer normal commands.
*/
......@@ -2064,10 +2065,13 @@ scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
switch (state) {
case SDEV_CREATED:
/* There are no legal states that come back to
* created. This is the manually initialised start
* state */
goto illegal;
switch (oldstate) {
case SDEV_CREATED_BLOCK:
break;
default:
goto illegal;
}
break;
case SDEV_RUNNING:
switch (oldstate) {
......@@ -2105,8 +2109,17 @@ scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
case SDEV_BLOCK:
switch (oldstate) {
case SDEV_CREATED:
case SDEV_RUNNING:
case SDEV_CREATED_BLOCK:
break;
default:
goto illegal;
}
break;
case SDEV_CREATED_BLOCK:
switch (oldstate) {
case SDEV_CREATED:
break;
default:
goto illegal;
......@@ -2394,8 +2407,12 @@ scsi_internal_device_block(struct scsi_device *sdev)
int err = 0;
err = scsi_device_set_state(sdev, SDEV_BLOCK);
if (err)
return err;
if (err) {
err = scsi_device_set_state(sdev, SDEV_CREATED_BLOCK);
if (err)
return err;
}
/*
* The device has transitioned to SDEV_BLOCK. Stop the
......@@ -2438,8 +2455,12 @@ scsi_internal_device_unblock(struct scsi_device *sdev)
* and goose the device queue if successful.
*/
err = scsi_device_set_state(sdev, SDEV_RUNNING);
if (err)
return err;
if (err) {
err = scsi_device_set_state(sdev, SDEV_CREATED);
if (err)
return err;
}
spin_lock_irqsave(q->queue_lock, flags);
blk_start_queue(q);
......
......@@ -730,6 +730,8 @@ static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result,
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.
......@@ -885,7 +887,17 @@ static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,
/* set the device running here so that slave configure
* may do I/O */
scsi_device_set_state(sdev, SDEV_RUNNING);
ret = scsi_device_set_state(sdev, SDEV_RUNNING);
if (ret) {
ret = scsi_device_set_state(sdev, SDEV_BLOCK);
if (ret) {
sdev_printk(KERN_ERR, sdev,
"in wrong state %s to complete scan\n",
scsi_device_state_name(sdev->sdev_state));
return SCSI_SCAN_NO_RESPONSE;
}
}
if (*bflags & BLIST_MS_192_BYTES_FOR_3F)
sdev->use_192_bytes_for_3f = 1;
......@@ -899,7 +911,7 @@ static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,
transport_configure_device(&sdev->sdev_gendev);
if (sdev->host->hostt->slave_configure) {
int ret = sdev->host->hostt->slave_configure(sdev);
ret = sdev->host->hostt->slave_configure(sdev);
if (ret) {
/*
* if LLDD reports slave not present, don't clutter
......
......@@ -34,6 +34,7 @@ static const struct {
{ SDEV_QUIESCE, "quiesce" },
{ SDEV_OFFLINE, "offline" },
{ SDEV_BLOCK, "blocked" },
{ SDEV_CREATED_BLOCK, "created-blocked" },
};
const char *scsi_device_state_name(enum scsi_device_state state)
......
......@@ -42,9 +42,11 @@ enum scsi_device_state {
* originate in the mid-layer) */
SDEV_OFFLINE, /* Device offlined (by error handling or
* user request */
SDEV_BLOCK, /* Device blocked by scsi lld. No scsi
* commands from user or midlayer should be issued
* to the scsi lld. */
SDEV_BLOCK, /* Device blocked by scsi lld. No
* scsi commands from user or midlayer
* should be issued to the scsi
* lld. */
SDEV_CREATED_BLOCK, /* same as above but for created devices */
};
enum scsi_device_event {
......@@ -393,11 +395,13 @@ static inline int scsi_device_online(struct scsi_device *sdev)
}
static inline int scsi_device_blocked(struct scsi_device *sdev)
{
return sdev->sdev_state == SDEV_BLOCK;
return sdev->sdev_state == SDEV_BLOCK ||
sdev->sdev_state == SDEV_CREATED_BLOCK;
}
static inline int scsi_device_created(struct scsi_device *sdev)
{
return sdev->sdev_state == SDEV_CREATED;
return sdev->sdev_state == SDEV_CREATED ||
sdev->sdev_state == SDEV_CREATED_BLOCK;
}
/* accessor functions for the SCSI parameters */
......
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