[PATCH 3.10 071/268] target/pscsi: Fix TYPE_TAPE + TYPE_MEDIMUM_CHANGER export

Willy Tarreau
2017-06-19T19:40:36Z

From: Nicholas Bellinger <nab@linux-iscsi.org>

commit a04e54f2c35823ca32d56afcd5cea5b783e2f51a upstream.

The following fixes a divide by zero OOPs with TYPE_TAPE
due to pscsi_tape_read_blocksize() failing causing a zero
sd->sector_size being propigated up via dev_attrib.hw_block_size.

It also fixes another long-standing bug where TYPE_TAPE and
TYPE_MEDIMUM_CHANGER where using pscsi_create_type_other(),
which does not call scsi_device_get() to take the device
reference. Instead, rename pscsi_create_type_rom() to
pscsi_create_type_nondisk() and use it for all cases.

Finally, also drop a dump_stack() in pscsi_get_blocks() for
non TYPE_DISK, which in modern target-core can get invoked
via target_sense_desc_format() during CHECK_CONDITION.

[js] cast max_sectors to unsigned to avoid warnings

Reported-by: Malcolm Haak <insanemal@gmail.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
---
drivers/target/target_core_pscsi.c | 47 ++++++++++----------------------------
1 file changed, 12 insertions(+), 35 deletions(-)

diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c
index 244776b..79fed11 100644
--- a/drivers/target/target_core_pscsi.c
+++ b/drivers/target/target_core_pscsi.c
@@ -157,7 +157,7 @@ static void pscsi_tape_read_blocksize(struct se_device *dev,

buf = kzalloc(12, GFP_KERNEL);
if (!buf)
- return;
+ goto out_free;

memset(cdb, 0, MAX_COMMAND_SIZE);
cdb[0] = MODE_SENSE;
@@ -172,9 +172,10 @@ static void pscsi_tape_read_blocksize(struct se_device *dev,
* If MODE_SENSE still returns zero, set the default value to 1024.
*/
sdev->sector_size = (buf[9] << 16) | (buf[10] << 8) | (buf[11]);
+out_free:
if (!sdev->sector_size)
sdev->sector_size = 1024;
-out_free:
+
kfree(buf);
}

@@ -317,9 +318,10 @@ static int pscsi_add_device_to_list(struct se_device *dev,
sd->lun, sd->queue_depth);
}

- dev->dev_attrib.hw_block_size = sd->sector_size;
+ dev->dev_attrib.hw_block_size =
+ min_not_zero((int)sd->sector_size, 512);
dev->dev_attrib.hw_max_sectors =
- min_t(int, sd->host->max_sectors, queue_max_hw_sectors(q));
+ min_not_zero((unsigned)sd->host->max_sectors, queue_max_hw_sectors(q));
dev->dev_attrib.hw_queue_depth = sd->queue_depth;

/*
@@ -342,8 +344,10 @@ static int pscsi_add_device_to_list(struct se_device *dev,
/*
* For TYPE_TAPE, attempt to determine blocksize with MODE_SENSE.
*/
- if (sd->type == TYPE_TAPE)
+ if (sd->type == TYPE_TAPE) {
pscsi_tape_read_blocksize(dev, sd);
+ dev->dev_attrib.hw_block_size = sd->sector_size;
+ }
return 0;
}

@@ -409,7 +413,7 @@ static int pscsi_create_type_disk(struct se_device *dev, struct scsi_device *sd)
/*
* Called with struct Scsi_Host->host_lock called.
*/
-static int pscsi_create_type_rom(struct se_device *dev, struct scsi_device *sd)
+static int pscsi_create_type_nondisk(struct se_device *dev, struct scsi_device *sd)
__releases(sh->host_lock)
{
struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
@@ -436,28 +440,6 @@ static int pscsi_create_type_rom(struct se_device *dev, struct scsi_device *sd)
return 0;
}

-/*
- * Called with struct Scsi_Host->host_lock called.
- */
-static int pscsi_create_type_other(struct se_device *dev,
- struct scsi_device *sd)
- __releases(sh->host_lock)
-{
- struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
- struct Scsi_Host *sh = sd->host;
- int ret;
-
- spin_unlock_irq(sh->host_lock);
- ret = pscsi_add_device_to_list(dev, sd);
- if (ret)
- return ret;
-
- pr_debug("CORE_PSCSI[%d] - Added Type: %s for %d:%d:%d:%d\n",
- phv->phv_host_id, scsi_device_type(sd->type), sh->host_no,
- sd->channel, sd->id, sd->lun);
- return 0;
-}
-
static int pscsi_configure_device(struct se_device *dev)
{
struct se_hba *hba = dev->se_hba;
@@ -545,11 +527,8 @@ static int pscsi_configure_device(struct se_device *dev)
case TYPE_DISK:
ret = pscsi_create_type_disk(dev, sd);
break;
- case TYPE_ROM:
- ret = pscsi_create_type_rom(dev, sd);
- break;
default:
- ret = pscsi_create_type_other(dev, sd);
+ ret = pscsi_create_type_nondisk(dev, sd);
break;
}

@@ -606,8 +585,7 @@ static void pscsi_free_device(struct se_device *dev)
else if (pdv->pdv_lld_host)
scsi_host_put(pdv->pdv_lld_host);

- if ((sd->type == TYPE_DISK) || (sd->type == TYPE_ROM))
- scsi_device_put(sd);
+ scsi_device_put(sd);

pdv->pdv_sd = NULL;
}
@@ -1125,7 +1103,6 @@ static sector_t pscsi_get_blocks(struct se_device *dev)
if (pdv->pdv_bd && pdv->pdv_bd->bd_part)
return pdv->pdv_bd->bd_part->nr_sects;

- dump_stack();
return 0;
}

--
2.8.0.rc2.1.gbe9624a