[SCSI] target: Convert backend ->create_virtdevice() call to return ERR_PTR

This patch converts the target_core_store_dev_enable() -> struct
se_subsystem_api->create_virtdevice() call to return proper ERR_PTR values
back up to configfs logic during backend dependent struct se_device ENABLE
exception conditions.

Along with the change to target_core_configfs.c, this includes converting IBLOCK,
FILEIO, pSCSI, and RAMDISK_* backend subsystem plugins to obtain upper level
PTR_ERR return codes (where available), and return via ERR_PTR during a
*_create_virtdev() failure.

Reported-by: Fubo Chen <fubo.chen@gmail.com>
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

1 files changed, 8 insertions, 7 deletions

diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c
index 96d98cc8f85b..0f4a50935a86 100644
--- a/drivers/target/target_core_iblock.c
+++ b/drivers/target/target_core_iblock.c
@@ -129,10 +129,11 @@ static struct se_device *iblock_create_virtdevice(
         struct request_queue *q;
         struct queue_limits *limits;
         u32 dev_flags = 0;
+        int ret = -EINVAL;
 
         if (!(ib_dev)) {
                 printk(KERN_ERR "Unable to locate struct iblock_dev parameter\n");
-                return 0;
+                return ERR_PTR(ret);
         }
         memset(&dev_limits, 0, sizeof(struct se_dev_limits));
         /*
@@ -141,7 +142,7 @@ static struct se_device *iblock_create_virtdevice(
         ib_dev->ibd_bio_set = bioset_create(32, 64);
         if (!(ib_dev->ibd_bio_set)) {
                 printk(KERN_ERR "IBLOCK: Unable to create bioset()\n");
-                return 0;
+                return ERR_PTR(-ENOMEM);
         }
         printk(KERN_INFO "IBLOCK: Created bio_set()\n");
         /*
@@ -153,8 +154,10 @@ static struct se_device *iblock_create_virtdevice(
 
         bd = blkdev_get_by_path(ib_dev->ibd_udev_path,
                                 FMODE_WRITE|FMODE_READ|FMODE_EXCL, ib_dev);
-        if (IS_ERR(bd))
+        if (IS_ERR(bd)) {
+                ret = PTR_ERR(bd);
                 goto failed;
+        }
         /*
          * Setup the local scope queue_limits from struct request_queue->limits
          * to pass into transport_add_device_to_core_hba() as struct se_dev_limits.
@@ -184,9 +187,7 @@ static struct se_device *iblock_create_virtdevice(
          * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
          * in ATA and we need to set TPE=1
          */
-        if (blk_queue_discard(bdev_get_queue(bd))) {
-                struct request_queue *q = bdev_get_queue(bd);
-
+        if (blk_queue_discard(q)) {
                 DEV_ATTRIB(dev)->max_unmap_lba_count =
                                 q->limits.max_discard_sectors;
                 /*
@@ -212,7 +213,7 @@ failed:
         ib_dev->ibd_bd = NULL;
         ib_dev->ibd_major = 0;
         ib_dev->ibd_minor = 0;
-        return NULL;
+        return ERR_PTR(ret);
 }
 
 static void iblock_free_device(void *p)