[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>

5 files changed, 34 insertions, 24 deletions

diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c
index c9254d7ad18a..9721ef28335c 100644
--- a/drivers/target/target_core_configfs.c
+++ b/drivers/target/target_core_configfs.c
@@ -1827,7 +1827,9 @@ static ssize_t target_core_store_dev_enable(
                 return -EINVAL;
 
         dev = t->create_virtdevice(hba, se_dev, se_dev->se_dev_su_ptr);
-        if (!(dev) || IS_ERR(dev))
+        if (IS_ERR(dev))
+                return PTR_ERR(dev);
+        else if (!dev)
                 return -EINVAL;
 
         se_dev->se_dev_ptr = dev;
diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c
index 7850c6ae06e4..03fa40f72ef7 100644
--- a/drivers/target/target_core_file.c
+++ b/drivers/target/target_core_file.c
@@ -134,7 +134,7 @@ static struct se_device *fd_create_virtdevice(
         mm_segment_t old_fs;
         struct file *file;
         struct inode *inode = NULL;
-        int dev_flags = 0, flags;
+        int dev_flags = 0, flags, ret = -EINVAL;
 
         memset(&dev_limits, 0, sizeof(struct se_dev_limits));
 
@@ -146,6 +146,7 @@ static struct se_device *fd_create_virtdevice(
         if (IS_ERR(dev_p)) {
                 printk(KERN_ERR "getname(%s) failed: %lu\n",
                         fd_dev->fd_dev_name, IS_ERR(dev_p));
+                ret = PTR_ERR(dev_p);
                 goto fail;
         }
 #if 0
@@ -165,8 +166,12 @@ static struct se_device *fd_create_virtdevice(
                 flags |= O_SYNC;
 
         file = filp_open(dev_p, flags, 0600);
-
-        if (IS_ERR(file) || !file || !file->f_dentry) {
+        if (IS_ERR(file)) {
+                printk(KERN_ERR "filp_open(%s) failed\n", dev_p);
+                ret = PTR_ERR(file);
+                goto fail;
+        }
+        if (!file || !file->f_dentry) {
                 printk(KERN_ERR "filp_open(%s) failed\n", dev_p);
                 goto fail;
         }
@@ -241,7 +246,7 @@ fail:
                 fd_dev->fd_file = NULL;
         }
         putname(dev_p);
-        return NULL;
+        return ERR_PTR(ret);
 }
 
 /*      fd_free_device(): (Part of se_subsystem_api_t template)
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)
diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c
index 3031ef8261ef..51fd309388fc 100644
--- a/drivers/target/target_core_pscsi.c
+++ b/drivers/target/target_core_pscsi.c
@@ -555,7 +555,7 @@ static struct se_device *pscsi_create_virtdevice(
         if (!(pdv)) {
                 printk(KERN_ERR "Unable to locate struct pscsi_dev_virt"
                                 " parameter\n");
-                return NULL;
+                return ERR_PTR(-EINVAL);
         }
         /*
          * If not running in PHV_LLD_SCSI_HOST_NO mode, locate the
@@ -565,7 +565,7 @@ static struct se_device *pscsi_create_virtdevice(
                 if (phv->phv_mode == PHV_LLD_SCSI_HOST_NO) {
                         printk(KERN_ERR "pSCSI: Unable to locate struct"
                                 " Scsi_Host for PHV_LLD_SCSI_HOST_NO\n");
-                        return NULL;
+                        return ERR_PTR(-ENODEV);
                 }
                 /*
                  * For the newer PHV_VIRUTAL_HOST_ID struct scsi_device
@@ -574,7 +574,7 @@ static struct se_device *pscsi_create_virtdevice(
                 if (!(se_dev->su_dev_flags & SDF_USING_UDEV_PATH)) {
                         printk(KERN_ERR "pSCSI: udev_path attribute has not"
                                 " been set before ENABLE=1\n");
-                        return NULL;
+                        return ERR_PTR(-EINVAL);
                 }
                 /*
                  * If no scsi_host_id= was passed for PHV_VIRUTAL_HOST_ID,
@@ -587,12 +587,12 @@ static struct se_device *pscsi_create_virtdevice(
                                 printk(KERN_ERR "pSCSI: Unable to set hba_mode"
                                         " with active devices\n");
                                 spin_unlock(&hba->device_lock);
-                                return NULL;
+                                return ERR_PTR(-EEXIST);
                         }
                         spin_unlock(&hba->device_lock);
 
                         if (pscsi_pmode_enable_hba(hba, 1) != 1)
-                                return NULL;
+                                return ERR_PTR(-ENODEV);
 
                         legacy_mode_enable = 1;
                         hba->hba_flags |= HBA_FLAGS_PSCSI_MODE;
@@ -602,14 +602,14 @@ static struct se_device *pscsi_create_virtdevice(
                         if (!(sh)) {
                                 printk(KERN_ERR "pSCSI: Unable to locate"
                                         " pdv_host_id: %d\n", pdv->pdv_host_id);
-                                return NULL;
+                                return ERR_PTR(-ENODEV);
                         }
                 }
         } else {
                 if (phv->phv_mode == PHV_VIRUTAL_HOST_ID) {
                         printk(KERN_ERR "pSCSI: PHV_VIRUTAL_HOST_ID set while"
                                 " struct Scsi_Host exists\n");
-                        return NULL;
+                        return ERR_PTR(-EEXIST);
                 }
         }
 
@@ -644,7 +644,7 @@ static struct se_device *pscsi_create_virtdevice(
                                 hba->hba_flags &= ~HBA_FLAGS_PSCSI_MODE;
                         }
                         pdv->pdv_sd = NULL;
-                        return NULL;
+                        return ERR_PTR(-ENODEV);
                 }
                 return dev;
         }
@@ -660,7 +660,7 @@ static struct se_device *pscsi_create_virtdevice(
                 hba->hba_flags &= ~HBA_FLAGS_PSCSI_MODE;
         }
 
-        return NULL;
+        return ERR_PTR(-ENODEV);
 }
 
 /*      pscsi_free_device(): (Part of se_subsystem_api_t template)
diff --git a/drivers/target/target_core_rd.c b/drivers/target/target_core_rd.c
index 8dc6d74c1d40..f36094f0596a 100644
--- a/drivers/target/target_core_rd.c
+++ b/drivers/target/target_core_rd.c
@@ -253,13 +253,15 @@ static struct se_device *rd_create_virtdevice(
         struct se_dev_limits dev_limits;
         struct rd_dev *rd_dev = p;
         struct rd_host *rd_host = hba->hba_ptr;
-        int dev_flags = 0;
+        int dev_flags = 0, ret = -EINVAL;
         char prod[16], rev[4];
 
         memset(&dev_limits, 0, sizeof(struct se_dev_limits));
 
-        if (rd_build_device_space(rd_dev) < 0)
+        if (rd_build_device_space(rd_dev) < 0) {
+                ret = -ENOMEM;
                 goto fail;
+        }
 
         snprintf(prod, 16, "RAMDISK-%s", (rd_dev->rd_direct) ? "DR" : "MCP");
         snprintf(rev, 4, "%s", (rd_dev->rd_direct) ? RD_DR_VERSION :
@@ -292,7 +294,7 @@ static struct se_device *rd_create_virtdevice(
 
 fail:
         rd_release_device_space(rd_dev);
-        return NULL;
+        return ERR_PTR(ret);
 }
 
 static struct se_device *rd_DIRECT_create_virtdevice(