[PATCH 01/29] cxlflash: Move global.mutex to caller of find_and_create_lun()

["Matthew R. Ochs" <mrochs@linux.vnet.ibm.com>]

From: Manoj Kumar <kumarmn@us.ibm.com>

Since the retrieved LUN is modified in the caller, hold the mutex
across modifications as well.

Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>
---
 drivers/scsi/cxlflash/lunmgt.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/cxlflash/lunmgt.c b/drivers/scsi/cxlflash/lunmgt.c
index d98ad0f..8c372fc 100644
--- a/drivers/scsi/cxlflash/lunmgt.c
+++ b/drivers/scsi/cxlflash/lunmgt.c
@@ -120,7 +120,8 @@ static struct glun_info *lookup_global(u8 *wwid)
  *
  * The LUN is kept both in a local list (per adapter) and in a global list
  * (across all adapters). Certain attributes of the LUN are local to the
- * adapter (such as index, port selection mask etc.).
+ * adapter (such as index, port selection mask, etc.).
+ *
  * The block allocation map is shared across all adapters (i.e. associated
  * wih the global list). Since different attributes are associated with
  * the per adapter and global entries, allocate two separate structures for each
@@ -128,6 +129,8 @@ static struct glun_info *lookup_global(u8 *wwid)
  *
  * Keep a pointer back from the local to the global entry.
  *
+ * This routine assumes the caller holds the global mutex.
+ *
  * Return: Found/Allocated local lun_info structure on success, NULL on failure
  */
 static struct llun_info *find_and_create_lun(struct scsi_device *sdev, u8 *wwid)
@@ -137,7 +140,6 @@ static struct llun_info *find_and_create_lun(struct scsi_device *sdev, u8 *wwid)
 	struct Scsi_Host *shost = sdev->host;
 	struct cxlflash_cfg *cfg = shost_priv(shost);
 
-	mutex_lock(&global.mutex);
 	if (unlikely(!wwid))
 		goto out;
 
@@ -169,7 +171,6 @@ static struct llun_info *find_and_create_lun(struct scsi_device *sdev, u8 *wwid)
 	list_add(&gli->list, &global.gluns);
 
 out:
-	mutex_unlock(&global.mutex);
 	pr_debug("%s: returning %p\n", __func__, lli);
 	return lli;
 }
@@ -235,6 +236,7 @@ int cxlflash_manage_lun(struct scsi_device *sdev,
 	u64 flags = manage->hdr.flags;
 	u32 chan = sdev->channel;
 
+	mutex_lock(&global.mutex);
 	lli = find_and_create_lun(sdev, manage->wwid);
 	pr_debug("%s: ENTER: WWID = %016llX%016llX, flags = %016llX li = %p\n",
 		 __func__, get_unaligned_le64(&manage->wwid[0]),
@@ -261,6 +263,7 @@ int cxlflash_manage_lun(struct scsi_device *sdev,
 	}
 
 out:
+	mutex_unlock(&global.mutex);
 	pr_debug("%s: returning rc=%d\n", __func__, rc);
 	return rc;
 }
-- 
2.1.0