Add "no BKL needed" comments to several drivers

This documents the fact that somebody looked at the relevant open()
functions and concluded that, due to their trivial nature, no locking was
needed.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>

4 files changed, 8 insertions, 2 deletions

diff --git a/drivers/scsi/3w-9xxx.c b/drivers/scsi/3w-9xxx.c
index b31faeccb9cd..2239d16fb9b5 100644
--- a/drivers/scsi/3w-9xxx.c
+++ b/drivers/scsi/3w-9xxx.c
@@ -862,6 +862,8 @@ out:
 } /* End twa_chrdev_ioctl() */
 
 /* This function handles open for the character device */
+/* NOTE that this function will race with remove; adding BKL
+   will not help. */
 static int twa_chrdev_open(struct inode *inode, struct file *file)
 {
         unsigned int minor_number;
diff --git a/drivers/scsi/3w-xxxx.c b/drivers/scsi/3w-xxxx.c
index 8c22329aa85e..bbff029536ea 100644
--- a/drivers/scsi/3w-xxxx.c
+++ b/drivers/scsi/3w-xxxx.c
@@ -1027,6 +1027,8 @@ out:
 } /* End tw_chrdev_ioctl() */
 
 /* This function handles open for the character device */
+/* NOTE that this function races with remove - adding BKL
+   won't help */
 static int tw_chrdev_open(struct inode *inode, struct file *file)
 {
         unsigned int minor_number;
diff --git a/drivers/scsi/megaraid.c b/drivers/scsi/megaraid.c
index 18551aaf5e09..c9aa2c45a699 100644
--- a/drivers/scsi/megaraid.c
+++ b/drivers/scsi/megaraid.c
@@ -3272,8 +3272,9 @@ mega_init_scb(adapter_t *adapter)
  * @filep - unused
  *
  * Routines for the character/ioctl interface to the driver. Find out if this
- * is a valid open. If yes, increment the module use count so that it cannot
- * be unloaded.
+ * is a valid open. 
+ *
+ * No BKL needed here.
  */
 static int
 megadev_open (struct inode *inode, struct file *filep)
diff --git a/drivers/scsi/megaraid/megaraid_sas.c b/drivers/scsi/megaraid/megaraid_sas.c
index 7d84c8bbcf3f..81374b7c555c 100644
--- a/drivers/scsi/megaraid/megaraid_sas.c
+++ b/drivers/scsi/megaraid/megaraid_sas.c
@@ -2860,6 +2860,7 @@ static void megasas_shutdown(struct pci_dev *pdev)
 
 /**
  * megasas_mgmt_open -  char node "open" entry point
+ * No BKL is needed here.
  */
 static int megasas_mgmt_open(struct inode *inode, struct file *filep)
 {