[PATCH 15/18] autofs: Add autofs_dev_ioctl_version() for AUTOFS_DEV_IOCTL_VERSION_CMD

From: Ian Kent
Date: Thu Aug 11 2016 - 22:48:56 EST


From: Tomohiro Kusumi <kusumi.tomohiro@xxxxxxxxx>

No functional changes, based on the following justification.

1. Make the code more consistent using the ioctl vector _ioctls[],
rather than assigning NULL only for this ioctl command.
2. Remove goto done; for better maintainability in the long run.
3. The existing code is based on the fact that validate_dev_ioctl()
sets ioctl version for any command, but AUTOFS_DEV_IOCTL_VERSION_CMD
should explicitly set it regardless of the default behavior.

Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@xxxxxxxxx>
Signed-off-by: Ian Kent <ikent@xxxxxxxxxx>
---
fs/autofs4/dev-ioctl.c | 25 +++++++++++++++++--------
1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c
index 13e7517..7289216 100644
--- a/fs/autofs4/dev-ioctl.c
+++ b/fs/autofs4/dev-ioctl.c
@@ -172,6 +172,17 @@ static struct autofs_sb_info *autofs_dev_ioctl_sbi(struct file *f)
return sbi;
}

+/* Return autofs dev ioctl version */
+static int autofs_dev_ioctl_version(struct file *fp,
+ struct autofs_sb_info *sbi,
+ struct autofs_dev_ioctl *param)
+{
+ /* This should have already been set. */
+ param->ver_major = AUTOFS_DEV_IOCTL_VERSION_MAJOR;
+ param->ver_minor = AUTOFS_DEV_IOCTL_VERSION_MINOR;
+ return 0;
+}
+
/* Return autofs module protocol version */
static int autofs_dev_ioctl_protover(struct file *fp,
struct autofs_sb_info *sbi,
@@ -590,7 +601,8 @@ static ioctl_fn lookup_dev_ioctl(unsigned int cmd)
int cmd;
ioctl_fn fn;
} _ioctls[] = {
- {cmd_idx(AUTOFS_DEV_IOCTL_VERSION_CMD), NULL},
+ {cmd_idx(AUTOFS_DEV_IOCTL_VERSION_CMD),
+ autofs_dev_ioctl_version},
{cmd_idx(AUTOFS_DEV_IOCTL_PROTOVER_CMD),
autofs_dev_ioctl_protover},
{cmd_idx(AUTOFS_DEV_IOCTL_PROTOSUBVER_CMD),
@@ -655,10 +667,6 @@ static int _autofs_dev_ioctl(unsigned int command,
if (err)
goto out;

- /* The validate routine above always sets the version */
- if (cmd == AUTOFS_DEV_IOCTL_VERSION_CMD)
- goto done;
-
fn = lookup_dev_ioctl(cmd);
if (!fn) {
pr_warn("unknown command 0x%08x\n", command);
@@ -672,9 +680,11 @@ static int _autofs_dev_ioctl(unsigned int command,
/*
* For obvious reasons the openmount can't have a file
* descriptor yet. We don't take a reference to the
- * file during close to allow for immediate release.
+ * file during close to allow for immediate release,
+ * and the same for retrieving ioctl version.
*/
- if (cmd != AUTOFS_DEV_IOCTL_OPENMOUNT_CMD &&
+ if (cmd != AUTOFS_DEV_IOCTL_VERSION_CMD &&
+ cmd != AUTOFS_DEV_IOCTL_OPENMOUNT_CMD &&
cmd != AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD) {
fp = fget(param->ioctlfd);
if (!fp) {
@@ -707,7 +717,6 @@ cont:

if (fp)
fput(fp);
-done:
if (err >= 0 && copy_to_user(user, param, AUTOFS_DEV_IOCTL_SIZE))
err = -EFAULT;
out: