autofs: update ioctl documentation regarding struct autofs_dev_ioctl

This is the same as bf72eda5 except that it's a different file.  Sync
documentation with changes made by 730c9eec in 2009.

Link: http://lkml.kernel.org/r/148577165630.9801.6081791213151121657.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <tkusumi@tuxera.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Tomohiro Kusumi 2017-02-27 14:27:08 -08:00 committed by Linus Torvalds
parent c5dd2ea064
commit 8848808094
2 changed files with 22 additions and 11 deletions

View File

@ -179,6 +179,7 @@ struct autofs_dev_ioctl {
* including this struct */
__s32 ioctlfd; /* automount command fd */
/* Command parameters */
union {
struct args_protover protover;
struct args_protosubver protosubver;

View File

@ -425,8 +425,20 @@ Each ioctl is passed a pointer to an `autofs_dev_ioctl` structure:
* including this struct */
__s32 ioctlfd; /* automount command fd */
__u32 arg1; /* Command parameters */
__u32 arg2;
/* Command parameters */
union {
struct args_protover protover;
struct args_protosubver protosubver;
struct args_openmount openmount;
struct args_ready ready;
struct args_fail fail;
struct args_setpipefd setpipefd;
struct args_timeout timeout;
struct args_requester requester;
struct args_expire expire;
struct args_askumount askumount;
struct args_ismountpoint ismountpoint;
};
char path[0];
};
@ -446,24 +458,22 @@ Commands are:
set version numbers.
- **AUTOFS_DEV_IOCTL_OPENMOUNT_CMD**: return an open file descriptor
on the root of an autofs filesystem. The filesystem is identified
by name and device number, which is stored in `arg1`. Device
numbers for existing filesystems can be found in
by name and device number, which is stored in `openmount.devid`.
Device numbers for existing filesystems can be found in
`/proc/self/mountinfo`.
- **AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD**: same as `close(ioctlfd)`.
- **AUTOFS_DEV_IOCTL_SETPIPEFD_CMD**: if the filesystem is in
catatonic mode, this can provide the write end of a new pipe
in `arg1` to re-establish communication with a daemon. The
process group of the calling process is used to identify the
in `setpipefd.pipefd` to re-establish communication with a daemon.
The process group of the calling process is used to identify the
daemon.
- **AUTOFS_DEV_IOCTL_REQUESTER_CMD**: `path` should be a
name within the filesystem that has been auto-mounted on.
On successful return, `arg1` and `arg2` will be the UID and GID
of the process which triggered that mount.
On successful return, `requester.uid` and `requester.gid` will be
the UID and GID of the process which triggered that mount.
- **AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD**: Check if path is a
mountpoint of a particular type - see separate documentation for
details.
- **AUTOFS_DEV_IOCTL_PROTOVER_CMD**:
- **AUTOFS_DEV_IOCTL_PROTOSUBVER_CMD**:
- **AUTOFS_DEV_IOCTL_READY_CMD**:
@ -473,7 +483,7 @@ Commands are:
- **AUTOFS_DEV_IOCTL_EXPIRE_CMD**:
- **AUTOFS_DEV_IOCTL_ASKUMOUNT_CMD**: These all have the same
function as the similarly named **AUTOFS_IOC** ioctls, except
that **FAIL** can be given an explicit error number in `arg1`
that **FAIL** can be given an explicit error number in `fail.status`
instead of assuming `ENOENT`, and this **EXPIRE** command
corresponds to **AUTOFS_IOC_EXPIRE_MULTI**.