Documentation/filesystems/autofs-mount-control.rst

1 .. SPDX-License-Identifier: GPL-2.0
16 autofs specific information stored in the super block. The operations
23 Currently autofs uses "umount -l" (lazy umount) to clear active mounts
43     /-      /etc/auto.direct
61 mounts are triggered for each sub-directory key by the inode lookup
72 them multi-mount map entries).
98 where the number of privileged ports available is exhausted.
111 in the mount super block. So the use of a file handle needs to be
121 implement an isolated operation it was decided to re-implement the
131 Since we're re-implementing the control interface, a couple of other
136 ENOENT so the re-implementation allows user space to send an actual
156 candidates are enumerated, almost for no other reason than to "count"
220 kernel space and return -EINVAL if the size parameter is smaller than
221 the structure size itself, -ENOMEM if the kernel memory allocation fails
222 or -EFAULT if the copy itself fails. Other checks include a version check
224 mismatch results in a -EINVAL return. If the size field is greater than
226 ensure it begins with a "/" and is NULL terminated, otherwise -EINVAL is
231 an error of -EBADF, -ENOTTY or -EINVAL (not an autofs descriptor) is
239 in autofs version 5.0.4 and later in file lib/dev-ioctl-lib.c of the
247 ------------------------
252 It returns 0 on success or the error -EINVAL if a version mismatch is
257 ------------------------------------------------------------------
268 ----------------------------------------------------------
284 --------------------------------------------------------
296 ------------------------------
308 On success the call also sets the process group id used to identify the
310 group of the caller.
314 ------------------------------
325 ----------------------------
334 ------------------------------
345 re-connect to mounts that may have used the original process uid and
352 ---------------------------
363 expire candidates can be found the ioctl returns -1 with errno set to
371 ------------------------------
382 ---------------------------------
393 field to the relevant super block magic number (described below) or 0 if
400 a mountpoint or contains a mount, such as a multi-mount without a root
405 If a path is supplied (and the ioctlfd field is set to -1) then the path