Lines Matching +full:sub +full:- +full:spaces
2 autofs - how it works
8 The goal of autofs is to provide on-demand mounting and race free
17 media with a media-changing robot.
23 filesystem can even be programmatic rather than database-backed,
31 There also needs to be a user-space program which looks up names
35 required with any user-space program. Subsequent text refers to this
75 So: non-empty (i.e. non-leaf) directories are never mount traps. Empty
93 "`stat`" will (normally) cause the `d_op->d_automount()` dentry operation
117 related behaviours are invoked, both using the `d_op->d_manage()`
124 - A return value of zero indicates that there is nothing special
132 - A return value of `-EISDIR` tells the VFS to ignore any mounts
133 on the directory and to not consider calling `->d_automount()`.
147 first. This means that d_manage cannot *always* return -EISDIR for
151 `d_manage` also returns `-EISDIR` if the dentry shouldn't be a
155 - Any other negative value is treated as an error and returned
160 - -ENOENT if the automount daemon failed to mount anything,
161 - -ENOMEM if it ran out of memory,
162 - -EINTR if a signal arrived while waiting for expiry to
164 - or any other error sent down by the automount daemon.
167 The second use case only occurs during an "RCU-walk" and so `rcu_walk`
170 An RCU-walk is a fast and lightweight process for walking down a
171 filename path (i.e. it is like running on tip-toes). RCU-walk cannot
173 to "REF-walk", which is slower but more robust.
175 RCU-walk will never call `->d_automount`; the filesystems must already
176 be mounted or RCU-walk cannot handle the path.
177 To determine if a mount-trap is safe for RCU-walk mode it calls
178 `->d_manage()` with `rcu_walk` set to `true`.
186 In the `rcu_walk` case, `d_manage()` cannot return -EISDIR to tell the
189 mounted, it *will* fall back to REF-walk. `d_manage()` cannot make the
190 VFS remain in RCU-walk mode, but can only tell it to get out of
191 RCU-walk mode by returning `-ECHILD`.
194 -ECHILD if there is any reason to believe it is unsafe to enter the
197 autofs will return `-ECHILD` if an expiry of the filesystem has been
226 will trigger normal auto-mount processing. In particular, `rmdir` and
228 filesystem would, so an attempt to access a recently-removed object is
231 With version 5, this is not safe except for unmounting from top-level
232 directories. As lower-level directories are never mount traps, other
256 considers if the entire mount-tree can be unmounted or not. For an
262 that has been mounted on instead of considering the top-level names.
284 name normally. As described above, this is unsafe for non-toplevel
285 mounts in a version-5 autofs. For this reason the current `automount(8)`
308 or not based on its process-group id number (see getpgid(1)).
375 - **AUTOFS_IOC_READY**:
379 - **AUTOFS_IOC_FAIL**:
382 - **AUTOFS_IOC_CATATONIC**:
386 - **AUTOFS_IOC_PROTOVER**:
388 - **AUTOFS_IOC_PROTOSUBVER**:
389 Returns the protocol sub-version which
391 - **AUTOFS_IOC_SETTIMEOUT**:
395 - **AUTOFS_IOC_ASKUMOUNT**:
396 Returns, in the pointed-to `int`, 1 if
400 - **AUTOFS_IOC_EXPIRE**:
416 - **AUTOFS_IOC_EXPIRE_MULTI**:
430 **AUTOFS_EXP_LEAVES** will select a leaf rather than a top-level
433 Communicating with autofs: char-device ioctls
445 document `autofs-mount-control.rst`, and are summarised briefly here.
484 - **AUTOFS_DEV_IOCTL_VERSION_CMD**:
487 - **AUTOFS_DEV_IOCTL_OPENMOUNT_CMD**:
493 - **AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD**:
495 - **AUTOFS_DEV_IOCTL_SETPIPEFD_CMD**:
498 in `setpipefd.pipefd` to re-establish communication with a daemon.
501 - **AUTOFS_DEV_IOCTL_REQUESTER_CMD**:
503 name within the filesystem that has been auto-mounted on.
506 - **AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD**:
508 mountpoint of a particular type - see separate documentation for
511 - **AUTOFS_DEV_IOCTL_PROTOVER_CMD**
512 - **AUTOFS_DEV_IOCTL_PROTOSUBVER_CMD**
513 - **AUTOFS_DEV_IOCTL_READY_CMD**
514 - **AUTOFS_DEV_IOCTL_FAIL_CMD**
515 - **AUTOFS_DEV_IOCTL_CATATONIC_CMD**
516 - **AUTOFS_DEV_IOCTL_TIMEOUT_CMD**
517 - **AUTOFS_DEV_IOCTL_EXPIRE_CMD**
518 - **AUTOFS_DEV_IOCTL_ASKUMOUNT_CMD**
536 Once in catatonic mode attempts to access non-existing names will
558 space based on the kernel mount list a no-op mount option ("ignore" is
565 autofs, name spaces, and shared mounts
568 With bind mounts and name spaces it is possible for an autofs
570 name spaces. For this to work sensibly, the autofs filesystem should
573 mount --make-shared /autofs/mount/point