Documentation/filesystems/mount_api.rst

4 Filesystem Mount API
11  (2) The filesystem context.
13  (3) The filesystem context operations.
15  (4) Filesystem context security.
17  (5) VFS filesystem context API.
31  (1) Create a filesystem context.
52 The first is invoked to set up the filesystem-specific parts of a filesystem
57 Note that security initialisation is done *after* the filesystem is called so
61 The Filesystem context
64 The creation and reconfiguration of a superblock is governed by a filesystem
92      These are operations that can be done on a filesystem context (see
100      A pointer to the file_system_type of the filesystem that is being
107      A pointer to the file system's private data.  This is where the filesystem
125      replaced by the filesystem to reflect other sources, such as the parent
146      qualify it (used by FUSE).  This is available for the filesystem to set if
193 VFS, security and filesystem mount options are set individually with
197 When mounting, the filesystem is allowed to take data from any of the pointers
201 The filesystem is also allowed to allocate resources and pin them with the
206 The Filesystem Context Operations
209 The filesystem context points to a table of operations::
222 manage the filesystem context.  They are as follows:
228      Called to clean up the filesystem-specific part of the filesystem context
236      Called when a filesystem context has been duplicated to duplicate the
237      filesystem-private data.  An error may be returned to indicate failure to
244 	 filesystem-private data safe for ->free().
251      Called when a parameter is being added to the filesystem context.  param
271      If the filesystem (e.g. NFS) needs to examine the data first and then
280      information stored in the filesystem context (reconfiguration goes via a
282      filesystem context and transfer them to the superblock it creates.
295      in the filesystem context.  It may detach any resources it desires from
296      the filesystem context and transfer them to the superblock.  The
305 Filesystem context Security
308 The filesystem context contains a security pointer that the LSMs can use for
333      any resources needed.  The original filesystem context is pointed to by
352      the parameter should be passed on to the filesystem, 1 to indicate that
358      returned to prevent it being passed to the filesystem.
399 VFS Filesystem context API
402 There are four operations for creating a filesystem context and one for
410      Allocate a filesystem context for the purpose of setting up a new mount,
413      fs_type->init_fs_context() to initialise the filesystem private data.
415      fs_type specifies the filesystem type that will manage the context and
425      Allocate a filesystem context for the purpose of reconfiguring an
436      Allocate a filesystem context for the purpose of creating a new mount for
438      filesystem type that will manage the context and the reference dentry
443      filesystem type as fs_type.
449      Duplicate a filesystem context, copying any options noted and duplicating
451      for use where a filesystem has to get a mount within a mount, such as NFS4
461      Destroy a filesystem context, releasing any resources it holds.  This
463      created a filesystem context.
467         filesystem contexts are not refcounted, so this causes unconditional
481      Supply a single mount parameter to the filesystem context.  This includes
483      parameter (which may be specified multiple times if the filesystem
490      filesystem.
529      the filesystem context to select/configure the superblock.  This invokes
536      Create a mount given the parameters in the specified filesystem context.
737 A number of helper functions are provided to help a filesystem or an LSM