source: rtems/doc/filesystem/mounting.t @ 9bc1e52a
Last change on this file since 9bc1e52a was 9bc1e52a, checked in by Joel Sherrill <joel.sherrill@…>, on 10/08/99 at 18:11:53

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1Mounting the base file system consists of the following:
3? Initialization of mount table chain control structure
4? Allocation of a -jnode- structure that will server as the root node of the `In Memory
5File System'
6? Initialization of the allocated -jnode- with the appropriate OPS, directory handlers
7and pathconf limits and options.
8? Allocation of a memory region for file system specific global management variables
9? Creation of first mount table entry for the base file system
10? Initialization of the first mount table chain entry to indicate that the mount point is
11NULL and the mounted file system is the base file system
14After the base file system has been mounted, the following operations are performed
15under its directory structure:
17? Creation of the /dev directory
18? Registration of devices under /dev directory
20Mounting and Unmounting File Systems
22? Characteristics of a Mount Point
23? The mount point must be a directory. It may have files and other directories under
24it. These files and directories will be hidden when the file system is mounted.
25? The task must have read/write/execute permissions to the mount point or the
26mount attempt will be rejected.
27? Only one file system can be mounted to a single mount point.
28? The Root of the mountable file system will be referenced by the name of the mount
29point after the mount is complete.
30? Mount table chain
31? Content of the mount table chain entry
33struct rtems_filesystem_mount_table_entry_tt
35        Chain_Node                                              Node;
36        rtems_filesystem_location_info_t                mt_point_node;
37        rtems_filesystem_location_info_t                mt_fs_root;
38        int                                                     options;
39        void                                                    *fs_info;
41        rtems_filesystem_limits_and_options_t   pathconf_limits_and_options;
43  /*
44   *  When someone adds a mounted filesystem on a real device,
45   *  this will need to be used.
46   *
47   *  The best option long term for this is probably an open file descriptor.
48   */
49        char                                                    *dev;
52? Adding entries to the chain during mount()
53When a file system is mounted, its presence and location in the file system
54hierarchy is recorded in a dynamic list structure known as a chain. A unique
55rtems_filesystem_mount_table_entry_tt structure is logged for each file system that is
56mounted. This includes the base file system.
58? Removing entries from the chain during unmount()
59When a file system is dismounted its entry in the mount table chain is extracted
60and the memory for this entry is freed.
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