Documentation/filesystems/sysv-fs.rst

1 .. SPDX-License-Identifier: GPL-2.0
8   - Xenix FS,
9   - SystemV/386 FS,
10   - Coherent FS.
14 * Answer the 'System V and Coherent filesystem support' question with 'y'
18     mount [-r] -t sysv device mountpoint
22                -t sysv
23                -t xenix
24                -t coherent
30 - Coherent FS:
32   - The "free list interleave" n:m is currently ignored.
33   - Only file systems with no filesystem name and no pack name are recognized.
34     (See Coherent "man mkfs" for a description of these features.)
36 - SystemV Release 2 FS:
47   - Minix FS     0x81 Linux/Minix
48   - Xenix FS     ??
49   - SystemV FS   ??
50   - Coherent FS  0x08 AIX bootable
54   - Minix FS     1024
55   - Xenix FS     1024 (also 512 ??)
56   - SystemV FS   1024 (also 512 and 2048)
57   - Coherent FS   512
66   - Minix FS     little endian  0 1
67   - Xenix FS     little endian  0 1
68   - SystemV FS   little endian  0 1
69   - Coherent FS  little endian  0 1
75   - Minix FS     little endian  0 1 2 3
76   - Xenix FS     little endian  0 1 2 3
77   - SystemV FS   little endian  0 1 2 3
78   - Coherent FS  PDP-11         2 3 0 1
82 * Inode on disk: "short", 0 means non-existent, the root dir ino is:
86   Xenix FS, SystemV FS, Coherent FS   2
95   Coherent FS  >=10000
100   - Minix FS
102   - Xenix FS, SystemV FS, Coherent FS
103       There is a cache of a certain number of free inodes in the super-block.
108   - Minix FS
110   - Xenix FS, SystemV FS, Coherent FS
117       0 on Xenix FS and SystemV FS, with a block zeroed out on Coherent FS.
119 * Super-block location:
125   Coherent FS  block 1 = bytes 512..1023
128 * Super-block layout:
130   - Minix FS::
141   - Xenix FS, SystemV FS, Coherent FS::
154                     short          s_dinfo[4]; -- SystemV FS only
157                     short          s_dinfo[4]; -- Xenix FS only
158                     unsigned short s_interleave_m,s_interleave_n; -- Coherent FS only
178         Coherent FS::
182     Note that Coherent FS has no magic.
186   - Minix FS::
196   - Xenix FS, SystemV FS, Coherent FS::
211   - Minix FS:
213              - 7 direct blocks
214 	     - 1 indirect block (pointers to blocks)
215              - 1 double-indirect block (pointer to pointers to blocks)
217   - Xenix FS, SystemV FS, Coherent FS:
219              - 10 direct blocks
220              -  1 indirect block (pointers to blocks)
221              -  1 double-indirect block (pointer to pointers to blocks)
222              -  1 triple-indirect block (pointer to pointers to pointers to blocks)
231   Coherent FS     64        8
236   - Minix FS::
241   - Xenix FS, SystemV FS, Coherent FS::
252   Coherent FS    16                32
257   - Minix FS     normal
258   - Xenix FS     kludge: as regular files with  chmod 1000
259   - SystemV FS   ??
260   - Coherent FS  kludge: as regular files with  chmod 1000