docs: filesystems: convert sysv-fs.txt to ReST

- Add a SPDX header;
- Add a document title;
- Some whitespace fixes and new line breaks;
- Mark literal blocks as such;
- Add table markups;
- Add it to filesystems/index.rst.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/5b96a6efba95773af439ab25a7dbe4d0edf8c867.1581955849.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

1 files changed, 0 insertions, 197 deletions

diff --git a/Documentation/filesystems/sysv-fs.txt b/Documentation/filesystems/sysv-fs.txt
deleted file mode 100644
index 253b50d1328e..000000000000
--- a/Documentation/filesystems/sysv-fs.txt
+++ /dev/null
@@ -1,197 +0,0 @@
-It implements all of
-  - Xenix FS,
-  - SystemV/386 FS,
-  - Coherent FS.
-
-To install:
-* Answer the 'System V and Coherent filesystem support' question with 'y'
-  when configuring the kernel.
-* To mount a disk or a partition, use
-    mount [-r] -t sysv device mountpoint
-  The file system type names
-               -t sysv
-               -t xenix
-               -t coherent
-  may be used interchangeably, but the last two will eventually disappear.
-
-Bugs in the present implementation:
-- Coherent FS:
-  - The "free list interleave" n:m is currently ignored.
-  - Only file systems with no filesystem name and no pack name are recognized.
-  (See Coherent "man mkfs" for a description of these features.)
-- SystemV Release 2 FS:
-  The superblock is only searched in the blocks 9, 15, 18, which
-  corresponds to the beginning of track 1 on floppy disks. No support
-  for this FS on hard disk yet.
-
-
-These filesystems are rather similar. Here is a comparison with Minix FS:
-
-* Linux fdisk reports on partitions
-  - Minix FS     0x81 Linux/Minix
-  - Xenix FS     ??
-  - SystemV FS   ??
-  - Coherent FS  0x08 AIX bootable
-
-* Size of a block or zone (data allocation unit on disk)
-  - Minix FS     1024
-  - Xenix FS     1024 (also 512 ??)
-  - SystemV FS   1024 (also 512 and 2048)
-  - Coherent FS   512
-
-* General layout: all have one boot block, one super block and
-  separate areas for inodes and for directories/data.
-  On SystemV Release 2 FS (e.g. Microport) the first track is reserved and
-  all the block numbers (including the super block) are offset by one track.
-
-* Byte ordering of "short" (16 bit entities) on disk:
-  - Minix FS     little endian  0 1
-  - Xenix FS     little endian  0 1
-  - SystemV FS   little endian  0 1
-  - Coherent FS  little endian  0 1
-  Of course, this affects only the file system, not the data of files on it!
-
-* Byte ordering of "long" (32 bit entities) on disk:
-  - Minix FS     little endian  0 1 2 3
-  - Xenix FS     little endian  0 1 2 3
-  - SystemV FS   little endian  0 1 2 3
-  - Coherent FS  PDP-11         2 3 0 1
-  Of course, this affects only the file system, not the data of files on it!
-
-* Inode on disk: "short", 0 means non-existent, the root dir ino is:
-  - Minix FS                            1
-  - Xenix FS, SystemV FS, Coherent FS   2
-
-* Maximum number of hard links to a file:
-  - Minix FS     250
-  - Xenix FS     ??
-  - SystemV FS   ??
-  - Coherent FS  >=10000
-
-* Free inode management:
-  - Minix FS                             a bitmap
-  - Xenix FS, SystemV FS, Coherent FS
-      There is a cache of a certain number of free inodes in the super-block.
-      When it is exhausted, new free inodes are found using a linear search.
-
-* Free block management:
-  - Minix FS                             a bitmap
-  - Xenix FS, SystemV FS, Coherent FS
-      Free blocks are organized in a "free list". Maybe a misleading term,
-      since it is not true that every free block contains a pointer to
-      the next free block. Rather, the free blocks are organized in chunks
-      of limited size, and every now and then a free block contains pointers
-      to the free blocks pertaining to the next chunk; the first of these
-      contains pointers and so on. The list terminates with a "block number"
-      0 on Xenix FS and SystemV FS, with a block zeroed out on Coherent FS.
-
-* Super-block location:
-  - Minix FS     block 1 = bytes 1024..2047
-  - Xenix FS     block 1 = bytes 1024..2047
-  - SystemV FS   bytes 512..1023
-  - Coherent FS  block 1 = bytes 512..1023
-
-* Super-block layout:
-  - Minix FS
-                    unsigned short s_ninodes;
-                    unsigned short s_nzones;
-                    unsigned short s_imap_blocks;
-                    unsigned short s_zmap_blocks;
-                    unsigned short s_firstdatazone;
-                    unsigned short s_log_zone_size;
-                    unsigned long s_max_size;
-                    unsigned short s_magic;
-  - Xenix FS, SystemV FS, Coherent FS
-                    unsigned short s_firstdatazone;
-                    unsigned long  s_nzones;
-                    unsigned short s_fzone_count;
-                    unsigned long  s_fzones[NICFREE];
-                    unsigned short s_finode_count;
-                    unsigned short s_finodes[NICINOD];
-                    char           s_flock;
-                    char           s_ilock;
-                    char           s_modified;
-                    char           s_rdonly;
-                    unsigned long  s_time;
-                    short          s_dinfo[4]; -- SystemV FS only
-                    unsigned long  s_free_zones;
-                    unsigned short s_free_inodes;
-                    short          s_dinfo[4]; -- Xenix FS only
-                    unsigned short s_interleave_m,s_interleave_n; -- Coherent FS only
-                    char           s_fname[6];
-                    char           s_fpack[6];
-    then they differ considerably:
-        Xenix FS
-                    char           s_clean;
-                    char           s_fill[371];
-                    long           s_magic;
-                    long           s_type;
-        SystemV FS
-                    long           s_fill[12 or 14];
-                    long           s_state;
-                    long           s_magic;
-                    long           s_type;
-        Coherent FS
-                    unsigned long  s_unique;
-    Note that Coherent FS has no magic.
-
-* Inode layout:
-  - Minix FS
-                    unsigned short i_mode;
-                    unsigned short i_uid;
-                    unsigned long  i_size;
-                    unsigned long  i_time;
-                    unsigned char  i_gid;
-                    unsigned char  i_nlinks;
-                    unsigned short i_zone[7+1+1];
-  - Xenix FS, SystemV FS, Coherent FS
-                    unsigned short i_mode;
-                    unsigned short i_nlink;
-                    unsigned short i_uid;
-                    unsigned short i_gid;
-                    unsigned long  i_size;
-                    unsigned char  i_zone[3*(10+1+1+1)];
-                    unsigned long  i_atime;
-                    unsigned long  i_mtime;
-                    unsigned long  i_ctime;
-
-* Regular file data blocks are organized as
-  - Minix FS
-               7 direct blocks
-               1 indirect block (pointers to blocks)
-               1 double-indirect block (pointer to pointers to blocks)
-  - Xenix FS, SystemV FS, Coherent FS
-              10 direct blocks
-               1 indirect block (pointers to blocks)
-               1 double-indirect block (pointer to pointers to blocks)
-               1 triple-indirect block (pointer to pointers to pointers to blocks)
-
-* Inode size, inodes per block
-  - Minix FS        32   32
-  - Xenix FS        64   16
-  - SystemV FS      64   16
-  - Coherent FS     64    8
-
-* Directory entry on disk
-  - Minix FS
-                    unsigned short inode;
-                    char name[14/30];
-  - Xenix FS, SystemV FS, Coherent FS
-                    unsigned short inode;
-                    char name[14];
-
-* Dir entry size, dir entries per block
-  - Minix FS     16/32    64/32
-  - Xenix FS     16       64
-  - SystemV FS   16       64
-  - Coherent FS  16       32
-
-* How to implement symbolic links such that the host fsck doesn't scream:
-  - Minix FS     normal
-  - Xenix FS     kludge: as regular files with  chmod 1000
-  - SystemV FS   ??
-  - Coherent FS  kludge: as regular files with  chmod 1000
-
-
-Notation: We often speak of a "block" but mean a zone (the allocation unit)
-and not the disk driver's notion of "block".