diff options
Diffstat (limited to 'Documentation/filesystems/affs.txt')
| -rw-r--r-- | Documentation/filesystems/affs.txt | 222 |
1 files changed, 0 insertions, 222 deletions
diff --git a/Documentation/filesystems/affs.txt b/Documentation/filesystems/affs.txt deleted file mode 100644 index 71b63c2b9841..000000000000 --- a/Documentation/filesystems/affs.txt +++ /dev/null @@ -1,222 +0,0 @@ -Overview of Amiga Filesystems -============================= - -Not all varieties of the Amiga filesystems are supported for reading and -writing. The Amiga currently knows six different filesystems: - -DOS\0 The old or original filesystem, not really suited for - hard disks and normally not used on them, either. - Supported read/write. - -DOS\1 The original Fast File System. Supported read/write. - -DOS\2 The old "international" filesystem. International means that - a bug has been fixed so that accented ("international") letters - in file names are case-insensitive, as they ought to be. - Supported read/write. - -DOS\3 The "international" Fast File System. Supported read/write. - -DOS\4 The original filesystem with directory cache. The directory - cache speeds up directory accesses on floppies considerably, - but slows down file creation/deletion. Doesn't make much - sense on hard disks. Supported read only. - -DOS\5 The Fast File System with directory cache. Supported read only. - -All of the above filesystems allow block sizes from 512 to 32K bytes. -Supported block sizes are: 512, 1024, 2048 and 4096 bytes. Larger blocks -speed up almost everything at the expense of wasted disk space. The speed -gain above 4K seems not really worth the price, so you don't lose too -much here, either. - -The muFS (multi user File System) equivalents of the above file systems -are supported, too. - -Mount options for the AFFS -========================== - -protect If this option is set, the protection bits cannot be altered. - -setuid[=uid] This sets the owner of all files and directories in the file - system to uid or the uid of the current user, respectively. - -setgid[=gid] Same as above, but for gid. - -mode=mode Sets the mode flags to the given (octal) value, regardless - of the original permissions. Directories will get an x - permission if the corresponding r bit is set. - This is useful since most of the plain AmigaOS files - will map to 600. - -nofilenametruncate - The file system will return an error when filename exceeds - standard maximum filename length (30 characters). - -reserved=num Sets the number of reserved blocks at the start of the - partition to num. You should never need this option. - Default is 2. - -root=block Sets the block number of the root block. This should never - be necessary. - -bs=blksize Sets the blocksize to blksize. Valid block sizes are 512, - 1024, 2048 and 4096. Like the root option, this should - never be necessary, as the affs can figure it out itself. - -quiet The file system will not return an error for disallowed - mode changes. - -verbose The volume name, file system type and block size will - be written to the syslog when the filesystem is mounted. - -mufs The filesystem is really a muFS, also it doesn't - identify itself as one. This option is necessary if - the filesystem wasn't formatted as muFS, but is used - as one. - -prefix=path Path will be prefixed to every absolute path name of - symbolic links on an AFFS partition. Default = "/". - (See below.) - -volume=name When symbolic links with an absolute path are created - on an AFFS partition, name will be prepended as the - volume name. Default = "" (empty string). - (See below.) - -Handling of the Users/Groups and protection flags -================================================= - -Amiga -> Linux: - -The Amiga protection flags RWEDRWEDHSPARWED are handled as follows: - - - R maps to r for user, group and others. On directories, R implies x. - - - If both W and D are allowed, w will be set. - - - E maps to x. - - - H and P are always retained and ignored under Linux. - - - A is always reset when a file is written to. - -User id and group id will be used unless set[gu]id are given as mount -options. Since most of the Amiga file systems are single user systems -they will be owned by root. The root directory (the mount point) of the -Amiga filesystem will be owned by the user who actually mounts the -filesystem (the root directory doesn't have uid/gid fields). - -Linux -> Amiga: - -The Linux rwxrwxrwx file mode is handled as follows: - - - r permission will set R for user, group and others. - - - w permission will set W and D for user, group and others. - - - x permission of the user will set E for plain files. - - - All other flags (suid, sgid, ...) are ignored and will - not be retained. - -Newly created files and directories will get the user and group ID -of the current user and a mode according to the umask. - -Symbolic links -============== - -Although the Amiga and Linux file systems resemble each other, there -are some, not always subtle, differences. One of them becomes apparent -with symbolic links. While Linux has a file system with exactly one -root directory, the Amiga has a separate root directory for each -file system (for example, partition, floppy disk, ...). With the Amiga, -these entities are called "volumes". They have symbolic names which -can be used to access them. Thus, symbolic links can point to a -different volume. AFFS turns the volume name into a directory name -and prepends the prefix path (see prefix option) to it. - -Example: -You mount all your Amiga partitions under /amiga/<volume> (where -<volume> is the name of the volume), and you give the option -"prefix=/amiga/" when mounting all your AFFS partitions. (They -might be "User", "WB" and "Graphics", the mount points /amiga/User, -/amiga/WB and /amiga/Graphics). A symbolic link referring to -"User:sc/include/dos/dos.h" will be followed to -"/amiga/User/sc/include/dos/dos.h". - -Examples -======== - -Command line: - mount Archive/Amiga/Workbench3.1.adf /mnt -t affs -o loop,verbose - mount /dev/sda3 /Amiga -t affs - -/etc/fstab entry: - /dev/sdb5 /amiga/Workbench affs noauto,user,exec,verbose 0 0 - -IMPORTANT NOTE -============== - -If you boot Windows 95 (don't know about 3.x, 98 and NT) while you -have an Amiga harddisk connected to your PC, it will overwrite -the bytes 0x00dc..0x00df of block 0 with garbage, thus invalidating -the Rigid Disk Block. Sheer luck has it that this is an unused -area of the RDB, so only the checksum doesn't match anymore. -Linux will ignore this garbage and recognize the RDB anyway, but -before you connect that drive to your Amiga again, you must -restore or repair your RDB. So please do make a backup copy of it -before booting Windows! - -If the damage is already done, the following should fix the RDB -(where <disk> is the device name). -DO AT YOUR OWN RISK: - - dd if=/dev/<disk> of=rdb.tmp count=1 - cp rdb.tmp rdb.fixed - dd if=/dev/zero of=rdb.fixed bs=1 seek=220 count=4 - dd if=rdb.fixed of=/dev/<disk> - -Bugs, Restrictions, Caveats -=========================== - -Quite a few things may not work as advertised. Not everything is -tested, though several hundred MB have been read and written using -this fs. For a most up-to-date list of bugs please consult -fs/affs/Changes. - -By default, filenames are truncated to 30 characters without warning. -'nofilenametruncate' mount option can change that behavior. - -Case is ignored by the affs in filename matching, but Linux shells -do care about the case. Example (with /wb being an affs mounted fs): - rm /wb/WRONGCASE -will remove /mnt/wrongcase, but - rm /wb/WR* -will not since the names are matched by the shell. - -The block allocation is designed for hard disk partitions. If more -than 1 process writes to a (small) diskette, the blocks are allocated -in an ugly way (but the real AFFS doesn't do much better). This -is also true when space gets tight. - -You cannot execute programs on an OFS (Old File System), since the -program files cannot be memory mapped due to the 488 byte blocks. -For the same reason you cannot mount an image on such a filesystem -via the loopback device. - -The bitmap valid flag in the root block may not be accurate when the -system crashes while an affs partition is mounted. There's currently -no way to fix a garbled filesystem without an Amiga (disk validator) -or manually (who would do this?). Maybe later. - -If you mount affs partitions on system startup, you may want to tell -fsck that the fs should not be checked (place a '0' in the sixth field -of /etc/fstab). - -It's not possible to read floppy disks with a normal PC or workstation -due to an incompatibility with the Amiga floppy controller. - -If you are interested in an Amiga Emulator for Linux, look at - -http://web.archive.org/web/*/http://www.freiburg.linux.de/~uae/ |