diff options
Diffstat (limited to 'Documentation/filesystems')
| -rw-r--r-- | Documentation/filesystems/00-INDEX | 2 | ||||
| -rw-r--r-- | Documentation/filesystems/bfs.txt | 59 | ||||
| -rw-r--r-- | Documentation/filesystems/proc.txt | 2 |
3 files changed, 62 insertions, 1 deletions
diff --git a/Documentation/filesystems/00-INDEX b/Documentation/filesystems/00-INDEX index b481c8a67..b4ffac022 100644 --- a/Documentation/filesystems/00-INDEX +++ b/Documentation/filesystems/00-INDEX @@ -4,6 +4,8 @@ adfs.txt - info and mount options for the Acorn Advanced Disc Filing System. affs.txt - info and mount options for the Amiga Fast File System. +bfs.txt + - info for the SCO UnixWare Boot Filesystem (BFS). coda.txt - description of the CODA filesystem. fat_cvf.txt diff --git a/Documentation/filesystems/bfs.txt b/Documentation/filesystems/bfs.txt new file mode 100644 index 000000000..a6179cad9 --- /dev/null +++ b/Documentation/filesystems/bfs.txt @@ -0,0 +1,59 @@ +The BFS filesystem is used on SCO UnixWare machines for /stand slice. +By default, if you attempt to mount it read-write it will be automatically +mounted read-only. If you want to enable (limited) write support, you need +to select "BFS write support" when configuring the kernel. The write support +at this stage is limited to the blocks preallocated for a given inode. +This means that writes beyond the value of inode->iu_eblock will fail with EIO. +In particular, this means you can create empty files but not write data to them +or you can write data to the existing files and increase their size but not the +number of blocks allocated to them. I am currently working on removing this +limitation, i.e. ability to migrate inodes within BFS filesystem. + +In order to access /stand partition under Linux you obviously need to +know the partition number and the kernel must support UnixWare disk slices +(CONFIG_UNIXWARE_DISKLABEL config option). However BFS support does not +depend on having UnixWare disklabel support because one can also mount +BFS filesystem via loopback: + +# losetup /dev/loop0 stand.img +# mount -t bfs /dev/loop0 /mnt/stand + +where stand.img is a file containing the image of BFS filesystem. +When you have finished using it and umounted you need to also deallocate +/dev/loop0 device by: + +# losetup -d /dev/loop0 + +You can simplify mounting by just typing: + +# mount -t bfs -o loop stand.img /mnt/stand + +this will allocate the first available loopback device (and load loop.o +kernel module if necessary) automatically. Beware that umount will not +deallocate /dev/loopN device if /etc/mtab file on your system is a +symbolic link to /proc/mounts. You will need to do it manually using +"-d" switch of losetup(8). Read losetup(8) manpage for more info. + +To create the BFS image under UnixWare you need to find out first which +slice contains it. The command prtvtoc(1M) is your friend: + +# prtvtoc /dev/rdsk/c0b0t0d0s0 + +(assuming your root disk is on target=0, lun=0, bus=0, controller=0). Then you +look for the slice with tag "STAND", which is usually slice 10. With this +information you can use dd(1) to create the BFS image: + +# umount /stand +# dd if=/dev/rdsk/c0b0t0d0sa of=stand.img bs=512 + +Just in case, you can verify that you have done the right thing by checking +the magic number: + +# od -Ad -tx4 stand.img | more + +The first 4 bytes should be 0x1BADFACE. + +If you have any questions or suggestions regarding this BFS implementation +please contact me: + +Tigran A. Aivazian <tigran@ocston.org>. diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index a17c05b0f..fef3bb743 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -190,7 +190,7 @@ Table 1-3: Kernel info in /proc ide Directory containing info about the IDE subsystem interrupts Interrupt usage ioports I/O port usage - kcore Kernel core image + kcore Kernel core image (can be ELF or A.OUT) kmsg Kernel messages ksyms Kernel symbol table loadavg Load average |