diff options
| -rw-r--r-- | Documentation/filesystems/sysv-fs.txt | 177 | ||||
| -rw-r--r-- | fs/sysv/CHANGES | 60 | ||||
| -rw-r--r-- | fs/sysv/ChangeLog | 106 | ||||
| -rw-r--r-- | fs/sysv/INTRO | 182 |
4 files changed, 168 insertions, 357 deletions
diff --git a/Documentation/filesystems/sysv-fs.txt b/Documentation/filesystems/sysv-fs.txt index d81722418010..253b50d1328e 100644 --- a/Documentation/filesystems/sysv-fs.txt +++ b/Documentation/filesystems/sysv-fs.txt @@ -1,11 +1,8 @@ -This is the implementation of the SystemV/Coherent filesystem for Linux. It implements all of - Xenix FS, - SystemV/386 FS, - Coherent FS. -This is version beta 4. - To install: * Answer the 'System V and Coherent filesystem support' question with 'y' when configuring the kernel. @@ -28,11 +25,173 @@ Bugs in the present implementation: for this FS on hard disk yet. -Please report any bugs and suggestions to - Bruno Haible <haible@ma2s2.mathematik.uni-karlsruhe.de> - Pascal Haible <haible@izfm.uni-stuttgart.de> - Krzysztof G. Baranowski <kgb@manjak.knm.org.pl> +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 -Bruno Haible -<haible@ma2s2.mathematik.uni-karlsruhe.de> +Notation: We often speak of a "block" but mean a zone (the allocation unit) +and not the disk driver's notion of "block". diff --git a/fs/sysv/CHANGES b/fs/sysv/CHANGES deleted file mode 100644 index 66ea6e92be66..000000000000 --- a/fs/sysv/CHANGES +++ /dev/null @@ -1,60 +0,0 @@ -Mon, 15 Dec 1997 Krzysztof G. Baranowski <kgb@manjak.knm.org.pl> - * namei.c: struct sysv_dir_inode_operations updated to use dentries. - -Fri, 23 Jan 1998 Krzysztof G. Baranowski <kgb@manjak.knm.org.pl> - * inode.c: corrected 1 track offset setting (in sb->sv_block_base). - Originally it was overridden (by setting to zero) - in detected_[xenix,sysv4,sysv2,coherent]. Thanks - to Andrzej Krzysztofowicz <ankry@mif.pg.gda.pl> - for identifying the problem. - -Tue, 27 Jan 1998 Krzysztof G. Baranowski <kgb@manjak.knm.org.pl> - * inode.c: added 2048-byte block support to SystemV FS. - Merged detected_bs[512,1024,2048]() into one function: - void detected_bs (u_char type, struct super_block *sb). - Thanks to Andrzej Krzysztofowicz <ankry@mif.pg.gda.pl> - for the patch. - -Wed, 4 Feb 1998 Krzysztof G. Baranowski <kgb@manjak.knm.org.pl> - * namei.c: removed static subdir(); is_subdir() from dcache.c - is used instead. Cosmetic changes. - -Thu, 3 Dec 1998 Al Viro (viro@parcelfarce.linux.theplanet.co.uk) - * namei.c (sysv_rmdir): - Bugectomy: old check for victim being busy - (inode->i_count) wasn't replaced (with checking - dentry->d_count) and escaped Linus in the last round - of changes. Shot and buried. - -Wed, 9 Dec 1998 AV - * namei.c (do_sysv_rename): - Fixed incorrect check for other owners + race. - Removed checks that went to VFS. - * namei.c (sysv_unlink): - Removed checks that went to VFS. - -Thu, 10 Dec 1998 AV - * namei.c (do_mknod): - Removed dead code - mknod is never asked to - create a symlink or directory. Incidentially, - it wouldn't do it right if it would be called. - -Sat, 26 Dec 1998 KGB - * inode.c (detect_sysv4): - Added detection of expanded s_type field (0x10, - 0x20 and 0x30). Forced read-only access in this case. - -Sun, 21 Mar 1999 AV - * namei.c (sysv_link): - Fixed i_count usage that resulted in dcache corruption. - * inode.c: - Filled ->delete_inode() method with sysv_delete_inode(). - sysv_put_inode() is gone, as it tried to do ->delete_ - _inode()'s job. - * ialloc.c: (sysv_free_inode): - Fixed race. - -Sun, 30 Apr 1999 AV - * namei.c (sysv_mknod): - Removed dead code (S_IFREG case is now passed to - ->create() by VFS). diff --git a/fs/sysv/ChangeLog b/fs/sysv/ChangeLog deleted file mode 100644 index f403f8b91b80..000000000000 --- a/fs/sysv/ChangeLog +++ /dev/null @@ -1,106 +0,0 @@ -Thu Feb 14 2002 Andrew Morton <akpm@zip.com.au> - - * dir_commit_chunk(): call writeout_one_page() as well as - waitfor_one_page() for IS_SYNC directories, so that we - actually do sync the directory. (forward-port from 2.4). - -Thu Feb 7 2002 Alexander Viro <viro@parcelfarce.linux.theplanet.co.uk> - - * super.c: switched to ->get_sb() - * ChangeLog: fixed dates ;-) - -2002-01-24 David S. Miller <davem@redhat.com> - - * inode.c: Include linux/init.h - -Mon Jan 21 2002 Alexander Viro <viro@parcelfarce.linux.theplanet.co.uk> - * ialloc.c (sysv_new_inode): zero SYSV_I(inode)->i_data out. - * i_vnode renamed to vfs_inode. Sorry, but let's keep that - consistent. - -Sat Jan 19 2002 Christoph Hellwig <hch@infradead.org> - - * include/linux/sysv_fs.h (SYSV_I): Get fs-private inode data using - list_entry() instead of inode->u. - * include/linux/sysv_fs_i.h: Add 'struct inode i_vnode' field to - sysv_inode_info structure. - * inode.c: Include <linux/slab.h>, implement alloc_inode/destroy_inode - sop methods, add infrastructure for per-fs inode slab cache. - * super.c (init_sysv_fs): Initialize inode cache, recover properly - in the case of failed register_filesystem for V7. - (exit_sysv_fs): Destroy inode cache. - -Sat Jan 19 2002 Christoph Hellwig <hch@infradead.org> - - * include/linux/sysv_fs.h: Include <linux/sysv_fs_i.h>, declare SYSV_I(). - * dir.c (sysv_find_entry): Use SYSV_I() instead of ->u.sysv_i to - access fs-private inode data. - * ialloc.c (sysv_new_inode): Likewise. - * inode.c (sysv_read_inode): Likewise. - (sysv_update_inode): Likewise. - * itree.c (get_branch): Likewise. - (sysv_truncate): Likewise. - * symlink.c (sysv_readlink): Likewise. - (sysv_follow_link): Likewise. - -Fri Jan 4 2002 Alexander Viro <viro@parcelfarce.linux.theplanet.co.uk> - - * ialloc.c (sysv_free_inode): Use sb->s_id instead of bdevname(). - * inode.c (sysv_read_inode): Likewise. - (sysv_update_inode): Likewise. - (sysv_sync_inode): Likewise. - * super.c (detect_sysv): Likewise. - (complete_read_super): Likewise. - (sysv_read_super): Likewise. - (v7_read_super): Likewise. - -Sun Dec 30 2001 Manfred Spraul <manfred@colorfullife.com> - - * dir.c (dir_commit_chunk): Do not set dir->i_version. - (sysv_readdir): Likewise. - -Thu Dec 27 2001 Alexander Viro <viro@parcelfarce.linux.theplanet.co.uk> - - * itree.c (get_block): Use map_bh() to fill out bh_result. - -Tue Dec 25 2001 Alexander Viro <viro@parcelfarce.linux.theplanet.co.uk> - - * super.c (sysv_read_super): Use sb_set_blocksize() to set blocksize. - (v7_read_super): Likewise. - -Tue Nov 27 2001 Alexander Viro <viro@parcelfarce.linux.theplanet.co.uk> - - * itree.c (get_block): Change type for iblock argument to sector_t. - * super.c (sysv_read_super): Set s_blocksize early. - (v7_read_super): Likewise. - * balloc.c (sysv_new_block): Use sb_bread(). instead of bread(). - (sysv_count_free_blocks): Likewise. - * ialloc.c (sysv_raw_inode): Likewise. - * itree.c (get_branch): Likewise. - (free_branches): Likewise. - * super.c (sysv_read_super): Likewise. - (v7_read_super): Likewise. - -Sat Dec 15 2001 Christoph Hellwig <hch@infradead.org> - - * inode.c (sysv_read_inode): Mark inode as bad in case of failure. - * super.c (complete_read_super): Check for bad root inode. - -Wed Nov 21 2001 Andrew Morton <andrewm@uow.edu.au> - - * file.c (sysv_sync_file): Call fsync_inode_data_buffers. - -Fri Oct 26 2001 Christoph Hellwig <hch@infradead.org> - - * dir.c, ialloc.c, namei.c, include/linux/sysv_fs_i.h: - Implement per-Inode lookup offset cache. - Modelled after Ted's ext2 patch. - -Fri Oct 26 2001 Christoph Hellwig <hch@infradead.org> - - * inode.c, super.c, include/linux/sysv_fs.h, - include/linux/sysv_fs_sb.h: - Remove symlink faking. Noone really wants to use these as - linux filesystems and native OSes don't support it anyway. - - diff --git a/fs/sysv/INTRO b/fs/sysv/INTRO deleted file mode 100644 index de4e4d17cac6..000000000000 --- a/fs/sysv/INTRO +++ /dev/null @@ -1,182 +0,0 @@ -This is the implementation of the SystemV/Coherent filesystem for Linux. -It grew out of separate filesystem implementations - - Xenix FS Doug Evans <dje@cygnus.com> June 1992 - SystemV FS Paul B. Monday <pmonday@eecs.wsu.edu> March-June 1993 - Coherent FS B. Haible <haible@ma2s2.mathematik.uni-karlsruhe.de> June 1993 - -and was merged together in July 1993. - -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". - - -Bruno Haible <haible@ma2s2.mathematik.uni-karlsruhe.de> |
