| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2000-2001 Christoph Hellwig. |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions |
| 7 | * are met: |
| 8 | * 1. Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions, and the following disclaimer, |
| 10 | * without modification. |
| 11 | * 2. The name of the author may not be used to endorse or promote products |
| 12 | * derived from this software without specific prior written permission. |
| 13 | * |
| 14 | * Alternatively, this software may be distributed under the terms of the |
| 15 | * GNU General Public License ("GPL"). |
| 16 | * |
| 17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
| 18 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 19 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 20 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR |
| 21 | * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 22 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 23 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 24 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 25 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 26 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 27 | * SUCH DAMAGE. |
| 28 | * |
| 29 | */ |
| 30 | #ifndef _VXFS_DIR_H_ |
| 31 | #define _VXFS_DIR_H_ |
| 32 | |
| 33 | /* |
| 34 | * Veritas filesystem driver - directory structure. |
| 35 | * |
| 36 | * This file contains the definition of the vxfs directory format. |
| 37 | */ |
| 38 | |
| 39 | |
| 40 | /* |
| 41 | * VxFS directory block header. |
| 42 | * |
| 43 | * This entry is the head of every filesystem block in a directory. |
| 44 | * It is used for free space managment and additionally includes |
| 45 | * a hash for speeding up directory search (lookup). |
| 46 | * |
| 47 | * The hash may be empty and in fact we do not use it all in the |
| 48 | * Linux driver for now. |
| 49 | */ |
| 50 | struct vxfs_dirblk { |
| 51 | u_int16_t d_free; /* free space in dirblock */ |
| 52 | u_int16_t d_nhash; /* no of hash chains */ |
| 53 | u_int16_t d_hash[1]; /* hash chain */ |
| 54 | }; |
| 55 | |
| 56 | /* |
| 57 | * VXFS_NAMELEN is the maximum length of the d_name field |
| 58 | * of an VxFS directory entry. |
| 59 | */ |
| 60 | #define VXFS_NAMELEN 256 |
| 61 | |
| 62 | /* |
| 63 | * VxFS directory entry. |
| 64 | */ |
| 65 | struct vxfs_direct { |
| 66 | vx_ino_t d_ino; /* inode number */ |
| 67 | u_int16_t d_reclen; /* record length */ |
| 68 | u_int16_t d_namelen; /* d_name length */ |
| 69 | u_int16_t d_hashnext; /* next hash entry */ |
| 70 | char d_name[VXFS_NAMELEN]; /* name */ |
| 71 | }; |
| 72 | |
| 73 | /* |
| 74 | * VXFS_DIRPAD defines the directory entry boundaries, is _must_ be |
| 75 | * a multiple of four. |
| 76 | * VXFS_NAMEMIN is the length of a directory entry with a NULL d_name. |
| 77 | * VXFS_DIRROUND is an internal macros that rounds a length to a value |
| 78 | * usable for directory sizes. |
| 79 | * VXFS_DIRLEN calculates the directory entry size for an entry with |
| 80 | * a d_name with size len. |
| 81 | */ |
| 82 | #define VXFS_DIRPAD 4 |
| 83 | #define VXFS_NAMEMIN ((int)((struct vxfs_direct *)0)->d_name) |
| 84 | #define VXFS_DIRROUND(len) ((VXFS_DIRPAD + (len) - 1) & ~(VXFS_DIRPAD -1)) |
| 85 | #define VXFS_DIRLEN(len) (VXFS_DIRROUND(VXFS_NAMEMIN + (len))) |
| 86 | |
| 87 | /* |
| 88 | * VXFS_DIRBLKOV is the overhead of a specific dirblock. |
| 89 | */ |
| 90 | #define VXFS_DIRBLKOV(dbp) ((sizeof(short) * dbp->d_nhash) + 4) |
| 91 | |
| 92 | #endif /* _VXFS_DIR_H_ */ |