1/* 2 * Copyright (c) 2000,2002-2003,2005 Silicon Graphics, Inc. 3 * All Rights Reserved. 4 * 5 * This program is free software; you can redistribute it and/or 6 * modify it under the terms of the GNU General Public License as 7 * published by the Free Software Foundation. 8 * 9 * This program is distributed in the hope that it would be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write the Free Software Foundation, 16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 17 */ 18#ifndef __XFS_ATTR_H__ 19#define __XFS_ATTR_H__ 20 21struct xfs_inode; 22struct xfs_da_args; 23struct xfs_attr_list_context; 24 25/* 26 * Large attribute lists are structured around Btrees where all the data 27 * elements are in the leaf nodes. Attribute names are hashed into an int, 28 * then that int is used as the index into the Btree. Since the hashval 29 * of an attribute name may not be unique, we may have duplicate keys. 30 * The internal links in the Btree are logical block offsets into the file. 31 * 32 * Small attribute lists use a different format and are packed as tightly 33 * as possible so as to fit into the literal area of the inode. 34 */ 35 36/*======================================================================== 37 * External interfaces 38 *========================================================================*/ 39 40 41#define ATTR_DONTFOLLOW 0x0001 /* -- unused, from IRIX -- */ 42#define ATTR_ROOT 0x0002 /* use attrs in root (trusted) namespace */ 43#define ATTR_TRUST 0x0004 /* -- unused, from IRIX -- */ 44#define ATTR_SECURE 0x0008 /* use attrs in security namespace */ 45#define ATTR_CREATE 0x0010 /* pure create: fail if attr already exists */ 46#define ATTR_REPLACE 0x0020 /* pure set: fail if attr does not exist */ 47 48#define ATTR_KERNOTIME 0x1000 /* [kernel] don't update inode timestamps */ 49#define ATTR_KERNOVAL 0x2000 /* [kernel] get attr size only, not value */ 50 51#define XFS_ATTR_FLAGS \ 52 { ATTR_DONTFOLLOW, "DONTFOLLOW" }, \ 53 { ATTR_ROOT, "ROOT" }, \ 54 { ATTR_TRUST, "TRUST" }, \ 55 { ATTR_SECURE, "SECURE" }, \ 56 { ATTR_CREATE, "CREATE" }, \ 57 { ATTR_REPLACE, "REPLACE" }, \ 58 { ATTR_KERNOTIME, "KERNOTIME" }, \ 59 { ATTR_KERNOVAL, "KERNOVAL" } 60 61/* 62 * The maximum size (into the kernel or returned from the kernel) of an 63 * attribute value or the buffer used for an attr_list() call. Larger 64 * sizes will result in an ERANGE return code. 65 */ 66#define ATTR_MAX_VALUELEN (64*1024) /* max length of a value */ 67 68/* 69 * Define how lists of attribute names are returned to the user from 70 * the attr_list() call. A large, 32bit aligned, buffer is passed in 71 * along with its size. We put an array of offsets at the top that each 72 * reference an attrlist_ent_t and pack the attrlist_ent_t's at the bottom. 73 */ 74typedef struct attrlist { 75 __s32 al_count; /* number of entries in attrlist */ 76 __s32 al_more; /* T/F: more attrs (do call again) */ 77 __s32 al_offset[1]; /* byte offsets of attrs [var-sized] */ 78} attrlist_t; 79 80/* 81 * Show the interesting info about one attribute. This is what the 82 * al_offset[i] entry points to. 83 */ 84typedef struct attrlist_ent { /* data from attr_list() */ 85 __u32 a_valuelen; /* number bytes in value of attr */ 86 char a_name[1]; /* attr name (NULL terminated) */ 87} attrlist_ent_t; 88 89/* 90 * Given a pointer to the (char*) buffer containing the attr_list() result, 91 * and an index, return a pointer to the indicated attribute in the buffer. 92 */ 93#define ATTR_ENTRY(buffer, index) \ 94 ((attrlist_ent_t *) \ 95 &((char *)buffer)[ ((attrlist_t *)(buffer))->al_offset[index] ]) 96 97/* 98 * Kernel-internal version of the attrlist cursor. 99 */ 100typedef struct attrlist_cursor_kern { 101 __u32 hashval; /* hash value of next entry to add */ 102 __u32 blkno; /* block containing entry (suggestion) */ 103 __u32 offset; /* offset in list of equal-hashvals */ 104 __u16 pad1; /* padding to match user-level */ 105 __u8 pad2; /* padding to match user-level */ 106 __u8 initted; /* T/F: cursor has been initialized */ 107} attrlist_cursor_kern_t; 108 109 110/*======================================================================== 111 * Structure used to pass context around among the routines. 112 *========================================================================*/ 113 114 115typedef int (*put_listent_func_t)(struct xfs_attr_list_context *, int, 116 unsigned char *, int, int, unsigned char *); 117 118typedef struct xfs_attr_list_context { 119 struct xfs_inode *dp; /* inode */ 120 struct attrlist_cursor_kern *cursor; /* position in list */ 121 char *alist; /* output buffer */ 122 int seen_enough; /* T/F: seen enough of list? */ 123 ssize_t count; /* num used entries */ 124 int dupcnt; /* count dup hashvals seen */ 125 int bufsize; /* total buffer size */ 126 int firstu; /* first used byte in buffer */ 127 int flags; /* from VOP call */ 128 int resynch; /* T/F: resynch with cursor */ 129 int put_value; /* T/F: need value for listent */ 130 put_listent_func_t put_listent; /* list output fmt function */ 131 int index; /* index into output buffer */ 132} xfs_attr_list_context_t; 133 134 135/*======================================================================== 136 * Function prototypes for the kernel. 137 *========================================================================*/ 138 139/* 140 * Overall external interface routines. 141 */ 142int xfs_attr_inactive(struct xfs_inode *dp); 143int xfs_attr_rmtval_get(struct xfs_da_args *args); 144int xfs_attr_list_int(struct xfs_attr_list_context *); 145 146#endif /* __XFS_ATTR_H__ */ 147