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 21 struct xfs_inode; 22 struct xfs_da_args; 23 struct 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 /* 52 * The maximum size (into the kernel or returned from the kernel) of an 53 * attribute value or the buffer used for an attr_list() call. Larger 54 * sizes will result in an ERANGE return code. 55 */ 56 #define ATTR_MAX_VALUELEN (64*1024) /* max length of a value */ 57 58 /* 59 * Define how lists of attribute names are returned to the user from 60 * the attr_list() call. A large, 32bit aligned, buffer is passed in 61 * along with its size. We put an array of offsets at the top that each 62 * reference an attrlist_ent_t and pack the attrlist_ent_t's at the bottom. 63 */ 64 typedef struct attrlist { 65 __s32 al_count; /* number of entries in attrlist */ 66 __s32 al_more; /* T/F: more attrs (do call again) */ 67 __s32 al_offset[1]; /* byte offsets of attrs [var-sized] */ 68 } attrlist_t; 69 70 /* 71 * Show the interesting info about one attribute. This is what the 72 * al_offset[i] entry points to. 73 */ 74 typedef struct attrlist_ent { /* data from attr_list() */ 75 __u32 a_valuelen; /* number bytes in value of attr */ 76 char a_name[1]; /* attr name (NULL terminated) */ 77 } attrlist_ent_t; 78 79 /* 80 * Given a pointer to the (char*) buffer containing the attr_list() result, 81 * and an index, return a pointer to the indicated attribute in the buffer. 82 */ 83 #define ATTR_ENTRY(buffer, index) \ 84 ((attrlist_ent_t *) \ 85 &((char *)buffer)[ ((attrlist_t *)(buffer))->al_offset[index] ]) 86 87 /* 88 * Kernel-internal version of the attrlist cursor. 89 */ 90 typedef struct attrlist_cursor_kern { 91 __u32 hashval; /* hash value of next entry to add */ 92 __u32 blkno; /* block containing entry (suggestion) */ 93 __u32 offset; /* offset in list of equal-hashvals */ 94 __u16 pad1; /* padding to match user-level */ 95 __u8 pad2; /* padding to match user-level */ 96 __u8 initted; /* T/F: cursor has been initialized */ 97 } attrlist_cursor_kern_t; 98 99 100 /*======================================================================== 101 * Structure used to pass context around among the routines. 102 *========================================================================*/ 103 104 105 typedef int (*put_listent_func_t)(struct xfs_attr_list_context *, int, 106 char *, int, int, char *); 107 108 typedef struct xfs_attr_list_context { 109 struct xfs_inode *dp; /* inode */ 110 struct attrlist_cursor_kern *cursor; /* position in list */ 111 char *alist; /* output buffer */ 112 int seen_enough; /* T/F: seen enough of list? */ 113 ssize_t count; /* num used entries */ 114 int dupcnt; /* count dup hashvals seen */ 115 int bufsize; /* total buffer size */ 116 int firstu; /* first used byte in buffer */ 117 int flags; /* from VOP call */ 118 int resynch; /* T/F: resynch with cursor */ 119 int put_value; /* T/F: need value for listent */ 120 put_listent_func_t put_listent; /* list output fmt function */ 121 int index; /* index into output buffer */ 122 } xfs_attr_list_context_t; 123 124 125 /*======================================================================== 126 * Function prototypes for the kernel. 127 *========================================================================*/ 128 129 /* 130 * Overall external interface routines. 131 */ 132 int xfs_attr_calc_size(struct xfs_inode *, int, int, int *); 133 int xfs_attr_inactive(struct xfs_inode *dp); 134 int xfs_attr_fetch(struct xfs_inode *, struct xfs_name *, char *, int *, int); 135 int xfs_attr_rmtval_get(struct xfs_da_args *args); 136 int xfs_attr_list_int(struct xfs_attr_list_context *); 137 138 #endif /* __XFS_ATTR_H__ */ 139