fs/xfs/xfs_attr.h

   1 /*
   2  * Copyright (c) 2000, 2002-2003 Silicon Graphics, Inc.  All Rights Reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of version 2 of the GNU General Public License as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it would be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  11  *
  12  * Further, this software is distributed without any warranty that it is
  13  * free of the rightful claim of any third person regarding infringement
  14  * or the like.  Any license provided herein, whether implied or
  15  * otherwise, applies only to this software file.  Patent licenses, if
  16  * any, provided herein do not apply to combinations of this program with
  17  * other software, or any other product whatsoever.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write the Free Software Foundation, Inc., 59
  21  * Temple Place - Suite 330, Boston MA 02111-1307, USA.
  22  *
  23  * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
  24  * Mountain View, CA  94043, or:
  25  *
  26  * http://www.sgi.com
  27  *
  28  * For further information regarding this notice, see:
  29  *
  30  * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
  31  */
  32 #ifndef __XFS_ATTR_H__
  33 #define __XFS_ATTR_H__
  34
  35 /*
  36  * xfs_attr.h
  37  *
  38  * Large attribute lists are structured around Btrees where all the data
  39  * elements are in the leaf nodes.  Attribute names are hashed into an int,
  40  * then that int is used as the index into the Btree.  Since the hashval
  41  * of an attribute name may not be unique, we may have duplicate keys.
  42  * The internal links in the Btree are logical block offsets into the file.
  43  *
  44  * Small attribute lists use a different format and are packed as tightly
  45  * as possible so as to fit into the literal area of the inode.
  46  */
  47
  48 /*========================================================================
  49  * External interfaces
  50  *========================================================================*/
  51
  52 struct cred;
  53 struct vnode;
  54
  55 typedef int (*attrset_t)(struct vnode *, char *, void *, size_t, int);
  56 typedef int (*attrget_t)(struct vnode *, char *, void *, size_t, int);
  57 typedef int (*attrremove_t)(struct vnode *, char *, int);
  58 typedef int (*attrexists_t)(struct vnode *);
  59 typedef int (*attrcapable_t)(struct vnode *, struct cred *);
  60
  61 typedef struct attrnames {
  62         char *          attr_name;
  63         unsigned int    attr_namelen;
  64         unsigned int    attr_flag;
  65         attrget_t       attr_get;
  66         attrset_t       attr_set;
  67         attrremove_t    attr_remove;
  68         attrexists_t    attr_exists;
  69         attrcapable_t   attr_capable;
  70 } attrnames_t;
  71
  72 #define ATTR_NAMECOUNT  4
  73 extern struct attrnames attr_user;
  74 extern struct attrnames attr_secure;
  75 extern struct attrnames attr_system;
  76 extern struct attrnames attr_trusted;
  77 extern struct attrnames *attr_namespaces[ATTR_NAMECOUNT];
  78
  79 extern attrnames_t *attr_lookup_namespace(char *, attrnames_t **, int);
  80 extern int attr_generic_list(struct vnode *, void *, size_t, int, ssize_t *);
  81
  82 #define ATTR_DONTFOLLOW 0x0001  /* -- unused, from IRIX -- */
  83 #define ATTR_ROOT       0x0002  /* use attrs in root (trusted) namespace */
  84 #define ATTR_TRUST      0x0004  /* -- unused, from IRIX -- */
  85 #define ATTR_SECURE     0x0008  /* use attrs in security namespace */
  86 #define ATTR_CREATE     0x0010  /* pure create: fail if attr already exists */
  87 #define ATTR_REPLACE    0x0020  /* pure set: fail if attr does not exist */
  88 #define ATTR_SYSTEM     0x0100  /* use attrs in system (pseudo) namespace */
  89
  90 #define ATTR_KERNACCESS 0x0400  /* [kernel] iaccess, inode held io-locked */
  91 #define ATTR_KERNOTIME  0x1000  /* [kernel] don't update inode timestamps */
  92 #define ATTR_KERNOVAL   0x2000  /* [kernel] get attr size only, not value */
  93 #define ATTR_KERNAMELS  0x4000  /* [kernel] list attr names (simple list) */
  94
  95 #define ATTR_KERNORMALS 0x0800  /* [kernel] normal attr list: user+secure */
  96 #define ATTR_KERNROOTLS 0x8000  /* [kernel] include root in the attr list */
  97 #define ATTR_KERNFULLS  (ATTR_KERNORMALS|ATTR_KERNROOTLS)
  98
  99 /*
 100  * The maximum size (into the kernel or returned from the kernel) of an
 101  * attribute value or the buffer used for an attr_list() call.  Larger
 102  * sizes will result in an ERANGE return code.
 103  */
 104 #define ATTR_MAX_VALUELEN       (64*1024)       /* max length of a value */
 105
 106 /*
 107  * Define how lists of attribute names are returned to the user from
 108  * the attr_list() call.  A large, 32bit aligned, buffer is passed in
 109  * along with its size.  We put an array of offsets at the top that each
 110  * reference an attrlist_ent_t and pack the attrlist_ent_t's at the bottom.
 111  */
 112 typedef struct attrlist {
 113         __s32   al_count;       /* number of entries in attrlist */
 114         __s32   al_more;        /* T/F: more attrs (do call again) */
 115         __s32   al_offset[1];   /* byte offsets of attrs [var-sized] */
 116 } attrlist_t;
 117
 118 /*
 119  * Show the interesting info about one attribute.  This is what the
 120  * al_offset[i] entry points to.
 121  */
 122 typedef struct attrlist_ent {   /* data from attr_list() */
 123         __u32   a_valuelen;     /* number bytes in value of attr */
 124         char    a_name[1];      /* attr name (NULL terminated) */
 125 } attrlist_ent_t;
 126
 127 /*
 128  * Given a pointer to the (char*) buffer containing the attr_list() result,
 129  * and an index, return a pointer to the indicated attribute in the buffer.
 130  */
 131 #define ATTR_ENTRY(buffer, index)               \
 132         ((attrlist_ent_t *)                     \
 133          &((char *)buffer)[ ((attrlist_t *)(buffer))->al_offset[index] ])
 134
 135 /*
 136  * Multi-attribute operation vector.
 137  */
 138 typedef struct attr_multiop {
 139         int     am_opcode;      /* operation to perform (ATTR_OP_GET, etc.) */
 140         int     am_error;       /* [out arg] result of this sub-op (an errno) */
 141         char    *am_attrname;   /* attribute name to work with */
 142         char    *am_attrvalue;  /* [in/out arg] attribute value (raw bytes) */
 143         int     am_length;      /* [in/out arg] length of value */
 144         int     am_flags;       /* bitwise OR of attr API flags defined above */
 145 } attr_multiop_t;
 146
 147 #define ATTR_OP_GET     1       /* return the indicated attr's value */
 148 #define ATTR_OP_SET     2       /* set/create the indicated attr/value pair */
 149 #define ATTR_OP_REMOVE  3       /* remove the indicated attr */
 150
 151 /*
 152  * Kernel-internal version of the attrlist cursor.
 153  */
 154 typedef struct attrlist_cursor_kern {
 155         __u32   hashval;        /* hash value of next entry to add */
 156         __u32   blkno;          /* block containing entry (suggestion) */
 157         __u32   offset;         /* offset in list of equal-hashvals */
 158         __u16   pad1;           /* padding to match user-level */
 159         __u8    pad2;           /* padding to match user-level */
 160         __u8    initted;        /* T/F: cursor has been initialized */
 161 } attrlist_cursor_kern_t;
 162
 163
 164 /*========================================================================
 165  * Function prototypes for the kernel.
 166  *========================================================================*/
 167
 168 struct xfs_inode;
 169 struct attrlist_cursor_kern;
 170 struct xfs_da_args;
 171
 172 /*
 173  * Overall external interface routines.
 174  */
 175 int xfs_attr_get(bhv_desc_t *, char *, char *, int *, int, struct cred *);
 176 int xfs_attr_set(bhv_desc_t *, char *, char *, int, int, struct cred *);
 177 int xfs_attr_remove(bhv_desc_t *, char *, int, struct cred *);
 178 int xfs_attr_list(bhv_desc_t *, char *, int, int,
 179                          struct attrlist_cursor_kern *, struct cred *);
 180 int xfs_attr_inactive(struct xfs_inode *dp);
 181
 182 int xfs_attr_shortform_getvalue(struct xfs_da_args *);
 183 int xfs_attr_fetch(struct xfs_inode *, char *, int,
 184                         char *, int *, int, struct cred *);
 185
 186 #endif  /* __XFS_ATTR_H__ */