fs/gfs2/eaops.c

   1 /*
   2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   3  * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
   4  *
   5  * This copyrighted material is made available to anyone wishing to use,
   6  * modify, copy, or redistribute it subject to the terms and conditions
   7  * of the GNU General Public License v.2.
   8  */
   9
  10 #include <linux/sched.h>
  11 #include <linux/slab.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/completion.h>
  14 #include <linux/buffer_head.h>
  15 #include <linux/xattr.h>
  16 #include <linux/gfs2_ondisk.h>
  17 #include <asm/uaccess.h>
  18
  19 #include "gfs2.h"
  20 #include "lm_interface.h"
  21 #include "incore.h"
  22 #include "acl.h"
  23 #include "eaops.h"
  24 #include "eattr.h"
  25 #include "util.h"
  26
  27 /**
  28  * gfs2_ea_name2type - get the type of the ea, and truncate type from the name
  29  * @namep: ea name, possibly with type appended
  30  *
  31  * Returns: GFS2_EATYPE_XXX
  32  */
  33
  34 unsigned int gfs2_ea_name2type(const char *name, char **truncated_name)
  35 {
  36         unsigned int type;
  37
  38         if (strncmp(name, "system.", 7) == 0) {
  39                 type = GFS2_EATYPE_SYS;
  40                 if (truncated_name)
  41                         *truncated_name = strchr(name, '.') + 1;
  42         } else if (strncmp(name, "user.", 5) == 0) {
  43                 type = GFS2_EATYPE_USR;
  44                 if (truncated_name)
  45                         *truncated_name = strchr(name, '.') + 1;
  46         } else {
  47                 type = GFS2_EATYPE_UNUSED;
  48                 if (truncated_name)
  49                         *truncated_name = NULL;
  50         }
  51
  52         return type;
  53 }
  54
  55 static int user_eo_get(struct gfs2_inode *ip, struct gfs2_ea_request *er)
  56 {
  57         struct inode *inode = ip->i_vnode;
  58         int error = permission(inode, MAY_READ, NULL);
  59         if (error)
  60                 return error;
  61
  62         return gfs2_ea_get_i(ip, er);
  63 }
  64
  65 static int user_eo_set(struct gfs2_inode *ip, struct gfs2_ea_request *er)
  66 {
  67         struct inode *inode = ip->i_vnode;
  68
  69         if (S_ISREG(inode->i_mode) ||
  70             (S_ISDIR(inode->i_mode) && !(inode->i_mode & S_ISVTX))) {
  71                 int error = permission(inode, MAY_WRITE, NULL);
  72                 if (error)
  73                         return error;
  74         } else
  75                 return -EPERM;
  76
  77         return gfs2_ea_set_i(ip, er);
  78 }
  79
  80 static int user_eo_remove(struct gfs2_inode *ip, struct gfs2_ea_request *er)
  81 {
  82         struct inode *inode = ip->i_vnode;
  83
  84         if (S_ISREG(inode->i_mode) ||
  85             (S_ISDIR(inode->i_mode) && !(inode->i_mode & S_ISVTX))) {
  86                 int error = permission(inode, MAY_WRITE, NULL);
  87                 if (error)
  88                         return error;
  89         } else
  90                 return -EPERM;
  91
  92         return gfs2_ea_remove_i(ip, er);
  93 }
  94
  95 static int system_eo_get(struct gfs2_inode *ip, struct gfs2_ea_request *er)
  96 {
  97         if (!GFS2_ACL_IS_ACCESS(er->er_name, er->er_name_len) &&
  98             !GFS2_ACL_IS_DEFAULT(er->er_name, er->er_name_len) &&
  99             !capable(CAP_SYS_ADMIN))
 100                 return -EPERM;
 101
 102         if (ip->i_sbd->sd_args.ar_posix_acl == 0 &&
 103             (GFS2_ACL_IS_ACCESS(er->er_name, er->er_name_len) ||
 104              GFS2_ACL_IS_DEFAULT(er->er_name, er->er_name_len)))
 105                 return -EOPNOTSUPP;
 106
 107
 108
 109         return gfs2_ea_get_i(ip, er);
 110 }
 111
 112 static int system_eo_set(struct gfs2_inode *ip, struct gfs2_ea_request *er)
 113 {
 114         int remove = 0;
 115         int error;
 116
 117         if (GFS2_ACL_IS_ACCESS(er->er_name, er->er_name_len)) {
 118                 if (!(er->er_flags & GFS2_ERF_MODE)) {
 119                         er->er_mode = ip->i_di.di_mode;
 120                         er->er_flags |= GFS2_ERF_MODE;
 121                 }
 122                 error = gfs2_acl_validate_set(ip, 1, er,
 123                                               &remove, &er->er_mode);
 124                 if (error)
 125                         return error;
 126                 error = gfs2_ea_set_i(ip, er);
 127                 if (error)
 128                         return error;
 129                 if (remove)
 130                         gfs2_ea_remove_i(ip, er);
 131                 return 0;
 132
 133         } else if (GFS2_ACL_IS_DEFAULT(er->er_name, er->er_name_len)) {
 134                 error = gfs2_acl_validate_set(ip, 0, er,
 135                                               &remove, NULL);
 136                 if (error)
 137                         return error;
 138                 if (!remove)
 139                         error = gfs2_ea_set_i(ip, er);
 140                 else {
 141                         error = gfs2_ea_remove_i(ip, er);
 142                         if (error == -ENODATA)
 143                                 error = 0;
 144                 }
 145                 return error;
 146         }
 147
 148         return -EPERM;
 149 }
 150
 151 static int system_eo_remove(struct gfs2_inode *ip, struct gfs2_ea_request *er)
 152 {
 153         if (GFS2_ACL_IS_ACCESS(er->er_name, er->er_name_len)) {
 154                 int error = gfs2_acl_validate_remove(ip, 1);
 155                 if (error)
 156                         return error;
 157
 158         } else if (GFS2_ACL_IS_DEFAULT(er->er_name, er->er_name_len)) {
 159                 int error = gfs2_acl_validate_remove(ip, 0);
 160                 if (error)
 161                         return error;
 162
 163         } else
 164                 return -EPERM;
 165
 166         return gfs2_ea_remove_i(ip, er);
 167 }
 168
 169 static struct gfs2_eattr_operations gfs2_user_eaops = {
 170         .eo_get = user_eo_get,
 171         .eo_set = user_eo_set,
 172         .eo_remove = user_eo_remove,
 173         .eo_name = "user",
 174 };
 175
 176 struct gfs2_eattr_operations gfs2_system_eaops = {
 177         .eo_get = system_eo_get,
 178         .eo_set = system_eo_set,
 179         .eo_remove = system_eo_remove,
 180         .eo_name = "system",
 181 };
 182
 183 struct gfs2_eattr_operations *gfs2_ea_ops[] = {
 184         NULL,
 185         &gfs2_user_eaops,
 186         &gfs2_system_eaops,
 187 };
 188