fs/xfs/xfs

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This source file includes following definitions.
xfs_acl_from_disk
xfs_acl_to_disk
xfs_get_acl
__xfs_set_acl
xfs_set_mode
xfs_set_acl
   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2008, Christoph Hellwig
   4  * All Rights Reserved.
   5  */
   6 #include "xfs.h"
   7 #include "xfs_shared.h"
   8 #include "xfs_format.h"
   9 #include "xfs_log_format.h"
  10 #include "xfs_trans_resv.h"
  11 #include "xfs_mount.h"
  12 #include "xfs_inode.h"
  13 #include "xfs_attr.h"
  14 #include "xfs_trace.h"
  15 #include <linux/posix_acl_xattr.h>
  16 
  17 
  18 /*
  19  * Locking scheme:
  20  *  - all ACL updates are protected by inode->i_mutex, which is taken before
  21  *    calling into this file.
  22  */
  23 
  24 STATIC struct posix_acl *
  25 xfs_acl_from_disk(
  26         const struct xfs_acl    *aclp,
  27         int                     len,
  28         int                     max_entries)
  29 {
  30         struct posix_acl_entry *acl_e;
  31         struct posix_acl *acl;
  32         const struct xfs_acl_entry *ace;
  33         unsigned int count, i;
  34 
  35         if (len < sizeof(*aclp))
  36                 return ERR_PTR(-EFSCORRUPTED);
  37         count = be32_to_cpu(aclp->acl_cnt);
  38         if (count > max_entries || XFS_ACL_SIZE(count) != len)
  39                 return ERR_PTR(-EFSCORRUPTED);
  40 
  41         acl = posix_acl_alloc(count, GFP_KERNEL);
  42         if (!acl)
  43                 return ERR_PTR(-ENOMEM);
  44 
  45         for (i = 0; i < count; i++) {
  46                 acl_e = &acl->a_entries[i];
  47                 ace = &aclp->acl_entry[i];
  48 
  49                 /*
  50                  * The tag is 32 bits on disk and 16 bits in core.
  51                  *
  52                  * Because every access to it goes through the core
  53                  * format first this is not a problem.
  54                  */
  55                 acl_e->e_tag = be32_to_cpu(ace->ae_tag);
  56                 acl_e->e_perm = be16_to_cpu(ace->ae_perm);
  57 
  58                 switch (acl_e->e_tag) {
  59                 case ACL_USER:
  60                         acl_e->e_uid = xfs_uid_to_kuid(be32_to_cpu(ace->ae_id));
  61                         break;
  62                 case ACL_GROUP:
  63                         acl_e->e_gid = xfs_gid_to_kgid(be32_to_cpu(ace->ae_id));
  64                         break;
  65                 case ACL_USER_OBJ:
  66                 case ACL_GROUP_OBJ:
  67                 case ACL_MASK:
  68                 case ACL_OTHER:
  69                         break;
  70                 default:
  71                         goto fail;
  72                 }
  73         }
  74         return acl;
  75 
  76 fail:
  77         posix_acl_release(acl);
  78         return ERR_PTR(-EINVAL);
  79 }
  80 
  81 STATIC void
  82 xfs_acl_to_disk(struct xfs_acl *aclp, const struct posix_acl *acl)
  83 {
  84         const struct posix_acl_entry *acl_e;
  85         struct xfs_acl_entry *ace;
  86         int i;
  87 
  88         aclp->acl_cnt = cpu_to_be32(acl->a_count);
  89         for (i = 0; i < acl->a_count; i++) {
  90                 ace = &aclp->acl_entry[i];
  91                 acl_e = &acl->a_entries[i];
  92 
  93                 ace->ae_tag = cpu_to_be32(acl_e->e_tag);
  94                 switch (acl_e->e_tag) {
  95                 case ACL_USER:
  96                         ace->ae_id = cpu_to_be32(xfs_kuid_to_uid(acl_e->e_uid));
  97                         break;
  98                 case ACL_GROUP:
  99                         ace->ae_id = cpu_to_be32(xfs_kgid_to_gid(acl_e->e_gid));
 100                         break;
 101                 default:
 102                         ace->ae_id = cpu_to_be32(ACL_UNDEFINED_ID);
 103                         break;
 104                 }
 105 
 106                 ace->ae_perm = cpu_to_be16(acl_e->e_perm);
 107         }
 108 }
 109 
 110 struct posix_acl *
 111 xfs_get_acl(struct inode *inode, int type)
 112 {
 113         struct xfs_inode *ip = XFS_I(inode);
 114         struct posix_acl *acl = NULL;
 115         struct xfs_acl *xfs_acl = NULL;
 116         unsigned char *ea_name;
 117         int error;
 118         int len;
 119 
 120         trace_xfs_get_acl(ip);
 121 
 122         switch (type) {
 123         case ACL_TYPE_ACCESS:
 124                 ea_name = SGI_ACL_FILE;
 125                 break;
 126         case ACL_TYPE_DEFAULT:
 127                 ea_name = SGI_ACL_DEFAULT;
 128                 break;
 129         default:
 130                 BUG();
 131         }
 132 
 133         /*
 134          * If we have a cached ACLs value just return it, not need to
 135          * go out to the disk.
 136          */
 137         len = XFS_ACL_MAX_SIZE(ip->i_mount);
 138         error = xfs_attr_get(ip, ea_name, (unsigned char **)&xfs_acl, &len,
 139                                 ATTR_ALLOC | ATTR_ROOT);
 140         if (error) {
 141                 /*
 142                  * If the attribute doesn't exist make sure we have a negative
 143                  * cache entry, for any other error assume it is transient.
 144                  */
 145                 if (error != -ENOATTR)
 146                         acl = ERR_PTR(error);
 147         } else  {
 148                 acl = xfs_acl_from_disk(xfs_acl, len,
 149                                         XFS_ACL_MAX_ENTRIES(ip->i_mount));
 150                 kmem_free(xfs_acl);
 151         }
 152         return acl;
 153 }
 154 
 155 int
 156 __xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
 157 {
 158         struct xfs_inode *ip = XFS_I(inode);
 159         unsigned char *ea_name;
 160         int error;
 161 
 162         switch (type) {
 163         case ACL_TYPE_ACCESS:
 164                 ea_name = SGI_ACL_FILE;
 165                 break;
 166         case ACL_TYPE_DEFAULT:
 167                 if (!S_ISDIR(inode->i_mode))
 168                         return acl ? -EACCES : 0;
 169                 ea_name = SGI_ACL_DEFAULT;
 170                 break;
 171         default:
 172                 return -EINVAL;
 173         }
 174 
 175         if (acl) {
 176                 struct xfs_acl *xfs_acl;
 177                 int len = XFS_ACL_MAX_SIZE(ip->i_mount);
 178 
 179                 xfs_acl = kmem_zalloc_large(len, 0);
 180                 if (!xfs_acl)
 181                         return -ENOMEM;
 182 
 183                 xfs_acl_to_disk(xfs_acl, acl);
 184 
 185                 /* subtract away the unused acl entries */
 186                 len -= sizeof(struct xfs_acl_entry) *
 187                          (XFS_ACL_MAX_ENTRIES(ip->i_mount) - acl->a_count);
 188 
 189                 error = xfs_attr_set(ip, ea_name, (unsigned char *)xfs_acl,
 190                                 len, ATTR_ROOT);
 191 
 192                 kmem_free(xfs_acl);
 193         } else {
 194                 /*
 195                  * A NULL ACL argument means we want to remove the ACL.
 196                  */
 197                 error = xfs_attr_remove(ip, ea_name, ATTR_ROOT);
 198 
 199                 /*
 200                  * If the attribute didn't exist to start with that's fine.
 201                  */
 202                 if (error == -ENOATTR)
 203                         error = 0;
 204         }
 205 
 206         if (!error)
 207                 set_cached_acl(inode, type, acl);
 208         return error;
 209 }
 210 
 211 static int
 212 xfs_set_mode(struct inode *inode, umode_t mode)
 213 {
 214         int error = 0;
 215 
 216         if (mode != inode->i_mode) {
 217                 struct iattr iattr;
 218 
 219                 iattr.ia_valid = ATTR_MODE | ATTR_CTIME;
 220                 iattr.ia_mode = mode;
 221                 iattr.ia_ctime = current_time(inode);
 222 
 223                 error = xfs_setattr_nonsize(XFS_I(inode), &iattr, XFS_ATTR_NOACL);
 224         }
 225 
 226         return error;
 227 }
 228 
 229 int
 230 xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
 231 {
 232         umode_t mode;
 233         bool set_mode = false;
 234         int error = 0;
 235 
 236         if (!acl)
 237                 goto set_acl;
 238 
 239         error = -E2BIG;
 240         if (acl->a_count > XFS_ACL_MAX_ENTRIES(XFS_M(inode->i_sb)))
 241                 return error;
 242 
 243         if (type == ACL_TYPE_ACCESS) {
 244                 error = posix_acl_update_mode(inode, &mode, &acl);
 245                 if (error)
 246                         return error;
 247                 set_mode = true;
 248         }
 249 
 250  set_acl:
 251         error =  __xfs_set_acl(inode, acl, type);
 252         if (error)
 253                 return error;
 254 
 255         /*
 256          * We set the mode after successfully updating the ACL xattr because the
 257          * xattr update can fail at ENOSPC and we don't want to change the mode
 258          * if the ACL update hasn't been applied.
 259          */
 260         if (set_mode)
 261                 error = xfs_set_mode(inode, mode);
 262 
 263         return error;
 264 }
/* [<][>][^][v][top][bottom][index][help] */
root/fs/xfs/xfs_acl.c

DEFINITIONS
