include/linux/vfs_compat.h

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright (C) 2011 Lawrence Livermore National Security, LLC.
  24  */
  25
  26 #ifndef _ZFS_VFS_H
  27 #define _ZFS_VFS_H
  28
  29 /*
  30  * 2.6.28 API change,
  31  * Added insert_inode_locked() helper function, prior to this most callers
  32  * used insert_inode_hash().  The older method doesn't check for collisions
  33  * in the inode_hashtable but it still acceptible for use.
  34  */
  35 #ifndef HAVE_INSERT_INODE_LOCKED
  36 static inline int
  37 insert_inode_locked(struct inode *ip)
  38 {
  39         insert_inode_hash(ip);
  40         return (0);
  41 }
  42 #endif /* HAVE_INSERT_INODE_LOCKED */
  43
  44 /*
  45  * 2.6.35 API change,
  46  * Add truncate_setsize() if it is not exported by the Linux kernel.
  47  *
  48  * Truncate the inode and pages associated with the inode. The pages are
  49  * unmapped and removed from cache.
  50  */
  51 #ifndef HAVE_TRUNCATE_SETSIZE
  52 static inline void
  53 truncate_setsize(struct inode *ip, loff_t new)
  54 {
  55         struct address_space *mapping = ip->i_mapping;
  56
  57         i_size_write(ip, new);
  58
  59         unmap_mapping_range(mapping, new + PAGE_SIZE - 1, 0, 1);
  60         truncate_inode_pages(mapping, new);
  61         unmap_mapping_range(mapping, new + PAGE_SIZE - 1, 0, 1);
  62 }
  63 #endif /* HAVE_TRUNCATE_SETSIZE */
  64
  65 #if defined(HAVE_BDI) && !defined(HAVE_BDI_SETUP_AND_REGISTER)
  66 /*
  67  * 2.6.34 API change,
  68  * Add bdi_setup_and_register() function if not yet provided by kernel.
  69  * It is used to quickly initialize and register a BDI for the filesystem.
  70  */
  71 extern atomic_long_t zfs_bdi_seq;
  72
  73 static inline int
  74 bdi_setup_and_register(
  75         struct backing_dev_info *bdi,
  76         char *name,
  77         unsigned int cap)
  78 {
  79         char tmp[32];
  80         int error;
  81
  82         bdi->name = name;
  83         bdi->capabilities = cap;
  84         error = bdi_init(bdi);
  85         if (error)
  86                 return (error);
  87
  88         sprintf(tmp, "%.28s%s", name, "-%d");
  89         error = bdi_register(bdi, NULL, tmp,
  90             atomic_long_inc_return(&zfs_bdi_seq));
  91         if (error) {
  92                 bdi_destroy(bdi);
  93                 return (error);
  94         }
  95
  96         return (error);
  97 }
  98 #endif /* HAVE_BDI && !HAVE_BDI_SETUP_AND_REGISTER */
  99
 100 /*
 101  * 2.6.38 API change,
 102  * LOOKUP_RCU flag introduced to distinguish rcu-walk from ref-walk cases.
 103  */
 104 #ifndef LOOKUP_RCU
 105 #define LOOKUP_RCU      0x0
 106 #endif /* LOOKUP_RCU */
 107
 108 /*
 109  * 3.2-rc1 API change,
 110  * Add set_nlink() if it is not exported by the Linux kernel.
 111  *
 112  * i_nlink is read-only in Linux 3.2, but it can be set directly in
 113  * earlier kernels.
 114  */
 115 #ifndef HAVE_SET_NLINK
 116 static inline void
 117 set_nlink(struct inode *inode, unsigned int nlink)
 118 {
 119         inode->i_nlink = nlink;
 120 }
 121 #endif /* HAVE_SET_NLINK */
 122
 123 /*
 124  * 3.3 API change,
 125  * The VFS .create, .mkdir and .mknod callbacks were updated to take a
 126  * umode_t type rather than an int.  To cleanly handle both definitions
 127  * the zpl_umode_t type is introduced and set accordingly.
 128  */
 129 #ifdef HAVE_MKDIR_UMODE_T
 130 typedef umode_t         zpl_umode_t;
 131 #else
 132 typedef int             zpl_umode_t;
 133 #endif
 134
 135 /*
 136  * 3.5 API change,
 137  * The clear_inode() function replaces end_writeback() and introduces an
 138  * ordering change regarding when the inode_sync_wait() occurs.  See the
 139  * configure check in config/kernel-clear-inode.m4 for full details.
 140  */
 141 #if defined(HAVE_EVICT_INODE) && !defined(HAVE_CLEAR_INODE)
 142 #define clear_inode(ip)         end_writeback(ip)
 143 #endif /* HAVE_EVICT_INODE && !HAVE_CLEAR_INODE */
 144
 145 /*
 146  * 3.6 API change,
 147  * The sget() helper function now takes the mount flags as an argument.
 148  */
 149 #ifdef HAVE_5ARG_SGET
 150 #define zpl_sget(type, cmp, set, fl, mtd)       sget(type, cmp, set, fl, mtd)
 151 #else
 152 #define zpl_sget(type, cmp, set, fl, mtd)       sget(type, cmp, set, mtd)
 153 #endif /* HAVE_5ARG_SGET */
 154
 155 #define ZFS_IOC_GETFLAGS        FS_IOC_GETFLAGS
 156 #define ZFS_IOC_SETFLAGS        FS_IOC_SETFLAGS
 157
 158 #if defined(SEEK_HOLE) && defined(SEEK_DATA) && !defined(HAVE_LSEEK_EXECUTE)
 159 static inline loff_t
 160 lseek_execute(
 161         struct file *filp,
 162         struct inode *inode,
 163         loff_t offset,
 164         loff_t maxsize)
 165 {
 166         if (offset < 0 && !(filp->f_mode & FMODE_UNSIGNED_OFFSET))
 167                 return (-EINVAL);
 168
 169         if (offset > maxsize)
 170                 return (-EINVAL);
 171
 172         if (offset != filp->f_pos) {
 173                 spin_lock(&filp->f_lock);
 174                 filp->f_pos = offset;
 175                 filp->f_version = 0;
 176                 spin_unlock(&filp->f_lock);
 177         }
 178
 179         return (offset);
 180 }
 181 #endif /* SEEK_HOLE && SEEK_DATA && !HAVE_LSEEK_EXECUTE */
 182
 183 #if defined(CONFIG_FS_POSIX_ACL)
 184 /*
 185  * These functions safely approximates the behavior of posix_acl_release()
 186  * which cannot be used because it calls the GPL-only symbol kfree_rcu().
 187  * The in-kernel version, which can access the RCU, frees the ACLs after
 188  * the grace period expires.  Because we're unsure how long that grace
 189  * period may be this implementation conservatively delays for 60 seconds.
 190  * This is several orders of magnitude larger than expected grace period.
 191  * At 60 seconds the kernel will also begin issuing RCU stall warnings.
 192  */
 193 #include <linux/posix_acl.h>
 194 #ifndef HAVE_POSIX_ACL_CACHING
 195 #define ACL_NOT_CACHED ((void *)(-1))
 196 #endif /* HAVE_POSIX_ACL_CACHING */
 197
 198 #if defined(HAVE_POSIX_ACL_RELEASE) && !defined(HAVE_POSIX_ACL_RELEASE_GPL_ONLY)
 199
 200 #define zpl_posix_acl_release(arg)              posix_acl_release(arg)
 201 #define zpl_set_cached_acl(ip, ty, n)           set_cached_acl(ip, ty, n)
 202 #define zpl_forget_cached_acl(ip, ty)           forget_cached_acl(ip, ty)
 203
 204 #else
 205
 206 static inline void
 207 zpl_posix_acl_free(void *arg) {
 208         kfree(arg);
 209 }
 210
 211 static inline void
 212 zpl_posix_acl_release(struct posix_acl *acl)
 213 {
 214         if ((acl == NULL) || (acl == ACL_NOT_CACHED))
 215                 return;
 216
 217         if (atomic_dec_and_test(&acl->a_refcount)) {
 218                 taskq_dispatch_delay(system_taskq, zpl_posix_acl_free, acl,
 219                     TQ_SLEEP, ddi_get_lbolt() + 60*HZ);
 220         }
 221 }
 222
 223 static inline void
 224 zpl_set_cached_acl(struct inode *ip, int type, struct posix_acl *newer) {
 225 #ifdef HAVE_POSIX_ACL_CACHING
 226         struct posix_acl *older = NULL;
 227
 228         spin_lock(&ip->i_lock);
 229
 230         if ((newer != ACL_NOT_CACHED) && (newer != NULL))
 231                 posix_acl_dup(newer);
 232
 233         switch (type) {
 234         case ACL_TYPE_ACCESS:
 235                 older = ip->i_acl;
 236                 rcu_assign_pointer(ip->i_acl, newer);
 237                 break;
 238         case ACL_TYPE_DEFAULT:
 239                 older = ip->i_default_acl;
 240                 rcu_assign_pointer(ip->i_default_acl, newer);
 241                 break;
 242         }
 243
 244         spin_unlock(&ip->i_lock);
 245
 246         zpl_posix_acl_release(older);
 247 #endif /* HAVE_POSIX_ACL_CACHING */
 248 }
 249
 250 static inline void
 251 zpl_forget_cached_acl(struct inode *ip, int type) {
 252         zpl_set_cached_acl(ip, type, (struct posix_acl *)ACL_NOT_CACHED);
 253 }
 254 #endif /* HAVE_POSIX_ACL_RELEASE */
 255
 256 /*
 257  * 2.6.38 API change,
 258  * The is_owner_or_cap() function was renamed to inode_owner_or_capable().
 259  */
 260 #ifdef HAVE_INODE_OWNER_OR_CAPABLE
 261 #define zpl_inode_owner_or_capable(ip)          inode_owner_or_capable(ip)
 262 #else
 263 #define zpl_inode_owner_or_capable(ip)          is_owner_or_cap(ip)
 264 #endif /* HAVE_INODE_OWNER_OR_CAPABLE */
 265
 266 #ifndef HAVE_POSIX_ACL_CHMOD
 267 static inline int
 268 posix_acl_chmod(struct posix_acl **acl, int flags, umode_t umode) {
 269         struct posix_acl *oldacl = *acl;
 270         mode_t mode = umode;
 271         int error;
 272
 273         *acl = posix_acl_clone(*acl, flags);
 274         zpl_posix_acl_release(oldacl);
 275
 276         if (!(*acl))
 277                 return (-ENOMEM);
 278
 279         error = posix_acl_chmod_masq(*acl, mode);
 280         if (error) {
 281                 zpl_posix_acl_release(*acl);
 282                 *acl = NULL;
 283         }
 284
 285         return (error);
 286 }
 287
 288 static inline int
 289 posix_acl_create(struct posix_acl **acl, int flags, umode_t *umodep) {
 290         struct posix_acl *oldacl = *acl;
 291         mode_t mode = *umodep;
 292         int error;
 293
 294         *acl = posix_acl_clone(*acl, flags);
 295         zpl_posix_acl_release(oldacl);
 296
 297         if (!(*acl))
 298                 return (-ENOMEM);
 299
 300         error = posix_acl_create_masq(*acl, &mode);
 301         *umodep = mode;
 302
 303         if (error < 0) {
 304                 zpl_posix_acl_release(*acl);
 305                 *acl = NULL;
 306         }
 307
 308         return (error);
 309 }
 310 #endif /* HAVE_POSIX_ACL_CHMOD */
 311
 312 #ifndef HAVE_CURRENT_UMASK
 313 static inline int
 314 current_umask(void)
 315 {
 316         return (current->fs->umask);
 317 }
 318 #endif /* HAVE_CURRENT_UMASK */
 319
 320 #ifdef HAVE_POSIX_ACL_EQUIV_MODE_UMODE_T
 321 typedef umode_t zpl_equivmode_t;
 322 #else
 323 typedef mode_t zpl_equivmode_t;
 324 #endif /* HAVE_POSIX_ACL_EQUIV_MODE_UMODE_T */
 325 #endif /* CONFIG_FS_POSIX_ACL */
 326
 327 #endif /* _ZFS_VFS_H */