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(struct backing_dev_info *bdi,char *name,unsigned int cap)
  75 {
  76         char tmp[32];
  77         int error;
  78
  79         bdi->name = name;
  80         bdi->capabilities = cap;
  81         error = bdi_init(bdi);
  82         if (error)
  83                 return (error);
  84
  85         sprintf(tmp, "%.28s%s", name, "-%d");
  86         error = bdi_register(bdi, NULL, tmp,
  87             atomic_long_inc_return(&zfs_bdi_seq));
  88         if (error) {
  89                 bdi_destroy(bdi);
  90                 return (error);
  91         }
  92
  93         return (error);
  94 }
  95 #endif /* HAVE_BDI && !HAVE_BDI_SETUP_AND_REGISTER */
  96
  97 /*
  98  * 2.6.38 API change,
  99  * LOOKUP_RCU flag introduced to distinguish rcu-walk from ref-walk cases.
 100  */
 101 #ifndef LOOKUP_RCU
 102 #define LOOKUP_RCU      0x0
 103 #endif /* LOOKUP_RCU */
 104
 105 /*
 106  * 3.2-rc1 API change,
 107  * Add set_nlink() if it is not exported by the Linux kernel.
 108  *
 109  * i_nlink is read-only in Linux 3.2, but it can be set directly in
 110  * earlier kernels.
 111  */
 112 #ifndef HAVE_SET_NLINK
 113 static inline void
 114 set_nlink(struct inode *inode, unsigned int nlink)
 115 {
 116         inode->i_nlink = nlink;
 117 }
 118 #endif /* HAVE_SET_NLINK */
 119
 120 /*
 121  * 3.3 API change,
 122  * The VFS .create, .mkdir and .mknod callbacks were updated to take a
 123  * umode_t type rather than an int.  To cleanly handle both definitions
 124  * the zpl_umode_t type is introduced and set accordingly.
 125  */
 126 #ifdef HAVE_MKDIR_UMODE_T
 127 typedef umode_t         zpl_umode_t;
 128 #else
 129 typedef int             zpl_umode_t;
 130 #endif
 131
 132 /*
 133  * 3.5 API change,
 134  * The clear_inode() function replaces end_writeback() and introduces an
 135  * ordering change regarding when the inode_sync_wait() occurs.  See the
 136  * configure check in config/kernel-clear-inode.m4 for full details.
 137  */
 138 #if defined(HAVE_EVICT_INODE) && !defined(HAVE_CLEAR_INODE)
 139 #define clear_inode(ip)         end_writeback(ip)
 140 #endif /* HAVE_EVICT_INODE && !HAVE_CLEAR_INODE */
 141
 142 /*
 143  * 3.6 API change,
 144  * The sget() helper function now takes the mount flags as an argument.
 145  */
 146 #ifdef HAVE_5ARG_SGET
 147 #define zpl_sget(type, cmp, set, fl, mtd)       sget(type, cmp, set, fl, mtd)
 148 #else
 149 #define zpl_sget(type, cmp, set, fl, mtd)       sget(type, cmp, set, mtd)
 150 #endif /* HAVE_5ARG_SGET */
 151
 152 #define ZFS_IOC_GETFLAGS        FS_IOC_GETFLAGS
 153 #define ZFS_IOC_SETFLAGS        FS_IOC_SETFLAGS
 154
 155 #if defined(SEEK_HOLE) && defined(SEEK_DATA) && !defined(HAVE_LSEEK_EXECUTE)
 156 static inline loff_t
 157 lseek_execute(struct file *filp, struct inode *inode,
 158               loff_t offset, loff_t maxsize)
 159 {
 160         if (offset < 0 && !(filp->f_mode & FMODE_UNSIGNED_OFFSET))
 161                 return (-EINVAL);
 162
 163         if (offset > maxsize)
 164                 return (-EINVAL);
 165
 166         if (offset != filp->f_pos) {
 167                 spin_lock(&filp->f_lock);
 168                 filp->f_pos = offset;
 169                 filp->f_version = 0;
 170                 spin_unlock(&filp->f_lock);
 171         }
 172
 173         return (offset);
 174 }
 175 #endif /* SEEK_HOLE && SEEK_DATA && !HAVE_LSEEK_EXECUTE */
 176
 177 #if defined(CONFIG_FS_POSIX_ACL)
 178 /*
 179  * These functions safely approximates the behavior of posix_acl_release()
 180  * which cannot be used because it calls the GPL-only symbol kfree_rcu().
 181  * The in-kernel version, which can access the RCU, frees the ACLs after
 182  * the grace period expires.  Because we're unsure how long that grace
 183  * period may be this implementation conservatively delays for 60 seconds.
 184  * This is several orders of magnitude larger than expected grace period.
 185  * At 60 seconds the kernel will also begin issuing RCU stall warnings.
 186  */
 187 #include <linux/posix_acl.h>
 188 #ifndef HAVE_POSIX_ACL_CACHING
 189 #define ACL_NOT_CACHED ((void *)(-1))
 190 #endif /* HAVE_POSIX_ACL_CACHING */
 191
 192 #if defined(HAVE_POSIX_ACL_RELEASE) && !defined(HAVE_POSIX_ACL_RELEASE_GPL_ONLY)
 193
 194 #define zpl_posix_acl_release(arg)              posix_acl_release(arg)
 195 #define zpl_set_cached_acl(ip, ty, n)           set_cached_acl(ip, ty, n)
 196 #define zpl_forget_cached_acl(ip, ty)           forget_cached_acl(ip, ty)
 197
 198 #else
 199
 200 static inline void
 201 zpl_posix_acl_free(void *arg) {
 202         kfree(arg);
 203 }
 204
 205 static inline void
 206 zpl_posix_acl_release(struct posix_acl *acl)
 207 {
 208         if ((acl == NULL) || (acl == ACL_NOT_CACHED))
 209                 return;
 210
 211         if (atomic_dec_and_test(&acl->a_refcount)) {
 212                 taskq_dispatch_delay(system_taskq, zpl_posix_acl_free, acl,
 213                     TQ_SLEEP, ddi_get_lbolt() + 60*HZ);
 214         }
 215 }
 216
 217 static inline void
 218 zpl_set_cached_acl(struct inode *ip, int type, struct posix_acl *newer) {
 219 #ifdef HAVE_POSIX_ACL_CACHING
 220         struct posix_acl *older = NULL;
 221
 222         spin_lock(&ip->i_lock);
 223
 224         if ((newer != ACL_NOT_CACHED) && (newer != NULL))
 225                 posix_acl_dup(newer);
 226
 227         switch(type) {
 228         case ACL_TYPE_ACCESS:
 229                 older = ip->i_acl;
 230                 rcu_assign_pointer(ip->i_acl,newer);
 231                 break;
 232         case ACL_TYPE_DEFAULT:
 233                 older = ip->i_default_acl;
 234                 rcu_assign_pointer(ip->i_default_acl,newer);
 235                 break;
 236         }
 237
 238         spin_unlock(&ip->i_lock);
 239
 240         zpl_posix_acl_release(older);
 241 #endif /* HAVE_POSIX_ACL_CACHING */
 242 }
 243
 244 static inline void
 245 zpl_forget_cached_acl(struct inode *ip, int type) {
 246         zpl_set_cached_acl(ip, type, (struct posix_acl *)ACL_NOT_CACHED);
 247 }
 248 #endif /* HAVE_POSIX_ACL_RELEASE */
 249
 250 /*
 251  * 2.6.38 API change,
 252  * The is_owner_or_cap() function was renamed to inode_owner_or_capable().
 253  */
 254 #ifdef HAVE_INODE_OWNER_OR_CAPABLE
 255 #define zpl_inode_owner_or_capable(ip)          inode_owner_or_capable(ip)
 256 #else
 257 #define zpl_inode_owner_or_capable(ip)          is_owner_or_cap(ip)
 258 #endif /* HAVE_INODE_OWNER_OR_CAPABLE */
 259
 260 #ifndef HAVE_POSIX_ACL_CHMOD
 261 static inline int
 262 posix_acl_chmod(struct posix_acl **acl, int flags, umode_t umode) {
 263         struct posix_acl *oldacl = *acl;
 264         mode_t mode = umode;
 265         int error;
 266
 267         *acl = posix_acl_clone(*acl, flags);
 268         zpl_posix_acl_release(oldacl);
 269
 270         if (!(*acl))
 271                 return (-ENOMEM);
 272
 273         error = posix_acl_chmod_masq(*acl, mode);
 274         if (error) {
 275                 zpl_posix_acl_release(*acl);
 276                 *acl = NULL;
 277         }
 278
 279         return (error);
 280 }
 281
 282 static inline int
 283 posix_acl_create(struct posix_acl** acl, int flags, umode_t* umodep) {
 284         struct posix_acl *oldacl = *acl;
 285         mode_t mode = *umodep;
 286         int error;
 287
 288         *acl = posix_acl_clone(*acl, flags);
 289         zpl_posix_acl_release(oldacl);
 290
 291         if (!(*acl))
 292                 return (-ENOMEM);
 293
 294         error = posix_acl_create_masq(*acl, &mode);
 295         *umodep = mode;
 296
 297         if (error < 0) {
 298                 zpl_posix_acl_release(*acl);
 299                 *acl = NULL;
 300         }
 301
 302         return (error);
 303 }
 304 #endif /* HAVE_POSIX_ACL_CHMOD */
 305
 306 #ifndef HAVE_CURRENT_UMASK
 307 static inline int
 308 current_umask(void)
 309 {
 310         return (current->fs->umask);
 311 }
 312 #endif /* HAVE_CURRENT_UMASK */
 313
 314 #ifdef HAVE_POSIX_ACL_EQUIV_MODE_UMODE_T
 315 typedef umode_t zpl_equivmode_t;
 316 #else
 317 typedef mode_t zpl_equivmode_t;
 318 #endif /* HAVE_POSIX_ACL_EQUIV_MODE_UMODE_T */
 319 #endif /* CONFIG_FS_POSIX_ACL */
 320
 321 #endif /* _ZFS_VFS_H */