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  * Copyright (C) 2015 Jörg Thalheim.
  25  */
  26
  27 #ifndef _ZFS_VFS_H
  28 #define _ZFS_VFS_H
  29
  30 #include <sys/taskq.h>
  31 #include <sys/cred.h>
  32 #include <linux/backing-dev.h>
  33 #include <linux/compat.h>
  34
  35 /*
  36  * 2.6.28 API change,
  37  * Added insert_inode_locked() helper function, prior to this most callers
  38  * used insert_inode_hash().  The older method doesn't check for collisions
  39  * in the inode_hashtable but it still acceptible for use.
  40  */
  41 #ifndef HAVE_INSERT_INODE_LOCKED
  42 static inline int
  43 insert_inode_locked(struct inode *ip)
  44 {
  45         insert_inode_hash(ip);
  46         return (0);
  47 }
  48 #endif /* HAVE_INSERT_INODE_LOCKED */
  49
  50 /*
  51  * 2.6.35 API change,
  52  * Add truncate_setsize() if it is not exported by the Linux kernel.
  53  *
  54  * Truncate the inode and pages associated with the inode. The pages are
  55  * unmapped and removed from cache.
  56  */
  57 #ifndef HAVE_TRUNCATE_SETSIZE
  58 static inline void
  59 truncate_setsize(struct inode *ip, loff_t new)
  60 {
  61         struct address_space *mapping = ip->i_mapping;
  62
  63         i_size_write(ip, new);
  64
  65         unmap_mapping_range(mapping, new + PAGE_SIZE - 1, 0, 1);
  66         truncate_inode_pages(mapping, new);
  67         unmap_mapping_range(mapping, new + PAGE_SIZE - 1, 0, 1);
  68 }
  69 #endif /* HAVE_TRUNCATE_SETSIZE */
  70
  71 /*
  72  * 2.6.32 - 2.6.33, bdi_setup_and_register() is not available.
  73  * 2.6.34 - 3.19, bdi_setup_and_register() takes 3 arguments.
  74  * 4.0 - 4.11, bdi_setup_and_register() takes 2 arguments.
  75  * 4.12 - x.y, super_setup_bdi_name() new interface.
  76  */
  77 #if defined(HAVE_SUPER_SETUP_BDI_NAME)
  78 extern atomic_long_t zfs_bdi_seq;
  79
  80 static inline int
  81 zpl_bdi_setup(struct super_block *sb, char *name)
  82 {
  83         return super_setup_bdi_name(sb, "%.28s-%ld", name,
  84             atomic_long_inc_return(&zfs_bdi_seq));
  85 }
  86 static inline void
  87 zpl_bdi_destroy(struct super_block *sb)
  88 {
  89 }
  90 #elif defined(HAVE_2ARGS_BDI_SETUP_AND_REGISTER)
  91 static inline int
  92 zpl_bdi_setup(struct super_block *sb, char *name)
  93 {
  94         struct backing_dev_info *bdi;
  95         int error;
  96
  97         bdi = kmem_zalloc(sizeof (struct backing_dev_info), KM_SLEEP);
  98         error = bdi_setup_and_register(bdi, name);
  99         if (error) {
 100                 kmem_free(bdi, sizeof (struct backing_dev_info));
 101                 return (error);
 102         }
 103
 104         sb->s_bdi = bdi;
 105
 106         return (0);
 107 }
 108 static inline void
 109 zpl_bdi_destroy(struct super_block *sb)
 110 {
 111         struct backing_dev_info *bdi = sb->s_bdi;
 112
 113         bdi_destroy(bdi);
 114         kmem_free(bdi, sizeof (struct backing_dev_info));
 115         sb->s_bdi = NULL;
 116 }
 117 #elif defined(HAVE_3ARGS_BDI_SETUP_AND_REGISTER)
 118 static inline int
 119 zpl_bdi_setup(struct super_block *sb, char *name)
 120 {
 121         struct backing_dev_info *bdi;
 122         int error;
 123
 124         bdi = kmem_zalloc(sizeof (struct backing_dev_info), KM_SLEEP);
 125         error = bdi_setup_and_register(bdi, name, BDI_CAP_MAP_COPY);
 126         if (error) {
 127                 kmem_free(sb->s_bdi, sizeof (struct backing_dev_info));
 128                 return (error);
 129         }
 130
 131         sb->s_bdi = bdi;
 132
 133         return (0);
 134 }
 135 static inline void
 136 zpl_bdi_destroy(struct super_block *sb)
 137 {
 138         struct backing_dev_info *bdi = sb->s_bdi;
 139
 140         bdi_destroy(bdi);
 141         kmem_free(bdi, sizeof (struct backing_dev_info));
 142         sb->s_bdi = NULL;
 143 }
 144 #else
 145 extern atomic_long_t zfs_bdi_seq;
 146
 147 static inline int
 148 zpl_bdi_setup(struct super_block *sb, char *name)
 149 {
 150         struct backing_dev_info *bdi;
 151         int error;
 152
 153         bdi = kmem_zalloc(sizeof (struct backing_dev_info), KM_SLEEP);
 154         bdi->name = name;
 155         bdi->capabilities = BDI_CAP_MAP_COPY;
 156
 157         error = bdi_init(bdi);
 158         if (error) {
 159                 kmem_free(bdi, sizeof (struct backing_dev_info));
 160                 return (error);
 161         }
 162
 163         error = bdi_register(bdi, NULL, "%.28s-%ld", name,
 164             atomic_long_inc_return(&zfs_bdi_seq));
 165         if (error) {
 166                 bdi_destroy(bdi);
 167                 kmem_free(bdi, sizeof (struct backing_dev_info));
 168                 return (error);
 169         }
 170
 171         sb->s_bdi = bdi;
 172
 173         return (0);
 174 }
 175 static inline void
 176 zpl_bdi_destroy(struct super_block *sb)
 177 {
 178         struct backing_dev_info *bdi = sb->s_bdi;
 179
 180         bdi_destroy(bdi);
 181         kmem_free(bdi, sizeof (struct backing_dev_info));
 182         sb->s_bdi = NULL;
 183 }
 184 #endif
 185
 186 /*
 187  * 4.14 adds SB_* flag definitions, define them to MS_* equivalents
 188  * if not set.
 189  */
 190 #ifndef SB_RDONLY
 191 #define SB_RDONLY       MS_RDONLY
 192 #endif
 193
 194 #ifndef SB_SILENT
 195 #define SB_SILENT       MS_SILENT
 196 #endif
 197
 198 #ifndef SB_ACTIVE
 199 #define SB_ACTIVE       MS_ACTIVE
 200 #endif
 201
 202 #ifndef SB_POSIXACL
 203 #define SB_POSIXACL     MS_POSIXACL
 204 #endif
 205
 206 #ifndef SB_MANDLOCK
 207 #define SB_MANDLOCK     MS_MANDLOCK
 208 #endif
 209
 210 #ifndef SB_NOATIME
 211 #define SB_NOATIME      MS_NOATIME
 212 #endif
 213
 214 /*
 215  * 2.6.38 API change,
 216  * LOOKUP_RCU flag introduced to distinguish rcu-walk from ref-walk cases.
 217  */
 218 #ifndef LOOKUP_RCU
 219 #define LOOKUP_RCU      0x0
 220 #endif /* LOOKUP_RCU */
 221
 222 /*
 223  * 3.2-rc1 API change,
 224  * Add set_nlink() if it is not exported by the Linux kernel.
 225  *
 226  * i_nlink is read-only in Linux 3.2, but it can be set directly in
 227  * earlier kernels.
 228  */
 229 #ifndef HAVE_SET_NLINK
 230 static inline void
 231 set_nlink(struct inode *inode, unsigned int nlink)
 232 {
 233         inode->i_nlink = nlink;
 234 }
 235 #endif /* HAVE_SET_NLINK */
 236
 237 /*
 238  * 3.3 API change,
 239  * The VFS .create, .mkdir and .mknod callbacks were updated to take a
 240  * umode_t type rather than an int.  To cleanly handle both definitions
 241  * the zpl_umode_t type is introduced and set accordingly.
 242  */
 243 #ifdef HAVE_MKDIR_UMODE_T
 244 typedef umode_t         zpl_umode_t;
 245 #else
 246 typedef int             zpl_umode_t;
 247 #endif
 248
 249 /*
 250  * 3.5 API change,
 251  * The clear_inode() function replaces end_writeback() and introduces an
 252  * ordering change regarding when the inode_sync_wait() occurs.  See the
 253  * configure check in config/kernel-clear-inode.m4 for full details.
 254  */
 255 #if defined(HAVE_EVICT_INODE) && !defined(HAVE_CLEAR_INODE)
 256 #define clear_inode(ip)         end_writeback(ip)
 257 #endif /* HAVE_EVICT_INODE && !HAVE_CLEAR_INODE */
 258
 259 /*
 260  * 3.6 API change,
 261  * The sget() helper function now takes the mount flags as an argument.
 262  */
 263 #ifdef HAVE_5ARG_SGET
 264 #define zpl_sget(type, cmp, set, fl, mtd)       sget(type, cmp, set, fl, mtd)
 265 #else
 266 #define zpl_sget(type, cmp, set, fl, mtd)       sget(type, cmp, set, mtd)
 267 #endif /* HAVE_5ARG_SGET */
 268
 269 #if defined(SEEK_HOLE) && defined(SEEK_DATA) && !defined(HAVE_LSEEK_EXECUTE)
 270 static inline loff_t
 271 lseek_execute(
 272         struct file *filp,
 273         struct inode *inode,
 274         loff_t offset,
 275         loff_t maxsize)
 276 {
 277         if (offset < 0 && !(filp->f_mode & FMODE_UNSIGNED_OFFSET))
 278                 return (-EINVAL);
 279
 280         if (offset > maxsize)
 281                 return (-EINVAL);
 282
 283         if (offset != filp->f_pos) {
 284                 spin_lock(&filp->f_lock);
 285                 filp->f_pos = offset;
 286                 filp->f_version = 0;
 287                 spin_unlock(&filp->f_lock);
 288         }
 289
 290         return (offset);
 291 }
 292 #endif /* SEEK_HOLE && SEEK_DATA && !HAVE_LSEEK_EXECUTE */
 293
 294 #if defined(CONFIG_FS_POSIX_ACL)
 295 /*
 296  * These functions safely approximates the behavior of posix_acl_release()
 297  * which cannot be used because it calls the GPL-only symbol kfree_rcu().
 298  * The in-kernel version, which can access the RCU, frees the ACLs after
 299  * the grace period expires.  Because we're unsure how long that grace
 300  * period may be this implementation conservatively delays for 60 seconds.
 301  * This is several orders of magnitude larger than expected grace period.
 302  * At 60 seconds the kernel will also begin issuing RCU stall warnings.
 303  */
 304
 305 #include <linux/posix_acl.h>
 306
 307 #if defined(HAVE_POSIX_ACL_RELEASE) && !defined(HAVE_POSIX_ACL_RELEASE_GPL_ONLY)
 308 #define zpl_posix_acl_release(arg)              posix_acl_release(arg)
 309 #else
 310 void zpl_posix_acl_release_impl(struct posix_acl *);
 311
 312 static inline void
 313 zpl_posix_acl_release(struct posix_acl *acl)
 314 {
 315         if ((acl == NULL) || (acl == ACL_NOT_CACHED))
 316                 return;
 317 #ifdef HAVE_ACL_REFCOUNT
 318         if (refcount_dec_and_test(&acl->a_refcount))
 319                 zpl_posix_acl_release_impl(acl);
 320 #else
 321         if (atomic_dec_and_test(&acl->a_refcount))
 322                 zpl_posix_acl_release_impl(acl);
 323 #endif
 324 }
 325 #endif /* HAVE_POSIX_ACL_RELEASE */
 326
 327 #ifdef HAVE_SET_CACHED_ACL_USABLE
 328 #define zpl_set_cached_acl(ip, ty, n)           set_cached_acl(ip, ty, n)
 329 #define zpl_forget_cached_acl(ip, ty)           forget_cached_acl(ip, ty)
 330 #else
 331 static inline void
 332 zpl_set_cached_acl(struct inode *ip, int type, struct posix_acl *newer)
 333 {
 334         struct posix_acl *older = NULL;
 335
 336         spin_lock(&ip->i_lock);
 337
 338         if ((newer != ACL_NOT_CACHED) && (newer != NULL))
 339                 posix_acl_dup(newer);
 340
 341         switch (type) {
 342         case ACL_TYPE_ACCESS:
 343                 older = ip->i_acl;
 344                 rcu_assign_pointer(ip->i_acl, newer);
 345                 break;
 346         case ACL_TYPE_DEFAULT:
 347                 older = ip->i_default_acl;
 348                 rcu_assign_pointer(ip->i_default_acl, newer);
 349                 break;
 350         }
 351
 352         spin_unlock(&ip->i_lock);
 353
 354         zpl_posix_acl_release(older);
 355 }
 356
 357 static inline void
 358 zpl_forget_cached_acl(struct inode *ip, int type)
 359 {
 360         zpl_set_cached_acl(ip, type, (struct posix_acl *)ACL_NOT_CACHED);
 361 }
 362 #endif /* HAVE_SET_CACHED_ACL_USABLE */
 363
 364 #ifndef HAVE___POSIX_ACL_CHMOD
 365 #ifdef HAVE_POSIX_ACL_CHMOD
 366 #define __posix_acl_chmod(acl, gfp, mode)       posix_acl_chmod(acl, gfp, mode)
 367 #define __posix_acl_create(acl, gfp, mode)      posix_acl_create(acl, gfp, mode)
 368 #else
 369 static inline int
 370 __posix_acl_chmod(struct posix_acl **acl, int flags, umode_t umode)
 371 {
 372         struct posix_acl *oldacl = *acl;
 373         mode_t mode = umode;
 374         int error;
 375
 376         *acl = posix_acl_clone(*acl, flags);
 377         zpl_posix_acl_release(oldacl);
 378
 379         if (!(*acl))
 380                 return (-ENOMEM);
 381
 382         error = posix_acl_chmod_masq(*acl, mode);
 383         if (error) {
 384                 zpl_posix_acl_release(*acl);
 385                 *acl = NULL;
 386         }
 387
 388         return (error);
 389 }
 390
 391 static inline int
 392 __posix_acl_create(struct posix_acl **acl, int flags, umode_t *umodep)
 393 {
 394         struct posix_acl *oldacl = *acl;
 395         mode_t mode = *umodep;
 396         int error;
 397
 398         *acl = posix_acl_clone(*acl, flags);
 399         zpl_posix_acl_release(oldacl);
 400
 401         if (!(*acl))
 402                 return (-ENOMEM);
 403
 404         error = posix_acl_create_masq(*acl, &mode);
 405         *umodep = mode;
 406
 407         if (error < 0) {
 408                 zpl_posix_acl_release(*acl);
 409                 *acl = NULL;
 410         }
 411
 412         return (error);
 413 }
 414 #endif /* HAVE_POSIX_ACL_CHMOD */
 415 #endif /* HAVE___POSIX_ACL_CHMOD */
 416
 417 #ifdef HAVE_POSIX_ACL_EQUIV_MODE_UMODE_T
 418 typedef umode_t zpl_equivmode_t;
 419 #else
 420 typedef mode_t zpl_equivmode_t;
 421 #endif /* HAVE_POSIX_ACL_EQUIV_MODE_UMODE_T */
 422
 423 /*
 424  * 4.8 API change,
 425  * posix_acl_valid() now must be passed a namespace, the namespace from
 426  * from super block associated with the given inode is used for this purpose.
 427  */
 428 #ifdef HAVE_POSIX_ACL_VALID_WITH_NS
 429 #define zpl_posix_acl_valid(ip, acl)  posix_acl_valid(ip->i_sb->s_user_ns, acl)
 430 #else
 431 #define zpl_posix_acl_valid(ip, acl)  posix_acl_valid(acl)
 432 #endif
 433
 434 #endif /* CONFIG_FS_POSIX_ACL */
 435
 436 /*
 437  * 2.6.38 API change,
 438  * The is_owner_or_cap() function was renamed to inode_owner_or_capable().
 439  */
 440 #ifdef HAVE_INODE_OWNER_OR_CAPABLE
 441 #define zpl_inode_owner_or_capable(ip)          inode_owner_or_capable(ip)
 442 #else
 443 #define zpl_inode_owner_or_capable(ip)          is_owner_or_cap(ip)
 444 #endif /* HAVE_INODE_OWNER_OR_CAPABLE */
 445
 446 /*
 447  * 3.19 API change
 448  * struct access f->f_dentry->d_inode was replaced by accessor function
 449  * file_inode(f)
 450  */
 451 #ifndef HAVE_FILE_INODE
 452 static inline struct inode *file_inode(const struct file *f)
 453 {
 454         return (f->f_dentry->d_inode);
 455 }
 456 #endif /* HAVE_FILE_INODE */
 457
 458 /*
 459  * 4.1 API change
 460  * struct access file->f_path.dentry was replaced by accessor function
 461  * file_dentry(f)
 462  */
 463 #ifndef HAVE_FILE_DENTRY
 464 static inline struct dentry *file_dentry(const struct file *f)
 465 {
 466         return (f->f_path.dentry);
 467 }
 468 #endif /* HAVE_FILE_DENTRY */
 469
 470 #ifdef HAVE_KUID_HELPERS
 471 static inline uid_t zfs_uid_read_impl(struct inode *ip)
 472 {
 473 #ifdef HAVE_SUPER_USER_NS
 474         return (from_kuid(ip->i_sb->s_user_ns, ip->i_uid));
 475 #else
 476         return (from_kuid(kcred->user_ns, ip->i_uid));
 477 #endif
 478 }
 479
 480 static inline uid_t zfs_uid_read(struct inode *ip)
 481 {
 482         return (zfs_uid_read_impl(ip));
 483 }
 484
 485 static inline gid_t zfs_gid_read_impl(struct inode *ip)
 486 {
 487 #ifdef HAVE_SUPER_USER_NS
 488         return (from_kgid(ip->i_sb->s_user_ns, ip->i_gid));
 489 #else
 490         return (from_kgid(kcred->user_ns, ip->i_gid));
 491 #endif
 492 }
 493
 494 static inline gid_t zfs_gid_read(struct inode *ip)
 495 {
 496         return (zfs_gid_read_impl(ip));
 497 }
 498
 499 static inline void zfs_uid_write(struct inode *ip, uid_t uid)
 500 {
 501 #ifdef HAVE_SUPER_USER_NS
 502         ip->i_uid = make_kuid(ip->i_sb->s_user_ns, uid);
 503 #else
 504         ip->i_uid = make_kuid(kcred->user_ns, uid);
 505 #endif
 506 }
 507
 508 static inline void zfs_gid_write(struct inode *ip, gid_t gid)
 509 {
 510 #ifdef HAVE_SUPER_USER_NS
 511         ip->i_gid = make_kgid(ip->i_sb->s_user_ns, gid);
 512 #else
 513         ip->i_gid = make_kgid(kcred->user_ns, gid);
 514 #endif
 515 }
 516
 517 #else
 518 static inline uid_t zfs_uid_read(struct inode *ip)
 519 {
 520         return (ip->i_uid);
 521 }
 522
 523 static inline gid_t zfs_gid_read(struct inode *ip)
 524 {
 525         return (ip->i_gid);
 526 }
 527
 528 static inline void zfs_uid_write(struct inode *ip, uid_t uid)
 529 {
 530         ip->i_uid = uid;
 531 }
 532
 533 static inline void zfs_gid_write(struct inode *ip, gid_t gid)
 534 {
 535         ip->i_gid = gid;
 536 }
 537 #endif
 538
 539 /*
 540  * 2.6.38 API change
 541  */
 542 #ifdef HAVE_FOLLOW_DOWN_ONE
 543 #define zpl_follow_down_one(path)               follow_down_one(path)
 544 #define zpl_follow_up(path)                     follow_up(path)
 545 #else
 546 #define zpl_follow_down_one(path)               follow_down(path)
 547 #define zpl_follow_up(path)                     follow_up(path)
 548 #endif
 549
 550 /*
 551  * 4.9 API change
 552  */
 553 #ifndef HAVE_SETATTR_PREPARE
 554 static inline int
 555 setattr_prepare(struct dentry *dentry, struct iattr *ia)
 556 {
 557         return (inode_change_ok(dentry->d_inode, ia));
 558 }
 559 #endif
 560
 561 /*
 562  * 4.11 API change
 563  * These macros are defined by kernel 4.11.  We define them so that the same
 564  * code builds under kernels < 4.11 and >= 4.11.  The macros are set to 0 so
 565  * that it will create obvious failures if they are accidentally used when built
 566  * against a kernel >= 4.11.
 567  */
 568
 569 #ifndef STATX_BASIC_STATS
 570 #define STATX_BASIC_STATS       0
 571 #endif
 572
 573 #ifndef AT_STATX_SYNC_AS_STAT
 574 #define AT_STATX_SYNC_AS_STAT   0
 575 #endif
 576
 577 /*
 578  * 4.11 API change
 579  * 4.11 takes struct path *, < 4.11 takes vfsmount *
 580  */
 581
 582 #ifdef HAVE_VFSMOUNT_IOPS_GETATTR
 583 #define ZPL_GETATTR_WRAPPER(func)                                       \
 584 static int                                                              \
 585 func(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)   \
 586 {                                                                       \
 587         struct path path = { .mnt = mnt, .dentry = dentry };            \
 588         return func##_impl(&path, stat, STATX_BASIC_STATS,              \
 589             AT_STATX_SYNC_AS_STAT);                                     \
 590 }
 591 #elif defined(HAVE_PATH_IOPS_GETATTR)
 592 #define ZPL_GETATTR_WRAPPER(func)                                       \
 593 static int                                                              \
 594 func(const struct path *path, struct kstat *stat, u32 request_mask,     \
 595     unsigned int query_flags)                                           \
 596 {                                                                       \
 597         return (func##_impl(path, stat, request_mask, query_flags));    \
 598 }
 599 #else
 600 #error
 601 #endif
 602
 603 /*
 604  * 4.9 API change
 605  * Preferred interface to get the current FS time.
 606  */
 607 #if !defined(HAVE_CURRENT_TIME)
 608 static inline struct timespec
 609 current_time(struct inode *ip)
 610 {
 611         return (timespec_trunc(current_kernel_time(), ip->i_sb->s_time_gran));
 612 }
 613 #endif
 614
 615 /*
 616  * 4.16 API change
 617  * Added iversion interface for managing inode version field.
 618  */
 619 #ifdef HAVE_INODE_SET_IVERSION
 620 #include <linux/iversion.h>
 621 #else
 622 static inline void
 623 inode_set_iversion(struct inode *ip, u64 val)
 624 {
 625         ip->i_version = val;
 626 }
 627 #endif
 628
 629 /*
 630  * Returns true when called in the context of a 32-bit system call.
 631  */
 632 static inline int
 633 zpl_is_32bit_api(void)
 634 {
 635 #ifdef CONFIG_COMPAT
 636 #ifdef HAVE_IN_COMPAT_SYSCALL
 637         return (in_compat_syscall());
 638 #else
 639         return (is_compat_task());
 640 #endif
 641 #else
 642         return (BITS_PER_LONG == 32);
 643 #endif
 644 }
 645
 646 #endif /* _ZFS_VFS_H */