libsyscall/wrappers/fs_snapshot.c

   1 /*
   2  * Copyright (c) 2016 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 #include <sys/snapshot.h>
  25 #include <sys/attr.h>
  26 #include <unistd.h>
  27 #include <errno.h>
  28 #include <stdint.h>
  29 #include <stdlib.h>
  30
  31 extern int __fs_snapshot(uint32_t, int, const char *, const char *, void *,
  32     uint32_t);
  33
  34 int
  35 fs_snapshot_create(int dirfd, const char *name, uint32_t flags)
  36 {
  37         return __fs_snapshot(SNAPSHOT_OP_CREATE, dirfd, name, NULL, NULL, flags);
  38 }
  39
  40 int
  41 fs_snapshot_list(int dirfd, struct attrlist *alist, void *attrbuf, size_t bufsize,
  42     uint32_t flags)
  43 {
  44         if (flags != 0) {
  45                 errno = EINVAL;
  46                 return (-1);
  47         }
  48
  49         return (getattrlistbulk(dirfd, alist, attrbuf, bufsize,
  50             FSOPT_LIST_SNAPSHOT));
  51 }
  52
  53 int
  54 fs_snapshot_delete(int dirfd, const char *name, uint32_t flags)
  55 {
  56         return __fs_snapshot(SNAPSHOT_OP_DELETE, dirfd, name, NULL, NULL, flags);
  57 }
  58
  59 int
  60 fs_snapshot_rename(int dirfd, const char *old, const char *new, uint32_t flags)
  61 {
  62         return __fs_snapshot(SNAPSHOT_OP_RENAME, dirfd, old, new, NULL, flags);
  63 }
  64
  65 int
  66 fs_snapshot_revert(int dirfd, const char *name, uint32_t flags)
  67 {
  68     return __fs_snapshot(SNAPSHOT_OP_REVERT, dirfd, name, NULL, NULL, flags);
  69 }
  70
  71 /*
  72  * XXX Temporary hack to do what mount_apfs(8) does. This will be removed and
  73  * replaced with a VFS_IOCTL based implementation in the kernel.
  74  */
  75 #include <sys/stat.h>
  76 #include "strings.h"
  77
  78 #ifndef SNAPSHOT_OP_MOUNT
  79 #define SNAPSHOT_OP_MOUNT 0x4
  80 #endif
  81
  82 #define FS_MOUNT_SNAPSHOT 2
  83 #define MAX_SNAPSHOT_NAMELEN    256
  84
  85 struct fs_mount_options {
  86         uint32_t fs_flags;
  87         uint8_t _padding_[2];
  88 };
  89
  90 struct fs_mount_args {
  91         char *specdev;
  92         struct fs_mount_options options;
  93         uint16_t mode;
  94         uint16_t _padding_[3];
  95         union {
  96                 struct {                        // FS_MOUNT_SNAPSHOT
  97                         dev_t snap_fsys;
  98                         char snap_name[MAX_SNAPSHOT_NAMELEN];
  99                 };
 100                 struct {                        // APFS_MOUNT_FOR_CONVERSION
 101                 };
 102         };
 103 };
 104
 105 int
 106 fs_snapshot_mount(int dirfd, const char *dir, const char *snapshot,
 107     uint32_t flags)
 108 {
 109         struct stat st;
 110         struct fs_mount_args mnt_args;
 111
 112         mnt_args.specdev = NULL;
 113         mnt_args.mode = FS_MOUNT_SNAPSHOT;
 114         if (fstat(dirfd, &st) == -1)
 115                 return (-1);
 116
 117         mnt_args.snap_fsys = st.st_dev;
 118         strlcpy(mnt_args.snap_name, snapshot, sizeof(mnt_args.snap_name));
 119         return (__fs_snapshot(SNAPSHOT_OP_MOUNT, dirfd, snapshot, dir,
 120             (void *)&mnt_args, flags));
 121 }