sysdeps/unix/sysv/linux/sys/mount.h

   1 /* Header file for mounting/unmount Linux filesystems.
   2    Copyright (C) 1996-2022 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 /* This is taken from /usr/include/linux/fs.h.  */
  20
  21 #ifndef _SYS_MOUNT_H
  22 #define _SYS_MOUNT_H    1
  23
  24 #include <fcntl.h>
  25 #include <features.h>
  26 #include <stdint.h>
  27 #include <stddef.h>
  28 #include <sys/ioctl.h>
  29
  30 #ifdef __has_include
  31 # if __has_include ("linux/mount.h")
  32 #  include "linux/mount.h"
  33 # endif
  34 #endif
  35
  36
  37 #define BLOCK_SIZE_BITS 10
  38 #define BLOCK_SIZE      (1<<BLOCK_SIZE_BITS)
  39
  40
  41 /* These are the fs-independent mount-flags: up to 16 flags are
  42    supported  */
  43 enum
  44 {
  45 #undef MS_RDONLY
  46   MS_RDONLY = 1,                /* Mount read-only.  */
  47 #define MS_RDONLY       MS_RDONLY
  48 #undef MS_NOSUID
  49   MS_NOSUID = 2,                /* Ignore suid and sgid bits.  */
  50 #define MS_NOSUID       MS_NOSUID
  51 #undef MS_NODEV
  52   MS_NODEV = 4,                 /* Disallow access to device special files.  */
  53 #define MS_NODEV        MS_NODEV
  54 #undef MS_NOEXEC
  55   MS_NOEXEC = 8,                /* Disallow program execution.  */
  56 #define MS_NOEXEC       MS_NOEXEC
  57 #undef MS_SYNCHRONOUS
  58   MS_SYNCHRONOUS = 16,          /* Writes are synced at once.  */
  59 #define MS_SYNCHRONOUS  MS_SYNCHRONOUS
  60 #undef MS_REMOUNT
  61   MS_REMOUNT = 32,              /* Alter flags of a mounted FS.  */
  62 #define MS_REMOUNT      MS_REMOUNT
  63 #undef MS_MANDLOCK
  64   MS_MANDLOCK = 64,             /* Allow mandatory locks on an FS.  */
  65 #define MS_MANDLOCK     MS_MANDLOCK
  66 #undef MS_DIRSYNC
  67   MS_DIRSYNC = 128,             /* Directory modifications are synchronous.  */
  68 #define MS_DIRSYNC      MS_DIRSYNC
  69 #undef MS_NOSYMFOLLOW
  70   MS_NOSYMFOLLOW = 256,         /* Do not follow symlinks.  */
  71 #define MS_NOSYMFOLLOW  MS_NOSYMFOLLOW
  72 #undef MS_NOATIME
  73   MS_NOATIME = 1024,            /* Do not update access times.  */
  74 #define MS_NOATIME      MS_NOATIME
  75 #undef MS_NODIRATIME
  76   MS_NODIRATIME = 2048,         /* Do not update directory access times.  */
  77 #define MS_NODIRATIME   MS_NODIRATIME
  78 #undef MS_BIND
  79   MS_BIND = 4096,               /* Bind directory at different place.  */
  80 #define MS_BIND         MS_BIND
  81 #undef MS_MOVE
  82   MS_MOVE = 8192,
  83 #define MS_MOVE         MS_MOVE
  84 #undef MS_REC
  85   MS_REC = 16384,
  86 #define MS_REC          MS_REC
  87 #undef MS_SILENT
  88   MS_SILENT = 32768,
  89 #define MS_SILENT       MS_SILENT
  90 #undef MS_POSIXACL
  91   MS_POSIXACL = 1 << 16,        /* VFS does not apply the umask.  */
  92 #define MS_POSIXACL     MS_POSIXACL
  93 #undef MS_UNBINDABLE
  94   MS_UNBINDABLE = 1 << 17,      /* Change to unbindable.  */
  95 #define MS_UNBINDABLE   MS_UNBINDABLE
  96 #undef MS_PRIVATE
  97   MS_PRIVATE = 1 << 18,         /* Change to private.  */
  98 #define MS_PRIVATE      MS_PRIVATE
  99 #undef MS_SLAVE
 100   MS_SLAVE = 1 << 19,           /* Change to slave.  */
 101 #define MS_SLAVE        MS_SLAVE
 102 #undef MS_SHARED
 103   MS_SHARED = 1 << 20,          /* Change to shared.  */
 104 #define MS_SHARED       MS_SHARED
 105 #undef MS_RELATIME
 106   MS_RELATIME = 1 << 21,        /* Update atime relative to mtime/ctime.  */
 107 #define MS_RELATIME     MS_RELATIME
 108 #undef MS_KERNMOUNT
 109   MS_KERNMOUNT = 1 << 22,       /* This is a kern_mount call.  */
 110 #define MS_KERNMOUNT    MS_KERNMOUNT
 111 #undef MS_I_VERSION
 112   MS_I_VERSION =  1 << 23,      /* Update inode I_version field.  */
 113 #define MS_I_VERSION    MS_I_VERSION
 114 #undef MS_STRICTATIME
 115   MS_STRICTATIME = 1 << 24,     /* Always perform atime updates.  */
 116 #define MS_STRICTATIME  MS_STRICTATIME
 117 #undef MS_LAZYTIME
 118   MS_LAZYTIME = 1 << 25,        /* Update the on-disk [acm]times lazily.  */
 119 #define MS_LAZYTIME     MS_LAZYTIME
 120 #undef MS_ACTIVE
 121   MS_ACTIVE = 1 << 30,
 122 #define MS_ACTIVE       MS_ACTIVE
 123 #undef MS_NOUSER
 124   MS_NOUSER = 1 << 31
 125 #define MS_NOUSER       MS_NOUSER
 126 };
 127
 128 /* Flags that can be altered by MS_REMOUNT  */
 129 #undef MS_RMT_MASK
 130 #define MS_RMT_MASK (MS_RDONLY|MS_SYNCHRONOUS|MS_MANDLOCK|MS_I_VERSION \
 131                      |MS_LAZYTIME)
 132
 133
 134 /* Magic mount flag number. Has to be or-ed to the flag values.  */
 135
 136 #undef MS_MGC_VAL
 137 #define MS_MGC_VAL 0xc0ed0000   /* Magic flag number to indicate "new" flags */
 138 #define MS_MGC_MSK 0xffff0000   /* Magic flag number mask */
 139
 140
 141 /* The read-only stuff doesn't really belong here, but any other place
 142    is probably as bad and I don't want to create yet another include
 143    file.  */
 144
 145 #undef BLKROSET
 146 #define BLKROSET   _IO(0x12, 93) /* Set device read-only (0 = read-write).  */
 147 #undef BLKROGET
 148 #define BLKROGET   _IO(0x12, 94) /* Get read-only status (0 = read_write).  */
 149 #undef BLKRRPART
 150 #define BLKRRPART  _IO(0x12, 95) /* Re-read partition table.  */
 151 #undef BLKGETSIZE
 152 #define BLKGETSIZE _IO(0x12, 96) /* Return device size.  */
 153 #undef BLKFLSBUF
 154 #define BLKFLSBUF  _IO(0x12, 97) /* Flush buffer cache.  */
 155 #undef BLKRASET
 156 #define BLKRASET   _IO(0x12, 98) /* Set read ahead for block device.  */
 157 #undef BLKRAGET
 158 #define BLKRAGET   _IO(0x12, 99) /* Get current read ahead setting.  */
 159 #undef BLKFRASET
 160 #define BLKFRASET  _IO(0x12,100) /* Set filesystem read-ahead.  */
 161 #undef BLKFRAGET
 162 #define BLKFRAGET  _IO(0x12,101) /* Get filesystem read-ahead.  */
 163 #undef BLKSECTSET
 164 #define BLKSECTSET _IO(0x12,102) /* Set max sectors per request.  */
 165 #undef BLKSECTGET
 166 #define BLKSECTGET _IO(0x12,103) /* Get max sectors per request.  */
 167 #undef BLKSSZGET
 168 #define BLKSSZGET  _IO(0x12,104) /* Get block device sector size.  */
 169 #undef BLKBSZGET
 170 #define BLKBSZGET  _IOR(0x12,112,size_t)
 171 #undef BLKBSZSET
 172 #define BLKBSZSET  _IOW(0x12,113,size_t)
 173 #undef BLKGETSIZE64
 174 #define BLKGETSIZE64 _IOR(0x12,114,size_t) /* return device size.  */
 175
 176
 177 /* Possible value for FLAGS parameter of `umount2'.  */
 178 enum
 179 {
 180   MNT_FORCE = 1,                /* Force unmounting.  */
 181 #define MNT_FORCE MNT_FORCE
 182   MNT_DETACH = 2,               /* Just detach from the tree.  */
 183 #define MNT_DETACH MNT_DETACH
 184   MNT_EXPIRE = 4,               /* Mark for expiry.  */
 185 #define MNT_EXPIRE MNT_EXPIRE
 186   UMOUNT_NOFOLLOW = 8           /* Don't follow symlink on umount.  */
 187 #define UMOUNT_NOFOLLOW UMOUNT_NOFOLLOW
 188 };
 189
 190
 191 /* fsmount flags.  */
 192 #define FSMOUNT_CLOEXEC         0x00000001
 193
 194 /* mount attributes used on fsmount.  */
 195 #define MOUNT_ATTR_RDONLY       0x00000001 /* Mount read-only.  */
 196 #define MOUNT_ATTR_NOSUID       0x00000002 /* Ignore suid and sgid bits.  */
 197 #define MOUNT_ATTR_NODEV        0x00000004 /* Disallow access to device special files.  */
 198 #define MOUNT_ATTR_NOEXEC       0x00000008 /* Disallow program execution.  */
 199 #define MOUNT_ATTR__ATIME       0x00000070 /* Setting on how atime should be updated.  */
 200 #define MOUNT_ATTR_RELATIME     0x00000000 /* - Update atime relative to mtime/ctime.  */
 201 #define MOUNT_ATTR_NOATIME      0x00000010 /* - Do not update access times.  */
 202 #define MOUNT_ATTR_STRICTATIME  0x00000020 /* - Always perform atime updates  */
 203 #define MOUNT_ATTR_NODIRATIME   0x00000080 /* Do not update directory access times.  */
 204 #define MOUNT_ATTR_IDMAP        0x00100000 /* Idmap mount to @userns_fd in struct mount_attr.  */
 205 #define MOUNT_ATTR_NOSYMFOLLOW  0x00200000 /* Do not follow symlinks.  */
 206
 207
 208 #ifndef MOUNT_ATTR_SIZE_VER0
 209 /* For mount_setattr.  */
 210 struct mount_attr
 211 {
 212   uint64_t attr_set;
 213   uint64_t attr_clr;
 214   uint64_t propagation;
 215   uint64_t userns_fd;
 216 };
 217 #endif
 218
 219 #define MOUNT_ATTR_SIZE_VER0    32 /* sizeof first published struct */
 220
 221 /* move_mount flags.  */
 222 #define MOVE_MOUNT_F_SYMLINKS   0x00000001 /* Follow symlinks on from path */
 223 #define MOVE_MOUNT_F_AUTOMOUNTS 0x00000002 /* Follow automounts on from path */
 224 #define MOVE_MOUNT_F_EMPTY_PATH 0x00000004 /* Empty from path permitted */
 225 #define MOVE_MOUNT_T_SYMLINKS   0x00000010 /* Follow symlinks on to path */
 226 #define MOVE_MOUNT_T_AUTOMOUNTS 0x00000020 /* Follow automounts on to path */
 227 #define MOVE_MOUNT_T_EMPTY_PATH 0x00000040 /* Empty to path permitted */
 228 #define MOVE_MOUNT_SET_GROUP    0x00000100 /* Set sharing group instead */
 229
 230
 231 /* fspick flags.  */
 232 #define FSPICK_CLOEXEC          0x00000001
 233 #define FSPICK_SYMLINK_NOFOLLOW 0x00000002
 234 #define FSPICK_NO_AUTOMOUNT     0x00000004
 235 #define FSPICK_EMPTY_PATH       0x00000008
 236
 237
 238 #ifndef FSOPEN_CLOEXEC
 239 /* The type of fsconfig call made.   */
 240 enum fsconfig_command
 241 {
 242   FSCONFIG_SET_FLAG       = 0,    /* Set parameter, supplying no value */
 243 # define FSCONFIG_SET_FLAG FSCONFIG_SET_FLAG
 244   FSCONFIG_SET_STRING     = 1,    /* Set parameter, supplying a string value */
 245 # define FSCONFIG_SET_STRING FSCONFIG_SET_STRING
 246   FSCONFIG_SET_BINARY     = 2,    /* Set parameter, supplying a binary blob value */
 247 # define FSCONFIG_SET_BINARY FSCONFIG_SET_BINARY
 248   FSCONFIG_SET_PATH       = 3,    /* Set parameter, supplying an object by path */
 249 # define FSCONFIG_SET_PATH FSCONFIG_SET_PATH
 250   FSCONFIG_SET_PATH_EMPTY = 4,    /* Set parameter, supplying an object by (empty) path */
 251 # define FSCONFIG_SET_PATH_EMPTY FSCONFIG_SET_PATH_EMPTY
 252   FSCONFIG_SET_FD         = 5,    /* Set parameter, supplying an object by fd */
 253 # define FSCONFIG_SET_FD FSCONFIG_SET_FD
 254   FSCONFIG_CMD_CREATE     = 6,    /* Invoke superblock creation */
 255 # define FSCONFIG_CMD_CREATE FSCONFIG_CMD_CREATE
 256   FSCONFIG_CMD_RECONFIGURE = 7,   /* Invoke superblock reconfiguration */
 257 # define FSCONFIG_CMD_RECONFIGURE FSCONFIG_CMD_RECONFIGURE
 258 };
 259 #endif
 260
 261 /* fsopen flags.  */
 262 #define FSOPEN_CLOEXEC          0x00000001
 263
 264 /* open_tree flags.  */
 265 #define OPEN_TREE_CLONE    1         /* Clone the target tree and attach the clone */
 266 #define OPEN_TREE_CLOEXEC  O_CLOEXEC /* Close the file on execve() */
 267
 268
 269 __BEGIN_DECLS
 270
 271 /* Mount a filesystem.  */
 272 extern int mount (const char *__special_file, const char *__dir,
 273                   const char *__fstype, unsigned long int __rwflag,
 274                   const void *__data) __THROW;
 275
 276 /* Unmount a filesystem.  */
 277 extern int umount (const char *__special_file) __THROW;
 278
 279 /* Unmount a filesystem.  Force unmounting if FLAGS is set to MNT_FORCE.  */
 280 extern int umount2 (const char *__special_file, int __flags) __THROW;
 281
 282 /* Open the filesystem referenced by FS_NAME so it can be configured for
 283    mouting.  */
 284 extern int fsopen (const char *__fs_name, unsigned int __flags) __THROW;
 285
 286 /* Create a mount representation for the FD created by fsopen using
 287    FLAGS with ATTR_FLAGS describing how the mount is to be performed.  */
 288 extern int fsmount (int __fd, unsigned int __flags,
 289                     unsigned int __ms_flags) __THROW;
 290
 291 /* Add the mounted FROM_DFD referenced by FROM_PATHNAME filesystem returned
 292    by fsmount in the hierarchy in the place TO_DFD reference by TO_PATHNAME
 293    using FLAGS.  */
 294 extern int move_mount (int __from_dfd, const char *__from_pathname,
 295                        int __to_dfd, const char *__to_pathname,
 296                        unsigned int flags) __THROW;
 297
 298 /* Set parameters and trigger CMD action on the FD context.  KEY, VALUE,
 299    and AUX are used depending ng of the CMD.  */
 300 extern int fsconfig (int __fd, unsigned int __cmd, const char *__key,
 301                      const void *__value, int __aux) __THROW;
 302
 303 /* Equivalent of fopen for an existing mount point.  */
 304 extern int fspick (int __dfd, const char *__path, unsigned int __flags)
 305   __THROW;
 306
 307 /* Open the mount point FILENAME in directory DFD using FLAGS.  */
 308 extern int open_tree (int __dfd, const char *__filename, unsigned int __flags)
 309   __THROW;
 310
 311 /* Change the mount properties of the mount or an entire mount tree.  If
 312    PATH is a relative pathname, then it is interpreted relative to the
 313    directory referred to by the file descriptor dirfd.  Otherwise if DFD is
 314    the special value AT_FDCWD then PATH is interpreted relative to the current
 315    working directory of the calling process.  */
 316 extern int mount_setattr (int __dfd, const char *__path, unsigned int __flags,
 317                           struct mount_attr *__uattr, size_t __usize)
 318   __THROW;
 319
 320 __END_DECLS
 321
 322 #endif /* _SYS_MOUNT_H */