include/uapi/linux/mount.h

   1 #ifndef _UAPI_LINUX_MOUNT_H
   2 #define _UAPI_LINUX_MOUNT_H
   3
   4 #include <linux/types.h>
   5
   6 /*
   7  * These are the fs-independent mount-flags: up to 32 flags are supported
   8  *
   9  * Usage of these is restricted within the kernel to core mount(2) code and
  10  * callers of sys_mount() only.  Filesystems should be using the SB_*
  11  * equivalent instead.
  12  */
  13 #define MS_RDONLY        1      /* Mount read-only */
  14 #define MS_NOSUID        2      /* Ignore suid and sgid bits */
  15 #define MS_NODEV         4      /* Disallow access to device special files */
  16 #define MS_NOEXEC        8      /* Disallow program execution */
  17 #define MS_SYNCHRONOUS  16      /* Writes are synced at once */
  18 #define MS_REMOUNT      32      /* Alter flags of a mounted FS */
  19 #define MS_MANDLOCK     64      /* Allow mandatory locks on an FS */
  20 #define MS_DIRSYNC      128     /* Directory modifications are synchronous */
  21 #define MS_NOSYMFOLLOW  256     /* Do not follow symlinks */
  22 #define MS_NOATIME      1024    /* Do not update access times. */
  23 #define MS_NODIRATIME   2048    /* Do not update directory access times */
  24 #define MS_BIND         4096
  25 #define MS_MOVE         8192
  26 #define MS_REC          16384
  27 #define MS_VERBOSE      32768   /* War is peace. Verbosity is silence.
  28                                    MS_VERBOSE is deprecated. */
  29 #define MS_SILENT       32768
  30 #define MS_POSIXACL     (1<<16) /* VFS does not apply the umask */
  31 #define MS_UNBINDABLE   (1<<17) /* change to unbindable */
  32 #define MS_PRIVATE      (1<<18) /* change to private */
  33 #define MS_SLAVE        (1<<19) /* change to slave */
  34 #define MS_SHARED       (1<<20) /* change to shared */
  35 #define MS_RELATIME     (1<<21) /* Update atime relative to mtime/ctime. */
  36 #define MS_KERNMOUNT    (1<<22) /* this is a kern_mount call */
  37 #define MS_I_VERSION    (1<<23) /* Update inode I_version field */
  38 #define MS_STRICTATIME  (1<<24) /* Always perform atime updates */
  39 #define MS_LAZYTIME     (1<<25) /* Update the on-disk [acm]times lazily */
  40
  41 /* These sb flags are internal to the kernel */
  42 #define MS_SUBMOUNT     (1<<26)
  43 #define MS_NOREMOTELOCK (1<<27)
  44 #define MS_NOSEC        (1<<28)
  45 #define MS_BORN         (1<<29)
  46 #define MS_ACTIVE       (1<<30)
  47 #define MS_NOUSER       (1<<31)
  48
  49 /*
  50  * Superblock flags that can be altered by MS_REMOUNT
  51  */
  52 #define MS_RMT_MASK     (MS_RDONLY|MS_SYNCHRONOUS|MS_MANDLOCK|MS_I_VERSION|\
  53                          MS_LAZYTIME)
  54
  55 /*
  56  * Old magic mount flag and mask
  57  */
  58 #define MS_MGC_VAL 0xC0ED0000
  59 #define MS_MGC_MSK 0xffff0000
  60
  61 /*
  62  * open_tree() flags.
  63  */
  64 #define OPEN_TREE_CLONE         1               /* Clone the target tree and attach the clone */
  65 #define OPEN_TREE_CLOEXEC       O_CLOEXEC       /* Close the file on execve() */
  66
  67 /*
  68  * move_mount() flags.
  69  */
  70 #define MOVE_MOUNT_F_SYMLINKS           0x00000001 /* Follow symlinks on from path */
  71 #define MOVE_MOUNT_F_AUTOMOUNTS         0x00000002 /* Follow automounts on from path */
  72 #define MOVE_MOUNT_F_EMPTY_PATH         0x00000004 /* Empty from path permitted */
  73 #define MOVE_MOUNT_T_SYMLINKS           0x00000010 /* Follow symlinks on to path */
  74 #define MOVE_MOUNT_T_AUTOMOUNTS         0x00000020 /* Follow automounts on to path */
  75 #define MOVE_MOUNT_T_EMPTY_PATH         0x00000040 /* Empty to path permitted */
  76 #define MOVE_MOUNT_SET_GROUP            0x00000100 /* Set sharing group instead */
  77 #define MOVE_MOUNT_BENEATH              0x00000200 /* Mount beneath top mount */
  78 #define MOVE_MOUNT__MASK                0x00000377
  79
  80 /*
  81  * fsopen() flags.
  82  */
  83 #define FSOPEN_CLOEXEC          0x00000001
  84
  85 /*
  86  * fspick() flags.
  87  */
  88 #define FSPICK_CLOEXEC          0x00000001
  89 #define FSPICK_SYMLINK_NOFOLLOW 0x00000002
  90 #define FSPICK_NO_AUTOMOUNT     0x00000004
  91 #define FSPICK_EMPTY_PATH       0x00000008
  92
  93 /*
  94  * The type of fsconfig() call made.
  95  */
  96 enum fsconfig_command {
  97         FSCONFIG_SET_FLAG       = 0,    /* Set parameter, supplying no value */
  98         FSCONFIG_SET_STRING     = 1,    /* Set parameter, supplying a string value */
  99         FSCONFIG_SET_BINARY     = 2,    /* Set parameter, supplying a binary blob value */
 100         FSCONFIG_SET_PATH       = 3,    /* Set parameter, supplying an object by path */
 101         FSCONFIG_SET_PATH_EMPTY = 4,    /* Set parameter, supplying an object by (empty) path */
 102         FSCONFIG_SET_FD         = 5,    /* Set parameter, supplying an object by fd */
 103         FSCONFIG_CMD_CREATE     = 6,    /* Create new or reuse existing superblock */
 104         FSCONFIG_CMD_RECONFIGURE = 7,   /* Invoke superblock reconfiguration */
 105         FSCONFIG_CMD_CREATE_EXCL = 8,   /* Create new superblock, fail if reusing existing superblock */
 106 };
 107
 108 /*
 109  * fsmount() flags.
 110  */
 111 #define FSMOUNT_CLOEXEC         0x00000001
 112
 113 /*
 114  * Mount attributes.
 115  */
 116 #define MOUNT_ATTR_RDONLY       0x00000001 /* Mount read-only */
 117 #define MOUNT_ATTR_NOSUID       0x00000002 /* Ignore suid and sgid bits */
 118 #define MOUNT_ATTR_NODEV        0x00000004 /* Disallow access to device special files */
 119 #define MOUNT_ATTR_NOEXEC       0x00000008 /* Disallow program execution */
 120 #define MOUNT_ATTR__ATIME       0x00000070 /* Setting on how atime should be updated */
 121 #define MOUNT_ATTR_RELATIME     0x00000000 /* - Update atime relative to mtime/ctime. */
 122 #define MOUNT_ATTR_NOATIME      0x00000010 /* - Do not update access times. */
 123 #define MOUNT_ATTR_STRICTATIME  0x00000020 /* - Always perform atime updates */
 124 #define MOUNT_ATTR_NODIRATIME   0x00000080 /* Do not update directory access times */
 125 #define MOUNT_ATTR_IDMAP        0x00100000 /* Idmap mount to @userns_fd in struct mount_attr. */
 126 #define MOUNT_ATTR_NOSYMFOLLOW  0x00200000 /* Do not follow symlinks */
 127
 128 /*
 129  * mount_setattr()
 130  */
 131 struct mount_attr {
 132         __u64 attr_set;
 133         __u64 attr_clr;
 134         __u64 propagation;
 135         __u64 userns_fd;
 136 };
 137
 138 /* List of all mount_attr versions. */
 139 #define MOUNT_ATTR_SIZE_VER0    32 /* sizeof first published struct */
 140
 141
 142 /*
 143  * Structure for getting mount/superblock/filesystem info with statmount(2).
 144  *
 145  * The interface is similar to statx(2): individual fields or groups can be
 146  * selected with the @mask argument of statmount().  Kernel will set the @mask
 147  * field according to the supported fields.
 148  *
 149  * If string fields are selected, then the caller needs to pass a buffer that
 150  * has space after the fixed part of the structure.  Nul terminated strings are
 151  * copied there and offsets relative to @str are stored in the relevant fields.
 152  * If the buffer is too small, then EOVERFLOW is returned.  The actually used
 153  * size is returned in @size.
 154  */
 155 struct statmount {
 156         __u32 size;             /* Total size, including strings */
 157         __u32 __spare1;
 158         __u64 mask;             /* What results were written */
 159         __u32 sb_dev_major;     /* Device ID */
 160         __u32 sb_dev_minor;
 161         __u64 sb_magic;         /* ..._SUPER_MAGIC */
 162         __u32 sb_flags;         /* SB_{RDONLY,SYNCHRONOUS,DIRSYNC,LAZYTIME} */
 163         __u32 fs_type;          /* [str] Filesystem type */
 164         __u64 mnt_id;           /* Unique ID of mount */
 165         __u64 mnt_parent_id;    /* Unique ID of parent (for root == mnt_id) */
 166         __u32 mnt_id_old;       /* Reused IDs used in proc/.../mountinfo */
 167         __u32 mnt_parent_id_old;
 168         __u64 mnt_attr;         /* MOUNT_ATTR_... */
 169         __u64 mnt_propagation;  /* MS_{SHARED,SLAVE,PRIVATE,UNBINDABLE} */
 170         __u64 mnt_peer_group;   /* ID of shared peer group */
 171         __u64 mnt_master;       /* Mount receives propagation from this ID */
 172         __u64 propagate_from;   /* Propagation from in current namespace */
 173         __u32 mnt_root;         /* [str] Root of mount relative to root of fs */
 174         __u32 mnt_point;        /* [str] Mountpoint relative to current root */
 175         __u64 __spare2[50];
 176         char str[];             /* Variable size part containing strings */
 177 };
 178
 179 /*
 180  * Structure for passing mount ID and miscellaneous parameters to statmount(2)
 181  * and listmount(2).
 182  *
 183  * For statmount(2) @param represents the request mask.
 184  * For listmount(2) @param represents the last listed mount id (or zero).
 185  */
 186 struct mnt_id_req {
 187         __u64 mnt_id;
 188         __u64 param;
 189 };
 190
 191 /*
 192  * @mask bits for statmount(2)
 193  */
 194 #define STATMOUNT_SB_BASIC              0x00000001U     /* Want/got sb_... */
 195 #define STATMOUNT_MNT_BASIC             0x00000002U     /* Want/got mnt_... */
 196 #define STATMOUNT_PROPAGATE_FROM        0x00000004U     /* Want/got propagate_from */
 197 #define STATMOUNT_MNT_ROOT              0x00000008U     /* Want/got mnt_root  */
 198 #define STATMOUNT_MNT_POINT             0x00000010U     /* Want/got mnt_point */
 199 #define STATMOUNT_FS_TYPE               0x00000020U     /* Want/got fs_type */
 200
 201 /*
 202  * Special @mnt_id values that can be passed to listmount
 203  */
 204 #define LSMT_ROOT               0xffffffffffffffff      /* root mount */
 205
 206 #endif /* _UAPI_LINUX_MOUNT_H */