9.32 mount/umount ¶

#define MNT_FAT   1
#define MNT_EXT   2
#define MNT_DEV   3

#define MS_RDONLY   0b0001
#define MS_REMOUNT  0b0010
#define MS_RELATIME 0b0100
#define MS_NOATIME  0b1000

#define MNT_FORCE 1

int mount(const char *source, int source_len, const char *target,
          int target_len, int fs_type, unsigned long flags);
int umount(const char *target, int target_len, int flags);

These syscalls mount and unmount filesystems. For mount, source is the source device while target is where to mount in the global virtual filesystem. For umount, target is the path to unmount.

For mount, fs_type can be one of the following values to choose the filesystem type to mount, it must be specified, detection is not done.

• MNT_FAT: FAT family filesystem.
• MNT_EXT: EXT family filesystem.
• MNT_DEV: DevFS filesystem, cannot be used.

For mount, flags allows:

• MNT_RDONLY: Mount as read-only.
• MNT_REMOUNT: Remount an existing filesystem.
• MNT_RELATIME: Use relative time for the mount, to know what it does, Generic filesystem options. Conflicts with MNT_NOATIME.\
• MNT_NOATIME: Do not track access times. To know what it does, Generic filesystem options.

For umount, flags allows the following options:

• MNT_FORCE: Unmount the filesystem even if busy, can cause data loss.

These syscalls returns 0 on success or -1 on failure, with the following errno:

• EFAULT: Incorrect addresses for the string arguments.
• EACCES: MAC forbid this operation.
• EINVAL: Wrong arguments.
• EBUSY: For umount, the mount is busy, and MNT_FORCE was not passed.