mount(2)mount(2)NAMEmount - mount a file system
C SYNOPSIS
#include <sys/types.h>
#include <sys/mount.h>
int mount (const char *spec, const char *dir, int mflag,
.../* char *fstyp, const char *dataptr, int datalen*/);
DESCRIPTIONmount requests that a removable file system contained on the block
special file identified by spec be mounted on the directory identified by
dir. spec and dir are pointers to path names. fstyp is the file system
type number. The sysfs(2) system call can be used to determine the file
system type number. If both the MS_DATA and MS_FSS flag bits of mflag
are off, the file system type defaults to the root file system type.
Only if either flag is on is fstyp used to indicate the file system type.
If the MS_DATA flag is set in mflag the system expects the dataptr and
datalen arguments to be present. Together they describe a block of
file-system specific data at address dataptr of length datalen. This is
interpreted by file-system specific code within the operating system and
its format depends on the file system type. If a particular file system
type does not require this data, dataptr and datalen should both be zero.
Note that MS_FSS is obsolete and is ignored if MS_DATA is also set, but
if MS_FSS is set and MS_DATA is not, dataptr and datalen are both assumed
to be zero.
After a successful call to mount, all references to the file dir refer to
the root directory on the mounted file system.
The low-order bit of mflag is used to control write permission on the
mounted file system: if 1, writing is forbidden; otherwise writing is
permitted according to individual file accessibility.
mount may be invoked only by a process with the super-user privilege. It
is intended for use only by the mount utility.
mount fails if one or more of the following are true:
EACCES Search permission is denied on a component of dir or
spec.
EPERM The calling process does not have the super-user
privilege.
EBUSY dir is currently mounted on, is someone's current
working directory, or is otherwise busy.
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EBUSY The device associated with spec is currently mounted.
EBUSY There are no more mount table entries.
EFAULT spec, dir, or datalen points outside the allocated
address space of the process.
EINVAL The super block has an invalid magic number or the
fstyp is invalid.
ELOOP Too many symbolic links were encountered in
translating spec or dir.
ENAMETOOLONG The length of the path argument exceeds {PATH_MAX},
or the length of a path component exceeds {NAME_MAX}
while _POSIX_NO_TRUNC is in effect.
ENOENT None of the named files exists or is a null pathname.
ENOTDIR A component of a path prefix is not a directory.
EREMOTE spec is remote and cannot be mounted.
ENOLINK path points to a remote machine and the link to that
machine is no longer active.
EMULTIHOP Components of path require hopping to multiple remote
machines and the file system type does not allow it.
ETIMEDOUT A component of path is located on a remote file
system which is not available [see intro(2)].
ENOTBLK spec is not a block special device.
ENXIO The device associated with spec does not exist.
ENOTDIR dir is not a directory.
EROFS spec is write protected and mflag requests write
permission.
ENOSPC The file system state in the super-block is not
FsOKAY and mflag requests write permission.
E2BIG The file system's size parameters are larger than the
size of special device spec. Either mkfs(1M) was run
on a different overlapping device or the device has
been changed with fx(1M) since mkfs was run.
EFSCORRUPTED The filesystem has a corruption forcing failure of
the mount.
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EWRONGFS The wrong filesystem type was supplied in fstyp, or
there is no filesystem on spec.
NOTES
It is the responsibility of the caller to assure that the block size of
the device corresponds to the blocksize of the filesystem being mounted.
This is particularly important with CDROM devices, as the default block
size of the device can vary between 512 bytes and 2048 bytes. The
mount(1M) command manages this for filesystems via dks(7M) DIOCSELFLAGS
and DIOCSELECT ioctls.
SEE ALSOfx(1M), mkfs(1M), mount(1M), sysfs(2), umount(2), dks(7M),fs(4), xfs(4)DIAGNOSTICS
Upon successful completion a value of 0 is returned. Otherwise, a value
of -1 is returned and errno is set to indicate the error.
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