+++ /dev/null
-.\" Copyright (C) 1993 Rickard E. Faith <faith@cs.unc.edu>
-.\" and Copyright (C) 1994 Andries E. Brouwer <aeb@cwi.nl>
-.\" and Copyright (C) 2002, 2005 Michael Kerrisk <mtk.manpages@gmail.com>
-.\"
-.\" %%%LICENSE_START(VERBATIM)
-.\" Permission is granted to make and distribute verbatim copies of this
-.\" manual provided the copyright notice and this permission notice are
-.\" preserved on all copies.
-.\"
-.\" Permission is granted to copy and distribute modified versions of this
-.\" manual under the conditions for verbatim copying, provided that the
-.\" entire resulting derived work is distributed under the terms of a
-.\" permission notice identical to this one.
-.\"
-.\" Since the Linux kernel and libraries are constantly changing, this
-.\" manual page may be incorrect or out-of-date. The author(s) assume no
-.\" responsibility for errors or omissions, or for damages resulting from
-.\" the use of the information contained herein. The author(s) may not
-.\" have taken the same level of care in the production of this manual,
-.\" which is licensed free of charge, as they might when working
-.\" professionally.
-.\"
-.\" Formatted or processed versions of this manual, if unaccompanied by
-.\" the source, must acknowledge the copyright and authors of this work.
-.\" %%%LICENSE_END
-.\"
-.\" Modified 1996-11-04 by Eric S. Raymond <esr@thyrsus.com>
-.\" Modified 2001-10-13 by Michael Kerrisk <mtk.manpages@gmail.com>
-.\" Added note on historical behavior of MS_NOSUID
-.\" Modified 2002-05-16 by Michael Kerrisk <mtk.manpages@gmail.com>
-.\" Extensive changes and additions
-.\" Modified 2002-05-27 by aeb
-.\" Modified 2002-06-11 by Michael Kerrisk <mtk.manpages@gmail.com>
-.\" Enhanced descriptions of MS_MOVE, MS_BIND, and MS_REMOUNT
-.\" Modified 2004-06-17 by Michael Kerrisk <mtk.manpages@gmail.com>
-.\" 2005-05-18, mtk, Added MNT_EXPIRE, plus a few other tidy-ups.
-.\" 2008-10-06, mtk: move umount*() material into separate umount.2 page.
-.\" 2008-10-06, mtk: Add discussion of namespaces.
-.\"
-.TH MOUNT 2 2014-09-21 "Linux" "Linux Programmer's Manual"
-.SH NAME
-mount \- mount filesystem
-.SH SYNOPSIS
-.nf
-.B "#include <sys/mount.h>"
-.sp
-.BI "int mount(const char *" source ", const char *" target ,
-.BI " const char *" filesystemtype ", unsigned long " mountflags ,
-.BI " const void *" data );
-.fi
-.SH DESCRIPTION
-.BR mount ()
-attaches the filesystem specified by
-.I source
-(which is often a device name, but can also be a directory name
-or a dummy) to the directory specified by
-.IR target .
-
-Appropriate privilege (Linux: the
-.B CAP_SYS_ADMIN
-capability) is required to mount filesystems.
-
-Since Linux 2.4 a single filesystem can be visible at
-multiple mount points, and multiple mounts can be stacked
-on the same mount point.
-.\" Multiple mounts on same mount point: since 2.3.99pre7.
-
-Values for the
-.I filesystemtype
-argument supported by the kernel are listed in
-.I /proc/filesystems
-(e.g., "minix", "ext2", "ext3", "jfs", "xfs", "reiserfs",
-"msdos", "proc", "nfs", "iso9660").
-Further types may become available when the appropriate modules
-are loaded.
-
-The
-.I mountflags
-argument may have the magic number 0xC0ED (\fBMS_MGC_VAL\fP)
-in the top 16 bits (this was required in kernel versions prior to 2.4, but
-is no longer required and ignored if specified),
-and various mount flags
-.\" (as defined in \fI<linux/fs.h>\fP for libc4 and libc5
-.\" and in \fI<sys/mount.h>\fP for glibc2)
-in the low order 16 bits:
-.\" FIXME 2.6.15 added flags for "shared subtree" functionality:
-.\" MS_UNBINDABLE, MS_PRIVATE, MS_SHARED, MS_SLAVE
-.\"
-.\" MS_PRIVATE.
-.\" All mounts are private by default. Previously shared mounts
-.\" can be remarked PRIVATE.
-.\" MS_SHARED
-.\" Mount points that are marked SHARED propagate mount events
-.\" to one another after bing cloned.
-.\" MS_SLAVE
-.\" A previously shared mount point can be marked SALVE, meaning
-.\" it receives propagated events, but does not propagate events.
-.\" MS_UNBINDABLE
-.\" mounts cannot be bound into other places, and will not be
-.\" propagated into new subtrees
-.\" mount --make-rshared ==> MS_SHARED | MS_REC
-.\"
-.\" These settings are visible in proc/mountinfo
-.\"
-.\" These need to be documented on this page.
-.\" See:
-.\" Documentation/filesystems/sharedsubtree.txt
-.\"
-.\" http://lwn.net/Articles/159077/
-.\"
-.\" http://myweb.sudhaa.com:2022/~ram/sharedsubtree/paper/sharedsubtree.1.pdf
-.\" Shared-Subtree Concept, Implementation, and Applications in Linux
-.\" Al Viro viro@ftp.linux.org.uk
-.\" Ram Pai linuxram@us.ibm.com
-.\"
-.\" http://foss.in/2005/slides/sharedsubtree1.pdf
-.\" Shared Subtree Concept and Implementation in the Linux Kernel
-.\" Ram Pai
-.\"
-.\" http://www.ibm.com/developerworks/linux/library/l-mount-namespaces/index.html
-.\" Applying mount namespaces
-.\"
-.\" Uncover practical applications for advanced Linux mounts features
-.\" Serge E. Hallyn (sergeh@us.ibm.com), Software Engineer, IBM
-.\" Ram Pai (linuxram@us.ibm.com), Software Engineer, IBM
-.\" Date: 17 Sep 2007
-.\"
-.\" FIXME 2.6.25 Added MS_I_VERSION, which needs to be documented.
-.\"
-.TP
-.BR MS_BIND " (Linux 2.4 onward)"
-.\" since 2.4.0-test9
-Perform a bind mount, making a file or a directory subtree visible at
-another point within a filesystem.
-Bind mounts may cross filesystem boundaries and span
-.BR chroot (2)
-jails.
-The
-.IR filesystemtype
-and
-.IR data
-arguments are ignored.
-Up until Linux 2.6.26,
-.I mountflags
-was also ignored
-.\" with the exception of the "hidden" MS_REC mountflags bit
-(the bind mount has the same mount options as
-the underlying mount point).
-.TP
-.BR MS_DIRSYNC " (since Linux 2.5.19)"
-Make directory changes on this filesystem synchronous.
-(This property can be obtained for individual directories
-or subtrees using
-.BR chattr (1).)
-.TP
-.B MS_MANDLOCK
-Permit mandatory locking on files in this filesystem.
-(Mandatory locking must still be enabled on a per-file basis,
-as described in
-.BR fcntl (2).)
-.\" FIXME Describe the MS_MOVE flag in more detail
-.TP
-.B MS_MOVE
-Move a subtree.
-.I source
-specifies an existing mount point and
-.I target
-specifies the new location.
-The move is atomic: at no point is the subtree unmounted.
-The
-.IR filesystemtype ", " mountflags ", and " data
-arguments are ignored.
-.TP
-.B MS_NOATIME
-Do not update access times for (all types of) files on this filesystem.
-.TP
-.B MS_NODEV
-Do not allow access to devices (special files) on this filesystem.
-.TP
-.B MS_NODIRATIME
-Do not update access times for directories on this filesystem.
-This flag provides a subset of the functionality provided by
-.BR MS_NOATIME ;
-that is,
-.BR MS_NOATIME
-implies
-.BR MS_NODIRATIME .
-.TP
-.B MS_NOEXEC
-Do not allow programs to be executed from this filesystem.
-.\" (Possibly useful for a filesystem that contains non-Linux executables.
-.\" Often used as a security feature, e.g., to make sure that restricted
-.\" users cannot execute files uploaded using ftp or so.)
-.TP
-.B MS_NOSUID
-Do not honor set-user-ID and set-group-ID bits when executing
-programs from this filesystem.
-.\" (This is a security feature to prevent users executing set-user-ID and
-.\" set-group-ID programs from removable disk devices.)
-.TP
-.B MS_RDONLY
-Mount filesystem read-only.
-.\"
-.\" FIXME Document MS_REC, available since 2.4.11.
-.\" This flag has meaning in conjunction with MS_BIND and
-.\" also with the shared subtree flags.
-.TP
-.BR MS_RELATIME " (since Linux 2.6.20)"
-When a file on this filesystem is accessed,
-update the file's last access time (atime) only if the current value
-of atime is less than or equal to the file's last modification time (mtime)
-or last status change time (ctime).
-This option is useful for programs, such as
-.BR mutt (1),
-that need to know when a file has been read since it was last modified.
-Since Linux 2.6.30, the kernel defaults to the behavior provided
-by this flag (unless
-.BR MS_NOATIME
-was specified), and the
-.B MS_STRICTATIME
-flag is required to obtain traditional semantics.
-In addition, since Linux 2.6.30,
-the file's last access time is always updated if it
-is more than 1 day old.
-.\" Matthew Garrett notes in the patch that added this behavior
-.\" that this lets utilities such as tmpreaper (which deletes
-.\" files based on last access time) work correctly.
-.TP
-.B MS_REMOUNT
-Remount an existing mount.
-This allows you to change the
-.I mountflags
-and
-.I data
-of an existing mount without having to unmount and remount the filesystem.
-.I target
-should be the same value specified in the initial
-.BR mount ()
-call;
-.I source
-and
-.I filesystemtype
-are ignored.
-The
-.I mountflags
-and
-.I data
-arguments should match the values used in the original
-.BR mount ()
-call, except for those parameters that are being deliberately changed.
-
-The following
-.I mountflags
-can be changed:
-.BR MS_RDONLY ,
-.BR MS_SYNCHRONOUS ,
-.BR MS_MANDLOCK ;
-before kernel 2.6.16, the following could also be changed:
-.B MS_NOATIME
-and
-.BR MS_NODIRATIME ;
-and, additionally, before kernel 2.4.10, the following could also be changed:
-.BR MS_NOSUID ,
-.BR MS_NODEV ,
-.BR MS_NOEXEC .
-.TP
-.BR MS_SILENT " (since Linux 2.6.17)"
-Suppress the display of certain
-.RI ( printk ())
-warning messages in the kernel log.
-This flag supersedes the misnamed and obsolete
-.BR MS_VERBOSE
-flag (available since Linux 2.4.12), which has the same meaning.
-.TP
-.BR MS_STRICTATIME " (since Linux 2.6.30)"
-Always update the last access time (atime) when files on this
-filesystem are accessed.
-(This was the default behavior before Linux 2.6.30.)
-Specifying this flag overrides the effect of setting the
-.BR MS_NOATIME
-and
-.BR MS_RELATIME
-flags.
-.TP
-.B MS_SYNCHRONOUS
-Make writes on this filesystem synchronous (as though
-the
-.B O_SYNC
-flag to
-.BR open (2)
-was specified for all file opens to this filesystem).
-.PP
-From Linux 2.4 onward, the
-.BR MS_NODEV ", " MS_NOEXEC ", and " MS_NOSUID
-flags are settable on a per-mount-point basis.
-From kernel 2.6.16 onward,
-.B MS_NOATIME
-and
-.B MS_NODIRATIME
-are also settable on a per-mount-point basis.
-The
-.B MS_RELATIME
-flag is also settable on a per-mount-point basis.
-.PP
-The
-.I data
-argument is interpreted by the different filesystems.
-Typically it is a string of comma-separated options
-understood by this filesystem.
-See
-.BR mount (8)
-for details of the options available for each filesystem type.
-.SH "RETURN VALUE"
-On success, zero is returned.
-On error, \-1 is returned, and
-.I errno
-is set appropriately.
-.SH ERRORS
-The error values given below result from filesystem type independent
-errors.
-Each filesystem type may have its own special errors and its
-own special behavior.
-See the Linux kernel source code for details.
-.TP
-.B EACCES
-A component of a path was not searchable.
-(See also
-.BR path_resolution (7).)
-Or, mounting a read-only filesystem was attempted without giving the
-.B MS_RDONLY
-flag.
-Or, the block device
-.I source
-is located on a filesystem mounted with the
-.B MS_NODEV
-option.
-.\" mtk: Probably: write permission is required for MS_BIND, with
-.\" the error EPERM if not present; CAP_DAC_OVERRIDE is required.
-.TP
-.B EBUSY
-.I source
-is already mounted.
-Or, it cannot be remounted read-only,
-because it still holds files open for writing.
-Or, it cannot be mounted on
-.I target
-because
-.I target
-is still busy (it is the working directory of some thread,
-the mount point of another device, has open files, etc.).
-.TP
-.B EFAULT
-One of the pointer arguments points outside the user address space.
-.TP
-.B EINVAL
-.I source
-had an invalid superblock.
-Or, a remount
-.RB ( MS_REMOUNT )
-was attempted, but
-.I source
-was not already mounted on
-.IR target .
-Or, a move
-.RB ( MS_MOVE )
-was attempted, but
-.I source
-was not a mount point, or was \(aq/\(aq.
-.TP
-.B ELOOP
-Too many links encountered during pathname resolution.
-Or, a move was attempted, while
-.I target
-is a descendant of
-.IR source .
-.TP
-.B EMFILE
-(In case no block device is required:)
-Table of dummy devices is full.
-.TP
-.B ENAMETOOLONG
-A pathname was longer than
-.BR MAXPATHLEN .
-.TP
-.B ENODEV
-.I filesystemtype
-not configured in the kernel.
-.TP
-.B ENOENT
-A pathname was empty or had a nonexistent component.
-.TP
-.B ENOMEM
-The kernel could not allocate a free page to copy filenames or data into.
-.TP
-.B ENOTBLK
-.I source
-is not a block device (and a device was required).
-.TP
-.B ENOTDIR
-.IR target ,
-or a prefix of
-.IR source ,
-is not a directory.
-.TP
-.B ENXIO
-The major number of the block device
-.I source
-is out of range.
-.TP
-.B EPERM
-The caller does not have the required privileges.
-.SH VERSIONS
-The definitions of
-.BR MS_DIRSYNC ,
-.BR MS_MOVE ,
-.BR MS_REC ,
-.BR MS_RELATIME ,
-and
-.BR MS_STRICTATIME
-were added to glibc headers in version 2.12.
-.\" FIXME . Definitions of the so-far-undocumented MS_UNBINDABLE, MS_PRIVATE,
-.\" MS_SHARED, and MS_SLAVE were (also) only added to glibc headers in 2.12.
-.SH "CONFORMING TO"
-This function is Linux-specific and should not be used in
-programs intended to be portable.
-.SH NOTES
-The original
-.B MS_SYNC
-flag was renamed
-.B MS_SYNCHRONOUS
-in 1.1.69
-when a different
-.B MS_SYNC
-was added to \fI<mman.h>\fP.
-.LP
-Before Linux 2.4 an attempt to execute a set-user-ID or set-group-ID program
-on a filesystem mounted with
-.B MS_NOSUID
-would fail with
-.BR EPERM .
-Since Linux 2.4 the set-user-ID and set-group-ID bits are
-just silently ignored in this case.
-.\" The change is in patch-2.4.0-prerelease.
-.SS Per-process namespaces
-Starting with kernel 2.4.19, Linux provides
-per-process mount namespaces.
-A mount namespace is the set of filesystem mounts that
-are visible to a process.
-Mount-point namespaces can be (and usually are)
-shared between multiple processes,
-and changes to the namespace (i.e., mounts and unmounts) by one process
-are visible to all other processes sharing the same namespace.
-(The pre-2.4.19 Linux situation can be considered as one in which
-a single namespace was shared by every process on the system.)
-
-A child process created by
-.BR fork (2)
-shares its parent's mount namespace;
-the mount namespace is preserved across an
-.BR execve (2).
-
-A process can obtain a private mount namespace if:
-it was created using the
-.BR clone (2)
-.BR CLONE_NEWNS
-flag,
-in which case its new namespace is initialized to be a
-.I copy
-of the namespace of the process that called
-.BR clone (2);
-or it calls
-.BR unshare (2)
-with the
-.BR CLONE_NEWNS
-flag,
-which causes the caller's mount namespace to obtain a private copy
-of the namespace that it was previously sharing with other processes,
-so that future mounts and unmounts by the caller are invisible
-to other processes (except child processes that the caller
-subsequently creates) and vice versa.
-
-The Linux-specific
-.I /proc/PID/mounts
-file exposes the list of mount points in the mount
-namespace of the process with the specified ID; see
-.BR proc (5)
-for details.
-.SH "SEE ALSO"
-.BR umount (2),
-.BR namespaces (7),
-.BR path_resolution (7),
-.BR lsblk (8),
-.BR mount (8),
-.BR umount (8)
-.SH COLOPHON
-This page is part of release 3.79 of the Linux
-.I man-pages
-project.
-A description of the project,
-information about reporting bugs,
-and the latest version of this page,
-can be found at
-\%http://www.kernel.org/doc/man\-pages/.
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