@@ -83,44 +83,6 @@ 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_PRIVATE
-.\" All mounts are private by default. Previously shared mounts
-.\" can be re-marked PRIVATE.
-.\" MS_SHARED
-.\" Mount points that are marked SHARED propagate mount events
-.\" to one another after being cloned.
-.\" mount --make-rshared ==> MS_SHARED | MS_REC
-.\" MS_SLAVE
-.\" A previously shared mount point can be marked SLAVE, 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
-.\"
-.\" 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/
-.\"
-.\" * https://www.kernel.org/doc/ols/2006/ols2006v2-pages-209-222.pdf
-.\" Shared-Subtree Concept, Implementation, and Applications in Linux
-.\" Al Viro viro@ftp.linux.org.uk
-.\" Ram Pai linuxram@us.ibm.com
-.\"
-.\" * 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
@@ -240,12 +202,32 @@ 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
+.BR MS_PRIVATE " (since Linux 2.6.15)"
+Set the mount propagation on this mountpoint to private. Mounts will not
+propagate to or from replicated subtrees.
+When used, this must be the only flag in
+.IR mountflags .
+The
+.IR source ,
+.IR filesystemtype ,
+and
+.IR data
+arguments are ignored.
+.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_REC " (since Linux 2.4.11)"
+When passed together with
+.BR MS_BIND ,
+recursively bind mount all mountpoints underneath the source subtree.
+When passed together with a shared subtree flag (one of
+.BR MS_PRIVATE ,
+.BR MS_SHARED ,
+.BR MS_SLAVE ", or"
+.BR MS_UNBINDABLE ),
+recursively apply the shared subtree setting to all mountpoints
+underneath the target subtree.
.TP
.BR MS_RELATIME " (since Linux 2.6.20)"
When a file on this filesystem is accessed,
@@ -306,6 +288,19 @@ and, additionally, before kernel 2.4.10, the following could also be changed:
.BR MS_NODEV ,
.BR MS_NOEXEC .
.TP
+.BR MS_SHARED " (since Linux 2.6.15)"
+Set the mount propagation on this mountpoint to shared.
+Mounts will be propagated to and from replicated subtrees
+(i.e., all replicas will continue to be the same).
+When used, this must be the only flag in
+.IR mountflags .
+The
+.IR source ,
+.IR filesystemtype ,
+and
+.IR data
+arguments are ignored.
+.TP
.BR MS_SILENT " (since Linux 2.6.17)"
Suppress the display of certain
.RI ( printk ())
@@ -314,6 +309,26 @@ 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_SLAVE " (since Linux 2.6.15)"
+Make this mountpoint a slave of its source mountpoint, referred to as
+its master.
+Mounts made underneath the master subtree will be propagated to this
+subtree, but mounts made underneath this subtree will not be propagated
+back to the master.
+Note that a slave mountpoint can still have either private propagation
+(see
+.BR MS_PRIVATE )
+or shared propagation (see
+.BR MS_SHARED ).
+When used, this must be the only flag in
+.IR mountflags .
+The
+.IR source ,
+.IR filesystemtype ,
+and
+.IR data
+arguments are ignored.
+.TP
.BR MS_STRICTATIME " (since Linux 2.6.30)"
Always update the last access time (atime) when files on this
filesystem are accessed.
@@ -331,6 +346,19 @@ the
flag to
.BR open (2)
was specified for all file opens to this filesystem).
+.TP
+.BR MS_UNBINDABLE " (since Linux 2.6.15)"
+Set the mount propagation on this mountpoint to private (see
+.BR MS_PRIVATE )
+and disallow bind mounts with this mountpoint as the source.
+When used, this must be the only flag in
+.IR mountflags .
+The
+.IR source ,
+.IR filesystemtype ,
+and
+.IR data
+arguments are ignored.
.PP
From Linux 2.4 onward, the
.BR MS_NODEV ", " MS_NOEXEC ", and " MS_NOSUID
@@ -408,6 +436,8 @@ Or, a move
was attempted, but
.I source
was not a mount point, or was \(aq/\(aq.
+Or, more than one shared subtree flag was given.
+Or, a shared subtree flag was given and additional flags were also used.
.TP
.B ELOOP
Too many links encountered during pathname resolution.
@@ -457,11 +487,13 @@ The definitions of
.BR MS_MOVE ,
.BR MS_REC ,
.BR MS_RELATIME ,
+.BR MS_STRICTATIME ,
+.BR MS_PRIVATE ,
+.BR MS_SHARED ,
+.BR MS_SLAVE ,
and
-.BR MS_STRICTATIME
+.BR MS_UNBINDABLE
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.