mount_attr(2type) — Linux manual page

mount_attr(2type)                                       mount_attr(2type)

NAME         top

       mount_attr - what mount properties to set and clear

LIBRARY         top

       Linux kernel headers

SYNOPSIS         top

       #include <sys/mount.h>

       struct mount_attr {
           u64 attr_set;     /* Mount properties to set */
           u64 attr_clr;     /* Mount properties to clear */
           u64 propagation;  /* Mount propagation type */
           u64 userns_fd;    /* User namespace file descriptor */
           /* ... */
       };

DESCRIPTION         top

       Specifies which mount properties should be changed with
       mount_setattr(2).

       The fields are as follows:

       .attr_set
              This field specifies which MOUNT_ATTR_* attribute flags to
              set.

       .attr_clr
              This field specifies which MOUNT_ATTR_* attribute flags to
              clear.

       .propagation
              This field specifies what mount propagation will be
              applied.  The valid values of this field are the same
              propagation types described in mount_namespaces(7).

       .userns_fd
              This field specifies a file descriptor that indicates which
              user namespace to use as a reference for ID-mapped mounts
              with MOUNT_ATTR_IDMAP.

STANDARDS         top

       Linux.

HISTORY         top

       Linux 5.12.  glibc 2.36.

       Extra fields may be appended to the structure, with a zero value
       in a new field resulting in the kernel behaving as though that
       extension field was not present.  Therefore, a user must zero-fill
       this structure on initialization.

SEE ALSO         top

       mount_setattr(2)

COLOPHON         top

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Linux man-pages 6.16            2025-09-21              mount_attr(2type)

Pages that refer to this page: fsmount(2),  mount_setattr(2),  open_tree(2)

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