{
    "mode": "man",
    "parameter": "proc_pid_mountinfo",
    "section": "5",
    "url": "https://www.chedong.com/phpMan.php/man/proc_pid_mountinfo/5/json",
    "generated": "2026-10-08T03:20:43Z",
    "sections": {
        "NAME": {
            "content": "/proc/pid/mountinfo - mount information\n",
            "subsections": []
        },
        "DESCRIPTION": {
            "content": "/proc/pid/mountinfo (since Linux 2.6.26)\nThis  file  contains  information  about  mounts in the process's mount namespace (see\nmountnamespaces(7)).  It supplies various information (e.g., propagation state,  root\nof  mount  for  bind mounts, identifier for each mount and its parent) that is missing\nfrom the (older) /proc/pid/mounts file, and fixes various  other  problems  with  that\nfile  (e.g.,  nonextensibility, failure to distinguish per-mount versus per-superblock\noptions).\n\nThe file contains lines of the form:\n\n36 35 98:0 /mnt1 /mnt2 rw,noatime master:1 - ext3 /dev/root rw,errors=continue\n(1)(2)(3)   (4)   (5)      (6)      (7)   (8) (9)   (10)         (11)\n\nThe numbers in parentheses are labels for the descriptions below:\n\n(1)  mount ID: a unique ID for the mount (may be reused after umount(2)).\n\n(2)  parent ID: the ID of the parent mount (or of self for  the  root  of  this  mount\nnamespace's mount tree).\n\nIf  a  new mount is stacked on top of a previous existing mount (so that it hides\nthe existing mount) at pathname P, then the parent of the new mount is the previ‐\nous mount at that location.  Thus, when looking at all the mounts  stacked  at  a\nparticular  location, the top-most mount is the one that is not the parent of any\nother mount at the same location.  (Note, however, that this top-most mount  will\nbe  accessible  only  if the longest path subprefix of P that is a mount point is\nnot itself hidden by a stacked mount.)\n\nIf the parent mount lies outside the process's root  directory  (see  chroot(2)),\nthe  ID  shown here won't have a corresponding record in mountinfo whose mount ID\n(field 1) matches this parent mount ID  (because  mounts  that  lie  outside  the\nprocess's  root directory are not shown in mountinfo).  As a special case of this\npoint, the process's root mount may  have  a  parent  mount  (for  the  initramfs\nfilesystem) that lies outside the process's root directory, and an entry for that\nmount will not appear in mountinfo.\n\n(3)  major:minor: the value of stdev for files on this filesystem (see stat(2)).\n\n(4)  root:  the  pathname  of  the directory in the filesystem which forms the root of\nthis mount.\n\n(5)  mount point: the pathname of the mount point relative to the process's  root  di‐\nrectory.\n\n(6)  mount options: per-mount options (see mount(2)).\n\n(7)  optional fields: zero or more fields of the form \"tag[:value]\"; see below.\n\n(8)  separator: the end of the optional fields is marked by a single hyphen.\n\n(9)  filesystem type: the filesystem type in the form \"type[.subtype]\".\n\n(10) mount source: filesystem-specific information or \"none\".\n\n(11) super options: per-superblock options (see mount(2)).\n\nCurrently,  the  possible  optional fields are shared, master, propagatefrom, and un‐\nbindable.  See mountnamespaces(7) for a description of these fields.  Parsers  should\nignore all unrecognized optional fields.\n\nFor  more  information  on  mount propagation see Documentation/filesystems/sharedsub‐\ntree.rst (or Documentation/filesystems/sharedsubtree.txt  before  Linux  5.8)  in  the\nLinux kernel source tree.\n",
            "subsections": []
        },
        "SEE ALSO": {
            "content": "proc(5)\n\nLinux man-pages 6.7                          2023-11-24                        procpidmountinfo(5)",
            "subsections": []
        }
    },
    "summary": "/proc/pid/mountinfo - mount information",
    "flags": [],
    "examples": [],
    "see_also": [
        {
            "name": "proc",
            "section": "5",
            "url": "https://www.chedong.com/phpMan.php/man/proc/5/json"
        }
    ]
}