MOUNT(8) MOUNT(8) mount - mount [-h|-V] mount [-l] [-t fstype] mount -a [-F] [-fnrsvw] [-t __] [-O _] mount [-fnrsvw] [-o options] |- mount [-fnrsvw] [-o ] [-t __] _ mount --bind|--rbind|--move olddir newdir mount --make-[r]{shared|slave|private|unbindable} _ Unix /. . mount . umount(8) . . mount : mount -t type device dir ( ) . -t . mount . (root) . " " . ( ) . : mount /dir mount ( ) /etc/fstab. --target --source . : mount --target /mountpoint ( ) . mount . . --all ( --all ). . findmnt(8) . '?'. ( ): mount [-l] [-t ] -l . . ( ) /dev/sda1 . NFS knuth.cwi.nl:/dir. . UUID LABEL. () : LABEL= . -L. UUID=uuid . UUID . -U. mount UUID . UUID fstab(5) . UUID . PARTLABEL= . mkfs mkswap. GUID (GPT). PARTUUID=uuid . mkfs mkswap. GUID (GPT). ID= udevd. WWN ( ) . ls /dev/disk/by-id udevd . udev udev . lsblk --fs (LABELs) UUID . blkid -p . UUID . lsblk -o +UUID,PARTUUID UUID . ( UUID=uuid) udev /dev/disk/by-{label,uuid,id,partuuid,partlabel} /etc/fstab. . mount(8) udev /etc/fstab . libblkid(3). proc - proc - . ( none : 'none already mounted' mount .) /etc/fstab /etc/mtab /proc/mounts /etc/fstab ( fstab(5)) . fstab(5) --fstab ( ). mount -a [-t ] [-O optlist] ( ) fstab ( / ) noauto. -F mount . fstab mtab . mount umount(8) /etc/mtab. /etc/mtab /etc/mtab /proc/mounts . mtab . mtab . mount . /etc/fstab -o: mount | -o /etc/fstab. --options-mode. . mount /etc/fstab ( LABEL UUID ID PARTUUID PARTLABEL) . foo /dir: mount /dev/foo /dir --options-source-force fstab. mount fstab. . fstab user . /dev/cdrom /cd iso9660 ro,user,noauto,unhide iso9660 : mount /cd mount fstab . mount. NFS CIFS . util-linux 2.35 mount libmount. suid (non-root). root ( fuse ). fstab(5). . users user fstab. owner user . /dev/fd . group . user . user=someone (/sbin/mount.) . For unprivileged users the mount target from fstab is opened before the filesystem is attached and the mount operation uses this file descriptor rather than the path, so the path is not resolved for the second time by the kernel. Symbolic links are not followed in the target path at all, a fstab entry with a symbolic link in the mount point path is unusable for unprivileged users and the mount fails. Warning When the new mount API is not available (Linux before 5.2, or mount(8) compiled without the support for it), the legacy mount(2) syscall is used. In this case the pinned target is referenced by a /proc/self/fd/ path, which requires a mounted /proc filesystem. Without /proc the target path is resolved by the kernel again and the inherent time-of-check-to-time-of-use (TOCTOU) window between the verification and the mount operation remains; if an ancestor directory of the mount target is writable by the unprivileged user, a path component could be swapped to redirect the mount to an unintended location. Administrators should ensure that mount target paths for user mounts do not traverse directories writable by unprivileged users. For mount source paths, mount(8) only canonicalizes (resolves symlinks) paths starting with /dev/ for unprivileged users and verifies the result stays within /dev/. Source paths outside /dev/ (e.g. disk images in user-writable directories) are kept as-is from fstab. Filesystem type auto-detection for unprivileged users relies exclusively on udev metadata rather than direct device probing; this means file images that are not registered with udev require an explicit filesystem type in fstab. (Bind mount) . : mount --bind olddir newdir fstab : /olddir /newdir none bind . "bind" VFS . "bind" . "bind". olddir newdir olddir. ( ). : mount --bind foo foo ( ) . : mount --rbind olddir newdir . ( _netdev) mount mount. util-linux 2.27 mount --bind. : mount -o bind,ro foo foo mount(2) . (atomic). () : mount --bind olddir newdir mount -o remount,bind,ro olddir newdir ( VFS) olddir newdir . VFS : nosuid nodev noexec noatime nodiratime relatime nosymfollow "remount,bind". ( ) . mount(2) ( -o rbind,ro). mount_setattr(2) libmount util-linux v2.39 "recursive" ( -o rbind,ro=recursive). FILESYSTEM-INDEPENDENT MOUNT OPTIONS. util-linux 2.31 mount bind /etc/fstab ( -o remount ). . . mount "remount,bind" /etc/fstab. util-linux 2.39 mount . . -o bind,rw - . mount(2) VFS . ( ). : mount --move olddir newdir olddir newdir. . olddir . . findmnt -o TARGET,PROPAGATION . 2.6.15 (shared) (private) (slave) (unbindable). . . . . Documentation/filesystems/sharedsubtree.txt mount_namespaces(7). : mount --make-shared mountpoint mount --make-slave mountpoint mount --make-private mountpoint mount --make-unbindable mountpoint . mount --make-rshared mountpoint mount --make-rslave mountpoint mount --make-rprivate mountpoint mount --make-runbindable mountpoint mount fstab(5) --make-*. . mount(2) . util-linux 2.23 mount () mount(8) . mount(2) . . fstab(5) (private *slave* *shared* *unbindable* *rprivate* *rslave* *rshared* *runbindable*). : mount --make-private --make-unbindable /dev/sda1 /foo : mount /dev/sda1 /foo mount --make-private /foo mount --make-unbindable /foo mount fstab -o -r -w . mount /sbin/mount.suffix. mount EXTERNAL HELPERS. mount : -a --all ( ) fstab ( noauto). (init scripts). systemd mount -a systemd. fstab. mount ( btrfs) . mount --all. fstab . /proc ( ) /sys ( UUID= LABEL=). /proc /sys mount -a /proc /sys fstab. --all . (-t -O) . 2.35 -o fstab ( --options-mode). swap fstab mount -a. swapon -a . swapon(8). mount -a fstab . findmnt --verify. --beneath ( ) . . Btrfs XFS : mount -t btrfs /dev/sdA /mnt mount --beneath -t xfs /dev/sdB /mnt umount /mnt -B --bind ( ). Bind mount operation. -c --no-canonicalize . mount ( fstab). -f . mount -i. . X-mount.nocanonicalize. mount /sbin/mount.. --exclusive (superblock) . . . --onlyonce. --onlyonce --exclusive "onlyonce" /A /A /B . "exclusive" . -F --fork ( -a.) mount . NFS . NFS . . /usr /usr/spool. -f, --fake . --fake /etc/mtab . /etc/mtab 2.39 . --fake libmount . . --fake mount(8) . -i, --internal-only /sbin/mount.filesystem . -L --label () . -l --show-labels . mount ( set-user-ID root) . ext2 ext3 ext4 e2label(8) XFS xfs_admin(8) reiserfs reiserfstune(8). -M --move . . -m --mkdir[=] ( ) . "-o X-mount.mkdir[=mode]" 0755. X-mount.mkdir . --map-groups --map-users inner:_outer_:_count_ Add the specified user/group mapping to an X-mount.idmap map. The inner ID is the starting ID as stored in the filesystem and the outer ID is the starting ID as it appears in the new mount. These options can be given multiple times to build up complete mappings for users and groups. For more details see X-mount.idmap below. --map-users /proc/PID/ns/user id-mapped. "-o X-mount.idmap=/proc/PID/ns/user" inner:_outer_:_count_ . X-mount.idmap . -n --no-mtab /etc/mtab. /etc . -N --namespace ns ns. ns (PID) . mount /etc/fstab /etc/mtab: ( /run/mount) mount(2) . mount(2). mount_namespaces(7) . -O --test-opts opts -a. -t -O -a. mount -a -O no_netdev netdev /etc/fstab. -t no . -t -O mount -a -t ext2 -O _netdev ext2 _netdev ext2 _netdev . -o --options opts . opts . : mount LABEL=mydisk -o noatime,nodev,nosuid . fstab. FILESYSTEM-INDEPENDENT MOUNT OPTIONS FILESYSTEM-SPECIFIC MOUNT OPTIONS. --onlyonce mount . --all . ( tmpfs). --exclusive. --options-mode fstab/mtab . ignore append prepend replace. append fstab . prepend -- fstab. . --options-source source . source fstab *mtab* *disable*. disable fstab *mtab* --options-source-force. fstab,mtab. --options-source-force fstab/mtab . -R --rbind ( ). Bind mount operation. -r --ro --read-only . -o ro. . ext3 ext4 (journal) . ext3 ext4 ro,noload blockdev(8). -s . . . mount.nfs . --source mount ( ) (). . --target ( ) (). . --target-prefix . fstab : mount --all --target-prefix /chroot -o X-mount.mkdir fstab /chroot ( X-mount.mkdir). --fstab fstab . -T --fstab fstab . strverscmp(3) "." .fstab. . initramfs chroot . mount --fstab /sbin/mount. fstab . ( ) fstab . -t --types fstype -t . . /proc/filesystems /lib/modules/$(uname -r)/kernel/fs . ext2 ext3 ext4 xfs btrfs vfat sysfs proc nfs cifs. mount umount(8) . '.subtype'. 'fuse.sshfs'. ( 'sshfs#example.com' ). If no -t option is given, or if the auto type is specified, mount will try to guess the desired type. The filesystem type is determined using udev metadata first, then by direct device probing via libblkid(3) for root users. If neither method identifies the type, mount will fall back to trying all types listed in /etc/filesystems, or if that file does not exist, /proc/filesystems. Types labeled "nodev" (e.g. devpts, proc and nfs) are skipped. If /etc/filesystems ends in a line with a single *, mount will read /proc/filesystems afterwards. While trying, all filesystem types will be mounted with the mount option silent. For unprivileged (non-root) users, direct device probing via libblkid(3) is disabled and filesystem type detection relies exclusively on udev metadata. This means file images that are not registered with udev require an explicit filesystem type in fstab. Creating a file /etc/filesystems can be useful to change the probe order (e.g., to try vfat before msdos or ext3 before ext2) or if you use a kernel module autoloader. -t /etc/fstab. -t no . no /etc/fstab. no -a. mount -a -t nomsdos,smbfs msdos smbfs. mount mount(2) . ( nfs nfs4 cifs smbfs ncpfs) . nfs nfs4 cifs smbfs ncpfs . mount /sbin/mount. ( ) . smbmount /sbin/mount.smbfs . -U --uuid uuid uuid . -v --verbose . 2.41 (API) . -w --rw --read-write . mount mount(2) . -o rw. -w mount . -h --help . -V --version . /etc/fstab. . /proc/mounts. ( tune2fs -l extN). (VFS) . . . nosuid *noexec* *nodiratime* *relatime* *noatime* *strictatime* *nosymfollow* . VFS : findmnt -o TARGET,VFS-OPTIONS,FS-OPTIONS v2.39 libmount VFS . ( rbind). "recursive" : mount -orbind,ro=recursive,noexec=recursive,nosuid /foo /bar /foo /bar /bar noexec /bar "nosuid". "recursive" VFS . (ro rw) mount(8). . "-o bind,remount,ro" VFS "-o remount,ro" VFS . . 2.41 libmount vfs fs ( ro=fs) . : mount -o ro=vfs /dev/sdc1 /A /A . "-o bind,remount,ro" . . sync ext2 ext3 ext4 fat vfat ufs xfs. async / . ( sync.) atime noatime inode . relatime *strictatime*. noatime inode ( ). inode ( ) nodiratime. auto -a. noauto ( -a ). context=context fscontext=context defcontext=context rootcontext=context context= VFAT SELinux ext3 ext4 SELinux. context= . xattr 2.4.. xattrs . context="system_u:object_r:removable_t. fscontext= xattr. fscontext . . . xattrs . context fscontext . defcontext=. xattr. rootcontext= inode inode . . @target . . : context mount . . : mount -t tmpfs none /mnt -o \ 'context="system_u:object_r:tmp_t:s0:c127,c456",noexec' selinux(8). defaults : rw suid dev exec auto nouser async. . . dev . nodev . diratime inode . . ( noatime.) nodiratime inode . ( noatime.) dirsync . : creat(2) link(2) unlink(2) symlink(2) mkdir(2) rmdir(2) mknod(2) rename(2). exec . noexec . group . nosuid nodev ( group,dev,suid). iversion (inode) i_version. noiversion (inode) i_version. mand . fcntl(2). 5.15. nomand . _netdev ( ). nofail . relatime (inode) . . ( noatime mutt(1) .) 2.6.30 ( noatime) strictatime . 2.6.30 . norelatime relatime. strictatime. strictatime atime . relatime noatime . /proc/mounts. nostrictatime (inode). lazytime (atime mtime ctime) (inode). (inode table) . : o (inode) o fsync(2) syncfs(2) sync(2) o (inode) o 24 (inode) . nolazytime lazytime. suid set-user-ID set-group-ID . nosuid set-user-ID set-group-ID . SELinux nosuid_transition nnp_nosuid_transition. silent (silent flag). loud (silent flag). owner . nosuid nodev ( owner,dev,suid). remount . . . bind . Bind mount operation. VFS (nodev,nosuid,noexec,ro) . mount(8) fstab /proc/self/mountinfo. --options-mode. ( v2.39 mount_setattr(2)) mount -o remount,ro=recursive "reset-unspecified" / . mount fstab. mount fstab ( mtab) . mount -o remount,rw /dev/foo /dir fstab ( mtab) loop= mount. mount -o remount,rw /dir mount fstab (-o). fstab /proc/self/mountinfo. mount --all (-O -t). : mount --all -o remount,ro -t vfat vfat . mount -o remount,ro /dir. mount fstab mtab . ro[=(recursive|vfs|fs)] . mount(2). recursive VFS . vfs fs . fs ( ) vfs . . Read-only Setting Notes. rw[=(recursive|vfs|fs)] . sync / . ( ) sync . user . mtab ( libmount /run/mount mtab ) . noexec nosuid nodev ( user,exec,dev,suid). nouser . . users . noexec nosuid nodev ( users,exec,dev,suid). X-* "X-" . ( mtab) mount. mount(2). X-appname.option. x-* X-* . umount(8) . libmount ( ). util-linux v2.30 x-* libmount ( X-* ) ( initrd systemd ) fstab . X-mount.auto-fstypes= . . "auto" . mount ( -t ). "no". X-mount.auto-fstypes="ext4,btrfs" ext4 btrfs X-mount.auto-fstypes="novfat,xfs" vfat xfs. auto-fstypes . : mount -t auto -o'X-mount.auto-fstypes="noext2,ext3"' /dev/sdc1 /mnt/test X-mount.mkdir[=] ( ) . mkdir(2) . 0755. (root) mount suid. x-mount.mkdir v2.30. --mkdir. X-mount.nocanonicalize[=] . mount . . "source" "target" ( ). . ( LABEL= UUID=) fstab. --no-canonicalize open_tree(2) (bind-mount) . Note that mount(8) ignores this option for unprivileged (non-root) users. In restricted mode symbolic links are not followed in the target path at all, so a mount with a symbolic link in the target fails. Source paths are only canonicalized when starting with /dev/. See section "Non-superuser mounts" above for more details. X-mount.noloop (loop device) . X-mount.subdir= . . . . mount(2). ( unshare --mount) mount(8) . unshare --mount --propagation shared. For unprivileged (non-root) users, this feature requires Linux >= 6.15 where the subdirectory is opened directly on the detached mount tree. . X-mount.owner=_|UID, X-mount.group=group|GID - . -N. X-mount.mode= (mode) - . X-mount.idmap=type:inner:outer:range [type:inner:outer:range], X-mount.idmap=file Use this option to create an idmapped mount. This feature requires the new file-descriptor-based mount API (available since Linux 5.2). An idmapped mount allows the ownership of all files located under a mount to be changed according to the ID-mapping associated with a user namespace. The ownership change is tied to the lifetime of, and localized to, the relevant mount. The relevant ID-mapping can be specified in two ways: o (ID-mapping) . The ID-mapping must be specified using the syntax type:inner:outer:range. Specifying u as the type prefix creates a UID-mapping, g creates a GID-mapping and omitting type or specifying b creates both a UID- and GID-mapping. The inner and outer IDs are given in the same order as in /proc/[pid]/uid_map (see user_namespaces(7)) and for --map-users above. For an idmapped mount this means that inner is the starting ID as stored in the filesystem, and outer is the starting ID as it appears in the new mount. The range parameter indicates how many IDs are to be mapped. It is possible to specify multiple ID-mappings. . /etc/fstab . \040. X-mount.idmap=0:0:1\040500:1000:1. For example, the ID-mapping X-mount.idmap=u:1000:0:1 g:1001:1:2 5000:1000:2 creates an idmapped mount where a file owned by UID 1000 in the filesystem appears as owned by UID 0 in the mount, GID 1001 appears as GID 1, GID 1002 appears as GID 2, UID and GID 5000 appear as 1000, and UID and GID 5001 appear as 1001. When an ID-mapping is specified directly, a new user namespace will be allocated with the requested ID-mapping. The newly created user namespace will be attached to the mount. o . The user namespace will then be attached to the mount, and the ID-mapping of the user namespace will become the ID-mapping of the mount. X-mount.idmap=/proc/PID/ns/user PID . nosymfollow . (readlink(1 *(readlink*(2 *(realpath*(1 *(realpath*(3 . . . . +----------------------+--------------------+ | | | |() | | | | | +----------------------+--------------------+ |btrfs | btrfs(5) | +----------------------+--------------------+ |cephfs | mount.ceph(8) | +----------------------+--------------------+ |cifs | mount.cifs(8) | +----------------------+--------------------+ |ext2, ext3, ext4 | ext4(5) | +----------------------+--------------------+ |fuse | fuse(8) | +----------------------+--------------------+ |nfs | nfs(5) | +----------------------+--------------------+ |tmpfs | tmpfs(5) | +----------------------+--------------------+ |xfs | xfs(5) | +----------------------+--------------------+ . . . -o. . Documentation/filesystems. adfs uid= gid= (: uid=gid=0). ownmask= othmask= '' '' ADFS (: 0700 0077 ). /usr/src/linux/Documentation/filesystems/adfs.rst. affs uid= gid= (: uid=gid=0 uid gid UID GID ). setuid= setgid= . mode= & 0777 . . . protect . usemp UID GID UID GID . ... verbose . prefix=_ . volume=_ ( 30 ) '/' . reserved= (: 2.) . root= . bs= . 512 1024 2048 4096. grpquota|noquota|quota|usrquota . ( "quota" /etc/fstab.) debugfs debugfs /sys/kernel/debug. 3.4 debugfs : uid=n, gid=n . mode= . devpts devpts /dev/pts. /dev/ptmx /dev/pts/<>. uid= gid= . UID GID . tty GID 5 gid=5 tty. mode= . 0600. mode=620 gid=5 "mesg y" . newinstance devpts devpts . devpts newinstance ( ). devpts newinstance . (containers) . 2.6.29. CONFIG_DEVPTS_MULTIPLE_INSTANCES . /dev/ptmx pts/ptmx. Documentation/filesystems/devpts.txt . ptmxmode= ptmx devpts. devpts ( newinstance ) ptmx devpts ( /dev/pts/ptmx). ptmx 0000. ptmxmode= ptmx newinstance. 2.6.29. CONFIG_DEVPTS_MULTIPLE_INSTANCES . fat (: fat msdos umsdos vfat.) blocksize={512|1024|2048} ( 512). . uid= gid= . (: UID GID .) umask= umask ( ). umask . . dmask= umask . umask . . fmask= umask . umask . . allow_utime= mtime/atime. : 20 . 2 . dmask . ( utime(2). : ~dmask & 022.) utime(2) CAP_FOWNER. FAT UID/GID . . check= : r[elaxed] ( verylongname.foobar verylong.foo) ( ). n[ormal] "relaxed" (* ? < ). . s[trict] "normal" MS-DOS (+ = ). codepage= (codepage) FAT VFAT. 437 . conv= . cvf_format=module CVF ( ) cvf_module . kmod cvf_format=xxx CVF . . cvf_option= CVF. . debug (debug). ( ). discard discard/TRIM . SSD LUN . dos1xfloppy BIOS Parameter Block . DOS 1.x 160 kiB 180 kiB 320 kiB 360 kiB. errors={panic|continue|remount-ro} FAT : (panic) ( ). fat={12|16|32} (fat) 12 16 32 . FAT . ! iocharset= 8 (Unicode) 16 . iso8859-1. . nfs={stale_rw|nostale_ro} FAT NFS. stale_rw: () inodes nfs . (/) NFS NFS ESTALE . nostale_ro: inode FAT. ESTALE inode. . . -o nfs stale_rw. tz=UTC ( FAT) UTC ( ). ( ) UTC . time_offset= FAT UTC. minutes UTC . settimeofday(2) . (DST) - . quiet quiet. (chown) (chmod) . ! rodir FAT ATTR_RO ( ). ATTR_RO ( ). ATTR_RO . showexec .EXE .COM .BAT. . sys_immutable ATTR_SYS FAT IMMUTABLE . . flush . . usefree " " (free clusters) FSINFO. . Windows . " " FSINFO . dots nodots dotsOK=[yes|no] Unix DOS FAT. hfs creator=cccc, type=cccc / (creator/type) MacOS finder . : '????'. uid=n, gid=n . (: UID GID .) dir_umask=n, file_umask=n, umask=n umask . umask . session=n (CDROM) . . . part=n n . . . quiet . hpfs uid= gid= . (: UID GID .) umask= umask ( ). umask . . case={lower|asis} . (: case=lower.) conv= . nocheck . iso9660 ISO 9660 (CD-ROMs). ( DVD. udf.) iso9660 8.3 ( DOS ) . / . Rock Ridge iso9660 UNIX. Rock Ridge UNIX ( ). norock Rock Ridge . map. nojoliet Microsoft Joliet . map. check={r[elaxed]|s[trict]} check=relaxed . norock map=normal. (: check=strict.) uid= gid= Rock Ridge. (: uid=0,gid=0.) map={n[ormal]|o[ff]|a[corn]} Rock Ridge ASCII ';1' ';' '.'. map=off . norock. (: map=normal.) map=acorn map=normal Acorn . mode= Rock Ridge (mode) . (: .) . unhide . ( .) block={512|1024|2048} . (: block=1024). conv= . cruft . 16 . session=x 0. sbsector=xxx xxx. vfat Joliet Microsoft. iocharset= Unicode 16 8 . iso8859-1. utf8 Unicode 16 UTF-8. jfs iocharset= Unicode ASCII. . iocharset=utf8 UTF8. CONFIG_NLS_UTF8 .config . resize= . JFS . . resize . nointegrity (journal). . . integrity . . nointegrity . errors={continue|remount-ro|panic} . ( (panic) .) noquota|quota|usrquota|grpquota . msdos fat. msdos . . ncpfs nfs ncpfs (struct ncp_mount_data) mount(2). ncpmount(8) mount (2.12) ncpfs. ntfs3 ntfs3 - iocharset= Unicode . (CONFIG_NLS_DEFAULT). : iocharset=utf8 uid=|gid=|umask= / NTFS. dmask=|fmask= umask fmask dmask . nohidden HIDDEN (FILE_ATTRIBUTE_HIDDEN) Windows . sys_immutable SYSTEM (FILE_ATTRIBUTE_SYSTEM) Windows . hide_dot_files HIDDEN (FILE_ATTRIBUTE_HIDDEN) Windows . HIDDEN . windows_names Windows ( " * / : < > ? \ | 0x20) ( ) (CON, AUX, NUL, PRN, LPT1-9, COM1-9) . . discard TRIM (SSD). force (dirty). . sparse (sparse). showmeta ( ) NTFS . . prealloc . . acl POSIX ACLs ( ). . NTFS ACLs. acl POSIX ACLs. overlay 3.18 overlay (union mount) . overlay - . . . overlayfs . trusted.* d_type readdir NFS . (overlay) . lowerdir upperdir : mount -t overlay overlay \ -olowerdir=/lower,upperdir=/upper,workdir=/work /merged lowerdir= . upperdir= (upperdir) . workdir= (workdir) (upperdir). userxattr xattr "user.overlay." "trusted.overlay.". overlayfs . redirect_dir={on|off|follow|nofollow} redirect_dir ( ). "{trusted|user}.overlay.redirect" overlay. . on . off "redirect_always_follow" . follow . nofollow ( "redirect_dir=off" "redirect_always_follow" ). index={on|off} Inode. "" . inode. uuid={on|off} UUID null UUID . UUID . lower/upper/work . nfs_export={on|off} NFS "nfs_export" overlay NFS. "nfs_export" copy_up (lower) . copy up. inode . "{trusted|user}.overlay.upper" inode . overlay o inode o copy_up o inode overlay o ( /) o UUID o inode "{trusted|user}.overlay.origin". overlay o UUID . o dentry . o . o whiteout ESTALE. overlay . o dentry overlay dentry inode . o dentry dentry overlay . dentry . copy_up dentry . overlay "" . "" "" . "" overlay . . overlay NFS ( "redirect_dir=nofollow"). overlay subtree_check exportfs NFS. NFS . . : index=off,nfs_export=on . xino={on|off|auto} "xino" st_ino fsid . "xino" inode fsid inode . inode xino overlay xino inode. metacopy={on|off} overlayfs ( ) chown/chmod. (WRITE). . volatile (volatile) . overlay . "volatile" (sync) . syncfs ( fsync) VFS. (writeback) upperdir . upperdir . overlay "volatile" "$workdir/work/incompat/volatile". overlay . upper work . upperdir "volatile". reiserfs Reiserfs (journaling). conv reiserfs 3.6 3.5 3.6 . reiserfs 3.5. hash={rupasov|tea|r5|detect} (hash) reiserfs . rupasov . . . tea Davis-Meyer Jeremy Fitzhardinge. . . EHASHCOLLISION r5. r5 rupasov. . detect mount reiserfs (superblock). . hashed_relocation . . no_unhashed_relocation . . noborder (border allocator) Yury Yu. Rupasov. . nolog (journaling). reiserfs . reiserfs . nolog . notail reiserfs ' ' . lilo(8). . replayonly . reiserfsck. resize= (online expansion) reiserfs. reiserfs . (LVM). resizer . user_xattr . attr(1). acl POSIX. acl(5). barrier=none / barrier=flush . barrier=none barrier=flush (). / reiserfs . . . ubifs UBIFS (flash) UBI. atime . ubiX_Y UBI X Y ubiY UBI 0 Y ubiX:NAME UBI X NAME ubi:NAME UBI 0 NAME ! :. : bulk_read . VFS . . . OneNAND " " NAND . no_bulk_read . . chk_data_crc CRC-32 . . no_chk_data_crc CRC-32 . CRC-32 . . CRC-32 . compr={none|lzo|zlib} . none. udf UDF " " OSTA DVD-ROM UDF/ISO-9660. . iso9660. uid= . uid=forget ( ) uid= UDF (uids) . 32 -1 UDF. "forget". gid= . gid=forget ( ) gid= UDF (gids) . 32 -1 UDF. "forget". umask= (inodes) . . mode= mode= . . dmode= dmode= dmode . . bs= . 2.6.30 2048. 2.6.30 4.11 2048. 4.11 4096. mkudffs(8) 2.0+ . unhide . undelete . adinicb (inode). () noadinicb . shortad UDF . longad UDF . () nostrict . iocharset= NLS. (compiled) CONFIG_UDF_NLS. utf8 UTF-8. novrs . session= . (= ) anchor= . (= 256) lastblock= . uid=ignore uid= . gid=ignore gid= . volume= . partition= . fileset= . rootdir= . ufs ufstype= UFS . . ufs . ufs . : old ufs . ( -r.) 44bsd BSD ( NetBSD FreeBSD OpenBSD). ufs2 FreeBSD 5.x . 5xbsd ufs2. sun SunOS Solaris Sparc. sunx86 Solaris x86. hp HP-UX . nextstep NeXTStep ( NeXT) ( ). nextstep-cd CDROM NextStep (block_size == 2048) . openstep OpenStep ( ). macOS . onerror= : panic (kernel panic). lock|umount|repair . umsdos msdos. dotsOK umsdos. vfat fat . dotsOK vfat. uni_xlate (Unicode) . . '' . {colon} vfat. u : '{colon}' (u & 0x3f) ((u>>6) & 0x3f) (u>>12). posix . . nonumtail name~num.ext. utf8 UTF8 8- . utf8=0 utf8=no utf8=false. uni_xlate UTF8. shortname= 8.3 . . (): lower . win95 . winnt . mixed . 2.6.32. usbfs devuid=uid devgid=gid devmode= usbfs (: uid=gid=0 mode=0644). . busuid=uid busgid=gid busmode= (bus) usbfs (: uid=gid=0 mode=0555). . listuid=uid listgid=gid listmode= (: uid=gid=0 mode=0444). . DM-VERITY verity device-mapper (crypto API) . dm-verity . libcryptsetup libmount ( dlopen(3)). libcryptsetup (root hash) . dm-verity: verity.hashdevice= dm-verity. verity.roothash=hex verity.hashdevice. verity.roothashfile. verity.roothashfile= verity.hashdevice. verity.roothash. verity.hashoffset= () (: 0) dm-verity . verity.fecdevice= (FEC) dm-verity. . CONFIG_DM_VERITY_FEC. verity.fecoffset= FEC () (: 0) dm-verity FEC. . verity.fecroots= FEC (: 2). . verity.roothashsig= pkcs7(1ssl) hash . ()crypt_activate_by_signed_key cryptsetup CONFIG_DM_VERITY_VERIFY_ROOTHASH_SIG. . . verity.oncorruption={ignore|restart|panic} . / . 4.1 libcrypsetup 2.3.4 . . util-linux v2.35. : mksquashfs /etc /tmp/etc.raw veritysetup format /tmp/etc.raw /tmp/etc.verity --root-hash-file=/tmp/etc.roothash openssl smime -sign -in /tmp/etc.roothash -nocerts -inkey private.key \ -signer private.crt -noattr -binary -outform der -out /tmp/etc.roothash.p7s mount -o verity.hashdevice=/tmp/etc.verity,verity.roothashfile=/tmp/etc.roothash,\ verity.roothashsig=/tmp/etc.roothash.p7s /tmp/etc.raw /mnt squashfs /etc hash verity /mnt. hash roothashsig. LOOP . mount /tmp/disk.img /mnt -t vfat -o loop=/dev/loop3 /dev/loop3 /tmp/disk.img /mnt. ( '-o loop' ) mount mount /tmp/disk.img /mnt -o loop mount libblkid : mount /tmp/disk.img /mnt mount -t ext4 /tmp/disk.img /mnt loop offset sizelimit losetup(8). ( ). 2.6.25 loop loop /etc/mtab. losetup -d umount -d. util-linux v2.29 mount . . mount ( OR): 0 1 2 ( loop) 4 8 16 /etc/mtab 32 64 mount -a 0 ( ) 32 ( ) 64 ( ). 126 /sbin/mount. ( util-linux v2.41) : /sbin/mount.suffix spec dir [-sfnv] [-N namespace] [-o options] [-t .subtype] suffix -sfnvoN . -t ( /sbin/mount.fuse -t fuse.sshfs). unbindable runbindable private rprivate slave rslave shared rshared auto noauto comment x-* loop offset sizelimit mount.. -o. (8). 126 execl(). LIBMOUNT_FORCE_MOUNT2={always|never|auto} mount(2) ( ). auto libmount mount(2) . libmount mount(2) LIBMOUNT_FORCE_MOUNT2 never. LIBMOUNT_FSTAB=<> fstab ( suid) LIBMOUNT_DEBUG=all libmount LIBBLKID_DEBUG=all libblkid LOOPDEV_DEBUG=all " /etc/fstab /etc/mtab /proc/mounts" . /etc/fstab /run/mount libmount /etc/mtab /proc/mounts /etc/mtab~ ( mtab ) /etc/mtab.tmp ( mtab ) /etc/filesystems mount 5 AT&T UNIX. . -o sync -o dirsync ( ext2 ext3 ext4 fat vfat ( BSD) sync). -o remount ( ext2fs sb gid umask fatfs). /etc/mtab /proc/mounts mtab . mount ( NFS -- mount NFS /proc/mount ). mtab /proc/mounts. NFS ( fcntl ioctl) noac. loop offset sizelimit mount . losetup(8) mount . Karel Zak mount(2) umount(2) filesystems(5) fstab(5) nfs(5) xfs(5) mount_namespaces(7) xattr(7) e2label(8) findmnt(8) losetup(8), lsblk(8) mke2fs(8) mountd(8) nfsd(8) swapon(8) tune2fs(8), umount(8) xfs_admin(8) . mount util-linux . util-linux 2.42.4 2026-09-21 MOUNT(8)