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docs: fs: cifs: convert to ReST and add to admin-guide book

The filenames for cifs documentation is not using the same
convention as almost all Kernel documents is using. So,
rename them to a more appropriate name. Then, manually convert
the documentation files for CIFS to ReST.

By doing a manual conversion, we can preserve the original
author's style, while making it to look more like the other
Kernel documents.

Most of the conversion here is trivial. The most complex one was
the README file (which was renamed to usage.rst).

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
alistair/sunxi64-5.4-dsi
Mauro Carvalho Chehab 2019-07-31 17:08:51 -03:00 committed by Jonathan Corbet
parent 9cdd273e29
commit f139291c71
9 changed files with 460 additions and 287 deletions

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@ -1,5 +1,10 @@
=======
Authors
=======
Original Author Original Author
=============== ---------------
Steve French (sfrench@samba.org) Steve French (sfrench@samba.org)
The author wishes to express his appreciation and thanks to: The author wishes to express his appreciation and thanks to:
@ -20,33 +25,34 @@ thanks to the Samba team for their technical advice and encouragement.
Patch Contributors Patch Contributors
------------------ ------------------
Zwane Mwaikambo
Andi Kleen - Zwane Mwaikambo
Amrut Joshi - Andi Kleen
Shobhit Dayal - Amrut Joshi
Sergey Vlasov - Shobhit Dayal
Richard Hughes - Sergey Vlasov
Yury Umanets - Richard Hughes
Mark Hamzy (for some of the early cifs IPv6 work) - Yury Umanets
Domen Puncer - Mark Hamzy (for some of the early cifs IPv6 work)
Jesper Juhl (in particular for lots of whitespace/formatting cleanup) - Domen Puncer
Vince Negri and Dave Stahl (for finding an important caching bug) - Jesper Juhl (in particular for lots of whitespace/formatting cleanup)
Adrian Bunk (kcalloc cleanups) - Vince Negri and Dave Stahl (for finding an important caching bug)
Miklos Szeredi - Adrian Bunk (kcalloc cleanups)
Kazeon team for various fixes especially for 2.4 version. - Miklos Szeredi
Asser Ferno (Change Notify support) - Kazeon team for various fixes especially for 2.4 version.
Shaggy (Dave Kleikamp) for innumerable small fs suggestions and some good cleanup - Asser Ferno (Change Notify support)
Gunter Kukkukk (testing and suggestions for support of old servers) - Shaggy (Dave Kleikamp) for innumerable small fs suggestions and some good cleanup
Igor Mammedov (DFS support) - Gunter Kukkukk (testing and suggestions for support of old servers)
Jeff Layton (many, many fixes, as well as great work on the cifs Kerberos code) - Igor Mammedov (DFS support)
Scott Lovenberg - Jeff Layton (many, many fixes, as well as great work on the cifs Kerberos code)
Pavel Shilovsky (for great work adding SMB2 support, and various SMB3 features) - Scott Lovenberg
Aurelien Aptel (for DFS SMB3 work and some key bug fixes) - Pavel Shilovsky (for great work adding SMB2 support, and various SMB3 features)
Ronnie Sahlberg (for SMB3 xattr work, bug fixes, and lots of great work on compounding) - Aurelien Aptel (for DFS SMB3 work and some key bug fixes)
Shirish Pargaonkar (for many ACL patches over the years) - Ronnie Sahlberg (for SMB3 xattr work, bug fixes, and lots of great work on compounding)
Sachin Prabhu (many bug fixes, including for reconnect, copy offload and security) - Shirish Pargaonkar (for many ACL patches over the years)
Paulo Alcantara - Sachin Prabhu (many bug fixes, including for reconnect, copy offload and security)
Long Li (some great work on RDMA, SMB Direct) - Paulo Alcantara
- Long Li (some great work on RDMA, SMB Direct)
Test case and Bug Report contributors Test case and Bug Report contributors

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=======
Changes
=======
See https://wiki.samba.org/index.php/LinuxCIFSKernel for summary See https://wiki.samba.org/index.php/LinuxCIFSKernel for summary
information (that may be easier to read than parsing the output of information (that may be easier to read than parsing the output of
"git log fs/cifs") about fixes/improvements to CIFS/SMB2/SMB3 support (changes "git log fs/cifs") about fixes/improvements to CIFS/SMB2/SMB3 support (changes

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@ -0,0 +1,21 @@
.. SPDX-License-Identifier: GPL-2.0
====
CIFS
====
.. toctree::
:maxdepth: 2
introduction
usage
todo
changes
authors
.. only:: subproject and html
Indices
=======
* :ref:`genindex`

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@ -1,3 +1,7 @@
============
Introduction
============
This is the client VFS module for the SMB3 NAS protocol as well This is the client VFS module for the SMB3 NAS protocol as well
as for older dialects such as the Common Internet File System (CIFS) as for older dialects such as the Common Internet File System (CIFS)
protocol which was the successor to the Server Message Block protocol which was the successor to the Server Message Block
@ -33,7 +37,9 @@
tools (including smbinfo and setcifsacl) that can be obtained from tools (including smbinfo and setcifsacl) that can be obtained from
https://git.samba.org/?p=cifs-utils.git https://git.samba.org/?p=cifs-utils.git
or or
git://git.samba.org/cifs-utils.git git://git.samba.org/cifs-utils.git
mount.cifs should be installed in the directory with the other mount helpers. mount.cifs should be installed in the directory with the other mount helpers.
@ -41,5 +47,7 @@
For more information on the module see the project wiki page at For more information on the module see the project wiki page at
https://wiki.samba.org/index.php/LinuxCIFS https://wiki.samba.org/index.php/LinuxCIFS
and and
https://wiki.samba.org/index.php/LinuxCIFS_utils https://wiki.samba.org/index.php/LinuxCIFS_utils

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====
TODO
====
Version 2.14 December 21, 2018 Version 2.14 December 21, 2018
A Partial List of Missing Features A Partial List of Missing Features
@ -8,6 +12,7 @@ for visible, important contributions to this module. Here
is a partial list of the known problems and missing features: is a partial list of the known problems and missing features:
a) SMB3 (and SMB3.1.1) missing optional features: a) SMB3 (and SMB3.1.1) missing optional features:
- multichannel (started), integration with RDMA - multichannel (started), integration with RDMA
- directory leases (improved metadata caching), started (root dir only) - directory leases (improved metadata caching), started (root dir only)
- T10 copy offload ie "ODX" (copy chunk, and "Duplicate Extents" ioctl - T10 copy offload ie "ODX" (copy chunk, and "Duplicate Extents" ioctl
@ -16,45 +21,46 @@ a) SMB3 (and SMB3.1.1) missing optional features:
b) improved sparse file support b) improved sparse file support
c) Directory entry caching relies on a 1 second timer, rather than c) Directory entry caching relies on a 1 second timer, rather than
using Directory Leases, currently only the root file handle is cached longer using Directory Leases, currently only the root file handle is cached longer
d) quota support (needs minor kernel change since quota calls d) quota support (needs minor kernel change since quota calls
to make it to network filesystems or deviceless filesystems) to make it to network filesystems or deviceless filesystems)
e) Additional use cases where we use "compoounding" (e.g. open/query/close e) Additional use cases where we use "compoounding" (e.g. open/query/close
and open/setinfo/close) to reduce the number of roundtrips, and also and open/setinfo/close) to reduce the number of roundtrips, and also
open to reduce redundant opens (using deferred close and reference counts more). open to reduce redundant opens (using deferred close and reference counts
more).
f) Finish inotify support so kde and gnome file list windows f) Finish inotify support so kde and gnome file list windows
will autorefresh (partially complete by Asser). Needs minor kernel will autorefresh (partially complete by Asser). Needs minor kernel
vfs change to support removing D_NOTIFY on a file. vfs change to support removing D_NOTIFY on a file.
g) Add GUI tool to configure /proc/fs/cifs settings and for display of g) Add GUI tool to configure /proc/fs/cifs settings and for display of
the CIFS statistics (started) the CIFS statistics (started)
h) implement support for security and trusted categories of xattrs h) implement support for security and trusted categories of xattrs
(requires minor protocol extension) to enable better support for SELINUX (requires minor protocol extension) to enable better support for SELINUX
i) Add support for tree connect contexts (see MS-SMB2) a new SMB3.1.1 protocol i) Add support for tree connect contexts (see MS-SMB2) a new SMB3.1.1 protocol
feature (may be especially useful for virtualization). feature (may be especially useful for virtualization).
j) Create UID mapping facility so server UIDs can be mapped on a per j) Create UID mapping facility so server UIDs can be mapped on a per
mount or a per server basis to client UIDs or nobody if no mapping mount or a per server basis to client UIDs or nobody if no mapping
exists. Also better integration with winbind for resolving SID owners exists. Also better integration with winbind for resolving SID owners
k) Add tools to take advantage of more smb3 specific ioctls and features k) Add tools to take advantage of more smb3 specific ioctls and features
(passthrough ioctl/fsctl for sending various SMB3 fsctls to the server (passthrough ioctl/fsctl for sending various SMB3 fsctls to the server
is in progress, and a passthrough query_info call is already implemented is in progress, and a passthrough query_info call is already implemented
in cifs.ko to allow smb3 info levels queries to be sent from userspace) in cifs.ko to allow smb3 info levels queries to be sent from userspace)
l) encrypted file support l) encrypted file support
m) improved stats gathering tools (perhaps integration with nfsometer?) m) improved stats gathering tools (perhaps integration with nfsometer?)
to extend and make easier to use what is currently in /proc/fs/cifs/Stats to extend and make easier to use what is currently in /proc/fs/cifs/Stats
n) allow setting more NTFS/SMB3 file attributes remotely (currently limited to compressed n) allow setting more NTFS/SMB3 file attributes remotely (currently limited to
file attribute via chflags) and improve user space tools for managing and compressed file attribute via chflags) and improve user space tools for
viewing them. managing and viewing them.
o) mount helper GUI (to simplify the various configuration options on mount) o) mount helper GUI (to simplify the various configuration options on mount)
@ -65,55 +71,56 @@ p) Add support for witness protocol (perhaps ioctl to cifs.ko from user space
different servers, and the server we are connected to has gone down. different servers, and the server we are connected to has gone down.
q) Allow mount.cifs to be more verbose in reporting errors with dialect q) Allow mount.cifs to be more verbose in reporting errors with dialect
or unsupported feature errors. or unsupported feature errors.
r) updating cifs documentation, and user guide. r) updating cifs documentation, and user guide.
s) Addressing bugs found by running a broader set of xfstests in standard s) Addressing bugs found by running a broader set of xfstests in standard
file system xfstest suite. file system xfstest suite.
t) split cifs and smb3 support into separate modules so legacy (and less t) split cifs and smb3 support into separate modules so legacy (and less
secure) CIFS dialect can be disabled in environments that don't need it secure) CIFS dialect can be disabled in environments that don't need it
and simplify the code. and simplify the code.
v) POSIX Extensions for SMB3.1.1 (started, create and mkdir support added v) POSIX Extensions for SMB3.1.1 (started, create and mkdir support added
so far). so far).
w) Add support for additional strong encryption types, and additional spnego w) Add support for additional strong encryption types, and additional spnego
authentication mechanisms (see MS-SMB2) authentication mechanisms (see MS-SMB2)
Known Bugs
==========
KNOWN BUGS
====================================
See http://bugzilla.samba.org - search on product "CifsVFS" for See http://bugzilla.samba.org - search on product "CifsVFS" for
current bug list. Also check http://bugzilla.kernel.org (Product = File System, Component = CIFS) current bug list. Also check http://bugzilla.kernel.org (Product = File System, Component = CIFS)
1) existing symbolic links (Windows reparse points) are recognized but 1) existing symbolic links (Windows reparse points) are recognized but
can not be created remotely. They are implemented for Samba and those that can not be created remotely. They are implemented for Samba and those that
support the CIFS Unix extensions, although earlier versions of Samba support the CIFS Unix extensions, although earlier versions of Samba
overly restrict the pathnames. overly restrict the pathnames.
2) follow_link and readdir code does not follow dfs junctions 2) follow_link and readdir code does not follow dfs junctions
but recognizes them but recognizes them
Misc testing to do Misc testing to do
================== ==================
1) check out max path names and max path name components against various server 1) check out max path names and max path name components against various server
types. Try nested symlinks (8 deep). Return max path name in stat -f information types. Try nested symlinks (8 deep). Return max path name in stat -f information
2) Improve xfstest's cifs/smb3 enablement and adapt xfstests where needed to test 2) Improve xfstest's cifs/smb3 enablement and adapt xfstests where needed to test
cifs/smb3 better cifs/smb3 better
3) Additional performance testing and optimization using iozone and similar - 3) Additional performance testing and optimization using iozone and similar -
there are some easy changes that can be done to parallelize sequential writes, there are some easy changes that can be done to parallelize sequential writes,
and when signing is disabled to request larger read sizes (larger than and when signing is disabled to request larger read sizes (larger than
negotiated size) and send larger write sizes to modern servers. negotiated size) and send larger write sizes to modern servers.
4) More exhaustively test against less common servers 4) More exhaustively test against less common servers
5) Continue to extend the smb3 "buildbot" which does automated xfstesting 5) Continue to extend the smb3 "buildbot" which does automated xfstesting
against Windows, Samba and Azure currently - to add additional tests and against Windows, Samba and Azure currently - to add additional tests and
to allow the buildbot to execute the tests faster. The URL for the to allow the buildbot to execute the tests faster. The URL for the
buildbot is: http://smb3-test-rhel-75.southcentralus.cloudapp.azure.com buildbot is: http://smb3-test-rhel-75.southcentralus.cloudapp.azure.com
6) Address various coverity warnings (most are not bugs per-se, but 6) Address various coverity warnings (most are not bugs per-se, but
the more warnings are addressed, the easier it is to spot real the more warnings are addressed, the easier it is to spot real
problems that static analyzers will point out in the future). problems that static analyzers will point out in the future).

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=====
Usage
=====
This module supports the SMB3 family of advanced network protocols (as well This module supports the SMB3 family of advanced network protocols (as well
as older dialects, originally called "CIFS" or SMB1). as older dialects, originally called "CIFS" or SMB1).
@ -11,43 +15,47 @@ Information Foundation. CIFS and now SMB3 has now become a defacto
standard for interoperating between Macs and Windows and major NAS appliances. standard for interoperating between Macs and Windows and major NAS appliances.
Please see Please see
MS-SMB2 (for detailed SMB2/SMB3/SMB3.1.1 protocol specification) MS-SMB2 (for detailed SMB2/SMB3/SMB3.1.1 protocol specification)
http://protocolfreedom.org/ and http://protocolfreedom.org/ and
http://samba.org/samba/PFIF/ http://samba.org/samba/PFIF/
for more details. for more details.
For questions or bug reports please contact: For questions or bug reports please contact:
smfrench@gmail.com smfrench@gmail.com
See the project page at: https://wiki.samba.org/index.php/LinuxCIFS_utils See the project page at: https://wiki.samba.org/index.php/LinuxCIFS_utils
Build instructions: Build instructions
================== ==================
For Linux: For Linux:
1) Download the kernel (e.g. from http://www.kernel.org) 1) Download the kernel (e.g. from http://www.kernel.org)
and change directory into the top of the kernel directory tree and change directory into the top of the kernel directory tree
(e.g. /usr/src/linux-2.5.73) (e.g. /usr/src/linux-2.5.73)
2) make menuconfig (or make xconfig) 2) make menuconfig (or make xconfig)
3) select cifs from within the network filesystem choices 3) select cifs from within the network filesystem choices
4) save and exit 4) save and exit
5) make 5) make
Installation instructions: Installation instructions
========================= =========================
If you have built the CIFS vfs as module (successfully) simply If you have built the CIFS vfs as module (successfully) simply
type "make modules_install" (or if you prefer, manually copy the file to type ``make modules_install`` (or if you prefer, manually copy the file to
the modules directory e.g. /lib/modules/2.4.10-4GB/kernel/fs/cifs/cifs.ko). the modules directory e.g. /lib/modules/2.4.10-4GB/kernel/fs/cifs/cifs.ko).
If you have built the CIFS vfs into the kernel itself, follow the instructions If you have built the CIFS vfs into the kernel itself, follow the instructions
for your distribution on how to install a new kernel (usually you for your distribution on how to install a new kernel (usually you
would simply type "make install"). would simply type ``make install``).
If you do not have the utility mount.cifs (in the Samba 4.x source tree and on If you do not have the utility mount.cifs (in the Samba 4.x source tree and on
the CIFS VFS web site) copy it to the same directory in which mount helpers the CIFS VFS web site) copy it to the same directory in which mount helpers
reside (usually /sbin). Although the helper software is not reside (usually /sbin). Although the helper software is not
required, mount.cifs is recommended. Most distros include a "cifs-utils" required, mount.cifs is recommended. Most distros include a ``cifs-utils``
package that includes this utility so it is recommended to install this. package that includes this utility so it is recommended to install this.
Note that running the Winbind pam/nss module (logon service) on all of your Note that running the Winbind pam/nss module (logon service) on all of your
@ -57,13 +65,16 @@ found at cifs-utils.git on git.samba.org
If cifs is built as a module, then the size and number of network buffers If cifs is built as a module, then the size and number of network buffers
and maximum number of simultaneous requests to one server can be configured. and maximum number of simultaneous requests to one server can be configured.
Changing these from their defaults is not recommended. By executing modinfo Changing these from their defaults is not recommended. By executing modinfo::
modinfo kernel/fs/cifs/cifs.ko modinfo kernel/fs/cifs/cifs.ko
on kernel/fs/cifs/cifs.ko the list of configuration changes that can be made on kernel/fs/cifs/cifs.ko the list of configuration changes that can be made
at module initialization time (by running insmod cifs.ko) can be seen. at module initialization time (by running insmod cifs.ko) can be seen.
Recommendations Recommendations
=============== ===============
To improve security the SMB2.1 dialect or later (usually will get SMB3) is now To improve security the SMB2.1 dialect or later (usually will get SMB3) is now
the new default. To use old dialects (e.g. to mount Windows XP) use "vers=1.0" the new default. To use old dialects (e.g. to mount Windows XP) use "vers=1.0"
on mount (or vers=2.0 for Windows Vista). Note that the CIFS (vers=1.0) is on mount (or vers=2.0 for Windows Vista). Note that the CIFS (vers=1.0) is
@ -72,26 +83,30 @@ many advanced security features such as downgrade attack detection
and encrypted shares and stronger signing and authentication algorithms. and encrypted shares and stronger signing and authentication algorithms.
There are additional mount options that may be helpful for SMB3 to get There are additional mount options that may be helpful for SMB3 to get
improved POSIX behavior (NB: can use vers=3.0 to force only SMB3, never 2.1): improved POSIX behavior (NB: can use vers=3.0 to force only SMB3, never 2.1):
"mfsymlinks" and "cifsacl" and "idsfromsid"
``mfsymlinks`` and ``cifsacl`` and ``idsfromsid``
Allowing User Mounts Allowing User Mounts
==================== ====================
To permit users to mount and unmount over directories they own is possible To permit users to mount and unmount over directories they own is possible
with the cifs vfs. A way to enable such mounting is to mark the mount.cifs with the cifs vfs. A way to enable such mounting is to mark the mount.cifs
utility as suid (e.g. "chmod +s /sbin/mount.cifs). To enable users to utility as suid (e.g. ``chmod +s /sbin/mount.cifs``). To enable users to
umount shares they mount requires umount shares they mount requires
1) mount.cifs version 1.4 or later 1) mount.cifs version 1.4 or later
2) an entry for the share in /etc/fstab indicating that a user may 2) an entry for the share in /etc/fstab indicating that a user may
unmount it e.g. unmount it e.g.::
//server/usersharename /mnt/username cifs user 0 0
//server/usersharename /mnt/username cifs user 0 0
Note that when the mount.cifs utility is run suid (allowing user mounts), Note that when the mount.cifs utility is run suid (allowing user mounts),
in order to reduce risks, the "nosuid" mount flag is passed in on mount to in order to reduce risks, the ``nosuid`` mount flag is passed in on mount to
disallow execution of an suid program mounted on the remote target. disallow execution of an suid program mounted on the remote target.
When mount is executed as root, nosuid is not passed in by default, When mount is executed as root, nosuid is not passed in by default,
and execution of suid programs on the remote target would be enabled and execution of suid programs on the remote target would be enabled
by default. This can be changed, as with nfs and other filesystems, by default. This can be changed, as with nfs and other filesystems,
by simply specifying "nosuid" among the mount options. For user mounts by simply specifying ``nosuid`` among the mount options. For user mounts
though to be able to pass the suid flag to mount requires rebuilding though to be able to pass the suid flag to mount requires rebuilding
mount.cifs with the following flag: CIFS_ALLOW_USR_SUID mount.cifs with the following flag: CIFS_ALLOW_USR_SUID
@ -100,13 +115,14 @@ later source tree in docs/manpages/mount.cifs.8
Allowing User Unmounts Allowing User Unmounts
====================== ======================
To permit users to ummount directories that they have user mounted (see above), To permit users to ummount directories that they have user mounted (see above),
the utility umount.cifs may be used. It may be invoked directly, or if the utility umount.cifs may be used. It may be invoked directly, or if
umount.cifs is placed in /sbin, umount can invoke the cifs umount helper umount.cifs is placed in /sbin, umount can invoke the cifs umount helper
(at least for most versions of the umount utility) for umount of cifs (at least for most versions of the umount utility) for umount of cifs
mounts, unless umount is invoked with -i (which will avoid invoking a umount mounts, unless umount is invoked with -i (which will avoid invoking a umount
helper). As with mount.cifs, to enable user unmounts umount.cifs must be marked helper). As with mount.cifs, to enable user unmounts umount.cifs must be marked
as suid (e.g. "chmod +s /sbin/umount.cifs") or equivalent (some distributions as suid (e.g. ``chmod +s /sbin/umount.cifs``) or equivalent (some distributions
allow adding entries to a file to the /etc/permissions file to achieve the allow adding entries to a file to the /etc/permissions file to achieve the
equivalent suid effect). For this utility to succeed the target path equivalent suid effect). For this utility to succeed the target path
must be a cifs mount, and the uid of the current user must match the uid must be a cifs mount, and the uid of the current user must match the uid
@ -120,6 +136,7 @@ or unpredictable UNC names.
Samba Considerations Samba Considerations
==================== ====================
Most current servers support SMB2.1 and SMB3 which are more secure, Most current servers support SMB2.1 and SMB3 which are more secure,
but there are useful protocol extensions for the older less secure CIFS but there are useful protocol extensions for the older less secure CIFS
dialect, so to get the maximum benefit if mounting using the older dialect dialect, so to get the maximum benefit if mounting using the older dialect
@ -129,13 +146,13 @@ Unix Extensions standard (e.g. almost any version of Samba ie version
Note that uid, gid and file permissions will display default values if you do Note that uid, gid and file permissions will display default values if you do
not have a server that supports the Unix extensions for CIFS (such as Samba not have a server that supports the Unix extensions for CIFS (such as Samba
2.2.5 or later). To enable the Unix CIFS Extensions in the Samba server, add 2.2.5 or later). To enable the Unix CIFS Extensions in the Samba server, add
the line: the line::
unix extensions = yes unix extensions = yes
to your smb.conf file on the server. Note that the following smb.conf settings to your smb.conf file on the server. Note that the following smb.conf settings
are also useful (on the Samba server) when the majority of clients are Unix or are also useful (on the Samba server) when the majority of clients are Unix or
Linux: Linux::
case sensitive = yes case sensitive = yes
delete readonly = yes delete readonly = yes
@ -147,31 +164,33 @@ cifs client, and that EA support is present in later versions of Samba (e.g.
shares on NTFS filesystems). Extended Attribute (xattr) support is an optional shares on NTFS filesystems). Extended Attribute (xattr) support is an optional
feature of most Linux filesystems which may require enabling via feature of most Linux filesystems which may require enabling via
make menuconfig. Client support for extended attributes (user xattr) can be make menuconfig. Client support for extended attributes (user xattr) can be
disabled on a per-mount basis by specifying "nouser_xattr" on mount. disabled on a per-mount basis by specifying ``nouser_xattr`` on mount.
The CIFS client can get and set POSIX ACLs (getfacl, setfacl) to Samba servers The CIFS client can get and set POSIX ACLs (getfacl, setfacl) to Samba servers
version 3.10 and later. Setting POSIX ACLs requires enabling both XATTR and version 3.10 and later. Setting POSIX ACLs requires enabling both XATTR and
then POSIX support in the CIFS configuration options when building the cifs then POSIX support in the CIFS configuration options when building the cifs
module. POSIX ACL support can be disabled on a per mount basic by specifying module. POSIX ACL support can be disabled on a per mount basic by specifying
"noacl" on mount. ``noacl`` on mount.
Some administrators may want to change Samba's smb.conf "map archive" and Some administrators may want to change Samba's smb.conf ``map archive`` and
"create mask" parameters from the default. Unless the create mask is changed ``create mask`` parameters from the default. Unless the create mask is changed
newly created files can end up with an unnecessarily restrictive default mode, newly created files can end up with an unnecessarily restrictive default mode,
which may not be what you want, although if the CIFS Unix extensions are which may not be what you want, although if the CIFS Unix extensions are
enabled on the server and client, subsequent setattr calls (e.g. chmod) can enabled on the server and client, subsequent setattr calls (e.g. chmod) can
fix the mode. Note that creating special devices (mknod) remotely fix the mode. Note that creating special devices (mknod) remotely
may require specifying a mkdev function to Samba if you are not using may require specifying a mkdev function to Samba if you are not using
Samba 3.0.6 or later. For more information on these see the manual pages Samba 3.0.6 or later. For more information on these see the manual pages
("man smb.conf") on the Samba server system. Note that the cifs vfs, (``man smb.conf``) on the Samba server system. Note that the cifs vfs,
unlike the smbfs vfs, does not read the smb.conf on the client system unlike the smbfs vfs, does not read the smb.conf on the client system
(the few optional settings are passed in on mount via -o parameters instead). (the few optional settings are passed in on mount via -o parameters instead).
Note that Samba 2.2.7 or later includes a fix that allows the CIFS VFS to delete Note that Samba 2.2.7 or later includes a fix that allows the CIFS VFS to delete
open files (required for strict POSIX compliance). Windows Servers already open files (required for strict POSIX compliance). Windows Servers already
supported this feature. Samba server does not allow symlinks that refer to files supported this feature. Samba server does not allow symlinks that refer to files
outside of the share, so in Samba versions prior to 3.0.6, most symlinks to outside of the share, so in Samba versions prior to 3.0.6, most symlinks to
files with absolute paths (ie beginning with slash) such as: files with absolute paths (ie beginning with slash) such as::
ln -s /mnt/foo bar ln -s /mnt/foo bar
would be forbidden. Samba 3.0.6 server or later includes the ability to create would be forbidden. Samba 3.0.6 server or later includes the ability to create
such symlinks safely by converting unsafe symlinks (ie symlinks to server such symlinks safely by converting unsafe symlinks (ie symlinks to server
files that are outside of the share) to a samba specific format on the server files that are outside of the share) to a samba specific format on the server
@ -182,18 +201,19 @@ later, but only for remote clients using the CIFS Unix extensions, and will
be invisbile to Windows clients and typically will not affect local be invisbile to Windows clients and typically will not affect local
applications running on the same server as Samba. applications running on the same server as Samba.
Use instructions: Use instructions
================ ================
Once the CIFS VFS support is built into the kernel or installed as a module Once the CIFS VFS support is built into the kernel or installed as a module
(cifs.ko), you can use mount syntax like the following to access Samba or (cifs.ko), you can use mount syntax like the following to access Samba or
Mac or Windows servers: Mac or Windows servers::
mount -t cifs //9.53.216.11/e$ /mnt -o username=myname,password=mypassword mount -t cifs //9.53.216.11/e$ /mnt -o username=myname,password=mypassword
Before -o the option -v may be specified to make the mount.cifs Before -o the option -v may be specified to make the mount.cifs
mount helper display the mount steps more verbosely. mount helper display the mount steps more verbosely.
After -o the following commonly used cifs vfs specific options After -o the following commonly used cifs vfs specific options
are supported: are supported::
username=<username> username=<username>
password=<password> password=<password>
@ -203,25 +223,28 @@ Other cifs mount options are described below. Use of TCP names (in addition to
ip addresses) is available if the mount helper (mount.cifs) is installed. If ip addresses) is available if the mount helper (mount.cifs) is installed. If
you do not trust the server to which are mounted, or if you do not have you do not trust the server to which are mounted, or if you do not have
cifs signing enabled (and the physical network is insecure), consider use cifs signing enabled (and the physical network is insecure), consider use
of the standard mount options "noexec" and "nosuid" to reduce the risk of of the standard mount options ``noexec`` and ``nosuid`` to reduce the risk of
running an altered binary on your local system (downloaded from a hostile server running an altered binary on your local system (downloaded from a hostile server
or altered by a hostile router). or altered by a hostile router).
Although mounting using format corresponding to the CIFS URL specification is Although mounting using format corresponding to the CIFS URL specification is
not possible in mount.cifs yet, it is possible to use an alternate format not possible in mount.cifs yet, it is possible to use an alternate format
for the server and sharename (which is somewhat similar to NFS style mount for the server and sharename (which is somewhat similar to NFS style mount
syntax) instead of the more widely used UNC format (i.e. \\server\share): syntax) instead of the more widely used UNC format (i.e. \\server\share)::
mount -t cifs tcp_name_of_server:share_name /mnt -o user=myname,pass=mypasswd mount -t cifs tcp_name_of_server:share_name /mnt -o user=myname,pass=mypasswd
When using the mount helper mount.cifs, passwords may be specified via alternate When using the mount helper mount.cifs, passwords may be specified via alternate
mechanisms, instead of specifying it after -o using the normal "pass=" syntax mechanisms, instead of specifying it after -o using the normal ``pass=`` syntax
on the command line: on the command line:
1) By including it in a credential file. Specify credentials=filename as one 1) By including it in a credential file. Specify credentials=filename as one
of the mount options. Credential files contain two lines of the mount options. Credential files contain two lines::
username=someuser
password=your_password username=someuser
password=your_password
2) By specifying the password in the PASSWD environment variable (similarly 2) By specifying the password in the PASSWD environment variable (similarly
the user name can be taken from the USER environment variable). the user name can be taken from the USER environment variable).
3) By specifying the password in a file by name via PASSWD_FILE 3) By specifying the password in a file by name via PASSWD_FILE
4) By specifying the password in a file by file descriptor via PASSWD_FD 4) By specifying the password in a file by file descriptor via PASSWD_FD
@ -229,6 +252,7 @@ If no password is provided, mount.cifs will prompt for password entry
Restrictions Restrictions
============ ============
Servers must support either "pure-TCP" (port 445 TCP/IP CIFS connections) or RFC Servers must support either "pure-TCP" (port 445 TCP/IP CIFS connections) or RFC
1001/1002 support for "Netbios-Over-TCP/IP." This is not likely to be a 1001/1002 support for "Netbios-Over-TCP/IP." This is not likely to be a
problem as most servers support this. problem as most servers support this.
@ -243,25 +267,32 @@ filenames (ie those which contain valid Linux characters, which normally
would be forbidden for Windows/CIFS semantics) as long as the server is would be forbidden for Windows/CIFS semantics) as long as the server is
configured for Unix Extensions (and the client has not disabled configured for Unix Extensions (and the client has not disabled
/proc/fs/cifs/LinuxExtensionsEnabled). In addition the mount option /proc/fs/cifs/LinuxExtensionsEnabled). In addition the mount option
"mapposix" can be used on CIFS (vers=1.0) to force the mapping of ``mapposix`` can be used on CIFS (vers=1.0) to force the mapping of
illegal Windows/NTFS/SMB characters to a remap range (this mount parm illegal Windows/NTFS/SMB characters to a remap range (this mount parm
is the default for SMB3). This remap ("mapposix") range is also is the default for SMB3). This remap (``mapposix``) range is also
compatible with Mac (and "Services for Mac" on some older Windows). compatible with Mac (and "Services for Mac" on some older Windows).
CIFS VFS Mount Options CIFS VFS Mount Options
====================== ======================
A partial list of the supported mount options follows: A partial list of the supported mount options follows:
username The user name to use when trying to establish
username
The user name to use when trying to establish
the CIFS session. the CIFS session.
password The user password. If the mount helper is password
The user password. If the mount helper is
installed, the user will be prompted for password installed, the user will be prompted for password
if not supplied. if not supplied.
ip The ip address of the target server ip
unc The target server Universal Network Name (export) to The ip address of the target server
unc
The target server Universal Network Name (export) to
mount. mount.
domain Set the SMB/CIFS workgroup name prepended to the domain
Set the SMB/CIFS workgroup name prepended to the
username during CIFS session establishment username during CIFS session establishment
forceuid Set the default uid for inodes to the uid forceuid
Set the default uid for inodes to the uid
passed in on mount. For mounts to servers passed in on mount. For mounts to servers
which do support the CIFS Unix extensions, such as a which do support the CIFS Unix extensions, such as a
properly configured Samba server, the server provides properly configured Samba server, the server provides
@ -276,7 +307,7 @@ A partial list of the supported mount options follows:
extensions, the default uid (and gid) returned on lookup extensions, the default uid (and gid) returned on lookup
of existing files will be the uid (gid) of the person of existing files will be the uid (gid) of the person
who executed the mount (root, except when mount.cifs who executed the mount (root, except when mount.cifs
is configured setuid for user mounts) unless the "uid=" is configured setuid for user mounts) unless the ``uid=``
(gid) mount option is specified. Also note that permission (gid) mount option is specified. Also note that permission
checks (authorization checks) on accesses to a file occur checks (authorization checks) on accesses to a file occur
at the server, but there are cases in which an administrator at the server, but there are cases in which an administrator
@ -286,22 +317,29 @@ A partial list of the supported mount options follows:
client, and a crude form of client side permission checking client, and a crude form of client side permission checking
can be enabled by specifying file_mode and dir_mode on can be enabled by specifying file_mode and dir_mode on
the client. (default) the client. (default)
forcegid (similar to above but for the groupid instead of uid) (default) forcegid
noforceuid Fill in file owner information (uid) by requesting it from (similar to above but for the groupid instead of uid) (default)
noforceuid
Fill in file owner information (uid) by requesting it from
the server if possible. With this option, the value given in the server if possible. With this option, the value given in
the uid= option (on mount) will only be used if the server the uid= option (on mount) will only be used if the server
can not support returning uids on inodes. can not support returning uids on inodes.
noforcegid (similar to above but for the group owner, gid, instead of uid) noforcegid
uid Set the default uid for inodes, and indicate to the (similar to above but for the group owner, gid, instead of uid)
uid
Set the default uid for inodes, and indicate to the
cifs kernel driver which local user mounted. If the server cifs kernel driver which local user mounted. If the server
supports the unix extensions the default uid is supports the unix extensions the default uid is
not used to fill in the owner fields of inodes (files) not used to fill in the owner fields of inodes (files)
unless the "forceuid" parameter is specified. unless the ``forceuid`` parameter is specified.
gid Set the default gid for inodes (similar to above). gid
file_mode If CIFS Unix extensions are not supported by the server Set the default gid for inodes (similar to above).
file_mode
If CIFS Unix extensions are not supported by the server
this overrides the default mode for file inodes. this overrides the default mode for file inodes.
fsc Enable local disk caching using FS-Cache (off by default). This fsc
option could be useful to improve performance on a slow link, Enable local disk caching using FS-Cache (off by default). This
option could be useful to improve performance on a slow link,
heavily loaded server and/or network where reading from the heavily loaded server and/or network where reading from the
disk is faster than reading from the server (over the network). disk is faster than reading from the server (over the network).
This could also impact scalability positively as the This could also impact scalability positively as the
@ -310,18 +348,22 @@ A partial list of the supported mount options follows:
type workloads. So, you need to consider carefully your type workloads. So, you need to consider carefully your
workload/scenario before using this option. Currently, local workload/scenario before using this option. Currently, local
disk caching is functional for CIFS files opened as read-only. disk caching is functional for CIFS files opened as read-only.
dir_mode If CIFS Unix extensions are not supported by the server dir_mode
If CIFS Unix extensions are not supported by the server
this overrides the default mode for directory inodes. this overrides the default mode for directory inodes.
port attempt to contact the server on this tcp port, before port
attempt to contact the server on this tcp port, before
trying the usual ports (port 445, then 139). trying the usual ports (port 445, then 139).
iocharset Codepage used to convert local path names to and from iocharset
Codepage used to convert local path names to and from
Unicode. Unicode is used by default for network path Unicode. Unicode is used by default for network path
names if the server supports it. If iocharset is names if the server supports it. If iocharset is
not specified then the nls_default specified not specified then the nls_default specified
during the local client kernel build will be used. during the local client kernel build will be used.
If server does not support Unicode, this parameter is If server does not support Unicode, this parameter is
unused. unused.
rsize default read size (usually 16K). The client currently rsize
default read size (usually 16K). The client currently
can not use rsize larger than CIFSMaxBufSize. CIFSMaxBufSize can not use rsize larger than CIFSMaxBufSize. CIFSMaxBufSize
defaults to 16K and may be changed (from 8K to the maximum defaults to 16K and may be changed (from 8K to the maximum
kmalloc size allowed by your kernel) at module install time kmalloc size allowed by your kernel) at module install time
@ -333,10 +375,12 @@ A partial list of the supported mount options follows:
newer servers (e.g. Samba 3.0.26 or later) do. rsize can be newer servers (e.g. Samba 3.0.26 or later) do. rsize can be
set from a minimum of 2048 to a maximum of 130048 (127K or set from a minimum of 2048 to a maximum of 130048 (127K or
CIFSMaxBufSize, whichever is smaller) CIFSMaxBufSize, whichever is smaller)
wsize default write size (default 57344) wsize
default write size (default 57344)
maximum wsize currently allowed by CIFS is 57344 (fourteen maximum wsize currently allowed by CIFS is 57344 (fourteen
4096 byte pages) 4096 byte pages)
actimeo=n attribute cache timeout in seconds (default 1 second). actimeo=n
attribute cache timeout in seconds (default 1 second).
After this timeout, the cifs client requests fresh attribute After this timeout, the cifs client requests fresh attribute
information from the server. This option allows to tune the information from the server. This option allows to tune the
attribute cache timeout to suit the workload needs. Shorter attribute cache timeout to suit the workload needs. Shorter
@ -345,49 +389,67 @@ A partial list of the supported mount options follows:
of calls to the server at the expense of less stricter cache of calls to the server at the expense of less stricter cache
coherency checks (i.e. incorrect attribute cache for a short coherency checks (i.e. incorrect attribute cache for a short
period of time). period of time).
rw mount the network share read-write (note that the rw
mount the network share read-write (note that the
server may still consider the share read-only) server may still consider the share read-only)
ro mount network share read-only ro
version used to distinguish different versions of the mount network share read-only
version
used to distinguish different versions of the
mount helper utility (not typically needed) mount helper utility (not typically needed)
sep if first mount option (after the -o), overrides sep
if first mount option (after the -o), overrides
the comma as the separator between the mount the comma as the separator between the mount
parms. e.g. parms. e.g.::
-o user=myname,password=mypassword,domain=mydom -o user=myname,password=mypassword,domain=mydom
could be passed instead with period as the separator by
could be passed instead with period as the separator by::
-o sep=.user=myname.password=mypassword.domain=mydom -o sep=.user=myname.password=mypassword.domain=mydom
this might be useful when comma is contained within username this might be useful when comma is contained within username
or password or domain. This option is less important or password or domain. This option is less important
when the cifs mount helper cifs.mount (version 1.1 or later) when the cifs mount helper cifs.mount (version 1.1 or later)
is used. is used.
nosuid Do not allow remote executables with the suid bit nosuid
Do not allow remote executables with the suid bit
program to be executed. This is only meaningful for mounts program to be executed. This is only meaningful for mounts
to servers such as Samba which support the CIFS Unix Extensions. to servers such as Samba which support the CIFS Unix Extensions.
If you do not trust the servers in your network (your mount If you do not trust the servers in your network (your mount
targets) it is recommended that you specify this option for targets) it is recommended that you specify this option for
greater security. greater security.
exec Permit execution of binaries on the mount. exec
noexec Do not permit execution of binaries on the mount. Permit execution of binaries on the mount.
dev Recognize block devices on the remote mount. noexec
nodev Do not recognize devices on the remote mount. Do not permit execution of binaries on the mount.
suid Allow remote files on this mountpoint with suid enabled to dev
Recognize block devices on the remote mount.
nodev
Do not recognize devices on the remote mount.
suid
Allow remote files on this mountpoint with suid enabled to
be executed (default for mounts when executed as root, be executed (default for mounts when executed as root,
nosuid is default for user mounts). nosuid is default for user mounts).
credentials Although ignored by the cifs kernel component, it is used by credentials
Although ignored by the cifs kernel component, it is used by
the mount helper, mount.cifs. When mount.cifs is installed it the mount helper, mount.cifs. When mount.cifs is installed it
opens and reads the credential file specified in order opens and reads the credential file specified in order
to obtain the userid and password arguments which are passed to to obtain the userid and password arguments which are passed to
the cifs vfs. the cifs vfs.
guest Although ignored by the kernel component, the mount.cifs guest
Although ignored by the kernel component, the mount.cifs
mount helper will not prompt the user for a password mount helper will not prompt the user for a password
if guest is specified on the mount options. If no if guest is specified on the mount options. If no
password is specified a null password will be used. password is specified a null password will be used.
perm Client does permission checks (vfs_permission check of uid perm
Client does permission checks (vfs_permission check of uid
and gid of the file against the mode and desired operation), and gid of the file against the mode and desired operation),
Note that this is in addition to the normal ACL check on the Note that this is in addition to the normal ACL check on the
target machine done by the server software. target machine done by the server software.
Client permission checking is enabled by default. Client permission checking is enabled by default.
noperm Client does not do permission checks. This can expose noperm
Client does not do permission checks. This can expose
files on this mount to access by other users on the local files on this mount to access by other users on the local
client system. It is typically only needed when the server client system. It is typically only needed when the server
supports the CIFS Unix Extensions but the UIDs/GIDs on the supports the CIFS Unix Extensions but the UIDs/GIDs on the
@ -399,7 +461,8 @@ A partial list of the supported mount options follows:
Note that this does not affect the normal ACL check on the Note that this does not affect the normal ACL check on the
target machine done by the server software (of the server target machine done by the server software (of the server
ACL against the user name provided at mount time). ACL against the user name provided at mount time).
serverino Use server's inode numbers instead of generating automatically serverino
Use server's inode numbers instead of generating automatically
incrementing inode numbers on the client. Although this will incrementing inode numbers on the client. Although this will
make it easier to spot hardlinked files (as they will have make it easier to spot hardlinked files (as they will have
the same inode numbers) and inode numbers may be persistent, the same inode numbers) and inode numbers may be persistent,
@ -414,12 +477,14 @@ A partial list of the supported mount options follows:
under nfsd requires this mount option on the cifs mount. under nfsd requires this mount option on the cifs mount.
This is now the default if server supports the This is now the default if server supports the
required network operation. required network operation.
noserverino Client generates inode numbers (rather than using the actual one noserverino
Client generates inode numbers (rather than using the actual one
from the server). These inode numbers will vary after from the server). These inode numbers will vary after
unmount or reboot which can confuse some applications, unmount or reboot which can confuse some applications,
but not all server filesystems support unique inode but not all server filesystems support unique inode
numbers. numbers.
setuids If the CIFS Unix extensions are negotiated with the server setuids
If the CIFS Unix extensions are negotiated with the server
the client will attempt to set the effective uid and gid of the client will attempt to set the effective uid and gid of
the local process on newly created files, directories, and the local process on newly created files, directories, and
devices (create, mkdir, mknod). If the CIFS Unix Extensions devices (create, mkdir, mknod). If the CIFS Unix Extensions
@ -427,8 +492,9 @@ A partial list of the supported mount options follows:
instead of using the default uid and gid specified on instead of using the default uid and gid specified on
the mount, cache the new file's uid and gid locally which means the mount, cache the new file's uid and gid locally which means
that the uid for the file can change when the inode is that the uid for the file can change when the inode is
reloaded (or the user remounts the share). reloaded (or the user remounts the share).
nosetuids The client will not attempt to set the uid and gid on nosetuids
The client will not attempt to set the uid and gid on
on newly created files, directories, and devices (create, on newly created files, directories, and devices (create,
mkdir, mknod) which will result in the server setting the mkdir, mknod) which will result in the server setting the
uid and gid to the default (usually the server uid of the uid and gid to the default (usually the server uid of the
@ -437,10 +503,12 @@ A partial list of the supported mount options follows:
Unix Extensions are not negotiated then the uid and gid for Unix Extensions are not negotiated then the uid and gid for
new files will appear to be the uid (gid) of the mounter or the new files will appear to be the uid (gid) of the mounter or the
uid (gid) parameter specified on the mount. uid (gid) parameter specified on the mount.
netbiosname When mounting to servers via port 139, specifies the RFC1001 netbiosname
When mounting to servers via port 139, specifies the RFC1001
source name to use to represent the client netbios machine source name to use to represent the client netbios machine
name when doing the RFC1001 netbios session initialize. name when doing the RFC1001 netbios session initialize.
direct Do not do inode data caching on files opened on this mount. direct
Do not do inode data caching on files opened on this mount.
This precludes mmapping files on this mount. In some cases This precludes mmapping files on this mount. In some cases
with fast networks and little or no caching benefits on the with fast networks and little or no caching benefits on the
client (e.g. when the application is doing large sequential client (e.g. when the application is doing large sequential
@ -451,24 +519,33 @@ A partial list of the supported mount options follows:
if oplock (caching token) is granted and held. Note that if oplock (caching token) is granted and held. Note that
direct allows write operations larger than page size direct allows write operations larger than page size
to be sent to the server. to be sent to the server.
strictcache Use for switching on strict cache mode. In this mode the strictcache
Use for switching on strict cache mode. In this mode the
client read from the cache all the time it has Oplock Level II, client read from the cache all the time it has Oplock Level II,
otherwise - read from the server. All written data are stored otherwise - read from the server. All written data are stored
in the cache, but if the client doesn't have Exclusive Oplock, in the cache, but if the client doesn't have Exclusive Oplock,
it writes the data to the server. it writes the data to the server.
rwpidforward Forward pid of a process who opened a file to any read or write rwpidforward
Forward pid of a process who opened a file to any read or write
operation on that file. This prevent applications like WINE operation on that file. This prevent applications like WINE
from failing on read and write if we use mandatory brlock style. from failing on read and write if we use mandatory brlock style.
acl Allow setfacl and getfacl to manage posix ACLs if server acl
Allow setfacl and getfacl to manage posix ACLs if server
supports them. (default) supports them. (default)
noacl Do not allow setfacl and getfacl calls on this mount noacl
user_xattr Allow getting and setting user xattrs (those attributes whose Do not allow setfacl and getfacl calls on this mount
name begins with "user." or "os2.") as OS/2 EAs (extended user_xattr
Allow getting and setting user xattrs (those attributes whose
name begins with ``user.`` or ``os2.``) as OS/2 EAs (extended
attributes) to the server. This allows support of the attributes) to the server. This allows support of the
setfattr and getfattr utilities. (default) setfattr and getfattr utilities. (default)
nouser_xattr Do not allow getfattr/setfattr to get/set/list xattrs nouser_xattr
mapchars Translate six of the seven reserved characters (not backslash) Do not allow getfattr/setfattr to get/set/list xattrs
mapchars
Translate six of the seven reserved characters (not backslash)::
*?<>|: *?<>|:
to the remap range (above 0xF000), which also to the remap range (above 0xF000), which also
allows the CIFS client to recognize files created with allows the CIFS client to recognize files created with
such characters by Windows's POSIX emulation. This can such characters by Windows's POSIX emulation. This can
@ -477,39 +554,47 @@ A partial list of the supported mount options follows:
whose names contain any of these seven characters). whose names contain any of these seven characters).
This has no effect if the server does not support This has no effect if the server does not support
Unicode on the wire. Unicode on the wire.
nomapchars Do not translate any of these seven characters (default). nomapchars
nocase Request case insensitive path name matching (case Do not translate any of these seven characters (default).
nocase
Request case insensitive path name matching (case
sensitive is the default if the server supports it). sensitive is the default if the server supports it).
(mount option "ignorecase" is identical to "nocase") (mount option ``ignorecase`` is identical to ``nocase``)
posixpaths If CIFS Unix extensions are supported, attempt to posixpaths
If CIFS Unix extensions are supported, attempt to
negotiate posix path name support which allows certain negotiate posix path name support which allows certain
characters forbidden in typical CIFS filenames, without characters forbidden in typical CIFS filenames, without
requiring remapping. (default) requiring remapping. (default)
noposixpaths If CIFS Unix extensions are supported, do not request noposixpaths
If CIFS Unix extensions are supported, do not request
posix path name support (this may cause servers to posix path name support (this may cause servers to
reject creatingfile with certain reserved characters). reject creatingfile with certain reserved characters).
nounix Disable the CIFS Unix Extensions for this mount (tree nounix
Disable the CIFS Unix Extensions for this mount (tree
connection). This is rarely needed, but it may be useful connection). This is rarely needed, but it may be useful
in order to turn off multiple settings all at once (ie in order to turn off multiple settings all at once (ie
posix acls, posix locks, posix paths, symlink support posix acls, posix locks, posix paths, symlink support
and retrieving uids/gids/mode from the server) or to and retrieving uids/gids/mode from the server) or to
work around a bug in server which implement the Unix work around a bug in server which implement the Unix
Extensions. Extensions.
nobrl Do not send byte range lock requests to the server. nobrl
Do not send byte range lock requests to the server.
This is necessary for certain applications that break This is necessary for certain applications that break
with cifs style mandatory byte range locks (and most with cifs style mandatory byte range locks (and most
cifs servers do not yet support requesting advisory cifs servers do not yet support requesting advisory
byte range locks). byte range locks).
forcemandatorylock Even if the server supports posix (advisory) byte range forcemandatorylock
Even if the server supports posix (advisory) byte range
locking, send only mandatory lock requests. For some locking, send only mandatory lock requests. For some
(presumably rare) applications, originally coded for (presumably rare) applications, originally coded for
DOS/Windows, which require Windows style mandatory byte range DOS/Windows, which require Windows style mandatory byte range
locking, they may be able to take advantage of this option, locking, they may be able to take advantage of this option,
forcing the cifs client to only send mandatory locks forcing the cifs client to only send mandatory locks
even if the cifs server would support posix advisory locks. even if the cifs server would support posix advisory locks.
"forcemand" is accepted as a shorter form of this mount ``forcemand`` is accepted as a shorter form of this mount
option. option.
nostrictsync If this mount option is set, when an application does an nostrictsync
If this mount option is set, when an application does an
fsync call then the cifs client does not send an SMB Flush fsync call then the cifs client does not send an SMB Flush
to the server (to force the server to write all dirty data to the server (to force the server to write all dirty data
for this file immediately to disk), although cifs still sends for this file immediately to disk), although cifs still sends
@ -522,41 +607,50 @@ A partial list of the supported mount options follows:
crash. If this mount option is not set, by default cifs will crash. If this mount option is not set, by default cifs will
send an SMB flush request (and wait for a response) on every send an SMB flush request (and wait for a response) on every
fsync call. fsync call.
nodfs Disable DFS (global name space support) even if the nodfs
Disable DFS (global name space support) even if the
server claims to support it. This can help work around server claims to support it. This can help work around
a problem with parsing of DFS paths with Samba server a problem with parsing of DFS paths with Samba server
versions 3.0.24 and 3.0.25. versions 3.0.24 and 3.0.25.
remount remount the share (often used to change from ro to rw mounts remount
or vice versa) remount the share (often used to change from ro to rw mounts
cifsacl Report mode bits (e.g. on stat) based on the Windows ACL for or vice versa)
the file. (EXPERIMENTAL) cifsacl
servern Specify the server 's netbios name (RFC1001 name) to use Report mode bits (e.g. on stat) based on the Windows ACL for
the file. (EXPERIMENTAL)
servern
Specify the server 's netbios name (RFC1001 name) to use
when attempting to setup a session to the server. when attempting to setup a session to the server.
This is needed for mounting to some older servers (such This is needed for mounting to some older servers (such
as OS/2 or Windows 98 and Windows ME) since they do not as OS/2 or Windows 98 and Windows ME) since they do not
support a default server name. A server name can be up support a default server name. A server name can be up
to 15 characters long and is usually uppercased. to 15 characters long and is usually uppercased.
sfu When the CIFS Unix Extensions are not negotiated, attempt to sfu
When the CIFS Unix Extensions are not negotiated, attempt to
create device files and fifos in a format compatible with create device files and fifos in a format compatible with
Services for Unix (SFU). In addition retrieve bits 10-12 Services for Unix (SFU). In addition retrieve bits 10-12
of the mode via the SETFILEBITS extended attribute (as of the mode via the SETFILEBITS extended attribute (as
SFU does). In the future the bottom 9 bits of the SFU does). In the future the bottom 9 bits of the
mode also will be emulated using queries of the security mode also will be emulated using queries of the security
descriptor (ACL). descriptor (ACL).
mfsymlinks Enable support for Minshall+French symlinks mfsymlinks
Enable support for Minshall+French symlinks
(see http://wiki.samba.org/index.php/UNIX_Extensions#Minshall.2BFrench_symlinks) (see http://wiki.samba.org/index.php/UNIX_Extensions#Minshall.2BFrench_symlinks)
This option is ignored when specified together with the This option is ignored when specified together with the
'sfu' option. Minshall+French symlinks are used even if 'sfu' option. Minshall+French symlinks are used even if
the server supports the CIFS Unix Extensions. the server supports the CIFS Unix Extensions.
sign Must use packet signing (helps avoid unwanted data modification sign
Must use packet signing (helps avoid unwanted data modification
by intermediate systems in the route). Note that signing by intermediate systems in the route). Note that signing
does not work with lanman or plaintext authentication. does not work with lanman or plaintext authentication.
seal Must seal (encrypt) all data on this mounted share before seal
Must seal (encrypt) all data on this mounted share before
sending on the network. Requires support for Unix Extensions. sending on the network. Requires support for Unix Extensions.
Note that this differs from the sign mount option in that it Note that this differs from the sign mount option in that it
causes encryption of data sent over this mounted share but other causes encryption of data sent over this mounted share but other
shares mounted to the same server are unaffected. shares mounted to the same server are unaffected.
locallease This option is rarely needed. Fcntl F_SETLEASE is locallease
This option is rarely needed. Fcntl F_SETLEASE is
used by some applications such as Samba and NFSv4 server to used by some applications such as Samba and NFSv4 server to
check to see whether a file is cacheable. CIFS has no way check to see whether a file is cacheable. CIFS has no way
to explicitly request a lease, but can check whether a file to explicitly request a lease, but can check whether a file
@ -569,50 +663,72 @@ A partial list of the supported mount options follows:
will allow the cifs client to check for leases (only) locally will allow the cifs client to check for leases (only) locally
for files which are not oplocked instead of denying leases for files which are not oplocked instead of denying leases
in that case. (EXPERIMENTAL) in that case. (EXPERIMENTAL)
sec Security mode. Allowed values are: sec
none attempt to connection as a null user (no name) Security mode. Allowed values are:
krb5 Use Kerberos version 5 authentication
krb5i Use Kerberos authentication and packet signing none
ntlm Use NTLM password hashing (default) attempt to connection as a null user (no name)
ntlmi Use NTLM password hashing with signing (if krb5
Use Kerberos version 5 authentication
krb5i
Use Kerberos authentication and packet signing
ntlm
Use NTLM password hashing (default)
ntlmi
Use NTLM password hashing with signing (if
/proc/fs/cifs/PacketSigningEnabled on or if /proc/fs/cifs/PacketSigningEnabled on or if
server requires signing also can be the default) server requires signing also can be the default)
ntlmv2 Use NTLMv2 password hashing ntlmv2
ntlmv2i Use NTLMv2 password hashing with packet signing Use NTLMv2 password hashing
lanman (if configured in kernel config) use older ntlmv2i
Use NTLMv2 password hashing with packet signing
lanman
(if configured in kernel config) use older
lanman hash lanman hash
hard Retry file operations if server is not responding hard
soft Limit retries to unresponsive servers (usually only Retry file operations if server is not responding
soft
Limit retries to unresponsive servers (usually only
one retry) before returning an error. (default) one retry) before returning an error. (default)
The mount.cifs mount helper also accepts a few mount options before -o The mount.cifs mount helper also accepts a few mount options before -o
including: including:
=============== ===============================================================
-S take password from stdin (equivalent to setting the environment -S take password from stdin (equivalent to setting the environment
variable "PASSWD_FD=0" variable ``PASSWD_FD=0``
-V print mount.cifs version -V print mount.cifs version
-? display simple usage information -? display simple usage information
=============== ===============================================================
With most 2.6 kernel versions of modutils, the version of the cifs kernel With most 2.6 kernel versions of modutils, the version of the cifs kernel
module can be displayed via modinfo. module can be displayed via modinfo.
Misc /proc/fs/cifs Flags and Debug Info Misc /proc/fs/cifs Flags and Debug Info
======================================= =======================================
Informational pseudo-files: Informational pseudo-files:
======================= =======================================================
DebugData Displays information about active CIFS sessions and DebugData Displays information about active CIFS sessions and
shares, features enabled as well as the cifs.ko shares, features enabled as well as the cifs.ko
version. version.
Stats Lists summary resource usage information as well as per Stats Lists summary resource usage information as well as per
share statistics. share statistics.
======================= =======================================================
Configuration pseudo-files: Configuration pseudo-files:
======================= =======================================================
SecurityFlags Flags which control security negotiation and SecurityFlags Flags which control security negotiation and
also packet signing. Authentication (may/must) also packet signing. Authentication (may/must)
flags (e.g. for NTLM and/or NTLMv2) may be combined with flags (e.g. for NTLM and/or NTLMv2) may be combined with
the signing flags. Specifying two different password the signing flags. Specifying two different password
hashing mechanisms (as "must use") on the other hand hashing mechanisms (as "must use") on the other hand
does not make much sense. Default flags are does not make much sense. Default flags are::
0x07007 0x07007
(NTLM, NTLMv2 and packet signing allowed). The maximum (NTLM, NTLMv2 and packet signing allowed). The maximum
allowable flags if you want to allow mounts to servers allowable flags if you want to allow mounts to servers
using weaker password hashes is 0x37037 (lanman, using weaker password hashes is 0x37037 (lanman,
@ -626,21 +742,21 @@ SecurityFlags Flags which control security negotiation and
laintext passwords using the older lanman dialect laintext passwords using the older lanman dialect
form of the session setup SMB. (e.g. for authentication form of the session setup SMB. (e.g. for authentication
using plain text passwords, set the SecurityFlags using plain text passwords, set the SecurityFlags
to 0x30030): to 0x30030)::
may use packet signing 0x00001 may use packet signing 0x00001
must use packet signing 0x01001 must use packet signing 0x01001
may use NTLM (most common password hash) 0x00002 may use NTLM (most common password hash) 0x00002
must use NTLM 0x02002 must use NTLM 0x02002
may use NTLMv2 0x00004 may use NTLMv2 0x00004
must use NTLMv2 0x04004 must use NTLMv2 0x04004
may use Kerberos security 0x00008 may use Kerberos security 0x00008
must use Kerberos 0x08008 must use Kerberos 0x08008
may use lanman (weak) password hash 0x00010 may use lanman (weak) password hash 0x00010
must use lanman password hash 0x10010 must use lanman password hash 0x10010
may use plaintext passwords 0x00020 may use plaintext passwords 0x00020
must use plaintext passwords 0x20020 must use plaintext passwords 0x20020
(reserved for future packet encryption) 0x00040 (reserved for future packet encryption) 0x00040
cifsFYI If set to non-zero value, additional debug information cifsFYI If set to non-zero value, additional debug information
will be logged to the system error log. This field will be logged to the system error log. This field
@ -650,13 +766,18 @@ cifsFYI If set to non-zero value, additional debug information
Some debugging statements are not compiled into the Some debugging statements are not compiled into the
cifs kernel unless CONFIG_CIFS_DEBUG2 is enabled in the cifs kernel unless CONFIG_CIFS_DEBUG2 is enabled in the
kernel configuration. cifsFYI may be set to one or kernel configuration. cifsFYI may be set to one or
nore of the following flags (7 sets them all): nore of the following flags (7 sets them all)::
log cifs informational messages 0x01
log return codes from cifs entry points 0x02
log slow responses (ie which take longer than 1 second)
CONFIG_CIFS_STATS2 must be enabled in .config 0x04
+-----------------------------------------------+------+
| log cifs informational messages | 0x01 |
+-----------------------------------------------+------+
| log return codes from cifs entry points | 0x02 |
+-----------------------------------------------+------+
| log slow responses | 0x04 |
| (ie which take longer than 1 second) | |
| | |
| CONFIG_CIFS_STATS2 must be enabled in .config | |
+-----------------------------------------------+------+
traceSMB If set to one, debug information is logged to the traceSMB If set to one, debug information is logged to the
system error log with the start of smb requests system error log with the start of smb requests
@ -674,11 +795,12 @@ LinuxExtensionsEnabled If set to one then the client will attempt to
support and want to map the uid and gid fields support and want to map the uid and gid fields
to values supplied at mount (rather than the to values supplied at mount (rather than the
actual values, then set this to zero. (default 1) actual values, then set this to zero. (default 1)
======================= =======================================================
These experimental features and tracing can be enabled by changing flags in These experimental features and tracing can be enabled by changing flags in
/proc/fs/cifs (after the cifs module has been installed or built into the /proc/fs/cifs (after the cifs module has been installed or built into the
kernel, e.g. insmod cifs). To enable a feature set it to 1 e.g. to enable kernel, e.g. insmod cifs). To enable a feature set it to 1 e.g. to enable
tracing to the kernel message log type: tracing to the kernel message log type::
echo 7 > /proc/fs/cifs/cifsFYI echo 7 > /proc/fs/cifs/cifsFYI
@ -688,7 +810,7 @@ SMB return codes while 4 enables logging of requests that take longer
than one second to complete (except for byte range lock requests). than one second to complete (except for byte range lock requests).
Setting it to 4 requires CONFIG_CIFS_STATS2 to be set in kernel configuration Setting it to 4 requires CONFIG_CIFS_STATS2 to be set in kernel configuration
(.config). Setting it to seven enables all three. Finally, tracing (.config). Setting it to seven enables all three. Finally, tracing
the start of smb requests and responses can be enabled via: the start of smb requests and responses can be enabled via::
echo 1 > /proc/fs/cifs/traceSMB echo 1 > /proc/fs/cifs/traceSMB
@ -700,10 +822,10 @@ server) SMB3 (or cifs) requests grouped by request type (read, write, close etc.
Also recorded is the total bytes read and bytes written to the server for Also recorded is the total bytes read and bytes written to the server for
that share. Note that due to client caching effects this can be less than the that share. Note that due to client caching effects this can be less than the
number of bytes read and written by the application running on the client. number of bytes read and written by the application running on the client.
Statistics can be reset to zero by "echo 0 > /proc/fs/cifs/Stats" which may be Statistics can be reset to zero by ``echo 0 > /proc/fs/cifs/Stats`` which may be
useful if comparing performance of two different scenarios. useful if comparing performance of two different scenarios.
Also note that "cat /proc/fs/cifs/DebugData" will display information about Also note that ``cat /proc/fs/cifs/DebugData`` will display information about
the active sessions and the shares that are mounted. the active sessions and the shares that are mounted.
Enabling Kerberos (extended security) works but requires version 1.2 or later Enabling Kerberos (extended security) works but requires version 1.2 or later
@ -725,19 +847,23 @@ space to ease network configuration and improve reliability.
To use cifs Kerberos and DFS support, the Linux keyutils package should be To use cifs Kerberos and DFS support, the Linux keyutils package should be
installed and something like the following lines should be added to the installed and something like the following lines should be added to the
/etc/request-key.conf file: /etc/request-key.conf file::
create cifs.spnego * * /usr/local/sbin/cifs.upcall %k create cifs.spnego * * /usr/local/sbin/cifs.upcall %k
create dns_resolver * * /usr/local/sbin/cifs.upcall %k create dns_resolver * * /usr/local/sbin/cifs.upcall %k
CIFS kernel module parameters CIFS kernel module parameters
============================= =============================
These module parameters can be specified or modified either during the time of These module parameters can be specified or modified either during the time of
module loading or during the runtime by using the interface module loading or during the runtime by using the interface::
/proc/module/cifs/parameters/<param> /proc/module/cifs/parameters/<param>
i.e. echo "value" > /sys/module/cifs/parameters/<param> i.e.::
1. enable_oplocks - Enable or disable oplocks. Oplocks are enabled by default. echo "value" > /sys/module/cifs/parameters/<param>
[Y/y/1]. To disable use any of [N/n/0].
================= ==========================================================
1. enable_oplocks Enable or disable oplocks. Oplocks are enabled by default.
[Y/y/1]. To disable use any of [N/n/0].
================= ==========================================================

View File

@ -77,6 +77,7 @@ configure specific aspects of kernel behavior to your liking.
blockdev/index blockdev/index
ext4 ext4
binderfs binderfs
cifs/index
xfs xfs
jfs jfs
ufs ufs

View File

@ -4099,7 +4099,7 @@ L: samba-technical@lists.samba.org (moderated for non-subscribers)
W: http://linux-cifs.samba.org/ W: http://linux-cifs.samba.org/
T: git git://git.samba.org/sfrench/cifs-2.6.git T: git git://git.samba.org/sfrench/cifs-2.6.git
S: Supported S: Supported
F: Documentation/filesystems/cifs/ F: Documentation/admin-guide/cifs/
F: fs/cifs/ F: fs/cifs/
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