diff options
Diffstat (limited to 'Documentation/filesystems')
| -rw-r--r-- | Documentation/filesystems/overlayfs.rst | 7 | ||||
| -rw-r--r-- | Documentation/filesystems/porting.rst | 9 | ||||
| -rw-r--r-- | Documentation/filesystems/proc.rst | 4 | ||||
| -rw-r--r-- | Documentation/filesystems/smb/index.rst | 1 | ||||
| -rw-r--r-- | Documentation/filesystems/smb/smbdirect.rst | 103 |
5 files changed, 123 insertions, 1 deletions
diff --git a/Documentation/filesystems/overlayfs.rst b/Documentation/filesystems/overlayfs.rst index 2db379b4b31e..4133a336486d 100644 --- a/Documentation/filesystems/overlayfs.rst +++ b/Documentation/filesystems/overlayfs.rst @@ -443,6 +443,13 @@ Only the data of the files in the "data-only" lower layers may be visible when a "metacopy" file in one of the lower layers above it, has a "redirect" to the absolute path of the "lower data" file in the "data-only" lower layer. +Instead of explicitly enabling "metacopy=on" it is sufficient to specify at +least one data-only layer to enable redirection of data to a data-only layer. +In this case other forms of metacopy are rejected. Note: this way data-only +layers may be used toghether with "userxattr", in which case careful attention +must be given to privileges needed to change the "user.overlay.redirect" xattr +to prevent misuse. + Since kernel version v6.8, "data-only" lower layers can also be added using the "datadir+" mount options and the fsconfig syscall from new mount api. For example:: diff --git a/Documentation/filesystems/porting.rst b/Documentation/filesystems/porting.rst index 3616d7161dab..a5734bdd1cc7 100644 --- a/Documentation/filesystems/porting.rst +++ b/Documentation/filesystems/porting.rst @@ -1249,3 +1249,12 @@ Using try_lookup_noperm() will require linux/namei.h to be included. Calling conventions for ->d_automount() have changed; we should *not* grab an extra reference to new mount - it should be returned with refcount 1. + +--- + +collect_mounts()/drop_collected_mounts()/iterate_mounts() are gone now. +Replacement is collect_paths()/drop_collected_path(), with no special +iterator needed. Instead of a cloned mount tree, the new interface returns +an array of struct path, one for each mount collect_mounts() would've +created. These struct path point to locations in the caller's namespace +that would be roots of the cloned mounts. diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst index 2a17865dfe39..5236cb52e357 100644 --- a/Documentation/filesystems/proc.rst +++ b/Documentation/filesystems/proc.rst @@ -584,7 +584,6 @@ encoded manner. The codes are the following: ms may share gd stack segment growns down pf pure PFN range - dw disabled write to the mapped file lo pages are locked in memory io memory mapped I/O area sr sequential read advise provided @@ -607,8 +606,11 @@ encoded manner. The codes are the following: mt arm64 MTE allocation tags are enabled um userfaultfd missing tracking uw userfaultfd wr-protect tracking + ui userfaultfd minor fault ss shadow/guarded control stack page sl sealed + lf lock on fault pages + dp always lazily freeable mapping == ======================================= Note that there is no guarantee that every flag and associated mnemonic will diff --git a/Documentation/filesystems/smb/index.rst b/Documentation/filesystems/smb/index.rst index 1c8597a679ab..6df23b0e45c8 100644 --- a/Documentation/filesystems/smb/index.rst +++ b/Documentation/filesystems/smb/index.rst @@ -8,3 +8,4 @@ CIFS ksmbd cifsroot + smbdirect diff --git a/Documentation/filesystems/smb/smbdirect.rst b/Documentation/filesystems/smb/smbdirect.rst new file mode 100644 index 000000000000..ca6927c0b2c0 --- /dev/null +++ b/Documentation/filesystems/smb/smbdirect.rst @@ -0,0 +1,103 @@ +.. SPDX-License-Identifier: GPL-2.0 + +=========================== +SMB Direct - SMB3 over RDMA +=========================== + +This document describes how to set up the Linux SMB client and server to +use RDMA. + +Overview +======== +The Linux SMB kernel client supports SMB Direct, which is a transport +scheme for SMB3 that uses RDMA (Remote Direct Memory Access) to provide +high throughput and low latencies by bypassing the traditional TCP/IP +stack. +SMB Direct on the Linux SMB client can be tested against KSMBD - a +kernel-space SMB server. + +Installation +============= +- Install an RDMA device. As long as the RDMA device driver is supported + by the kernel, it should work. This includes both software emulators (soft + RoCE, soft iWARP) and hardware devices (InfiniBand, RoCE, iWARP). + +- Install a kernel with SMB Direct support. The first kernel release to + support SMB Direct on both the client and server side is 5.15. Therefore, + a distribution compatible with kernel 5.15 or later is required. + +- Install cifs-utils, which provides the `mount.cifs` command to mount SMB + shares. + +- Configure the RDMA stack + + Make sure that your kernel configuration has RDMA support enabled. Under + Device Drivers -> Infiniband support, update the kernel configuration to + enable Infiniband support. + + Enable the appropriate IB HCA support or iWARP adapter support, + depending on your hardware. + + If you are using InfiniBand, enable IP-over-InfiniBand support. + + For soft RDMA, enable either the soft iWARP (`RDMA _SIW`) or soft RoCE + (`RDMA_RXE`) module. Install the `iproute2` package and use the + `rdma link add` command to load the module and create an + RDMA interface. + + e.g. if your local ethernet interface is `eth0`, you can use: + + .. code-block:: bash + + sudo rdma link add siw0 type siw netdev eth0 + +- Enable SMB Direct support for both the server and the client in the kernel + configuration. + + Server Setup + + .. code-block:: text + + Network File Systems ---> + <M> SMB3 server support + [*] Support for SMB Direct protocol + + Client Setup + + .. code-block:: text + + Network File Systems ---> + <M> SMB3 and CIFS support (advanced network filesystem) + [*] SMB Direct support + +- Build and install the kernel. SMB Direct support will be enabled in the + cifs.ko and ksmbd.ko modules. + +Setup and Usage +================ + +- Set up and start a KSMBD server as described in the `KSMBD documentation + <https://www.kernel.org/doc/Documentation/filesystems/smb/ksmbd.rst>`_. + Also add the "server multi channel support = yes" parameter to ksmbd.conf. + +- On the client, mount the share with `rdma` mount option to use SMB Direct + (specify a SMB version 3.0 or higher using `vers`). + + For example: + + .. code-block:: bash + + mount -t cifs //server/share /mnt/point -o vers=3.1.1,rdma + +- To verify that the mount is using SMB Direct, you can check dmesg for the + following log line after mounting: + + .. code-block:: text + + CIFS: VFS: RDMA transport established + + Or, verify `rdma` mount option for the share in `/proc/mounts`: + + .. code-block:: bash + + cat /proc/mounts | grep cifs |