- Add a SPDX header; - Adjust document title; - Some whitespace fixes and new line breaks; - Add it to filesystems/index.rst. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx> --- Documentation/admin-guide/ext4.rst | 2 +- Documentation/filesystems/{dax.txt => dax.rst} | 9 +++++++-- Documentation/filesystems/ext2.rst | 2 +- Documentation/filesystems/index.rst | 1 + 4 files changed, 10 insertions(+), 4 deletions(-) rename Documentation/filesystems/{dax.txt => dax.rst} (97%) diff --git a/Documentation/admin-guide/ext4.rst b/Documentation/admin-guide/ext4.rst index 9443fcef1876..103bcc345bad 100644 --- a/Documentation/admin-guide/ext4.rst +++ b/Documentation/admin-guide/ext4.rst @@ -392,7 +392,7 @@ When mounting an ext4 filesystem, the following option are accepted: dax Use direct access (no page cache). See - Documentation/filesystems/dax.txt. Note that this option is + Documentation/filesystems/dax.rst. Note that this option is incompatible with data=journal. Data Mode diff --git a/Documentation/filesystems/dax.txt b/Documentation/filesystems/dax.rst similarity index 97% rename from Documentation/filesystems/dax.txt rename to Documentation/filesystems/dax.rst index 735f3859b19f..5838144f80f0 100644 --- a/Documentation/filesystems/dax.txt +++ b/Documentation/filesystems/dax.rst @@ -1,5 +1,8 @@ +.. SPDX-License-Identifier: GPL-2.0 + +======================= Direct Access for files ------------------------ +======================= Motivation ---------- @@ -46,6 +49,7 @@ stall the CPU for an extended period, you should also not attempt to implement direct_access. These block devices may be used for inspiration: + - brd: RAM backed block device driver - dcssblk: s390 dcss block device driver - pmem: NVDIMM persistent memory driver @@ -55,6 +59,7 @@ Implementation Tips for Filesystem Writers ------------------------------------------ Filesystem support consists of + - adding support to mark inodes as being DAX by setting the S_DAX flag in i_flags - implementing ->read_iter and ->write_iter operations which use dax_iomap_rw() @@ -127,6 +132,6 @@ by adding optional struct page support for pages under the control of the driver (see CONFIG_NVDIMM_PFN in drivers/nvdimm for an example of how to do this). In the non struct page cases O_DIRECT reads/writes to those memory ranges from a non-DAX file will fail (note that O_DIRECT -reads/writes _of a DAX file_ do work, it is the memory that is being +reads/writes _of a DAX ``file_`` do work, it is the memory that is being accessed that is key here). Other things that will not work in the non struct page case include RDMA, sendfile() and splice(). diff --git a/Documentation/filesystems/ext2.rst b/Documentation/filesystems/ext2.rst index d83dbbb162e2..fa416b7a5802 100644 --- a/Documentation/filesystems/ext2.rst +++ b/Documentation/filesystems/ext2.rst @@ -24,7 +24,7 @@ check=none, nocheck (*) Don't do extra checking of bitmaps on mount (check=normal and check=strict options removed) dax Use direct access (no page cache). See - Documentation/filesystems/dax.txt. + Documentation/filesystems/dax.rst. debug Extra debugging information is sent to the kernel syslog. Useful for developers. diff --git a/Documentation/filesystems/index.rst b/Documentation/filesystems/index.rst index c4f95f76ba6a..8e3ccb4ed483 100644 --- a/Documentation/filesystems/index.rst +++ b/Documentation/filesystems/index.rst @@ -24,6 +24,7 @@ algorithms work. splice locking directory-locking + dax automount-support -- 2.25.2