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authorMauro Carvalho Chehab <mchehab+huawei@kernel.org>2020-02-17 19:12:17 +0300
committerJonathan Corbet <corbet@lwn.net>2020-03-03 00:04:40 +0300
commit18ccb2233fc5f7c27b5be17f5b6585c2fa62d919 (patch)
tree67b84fa64cdd361263974eda0073d30535b9c680 /Documentation/filesystems
parent7cbb468f0c70878fe64d324790ee049c1881af7c (diff)
downloadlinux-18ccb2233fc5f7c27b5be17f5b6585c2fa62d919.tar.xz
docs: filesystems: convert orangefs.txt to ReST
- Add a SPDX header; - Adjust document and section titles; - Some whitespace fixes and new line breaks; - Mark literal blocks as such; - Add it to filesystems/index.rst. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/6f438eeff5b029d229197a602bd9b74004fe9b63.1581955849.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Diffstat (limited to 'Documentation/filesystems')
-rw-r--r--Documentation/filesystems/index.rst1
-rw-r--r--Documentation/filesystems/orangefs.rst (renamed from Documentation/filesystems/orangefs.txt)187
2 files changed, 107 insertions, 81 deletions
diff --git a/Documentation/filesystems/index.rst b/Documentation/filesystems/index.rst
index fbee77175840..fed53f831192 100644
--- a/Documentation/filesystems/index.rst
+++ b/Documentation/filesystems/index.rst
@@ -79,6 +79,7 @@ Documentation for filesystem implementations.
ocfs2
ocfs2-online-filecheck
omfs
+ orangefs
overlayfs
virtiofs
vfat
diff --git a/Documentation/filesystems/orangefs.txt b/Documentation/filesystems/orangefs.rst
index f4ba94950e3f..7d6d4cad73c4 100644
--- a/Documentation/filesystems/orangefs.txt
+++ b/Documentation/filesystems/orangefs.rst
@@ -1,3 +1,6 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+========
ORANGEFS
========
@@ -21,25 +24,25 @@ Orangefs features include:
* Stateless
-MAILING LIST ARCHIVES
+Mailing List Archives
=====================
http://lists.orangefs.org/pipermail/devel_lists.orangefs.org/
-MAILING LIST SUBMISSIONS
+Mailing List Submissions
========================
devel@lists.orangefs.org
-DOCUMENTATION
+Documentation
=============
http://www.orangefs.org/documentation/
-USERSPACE FILESYSTEM SOURCE
+Userspace Filesystem Source
===========================
http://www.orangefs.org/download
@@ -48,16 +51,16 @@ Orangefs versions prior to 2.9.3 would not be compatible with the
upstream version of the kernel client.
-RUNNING ORANGEFS ON A SINGLE SERVER
+Running ORANGEFS On a Single Server
===================================
OrangeFS is usually run in large installations with multiple servers and
clients, but a complete filesystem can be run on a single machine for
development and testing.
-On Fedora, install orangefs and orangefs-server.
+On Fedora, install orangefs and orangefs-server::
-dnf -y install orangefs orangefs-server
+ dnf -y install orangefs orangefs-server
There is an example server configuration file in
/etc/orangefs/orangefs.conf. Change localhost to your hostname if
@@ -70,29 +73,29 @@ single line. Uncomment it and change the hostname if necessary. This
controls clients which use libpvfs2. This does not control the
pvfs2-client-core.
-Create the filesystem.
+Create the filesystem::
-pvfs2-server -f /etc/orangefs/orangefs.conf
+ pvfs2-server -f /etc/orangefs/orangefs.conf
-Start the server.
+Start the server::
-systemctl start orangefs-server
+ systemctl start orangefs-server
-Test the server.
+Test the server::
-pvfs2-ping -m /pvfsmnt
+ pvfs2-ping -m /pvfsmnt
Start the client. The module must be compiled in or loaded before this
-point.
+point::
-systemctl start orangefs-client
+ systemctl start orangefs-client
-Mount the filesystem.
+Mount the filesystem::
-mount -t pvfs2 tcp://localhost:3334/orangefs /pvfsmnt
+ mount -t pvfs2 tcp://localhost:3334/orangefs /pvfsmnt
-BUILDING ORANGEFS ON A SINGLE SERVER
+Building ORANGEFS on a Single Server
====================================
Where OrangeFS cannot be installed from distribution packages, it may be
@@ -102,49 +105,51 @@ You can omit --prefix if you don't care that things are sprinkled around
in /usr/local. As of version 2.9.6, OrangeFS uses Berkeley DB by
default, we will probably be changing the default to LMDB soon.
-./configure --prefix=/opt/ofs --with-db-backend=lmdb
+::
-make
+ ./configure --prefix=/opt/ofs --with-db-backend=lmdb
-make install
+ make
-Create an orangefs config file.
+ make install
-/opt/ofs/bin/pvfs2-genconfig /etc/pvfs2.conf
+Create an orangefs config file::
-Create an /etc/pvfs2tab file.
+ /opt/ofs/bin/pvfs2-genconfig /etc/pvfs2.conf
-echo tcp://localhost:3334/orangefs /pvfsmnt pvfs2 defaults,noauto 0 0 > \
- /etc/pvfs2tab
+Create an /etc/pvfs2tab file::
-Create the mount point you specified in the tab file if needed.
+ echo tcp://localhost:3334/orangefs /pvfsmnt pvfs2 defaults,noauto 0 0 > \
+ /etc/pvfs2tab
-mkdir /pvfsmnt
+Create the mount point you specified in the tab file if needed::
-Bootstrap the server.
+ mkdir /pvfsmnt
-/opt/ofs/sbin/pvfs2-server -f /etc/pvfs2.conf
+Bootstrap the server::
-Start the server.
+ /opt/ofs/sbin/pvfs2-server -f /etc/pvfs2.conf
-/opt/osf/sbin/pvfs2-server /etc/pvfs2.conf
+Start the server::
+
+ /opt/osf/sbin/pvfs2-server /etc/pvfs2.conf
Now the server should be running. Pvfs2-ls is a simple
-test to verify that the server is running.
+test to verify that the server is running::
-/opt/ofs/bin/pvfs2-ls /pvfsmnt
+ /opt/ofs/bin/pvfs2-ls /pvfsmnt
If stuff seems to be working, load the kernel module and
-turn on the client core.
+turn on the client core::
-/opt/ofs/sbin/pvfs2-client -p /opt/osf/sbin/pvfs2-client-core
+ /opt/ofs/sbin/pvfs2-client -p /opt/osf/sbin/pvfs2-client-core
-Mount your filesystem.
+Mount your filesystem::
-mount -t pvfs2 tcp://localhost:3334/orangefs /pvfsmnt
+ mount -t pvfs2 tcp://localhost:3334/orangefs /pvfsmnt
-RUNNING XFSTESTS
+Running xfstests
================
It is useful to use a scratch filesystem with xfstests. This can be
@@ -159,21 +164,23 @@ Then there are two FileSystem sections: orangefs and scratch.
This change should be made before creating the filesystem.
-pvfs2-server -f /etc/orangefs/orangefs.conf
+::
+
+ pvfs2-server -f /etc/orangefs/orangefs.conf
-To run xfstests, create /etc/xfsqa.config.
+To run xfstests, create /etc/xfsqa.config::
-TEST_DIR=/orangefs
-TEST_DEV=tcp://localhost:3334/orangefs
-SCRATCH_MNT=/scratch
-SCRATCH_DEV=tcp://localhost:3334/scratch
+ TEST_DIR=/orangefs
+ TEST_DEV=tcp://localhost:3334/orangefs
+ SCRATCH_MNT=/scratch
+ SCRATCH_DEV=tcp://localhost:3334/scratch
-Then xfstests can be run
+Then xfstests can be run::
-./check -pvfs2
+ ./check -pvfs2
-OPTIONS
+Options
=======
The following mount options are accepted:
@@ -193,32 +200,32 @@ The following mount options are accepted:
Distributed locking is being worked on for the future.
-DEBUGGING
+Debugging
=========
If you want the debug (GOSSIP) statements in a particular
-source file (inode.c for example) go to syslog:
+source file (inode.c for example) go to syslog::
echo inode > /sys/kernel/debug/orangefs/kernel-debug
-No debugging (the default):
+No debugging (the default)::
echo none > /sys/kernel/debug/orangefs/kernel-debug
-Debugging from several source files:
+Debugging from several source files::
echo inode,dir > /sys/kernel/debug/orangefs/kernel-debug
-All debugging:
+All debugging::
echo all > /sys/kernel/debug/orangefs/kernel-debug
-Get a list of all debugging keywords:
+Get a list of all debugging keywords::
cat /sys/kernel/debug/orangefs/debug-help
-PROTOCOL BETWEEN KERNEL MODULE AND USERSPACE
+Protocol between Kernel Module and Userspace
============================================
Orangefs is a user space filesystem and an associated kernel module.
@@ -234,7 +241,8 @@ The kernel module implements a pseudo device that userspace
can read from and write to. Userspace can also manipulate the
kernel module through the pseudo device with ioctl.
-THE BUFMAP:
+The Bufmap
+----------
At startup userspace allocates two page-size-aligned (posix_memalign)
mlocked memory buffers, one is used for IO and one is used for readdir
@@ -250,7 +258,8 @@ copied from user space to kernel space with copy_from_user and is used
to initialize the kernel module's "bufmap" (struct orangefs_bufmap), which
then contains:
- * refcnt - a reference counter
+ * refcnt
+ - a reference counter
* desc_size - PVFS2_BUFMAP_DEFAULT_DESC_SIZE (4194304) - the IO buffer's
partition size, which represents the filesystem's block size and
is used for s_blocksize in super blocks.
@@ -259,17 +268,19 @@ then contains:
* desc_shift - log2(desc_size), used for s_blocksize_bits in super blocks.
* total_size - the total size of the IO buffer.
* page_count - the number of 4096 byte pages in the IO buffer.
- * page_array - a pointer to page_count * (sizeof(struct page*)) bytes
+ * page_array - a pointer to ``page_count * (sizeof(struct page*))`` bytes
of kcalloced memory. This memory is used as an array of pointers
to each of the pages in the IO buffer through a call to get_user_pages.
- * desc_array - a pointer to desc_count * (sizeof(struct orangefs_bufmap_desc))
+ * desc_array - a pointer to ``desc_count * (sizeof(struct orangefs_bufmap_desc))``
bytes of kcalloced memory. This memory is further intialized:
user_desc is the kernel's copy of the IO buffer's ORANGEFS_dev_map_desc
structure. user_desc->ptr points to the IO buffer.
- pages_per_desc = bufmap->desc_size / PAGE_SIZE
- offset = 0
+ ::
+
+ pages_per_desc = bufmap->desc_size / PAGE_SIZE
+ offset = 0
bufmap->desc_array[0].page_array = &bufmap->page_array[offset]
bufmap->desc_array[0].array_count = pages_per_desc = 1024
@@ -293,7 +304,8 @@ then contains:
* readdir_index_lock - a spinlock to protect readdir_index_array during
update.
-OPERATIONS:
+Operations
+----------
The kernel module builds an "op" (struct orangefs_kernel_op_s) when it
needs to communicate with userspace. Part of the op contains the "upcall"
@@ -308,13 +320,19 @@ in flight at any given time.
Ops are stateful:
- * unknown - op was just initialized
- * waiting - op is on request_list (upward bound)
- * inprogr - op is in progress (waiting for downcall)
- * serviced - op has matching downcall; ok
- * purged - op has to start a timer since client-core
+ * unknown
+ - op was just initialized
+ * waiting
+ - op is on request_list (upward bound)
+ * inprogr
+ - op is in progress (waiting for downcall)
+ * serviced
+ - op has matching downcall; ok
+ * purged
+ - op has to start a timer since client-core
exited uncleanly before servicing op
- * given up - submitter has given up waiting for it
+ * given up
+ - submitter has given up waiting for it
When some arbitrary userspace program needs to perform a
filesystem operation on Orangefs (readdir, I/O, create, whatever)
@@ -389,10 +407,15 @@ union of structs, each of which is associated with a particular
response type.
The several members outside of the union are:
- - int32_t type - type of operation.
- - int32_t status - return code for the operation.
- - int64_t trailer_size - 0 unless readdir operation.
- - char *trailer_buf - initialized to NULL, used during readdir operations.
+
+ ``int32_t type``
+ - type of operation.
+ ``int32_t status``
+ - return code for the operation.
+ ``int64_t trailer_size``
+ - 0 unless readdir operation.
+ ``char *trailer_buf``
+ - initialized to NULL, used during readdir operations.
The appropriate member inside the union is filled out for any
particular response.
@@ -449,18 +472,20 @@ Userspace uses writev() on /dev/pvfs2-req to pass responses to the requests
made by the kernel side.
A buffer_list containing:
+
- a pointer to the prepared response to the request from the
kernel (struct pvfs2_downcall_t).
- and also, in the case of a readdir request, a pointer to a
buffer containing descriptors for the objects in the target
directory.
+
... is sent to the function (PINT_dev_write_list) which performs
the writev.
PINT_dev_write_list has a local iovec array: struct iovec io_array[10];
The first four elements of io_array are initialized like this for all
-responses:
+responses::
io_array[0].iov_base = address of local variable "proto_ver" (int32_t)
io_array[0].iov_len = sizeof(int32_t)
@@ -475,7 +500,7 @@ responses:
of global variable vfs_request (vfs_request_t)
io_array[3].iov_len = sizeof(pvfs2_downcall_t)
-Readdir responses initialize the fifth element io_array like this:
+Readdir responses initialize the fifth element io_array like this::
io_array[4].iov_base = contents of member trailer_buf (char *)
from out_downcall member of global variable
@@ -517,13 +542,13 @@ from a dentry is cheap, obtaining it from userspace is relatively expensive,
hence the motivation to use the dentry when possible.
The timeout values d_time and getattr_time are jiffy based, and the
-code is designed to avoid the jiffy-wrap problem:
+code is designed to avoid the jiffy-wrap problem::
-"In general, if the clock may have wrapped around more than once, there
-is no way to tell how much time has elapsed. However, if the times t1
-and t2 are known to be fairly close, we can reliably compute the
-difference in a way that takes into account the possibility that the
-clock may have wrapped between times."
+ "In general, if the clock may have wrapped around more than once, there
+ is no way to tell how much time has elapsed. However, if the times t1
+ and t2 are known to be fairly close, we can reliably compute the
+ difference in a way that takes into account the possibility that the
+ clock may have wrapped between times."
- from course notes by instructor Andy Wang
+from course notes by instructor Andy Wang