The patch titled
Subject: docs: add documentation about /proc/<pid>/fdinfo/<fd> output
has been added to the -mm tree. Its filename is
docs-add-documentation-about-proc-pid-fdinfo-fd-output.patch
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------------------------------------------------------
From: Cyrill Gorcunov <gorcunov@xxxxxxxxxx>
Subject: docs: add documentation about /proc/<pid>/fdinfo/<fd> output
Signed-off-by: Cyrill Gorcunov <gorcunov@xxxxxxxxxx>
Cc: Pavel Emelyanov <xemul@xxxxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Andrey Vagin <avagin@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Cc: James Bottomley <jbottomley@xxxxxxxxxxxxx>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Cc: Matthew Helsley <matt.helsley@xxxxxxxxx>
Cc: "J. Bruce Fields" <bfields@xxxxxxxxxxxx>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/filesystems/proc.txt | 81 +++++++++++++++++++++++++++
1 file changed, 81 insertions(+)
diff -puN Documentation/filesystems/proc.txt~docs-add-documentation-about-proc-pid-fdinfo-fd-output Documentation/filesystems/proc.txt
--- a/Documentation/filesystems/proc.txt~docs-add-documentation-about-proc-pid-fdinfo-fd-output
+++ a/Documentation/filesystems/proc.txt
@@ -41,6 +41,7 @@ Table of Contents
3.5 /proc/<pid>/mountinfo - Information about mounts
3.6 /proc/<pid>/comm & /proc/<pid>/task/<tid>/comm
3.7 /proc/<pid>/task/<tid>/children - Information about task children
+ 3.8 /proc/<pid>/fdinfo/<fd> - Information about opened file
4 Configuring procfs
4.1 Mount options
@@ -1633,6 +1634,86 @@ pids, so one need to either stop or free
if precise results are needed.
+3.7 /proc/<pid>/fdinfo/<fd> - Information about opened file
+---------------------------------------------------------------
+This file provides information associated with an opened file. The regular
+files have at least two fields -- 'pos' and 'flags'. The 'pos' represents
+the current offset of the opened file in decimal form [see lseek(2) for
+details] and the 'flags' denotes octal O_xxx mask the file has been
+created with [see open(2) for details].
+
+A typical output is
+
+ pos: 0
+ flags: 0100002
+
+The files such as eventfd, fsnotify, signalfd, epoll among the regular pos/flags
+pair provide additional information peculiar to the objects they represent.
+
+ Eventfd files
+ ~~~~~~~~~~~~~
+ pos: 0
+ flags: 04002
+ eventfd-count: 5a
+
+ where 'eventfd-count' is hex value of a counter.
+
+ Signalfd files
+ ~~~~~~~~~~~~~~
+ pos: 0
+ flags: 04002
+ sigmask: 0000000000000200
+
+ where 'sigmask' is hex value of the signal mask associated
+ with a file.
+
+ Epoll files
+ ~~~~~~~~~~~
+ pos: 0
+ flags: 02
+ tfd: 5 events: 1d data: ffffffffffffffff
+
+ where 'tfd' is a target file descriptor number in decimal form,
+ 'events' is events mask being watched and the 'data' is data
+ associated with a target [see epoll(7) for more details].
+
+ Fsnotify files
+ ~~~~~~~~~~~~~~
+ For inotify files the format is the following
+
+ pos: 0
+ flags: 02000000
+ inotify wd:3 ino:9e7e sdev:800013 mask:800afce ignored_mask:0 fhandle-bytes:8 fhandle-type:1 f_handle:7e9e0000640d1b6d
+
+ where 'wd' is a watch descriptor in decimal form, ie a target file
+ descriptor number, 'ino' and 'sdev' are inode and device where the
+ target file lays on and the 'mask' is the mask of events, all in hex
+ form [see inotify(7) for more details].
+
+ In case if the kernel built with exportfs the path to the target file
+ is encoded as a file handle. The file handle provided by three fields
+ 'fhandle-bytes', 'fhandle-type' and 'f_handle', all in hex format.
+
+ If the kernel is built without exportfs support the file handle won't be
+ printed out.
+
+ For fanotify files the format is the following
+
+ pos: 0
+ flags: 02
+ fanotify ino:2 sdev:800013 mask:1 ignored_mask:40000000 fhandle-bytes:8 fhandle-type:1 f_handle:0200000000000000
+
+ or
+
+ pos: 0
+ flags: 02
+ fanotify mnt_id:13 mask:1 ignored_mask:40000000
+
+ where 'ino', 'sdev' are target inode and device, 'mnt_id' is the mount point identifier,
+ 'mask' is the events mask used and 'ignored_mask' is the mask of events which are
+ to be ignored. All written in hex format.
+
+
------------------------------------------------------------------------------
Configuring procfs
------------------------------------------------------------------------------
_
Patches currently in -mm which might be from gorcunov@xxxxxxxxxx are
origin.patch
linux-next.patch
procfs-add-vmflags-field-in-smaps-output-v4.patch
procfs-add-vmflags-field-in-smaps-output-v4-fix.patch
proc-pid-status-add-seccomp-field.patch
kcmp-selftests-make-run_tests-fix.patch
kcmp-selftests-print-fail-status-instead-of-cause-make-error.patch
tools-testing-selftests-kcmp-kcmp_testc-print-reason-for-failure-in-kcmp_test.patch
procfs-add-ability-to-plug-in-auxiliary-fdinfo-providers.patch
fs-eventfd-add-procfs-fdinfo-helper.patch
fs-epoll-add-procfs-fdinfo-helper-v2.patch
fs-epoll-add-procfs-fdinfo-helper-v2-fs-epoll-drop-enabled-field-from-fdinfo-output.patch
fdinfo-show-sigmask-for-signalfd-fd-v3.patch
fs-exportfs-escape-nil-dereference-if-no-s_export_op-present.patch
fs-exportfs-add-exportfs_encode_inode_fh-helper.patch
fs-notify-add-procfs-fdinfo-helper-v7.patch
fs-notify-add-procfs-fdinfo-helper-v7-fix-fix.patch
fs-notify-add-procfs-fdinfo-helper-v7-add-missing-space-after-prefix.patch
fs-notify-add-procfs-fdinfo-helper-v7-dont-forget-to-provide-fhandle-for-inode-fanotify.patch
docs-add-documentation-about-proc-pid-fdinfo-fd-output.patch
docs-add-documentation-about-proc-pid-fdinfo-fd-output-fix.patch
fs-notify-add-procfs-fdinfo-helper-v7-fix.patch
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