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-rw-r--r--Documentation/filesystems/fiemap.txt3
-rw-r--r--Documentation/filesystems/inotify.txt197
-rw-r--r--Documentation/filesystems/nfs/pnfs.txt13
-rw-r--r--Documentation/filesystems/ocfs2.txt4
-rw-r--r--Documentation/filesystems/proc.txt25
-rw-r--r--Documentation/filesystems/seq_file.txt12
-rw-r--r--Documentation/filesystems/xfs.txt22
7 files changed, 56 insertions, 220 deletions
diff --git a/Documentation/filesystems/fiemap.txt b/Documentation/filesystems/fiemap.txt
index 1b805a0efbb0..f6d9c99103a4 100644
--- a/Documentation/filesystems/fiemap.txt
+++ b/Documentation/filesystems/fiemap.txt
@@ -196,7 +196,8 @@ struct fiemap_extent_info {
196}; 196};
197 197
198It is intended that the file system should not need to access any of this 198It is intended that the file system should not need to access any of this
199structure directly. 199structure directly. Filesystem handlers should be tolerant to signals and return
200EINTR once fatal signal received.
200 201
201 202
202Flag checking should be done at the beginning of the ->fiemap callback via the 203Flag checking should be done at the beginning of the ->fiemap callback via the
diff --git a/Documentation/filesystems/inotify.txt b/Documentation/filesystems/inotify.txt
index cfd02712b83e..51f61db787fb 100644
--- a/Documentation/filesystems/inotify.txt
+++ b/Documentation/filesystems/inotify.txt
@@ -4,201 +4,10 @@
4 4
5 5
6Document started 15 Mar 2005 by Robert Love <rml@novell.com> 6Document started 15 Mar 2005 by Robert Love <rml@novell.com>
7Document updated 4 Jan 2015 by Zhang Zhen <zhenzhang.zhang@huawei.com>
8 --Deleted obsoleted interface, just refer to manpages for user interface.
7 9
8 10(i) Rationale
9(i) User Interface
10
11Inotify is controlled by a set of three system calls and normal file I/O on a
12returned file descriptor.
13
14First step in using inotify is to initialise an inotify instance:
15
16 int fd = inotify_init ();
17
18Each instance is associated with a unique, ordered queue.
19
20Change events are managed by "watches". A watch is an (object,mask) pair where
21the object is a file or directory and the mask is a bit mask of one or more
22inotify events that the application wishes to receive. See <linux/inotify.h>
23for valid events. A watch is referenced by a watch descriptor, or wd.
24
25Watches are added via a path to the file.
26
27Watches on a directory will return events on any files inside of the directory.
28
29Adding a watch is simple:
30
31 int wd = inotify_add_watch (fd, path, mask);
32
33Where "fd" is the return value from inotify_init(), path is the path to the
34object to watch, and mask is the watch mask (see <linux/inotify.h>).
35
36You can update an existing watch in the same manner, by passing in a new mask.
37
38An existing watch is removed via
39
40 int ret = inotify_rm_watch (fd, wd);
41
42Events are provided in the form of an inotify_event structure that is read(2)
43from a given inotify instance. The filename is of dynamic length and follows
44the struct. It is of size len. The filename is padded with null bytes to
45ensure proper alignment. This padding is reflected in len.
46
47You can slurp multiple events by passing a large buffer, for example
48
49 size_t len = read (fd, buf, BUF_LEN);
50
51Where "buf" is a pointer to an array of "inotify_event" structures at least
52BUF_LEN bytes in size. The above example will return as many events as are
53available and fit in BUF_LEN.
54
55Each inotify instance fd is also select()- and poll()-able.
56
57You can find the size of the current event queue via the standard FIONREAD
58ioctl on the fd returned by inotify_init().
59
60All watches are destroyed and cleaned up on close.
61
62
63(ii)
64
65Prototypes:
66
67 int inotify_init (void);
68 int inotify_add_watch (int fd, const char *path, __u32 mask);
69 int inotify_rm_watch (int fd, __u32 mask);
70
71
72(iii) Kernel Interface
73
74Inotify's kernel API consists a set of functions for managing watches and an
75event callback.
76
77To use the kernel API, you must first initialize an inotify instance with a set
78of inotify_operations. You are given an opaque inotify_handle, which you use
79for any further calls to inotify.
80
81 struct inotify_handle *ih = inotify_init(my_event_handler);
82
83You must provide a function for processing events and a function for destroying
84the inotify watch.
85
86 void handle_event(struct inotify_watch *watch, u32 wd, u32 mask,
87 u32 cookie, const char *name, struct inode *inode)
88
89 watch - the pointer to the inotify_watch that triggered this call
90 wd - the watch descriptor
91 mask - describes the event that occurred
92 cookie - an identifier for synchronizing events
93 name - the dentry name for affected files in a directory-based event
94 inode - the affected inode in a directory-based event
95
96 void destroy_watch(struct inotify_watch *watch)
97
98You may add watches by providing a pre-allocated and initialized inotify_watch
99structure and specifying the inode to watch along with an inotify event mask.
100You must pin the inode during the call. You will likely wish to embed the
101inotify_watch structure in a structure of your own which contains other
102information about the watch. Once you add an inotify watch, it is immediately
103subject to removal depending on filesystem events. You must grab a reference if
104you depend on the watch hanging around after the call.
105
106 inotify_init_watch(&my_watch->iwatch);
107 inotify_get_watch(&my_watch->iwatch); // optional
108 s32 wd = inotify_add_watch(ih, &my_watch->iwatch, inode, mask);
109 inotify_put_watch(&my_watch->iwatch); // optional
110
111You may use the watch descriptor (wd) or the address of the inotify_watch for
112other inotify operations. You must not directly read or manipulate data in the
113inotify_watch. Additionally, you must not call inotify_add_watch() more than
114once for a given inotify_watch structure, unless you have first called either
115inotify_rm_watch() or inotify_rm_wd().
116
117To determine if you have already registered a watch for a given inode, you may
118call inotify_find_watch(), which gives you both the wd and the watch pointer for
119the inotify_watch, or an error if the watch does not exist.
120
121 wd = inotify_find_watch(ih, inode, &watchp);
122
123You may use container_of() on the watch pointer to access your own data
124associated with a given watch. When an existing watch is found,
125inotify_find_watch() bumps the refcount before releasing its locks. You must
126put that reference with:
127
128 put_inotify_watch(watchp);
129
130Call inotify_find_update_watch() to update the event mask for an existing watch.
131inotify_find_update_watch() returns the wd of the updated watch, or an error if
132the watch does not exist.
133
134 wd = inotify_find_update_watch(ih, inode, mask);
135
136An existing watch may be removed by calling either inotify_rm_watch() or
137inotify_rm_wd().
138
139 int ret = inotify_rm_watch(ih, &my_watch->iwatch);
140 int ret = inotify_rm_wd(ih, wd);
141
142A watch may be removed while executing your event handler with the following:
143
144 inotify_remove_watch_locked(ih, iwatch);
145
146Call inotify_destroy() to remove all watches from your inotify instance and
147release it. If there are no outstanding references, inotify_destroy() will call
148your destroy_watch op for each watch.
149
150 inotify_destroy(ih);
151
152When inotify removes a watch, it sends an IN_IGNORED event to your callback.
153You may use this event as an indication to free the watch memory. Note that
154inotify may remove a watch due to filesystem events, as well as by your request.
155If you use IN_ONESHOT, inotify will remove the watch after the first event, at
156which point you may call the final inotify_put_watch.
157
158(iv) Kernel Interface Prototypes
159
160 struct inotify_handle *inotify_init(struct inotify_operations *ops);
161
162 inotify_init_watch(struct inotify_watch *watch);
163
164 s32 inotify_add_watch(struct inotify_handle *ih,
165 struct inotify_watch *watch,
166 struct inode *inode, u32 mask);
167
168 s32 inotify_find_watch(struct inotify_handle *ih, struct inode *inode,
169 struct inotify_watch **watchp);
170
171 s32 inotify_find_update_watch(struct inotify_handle *ih,
172 struct inode *inode, u32 mask);
173
174 int inotify_rm_wd(struct inotify_handle *ih, u32 wd);
175
176 int inotify_rm_watch(struct inotify_handle *ih,
177 struct inotify_watch *watch);
178
179 void inotify_remove_watch_locked(struct inotify_handle *ih,
180 struct inotify_watch *watch);
181
182 void inotify_destroy(struct inotify_handle *ih);
183
184 void get_inotify_watch(struct inotify_watch *watch);
185 void put_inotify_watch(struct inotify_watch *watch);
186
187
188(v) Internal Kernel Implementation
189
190Each inotify instance is represented by an inotify_handle structure.
191Inotify's userspace consumers also have an inotify_device which is
192associated with the inotify_handle, and on which events are queued.
193
194Each watch is associated with an inotify_watch structure. Watches are chained
195off of each associated inotify_handle and each associated inode.
196
197See fs/notify/inotify/inotify_fsnotify.c and fs/notify/inotify/inotify_user.c
198for the locking and lifetime rules.
199
200
201(vi) Rationale
202 11
203Q: What is the design decision behind not tying the watch to the open fd of 12Q: What is the design decision behind not tying the watch to the open fd of
204 the watched object? 13 the watched object?
diff --git a/Documentation/filesystems/nfs/pnfs.txt b/Documentation/filesystems/nfs/pnfs.txt
index adc81a35fe2d..44a9f2493a88 100644
--- a/Documentation/filesystems/nfs/pnfs.txt
+++ b/Documentation/filesystems/nfs/pnfs.txt
@@ -57,15 +57,16 @@ bit is set, preventing any new lsegs from being added.
57layout drivers 57layout drivers
58-------------- 58--------------
59 59
60PNFS utilizes what is called layout drivers. The STD defines 3 basic 60PNFS utilizes what is called layout drivers. The STD defines 4 basic
61layout types: "files" "objects" and "blocks". For each of these types 61layout types: "files", "objects", "blocks", and "flexfiles". For each
62there is a layout-driver with a common function-vectors table which 62of these types there is a layout-driver with a common function-vectors
63are called by the nfs-client pnfs-core to implement the different layout 63table which are called by the nfs-client pnfs-core to implement the
64types. 64different layout types.
65 65
66Files-layout-driver code is in: fs/nfs/nfs4filelayout.c && nfs4filelayoutdev.c 66Files-layout-driver code is in: fs/nfs/filelayout/.. directory
67Objects-layout-deriver code is in: fs/nfs/objlayout/.. directory 67Objects-layout-deriver code is in: fs/nfs/objlayout/.. directory
68Blocks-layout-deriver code is in: fs/nfs/blocklayout/.. directory 68Blocks-layout-deriver code is in: fs/nfs/blocklayout/.. directory
69Flexfiles-layout-driver code is in: fs/nfs/flexfilelayout/.. directory
69 70
70objects-layout setup 71objects-layout setup
71-------------------- 72--------------------
diff --git a/Documentation/filesystems/ocfs2.txt b/Documentation/filesystems/ocfs2.txt
index 7618a287aa41..28f8c08201e2 100644
--- a/Documentation/filesystems/ocfs2.txt
+++ b/Documentation/filesystems/ocfs2.txt
@@ -100,3 +100,7 @@ coherency=full (*) Disallow concurrent O_DIRECT writes, cluster inode
100coherency=buffered Allow concurrent O_DIRECT writes without EX lock among 100coherency=buffered Allow concurrent O_DIRECT writes without EX lock among
101 nodes, which gains high performance at risk of getting 101 nodes, which gains high performance at risk of getting
102 stale data on other nodes. 102 stale data on other nodes.
103journal_async_commit Commit block can be written to disk without waiting
104 for descriptor blocks. If enabled older kernels cannot
105 mount the device. This will enable 'journal_checksum'
106 internally.
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index aae9dd13c91f..cf8fc2f0b34b 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -28,7 +28,7 @@ Table of Contents
28 1.6 Parallel port info in /proc/parport 28 1.6 Parallel port info in /proc/parport
29 1.7 TTY info in /proc/tty 29 1.7 TTY info in /proc/tty
30 1.8 Miscellaneous kernel statistics in /proc/stat 30 1.8 Miscellaneous kernel statistics in /proc/stat
31 1.9 Ext4 file system parameters 31 1.9 Ext4 file system parameters
32 32
33 2 Modifying System Parameters 33 2 Modifying System Parameters
34 34
@@ -42,6 +42,7 @@ Table of Contents
42 3.6 /proc/<pid>/comm & /proc/<pid>/task/<tid>/comm 42 3.6 /proc/<pid>/comm & /proc/<pid>/task/<tid>/comm
43 3.7 /proc/<pid>/task/<tid>/children - Information about task children 43 3.7 /proc/<pid>/task/<tid>/children - Information about task children
44 3.8 /proc/<pid>/fdinfo/<fd> - Information about opened file 44 3.8 /proc/<pid>/fdinfo/<fd> - Information about opened file
45 3.9 /proc/<pid>/map_files - Information about memory mapped files
45 46
46 4 Configuring procfs 47 4 Configuring procfs
47 4.1 Mount options 48 4.1 Mount options
@@ -1763,6 +1764,28 @@ pair provide additional information particular to the objects they represent.
1763 with TIMER_ABSTIME option which will be shown in 'settime flags', but 'it_value' 1764 with TIMER_ABSTIME option which will be shown in 'settime flags', but 'it_value'
1764 still exhibits timer's remaining time. 1765 still exhibits timer's remaining time.
1765 1766
17673.9 /proc/<pid>/map_files - Information about memory mapped files
1768---------------------------------------------------------------------
1769This directory contains symbolic links which represent memory mapped files
1770the process is maintaining. Example output:
1771
1772 | lr-------- 1 root root 64 Jan 27 11:24 333c600000-333c620000 -> /usr/lib64/ld-2.18.so
1773 | lr-------- 1 root root 64 Jan 27 11:24 333c81f000-333c820000 -> /usr/lib64/ld-2.18.so
1774 | lr-------- 1 root root 64 Jan 27 11:24 333c820000-333c821000 -> /usr/lib64/ld-2.18.so
1775 | ...
1776 | lr-------- 1 root root 64 Jan 27 11:24 35d0421000-35d0422000 -> /usr/lib64/libselinux.so.1
1777 | lr-------- 1 root root 64 Jan 27 11:24 400000-41a000 -> /usr/bin/ls
1778
1779The name of a link represents the virtual memory bounds of a mapping, i.e.
1780vm_area_struct::vm_start-vm_area_struct::vm_end.
1781
1782The main purpose of the map_files is to retrieve a set of memory mapped
1783files in a fast way instead of parsing /proc/<pid>/maps or
1784/proc/<pid>/smaps, both of which contain many more records. At the same
1785time one can open(2) mappings from the listings of two processes and
1786comparing their inode numbers to figure out which anonymous memory areas
1787are actually shared.
1788
1766------------------------------------------------------------------------------ 1789------------------------------------------------------------------------------
1767Configuring procfs 1790Configuring procfs
1768------------------------------------------------------------------------------ 1791------------------------------------------------------------------------------
diff --git a/Documentation/filesystems/seq_file.txt b/Documentation/filesystems/seq_file.txt
index b797ed38de46..9de4303201e1 100644
--- a/Documentation/filesystems/seq_file.txt
+++ b/Documentation/filesystems/seq_file.txt
@@ -194,16 +194,16 @@ which is in the string esc will be represented in octal form in the output.
194 194
195There are also a pair of functions for printing filenames: 195There are also a pair of functions for printing filenames:
196 196
197 int seq_path(struct seq_file *m, struct path *path, char *esc); 197 int seq_path(struct seq_file *m, const struct path *path,
198 int seq_path_root(struct seq_file *m, struct path *path, 198 const char *esc);
199 struct path *root, char *esc) 199 int seq_path_root(struct seq_file *m, const struct path *path,
200 const struct path *root, const char *esc)
200 201
201Here, path indicates the file of interest, and esc is a set of characters 202Here, path indicates the file of interest, and esc is a set of characters
202which should be escaped in the output. A call to seq_path() will output 203which should be escaped in the output. A call to seq_path() will output
203the path relative to the current process's filesystem root. If a different 204the path relative to the current process's filesystem root. If a different
204root is desired, it can be used with seq_path_root(). Note that, if it 205root is desired, it can be used with seq_path_root(). If it turns out that
205turns out that path cannot be reached from root, the value of root will be 206path cannot be reached from root, seq_path_root() returns SEQ_SKIP.
206changed in seq_file_root() to a root which *does* work.
207 207
208A function producing complicated output may want to check 208A function producing complicated output may want to check
209 bool seq_has_overflowed(struct seq_file *m); 209 bool seq_has_overflowed(struct seq_file *m);
diff --git a/Documentation/filesystems/xfs.txt b/Documentation/filesystems/xfs.txt
index 5be51fd888bd..0bfafe108357 100644
--- a/Documentation/filesystems/xfs.txt
+++ b/Documentation/filesystems/xfs.txt
@@ -287,9 +287,9 @@ The following sysctls are available for the XFS filesystem:
287 XFS_ERRLEVEL_LOW: 1 287 XFS_ERRLEVEL_LOW: 1
288 XFS_ERRLEVEL_HIGH: 5 288 XFS_ERRLEVEL_HIGH: 5
289 289
290 fs.xfs.panic_mask (Min: 0 Default: 0 Max: 127) 290 fs.xfs.panic_mask (Min: 0 Default: 0 Max: 255)
291 Causes certain error conditions to call BUG(). Value is a bitmask; 291 Causes certain error conditions to call BUG(). Value is a bitmask;
292 AND together the tags which represent errors which should cause panics: 292 OR together the tags which represent errors which should cause panics:
293 293
294 XFS_NO_PTAG 0 294 XFS_NO_PTAG 0
295 XFS_PTAG_IFLUSH 0x00000001 295 XFS_PTAG_IFLUSH 0x00000001
@@ -299,6 +299,7 @@ The following sysctls are available for the XFS filesystem:
299 XFS_PTAG_SHUTDOWN_CORRUPT 0x00000010 299 XFS_PTAG_SHUTDOWN_CORRUPT 0x00000010
300 XFS_PTAG_SHUTDOWN_IOERROR 0x00000020 300 XFS_PTAG_SHUTDOWN_IOERROR 0x00000020
301 XFS_PTAG_SHUTDOWN_LOGERROR 0x00000040 301 XFS_PTAG_SHUTDOWN_LOGERROR 0x00000040
302 XFS_PTAG_FSBLOCK_ZERO 0x00000080
302 303
303 This option is intended for debugging only. 304 This option is intended for debugging only.
304 305
@@ -348,16 +349,13 @@ The following sysctls are available for the XFS filesystem:
348Deprecated Sysctls 349Deprecated Sysctls
349================== 350==================
350 351
351 fs.xfs.xfsbufd_centisecs (Min: 50 Default: 100 Max: 3000) 352None at present.
352 Dirty metadata is now tracked by the log subsystem and
353 flushing is driven by log space and idling demands. The
354 xfsbufd no longer exists, so this syctl does nothing.
355 353
356 Due for removal in 3.14.
357 354
358 fs.xfs.age_buffer_centisecs (Min: 100 Default: 1500 Max: 720000) 355Removed Sysctls
359 Dirty metadata is now tracked by the log subsystem and 356===============
360 flushing is driven by log space and idling demands. The
361 xfsbufd no longer exists, so this syctl does nothing.
362 357
363 Due for removal in 3.14. 358 Name Removed
359 ---- -------
360 fs.xfs.xfsbufd_centisec v3.20
361 fs.xfs.age_buffer_centisecs v3.20