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-rw-r--r--Documentation/keys.txt18
-rw-r--r--Documentation/md.txt120
-rw-r--r--Documentation/power/interface.txt11
-rw-r--r--Documentation/power/swsusp.txt5
4 files changed, 136 insertions, 18 deletions
diff --git a/Documentation/keys.txt b/Documentation/keys.txt
index 31154882000a..6304db59bfe4 100644
--- a/Documentation/keys.txt
+++ b/Documentation/keys.txt
@@ -860,24 +860,6 @@ The structure has a number of fields, some of which are mandatory:
860 It is safe to sleep in this method. 860 It is safe to sleep in this method.
861 861
862 862
863 (*) int (*duplicate)(struct key *key, const struct key *source);
864
865 If this type of key can be duplicated, then this method should be
866 provided. It is called to copy the payload attached to the source into the
867 new key. The data length on the new key will have been updated and the
868 quota adjusted already.
869
870 This method will be called with the source key's semaphore read-locked to
871 prevent its payload from being changed, thus RCU constraints need not be
872 applied to the source key.
873
874 This method does not have to lock the destination key in order to attach a
875 payload. The fact that KEY_FLAG_INSTANTIATED is not set in key->flags
876 prevents anything else from gaining access to the key.
877
878 It is safe to sleep in this method.
879
880
881 (*) int (*update)(struct key *key, const void *data, size_t datalen); 863 (*) int (*update)(struct key *key, const void *data, size_t datalen);
882 864
883 If this type of key can be updated, then this method should be provided. 865 If this type of key can be updated, then this method should be provided.
diff --git a/Documentation/md.txt b/Documentation/md.txt
index 23e6cce40f9c..03a13c462cf2 100644
--- a/Documentation/md.txt
+++ b/Documentation/md.txt
@@ -51,6 +51,30 @@ superblock can be autodetected and run at boot time.
51The kernel parameter "raid=partitionable" (or "raid=part") means 51The kernel parameter "raid=partitionable" (or "raid=part") means
52that all auto-detected arrays are assembled as partitionable. 52that all auto-detected arrays are assembled as partitionable.
53 53
54Boot time assembly of degraded/dirty arrays
55-------------------------------------------
56
57If a raid5 or raid6 array is both dirty and degraded, it could have
58undetectable data corruption. This is because the fact that it is
59'dirty' means that the parity cannot be trusted, and the fact that it
60is degraded means that some datablocks are missing and cannot reliably
61be reconstructed (due to no parity).
62
63For this reason, md will normally refuse to start such an array. This
64requires the sysadmin to take action to explicitly start the array
65desipite possible corruption. This is normally done with
66 mdadm --assemble --force ....
67
68This option is not really available if the array has the root
69filesystem on it. In order to support this booting from such an
70array, md supports a module parameter "start_dirty_degraded" which,
71when set to 1, bypassed the checks and will allows dirty degraded
72arrays to be started.
73
74So, to boot with a root filesystem of a dirty degraded raid[56], use
75
76 md-mod.start_dirty_degraded=1
77
54 78
55Superblock formats 79Superblock formats
56------------------ 80------------------
@@ -141,6 +165,70 @@ All md devices contain:
141 in a fully functional array. If this is not yet known, the file 165 in a fully functional array. If this is not yet known, the file
142 will be empty. If an array is being resized (not currently 166 will be empty. If an array is being resized (not currently
143 possible) this will contain the larger of the old and new sizes. 167 possible) this will contain the larger of the old and new sizes.
168 Some raid level (RAID1) allow this value to be set while the
169 array is active. This will reconfigure the array. Otherwise
170 it can only be set while assembling an array.
171
172 chunk_size
173 This is the size if bytes for 'chunks' and is only relevant to
174 raid levels that involve striping (1,4,5,6,10). The address space
175 of the array is conceptually divided into chunks and consecutive
176 chunks are striped onto neighbouring devices.
177 The size should be atleast PAGE_SIZE (4k) and should be a power
178 of 2. This can only be set while assembling an array
179
180 component_size
181 For arrays with data redundancy (i.e. not raid0, linear, faulty,
182 multipath), all components must be the same size - or at least
183 there must a size that they all provide space for. This is a key
184 part or the geometry of the array. It is measured in sectors
185 and can be read from here. Writing to this value may resize
186 the array if the personality supports it (raid1, raid5, raid6),
187 and if the component drives are large enough.
188
189 metadata_version
190 This indicates the format that is being used to record metadata
191 about the array. It can be 0.90 (traditional format), 1.0, 1.1,
192 1.2 (newer format in varying locations) or "none" indicating that
193 the kernel isn't managing metadata at all.
194
195 level
196 The raid 'level' for this array. The name will often (but not
197 always) be the same as the name of the module that implements the
198 level. To be auto-loaded the module must have an alias
199 md-$LEVEL e.g. md-raid5
200 This can be written only while the array is being assembled, not
201 after it is started.
202
203 new_dev
204 This file can be written but not read. The value written should
205 be a block device number as major:minor. e.g. 8:0
206 This will cause that device to be attached to the array, if it is
207 available. It will then appear at md/dev-XXX (depending on the
208 name of the device) and further configuration is then possible.
209
210 sync_speed_min
211 sync_speed_max
212 This are similar to /proc/sys/dev/raid/speed_limit_{min,max}
213 however they only apply to the particular array.
214 If no value has been written to these, of if the word 'system'
215 is written, then the system-wide value is used. If a value,
216 in kibibytes-per-second is written, then it is used.
217 When the files are read, they show the currently active value
218 followed by "(local)" or "(system)" depending on whether it is
219 a locally set or system-wide value.
220
221 sync_completed
222 This shows the number of sectors that have been completed of
223 whatever the current sync_action is, followed by the number of
224 sectors in total that could need to be processed. The two
225 numbers are separated by a '/' thus effectively showing one
226 value, a fraction of the process that is complete.
227
228 sync_speed
229 This shows the current actual speed, in K/sec, of the current
230 sync_action. It is averaged over the last 30 seconds.
231
144 232
145As component devices are added to an md array, they appear in the 'md' 233As component devices are added to an md array, they appear in the 'md'
146directory as new directories named 234directory as new directories named
@@ -167,6 +255,38 @@ Each directory contains:
167 of being recoverred to 255 of being recoverred to
168 This list make grow in future. 256 This list make grow in future.
169 257
258 errors
259 An approximate count of read errors that have been detected on
260 this device but have not caused the device to be evicted from
261 the array (either because they were corrected or because they
262 happened while the array was read-only). When using version-1
263 metadata, this value persists across restarts of the array.
264
265 This value can be written while assembling an array thus
266 providing an ongoing count for arrays with metadata managed by
267 userspace.
268
269 slot
270 This gives the role that the device has in the array. It will
271 either be 'none' if the device is not active in the array
272 (i.e. is a spare or has failed) or an integer less than the
273 'raid_disks' number for the array indicating which possition
274 it currently fills. This can only be set while assembling an
275 array. A device for which this is set is assumed to be working.
276
277 offset
278 This gives the location in the device (in sectors from the
279 start) where data from the array will be stored. Any part of
280 the device before this offset us not touched, unless it is
281 used for storing metadata (Formats 1.1 and 1.2).
282
283 size
284 The amount of the device, after the offset, that can be used
285 for storage of data. This will normally be the same as the
286 component_size. This can be written while assembling an
287 array. If a value less than the current component_size is
288 written, component_size will be reduced to this value.
289
170 290
171An active md device will also contain and entry for each active device 291An active md device will also contain and entry for each active device
172in the array. These are named 292in the array. These are named
diff --git a/Documentation/power/interface.txt b/Documentation/power/interface.txt
index f5ebda5f4276..bd4ffb5bd49a 100644
--- a/Documentation/power/interface.txt
+++ b/Documentation/power/interface.txt
@@ -41,3 +41,14 @@ to. Writing to this file will accept one of
41It will only change to 'firmware' or 'platform' if the system supports 41It will only change to 'firmware' or 'platform' if the system supports
42it. 42it.
43 43
44/sys/power/image_size controls the size of the image created by
45the suspend-to-disk mechanism. It can be written a string
46representing a non-negative integer that will be used as an upper
47limit of the image size, in megabytes. The suspend-to-disk mechanism will
48do its best to ensure the image size will not exceed that number. However,
49if this turns out to be impossible, it will try to suspend anyway using the
50smallest image possible. In particular, if "0" is written to this file, the
51suspend image will be as small as possible.
52
53Reading from this file will display the current image size limit, which
54is set to 500 MB by default.
diff --git a/Documentation/power/swsusp.txt b/Documentation/power/swsusp.txt
index b0d50840788e..cd0fcd89a6f0 100644
--- a/Documentation/power/swsusp.txt
+++ b/Documentation/power/swsusp.txt
@@ -27,6 +27,11 @@ echo shutdown > /sys/power/disk; echo disk > /sys/power/state
27 27
28echo platform > /sys/power/disk; echo disk > /sys/power/state 28echo platform > /sys/power/disk; echo disk > /sys/power/state
29 29
30If you want to limit the suspend image size to N megabytes, do
31
32echo N > /sys/power/image_size
33
34before suspend (it is limited to 500 MB by default).
30 35
31Encrypted suspend image: 36Encrypted suspend image:
32------------------------ 37------------------------