block: send disk "change" event for rescan_partitions()

[linux-2.6-omap-h63xx.git] / Documentation / md.txt

diff --git a/Documentation/md.txt b/Documentation/md.txt
index 2202f5dc8ac208381a241bd5fc6b56b73c81ea9a..396cdd982c26505ee39a577a64a7fb2c7472985e 100644 (file)
--- a/Documentation/md.txt
+++ b/Documentation/md.txt
@@ -178,6 +178,21 @@ All md devices contain:
      The size should be at least PAGE_SIZE (4k) and should be a power
      of 2.  This can only be set while assembling an array
 
      The size should be at least PAGE_SIZE (4k) and should be a power
      of 2.  This can only be set while assembling an array
 

+  layout
+     The "layout" for the array for the particular level.  This is
+     simply a number that is interpretted differently by different
+     levels.  It can be written while assembling an array.
+
+  reshape_position
+     This is either "none" or a sector number within the devices of
+     the array where "reshape" is up to.  If this is set, the three
+     attributes mentioned above (raid_disks, chunk_size, layout) can
+     potentially have 2 values, an old and a new value.  If these
+     values differ, reading the attribute returns
+        new (old)
+     and writing will effect the 'new' value, leaving the 'old'
+     unchanged.
+

   component_size
      For arrays with data redundancy (i.e. not raid0, linear, faulty,
      multipath), all components must be the same size - or at least
   component_size
      For arrays with data redundancy (i.e. not raid0, linear, faulty,
      multipath), all components must be the same size - or at least


@@ -193,11 +208,6 @@ All md devices contain:
      1.2 (newer format in varying locations) or "none" indicating that
      the kernel isn't managing metadata at all.
 
      1.2 (newer format in varying locations) or "none" indicating that
      the kernel isn't managing metadata at all.
 

-  layout
-     The "layout" for the array for the particular level.  This is
-     simply a number that is interpretted differently by different
-     levels.  It can be written while assembling an array.
-

   resync_start
      The point at which resync should start.  If no resync is needed,
      this will be a very large number.  At array creation it will
   resync_start
      The point at which resync should start.  If no resync is needed,
      this will be a very large number.  At array creation it will


@@ -259,29 +269,6 @@ All md devices contain:
          like active, but no writes have been seen for a while (safe_mode_delay).
 
 
          like active, but no writes have been seen for a while (safe_mode_delay).
 
 

-   sync_speed_min
-   sync_speed_max
-     This are similar to /proc/sys/dev/raid/speed_limit_{min,max}
-     however they only apply to the particular array.
-     If no value has been written to these, of if the word 'system'
-     is written, then the system-wide value is used.  If a value,
-     in kibibytes-per-second is written, then it is used.
-     When the files are read, they show the currently active value
-     followed by "(local)" or "(system)" depending on whether it is
-     a locally set or system-wide value.
-
-   sync_completed
-     This shows the number of sectors that have been completed of
-     whatever the current sync_action is, followed by the number of
-     sectors in total that could need to be processed.  The two
-     numbers are separated by a '/'  thus effectively showing one
-     value, a fraction of the process that is complete.
-
-   sync_speed
-     This shows the current actual speed, in K/sec, of the current
-     sync_action.  It is averaged over the last 30 seconds.
-
-

 As component devices are added to an md array, they appear in the 'md'
 directory as new directories named
       dev-XXX
 As component devices are added to an md array, they appear in the 'md'
 directory as new directories named
       dev-XXX


@@ -412,6 +399,45 @@ also have
       Note that the numbers are 'bit' numbers, not 'block' numbers.
       They should be scaled by the bitmap_chunksize.
 
       Note that the numbers are 'bit' numbers, not 'block' numbers.
       They should be scaled by the bitmap_chunksize.
 

+   sync_speed_min
+   sync_speed_max
+     This are similar to /proc/sys/dev/raid/speed_limit_{min,max}
+     however they only apply to the particular array.
+     If no value has been written to these, of if the word 'system'
+     is written, then the system-wide value is used.  If a value,
+     in kibibytes-per-second is written, then it is used.
+     When the files are read, they show the currently active value
+     followed by "(local)" or "(system)" depending on whether it is
+     a locally set or system-wide value.
+
+   sync_completed
+     This shows the number of sectors that have been completed of
+     whatever the current sync_action is, followed by the number of
+     sectors in total that could need to be processed.  The two
+     numbers are separated by a '/'  thus effectively showing one
+     value, a fraction of the process that is complete.
+     A 'select' on this attribute will return when resync completes,
+     when it reaches the current sync_max (below) and possibly at
+     other times.
+
+   sync_max
+     This is a number of sectors at which point a resync/recovery
+     process will pause.  When a resync is active, the value can
+     only ever be increased, never decreased.  The value of 'max'
+     effectively disables the limit.
+
+
+   sync_speed
+     This shows the current actual speed, in K/sec, of the current
+     sync_action.  It is averaged over the last 30 seconds.
+
+   suspend_lo
+   suspend_hi
+     The two values, given as numbers of sectors, indicate a range
+     within the array where IO will be blocked.  This is currently
+     only supported for raid4/5/6.
+
+

 Each active md device may also have attributes specific to the
 personality module that manages it.
 These are specific to the implementation of the module and could
 Each active md device may also have attributes specific to the
 personality module that manages it.
 These are specific to the implementation of the module and could