Make sure all changes to md/dev-XX/state are notified

The important state change happens during an interrupt
in md_error.  So just set a flag there and call sysfs_notify
later in process context.

Signed-off-by: Neil Brown <neilb@suse.de>

1 files changed, 10 insertions, 0 deletions

diff --git a/Documentation/md.txt b/Documentation/md.txt
index eb6e69e3732e..e06cc59437e4 100644
--- a/Documentation/md.txt
+++ b/Documentation/md.txt
@@ -297,6 +297,10 @@ Each directory contains:
               writemostly - device will only be subject to read
                          requests if there are no other options.
                          This applies only to raid1 arrays.
+              blocked  - device has failed, metadata is "external",
+                         and the failure hasn't been acknowledged yet.
+                         Writes that would write to this device if
+                         it were not faulty are blocked.
               spare    - device is working, but not a full member.
                          This includes spares that are in the process
                          of being recovered to
@@ -306,6 +310,12 @@ Each directory contains:
         Writing "remove" removes the device from the array.
         Writing "writemostly" sets the writemostly flag.
         Writing "-writemostly" clears the writemostly flag.
+        Writing "blocked" sets the "blocked" flag.
+        Writing "-blocked" clear the "blocked" flag and allows writes
+                to complete.
+
+        This file responds to select/poll. Any change to 'faulty'
+        or 'blocked' causes an event.
 
       errors
         An approximate count of read errors that have been detected on