Make sure all changes to md/dev-XX/state are notified
Neil Brown [Fri, 27 Jun 2008 22:31:44 +0000 (08:31 +1000)]
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>

Documentation/md.txt
drivers/md/md.c
include/linux/raid/md_k.h

index eb6e69e..e06cc59 100644 (file)
@@ -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
index 60d4cad..dc99d95 100644 (file)
@@ -1886,6 +1886,8 @@ state_store(mdk_rdev_t *rdev, const char *buf, size_t len)
 
                err = 0;
        }
+       if (!err)
+               sysfs_notify(&rdev->kobj, NULL, "state");
        return err ? err : len;
 }
 static struct rdev_sysfs_entry rdev_state =
@@ -1979,7 +1981,8 @@ slot_store(mdk_rdev_t *rdev, const char *buf, size_t len)
                if (err) {
                        rdev->raid_disk = -1;
                        return err;
-               }
+               } else
+                       sysfs_notify(&rdev->kobj, NULL, "state");
                sprintf(nm, "rd%d", rdev->raid_disk);
                if (sysfs_create_link(&rdev->mddev->kobj, &rdev->kobj, nm))
                        printk(KERN_WARNING
@@ -1996,6 +1999,7 @@ slot_store(mdk_rdev_t *rdev, const char *buf, size_t len)
                clear_bit(Faulty, &rdev->flags);
                clear_bit(WriteMostly, &rdev->flags);
                set_bit(In_sync, &rdev->flags);
+               sysfs_notify(&rdev->kobj, NULL, "state");
        }
        return len;
 }
@@ -3525,6 +3529,7 @@ static int do_md_run(mddev_t * mddev)
                                return -EINVAL;
                        }
                }
+               sysfs_notify(&rdev->kobj, NULL, "state");
        }
 
        md_probe(mddev->unit, NULL, NULL);
@@ -4256,6 +4261,8 @@ static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info)
                }
                if (err)
                        export_rdev(rdev);
+               else
+                       sysfs_notify(&rdev->kobj, NULL, "state");
 
                md_update_sb(mddev, 1);
                if (mddev->degraded)
@@ -5115,6 +5122,7 @@ void md_error(mddev_t *mddev, mdk_rdev_t *rdev)
        mddev->pers->error_handler(mddev,rdev);
        if (mddev->degraded)
                set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
+       set_bit(StateChanged, &rdev->flags);
        set_bit(MD_RECOVERY_INTR, &mddev->recovery);
        set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
        md_wakeup_thread(mddev->thread);
@@ -6037,6 +6045,10 @@ void md_check_recovery(mddev_t *mddev)
                if (mddev->flags)
                        md_update_sb(mddev, 0);
 
+               rdev_for_each(rdev, rtmp, mddev)
+                       if (test_and_clear_bit(StateChanged, &rdev->flags))
+                               sysfs_notify(&rdev->kobj, NULL, "state");
+
 
                if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
                    !test_bit(MD_RECOVERY_DONE, &mddev->recovery)) {
index 62aa9c9..df30c43 100644 (file)
@@ -87,6 +87,9 @@ struct mdk_rdev_s
 #define Blocked                8               /* An error occured on an externally
                                         * managed array, don't allow writes
                                         * until it is cleared */
+#define StateChanged   9               /* Faulty or Blocked has changed during
+                                        * interrupt, so it needs to be
+                                        * notified by the thread */
        wait_queue_head_t blocked_wait;
 
        int desc_nr;                    /* descriptor index in the superblock */