From 06e3c817b750c131a20e82eed57a17841ea88ed2 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Sat, 12 Dec 2009 21:17:12 -0700 Subject: md: add 'recovery_start' per-device sysfs attribute Enable external metadata arrays to manage rebuild checkpointing via a md/dev-XXX/recovery_start attribute which reflects rdev->recovery_offset Also update resync_start_store to allow 'none' to be written, for consistency. Signed-off-by: Dan Williams Signed-off-by: NeilBrown --- Documentation/md.txt | 27 +++++++++++++++++++++++---- 1 file changed, 23 insertions(+), 4 deletions(-) (limited to 'Documentation/md.txt') diff --git a/Documentation/md.txt b/Documentation/md.txt index 21d26fb5d02b..188f4768f1d5 100644 --- a/Documentation/md.txt +++ b/Documentation/md.txt @@ -233,9 +233,9 @@ All md devices contain: 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 - default to 0, though starting the array as 'clean' will - set it much larger. + this will be a very large number (or 'none' since 2.6.30-rc1). At + array creation it will default to 0, though starting the array as + 'clean' will set it much larger. new_dev This file can be written but not read. The value written should @@ -379,8 +379,9 @@ Each directory contains: 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 + Writing "-blocked" clears the "blocked" flag and allows writes to complete. + Writing "in_sync" sets the in_sync flag. This file responds to select/poll. Any change to 'faulty' or 'blocked' causes an event. @@ -417,6 +418,24 @@ Each directory contains: array. If a value less than the current component_size is written, it will be rejected. + recovery_start + + When the device is not 'in_sync', this records the number of + sectors from the start of the device which are known to be + correct. This is normally zero, but during a recovery + operation is will steadily increase, and if the recovery is + interrupted, restoring this value can cause recovery to + avoid repeating the earlier blocks. With v1.x metadata, this + value is saved and restored automatically. + + This can be set whenever the device is not an active member of + the array, either before the array is activated, or before + the 'slot' is set. + + Setting this to 'none' is equivalent to setting 'in_sync'. + Setting to any other value also clears the 'in_sync' flag. + + An active md device will also contain and entry for each active device in the array. These are named -- cgit v1.2.3-59-g8ed1b