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authorPaul Clements <paul.clements@steeleye.com>2006-10-03 01:15:49 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-10-03 08:04:17 -0700
commit9b1d1dac181d8c1b9492e05cee660a985d035a06 (patch)
treeaf12b1eaac4e0f7f3528ec26a223faeabed35845 /include/linux/raid/bitmap.h
parent76186dd8b73d2b7b9b4c8629b89c845e97009801 (diff)
downloadlwn-9b1d1dac181d8c1b9492e05cee660a985d035a06.tar.gz
lwn-9b1d1dac181d8c1b9492e05cee660a985d035a06.zip
[PATCH] md: new sysfs interface for setting bits in the write-intent-bitmap
Add a new sysfs interface that allows the bitmap of an array to be dirtied. The interface is write-only, and is used as follows: echo "1000" > /sys/block/md2/md/bitmap (dirty the bit for chunk 1000 [offset 0] in the in-memory and on-disk bitmaps of array md2) echo "1000-2000" > /sys/block/md1/md/bitmap (dirty the bits for chunks 1000-2000 in md1's bitmap) This is useful, for example, in cluster environments where you may need to combine two disjoint bitmaps into one (following a server failure, after a secondary server has taken over the array). By combining the bitmaps on the two servers, a full resync can be avoided (This was discussed on the list back on March 18, 2005, "[PATCH 1/2] md bitmap bug fixes" thread). Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include/linux/raid/bitmap.h')
-rw-r--r--include/linux/raid/bitmap.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/raid/bitmap.h b/include/linux/raid/bitmap.h
index 63df898fe2e9..84d887751855 100644
--- a/include/linux/raid/bitmap.h
+++ b/include/linux/raid/bitmap.h
@@ -265,6 +265,8 @@ int bitmap_update_sb(struct bitmap *bitmap);
int bitmap_setallbits(struct bitmap *bitmap);
void bitmap_write_all(struct bitmap *bitmap);
+void bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e);
+
/* these are exported */
int bitmap_startwrite(struct bitmap *bitmap, sector_t offset,
unsigned long sectors, int behind);