[PATCH] md: always honour md bitmap being read from disk
The code currently will ignore the bitmap if the array seem to be in-sync.
This is wrong if the array is degraded, and probably wrong anyway. If the
bitmap says some chunks are not in in-sync, and the superblock says everything
IS in sync, then something is clearly wrong, and it is safer to trust the
bitmap.
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 70bca95..09d32db 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -818,8 +818,7 @@
return 0;
}
-static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset,
- unsigned long sectors, int in_sync);
+static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset);
/* * bitmap_init_from_disk -- called at bitmap_create time to initialize
* the in-memory bitmap from the on-disk bitmap -- also, sets up the
* memory mapping of the bitmap file
@@ -828,7 +827,7 @@
* previously kicked from the array, we mark all the bits as
* 1's in order to cause a full resync.
*/
-static int bitmap_init_from_disk(struct bitmap *bitmap, int in_sync)
+static int bitmap_init_from_disk(struct bitmap *bitmap)
{
unsigned long i, chunks, index, oldindex, bit;
struct page *page = NULL, *oldpage = NULL;
@@ -929,8 +928,7 @@
}
if (test_bit(bit, page_address(page))) {
/* if the disk bit is set, set the memory bit */
- bitmap_set_memory_bits(bitmap,
- i << CHUNK_BLOCK_SHIFT(bitmap), 1, in_sync);
+ bitmap_set_memory_bits(bitmap, i << CHUNK_BLOCK_SHIFT(bitmap));
bit_cnt++;
}
}
@@ -1426,35 +1424,30 @@
}
}
-static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset,
- unsigned long sectors, int in_sync)
+static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset)
{
/* For each chunk covered by any of these sectors, set the
- * counter to 1 and set resync_needed unless in_sync. They should all
+ * counter to 1 and set resync_needed. They should all
* be 0 at this point
*/
- while (sectors) {
- int secs;
- bitmap_counter_t *bmc;
- spin_lock_irq(&bitmap->lock);
- bmc = bitmap_get_counter(bitmap, offset, &secs, 1);
- if (!bmc) {
- spin_unlock_irq(&bitmap->lock);
- return;
- }
- if (! *bmc) {
- struct page *page;
- *bmc = 1 | (in_sync? 0 : NEEDED_MASK);
- bitmap_count_page(bitmap, offset, 1);
- page = filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap));
- set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
- }
+
+ int secs;
+ bitmap_counter_t *bmc;
+ spin_lock_irq(&bitmap->lock);
+ bmc = bitmap_get_counter(bitmap, offset, &secs, 1);
+ if (!bmc) {
spin_unlock_irq(&bitmap->lock);
- if (sectors > secs)
- sectors -= secs;
- else
- sectors = 0;
+ return;
}
+ if (! *bmc) {
+ struct page *page;
+ *bmc = 1 | NEEDED_MASK;
+ bitmap_count_page(bitmap, offset, 1);
+ page = filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap));
+ set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
+ }
+ spin_unlock_irq(&bitmap->lock);
+
}
/*
@@ -1565,7 +1558,8 @@
/* now that we have some pages available, initialize the in-memory
* bitmap from the on-disk bitmap */
- err = bitmap_init_from_disk(bitmap, mddev->recovery_cp == MaxSector);
+ err = bitmap_init_from_disk(bitmap);
+
if (err)
return err;