[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>
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@ -818,8 +818,7 @@ int bitmap_unplug(struct bitmap *bitmap)
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return 0;
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}
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static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset,
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unsigned long sectors, int in_sync);
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static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset);
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/* * bitmap_init_from_disk -- called at bitmap_create time to initialize
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* the in-memory bitmap from the on-disk bitmap -- also, sets up the
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* memory mapping of the bitmap file
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@ -828,7 +827,7 @@ static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset,
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* previously kicked from the array, we mark all the bits as
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* 1's in order to cause a full resync.
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*/
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static int bitmap_init_from_disk(struct bitmap *bitmap, int in_sync)
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static int bitmap_init_from_disk(struct bitmap *bitmap)
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{
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unsigned long i, chunks, index, oldindex, bit;
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struct page *page = NULL, *oldpage = NULL;
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@ -929,8 +928,7 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, int in_sync)
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}
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if (test_bit(bit, page_address(page))) {
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/* if the disk bit is set, set the memory bit */
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bitmap_set_memory_bits(bitmap,
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i << CHUNK_BLOCK_SHIFT(bitmap), 1, in_sync);
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bitmap_set_memory_bits(bitmap, i << CHUNK_BLOCK_SHIFT(bitmap));
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bit_cnt++;
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}
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}
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@ -1426,35 +1424,30 @@ void bitmap_close_sync(struct bitmap *bitmap)
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}
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}
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static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset,
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unsigned long sectors, int in_sync)
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static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset)
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{
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/* For each chunk covered by any of these sectors, set the
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* counter to 1 and set resync_needed unless in_sync. They should all
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* counter to 1 and set resync_needed. They should all
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* be 0 at this point
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*/
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while (sectors) {
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int secs;
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bitmap_counter_t *bmc;
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spin_lock_irq(&bitmap->lock);
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bmc = bitmap_get_counter(bitmap, offset, &secs, 1);
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if (!bmc) {
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spin_unlock_irq(&bitmap->lock);
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return;
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}
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if (! *bmc) {
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struct page *page;
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*bmc = 1 | (in_sync? 0 : NEEDED_MASK);
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bitmap_count_page(bitmap, offset, 1);
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page = filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap));
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set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
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}
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int secs;
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bitmap_counter_t *bmc;
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spin_lock_irq(&bitmap->lock);
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bmc = bitmap_get_counter(bitmap, offset, &secs, 1);
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if (!bmc) {
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spin_unlock_irq(&bitmap->lock);
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if (sectors > secs)
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sectors -= secs;
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else
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sectors = 0;
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return;
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}
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if (! *bmc) {
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struct page *page;
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*bmc = 1 | NEEDED_MASK;
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bitmap_count_page(bitmap, offset, 1);
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page = filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap));
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set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
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}
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spin_unlock_irq(&bitmap->lock);
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}
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/*
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@ -1565,7 +1558,8 @@ int bitmap_create(mddev_t *mddev)
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/* now that we have some pages available, initialize the in-memory
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* bitmap from the on-disk bitmap */
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err = bitmap_init_from_disk(bitmap, mddev->recovery_cp == MaxSector);
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err = bitmap_init_from_disk(bitmap);
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if (err)
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return err;
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