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authorNeilBrown <neilb@suse.de>2007-05-21 11:33:10 +1000
committerChris Wright <chrisw@sous-sol.org>2007-06-11 11:36:44 -0700
commitae9e80bd6e189ce3947df348a06d6178fc323f9d (patch)
tree78454fc1b34c0b58510fd384adaa63fae7df31ae
parentfb5cded6f5a16342520eded69b993828965155cf (diff)
[PATCH] md: Don't write more than is required of the last page of a bitmap
It is possible that real data or metadata follows the bitmap without full page alignment. So limit the last write to be only the required number of bytes, rounded up to the hard sector size of the device. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--drivers/md/bitmap.c17
-rw-r--r--include/linux/raid/bitmap.h1
2 files changed, 13 insertions, 5 deletions
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index e61e0efe9ec7..fd563a979bcf 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -255,19 +255,25 @@ static struct page *read_sb_page(mddev_t *mddev, long offset, unsigned long inde
}
-static int write_sb_page(mddev_t *mddev, long offset, struct page *page, int wait)
+static int write_sb_page(struct bitmap *bitmap, struct page *page, int wait)
{
mdk_rdev_t *rdev;
struct list_head *tmp;
+ mddev_t *mddev = bitmap->mddev;
ITERATE_RDEV(mddev, rdev, tmp)
if (test_bit(In_sync, &rdev->flags)
- && !test_bit(Faulty, &rdev->flags))
+ && !test_bit(Faulty, &rdev->flags)) {
+ int size = PAGE_SIZE;
+ if (page->index == bitmap->file_pages-1)
+ size = roundup(bitmap->last_page_size,
+ bdev_hardsect_size(rdev->bdev));
md_super_write(mddev, rdev,
- (rdev->sb_offset<<1) + offset
+ (rdev->sb_offset<<1) + bitmap->offset
+ page->index * (PAGE_SIZE/512),
- PAGE_SIZE,
+ size,
page);
+ }
if (wait)
md_super_wait(mddev);
@@ -282,7 +288,7 @@ static int write_page(struct bitmap *bitmap, struct page *page, int wait)
struct buffer_head *bh;
if (bitmap->file == NULL)
- return write_sb_page(bitmap->mddev, bitmap->offset, page, wait);
+ return write_sb_page(bitmap, page, wait);
bh = page_buffers(page);
@@ -923,6 +929,7 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
}
bitmap->filemap[bitmap->file_pages++] = page;
+ bitmap->last_page_size = count;
}
paddr = kmap_atomic(page, KM_USER0);
if (bitmap->flags & BITMAP_HOSTENDIAN)
diff --git a/include/linux/raid/bitmap.h b/include/linux/raid/bitmap.h
index 6db9a4c15355..dd5a05d03d4f 100644
--- a/include/linux/raid/bitmap.h
+++ b/include/linux/raid/bitmap.h
@@ -232,6 +232,7 @@ struct bitmap {
struct page **filemap; /* list of cache pages for the file */
unsigned long *filemap_attr; /* attributes associated w/ filemap pages */
unsigned long file_pages; /* number of pages in the file */
+ int last_page_size; /* bytes in the last page */
unsigned long flags;