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authorNeilBrown <neilb@suse.de>2008-12-19 16:25:01 +1100
committerNeilBrown <neilb@suse.de>2008-12-19 16:25:01 +1100
commita2ed9615e3222645007fc19991aedf30eed3ecfd (patch)
tree2a07cc815f5c348f085ad96a5660e3213da955f4 /drivers
parent55dac3a5553b13891f0ae4bbd11920619b5436d4 (diff)
downloadconfigs-a2ed9615e3222645007fc19991aedf30eed3ecfd.tar.gz
md: Don't read past end of bitmap when reading bitmap.
When we read the write-intent-bitmap off the device, we currently read a whole number of pages. When PAGE_SIZE is 4K, this works due to the alignment we enforce on the superblock and bitmap. When PAGE_SIZE is 64K, this case read past the end-of-device which causes an error. When we write the superblock, we ensure to clip the last page to just be the required size. Copy that code into the read path to just read the required number of sectors. Signed-off-by: Neil Brown <neilb@suse.de> Cc: stable@kernel.org
Diffstat (limited to 'drivers')
-rw-r--r--drivers/md/bitmap.c22
1 files changed, 17 insertions, 5 deletions
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index ac89a5deaca..ab7c8e4a61f 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -208,16 +208,19 @@ static void bitmap_checkfree(struct bitmap *bitmap, unsigned long page)
*/
/* IO operations when bitmap is stored near all superblocks */
-static struct page *read_sb_page(mddev_t *mddev, long offset, unsigned long index)
+static struct page *read_sb_page(mddev_t *mddev, long offset,
+ struct page *page,
+ unsigned long index, int size)
{
/* choose a good rdev and read the page from there */
mdk_rdev_t *rdev;
struct list_head *tmp;
- struct page *page = alloc_page(GFP_KERNEL);
sector_t target;
if (!page)
+ page = alloc_page(GFP_KERNEL);
+ if (!page)
return ERR_PTR(-ENOMEM);
rdev_for_each(rdev, tmp, mddev) {
@@ -227,7 +230,9 @@ static struct page *read_sb_page(mddev_t *mddev, long offset, unsigned long inde
target = rdev->sb_start + offset + index * (PAGE_SIZE/512);
- if (sync_page_io(rdev->bdev, target, PAGE_SIZE, page, READ)) {
+ if (sync_page_io(rdev->bdev, target,
+ roundup(size, bdev_hardsect_size(rdev->bdev)),
+ page, READ)) {
page->index = index;
attach_page_buffers(page, NULL); /* so that free_buffer will
* quietly no-op */
@@ -544,7 +549,9 @@ static int bitmap_read_sb(struct bitmap *bitmap)
bitmap->sb_page = read_page(bitmap->file, 0, bitmap, bytes);
} else {
- bitmap->sb_page = read_sb_page(bitmap->mddev, bitmap->offset, 0);
+ bitmap->sb_page = read_sb_page(bitmap->mddev, bitmap->offset,
+ NULL,
+ 0, sizeof(bitmap_super_t));
}
if (IS_ERR(bitmap->sb_page)) {
err = PTR_ERR(bitmap->sb_page);
@@ -957,11 +964,16 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
*/
page = bitmap->sb_page;
offset = sizeof(bitmap_super_t);
+ read_sb_page(bitmap->mddev, bitmap->offset,
+ page,
+ index, count);
} else if (file) {
page = read_page(file, index, bitmap, count);
offset = 0;
} else {
- page = read_sb_page(bitmap->mddev, bitmap->offset, index);
+ page = read_sb_page(bitmap->mddev, bitmap->offset,
+ NULL,
+ index, count);
offset = 0;
}
if (IS_ERR(page)) { /* read error */