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| author | NeilBrown <neilb@cse.unsw.edu.au> | 2005-09-09 16:23:53 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-09-09 16:39:12 -0700 |
| commit | 0002b2718dd04da67c21f8a7830de8d95a9b0345 (patch) | |
| tree | c84f916df71293e0e15643a8a07d9508d1404395 /drivers/md | |
| parent | 773f7834425e83144c95fbbc553ced3c2b74b828 (diff) | |
| download | linux-0002b2718dd04da67c21f8a7830de8d95a9b0345.tar.bz2 | |
[PATCH] md: limit size of sb read/written to appropriate amount
version-1 superblocks are not (normally) 4K long, and can be of variable size.
Writing the full 4K can cause corruption (but only in non-default
configurations).
With this patch the super-block-flavour can choose a size to read, and set a
size to write based on what it finds.
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>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/md.c | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c index 1be3f2de396b..be7873c61b3c 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -393,7 +393,7 @@ int sync_page_io(struct block_device *bdev, sector_t sector, int size, return ret; } -static int read_disk_sb(mdk_rdev_t * rdev) +static int read_disk_sb(mdk_rdev_t * rdev, int size) { char b[BDEVNAME_SIZE]; if (!rdev->sb_page) { @@ -404,7 +404,7 @@ static int read_disk_sb(mdk_rdev_t * rdev) return 0; - if (!sync_page_io(rdev->bdev, rdev->sb_offset<<1, MD_SB_BYTES, rdev->sb_page, READ)) + if (!sync_page_io(rdev->bdev, rdev->sb_offset<<1, size, rdev->sb_page, READ)) goto fail; rdev->sb_loaded = 1; return 0; @@ -531,7 +531,7 @@ static int super_90_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version sb_offset = calc_dev_sboffset(rdev->bdev); rdev->sb_offset = sb_offset; - ret = read_disk_sb(rdev); + ret = read_disk_sb(rdev, MD_SB_BYTES); if (ret) return ret; ret = -EINVAL; @@ -564,6 +564,7 @@ static int super_90_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version rdev->preferred_minor = sb->md_minor; rdev->data_offset = 0; + rdev->sb_size = MD_SB_BYTES; if (sb->level == LEVEL_MULTIPATH) rdev->desc_nr = -1; @@ -837,6 +838,7 @@ static int super_1_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version) int ret; sector_t sb_offset; char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE]; + int bmask; /* * Calculate the position of the superblock. @@ -865,7 +867,10 @@ static int super_1_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version) } rdev->sb_offset = sb_offset; - ret = read_disk_sb(rdev); + /* superblock is rarely larger than 1K, but it can be larger, + * and it is safe to read 4k, so we do that + */ + ret = read_disk_sb(rdev, 4096); if (ret) return ret; @@ -891,6 +896,11 @@ static int super_1_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version) rdev->preferred_minor = 0xffff; rdev->data_offset = le64_to_cpu(sb->data_offset); + rdev->sb_size = le32_to_cpu(sb->max_dev) * 2 + 256; + bmask = block_size(rdev->bdev)-1; + if (rdev->sb_size & bmask) + rdev-> sb_size = (rdev->sb_size | bmask)+1; + if (refdev == 0) return 1; else { @@ -1375,7 +1385,7 @@ repeat: dprintk("%s ", bdevname(rdev->bdev,b)); if (!rdev->faulty) { md_super_write(mddev,rdev, - rdev->sb_offset<<1, MD_SB_BYTES, + rdev->sb_offset<<1, rdev->sb_size, rdev->sb_page); dprintk(KERN_INFO "(write) %s's sb offset: %llu\n", bdevname(rdev->bdev,b), |