hfsplus: fix overflow in hfsplus_get_block

For filesystems larger than 2TB the final sector number passed to
map_bh might overflow the range representable in a 32-bit data type.
Make sure we use a sector_t for it and the arithmetics calculating it.

Signed-off-by: Christoph Hellwig <hch@tuxera.com>
This commit is contained in:
Christoph Hellwig 2011-02-16 09:34:17 +01:00 committed by Christoph Hellwig
parent 2b4f9ca8a5
commit bf1a1b31fa

View File

@ -209,6 +209,7 @@ int hfsplus_get_block(struct inode *inode, sector_t iblock,
struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
int res = -EIO;
u32 ablock, dblock, mask;
sector_t sector;
int was_dirty = 0;
int shift;
@ -255,10 +256,12 @@ int hfsplus_get_block(struct inode *inode, sector_t iblock,
done:
dprint(DBG_EXTENT, "get_block(%lu): %llu - %u\n",
inode->i_ino, (long long)iblock, dblock);
mask = (1 << sbi->fs_shift) - 1;
map_bh(bh_result, sb,
(dblock << sbi->fs_shift) + sbi->blockoffset +
(iblock & mask));
sector = ((sector_t)dblock << sbi->fs_shift) +
sbi->blockoffset + (iblock & mask);
map_bh(bh_result, sb, sector);
if (create) {
set_buffer_new(bh_result);
hip->phys_size += sb->s_blocksize;