From 45c4d015a92f72ec47acd0c7557abdc0c8a6499d Mon Sep 17 00:00:00 2001 From: Mark Lord Date: Wed, 7 Apr 2010 13:52:08 -0400 Subject: libata: Fix accesses at LBA28 boundary (old bug, but nasty) (v2) Most drives from Seagate, Hitachi, and possibly other brands, do not allow LBA28 access to sector number 0x0fffffff (2^28 - 1). So instead use LBA48 for such accesses. This bug could bite a lot of systems, especially when the user has taken care to align partitions to 4KB boundaries. On misaligned systems, it is less likely to be encountered, since a 4KB read would end at 0x10000000 rather than at 0x0fffffff. Signed-off-by: Mark Lord Signed-off-by: Jeff Garzik --- include/linux/ata.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/linux/ata.h b/include/linux/ata.h index b4c85e2adef..700c5b9b358 100644 --- a/include/linux/ata.h +++ b/include/linux/ata.h @@ -1025,8 +1025,8 @@ static inline int ata_ok(u8 status) static inline int lba_28_ok(u64 block, u32 n_block) { - /* check the ending block number */ - return ((block + n_block) < ((u64)1 << 28)) && (n_block <= 256); + /* check the ending block number: must be LESS THAN 0x0fffffff */ + return ((block + n_block) < ((1 << 28) - 1)) && (n_block <= 256); } static inline int lba_48_ok(u64 block, u32 n_block) -- cgit v1.2.3