Commit ac8672ea authored by Tejun Heo's avatar Tejun Heo Committed by Jeff Garzik

libata: fix off-by-one error in ata_tf_read_block()

ata_tf_read_block() has off-by-one error when converting CHS address
to LBA.  The bug isn't very visible because ata_tf_read_block() is
used only when generating sense data for a failed RW command and CHS
addressing isn't used too often these days.

This problem was spotted by Atsushi Nemoto.
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Reported-by: default avatarAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: default avatarJeff Garzik <jgarzik@redhat.com>
parent 1b549dcb
...@@ -709,7 +709,13 @@ u64 ata_tf_read_block(struct ata_taskfile *tf, struct ata_device *dev) ...@@ -709,7 +709,13 @@ u64 ata_tf_read_block(struct ata_taskfile *tf, struct ata_device *dev)
head = tf->device & 0xf; head = tf->device & 0xf;
sect = tf->lbal; sect = tf->lbal;
block = (cyl * dev->heads + head) * dev->sectors + sect; if (!sect) {
ata_dev_printk(dev, KERN_WARNING, "device reported "
"invalid CHS sector 0\n");
sect = 1; /* oh well */
}
block = (cyl * dev->heads + head) * dev->sectors + sect - 1;
} }
return block; return block;
......
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