Commit 51b86f9a authored by Michael Lass's avatar Michael Lass Committed by Mike Snitzer

dm: make sure to obey max_io_len_target_boundary

Commit 61697a6a ("dm: eliminate 'split_discard_bios' flag from DM
target interface") incorrectly removed code from
__send_changing_extent_only() that is required to impose a per-target IO
boundary on IO that exceeds max_io_len_target_boundary().  Otherwise
"special" IO (e.g. DISCARD, WRITE SAME, WRITE ZEROES) can write beyond
where allowed.

Fix this by restoring the max_io_len_target_boundary() limit in
__send_changing_extent_only()

Fixes: 61697a6a ("dm: eliminate 'split_discard_bios' flag from DM target interface")
Cc: stable@vger.kernel.org # 5.1+
Signed-off-by: default avatarMichael Lass <bevan@bi-co.net>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent 8454fca4
......@@ -1469,7 +1469,7 @@ static unsigned get_num_write_zeroes_bios(struct dm_target *ti)
static int __send_changing_extent_only(struct clone_info *ci, struct dm_target *ti,
unsigned num_bios)
{
unsigned len = ci->sector_count;
unsigned len;
/*
* Even though the device advertised support for this type of
......@@ -1480,6 +1480,8 @@ static int __send_changing_extent_only(struct clone_info *ci, struct dm_target *
if (!num_bios)
return -EOPNOTSUPP;
len = min((sector_t)ci->sector_count, max_io_len_target_boundary(ci->sector, ti));
__send_duplicate_bios(ci, ti, num_bios, &len);
ci->sector += len;
......
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