3.13.11-ckt19 -stable review patch. If anyone has any objections, please let me know.
------------------ From: "Darrick J. Wong" <[email protected]> commit e5db29806b99ce2b2640d2e4d4fcb983cea115c5 upstream. Since it's possible for the discard and write same queue limits to change while the upper level command is being sliced and diced, fix up both of them (a) to reject IO if the special command is unsupported at the start of the function and (b) read the limits once and let the commands error out on their own if the status happens to change. Signed-off-by: Darrick J. Wong <[email protected]> Signed-off-by: Mikulas Patocka <[email protected]> Signed-off-by: Mike Snitzer <[email protected]> Signed-off-by: Kamal Mostafa <[email protected]> --- drivers/md/dm-io.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c index 951addc..d4e1a17 100644 --- a/drivers/md/dm-io.c +++ b/drivers/md/dm-io.c @@ -289,9 +289,16 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where, struct request_queue *q = bdev_get_queue(where->bdev); unsigned short logical_block_size = queue_logical_block_size(q); sector_t num_sectors; + unsigned int uninitialized_var(special_cmd_max_sectors); - /* Reject unsupported discard requests */ - if ((rw & REQ_DISCARD) && !blk_queue_discard(q)) { + /* + * Reject unsupported discard and write same requests. + */ + if (rw & REQ_DISCARD) + special_cmd_max_sectors = q->limits.max_discard_sectors; + else if (rw & REQ_WRITE_SAME) + special_cmd_max_sectors = q->limits.max_write_same_sectors; + if ((rw & (REQ_DISCARD | REQ_WRITE_SAME)) && special_cmd_max_sectors == 0) { dec_count(io, region, -EOPNOTSUPP); return; } @@ -317,7 +324,7 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where, store_io_and_region_in_bio(bio, io, region); if (rw & REQ_DISCARD) { - num_sectors = min_t(sector_t, q->limits.max_discard_sectors, remaining); + num_sectors = min_t(sector_t, special_cmd_max_sectors, remaining); bio->bi_size = num_sectors << SECTOR_SHIFT; remaining -= num_sectors; } else if (rw & REQ_WRITE_SAME) { @@ -326,7 +333,7 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where, */ dp->get_page(dp, &page, &len, &offset); bio_add_page(bio, page, logical_block_size, offset); - num_sectors = min_t(sector_t, q->limits.max_write_same_sectors, remaining); + num_sectors = min_t(sector_t, special_cmd_max_sectors, remaining); bio->bi_size = num_sectors << SECTOR_SHIFT; offset = 0; -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
