linux/drivers/block/loop.c, branch v4.14

loop: set physical block size to logical block size

2017-09-06T17:08:49Z

Commit 6c6b6f28b333 ("loop: set physical block size to PAGE_SIZE") caused mkfs.xfs to barf on ppc64 [1]. Always using PAGE_SIZE as the physical block size still makes the most sense semantically, but let's just lie and always set it to the same value as the logical block size (same goes for io_min). In the future we might want to at least bump up io_min to PAGE_SIZE but I'm sick of these stupid changes so let's play it safe. 1: https://marc.info/?l=linux-xfs&m=150459024723753&w=2 Tested-by: Chandan Rajendra Signed-off-by: Omar Sandoval Signed-off-by: Jens Axboe

block/loop: fix use after free

2017-09-01T19:57:33Z

lo_rw_aio->call_read_iter-> 1 aops->direct_IO 2 iov_iter_revert lo_rw_aio_complete could happen between 1 and 2, the bio and bvec could be freed before 2, which accesses bvec. Signed-off-by: Shaohua Li Signed-off-by: Jens Axboe

block/loop: allow request merge for directio mode

2017-09-01T14:44:34Z

Currently loop disables merge. While it makes sense for buffer IO mode, directio mode can benefit from request merge. Without merge, loop could send small size IO to underlayer disk and harm performance. Reviewed-by: Omar Sandoval Signed-off-by: Shaohua Li Signed-off-by: Jens Axboe

block/loop: set hw_sectors

2017-09-01T14:44:32Z

Loop can handle any size of request. Limiting it to 255 sectors just burns the CPU for bio split and request merge for underlayer disk and also cause bad fs block allocation in directio mode. Reviewed-by: Omar Sandoval Reviewed-by: Ming Lei Signed-off-by: Shaohua Li Signed-off-by: Jens Axboe

loop: fold loop_switch() into callers

2017-08-31T19:51:16Z

The comments here are really outdated, and blk-mq made flushing much simpler, so just fold the two cases into the callers. Reviewed-by: Ming Lei Reviewed-by: Hannes Reinecke Signed-off-by: Omar Sandoval Signed-off-by: Jens Axboe

loop: add ioctl for changing logical block size

2017-08-31T19:51:14Z

This is a different approach from the first attempt in f2c6df7dbf9a ("loop: support 4k physical blocksize"). Rather than extending LOOP_{GET,SET}_STATUS, add a separate ioctl just for setting the block size. Reviewed-by: Ming Lei Reviewed-by: Hannes Reinecke Signed-off-by: Omar Sandoval Signed-off-by: Jens Axboe

loop: set physical block size to PAGE_SIZE

2017-08-31T19:51:12Z

The physical block size is "the lowest possible sector size that the hardware can operate on without reverting to read-modify-write operations" (from the comment on blk_queue_physical_block_size()). Since loop does buffered I/O on the backing file by default, the RMW unit is a page. This isn't the case for direct I/O mode, but let's keep it simple. Reviewed-by: Ming Lei Reviewed-by: Hannes Reinecke Signed-off-by: Omar Sandoval Signed-off-by: Jens Axboe

loop: get rid of lo_blocksize

2017-08-31T19:51:10Z

This is only used for setting the soft block size on the struct block_device once and then never used again. Reviewed-by: Ming Lei Reviewed-by: Hannes Reinecke Signed-off-by: Omar Sandoval Signed-off-by: Jens Axboe

Merge tag 'v4.13-rc7' into for-4.14/block-postmerge

2017-08-28T19:00:44Z

Linux 4.13-rc7 Signed-off-by: Jens Axboe

Revert "loop: support 4k physical blocksize"

2017-08-23T21:57:55Z

There's some stuff still up in the air, let's not get stuck with a subpar ABI. I'll follow up with something better for 4.14. Signed-off-by: Omar Sandoval Signed-off-by: Jens Axboe