From 1fdb8188c3d505452b40cdb365b1bb32be533a8e Mon Sep 17 00:00:00 2001 From: Yunlong Xing Date: Mon, 14 Apr 2025 11:01:59 +0800 Subject: loop: aio inherit the ioprio of original request Set cmd->iocb.ki_ioprio to the ioprio of loop device's request. The purpose is to inherit the original request ioprio in the aio flow. Signed-off-by: Yunlong Xing Signed-off-by: Zhiguo Niu Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20250414030159.501180-1-yunlong.xing@unisoc.com Signed-off-by: Jens Axboe --- drivers/block/loop.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/block/loop.c') diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 674527d770dc..dd7f33d47f4f 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -447,7 +447,7 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd, cmd->iocb.ki_filp = file; cmd->iocb.ki_complete = lo_rw_aio_complete; cmd->iocb.ki_flags = IOCB_DIRECT; - cmd->iocb.ki_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 0); + cmd->iocb.ki_ioprio = req_get_ioprio(rq); if (rw == ITER_SOURCE) ret = file->f_op->write_iter(&cmd->iocb, &iter); -- cgit v1.2.3 From e7bc0010ceb403d025100698586c8e760921d471 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= Date: Tue, 15 Apr 2025 10:51:47 +0200 Subject: loop: properly send KOBJ_CHANGED uevent for disk device MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The original commit message and the wording "uncork" in the code comment indicate that it is expected that the suppressed event instances are automatically sent after unsuppressing. This is not the case, instead they are discarded. In effect this means that no "changed" events are emitted on the device itself by default. While each discovered partition does trigger a changed event on the device, devices without partitions don't have any event emitted. This makes udev miss the device creation and prompted workarounds in userspace. See the linked util-linux/losetup bug. Explicitly emit the events and drop the confusingly worded comments. Link: https://github.com/util-linux/util-linux/issues/2434 Fixes: 498ef5c777d9 ("loop: suppress uevents while reconfiguring the device") Cc: stable@vger.kernel.org Signed-off-by: Thomas Weißschuh Link: https://lore.kernel.org/r/20250415-loop-uevent-changed-v2-1-0c4e6a923b2a@linutronix.de Signed-off-by: Jens Axboe --- drivers/block/loop.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/block/loop.c') diff --git a/drivers/block/loop.c b/drivers/block/loop.c index dd7f33d47f4f..3be7f00e7fc7 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -667,8 +667,8 @@ static int loop_change_fd(struct loop_device *lo, struct block_device *bdev, error = 0; done: - /* enable and uncork uevent now that we are done */ dev_set_uevent_suppress(disk_to_dev(lo->lo_disk), 0); + kobject_uevent(&disk_to_dev(lo->lo_disk)->kobj, KOBJ_CHANGE); return error; out_err: @@ -1129,8 +1129,8 @@ static int loop_configure(struct loop_device *lo, blk_mode_t mode, if (partscan) clear_bit(GD_SUPPRESS_PART_SCAN, &lo->lo_disk->state); - /* enable and uncork uevent now that we are done */ dev_set_uevent_suppress(disk_to_dev(lo->lo_disk), 0); + kobject_uevent(&disk_to_dev(lo->lo_disk)->kobj, KOBJ_CHANGE); loop_global_unlock(lo, is_loop); if (partscan) -- cgit v1.2.3 From 0dba7a05b9e47d8b546399117b0ddf2426dc6042 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= Date: Tue, 15 Apr 2025 16:55:06 +0200 Subject: loop: LOOP_SET_FD: send uevents for partitions MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Remove the suppression of the uevents before scanning for partitions. The partitions inherit their suppression settings from their parent device, which lead to the uevents being dropped. This is similar to the same changes for LOOP_CONFIGURE done in commit bb430b694226 ("loop: LOOP_CONFIGURE: send uevents for partitions"). Fixes: 498ef5c777d9 ("loop: suppress uevents while reconfiguring the device") Cc: stable@vger.kernel.org Signed-off-by: Thomas Weißschuh Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20250415-loop-uevent-changed-v3-1-60ff69ac6088@linutronix.de Signed-off-by: Jens Axboe --- drivers/block/loop.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/block/loop.c') diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 3be7f00e7fc7..e9ec7a45f3f2 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -662,12 +662,12 @@ static int loop_change_fd(struct loop_device *lo, struct block_device *bdev, * dependency. */ fput(old_file); + dev_set_uevent_suppress(disk_to_dev(lo->lo_disk), 0); if (partscan) loop_reread_partitions(lo); error = 0; done: - dev_set_uevent_suppress(disk_to_dev(lo->lo_disk), 0); kobject_uevent(&disk_to_dev(lo->lo_disk)->kobj, KOBJ_CHANGE); return error; @@ -675,6 +675,7 @@ out_err: loop_global_unlock(lo, is_loop); out_putf: fput(file); + dev_set_uevent_suppress(disk_to_dev(lo->lo_disk), 0); goto done; } -- cgit v1.2.3 From f2fed441c69b9237760840a45a004730ff324faf Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 9 Apr 2025 15:09:40 +0200 Subject: loop: stop using vfs_iter_{read,write} for buffered I/O vfs_iter_{read,write} always perform direct I/O when the file has the O_DIRECT flag set, which breaks disabling direct I/O using the LOOP_SET_STATUS / LOOP_SET_STATUS64 ioctls. This was recenly reported as a regression, but as far as I can tell was only uncovered by better checking for block sizes and has been around since the direct I/O support was added. Fix this by using the existing aio code that calls the raw read/write iter methods instead. Note that despite the comments there is no need for block drivers to ever call flush_dcache_page themselves, and the call is a left-over from prehistoric times. Fixes: ab1cb278bc70 ("block: loop: introduce ioctl command of LOOP_SET_DIRECT_IO") Reported-by: Darrick J. Wong Signed-off-by: Christoph Hellwig Reviewed-by: Ming Lei Tested-by: Darrick J. Wong Link: https://lore.kernel.org/r/20250409130940.3685677-1-hch@lst.de Signed-off-by: Jens Axboe --- drivers/block/loop.c | 112 ++++++++------------------------------------------- 1 file changed, 17 insertions(+), 95 deletions(-) (limited to 'drivers/block/loop.c') diff --git a/drivers/block/loop.c b/drivers/block/loop.c index e9ec7a45f3f2..46cba261075f 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -211,72 +211,6 @@ static void loop_set_size(struct loop_device *lo, loff_t size) kobject_uevent(&disk_to_dev(lo->lo_disk)->kobj, KOBJ_CHANGE); } -static int lo_write_bvec(struct file *file, struct bio_vec *bvec, loff_t *ppos) -{ - struct iov_iter i; - ssize_t bw; - - iov_iter_bvec(&i, ITER_SOURCE, bvec, 1, bvec->bv_len); - - bw = vfs_iter_write(file, &i, ppos, 0); - - if (likely(bw == bvec->bv_len)) - return 0; - - printk_ratelimited(KERN_ERR - "loop: Write error at byte offset %llu, length %i.\n", - (unsigned long long)*ppos, bvec->bv_len); - if (bw >= 0) - bw = -EIO; - return bw; -} - -static int lo_write_simple(struct loop_device *lo, struct request *rq, - loff_t pos) -{ - struct bio_vec bvec; - struct req_iterator iter; - int ret = 0; - - rq_for_each_segment(bvec, rq, iter) { - ret = lo_write_bvec(lo->lo_backing_file, &bvec, &pos); - if (ret < 0) - break; - cond_resched(); - } - - return ret; -} - -static int lo_read_simple(struct loop_device *lo, struct request *rq, - loff_t pos) -{ - struct bio_vec bvec; - struct req_iterator iter; - struct iov_iter i; - ssize_t len; - - rq_for_each_segment(bvec, rq, iter) { - iov_iter_bvec(&i, ITER_DEST, &bvec, 1, bvec.bv_len); - len = vfs_iter_read(lo->lo_backing_file, &i, &pos, 0); - if (len < 0) - return len; - - flush_dcache_page(bvec.bv_page); - - if (len != bvec.bv_len) { - struct bio *bio; - - __rq_for_each_bio(bio, rq) - zero_fill_bio(bio); - break; - } - cond_resched(); - } - - return 0; -} - static void loop_clear_limits(struct loop_device *lo, int mode) { struct queue_limits lim = queue_limits_start_update(lo->lo_queue); @@ -342,7 +276,7 @@ static void lo_complete_rq(struct request *rq) struct loop_cmd *cmd = blk_mq_rq_to_pdu(rq); blk_status_t ret = BLK_STS_OK; - if (!cmd->use_aio || cmd->ret < 0 || cmd->ret == blk_rq_bytes(rq) || + if (cmd->ret < 0 || cmd->ret == blk_rq_bytes(rq) || req_op(rq) != REQ_OP_READ) { if (cmd->ret < 0) ret = errno_to_blk_status(cmd->ret); @@ -358,14 +292,13 @@ static void lo_complete_rq(struct request *rq) cmd->ret = 0; blk_mq_requeue_request(rq, true); } else { - if (cmd->use_aio) { - struct bio *bio = rq->bio; + struct bio *bio = rq->bio; - while (bio) { - zero_fill_bio(bio); - bio = bio->bi_next; - } + while (bio) { + zero_fill_bio(bio); + bio = bio->bi_next; } + ret = BLK_STS_IOERR; end_io: blk_mq_end_request(rq, ret); @@ -445,9 +378,14 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd, cmd->iocb.ki_pos = pos; cmd->iocb.ki_filp = file; - cmd->iocb.ki_complete = lo_rw_aio_complete; - cmd->iocb.ki_flags = IOCB_DIRECT; cmd->iocb.ki_ioprio = req_get_ioprio(rq); + if (cmd->use_aio) { + cmd->iocb.ki_complete = lo_rw_aio_complete; + cmd->iocb.ki_flags = IOCB_DIRECT; + } else { + cmd->iocb.ki_complete = NULL; + cmd->iocb.ki_flags = 0; + } if (rw == ITER_SOURCE) ret = file->f_op->write_iter(&cmd->iocb, &iter); @@ -458,7 +396,7 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd, if (ret != -EIOCBQUEUED) lo_rw_aio_complete(&cmd->iocb, ret); - return 0; + return -EIOCBQUEUED; } static int do_req_filebacked(struct loop_device *lo, struct request *rq) @@ -466,15 +404,6 @@ static int do_req_filebacked(struct loop_device *lo, struct request *rq) struct loop_cmd *cmd = blk_mq_rq_to_pdu(rq); loff_t pos = ((loff_t) blk_rq_pos(rq) << 9) + lo->lo_offset; - /* - * lo_write_simple and lo_read_simple should have been covered - * by io submit style function like lo_rw_aio(), one blocker - * is that lo_read_simple() need to call flush_dcache_page after - * the page is written from kernel, and it isn't easy to handle - * this in io submit style function which submits all segments - * of the req at one time. And direct read IO doesn't need to - * run flush_dcache_page(). - */ switch (req_op(rq)) { case REQ_OP_FLUSH: return lo_req_flush(lo, rq); @@ -490,15 +419,9 @@ static int do_req_filebacked(struct loop_device *lo, struct request *rq) case REQ_OP_DISCARD: return lo_fallocate(lo, rq, pos, FALLOC_FL_PUNCH_HOLE); case REQ_OP_WRITE: - if (cmd->use_aio) - return lo_rw_aio(lo, cmd, pos, ITER_SOURCE); - else - return lo_write_simple(lo, rq, pos); + return lo_rw_aio(lo, cmd, pos, ITER_SOURCE); case REQ_OP_READ: - if (cmd->use_aio) - return lo_rw_aio(lo, cmd, pos, ITER_DEST); - else - return lo_read_simple(lo, rq, pos); + return lo_rw_aio(lo, cmd, pos, ITER_DEST); default: WARN_ON_ONCE(1); return -EIO; @@ -1922,7 +1845,6 @@ static void loop_handle_cmd(struct loop_cmd *cmd) struct loop_device *lo = rq->q->queuedata; int ret = 0; struct mem_cgroup *old_memcg = NULL; - const bool use_aio = cmd->use_aio; if (write && (lo->lo_flags & LO_FLAGS_READ_ONLY)) { ret = -EIO; @@ -1952,7 +1874,7 @@ static void loop_handle_cmd(struct loop_cmd *cmd) } failed: /* complete non-aio request */ - if (!use_aio || ret) { + if (ret != -EIOCBQUEUED) { if (ret == -EOPNOTSUPP) cmd->ret = ret; else -- cgit v1.2.3