From: Omar Sandoval <[email protected]> The comments here are really outdated, and blk-mq made flushing much simpler, so just fold the two cases into the callers.
Signed-off-by: Omar Sandoval <[email protected]> --- drivers/block/loop.c | 76 ++++++++-------------------------------------------- 1 file changed, 11 insertions(+), 65 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 6b1d932028e3..e60b4ac77577 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -546,72 +546,12 @@ static int do_req_filebacked(struct loop_device *lo, struct request *rq) } } -struct switch_request { - struct file *file; - struct completion wait; -}; - static inline void loop_update_dio(struct loop_device *lo) { __loop_update_dio(lo, io_is_direct(lo->lo_backing_file) | lo->use_dio); } -/* - * Do the actual switch; called from the BIO completion routine - */ -static void do_loop_switch(struct loop_device *lo, struct switch_request *p) -{ - struct file *file = p->file; - struct file *old_file = lo->lo_backing_file; - struct address_space *mapping; - - /* if no new file, only flush of queued bios requested */ - if (!file) - return; - - mapping = file->f_mapping; - mapping_set_gfp_mask(old_file->f_mapping, lo->old_gfp_mask); - lo->lo_backing_file = file; - lo->old_gfp_mask = mapping_gfp_mask(mapping); - mapping_set_gfp_mask(mapping, lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS)); - loop_update_dio(lo); -} - -/* - * loop_switch performs the hard work of switching a backing store. - * First it needs to flush existing IO, it does this by sending a magic - * BIO down the pipe. The completion of this BIO does the actual switch. - */ -static int loop_switch(struct loop_device *lo, struct file *file) -{ - struct switch_request w; - - w.file = file; - - /* freeze queue and wait for completion of scheduled requests */ - blk_mq_freeze_queue(lo->lo_queue); - - /* do the switch action */ - do_loop_switch(lo, &w); - - /* unfreeze */ - blk_mq_unfreeze_queue(lo->lo_queue); - - return 0; -} - -/* - * Helper to flush the IOs in loop, but keeping loop thread running - */ -static int loop_flush(struct loop_device *lo) -{ - /* loop not yet configured, no running thread, nothing to flush */ - if (lo->lo_state != Lo_bound) - return 0; - return loop_switch(lo, NULL); -} - static void loop_reread_partitions(struct loop_device *lo, struct block_device *bdev) { @@ -676,9 +616,14 @@ static int loop_change_fd(struct loop_device *lo, struct block_device *bdev, goto out_putf; /* and ... switch */ - error = loop_switch(lo, file); - if (error) - goto out_putf; + blk_mq_freeze_queue(lo->lo_queue); + mapping_set_gfp_mask(old_file->f_mapping, lo->old_gfp_mask); + lo->lo_backing_file = file; + lo->old_gfp_mask = mapping_gfp_mask(file->f_mapping); + mapping_set_gfp_mask(file->f_mapping, + lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS)); + loop_update_dio(lo); + blk_mq_unfreeze_queue(lo->lo_queue); fput(old_file); if (lo->lo_flags & LO_FLAGS_PARTSCAN) @@ -1601,12 +1546,13 @@ static void lo_release(struct gendisk *disk, fmode_t mode) err = loop_clr_fd(lo); if (!err) return; - } else { + } else if (lo->lo_state == Lo_bound) { /* * Otherwise keep thread (if running) and config, * but flush possible ongoing bios in thread. */ - loop_flush(lo); + blk_mq_freeze_queue(lo->lo_queue); + blk_mq_unfreeze_queue(lo->lo_queue); } mutex_unlock(&lo->lo_ctl_mutex); -- 2.14.1
