From: Omar Sandoval <osandov@xxxxxx>
The comments here are really outdated, and blk-mq made flushing much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 <osandov@xxxxxx>
---
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
