diff options
| -rw-r--r-- | drivers/block/loop.c | 38 |
1 files changed, 35 insertions, 3 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c index fb06ed65921..66cfff79938 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -624,20 +624,38 @@ static int loop_switch(struct loop_device *lo, struct file *file) } /* + * 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_thread) + return 0; + + return loop_switch(lo, NULL); +} + +/* * 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 = file->f_mapping; + struct address_space *mapping; + + /* if no new file, only flush of queued bios requested */ + if (!file) + goto out; + mapping = file->f_mapping; mapping_set_gfp_mask(old_file->f_mapping, lo->old_gfp_mask); lo->lo_backing_file = file; lo->lo_blocksize = S_ISBLK(mapping->host->i_mode) ? mapping->host->i_bdev->bd_block_size : PAGE_SIZE; lo->old_gfp_mask = mapping_gfp_mask(mapping); mapping_set_gfp_mask(mapping, lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS)); +out: complete(&p->wait); } @@ -1345,11 +1363,25 @@ static int lo_release(struct gendisk *disk, fmode_t mode) struct loop_device *lo = disk->private_data; mutex_lock(&lo->lo_ctl_mutex); - --lo->lo_refcnt; - if ((lo->lo_flags & LO_FLAGS_AUTOCLEAR) && !lo->lo_refcnt) + if (--lo->lo_refcnt) + goto out; + + if (lo->lo_flags & LO_FLAGS_AUTOCLEAR) { + /* + * In autoclear mode, stop the loop thread + * and remove configuration after last close. + */ loop_clr_fd(lo, NULL); + } else { + /* + * Otherwise keep thread (if running) and config, + * but flush possible ongoing bios in thread. + */ + loop_flush(lo); + } +out: mutex_unlock(&lo->lo_ctl_mutex); return 0; |