Commit f278eb3d8178 ("block: hold ->invalidate_lock in blkdev_fallocate")
adds ->invalidate_lock in blkdev_fallocate() for preventing stale data
from being read during fallocate().
However, the side effect is that blkdev_fallocate() becomes serialized
since blkdev_fallocate() always blocks.
Add one atomic fallocate counter for allowing blkdev_fallocate() to
be run concurrently so that discard/write_zero bios from different
fallocate() can be submitted in parallel.
Cc: Jan Kara <jack@xxxxxxx>
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
block/fops.c | 6 ++++--
include/linux/blk_types.h | 2 ++
2 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/block/fops.c b/block/fops.c
index 9f2ecec406b0..368866b15e68 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -651,7 +651,8 @@ static long blkdev_fallocate(struct file *file, int mode, loff_t start,
if ((start | len) & (bdev_logical_block_size(bdev) - 1))
return -EINVAL;
- filemap_invalidate_lock(inode->i_mapping);
+ if (atomic_inc_return(&bdev->bd_fallocate_count) == 1)
+ filemap_invalidate_lock(inode->i_mapping);
/* Invalidate the page cache, including dirty pages. */
error = truncate_bdev_range(bdev, file->f_mode, start, end);
@@ -679,7 +680,8 @@ static long blkdev_fallocate(struct file *file, int mode, loff_t start,
}
fail:
- filemap_invalidate_unlock(inode->i_mapping);
+ if (!atomic_dec_return(&bdev->bd_fallocate_count))
+ filemap_invalidate_unlock(inode->i_mapping);
return error;
}
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 1973ef9bd40f..9ccd841ea8ed 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -58,6 +58,8 @@ struct block_device {
struct gendisk * bd_disk;
struct request_queue * bd_queue;
+ atomic_t bd_fallocate_count;
+
/* The counter of freeze processes */
int bd_fsfreeze_count;
/* Mutex for freeze */
--
2.31.1
