Commit 2a162ce9 authored Apr 06, 2015 by Davide Italiano Committed by David Sterba Apr 04, 2016

Btrfs: Improve FL_KEEP_SIZE handling in fallocate



- We call inode_size_ok() only if FL_KEEP_SIZE isn't specified.
- As an optimisation we can skip the call if (off + len)
  isn't greater than the current size of the file. This operation
  is called under the lock so the less work we do, the better.
- If we call inode_size_ok() pass to it the correct value rather
  than a more conservative estimation.

Signed-off-by: Davide Italiano <dccitaliano@gmail.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

parent 232cad84

fs/btrfs/file.c

+6 −3

Original line number	Diff line number	Diff line
		@@ -2682,9 +2682,12 @@ static long btrfs_fallocate(struct file *file, int mode,
		return ret;

		inode_lock(inode);
		ret = inode_newsize_ok(inode, alloc_end);

		if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size) {
		ret = inode_newsize_ok(inode, offset + len);
		if (ret)
		goto out;
		}

		/*
		* TODO: Move these two operations after we have checked