Commit 6b7d6e93 authored Nov 01, 2017 by Nikolay Borisov Committed by David Sterba Jan 22, 2018

btrfs: Move loop termination condition in while()

Fallocating a file in btrfs goes through several stages. The one before
actually inserting the fallocated extents is to create a qgroup
reservation, covering the desired range. To this end there is a loop in
btrfs_fallocate which checks to see if there are holes in the fallocated
range or !PREALLOC extents past EOF and if so create qgroup reservations
for them. Unfortunately, the main condition of the loop is burried right
at the end of its body rather than in the actual while statement which
makes it non-obvious. Fix this by moving the condition in the while
statement where it belongs. No functional changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

parent 47dba171

fs/btrfs/file.c

+1 −3

Original line number	Diff line number	Diff line
		@@ -2922,7 +2922,7 @@ static long btrfs_fallocate(struct file *file, int mode,

		/* First, check if we exceed the qgroup limit */
		INIT_LIST_HEAD(&reserve_list);
		while (1) {
		while (cur_offset < alloc_end) {
		em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, cur_offset,
		alloc_end - cur_offset, 0);
		if (IS_ERR(em)) {
		@@ -2958,8 +2958,6 @@ static long btrfs_fallocate(struct file *file, int mode,
		}
		free_extent_map(em);
		cur_offset = last_byte;
		if (cur_offset >= alloc_end)
		break;
		}

		/*

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