[PATCH 4/4] Btrfs: remove no longer needed range length checks for deduplication

[fdmanana@kernel.org]

From: Filipe Manana <fdmanana@suse.com>

Comparing the content of the pages in the range to deduplicate is now done
by the generic helper generic_remap_file_range_prep(), which takes care of
ensuring we do not compare/deduplicate undefined data beyond a file's eof
(range from eof to the next block boundary). So remove these checks which
are now redundant.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
---
 fs/btrfs/ioctl.c | 19 ++-----------------
 1 file changed, 2 insertions(+), 17 deletions(-)

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 4e9efc93340e..3a27efa2b955 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3206,31 +3206,16 @@ static void btrfs_double_inode_lock(struct inode *inode1, struct inode *inode2)
 	inode_lock_nested(inode2, I_MUTEX_CHILD);
 }
 
-static int btrfs_extent_same_range(struct inode *src, u64 loff, u64 olen,
+static int btrfs_extent_same_range(struct inode *src, u64 loff, u64 len,
 				   struct inode *dst, u64 dst_loff)
 {
-	u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize;
 	int ret;
-	u64 len = olen;
-
-	if (loff + len == src->i_size)
-		len = ALIGN(src->i_size, bs) - loff;
-	/*
-	 * For same inode case we don't want our length pushed out past i_size
-	 * as comparing that data range makes no sense.
-	 *
-	 * This effectively means we require aligned extents for the single
-	 * inode case, whereas the other cases allow an unaligned length so long
-	 * as it ends at i_size.
-	 */
-	if (dst == src && len != olen)
-		return -EINVAL;
 
 	/*
 	 * Lock destination range to serialize with concurrent readpages().
 	 */
 	lock_extent(&BTRFS_I(dst)->io_tree, dst_loff, dst_loff + len - 1);
-	ret = btrfs_clone(src, dst, loff, olen, len, dst_loff, 1);
+	ret = btrfs_clone(src, dst, loff, len, len, dst_loff, 1);
 	unlock_extent(&BTRFS_I(dst)->io_tree, dst_loff, dst_loff + len - 1);
 
 	return ret;
-- 
2.11.0