Btrfs: refactor btrfs_extent_same() slightly

This was originally a prep patch for changing the behavior on len=0, but
we went another direction with that. This still makes the function
slightly easier to follow.

Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 12 insertions, 21 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 529cc273e817..77f93a1e65c7 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3125,26 +3125,27 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
         int ret;
         u64 len = olen;
         struct cmp_pages cmp;
-        int same_inode = 0;
+        bool same_inode = (src == dst);
         u64 same_lock_start = 0;
         u64 same_lock_len = 0;
 
-        if (src == dst)
-                same_inode = 1;
-
         if (len == 0)
                 return 0;
 
-        if (same_inode) {
+        if (same_inode)
                 inode_lock(src);
+        else
+                btrfs_double_inode_lock(src, dst);
 
-                ret = extent_same_check_offsets(src, loff, &len, olen);
-                if (ret)
-                        goto out_unlock;
-                ret = extent_same_check_offsets(src, dst_loff, &len, olen);
-                if (ret)
-                        goto out_unlock;
+        ret = extent_same_check_offsets(src, loff, &len, olen);
+        if (ret)
+                goto out_unlock;
 
+        ret = extent_same_check_offsets(dst, dst_loff, &len, olen);
+        if (ret)
+                goto out_unlock;
+
+        if (same_inode) {
                 /*
                  * Single inode case wants the same checks, except we
                  * don't want our length pushed out past i_size as
@@ -3172,16 +3173,6 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
 
                 same_lock_start = min_t(u64, loff, dst_loff);
                 same_lock_len = max_t(u64, loff, dst_loff) + len - same_lock_start;
-        } else {
-                btrfs_double_inode_lock(src, dst);
-
-                ret = extent_same_check_offsets(src, loff, &len, olen);
-                if (ret)
-                        goto out_unlock;
-
-                ret = extent_same_check_offsets(dst, dst_loff, &len, olen);
-                if (ret)
-                        goto out_unlock;
         }
 
         /* don't make the dst file partly checksummed */