Btrfs: split btrfs_extent_same

Split btrfs_extent_same() to two parts where one is the main EXTENT_SAME
entry and a helper that can be repeatedly called on a range.  This will
be used in following patches.

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index ad1752bc80a7615939a74b9e51c18e946eab3897..ec0f380f85a150923af77ee6bd62e9807d800b26 100644 (file)
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3027,8 +3027,8 @@ static int extent_same_check_offsets(struct inode *inode, u64 off, u64 *plen,
        return 0;
 }
 
-static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
-                            struct inode *dst, u64 dst_loff)
+static int btrfs_extent_same_range(struct inode *src, u64 loff, u64 olen,
+                              struct inode *dst, u64 dst_loff)
 {
        int ret;
        u64 len = olen;
@@ -3037,21 +3037,13 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
        u64 same_lock_start = 0;
        u64 same_lock_len = 0;
 
-       if (len == 0)
-               return 0;
-
-       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;
+               return ret;
 
        ret = extent_same_check_offsets(dst, dst_loff, &len, olen);
        if (ret)
-               goto out_unlock;
+               return ret;
 
        if (same_inode) {
                /*
@@ -3068,32 +3060,21 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
                 * allow an unaligned length so long as it ends at
                 * i_size.
                 */
-               if (len != olen) {
-                       ret = -EINVAL;
-                       goto out_unlock;
-               }
+               if (len != olen)
+                       return -EINVAL;
 
                /* Check for overlapping ranges */
-               if (dst_loff + len > loff && dst_loff < loff + len) {
-                       ret = -EINVAL;
-                       goto out_unlock;
-               }
+               if (dst_loff + len > loff && dst_loff < loff + len)
+                       return -EINVAL;
 
                same_lock_start = min_t(u64, loff, dst_loff);
                same_lock_len = max_t(u64, loff, dst_loff) + len - same_lock_start;
        }
 
-       /* don't make the dst file partly checksummed */
-       if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
-           (BTRFS_I(dst)->flags & BTRFS_INODE_NODATASUM)) {
-               ret = -EINVAL;
-               goto out_unlock;
-       }
-
 again:
        ret = btrfs_cmp_data_prepare(src, loff, dst, dst_loff, olen, &cmp);
        if (ret)
-               goto out_unlock;
+               return ret;
 
        if (same_inode)
                ret = lock_extent_range(src, same_lock_start, same_lock_len,
@@ -3143,6 +3124,33 @@ again:
                btrfs_double_extent_unlock(src, loff, dst, dst_loff, len);
 
        btrfs_cmp_data_free(&cmp);
+
+       return ret;
+}
+
+static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
+                            struct inode *dst, u64 dst_loff)
+{
+       int ret;
+       bool same_inode = (src == dst);
+
+       if (olen == 0)
+               return 0;
+
+       if (same_inode)
+               inode_lock(src);
+       else
+               btrfs_double_inode_lock(src, dst);
+
+       /* don't make the dst file partly checksummed */
+       if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
+           (BTRFS_I(dst)->flags & BTRFS_INODE_NODATASUM)) {
+               ret = -EINVAL;
+               goto out_unlock;
+       }
+
+       ret = btrfs_extent_same_range(src, loff, olen, dst, dst_loff);
+
 out_unlock:
        if (same_inode)
                inode_unlock(src);