xfs: refactor xfs_file_iomap_begin_delay

Rejuggle the return path to prepare for filling out a source iomap.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index 2cd5465..38e0b12 100644 (file)
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -539,7 +539,6 @@ xfs_file_iomap_begin_delay(
        struct xfs_iext_cursor  icur, ccur;
        xfs_fsblock_t           prealloc_blocks = 0;
        bool                    eof = false, cow_eof = false, shared = false;
-       u16                     iomap_flags = 0;
        int                     whichfork = XFS_DATA_FORK;
        int                     error = 0;
 
@@ -600,8 +599,7 @@ xfs_file_iomap_begin_delay(
                                &ccur, &cmap);
                if (!cow_eof && cmap.br_startoff <= offset_fsb) {
                        trace_xfs_reflink_cow_found(ip, &cmap);
-                       whichfork = XFS_COW_FORK;
-                       goto done;
+                       goto found_cow;
                }
        }
 
@@ -615,7 +613,7 @@ xfs_file_iomap_begin_delay(
                    ((flags & IOMAP_ZERO) && imap.br_state != XFS_EXT_NORM)) {
                        trace_xfs_iomap_found(ip, offset, count, XFS_DATA_FORK,
                                        &imap);
-                       goto done;
+                       goto found_imap;
                }
 
                xfs_trim_extent(&imap, offset_fsb, end_fsb - offset_fsb);
@@ -629,7 +627,7 @@ xfs_file_iomap_begin_delay(
                if (!shared) {
                        trace_xfs_iomap_found(ip, offset, count, XFS_DATA_FORK,
                                        &imap);
-                       goto done;
+                       goto found_imap;
                }
 
                /*
@@ -703,35 +701,37 @@ retry:
                goto out_unlock;
        }
 
+       if (whichfork == XFS_COW_FORK) {
+               trace_xfs_iomap_alloc(ip, offset, count, whichfork, &cmap);
+               goto found_cow;
+       }
+
        /*
         * Flag newly allocated delalloc blocks with IOMAP_F_NEW so we punch
         * them out if the write happens to fail.
         */
-       if (whichfork == XFS_DATA_FORK) {
-               iomap_flags |= IOMAP_F_NEW;
-               trace_xfs_iomap_alloc(ip, offset, count, whichfork, &imap);
-       } else {
-               trace_xfs_iomap_alloc(ip, offset, count, whichfork, &cmap);
-       }
-done:
-       if (whichfork == XFS_COW_FORK) {
-               if (imap.br_startoff > offset_fsb) {
-                       xfs_trim_extent(&cmap, offset_fsb,
-                                       imap.br_startoff - offset_fsb);
-                       error = xfs_bmbt_to_iomap(ip, iomap, &cmap,
-                                       IOMAP_F_SHARED);
-                       goto out_unlock;
-               }
+       xfs_iunlock(ip, XFS_ILOCK_EXCL);
+       trace_xfs_iomap_alloc(ip, offset, count, whichfork, &imap);
+       return xfs_bmbt_to_iomap(ip, iomap, &imap, IOMAP_F_NEW);
+
+found_imap:
+       xfs_iunlock(ip, XFS_ILOCK_EXCL);
+       return xfs_bmbt_to_iomap(ip, iomap, &imap, 0);
+
+found_cow:
+       xfs_iunlock(ip, XFS_ILOCK_EXCL);
+       if (imap.br_startoff <= offset_fsb) {
                /* ensure we only report blocks we have a reservation for */
                xfs_trim_extent(&imap, cmap.br_startoff, cmap.br_blockcount);
-               shared = true;
+               return xfs_bmbt_to_iomap(ip, iomap, &imap, IOMAP_F_SHARED);
        }
-       if (shared)
-               iomap_flags |= IOMAP_F_SHARED;
-       error = xfs_bmbt_to_iomap(ip, iomap, &imap, iomap_flags);
+       xfs_trim_extent(&cmap, offset_fsb, imap.br_startoff - offset_fsb);
+       return xfs_bmbt_to_iomap(ip, iomap, &cmap, IOMAP_F_SHARED);
+
 out_unlock:
        xfs_iunlock(ip, XFS_ILOCK_EXCL);
        return error;
+
 }
 
 int