xfs: simplify xfs_reflink_convert_cow

Source kernel commit: b121459c7a56d2fb5a8ca6727bf9f87982738b01

Instead of looking up extents to convert and calling xfs_bmapi_write on
each of them just let xfs_bmapi_write handle the full range.  To make
this robust add a new XFS_BMAPI_CONVERT_ONLY that only converts ranges
and never allocates blocks.

[darrick: shorten the stringified CONVERT_ONLY trace flag]

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>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>

diff --git a/libxfs/xfs_bmap.c b/libxfs/xfs_bmap.c
index 0821397e482209aace818cbe0e0beaf435a5cc2c..3d1bfa9a0847ef6fcb9b54332830e17f9b43bc3b 100644 (file)
--- a/libxfs/xfs_bmap.c
+++ b/libxfs/xfs_bmap.c
@@ -4322,7 +4322,8 @@ xfs_bmapi_write(
                 * First, deal with the hole before the allocated space
                 * that we found, if any.
                 */
-               if (need_alloc || wasdelay) {
+               if ((need_alloc || wasdelay) &&
+                   !(flags & XFS_BMAPI_CONVERT_ONLY)) {
                        bma.eof = eof;
                        bma.conv = !!(flags & XFS_BMAPI_CONVERT);
                        bma.wasdel = wasdelay;

diff --git a/libxfs/xfs_bmap.h b/libxfs/xfs_bmap.h
index b6a395949d0cbc5a90ed35e1e6214fdf61e1b9f9..e36d75799cd564f0b327e68285b38e9733333a72 100644 (file)
--- a/libxfs/xfs_bmap.h
+++ b/libxfs/xfs_bmap.h
@@ -113,6 +113,9 @@ struct xfs_extent_free_item
 /* Only convert delalloc space, don't allocate entirely new extents */
 #define XFS_BMAPI_DELALLOC     0x400
 
+/* Only convert unwritten extents, don't allocate new blocks */
+#define XFS_BMAPI_CONVERT_ONLY 0x800
+
 #define XFS_BMAPI_FLAGS \
        { XFS_BMAPI_ENTIRE,     "ENTIRE" }, \
        { XFS_BMAPI_METADATA,   "METADATA" }, \
@@ -124,7 +127,8 @@ struct xfs_extent_free_item
        { XFS_BMAPI_ZERO,       "ZERO" }, \
        { XFS_BMAPI_REMAP,      "REMAP" }, \
        { XFS_BMAPI_COWFORK,    "COWFORK" }, \
-       { XFS_BMAPI_DELALLOC,   "DELALLOC" }
+       { XFS_BMAPI_DELALLOC,   "DELALLOC" }, \
+       { XFS_BMAPI_CONVERT_ONLY, "CONVERT_ONLY" }
 
 
 static inline int xfs_bmapi_aflag(int w)