xfs: introduce the CoW fork
Introduce a new in-core fork for storing copy-on-write delalloc
reservations and allocated extents that are in the process of being
written out.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/fs/xfs/libxfs/xfs_bmap.h b/fs/xfs/libxfs/xfs_bmap.h
index 85e3b9d..8774127 100644
--- a/fs/xfs/libxfs/xfs_bmap.h
+++ b/fs/xfs/libxfs/xfs_bmap.h
@@ -107,6 +107,9 @@
*/
#define XFS_BMAPI_REMAP 0x100
+/* Map something in the CoW fork. */
+#define XFS_BMAPI_COWFORK 0x200
+
#define XFS_BMAPI_FLAGS \
{ XFS_BMAPI_ENTIRE, "ENTIRE" }, \
{ XFS_BMAPI_METADATA, "METADATA" }, \
@@ -116,12 +119,23 @@
{ XFS_BMAPI_CONTIG, "CONTIG" }, \
{ XFS_BMAPI_CONVERT, "CONVERT" }, \
{ XFS_BMAPI_ZERO, "ZERO" }, \
- { XFS_BMAPI_REMAP, "REMAP" }
+ { XFS_BMAPI_REMAP, "REMAP" }, \
+ { XFS_BMAPI_COWFORK, "COWFORK" }
static inline int xfs_bmapi_aflag(int w)
{
- return (w == XFS_ATTR_FORK ? XFS_BMAPI_ATTRFORK : 0);
+ return (w == XFS_ATTR_FORK ? XFS_BMAPI_ATTRFORK :
+ (w == XFS_COW_FORK ? XFS_BMAPI_COWFORK : 0));
+}
+
+static inline int xfs_bmapi_whichfork(int bmapi_flags)
+{
+ if (bmapi_flags & XFS_BMAPI_COWFORK)
+ return XFS_COW_FORK;
+ else if (bmapi_flags & XFS_BMAPI_ATTRFORK)
+ return XFS_ATTR_FORK;
+ return XFS_DATA_FORK;
}
/*
@@ -142,13 +156,15 @@
#define BMAP_LEFT_VALID (1 << 6)
#define BMAP_RIGHT_VALID (1 << 7)
#define BMAP_ATTRFORK (1 << 8)
+#define BMAP_COWFORK (1 << 9)
#define XFS_BMAP_EXT_FLAGS \
{ BMAP_LEFT_CONTIG, "LC" }, \
{ BMAP_RIGHT_CONTIG, "RC" }, \
{ BMAP_LEFT_FILLING, "LF" }, \
{ BMAP_RIGHT_FILLING, "RF" }, \
- { BMAP_ATTRFORK, "ATTR" }
+ { BMAP_ATTRFORK, "ATTR" }, \
+ { BMAP_COWFORK, "COW" }
/*