[Ocfs2-devel] [RFC PATCH 1/3] fiemap: Introduce FIEMAP_FLAG_COW flag to map shared extents
Jeff Liu
jeff.liu at oracle.com
Tue Feb 19 19:59:22 PST 2013
Introduce a new flag FIEMAP_FLAG_COW to fiemap ioctl(2) interface.
If this flag is set, the kernel will only return the mapped extents
which are in copy-on-write state.
Signed-off-by: Jie Liu <jeff.liu at oracle.com>
Cc: Alexander Viro <viro at zeniv.linux.org.uk>
Cc: Andreas Dilger <adilger at dilger.ca>
Cc: Dave Chinner <david at fromorbit.com>
Cc: Mark Fasheh <mfasheh at suse.com>
Cc: Joel Becker <jlbec at evilplan.org>
Cc: Jan Kara <jack at suse.de>
Cc: Chris Mason <chris.mason at fusionio.com>
Cc: Christoph Hellwig <hch at infradead.org>
---
include/uapi/linux/fiemap.h | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/include/uapi/linux/fiemap.h b/include/uapi/linux/fiemap.h
index d830747..693dff4 100644
--- a/include/uapi/linux/fiemap.h
+++ b/include/uapi/linux/fiemap.h
@@ -40,8 +40,10 @@ struct fiemap {
#define FIEMAP_FLAG_SYNC 0x00000001 /* sync file data before map */
#define FIEMAP_FLAG_XATTR 0x00000002 /* map extended attribute tree */
+#define FIEMAP_FLAG_COW 0x00000004 /* map copy-on-write extents */
-#define FIEMAP_FLAGS_COMPAT (FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR)
+#define FIEMAP_FLAGS_COMPAT (FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR | \
+ FIEMAP_FLAG_COW)
#define FIEMAP_EXTENT_LAST 0x00000001 /* Last extent in file. */
#define FIEMAP_EXTENT_UNKNOWN 0x00000002 /* Data location unknown. */
--
1.7.9.5
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