ocfs2: set append dio as a ro compat feature

Intruduce a bit OCFS2_FEATURE_RO_COMPAT_APPEND_DIO and check it in write flow. If the bit is not set, fall back to the old way. Signed-off-by: Joseph Qi <[email protected]> Cc: Weiwei Wang <[email protected]> Cc: Joel Becker <[email protected]> Cc: Junxiao Bi <[email protected]> Cc: Mark Fasheh <[email protected]> Cc: Xuejiufei <[email protected]> Cc: alex chen <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
kawasaki · Feb 17, 2015 · 160cc26 · 160cc26
1 parent 4813962
commit 160cc26
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Showing 3 changed files with 31 additions and 2 deletions.
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
@@ -2212,6 +2212,15 @@ static int ocfs2_prepare_inode_for_write(struct file *file,
 			break;
 		}
 
+		/*
+		 * Fallback to old way if the feature bit is not set.
+		 */
+		if (end > i_size_read(inode) &&
+				!ocfs2_supports_append_dio(osb)) {
+			*direct_io = 0;
+			break;
+		}
+
 		/*
 		 * We don't fill holes during direct io, so
 		 * check for them here. If any are found, the
@@ -2220,7 +2229,13 @@ static int ocfs2_prepare_inode_for_write(struct file *file,
 		 */
 		ret = ocfs2_check_range_for_holes(inode, saved_pos, count);
 		if (ret == 1) {
-			*direct_io = 0;
+			/*
+			 * Fallback to old way if the feature bit is not set.
+			 * Otherwise try dio first and then complete the rest
+			 * request through buffer io.
+			 */
+			if (!ocfs2_supports_append_dio(osb))
+				*direct_io = 0;
 			ret = 0;
 		} else if (ret < 0)
 			mlog_errno(ret);

diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
@@ -500,6 +500,14 @@ static inline int ocfs2_writes_unwritten_extents(struct ocfs2_super *osb)
 	return 0;
 }
 
+static inline int ocfs2_supports_append_dio(struct ocfs2_super *osb)
+{
+	if (osb->s_feature_ro_compat & OCFS2_FEATURE_RO_COMPAT_APPEND_DIO)
+		return 1;
+	return 0;
+}
+
+
 static inline int ocfs2_supports_inline_data(struct ocfs2_super *osb)
 {
 	if (osb->s_feature_incompat & OCFS2_FEATURE_INCOMPAT_INLINE_DATA)

diff --git a/fs/ocfs2/ocfs2_fs.h b/fs/ocfs2/ocfs2_fs.h
@@ -105,7 +105,8 @@
 					 | OCFS2_FEATURE_INCOMPAT_CLUSTERINFO)
 #define OCFS2_FEATURE_RO_COMPAT_SUPP	(OCFS2_FEATURE_RO_COMPAT_UNWRITTEN \
 					 | OCFS2_FEATURE_RO_COMPAT_USRQUOTA \
-					 | OCFS2_FEATURE_RO_COMPAT_GRPQUOTA)
+					 | OCFS2_FEATURE_RO_COMPAT_GRPQUOTA \
+					 | OCFS2_FEATURE_RO_COMPAT_APPEND_DIO)
 
 /*
  * Heartbeat-only devices are missing journals and other files.  The
@@ -199,6 +200,11 @@
 #define OCFS2_FEATURE_RO_COMPAT_USRQUOTA	0x0002
 #define OCFS2_FEATURE_RO_COMPAT_GRPQUOTA	0x0004
 
+/*
+ * Append Direct IO support
+ */
+#define OCFS2_FEATURE_RO_COMPAT_APPEND_DIO	0x0008
+
 /* The byte offset of the first backup block will be 1G.
  * The following will be 4G, 16G, 64G, 256G and 1T.
  */