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 <joseph.qi@huawei.com>
Cc: Weiwei Wang <wangww631@huawei.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Xuejiufei <xuejiufei@huawei.com>
Cc: alex chen <alex.chen@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 784f2c72c992a2762666840870443259d4cc30cb..46e0d4e857c7f493f512196603d3725ca8d3dfaa 100644 (file)
--- 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
index 7e39cd654834e9dff8665b60e689c72116582e14..8490c64d34fef4fd0421c4bb7e7c7ea9f6d87bca 100644 (file)
--- 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
index cf4fa43af78e54d4fe5c1c76028aadc06a2baa21..20e37a3ed26f3eb721ad45c2699a6332a098cee8 100644 (file)
--- 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.
  */