Joseph Qi
2015-Jan-20 08:35 UTC
[Ocfs2-devel] [PATCH 9/9 v6] 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 at huawei.com>
Cc: Weiwei Wang <wangww631 at huawei.com>
---
fs/ocfs2/file.c | 17 ++++++++++++++++-
fs/ocfs2/ocfs2.h | 8 ++++++++
fs/ocfs2/ocfs2_fs.h | 8 +++++++-
3 files changed, 31 insertions(+), 2 deletions(-)
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 4a712cf..41700d8 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -2213,6 +2213,15 @@ static int ocfs2_prepare_inode_for_write(struct file
*file,
}
/*
+ * 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
* caller will have to retake some cluster
@@ -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 131cc1c..bcc1cd6 100644
--- a/fs/ocfs2/ocfs2.h
+++ b/fs/ocfs2/ocfs2.h
@@ -498,6 +498,14 @@ 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 cf4fa43..20e37a3 100644
--- 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.
*/
--
1.8.4.3