[PATCH 056/102] xfs: reimplement fdatasync support

Dave Chinner
2012-08-23T05:04:07Z

From: Christoph Hellwig <hch@infradead.org>

Upstream commit: 8f639ddea0c4978ae9b4e46ea041c9e5afe0ee8d

Add an in-memory only flag to say we logged timestamps only, and use it to
check if fdatasync can optimize away the log force.

Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
---
fs/xfs/linux-2.6/xfs_file.c | 7 +++++--
fs/xfs/linux-2.6/xfs_super.c | 2 +-
fs/xfs/xfs_inode_item.c | 3 ++-
fs/xfs/xfs_inode_item.h | 11 ++++++++++-
4 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/fs/xfs/linux-2.6/xfs_file.c b/fs/xfs/linux-2.6/xfs_file.c
index a575a63..1dbd1d8 100644
--- a/fs/xfs/linux-2.6/xfs_file.c
+++ b/fs/xfs/linux-2.6/xfs_file.c
@@ -191,8 +191,11 @@ xfs_file_fsync(
* to flush the log up to the latest LSN that touched the inode.
*/
xfs_ilock(ip, XFS_ILOCK_SHARED);
- if (xfs_ipincount(ip))
- lsn = ip->i_itemp->ili_last_lsn;
+ if (xfs_ipincount(ip)) {
+ if (!datasync ||
+ (ip->i_itemp->ili_fields & ~XFS_ILOG_TIMESTAMP))
+ lsn = ip->i_itemp->ili_last_lsn;
+ }
xfs_iunlock(ip, XFS_ILOCK_SHARED);

if (lsn)
diff --git a/fs/xfs/linux-2.6/xfs_super.c b/fs/xfs/linux-2.6/xfs_super.c
index c12df49..ec5ca7b 100644
--- a/fs/xfs/linux-2.6/xfs_super.c
+++ b/fs/xfs/linux-2.6/xfs_super.c
@@ -944,7 +944,7 @@ xfs_fs_dirty_inode(
ip->i_d.di_mtime.t_nsec = (__int32_t)inode->i_mtime.tv_nsec;

xfs_trans_ijoin(tp, ip);
- xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+ xfs_trans_log_inode(tp, ip, XFS_ILOG_TIMESTAMP);
error = xfs_trans_commit(tp, 0);
xfs_iunlock(ip, XFS_ILOCK_EXCL);
if (error)
diff --git a/fs/xfs/xfs_inode_item.c b/fs/xfs/xfs_inode_item.c
index 45514c5..a76d1b9 100644
--- a/fs/xfs/xfs_inode_item.c
+++ b/fs/xfs/xfs_inode_item.c
@@ -438,7 +438,8 @@ out:
* games in recovery easier, which isn't a big deal as just about any
* transaction would dirty it anyway.
*/
- iip->ili_format.ilf_fields = XFS_ILOG_CORE | iip->ili_fields;
+ iip->ili_format.ilf_fields = XFS_ILOG_CORE |
+ (iip->ili_fields & ~XFS_ILOG_TIMESTAMP);
ASSERT(nvecs == lip->li_desc->lid_size);
iip->ili_format.ilf_size = nvecs;
}
diff --git a/fs/xfs/xfs_inode_item.h b/fs/xfs/xfs_inode_item.h
index bc183d8..41d61c3 100644
--- a/fs/xfs/xfs_inode_item.h
+++ b/fs/xfs/xfs_inode_item.h
@@ -86,6 +86,15 @@ typedef struct xfs_inode_log_format_64 {
#define XFS_ILOG_AEXT 0x080 /* log i_af.if_extents */
#define XFS_ILOG_ABROOT 0x100 /* log i_af.i_broot */

+
+/*
+ * The timestamps are dirty, but not necessarily anything else in the inode
+ * core. Unlike the other fields above this one must never make it to disk
+ * in the ilf_fields of the inode_log_format, but is purely store in-memory in
+ * ili_fields in the inode_log_item.
+ */
+#define XFS_ILOG_TIMESTAMP 0x4000
+
#define XFS_ILOG_NONCORE (XFS_ILOG_DDATA | XFS_ILOG_DEXT | \
XFS_ILOG_DBROOT | XFS_ILOG_DEV | \
XFS_ILOG_UUID | XFS_ILOG_ADATA | \
@@ -101,7 +110,7 @@ typedef struct xfs_inode_log_format_64 {
XFS_ILOG_DEXT | XFS_ILOG_DBROOT | \
XFS_ILOG_DEV | XFS_ILOG_UUID | \
XFS_ILOG_ADATA | XFS_ILOG_AEXT | \
- XFS_ILOG_ABROOT)
+ XFS_ILOG_ABROOT | XFS_ILOG_TIMESTAMP)

static inline int xfs_ilog_fbroot(int w)
{