[PATCH 06/18] xfs: create a log incompat flag for atomic extent swapping

["Darrick J. Wong" <darrick.wong@xxxxxxxxxx>]

From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>

Create a log incompat flag so that we only attempt to process swap
extent log items if the filesystem supports it.

Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
 fs/xfs/libxfs/xfs_format.h |   11 ++++++++++-
 fs/xfs/libxfs/xfs_fs.h     |    1 +
 fs/xfs/libxfs/xfs_sb.c     |    2 ++
 fs/xfs/xfs_super.c         |    4 ++++
 4 files changed, 17 insertions(+), 1 deletion(-)


diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
index 34babf402e14..63ed62a92c9c 100644
--- a/fs/xfs/libxfs/xfs_format.h
+++ b/fs/xfs/libxfs/xfs_format.h
@@ -500,7 +500,10 @@ xfs_sb_has_incompat_feature(
 	return (sbp->sb_features_incompat & feature) != 0;
 }
 
-#define XFS_SB_FEAT_INCOMPAT_LOG_ALL 0
+#define XFS_SB_FEAT_INCOMPAT_LOG_ATOMIC_SWAP (1 << 0)
+#define XFS_SB_FEAT_INCOMPAT_LOG_ALL \
+		(XFS_SB_FEAT_INCOMPAT_LOG_ATOMIC_SWAP)
+
 #define XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN	~XFS_SB_FEAT_INCOMPAT_LOG_ALL
 static inline bool
 xfs_sb_has_incompat_log_feature(
@@ -614,6 +617,12 @@ static inline bool xfs_sb_version_hasrtrmapbt(struct xfs_sb *sbp)
 	       xfs_sb_version_hasrmapbt(sbp);
 }
 
+static inline bool xfs_sb_version_hasatomicswap(struct xfs_sb *sbp)
+{
+	return XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5 &&
+		(sbp->sb_features_log_incompat & XFS_SB_FEAT_INCOMPAT_LOG_ATOMIC_SWAP);
+}
+
 /*
  * end of superblock version macros
  */
diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h
index c5b75082b9db..d278ca5731e4 100644
--- a/fs/xfs/libxfs/xfs_fs.h
+++ b/fs/xfs/libxfs/xfs_fs.h
@@ -251,6 +251,7 @@ typedef struct xfs_fsop_resblks {
 #define XFS_FSOP_GEOM_FLAGS_RMAPBT	(1 << 19) /* reverse mapping btree */
 #define XFS_FSOP_GEOM_FLAGS_REFLINK	(1 << 20) /* files can share blocks */
 #define XFS_FSOP_GEOM_FLAGS_BIGTIME	(1 << 21) /* 64-bit nsec timestamps */
+#define XFS_FSOP_GEOM_FLAGS_ATOMIC_SWAP	(1 << 22) /* atomic swapext */
 
 /*
  * Minimum and maximum sizes need for growth checks.
diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
index c50f589824f0..16094fd1a75e 100644
--- a/fs/xfs/libxfs/xfs_sb.c
+++ b/fs/xfs/libxfs/xfs_sb.c
@@ -1205,6 +1205,8 @@ xfs_fs_geometry(
 		geo->flags |= XFS_FSOP_GEOM_FLAGS_REFLINK;
 	if (xfs_sb_version_hasbigtime(sbp))
 		geo->flags |= XFS_FSOP_GEOM_FLAGS_BIGTIME;
+	if (xfs_sb_version_hasatomicswap(sbp))
+		geo->flags |= XFS_FSOP_GEOM_FLAGS_ATOMIC_SWAP;
 	if (xfs_sb_version_hassector(sbp))
 		geo->logsectsize = sbp->sb_logsectsize;
 	else
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index a17e824c6084..42d82c9d2a1d 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1647,6 +1647,10 @@ xfs_fc_fill_super(
 		xfs_warn(mp,
  "EXPERIMENTAL inode btree counters feature in use. Use at your own risk!");
 
+	if (xfs_sb_version_hasatomicswap(&mp->m_sb))
+		xfs_warn(mp,
+ "EXPERIMENTAL atomic file range swap feature in use. Use at your own risk!");
+
 	error = xfs_mountfs(mp);
 	if (error)
 		goto out_filestream_unmount;