xfs: reflect sb features in xfs_mount

Currently on-disk feature checks require decoding the superblock
fileds and so can be non-trivial. We have almost 400 hundred
individual feature checks in the XFS code, so this is a significant
amount of code. To reduce runtime check overhead, pre-process all
the version flags into a features field in the xfs_mount at mount
time so we can convert all the feature checks to a simple flag
check.

There is also a need to convert the dynamic feature flags to update
the m_features field. This is required for attr, attr2 and quota
features. New xfs_mount based wrappers are added for this.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

fs/xfs/libxfs/xfs_format.h

@@ -405,7 +405,7 @@ static inline bool xfs_sb_version_hasprojid32bit(struct xfs_sb *sbp)
 		(sbp->sb_features2 & XFS_SB_VERSION2_PROJID32BIT));
 }
 
-static inline void xfs_sb_version_addprojid32bit(struct xfs_sb *sbp)
+static inline void xfs_sb_version_addprojid32(struct xfs_sb *sbp)
 {
 	sbp->sb_versionnum |= XFS_SB_VERSION_MOREBITSBIT;
 	sbp->sb_features2 |= XFS_SB_VERSION2_PROJID32BIT;

fs/xfs/libxfs/xfs_sb.c

@@ -30,6 +30,72 @@
  * Physical superblock buffer manipulations. Shared with libxfs in userspace.
  */
 
+uint64_t
+xfs_sb_version_to_features(
+	struct xfs_sb	*sbp)
+{
+	uint64_t	features = 0;
+
+	/* optional V4 features */
+	if (sbp->sb_rblocks > 0)
+		features |= XFS_FEAT_REALTIME;
+	if (sbp->sb_versionnum & XFS_SB_VERSION_ATTRBIT)
+		features |= XFS_FEAT_ATTR;
+	if (sbp->sb_versionnum & XFS_SB_VERSION_QUOTABIT)
+		features |= XFS_FEAT_QUOTA;
+	if (sbp->sb_versionnum & XFS_SB_VERSION_ALIGNBIT)
+		features |= XFS_FEAT_ALIGN;
+	if (sbp->sb_versionnum & XFS_SB_VERSION_LOGV2BIT)
+		features |= XFS_FEAT_LOGV2;
+	if (sbp->sb_versionnum & XFS_SB_VERSION_DALIGNBIT)
+		features |= XFS_FEAT_DALIGN;
+	if (sbp->sb_versionnum & XFS_SB_VERSION_EXTFLGBIT)
+		features |= XFS_FEAT_EXTFLG;
+	if (sbp->sb_versionnum & XFS_SB_VERSION_SECTORBIT)
+		features |= XFS_FEAT_SECTOR;
+	if (sbp->sb_versionnum & XFS_SB_VERSION_BORGBIT)
+		features |= XFS_FEAT_ASCIICI;
+	if (sbp->sb_versionnum & XFS_SB_VERSION_MOREBITSBIT) {
+		if (sbp->sb_features2 & XFS_SB_VERSION2_LAZYSBCOUNTBIT)
+			features |= XFS_FEAT_LAZYSBCOUNT;
+		if (sbp->sb_features2 & XFS_SB_VERSION2_ATTR2BIT)
+			features |= XFS_FEAT_ATTR2;
+		if (sbp->sb_features2 & XFS_SB_VERSION2_PROJID32BIT)
+			features |= XFS_FEAT_PROJID32;
+		if (sbp->sb_features2 & XFS_SB_VERSION2_FTYPE)
+			features |= XFS_FEAT_FTYPE;
+	}
+
+	if (XFS_SB_VERSION_NUM(sbp) != XFS_SB_VERSION_5)
+		return features;
+
+	/* Always on V5 features */
+	features |= XFS_FEAT_ALIGN | XFS_FEAT_LOGV2 | XFS_FEAT_EXTFLG |
+		    XFS_FEAT_LAZYSBCOUNT | XFS_FEAT_ATTR2 | XFS_FEAT_PROJID32 |
+		    XFS_FEAT_V3INODES | XFS_FEAT_CRC | XFS_FEAT_PQUOTINO;
+
+	/* Optional V5 features */
+	if (sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_FINOBT)
+		features |= XFS_FEAT_FINOBT;
+	if (sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_RMAPBT)
+		features |= XFS_FEAT_RMAPBT;
+	if (sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_REFLINK)
+		features |= XFS_FEAT_REFLINK;
+	if (sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_INOBTCNT)
+		features |= XFS_FEAT_INOBTCNT;
+	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_FTYPE)
+		features |= XFS_FEAT_FTYPE;
+	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_SPINODES)
+		features |= XFS_FEAT_SPINODES;
+	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_META_UUID)
+		features |= XFS_FEAT_META_UUID;
+	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_BIGTIME)
+		features |= XFS_FEAT_BIGTIME;
+	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR)
+		features |= XFS_FEAT_NEEDSREPAIR;
+	return features;
+}
+
 /* Check all the superblock fields we care about when reading one in. */
 STATIC int
 xfs_validate_sb_read(

fs/xfs/libxfs/xfs_sb.h

@@ -20,6 +20,7 @@ extern void	xfs_sb_mount_common(struct xfs_mount *mp, struct xfs_sb *sbp);
 extern void	xfs_sb_from_disk(struct xfs_sb *to, struct xfs_dsb *from);
 extern void	xfs_sb_to_disk(struct xfs_dsb *to, struct xfs_sb *from);
 extern void	xfs_sb_quota_from_disk(struct xfs_sb *sbp);
+extern uint64_t	xfs_sb_version_to_features(struct xfs_sb *sbp);
 
 extern int	xfs_update_secondary_sbs(struct xfs_mount *mp);
 

fs/xfs/xfs_log_recover.c

@@ -3348,6 +3348,7 @@ xlog_do_recover(
 	xfs_buf_relse(bp);
 
 	/* re-initialise in-core superblock and geometry structures */
+	mp->m_features |= xfs_sb_version_to_features(sbp);
 	xfs_reinit_percpu_counters(mp);
 	error = xfs_initialize_perag(mp, sbp->sb_agcount, &mp->m_maxagi);
 	if (error) {

fs/xfs/xfs_mount.c

@@ -225,6 +225,7 @@ reread:
 		goto reread;
 	}
 
+	mp->m_features |= xfs_sb_version_to_features(sbp);
 	xfs_reinit_percpu_counters(mp);
 
 	/* no need to be quiet anymore, so reset the buf ops */

fs/xfs/xfs_mount.h

@@ -147,6 +147,7 @@ typedef struct xfs_mount {
 	int			m_fixedfsid[2];	/* unchanged for life of FS */
 	uint			m_qflags;	/* quota status flags */
 	uint64_t		m_flags;	/* global mount flags */
+	uint64_t		m_features;	/* active filesystem features */
 	uint64_t		m_low_space[XFS_LOWSP_MAX];
 	uint64_t		m_low_rtexts[XFS_LOWSP_MAX];
 	struct xfs_ino_geometry	m_ino_geo;	/* inode geometry */
@@ -243,6 +244,81 @@ typedef struct xfs_mount {
 
 #define M_IGEO(mp)		(&(mp)->m_ino_geo)
 
+/*
+ * Flags for m_features.
+ *
+ * These are all the active features in the filesystem, regardless of how
+ * they are configured.
+ */
+#define XFS_FEAT_ATTR		(1ULL << 0)	/* xattrs present in fs */
+#define XFS_FEAT_NLINK		(1ULL << 1)	/* 32 bit link counts */
+#define XFS_FEAT_QUOTA		(1ULL << 2)	/* quota active */
+#define XFS_FEAT_ALIGN		(1ULL << 3)	/* inode alignment */
+#define XFS_FEAT_DALIGN		(1ULL << 4)	/* data alignment */
+#define XFS_FEAT_LOGV2		(1ULL << 5)	/* version 2 logs */
+#define XFS_FEAT_SECTOR		(1ULL << 6)	/* sector size > 512 bytes */
+#define XFS_FEAT_EXTFLG		(1ULL << 7)	/* unwritten extents */
+#define XFS_FEAT_ASCIICI	(1ULL << 8)	/* ASCII only case-insens. */
+#define XFS_FEAT_LAZYSBCOUNT	(1ULL << 9)	/* Superblk counters */
+#define XFS_FEAT_ATTR2		(1ULL << 10)	/* dynamic attr fork */
+#define XFS_FEAT_PARENT		(1ULL << 11)	/* parent pointers */
+#define XFS_FEAT_PROJID32	(1ULL << 12)	/* 32 bit project id */
+#define XFS_FEAT_CRC		(1ULL << 13)	/* metadata CRCs */
+#define XFS_FEAT_V3INODES	(1ULL << 14)	/* Version 3 inodes */
+#define XFS_FEAT_PQUOTINO	(1ULL << 15)	/* non-shared proj/grp quotas */
+#define XFS_FEAT_FTYPE		(1ULL << 16)	/* inode type in dir */
+#define XFS_FEAT_FINOBT		(1ULL << 17)	/* free inode btree */
+#define XFS_FEAT_RMAPBT		(1ULL << 18)	/* reverse map btree */
+#define XFS_FEAT_REFLINK	(1ULL << 19)	/* reflinked files */
+#define XFS_FEAT_SPINODES	(1ULL << 20)	/* sparse inode chunks */
+#define XFS_FEAT_META_UUID	(1ULL << 21)	/* metadata UUID */
+#define XFS_FEAT_REALTIME	(1ULL << 22)	/* realtime device present */
+#define XFS_FEAT_INOBTCNT	(1ULL << 23)	/* inobt block counts */
+#define XFS_FEAT_BIGTIME	(1ULL << 24)	/* large timestamps */
+#define XFS_FEAT_NEEDSREPAIR	(1ULL << 25)	/* needs xfs_repair */
+
+#define __XFS_HAS_FEAT(name, NAME) \
+static inline bool xfs_has_ ## name (struct xfs_mount *mp) \
+{ \
+	return mp->m_features & XFS_FEAT_ ## NAME; \
+}
+
+/* Some features can be added dynamically so they need a set wrapper, too. */
+#define __XFS_ADD_FEAT(name, NAME) \
+	__XFS_HAS_FEAT(name, NAME); \
+static inline void xfs_add_ ## name (struct xfs_mount *mp) \
+{ \
+	mp->m_features |= XFS_FEAT_ ## NAME; \
+	xfs_sb_version_add ## name(&mp->m_sb); \
+}
+
+__XFS_ADD_FEAT(attr, ATTR)
+__XFS_HAS_FEAT(nlink, NLINK)
+__XFS_ADD_FEAT(quota, QUOTA)
+__XFS_HAS_FEAT(align, ALIGN)
+__XFS_HAS_FEAT(dalign, DALIGN)
+__XFS_HAS_FEAT(logv2, LOGV2)
+__XFS_HAS_FEAT(sector, SECTOR)
+__XFS_HAS_FEAT(extflg, EXTFLG)
+__XFS_HAS_FEAT(asciici, ASCIICI)
+__XFS_HAS_FEAT(lazysbcount, LAZYSBCOUNT)
+__XFS_ADD_FEAT(attr2, ATTR2)
+__XFS_HAS_FEAT(parent, PARENT)
+__XFS_ADD_FEAT(projid32, PROJID32)
+__XFS_HAS_FEAT(crc, CRC)
+__XFS_HAS_FEAT(v3inodes, V3INODES)
+__XFS_HAS_FEAT(pquotino, PQUOTINO)
+__XFS_HAS_FEAT(ftype, FTYPE)
+__XFS_HAS_FEAT(finobt, FINOBT)
+__XFS_HAS_FEAT(rmapbt, RMAPBT)
+__XFS_HAS_FEAT(reflink, REFLINK)
+__XFS_HAS_FEAT(sparseinodes, SPINODES)
+__XFS_HAS_FEAT(metauuid, META_UUID)
+__XFS_HAS_FEAT(realtime, REALTIME)
+__XFS_HAS_FEAT(inobtcounts, REALTIME)
+__XFS_HAS_FEAT(bigtime, REALTIME)
+__XFS_HAS_FEAT(needsrepair, REALTIME)
+
 /*
  * Flags for m_flags.
  */

fs/xfs/xfs_rtalloc.c

@@ -1131,6 +1131,9 @@ error_cancel:
 		error = xfs_trans_commit(tp);
 		if (error)
 			break;
+
+		/* Ensure the mount RT feature flag is now set. */
+		mp->m_features |= XFS_FEAT_REALTIME;
 	}
 	if (error)
 		goto out_free;