xfs: convert remaining mount flags to state flags

The remaining mount flags kept in m_flags are actually runtime state
flags. These change dynamically, so they really should be updated
atomically so we don't potentially lose an update due to racing
modifications.

Convert these remaining flags to be stored in m_opstate and use
atomic bitops to set and clear the flags. This also adds a couple of
simple wrappers for common state checks - read only and shutdown.

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

1 files changed, 23 insertions, 19 deletions

diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index 037248e12034..876bb19210a4 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -146,7 +146,6 @@ typedef struct xfs_mount {
 	uint			m_rsumsize;	/* size of rt summary, bytes */
 	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];
@@ -342,8 +341,8 @@ __XFS_HAS_FEAT(needsrepair, NEEDSREPAIR)
 /*
  * Mount features
  *
- * These do not change dynamically - features that can come and go,
- * such as 32 bit inodes and read-only state, are kept as flags rather than
+ * These do not change dynamically - features that can come and go, such as 32
+ * bit inodes and read-only state, are kept as operational state rather than
  * features.
  */
 __XFS_HAS_FEAT(noattr2, NOATTR2)
@@ -364,31 +363,28 @@ __XFS_HAS_FEAT(norecovery, NORECOVERY)
 __XFS_HAS_FEAT(nouuid, NOUUID)
 
 /*
- * Flags for m_flags.
+ * Operational mount state flags
+ *
+ * Use these with atomic bit ops only!
  */
-#define XFS_MOUNT_WSYNC		(1ULL << 0)	/* for nfs - all metadata ops
-						   must be synchronous except
-						   for space allocations */
-#define XFS_MOUNT_UNMOUNTING	(1ULL << 1)	/* filesystem is unmounting */
-#define XFS_MOUNT_WAS_CLEAN	(1ULL << 2)
-#define XFS_MOUNT_FS_SHUTDOWN	(1ULL << 3)	/* atomic stop of all filesystem
-						   operations, typically for
-						   disk errors in metadata */
-#define XFS_MOUNT_32BITINODES	(1ULL << 15)	/* inode32 allocator active */
-#define XFS_MOUNT_RDONLY	(1ULL << 4)	/* read-only fs */
+#define XFS_OPSTATE_UNMOUNTING		0	/* filesystem is unmounting */
+#define XFS_OPSTATE_CLEAN		1	/* mount was clean */
+#define XFS_OPSTATE_SHUTDOWN		2	/* stop all fs operations */
+#define XFS_OPSTATE_INODE32		3	/* inode32 allocator active */
+#define XFS_OPSTATE_READONLY		4	/* read-only fs */
 
 /*
  * If set, inactivation worker threads will be scheduled to process queued
  * inodegc work.  If not, queued inodes remain in memory waiting to be
  * processed.
  */
-#define XFS_OPSTATE_INODEGC_ENABLED	0
+#define XFS_OPSTATE_INODEGC_ENABLED	5
 /*
  * If set, background speculative prealloc gc worker threads will be scheduled
  * to process queued blockgc work.  If not, inodes retain their preallocations
  * until explicitly deleted.
  */
-#define XFS_OPSTATE_BLOCKGC_ENABLED	1
+#define XFS_OPSTATE_BLOCKGC_ENABLED	6
 
 #define __XFS_IS_OPSTATE(name, NAME) \
 static inline bool xfs_is_ ## name (struct xfs_mount *mp) \
@@ -404,10 +400,20 @@ static inline bool xfs_set_ ## name (struct xfs_mount *mp) \
 	return test_and_set_bit(XFS_OPSTATE_ ## NAME, &mp->m_opstate); \
 }
 
+__XFS_IS_OPSTATE(unmounting, UNMOUNTING)
+__XFS_IS_OPSTATE(clean, CLEAN)
+__XFS_IS_OPSTATE(shutdown, SHUTDOWN)
+__XFS_IS_OPSTATE(inode32, INODE32)
+__XFS_IS_OPSTATE(readonly, READONLY)
 __XFS_IS_OPSTATE(inodegc_enabled, INODEGC_ENABLED)
 __XFS_IS_OPSTATE(blockgc_enabled, BLOCKGC_ENABLED)
 
 #define XFS_OPSTATE_STRINGS \
+	{ (1UL << XFS_OPSTATE_UNMOUNTING),		"unmounting" }, \
+	{ (1UL << XFS_OPSTATE_CLEAN),			"clean" }, \
+	{ (1UL << XFS_OPSTATE_SHUTDOWN),		"shutdown" }, \
+	{ (1UL << XFS_OPSTATE_INODE32),			"inode32" }, \
+	{ (1UL << XFS_OPSTATE_READONLY),		"read_only" }, \
 	{ (1UL << XFS_OPSTATE_INODEGC_ENABLED),		"inodegc" }, \
 	{ (1UL << XFS_OPSTATE_BLOCKGC_ENABLED),		"blockgc" }
 
@@ -418,9 +424,7 @@ __XFS_IS_OPSTATE(blockgc_enabled, BLOCKGC_ENABLED)
 #define XFS_MAX_IO_LOG		30	/* 1G */
 #define XFS_MIN_IO_LOG		PAGE_SHIFT
 
-#define XFS_LAST_UNMOUNT_WAS_CLEAN(mp)	\
-				((mp)->m_flags & XFS_MOUNT_WAS_CLEAN)
-#define XFS_FORCED_SHUTDOWN(mp)	((mp)->m_flags & XFS_MOUNT_FS_SHUTDOWN)
+#define XFS_FORCED_SHUTDOWN(mp)		xfs_is_shutdown(mp)
 void xfs_do_force_shutdown(struct xfs_mount *mp, int flags, char *fname,
 		int lnnum);
 #define xfs_force_shutdown(m,f)	\