xfs: refactor realtime inode locking

Create helper functions to deal with locking realtime metadata inodes.
This enables us to maintain correct locking order once we start adding
the realtime rmap and refcount btree inodes.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>

8 files changed, 87 insertions, 23 deletions

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index ff8801c6c063..dbf68a2b3f1a 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -5408,12 +5408,9 @@ __xfs_bunmapi(
 
 	if (isrt) {
 		/*
-		 * Synchronize by locking the bitmap inode.
+		 * Synchronize by locking the realtime bitmap.
 		 */
-		xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL|XFS_ILOCK_RTBITMAP);
-		xfs_trans_ijoin(tp, mp->m_rbmip, XFS_ILOCK_EXCL);
-		xfs_ilock(mp->m_rsumip, XFS_ILOCK_EXCL|XFS_ILOCK_RTSUM);
-		xfs_trans_ijoin(tp, mp->m_rsumip, XFS_ILOCK_EXCL);
+		xfs_rtbitmap_lock(tp, mp);
 	}
 
 	extno = 0;
diff --git a/fs/xfs/libxfs/xfs_rtbitmap.c b/fs/xfs/libxfs/xfs_rtbitmap.c
index b74261abd238..46095acec709 100644
--- a/fs/xfs/libxfs/xfs_rtbitmap.c
+++ b/fs/xfs/libxfs/xfs_rtbitmap.c
@@ -1251,3 +1251,60 @@ xfs_rtsummary_wordcount(
 	blocks = xfs_rtsummary_blockcount(mp, rsumlevels, rbmblocks);
 	return XFS_FSB_TO_B(mp, blocks) >> XFS_WORDLOG;
 }
+
+/*
+ * Lock both realtime free space metadata inodes for a freespace update.  If a
+ * transaction is given, the inodes will be joined to the transaction and the
+ * ILOCKs will be released on transaction commit.
+ */
+void
+xfs_rtbitmap_lock(
+	struct xfs_trans	*tp,
+	struct xfs_mount	*mp)
+{
+	xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL | XFS_ILOCK_RTBITMAP);
+	if (tp)
+		xfs_trans_ijoin(tp, mp->m_rbmip, XFS_ILOCK_EXCL);
+
+	xfs_ilock(mp->m_rsumip, XFS_ILOCK_EXCL | XFS_ILOCK_RTSUM);
+	if (tp)
+		xfs_trans_ijoin(tp, mp->m_rsumip, XFS_ILOCK_EXCL);
+}
+
+/* Unlock both realtime free space metadata inodes after a freespace update. */
+void
+xfs_rtbitmap_unlock(
+	struct xfs_mount	*mp)
+{
+	xfs_iunlock(mp->m_rsumip, XFS_ILOCK_EXCL | XFS_ILOCK_RTSUM);
+	xfs_iunlock(mp->m_rbmip, XFS_ILOCK_EXCL | XFS_ILOCK_RTBITMAP);
+}
+
+/*
+ * Lock the realtime free space metadata inodes for a freespace scan.  Callers
+ * must walk metadata blocks in order of increasing file offset.
+ */
+void
+xfs_rtbitmap_lock_shared(
+	struct xfs_mount	*mp,
+	unsigned int		rbmlock_flags)
+{
+	if (rbmlock_flags & XFS_RBMLOCK_BITMAP)
+		xfs_ilock(mp->m_rbmip, XFS_ILOCK_SHARED | XFS_ILOCK_RTBITMAP);
+
+	if (rbmlock_flags & XFS_RBMLOCK_SUMMARY)
+		xfs_ilock(mp->m_rsumip, XFS_ILOCK_SHARED | XFS_ILOCK_RTSUM);
+}
+
+/* Unlock the realtime free space metadata inodes after a freespace scan. */
+void
+xfs_rtbitmap_unlock_shared(
+	struct xfs_mount	*mp,
+	unsigned int		rbmlock_flags)
+{
+	if (rbmlock_flags & XFS_RBMLOCK_SUMMARY)
+		xfs_iunlock(mp->m_rsumip, XFS_ILOCK_SHARED | XFS_ILOCK_RTSUM);
+
+	if (rbmlock_flags & XFS_RBMLOCK_BITMAP)
+		xfs_iunlock(mp->m_rbmip, XFS_ILOCK_SHARED | XFS_ILOCK_RTBITMAP);
+}
diff --git a/fs/xfs/libxfs/xfs_rtbitmap.h b/fs/xfs/libxfs/xfs_rtbitmap.h
index 1f3fc1a3b28d..43c4897f151a 100644
--- a/fs/xfs/libxfs/xfs_rtbitmap.h
+++ b/fs/xfs/libxfs/xfs_rtbitmap.h
@@ -279,6 +279,19 @@ xfs_suminfo_t xfs_suminfo_get(struct xfs_mount *mp,
 		union xfs_suminfo_ondisk *infoptr);
 void xfs_suminfo_add(struct xfs_mount *mp, union xfs_suminfo_ondisk *infoptr,
 		int delta);
+
+void xfs_rtbitmap_lock(struct xfs_trans *tp, struct xfs_mount *mp);
+void xfs_rtbitmap_unlock(struct xfs_mount *mp);
+
+/* Lock the rt bitmap inode in shared mode */
+#define XFS_RBMLOCK_BITMAP	(1U << 0)
+/* Lock the rt summary inode in shared mode */
+#define XFS_RBMLOCK_SUMMARY	(1U << 1)
+
+void xfs_rtbitmap_lock_shared(struct xfs_mount *mp,
+		unsigned int rbmlock_flags);
+void xfs_rtbitmap_unlock_shared(struct xfs_mount *mp,
+		unsigned int rbmlock_flags);
 #else /* CONFIG_XFS_RT */
 # define xfs_rtfree_extent(t,b,l)			(-ENOSYS)
 # define xfs_rtfree_blocks(t,rb,rl)			(-ENOSYS)
@@ -295,6 +308,10 @@ xfs_rtbitmap_blockcount(struct xfs_mount *mp, xfs_rtbxlen_t rtextents)
 # define xfs_rtbitmap_wordcount(mp, r)			(0)
 # define xfs_rtsummary_blockcount(mp, l, b)		(0)
 # define xfs_rtsummary_wordcount(mp, l, b)		(0)
+# define xfs_rtbitmap_lock(tp, mp)		do { } while (0)
+# define xfs_rtbitmap_unlock(mp)		do { } while (0)
+# define xfs_rtbitmap_lock_shared(mp, lf)	do { } while (0)
+# define xfs_rtbitmap_unlock_shared(mp, lf)	do { } while (0)
 #endif /* CONFIG_XFS_RT */
 
 #endif /* __XFS_RTBITMAP_H__ */
diff --git a/fs/xfs/scrub/common.c b/fs/xfs/scrub/common.c
index ee9667565e2c..f30cd0daff44 100644
--- a/fs/xfs/scrub/common.c
+++ b/fs/xfs/scrub/common.c
@@ -32,6 +32,7 @@
 #include "xfs_quota.h"
 #include "xfs_error.h"
 #include "xfs_swapext.h"
+#include "xfs_rtbitmap.h"
 #include "scrub/scrub.h"
 #include "scrub/common.h"
 #include "scrub/trace.h"
diff --git a/fs/xfs/scrub/fscounters.c b/fs/xfs/scrub/fscounters.c
index 680b2e1d2940..043fb5777290 100644
--- a/fs/xfs/scrub/fscounters.c
+++ b/fs/xfs/scrub/fscounters.c
@@ -470,7 +470,7 @@ xchk_fscount_count_frextents(
 	if (!xfs_has_realtime(mp))
 		return 0;
 
-	xfs_ilock(sc->mp->m_rbmip, XFS_ILOCK_SHARED | XFS_ILOCK_RTBITMAP);
+	xfs_rtbitmap_lock_shared(sc->mp, XFS_RBMLOCK_BITMAP);
 	error = xfs_rtalloc_query_all(sc->mp, sc->tp,
 			xchk_fscount_add_frextent, fsc);
 	if (error) {
@@ -479,7 +479,7 @@ xchk_fscount_count_frextents(
 	}
 
 out_unlock:
-	xfs_iunlock(sc->mp->m_rbmip, XFS_ILOCK_SHARED | XFS_ILOCK_RTBITMAP);
+	xfs_rtbitmap_unlock_shared(sc->mp, XFS_RBMLOCK_BITMAP);
 	return error;
 }
 #else
diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
index 2fe95c9a15bd..9ce3a8f2ff88 100644
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c
@@ -131,10 +131,7 @@ retry:
 	 * Lock out modifications to both the RT bitmap and summary inodes
 	 */
 	if (!rtlocked) {
-		xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL|XFS_ILOCK_RTBITMAP);
-		xfs_trans_ijoin(ap->tp, mp->m_rbmip, XFS_ILOCK_EXCL);
-		xfs_ilock(mp->m_rsumip, XFS_ILOCK_EXCL|XFS_ILOCK_RTSUM);
-		xfs_trans_ijoin(ap->tp, mp->m_rsumip, XFS_ILOCK_EXCL);
+		xfs_rtbitmap_lock(ap->tp, mp);
 		rtlocked = true;
 	}
 
diff --git a/fs/xfs/xfs_fsmap.c b/fs/xfs/xfs_fsmap.c
index 8d0a6f480d2a..71053f840ea4 100644
--- a/fs/xfs/xfs_fsmap.c
+++ b/fs/xfs/xfs_fsmap.c
@@ -525,7 +525,7 @@ xfs_getfsmap_rtdev_rtbitmap_query(
 	unsigned int			mod;
 	int				error;
 
-	xfs_ilock(mp->m_rbmip, XFS_ILOCK_SHARED | XFS_ILOCK_RTBITMAP);
+	xfs_rtbitmap_lock_shared(mp, XFS_RBMLOCK_BITMAP);
 
 	/*
 	 * Set up query parameters to return free rtextents covering the range
@@ -551,7 +551,7 @@ xfs_getfsmap_rtdev_rtbitmap_query(
 	if (error)
 		goto err;
 err:
-	xfs_iunlock(mp->m_rbmip, XFS_ILOCK_SHARED | XFS_ILOCK_RTBITMAP);
+	xfs_rtbitmap_unlock_shared(mp, XFS_RBMLOCK_BITMAP);
 	return error;
 }
 
diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
index 674ca3dab72e..11bea1c60eda 100644
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -1081,10 +1081,10 @@ xfs_growfs_rt(
 		if (error)
 			break;
 		/*
-		 * Lock out other callers by grabbing the bitmap inode lock.
+		 * Lock out other callers by grabbing the bitmap and summary
+		 * inode locks and joining them to the transaction.
 		 */
-		xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL | XFS_ILOCK_RTBITMAP);
-		xfs_trans_ijoin(tp, mp->m_rbmip, XFS_ILOCK_EXCL);
+		xfs_rtbitmap_lock(tp, mp);
 		/*
 		 * Update the bitmap inode's size ondisk and incore.  We need
 		 * to update the incore size so that inode inactivation won't
@@ -1095,11 +1095,6 @@ xfs_growfs_rt(
 		i_size_write(VFS_I(mp->m_rbmip), mp->m_rbmip->i_disk_size);
 		xfs_trans_log_inode(tp, mp->m_rbmip, XFS_ILOG_CORE);
 		/*
-		 * Get the summary inode into the transaction.
-		 */
-		xfs_ilock(mp->m_rsumip, XFS_ILOCK_EXCL | XFS_ILOCK_RTSUM);
-		xfs_trans_ijoin(tp, mp->m_rsumip, XFS_ILOCK_EXCL);
-		/*
 		 * Update the summary inode's size.  We need to update the
 		 * incore size so that inode inactivation won't punch what it
 		 * thinks are "posteof" blocks.
@@ -1338,10 +1333,10 @@ xfs_rtalloc_reinit_frextents(
 	uint64_t		val = 0;
 	int			error;
 
-	xfs_ilock(mp->m_rbmip, XFS_ILOCK_SHARED | XFS_ILOCK_RTBITMAP);
+	xfs_rtbitmap_lock_shared(mp, XFS_RBMLOCK_BITMAP);
 	error = xfs_rtalloc_query_all(mp, NULL, xfs_rtalloc_count_frextent,
 			&val);
-	xfs_iunlock(mp->m_rbmip, XFS_ILOCK_SHARED | XFS_ILOCK_RTBITMAP);
+	xfs_rtbitmap_unlock_shared(mp, XFS_RBMLOCK_BITMAP);
 	if (error)
 		return error;