xfs: refactor realtime inode lockingrefactor-rt-locking_2020-10-26

Refactor realtime metadata inode locking so that we can get some sense
here.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

6 files changed, 58 insertions, 23 deletions

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index f267503485e1..b470f5d2053e 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -5396,12 +5396,9 @@ __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_rtlock(tp, mp, XFS_RTLOCK_ALLOC);
 	}
 
 	extno = 0;
diff --git a/fs/xfs/scrub/common.c b/fs/xfs/scrub/common.c
index 952dfb234bf2..971bc43d039c 100644
--- a/fs/xfs/scrub/common.c
+++ b/fs/xfs/scrub/common.c
@@ -27,6 +27,7 @@
 #include "xfs_trans_priv.h"
 #include "xfs_attr.h"
 #include "xfs_reflink.h"
+#include "xfs_rtalloc.h"
 #include "scrub/scrub.h"
 #include "scrub/common.h"
 #include "scrub/trace.h"
@@ -610,8 +611,7 @@ xchk_rt_init(
 	struct xfs_mount	*mp = sc->mp;
 
 	memset(sr, 0, sizeof(*sr));
-	xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL | XFS_ILOCK_RTBITMAP);
-	xfs_ilock(mp->m_rsumip, XFS_ILOCK_EXCL | XFS_ILOCK_RTSUM);
+	xfs_rtlock(NULL, mp, XFS_RTLOCK_ALL);
 	sr->locked = true;
 }
 
@@ -627,8 +627,7 @@ xchk_rt_unlock(
 	if (!sr->locked)
 		return;
 
-	xfs_iunlock(sc->mp->m_rsumip, XFS_ILOCK_EXCL);
-	xfs_iunlock(sc->mp->m_rbmip, XFS_ILOCK_EXCL);
+	xfs_rtunlock(sc->mp, XFS_RTLOCK_ALL);
 	sr->locked = false;
 }
 
diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
index b84226bba539..534c8657eeb5 100644
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c
@@ -118,10 +118,7 @@ xfs_bmap_rtalloc(
 	/*
 	 * Lock out modifications to both the RT bitmap and summary inodes
 	 */
-	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_rtlock(ap->tp, mp, XFS_RTLOCK_ALLOC);
 
 	/*
 	 * If it's an allocation to an empty file at offset 0,
diff --git a/fs/xfs/xfs_fsmap.c b/fs/xfs/xfs_fsmap.c
index 9ce5e7d5bf8f..c8eb222a6e70 100644
--- a/fs/xfs/xfs_fsmap.c
+++ b/fs/xfs/xfs_fsmap.c
@@ -524,7 +524,7 @@ xfs_getfsmap_rtdev_rtbitmap_query(
 	struct xfs_rtalloc_rec		ahigh = { 0 };
 	int				error;
 
-	xfs_ilock(tp->t_mountp->m_rbmip, XFS_ILOCK_SHARED);
+	xfs_rtlock(NULL, tp->t_mountp, XFS_RTLOCK_ALL);
 
 	alow.ar_startext = info->low.rm_startblock;
 	ahigh.ar_startext = info->high.rm_startblock;
@@ -542,7 +542,7 @@ xfs_getfsmap_rtdev_rtbitmap_query(
 	if (error)
 		goto err;
 err:
-	xfs_iunlock(tp->t_mountp->m_rbmip, XFS_ILOCK_SHARED);
+	xfs_rtunlock(tp->t_mountp, XFS_RTLOCK_ALL);
 	return error;
 }
 
diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
index 30d162643b6b..6b809a31eed2 100644
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -1025,10 +1025,10 @@ 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_rtlock(tp, mp, XFS_RTLOCK_ALLOC);
 		/*
 		 * Update the bitmap inode's size ondisk and incore.  We need
 		 * to update the incore size so that inode inactivation won't
@@ -1039,11 +1039,6 @@ xfs_growfs_rt(
 		i_size_write(VFS_I(mp->m_rbmip), mp->m_rbmip->i_d.di_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.
@@ -1343,3 +1338,41 @@ xfs_rtpick_extent(
 	*pick = b;
 	return 0;
 }
+
+/*
+ * Lock the metadata inodes for the realtime volume.  If a transaction is
+ * given, the rt metadata inode will be joined to the transaction and the lock
+ * will be released on transaction commit.
+ */
+void
+xfs_rtlock(
+	struct xfs_trans	*tp,
+	struct xfs_mount	*mp,
+	unsigned int		lock_flags)
+{
+	ASSERT(!(lock_flags & ~XFS_RTLOCK_ALL));
+
+	xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL | XFS_ILOCK_RTBITMAP);
+	if (tp)
+		xfs_trans_ijoin(tp, mp->m_rbmip, XFS_ILOCK_EXCL);
+
+	if (lock_flags & XFS_RTLOCK_ALLOC) {
+		xfs_ilock(mp->m_rsumip, XFS_ILOCK_EXCL | XFS_ILOCK_RTSUM);
+		if (tp)
+			xfs_trans_ijoin(tp, mp->m_rsumip, XFS_ILOCK_EXCL);
+	}
+}
+
+/* Unlock the realtime metadata inodes. */
+void
+xfs_rtunlock(
+	struct xfs_mount	*mp,
+	unsigned int		lock_flags)
+{
+	ASSERT(!(lock_flags & ~XFS_RTLOCK_ALL));
+
+	if (lock_flags & XFS_RTLOCK_ALLOC)
+		xfs_iunlock(mp->m_rsumip, XFS_ILOCK_EXCL | XFS_ILOCK_RTSUM);
+
+	xfs_iunlock(mp->m_rbmip, XFS_ILOCK_EXCL | XFS_ILOCK_RTBITMAP);
+}
diff --git a/fs/xfs/xfs_rtalloc.h b/fs/xfs/xfs_rtalloc.h
index 93e77b221355..8a22e0e74d65 100644
--- a/fs/xfs/xfs_rtalloc.h
+++ b/fs/xfs/xfs_rtalloc.h
@@ -135,6 +135,13 @@ bool xfs_verify_rtbno(struct xfs_mount *mp, xfs_rtblock_t rtbno);
 int xfs_rtalloc_extent_is_free(struct xfs_mount *mp, struct xfs_trans *tp,
 			       xfs_rtblock_t start, xfs_extlen_t len,
 			       bool *is_free);
+
+#define XFS_RTLOCK_ALLOC	(1 << 0) /* rt allocation */
+#define XFS_RTLOCK_ALL		(XFS_RTLOCK_ALLOC)
+
+void xfs_rtlock(struct xfs_trans *tp, struct xfs_mount *mp,
+		unsigned int rtlock_flags);
+void xfs_rtunlock(struct xfs_mount *mp, unsigned int lock_flags);
 #else
 # define xfs_rtallocate_extent(t,b,min,max,l,f,p,rb)    (ENOSYS)
 # define xfs_rtfree_extent(t,b,l)                       (ENOSYS)
@@ -157,6 +164,8 @@ xfs_rtmount_init(
 }
 # define xfs_rtmount_inodes(m)  (((mp)->m_sb.sb_rblocks == 0)? 0 : (ENOSYS))
 # define xfs_rtunmount_inodes(m)
+# define xfs_rtlock(tp, mp, lock_flags)
+# define xfs_rtunlock(mp, lock_flags)
 #endif	/* CONFIG_XFS_RT */
 
 #endif	/* __XFS_RTALLOC_H__ */