From: Brian Foster <bfoster@redhat.com>
Date: Thu, 16 Jan 2020 22:13:32 +0000 (-0500)
Subject: xfs: track active state of allocation btree cursors
X-Git-Tag: v5.5.0-rc0~105
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7777d8c6f4808e123e9dcdb1472d0bdc3ee2fa79;p=thirdparty%2Fxfsprogs-dev.git

xfs: track active state of allocation btree cursors

Source kernel commit: f6b428a46d60186a38105c71fa435f31240721f9

The upcoming allocation algorithm update searches multiple
allocation btree cursors concurrently. As such, it requires an
active state to track when a particular cursor should continue
searching. While active state will be modified based on higher level
logic, we can define base functionality based on the result of
allocation btree lookups.

Define an active flag in the private area of the btree cursor.
Update it based on the result of lookups in the existing allocation
btree helpers. Finally, provide a new helper to query the current
state.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
---

diff --git a/libxfs/xfs_alloc.c b/libxfs/xfs_alloc.c
index 76af2f2fb..23a902818 100644
--- a/libxfs/xfs_alloc.c
+++ b/libxfs/xfs_alloc.c
@@ -141,9 +141,13 @@ xfs_alloc_lookup_eq(
 	xfs_extlen_t		len,	/* length of extent */
 	int			*stat)	/* success/failure */
 {
+	int			error;
+
 	cur->bc_rec.a.ar_startblock = bno;
 	cur->bc_rec.a.ar_blockcount = len;
-	return xfs_btree_lookup(cur, XFS_LOOKUP_EQ, stat);
+	error = xfs_btree_lookup(cur, XFS_LOOKUP_EQ, stat);
+	cur->bc_private.a.priv.abt.active = (*stat == 1);
+	return error;
 }
 
 /*
@@ -157,9 +161,13 @@ xfs_alloc_lookup_ge(
 	xfs_extlen_t		len,	/* length of extent */
 	int			*stat)	/* success/failure */
 {
+	int			error;
+
 	cur->bc_rec.a.ar_startblock = bno;
 	cur->bc_rec.a.ar_blockcount = len;
-	return xfs_btree_lookup(cur, XFS_LOOKUP_GE, stat);
+	error = xfs_btree_lookup(cur, XFS_LOOKUP_GE, stat);
+	cur->bc_private.a.priv.abt.active = (*stat == 1);
+	return error;
 }
 
 /*
@@ -173,9 +181,19 @@ xfs_alloc_lookup_le(
 	xfs_extlen_t		len,	/* length of extent */
 	int			*stat)	/* success/failure */
 {
+	int			error;
 	cur->bc_rec.a.ar_startblock = bno;
 	cur->bc_rec.a.ar_blockcount = len;
-	return xfs_btree_lookup(cur, XFS_LOOKUP_LE, stat);
+	error = xfs_btree_lookup(cur, XFS_LOOKUP_LE, stat);
+	cur->bc_private.a.priv.abt.active = (*stat == 1);
+	return error;
+}
+
+static inline bool
+xfs_alloc_cur_active(
+	struct xfs_btree_cur	*cur)
+{
+	return cur && cur->bc_private.a.priv.abt.active;
 }
 
 /*
diff --git a/libxfs/xfs_alloc_btree.c b/libxfs/xfs_alloc_btree.c
index 361b64247..d39c973ab 100644
--- a/libxfs/xfs_alloc_btree.c
+++ b/libxfs/xfs_alloc_btree.c
@@ -503,6 +503,7 @@ xfs_allocbt_init_cursor(
 
 	cur->bc_private.a.agbp = agbp;
 	cur->bc_private.a.agno = agno;
+	cur->bc_private.a.priv.abt.active = false;
 
 	if (xfs_sb_version_hascrc(&mp->m_sb))
 		cur->bc_flags |= XFS_BTREE_CRC_BLOCKS;
diff --git a/libxfs/xfs_btree.h b/libxfs/xfs_btree.h
index ff8343b0a..cfd8450a9 100644
--- a/libxfs/xfs_btree.h
+++ b/libxfs/xfs_btree.h
@@ -183,6 +183,9 @@ union xfs_btree_cur_private {
 		unsigned long	nr_ops;		/* # record updates */
 		int		shape_changes;	/* # of extent splits */
 	} refc;
+	struct {
+		bool		active;		/* allocation cursor state */
+	} abt;
 };
 
 /*