[PATCH 2/3] xfs: simplify the perage inode walk infrastructure

[Christoph Hellwig <hch@lst.de>]

Remove the generic xfs_inode_walk and just open code the only caller.
Note that this leads to a somewhat ugly forward delcaration for
xfs_blockgc_scan_inode, but with other changes in that area pending
it seems like the lesser evil.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/xfs/xfs_icache.c | 103 +++++++++++++-------------------------------
 fs/xfs/xfs_icache.h |  11 -----
 2 files changed, 30 insertions(+), 84 deletions(-)

diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
index c0d084e3526a9c..7fdf77df66269c 100644
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -728,11 +728,9 @@ xfs_icache_inode_is_allocated(
  */
 STATIC bool
 xfs_inode_walk_ag_grab(
-	struct xfs_inode	*ip,
-	int			flags)
+	struct xfs_inode	*ip)
 {
 	struct inode		*inode = VFS_I(ip);
-	bool			newinos = !!(flags & XFS_INODE_WALK_INEW_WAIT);
 
 	ASSERT(rcu_read_lock_held());
 
@@ -742,8 +740,7 @@ xfs_inode_walk_ag_grab(
 		goto out_unlock_noent;
 
 	/* avoid new or reclaimable inodes. Leave for reclaim code to flush */
-	if ((!newinos && __xfs_iflags_test(ip, XFS_INEW)) ||
-	    __xfs_iflags_test(ip, XFS_IRECLAIMABLE | XFS_IRECLAIM))
+	if (__xfs_iflags_test(ip, XFS_INEW | XFS_IRECLAIMABLE | XFS_IRECLAIM))
 		goto out_unlock_noent;
 	spin_unlock(&ip->i_flags_lock);
 
@@ -763,17 +760,19 @@ xfs_inode_walk_ag_grab(
 	return false;
 }
 
+static int
+xfs_blockgc_scan_inode(
+	struct xfs_inode	*ip,
+	void			*args);
+
 /*
  * For a given per-AG structure @pag, grab, @execute, and rele all incore
  * inodes with the given radix tree @tag.
  */
 STATIC int
-xfs_inode_walk_ag(
+xfs_blockgc_free_space_ag(
 	struct xfs_perag	*pag,
-	int			iter_flags,
-	int			(*execute)(struct xfs_inode *ip, void *args),
-	void			*args,
-	int			tag)
+	struct xfs_eofblocks	*eofb)
 {
 	struct xfs_mount	*mp = pag->pag_mount;
 	uint32_t		first_index;
@@ -793,17 +792,9 @@ xfs_inode_walk_ag(
 		int		i;
 
 		rcu_read_lock();
-
-		if (tag == XFS_ICI_NO_TAG)
-			nr_found = radix_tree_gang_lookup(&pag->pag_ici_root,
-					(void **)batch, first_index,
-					XFS_LOOKUP_BATCH);
-		else
-			nr_found = radix_tree_gang_lookup_tag(
-					&pag->pag_ici_root,
-					(void **) batch, first_index,
-					XFS_LOOKUP_BATCH, tag);
-
+		nr_found = radix_tree_gang_lookup_tag(&pag->pag_ici_root,
+				(void **) batch, first_index,
+				XFS_LOOKUP_BATCH, XFS_ICI_BLOCKGC_TAG);
 		if (!nr_found) {
 			rcu_read_unlock();
 			break;
@@ -816,7 +807,7 @@ xfs_inode_walk_ag(
 		for (i = 0; i < nr_found; i++) {
 			struct xfs_inode *ip = batch[i];
 
-			if (done || !xfs_inode_walk_ag_grab(ip, iter_flags))
+			if (done || !xfs_inode_walk_ag_grab(ip))
 				batch[i] = NULL;
 
 			/*
@@ -844,10 +835,7 @@ xfs_inode_walk_ag(
 		for (i = 0; i < nr_found; i++) {
 			if (!batch[i])
 				continue;
-			if ((iter_flags & XFS_INODE_WALK_INEW_WAIT) &&
-			    xfs_iflags_test(batch[i], XFS_INEW))
-				xfs_inew_wait(batch[i]);
-			error = execute(batch[i], args);
+			error = xfs_blockgc_scan_inode(batch[i], eofb);
 			xfs_irele(batch[i]);
 			if (error == -EAGAIN) {
 				skipped++;
@@ -872,49 +860,6 @@ xfs_inode_walk_ag(
 	return last_error;
 }
 
-/* Fetch the next (possibly tagged) per-AG structure. */
-static inline struct xfs_perag *
-xfs_inode_walk_get_perag(
-	struct xfs_mount	*mp,
-	xfs_agnumber_t		agno,
-	int			tag)
-{
-	if (tag == XFS_ICI_NO_TAG)
-		return xfs_perag_get(mp, agno);
-	return xfs_perag_get_tag(mp, agno, tag);
-}
-
-/*
- * Call the @execute function on all incore inodes matching the radix tree
- * @tag.
- */
-int
-xfs_inode_walk(
-	struct xfs_mount	*mp,
-	int			iter_flags,
-	int			(*execute)(struct xfs_inode *ip, void *args),
-	void			*args,
-	int			tag)
-{
-	struct xfs_perag	*pag;
-	int			error = 0;
-	int			last_error = 0;
-	xfs_agnumber_t		ag;
-
-	ag = 0;
-	while ((pag = xfs_inode_walk_get_perag(mp, ag, tag))) {
-		ag = pag->pag_agno + 1;
-		error = xfs_inode_walk_ag(pag, iter_flags, execute, args, tag);
-		xfs_perag_put(pag);
-		if (error) {
-			last_error = error;
-			if (error == -EFSCORRUPTED)
-				break;
-		}
-	}
-	return last_error;
-}
-
 /*
  * Grab the inode for reclaim exclusively.
  *
@@ -1617,8 +1562,7 @@ xfs_blockgc_worker(
 
 	if (!sb_start_write_trylock(mp->m_super))
 		return;
-	error = xfs_inode_walk_ag(pag, 0, xfs_blockgc_scan_inode, NULL,
-			XFS_ICI_BLOCKGC_TAG);
+	error = xfs_blockgc_free_space_ag(pag, NULL);
 	if (error)
 		xfs_info(mp, "AG %u preallocation gc worker failed, err=%d",
 				pag->pag_agno, error);
@@ -1634,10 +1578,23 @@ xfs_blockgc_free_space(
 	struct xfs_mount	*mp,
 	struct xfs_eofblocks	*eofb)
 {
+	struct xfs_perag	*pag;
+	xfs_agnumber_t		ag = 0;
+	int			error = 0, last_error = 0;
+
 	trace_xfs_blockgc_free_space(mp, eofb, _RET_IP_);
 
-	return xfs_inode_walk(mp, 0, xfs_blockgc_scan_inode, eofb,
-			XFS_ICI_BLOCKGC_TAG);
+	while ((pag = xfs_perag_get_tag(mp, ag, XFS_ICI_BLOCKGC_TAG))) {
+		ag = pag->pag_agno + 1;
+		error = xfs_blockgc_free_space_ag(pag, eofb);
+		xfs_perag_put(pag);
+		if (error) {
+			if (error == -EFSCORRUPTED)
+				return error;
+			last_error = error;
+		}
+	}
+	return last_error;
 }
 
 /*
diff --git a/fs/xfs/xfs_icache.h b/fs/xfs/xfs_icache.h
index d70d93c2bb1084..da390097546c67 100644
--- a/fs/xfs/xfs_icache.h
+++ b/fs/xfs/xfs_icache.h
@@ -20,8 +20,6 @@ struct xfs_eofblocks {
 /*
  * tags for inode radix tree
  */
-#define XFS_ICI_NO_TAG		(-1)	/* special flag for an untagged lookup
-					   in xfs_inode_walk */
 #define XFS_ICI_RECLAIM_TAG	0	/* inode is to be reclaimed */
 /* Inode has speculative preallocations (posteof or cow) to clean. */
 #define XFS_ICI_BLOCKGC_TAG	1
@@ -34,11 +32,6 @@ struct xfs_eofblocks {
 #define XFS_IGET_DONTCACHE	0x4
 #define XFS_IGET_INCORE		0x8	/* don't read from disk or reinit */
 
-/*
- * flags for AG inode iterator
- */
-#define XFS_INODE_WALK_INEW_WAIT	0x1	/* wait on new inodes */
-
 int xfs_iget(struct xfs_mount *mp, struct xfs_trans *tp, xfs_ino_t ino,
 	     uint flags, uint lock_flags, xfs_inode_t **ipp);
 
@@ -68,10 +61,6 @@ void xfs_inode_clear_cowblocks_tag(struct xfs_inode *ip);
 
 void xfs_blockgc_worker(struct work_struct *work);
 
-int xfs_inode_walk(struct xfs_mount *mp, int iter_flags,
-	int (*execute)(struct xfs_inode *ip, void *args),
-	void *args, int tag);
-
 int xfs_icache_inode_is_allocated(struct xfs_mount *mp, struct xfs_trans *tp,
 				  xfs_ino_t ino, bool *inuse);
 
-- 
2.30.1