xfs: hide xfs_inode_is_allocated in scrub common code

This function is only used by online fsck, so let's move it there.
In the next patch, we'll fix it to work properly and to require that the
caller hold the AGI buffer locked.  No major changes aside from
adjusting the signature a bit.

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

3 files changed, 40 insertions, 2 deletions

diff --git a/fs/xfs/scrub/common.c b/fs/xfs/scrub/common.c
index 82d2a85d6461..3ba329526266 100644
--- a/fs/xfs/scrub/common.c
+++ b/fs/xfs/scrub/common.c
@@ -1230,3 +1230,40 @@ xchk_fsgates_enable(
 
 	sc->flags |= scrub_fsgates;
 }
+
+/*
+ * Decide if this is this a cached inode that's also allocated.
+ *
+ * Look up an inode by number in the given file system.  If the inode is
+ * in cache and isn't in purgatory, return 1 if the inode is allocated
+ * and 0 if it is not.  For all other cases (not in cache, being torn
+ * down, etc.), return a negative error code.
+ *
+ * The caller has to prevent inode allocation and freeing activity,
+ * presumably by locking the AGI buffer.   This is to ensure that an
+ * inode cannot transition from allocated to freed until the caller is
+ * ready to allow that.  If the inode is in an intermediate state (new,
+ * reclaimable, or being reclaimed), -EAGAIN will be returned; if the
+ * inode is not in the cache, -ENOENT will be returned.  The caller must
+ * deal with these scenarios appropriately.
+ *
+ * This is a specialized use case for the online scrubber; if you're
+ * reading this, you probably want xfs_iget.
+ */
+int
+xchk_inode_is_allocated(
+	struct xfs_scrub	*sc,
+	xfs_ino_t		ino,
+	bool			*inuse)
+{
+	struct xfs_inode	*ip;
+	int			error;
+
+	error = xfs_iget(sc->mp, sc->tp, ino, XFS_IGET_INCORE, 0, &ip);
+	if (error)
+		return error;
+
+	*inuse = !!(VFS_I(ip)->i_mode);
+	xfs_irele(ip);
+	return 0;
+}
diff --git a/fs/xfs/scrub/common.h b/fs/xfs/scrub/common.h
index 4f7cb410904d..a2d2e0749554 100644
--- a/fs/xfs/scrub/common.h
+++ b/fs/xfs/scrub/common.h
@@ -203,4 +203,6 @@ static inline bool xchk_need_intent_drain(struct xfs_scrub *sc)
 
 void xchk_fsgates_enable(struct xfs_scrub *sc, unsigned int scrub_fshooks);
 
+int xchk_inode_is_allocated(struct xfs_scrub *sc, xfs_ino_t ino, bool *inuse);
+
 #endif	/* __XFS_SCRUB_COMMON_H__ */
diff --git a/fs/xfs/scrub/ialloc.c b/fs/xfs/scrub/ialloc.c
index 575f22a02ebe..3a3d750b02e0 100644
--- a/fs/xfs/scrub/ialloc.c
+++ b/fs/xfs/scrub/ialloc.c
@@ -328,8 +328,7 @@ xchk_iallocbt_check_cluster_ifree(
 		goto out;
 	}
 
-	error = xfs_icache_inode_is_allocated(mp, bs->cur->bc_tp, fsino,
-			&ino_inuse);
+	error = xchk_inode_is_allocated(bs->sc, fsino, &ino_inuse);
 	if (error == -ENODATA) {
 		/* Not cached, just read the disk buffer */
 		freemask_ok = irec_free ^ !!(dip->di_mode);