ubifs: Export pnode_lookup as ubifs_pnode_lookup

ubifs_lpt_lookup could be implemented using pnode_lookup. To make that
possible move pnode_lookup from lpt.c to lpt_commit.c. Rename it to
ubifs_pnode_lookup since it's now exported.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Richard Weinberger <richard@nod.at>

1 files changed, 32 insertions, 0 deletions

diff --git a/fs/ubifs/lpt.c b/fs/ubifs/lpt.c
index 31393370e334..ed0c67fe7500 100644
--- a/fs/ubifs/lpt.c
+++ b/fs/ubifs/lpt.c
@@ -1439,6 +1439,38 @@ struct ubifs_pnode *ubifs_get_pnode(struct ubifs_info *c,
 }
 
 /**
+ * ubifs_pnode_lookup - lookup a pnode in the LPT.
+ * @c: UBIFS file-system description object
+ * @i: pnode number (0 to (main_lebs - 1) / UBIFS_LPT_FANOUT)
+ *
+ * This function returns a pointer to the pnode on success or a negative
+ * error code on failure.
+ */
+struct ubifs_pnode *ubifs_pnode_lookup(struct ubifs_info *c, int i)
+{
+        int err, h, iip, shft;
+        struct ubifs_nnode *nnode;
+
+        if (!c->nroot) {
+                err = ubifs_read_nnode(c, NULL, 0);
+                if (err)
+                        return ERR_PTR(err);
+        }
+        i <<= UBIFS_LPT_FANOUT_SHIFT;
+        nnode = c->nroot;
+        shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT;
+        for (h = 1; h < c->lpt_hght; h++) {
+                iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
+                shft -= UBIFS_LPT_FANOUT_SHIFT;
+                nnode = ubifs_get_nnode(c, nnode, iip);
+                if (IS_ERR(nnode))
+                        return ERR_CAST(nnode);
+        }
+        iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
+        return ubifs_get_pnode(c, nnode, iip);
+}
+
+/**
  * ubifs_lpt_lookup - lookup LEB properties in the LPT.
  * @c: UBIFS file-system description object
  * @lnum: LEB number to lookup