__nameiparent, __namei, and __namex don't acquire refs

nameiparent, namei, and __namex don't acquire refs
7fe2e84a · Silas Boyd-Wickizer · 7f44eed2 · 7fe2e84a · 7fe2e84a
--- a/include/kernel.hh
+++ b/include/kernel.hh
@@ -102,6 +102,9 @@ struct inode*   nameiparent(inode *cwd, const char*, char*);
 int             dirlink(struct inode*, const char*, u32);
 void            dir_init(struct inode *dp);
 void	        dir_flush(struct inode *dp);
+inode*          __nameiparent(inode *cwd, const char *path,
+                              char *name, bool* haveref);
+inode*          __namei(inode *cwd, const char *path, bool* haveref);

 // futex.cc
 typedef u64* futexkey_t;

--- a/kernel/fs.cc
+++ b/kernel/fs.cc
@@ -318,12 +318,14 @@ iget(u32 dev, u32 inum)
  bool haveref;
  inode* ip;

-  scoped_gc_epoch e;
 retry:
-  ip = __iget(dev, inum, &haveref);
-  if (!haveref)
-    if (!ip->tryinc())
-      goto retry;
+  {
+    scoped_gc_epoch e;
+    ip = __iget(dev, inum, &haveref);
+    if (!haveref)
+      if (!ip->tryinc())
+        goto retry;
+  }
  return ip;
 }

@@ -828,13 +830,16 @@ skipelem(const char **rpath, char *name)
 // If parent != 0, return the inode for the parent and copy the final
 // path element into name, which must have room for DIRSIZ bytes.
 static struct inode*
-namex(inode *cwd, const char *path, int nameiparent, char *name)
+__namex(inode *cwd, const char *path, int nameiparent, char *name,
+        bool* retref)
 {
+
+  // Assumes caller is holding a gc_epoch
+
  struct inode *ip, *next;
  bool haveref;
  int r;

-  scoped_gc_epoch e;
  if(*path == '/') 
    ip = the_root;
  else
@@ -858,8 +863,7 @@ namex(inode *cwd, const char *path, int nameiparent, char *name)
      return 0;
    if(nameiparent && *path == '\0'){
      // Stop one level early.
-      if (!haveref)
-        idup(ip);
+      *retref = haveref;
      return ip;
    }

@@ -883,23 +887,58 @@ namex(inode *cwd, const char *path, int nameiparent, char *name)
  // mtreadavar("inode:%x.%x", ip->dev, ip->inum);
  mtwriteavar("inode:%x.%x", ip->dev, ip->inum);

-  if (!haveref)
-    idup(ip);
+  *retref = haveref;
  return ip;
 }

-struct inode*
+inode*
+__namei(inode *cwd, const char *path, bool* haveref)
+{
+  // Assumes caller is holding a gc_epoch
+  char name[DIRSIZ];
+  return __namex(cwd, path, 0, name, haveref);
+}
+
+inode*
 namei(inode *cwd, const char *path)
 {
  char name[DIRSIZ];
-  struct inode *r = namex(cwd, path, 0, name);
-  //cprintf("namei: %s -> %x (%d)\n", path, r, r?r->inum:0);
-  return r;
+  bool haveref;
+
+  inode* ip;
+retry:
+  {
+    scoped_gc_epoch e;
+    ip = __namex(cwd, path, 0, name, &haveref);
+    if (ip != nullptr && !haveref)
+      if (!ip->tryinc())
+        goto retry;
+  }
+
+  return ip;
 }

-struct inode*
-nameiparent(inode *cwd, const char *path, char *name)
+inode*
+__nameiparent(inode *cwd, const char *path, char *name, bool* haveref)
 {
-  return namex(cwd, path, 1, name);
+  // Assumes caller is holding a gc_epoch
+  return __namex(cwd, path, 1, name, haveref);
 }

+
+inode*
+nameiparent(inode *cwd, const char *path, char *name)
+{
+  bool haveref;
+
+  inode* ip;
+retry:
+  {
+    scoped_gc_epoch e;
+    ip = __namex(cwd, path, 1, name, &haveref);
+    if (ip != nullptr && !haveref)
+      if (!ip->tryinc())
+        goto retry;
+  }
+  return ip;
+}