- Add conditional VFS Giant locking to getdents_common() (linux ABIs),

  ibcs2_getdents(), ibcs2_read(), ogetdirentries(), svr4_sys_getdents(),
  and svr4_sys_getdents64() similar to that in getdirentries().
- Mark ibcs2_getdents(), ibcs2_read(), linux_getdents(), linux_getdents64(),
  linux_readdir(), ogetdirentries(), svr4_sys_getdents(), and
  svr4_sys_getdents64() MPSAFE.

1 files changed, 14 insertions, 13 deletions

diff --git a/sys/compat/linux/linux_file.c b/sys/compat/linux/linux_file.c
index ca6b7a6..cd50aa4 100644
--- a/sys/compat/linux/linux_file.c
+++ b/sys/compat/linux/linux_file.c
@@ -259,7 +259,17 @@ getdents_common(struct thread *td, struct linux_getdents64_args *args,
 	struct l_dirent64 linux_dirent64;
 	int buflen, error, eofflag, nbytes, justone;
 	u_long *cookies = NULL, *cookiep;
-	int ncookies;
+	int ncookies, vfslocked;
+
+	nbytes = args->count;
+	if (nbytes == 1) {
+		/* readdir(2) case. Always struct dirent. */
+		if (is64bit)
+			return (EINVAL);
+		nbytes = sizeof(linux_dirent);
+		justone = 1;
+	} else
+		justone = 0;
 
 	if ((error = getvnode(td->td_proc->p_fd, args->fd, &fp)) != 0)
 		return (error);
@@ -270,23 +280,13 @@ getdents_common(struct thread *td, struct linux_getdents64_args *args,
 	}
 
 	vp = fp->f_vnode;
+	vfslocked = VFS_LOCK_GIANT(vp->v_mount);
 	if (vp->v_type != VDIR) {
+		VFS_UNLOCK_GIANT(vfslocked);
 		fdrop(fp, td);
 		return (EINVAL);
 	}
 
-	nbytes = args->count;
-	if (nbytes == 1) {
-		/* readdir(2) case. Always struct dirent. */
-		if (is64bit) {
-			fdrop(fp, td);
-			return (EINVAL);
-		}
-		nbytes = sizeof(linux_dirent);
-		justone = 1;
-	} else
-		justone = 0;
-
 	off = fp->f_offset;
 
 	buflen = max(LINUX_DIRBLKSIZ, nbytes);
@@ -439,6 +439,7 @@ out:
 		free(cookies, M_TEMP);
 
 	VOP_UNLOCK(vp, 0, td);
+	VFS_UNLOCK_GIANT(vfslocked);
 	fdrop(fp, td);
 	free(buf, M_TEMP);
 	return (error);