svn commit: r259254 - head/sys/fs/devfs

[Alexander Motin]

Author: mav
Date: Thu Dec 12 11:05:48 2013
New Revision: 259254
URL: http://svnweb.freebsd.org/changeset/base/259254

Log:
  Fix long known bug with handling device aliases residing not in devfs root.
  
  Historically creation of device aliases created symbolic links using only
  name of target device as a link target, not considering current directory.
  Fix that by adding number of "../" chunks to the terget device name,
  required to get out of the current directory to devfs root first.
  
  MFC after:	1 month

Modified:
  head/sys/fs/devfs/devfs_devs.c

Modified: head/sys/fs/devfs/devfs_devs.c
==============================================================================
--- head/sys/fs/devfs/devfs_devs.c	Thu Dec 12 10:57:16 2013	(r259253)
+++ head/sys/fs/devfs/devfs_devs.c	Thu Dec 12 11:05:48 2013	(r259254)
@@ -486,9 +486,9 @@ devfs_populate_loop(struct devfs_mount *
 {
 	struct cdev_priv *cdp;
 	struct devfs_dirent *de;
-	struct devfs_dirent *dd;
+	struct devfs_dirent *dd, *dt;
 	struct cdev *pdev;
-	int de_flags, j;
+	int de_flags, depth, j;
 	char *q, *s;
 
 	sx_assert(&dm->dm_lock, SX_XLOCKED);
@@ -589,9 +589,17 @@ devfs_populate_loop(struct devfs_mount *
 			de->de_mode = 0755;
 			de->de_dirent->d_type = DT_LNK;
 			pdev = cdp->cdp_c.si_parent;
-			j = strlen(pdev->si_name) + 1;
+			dt = dd;
+			depth = 0;
+			while (dt != dm->dm_rootdir &&
+			    (dt = devfs_parent_dirent(dt)) != NULL)
+				depth++;
+			j = depth * 3 + strlen(pdev->si_name) + 1;
 			de->de_symlink = malloc(j, M_DEVFS, M_WAITOK);
-			bcopy(pdev->si_name, de->de_symlink, j);
+			de->de_symlink[0] = 0;
+			while (depth-- > 0)
+				strcat(de->de_symlink, "../");
+			strcat(de->de_symlink, pdev->si_name);
 		} else {
 			de->de_uid = cdp->cdp_c.si_uid;
 			de->de_gid = cdp->cdp_c.si_gid;