xnu-344.tar.gz

[apple/xnu.git] / bsd / vfs / vfs_lookup.c

diff --git a/bsd/vfs/vfs_lookup.c b/bsd/vfs/vfs_lookup.c
index f7eb1ca2a273563155461bdd800d91638fb7c6bb..9d8aea2993fc0352bfcb48c90d87b7ecdc32d5b2 100644 (file)
--- a/bsd/vfs/vfs_lookup.c
+++ b/bsd/vfs/vfs_lookup.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved.
  *
  * @APPLE_LICENSE_HEADER_START@
  * 
@@ -292,7 +292,9 @@ lookup(ndp)
        int namemax = 0;                        /* maximun number of bytes for filename returned by pathconf() */
        int docache;                    /* == 0 do not cache last component */
        int wantparent;                 /* 1 => wantparent or lockparent flag */
+       int dp_unlocked = 0;    /* 1 => dp already VOP_UNLOCK()-ed */
        int rdonly;                     /* lookup read-only flag bit */
+       int trailing_slash;
        int error = 0;
        struct componentname *cnp = &ndp->ni_cnd;
        struct proc *p = cnp->cn_proc;
@@ -344,6 +346,25 @@ dirloop:
 #endif
        ndp->ni_pathlen -= cnp->cn_namelen;
        ndp->ni_next = cp;
+
+       /*
+        * Replace multiple slashes by a single slash and trailing slashes
+        * by a null.  This must be done before VOP_LOOKUP() because some
+        * fs's don't know about trailing slashes.  Remember if there were
+        * trailing slashes to handle symlinks, existing non-directories
+        * and non-existing files that won't be directories specially later.
+        */
+       trailing_slash = 0;
+       while (*cp == '/' && (cp[1] == '/' || cp[1] == '\0')) {
+               cp++;
+               ndp->ni_pathlen--;
+               if (*cp == '\0') {
+                       trailing_slash = 1;
+                       *ndp->ni_next = '\0';
+               }
+       }
+       ndp->ni_next = cp;
+
        cnp->cn_flags |= MAKEENTRY;
        if (*cp == '\0' && docache == 0)
                cnp->cn_flags &= ~MAKEENTRY;
@@ -405,6 +426,11 @@ dirloop:
                        if ((dp->v_flag & VROOT) == 0 ||
                            (cnp->cn_flags & NOCROSSMOUNT))
                                break;
+                       if (dp->v_mount == NULL) {      /* forced umount */
+                               error = EBADF;
+                               goto bad;
+                       }
+
                        tdp = dp;
                        dp = dp->v_mount->mnt_vnodecovered;
                        vput(tdp);
@@ -428,7 +454,7 @@ unionlookup:
                printf("not found\n");
 #endif
                if ((error == ENOENT) &&
-                   (dp->v_flag & VROOT) &&
+                   (dp->v_flag & VROOT) && (dp->v_mount != NULL) &&
                    (dp->v_mount->mnt_flag & MNT_UNION)) {
                        tdp = dp;
                        dp = dp->v_mount->mnt_vnodecovered;
@@ -448,6 +474,11 @@ unionlookup:
                        error = EROFS;
                        goto bad;
                }
+               if (*cp == '\0' && trailing_slash &&
+                       !(cnp->cn_flags & WILLBEDIR)) {
+                       error = ENOENT;
+                       goto bad;
+               }
                /*
                 * We return with ni_vp NULL to indicate that the entry
                 * doesn't currently exist, leaving a pointer to the
@@ -485,11 +516,14 @@ unionlookup:
               (cnp->cn_flags & NOCROSSMOUNT) == 0) {
                if (vfs_busy(mp, 0, 0, p))
                        continue;
+               VOP_UNLOCK(dp, 0, p);
                error = VFS_ROOT(mp, &tdp);
                vfs_unbusy(mp, p);
-               if (error)
+               if (error) {
+                       dp_unlocked = 1;                /* Signal error path 'dp' has already been unlocked */
                        goto bad2;
-               vput(dp);
+               };
+               vrele(dp);
                ndp->ni_vp = dp = tdp;
        }
 
@@ -497,11 +531,20 @@ unionlookup:
         * Check for symbolic link
         */
        if ((dp->v_type == VLNK) &&
-           ((cnp->cn_flags & FOLLOW) || *ndp->ni_next == '/')) {
+           ((cnp->cn_flags & FOLLOW) || trailing_slash ||
+               *ndp->ni_next == '/')) {
                cnp->cn_flags |= ISSYMLINK;
                return (0);
        }
 
+       /*
+        * Check for bogus trailing slashes.
+        */
+        if (trailing_slash && dp->v_type != VDIR) {
+               error = ENOTDIR;
+               goto bad2;
+        }
+
 nextname:
        /*
         * Not a symbolic link.  If more pathname,
@@ -542,7 +585,11 @@ bad2:
                VOP_UNLOCK(ndp->ni_dvp, 0, p);
        vrele(ndp->ni_dvp);
 bad:
-       vput(dp);
+       if (dp_unlocked) {
+               vrele(dp);
+       } else {
+               vput(dp);
+       };
        ndp->ni_vp = NULL;
        if (kdebug_enable)
                kdebug_lookup(dp, cnp);
@@ -696,7 +743,7 @@ bad:
 }
 
 
-#define NUMPARMS 7
+#define NUMPARMS 23
 
 kdebug_lookup(dp, cnp)
         struct vnode *dp;
@@ -704,6 +751,7 @@ kdebug_lookup(dp, cnp)
 {
         register int i, n;
        register int dbg_namelen;
+       register int save_dbg_namelen;
        register char *dbg_nameptr;
        long dbg_parms[NUMPARMS];
        char dbg_buf[4];
@@ -716,6 +764,7 @@ kdebug_lookup(dp, cnp)
        if (dbg_namelen > sizeof(dbg_parms))
            dbg_namelen = sizeof(dbg_parms);
        dbg_nameptr -= dbg_namelen;
+       save_dbg_namelen = dbg_namelen;
 
        i = 0;
 
@@ -744,8 +793,19 @@ kdebug_lookup(dp, cnp)
            else
                dbg_parms[i++] = 0;
        }
-       KERNEL_DEBUG_CONSTANT((FSDBG_CODE(DBG_FSRW,36)) | DBG_FUNC_NONE,
+
+       /*
+         In the event that we collect multiple, consecutive pathname
+         entries, we must mark the start of the path's string.
+       */
+       KERNEL_DEBUG_CONSTANT((FSDBG_CODE(DBG_FSRW,36)) | DBG_FUNC_START,
                              dp, dbg_parms[0], dbg_parms[1], dbg_parms[2], 0);
-       KERNEL_DEBUG_CONSTANT((FSDBG_CODE(DBG_FSRW,36)) | DBG_FUNC_NONE,
-                             dbg_parms[3], dbg_parms[4], dbg_parms[5], dbg_parms[6], 0);
+
+       for (dbg_namelen = save_dbg_namelen-12, i=3;
+            dbg_namelen > 0;
+            dbg_namelen -=(4 * sizeof(long)), i+= 4)
+         {
+           KERNEL_DEBUG_CONSTANT((FSDBG_CODE(DBG_FSRW,36)) | DBG_FUNC_NONE,
+                                 dbg_parms[i], dbg_parms[i+1], dbg_parms[i+2], dbg_parms[i+3], 0);
+         }
 }