lkml.org 
[lkml]   [2004]   [Oct]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Subject[PATCH 24/28] VFS: Fixup for ->follow_link on root of filesystem
    Date
    From
    When a follow_link dentry call is made, the implementation expects the
    dentry to be followed as well as a nameidata struct to be filled in.
    The received nd->mnt is expected to contain the vfsmount of the dentry
    being followed, so that a subsequent call to vfs_follow_link may
    properly pivot off that mount and onto another vfsmount as the path of
    the link is walked, thus keeping reference counts proper.

    The changes made in fs/namei.c@1.42 break this behaviour if the dentry
    being follow_link'ed is a root dentry. This is because follow_mount
    follows down next.mnt and not nd->mnt like it used to. So, if a root
    dentry has a follow_link op, the nd->mnt it receives is in fact the
    vfsmount of the mount it is mounted upon (which breaks reference counts).

    Signed-off-by: Mike Waychison <michael.waychison@sun.com>
    ---

    namei.c | 2 ++
    1 files changed, 2 insertions(+)

    Index: linux-2.6.9-quilt/fs/namei.c
    ===================================================================
    --- linux-2.6.9-quilt.orig/fs/namei.c 2004-10-22 17:17:34.762179488 -0400
    +++ linux-2.6.9-quilt/fs/namei.c 2004-10-22 17:17:46.571384216 -0400
    @@ -755,6 +755,7 @@ int fastcall link_path_walk(const char *

    if (inode->i_op->follow_link) {
    mntget(next.mnt);
    + nd->mnt = next.mnt;
    err = do_follow_link(next.dentry, nd);
    dput(next.dentry);
    mntput(next.mnt);
    @@ -809,6 +810,7 @@ last_component:
    if ((lookup_flags & LOOKUP_FOLLOW)
    && inode && inode->i_op && inode->i_op->follow_link) {
    mntget(next.mnt);
    + nd->mnt = next.mnt;
    err = do_follow_link(next.dentry, nd);
    dput(next.dentry);
    mntput(next.mnt);
    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2005-03-22 14:07    [W:3.164 / U:0.728 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site