gfs2: Allow gfs2_xattr_set to be called with the glock held

On the following call path:

  gfs2_setattr -> setattr_prepare -> ... ->
    cap_inode_killpriv -> ... ->
      gfs2_xattr_set

the glock is locked in gfs2_setattr, so check for recursive locking in
gfs2_xattr_set as gfs2_xattr_get already does.  While at it, get rid of
need_unlock in gfs2_xattr_get.

Fixes xfstest generic/093.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Acked-by: Abhijith Das <adas@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
This commit is contained in:
Andreas Gruenbacher 2017-10-13 00:39:38 +02:00
parent b2623c2fe6
commit d0920a9cd7

View File

@ -610,7 +610,6 @@ static int gfs2_xattr_get(const struct xattr_handler *handler,
{
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_holder gh;
bool need_unlock = false;
int ret;
/* During lookup, SELinux calls this function with the glock locked. */
@ -619,10 +618,11 @@ static int gfs2_xattr_get(const struct xattr_handler *handler,
ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &gh);
if (ret)
return ret;
need_unlock = true;
} else {
gfs2_holder_mark_uninitialized(&gh);
}
ret = __gfs2_xattr_get(inode, name, buffer, size, handler->flags);
if (need_unlock)
if (gfs2_holder_initialized(&gh))
gfs2_glock_dq_uninit(&gh);
return ret;
}
@ -1244,11 +1244,20 @@ static int gfs2_xattr_set(const struct xattr_handler *handler,
if (ret)
return ret;
ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
if (ret)
return ret;
/* May be called from gfs_setattr with the glock locked. */
if (!gfs2_glock_is_locked_by_me(ip->i_gl)) {
ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
if (ret)
return ret;
} else {
if (WARN_ON_ONCE(ip->i_gl->gl_state != LM_ST_EXCLUSIVE))
return -EIO;
gfs2_holder_mark_uninitialized(&gh);
}
ret = __gfs2_xattr_set(inode, name, value, size, flags, handler->flags);
gfs2_glock_dq_uninit(&gh);
if (gfs2_holder_initialized(&gh))
gfs2_glock_dq_uninit(&gh);
return ret;
}