[lkml]   [2010]   [Sep]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: [PATCH 09/10] VFS: Remove read-only checks from dentry_permission
    On Mon, 06 Sep 2010, NeilBrown wrote:
    > It is not sufficient to depend on the the "filesystem is readonly"
    > tests in dentry_permission as it does not check if the vfsmnt is
    > readonly.
    > All call sites already call mnt_want_write or __mnt_is_readonly which
    > includes the test on MS_RDONLY.

    Last time I checked I found some holes (in nfsd IIRC). That was a
    long time ago and things may have changed.

    That check could be replaced with a

    if (IS_RDONLY(inode) &&
    (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)))

    which would catch these cases but only if the superblock was marked
    r/o. Otherwise it's basically impossible to make sure the callers of
    the VFS play by the rules. That was one reason I advocated a
    path_... interface for the VFS instead of the current dentry based
    one, but Al didn't like it.


     \ /
      Last update: 2010-09-06 21:13    [W:0.019 / U:10.380 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site