Messages in this thread | | | Date | Thu, 24 Apr 2008 13:29:49 -0400 | From | Erez Zadok <> | Subject | Re: [patch 00/13] vfs: add helpers to check r/o bind mounts |
| |
In message <20080424142857.GF15214@ZenIV.linux.org.uk>, Al Viro writes: > On Thu, Apr 24, 2008 at 04:09:18PM +0200, Miklos Szeredi wrote: [...] > FWIW, I'm not all that happy about the way ecryptfs_interpose() is done, > while we are at it. We get the sucker opened by whoever steps on given > place in the tree first, with subsequent operations done using the resulting > struct file. With fallback to r/o open. What happens to somebody who > tries to open it with enough permissions to do r/w?
Yes, ecryptfs_interpose() calls ecryptfs_init_persistent_file() which calls dentry_open(O_RDWR). What's the proposed solution for this in the face of r/o vfsmounts? How could ecryptfs avoid calling this dentry_open in the first place?
For unionfs, all I need is return -EROFS or the like to trigger a possible copyup.
Erez.
| |