On Fri, 20 Nov 2009, Josef Bacik wrote: > On Fri, Nov 13, 2009 at 02:55:24PM +0100, Miklos Szeredi wrote: > > On Fri, 13 Nov 2009, Eric Paris wrote: > > > mount S ffff88001f86bd28 0 4126 4120 0x00000080 > > > mount S ffff88001f86bd28 0 4126 4120 0x00000080 > > > ffff88001f86bc38 0000000000000086 0000000000000011 ffff88001f86bc08 > > > 0000000000000700 0000000000000000 0000000000000013 ffffffff815884cd > > > ffff8800377532c8 000000000000f8e0 ffff8800377532c8 0000000000015600 > > > Call Trace: > > > [<ffffffffa01bec71>] fuse_get_req+0xb8/0x15b [fuse] > > > [<ffffffffa01bf359>] fuse_getxattr+0x58/0x14f [fuse] > > > [<ffffffff811b9ea2>] get_vfs_caps_from_disk+0x52/0xcd > > > [<ffffffff81093809>] audit_copy_inode+0x83/0xb1 > > > [<ffffffff81093d4f>] __audit_inode+0x1ee/0x1fd > > > [<ffffffff81104789>] audit_inode+0x28/0x2a > > > [<ffffffff811066b4>] do_path_lookup+0x63/0x8b > > > [<ffffffff81107c9c>] user_path_at+0x56/0x93 > > > [<ffffffff810ffaf0>] sys_readlinkat+0x2d/0x91 > > > [<ffffffff810ffb6f>] sys_readlink+0x1b/0x1d > > > [<ffffffff81011cf2>] system_call_fastpath+0x16/0x1b > > > > > > Userspace called readlink() and the audit system (after the vfs worked > > > out the path) needs to collect any fcaps. > > > > OK, this is a different problem than what I thought. Agreed, audit is > > not doing anything wrong here. > > > > The cause seems to be that fuse calls "mount -i -f ..." to add the > > filesystem entry to /etc/mtab. mount(8) then goes off and tries to > > canonicalize the path, calling readlink() on the mountpoint. Which is > > unnecessary, really. The path has already been canonicalized, but > > unfortunately there's no way currently to tell this to mount. > > > > In this light, the patch by Josef might be OK as a workaround, but > > I'll look at better ways to fix this. > > > > Josef, can you check whether the mtab is still correctly updated with > > your patch? > > > > Hey Miklos, have you come up with a better solution yet? Alot of users are > hitting this in Fedora and I'd like to get a fix into place for them soon. Well, two solutions come to mind: 1) add a "--no-canonicalize" option to mount(8) and umount(8) 2) copy the /etc/mtab manipulating code from util-linux to fuse and omit the path canonicalization I think 1) is simpler and easier to maintain, but also requires updates to util-linux-ng in addition to fuse userspace. Karel, would you accept such an option? Thanks, Miklos -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
