Pavel Emelyanov <xemul@xxxxxxxxxxxxx> writes: > On 08/21/2012 02:42 PM, Aneesh Kumar K.V wrote: >> Pavel Emelyanov <xemul@xxxxxxxxxxxxx> writes: >> >>> On 08/20/2012 11:32 PM, J. Bruce Fields wrote: >>>> On Mon, Aug 20, 2012 at 11:06:06PM +0400, Cyrill Gorcunov wrote: >>>>> On Mon, Aug 20, 2012 at 02:32:25PM -0400, J. Bruce Fields wrote: >>>>>> On Mon, Aug 20, 2012 at 08:33:38PM +0400, Cyrill Gorcunov wrote: >>>>>>> On Mon, Aug 20, 2012 at 07:49:23PM +0530, Aneesh Kumar K.V wrote: >>>>>>>> Cyrill Gorcunov <gorcunov@xxxxxxxxxx> writes: >>>>>>>> >>>>>>>>> To provide fsnotify object inodes being watched without >>>>>>>>> binding to alphabetical path we need to encode them with >>>>>>>>> exportfs help. This patch adds a helper which operates >>>>>>>>> with plain inodes directly. >>>>>>>> >>>>>>>> doesn't name_to_handle_at() work for you ? It also allows to get a file >>>>>>>> handle using file descriptor. >>>>>>> >>>>>>> Hi, sorry for dealy. Well, the last idea is to get rid of this helper, >>>>>>> I've sent out an updated version where ino+dev is only printed. >>>>>> >>>>>> I don't understand how ino and dev are useful to you, though, if you're >>>>>> still hoping to be able to look up inodes using this information later >>>>>> on. >>>>> >>>>> Hi Bruce, I believe having ino+dev is better than nothing. Otherwise we >>>>> simply have no clue which targets are bound to inotify mark. Sometime >>>>> (!) we can try to generate fhandle in userspace from this ino+dev bundle >>>>> and then open the target file. >>>> >>>> That's insufficient to generate a filehandle in general. >>> >>> Yes, sure, but for live migration having inode and device is enough and that's why. >>> We can use two ways of having a filesystem on the target machine in the same >>> state (from paths points of view) as it was on destination one: >>> >>> 1. copy file tree in a rsync manner >>> 2. copy a virtual disk image file >>> >>> In the 1st case we can map inode number to path easily, since we iterate over a filesystem >>> anyway. I agree, that rsync is not perfect for migration but still. >>> >>> In the 2nd case we can generate filehandle out of an inode number only since we _do_ know >>> that inode will not get reused. >> >> If you are going to to use open_by_handle, then that handle is not >> sufficient right ? Or do you have open_by_inode ? as part of c/r ? > > Why? For e.g. ext4 you can construct a handle in userspace and open by > it. open_by_handle use exportfs_decode_fh which use file system specific fh_to_dentry foe ext4 we require a generation number inode = get_inode(sb, fid->i32.ino, fid->i32.gen); For brtfs objectid = fid->objectid; root_objectid = fid->root_objectid; generation = fid->gen; return btrfs_get_dentry(sb, objectid, root_objectid, generation, 1); -aneesh -- 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
