Mikulas Patocka wrote: > >>> This sounds like a bug to me. It seems like we should have a one to one >>> correspondence of filehandle -> inode. In what situations would this not be the >>> case? >> >> Well, the NFS protocol allows that [see rfc1813, p. 21: "If two file handles from >> the same server are equal, they must refer to the same file, but if they are not >> equal, no conclusions can be drawn."] >> >> As an example, some file systems encode hint information into the filehandle >> and the hints may change over time, another example is encoding parent >> information into the filehandle and then handles representing hard links >> to the same file from different directories will differ. > >BTW. how does (or how should?) NFS client deal with cache coherency if >filehandles for the same file differ? > Trond can probably answer this better than me... As I read it, currently the nfs client matches both the fileid and the filehandle (in nfs_find_actor). This means that different filehandles for the same file would result in different inodes :(. Strictly following the nfs protocol, comparing only the fileid should be enough IF fileids are indeed unique within the filesystem. Comparing the filehandle works as a workaround when the exported filesystem (or the nfs server) violates that. From a user stand point I think that this should be configurable, probably per mount point. >Mikulas > - 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
