2018-03-16 5:48 GMT+08:00 Amir Goldstein <amir73il@xxxxxxxxx>: > On Thu, Mar 15, 2018 at 8:40 PM, Amir Goldstein <amir73il@xxxxxxxxx> wrote: >> On Thu, Mar 15, 2018 at 4:30 PM, Eddie Horng <eddiehorng.tw@xxxxxxxxx> wrote: > [...] >> The problem *is* with nfsd+overlayfs, because nfsd verifies >> in compose_entry_fh() that (dchild->d_inode->i_ino == ino), but it is not. >> In that case, encode_entryplus_baggage() falls back to encoding xdr_zero. >> In overlayfs stat.st_ino is consistent with readdir d_ino since kernel version >> v4.15 and only for all layers on the same fs. >> >> However, there is no guaranty that inode->i_ino is the same as stat.st_ino. >> Overlayfs exposes only stat.st_ino to user (as well as readdir d_ino), but >> never (to my knowledge) does it expose inode->i_ino. >> >> There was a nfsd fix for a somewhat similar problem that went into v4.16-rc1: >> 76c479480b9a nfsd: encode stat->mtime for getattr instead of inode->i_mtime >> >> The solution to the problem is to either convert all references of >> nfsd to i_inode >> with references to st_ino, or make sure to set inode->i_ino correctly for >> overlayfs inodes. >> >> From first glimps, the change in nfsd looks non trivial. >> The change to overlayfs seems doable, but didn't look closely yet. >> Will try to come up with test patch for you. >> > > Eddie, > > Please try this patch. It worked for me. > > Thanks, > Amir. Hi Amir, The patch works like a charm in my first test, but when I switch lower layer to different fs then upper and merged, problem comes again. The configuration is: /dev/loop0 /ro_mount ext4 rw,relatime,data=ordered 0 0 none /share overlay rw,relatime,lowerdir=/ro_mount,upperdir=/base/upper,workdir=/base/work,index=on,nfs_export=on 0 0 localhost:/share /mnt/n nfs rw,relatime,vers=3,rsize=1048576,wsize=1048576,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=127.0.0.1,mountvers=3,mountport=40970,mountproto=udp,local_lock=none,addr=127.0.0.1 0 0 /ro_mount/ |-- lost+found |-- ro-dir `-- ro-file result: readdir: lost+found ino(b) type(0) readdir: ro-file ino(c) type(0) readdir: .. ino(e0001) type(0) readdir: ro-dir ino(2003) type(0) readdir: . ino(e0003) type(0) ps. /ro_mount is created by: truncate -s 1g image mkfs.ext4 image mount image /ro_mount thanks, Eddie -- To unsubscribe from this list: send the line "unsubscribe linux-unionfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
