On Tue, Sep 29, 2015 at 6:44 PM, Jeremy Allison <jra@xxxxxxxxx> wrote: > On Mon, Sep 28, 2015 at 09:48:06PM -0500, Steve French wrote: >> directory listings of large directories on smb2/smb3 mounts to Samba >> sometimes shows the >> >> "Autodisabling the use of server inode numbers ..." message in dmesg. >> >> I have narrowed it down to cases where Samba is displaying symlink >> source and target with the same inode number (the client does not know >> they are symlinks since Samba does not set that file type when Unix >> Extensions are not available). Interestingly small directories with >> either symlinks or hardlinks in them don't cause the client to detect >> the inode number collision (which causes the server inode message to >> be displayed). > > Yes, that's going to happen if symlinks are within the share > without UNIX extensions I'm afraid. We report them as the same file > (as they are). > >> cifs_find_inode in fs/cifs/inode.c has the following check (after >> making sure that the inode numbers and mode of the two are the same >> and that they are not directories and that their creation time is the >> same) >> >> /* if it's not a directory or has no dentries, then flag it */ >> if (S_ISDIR(inode->i_mode) && !hlist_empty(&inode->i_dentry)) >> fattr->cf_flags |= CIFS_FATTR_INO_COLLISION; >> >> Not sure what causes the collision in the case of a larger directory >> but not a smaller one. It is puzzling because the source and target >> look (to the SMB3 client) similar to hardlinks with the same metadata >> except for file name (Samba server does not emulate symlinks as SMB3 >> symlink reparse points or apple style symlinks so they look more like >> hardlinks to the client) > > Nothing to do with directory size. Any link is going to do this > if it points within the share. The Samba behavior doesn't change based on directory size but the VFS dcache/inode behavior clearly has something to do with how many or what additional entries are in the directory. I easily can prove that - I created two directories 1) one with symlinks 2) one with hardlinks ls on those two directories did not result in the problem, while ls on a larger directory did (when it hit the 2nd file - ie the target of the symlink), and ls of a directory in between in size did not. -- Thanks, Steve -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
