On Apr 20, 2012, at 5:35 PM, Myklebust, Trond wrote: > On Fri, 2012-04-20 at 20:51 +0000, Adamson, Dros wrote: >> On Apr 20, 2012, at 4:13 PM, Myklebust, Trond wrote: >> >>> On Fri, 2012-04-20 at 19:57 +0000, Adamson, Dros wrote: >>>> On Apr 20, 2012, at 3:45 PM, Jim Rees wrote: >>>> >>>>> Weston Andros Adamson wrote: >>>>> >>>>> nfs4_path() was parsing the path component by splitting on the first colon. >>>>> This is wrong when an IPv6 address is used to mount a server. >>>>> >>>>> For example, having mounted 'fc00::10:/export', nfs4_path() returned >>>>> ':10:/export'. This causes referrals (using IPv4 or IPv6 addresses) to fail >>>>> in nfs4_validate_fspath(). >>>>> >>>>> Parsing the path component by using the *last* colon works with >>>>> IPv6 as well as IPv4 addrs. >>>>> >>>>> What if your mount is: >>>>> >>>>> server.edu:/export/:I-like-colons: >>>>> >>>>> It seems to me something has to give. Either we require v6 addresses be >>>>> enclosed in [], export dirs start with "/", or exports have no ":". >>>> >>>> >>>> Yeah, you're right. >>>> >>>> Although IPv6 addrs must be enclosed in [] to work with mount, it's always displayed in the kernel without the []. >>>> >>>> I suppose the correct fix is to always display IPv6 addresses enclosed in [], which might touch a *lot* of places. >>>> >>>> Thoughts? I'll wait for others to chime in before I go fixing this. I have a set of nfsd and mountd patches that deal with similar issues on the server side. I'll clean those up and submit them before getting back to this. >>> >>> We do know which part is the hostname, and which is the pathname. If you >>> look at "try_location()", you'll see that the hostname is stored in >>> location->servers, and is then copied into this empty buffer. >>> >>> If you want to test if that is an IPv6 address so that you can enclose >>> it in [], then that should be fairly easy to do right there… >> >> Right, we have separate hostname and pathname for each fs_location4, but I'm talking about the return value of nfs_path() which is used to determine the server-side path on an arbitrary dentry on the *current* mountpoint (not the referral server). >> The path part of nfs_path() is then compared against the fs_path of the nfs4_fs_locations struct (this is all in nfs4_validate_fspath). >> >> Having nfs_path return [] wrapped IPv6 addresses basically means changing the devname to that format (d_fsdata is used by nfs_path()). I'm concerned about changing the format of devname - its used all over the place. >> >> So the options are: >> 1) change the format of devname >> 2) change how nfs4_validate_fspath gets the server-side path component of the current mount (don't use nfs_path()) >> >> I'll try option 1 and see what breaks. > > That really should not be necessary. > > If you are using an IPv6 address, you are supposed to mount using the [] > format. If not, then expect things to break. > Yes, I am mounting with a [] escaped IPv6 addr. > The real bug here is in nfs4_path: it tries to parse the ':' that are > part of the IPv6 address even if we use the square bracket delimiters. > Instead, we should be following the example of nfs_parse_devname. The [] escaping is stripped well before nfs4_path. > > I suggest breaking out the first half of nfs_parse_devname into a > function that returns the host name part of a mount path, and that can > be called by nfs4_path too. Yes, something like that could work, but we still have the same issue - dentry->d_fsdata never has [] escaping. -dros
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