On Tue, Mar 4, 2014 at 1:09 PM, Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> wrote: > > On Mar 4, 2014, at 12:31, andros@xxxxxxxxxx wrote: > >> From: Andy Adamson <andros@xxxxxxxxxx> >> >> This is an expanded version of the "NFSv4 always compare stateids in nfs4_stateid_is_current" patch I sent on Feb 27. >> >> Found at Connectathon 2014 and NetApp internal testing. >> >> nfs4_stateid_is_current is used on the NFSv4 I/O path to determine if a >> stateid has changed. The idea is that if there is a stateid expire error >> such as NFS4ERR_BAD_STATEID and the stateid used that induced the error has >> changed, then we can just resend the RPC from the call prepare state with >> the changed stateid instead of kicking off recovery as the changed stateid >> indicates it already had been recovered. >> >> This patch set fixes a false positive that resulted in an NFS4ERR_BAD_STATEID >> infinite loop. Trond pointed out that the nfs4_select_rw_stateid -EIO error >> is special in that it indicates a lost lock. >> >> As I examined the use of nfs4_select_rw_stateid, I addressed some other errors >> in the use of nfs4_set_rw_stateid and friends in setattr and filelayout >> prepare functions. >> >> Just tested with connectathon tests. Will test more once I'm back in town... > > One question: > > Do we need the EWOULDBLOCK case at all in nfs4_copy_lock_stateid/nfs4_copy_open_stateid? Looking at the code, it seems particularly redundant for the case of NFSv4.1, where we set the seqid to '0'. Given that we do the nfs4_stateid_is_current() test, it seems unnecessary in the case of NFSv4.0 too... Yes - Even though you mentioned it's importance at Connectathon, I could not find a use of the EWOULDBLOCK return. > > So, how about just throwing out the EWOULDBLOCK returns, then keeping nfs4_stateid_is_current() as it is, So, you mean keeping nfs4_stateid_is_current as a boolean, and then assume that a false return == -EIO? I don't like that because that is how this bug was created - mixing bool and int functions. > fixing up _nfs4_do_setattr to only deal with the -EIO case, Yes. and then fixing up the file layout uses of nfs4_select_rw_stateid() to check the return values? As I did in the last patch... > > _________________________________ > Trond Myklebust > Linux NFS client maintainer, PrimaryData > trond.myklebust@xxxxxxxxxxxxxxx > > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
