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... So, how about just throwing out the EWOULDBLOCK returns, then keeping nfs4_stateid_is_current() as it is, fixing up _nfs4_do_setattr to only deal with the -EIO case, and then fixing up the file layout uses of nfs4_select_rw_stateid() to check the return values? _________________________________ 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
