On 3/21/22 2:44 PM, J. Bruce Fields wrote:
On Thu, Mar 17, 2022 at 12:43:42AM -0700, Dai Ngo wrote:Update nfs4_get_vfs_file and nfs4_upgrade_open to handle share reservation conflict with courtesy client. Update nfs4_get_vfs_file and nfs4_upgrade_open to handle share reservation conflict with courtesy client. When we have deny/access conflict we walk the fi_stateids of the file in question, looking for open stateid and check the deny/access of that stateid against the one from the open request. If there is a conflict then we check if the client that owns that stateid is a courtesy client. If it is then we set the client state to CLIENT_EXPIRED and allow the open request to continue. We have to scan all the stateid's of the file since the conflict can be caused by multiple open stateid's. Client with CLIENT_EXPIRED is expired by the laundromat. Signed-off-by: Dai Ngo <dai.ngo@xxxxxxxxxx> --- fs/nfsd/nfs4state.c | 99 ++++++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 91 insertions(+), 8 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index f20c75890594..c6b5e05c9c34 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -4950,9 +4950,75 @@ nfsd4_truncate(struct svc_rqst *rqstp, struct svc_fh *fh, return nfsd_setattr(rqstp, fh, &iattr, 0, (time64_t)0); }+static bool+nfs4_check_access_deny_bmap(struct nfs4_ol_stateid *stp, u32 access, + bool share_access) +{ + if (share_access) { + if (!stp->st_deny_bmap) + return false; + + if ((stp->st_deny_bmap & (1 << NFS4_SHARE_DENY_BOTH)) || + (access & NFS4_SHARE_ACCESS_READ && + stp->st_deny_bmap & (1 << NFS4_SHARE_DENY_READ)) || + (access & NFS4_SHARE_ACCESS_WRITE && + stp->st_deny_bmap & (1 << NFS4_SHARE_DENY_WRITE))) { + return true; + } + return false;Looks like you could do this with just: return share_access & bmap_to_share_mode(stp->st_deny_bmap);
Thanks, this makes it much simpler. Fix in v18.
+ } + if ((access & NFS4_SHARE_DENY_BOTH) || + (access & NFS4_SHARE_DENY_READ && + stp->st_access_bmap & (1 << NFS4_SHARE_ACCESS_READ)) || + (access & NFS4_SHARE_DENY_WRITE && + stp->st_access_bmap & (1 << NFS4_SHARE_ACCESS_WRITE))) { + return true; + }Likewise.
Fix in v18.
Also, I think it'd be simpler to check for both access and deny conflicts here, instead of just one or the other.
I'm not clear here. I remove nfs4_check_access_deny_bmap, fold this functionality into nfs4_resolve_deny_conflicts_locked by making use of bmap_to_share_mode.
+ return false; +} + +/* + * Check whether courtesy clients have conflicting access + * + * access: is op_share_access if share_access is true. + * Check if access mode, op_share_access, would conflict with + * the current deny mode of the file 'fp'. + * access: is op_share_deny if share_access is false. + * Check if the deny mode, op_share_deny, would conflict with + * current access of the file 'fp'. + * stp: skip checking this entry. + * new_stp: normal open, not open upgrade. + * + * Function returns: + * true - access/deny mode conflict with normal client. + * false - no conflict or conflict with courtesy client(s) is resolved. + */ +static bool +nfs4_resolve_deny_conflicts_locked(struct nfs4_file *fp, bool new_stp, + struct nfs4_ol_stateid *stp, u32 access, bool share_access) +{ + struct nfs4_ol_stateid *st; + struct nfs4_client *clp; + bool conflict = false; + + lockdep_assert_held(&fp->fi_lock); + list_for_each_entry(st, &fp->fi_stateids, st_perfile) { + if (st->st_openstp || (st == stp && new_stp) ||I'd split this into separate if statements and add a comment at least for the st_openstp case, which isn't too obvious: if (st->st_openstp) /* ignore lock stateids */ continue;
Fix in v18.
+ (!nfs4_check_access_deny_bmap(st, + access, share_access))) + continue; + clp = st->st_stid.sc_client; + if (nfsd4_expire_courtesy_clnt(clp)) + continue; + conflict = true; + break; + } + return conflict; +} + static __be32 nfs4_get_vfs_file(struct svc_rqst *rqstp, struct nfs4_file *fp, struct svc_fh *cur_fh, struct nfs4_ol_stateid *stp, - struct nfsd4_open *open) + struct nfsd4_open *open, bool new_stp) { struct nfsd_file *nf = NULL; __be32 status; @@ -4968,15 +5034,29 @@ static __be32 nfs4_get_vfs_file(struct svc_rqst *rqstp, struct nfs4_file *fp, */ status = nfs4_file_check_deny(fp, open->op_share_deny); if (status != nfs_ok) { - spin_unlock(&fp->fi_lock); - goto out; + if (status != nfserr_share_denied) { + spin_unlock(&fp->fi_lock); + goto out; + } + if (nfs4_resolve_deny_conflicts_locked(fp, new_stp, + stp, open->op_share_deny, false)) { + spin_unlock(&fp->fi_lock); + goto out; + } }/* set access to the file */status = nfs4_file_get_access(fp, open->op_share_access); if (status != nfs_ok) { - spin_unlock(&fp->fi_lock); - goto out; + if (status != nfserr_share_denied) { + spin_unlock(&fp->fi_lock); + goto out; + } + if (nfs4_resolve_deny_conflicts_locked(fp, new_stp, + stp, open->op_share_access, true)) { + spin_unlock(&fp->fi_lock); + goto out; + } }/* Set access bits in stateid */@@ -5027,7 +5107,7 @@ nfs4_upgrade_open(struct svc_rqst *rqstp, struct nfs4_file *fp, struct svc_fh *c unsigned char old_deny_bmap = stp->st_deny_bmap;if (!test_access(open->op_share_access, stp))- return nfs4_get_vfs_file(rqstp, fp, cur_fh, stp, open); + return nfs4_get_vfs_file(rqstp, fp, cur_fh, stp, open, false);/* test and set deny mode */spin_lock(&fp->fi_lock); @@ -5036,7 +5116,10 @@ nfs4_upgrade_open(struct svc_rqst *rqstp, struct nfs4_file *fp, struct svc_fh *c set_deny(open->op_share_deny, stp); fp->fi_share_deny |= (open->op_share_deny & NFS4_SHARE_DENY_BOTH); - } + } else if (status == nfserr_share_denied && + !nfs4_resolve_deny_conflicts_locked(fp, false, stp, + open->op_share_deny, false))Looks to me like these nfs4_resolve_deny_conflicts_locked() calls could go into nfs4_file_check_deny and nfs4_file_get_access instead.
Fix in v18. -Dai
--b.+ status = nfs_ok; spin_unlock(&fp->fi_lock);if (status != nfs_ok)@@ -5376,7 +5459,7 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nf goto out; } } else { - status = nfs4_get_vfs_file(rqstp, fp, current_fh, stp, open); + status = nfs4_get_vfs_file(rqstp, fp, current_fh, stp, open, true); if (status) { stp->st_stid.sc_type = NFS4_CLOSED_STID; release_open_stateid(stp); -- 2.9.5
