This is a note to let you know that I've just added the patch titled NFSD: add support for share reservation conflict to courteous server to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: nfsd-add-support-for-share-reservation-conflict-to-c.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit aa41cb7955548a9bbd10ca15779a1b3942d3593e Author: Dai Ngo <dai.ngo@xxxxxxxxxx> Date: Mon May 2 14:19:22 2022 -0700 NFSD: add support for share reservation conflict to courteous server [ Upstream commit 3d69427151806656abf129342028f3f4e5e1fee0 ] This patch allows expired client with open state to be in COURTESY state. Share/access conflict with COURTESY client is resolved by setting COURTESY client to EXPIRABLE state, schedule laundromat to run and returning nfserr_jukebox to the request client. Reviewed-by: J. Bruce Fields <bfields@xxxxxxxxxxxx> Signed-off-by: Dai Ngo <dai.ngo@xxxxxxxxxx> Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 74c0a88904047..4ba0a70d8990f 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -705,6 +705,57 @@ static unsigned int file_hashval(struct svc_fh *fh) static struct hlist_head file_hashtbl[FILE_HASH_SIZE]; +/* + * Check if courtesy clients have conflicting access and resolve it if possible + * + * 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: + * false - access/deny mode conflict with normal client. + * true - 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; + bool resolvable = true; + unsigned char bmap; + struct nfsd_net *nn; + struct nfs4_client *clp; + + lockdep_assert_held(&fp->fi_lock); + list_for_each_entry(st, &fp->fi_stateids, st_perfile) { + /* ignore lock stateid */ + if (st->st_openstp) + continue; + if (st == stp && new_stp) + continue; + /* check file access against deny mode or vice versa */ + bmap = share_access ? st->st_deny_bmap : st->st_access_bmap; + if (!(access & bmap_to_share_mode(bmap))) + continue; + clp = st->st_stid.sc_client; + if (try_to_expire_client(clp)) + continue; + resolvable = false; + break; + } + if (resolvable) { + clp = stp->st_stid.sc_client; + nn = net_generic(clp->net, nfsd_net_id); + mod_delayed_work(laundry_wq, &nn->laundromat_work, 0); + } + return resolvable; +} + static void __nfs4_file_get_access(struct nfs4_file *fp, u32 access) { @@ -4985,7 +5036,7 @@ nfsd4_truncate(struct svc_rqst *rqstp, struct svc_fh *fh, 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; @@ -5001,6 +5052,13 @@ 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) { + 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)) + status = nfserr_jukebox; spin_unlock(&fp->fi_lock); goto out; } @@ -5008,6 +5066,13 @@ static __be32 nfs4_get_vfs_file(struct svc_rqst *rqstp, struct nfs4_file *fp, /* set access to the file */ status = nfs4_file_get_access(fp, open->op_share_access); if (status != nfs_ok) { + 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)) + status = nfserr_jukebox; spin_unlock(&fp->fi_lock); goto out; } @@ -5054,21 +5119,29 @@ static __be32 nfs4_get_vfs_file(struct svc_rqst *rqstp, struct nfs4_file *fp, } static __be32 -nfs4_upgrade_open(struct svc_rqst *rqstp, struct nfs4_file *fp, struct svc_fh *cur_fh, struct nfs4_ol_stateid *stp, struct nfsd4_open *open) +nfs4_upgrade_open(struct svc_rqst *rqstp, struct nfs4_file *fp, + struct svc_fh *cur_fh, struct nfs4_ol_stateid *stp, + struct nfsd4_open *open) { __be32 status; 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); status = nfs4_file_check_deny(fp, open->op_share_deny); if (status == nfs_ok) { - set_deny(open->op_share_deny, stp); - fp->fi_share_deny |= + if (status != nfserr_share_denied) { + set_deny(open->op_share_deny, stp); + fp->fi_share_deny |= (open->op_share_deny & NFS4_SHARE_DENY_BOTH); + } else { + if (nfs4_resolve_deny_conflicts_locked(fp, false, + stp, open->op_share_deny, false)) + status = nfserr_jukebox; + } } spin_unlock(&fp->fi_lock); @@ -5409,7 +5482,7 @@ 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); @@ -5643,6 +5716,26 @@ static void nfsd4_ssc_expire_umount(struct nfsd_net *nn) } #endif +static bool +nfs4_has_any_locks(struct nfs4_client *clp) +{ + int i; + struct nfs4_stateowner *so; + + spin_lock(&clp->cl_lock); + for (i = 0; i < OWNER_HASH_SIZE; i++) { + list_for_each_entry(so, &clp->cl_ownerstr_hashtbl[i], + so_strhash) { + if (so->so_is_open_owner) + continue; + spin_unlock(&clp->cl_lock); + return true; + } + } + spin_unlock(&clp->cl_lock); + return false; +} + /* * place holder for now, no check for lock blockers yet */ @@ -5650,8 +5743,8 @@ static bool nfs4_anylock_blockers(struct nfs4_client *clp) { if (atomic_read(&clp->cl_delegs_in_recall) || - client_has_openowners(clp) || - !list_empty(&clp->async_copies)) + !list_empty(&clp->async_copies) || + nfs4_has_any_locks(clp)) return true; return false; }