From: Chuck Lever Date: Sat, 16 Dec 2023 16:57:43 +0000 (-0500) Subject: NFSD: Revert 6c41d9a9bd0298002805758216a9c44e38a8500d X-Git-Tag: v6.7-rc7~29^2~2 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=862bee84d77fa01cc8929656ae77781abf917863;p=linux-2.6-block.git NFSD: Revert 6c41d9a9bd0298002805758216a9c44e38a8500d For some reason, the wait_on_bit() in nfsd4_deleg_getattr_conflict() is waiting forever, preventing a clean server shutdown. The requesting client might also hang waiting for a reply to the conflicting GETATTR. Invoking wait_on_bit() in an nfsd thread context is a hazard. The correct fix is to replace this wait_on_bit() call site with a mechanism that defers the conflicting GETATTR until the CB_GETATTR completes or is known to have failed. That will require some surgery and extended testing and it's late in the v6.7-rc cycle, so I'm reverting now in favor of trying again in a subsequent kernel release. This is my fault: I should have recognized the ramifications of calling wait_on_bit() in here before accepting this patch. Thanks to Dai Ngo for diagnosing the issue. Reported-by: Wolfgang Walter Closes: https://lore.kernel.org/linux-nfs/e3d43ecdad554fbdcaa7181833834f78@stwm.de/ Signed-off-by: Chuck Lever --- diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 3709e58f0a4a..31909f59d319 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -127,7 +127,6 @@ static void free_session(struct nfsd4_session *); static const struct nfsd4_callback_ops nfsd4_cb_recall_ops; static const struct nfsd4_callback_ops nfsd4_cb_notify_lock_ops; -static const struct nfsd4_callback_ops nfsd4_cb_getattr_ops; static struct workqueue_struct *laundry_wq; @@ -1190,10 +1189,6 @@ alloc_init_deleg(struct nfs4_client *clp, struct nfs4_file *fp, dp->dl_recalled = false; nfsd4_init_cb(&dp->dl_recall, dp->dl_stid.sc_client, &nfsd4_cb_recall_ops, NFSPROC4_CLNT_CB_RECALL); - nfsd4_init_cb(&dp->dl_cb_fattr.ncf_getattr, dp->dl_stid.sc_client, - &nfsd4_cb_getattr_ops, NFSPROC4_CLNT_CB_GETATTR); - dp->dl_cb_fattr.ncf_file_modified = false; - dp->dl_cb_fattr.ncf_cb_bmap[0] = FATTR4_WORD0_CHANGE | FATTR4_WORD0_SIZE; get_nfs4_file(fp); dp->dl_stid.sc_file = fp; return dp; @@ -2901,56 +2896,11 @@ nfsd4_cb_recall_any_release(struct nfsd4_callback *cb) spin_unlock(&nn->client_lock); } -static int -nfsd4_cb_getattr_done(struct nfsd4_callback *cb, struct rpc_task *task) -{ - struct nfs4_cb_fattr *ncf = - container_of(cb, struct nfs4_cb_fattr, ncf_getattr); - - ncf->ncf_cb_status = task->tk_status; - switch (task->tk_status) { - case -NFS4ERR_DELAY: - rpc_delay(task, 2 * HZ); - return 0; - default: - return 1; - } -} - -static void -nfsd4_cb_getattr_release(struct nfsd4_callback *cb) -{ - struct nfs4_cb_fattr *ncf = - container_of(cb, struct nfs4_cb_fattr, ncf_getattr); - struct nfs4_delegation *dp = - container_of(ncf, struct nfs4_delegation, dl_cb_fattr); - - nfs4_put_stid(&dp->dl_stid); - clear_bit(CB_GETATTR_BUSY, &ncf->ncf_cb_flags); - wake_up_bit(&ncf->ncf_cb_flags, CB_GETATTR_BUSY); -} - static const struct nfsd4_callback_ops nfsd4_cb_recall_any_ops = { .done = nfsd4_cb_recall_any_done, .release = nfsd4_cb_recall_any_release, }; -static const struct nfsd4_callback_ops nfsd4_cb_getattr_ops = { - .done = nfsd4_cb_getattr_done, - .release = nfsd4_cb_getattr_release, -}; - -void nfs4_cb_getattr(struct nfs4_cb_fattr *ncf) -{ - struct nfs4_delegation *dp = - container_of(ncf, struct nfs4_delegation, dl_cb_fattr); - - if (test_and_set_bit(CB_GETATTR_BUSY, &ncf->ncf_cb_flags)) - return; - refcount_inc(&dp->dl_stid.sc_count); - nfsd4_run_cb(&ncf->ncf_getattr); -} - static struct nfs4_client *create_client(struct xdr_netobj name, struct svc_rqst *rqstp, nfs4_verifier *verf) { @@ -5686,8 +5636,6 @@ nfs4_open_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp, struct svc_fh *parent = NULL; int cb_up; int status = 0; - struct kstat stat; - struct path path; cb_up = nfsd4_cb_channel_good(oo->oo_owner.so_client); open->op_recall = false; @@ -5725,18 +5673,6 @@ nfs4_open_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp, if (open->op_share_access & NFS4_SHARE_ACCESS_WRITE) { open->op_delegate_type = NFS4_OPEN_DELEGATE_WRITE; trace_nfsd_deleg_write(&dp->dl_stid.sc_stateid); - path.mnt = currentfh->fh_export->ex_path.mnt; - path.dentry = currentfh->fh_dentry; - if (vfs_getattr(&path, &stat, - (STATX_SIZE | STATX_CTIME | STATX_CHANGE_COOKIE), - AT_STATX_SYNC_AS_STAT)) { - nfs4_put_stid(&dp->dl_stid); - destroy_delegation(dp); - goto out_no_deleg; - } - dp->dl_cb_fattr.ncf_cur_fsize = stat.size; - dp->dl_cb_fattr.ncf_initial_cinfo = - nfsd4_change_attribute(&stat, d_inode(currentfh->fh_dentry)); } else { open->op_delegate_type = NFS4_OPEN_DELEGATE_READ; trace_nfsd_deleg_read(&dp->dl_stid.sc_stateid); @@ -8489,8 +8425,6 @@ nfsd4_get_writestateid(struct nfsd4_compound_state *cstate, * nfsd4_deleg_getattr_conflict - Recall if GETATTR causes conflict * @rqstp: RPC transaction context * @inode: file to be checked for a conflict - * @modified: return true if file was modified - * @size: new size of file if modified is true * * This function is called when there is a conflict between a write * delegation and a change/size GETATTR from another client. The server @@ -8499,23 +8433,21 @@ nfsd4_get_writestateid(struct nfsd4_compound_state *cstate, * delegation before replying to the GETATTR. See RFC 8881 section * 18.7.4. * + * The current implementation does not support CB_GETATTR yet. However + * this can avoid recalling the delegation could be added in follow up + * work. + * * Returns 0 if there is no conflict; otherwise an nfs_stat * code is returned. */ __be32 -nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp, struct inode *inode, - bool *modified, u64 *size) +nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp, struct inode *inode) { + __be32 status; struct file_lock_context *ctx; - struct nfs4_delegation *dp; - struct nfs4_cb_fattr *ncf; struct file_lock *fl; - struct iattr attrs; - __be32 status; - - might_sleep(); + struct nfs4_delegation *dp; - *modified = false; ctx = locks_inode_context(inode); if (!ctx) return 0; @@ -8542,34 +8474,10 @@ nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp, struct inode *inode, break_lease: spin_unlock(&ctx->flc_lock); nfsd_stats_wdeleg_getattr_inc(); - - dp = fl->fl_owner; - ncf = &dp->dl_cb_fattr; - nfs4_cb_getattr(&dp->dl_cb_fattr); - wait_on_bit(&ncf->ncf_cb_flags, CB_GETATTR_BUSY, TASK_INTERRUPTIBLE); - if (ncf->ncf_cb_status) { - status = nfserrno(nfsd_open_break_lease(inode, NFSD_MAY_READ)); - if (status != nfserr_jukebox || - !nfsd_wait_for_delegreturn(rqstp, inode)) - return status; - } - if (!ncf->ncf_file_modified && - (ncf->ncf_initial_cinfo != ncf->ncf_cb_change || - ncf->ncf_cur_fsize != ncf->ncf_cb_fsize)) - ncf->ncf_file_modified = true; - if (ncf->ncf_file_modified) { - /* - * The server would not update the file's metadata - * with the client's modified size. - */ - attrs.ia_mtime = attrs.ia_ctime = current_time(inode); - attrs.ia_valid = ATTR_MTIME | ATTR_CTIME; - setattr_copy(&nop_mnt_idmap, inode, &attrs); - mark_inode_dirty(inode); - ncf->ncf_cur_fsize = ncf->ncf_cb_fsize; - *size = ncf->ncf_cur_fsize; - *modified = true; - } + status = nfserrno(nfsd_open_break_lease(inode, NFSD_MAY_READ)); + if (status != nfserr_jukebox || + !nfsd_wait_for_delegreturn(rqstp, inode)) + return status; return 0; } break; diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index ec4ed6206df1..b499fe9caa32 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -3505,9 +3505,7 @@ nfsd4_encode_fattr4(struct svc_rqst *rqstp, struct xdr_stream *xdr, u32 attrmask[3]; unsigned long mask[2]; } u; - bool file_modified; unsigned long bit; - u64 size = 0; WARN_ON_ONCE(bmval[1] & NFSD_WRITEONLY_ATTRS_WORD1); WARN_ON_ONCE(!nfsd_attrs_supported(minorversion, bmval)); @@ -3534,8 +3532,7 @@ nfsd4_encode_fattr4(struct svc_rqst *rqstp, struct xdr_stream *xdr, } args.size = 0; if (u.attrmask[0] & (FATTR4_WORD0_CHANGE | FATTR4_WORD0_SIZE)) { - status = nfsd4_deleg_getattr_conflict(rqstp, d_inode(dentry), - &file_modified, &size); + status = nfsd4_deleg_getattr_conflict(rqstp, d_inode(dentry)); if (status) goto out; } @@ -3545,7 +3542,7 @@ nfsd4_encode_fattr4(struct svc_rqst *rqstp, struct xdr_stream *xdr, AT_STATX_SYNC_AS_STAT); if (err) goto out_nfserr; - args.size = file_modified ? size : args.stat.size; + args.size = args.stat.size; if (!(args.stat.result_mask & STATX_BTIME)) /* underlying FS does not offer btime so we can't share it */ diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h index f96eaa8e9413..0bbbe57e027d 100644 --- a/fs/nfsd/state.h +++ b/fs/nfsd/state.h @@ -125,16 +125,8 @@ struct nfs4_cb_fattr { /* from CB_GETATTR reply */ u64 ncf_cb_change; u64 ncf_cb_fsize; - - unsigned long ncf_cb_flags; - bool ncf_file_modified; - u64 ncf_initial_cinfo; - u64 ncf_cur_fsize; }; -/* bits for ncf_cb_flags */ -#define CB_GETATTR_BUSY 0 - /* * Represents a delegation stateid. The nfs4_client holds references to these * and they are put when it is being destroyed or when the delegation is @@ -754,6 +746,5 @@ static inline bool try_to_expire_client(struct nfs4_client *clp) } extern __be32 nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp, - struct inode *inode, bool *file_modified, u64 *size); -extern void nfs4_cb_getattr(struct nfs4_cb_fattr *ncf); + struct inode *inode); #endif /* NFSD4_STATE_H */