diff options
| -rw-r--r-- | Documentation/filesystems/nfs/reexport.rst | 10 | ||||
| -rw-r--r-- | fs/nfs/export.c | 3 | ||||
| -rw-r--r-- | fs/nfsd/nfs4state.c | 18 | ||||
| -rw-r--r-- | include/linux/exportfs.h | 14 |
4 files changed, 40 insertions, 5 deletions
diff --git a/Documentation/filesystems/nfs/reexport.rst b/Documentation/filesystems/nfs/reexport.rst index ff9ae4a46530..044be965d75e 100644 --- a/Documentation/filesystems/nfs/reexport.rst +++ b/Documentation/filesystems/nfs/reexport.rst @@ -26,9 +26,13 @@ Reboot recovery --------------- The NFS protocol's normal reboot recovery mechanisms don't work for the -case when the reexport server reboots. Clients will lose any locks -they held before the reboot, and further IO will result in errors. -Closing and reopening files should clear the errors. +case when the reexport server reboots because the source server has not +rebooted, and so it is not in grace. Since the source server is not in +grace, it cannot offer any guarantees that the file won't have been +changed between the locks getting lost and any attempt to recover them. +The same applies to delegations and any associated locks. Clients are +not allowed to get file locks or delegations from a reexport server, any +attempts will fail with operation not supported. Filehandle limits ----------------- diff --git a/fs/nfs/export.c b/fs/nfs/export.c index be686b8e0c54..e9c233b6fd20 100644 --- a/fs/nfs/export.c +++ b/fs/nfs/export.c @@ -154,5 +154,6 @@ const struct export_operations nfs_export_ops = { EXPORT_OP_CLOSE_BEFORE_UNLINK | EXPORT_OP_REMOTE_FS | EXPORT_OP_NOATOMIC_ATTR | - EXPORT_OP_FLUSH_ON_CLOSE, + EXPORT_OP_FLUSH_ON_CLOSE | + EXPORT_OP_NOLOCKS, }; diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 0f97f2c62b3a..e806fd97cca9 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -6010,6 +6010,15 @@ nfs4_set_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp, if (!nf) return ERR_PTR(-EAGAIN); + /* + * File delegations and associated locks cannot be recovered if the + * export is from an NFS proxy server. + */ + if (exportfs_cannot_lock(nf->nf_file->f_path.mnt->mnt_sb->s_export_op)) { + nfsd_file_put(nf); + return ERR_PTR(-EOPNOTSUPP); + } + spin_lock(&state_lock); spin_lock(&fp->fi_lock); if (nfs4_delegation_exists(clp, fp)) @@ -8148,6 +8157,10 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, status = fh_verify(rqstp, &cstate->current_fh, S_IFREG, 0); if (status != nfs_ok) return status; + if (exportfs_cannot_lock(cstate->current_fh.fh_dentry->d_sb->s_export_op)) { + status = nfserr_notsupp; + goto out; + } if (lock->lk_is_new) { if (nfsd4_has_session(cstate)) @@ -8487,6 +8500,11 @@ nfsd4_locku(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, status = nfserr_lock_range; goto put_stateid; } + if (exportfs_cannot_lock(nf->nf_file->f_path.mnt->mnt_sb->s_export_op)) { + status = nfserr_notsupp; + goto put_file; + } + file_lock = locks_alloc_lock(); if (!file_lock) { dprintk("NFSD: %s: unable to allocate lock!\n", __func__); diff --git a/include/linux/exportfs.h b/include/linux/exportfs.h index a087606ace19..fc93f0abf513 100644 --- a/include/linux/exportfs.h +++ b/include/linux/exportfs.h @@ -279,10 +279,22 @@ struct export_operations { atomic attribute updates */ #define EXPORT_OP_FLUSH_ON_CLOSE (0x20) /* fs flushes file data on close */ -#define EXPORT_OP_ASYNC_LOCK (0x40) /* fs can do async lock request */ +#define EXPORT_OP_NOLOCKS (0x40) /* no file locking support */ unsigned long flags; }; +/** + * exportfs_cannot_lock() - check if export implements file locking + * @export_ops: the nfs export operations to check + * + * Returns true if the export does not support file locking. + */ +static inline bool +exportfs_cannot_lock(const struct export_operations *export_ops) +{ + return export_ops->flags & EXPORT_OP_NOLOCKS; +} + extern int exportfs_encode_inode_fh(struct inode *inode, struct fid *fid, int *max_len, struct inode *parent, int flags); |