Return-Path: Sender: Trond Myklebust From: Trond Myklebust To: Benjamin Coddington Cc: linux-nfs@vger.kernel.org Subject: [PATCH v2 2/3] NFS: Be more targeted about readdirplus use when doing lookup/revalidation Date: Fri, 2 Dec 2016 09:21:34 -0500 Message-Id: <20161202142135.11515-3-trond.myklebust@primarydata.com> In-Reply-To: <20161202142135.11515-2-trond.myklebust@primarydata.com> References: <20161202142135.11515-1-trond.myklebust@primarydata.com> <20161202142135.11515-2-trond.myklebust@primarydata.com> List-ID: There is little point in setting NFS_INO_ADVISE_RDPLUS in nfs_lookup and nfs_lookup_revalidate() unless a process is actually doing readdir on the parent directory. Furthermore, there is little point in using readdirplus if we're trying to revalidate a negative dentry. Signed-off-by: Trond Myklebust --- fs/nfs/dir.c | 30 +++++++++++++++++++----------- 1 file changed, 19 insertions(+), 11 deletions(-) diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 9220bc7b9cd7..22835150579a 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -455,14 +455,18 @@ bool nfs_use_readdirplus(struct inode *dir, struct dir_context *ctx) } /* - * This function is called by the lookup code to request the use of - * readdirplus to accelerate any future lookups in the same + * This function is called by the lookup and getattr code to request the + * use of readdirplus to accelerate any future lookups in the same * directory. */ static void nfs_advise_use_readdirplus(struct inode *dir) { - set_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(dir)->flags); + struct nfs_inode *nfsi = NFS_I(dir); + + if (nfs_server_capable(dir, NFS_CAP_READDIRPLUS) && + !list_empty(&nfsi->open_files)) + set_bit(NFS_INO_ADVISE_RDPLUS, &nfsi->flags); } /* @@ -475,8 +479,11 @@ void nfs_advise_use_readdirplus(struct inode *dir) */ void nfs_force_use_readdirplus(struct inode *dir) { - if (!list_empty(&NFS_I(dir)->open_files)) { - nfs_advise_use_readdirplus(dir); + struct nfs_inode *nfsi = NFS_I(dir); + + if (nfs_server_capable(dir, NFS_CAP_READDIRPLUS) && + !list_empty(&nfsi->open_files)) { + set_bit(NFS_INO_ADVISE_RDPLUS, &nfsi->flags); invalidate_mapping_pages(dir->i_mapping, 0, -1); } } @@ -1150,7 +1157,7 @@ static int nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags) return -ECHILD; goto out_bad; } - goto out_valid_noent; + goto out_valid; } if (is_bad_inode(inode)) { @@ -1173,6 +1180,7 @@ static int nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags) return -ECHILD; goto out_zap_parent; } + nfs_advise_use_readdirplus(dir); goto out_valid; } @@ -1208,12 +1216,12 @@ static int nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags) nfs_free_fhandle(fhandle); nfs4_label_free(label); + /* set a readdirplus hint that we had a cache miss */ + nfs_force_use_readdirplus(dir); + out_set_verifier: nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); out_valid: - /* Success: notify readdir to use READDIRPLUS */ - nfs_advise_use_readdirplus(dir); - out_valid_noent: if (flags & LOOKUP_RCU) { if (parent != ACCESS_ONCE(dentry->d_parent)) return -ECHILD; @@ -1413,8 +1421,8 @@ struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, unsigned in if (IS_ERR(res)) goto out_label; - /* Success: notify readdir to use READDIRPLUS */ - nfs_advise_use_readdirplus(dir); + /* Notify readdir to use READDIRPLUS */ + nfs_force_use_readdirplus(dir); no_entry: res = d_splice_alias(inode, dentry); -- 2.9.3