From 9ccee940bd5b766b6dab6c1a80908b9490a4850d Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Thu, 4 Jan 2018 17:46:09 -0500 Subject: [PATCH] Support statx() mask and query flags parameters Support the query flags AT_STATX_FORCE_SYNC by forcing an attribute revalidation, and AT_STATX_DONT_SYNC by returning cached attributes only. Use the mask to optimise away server revalidation for attributes that are not being requested by the user. Signed-off-by: Trond Myklebust --- fs/nfs/inode.c | 52 +++++++++++++++++++++++++++++++++++++------------- 1 file changed, 39 insertions(+), 13 deletions(-) diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index b992d2382ffa37..deeb7d1097d018 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -735,12 +735,20 @@ int nfs_getattr(const struct path *path, struct kstat *stat, u32 request_mask, unsigned int query_flags) { struct inode *inode = d_inode(path->dentry); - int need_atime = NFS_I(inode)->cache_validity & NFS_INO_INVALID_ATIME; + struct nfs_server *server = NFS_SERVER(inode); + unsigned long cache_validity; int err = 0; + bool force_sync = query_flags & AT_STATX_FORCE_SYNC; + bool do_update = false; trace_nfs_getattr_enter(inode); + + if ((query_flags & AT_STATX_DONT_SYNC) && !force_sync) + goto out_no_update; + /* Flush out writes to the server in order to update c/mtime. */ - if (S_ISREG(inode->i_mode)) { + if ((request_mask & (STATX_CTIME|STATX_MTIME)) && + S_ISREG(inode->i_mode)) { err = filemap_write_and_wait(inode->i_mapping); if (err) goto out; @@ -757,24 +765,42 @@ int nfs_getattr(const struct path *path, struct kstat *stat, */ if ((path->mnt->mnt_flags & MNT_NOATIME) || ((path->mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode))) - need_atime = 0; - - if (need_atime || nfs_need_revalidate_inode(inode)) { - struct nfs_server *server = NFS_SERVER(inode); - + request_mask &= ~STATX_ATIME; + + /* Is the user requesting attributes that might need revalidation? */ + if (!(request_mask & (STATX_MODE|STATX_NLINK|STATX_ATIME|STATX_CTIME| + STATX_MTIME|STATX_UID|STATX_GID| + STATX_SIZE|STATX_BLOCKS))) + goto out_no_revalidate; + + /* Check whether the cached attributes are stale */ + do_update |= force_sync || nfs_attribute_cache_expired(inode); + cache_validity = READ_ONCE(NFS_I(inode)->cache_validity); + do_update |= cache_validity & + (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_LABEL); + if (request_mask & STATX_ATIME) + do_update |= cache_validity & NFS_INO_INVALID_ATIME; + if (request_mask & (STATX_CTIME|STATX_MTIME)) + do_update |= cache_validity & NFS_INO_REVAL_PAGECACHE; + if (do_update) { + /* Update the attribute cache */ if (!(server->flags & NFS_MOUNT_NOAC)) nfs_readdirplus_parent_cache_miss(path->dentry); else nfs_readdirplus_parent_cache_hit(path->dentry); err = __nfs_revalidate_inode(server, inode); + if (err) + goto out; } else nfs_readdirplus_parent_cache_hit(path->dentry); - if (!err) { - generic_fillattr(inode, stat); - stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode)); - if (S_ISDIR(inode->i_mode)) - stat->blksize = NFS_SERVER(inode)->dtsize; - } +out_no_revalidate: + /* Only return attributes that were revalidated. */ + stat->result_mask &= request_mask; +out_no_update: + generic_fillattr(inode, stat); + stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode)); + if (S_ISDIR(inode->i_mode)) + stat->blksize = NFS_SERVER(inode)->dtsize; out: trace_nfs_getattr_exit(inode, err); return err;