From: David Howells Subject: [PATCH 4/6] statx: NFS: Return enhanced file attributes Date: Fri, 29 Apr 2016 13:58:06 +0100 Message-ID: <20160429125806.23636.51590.stgit@warthog.procyon.org.uk> References: <20160429125736.23636.47874.stgit@warthog.procyon.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: linux-afs@vger.kernel.org, linux-nfs@vger.kernel.org, samba-technical@lists.samba.org, linux-kernel@vger.kernel.org, dhowells@redhat.com, linux-ext4@vger.kernel.org To: linux-fsdevel@vger.kernel.org Return-path: In-Reply-To: <20160429125736.23636.47874.stgit@warthog.procyon.org.uk> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org Return enhanced file atrributes from the NFS filesystem. This includes the following: (1) The change attribute as st_version if NFSv4. (2) STATX_INFO_AUTOMOUNT and STATX_INFO_FABRICATED are set on referral or submount directories that are automounted upon. NFS shows one directory with a different FSID, but the local filesystem has two: the mountpoint directory and the root of the filesystem mounted upon it. (3) STATX_INFO_REMOTE is set on files acquired over NFS. (4) STATX_IOC_FLAGS is set and if the atime is unavailable on a file, st_ioc_flags will have FL_NOATIME_FL set in it. Furthermore, what nfs_getattr() does can be controlled as follows: (1) If AT_NO_ATTR_SYNC is indicated then this will suppress the flushing of outstanding writes and the rereading of the inode's attributes with the server as detailed below. (2) Otherwise: (a) If AT_FORCE_ATTR_SYNC is indicated, or mtime, ctime or data_version (NFSv4 only) are requested then the outstanding writes will be written to the server first. (b) The inode's attributes will be reread from the server: (i) if AT_FORCE_ATTR_SYNC is indicated; (ii) if atime is requested (and atime updating is not suppressed by a mount flag); or (iii) if the cached attributes have expired; If the inode isn't synchronised, then the cached attributes will be used - even if expired - without reference to the server. Example output: [root@andromeda ~]# ./samples/statx/test-statx /warthog/ statx(/warthog/) = 0 results=37ef Size: 4096 Blocks: 8 IO Block: 1048576 directory Device: 00:26 Inode: 2 Links: 122 Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041 Access: 2015-10-30 16:15:41.730925545+0000 Modify: 2015-10-07 10:33:19.896108112+0100 Change: 2015-10-07 10:33:19.896108112+0100 Data version: 5614e6df35698650h Inode flags: 00000000 (-------- -------- -------- --------) Information: 00000010 (-------- -------- -------- ---r----) IO-blocksize: blksize=1048576 Note that the NFS4 protocol potentially provides a creation time that could be passed through this interface and system, hidden and archive values that could be passed as IOC flags. There is also a backup time that could be added. Signed-off-by: David Howells --- fs/nfs/inode.c | 41 ++++++++++++++++++++++++++++++++++------- 1 file changed, 34 insertions(+), 7 deletions(-) diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index 738c84a42eb0..8637236bca0c 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -655,12 +655,23 @@ static bool nfs_need_revalidate_inode(struct inode *inode) int nfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) { struct inode *inode = d_inode(dentry); - int need_atime = NFS_I(inode)->cache_validity & NFS_INO_INVALID_ATIME; + bool force_sync = stat->query_flags & AT_FORCE_ATTR_SYNC; + bool suppress_sync = stat->query_flags & AT_NO_ATTR_SYNC; + bool need_atime = NFS_I(inode)->cache_validity & NFS_INO_INVALID_ATIME; int err = 0; trace_nfs_getattr_enter(inode); - /* Flush out writes to the server in order to update c/mtime. */ - if (S_ISREG(inode->i_mode)) { + + if (NFS_SERVER(inode)->nfs_client->rpc_ops->version < 4) + stat->request_mask &= ~STATX_VERSION; + + /* Flush out writes to the server in order to update c/mtime or data + * version if the user wants them. + */ + if (S_ISREG(inode->i_mode) && !suppress_sync && + (force_sync || (stat->request_mask & + (STATX_MTIME | STATX_CTIME | STATX_VERSION))) + ) { inode_lock(inode); err = nfs_sync_inode(inode); inode_unlock(inode); @@ -677,11 +688,13 @@ int nfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) * - NFS never sets MS_NOATIME or MS_NODIRATIME so there is * no point in checking those. */ - if ((mnt->mnt_flags & MNT_NOATIME) || - ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode))) - need_atime = 0; + if (!(stat->request_mask & STATX_ATIME) || + (mnt->mnt_flags & MNT_NOATIME) || + ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode))) + need_atime = false; - if (need_atime || nfs_need_revalidate_inode(inode)) { + if (!suppress_sync && + (force_sync || need_atime || nfs_need_revalidate_inode(inode))) { struct nfs_server *server = NFS_SERVER(inode); if (server->caps & NFS_CAP_READDIRPLUS) @@ -694,6 +707,20 @@ int nfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) if (S_ISDIR(inode->i_mode)) stat->blksize = NFS_SERVER(inode)->dtsize; } + + generic_fillattr(inode, stat); + stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode)); + + if (stat->request_mask & STATX_VERSION) { + stat->version = inode->i_version; + stat->result_mask |= STATX_VERSION; + } + + if (IS_AUTOMOUNT(inode)) + stat->information |= STATX_INFO_FABRICATED; + + stat->information |= STATX_INFO_REMOTE; + out: trace_nfs_getattr_exit(inode, err); return err;