On Apr 29, 2016, at 6:58 AM, David Howells wrote: > > 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. This is not implemented in this patch, and should removed from the commit message. The generic_fillattr() change in [1/6] will clear the STATX_ATIME flag if IS_NOATIME() is true, so maybe that is enough for what you intended? Cheers, Andreas > 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; > > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html Cheers, Andreas