On Fri, Apr 12, 2019 at 3:29 AM Jeff Layton <jlayton@xxxxxxxxxx> wrote: > > cephfs can benefit from statx. We can have the client just request caps > sufficient for the needed attributes and leave off the rest. > > Also, recognize when AT_STATX_DONT_SYNC is set, and just scrape the > inode without doing any call in that case. Force a call to the MDS in > the event that AT_STATX_FORCE_SYNC is set. > > Link: http://tracker.ceph.com/issues/39258 > Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx> > --- > fs/ceph/inode.c | 85 +++++++++++++++++++++++++++++++++---------------- > 1 file changed, 57 insertions(+), 28 deletions(-) > > v2: eliminate a goto, clean up comments, add Link: to changelog > diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c > index 2d61ddda9bf5..b33ba16f7ae8 100644 > --- a/fs/ceph/inode.c > +++ b/fs/ceph/inode.c > @@ -2255,43 +2255,72 @@ int ceph_permission(struct inode *inode, int mask) > return err; > } > > +/* Craft a mask of needed caps given a set of requested statx attrs. */ > +static int statx_to_caps(u32 want) > +{ > + int mask = 0; > + > + if (want & (STATX_MODE|STATX_UID|STATX_GID|STATX_CTIME)) > + mask |= CEPH_CAP_AUTH_SHARED; > + > + if (want & (STATX_NLINK|STATX_CTIME)) > + mask |= CEPH_CAP_LINK_SHARED; > + > + if (want & (STATX_ATIME|STATX_MTIME|STATX_CTIME|STATX_SIZE| > + STATX_BLOCKS)) > + mask |= CEPH_CAP_FILE_SHARED; > + > + if (want & (STATX_CTIME)) > + mask |= CEPH_CAP_XATTR_SHARED; > + > + return mask; > +} > + > /* > - * Get all attributes. Hopefully somedata we'll have a statlite() > - * and can limit the fields we require to be accurate. > + * Get all the attributes. If we have sufficient caps for the requested attrs, > + * then we can avoid talking to the MDS at all. > */ > int ceph_getattr(const struct path *path, struct kstat *stat, > u32 request_mask, unsigned int flags) > { > struct inode *inode = d_inode(path->dentry); > struct ceph_inode_info *ci = ceph_inode(inode); > - int err; > + int err = 0; > > - err = ceph_do_getattr(inode, CEPH_STAT_CAP_INODE_ALL, false); > - if (!err) { > - generic_fillattr(inode, stat); > - stat->ino = ceph_translate_ino(inode->i_sb, inode->i_ino); > - if (ceph_snap(inode) == CEPH_NOSNAP) > - stat->dev = inode->i_sb->s_dev; > + /* Skip the getattr altogether if we're asked not to sync */ > + if (!(flags & AT_STATX_DONT_SYNC)) { > + err = ceph_do_getattr(inode, statx_to_caps(request_mask), > + flags & AT_STATX_FORCE_SYNC); > + if (err) > + return err; > + } > + > + generic_fillattr(inode, stat); > + stat->ino = ceph_translate_ino(inode->i_sb, inode->i_ino); > + if (ceph_snap(inode) == CEPH_NOSNAP) > + stat->dev = inode->i_sb->s_dev; > + else > + stat->dev = ci->i_snapid_map ? ci->i_snapid_map->dev : 0; > + > + if (S_ISDIR(inode->i_mode)) { > + if (ceph_test_mount_opt(ceph_sb_to_client(inode->i_sb), > + RBYTES)) > + stat->size = ci->i_rbytes; > else > - stat->dev = ci->i_snapid_map ? ci->i_snapid_map->dev : 0; > - > - if (S_ISDIR(inode->i_mode)) { > - if (ceph_test_mount_opt(ceph_sb_to_client(inode->i_sb), > - RBYTES)) > - stat->size = ci->i_rbytes; > - else > - stat->size = ci->i_files + ci->i_subdirs; > - stat->blocks = 0; > - stat->blksize = 65536; > - /* > - * Some applications rely on the number of st_nlink > - * value on directories to be either 0 (if unlinked) > - * or 2 + number of subdirectories. > - */ > - if (stat->nlink == 1) > - /* '.' + '..' + subdirs */ > - stat->nlink = 1 + 1 + ci->i_subdirs; > - } > + stat->size = ci->i_files + ci->i_subdirs; > + stat->blocks = 0; > + stat->blksize = 65536; > + /* > + * Some applications rely on the number of st_nlink > + * value on directories to be either 0 (if unlinked) > + * or 2 + number of subdirectories. > + */ > + if (stat->nlink == 1) > + /* '.' + '..' + subdirs */ > + stat->nlink = 1 + 1 + ci->i_subdirs; > } > + > + /* Mask off any higher bits (e.g. btime) until we have support */ > + stat->result_mask = request_mask & STATX_BASIC_STATS; > return err; > } > -- > 2.20.1 > Reviewed-by: "Yan, Zheng" <zyan@xxxxxxxxxx>
