On Thu, 2020-01-16 at 23:09 +0800, Yan, Zheng wrote:
> On 1/16/20 4:59 AM, Jeff Layton wrote:
> > With the Octopus release, the MDS will hand out directory create caps.
> >
> > If we have Fxc caps on the directory, and complete directory information
> > or a known negative dentry, then we can return without waiting on the
> > reply, allowing the open() call to return very quickly to userland.
> >
> > We use the normal ceph_fill_inode() routine to fill in the inode, so we
> > have to gin up some reply inode information with what we'd expect the
> > newly-created inode to have. The client assumes that it has a full set
> > of caps on the new inode, and that the MDS will revoke them when there
> > is conflicting access.
> >
> > This functionality is gated on the enable_async_dirops module option,
> > along with async unlinks, and on the server supporting the necessary
> > CephFS feature bit.
> >
> > Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
> > ---
> > fs/ceph/file.c | 196 +++++++++++++++++++++++++++++++++--
> > include/linux/ceph/ceph_fs.h | 3 +
> > 2 files changed, 190 insertions(+), 9 deletions(-)
> >
> > diff --git a/fs/ceph/file.c b/fs/ceph/file.c
> > index b44ccbc85fe4..2742417fa5ec 100644
> > --- a/fs/ceph/file.c
> > +++ b/fs/ceph/file.c
> > @@ -448,6 +448,169 @@ cache_file_layout(struct inode *dst, struct inode *src)
> > spin_unlock(&cdst->i_ceph_lock);
> > }
> >
> > +/*
> > + * Try to set up an async create. We need caps, a file layout, and inode number,
> > + * and either a lease on the dentry or complete dir info. If any of those
> > + * criteria are not satisfied, then return false and the caller can go
> > + * synchronous.
> > + */
> > +static bool try_prep_async_create(struct inode *dir, struct dentry *dentry,
> > + struct ceph_file_layout *lo,
> > + unsigned long *pino)
> > +{
> > + struct ceph_inode_info *ci = ceph_inode(dir);
> > + bool ret = false;
> > + unsigned long ino;
> > +
> > + spin_lock(&ci->i_ceph_lock);
> > + /* No auth cap means no chance for Dc caps */
> > + if (!ci->i_auth_cap)
> > + goto no_async;
> > +
> > + /* Any delegated inos? */
> > + if (xa_empty(&ci->i_auth_cap->session->s_delegated_inos))
> > + goto no_async;
> > +
> > + if (!ceph_file_layout_is_valid(&ci->i_cached_layout))
> > + goto no_async;
> > +
> > + /* Use LOOKUP_RCU since we're under i_ceph_lock */
> > + if (!__ceph_dir_is_complete(ci) &&
> > + !dentry_lease_is_valid(dentry, LOOKUP_RCU))
> > + goto no_async;
> > +
> > + if (!(__ceph_caps_issued(ci, NULL) &
> > + (CEPH_CAP_FILE_EXCL | CEPH_CAP_DIR_CREATE)))
> > + goto no_async;
> > +
>
> (ceph_caps_issued(ci, NULL) &
> CEPH_CAP_FILE_EXCL | CEPH_CAP_DIR_CREATE)) ==
> (CEPH_CAP_FILE_EXCL | CEPH_CAP_DIR_CREATE)
>
Good catch! Fixed in my tree. Retesting now and will fold that one in.
> > + ino = ceph_get_deleg_ino(ci->i_auth_cap->session);
> > + if (!ino)
> > + goto no_async;
> > +
> > + *pino = ino;
> > + ceph_take_cap_refs(ci, CEPH_CAP_FILE_EXCL | CEPH_CAP_DIR_CREATE, false);
> > + memcpy(lo, &ci->i_cached_layout, sizeof(*lo));
> > + rcu_assign_pointer(lo->pool_ns,
> > + ceph_try_get_string(ci->i_cached_layout.pool_ns));
> > + ret = true;
> > +no_async:
> > + spin_unlock(&ci->i_ceph_lock);
> > + return ret;
> > +}
> > +
> > +static void ceph_async_create_cb(struct ceph_mds_client *mdsc,
> > + struct ceph_mds_request *req)
> > +{
> > + mapping_set_error(req->r_parent->i_mapping, req->r_err);
> > +
> > + if (req->r_target_inode) {
> > + struct ceph_inode_info *ci = ceph_inode(req->r_target_inode);
> > + u64 ino = ceph_vino(req->r_target_inode).ino;
> > +
> > + if (req->r_deleg_ino != ino)
> > + pr_warn("%s: inode number mismatch! err=%d deleg_ino=0x%lx target=0x%llx\n",
> > + __func__, req->r_err, req->r_deleg_ino, ino);
> > + mapping_set_error(req->r_target_inode->i_mapping, req->r_err);
> > +
> > + spin_lock(&ci->i_ceph_lock);
> > + if (ci->i_ceph_flags & CEPH_I_ASYNC_CREATE) {
> > + ci->i_ceph_flags &= ~CEPH_I_ASYNC_CREATE;
> > + wake_up_bit(&ci->i_ceph_flags, CEPH_ASYNC_CREATE_BIT);
> > + }
> > + spin_unlock(&ci->i_ceph_lock);
> > + } else {
> > + pr_warn("%s: no req->r_target_inode for 0x%lx\n", __func__,
> > + req->r_deleg_ino);
> > + }
> > + ceph_put_cap_refs(ceph_inode(req->r_parent),
> > + CEPH_CAP_FILE_EXCL | CEPH_CAP_DIR_CREATE);
> > +}
> > +
> > +static int ceph_finish_async_create(struct inode *dir, struct dentry *dentry,
> > + struct file *file, umode_t mode,
> > + struct ceph_mds_request *req,
> > + struct ceph_acl_sec_ctx *as_ctx,
> > + struct ceph_file_layout *lo)
> > +{
> > + int ret;
> > + char xattr_buf[4];
> > + struct ceph_mds_reply_inode in = { };
> > + struct ceph_mds_reply_info_in iinfo = { .in = &in };
> > + struct ceph_inode_info *ci = ceph_inode(dir);
> > + struct inode *inode;
> > + struct timespec64 now;
> > + struct ceph_vino vino = { .ino = req->r_deleg_ino,
> > + .snap = CEPH_NOSNAP };
> > +
> > + ktime_get_real_ts64(&now);
> > +
> > + inode = ceph_get_inode(dentry->d_sb, vino);
> > + if (IS_ERR(inode))
> > + return PTR_ERR(inode);
> > +
> > + iinfo.inline_version = CEPH_INLINE_NONE;
> > + iinfo.change_attr = 1;
> > + ceph_encode_timespec64(&iinfo.btime, &now);
> > +
> > + iinfo.xattr_len = ARRAY_SIZE(xattr_buf);
> > + iinfo.xattr_data = xattr_buf;
> > + memset(iinfo.xattr_data, 0, iinfo.xattr_len);
> > +
> > + in.ino = cpu_to_le64(vino.ino);
> > + in.snapid = cpu_to_le64(CEPH_NOSNAP);
> > + in.version = cpu_to_le64(1); // ???
> > + in.cap.caps = in.cap.wanted = cpu_to_le32(CEPH_CAP_ALL_FILE);
> > + in.cap.cap_id = cpu_to_le64(1);
> > + in.cap.realm = cpu_to_le64(ci->i_snap_realm->ino);
> > + in.cap.flags = CEPH_CAP_FLAG_AUTH;
> > + in.ctime = in.mtime = in.atime = iinfo.btime;
> > + in.mode = cpu_to_le32((u32)mode);
> > + in.truncate_seq = cpu_to_le32(1);
> > + in.truncate_size = cpu_to_le64(-1ULL);
> > + in.xattr_version = cpu_to_le64(1);
> > + in.uid = cpu_to_le32(from_kuid(&init_user_ns, current_fsuid()));
> > + in.gid = cpu_to_le32(from_kgid(&init_user_ns, dir->i_mode & S_ISGID ?
> > + dir->i_gid : current_fsgid()));
> > + in.nlink = cpu_to_le32(1);
> > + in.max_size = cpu_to_le64(lo->stripe_unit);
> > +
> > + ceph_file_layout_to_legacy(lo, &in.layout);
> > +
> > + ret = ceph_fill_inode(inode, NULL, &iinfo, NULL, req->r_session,
> > + req->r_fmode, NULL);
> > + if (ret) {
> > + dout("%s failed to fill inode: %d\n", __func__, ret);
> > + if (inode->i_state & I_NEW)
> > + discard_new_inode(inode);
> > + } else {
> > + struct dentry *dn;
> > +
> > + dout("%s d_adding new inode 0x%llx to 0x%lx/%s\n", __func__,
> > + vino.ino, dir->i_ino, dentry->d_name.name);
> > + ceph_dir_clear_ordered(dir);
> > + ceph_init_inode_acls(inode, as_ctx);
> > + if (inode->i_state & I_NEW) {
> > + /*
> > + * If it's not I_NEW, then someone created this before
> > + * we got here. Assume the server is aware of it at
> > + * that point and don't worry about setting
> > + * CEPH_I_ASYNC_CREATE.
> > + */
> > + ceph_inode(inode)->i_ceph_flags = CEPH_I_ASYNC_CREATE;
> > + unlock_new_inode(inode);
> > + }
> > + if (d_in_lookup(dentry) || d_really_is_negative(dentry)) {
> > + if (!d_unhashed(dentry))
> > + d_drop(dentry);
> > + dn = d_splice_alias(inode, dentry);
> > + WARN_ON_ONCE(dn && dn != dentry);
> > + }
> > + file->f_mode |= FMODE_CREATED;
> > + ret = finish_open(file, dentry, ceph_open);
> > + }
> > + return ret;
> > +}
> > +
> > /*
> > * Do a lookup + open with a single request. If we get a non-existent
> > * file or symlink, return 1 so the VFS can retry.
> > @@ -460,6 +623,7 @@ int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
> > struct ceph_mds_request *req;
> > struct dentry *dn;
> > struct ceph_acl_sec_ctx as_ctx = {};
> > + bool try_async = enable_async_dirops;
> > int mask;
> > int err;
> >
> > @@ -492,28 +656,41 @@ int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
> > }
> > req->r_dentry = dget(dentry);
> > req->r_num_caps = 2;
> > + mask = CEPH_STAT_CAP_INODE | CEPH_CAP_AUTH_SHARED;
> > + if (ceph_security_xattr_wanted(dir))
> > + mask |= CEPH_CAP_XATTR_SHARED;
> > + req->r_args.open.mask = cpu_to_le32(mask);
> > + req->r_parent = dir;
> > +
> > if (flags & O_CREAT) {
> > + struct ceph_file_layout lo;
> > +
> > req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL;
> > req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
> > if (as_ctx.pagelist) {
> > req->r_pagelist = as_ctx.pagelist;
> > as_ctx.pagelist = NULL;
> > }
> > + if (try_async && try_prep_async_create(dir, dentry, &lo,
> > + &req->r_deleg_ino)) {
> > + set_bit(CEPH_MDS_R_ASYNC, &req->r_req_flags);
> > + req->r_callback = ceph_async_create_cb;
> > + err = ceph_mdsc_submit_request(mdsc, dir, req);
> > + if (!err)
> > + err = ceph_finish_async_create(dir, dentry,
> > + file, mode, req,
> > + &as_ctx, &lo);
> > + goto out_req;
> > + }
> > }
> >
> > - mask = CEPH_STAT_CAP_INODE | CEPH_CAP_AUTH_SHARED;
> > - if (ceph_security_xattr_wanted(dir))
> > - mask |= CEPH_CAP_XATTR_SHARED;
> > - req->r_args.open.mask = cpu_to_le32(mask);
> > -
> > - req->r_parent = dir;
> > set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
> > err = ceph_mdsc_do_request(mdsc,
> > (flags & (O_CREAT|O_TRUNC)) ? dir : NULL,
> > req);
> > err = ceph_handle_snapdir(req, dentry, err);
> > if (err)
> > - goto out_req;
> > + goto out_fmode;
> >
> > if ((flags & O_CREAT) && !req->r_reply_info.head->is_dentry)
> > err = ceph_handle_notrace_create(dir, dentry);
> > @@ -527,7 +704,7 @@ int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
> > dn = NULL;
> > }
> > if (err)
> > - goto out_req;
> > + goto out_fmode;
> > if (dn || d_really_is_negative(dentry) || d_is_symlink(dentry)) {
> > /* make vfs retry on splice, ENOENT, or symlink */
> > dout("atomic_open finish_no_open on dn %p\n", dn);
> > @@ -543,9 +720,10 @@ int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
> > }
> > err = finish_open(file, dentry, ceph_open);
> > }
> > -out_req:
> > +out_fmode:
> > if (!req->r_err && req->r_target_inode)
> > ceph_put_fmode(ceph_inode(req->r_target_inode), req->r_fmode);
> > +out_req:
> > ceph_mdsc_put_request(req);
> > out_ctx:
> > ceph_release_acl_sec_ctx(&as_ctx);
> > diff --git a/include/linux/ceph/ceph_fs.h b/include/linux/ceph/ceph_fs.h
> > index 91d09cf37649..e035c5194005 100644
> > --- a/include/linux/ceph/ceph_fs.h
> > +++ b/include/linux/ceph/ceph_fs.h
> > @@ -659,6 +659,9 @@ int ceph_flags_to_mode(int flags);
> > #define CEPH_CAP_ANY (CEPH_CAP_ANY_RD | CEPH_CAP_ANY_EXCL | \
> > CEPH_CAP_ANY_FILE_WR | CEPH_CAP_FILE_LAZYIO | \
> > CEPH_CAP_PIN)
> > +#define CEPH_CAP_ALL_FILE (CEPH_CAP_PIN | CEPH_CAP_ANY_SHARED | \
> > + CEPH_CAP_AUTH_EXCL | CEPH_CAP_XATTR_EXCL | \
> > + CEPH_CAP_ANY_FILE_RD | CEPH_CAP_ANY_FILE_WR)
> >
> > #define CEPH_CAP_LOCKS (CEPH_LOCK_IFILE | CEPH_LOCK_IAUTH | CEPH_LOCK_ILINK | \
> > CEPH_LOCK_IXATTR)
> >
--
Jeff Layton <jlayton@xxxxxxxxxx>
