With the Octopus release, the MDS will hand out directoy 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 a
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 Octopus
CephFS feature bit.
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
fs/ceph/caps.c | 7 +-
fs/ceph/file.c | 178 +++++++++++++++++++++++++++++++++--
fs/ceph/mds_client.c | 12 ++-
fs/ceph/mds_client.h | 3 +-
fs/ceph/super.h | 2 +
include/linux/ceph/ceph_fs.h | 8 +-
6 files changed, 191 insertions(+), 19 deletions(-)
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index b96fb1378479..21a8a2ddc94b 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -654,6 +654,10 @@ void ceph_add_cap(struct inode *inode,
session->s_nr_caps++;
spin_unlock(&session->s_cap_lock);
} else {
+ /* Did an async create race with the reply? */
+ if (cap_id == CEPH_CAP_ID_TBD && cap->issued == issued)
+ return;
+
spin_lock(&session->s_cap_lock);
list_move_tail(&cap->session_caps, &session->s_caps);
spin_unlock(&session->s_cap_lock);
@@ -672,7 +676,8 @@ void ceph_add_cap(struct inode *inode,
*/
if (ceph_seq_cmp(seq, cap->seq) <= 0) {
WARN_ON(cap != ci->i_auth_cap);
- WARN_ON(cap->cap_id != cap_id);
+ WARN_ON(cap_id != CEPH_CAP_ID_TBD &&
+ cap->cap_id != cap_id);
seq = cap->seq;
mseq = cap->mseq;
issued |= cap->issued;
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index d4d7a277faf1..706abd71b731 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -450,6 +450,141 @@ copy_file_layout(struct inode *dst, struct inode *src)
spin_unlock(&cdst->i_ceph_lock);
}
+static bool get_caps_for_async_create(struct inode *dir, struct dentry *dentry)
+{
+ struct ceph_inode_info *ci = ceph_inode(dir);
+ int ret, want, got;
+
+ /*
+ * We can do an async create if we either have a valid negative dentry
+ * or the complete contents of the directory. Do a quick check without
+ * cap refs.
+ */
+ if ((d_in_lookup(dentry) && !__ceph_dir_is_complete(ci)) ||
+ !ceph_file_layout_is_valid(&ci->i_layout))
+ return false;
+
+ /* Try to get caps */
+ want = CEPH_CAP_FILE_EXCL | CEPH_CAP_DIR_CREATE;
+ ret = ceph_try_get_caps(dir, 0, want, true, &got);
+ dout("Fx on %p ret=%d got=%d\n", dir, ret, got);
+ if (ret != 1)
+ return false;
+ if (got != want) {
+ ceph_put_cap_refs(ci, got);
+ return false;
+ }
+
+ /* Check again, now that we hold cap refs */
+ if ((d_in_lookup(dentry) && !__ceph_dir_is_complete(ci)) ||
+ !ceph_file_layout_is_valid(&ci->i_layout)) {
+ ceph_put_cap_refs(ci, got);
+ return false;
+ }
+
+ return true;
+}
+
+static void ceph_async_create_cb(struct ceph_mds_client *mdsc,
+ struct ceph_mds_request *req)
+{
+ /* If we never sent anything then nothing to clean up */
+ if (req->r_err == -ECHILD)
+ goto out;
+
+ mapping_set_error(req->r_parent->i_mapping, req->r_err);
+
+ if (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);
+ } else {
+ pr_warn("%s: no req->r_target_inode for 0x%lx\n", __func__,
+ req->r_deleg_ino);
+ }
+out:
+ ceph_put_cap_refs(ceph_inode(req->r_parent),
+ CEPH_CAP_FILE_EXCL | CEPH_CAP_DIR_CREATE);
+}
+
+static int ceph_finish_async_open(struct inode *dir, struct dentry *dentry,
+ struct file *file, umode_t mode,
+ struct ceph_mds_request *req,
+ struct ceph_acl_sec_ctx *as_ctx)
+{
+ int ret;
+ 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);
+
+ /* If we can't get a buffer, just carry on */
+ iinfo.xattr_data = kzalloc(4, GFP_NOFS);
+ if (iinfo.xattr_data)
+ iinfo.xattr_len = 4;
+
+ iinfo.inline_version = CEPH_INLINE_NONE;
+ iinfo.change_attr = 1;
+ ceph_encode_timespec64(&iinfo.btime, &now);
+
+ 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(CEPH_CAP_ID_TBD);
+ 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(ci->i_truncate_size);
+ in.max_size = cpu_to_le64(ci->i_max_size);
+ 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, current_fsgid()));
+ in.nlink = cpu_to_le32(1);
+
+ ceph_file_layout_to_legacy(&ci->i_layout, &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)
+ 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.
@@ -462,6 +597,7 @@ 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;
@@ -486,6 +622,7 @@ int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
return -ENOENT;
}
+retry:
/* do the open */
req = prepare_open_request(dir->i_sb, flags, mode);
if (IS_ERR(req)) {
@@ -494,6 +631,12 @@ 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) {
req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL;
req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
@@ -501,21 +644,37 @@ int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
req->r_pagelist = as_ctx.pagelist;
as_ctx.pagelist = NULL;
}
+ if (try_async && get_caps_for_async_create(dir, dentry)) {
+ set_bit(CEPH_MDS_R_DELEG_INO, &req->r_req_flags);
+ req->r_callback = ceph_async_create_cb;
+ err = ceph_mdsc_submit_request(mdsc, dir, req);
+ switch (err) {
+ case 0:
+ /* set up inode, dentry and return */
+ err = ceph_finish_async_open(dir, dentry, file,
+ mode, req, &as_ctx);
+ goto out_req;
+ case -ECHILD:
+ /* do a sync create */
+ try_async = false;
+ as_ctx.pagelist = req->r_pagelist;
+ req->r_pagelist = NULL;
+ ceph_mdsc_put_request(req);
+ goto retry;
+ default:
+ /* Hard error, give up */
+ 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);
@@ -529,7 +688,7 @@ 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);
@@ -545,9 +704,10 @@ 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/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 9e7492b21b50..c76d6e7f8136 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -2620,14 +2620,16 @@ static int __prepare_send_request(struct ceph_mds_client *mdsc,
flags |= CEPH_MDS_FLAG_REPLAY;
if (req->r_parent)
flags |= CEPH_MDS_FLAG_WANT_DENTRY;
- rhead->flags = cpu_to_le32(flags);
- rhead->num_fwd = req->r_num_fwd;
- rhead->num_retry = req->r_attempts - 1;
- if (test_bit(CEPH_MDS_R_DELEG_INO, &req->r_req_flags))
+ if (test_bit(CEPH_MDS_R_DELEG_INO, &req->r_req_flags)) {
rhead->ino = cpu_to_le64(req->r_deleg_ino);
- else
+ flags |= CEPH_MDS_FLAG_ASYNC;
+ } else {
rhead->ino = 0;
+ }
+ rhead->flags = cpu_to_le32(flags);
+ rhead->num_fwd = req->r_num_fwd;
+ rhead->num_retry = req->r_attempts - 1;
dout(" r_parent = %p\n", req->r_parent);
return 0;
}
diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h
index e0b36be7c44f..49e6cd5a07a2 100644
--- a/fs/ceph/mds_client.h
+++ b/fs/ceph/mds_client.h
@@ -39,8 +39,7 @@ enum ceph_feature_type {
CEPHFS_FEATURE_REPLY_ENCODING, \
CEPHFS_FEATURE_LAZY_CAP_WANTED, \
CEPHFS_FEATURE_MULTI_RECONNECT, \
- \
- CEPHFS_FEATURE_MAX, \
+ CEPHFS_FEATURE_OCTOPUS, \
}
#define CEPHFS_FEATURES_CLIENT_REQUIRED {}
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index ec4d66d7c261..33e03fbba888 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -136,6 +136,8 @@ struct ceph_fs_client {
#endif
};
+/* Special placeholder value for a cap_id during an asynchronous create. */
+#define CEPH_CAP_ID_TBD -1ULL
/*
* File i/o capability. This tracks shared state with the metadata
diff --git a/include/linux/ceph/ceph_fs.h b/include/linux/ceph/ceph_fs.h
index a099f60feb7b..b127563e21a1 100644
--- a/include/linux/ceph/ceph_fs.h
+++ b/include/linux/ceph/ceph_fs.h
@@ -444,8 +444,9 @@ union ceph_mds_request_args {
} __attribute__ ((packed)) lookupino;
} __attribute__ ((packed));
-#define CEPH_MDS_FLAG_REPLAY 1 /* this is a replayed op */
-#define CEPH_MDS_FLAG_WANT_DENTRY 2 /* want dentry in reply */
+#define CEPH_MDS_FLAG_REPLAY 1 /* this is a replayed op */
+#define CEPH_MDS_FLAG_WANT_DENTRY 2 /* want dentry in reply */
+#define CEPH_MDS_FLAG_ASYNC 4 /* request is asynchronous */
struct ceph_mds_request_head {
__le64 oldest_client_tid;
@@ -658,6 +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)
--
2.24.1
