path: root/fs/ceph/mds_client.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _FS_CEPH_MDS_CLIENT_H
#define _FS_CEPH_MDS_CLIENT_H

#include <linux/completion.h>
#include <linux/kref.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/rbtree.h>
#include <linux/spinlock.h>
#include <linux/refcount.h>
#include <linux/utsname.h>
#include <linux/ktime.h>

#include <linux/ceph/types.h>
#include <linux/ceph/messenger.h>
#include <linux/ceph/mdsmap.h>
#include <linux/ceph/auth.h>

#include "metric.h"
#include "super.h"

/* The first 8 bits are reserved for old ceph releases */
enum ceph_feature_type {
	CEPHFS_FEATURE_MIMIC = 8,
	CEPHFS_FEATURE_REPLY_ENCODING,
	CEPHFS_FEATURE_RECLAIM_CLIENT,
	CEPHFS_FEATURE_LAZY_CAP_WANTED,
	CEPHFS_FEATURE_MULTI_RECONNECT,
	CEPHFS_FEATURE_DELEG_INO,
	CEPHFS_FEATURE_METRIC_COLLECT,

	CEPHFS_FEATURE_MAX = CEPHFS_FEATURE_METRIC_COLLECT,
};

/*
 * This will always have the highest feature bit value
 * as the last element of the array.
 */
#define CEPHFS_FEATURES_CLIENT_SUPPORTED {	\
	0, 1, 2, 3, 4, 5, 6, 7,			\
	CEPHFS_FEATURE_MIMIC,			\
	CEPHFS_FEATURE_REPLY_ENCODING,		\
	CEPHFS_FEATURE_LAZY_CAP_WANTED,		\
	CEPHFS_FEATURE_MULTI_RECONNECT,		\
	CEPHFS_FEATURE_DELEG_INO,		\
	CEPHFS_FEATURE_METRIC_COLLECT,		\
						\
	CEPHFS_FEATURE_MAX,			\
}
#define CEPHFS_FEATURES_CLIENT_REQUIRED {}

/*
 * Some lock dependencies:
 *
 * session->s_mutex
 *         mdsc->mutex
 *
 *         mdsc->snap_rwsem
 *
 *         ci->i_ceph_lock
 *                 mdsc->snap_flush_lock
 *                 mdsc->cap_delay_lock
 *
 */

struct ceph_fs_client;
struct ceph_cap;

/*
 * parsed info about a single inode.  pointers are into the encoded
 * on-wire structures within the mds reply message payload.
 */
struct ceph_mds_reply_info_in {
	struct ceph_mds_reply_inode *in;
	struct ceph_dir_layout dir_layout;
	u32 symlink_len;
	char *symlink;
	u32 xattr_len;
	char *xattr_data;
	u64 inline_version;
	u32 inline_len;
	char *inline_data;
	u32 pool_ns_len;
	char *pool_ns_data;
	u64 max_bytes;
	u64 max_files;
	s32 dir_pin;
	struct ceph_timespec btime;
	struct ceph_timespec snap_btime;
	u64 change_attr;
};

struct ceph_mds_reply_dir_entry {
	char                          *name;
	u32                           name_len;
	struct ceph_mds_reply_lease   *lease;
	struct ceph_mds_reply_info_in inode;
	loff_t			      offset;
};

/*
 * parsed info about an mds reply, including information about
 * either: 1) the target inode and/or its parent directory and dentry,
 * and directory contents (for readdir results), or
 * 2) the file range lock info (for fcntl F_GETLK results).
 */
struct ceph_mds_reply_info_parsed {
	struct ceph_mds_reply_head    *head;

	/* trace */
	struct ceph_mds_reply_info_in diri, targeti;
	struct ceph_mds_reply_dirfrag *dirfrag;
	char                          *dname;
	u32                           dname_len;
	struct ceph_mds_reply_lease   *dlease;

	/* extra */
	union {
		/* for fcntl F_GETLK results */
		struct ceph_filelock *filelock_reply;

		/* for readdir results */
		struct {
			struct ceph_mds_reply_dirfrag *dir_dir;
			size_t			      dir_buf_size;
			int                           dir_nr;
			bool			      dir_end;
			bool			      dir_complete;
			bool			      hash_order;
			bool			      offset_hash;
			struct ceph_mds_reply_dir_entry  *dir_entries;
		};

		/* for create results */
		struct {
			bool has_create_ino;
			u64 ino;
		};
	};

	/* encoded blob describing snapshot contexts for certain
	   operations (e.g., open) */
	void *snapblob;
	int snapblob_len;
};


/*
 * cap releases are batched and sent to the MDS en masse.
 *
 * Account for per-message overhead of mds_cap_release header
 * and __le32 for osd epoch barrier trailing field.
 */
#define CEPH_CAPS_PER_RELEASE ((PAGE_SIZE - sizeof(u32) -		\
				sizeof(struct ceph_mds_cap_release)) /	\
			        sizeof(struct ceph_mds_cap_item))


/*
 * state associated with each MDS<->client session
 */
enum {
	CEPH_MDS_SESSION_NEW = 1,
	CEPH_MDS_SESSION_OPENING = 2,
	CEPH_MDS_SESSION_OPEN = 3,
	CEPH_MDS_SESSION_HUNG = 4,
	CEPH_MDS_SESSION_RESTARTING = 5,
	CEPH_MDS_SESSION_RECONNECTING = 6,
	CEPH_MDS_SESSION_CLOSING = 7,
	CEPH_MDS_SESSION_CLOSED = 8,
	CEPH_MDS_SESSION_REJECTED = 9,
};

struct ceph_mds_session {
	struct ceph_mds_client *s_mdsc;
	int               s_mds;
	int               s_state;
	unsigned long     s_ttl;      /* time until mds kills us */
	unsigned long	  s_features;
	u64               s_seq;      /* incoming msg seq # */
	struct mutex      s_mutex;    /* serialize session messages */

	struct ceph_connection s_con;

	struct ceph_auth_handshake s_auth;

	/* protected by s_gen_ttl_lock */
	spinlock_t        s_gen_ttl_lock;
	u32               s_cap_gen;  /* inc each time we get mds stale msg */
	unsigned long     s_cap_ttl;  /* when session caps expire */

	/* protected by s_cap_lock */
	spinlock_t        s_cap_lock;
	refcount_t        s_ref;
	struct list_head  s_caps;     /* all caps issued by this session */
	struct ceph_cap  *s_cap_iterator;
	int               s_nr_caps;
	int               s_num_cap_releases;
	int		  s_cap_reconnect;
	int		  s_readonly;
	struct list_head  s_cap_releases; /* waiting cap_release messages */
	struct work_struct s_cap_release_work;

	/* See ceph_inode_info->i_dirty_item. */
	struct list_head  s_cap_dirty;	      /* inodes w/ dirty caps */

	/* See ceph_inode_info->i_flushing_item. */
	struct list_head  s_cap_flushing;     /* inodes w/ flushing caps */

	unsigned long     s_renew_requested; /* last time we sent a renew req */
	u64               s_renew_seq;

	struct list_head  s_waiting;  /* waiting requests */
	struct list_head  s_unsafe;   /* unsafe requests */
	struct xarray	  s_delegated_inos;
};

/*
 * modes of choosing which MDS to send a request to
 */
enum {
	USE_ANY_MDS,
	USE_RANDOM_MDS,
	USE_AUTH_MDS,   /* prefer authoritative mds for this metadata item */
};

struct ceph_mds_request;
struct ceph_mds_client;

/*
 * request completion callback
 */
typedef void (*ceph_mds_request_callback_t) (struct ceph_mds_client *mdsc,
					     struct ceph_mds_request *req);
/*
 * wait for request completion callback
 */
typedef int (*ceph_mds_request_wait_callback_t) (struct ceph_mds_client *mdsc,
						 struct ceph_mds_request *req);

/*
 * an in-flight mds request
 */
struct ceph_mds_request {
	u64 r_tid;                   /* transaction id */
	struct rb_node r_node;
	struct ceph_mds_client *r_mdsc;

	struct kref       r_kref;
	int r_op;                    /* mds op code */

	/* operation on what? */
	struct inode *r_inode;              /* arg1 */
	struct dentry *r_dentry;            /* arg1 */
	struct dentry *r_old_dentry;        /* arg2: rename from or link from */
	struct inode *r_old_dentry_dir;     /* arg2: old dentry's parent dir */
	char *r_path1, *r_path2;
	struct ceph_vino r_ino1, r_ino2;

	struct inode *r_parent;		    /* parent dir inode */
	struct inode *r_target_inode;       /* resulting inode */

#define CEPH_MDS_R_DIRECT_IS_HASH	(1) /* r_direct_hash is valid */
#define CEPH_MDS_R_ABORTED		(2) /* call was aborted */
#define CEPH_MDS_R_GOT_UNSAFE		(3) /* got an unsafe reply */
#define CEPH_MDS_R_GOT_SAFE		(4) /* got a safe reply */
#define CEPH_MDS_R_GOT_RESULT		(5) /* got a result */
#define CEPH_MDS_R_DID_PREPOPULATE	(6) /* prepopulated readdir */
#define CEPH_MDS_R_PARENT_LOCKED	(7) /* is r_parent->i_rwsem wlocked? */
#define CEPH_MDS_R_ASYNC		(8) /* async request */
	unsigned long	r_req_flags;

	struct mutex r_fill_mutex;

	union ceph_mds_request_args r_args;
	int r_fmode;        /* file mode, if expecting cap */
	kuid_t r_uid;
	kgid_t r_gid;
	int r_request_release_offset;
	struct timespec64 r_stamp;

	/* for choosing which mds to send this request to */
	int r_direct_mode;
	u32 r_direct_hash;      /* choose dir frag based on this dentry hash */

	/* data payload is used for xattr ops */
	struct ceph_pagelist *r_pagelist;

	/* what caps shall we drop? */
	int r_inode_drop, r_inode_unless;
	int r_dentry_drop, r_dentry_unless;
	int r_old_dentry_drop, r_old_dentry_unless;
	struct inode *r_old_inode;
	int r_old_inode_drop, r_old_inode_unless;

	struct ceph_msg  *r_request;  /* original request */
	struct ceph_msg  *r_reply;
	struct ceph_mds_reply_info_parsed r_reply_info;
	int r_err;


	struct page *r_locked_page;
	int r_dir_caps;
	int r_num_caps;
	u32               r_readdir_offset;

	unsigned long r_timeout;  /* optional.  jiffies, 0 is "wait forever" */
	unsigned long r_started;  /* start time to measure timeout against */
	unsigned long r_start_latency;  /* start time to measure latency */
	unsigned long r_end_latency;    /* finish time to measure latency */
	unsigned long r_request_started; /* start time for mds request only,
					    used to measure lease durations */

	/* link unsafe requests to parent directory, for fsync */
	struct inode	*r_unsafe_dir;
	struct list_head r_unsafe_dir_item;

	/* unsafe requests that modify the target inode */
	struct list_head r_unsafe_target_item;

	struct ceph_mds_session *r_session;

	int               r_attempts;   /* resend attempts */
	int               r_num_fwd;    /* number of forward attem