text: /* SPDX-License-Identifier: GPL-2.0 */
  /*
   * NFSv4 flexfile layout driver data structures.
   *
   * Copyright (c) 2014, Primary Data, Inc. All rights reserved.
   *
   * Tao Peng <bergwolf@primarydata.com>
   */
  
  #ifndef FS_NFS_NFS4FLEXFILELAYOUT_H
  #define FS_NFS_NFS4FLEXFILELAYOUT_H
  
  #define FF_FLAGS_NO_LAYOUTCOMMIT 1
  #define FF_FLAGS_NO_IO_THRU_MDS  2
  #define FF_FLAGS_NO_READ_IO      4
  
  #include <linux/refcount.h>
  #include "../pnfs.h"
  
  /* XXX: Let's filter out insanely large mirror count for now to avoid oom
   * due to network error etc. */
  #define NFS4_FLEXFILE_LAYOUT_MAX_MIRROR_CNT 4096
  
  /* LAYOUTSTATS report interval in ms */
  #define FF_LAYOUTSTATS_REPORT_INTERVAL (60000L)
  #define FF_LAYOUTSTATS_MAXDEV 4
  
  struct nfs4_ff_ds_version {
  	u32				version;
  	u32				minor_version;
  	u32				rsize;
  	u32				wsize;
  	bool				tightly_coupled;
  };
  
  /* chained in global deviceid hlist */
  struct nfs4_ff_layout_ds {
  	struct nfs4_deviceid_node	id_node;
  	u32				ds_versions_cnt;
  	struct nfs4_ff_ds_version	*ds_versions;
  	struct nfs4_pnfs_ds		*ds;
  };
  
  struct nfs4_ff_layout_ds_err {
  	struct list_head		list; /* linked in mirror error_list */
  	u64				offset;
  	u64				length;
  	int				status;
  	enum nfs_opnum4			opnum;
  	nfs4_stateid			stateid;
  	struct nfs4_deviceid		deviceid;
  };
  
  struct nfs4_ff_io_stat {
  	__u64				ops_requested;
  	__u64				bytes_requested;
  	__u64				ops_completed;
  	__u64				bytes_completed;
  	__u64				bytes_not_delivered;
  	ktime_t				total_busy_time;
  	ktime_t				aggregate_completion_time;
  };
  
  struct nfs4_ff_busy_timer {
  	ktime_t start_time;
  	atomic_t n_ops;
  };
  
  struct nfs4_ff_layoutstat {
  	struct nfs4_ff_io_stat io_stat;
  	struct nfs4_ff_busy_timer busy_timer;
  };
  
  struct nfs4_ff_layout_mirror {
  	struct pnfs_layout_hdr		*layout;
  	struct list_head		mirrors;
  	u32				ds_count;
  	u32				efficiency;
  	struct nfs4_deviceid		devid;
  	struct nfs4_ff_layout_ds	*mirror_ds;
  	u32				fh_versions_cnt;
  	struct nfs_fh			*fh_versions;
  	nfs4_stateid			stateid;
  	const struct cred __rcu		*ro_cred;
  	const struct cred __rcu		*rw_cred;
  	refcount_t			ref;
  	spinlock_t			lock;
  	unsigned long			flags;
  	struct nfs4_ff_layoutstat	read_stat;
  	struct nfs4_ff_layoutstat	write_stat;
  	ktime_t				start_time;
  	u32				report_interval;
  };
  
  #define NFS4_FF_MIRROR_STAT_AVAIL	(0)
  
  struct nfs4_ff_layout_segment {
  	struct pnfs_layout_segment	generic_hdr;
  	u64				stripe_unit;
  	u32				flags;
  	u32				mirror_array_cnt;
  	struct nfs4_ff_layout_mirror	*mirror_array[];
  };
  
  struct nfs4_flexfile_layout {
  	struct pnfs_layout_hdr generic_hdr;
  	struct pnfs_ds_commit_info commit_info;
  	struct list_head	mirrors;
  	struct list_head	error_list; /* nfs4_ff_layout_ds_err */
  	ktime_t			last_report_time; /* Layoutstat report times */
  };
  
  struct nfs4_flexfile_layoutreturn_args {
  	struct list_head errors;
  	struct nfs42_layoutstat_devinfo devinfo[FF_LAYOUTSTATS_MAXDEV];
  	unsigned int num_errors;
  	unsigned int num_dev;
  	struct page *pages[1];
  };
  
  static inline struct nfs4_flexfile_layout *
  FF_LAYOUT_FROM_HDR(struct pnfs_layout_hdr *lo)
  {
  	return container_of(lo, struct nfs4_flexfile_layout, generic_hdr);
  }
  
  static inline struct nfs4_ff_layout_segment *
  FF_LAYOUT_LSEG(struct pnfs_layout_segment *lseg)
  {
  	return container_of(lseg,
  			    struct nfs4_ff_layout_segment,
  			    generic_hdr);
  }
  
  static inline struct nfs4_ff_layout_ds *
  FF_LAYOUT_MIRROR_DS(struct nfs4_deviceid_node *node)
  {
  	return container_of(node, struct nfs4_ff_layout_ds, id_node);
  }
  
  static inline struct nfs4_ff_layout_mirror *
  FF_LAYOUT_COMP(struct pnfs_layout_segment *lseg, u32 idx)
  {
  	struct nfs4_ff_layout_segment *fls = FF_LAYOUT_LSEG(lseg);
  
  	if (idx < fls->mirror_array_cnt)
  		return fls->mirror_array[idx];
  	return NULL;
  }
  
  static inline struct nfs4_deviceid_node *
  FF_LAYOUT_DEVID_NODE(struct pnfs_layout_segment *lseg, u32 idx)
  {
  	struct nfs4_ff_layout_mirror *mirror = FF_LAYOUT_COMP(lseg, idx);
  
  	if (mirror != NULL) {
  		struct nfs4_ff_layout_ds *mirror_ds = mirror->mirror_ds;
  
  		if (!IS_ERR_OR_NULL(mirror_ds))
  			return &mirror_ds->id_node;
  	}
  	return NULL;
  }
  
  static inline u32
  FF_LAYOUT_MIRROR_COUNT(struct pnfs_layout_segment *lseg)
  {
  	return FF_LAYOUT_LSEG(lseg)->mirror_array_cnt;
  }
  
  static inline bool
  ff_layout_no_fallback_to_mds(struct pnfs_layout_segment *lseg)
  {
  	return FF_LAYOUT_LSEG(lseg)->flags & FF_FLAGS_NO_IO_THRU_MDS;
  }
  
  static inline bool
  ff_layout_no_read_on_rw(struct pnfs_layout_segment *lseg)
  {
  	return FF_LAYOUT_LSEG(lseg)->flags & FF_FLAGS_NO_READ_IO;
  }
  
  static inline int
  nfs4_ff_layout_ds_version(const struct nfs4_ff_layout_mirror *mirror)
  {
  	return mirror->mirror_ds->ds_versions[0].version;
  }
  
  struct nfs4_ff_layout_ds *
  nfs4_ff_alloc_deviceid_node(struct nfs_server *server, struct pnfs_device *pdev,
  			    gfp_t gfp_flags);
  void nfs4_ff_layout_put_deviceid(struct nfs4_ff_layout_ds *mirror_ds);
  void nfs4_ff_layout_free_deviceid(struct nfs4_ff_layout_ds *mirror_ds);
  int ff_layout_track_ds_error(struct nfs4_flexfile_layout *flo,
  			     struct nfs4_ff_layout_mirror *mirror, u64 offset,
  			     u64 length, int status, enum nfs_opnum4 opnum,
  			     gfp_t gfp_flags);
  void ff_layout_send_layouterror(struct pnfs_layout_segment *lseg);
  int ff_layout_encode_ds_ioerr(struct xdr_stream *xdr, const struct list_head *head);
  void ff_layout_free_ds_ioerr(struct list_head *head);
  unsigned int ff_layout_fetch_ds_ioerr(struct pnfs_layout_hdr *lo,
  		const struct pnfs_layout_range *range,
  		struct list_head *head,
  		unsigned int maxnum);
  struct nfs_fh *
  nfs4_ff_layout_select_ds_fh(struct nfs4_ff_layout_mirror *mirror);
  void
  nfs4_ff_layout_select_ds_stateid(const struct nfs4_ff_layout_mirror *mirror,
  		nfs4_stateid *stateid);
  
  struct nfs4_pnfs_ds *
  nfs4_ff_layout_prepare_ds(struct pnfs_layout_segment *lseg,
  			  struct nfs4_ff_layout_mirror *mirror,
  			  bool fail_return);
  
  struct rpc_clnt *
  nfs4_ff_find_or_create_ds_client(struct nfs4_ff_layout_mirror *mirror,
  				 struct nfs_client *ds_clp,
  				 struct inode *inode);
  const struct cred *ff_layout_get_ds_cred(struct nfs4_ff_layout_mirror *mirror,
  					 const struct pnfs_layout_range *range,
  					 const struct cred *mdscred);
  bool ff_layout_avoid_mds_available_ds(struct pnfs_layout_segment *lseg);
  bool ff_layout_avoid_read_on_rw(struct pnfs_layout_segment *lseg);
  
  #endif /* FS_NFS_NFS4FLEXFILELAYOUT_H */
  