/*
 *  pNFS client data structures.
 *
 *  Copyright (c) 2002
 *  The Regents of the University of Michigan
 *  All Rights Reserved
 *
 *  Dean Hildebrand <dhildebz@umich.edu>
 *
 *  Permission is granted to use, copy, create derivative works, and
 *  redistribute this software and such derivative works for any purpose,
 *  so long as the name of the University of Michigan is not used in
 *  any advertising or publicity pertaining to the use or distribution
 *  of this software without specific, written prior authorization. If
 *  the above copyright notice or any other identification of the
 *  University of Michigan is included in any copy of any portion of
 *  this software, then the disclaimer below must also be included.
 *
 *  This software is provided as is, without representation or warranty
 *  of any kind either express or implied, including without limitation
 *  the implied warranties of merchantability, fitness for a particular
 *  purpose, or noninfringement.  The Regents of the University of
 *  Michigan shall not be liable for any damages, including special,
 *  indirect, incidental, or consequential damages, with respect to any
 *  claim arising out of or in connection with the use of the software,
 *  even if it has been or is hereafter advised of the possibility of
 *  such damages.
 */

#ifndef FS_NFS_PNFS_H
#define FS_NFS_PNFS_H

#include <linux/nfs_fs.h>
#include <linux/nfs_page.h>

enum {
        NFS_LSEG_VALID = 0,     /* cleared when lseg is recalled/returned */
        NFS_LSEG_ROC,           /* roc bit received from server */
        NFS_LSEG_LAYOUTCOMMIT,  /* layoutcommit bit set for layoutcommit */
};

struct pnfs_layout_segment {
        struct list_head pls_list;
        struct list_head pls_lc_list;
        struct pnfs_layout_range pls_range;
        atomic_t pls_refcount;
        unsigned long pls_flags;
        struct pnfs_layout_hdr *pls_layout;
};

enum pnfs_try_status {
        PNFS_ATTEMPTED     = 0,
        PNFS_NOT_ATTEMPTED = 1,
};

#ifdef CONFIG_NFS_V4_1

#define LAYOUT_NFSV4_1_MODULE_PREFIX "nfs-layouttype4"

enum {
        NFS_LAYOUT_RO_FAILED = 0,       /* get ro layout failed stop trying */
        NFS_LAYOUT_RW_FAILED,           /* get rw layout failed stop trying */
        NFS_LAYOUT_BULK_RECALL,         /* bulk recall affecting layout */
        NFS_LAYOUT_ROC,                 /* some lseg had roc bit set */
        NFS_LAYOUT_DESTROYED,           /* no new use of layout allowed */
        NFS_LAYOUT_INVALID,             /* layout is being destroyed */
        NFS_LAYOUT_RETURNED,            /* layout has already been returned */
};

enum layoutdriver_policy_flags {
        /* Should the pNFS client commit and return the layout upon a setattr */
        PNFS_LAYOUTRET_ON_SETATTR       = 1 << 0,
        PNFS_LAYOUTRET_ON_ERROR         = 1 << 1,
};

struct nfs4_deviceid_node;

/* Per-layout driver specific registration structure */
struct pnfs_layoutdriver_type {
        struct list_head pnfs_tblid;
        const u32 id;
        const char *name;
        struct module *owner;
        unsigned flags;

        int (*set_layoutdriver) (struct nfs_server *, const struct nfs_fh *);
        int (*clear_layoutdriver) (struct nfs_server *);

        struct pnfs_layout_hdr * (*alloc_layout_hdr) (struct inode *inode, gfp_t gfp_flags);
        void (*free_layout_hdr) (struct pnfs_layout_hdr *);

        struct pnfs_layout_segment * (*alloc_lseg) (struct pnfs_layout_hdr *layoutid, struct nfs4_layoutget_res *lgr, gfp_t gfp_flags);
        void (*free_lseg) (struct pnfs_layout_segment *lseg);

        /* test for nfs page cache coalescing */
        const struct nfs_pageio_ops *pg_read_ops;
        const struct nfs_pageio_ops *pg_write_ops;

        struct pnfs_ds_commit_info *(*get_ds_info) (struct inode *inode);
        void (*mark_request_commit) (struct nfs_page *req,
                                     struct pnfs_layout_segment *lseg,
                                     struct nfs_commit_info *cinfo);
        void (*clear_request_commit) (struct nfs_page *req,
                                      struct nfs_commit_info *cinfo);
        int (*scan_commit_lists) (struct nfs_commit_info *cinfo,
                                  int max);
        void (*recover_commit_reqs) (struct list_head *list,
                                     struct nfs_commit_info *cinfo);
        int (*commit_pagelist)(struct inode *inode,
                               struct list_head *mds_pages,
                               int how,
                               struct nfs_commit_info *cinfo);

        /*
         * Return PNFS_ATTEMPTED to indicate the layout code has attempted
         * I/O, else return PNFS_NOT_ATTEMPTED to fall back to normal NFS
         */
        enum pnfs_try_status (*read_pagelist) (struct nfs_read_data *nfs_data);
        enum pnfs_try_status (*write_pagelist) (struct nfs_write_data *nfs_data, int how);

        void (*free_deviceid_node) (struct nfs4_deviceid_node *);

        void (*encode_layoutreturn) (struct pnfs_layout_hdr *layoutid,
                                     struct xdr_stream *xdr,
                                     const struct nfs4_layoutreturn_args *args);

        void (*cleanup_layoutcommit) (struct nfs4_layoutcommit_data *data);

        void (*encode_layoutcommit) (struct pnfs_layout_hdr *layoutid,
                                     struct xdr_stream *xdr,
                                     const struct nfs4_layoutcommit_args *args);
};

struct pnfs_layout_hdr {
        atomic_t                plh_refcount;
        struct list_head        plh_layouts;   /* other client layouts */
        struct list_head        plh_bulk_recall; /* clnt list of bulk recalls */
        struct list_head        plh_segs;      /* layout segments list */
        nfs4_stateid            plh_stateid;
        atomic_t                plh_outstanding; /* number of RPCs out */
        unsigned long           plh_block_lgets; /* block LAYOUTGET if >0 */
        u32                     plh_barrier; /* ignore lower seqids */
        unsigned long           plh_flags;
        loff_t                  plh_lwb; /* last write byte for layoutcommit */
        struct rpc_cred         *plh_lc_cred; /* layoutcommit cred */
        struct inode            *plh_inode;
};

struct pnfs_device {
        struct nfs4_deviceid dev_id;
        unsigned int  layout_type;
        unsigned int  mincount;
        struct page **pages;
        unsigned int  pgbase;
        unsigned int  pglen;
};

#define NFS4_PNFS_GETDEVLIST_MAXNUM 16

struct pnfs_devicelist {
        unsigned int            eof;
        unsigned int            num_devs;
        struct nfs4_deviceid    dev_id[NFS4_PNFS_GETDEVLIST_MAXNUM];
};

extern int pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *);
extern void pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *);

/* nfs4proc.c */
extern int nfs4_proc_getdevicelist(struct nfs_server *server,
                                   const struct nfs_fh *fh,
                                   struct pnfs_devicelist *devlist);
extern int nfs4_proc_getdeviceinfo(struct nfs_server *server,
                                   struct pnfs_device *dev);
extern void nfs4_proc_layoutget(struct nfs4_layoutget *lgp, gfp_t gfp_flags);
extern int nfs4_proc_layoutreturn(struct nfs4_layoutreturn *lrp);

/* pnfs.c */
void get_layout_hdr(struct pnfs_layout_hdr *lo);
void put_lseg(struct pnfs_layout_segment *lseg);

void pnfs_pageio_init_read(struct nfs_pageio_descriptor *, struct inode *,
                           const struct nfs_pgio_completion_ops *);
void pnfs_pageio_init_write(struct nfs_pageio_descriptor *, struct inode *,
                            int, const struct nfs_pgio_completion_ops *);

void set_pnfs_layoutdriver(struct nfs_server *, const struct nfs_fh *, u32);
void unset_pnfs_layoutdriver(struct nfs_server *);
void pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *, struct nfs_page *);
int pnfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc);
void pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *, struct nfs_page *);
int pnfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc);
bool pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev, struct nfs_page *req);
void pnfs_set_lo_fail(struct pnfs_layout_segment *lseg);
int pnfs_layout_process(struct nfs4_layoutget *lgp);
void pnfs_free_lseg_list(struct list_head *tmp_list);
void pnfs_destroy_layout(struct nfs_inode *);
void pnfs_destroy_all_layouts(struct nfs_client *);
void put_layout_hdr(struct pnfs_layout_hdr *lo);
void pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo,
                             const nfs4_stateid *new,
                             bool update_barrier);
int pnfs_choose_layoutget_stateid(nfs4_stateid *dst,
                                  struct pnfs_layout_hdr *lo,
                                  struct nfs4_state *open_state);
int mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
                                struct list_head *tmp_list,
                                struct pnfs_layout_range *recall_range);
bool pnfs_roc(struct inode *ino);
void pnfs_roc_release(struct inode *ino);
void pnfs_roc_set_barrier(struct inode *ino, u32 barrier);
bool pnfs_roc_drain(struct inode *ino, u32 *barrier);
void pnfs_set_layoutcommit(struct nfs_write_data *wdata);
void pnfs_cleanup_layoutcommit(struct nfs4_layoutcommit_data *data);
int pnfs_layoutcommit_inode(struct inode *inode, bool sync);
int _pnfs_return_layout(struct inode *);
void pnfs_ld_write_done(struct nfs_write_data *);
void pnfs_ld_read_done(struct nfs_read_data *);
struct pnfs_layout_segment *pnfs_update_layout(struct inode *ino,
                                               struct nfs_open_context *ctx,
                                               loff_t pos,
                                               u64 count,
                                               enum pnfs_iomode iomode,
                                               gfp_t gfp_flags);

void nfs4_deviceid_mark_client_invalid(struct nfs_client *clp);
int pnfs_read_done_resend_to_mds(struct inode *inode, struct list_head *head,
                        const struct nfs_pgio_completion_ops *compl_ops);
int pnfs_write_done_resend_to_mds(struct inode *inode, struct list_head *head,
                        const struct nfs_pgio_completion_ops *compl_ops);
struct nfs4_threshold *pnfs_mdsthreshold_alloc(void);

/* nfs4_deviceid_flags */
enum {
        NFS_DEVICEID_INVALID = 0,       /* set when MDS clientid recalled */
};

/* pnfs_dev.c */
struct nfs4_deviceid_node {
        struct hlist_node               node;
        struct hlist_node               tmpnode;
        const struct pnfs_layoutdriver_type *ld;
        const struct nfs_client         *nfs_client;
        unsigned long                   flags;
        struct nfs4_deviceid            deviceid;
        atomic_t                        ref;
};

struct nfs4_deviceid_node *nfs4_find_get_deviceid(const struct pnfs_layoutdriver_type *, const struct nfs_client *, const struct nfs4_deviceid *);
void nfs4_delete_deviceid(const struct pnfs_layoutdriver_type *, const struct nfs_client *, const struct nfs4_deviceid *);
void nfs4_init_deviceid_node(struct nfs4_deviceid_node *,
                             const struct pnfs_layoutdriver_type *,
                             const struct nfs_client *,
                             const struct nfs4_deviceid *);
struct nfs4_deviceid_node *nfs4_insert_deviceid_node(struct nfs4_deviceid_node *);
bool nfs4_put_deviceid_node(struct nfs4_deviceid_node *);
void nfs4_deviceid_purge_client(const struct nfs_client *);

static inline void
pnfs_mark_layout_returned(struct pnfs_layout_hdr *lo)
{
        set_bit(NFS_LAYOUT_RETURNED, &lo->plh_flags);
}

static inline void
pnfs_clear_layout_returned(struct pnfs_layout_hdr *lo)
{
        clear_bit(NFS_LAYOUT_RETURNED, &lo->plh_flags);
}

static inline bool
pnfs_test_layout_returned(struct pnfs_layout_hdr *lo)
{
        return test_bit(NFS_LAYOUT_RETURNED, &lo->plh_flags);
}

static inline int lo_fail_bit(u32 iomode)
{
        return iomode == IOMODE_RW ?
                         NFS_LAYOUT_RW_FAILED : NFS_LAYOUT_RO_FAILED;
}

static inline struct pnfs_layout_segment *
get_lseg(struct pnfs_layout_segment *lseg)
{
        if (lseg) {
                atomic_inc(&lseg->pls_refcount);
                smp_mb__after_atomic_inc();
        }
        return lseg;
}

/* Return true if a layout driver is being used for this mountpoint */
static inline int pnfs_enabled_sb(struct nfs_server *nfss)
{
        return nfss->pnfs_curr_ld != NULL;
}

static inline int
pnfs_commit_list(struct inode *inode, struct list_head *mds_pages, int how,
                 struct nfs_commit_info *cinfo)
{
        if (cinfo->ds == NULL || cinfo->ds->ncommitting == 0)
                return PNFS_NOT_ATTEMPTED;
        return NFS_SERVER(inode)->pnfs_curr_ld->commit_pagelist(inode, mds_pages, how, cinfo);
}

static inline struct pnfs_ds_commit_info *
pnfs_get_ds_info(struct inode *inode)
{
        struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;

        if (ld == NULL || ld->get_ds_info == NULL)
                return NULL;
        return ld->get_ds_info(inode);
}

static inline bool
pnfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg,
                         struct nfs_commit_info *cinfo)
{
        struct inode *inode = req->wb_context->dentry->d_inode;
        struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;

        if (lseg == NULL || ld->mark_request_commit == NULL)
                return false;
        ld->mark_request_commit(req, lseg, cinfo);
        return true;
}

static inline bool
pnfs_clear_request_commit(struct nfs_page *req, struct nfs_commit_info *cinfo)
{
        struct inode *inode = req->wb_context->dentry->d_inode;
        struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;

        if (ld == NULL || ld->clear_request_commit == NULL)
                return false;
        ld->clear_request_commit(req, cinfo);
        return true;
}

static inline int
pnfs_scan_commit_lists(struct inode *inode, struct nfs_commit_info *cinfo,
                       int max)
{
        if (cinfo->ds == NULL || cinfo->ds->nwritten == 0)
                return 0;
        else
                return NFS_SERVER(inode)->pnfs_curr_ld->scan_commit_lists(cinfo, max);
}

static inline void
pnfs_recover_commit_reqs(struct inode *inode, struct list_head *list,
                         struct nfs_commit_info *cinfo)
{
        if (cinfo->ds == NULL || cinfo->ds->nwritten == 0)
                return;
        NFS_SERVER(inode)->pnfs_curr_ld->recover_commit_reqs(list, cinfo);
}

/* Should the pNFS client commit and return the layout upon a setattr */
static inline bool
pnfs_ld_layoutret_on_setattr(struct inode *inode)
{
        if (!pnfs_enabled_sb(NFS_SERVER(inode)))
                return false;
        return NFS_SERVER(inode)->pnfs_curr_ld->flags &
                PNFS_LAYOUTRET_ON_SETATTR;
}

static inline int pnfs_return_layout(struct inode *ino)
{
        struct nfs_inode *nfsi = NFS_I(ino);
        struct nfs_server *nfss = NFS_SERVER(ino);

        if (pnfs_enabled_sb(nfss) && nfsi->layout)
                return _pnfs_return_layout(ino);

        return 0;
}

static inline bool
pnfs_use_threshold(struct nfs4_threshold **dst, struct nfs4_threshold *src,
                   struct nfs_server *nfss)
{
        return (dst && src && src->bm != 0 && nfss->pnfs_curr_ld &&
                                        nfss->pnfs_curr_ld->id == src->l_type);
}

#ifdef NFS_DEBUG
void nfs4_print_deviceid(const struct nfs4_deviceid *dev_id);
#else
static inline void nfs4_print_deviceid(const struct nfs4_deviceid *dev_id)
{
}
#endif /* NFS_DEBUG */
#else  /* CONFIG_NFS_V4_1 */

static inline void pnfs_destroy_all_layouts(struct nfs_client *clp)
{
}

static inline void pnfs_destroy_layout(struct nfs_inode *nfsi)
{
}

static inline struct pnfs_layout_segment *
get_lseg(struct pnfs_layout_segment *lseg)
{
        return NULL;
}

static inline void put_lseg(struct pnfs_layout_segment *lseg)
{
}

static inline int pnfs_return_layout(struct inode *ino)
{
        return 0;
}

static inline bool
pnfs_ld_layoutret_on_setattr(struct inode *inode)
{
        return false;
}

static inline bool
pnfs_roc(struct inode *ino)
{
        return false;
}

static inline void
pnfs_roc_release(struct inode *ino)
{
}

static inline void
pnfs_roc_set_barrier(struct inode *ino, u32 barrier)
{
}

static inline bool
pnfs_roc_drain(struct inode *ino, u32 *barrier)
{
        return false;
}

static inline void set_pnfs_layoutdriver(struct nfs_server *s,
                                         const struct nfs_fh *mntfh, u32 id)
{
}

static inline void unset_pnfs_layoutdriver(struct nfs_server *s)
{
}

static inline void pnfs_pageio_init_read(struct nfs_pageio_descriptor *pgio, struct inode *inode,
                                         const struct nfs_pgio_completion_ops *compl_ops)
{
        nfs_pageio_init_read(pgio, inode, compl_ops);
}

static inline void pnfs_pageio_init_write(struct nfs_pageio_descriptor *pgio, struct inode *inode, int ioflags,
                                          const struct nfs_pgio_completion_ops *compl_ops)
{
        nfs_pageio_init_write(pgio, inode, ioflags, compl_ops);
}

static inline int
pnfs_commit_list(struct inode *inode, struct list_head *mds_pages, int how,
                 struct nfs_commit_info *cinfo)
{
        return PNFS_NOT_ATTEMPTED;
}

static inline struct pnfs_ds_commit_info *
pnfs_get_ds_info(struct inode *inode)
{
        return NULL;
}

static inline bool
pnfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg,
                         struct nfs_commit_info *cinfo)
{
        return false;
}

static inline bool
pnfs_clear_request_commit(struct nfs_page *req, struct nfs_commit_info *cinfo)
{
        return false;
}

static inline int
pnfs_scan_commit_lists(struct inode *inode, struct nfs_commit_info *cinfo,
                       int max)
{
        return 0;
}

static inline void
pnfs_recover_commit_reqs(struct inode *inode, struct list_head *list,
                         struct nfs_commit_info *cinfo)
{
}

static inline int pnfs_layoutcommit_inode(struct inode *inode, bool sync)
{
        return 0;
}

static inline bool
pnfs_use_threshold(struct nfs4_threshold **dst, struct nfs4_threshold *src,
                   struct nfs_server *nfss)
{
        return false;
}

static inline struct nfs4_threshold *pnfs_mdsthreshold_alloc(void)
{
        return NULL;
}

#endif /* CONFIG_NFS_V4_1 */

#endif /* FS_NFS_PNFS_H */