/*
 *  linux/fs/nfs/proc.c
 *
 *  Copyright (C) 1992, 1993, 1994  Rick Sladkey
 *
 *  OS-independent nfs remote procedure call functions
 *
 *  Tuned by Alan Cox <A.Cox@swansea.ac.uk> for >3K buffers
 *  so at last we can have decent(ish) throughput off a 
 *  Sun server.
 *
 *  Coding optimized and cleaned up by Florian La Roche.
 *  Note: Error returns are optimized for NFS_OK, which isn't translated via
 *  nfs_stat_to_errno(), but happens to be already the right return code.
 *
 *  Also, the code currently doesn't check the size of the packet, when
 *  it decodes the packet.
 *
 *  Feel free to fix it and mail me the diffs if it worries you.
 *
 *  Completely rewritten to support the new RPC call interface;
 *  rewrote and moved the entire XDR stuff to xdr.c
 *  --Olaf Kirch June 1996
 *
 *  The code below initializes all auto variables explicitly, otherwise
 *  it will fail to work as a module (gcc generates a memset call for an
 *  incomplete struct).
 */

#include <linux/types.h>
#include <linux/param.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/in.h>
#include <linux/pagemap.h>
#include <linux/sunrpc/clnt.h>
#include <linux/nfs.h>
#include <linux/nfs2.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_page.h>
#include <linux/lockd/bind.h>
#include "internal.h"

#define NFSDBG_FACILITY         NFSDBG_PROC

/*
 * Bare-bones access to getattr: this is for nfs_read_super.
 */
static int
nfs_proc_get_root(struct nfs_server *server, struct nfs_fh *fhandle,
                  struct nfs_fsinfo *info)
{
        struct nfs_fattr *fattr = info->fattr;
        struct nfs2_fsstat fsinfo;
        struct rpc_message msg = {
                .rpc_proc       = &nfs_procedures[NFSPROC_GETATTR],
                .rpc_argp       = fhandle,
                .rpc_resp       = fattr,
        };
        int status;

        dprintk("%s: call getattr\n", __func__);
        nfs_fattr_init(fattr);
        status = rpc_call_sync(server->client, &msg, 0);
        /* Retry with default authentication if different */
        if (status && server->nfs_client->cl_rpcclient != server->client)
                status = rpc_call_sync(server->nfs_client->cl_rpcclient, &msg, 0);
        dprintk("%s: reply getattr: %d\n", __func__, status);
        if (status)
                return status;
        dprintk("%s: call statfs\n", __func__);
        msg.rpc_proc = &nfs_procedures[NFSPROC_STATFS];
        msg.rpc_resp = &fsinfo;
        status = rpc_call_sync(server->client, &msg, 0);
        /* Retry with default authentication if different */
        if (status && server->nfs_client->cl_rpcclient != server->client)
                status = rpc_call_sync(server->nfs_client->cl_rpcclient, &msg, 0);
        dprintk("%s: reply statfs: %d\n", __func__, status);
        if (status)
                return status;
        info->rtmax  = NFS_MAXDATA;
        info->rtpref = fsinfo.tsize;
        info->rtmult = fsinfo.bsize;
        info->wtmax  = NFS_MAXDATA;
        info->wtpref = fsinfo.tsize;
        info->wtmult = fsinfo.bsize;
        info->dtpref = fsinfo.tsize;
        info->maxfilesize = 0x7FFFFFFF;
        info->lease_time = 0;
        return 0;
}

/*
 * One function for each procedure in the NFS protocol.
 */
static int
nfs_proc_getattr(struct nfs_server *server, struct nfs_fh *fhandle,
                struct nfs_fattr *fattr)
{
        struct rpc_message msg = {
                .rpc_proc       = &nfs_procedures[NFSPROC_GETATTR],
                .rpc_argp       = fhandle,
                .rpc_resp       = fattr,
        };
        int     status;

        dprintk("NFS call  getattr\n");
        nfs_fattr_init(fattr);
        status = rpc_call_sync(server->client, &msg, 0);
        dprintk("NFS reply getattr: %d\n", status);
        return status;
}

static int
nfs_proc_setattr(struct dentry *dentry, struct nfs_fattr *fattr,
                 struct iattr *sattr)
{
        struct inode *inode = dentry->d_inode;
        struct nfs_sattrargs    arg = { 
                .fh     = NFS_FH(inode),
                .sattr  = sattr
        };
        struct rpc_message msg = {
                .rpc_proc       = &nfs_procedures[NFSPROC_SETATTR],
                .rpc_argp       = &arg,
                .rpc_resp       = fattr,
        };
        int     status;

        /* Mask out the non-modebit related stuff from attr->ia_mode */
        sattr->ia_mode &= S_IALLUGO;

        dprintk("NFS call  setattr\n");
        if (sattr->ia_valid & ATTR_FILE)
                msg.rpc_cred = nfs_file_cred(sattr->ia_file);
        nfs_fattr_init(fattr);
        status = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
        if (status == 0)
                nfs_setattr_update_inode(inode, sattr);
        dprintk("NFS reply setattr: %d\n", status);
        return status;
}

static int
nfs_proc_lookup(struct inode *dir, struct qstr *name,
                struct nfs_fh *fhandle, struct nfs_fattr *fattr)
{
        struct nfs_diropargs    arg = {
                .fh             = NFS_FH(dir),
                .name           = name->name,
                .len            = name->len
        };
        struct nfs_diropok      res = {
                .fh             = fhandle,
                .fattr          = fattr
        };
        struct rpc_message msg = {
                .rpc_proc       = &nfs_procedures[NFSPROC_LOOKUP],
                .rpc_argp       = &arg,
                .rpc_resp       = &res,
        };
        int                     status;

        dprintk("NFS call  lookup %s\n", name->name);
        nfs_fattr_init(fattr);
        status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
        dprintk("NFS reply lookup: %d\n", status);
        return status;
}

static int nfs_proc_readlink(struct inode *inode, struct page *page,
                unsigned int pgbase, unsigned int pglen)
{
        struct nfs_readlinkargs args = {
                .fh             = NFS_FH(inode),
                .pgbase         = pgbase,
                .pglen          = pglen,
                .pages          = &page
        };
        struct rpc_message msg = {
                .rpc_proc       = &nfs_procedures[NFSPROC_READLINK],
                .rpc_argp       = &args,
        };
        int                     status;

        dprintk("NFS call  readlink\n");
        status = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
        dprintk("NFS reply readlink: %d\n", status);
        return status;
}

static int
nfs_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
                int flags, struct nameidata *nd)
{
        struct nfs_fh           fhandle;
        struct nfs_fattr        fattr;
        struct nfs_createargs   arg = {
                .fh             = NFS_FH(dir),
                .name           = dentry->d_name.name,
                .len            = dentry->d_name.len,
                .sattr          = sattr
        };
        struct nfs_diropok      res = {
                .fh             = &fhandle,
                .fattr          = &fattr
        };
        struct rpc_message msg = {
                .rpc_proc       = &nfs_procedures[NFSPROC_CREATE],
                .rpc_argp       = &arg,
                .rpc_resp       = &res,
        };
        int                     status;

        nfs_fattr_init(&fattr);
        dprintk("NFS call  create %s\n", dentry->d_name.name);
        status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
        nfs_mark_for_revalidate(dir);
        if (status == 0)
                status = nfs_instantiate(dentry, &fhandle, &fattr);
        dprintk("NFS reply create: %d\n", status);
        return status;
}

/*
 * In NFSv2, mknod is grafted onto the create call.
 */
static int
nfs_proc_mknod(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
               dev_t rdev)
{
        struct nfs_fh fhandle;
        struct nfs_fattr fattr;
        struct nfs_createargs   arg = {
                .fh             = NFS_FH(dir),
                .name           = dentry->d_name.name,
                .len            = dentry->d_name.len,
                .sattr          = sattr
        };
        struct nfs_diropok      res = {
                .fh             = &fhandle,
                .fattr          = &fattr
        };
        struct rpc_message msg = {
                .rpc_proc       = &nfs_procedures[NFSPROC_CREATE],
                .rpc_argp       = &arg,
                .rpc_resp       = &res,
        };
        int status, mode;

        dprintk("NFS call  mknod %s\n", dentry->d_name.name);

        mode = sattr->ia_mode;
        if (S_ISFIFO(mode)) {
                sattr->ia_mode = (mode & ~S_IFMT) | S_IFCHR;
                sattr->ia_valid &= ~ATTR_SIZE;
        } else if (S_ISCHR(mode) || S_ISBLK(mode)) {
                sattr->ia_valid |= ATTR_SIZE;
                sattr->ia_size = new_encode_dev(rdev);/* get out your barf bag */
        }

        nfs_fattr_init(&fattr);
        status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
        nfs_mark_for_revalidate(dir);

        if (status == -EINVAL && S_ISFIFO(mode)) {
                sattr->ia_mode = mode;
                nfs_fattr_init(&fattr);
                status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
        }
        if (status == 0)
                status = nfs_instantiate(dentry, &fhandle, &fattr);
        dprintk("NFS reply mknod: %d\n", status);
        return status;
}
  
static int
nfs_proc_remove(struct inode *dir, struct qstr *name)
{
        struct nfs_removeargs arg = {
                .fh = NFS_FH(dir),
                .name.len = name->len,
                .name.name = name->name,
        };
        struct rpc_message msg = { 
                .rpc_proc = &nfs_procedures[NFSPROC_REMOVE],
                .rpc_argp = &arg,
        };
        int                     status;

        dprintk("NFS call  remove %s\n", name->name);
        status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
        nfs_mark_for_revalidate(dir);

        dprintk("NFS reply remove: %d\n", status);
        return status;
}

static void
nfs_proc_unlink_setup(struct rpc_message *msg, struct inode *dir)
{
        msg->rpc_proc = &nfs_procedures[NFSPROC_REMOVE];
}

static int nfs_proc_unlink_done(struct rpc_task *task, struct inode *dir)
{
        nfs_mark_for_revalidate(dir);
        return 1;
}

static int
nfs_proc_rename(struct inode *old_dir, struct qstr *old_name,
                struct inode *new_dir, struct qstr *new_name)
{
        struct nfs_renameargs   arg = {
                .fromfh         = NFS_FH(old_dir),
                .fromname       = old_name->name,
                .fromlen        = old_name->len,
                .tofh           = NFS_FH(new_dir),
                .toname         = new_name->name,
                .tolen          = new_name->len
        };
        struct rpc_message msg = {
                .rpc_proc       = &nfs_procedures[NFSPROC_RENAME],
                .rpc_argp       = &arg,
        };
        int                     status;

        dprintk("NFS call  rename %s -> %s\n", old_name->name, new_name->name);
        status = rpc_call_sync(NFS_CLIENT(old_dir), &msg, 0);
        nfs_mark_for_revalidate(old_dir);
        nfs_mark_for_revalidate(new_dir);
        dprintk("NFS reply rename: %d\n", status);
        return status;
}

static int
nfs_proc_link(struct inode *inode, struct inode *dir, struct qstr *name)
{
        struct nfs_linkargs     arg = {
                .fromfh         = NFS_FH(inode),
                .tofh           = NFS_FH(dir),
                .toname         = name->name,
                .tolen          = name->len
        };
        struct rpc_message msg = {
                .rpc_proc       = &nfs_procedures[NFSPROC_LINK],
                .rpc_argp       = &arg,
        };
        int                     status;

        dprintk("NFS call  link %s\n", name->name);
        status = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
        nfs_mark_for_revalidate(inode);
        nfs_mark_for_revalidate(dir);
        dprintk("NFS reply link: %d\n", status);
        return status;
}

static int
nfs_proc_symlink(struct inode *dir, struct dentry *dentry, struct page *page,
                 unsigned int len, struct iattr *sattr)
{
        struct nfs_fh fhandle;
        struct nfs_fattr fattr;
        struct nfs_symlinkargs  arg = {
                .fromfh         = NFS_FH(dir),
                .fromname       = dentry->d_name.name,
                .fromlen        = dentry->d_name.len,
                .pages          = &page,
                .pathlen        = len,
                .sattr          = sattr
        };
        struct rpc_message msg = {
                .rpc_proc       = &nfs_procedures[NFSPROC_SYMLINK],
                .rpc_argp       = &arg,
        };
        int                     status;

        if (len > NFS2_MAXPATHLEN)
                return -ENAMETOOLONG;

        dprintk("NFS call  symlink %s\n", dentry->d_name.name);

        status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
        nfs_mark_for_revalidate(dir);

        /*
         * V2 SYMLINK requests don't return any attributes.  Setting the
         * filehandle size to zero indicates to nfs_instantiate that it
         * should fill in the data with a LOOKUP call on the wire.
         */
        if (status == 0) {
                nfs_fattr_init(&fattr);
                fhandle.size = 0;
                status = nfs_instantiate(dentry, &fhandle, &fattr);
        }

        dprintk("NFS reply symlink: %d\n", status);
        return status;
}

static int
nfs_proc_mkdir(struct inode *dir, struct dentry *dentry, struct iattr *sattr)
{
        struct nfs_fh fhandle;
        struct nfs_fattr fattr;
        struct nfs_createargs   arg = {
                .fh             = NFS_FH(dir),
                .name           = dentry->d_name.name,
                .len            = dentry->d_name.len,
                .sattr          = sattr
        };
        struct nfs_diropok      res = {
                .fh             = &fhandle,
                .fattr          = &fattr
        };
        struct rpc_message msg = {
                .rpc_proc       = &nfs_procedures[NFSPROC_MKDIR],
                .rpc_argp       = &arg,
                .rpc_resp       = &res,
        };
        int                     status;

        dprintk("NFS call  mkdir %s\n", dentry->d_name.name);
        nfs_fattr_init(&fattr);
        status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
        nfs_mark_for_revalidate(dir);
        if (status == 0)
                status = nfs_instantiate(dentry, &fhandle, &fattr);
        dprintk("NFS reply mkdir: %d\n", status);
        return status;
}

static int
nfs_proc_rmdir(struct inode *dir, struct qstr *name)
{
        struct nfs_diropargs    arg = {
                .fh             = NFS_FH(dir),
                .name           = name->name,
                .len            = name->len
        };
        struct rpc_message msg = {
                .rpc_proc       = &nfs_procedures[NFSPROC_RMDIR],
                .rpc_argp       = &arg,
        };
        int                     status;

        dprintk("NFS call  rmdir %s\n", name->name);
        status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
        nfs_mark_for_revalidate(dir);
        dprintk("NFS reply rmdir: %d\n", status);
        return status;
}

/*
 * The READDIR implementation is somewhat hackish - we pass a temporary
 * buffer to the encode function, which installs it in the receive
 * the receive iovec. The decode function just parses the reply to make
 * sure it is syntactically correct; the entries itself are decoded
 * from nfs_readdir by calling the decode_entry function directly.
 */
static int
nfs_proc_readdir(struct dentry *dentry, struct rpc_cred *cred,
                 u64 cookie, struct page *page, unsigned int count, int plus)
{
        struct inode            *dir = dentry->d_inode;
        struct nfs_readdirargs  arg = {
                .fh             = NFS_FH(dir),
                .cookie         = cookie,
                .count          = count,
                .pages          = &page,
        };
        struct rpc_message      msg = {
                .rpc_proc       = &nfs_procedures[NFSPROC_READDIR],
                .rpc_argp       = &arg,
                .rpc_cred       = cred,
        };
        int                     status;

        dprintk("NFS call  readdir %d\n", (unsigned int)cookie);
        status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);

        nfs_invalidate_atime(dir);

        dprintk("NFS reply readdir: %d\n", status);
        return status;
}

static int
nfs_proc_statfs(struct nfs_server *server, struct nfs_fh *fhandle,
                        struct nfs_fsstat *stat)
{
        struct nfs2_fsstat fsinfo;
        struct rpc_message msg = {
                .rpc_proc       = &nfs_procedures[NFSPROC_STATFS],
                .rpc_argp       = fhandle,
                .rpc_resp       = &fsinfo,
        };
        int     status;

        dprintk("NFS call  statfs\n");
        nfs_fattr_init(stat->fattr);
        status = rpc_call_sync(server->client, &msg, 0);
        dprintk("NFS reply statfs: %d\n", status);
        if (status)
                goto out;
        stat->tbytes = (u64)fsinfo.blocks * fsinfo.bsize;
        stat->fbytes = (u64)fsinfo.bfree  * fsinfo.bsize;
        stat->abytes = (u64)fsinfo.bavail * fsinfo.bsize;
        stat->tfiles = 0;
        stat->ffiles = 0;
        stat->afiles = 0;
out:
        return status;
}

static int
nfs_proc_fsinfo(struct nfs_server *server, struct nfs_fh *fhandle,
                        struct nfs_fsinfo *info)
{
        struct nfs2_fsstat fsinfo;
        struct rpc_message msg = {
                .rpc_proc       = &nfs_procedures[NFSPROC_STATFS],
                .rpc_argp       = fhandle,
                .rpc_resp       = &fsinfo,
        };
        int     status;

        dprintk("NFS call  fsinfo\n");
        nfs_fattr_init(info->fattr);
        status = rpc_call_sync(server->client, &msg, 0);
        dprintk("NFS reply fsinfo: %d\n", status);
        if (status)
                goto out;
        info->rtmax  = NFS_MAXDATA;
        info->rtpref = fsinfo.tsize;
        info->rtmult = fsinfo.bsize;
        info->wtmax  = NFS_MAXDATA;
        info->wtpref = fsinfo.tsize;
        info->wtmult = fsinfo.bsize;
        info->dtpref = fsinfo.tsize;
        info->maxfilesize = 0x7FFFFFFF;
        info->lease_time = 0;
out:
        return status;
}

static int
nfs_proc_pathconf(struct nfs_server *server, struct nfs_fh *fhandle,
                  struct nfs_pathconf *info)
{
        info->max_link = 0;
        info->max_namelen = NFS2_MAXNAMLEN;
        return 0;
}

static int nfs_read_done(struct rpc_task *task, struct nfs_read_data *data)
{
        nfs_invalidate_atime(data->inode);
        if (task->tk_status >= 0) {
                nfs_refresh_inode(data->inode, data->res.fattr);
                /* Emulate the eof flag, which isn't normally needed in NFSv2
                 * as it is guaranteed to always return the file attributes
                 */
                if (data->args.offset + data->args.count >= data->res.fattr->size)
                        data->res.eof = 1;
        }
        return 0;
}

static void nfs_proc_read_setup(struct nfs_read_data *data, struct rpc_message *msg)
{
        msg->rpc_proc = &nfs_procedures[NFSPROC_READ];
}

static int nfs_write_done(struct rpc_task *task, struct nfs_write_data *data)
{
        if (task->tk_status >= 0)
                nfs_post_op_update_inode_force_wcc(data->inode, data->res.fattr);
        return 0;
}

static void nfs_proc_write_setup(struct nfs_write_data *data, struct rpc_message *msg)
{
        /* Note: NFSv2 ignores @stable and always uses NFS_FILE_SYNC */
        data->args.stable = NFS_FILE_SYNC;
        msg->rpc_proc = &nfs_procedures[NFSPROC_WRITE];
}

static void
nfs_proc_commit_setup(struct nfs_write_data *data, struct rpc_message *msg)
{
        BUG();
}

static int
nfs_proc_lock(struct file *filp, int cmd, struct file_lock *fl)
{
        struct inode *inode = filp->f_path.dentry->d_inode;

        return nlmclnt_proc(NFS_SERVER(inode)->nlm_host, cmd, fl);
}

/* Helper functions for NFS lock bounds checking */
#define NFS_LOCK32_OFFSET_MAX ((__s32)0x7fffffffUL)
static int nfs_lock_check_bounds(const struct file_lock *fl)
{
        __s32 start, end;

        start = (__s32)fl->fl_start;
        if ((loff_t)start != fl->fl_start)
                goto out_einval;

        if (fl->fl_end != OFFSET_MAX) {
                end = (__s32)fl->fl_end;
                if ((loff_t)end != fl->fl_end)
                        goto out_einval;
        } else
                end = NFS_LOCK32_OFFSET_MAX;

        if (start < 0 || start > end)
                goto out_einval;
        return 0;
out_einval:
        return -EINVAL;
}

const struct nfs_rpc_ops nfs_v2_clientops = {
        .version        = 2,                   /* protocol version */
        .dentry_ops     = &nfs_dentry_operations,
        .dir_inode_ops  = &nfs_dir_inode_operations,
        .file_inode_ops = &nfs_file_inode_operations,
        .getroot        = nfs_proc_get_root,
        .getattr        = nfs_proc_getattr,
        .setattr        = nfs_proc_setattr,
        .lookup         = nfs_proc_lookup,
        .access         = NULL,                /* access */
        .readlink       = nfs_proc_readlink,
        .create         = nfs_proc_create,
        .remove         = nfs_proc_remove,
        .unlink_setup   = nfs_proc_unlink_setup,
        .unlink_done    = nfs_proc_unlink_done,
        .rename         = nfs_proc_rename,
        .link           = nfs_proc_link,
        .symlink        = nfs_proc_symlink,
        .mkdir          = nfs_proc_mkdir,
        .rmdir          = nfs_proc_rmdir,
        .readdir        = nfs_proc_readdir,
        .mknod          = nfs_proc_mknod,
        .statfs         = nfs_proc_statfs,
        .fsinfo         = nfs_proc_fsinfo,
        .pathconf       = nfs_proc_pathconf,
        .decode_dirent  = nfs_decode_dirent,
        .read_setup     = nfs_proc_read_setup,
        .read_done      = nfs_read_done,
        .write_setup    = nfs_proc_write_setup,
        .write_done     = nfs_write_done,
        .commit_setup   = nfs_proc_commit_setup,
        .lock           = nfs_proc_lock,
        .lock_check_bounds = nfs_lock_check_bounds,
        .close_context  = nfs_close_context,
};