proc.c

《嵌入式系统设计与实例开发实验教材二源码》Linux内核移植与编译实验

/*
 *  linux/fs/nfs/proc.c
 *
 *  Copyright (C) 1992, 1993, 1994  Rick Sladkey
 *
 *  OS-independent nfs remote procedure call functions
 *
 *  Tuned by Alan Cox <[e-mail]> 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/sched.h>
#include <linux/mm.h>
#include <linux/utsname.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>

#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_fattr *fattr)
{
	int		status;

	dprintk("NFS call  getroot\n");
	fattr->valid = 0;
	status = rpc_call(server->client, NFSPROC_GETATTR, fhandle, fattr, 0);
	dprintk("NFS reply getroot\n");
	return status;
}

/*
 * One function for each procedure in the NFS protocol.
 */
static int
nfs_proc_getattr(struct inode *inode, struct nfs_fattr *fattr)
{
	int	status;

	dprintk("NFS call  getattr\n");
	fattr->valid = 0;
	status = rpc_call(NFS_CLIENT(inode), NFSPROC_GETATTR,
				NFS_FH(inode), fattr, 0);
	dprintk("NFS reply getattr\n");
	return status;
}

static int
nfs_proc_setattr(struct inode *inode, struct nfs_fattr *fattr,
		 struct iattr *sattr)
{
	struct nfs_sattrargs	arg = { NFS_FH(inode), sattr };
	int	status;

	dprintk("NFS call  setattr\n");
	fattr->valid = 0;
	status = rpc_call(NFS_CLIENT(inode), NFSPROC_SETATTR, &arg, fattr, 0);
	dprintk("NFS reply setattr\n");
	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 = { NFS_FH(dir), name->name, name->len };
	struct nfs_diropok	res = { fhandle, fattr };
	int			status;

	dprintk("NFS call  lookup %s\n", name->name);
	fattr->valid = 0;
	status = rpc_call(NFS_CLIENT(dir), NFSPROC_LOOKUP, &arg, &res, 0);
	dprintk("NFS reply lookup: %d\n", status);
	return status;
}

static int
nfs_proc_readlink(struct inode *inode, void *buffer, unsigned int bufsiz)
{
	struct nfs_readlinkargs	args = { NFS_FH(inode), buffer, bufsiz };
	struct nfs_readlinkres	res = { buffer, bufsiz };
	int			status;

	dprintk("NFS call  readlink\n");
	status = rpc_call(NFS_CLIENT(inode), NFSPROC_READLINK,
					&args, &res, 0);
	dprintk("NFS reply readlink: %d\n", status);
	return status;
}

static int
nfs_proc_read(struct inode *inode, struct rpc_cred *cred,
	      struct nfs_fattr *fattr, int flags,
	      loff_t offset, unsigned int count, void *buffer, int *eofp)
{
	struct nfs_readargs	arg = { NFS_FH(inode), offset, count, 1,
				       {{ buffer, count }, {0,0}, {0,0}, {0,0},
					{0,0}, {0,0}, {0,0}, {0,0}} };
	struct nfs_readres	res = { fattr, count, 0};
	struct rpc_message	msg = { NFSPROC_READ, &arg, &res, cred };
	int			status;

	dprintk("NFS call  read %d @ %Ld\n", count, (long long)offset);
	fattr->valid = 0;
	status = rpc_call_sync(NFS_CLIENT(inode), &msg, flags);

	dprintk("NFS reply read: %d\n", status);
	*eofp = res.eof;
	return status;
}

static int
nfs_proc_write(struct inode *inode, struct rpc_cred *cred,
	       struct nfs_fattr *fattr, int how,
	       loff_t offset, unsigned int count,
	       void *buffer, struct nfs_writeverf *verf)
{
	struct nfs_writeargs	arg = {NFS_FH(inode), offset, count,
					NFS_FILE_SYNC, 1,
					{{buffer, count}, {0,0}, {0,0}, {0,0},
					 {0,0}, {0,0}, {0,0}, {0,0}}};
	struct nfs_writeres     res = {fattr, verf, count};
	struct rpc_message	msg = { NFSPROC_WRITE, &arg, &res, cred };
	int			status, flags = 0;

	dprintk("NFS call  write %d @ %Ld\n", count, (long long)offset);
	fattr->valid = 0;
	if (how & NFS_RW_SWAP)
		flags |= NFS_RPC_SWAPFLAGS;
	status = rpc_call_sync(NFS_CLIENT(inode), &msg, flags);

	dprintk("NFS reply write: %d\n", status);
	verf->committed = NFS_FILE_SYNC;      /* NFSv2 always syncs data */
	return status < 0? status : count;
}

static int
nfs_proc_create(struct inode *dir, struct qstr *name, struct iattr *sattr,
		int flags, struct nfs_fh *fhandle, struct nfs_fattr *fattr)
{
	struct nfs_createargs	arg = { NFS_FH(dir), name->name,
					name->len, sattr };
	struct nfs_diropok	res = { fhandle, fattr };
	int			status;

	fattr->valid = 0;
	dprintk("NFS call  create %s\n", name->name);
	status = rpc_call(NFS_CLIENT(dir), NFSPROC_CREATE, &arg, &res, 0);
	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 qstr *name, struct iattr *sattr,
	       dev_t rdev, struct nfs_fh *fhandle, struct nfs_fattr *fattr)
{
	struct nfs_createargs	arg = { NFS_FH(dir), name->name,
						     name->len, sattr };
	struct nfs_diropok	res = { fhandle, fattr };
	int			status, mode;

	dprintk("NFS call  mknod %s\n", 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   = rdev;	/* get out your barf bag */
	}

	fattr->valid = 0;
	status = rpc_call(NFS_CLIENT(dir), NFSPROC_CREATE, &arg, &res, 0);

	if (status == -EINVAL && S_ISFIFO(mode)) {
		sattr->ia_mode = mode;
		fattr->valid = 0;
		status = rpc_call(NFS_CLIENT(dir), NFSPROC_CREATE, &arg, &res, 0);
	}
	dprintk("NFS reply mknod: %d\n", status);
	return status;
}
  
static int
nfs_proc_remove(struct inode *dir, struct qstr *name)
{
	struct nfs_diropargs	arg = { NFS_FH(dir), name->name, name->len };
	struct rpc_message	msg = { NFSPROC_REMOVE, &arg, NULL, NULL };
	int			status;

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

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

static int
nfs_proc_unlink_setup(struct rpc_message *msg, struct dentry *dir, struct qstr *name)
{
	struct nfs_diropargs	*arg;

	arg = (struct nfs_diropargs *)kmalloc(sizeof(*arg), GFP_KERNEL);
	if (!arg)
		return -ENOMEM;
	arg->fh = NFS_FH(dir->d_inode);
	arg->name = name->name;
	arg->len = name->len;
	msg->rpc_proc = NFSPROC_REMOVE;
	msg->rpc_argp = arg;
	return 0;
}

static void
nfs_proc_unlink_done(struct dentry *dir, struct rpc_message *msg)
{
	if (msg->rpc_argp) {
		NFS_CACHEINV(dir->d_inode);
		kfree(msg->rpc_argp);
	}
}

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 = { NFS_FH(old_dir), old_name->name,
					old_name->len,
					NFS_FH(new_dir), new_name->name,
					new_name->len};
	int			status;

	dprintk("NFS call  rename %s -> %s\n", old_name->name, new_name->name);
	status = rpc_call(NFS_CLIENT(old_dir), NFSPROC_RENAME, &arg, NULL, 0);
	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 = { NFS_FH(inode), NFS_FH(dir),
					name->name, name->len };
	int			status;

	dprintk("NFS call  link %s\n", name->name);
	status = rpc_call(NFS_CLIENT(inode), NFSPROC_LINK, &arg, NULL, 0);
	dprintk("NFS reply link: %d\n", status);
	return status;
}

static int
nfs_proc_symlink(struct inode *dir, struct qstr *name, struct qstr *path,
		 struct iattr *sattr, struct nfs_fh *fhandle,
		 struct nfs_fattr *fattr)
{
	struct nfs_symlinkargs	arg = { NFS_FH(dir), name->name, name->len,
					path->name, path->len, sattr };
	int			status;

	dprintk("NFS call  symlink %s -> %s\n", name->name, path->name);
	fattr->valid = 0;
	status = rpc_call(NFS_CLIENT(dir), NFSPROC_SYMLINK, &arg, NULL, 0);
	dprintk("NFS reply symlink: %d\n", status);
	return status;
}

static int
nfs_proc_mkdir(struct inode *dir, struct qstr *name, struct iattr *sattr,
	       struct nfs_fh *fhandle, struct nfs_fattr *fattr)
{
	struct nfs_createargs	arg = { NFS_FH(dir), name->name, name->len,
					sattr };
	struct nfs_diropok	res = { fhandle, fattr };
	int			status;

	dprintk("NFS call  mkdir %s\n", name->name);
	fattr->valid = 0;
	status = rpc_call(NFS_CLIENT(dir), NFSPROC_MKDIR, &arg, &res, 0);
	dprintk("NFS reply mkdir: %d\n", status);
	return status;
}

static int
nfs_proc_rmdir(struct inode *dir, struct qstr *name)
{
	struct nfs_diropargs	arg = { NFS_FH(dir), name->name, name->len };
	int			status;

	dprintk("NFS call  rmdir %s\n", name->name);
	status = rpc_call(NFS_CLIENT(dir), NFSPROC_RMDIR, &arg, NULL, 0);
	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 inode *dir, struct rpc_cred *cred,
		 __u64 cookie, void *entry, 
		 unsigned int size, int plus)
{
	struct nfs_readdirargs	arg;
	struct nfs_readdirres	res;
	struct rpc_message	msg = { NFSPROC_READDIR, &arg, &res, cred };
	int			status;

	arg.fh = NFS_FH(dir);
	arg.cookie = cookie;
	arg.buffer = entry;
	arg.bufsiz = size;
	res.buffer = entry;
	res.bufsiz = size;

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

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

static int
nfs_proc_statfs(struct nfs_server *server, struct nfs_fh *fhandle,
			struct nfs_fsinfo *info)
{
	int	status;

	dprintk("NFS call  statfs\n");
	memset((char *)info, 0, sizeof(*info));
	status = rpc_call(server->client, NFSPROC_STATFS, fhandle, info, 0);
	dprintk("NFS reply statfs: %d\n", status);
	return status;
}

extern u32 * nfs_decode_dirent(u32 *, struct nfs_entry *, int);

struct nfs_rpc_ops     nfs_v2_clientops = {
       2,		       /* protocol version */
       nfs_proc_get_root,
       nfs_proc_getattr,
       nfs_proc_setattr,
       nfs_proc_lookup,
       NULL,		       /* access */
       nfs_proc_readlink,
       nfs_proc_read,
       nfs_proc_write,
       NULL,		       /* commit */
       nfs_proc_create,
       nfs_proc_remove,
       nfs_proc_unlink_setup,
       nfs_proc_unlink_done,
       nfs_proc_rename,
       nfs_proc_link,
       nfs_proc_symlink,
       nfs_proc_mkdir,
       nfs_proc_rmdir,
       nfs_proc_readdir,
       nfs_proc_mknod,
       nfs_proc_statfs,
       nfs_decode_dirent,
};