Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*
 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
 * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
 *
 * This copyrighted material is made available to anyone wishing to use,
 * modify, copy, or redistribute it subject to the terms and conditions
 * of the GNU General Public License version 2.
 */
 
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/exportfs.h>
#include <linux/gfs2_ondisk.h>
#include <linux/crc32.h>
#include <linux/lm_interface.h>
 
#include "gfs2.h"
#include "incore.h"
#include "dir.h"
#include "glock.h"
#include "glops.h"
#include "inode.h"
#include "ops_dentry.h"
#include "ops_fstype.h"
#include "rgrp.h"
#include "util.h"
 
#define GFS2_SMALL_FH_SIZE 4
#define GFS2_LARGE_FH_SIZE 8
#define GFS2_OLD_FH_SIZE 10
 
static int gfs2_encode_fh(struct dentry *dentry, __u32 *p, int *len,
			  int connectable)
{
	__be32 *fh = (__force __be32 *)p;
	struct inode *inode = dentry->d_inode;
	struct super_block *sb = inode->i_sb;
	struct gfs2_inode *ip = GFS2_I(inode);
 
	if (*len < GFS2_SMALL_FH_SIZE ||
	    (connectable && *len < GFS2_LARGE_FH_SIZE))
		return 255;
 
	fh[0] = cpu_to_be32(ip->i_no_formal_ino >> 32);
	fh[1] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF);
	fh[2] = cpu_to_be32(ip->i_no_addr >> 32);
	fh[3] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF);
	*len = GFS2_SMALL_FH_SIZE;
 
	if (!connectable || inode == sb->s_root->d_inode)
		return *len;
 
	spin_lock(&dentry->d_lock);
	inode = dentry->d_parent->d_inode;
	ip = GFS2_I(inode);
	igrab(inode);
	spin_unlock(&dentry->d_lock);
 
	fh[4] = cpu_to_be32(ip->i_no_formal_ino >> 32);
	fh[5] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF);
	fh[6] = cpu_to_be32(ip->i_no_addr >> 32);
	fh[7] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF);
	*len = GFS2_LARGE_FH_SIZE;
 
	iput(inode);
 
	return *len;
}
 
struct get_name_filldir {
	struct gfs2_inum_host inum;
	char *name;
};
 
static int get_name_filldir(void *opaque, const char *name, int length,
			    loff_t offset, u64 inum, unsigned int type)
{
	struct get_name_filldir *gnfd = opaque;
 
	if (inum != gnfd->inum.no_addr)
		return 0;
 
	memcpy(gnfd->name, name, length);
	gnfd->name[length] = 0;
 
	return 1;
}
 
static int gfs2_get_name(struct dentry *parent, char *name,
			 struct dentry *child)
{
	struct inode *dir = parent->d_inode;
	struct inode *inode = child->d_inode;
	struct gfs2_inode *dip, *ip;
	struct get_name_filldir gnfd;
	struct gfs2_holder gh;
	u64 offset = 0;
	int error;
 
	if (!dir)
		return -EINVAL;
 
	if (!S_ISDIR(dir->i_mode) || !inode)
		return -EINVAL;
 
	dip = GFS2_I(dir);
	ip = GFS2_I(inode);
 
	*name = 0;
	gnfd.inum.no_addr = ip->i_no_addr;
	gnfd.inum.no_formal_ino = ip->i_no_formal_ino;
	gnfd.name = name;
 
	error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh);
	if (error)
		return error;
 
	error = gfs2_dir_read(dir, &offset, &gnfd, get_name_filldir);
 
	gfs2_glock_dq_uninit(&gh);
 
	if (!error && !*name)
		error = -ENOENT;
 
	return error;
}
 
static struct dentry *gfs2_get_parent(struct dentry *child)
{
	struct qstr dotdot;
	struct inode *inode;
	struct dentry *dentry;
 
	gfs2_str2qstr(&dotdot, "..");
	inode = gfs2_lookupi(child->d_inode, &dotdot, 1, NULL);
 
	if (!inode)
		return ERR_PTR(-ENOENT);
	/*
	 * In case of an error, @inode carries the error value, and we
	 * have to return that as a(n invalid) pointer to dentry.
	 */
	if (IS_ERR(inode))
		return ERR_PTR(PTR_ERR(inode));
 
	dentry = d_alloc_anon(inode);
	if (!dentry) {
		iput(inode);
		return ERR_PTR(-ENOMEM);
	}
 
	dentry->d_op = &gfs2_dops;
	return dentry;
}
 
static struct dentry *gfs2_get_dentry(struct super_block *sb,
		struct gfs2_inum_host *inum)
{
	struct gfs2_sbd *sdp = sb->s_fs_info;
	struct gfs2_holder i_gh, ri_gh, rgd_gh;
	struct gfs2_rgrpd *rgd;
	struct inode *inode;
	struct dentry *dentry;
	int error;
 
	/* System files? */
 
	inode = gfs2_ilookup(sb, inum->no_addr);
	if (inode) {
		if (GFS2_I(inode)->i_no_formal_ino != inum->no_formal_ino) {
			iput(inode);
			return ERR_PTR(-ESTALE);
		}
		goto out_inode;
	}
 
	error = gfs2_glock_nq_num(sdp, inum->no_addr, &gfs2_inode_glops,
				  LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
	if (error)
		return ERR_PTR(error);
 
	error = gfs2_rindex_hold(sdp, &ri_gh);
	if (error)
		goto fail;
 
	error = -EINVAL;
	rgd = gfs2_blk2rgrpd(sdp, inum->no_addr);
	if (!rgd)
		goto fail_rindex;
 
	error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_SHARED, 0, &rgd_gh);
	if (error)
		goto fail_rindex;
 
	error = -ESTALE;
	if (gfs2_get_block_type(rgd, inum->no_addr) != GFS2_BLKST_DINODE)
		goto fail_rgd;
 
	gfs2_glock_dq_uninit(&rgd_gh);
	gfs2_glock_dq_uninit(&ri_gh);
 
	inode = gfs2_inode_lookup(sb, DT_UNKNOWN,
					inum->no_addr,
					0, 0);
	if (!inode)
		goto fail;
	if (IS_ERR(inode)) {
		error = PTR_ERR(inode);
		goto fail;
	}
 
	error = gfs2_inode_refresh(GFS2_I(inode));
	if (error) {
		iput(inode);
		goto fail;
	}
 
	/* Pick up the works we bypass in gfs2_inode_lookup */
	if (inode->i_state & I_NEW) 
		gfs2_set_iop(inode);
 
	if (GFS2_I(inode)->i_no_formal_ino != inum->no_formal_ino) {
		iput(inode);
		goto fail;
	}
 
	error = -EIO;
	if (GFS2_I(inode)->i_di.di_flags & GFS2_DIF_SYSTEM) {
		iput(inode);
		goto fail;
	}
 
	gfs2_glock_dq_uninit(&i_gh);
 
out_inode:
	dentry = d_alloc_anon(inode);
	if (!dentry) {
		iput(inode);
		return ERR_PTR(-ENOMEM);
	}
 
	dentry->d_op = &gfs2_dops;
	return dentry;
 
fail_rgd:
	gfs2_glock_dq_uninit(&rgd_gh);
 
fail_rindex:
	gfs2_glock_dq_uninit(&ri_gh);
 
fail:
	gfs2_glock_dq_uninit(&i_gh);
	return ERR_PTR(error);
}
 
static struct dentry *gfs2_fh_to_dentry(struct super_block *sb, struct fid *fid,
		int fh_len, int fh_type)
{
	struct gfs2_inum_host this;
	__be32 *fh = (__force __be32 *)fid->raw;
 
	switch (fh_type) {
	case GFS2_SMALL_FH_SIZE:
	case GFS2_LARGE_FH_SIZE:
	case GFS2_OLD_FH_SIZE:
		this.no_formal_ino = ((u64)be32_to_cpu(fh[0])) << 32;
		this.no_formal_ino |= be32_to_cpu(fh[1]);
		this.no_addr = ((u64)be32_to_cpu(fh[2])) << 32;
		this.no_addr |= be32_to_cpu(fh[3]);
		return gfs2_get_dentry(sb, &this);
	default:
		return NULL;
	}
}
 
static struct dentry *gfs2_fh_to_parent(struct super_block *sb, struct fid *fid,
		int fh_len, int fh_type)
{
	struct gfs2_inum_host parent;
	__be32 *fh = (__force __be32 *)fid->raw;
 
	switch (fh_type) {
	case GFS2_LARGE_FH_SIZE:
	case GFS2_OLD_FH_SIZE:
		parent.no_formal_ino = ((u64)be32_to_cpu(fh[4])) << 32;
		parent.no_formal_ino |= be32_to_cpu(fh[5]);
		parent.no_addr = ((u64)be32_to_cpu(fh[6])) << 32;
		parent.no_addr |= be32_to_cpu(fh[7]);
		return gfs2_get_dentry(sb, &parent);
	default:
		return NULL;
	}
}
 
const struct export_operations gfs2_export_ops = {
	.encode_fh = gfs2_encode_fh,
	.fh_to_dentry = gfs2_fh_to_dentry,
	.fh_to_parent = gfs2_fh_to_parent,
	.get_name = gfs2_get_name,
	.get_parent = gfs2_get_parent,
};