eattr.c

linux 内核源代码

{
	struct ea_set es;
	unsigned int blks = 2;
	int error;

	memset(&es, 0, sizeof(struct ea_set));
	es.es_er = er;
	es.es_el = el;

	error = ea_foreach(ip, ea_set_simple, &es);
	if (error > 0)
		return 0;
	if (error)
		return error;

	if (!(ip->i_di.di_flags & GFS2_DIF_EA_INDIRECT))
		blks++;
	if (GFS2_EAREQ_SIZE_STUFFED(er) > GFS2_SB(&ip->i_inode)->sd_jbsize)
		blks += DIV_ROUND_UP(er->er_data_len, GFS2_SB(&ip->i_inode)->sd_jbsize);

	return ea_alloc_skeleton(ip, er, blks, ea_set_block, el);
}

static int ea_set_remove_unstuffed(struct gfs2_inode *ip,
				   struct gfs2_ea_location *el)
{
	if (el->el_prev && GFS2_EA2NEXT(el->el_prev) != el->el_ea) {
		el->el_prev = GFS2_EA2NEXT(el->el_prev);
		gfs2_assert_withdraw(GFS2_SB(&ip->i_inode),
				     GFS2_EA2NEXT(el->el_prev) == el->el_ea);
	}

	return ea_remove_unstuffed(ip, el->el_bh, el->el_ea, el->el_prev,0);
}

int gfs2_ea_set_i(struct gfs2_inode *ip, struct gfs2_ea_request *er)
{
	struct gfs2_ea_location el;
	int error;

	if (!ip->i_di.di_eattr) {
		if (er->er_flags & XATTR_REPLACE)
			return -ENODATA;
		return ea_init(ip, er);
	}

	error = gfs2_ea_find(ip, er, &el);
	if (error)
		return error;

	if (el.el_ea) {
		if (ip->i_di.di_flags & GFS2_DIF_APPENDONLY) {
			brelse(el.el_bh);
			return -EPERM;
		}

		error = -EEXIST;
		if (!(er->er_flags & XATTR_CREATE)) {
			int unstuffed = !GFS2_EA_IS_STUFFED(el.el_ea);
			error = ea_set_i(ip, er, &el);
			if (!error && unstuffed)
				ea_set_remove_unstuffed(ip, &el);
		}

		brelse(el.el_bh);
	} else {
		error = -ENODATA;
		if (!(er->er_flags & XATTR_REPLACE))
			error = ea_set_i(ip, er, NULL);
	}

	return error;
}

int gfs2_ea_set(struct gfs2_inode *ip, struct gfs2_ea_request *er)
{
	struct gfs2_holder i_gh;
	int error;

	if (!er->er_name_len || er->er_name_len > GFS2_EA_MAX_NAME_LEN)
		return -EINVAL;
	if (!er->er_data || !er->er_data_len) {
		er->er_data = NULL;
		er->er_data_len = 0;
	}
	error = ea_check_size(GFS2_SB(&ip->i_inode), er);
	if (error)
		return error;

	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
	if (error)
		return error;

	if (IS_IMMUTABLE(&ip->i_inode))
		error = -EPERM;
	else
		error = gfs2_ea_ops[er->er_type]->eo_set(ip, er);

	gfs2_glock_dq_uninit(&i_gh);

	return error;
}

static int ea_remove_stuffed(struct gfs2_inode *ip, struct gfs2_ea_location *el)
{
	struct gfs2_ea_header *ea = el->el_ea;
	struct gfs2_ea_header *prev = el->el_prev;
	struct buffer_head *dibh;
	int error;

	error = gfs2_trans_begin(GFS2_SB(&ip->i_inode), RES_DINODE + RES_EATTR, 0);
	if (error)
		return error;

	gfs2_trans_add_bh(ip->i_gl, el->el_bh, 1);

	if (prev) {
		u32 len;

		len = GFS2_EA_REC_LEN(prev) + GFS2_EA_REC_LEN(ea);
		prev->ea_rec_len = cpu_to_be32(len);

		if (GFS2_EA_IS_LAST(ea))
			prev->ea_flags |= GFS2_EAFLAG_LAST;
	} else
		ea->ea_type = GFS2_EATYPE_UNUSED;

	error = gfs2_meta_inode_buffer(ip, &dibh);
	if (!error) {
		ip->i_inode.i_ctime = CURRENT_TIME;
		gfs2_trans_add_bh(ip->i_gl, dibh, 1);
		gfs2_dinode_out(ip, dibh->b_data);
		brelse(dibh);
	}

	gfs2_trans_end(GFS2_SB(&ip->i_inode));

	return error;
}

int gfs2_ea_remove_i(struct gfs2_inode *ip, struct gfs2_ea_request *er)
{
	struct gfs2_ea_location el;
	int error;

	if (!ip->i_di.di_eattr)
		return -ENODATA;

	error = gfs2_ea_find(ip, er, &el);
	if (error)
		return error;
	if (!el.el_ea)
		return -ENODATA;

	if (GFS2_EA_IS_STUFFED(el.el_ea))
		error = ea_remove_stuffed(ip, &el);
	else
		error = ea_remove_unstuffed(ip, el.el_bh, el.el_ea, el.el_prev,
					    0);

	brelse(el.el_bh);

	return error;
}

/**
 * gfs2_ea_remove - sets (or creates or replaces) an extended attribute
 * @ip: pointer to the inode of the target file
 * @er: request information
 *
 * Returns: errno
 */

int gfs2_ea_remove(struct gfs2_inode *ip, struct gfs2_ea_request *er)
{
	struct gfs2_holder i_gh;
	int error;

	if (!er->er_name_len || er->er_name_len > GFS2_EA_MAX_NAME_LEN)
		return -EINVAL;

	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
	if (error)
		return error;

	if (IS_IMMUTABLE(&ip->i_inode) || IS_APPEND(&ip->i_inode))
		error = -EPERM;
	else
		error = gfs2_ea_ops[er->er_type]->eo_remove(ip, er);

	gfs2_glock_dq_uninit(&i_gh);

	return error;
}

static int ea_acl_chmod_unstuffed(struct gfs2_inode *ip,
				  struct gfs2_ea_header *ea, char *data)
{
	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
	struct buffer_head **bh;
	unsigned int amount = GFS2_EA_DATA_LEN(ea);
	unsigned int nptrs = DIV_ROUND_UP(amount, sdp->sd_jbsize);
	__be64 *dataptrs = GFS2_EA2DATAPTRS(ea);
	unsigned int x;
	int error;

	bh = kcalloc(nptrs, sizeof(struct buffer_head *), GFP_KERNEL);
	if (!bh)
		return -ENOMEM;

	error = gfs2_trans_begin(sdp, nptrs + RES_DINODE, 0);
	if (error)
		goto out;

	for (x = 0; x < nptrs; x++) {
		error = gfs2_meta_read(ip->i_gl, be64_to_cpu(*dataptrs), 0,
				       bh + x);
		if (error) {
			while (x--)
				brelse(bh[x]);
			goto fail;
		}
		dataptrs++;
	}

	for (x = 0; x < nptrs; x++) {
		error = gfs2_meta_wait(sdp, bh[x]);
		if (error) {
			for (; x < nptrs; x++)
				brelse(bh[x]);
			goto fail;
		}
		if (gfs2_metatype_check(sdp, bh[x], GFS2_METATYPE_ED)) {
			for (; x < nptrs; x++)
				brelse(bh[x]);
			error = -EIO;
			goto fail;
		}

		gfs2_trans_add_bh(ip->i_gl, bh[x], 1);

		memcpy(bh[x]->b_data + sizeof(struct gfs2_meta_header), data,
		       (sdp->sd_jbsize > amount) ? amount : sdp->sd_jbsize);

		amount -= sdp->sd_jbsize;
		data += sdp->sd_jbsize;

		brelse(bh[x]);
	}

out:
	kfree(bh);
	return error;

fail:
	gfs2_trans_end(sdp);
	kfree(bh);
	return error;
}

int gfs2_ea_acl_chmod(struct gfs2_inode *ip, struct gfs2_ea_location *el,
		      struct iattr *attr, char *data)
{
	struct buffer_head *dibh;
	int error;

	if (GFS2_EA_IS_STUFFED(el->el_ea)) {
		error = gfs2_trans_begin(GFS2_SB(&ip->i_inode), RES_DINODE + RES_EATTR, 0);
		if (error)
			return error;

		gfs2_trans_add_bh(ip->i_gl, el->el_bh, 1);
		memcpy(GFS2_EA2DATA(el->el_ea), data,
		       GFS2_EA_DATA_LEN(el->el_ea));
	} else
		error = ea_acl_chmod_unstuffed(ip, el->el_ea, data);

	if (error)
		return error;

	error = gfs2_meta_inode_buffer(ip, &dibh);
	if (!error) {
		error = inode_setattr(&ip->i_inode, attr);
		gfs2_assert_warn(GFS2_SB(&ip->i_inode), !error);
		gfs2_trans_add_bh(ip->i_gl, dibh, 1);
		gfs2_dinode_out(ip, dibh->b_data);
		brelse(dibh);
	}

	gfs2_trans_end(GFS2_SB(&ip->i_inode));

	return error;
}

static int ea_dealloc_indirect(struct gfs2_inode *ip)
{
	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
	struct gfs2_rgrp_list rlist;
	struct buffer_head *indbh, *dibh;
	__be64 *eablk, *end;
	unsigned int rg_blocks = 0;
	u64 bstart = 0;
	unsigned int blen = 0;
	unsigned int blks = 0;
	unsigned int x;
	int error;

	memset(&rlist, 0, sizeof(struct gfs2_rgrp_list));

	error = gfs2_meta_read(ip->i_gl, ip->i_di.di_eattr, DIO_WAIT, &indbh);
	if (error)
		return error;

	if (gfs2_metatype_check(sdp, indbh, GFS2_METATYPE_IN)) {
		error = -EIO;
		goto out;
	}

	eablk = (__be64 *)(indbh->b_data + sizeof(struct gfs2_meta_header));
	end = eablk + sdp->sd_inptrs;

	for (; eablk < end; eablk++) {
		u64 bn;

		if (!*eablk)
			break;
		bn = be64_to_cpu(*eablk);

		if (bstart + blen == bn)
			blen++;
		else {
			if (bstart)
				gfs2_rlist_add(sdp, &rlist, bstart);
			bstart = bn;
			blen = 1;
		}
		blks++;
	}
	if (bstart)
		gfs2_rlist_add(sdp, &rlist, bstart);
	else
		goto out;

	gfs2_rlist_alloc(&rlist, LM_ST_EXCLUSIVE, 0);

	for (x = 0; x < rlist.rl_rgrps; x++) {
		struct gfs2_rgrpd *rgd;
		rgd = rlist.rl_ghs[x].gh_gl->gl_object;
		rg_blocks += rgd->rd_length;
	}

	error = gfs2_glock_nq_m(rlist.rl_rgrps, rlist.rl_ghs);
	if (error)
		goto out_rlist_free;

	error = gfs2_trans_begin(sdp, rg_blocks + RES_DINODE + RES_INDIRECT +
				 RES_STATFS + RES_QUOTA, blks);
	if (error)
		goto out_gunlock;

	gfs2_trans_add_bh(ip->i_gl, indbh, 1);

	eablk = (__be64 *)(indbh->b_data + sizeof(struct gfs2_meta_header));
	bstart = 0;
	blen = 0;

	for (; eablk < end; eablk++) {
		u64 bn;

		if (!*eablk)
			break;
		bn = be64_to_cpu(*eablk);

		if (bstart + blen == bn)
			blen++;
		else {
			if (bstart)
				gfs2_free_meta(ip, bstart, blen);
			bstart = bn;
			blen = 1;
		}

		*eablk = 0;
		if (!ip->i_di.di_blocks)
			gfs2_consist_inode(ip);
		ip->i_di.di_blocks--;
		gfs2_set_inode_blocks(&ip->i_inode);
	}
	if (bstart)
		gfs2_free_meta(ip, bstart, blen);

	ip->i_di.di_flags &= ~GFS2_DIF_EA_INDIRECT;

	error = gfs2_meta_inode_buffer(ip, &dibh);
	if (!error) {
		gfs2_trans_add_bh(ip->i_gl, dibh, 1);
		gfs2_dinode_out(ip, dibh->b_data);
		brelse(dibh);
	}

	gfs2_trans_end(sdp);

out_gunlock:
	gfs2_glock_dq_m(rlist.rl_rgrps, rlist.rl_ghs);
out_rlist_free:
	gfs2_rlist_free(&rlist);
out:
	brelse(indbh);
	return error;
}

static int ea_dealloc_block(struct gfs2_inode *ip)
{
	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
	struct gfs2_alloc *al = &ip->i_alloc;
	struct gfs2_rgrpd *rgd;
	struct buffer_head *dibh;
	int error;

	rgd = gfs2_blk2rgrpd(sdp, ip->i_di.di_eattr);
	if (!rgd) {
		gfs2_consist_inode(ip);
		return -EIO;
	}

	error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE, 0,
				   &al->al_rgd_gh);
	if (error)
		return error;

	error = gfs2_trans_begin(sdp, RES_RG_BIT + RES_DINODE + RES_STATFS +
				 RES_QUOTA, 1);
	if (error)
		goto out_gunlock;

	gfs2_free_meta(ip, ip->i_di.di_eattr, 1);

	ip->i_di.di_eattr = 0;
	if (!ip->i_di.di_blocks)
		gfs2_consist_inode(ip);
	ip->i_di.di_blocks--;
	gfs2_set_inode_blocks(&ip->i_inode);

	error = gfs2_meta_inode_buffer(ip, &dibh);
	if (!error) {
		gfs2_trans_add_bh(ip->i_gl, dibh, 1);
		gfs2_dinode_out(ip, dibh->b_data);
		brelse(dibh);
	}

	gfs2_trans_end(sdp);

out_gunlock:
	gfs2_glock_dq_uninit(&al->al_rgd_gh);
	return error;
}

/**
 * gfs2_ea_dealloc - deallocate the extended attribute fork
 * @ip: the inode
 *
 * Returns: errno
 */

int gfs2_ea_dealloc(struct gfs2_inode *ip)
{
	struct gfs2_alloc *al;
	int error;

	al = gfs2_alloc_get(ip);

	error = gfs2_quota_hold(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
	if (error)
		goto out_alloc;

	error = gfs2_rindex_hold(GFS2_SB(&ip->i_inode), &al->al_ri_gh);
	if (error)
		goto out_quota;

	error = ea_foreach(ip, ea_dealloc_unstuffed, NULL);
	if (error)
		goto out_rindex;

	if (ip->i_di.di_flags & GFS2_DIF_EA_INDIRECT) {
		error = ea_dealloc_indirect(ip);
		if (error)
			goto out_rindex;
	}

	error = ea_dealloc_block(ip);

out_rindex:
	gfs2_glock_dq_uninit(&al->al_ri_gh);
out_quota:
	gfs2_quota_unhold(ip);
out_alloc:
	gfs2_alloc_put(ip);
	return error;
}