path: root/fs/gfs2/xattr.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
 * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
 */

#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/xattr.h>
#include <linux/gfs2_ondisk.h>
#include <linux/posix_acl_xattr.h>
#include <linux/uaccess.h>

#include "gfs2.h"
#include "incore.h"
#include "acl.h"
#include "xattr.h"
#include "glock.h"
#include "inode.h"
#include "meta_io.h"
#include "quota.h"
#include "rgrp.h"
#include "super.h"
#include "trans.h"
#include "util.h"

/*
 * ea_calc_size - returns the actual number of bytes the request will take up
 *                (not counting any unstuffed data blocks)
 *
 * Returns: 1 if the EA should be stuffed
 */

static int ea_calc_size(struct gfs2_sbd *sdp, unsigned int nsize, size_t dsize,
			unsigned int *size)
{
	unsigned int jbsize = sdp->sd_jbsize;

	/* Stuffed */
	*size = ALIGN(sizeof(struct gfs2_ea_header) + nsize + dsize, 8);

	if (*size <= jbsize)
		return 1;

	/* Unstuffed */
	*size = ALIGN(sizeof(struct gfs2_ea_header) + nsize +
		      (sizeof(__be64) * DIV_ROUND_UP(dsize, jbsize)), 8);

	return 0;
}

static int ea_check_size(struct gfs2_sbd *sdp, unsigned int nsize, size_t dsize)
{
	unsigned int size;

	if (dsize > GFS2_EA_MAX_DATA_LEN)
		return -ERANGE;

	ea_calc_size(sdp, nsize, dsize, &size);

	/* This can only happen with 512 byte blocks */
	if (size > sdp->sd_jbsize)
		return -ERANGE;

	return 0;
}

static bool gfs2_eatype_valid(struct gfs2_sbd *sdp, u8 type)
{
	switch(sdp->sd_sb.sb_fs_format) {
	case GFS2_FS_FORMAT_MAX:
		return true;

	case GFS2_FS_FORMAT_MIN:
		return type <= GFS2_EATYPE_SECURITY;

	default:
		return false;
	}
}

typedef int (*ea_call_t) (struct gfs2_inode *ip, struct buffer_head *bh,
			  struct gfs2_ea_header *ea,
			  struct gfs2_ea_header *prev, void *private);

static int ea_foreach_i(struct gfs2_inode *ip, struct buffer_head *bh,
			ea_call_t ea_call, void *data)
{
	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
	struct gfs2_ea_header *ea, *prev = NULL;
	int error = 0;

	if (gfs2_metatype_check(GFS2_SB(&ip->i_inode), bh, GFS2_METATYPE_EA))
		return -EIO;

	for (ea = GFS2_EA_BH2FIRST(bh);; prev = ea, ea = GFS2_EA2NEXT(ea)) {
		if (!GFS2_EA_REC_LEN(ea))
			goto fail;
		if (!(bh->b_data <= (char *)ea && (char *)GFS2_EA2NEXT(ea) <=
						  bh->b_data + bh->b_size))
			goto fail;
		if (!gfs2_eatype_valid(sdp, ea->ea_type))
			goto fail;
		error = ea_call(ip, bh, ea, prev, data);
		if (error)
			return error;

		if (GFS2_EA_IS_LAST(ea)) {
			if ((char *)GFS2_EA2NEXT(ea) !=
			    bh->b_data + bh->b_size)
				goto fail;
			break;
		}
	}

	return error;

fail:
	gfs2_consist_inode(ip);
	return -EIO;
}

static int ea_foreach(struct gfs2_inode *ip, ea_call_t ea_call, void *data)
{
	struct buffer_head *bh, *eabh;
	__be64 *eablk, *end;
	int error;

	error = gfs2_meta_read(ip->i_gl, ip->i_eattr, DIO_WAIT, 0, &bh);
	if (error)
		return error;

	if (!(ip->i_diskflags & GFS2_DIF_EA_INDIRECT)) {
		error = ea_foreach_i(ip, bh, ea_call, data);
		goto out;
	}

	if (gfs2_metatype_check(GFS2_SB(&ip->i_inode), bh, GFS2_METATYPE_IN)) {
		error = -EIO;
		goto out;
	}

	eablk = (__be64 *)(bh->b_data + sizeof(struct gfs2_meta_header));
	end = eablk + GFS2_SB(&ip->i_inode)->sd_inptrs;

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

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

		error = gfs2_meta_read(ip->i_gl, bn, DIO_WAIT, 0, &eabh);
		if (error)
			break;
		error = ea_foreach_i(ip, eabh, ea_call, data);
		brelse(eabh);
		if (error)
			break;
	}
out:
	brelse(bh);
	return error;
}

struct ea_find {
	int type;
	const char *name;
	size_t namel;
	struct gfs2_ea_location *ef_el;
};

static int ea_find_i(struct gfs2_inode *ip, struct buffer_head *bh,
		     struct gfs2_ea_header *ea, struct gfs2_ea_header *prev,
		     void *private)
{
	struct ea_find *ef = private;

	if (ea->ea_type == GFS2_EATYPE_UNUSED)
		return 0;

	if (ea->ea_type == ef->type) {
		if (ea->ea_name_len == ef->namel &&
		    !memcmp(GFS2_EA2NAME(ea), ef->name, ea->ea_name_len)) {
			struct gfs2_ea_location *el = ef->ef_el;
			get_bh(bh);
			el->el_bh = bh;
			el->el_ea = ea;
			el->el_prev = prev;
			return 1;
		}
	}

	return 0;
}

static int gfs2_ea_find(struct gfs2_inode *ip, int type, const char *name,
			struct gfs2_ea_location *el)
{
	struct ea_find ef;
	int error;

	ef.type = type;
	ef.name = name;
	ef.namel = strlen(name);
	ef.ef_el = el;

	memset(el, 0, sizeof(struct gfs2_ea_location));

	error = ea_foreach(ip, ea_find_i, &ef);
	if (error > 0)
		return 0;

	return error;
}

/*
 * ea_dealloc_unstuffed
 *
 * Take advantage of the fact that all unstuffed blocks are
 * allocated from the same RG.  But watch, this may not always
 * be true.
 *
 * Returns: errno
 */

static int ea_dealloc_unstuffed(struct gfs2_inode *ip, struct buffer_head *bh,
				struct gfs2_ea_header *ea,
				struct gfs2_ea_header *prev, void *private)
{
	int *leave = private;
	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
	struct gfs2_rgrpd *rgd;
	struct gfs2_holder rg_gh;
	__be64 *dataptrs;
	u64 bn = 0;
	u64 bstart = 0;
	unsigned int blen = 0;
	unsigned int blks = 0;
	unsigned int x;
	int error;

	error = gfs2_rindex_update(sdp);
	if (error)
		return error;

	if (GFS2_EA_IS_STUFFED(ea))
		return 0;

	dataptrs = GFS2_EA2DATAPTRS(ea);
	for (x = 0; x < ea->ea_num_ptrs; x++, dataptrs++) {
		if (*dataptrs) {
			blks++;
			bn = be64_to_cpu(*dataptrs);
		}
	}
	if (!blks)
		return 0;

	rgd = gfs2_blk2rgrpd(sdp, bn, 1);
	if (!rgd) {
		gfs2_consist_inode(ip);
		return -EIO;
	}

	error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE,
				   LM_FLAG_NODE_SCOPE, &rg_gh);
	if (error)
		return error;

	error = gfs2_trans_begin(sdp, rgd->rd_length + RES_DINODE +
				 RES_EATTR + RES_STATFS + RES_QUOTA, blks);
	if (error)
		goto out_gunlock;

	gfs2_trans_add_meta(ip->i_gl, bh);

	dataptrs = GFS2_EA2DATAPTRS(ea);
	for (x = 0; x < ea->ea_num_ptrs; x++, dataptrs++) {
		if (!*dataptrs)
			break;
		bn = be64_to_cpu(*dataptrs);

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

		*dataptrs = 0;
		gfs2_add_inode_blocks(&ip->i_inode, -1);
	}
	if (bstart)
		gfs2_free_meta(ip, rgd, bstart, blen);

	if (prev && !leave) {
		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;
		ea->ea_num_ptrs = 0;
	}

	ip->i_inode.i_ctime = current_time(&ip->i_inode);
	__mark_inode_dirty(&ip->i_inode, I_DIRTY_DATASYNC);

	gfs2_trans_end(sdp);

out_gunlock:
	gfs2_glock_dq_uninit(&rg_gh);
	return error;
}

static int ea_remove_unstuffed(struct gfs2_inode *ip, struct buffer_head *bh,
			       struct gfs2_ea_header *ea,
			       struct gfs2_ea_header *prev, int leave)
{
	int error;

	error = gfs2_rindex_update(GFS2_SB(&ip->i_inode));
	if (error)
		return error;

	error = gfs2_quota_hold(ip, NO_UID_QUOTA_CHANGE, NO_GID_QUOTA_CHANGE);
	if (error)
		goto out_alloc;

	error = ea_dealloc_unstuffed(ip, bh, ea, prev, (leave) ? &error : NULL);

	gfs2_quota_unhold(ip);
out_alloc:
	return error;
}

struct ea_list {
	struct gfs2_ea_request *ei_er;
	unsigned int ei_size;
};

static int ea_list_i(struct gfs2_inode *ip, struct buffer_head *bh,
		     struct gfs2_ea_header *ea, struct gfs2_ea_header *prev,
		     void *private)
{
	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
	struct ea_list *ei = private;
	struct gfs2_ea_request *er = ei->ei_er;
	unsigned int ea_size;
	char *prefix;
	unsigned int l;

	if (ea->ea_type == GFS2_EATYPE_UNUSED)
		return 0;

	BUG_ON(ea->ea_type > GFS2_EATYPE_SECURITY &&
	       sdp->sd_sb.sb_fs_format == GFS2_FS_FORMAT_MIN);
	switch (ea->ea_type) {
	case GFS2_EATYPE_USR:
		prefix = "user.";
		l = 5;
		break;
	case GFS2_EATYPE_SYS:
		prefix = "system.";
		l = 7;
		break;
	case GFS2_EATYPE_SECURITY:
		prefix = "security.";
		l = 9;
		break;
	case GFS2_EATYPE_TRUSTED:
		prefix = "trusted.";
		l = 8;
		break;
	default:
		return 0;
	}

	ea_size = l + ea->ea_name_len + 1;
	if (er->er_data_len) {
		if (ei->ei_size + ea_size > er->er_data_len)
			return -ERANGE;

		me