[linux.git] / fs / quota / quota_v1.c

// SPDX-License-Identifier: GPL-2.0-only
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/quota.h>
#include <linux/quotaops.h>
#include <linux/dqblk_v1.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>

#include <asm/byteorder.h>

#include "quotaio_v1.h"

MODULE_AUTHOR("Jan Kara");
MODULE_DESCRIPTION("Old quota format support");
MODULE_LICENSE("GPL");

#define QUOTABLOCK_BITS 10
#define QUOTABLOCK_SIZE (1 << QUOTABLOCK_BITS)

static inline qsize_t v1_stoqb(qsize_t space)
{
	return (space + QUOTABLOCK_SIZE - 1) >> QUOTABLOCK_BITS;
}

static inline qsize_t v1_qbtos(qsize_t blocks)
{
	return blocks << QUOTABLOCK_BITS;
}

static void v1_disk2mem_dqblk(struct mem_dqblk *m, struct v1_disk_dqblk *d)
{
	m->dqb_ihardlimit = d->dqb_ihardlimit;
	m->dqb_isoftlimit = d->dqb_isoftlimit;
	m->dqb_curinodes = d->dqb_curinodes;
	m->dqb_bhardlimit = v1_qbtos(d->dqb_bhardlimit);
	m->dqb_bsoftlimit = v1_qbtos(d->dqb_bsoftlimit);
	m->dqb_curspace = v1_qbtos(d->dqb_curblocks);
	m->dqb_itime = d->dqb_itime;
	m->dqb_btime = d->dqb_btime;
}

static void v1_mem2disk_dqblk(struct v1_disk_dqblk *d, struct mem_dqblk *m)
{
	d->dqb_ihardlimit = m->dqb_ihardlimit;
	d->dqb_isoftlimit = m->dqb_isoftlimit;
	d->dqb_curinodes = m->dqb_curinodes;
	d->dqb_bhardlimit = v1_stoqb(m->dqb_bhardlimit);
	d->dqb_bsoftlimit = v1_stoqb(m->dqb_bsoftlimit);
	d->dqb_curblocks = v1_stoqb(m->dqb_curspace);
	d->dqb_itime = m->dqb_itime;
	d->dqb_btime = m->dqb_btime;
}

static int v1_read_dqblk(struct dquot *dquot)
{
	int type = dquot->dq_id.type;
	struct v1_disk_dqblk dqblk;
	struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);

	if (!dqopt->files[type])
		return -EINVAL;

	/* Set structure to 0s in case read fails/is after end of file */
	memset(&dqblk, 0, sizeof(struct v1_disk_dqblk));
	dquot->dq_sb->s_op->quota_read(dquot->dq_sb, type, (char *)&dqblk,
			sizeof(struct v1_disk_dqblk),
			v1_dqoff(from_kqid(&init_user_ns, dquot->dq_id)));

	v1_disk2mem_dqblk(&dquot->dq_dqb, &dqblk);
	if (dquot->dq_dqb.dqb_bhardlimit == 0 &&
	    dquot->dq_dqb.dqb_bsoftlimit == 0 &&
	    dquot->dq_dqb.dqb_ihardlimit == 0 &&
	    dquot->dq_dqb.dqb_isoftlimit == 0)
		set_bit(DQ_FAKE_B, &dquot->dq_flags);
	dqstats_inc(DQST_READS);

	return 0;
}

static int v1_commit_dqblk(struct dquot *dquot)
{
	short type = dquot->dq_id.type;
	ssize_t ret;
	struct v1_disk_dqblk dqblk;

	v1_mem2disk_dqblk(&dqblk, &dquot->dq_dqb);
	if (((type == USRQUOTA) && uid_eq(dquot->dq_id.uid, GLOBAL_ROOT_UID)) ||
	    ((type == GRPQUOTA) && gid_eq(dquot->dq_id.gid, GLOBAL_ROOT_GID))) {
		dqblk.dqb_btime =
			sb_dqopt(dquot->dq_sb)->info[type].dqi_bgrace;
		dqblk.dqb_itime =
			sb_dqopt(dquot->dq_sb)->info[type].dqi_igrace;
	}
	ret = 0;
	if (sb_dqopt(dquot->dq_sb)->files[type])
		ret = dquot->dq_sb->s_op->quota_write(dquot->dq_sb, type,
			(char *)&dqblk, sizeof(struct v1_disk_dqblk),
			v1_dqoff(from_kqid(&init_user_ns, dquot->dq_id)));
	if (ret != sizeof(struct v1_disk_dqblk)) {
		quota_error(dquot->dq_sb, "dquota write failed");
		if (ret >= 0)
			ret = -EIO;
		goto out;
	}
	ret = 0;

out:
	dqstats_inc(DQST_WRITES);

	return ret;
}

/* Magics of new quota format */
#define V2_INITQMAGICS {\
	0xd9c01f11,     /* USRQUOTA */\
	0xd9c01927      /* GRPQUOTA */\
}

/* Header of new quota format */
struct v2_disk_dqheader {
	__le32 dqh_magic;        /* Magic number identifying file */
	__le32 dqh_version;      /* File version */
};

static int v1_check_quota_file(struct super_block *sb, int type)
{
	struct inode *inode = sb_dqopt(sb)->files[type];
	ulong blocks;
	size_t off;
	struct v2_disk_dqheader dqhead;
	ssize_t size;
	loff_t isize;
	static const uint quota_magics[] = V2_INITQMAGICS;

	isize = i_size_read(inode);
	if (!isize)
		return 0;
	blocks = isize >> BLOCK_SIZE_BITS;
	off = isize & (BLOCK_SIZE - 1);
	if ((blocks % sizeof(struct v1_disk_dqblk) * BLOCK_SIZE + off) %
	    sizeof(struct v1_disk_dqblk))
		return 0;
	/* Doublecheck whether we didn't get file with new format - with old
	 * quotactl() this could happen */
	size = sb->s_op->quota_read(sb, type, (char *)&dqhead,
				    sizeof(struct v2_disk_dqheader), 0);
	if (size != sizeof(struct v2_disk_dqheader))
		return 1;	/* Probably not new format */
	if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type])
		return 1;	/* Definitely not new format */
	printk(KERN_INFO
	       "VFS: %s: Refusing to turn on old quota format on given file."
	       " It probably contains newer quota format.\n", sb->s_id);
        return 0;		/* Seems like a new format file -> refuse it */
}

static int v1_read_file_info(struct super_block *sb, int type)
{
	struct quota_info *dqopt = sb_dqopt(sb);
	struct v1_disk_dqblk dqblk;
	int ret;

	down_read(&dqopt->dqio_sem);
	ret = sb->s_op->quota_read(sb, type, (char *)&dqblk,
				sizeof(struct v1_disk_dqblk), v1_dqoff(0));
	if (ret != sizeof(struct v1_disk_dqblk)) {
		if (ret >= 0)
			ret = -EIO;
		goto out;
	}
	ret = 0;
	/* limits are stored as unsigned 32-bit data */
	dqopt->info[type].dqi_max_spc_limit = 0xffffffffULL << QUOTABLOCK_BITS;
	dqopt->info[type].dqi_max_ino_limit = 0xffffffff;
	dqopt->info[type].dqi_igrace =
			dqblk.dqb_itime ? dqblk.dqb_itime : MAX_IQ_TIME;
	dqopt->info[type].dqi_bgrace =
			dqblk.dqb_btime ? dqblk.dqb_btime : MAX_DQ_TIME;
out:
	up_read(&dqopt->dqio_sem);
	return ret;
}

static int v1_write_file_info(struct super_block *sb, int type)
{
	struct quota_info *dqopt = sb_dqopt(sb);
	struct v1_disk_dqblk dqblk;
	int ret;

	down_write(&dqopt->dqio_sem);
	ret = sb->s_op->quota_read(sb, type, (char *)&dqblk,
				sizeof(struct v1_disk_dqblk), v1_dqoff(0));
	if (ret != sizeof(struct v1_disk_dqblk)) {
		if (ret >= 0)
			ret = -EIO;
		goto out;
	}
	spin_lock(&dq_data_lock);
	dqopt->info[type].dqi_flags &= ~DQF_INFO_DIRTY;
	dqblk.dqb_itime = dqopt->info[type].dqi_igrace;
	dqblk.dqb_btime = dqopt->info[type].dqi_bgrace;
	spin_unlock(&dq_data_lock);
	ret = sb->s_op->quota_write(sb, type, (char *)&dqblk,
	      sizeof(struct v1_disk_dqblk), v1_dqoff(0));
	if (ret == sizeof(struct v1_disk_dqblk))
		ret = 0;
	else if (ret > 0)
		ret = -EIO;
out:
	up_write(&dqopt->dqio_sem);
	return ret;
}

static const struct quota_format_ops v1_format_ops = {
	.check_quota_file	= v1_check_quota_file,
	.read_file_info		= v1_read_file_info,
	.write_file_info	= v1_write_file_info,
	.read_dqblk		= v1_read_dqblk,
	.commit_dqblk		= v1_commit_dqblk,
};

static struct quota_format_type v1_quota_format = {
	.qf_fmt_id	= QFMT_VFS_OLD,
	.qf_ops		= &v1_format_ops,
	.qf_owner	= THIS_MODULE
};

static int __init init_v1_quota_format(void)
{
        return register_quota_format(&v1_quota_format);
}

static void __exit exit_v1_quota_format(void)
{
        unregister_quota_format(&v1_quota_format);
}

module_init(init_v1_quota_format);
module_exit(exit_v1_quota_format);
Commit	Line	Data
09c434b8	1	// SPDX-License-Identifier: GPL-2.0-only
1da177e4 LT	2	#include <linux/errno.h>
	3	#include <linux/fs.h>
	4	#include <linux/quota.h>
74abb989	5	#include <linux/quotaops.h>
1da177e4	6	#include <linux/dqblk_v1.h>
1da177e4 LT	7	#include <linux/kernel.h>
	8	#include <linux/init.h>
	9	#include <linux/module.h>
	10
	11	#include <asm/byteorder.h>
	12
cf770c13 JK	13	#include "quotaio_v1.h"
cf770c13 JK	14
1da177e4 LT	15	MODULE_AUTHOR("Jan Kara");
	16	MODULE_DESCRIPTION("Old quota format support");
	17	MODULE_LICENSE("GPL");
	18
12095460 JK	19	#define QUOTABLOCK_BITS 10
	20	#define QUOTABLOCK_SIZE (1 << QUOTABLOCK_BITS)
	21
	22	static inline qsize_t v1_stoqb(qsize_t space)
	23	{
	24	return (space + QUOTABLOCK_SIZE - 1) >> QUOTABLOCK_BITS;
	25	}
	26
	27	static inline qsize_t v1_qbtos(qsize_t blocks)
	28	{
	29	return blocks << QUOTABLOCK_BITS;
	30	}
	31
1da177e4 LT	32	static void v1_disk2mem_dqblk(struct mem_dqblk m, struct v1_disk_dqblk d)
	33	{
	34	m->dqb_ihardlimit = d->dqb_ihardlimit;
	35	m->dqb_isoftlimit = d->dqb_isoftlimit;
	36	m->dqb_curinodes = d->dqb_curinodes;
12095460 JK	37	m->dqb_bhardlimit = v1_qbtos(d->dqb_bhardlimit);
	38	m->dqb_bsoftlimit = v1_qbtos(d->dqb_bsoftlimit);
	39	m->dqb_curspace = v1_qbtos(d->dqb_curblocks);
1da177e4 LT	40	m->dqb_itime = d->dqb_itime;
	41	m->dqb_btime = d->dqb_btime;
	42	}
	43
	44	static void v1_mem2disk_dqblk(struct v1_disk_dqblk d, struct mem_dqblk m)
	45	{
	46	d->dqb_ihardlimit = m->dqb_ihardlimit;
	47	d->dqb_isoftlimit = m->dqb_isoftlimit;
	48	d->dqb_curinodes = m->dqb_curinodes;
12095460 JK	49	d->dqb_bhardlimit = v1_stoqb(m->dqb_bhardlimit);
	50	d->dqb_bsoftlimit = v1_stoqb(m->dqb_bsoftlimit);
	51	d->dqb_curblocks = v1_stoqb(m->dqb_curspace);
1da177e4 LT	52	d->dqb_itime = m->dqb_itime;
	53	d->dqb_btime = m->dqb_btime;
	54	}
	55
	56	static int v1_read_dqblk(struct dquot *dquot)
	57	{
4c376dca	58	int type = dquot->dq_id.type;
1da177e4	59	struct v1_disk_dqblk dqblk;
e342e38d	60	struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
1da177e4	61
e342e38d	62	if (!dqopt->files[type])
1da177e4 LT	63	return -EINVAL;
	64
	65	/* Set structure to 0s in case read fails/is after end of file */
	66	memset(&dqblk, 0, sizeof(struct v1_disk_dqblk));
268157ba	67	dquot->dq_sb->s_op->quota_read(dquot->dq_sb, type, (char *)&dqblk,
4c376dca EB	68	sizeof(struct v1_disk_dqblk),
4c376dca EB	69	v1_dqoff(from_kqid(&init_user_ns, dquot->dq_id)));
1da177e4 LT	70
1da177e4 LT	71	v1_disk2mem_dqblk(&dquot->dq_dqb, &dqblk);
268157ba JK	72	if (dquot->dq_dqb.dqb_bhardlimit == 0 &&
	73	dquot->dq_dqb.dqb_bsoftlimit == 0 &&
	74	dquot->dq_dqb.dqb_ihardlimit == 0 &&
	75	dquot->dq_dqb.dqb_isoftlimit == 0)
1da177e4	76	set_bit(DQ_FAKE_B, &dquot->dq_flags);
dde95888	77	dqstats_inc(DQST_READS);
1da177e4 LT	78
	79	return 0;
	80	}
	81
	82	static int v1_commit_dqblk(struct dquot *dquot)
	83	{
4c376dca	84	short type = dquot->dq_id.type;
1da177e4 LT	85	ssize_t ret;
	86	struct v1_disk_dqblk dqblk;
	87
	88	v1_mem2disk_dqblk(&dqblk, &dquot->dq_dqb);
4c376dca EB	89	if (((type == USRQUOTA) && uid_eq(dquot->dq_id.uid, GLOBAL_ROOT_UID)) \|\|
4c376dca EB	90	((type == GRPQUOTA) && gid_eq(dquot->dq_id.gid, GLOBAL_ROOT_GID))) {
268157ba JK	91	dqblk.dqb_btime =
	92	sb_dqopt(dquot->dq_sb)->info[type].dqi_bgrace;
	93	dqblk.dqb_itime =
	94	sb_dqopt(dquot->dq_sb)->info[type].dqi_igrace;
1da177e4 LT	95	}
	96	ret = 0;
	97	if (sb_dqopt(dquot->dq_sb)->files[type])
268157ba JK	98	ret = dquot->dq_sb->s_op->quota_write(dquot->dq_sb, type,
268157ba JK	99	(char *)&dqblk, sizeof(struct v1_disk_dqblk),
4c376dca	100	v1_dqoff(from_kqid(&init_user_ns, dquot->dq_id)));
1da177e4	101	if (ret != sizeof(struct v1_disk_dqblk)) {
fb5ffb0e	102	quota_error(dquot->dq_sb, "dquota write failed");
1da177e4 LT	103	if (ret >= 0)
	104	ret = -EIO;
	105	goto out;
	106	}
	107	ret = 0;
	108
	109	out:
dde95888	110	dqstats_inc(DQST_WRITES);
1da177e4 LT	111
	112	return ret;
	113	}
	114
	115	/* Magics of new quota format */
	116	#define V2_INITQMAGICS {\
	117	0xd9c01f11, /* USRQUOTA */\
	118	0xd9c01927 /* GRPQUOTA */\
	119	}
	120
	121	/* Header of new quota format */
	122	struct v2_disk_dqheader {
	123	__le32 dqh_magic; /* Magic number identifying file */
	124	__le32 dqh_version; /* File version */
	125	};
	126
	127	static int v1_check_quota_file(struct super_block *sb, int type)
	128	{
	129	struct inode *inode = sb_dqopt(sb)->files[type];
	130	ulong blocks;
27942ef5	131	size_t off;
1da177e4 LT	132	struct v2_disk_dqheader dqhead;
	133	ssize_t size;
	134	loff_t isize;
	135	static const uint quota_magics[] = V2_INITQMAGICS;
	136
	137	isize = i_size_read(inode);
	138	if (!isize)
	139	return 0;
	140	blocks = isize >> BLOCK_SIZE_BITS;
	141	off = isize & (BLOCK_SIZE - 1);
268157ba JK	142	if ((blocks % sizeof(struct v1_disk_dqblk) * BLOCK_SIZE + off) %
268157ba JK	143	sizeof(struct v1_disk_dqblk))
1da177e4	144	return 0;
268157ba JK	145	/* Doublecheck whether we didn't get file with new format - with old
	146	* quotactl() this could happen */
	147	size = sb->s_op->quota_read(sb, type, (char *)&dqhead,
	148	sizeof(struct v2_disk_dqheader), 0);
1da177e4 LT	149	if (size != sizeof(struct v2_disk_dqheader))
	150	return 1; /* Probably not new format */
	151	if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type])
	152	return 1; /* Definitely not new format */
268157ba JK	153	printk(KERN_INFO
	154	"VFS: %s: Refusing to turn on old quota format on given file."
	155	" It probably contains newer quota format.\n", sb->s_id);
1da177e4 LT	156	return 0; /* Seems like a new format file -> refuse it */
	157	}
	158
	159	static int v1_read_file_info(struct super_block *sb, int type)
	160	{
	161	struct quota_info *dqopt = sb_dqopt(sb);
	162	struct v1_disk_dqblk dqblk;
	163	int ret;
	164
42fdb858	165	down_read(&dqopt->dqio_sem);
268157ba JK	166	ret = sb->s_op->quota_read(sb, type, (char *)&dqblk,
	167	sizeof(struct v1_disk_dqblk), v1_dqoff(0));
	168	if (ret != sizeof(struct v1_disk_dqblk)) {
1da177e4 LT	169	if (ret >= 0)
	170	ret = -EIO;
	171	goto out;
	172	}
	173	ret = 0;
338bf9af	174	/* limits are stored as unsigned 32-bit data */
b10a0819 JK	175	dqopt->info[type].dqi_max_spc_limit = 0xffffffffULL << QUOTABLOCK_BITS;
b10a0819 JK	176	dqopt->info[type].dqi_max_ino_limit = 0xffffffff;
268157ba JK	177	dqopt->info[type].dqi_igrace =
	178	dqblk.dqb_itime ? dqblk.dqb_itime : MAX_IQ_TIME;
	179	dqopt->info[type].dqi_bgrace =
	180	dqblk.dqb_btime ? dqblk.dqb_btime : MAX_DQ_TIME;
1da177e4	181	out:
42fdb858	182	up_read(&dqopt->dqio_sem);
1da177e4 LT	183	return ret;
	184	}
	185
	186	static int v1_write_file_info(struct super_block *sb, int type)
	187	{
	188	struct quota_info *dqopt = sb_dqopt(sb);
	189	struct v1_disk_dqblk dqblk;
	190	int ret;
	191
9a8ae30e	192	down_write(&dqopt->dqio_sem);
268157ba JK	193	ret = sb->s_op->quota_read(sb, type, (char *)&dqblk,
	194	sizeof(struct v1_disk_dqblk), v1_dqoff(0));
	195	if (ret != sizeof(struct v1_disk_dqblk)) {
1da177e4 LT	196	if (ret >= 0)
	197	ret = -EIO;
	198	goto out;
	199	}
15512377 JK	200	spin_lock(&dq_data_lock);
15512377 JK	201	dqopt->info[type].dqi_flags &= ~DQF_INFO_DIRTY;
1da177e4 LT	202	dqblk.dqb_itime = dqopt->info[type].dqi_igrace;
1da177e4 LT	203	dqblk.dqb_btime = dqopt->info[type].dqi_bgrace;
15512377	204	spin_unlock(&dq_data_lock);
1da177e4 LT	205	ret = sb->s_op->quota_write(sb, type, (char *)&dqblk,
	206	sizeof(struct v1_disk_dqblk), v1_dqoff(0));
	207	if (ret == sizeof(struct v1_disk_dqblk))
	208	ret = 0;
	209	else if (ret > 0)
	210	ret = -EIO;
	211	out:
9a8ae30e	212	up_write(&dqopt->dqio_sem);
1da177e4 LT	213	return ret;
	214	}
	215
1472da5f	216	static const struct quota_format_ops v1_format_ops = {
1da177e4 LT	217	.check_quota_file = v1_check_quota_file,
	218	.read_file_info = v1_read_file_info,
	219	.write_file_info = v1_write_file_info,
1da177e4 LT	220	.read_dqblk = v1_read_dqblk,
	221	.commit_dqblk = v1_commit_dqblk,
	222	};
	223
	224	static struct quota_format_type v1_quota_format = {
	225	.qf_fmt_id = QFMT_VFS_OLD,
	226	.qf_ops = &v1_format_ops,
	227	.qf_owner = THIS_MODULE
	228	};
	229
	230	static int __init init_v1_quota_format(void)
	231	{
	232	return register_quota_format(&v1_quota_format);
	233	}
	234
	235	static void __exit exit_v1_quota_format(void)
	236	{
	237	unregister_quota_format(&v1_quota_format);
	238	}
	239
	240	module_init(init_v1_quota_format);
	241	module_exit(exit_v1_quota_format);
	242