[mirror_ubuntu-artful-kernel.git] / fs / quota / quota_v1.c

#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;
	qid_t qid;

	if (!sb_dqopt(dquot->dq_sb)->files[type])
		return -EINVAL;

	qid = from_kqid(dquot->dq_sb->s_user_ns, dquot->dq_id);
	if (qid == (qid_t)-1)
		return -EOVERFLOW;

	/* 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(qid));

	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;
	qid_t qid = from_kqid(dquot->dq_sb->s_user_ns, dquot->dq_id);

	if (qid == (qid_t)-1)
		return -EOVERFLOW;

	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(qid));
	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;

	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:
	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;

	dqopt->info[type].dqi_flags &= ~DQF_INFO_DIRTY;
	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;
	}
	dqblk.dqb_itime = dqopt->info[type].dqi_igrace;
	dqblk.dqb_btime = dqopt->info[type].dqi_bgrace;
	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:
	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,
	.free_file_info		= NULL,
	.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
1da177e4 LT	1	#include <linux/errno.h>
	2	#include <linux/fs.h>
	3	#include <linux/quota.h>
74abb989	4	#include <linux/quotaops.h>
1da177e4	5	#include <linux/dqblk_v1.h>
1da177e4 LT	6	#include <linux/kernel.h>
	7	#include <linux/init.h>
	8	#include <linux/module.h>
	9
	10	#include <asm/byteorder.h>
	11
cf770c13 JK	12	#include "quotaio_v1.h"
cf770c13 JK	13
1da177e4 LT	14	MODULE_AUTHOR("Jan Kara");
	15	MODULE_DESCRIPTION("Old quota format support");
	16	MODULE_LICENSE("GPL");
	17
12095460 JK	18	#define QUOTABLOCK_BITS 10
	19	#define QUOTABLOCK_SIZE (1 << QUOTABLOCK_BITS)
	20
	21	static inline qsize_t v1_stoqb(qsize_t space)
	22	{
	23	return (space + QUOTABLOCK_SIZE - 1) >> QUOTABLOCK_BITS;
	24	}
	25
	26	static inline qsize_t v1_qbtos(qsize_t blocks)
	27	{
	28	return blocks << QUOTABLOCK_BITS;
	29	}
	30
1da177e4 LT	31	static void v1_disk2mem_dqblk(struct mem_dqblk m, struct v1_disk_dqblk d)
	32	{
	33	m->dqb_ihardlimit = d->dqb_ihardlimit;
	34	m->dqb_isoftlimit = d->dqb_isoftlimit;
	35	m->dqb_curinodes = d->dqb_curinodes;
12095460 JK	36	m->dqb_bhardlimit = v1_qbtos(d->dqb_bhardlimit);
	37	m->dqb_bsoftlimit = v1_qbtos(d->dqb_bsoftlimit);
	38	m->dqb_curspace = v1_qbtos(d->dqb_curblocks);
1da177e4 LT	39	m->dqb_itime = d->dqb_itime;
	40	m->dqb_btime = d->dqb_btime;
	41	}
	42
	43	static void v1_mem2disk_dqblk(struct v1_disk_dqblk d, struct mem_dqblk m)
	44	{
	45	d->dqb_ihardlimit = m->dqb_ihardlimit;
	46	d->dqb_isoftlimit = m->dqb_isoftlimit;
	47	d->dqb_curinodes = m->dqb_curinodes;
12095460 JK	48	d->dqb_bhardlimit = v1_stoqb(m->dqb_bhardlimit);
	49	d->dqb_bsoftlimit = v1_stoqb(m->dqb_bsoftlimit);
	50	d->dqb_curblocks = v1_stoqb(m->dqb_curspace);
1da177e4 LT	51	d->dqb_itime = m->dqb_itime;
	52	d->dqb_btime = m->dqb_btime;
	53	}
	54
	55	static int v1_read_dqblk(struct dquot *dquot)
	56	{
4c376dca	57	int type = dquot->dq_id.type;
1da177e4	58	struct v1_disk_dqblk dqblk;
8010267b	59	qid_t qid;
1da177e4 LT	60
	61	if (!sb_dqopt(dquot->dq_sb)->files[type])
	62	return -EINVAL;
	63
8010267b LH	64	qid = from_kqid(dquot->dq_sb->s_user_ns, dquot->dq_id);
	65	if (qid == (qid_t)-1)
	66	return -EOVERFLOW;
	67
1da177e4 LT	68	/* Set structure to 0s in case read fails/is after end of file */
1da177e4 LT	69	memset(&dqblk, 0, sizeof(struct v1_disk_dqblk));
268157ba	70	dquot->dq_sb->s_op->quota_read(dquot->dq_sb, type, (char *)&dqblk,
4c376dca	71	sizeof(struct v1_disk_dqblk),
8010267b	72	v1_dqoff(qid));
1da177e4 LT	73
1da177e4 LT	74	v1_disk2mem_dqblk(&dquot->dq_dqb, &dqblk);
268157ba JK	75	if (dquot->dq_dqb.dqb_bhardlimit == 0 &&
	76	dquot->dq_dqb.dqb_bsoftlimit == 0 &&
	77	dquot->dq_dqb.dqb_ihardlimit == 0 &&
	78	dquot->dq_dqb.dqb_isoftlimit == 0)
1da177e4	79	set_bit(DQ_FAKE_B, &dquot->dq_flags);
dde95888	80	dqstats_inc(DQST_READS);
1da177e4 LT	81
	82	return 0;
	83	}
	84
	85	static int v1_commit_dqblk(struct dquot *dquot)
	86	{
4c376dca	87	short type = dquot->dq_id.type;
1da177e4 LT	88	ssize_t ret;
1da177e4 LT	89	struct v1_disk_dqblk dqblk;
8010267b LH	90	qid_t qid = from_kqid(dquot->dq_sb->s_user_ns, dquot->dq_id);
	91
	92	if (qid == (qid_t)-1)
	93	return -EOVERFLOW;
1da177e4 LT	94
1da177e4 LT	95	v1_mem2disk_dqblk(&dqblk, &dquot->dq_dqb);
4c376dca EB	96	if (((type == USRQUOTA) && uid_eq(dquot->dq_id.uid, GLOBAL_ROOT_UID)) \|\|
4c376dca EB	97	((type == GRPQUOTA) && gid_eq(dquot->dq_id.gid, GLOBAL_ROOT_GID))) {
268157ba JK	98	dqblk.dqb_btime =
	99	sb_dqopt(dquot->dq_sb)->info[type].dqi_bgrace;
	100	dqblk.dqb_itime =
	101	sb_dqopt(dquot->dq_sb)->info[type].dqi_igrace;
1da177e4 LT	102	}
	103	ret = 0;
	104	if (sb_dqopt(dquot->dq_sb)->files[type])
268157ba JK	105	ret = dquot->dq_sb->s_op->quota_write(dquot->dq_sb, type,
268157ba JK	106	(char *)&dqblk, sizeof(struct v1_disk_dqblk),
8010267b	107	v1_dqoff(qid));
1da177e4	108	if (ret != sizeof(struct v1_disk_dqblk)) {
fb5ffb0e	109	quota_error(dquot->dq_sb, "dquota write failed");
1da177e4 LT	110	if (ret >= 0)
	111	ret = -EIO;
	112	goto out;
	113	}
	114	ret = 0;
	115
	116	out:
dde95888	117	dqstats_inc(DQST_WRITES);
1da177e4 LT	118
	119	return ret;
	120	}
	121
	122	/* Magics of new quota format */
	123	#define V2_INITQMAGICS {\
	124	0xd9c01f11, /* USRQUOTA */\
	125	0xd9c01927 /* GRPQUOTA */\
	126	}
	127
	128	/* Header of new quota format */
	129	struct v2_disk_dqheader {
	130	__le32 dqh_magic; /* Magic number identifying file */
	131	__le32 dqh_version; /* File version */
	132	};
	133
	134	static int v1_check_quota_file(struct super_block *sb, int type)
	135	{
	136	struct inode *inode = sb_dqopt(sb)->files[type];
	137	ulong blocks;
	138	size_t off;
	139	struct v2_disk_dqheader dqhead;
	140	ssize_t size;
	141	loff_t isize;
	142	static const uint quota_magics[] = V2_INITQMAGICS;
	143
	144	isize = i_size_read(inode);
	145	if (!isize)
	146	return 0;
	147	blocks = isize >> BLOCK_SIZE_BITS;
	148	off = isize & (BLOCK_SIZE - 1);
268157ba JK	149	if ((blocks % sizeof(struct v1_disk_dqblk) * BLOCK_SIZE + off) %
268157ba JK	150	sizeof(struct v1_disk_dqblk))
1da177e4	151	return 0;
268157ba JK	152	/* Doublecheck whether we didn't get file with new format - with old
	153	* quotactl() this could happen */
	154	size = sb->s_op->quota_read(sb, type, (char *)&dqhead,
	155	sizeof(struct v2_disk_dqheader), 0);
1da177e4 LT	156	if (size != sizeof(struct v2_disk_dqheader))
	157	return 1; /* Probably not new format */
	158	if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type])
	159	return 1; /* Definitely not new format */
268157ba JK	160	printk(KERN_INFO
	161	"VFS: %s: Refusing to turn on old quota format on given file."
	162	" It probably contains newer quota format.\n", sb->s_id);
1da177e4 LT	163	return 0; /* Seems like a new format file -> refuse it */
	164	}
	165
	166	static int v1_read_file_info(struct super_block *sb, int type)
	167	{
	168	struct quota_info *dqopt = sb_dqopt(sb);
	169	struct v1_disk_dqblk dqblk;
	170	int ret;
	171
268157ba JK	172	ret = sb->s_op->quota_read(sb, type, (char *)&dqblk,
	173	sizeof(struct v1_disk_dqblk), v1_dqoff(0));
	174	if (ret != sizeof(struct v1_disk_dqblk)) {
1da177e4 LT	175	if (ret >= 0)
	176	ret = -EIO;
	177	goto out;
	178	}
	179	ret = 0;
338bf9af	180	/* limits are stored as unsigned 32-bit data */
b10a0819 JK	181	dqopt->info[type].dqi_max_spc_limit = 0xffffffffULL << QUOTABLOCK_BITS;
b10a0819 JK	182	dqopt->info[type].dqi_max_ino_limit = 0xffffffff;
268157ba JK	183	dqopt->info[type].dqi_igrace =
	184	dqblk.dqb_itime ? dqblk.dqb_itime : MAX_IQ_TIME;
	185	dqopt->info[type].dqi_bgrace =
	186	dqblk.dqb_btime ? dqblk.dqb_btime : MAX_DQ_TIME;
1da177e4 LT	187	out:
	188	return ret;
	189	}
	190
	191	static int v1_write_file_info(struct super_block *sb, int type)
	192	{
	193	struct quota_info *dqopt = sb_dqopt(sb);
	194	struct v1_disk_dqblk dqblk;
	195	int ret;
	196
	197	dqopt->info[type].dqi_flags &= ~DQF_INFO_DIRTY;
268157ba JK	198	ret = sb->s_op->quota_read(sb, type, (char *)&dqblk,
	199	sizeof(struct v1_disk_dqblk), v1_dqoff(0));
	200	if (ret != sizeof(struct v1_disk_dqblk)) {
1da177e4 LT	201	if (ret >= 0)
	202	ret = -EIO;
	203	goto out;
	204	}
	205	dqblk.dqb_itime = dqopt->info[type].dqi_igrace;
	206	dqblk.dqb_btime = dqopt->info[type].dqi_bgrace;
	207	ret = sb->s_op->quota_write(sb, type, (char *)&dqblk,
	208	sizeof(struct v1_disk_dqblk), v1_dqoff(0));
	209	if (ret == sizeof(struct v1_disk_dqblk))
	210	ret = 0;
	211	else if (ret > 0)
	212	ret = -EIO;
	213	out:
	214	return ret;
	215	}
	216
1472da5f	217	static const struct quota_format_ops v1_format_ops = {
1da177e4 LT	218	.check_quota_file = v1_check_quota_file,
	219	.read_file_info = v1_read_file_info,
	220	.write_file_info = v1_write_file_info,
	221	.free_file_info = NULL,
	222	.read_dqblk = v1_read_dqblk,
	223	.commit_dqblk = v1_commit_dqblk,
	224	};
	225
	226	static struct quota_format_type v1_quota_format = {
	227	.qf_fmt_id = QFMT_VFS_OLD,
	228	.qf_ops = &v1_format_ops,
	229	.qf_owner = THIS_MODULE
	230	};
	231
	232	static int __init init_v1_quota_format(void)
	233	{
	234	return register_quota_format(&v1_quota_format);
	235	}
	236
	237	static void __exit exit_v1_quota_format(void)
	238	{
	239	unregister_quota_format(&v1_quota_format);
	240	}
	241
	242	module_init(init_v1_quota_format);
	243	module_exit(exit_v1_quota_format);
	244