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linux/fs/quota/quota_v1.c
Eric W. Biederman 4c376dcae8 userns: Convert struct dquot dq_id to be a struct kqid 
Change struct dquot dq_id to a struct kqid and remove the now
unecessary dq_type.

Make minimal changes to dquot, quota_tree, quota_v1, quota_v2, ext3,
ext4, and ocfs2 to deal with the change in quota structures and
signatures.  The ocfs2 changes are larger than most because of the
extensive tracing throughout the ocfs2 quota code that prints out
dq_id.

quota_tree.c:get_index is modified to take a struct kqid instead of a
qid_t because all of it's callers pass in dquot->dq_id and it allows
me to introduce only a single conversion.

The rest of the changes are either just replacing dq_type with dq_id.type,
adding conversions to deal with the change in type and occassionally
adding qid_eq to allow quota id comparisons in a user namespace safe way.

Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Theodore Tso <tytso@mit.edu>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-09-18 01:01:41 -07:00

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#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;
if (!sb_dqopt(dquot->dq_sb)->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;
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_maxblimit = 0xffffffff;
dqopt->info[type].dqi_maxilimit = 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);
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