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1// SPDX-License-Identifier: GPL-2.0-only2#include <linux/errno.h>3#include <linux/fs.h>4#include <linux/quota.h>5#include <linux/quotaops.h>6#include <linux/dqblk_v1.h>7#include <linux/kernel.h>8#include <linux/init.h>9#include <linux/module.h>10 11#include <asm/byteorder.h>12 13#include "quotaio_v1.h"14 15MODULE_AUTHOR("Jan Kara");16MODULE_DESCRIPTION("Old quota format support");17MODULE_LICENSE("GPL");18 19#define QUOTABLOCK_BITS 1020#define QUOTABLOCK_SIZE (1 << QUOTABLOCK_BITS)21 22static inline qsize_t v1_stoqb(qsize_t space)23{24 return (space + QUOTABLOCK_SIZE - 1) >> QUOTABLOCK_BITS;25}26 27static inline qsize_t v1_qbtos(qsize_t blocks)28{29 return blocks << QUOTABLOCK_BITS;30}31 32static 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;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);40 m->dqb_itime = d->dqb_itime;41 m->dqb_btime = d->dqb_btime;42}43 44static 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;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);52 d->dqb_itime = m->dqb_itime;53 d->dqb_btime = m->dqb_btime;54}55 56static int v1_read_dqblk(struct dquot *dquot)57{58 int type = dquot->dq_id.type;59 struct v1_disk_dqblk dqblk;60 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);61 62 if (!dqopt->files[type])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));67 dquot->dq_sb->s_op->quota_read(dquot->dq_sb, type, (char *)&dqblk,68 sizeof(struct v1_disk_dqblk),69 v1_dqoff(from_kqid(&init_user_ns, dquot->dq_id)));70 71 v1_disk2mem_dqblk(&dquot->dq_dqb, &dqblk);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)76 set_bit(DQ_FAKE_B, &dquot->dq_flags);77 dqstats_inc(DQST_READS);78 79 return 0;80}81 82static int v1_commit_dqblk(struct dquot *dquot)83{84 short type = dquot->dq_id.type;85 ssize_t ret;86 struct v1_disk_dqblk dqblk;87 88 v1_mem2disk_dqblk(&dqblk, &dquot->dq_dqb);89 if (((type == USRQUOTA) && uid_eq(dquot->dq_id.uid, GLOBAL_ROOT_UID)) ||90 ((type == GRPQUOTA) && gid_eq(dquot->dq_id.gid, GLOBAL_ROOT_GID))) {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;95 }96 ret = 0;97 if (sb_dqopt(dquot->dq_sb)->files[type])98 ret = dquot->dq_sb->s_op->quota_write(dquot->dq_sb, type,99 (char *)&dqblk, sizeof(struct v1_disk_dqblk),100 v1_dqoff(from_kqid(&init_user_ns, dquot->dq_id)));101 if (ret != sizeof(struct v1_disk_dqblk)) {102 quota_error(dquot->dq_sb, "dquota write failed");103 if (ret >= 0)104 ret = -EIO;105 goto out;106 }107 ret = 0;108 109out:110 dqstats_inc(DQST_WRITES);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 */122struct v2_disk_dqheader {123 __le32 dqh_magic; /* Magic number identifying file */124 __le32 dqh_version; /* File version */125};126 127static int v1_check_quota_file(struct super_block *sb, int type)128{129 struct inode *inode = sb_dqopt(sb)->files[type];130 ulong blocks;131 size_t off;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);142 if ((blocks % sizeof(struct v1_disk_dqblk) * BLOCK_SIZE + off) %143 sizeof(struct v1_disk_dqblk))144 return 0;145 /* Doublecheck whether we didn't get file with new format - with old146 * quotactl() this could happen */147 size = sb->s_op->quota_read(sb, type, (char *)&dqhead,148 sizeof(struct v2_disk_dqheader), 0);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 */153 printk(KERN_INFO154 "VFS: %s: Refusing to turn on old quota format on given file."155 " It probably contains newer quota format.\n", sb->s_id);156 return 0; /* Seems like a new format file -> refuse it */157}158 159static 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 unsigned int memalloc;164 int ret;165 166 down_read(&dqopt->dqio_sem);167 memalloc = memalloc_nofs_save();168 ret = sb->s_op->quota_read(sb, type, (char *)&dqblk,169 sizeof(struct v1_disk_dqblk), v1_dqoff(0));170 if (ret != sizeof(struct v1_disk_dqblk)) {171 if (ret >= 0)172 ret = -EIO;173 goto out;174 }175 ret = 0;176 /* limits are stored as unsigned 32-bit data */177 dqopt->info[type].dqi_max_spc_limit = 0xffffffffULL << QUOTABLOCK_BITS;178 dqopt->info[type].dqi_max_ino_limit = 0xffffffff;179 dqopt->info[type].dqi_igrace =180 dqblk.dqb_itime ? dqblk.dqb_itime : MAX_IQ_TIME;181 dqopt->info[type].dqi_bgrace =182 dqblk.dqb_btime ? dqblk.dqb_btime : MAX_DQ_TIME;183out:184 memalloc_nofs_restore(memalloc);185 up_read(&dqopt->dqio_sem);186 return ret;187}188 189static int v1_write_file_info(struct super_block *sb, int type)190{191 struct quota_info *dqopt = sb_dqopt(sb);192 struct v1_disk_dqblk dqblk;193 unsigned int memalloc;194 int ret;195 196 down_write(&dqopt->dqio_sem);197 memalloc = memalloc_nofs_save();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)) {201 if (ret >= 0)202 ret = -EIO;203 goto out;204 }205 spin_lock(&dq_data_lock);206 dqopt->info[type].dqi_flags &= ~DQF_INFO_DIRTY;207 dqblk.dqb_itime = dqopt->info[type].dqi_igrace;208 dqblk.dqb_btime = dqopt->info[type].dqi_bgrace;209 spin_unlock(&dq_data_lock);210 ret = sb->s_op->quota_write(sb, type, (char *)&dqblk,211 sizeof(struct v1_disk_dqblk), v1_dqoff(0));212 if (ret == sizeof(struct v1_disk_dqblk))213 ret = 0;214 else if (ret >= 0)215 ret = -EIO;216out:217 memalloc_nofs_restore(memalloc);218 up_write(&dqopt->dqio_sem);219 return ret;220}221 222static const struct quota_format_ops v1_format_ops = {223 .check_quota_file = v1_check_quota_file,224 .read_file_info = v1_read_file_info,225 .write_file_info = v1_write_file_info,226 .read_dqblk = v1_read_dqblk,227 .commit_dqblk = v1_commit_dqblk,228};229 230static struct quota_format_type v1_quota_format = {231 .qf_fmt_id = QFMT_VFS_OLD,232 .qf_ops = &v1_format_ops,233 .qf_owner = THIS_MODULE234};235 236static int __init init_v1_quota_format(void)237{238 register_quota_format(&v1_quota_format);239 return 0;240}241 242static void __exit exit_v1_quota_format(void)243{244 unregister_quota_format(&v1_quota_format);245}246 247module_init(init_v1_quota_format);248module_exit(exit_v1_quota_format);249 250