1 #include <linux/errno.h> 2 #include <linux/fs.h> 3 #include <linux/quota.h> 4 #include <linux/quotaops.h> 5 #include <linux/dqblk_v1.h> 6 #include <linux/kernel.h> 7 #include <linux/init.h> 8 #include <linux/module.h> 9 10 #include <asm/byteorder.h> 11 12 #include "quotaio_v1.h" 13 14 MODULE_AUTHOR("Jan Kara"); 15 MODULE_DESCRIPTION("Old quota format support"); 16 MODULE_LICENSE("GPL"); 17 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 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; 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); 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; 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); 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 { 57 int type = dquot->dq_id.type; 58 struct v1_disk_dqblk dqblk; 59 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 60 61 if (!dqopt->files[type]) 62 return -EINVAL; 63 64 /* Set structure to 0s in case read fails/is after end of file */ 65 memset(&dqblk, 0, sizeof(struct v1_disk_dqblk)); 66 dquot->dq_sb->s_op->quota_read(dquot->dq_sb, type, (char *)&dqblk, 67 sizeof(struct v1_disk_dqblk), 68 v1_dqoff(from_kqid(&init_user_ns, dquot->dq_id))); 69 70 v1_disk2mem_dqblk(&dquot->dq_dqb, &dqblk); 71 if (dquot->dq_dqb.dqb_bhardlimit == 0 && 72 dquot->dq_dqb.dqb_bsoftlimit == 0 && 73 dquot->dq_dqb.dqb_ihardlimit == 0 && 74 dquot->dq_dqb.dqb_isoftlimit == 0) 75 set_bit(DQ_FAKE_B, &dquot->dq_flags); 76 dqstats_inc(DQST_READS); 77 78 return 0; 79 } 80 81 static int v1_commit_dqblk(struct dquot *dquot) 82 { 83 short type = dquot->dq_id.type; 84 ssize_t ret; 85 struct v1_disk_dqblk dqblk; 86 87 v1_mem2disk_dqblk(&dqblk, &dquot->dq_dqb); 88 if (((type == USRQUOTA) && uid_eq(dquot->dq_id.uid, GLOBAL_ROOT_UID)) || 89 ((type == GRPQUOTA) && gid_eq(dquot->dq_id.gid, GLOBAL_ROOT_GID))) { 90 dqblk.dqb_btime = 91 sb_dqopt(dquot->dq_sb)->info[type].dqi_bgrace; 92 dqblk.dqb_itime = 93 sb_dqopt(dquot->dq_sb)->info[type].dqi_igrace; 94 } 95 ret = 0; 96 if (sb_dqopt(dquot->dq_sb)->files[type]) 97 ret = dquot->dq_sb->s_op->quota_write(dquot->dq_sb, type, 98 (char *)&dqblk, sizeof(struct v1_disk_dqblk), 99 v1_dqoff(from_kqid(&init_user_ns, dquot->dq_id))); 100 if (ret != sizeof(struct v1_disk_dqblk)) { 101 quota_error(dquot->dq_sb, "dquota write failed"); 102 if (ret >= 0) 103 ret = -EIO; 104 goto out; 105 } 106 ret = 0; 107 108 out: 109 dqstats_inc(DQST_WRITES); 110 111 return ret; 112 } 113 114 /* Magics of new quota format */ 115 #define V2_INITQMAGICS {\ 116 0xd9c01f11, /* USRQUOTA */\ 117 0xd9c01927 /* GRPQUOTA */\ 118 } 119 120 /* Header of new quota format */ 121 struct v2_disk_dqheader { 122 __le32 dqh_magic; /* Magic number identifying file */ 123 __le32 dqh_version; /* File version */ 124 }; 125 126 static int v1_check_quota_file(struct super_block *sb, int type) 127 { 128 struct inode *inode = sb_dqopt(sb)->files[type]; 129 ulong blocks; 130 size_t off; 131 struct v2_disk_dqheader dqhead; 132 ssize_t size; 133 loff_t isize; 134 static const uint quota_magics[] = V2_INITQMAGICS; 135 136 isize = i_size_read(inode); 137 if (!isize) 138 return 0; 139 blocks = isize >> BLOCK_SIZE_BITS; 140 off = isize & (BLOCK_SIZE - 1); 141 if ((blocks % sizeof(struct v1_disk_dqblk) * BLOCK_SIZE + off) % 142 sizeof(struct v1_disk_dqblk)) 143 return 0; 144 /* Doublecheck whether we didn't get file with new format - with old 145 * quotactl() this could happen */ 146 size = sb->s_op->quota_read(sb, type, (char *)&dqhead, 147 sizeof(struct v2_disk_dqheader), 0); 148 if (size != sizeof(struct v2_disk_dqheader)) 149 return 1; /* Probably not new format */ 150 if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type]) 151 return 1; /* Definitely not new format */ 152 printk(KERN_INFO 153 "VFS: %s: Refusing to turn on old quota format on given file." 154 " It probably contains newer quota format.\n", sb->s_id); 155 return 0; /* Seems like a new format file -> refuse it */ 156 } 157 158 static int v1_read_file_info(struct super_block *sb, int type) 159 { 160 struct quota_info *dqopt = sb_dqopt(sb); 161 struct v1_disk_dqblk dqblk; 162 int ret; 163 164 down_read(&dqopt->dqio_sem); 165 ret = sb->s_op->quota_read(sb, type, (char *)&dqblk, 166 sizeof(struct v1_disk_dqblk), v1_dqoff(0)); 167 if (ret != sizeof(struct v1_disk_dqblk)) { 168 if (ret >= 0) 169 ret = -EIO; 170 goto out; 171 } 172 ret = 0; 173 /* limits are stored as unsigned 32-bit data */ 174 dqopt->info[type].dqi_max_spc_limit = 0xffffffffULL << QUOTABLOCK_BITS; 175 dqopt->info[type].dqi_max_ino_limit = 0xffffffff; 176 dqopt->info[type].dqi_igrace = 177 dqblk.dqb_itime ? dqblk.dqb_itime : MAX_IQ_TIME; 178 dqopt->info[type].dqi_bgrace = 179 dqblk.dqb_btime ? dqblk.dqb_btime : MAX_DQ_TIME; 180 out: 181 up_read(&dqopt->dqio_sem); 182 return ret; 183 } 184 185 static int v1_write_file_info(struct super_block *sb, int type) 186 { 187 struct quota_info *dqopt = sb_dqopt(sb); 188 struct v1_disk_dqblk dqblk; 189 int ret; 190 191 down_write(&dqopt->dqio_sem); 192 ret = sb->s_op->quota_read(sb, type, (char *)&dqblk, 193 sizeof(struct v1_disk_dqblk), v1_dqoff(0)); 194 if (ret != sizeof(struct v1_disk_dqblk)) { 195 if (ret >= 0) 196 ret = -EIO; 197 goto out; 198 } 199 spin_lock(&dq_data_lock); 200 dqopt->info[type].dqi_flags &= ~DQF_INFO_DIRTY; 201 dqblk.dqb_itime = dqopt->info[type].dqi_igrace; 202 dqblk.dqb_btime = dqopt->info[type].dqi_bgrace; 203 spin_unlock(&dq_data_lock); 204 ret = sb->s_op->quota_write(sb, type, (char *)&dqblk, 205 sizeof(struct v1_disk_dqblk), v1_dqoff(0)); 206 if (ret == sizeof(struct v1_disk_dqblk)) 207 ret = 0; 208 else if (ret > 0) 209 ret = -EIO; 210 out: 211 up_write(&dqopt->dqio_sem); 212 return ret; 213 } 214 215 static const struct quota_format_ops v1_format_ops = { 216 .check_quota_file = v1_check_quota_file, 217 .read_file_info = v1_read_file_info, 218 .write_file_info = v1_write_file_info, 219 .free_file_info = NULL, 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); 242 243