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_type; 58 struct v1_disk_dqblk dqblk; 59 60 if (!sb_dqopt(dquot->dq_sb)->files[type]) 61 return -EINVAL; 62 63 /* Set structure to 0s in case read fails/is after end of file */ 64 memset(&dqblk, 0, sizeof(struct v1_disk_dqblk)); 65 dquot->dq_sb->s_op->quota_read(dquot->dq_sb, type, (char *)&dqblk, 66 sizeof(struct v1_disk_dqblk), v1_dqoff(dquot->dq_id)); 67 68 v1_disk2mem_dqblk(&dquot->dq_dqb, &dqblk); 69 if (dquot->dq_dqb.dqb_bhardlimit == 0 && 70 dquot->dq_dqb.dqb_bsoftlimit == 0 && 71 dquot->dq_dqb.dqb_ihardlimit == 0 && 72 dquot->dq_dqb.dqb_isoftlimit == 0) 73 set_bit(DQ_FAKE_B, &dquot->dq_flags); 74 dqstats_inc(DQST_READS); 75 76 return 0; 77 } 78 79 static int v1_commit_dqblk(struct dquot *dquot) 80 { 81 short type = dquot->dq_type; 82 ssize_t ret; 83 struct v1_disk_dqblk dqblk; 84 85 v1_mem2disk_dqblk(&dqblk, &dquot->dq_dqb); 86 if (dquot->dq_id == 0) { 87 dqblk.dqb_btime = 88 sb_dqopt(dquot->dq_sb)->info[type].dqi_bgrace; 89 dqblk.dqb_itime = 90 sb_dqopt(dquot->dq_sb)->info[type].dqi_igrace; 91 } 92 ret = 0; 93 if (sb_dqopt(dquot->dq_sb)->files[type]) 94 ret = dquot->dq_sb->s_op->quota_write(dquot->dq_sb, type, 95 (char *)&dqblk, sizeof(struct v1_disk_dqblk), 96 v1_dqoff(dquot->dq_id)); 97 if (ret != sizeof(struct v1_disk_dqblk)) { 98 quota_error(dquot->dq_sb, "dquota write failed"); 99 if (ret >= 0) 100 ret = -EIO; 101 goto out; 102 } 103 ret = 0; 104 105 out: 106 dqstats_inc(DQST_WRITES); 107 108 return ret; 109 } 110 111 /* Magics of new quota format */ 112 #define V2_INITQMAGICS {\ 113 0xd9c01f11, /* USRQUOTA */\ 114 0xd9c01927 /* GRPQUOTA */\ 115 } 116 117 /* Header of new quota format */ 118 struct v2_disk_dqheader { 119 __le32 dqh_magic; /* Magic number identifying file */ 120 __le32 dqh_version; /* File version */ 121 }; 122 123 static int v1_check_quota_file(struct super_block *sb, int type) 124 { 125 struct inode *inode = sb_dqopt(sb)->files[type]; 126 ulong blocks; 127 size_t off; 128 struct v2_disk_dqheader dqhead; 129 ssize_t size; 130 loff_t isize; 131 static const uint quota_magics[] = V2_INITQMAGICS; 132 133 isize = i_size_read(inode); 134 if (!isize) 135 return 0; 136 blocks = isize >> BLOCK_SIZE_BITS; 137 off = isize & (BLOCK_SIZE - 1); 138 if ((blocks % sizeof(struct v1_disk_dqblk) * BLOCK_SIZE + off) % 139 sizeof(struct v1_disk_dqblk)) 140 return 0; 141 /* Doublecheck whether we didn't get file with new format - with old 142 * quotactl() this could happen */ 143 size = sb->s_op->quota_read(sb, type, (char *)&dqhead, 144 sizeof(struct v2_disk_dqheader), 0); 145 if (size != sizeof(struct v2_disk_dqheader)) 146 return 1; /* Probably not new format */ 147 if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type]) 148 return 1; /* Definitely not new format */ 149 printk(KERN_INFO 150 "VFS: %s: Refusing to turn on old quota format on given file." 151 " It probably contains newer quota format.\n", sb->s_id); 152 return 0; /* Seems like a new format file -> refuse it */ 153 } 154 155 static int v1_read_file_info(struct super_block *sb, int type) 156 { 157 struct quota_info *dqopt = sb_dqopt(sb); 158 struct v1_disk_dqblk dqblk; 159 int ret; 160 161 ret = sb->s_op->quota_read(sb, type, (char *)&dqblk, 162 sizeof(struct v1_disk_dqblk), v1_dqoff(0)); 163 if (ret != sizeof(struct v1_disk_dqblk)) { 164 if (ret >= 0) 165 ret = -EIO; 166 goto out; 167 } 168 ret = 0; 169 /* limits are stored as unsigned 32-bit data */ 170 dqopt->info[type].dqi_maxblimit = 0xffffffff; 171 dqopt->info[type].dqi_maxilimit = 0xffffffff; 172 dqopt->info[type].dqi_igrace = 173 dqblk.dqb_itime ? dqblk.dqb_itime : MAX_IQ_TIME; 174 dqopt->info[type].dqi_bgrace = 175 dqblk.dqb_btime ? dqblk.dqb_btime : MAX_DQ_TIME; 176 out: 177 return ret; 178 } 179 180 static int v1_write_file_info(struct super_block *sb, int type) 181 { 182 struct quota_info *dqopt = sb_dqopt(sb); 183 struct v1_disk_dqblk dqblk; 184 int ret; 185 186 dqopt->info[type].dqi_flags &= ~DQF_INFO_DIRTY; 187 ret = sb->s_op->quota_read(sb, type, (char *)&dqblk, 188 sizeof(struct v1_disk_dqblk), v1_dqoff(0)); 189 if (ret != sizeof(struct v1_disk_dqblk)) { 190 if (ret >= 0) 191 ret = -EIO; 192 goto out; 193 } 194 dqblk.dqb_itime = dqopt->info[type].dqi_igrace; 195 dqblk.dqb_btime = dqopt->info[type].dqi_bgrace; 196 ret = sb->s_op->quota_write(sb, type, (char *)&dqblk, 197 sizeof(struct v1_disk_dqblk), v1_dqoff(0)); 198 if (ret == sizeof(struct v1_disk_dqblk)) 199 ret = 0; 200 else if (ret > 0) 201 ret = -EIO; 202 out: 203 return ret; 204 } 205 206 static const struct quota_format_ops v1_format_ops = { 207 .check_quota_file = v1_check_quota_file, 208 .read_file_info = v1_read_file_info, 209 .write_file_info = v1_write_file_info, 210 .free_file_info = NULL, 211 .read_dqblk = v1_read_dqblk, 212 .commit_dqblk = v1_commit_dqblk, 213 }; 214 215 static struct quota_format_type v1_quota_format = { 216 .qf_fmt_id = QFMT_VFS_OLD, 217 .qf_ops = &v1_format_ops, 218 .qf_owner = THIS_MODULE 219 }; 220 221 static int __init init_v1_quota_format(void) 222 { 223 return register_quota_format(&v1_quota_format); 224 } 225 226 static void __exit exit_v1_quota_format(void) 227 { 228 unregister_quota_format(&v1_quota_format); 229 } 230 231 module_init(init_v1_quota_format); 232 module_exit(exit_v1_quota_format); 233 234