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.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 printk(KERN_WARNING "VFS: dquota write failed on dev %s\n", 99 dquot->dq_sb->s_id); 100 if (ret >= 0) 101 ret = -EIO; 102 goto out; 103 } 104 ret = 0; 105 106 out: 107 dqstats.writes++; 108 109 return ret; 110 } 111 112 /* Magics of new quota format */ 113 #define V2_INITQMAGICS {\ 114 0xd9c01f11, /* USRQUOTA */\ 115 0xd9c01927 /* GRPQUOTA */\ 116 } 117 118 /* Header of new quota format */ 119 struct v2_disk_dqheader { 120 __le32 dqh_magic; /* Magic number identifying file */ 121 __le32 dqh_version; /* File version */ 122 }; 123 124 static int v1_check_quota_file(struct super_block *sb, int type) 125 { 126 struct inode *inode = sb_dqopt(sb)->files[type]; 127 ulong blocks; 128 size_t off; 129 struct v2_disk_dqheader dqhead; 130 ssize_t size; 131 loff_t isize; 132 static const uint quota_magics[] = V2_INITQMAGICS; 133 134 isize = i_size_read(inode); 135 if (!isize) 136 return 0; 137 blocks = isize >> BLOCK_SIZE_BITS; 138 off = isize & (BLOCK_SIZE - 1); 139 if ((blocks % sizeof(struct v1_disk_dqblk) * BLOCK_SIZE + off) % 140 sizeof(struct v1_disk_dqblk)) 141 return 0; 142 /* Doublecheck whether we didn't get file with new format - with old 143 * quotactl() this could happen */ 144 size = sb->s_op->quota_read(sb, type, (char *)&dqhead, 145 sizeof(struct v2_disk_dqheader), 0); 146 if (size != sizeof(struct v2_disk_dqheader)) 147 return 1; /* Probably not new format */ 148 if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type]) 149 return 1; /* Definitely not new format */ 150 printk(KERN_INFO 151 "VFS: %s: Refusing to turn on old quota format on given file." 152 " It probably contains newer quota format.\n", sb->s_id); 153 return 0; /* Seems like a new format file -> refuse it */ 154 } 155 156 static int v1_read_file_info(struct super_block *sb, int type) 157 { 158 struct quota_info *dqopt = sb_dqopt(sb); 159 struct v1_disk_dqblk dqblk; 160 int ret; 161 162 ret = sb->s_op->quota_read(sb, type, (char *)&dqblk, 163 sizeof(struct v1_disk_dqblk), v1_dqoff(0)); 164 if (ret != sizeof(struct v1_disk_dqblk)) { 165 if (ret >= 0) 166 ret = -EIO; 167 goto out; 168 } 169 ret = 0; 170 /* limits are stored as unsigned 32-bit data */ 171 dqopt->info[type].dqi_maxblimit = 0xffffffff; 172 dqopt->info[type].dqi_maxilimit = 0xffffffff; 173 dqopt->info[type].dqi_igrace = 174 dqblk.dqb_itime ? dqblk.dqb_itime : MAX_IQ_TIME; 175 dqopt->info[type].dqi_bgrace = 176 dqblk.dqb_btime ? dqblk.dqb_btime : MAX_DQ_TIME; 177 out: 178 return ret; 179 } 180 181 static int v1_write_file_info(struct super_block *sb, int type) 182 { 183 struct quota_info *dqopt = sb_dqopt(sb); 184 struct v1_disk_dqblk dqblk; 185 int ret; 186 187 dqopt->info[type].dqi_flags &= ~DQF_INFO_DIRTY; 188 ret = sb->s_op->quota_read(sb, type, (char *)&dqblk, 189 sizeof(struct v1_disk_dqblk), v1_dqoff(0)); 190 if (ret != sizeof(struct v1_disk_dqblk)) { 191 if (ret >= 0) 192 ret = -EIO; 193 goto out; 194 } 195 dqblk.dqb_itime = dqopt->info[type].dqi_igrace; 196 dqblk.dqb_btime = dqopt->info[type].dqi_bgrace; 197 ret = sb->s_op->quota_write(sb, type, (char *)&dqblk, 198 sizeof(struct v1_disk_dqblk), v1_dqoff(0)); 199 if (ret == sizeof(struct v1_disk_dqblk)) 200 ret = 0; 201 else if (ret > 0) 202 ret = -EIO; 203 out: 204 return ret; 205 } 206 207 static const struct quota_format_ops v1_format_ops = { 208 .check_quota_file = v1_check_quota_file, 209 .read_file_info = v1_read_file_info, 210 .write_file_info = v1_write_file_info, 211 .free_file_info = NULL, 212 .read_dqblk = v1_read_dqblk, 213 .commit_dqblk = v1_commit_dqblk, 214 }; 215 216 static struct quota_format_type v1_quota_format = { 217 .qf_fmt_id = QFMT_VFS_OLD, 218 .qf_ops = &v1_format_ops, 219 .qf_owner = THIS_MODULE 220 }; 221 222 static int __init init_v1_quota_format(void) 223 { 224 return register_quota_format(&v1_quota_format); 225 } 226 227 static void __exit exit_v1_quota_format(void) 228 { 229 unregister_quota_format(&v1_quota_format); 230 } 231 232 module_init(init_v1_quota_format); 233 module_exit(exit_v1_quota_format); 234 235