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 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), 67 v1_dqoff(from_kqid(&init_user_ns, dquot->dq_id))); 68 69 v1_disk2mem_dqblk(&dquot->dq_dqb, &dqblk); 70 if (dquot->dq_dqb.dqb_bhardlimit == 0 && 71 dquot->dq_dqb.dqb_bsoftlimit == 0 && 72 dquot->dq_dqb.dqb_ihardlimit == 0 && 73 dquot->dq_dqb.dqb_isoftlimit == 0) 74 set_bit(DQ_FAKE_B, &dquot->dq_flags); 75 dqstats_inc(DQST_READS); 76 77 return 0; 78 } 79 80 static int v1_commit_dqblk(struct dquot *dquot) 81 { 82 short type = dquot->dq_id.type; 83 ssize_t ret; 84 struct v1_disk_dqblk dqblk; 85 86 v1_mem2disk_dqblk(&dqblk, &dquot->dq_dqb); 87 if (((type == USRQUOTA) && uid_eq(dquot->dq_id.uid, GLOBAL_ROOT_UID)) || 88 ((type == GRPQUOTA) && gid_eq(dquot->dq_id.gid, GLOBAL_ROOT_GID))) { 89 dqblk.dqb_btime = 90 sb_dqopt(dquot->dq_sb)->info[type].dqi_bgrace; 91 dqblk.dqb_itime = 92 sb_dqopt(dquot->dq_sb)->info[type].dqi_igrace; 93 } 94 ret = 0; 95 if (sb_dqopt(dquot->dq_sb)->files[type]) 96 ret = dquot->dq_sb->s_op->quota_write(dquot->dq_sb, type, 97 (char *)&dqblk, sizeof(struct v1_disk_dqblk), 98 v1_dqoff(from_kqid(&init_user_ns, dquot->dq_id))); 99 if (ret != sizeof(struct v1_disk_dqblk)) { 100 quota_error(dquot->dq_sb, "dquota write failed"); 101 if (ret >= 0) 102 ret = -EIO; 103 goto out; 104 } 105 ret = 0; 106 107 out: 108 dqstats_inc(DQST_WRITES); 109 110 return ret; 111 } 112 113 /* Magics of new quota format */ 114 #define V2_INITQMAGICS {\ 115 0xd9c01f11, /* USRQUOTA */\ 116 0xd9c01927 /* GRPQUOTA */\ 117 } 118 119 /* Header of new quota format */ 120 struct v2_disk_dqheader { 121 __le32 dqh_magic; /* Magic number identifying file */ 122 __le32 dqh_version; /* File version */ 123 }; 124 125 static int v1_check_quota_file(struct super_block *sb, int type) 126 { 127 struct inode *inode = sb_dqopt(sb)->files[type]; 128 ulong blocks; 129 size_t off; 130 struct v2_disk_dqheader dqhead; 131 ssize_t size; 132 loff_t isize; 133 static const uint quota_magics[] = V2_INITQMAGICS; 134 135 isize = i_size_read(inode); 136 if (!isize) 137 return 0; 138 blocks = isize >> BLOCK_SIZE_BITS; 139 off = isize & (BLOCK_SIZE - 1); 140 if ((blocks % sizeof(struct v1_disk_dqblk) * BLOCK_SIZE + off) % 141 sizeof(struct v1_disk_dqblk)) 142 return 0; 143 /* Doublecheck whether we didn't get file with new format - with old 144 * quotactl() this could happen */ 145 size = sb->s_op->quota_read(sb, type, (char *)&dqhead, 146 sizeof(struct v2_disk_dqheader), 0); 147 if (size != sizeof(struct v2_disk_dqheader)) 148 return 1; /* Probably not new format */ 149 if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type]) 150 return 1; /* Definitely not new format */ 151 printk(KERN_INFO 152 "VFS: %s: Refusing to turn on old quota format on given file." 153 " It probably contains newer quota format.\n", sb->s_id); 154 return 0; /* Seems like a new format file -> refuse it */ 155 } 156 157 static int v1_read_file_info(struct super_block *sb, int type) 158 { 159 struct quota_info *dqopt = sb_dqopt(sb); 160 struct v1_disk_dqblk dqblk; 161 int ret; 162 163 ret = sb->s_op->quota_read(sb, type, (char *)&dqblk, 164 sizeof(struct v1_disk_dqblk), v1_dqoff(0)); 165 if (ret != sizeof(struct v1_disk_dqblk)) { 166 if (ret >= 0) 167 ret = -EIO; 168 goto out; 169 } 170 ret = 0; 171 /* limits are stored as unsigned 32-bit data */ 172 dqopt->info[type].dqi_maxblimit = 0xffffffff; 173 dqopt->info[type].dqi_maxilimit = 0xffffffff; 174 dqopt->info[type].dqi_igrace = 175 dqblk.dqb_itime ? dqblk.dqb_itime : MAX_IQ_TIME; 176 dqopt->info[type].dqi_bgrace = 177 dqblk.dqb_btime ? dqblk.dqb_btime : MAX_DQ_TIME; 178 out: 179 return ret; 180 } 181 182 static int v1_write_file_info(struct super_block *sb, int type) 183 { 184 struct quota_info *dqopt = sb_dqopt(sb); 185 struct v1_disk_dqblk dqblk; 186 int ret; 187 188 dqopt->info[type].dqi_flags &= ~DQF_INFO_DIRTY; 189 ret = sb->s_op->quota_read(sb, type, (char *)&dqblk, 190 sizeof(struct v1_disk_dqblk), v1_dqoff(0)); 191 if (ret != sizeof(struct v1_disk_dqblk)) { 192 if (ret >= 0) 193 ret = -EIO; 194 goto out; 195 } 196 dqblk.dqb_itime = dqopt->info[type].dqi_igrace; 197 dqblk.dqb_btime = dqopt->info[type].dqi_bgrace; 198 ret = sb->s_op->quota_write(sb, type, (char *)&dqblk, 199 sizeof(struct v1_disk_dqblk), v1_dqoff(0)); 200 if (ret == sizeof(struct v1_disk_dqblk)) 201 ret = 0; 202 else if (ret > 0) 203 ret = -EIO; 204 out: 205 return ret; 206 } 207 208 static const struct quota_format_ops v1_format_ops = { 209 .check_quota_file = v1_check_quota_file, 210 .read_file_info = v1_read_file_info, 211 .write_file_info = v1_write_file_info, 212 .free_file_info = NULL, 213 .read_dqblk = v1_read_dqblk, 214 .commit_dqblk = v1_commit_dqblk, 215 }; 216 217 static struct quota_format_type v1_quota_format = { 218 .qf_fmt_id = QFMT_VFS_OLD, 219 .qf_ops = &v1_format_ops, 220 .qf_owner = THIS_MODULE 221 }; 222 223 static int __init init_v1_quota_format(void) 224 { 225 return register_quota_format(&v1_quota_format); 226 } 227 228 static void __exit exit_v1_quota_format(void) 229 { 230 unregister_quota_format(&v1_quota_format); 231 } 232 233 module_init(init_v1_quota_format); 234 module_exit(exit_v1_quota_format); 235 236