diff options
Diffstat (limited to 'kernel/fs/quota/quota_v1.c')
| -rw-r--r-- | kernel/fs/quota/quota_v1.c | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/kernel/fs/quota/quota_v1.c b/kernel/fs/quota/quota_v1.c new file mode 100644 index 000000000..8fe79bece --- /dev/null +++ b/kernel/fs/quota/quota_v1.c @@ -0,0 +1,235 @@ +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/quota.h> +#include <linux/quotaops.h> +#include <linux/dqblk_v1.h> +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/module.h> + +#include <asm/byteorder.h> + +#include "quotaio_v1.h" + +MODULE_AUTHOR("Jan Kara"); +MODULE_DESCRIPTION("Old quota format support"); +MODULE_LICENSE("GPL"); + +#define QUOTABLOCK_BITS 10 +#define QUOTABLOCK_SIZE (1 << QUOTABLOCK_BITS) + +static inline qsize_t v1_stoqb(qsize_t space) +{ + return (space + QUOTABLOCK_SIZE - 1) >> QUOTABLOCK_BITS; +} + +static inline qsize_t v1_qbtos(qsize_t blocks) +{ + return blocks << QUOTABLOCK_BITS; +} + +static void v1_disk2mem_dqblk(struct mem_dqblk *m, struct v1_disk_dqblk *d) +{ + m->dqb_ihardlimit = d->dqb_ihardlimit; + m->dqb_isoftlimit = d->dqb_isoftlimit; + m->dqb_curinodes = d->dqb_curinodes; + m->dqb_bhardlimit = v1_qbtos(d->dqb_bhardlimit); + m->dqb_bsoftlimit = v1_qbtos(d->dqb_bsoftlimit); + m->dqb_curspace = v1_qbtos(d->dqb_curblocks); + m->dqb_itime = d->dqb_itime; + m->dqb_btime = d->dqb_btime; +} + +static void v1_mem2disk_dqblk(struct v1_disk_dqblk *d, struct mem_dqblk *m) +{ + d->dqb_ihardlimit = m->dqb_ihardlimit; + d->dqb_isoftlimit = m->dqb_isoftlimit; + d->dqb_curinodes = m->dqb_curinodes; + d->dqb_bhardlimit = v1_stoqb(m->dqb_bhardlimit); + d->dqb_bsoftlimit = v1_stoqb(m->dqb_bsoftlimit); + d->dqb_curblocks = v1_stoqb(m->dqb_curspace); + d->dqb_itime = m->dqb_itime; + d->dqb_btime = m->dqb_btime; +} + +static int v1_read_dqblk(struct dquot *dquot) +{ + int type = dquot->dq_id.type; + struct v1_disk_dqblk dqblk; + + if (!sb_dqopt(dquot->dq_sb)->files[type]) + return -EINVAL; + + /* Set structure to 0s in case read fails/is after end of file */ + memset(&dqblk, 0, sizeof(struct v1_disk_dqblk)); + dquot->dq_sb->s_op->quota_read(dquot->dq_sb, type, (char *)&dqblk, + sizeof(struct v1_disk_dqblk), + v1_dqoff(from_kqid(&init_user_ns, dquot->dq_id))); + + v1_disk2mem_dqblk(&dquot->dq_dqb, &dqblk); + if (dquot->dq_dqb.dqb_bhardlimit == 0 && + dquot->dq_dqb.dqb_bsoftlimit == 0 && + dquot->dq_dqb.dqb_ihardlimit == 0 && + dquot->dq_dqb.dqb_isoftlimit == 0) + set_bit(DQ_FAKE_B, &dquot->dq_flags); + dqstats_inc(DQST_READS); + + return 0; +} + +static int v1_commit_dqblk(struct dquot *dquot) +{ + short type = dquot->dq_id.type; + ssize_t ret; + struct v1_disk_dqblk dqblk; + + v1_mem2disk_dqblk(&dqblk, &dquot->dq_dqb); + if (((type == USRQUOTA) && uid_eq(dquot->dq_id.uid, GLOBAL_ROOT_UID)) || + ((type == GRPQUOTA) && gid_eq(dquot->dq_id.gid, GLOBAL_ROOT_GID))) { + dqblk.dqb_btime = + sb_dqopt(dquot->dq_sb)->info[type].dqi_bgrace; + dqblk.dqb_itime = + sb_dqopt(dquot->dq_sb)->info[type].dqi_igrace; + } + ret = 0; + if (sb_dqopt(dquot->dq_sb)->files[type]) + ret = dquot->dq_sb->s_op->quota_write(dquot->dq_sb, type, + (char *)&dqblk, sizeof(struct v1_disk_dqblk), + v1_dqoff(from_kqid(&init_user_ns, dquot->dq_id))); + if (ret != sizeof(struct v1_disk_dqblk)) { + quota_error(dquot->dq_sb, "dquota write failed"); + if (ret >= 0) + ret = -EIO; + goto out; + } + ret = 0; + +out: + dqstats_inc(DQST_WRITES); + + return ret; +} + +/* Magics of new quota format */ +#define V2_INITQMAGICS {\ + 0xd9c01f11, /* USRQUOTA */\ + 0xd9c01927 /* GRPQUOTA */\ +} + +/* Header of new quota format */ +struct v2_disk_dqheader { + __le32 dqh_magic; /* Magic number identifying file */ + __le32 dqh_version; /* File version */ +}; + +static int v1_check_quota_file(struct super_block *sb, int type) +{ + struct inode *inode = sb_dqopt(sb)->files[type]; + ulong blocks; + size_t off; + struct v2_disk_dqheader dqhead; + ssize_t size; + loff_t isize; + static const uint quota_magics[] = V2_INITQMAGICS; + + isize = i_size_read(inode); + if (!isize) + return 0; + blocks = isize >> BLOCK_SIZE_BITS; + off = isize & (BLOCK_SIZE - 1); + if ((blocks % sizeof(struct v1_disk_dqblk) * BLOCK_SIZE + off) % + sizeof(struct v1_disk_dqblk)) + return 0; + /* Doublecheck whether we didn't get file with new format - with old + * quotactl() this could happen */ + size = sb->s_op->quota_read(sb, type, (char *)&dqhead, + sizeof(struct v2_disk_dqheader), 0); + if (size != sizeof(struct v2_disk_dqheader)) + return 1; /* Probably not new format */ + if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type]) + return 1; /* Definitely not new format */ + printk(KERN_INFO + "VFS: %s: Refusing to turn on old quota format on given file." + " It probably contains newer quota format.\n", sb->s_id); + return 0; /* Seems like a new format file -> refuse it */ +} + +static int v1_read_file_info(struct super_block *sb, int type) +{ + struct quota_info *dqopt = sb_dqopt(sb); + struct v1_disk_dqblk dqblk; + int ret; + + ret = sb->s_op->quota_read(sb, type, (char *)&dqblk, + sizeof(struct v1_disk_dqblk), v1_dqoff(0)); + if (ret != sizeof(struct v1_disk_dqblk)) { + if (ret >= 0) + ret = -EIO; + goto out; + } + ret = 0; + /* limits are stored as unsigned 32-bit data */ + dqopt->info[type].dqi_max_spc_limit = 0xffffffffULL << QUOTABLOCK_BITS; + dqopt->info[type].dqi_max_ino_limit = 0xffffffff; + dqopt->info[type].dqi_igrace = + dqblk.dqb_itime ? dqblk.dqb_itime : MAX_IQ_TIME; + dqopt->info[type].dqi_bgrace = + dqblk.dqb_btime ? dqblk.dqb_btime : MAX_DQ_TIME; +out: + return ret; +} + +static int v1_write_file_info(struct super_block *sb, int type) +{ + struct quota_info *dqopt = sb_dqopt(sb); + struct v1_disk_dqblk dqblk; + int ret; + + dqopt->info[type].dqi_flags &= ~DQF_INFO_DIRTY; + ret = sb->s_op->quota_read(sb, type, (char *)&dqblk, + sizeof(struct v1_disk_dqblk), v1_dqoff(0)); + if (ret != sizeof(struct v1_disk_dqblk)) { + if (ret >= 0) + ret = -EIO; + goto out; + } + dqblk.dqb_itime = dqopt->info[type].dqi_igrace; + dqblk.dqb_btime = dqopt->info[type].dqi_bgrace; + ret = sb->s_op->quota_write(sb, type, (char *)&dqblk, + sizeof(struct v1_disk_dqblk), v1_dqoff(0)); + if (ret == sizeof(struct v1_disk_dqblk)) + ret = 0; + else if (ret > 0) + ret = -EIO; +out: + return ret; +} + +static const struct quota_format_ops v1_format_ops = { + .check_quota_file = v1_check_quota_file, + .read_file_info = v1_read_file_info, + .write_file_info = v1_write_file_info, + .free_file_info = NULL, + .read_dqblk = v1_read_dqblk, + .commit_dqblk = v1_commit_dqblk, +}; + +static struct quota_format_type v1_quota_format = { + .qf_fmt_id = QFMT_VFS_OLD, + .qf_ops = &v1_format_ops, + .qf_owner = THIS_MODULE +}; + +static int __init init_v1_quota_format(void) +{ + return register_quota_format(&v1_quota_format); +} + +static void __exit exit_v1_quota_format(void) +{ + unregister_quota_format(&v1_quota_format); +} + +module_init(init_v1_quota_format); +module_exit(exit_v1_quota_format); + |