1 files changed, 218 insertions, 0 deletions

diff --git a/fs/quota/quota_v1.c b/fs/quota/quota_v1.c
new file mode 100644
index 000000000000..b4af1c69ad16
--- /dev/null
+++ b/fs/quota/quota_v1.c
@@ -0,0 +1,218 @@
+#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_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(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.reads++;
+
+        return 0;
+}
+
+static int v1_commit_dqblk(struct dquot *dquot)
+{
+        short type = dquot->dq_type;
+        ssize_t ret;
+        struct v1_disk_dqblk dqblk;
+
+        v1_mem2disk_dqblk(&dqblk, &dquot->dq_dqb);
+        if (dquot->dq_id == 0) {
+                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(dquot->dq_id));
+        if (ret != sizeof(struct v1_disk_dqblk)) {
+                printk(KERN_WARNING "VFS: dquota write failed on dev %s\n",
+                        dquot->dq_sb->s_id);
+                if (ret >= 0)
+                        ret = -EIO;
+                goto out;
+        }
+        ret = 0;
+
+out:
+        dqstats.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;
+
+        if ((ret = sb->s_op->quota_read(sb, type, (char *)&dqblk, sizeof(struct v1_disk_dqblk), v1_dqoff(0))) != 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_maxblimit = 0xffffffff;
+        dqopt->info[type].dqi_maxilimit = 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;
+        if ((ret = sb->s_op->quota_read(sb, type, (char *)&dqblk,
+            sizeof(struct v1_disk_dqblk), v1_dqoff(0))) != 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 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);
+