Re: [PATCH] quota: additional range checks and mem_dqblk updates to handle 64-bit limits

[Andrew Perepechko <Andrew.Perepechko@Sun.COM>]

mem_dqblk is extended to hold 64-bit quota limits, checks are added to deny
setting quota limits which aren't supported by a quota format module

Signed-off-by: Andrew Perepechko <andrew.perepechko@sun.com>

---

 fs/dquot.c            |   22 +++++++++++++++++-----
 fs/quota_v1.c         |    3 +++
 fs/quota_v2.c         |   13 ++++++++-----
 include/linux/quota.h |   12 +++++++-----
 4 files changed, 35 insertions(+), 15 deletions(-)

diff -rNpu quota.orig/fs/dquot.c quota/fs/dquot.c
--- quota.orig/fs/dquot.c	2008-01-25 01:58:37.000000000 +0300
+++ quota/fs/dquot.c	2008-03-07 01:37:46.000000000 +0300
@@ -1703,10 +1703,19 @@ int vfs_get_dqblk(struct super_block *sb
 }
 
 /* Generic routine for setting common part of quota structure */
-static void do_set_dqblk(struct dquot *dquot, struct if_dqblk *di)
+static int do_set_dqblk(struct dquot *dquot, struct if_dqblk *di)
 {
 	struct mem_dqblk *dm = &dquot->dq_dqb;
 	int check_blim = 0, check_ilim = 0;
+	struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type];
+
+	if ((di->dqb_valid & QIF_BLIMITS &&
+	     (di->dqb_bhardlimit > dqi->dqi_maxblimit ||
+	      di->dqb_bsoftlimit > dqi->dqi_maxblimit)) ||
+	    (di->dqb_valid & QIF_ILIMITS &&
+	     (di->dqb_ihardlimit > dqi->dqi_maxilimit ||
+	      di->dqb_isoftlimit > dqi->dqi_maxilimit)))
+		return -ERANGE;
 
 	spin_lock(&dq_data_lock);
 	if (di->dqb_valid & QIF_SPACE) {
@@ -1738,7 +1747,7 @@ static void do_set_dqblk(struct dquot *d
 			clear_bit(DQ_BLKS_B, &dquot->dq_flags);
 		}
 		else if (!(di->dqb_valid & QIF_BTIME))	/* Set grace only if user hasn't provided his own... */
-			dm->dqb_btime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_bgrace;
+			dm->dqb_btime = get_seconds() + dqi->dqi_bgrace;
 	}
 	if (check_ilim) {
 		if (!dm->dqb_isoftlimit || dm->dqb_curinodes < dm->dqb_isoftlimit) {
@@ -1746,7 +1755,7 @@ static void do_set_dqblk(struct dquot *d
 			clear_bit(DQ_INODES_B, &dquot->dq_flags);
 		}
 		else if (!(di->dqb_valid & QIF_ITIME))	/* Set grace only if user hasn't provided his own... */
-			dm->dqb_itime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace;
+			dm->dqb_itime = get_seconds() + dqi->dqi_igrace;
 	}
 	if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit || dm->dqb_isoftlimit)
 		clear_bit(DQ_FAKE_B, &dquot->dq_flags);
@@ -1754,21 +1763,24 @@ static void do_set_dqblk(struct dquot *d
 		set_bit(DQ_FAKE_B, &dquot->dq_flags);
 	spin_unlock(&dq_data_lock);
 	mark_dquot_dirty(dquot);
+
+	return 0;
 }
 
 int vfs_set_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *di)
 {
 	struct dquot *dquot;
+	int rc;
 
 	mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
 	if (!(dquot = dqget(sb, id, type))) {
 		mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
 		return -ESRCH;
 	}
-	do_set_dqblk(dquot, di);
+	rc = do_set_dqblk(dquot, di);
 	dqput(dquot);
 	mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
-	return 0;
+	return rc;
 }
 
 /* Generic routine for getting common part of quota file information */
diff -rNpu quota.orig/fs/quota_v1.c quota/fs/quota_v1.c
--- quota.orig/fs/quota_v1.c	2008-01-25 01:58:37.000000000 +0300
+++ quota/fs/quota_v1.c	2008-03-07 01:39:00.000000000 +0300
@@ -139,6 +139,9 @@ static int v1_read_file_info(struct supe
 		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:
diff -rNpu quota.orig/fs/quota_v2.c quota/fs/quota_v2.c
--- quota.orig/fs/quota_v2.c	2008-01-25 01:58:37.000000000 +0300
+++ quota/fs/quota_v2.c	2008-03-07 02:40:23.000000000 +0300
@@ -59,6 +59,9 @@ static int v2_read_file_info(struct supe
 			sb->s_id);
 		return -1;
 	}
+	/* limits are stored as unsigned 32-bit data */
+	info->dqi_maxblimit = 0xffffffff;
+	info->dqi_maxilimit = 0xffffffff;
 	info->dqi_bgrace = le32_to_cpu(dinfo.dqi_bgrace);
 	info->dqi_igrace = le32_to_cpu(dinfo.dqi_igrace);
 	info->dqi_flags = le32_to_cpu(dinfo.dqi_flags);
@@ -108,12 +113,12 @@ static void disk2memdqb(struct mem_dqblk
 
 static void mem2diskdqb(struct v2_disk_dqblk *d, struct mem_dqblk *m, qid_t id)
 {
-	d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
-	d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
-	d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
+	d->dqb_ihardlimit = cpu_to_le32((u32)m->dqb_ihardlimit);
+	d->dqb_isoftlimit = cpu_to_le32((u32)m->dqb_isoftlimit);
+	d->dqb_curinodes = cpu_to_le32((u32)m->dqb_curinodes);
 	d->dqb_itime = cpu_to_le64(m->dqb_itime);
-	d->dqb_bhardlimit = cpu_to_le32(m->dqb_bhardlimit);
-	d->dqb_bsoftlimit = cpu_to_le32(m->dqb_bsoftlimit);
+	d->dqb_bhardlimit = cpu_to_le32((u32)m->dqb_bhardlimit);
+	d->dqb_bsoftlimit = cpu_to_le32((u32)m->dqb_bsoftlimit);
 	d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
 	d->dqb_btime = cpu_to_le64(m->dqb_btime);
 	d->dqb_id = cpu_to_le32(id);
diff -rNpu quota.orig/include/linux/quota.h quota/include/linux/quota.h
--- quota.orig/include/linux/quota.h	2008-01-25 01:58:37.000000000 +0300
+++ quota/include/linux/quota.h	2008-03-06 23:18:10.000000000 +0300
@@ -181,12 +181,12 @@ extern spinlock_t dq_data_lock;
  * Data for one user/group kept in memory
  */
 struct mem_dqblk {
-	__u32 dqb_bhardlimit;	/* absolute limit on disk blks alloc */
-	__u32 dqb_bsoftlimit;	/* preferred limit on disk blks */
+	qsize_t dqb_bhardlimit;	/* absolute limit on disk blks alloc */
+	qsize_t dqb_bsoftlimit;	/* preferred limit on disk blks */
 	qsize_t dqb_curspace;	/* current used space */
-	__u32 dqb_ihardlimit;	/* absolute limit on allocated inodes */
-	__u32 dqb_isoftlimit;	/* preferred inode limit */
-	__u32 dqb_curinodes;	/* current # allocated inodes */
+	qsize_t dqb_ihardlimit;	/* absolute limit on allocated inodes */
+	qsize_t dqb_isoftlimit;	/* preferred inode limit */
+	qsize_t dqb_curinodes;	/* current # allocated inodes */
 	time_t dqb_btime;	/* time limit for excessive disk use */
 	time_t dqb_itime;	/* time limit for excessive inode use */
 };
@@ -202,6 +202,8 @@ struct mem_dqinfo {
 	unsigned long dqi_flags;
 	unsigned int dqi_bgrace;
 	unsigned int dqi_igrace;
+	qsize_t dqi_maxblimit;
+	qsize_t dqi_maxilimit;
 	union {
 		struct v1_mem_dqinfo v1_i;
 		struct v2_mem_dqinfo v2_i;