blkio-throttle: limit max iops value to UINT_MAX

- Limit max iops value to UINT_MAX and return error to user if value is more
  than that instead of accepting bigger values and truncating implicitly.

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

2 files changed, 10 insertions, 4 deletions

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 52c12130a5de..0f59b23096db 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -656,10 +656,10 @@ static int blkio_policy_parse_and_set(char *buf,
 {
         char *s[4], *p, *major_s = NULL, *minor_s = NULL;
         int ret;
-        unsigned long major, minor, temp, iops;
+        unsigned long major, minor, temp;
         int i = 0;
         dev_t dev;
-        u64 bps;
+        u64 bps, iops;
 
         memset(s, 0, sizeof(s));
 
@@ -731,13 +731,16 @@ static int blkio_policy_parse_and_set(char *buf,
                         break;
                 case BLKIO_THROTL_read_iops_device:
                 case BLKIO_THROTL_write_iops_device:
-                        ret = strict_strtoul(s[1], 10, &iops);
+                        ret = strict_strtoull(s[1], 10, &iops);
                         if (ret)
                                 return -EINVAL;
 
+                        if (iops > THROTL_IOPS_MAX)
+                                return -EINVAL;
+
                         newpn->plid = plid;
                         newpn->fileid = fileid;
-                        newpn->val.iops = iops;
+                        newpn->val.iops = (unsigned int)iops;
                         break;
                 }
                 break;
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index 034c35562dba..ea4861bdd549 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -20,6 +20,9 @@ enum blkio_policy_id {
         BLKIO_POLICY_THROTL,            /* Throttling */
 };
 
+/* Max limits for throttle policy */
+#define THROTL_IOPS_MAX         UINT_MAX
+
 #if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
 
 #ifndef CONFIG_BLK_CGROUP