[PATCH 13/29] staging: lustre: llite: report back to user bad stripe count

From: James Simmons
Date: Thu Oct 27 2016 - 18:13:08 EST


From: wang di <di.wang@xxxxxxxxx>

If the user is requesting a stripe count larger than what
is supported in the file system then report back to the
user an error as well as what is the largest possible
striping.

Signed-off-by: wang di <di.wang@xxxxxxxxx>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-6602
Reviewed-on: http://review.whamcloud.com/15162
Reviewed-by: Andreas Dilger <andreas.dilger@xxxxxxxxx>
Reviewed-by: James Simmons <uja.ornl@xxxxxxxxx>
Reviewed-by: Oleg Drokin <oleg.drokin@xxxxxxxxx>
Signed-off-by: James Simmons <jsimmons@xxxxxxxxxxxxx>
---
drivers/staging/lustre/lustre/llite/dir.c | 12 ++++++++++++
1 files changed, 12 insertions(+), 0 deletions(-)

diff --git a/drivers/staging/lustre/lustre/llite/dir.c b/drivers/staging/lustre/lustre/llite/dir.c
index fb367ae..64a32d5 100644
--- a/drivers/staging/lustre/lustre/llite/dir.c
+++ b/drivers/staging/lustre/lustre/llite/dir.c
@@ -1195,6 +1195,7 @@ static long ll_dir_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
struct lmv_user_md *tmp = NULL;
union lmv_mds_md *lmm = NULL;
u64 valid = 0;
+ int max_stripe_count;
int stripe_count;
int mdt_index;
int lum_size;
@@ -1206,6 +1207,7 @@ static long ll_dir_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
if (copy_from_user(&lum, ulmv, sizeof(*ulmv)))
return -EFAULT;

+ max_stripe_count = lum.lum_stripe_count;
/*
* lum_magic will indicate which stripe the ioctl will like
* to get, LMV_MAGIC_V1 is for normal LMV stripe, LMV_USER_MAGIC
@@ -1240,6 +1242,16 @@ static long ll_dir_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
}

stripe_count = lmv_mds_md_stripe_count_get(lmm);
+ if (max_stripe_count < stripe_count) {
+ lum.lum_stripe_count = stripe_count;
+ if (copy_to_user(ulmv, &lum, sizeof(lum))) {
+ rc = -EFAULT;
+ goto finish_req;
+ }
+ rc = -E2BIG;
+ goto finish_req;
+ }
+
lum_size = lmv_user_md_size(stripe_count, LMV_MAGIC_V1);
tmp = kzalloc(lum_size, GFP_NOFS);
if (!tmp) {
--
1.7.1