staging: lustre: llite: report back to user bad stripe count

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@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-6602
Reviewed-on: http://review.whamcloud.com/15162
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/lustre/lustre/llite/dir.c b/drivers/staging/lustre/lustre/llite/dir.c
index fb367ae..64a32d5 100644 (file)
--- a/drivers/staging/lustre/lustre/llite/dir.c
+++ b/drivers/staging/lustre/lustre/llite/dir.c
@@ -1195,6 +1195,7 @@ lmv_out_free:
                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 @@ lmv_out_free:
                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 @@ lmv_out_free:
                }
 
                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) {