From: Emoly Liu <emoly@whamcloud.com>
Date: Tue, 19 Jan 2021 04:06:06 +0000 (+0800)
Subject: LU-14337 lov: return stripe_count=1 instead of 0 for DoM files
X-Git-Tag: 2.14.0-RC1~7
X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=commitdiff_plain;h=b538826f2bdb39b5dda5bd1131b5b715c51d0bcd

LU-14337 lov: return stripe_count=1 instead of 0 for DoM files

Return stripe_count=1 instead of 0 for DoM files to avoid
divide-by-zero for older userspace that calls this ioctl,
e.g. lustre ADIO driver.

Signed-off-by: Emoly Liu <emoly@whamcloud.com>
Change-Id: I43c5e01bdee834f9a05a669a3e6f3d5cd926cb87
Reviewed-on: https://review.whamcloud.com/41265
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Mike Pershin <mpershin@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
---

diff --git a/lustre/lov/lov_pack.c b/lustre/lov/lov_pack.c
index 77127d5..528f067 100644
--- a/lustre/lov/lov_pack.c
+++ b/lustre/lov/lov_pack.c
@@ -469,6 +469,14 @@ int lov_getstripe(const struct lu_env *env, struct lov_object *obj,
 		lmm = lmmk;
 		lmm_size = lmmk_size;
 	}
+
+	/**
+	 * Return stripe_count=1 instead of 0 for DoM files to avoid
+	 * divide-by-zero for older userspace that calls this ioctl,
+	 * e.g. lustre ADIO driver.
+	 */
+	if ((lum.lmm_stripe_count == 0) && (lum.lmm_pattern & LOV_PATTERN_MDT))
+		lum.lmm_stripe_count = 1;
 	/**
 	 * User specified limited buffer size, usually the buffer is
 	 * from ll_lov_setstripe(), and the buffer can only hold basic