From: Lai Siyao <lai.siyao@whamcloud.com>
Date: Sat, 29 Jan 2022 05:14:40 +0000 (-0500)
Subject: LU-15502 llite: set default LMV hash type with 2.12 MDS
X-Git-Tag: 2.15.0-RC1~7
X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=commitdiff_plain;h=51c6d596d4f3e82decb037c02e8b5d095e0a4962

LU-15502 llite: set default LMV hash type with 2.12 MDS

If default LMV hash type is CRUSH, or unset, it should be converted
to fnv_16_64, because 2.12 MDS doesn't understand this.

Fix LMV_HASH_FLAG_KNOWN to match actual known flags.

Test-Parameters: testlist=sanity env=ONLY=300 mdtcount=2 serverversion=2.12 serverdistro=el7.9
Fixes: 0a1cf8da8069 ("LU-11025 dne: introduce new directory hash type: "crush")
Fixes: bb60caa1c6e7 ("LU-14459 lmv: change default hash type to crush")
Signed-off-by: Lai Siyao <lai.siyao@whamcloud.com>
Change-Id: Ie2ad5a456040dcd01bc2c5ab96db52bf944abbd2
Reviewed-on: https://review.whamcloud.com/46378
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Patrick Farrell <pfarrell@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
---

diff --git a/lustre/include/uapi/linux/lustre/lustre_user.h b/lustre/include/uapi/linux/lustre/lustre_user.h
index b7cccc8..ba5e276 100644
--- a/lustre/include/uapi/linux/lustre/lustre_user.h
+++ b/lustre/include/uapi/linux/lustre/lustre_user.h
@@ -1042,7 +1042,7 @@ static inline bool lmv_is_known_hash_type(__u32 type)
 #define LMV_HASH_FLAG_LAYOUT_CHANGE	\
 	(LMV_HASH_FLAG_MIGRATION | LMV_HASH_FLAG_SPLIT | LMV_HASH_FLAG_MERGE)
 
-#define LMV_HASH_FLAG_KNOWN		0xfe000000
+#define LMV_HASH_FLAG_KNOWN		0xbe000000
 
 /* both SPLIT and MIGRATION are set for directory split */
 static inline bool lmv_hash_is_splitting(__u32 hash)
diff --git a/lustre/llite/dir.c b/lustre/llite/dir.c
index 0a3b4b6..fedc5bb 100644
--- a/lustre/llite/dir.c
+++ b/lustre/llite/dir.c
@@ -496,7 +496,7 @@ static int ll_dir_setdirstripe(struct dentry *dparent, struct lmv_user_md *lump,
 		enum lmv_hash_type type = lump->lum_hash_type &
 					  LMV_HASH_TYPE_MASK;
 
-		if (type == LMV_HASH_TYPE_CRUSH ||
+		if (type >= LMV_HASH_TYPE_CRUSH ||
 		    type == LMV_HASH_TYPE_UNKNOWN)
 			lump->lum_hash_type = (lump->lum_hash_type ^ type) |
 					      LMV_HASH_TYPE_FNV_1A_64;
@@ -620,12 +620,29 @@ int ll_dir_setstripe(struct inode *inode, struct lov_user_md *lump,
 		case LOV_USER_MAGIC_COMP_V1:
 			lum_size = ((struct lov_comp_md_v1 *)lump)->lcm_size;
 			break;
-		case LMV_USER_MAGIC:
-			if (lump->lmm_magic != cpu_to_le32(LMV_USER_MAGIC))
-				lustre_swab_lmv_user_md(
-					(struct lmv_user_md *)lump);
-			lum_size = sizeof(struct lmv_user_md);
+		case LMV_USER_MAGIC: {
+			struct lmv_user_md *lmv = (struct lmv_user_md *)lump;
+
+			/* MDS < 2.14 doesn't support 'crush' hash type, and
+			 * cannot handle unknown hash if client doesn't set a
+			 * valid one. switch to fnv_1a_64.
+			 */
+			if (!(exp_connect_flags2(sbi->ll_md_exp) &
+			      OBD_CONNECT2_CRUSH)) {
+				enum lmv_hash_type type = lmv->lum_hash_type &
+							  LMV_HASH_TYPE_MASK;
+
+				if (type >= LMV_HASH_TYPE_CRUSH ||
+				    type == LMV_HASH_TYPE_UNKNOWN)
+					lmv->lum_hash_type =
+						(lmv->lum_hash_type ^ type) |
+						LMV_HASH_TYPE_FNV_1A_64;
+			}
+			if (lmv->lum_magic != cpu_to_le32(LMV_USER_MAGIC))
+				lustre_swab_lmv_user_md(lmv);
+			lum_size = sizeof(*lmv);
 			break;
+		}
 		case LOV_USER_MAGIC_SPECIFIC: {
 			struct lov_user_md_v3 *v3 =
 				(struct lov_user_md_v3 *)lump;