[lustre-devel] [PATCH 01/15] lustre: uapi: support fixed directory layout

[James Simmons]

From: Lai Siyao <lai.siyao at whamcloud.com>

User may not want directories split automatically in some cases:
*.directory migrated.
* directory restriped.

To support this, an LMV flag LMV_HASH_FLAG_FIXED is added, and it will
be set on migrated/restriped directories. NB, if directory is migrated
or restriped to a one-stripe directory, it won't be transformed into a
plain directory, because this flag needs to be kept.

WC-bug-id: https://jira.whamcloud.com/browse/LU-14459
Lustre-commit: 4c2514f483280137 ("LU-14459 mdt: support fixed directory layout")
Signed-off-by: Lai Siyao <lai.siyao at whamcloud.com>
Reviewed-on: https://review.whamcloud.com/43291
Reviewed-by: Andreas Dilger <adilger at whamcloud.com>
Reviewed-by: Hongchao Zhang <hongchao at whamcloud.com>
Reviewed-by: Oleg Drokin <green at whamcloud.com>
Signed-off-by: James Simmons <jsimmons at infradead.org>
---
 fs/lustre/ptlrpc/wiretest.c             | 1 +
 include/uapi/linux/lustre/lustre_user.h | 5 +++++
 2 files changed, 6 insertions(+)

diff --git a/fs/lustre/ptlrpc/wiretest.c b/fs/lustre/ptlrpc/wiretest.c
index 4301bd4..7d504bd 100644
--- a/fs/lustre/ptlrpc/wiretest.c
+++ b/fs/lustre/ptlrpc/wiretest.c
@@ -1778,6 +1778,7 @@ void lustre_assert_wire_constants(void)
 	BUILD_BUG_ON(LMV_MAGIC_V1 != 0x0CD20CD0);
 	BUILD_BUG_ON(LMV_MAGIC_STRIPE != 0x0CD40CD0);
 	BUILD_BUG_ON(LMV_HASH_TYPE_MASK != 0x0000ffff);
+	BUILD_BUG_ON(LMV_HASH_FLAG_FIXED != 0x02000000);
 	BUILD_BUG_ON(LMV_HASH_FLAG_MERGE != 0x04000000);
 	BUILD_BUG_ON(LMV_HASH_FLAG_SPLIT != 0x08000000);
 	BUILD_BUG_ON(LMV_HASH_FLAG_LOST_LMV != 0x10000000);
diff --git a/include/uapi/linux/lustre/lustre_user.h b/include/uapi/linux/lustre/lustre_user.h
index b317bbf..7fcc009 100644
--- a/include/uapi/linux/lustre/lustre_user.h
+++ b/include/uapi/linux/lustre/lustre_user.h
@@ -718,6 +718,9 @@ static inline bool lmv_is_known_hash_type(__u32 type)
 	       (type & LMV_HASH_TYPE_MASK) == LMV_HASH_TYPE_CRUSH;
 }
 
+/* fixed layout, such directories won't split automatically */
+/* NB, update LMV_HASH_FLAG_KNOWN when adding new flag */
+#define LMV_HASH_FLAG_FIXED		0x02000000
 #define LMV_HASH_FLAG_MERGE		0x04000000
 #define LMV_HASH_FLAG_SPLIT		0x08000000
 
@@ -733,6 +736,8 @@ 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
+
 /* both SPLIT and MIGRATION are set for directory split */
 static inline bool lmv_hash_is_splitting(__u32 hash)
 {
-- 
1.8.3.1