Received-SPF: pass (google.com: best guess record for domain of linux-ext4-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Harshad Shirwadkar <harshadshirwadkar@gmail.com>
To:     linux-ext4@vger.kernel.org
Cc:     tytso@mit.edu, Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Subject: [PATCH v6 12/20] ext4: add fast commit on-disk format structs
Date:   Wed,  8 Apr 2020 14:55:22 -0700
Message-Id: <20200408215530.25649-12-harshads@google.com>
In-Reply-To: <20200408215530.25649-1-harshads@google.com>
References: <20200408215530.25649-1-harshads@google.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-ext4-owner@vger.kernel.org
Precedence: bulk

From: Harshad Shirwadkar <harshadshirwadkar@gmail.com>

Add structs representing on-disk format of the commit header and
tlvs in the commit header.

Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
---
 fs/ext4/ext4_jbd2.c |  1 +
 fs/ext4/ext4_jbd2.h | 45 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 46 insertions(+)

diff --git a/fs/ext4/ext4_jbd2.c b/fs/ext4/ext4_jbd2.c
index 4bef01f9814a..fca478a3b7e9 100644
--- a/fs/ext4/ext4_jbd2.c
+++ b/fs/ext4/ext4_jbd2.c
@@ -4,6 +4,7 @@
  */
 
 #include "ext4_jbd2.h"
+#include "ext4_extents.h"
 
 #include <trace/events/ext4.h>
 
diff --git a/fs/ext4/ext4_jbd2.h b/fs/ext4/ext4_jbd2.h
index b1239d6be713..b8ac3f29949d 100644
--- a/fs/ext4/ext4_jbd2.h
+++ b/fs/ext4/ext4_jbd2.h
@@ -529,7 +529,52 @@ static inline int ext4_should_dioread_nolock(struct inode *inode)
 	return 1;
 }
 
+/* Ext4 fast commit related info */
+
+/* Magic of fast commit header */
+#define EXT4_FC_MAGIC			0xE2540090
+
 #define EXT4_NUM_FC_BLKS		128
+
+struct ext4_fc_commit_hdr {
+	/* Fast commit magic, should be EXT4_FC_MAGIC */
+	__le32 fc_magic;
+	/* Features used by this fast commit block */
+	__u8 fc_features;
+	/* Number of TLVs in this fast commmit block */
+	__le16 fc_num_tlvs;
+	/* Inode number */
+	__le32 fc_ino;
+	/* Csum(hdr+contents) */
+	__le32 fc_csum;
+};
+
+/* Fast commit on disk tag length structure */
+struct ext4_fc_tl {
+	__le16 fc_tag;
+	__le16 fc_len;
+};
+
+/* On disk fast commit tlv value structure for dirent tags:
+ *  - EXT4_FC_TAG_CREATE_DENTRY
+ *  - EXT4_FC_TAG_ADD_DENTRY
+ *  - EXT4_FC_TAG_DEL_DENTRY
+ */
+struct ext4_fc_dentry_info {
+	__le32 fc_parent_ino;
+	__le32 fc_ino;
+	u8 fc_dname[0];
+};
+
+/*
+ * On disk fast commit tlv value structure for tag
+ * EXT4_FC_TAG_HOLE.
+ */
+struct ext4_fc_lrange {
+	__le32 fc_lblk;
+	__le32 fc_len;
+};
+
 void ext4_init_fast_commit(struct super_block *sb, journal_t *journal);
 void ext4_init_inode_fc_info(struct inode *inode);
 void ext4_fc_track_range(struct inode *inode, ext4_lblk_t start,
-- 
2.26.0.110.g2183baf09c-goog