nilfs2: move nilfs_bmap_write call out of nilfs_write_inode_common

Before converting the disk inode management metadata file ifile, the call
to nilfs_bmap_write(), the i_device_code setting, and the zero-fill code
for inodes on the super root block are moved from
nilfs_write_inode_common() to its callers.

This cleanup simplifies the role and arguments of
nilfs_write_inode_common() and collects calls to nilfs_bmap_write() to the
log writing code.

Also, add and use a new helper nilfs_write_root_mdt_inode() to avoid code
duplication in the data export routine nilfs_segctor_fill_in_super_root()
to the super root block's buffer.

Link: https://lkml.kernel.org/r/20240122140202.6950-9-konishi.ryusuke@gmail.comSigned-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

fs/nilfs2/inode.c

@@ -759,8 +759,18 @@ struct inode *nilfs_iget_for_shadow(struct inode *inode)
 	return s_inode;
 }
 
+/**
+ * nilfs_write_inode_common - export common inode information to on-disk inode
+ * @inode:     inode object
+ * @raw_inode: on-disk inode
+ *
+ * This function writes standard information from the on-memory inode @inode
+ * to @raw_inode on ifile, cpfile or a super root block.  Since inode bmap
+ * data is not exported, nilfs_bmap_write() must be called separately during
+ * log writing.
+ */
 void nilfs_write_inode_common(struct inode *inode,
-			      struct nilfs_inode *raw_inode, int has_bmap)
+			      struct nilfs_inode *raw_inode)
 {
 	struct nilfs_inode_info *ii = NILFS_I(inode);
 
@@ -778,21 +788,6 @@ void nilfs_write_inode_common(struct inode *inode,
 	raw_inode->i_flags = cpu_to_le32(ii->i_flags);
 	raw_inode->i_generation = cpu_to_le32(inode->i_generation);
 
-	if (NILFS_ROOT_METADATA_FILE(inode->i_ino)) {
-		struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
-
-		/* zero-fill unused portion in the case of super root block */
-		raw_inode->i_xattr = 0;
-		raw_inode->i_pad = 0;
-		memset((void *)raw_inode + sizeof(*raw_inode), 0,
-		       nilfs->ns_inode_size - sizeof(*raw_inode));
-	}
-
-	if (has_bmap)
-		nilfs_bmap_write(ii->i_bmap, raw_inode);
-	else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
-		raw_inode->i_device_code =
-			cpu_to_le64(huge_encode_dev(inode->i_rdev));
 	/*
 	 * When extending inode, nilfs->ns_inode_size should be checked
 	 * for substitutions of appended fields.
@@ -813,12 +808,11 @@ void nilfs_update_inode(struct inode *inode, struct buffer_head *ibh, int flags)
 	if (flags & I_DIRTY_DATASYNC)
 		set_bit(NILFS_I_INODE_SYNC, &ii->i_state);
 
-	nilfs_write_inode_common(inode, raw_inode, 0);
-		/*
-		 * XXX: call with has_bmap = 0 is a workaround to avoid
-		 * deadlock of bmap.  This delays update of i_bmap to just
-		 * before writing.
-		 */
+	nilfs_write_inode_common(inode, raw_inode);
+
+	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
+		raw_inode->i_device_code =
+			cpu_to_le64(huge_encode_dev(inode->i_rdev));
 
 	nilfs_ifile_unmap_inode(ifile, ino, ibh);
 }

fs/nilfs2/nilfs.h

@@ -256,7 +256,8 @@ extern struct inode *nilfs_new_inode(struct inode *, umode_t);
 extern int nilfs_get_block(struct inode *, sector_t, struct buffer_head *, int);
 extern void nilfs_set_inode_flags(struct inode *);
 extern int nilfs_read_inode_common(struct inode *, struct nilfs_inode *);
-extern void nilfs_write_inode_common(struct inode *, struct nilfs_inode *, int);
+void nilfs_write_inode_common(struct inode *inode,
+			      struct nilfs_inode *raw_inode);
 struct inode *nilfs_ilookup(struct super_block *sb, struct nilfs_root *root,
 			    unsigned long ino);
 struct inode *nilfs_iget_locked(struct super_block *sb, struct nilfs_root *root,

fs/nilfs2/segment.c

@@ -913,6 +913,7 @@ static int nilfs_segctor_fill_in_checkpoint(struct nilfs_sc_info *sci)
 	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
 	struct buffer_head *bh_cp;
 	struct nilfs_checkpoint *raw_cp;
+	struct inode *ifile;
 	int err;
 
 	err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 0,
@@ -941,8 +942,10 @@ static int nilfs_segctor_fill_in_checkpoint(struct nilfs_sc_info *sci)
 	else
 		nilfs_checkpoint_set_minor(raw_cp);
 
-	nilfs_write_inode_common(sci->sc_root->ifile,
-				 &raw_cp->cp_ifile_inode, 1);
+	ifile = sci->sc_root->ifile;
+	nilfs_write_inode_common(ifile, &raw_cp->cp_ifile_inode);
+	nilfs_bmap_write(NILFS_I(ifile)->i_bmap, &raw_cp->cp_ifile_inode);
+
 	nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
 	return 0;
 
@@ -977,6 +980,33 @@ static void nilfs_segctor_fill_in_file_bmap(struct nilfs_sc_info *sci)
 	}
 }
 
+/**
+ * nilfs_write_root_mdt_inode - export root metadata inode information to
+ *                              the on-disk inode
+ * @inode:     inode object of the root metadata file
+ * @raw_inode: on-disk inode
+ *
+ * nilfs_write_root_mdt_inode() writes inode information and bmap data of
+ * @inode to the inode area of the metadata file allocated on the super root
+ * block created to finalize the log.  Since super root blocks are configured
+ * each time, this function zero-fills the unused area of @raw_inode.
+ */
+static void nilfs_write_root_mdt_inode(struct inode *inode,
+				       struct nilfs_inode *raw_inode)
+{
+	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
+
+	nilfs_write_inode_common(inode, raw_inode);
+
+	/* zero-fill unused portion of raw_inode */
+	raw_inode->i_xattr = 0;
+	raw_inode->i_pad = 0;
+	memset((void *)raw_inode + sizeof(*raw_inode), 0,
+	       nilfs->ns_inode_size - sizeof(*raw_inode));
+
+	nilfs_bmap_write(NILFS_I(inode)->i_bmap, raw_inode);
+}
+
 static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci,
 					     struct the_nilfs *nilfs)
 {
@@ -998,12 +1028,13 @@ static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci,
 			      nilfs->ns_nongc_ctime : sci->sc_seg_ctime);
 	raw_sr->sr_flags = 0;
 
-	nilfs_write_inode_common(nilfs->ns_dat, (void *)raw_sr +
-				 NILFS_SR_DAT_OFFSET(isz), 1);
-	nilfs_write_inode_common(nilfs->ns_cpfile, (void *)raw_sr +
-				 NILFS_SR_CPFILE_OFFSET(isz), 1);
-	nilfs_write_inode_common(nilfs->ns_sufile, (void *)raw_sr +
-				 NILFS_SR_SUFILE_OFFSET(isz), 1);
+	nilfs_write_root_mdt_inode(nilfs->ns_dat, (void *)raw_sr +
+				   NILFS_SR_DAT_OFFSET(isz));
+	nilfs_write_root_mdt_inode(nilfs->ns_cpfile, (void *)raw_sr +
+				   NILFS_SR_CPFILE_OFFSET(isz));
+	nilfs_write_root_mdt_inode(nilfs->ns_sufile, (void *)raw_sr +
+				   NILFS_SR_SUFILE_OFFSET(isz));
+
 	memset((void *)raw_sr + srsz, 0, nilfs->ns_blocksize - srsz);
 	set_buffer_uptodate(bh_sr);
 	unlock_buffer(bh_sr);