Re: [PATCH] let fat handle MS_SYNCHRONOUS flag

[Colin Leroy <colin@colino.net>]

On 24 Nov 2004 at 23h11, OGAWA Hirofumi wrote:

Hi, 

> Aren't you forgetting to update the inode and various metadata (e.g. FAT)?

Don't really know what to do about this one; where should I look ?

this second patch seems a step in the right direction to me, based off your
previous comments:

Signed-off-by: Colin Leroy <colin@colino.net>
diff -ur /tmp/linux-2.6.9/fs/fat/dir.c fs/fat/dir.c
--- /tmp/linux-2.6.9/fs/fat/dir.c	2004-11-24 15:57:17.776119552 +0100
+++ fs/fat/dir.c	2004-11-24 15:58:41.664366600 +0100
@@ -760,10 +760,14 @@
 	de[1].start = cpu_to_le16(MSDOS_I(parent)->i_logstart);
 	de[1].starthi = cpu_to_le16(MSDOS_I(parent)->i_logstart>>16);
 	mark_buffer_dirty(bh);
-	brelse(bh);
 	dir->i_atime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
 	mark_inode_dirty(dir);
 
+	if (dir->i_sb->s_flags & MS_SYNCHRONOUS)
+		sync_dirty_buffer(bh);
+
+	brelse(bh);
+
 	return 0;
 }
 
diff -ur /tmp/linux-2.6.9/fs/fat/file.c fs/fat/file.c
--- /tmp/linux-2.6.9/fs/fat/file.c	2004-10-18 23:53:44.000000000 +0200
+++ fs/fat/file.c	2004-11-24 15:49:22.375391448 +0100
@@ -74,18 +74,30 @@
 {
 	struct inode *inode = filp->f_dentry->d_inode;
 	int retval;
+	struct super_block *sb = inode->i_sb;
 
 	retval = generic_file_write(filp, buf, count, ppos);
 	if (retval > 0) {
 		inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 		MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
 		mark_inode_dirty(inode);
+		if (sb->s_flags & MS_SYNCHRONOUS) {
+			struct buffer_head *bh;
+			loff_t i_pos = MSDOS_I(inode)->i_pos;
+			bh = sb_bread(sb, 
+				i_pos >> MSDOS_SB(sb)->dir_per_block_bits);
+			if (!bh)
+				return -EIO;
+			sync_dirty_buffer(bh);
+			brelse(bh);
+		}
 	}
 	return retval;
 }
 
 void fat_truncate(struct inode *inode)
 {
+	struct super_block *sb = inode->i_sb;
 	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
 	const unsigned int cluster_size = sbi->cluster_size;
 	int nr_clusters;
@@ -105,4 +117,13 @@
 	unlock_kernel();
 	inode->i_ctime = inode->i_mtime = CURRENT_TIME;
 	mark_inode_dirty(inode);
+	if (sb->s_flags & MS_SYNCHRONOUS) {
+		struct buffer_head *bh;
+		loff_t i_pos = MSDOS_I(inode)->i_pos;
+		bh = sb_bread(sb, i_pos >> MSDOS_SB(sb)->dir_per_block_bits);
+		if (!bh)
+			return;
+		sync_dirty_buffer(bh);
+		brelse(bh);
+	}
 }
diff -ur /tmp/linux-2.6.9/fs/fat/inode.c fs/fat/inode.c
--- /tmp/linux-2.6.9/fs/fat/inode.c	2004-11-24 15:57:17.783118488 +0100
+++ fs/fat/inode.c	2004-11-18 15:00:55.000000000 +0100
@@ -1273,8 +1273,12 @@
 	}
 	spin_unlock(&sbi->inode_hash_lock);
 	mark_buffer_dirty(bh);
-	brelse(bh);
 	unlock_kernel();
+
+	if (sb->s_flags & MS_SYNCHRONOUS)
+		sync_dirty_buffer(bh);
+	brelse(bh);
+
 	return 0;
 }