HPFS: Introduce a global mutex and lock it on every callback from VFS.

Introduce a global mutex and lock it on every callback from VFS.

Performance doesn't matter, reviewing the whole code for locking correctness
would be too complicated, so simply lock it all.

Signed-off-by: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 19 insertions, 8 deletions

diff --git a/fs/hpfs/file.c b/fs/hpfs/file.c
index 9b9eb6933e43..09a642f853e1 100644
--- a/fs/hpfs/file.c
+++ b/fs/hpfs/file.c
@@ -48,38 +48,46 @@ static secno hpfs_bmap(struct inode *inode, unsigned file_secno)
 static void hpfs_truncate(struct inode *i)
 {
 	if (IS_IMMUTABLE(i)) return /*-EPERM*/;
-	hpfs_lock(i->i_sb);
+	hpfs_lock_assert(i->i_sb);
+
 	hpfs_i(i)->i_n_secs = 0;
 	i->i_blocks = 1 + ((i->i_size + 511) >> 9);
 	hpfs_i(i)->mmu_private = i->i_size;
 	hpfs_truncate_btree(i->i_sb, i->i_ino, 1, ((i->i_size + 511) >> 9));
 	hpfs_write_inode(i);
 	hpfs_i(i)->i_n_secs = 0;
-	hpfs_unlock(i->i_sb);
 }
 
 static int hpfs_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create)
 {
+	int r;
 	secno s;
+	hpfs_lock(inode->i_sb);
 	s = hpfs_bmap(inode, iblock);
 	if (s) {
 		map_bh(bh_result, inode->i_sb, s);
-		return 0;
+		goto ret_0;
 	}
-	if (!create) return 0;
+	if (!create) goto ret_0;
 	if (iblock<<9 != hpfs_i(inode)->mmu_private) {
 		BUG();
-		return -EIO;
+		r = -EIO;
+		goto ret_r;
 	}
 	if ((s = hpfs_add_sector_to_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1)) == -1) {
 		hpfs_truncate_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1);
-		return -ENOSPC;
+		r = -ENOSPC;
+		goto ret_r;
 	}
 	inode->i_blocks++;
 	hpfs_i(inode)->mmu_private += 512;
 	set_buffer_new(bh_result);
 	map_bh(bh_result, inode->i_sb, s);
-	return 0;
+	ret_0:
+	r = 0;
+	ret_r:
+	hpfs_unlock(inode->i_sb);
+	return r;
 }
 
 static int hpfs_writepage(struct page *page, struct writeback_control *wbc)
@@ -130,8 +138,11 @@ static ssize_t hpfs_file_write(struct file *file, const char __user *buf,
 	ssize_t retval;
 
 	retval = do_sync_write(file, buf, count, ppos);
-	if (retval > 0)
+	if (retval > 0) {
+		hpfs_lock(file->f_path.dentry->d_sb);
 		hpfs_i(file->f_path.dentry->d_inode)->i_dirty = 1;
+		hpfs_unlock(file->f_path.dentry->d_sb);
+	}
 	return retval;
 }