[PATCH] hpfs: clean up lock ordering

	hpfs_{lock,unlock}_{2,3}inodes() killed; all places that take more than
one lock have ->i_sem held by VFS on all inodes involved and all hpfs per-inode
locks are of the same type.  IOW, we can replace these guys with multiple
hpfs_lock_inode() - order doesn't matter here.

fs/hpfs/buffer.c

@@ -60,74 +60,6 @@ void hpfs_unlock_inode(struct inode *i)
 	}
 }
 
-void hpfs_lock_2inodes(struct inode *i1, struct inode *i2)
-{
-	if (!i2 || i1 == i2) {
-		hpfs_lock_inode(i1);
-	} else if (!i1) {
-		hpfs_lock_inode(i2);
-	} else {
-		struct hpfs_inode_info *hpfs_i1 = hpfs_i(i1);
-		struct hpfs_inode_info *hpfs_i2 = hpfs_i(i2);
-		if (i1->i_ino < i2->i_ino) {
-			down(&hpfs_i1->i_sem);
-			down(&hpfs_i2->i_sem);
-		} else {
-			down(&hpfs_i2->i_sem);
-			down(&hpfs_i1->i_sem);
-		}
-	}
-}
-
-void hpfs_unlock_2inodes(struct inode *i1, struct inode *i2)
-{
-	/* order of up() doesn't matter here */
-	hpfs_unlock_inode(i1);
-	hpfs_unlock_inode(i2);
-}
-
-void hpfs_lock_3inodes(struct inode *i1, struct inode *i2, struct inode *i3)
-{
-	if (!i1) { hpfs_lock_2inodes(i2, i3); return; }
-	if (!i2) { hpfs_lock_2inodes(i1, i3); return; }
-	if (!i3) { hpfs_lock_2inodes(i1, i2); return; }
-	if (i1->i_ino < i2->i_ino && i1->i_ino < i3->i_ino) {
-		struct hpfs_inode_info *hpfs_i1 = hpfs_i(i1);
-		down(&hpfs_i1->i_sem);
-		hpfs_lock_2inodes(i2, i3);
-	} else if (i2->i_ino < i1->i_ino && i2->i_ino < i3->i_ino) {
-		struct hpfs_inode_info *hpfs_i2 = hpfs_i(i2);
-		down(&hpfs_i2->i_sem);
-		hpfs_lock_2inodes(i1, i3);
-	} else if (i3->i_ino < i1->i_ino && i3->i_ino < i2->i_ino) {
-		struct hpfs_inode_info *hpfs_i3 = hpfs_i(i3);
-		down(&hpfs_i3->i_sem);
-		hpfs_lock_2inodes(i1, i2);
-	} else if (i1->i_ino != i2->i_ino) hpfs_lock_2inodes(i1, i2);
-	else hpfs_lock_2inodes(i1, i3);
-}
-		
-void hpfs_unlock_3inodes(struct inode *i1, struct inode *i2, struct inode *i3)
-{
-	if (!i1) { hpfs_unlock_2inodes(i2, i3); return; }
-	if (!i2) { hpfs_unlock_2inodes(i1, i3); return; }
-	if (!i3) { hpfs_unlock_2inodes(i1, i2); return; }
-	if (i1->i_ino < i2->i_ino && i1->i_ino < i3->i_ino) {
-		struct hpfs_inode_info *hpfs_i1 = hpfs_i(i1);
-		hpfs_unlock_2inodes(i2, i3);
-		up(&hpfs_i1->i_sem);
-	} else if (i2->i_ino < i1->i_ino && i2->i_ino < i3->i_ino) {
-		struct hpfs_inode_info *hpfs_i2 = hpfs_i(i2);
-		hpfs_unlock_2inodes(i1, i3);
-		up(&hpfs_i2->i_sem);
-	} else if (i3->i_ino < i1->i_ino && i3->i_ino < i2->i_ino) {
-		struct hpfs_inode_info *hpfs_i3 = hpfs_i(i3);
-		hpfs_unlock_2inodes(i1, i2);
-		up(&hpfs_i3->i_sem);
-	} else if (i1->i_ino != i2->i_ino) hpfs_unlock_2inodes(i1, i2);
-	else hpfs_unlock_2inodes(i1, i3);
-}
-
 /* Map a sector into a buffer and return pointers to it and to the buffer. */
 
 void *hpfs_map_sector(struct super_block *s, unsigned secno, struct buffer_head **bhp,

fs/hpfs/hpfs_fn.h

@@ -196,10 +196,6 @@ void hpfs_lock_iget(struct super_block *, int);
 void hpfs_unlock_iget(struct super_block *);
 void hpfs_lock_inode(struct inode *);
 void hpfs_unlock_inode(struct inode *);
-void hpfs_lock_2inodes(struct inode *, struct inode *);
-void hpfs_unlock_2inodes(struct inode *, struct inode *);
-void hpfs_lock_3inodes(struct inode *, struct inode *, struct inode *);
-void hpfs_unlock_3inodes(struct inode *, struct inode *, struct inode *);
 void *hpfs_map_sector(struct super_block *, unsigned, struct buffer_head **, int);
 void *hpfs_get_sector(struct super_block *, unsigned, struct buffer_head **);
 void *hpfs_map_4sectors(struct super_block *, unsigned, struct quad_buffer_head *, int);

fs/hpfs/namei.c

@@ -349,7 +349,8 @@ int hpfs_unlink(struct inode *dir, struct dentry *dentry)
 	lock_kernel();
 	hpfs_adjust_length((char *)name, &len);
 again:
-	hpfs_lock_2inodes(dir, inode);
+	hpfs_lock_inode(dir);
+	hpfs_lock_inode(inode);
 	err = -ENOENT;
 	de = map_dirent(dir, hpfs_i(dir)->i_dno, (char *)name, len, &dno, &qbh);
 	if (!de)
@@ -376,7 +377,8 @@ int hpfs_unlink(struct inode *dir, struct dentry *dentry)
 		if (rep++)
 			break;
 
-		hpfs_unlock_2inodes(dir, inode);
+		hpfs_unlock_inode(inode);
+		hpfs_unlock_inode(dir);
 		d_drop(dentry);
 		spin_lock(&dentry->d_lock);
 		if (atomic_read(&dentry->d_count) > 1 ||
@@ -407,7 +409,8 @@ int hpfs_unlink(struct inode *dir, struct dentry *dentry)
 out1:
 	hpfs_brelse4(&qbh);
 out:
-	hpfs_unlock_2inodes(dir, inode);
+	hpfs_unlock_inode(inode);
+	hpfs_unlock_inode(dir);
 	unlock_kernel();
 	return err;
 }
@@ -427,7 +430,8 @@ int hpfs_rmdir(struct inode *dir, struct dentry *dentry)
 
 	hpfs_adjust_length((char *)name, &len);
 	lock_kernel();
-	hpfs_lock_2inodes(dir, inode);
+	hpfs_lock_inode(dir);
+	hpfs_lock_inode(inode);
 	err = -ENOENT;
 	de = map_dirent(dir, hpfs_i(dir)->i_dno, (char *)name, len, &dno, &qbh);
 	if (!de)
@@ -465,7 +469,8 @@ int hpfs_rmdir(struct inode *dir, struct dentry *dentry)
 out1:
 	hpfs_brelse4(&qbh);
 out:
-	hpfs_unlock_2inodes(dir, inode);
+	hpfs_unlock_inode(inode);
+	hpfs_unlock_inode(dir);
 	unlock_kernel();
 	return err;
 }
@@ -522,7 +527,10 @@ int hpfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	hpfs_adjust_length((char *)old_name, &old_len);
 
 	lock_kernel();
-	hpfs_lock_3inodes(old_dir, new_dir, i);
+	hpfs_lock_inode(old_dir);
+	if (new_dir != old_dir)
+		hpfs_lock_inode(new_dir);
+	hpfs_lock_inode(i);
 	
 	/* Erm? Moving over the empty non-busy directory is perfectly legal */
 	if (new_inode && S_ISDIR(new_inode->i_mode)) {
@@ -601,7 +609,10 @@ int hpfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	hpfs_i(i)->i_conv = hpfs_sb(i->i_sb)->sb_conv;
 	hpfs_decide_conv(i, (char *)new_name, new_len);
 	end1:
-	hpfs_unlock_3inodes(old_dir, new_dir, i);
+	hpfs_unlock_inode(i);
+	if (old_dir != new_dir)
+		hpfs_unlock_inode(new_dir);
+	hpfs_unlock_inode(old_dir);
 	unlock_kernel();
 	return err;
 }