Btrfs: convert the inode bit field to use the actual bit operations

Miao pointed this out while I was working on an orphan problem that messing
with a bitfield where different ranges are protected by different locks
doesn't work out right.  Turns out we've been doing this forever where we
have different parts of the bit field protected by either no lock at all or
different locks which could cause all sorts of weird problems including the
issue I was hitting.  So instead make a runtime_flags thing that we use the
normal bit operations on that are all atomic so we can keep having our
no/different locking for the different flags and then make force_compress
it's own thing so it can be treated normally.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>

1 files changed, 12 insertions, 16 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 9a1b96f..91ad639 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2182,10 +2182,9 @@ int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
 		insert = 1;
 	}
 
-	if (!BTRFS_I(inode)->orphan_meta_reserved) {
-		BTRFS_I(inode)->orphan_meta_reserved = 1;
+	if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
+			      &BTRFS_I(inode)->runtime_flags))
 		reserve = 1;
-	}
 	spin_unlock(&root->orphan_lock);
 
 	/* grab metadata reservation from transaction handle */
@@ -2233,10 +2232,9 @@ int btrfs_orphan_del(struct btrfs_trans_handle *trans, struct inode *inode)
 		delete_item = 1;
 	}
 
-	if (BTRFS_I(inode)->orphan_meta_reserved) {
-		BTRFS_I(inode)->orphan_meta_reserved = 0;
+	if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
+			       &BTRFS_I(inode)->runtime_flags))
 		release_rsv = 1;
-	}
 	spin_unlock(&root->orphan_lock);
 
 	if (trans && delete_item) {
@@ -3642,7 +3640,8 @@ static int btrfs_setsize(struct inode *inode, loff_t newsize)
 		 * any new writes get down to disk quickly.
 		 */
 		if (newsize == 0)
-			BTRFS_I(inode)->ordered_data_close = 1;
+			set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
+				&BTRFS_I(inode)->runtime_flags);
 
 		/* we don't support swapfiles, so vmtruncate shouldn't fail */
 		truncate_setsize(inode, newsize);
@@ -4102,7 +4101,7 @@ static struct inode *new_simple_dir(struct super_block *s,
 
 	BTRFS_I(inode)->root = root;
 	memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
-	BTRFS_I(inode)->dummy_inode = 1;
+	set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
 
 	inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
 	inode->i_op = &btrfs_dir_ro_inode_operations;
@@ -4406,7 +4405,7 @@ int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
 	int ret = 0;
 	bool nolock = false;
 
-	if (BTRFS_I(inode)->dummy_inode)
+	if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
 		return 0;
 
 	if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(root, inode))
@@ -4439,7 +4438,7 @@ int btrfs_dirty_inode(struct inode *inode)
 	struct btrfs_trans_handle *trans;
 	int ret;
 
-	if (BTRFS_I(inode)->dummy_inode)
+	if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
 		return 0;
 
 	trans = btrfs_join_transaction(root);
@@ -6752,7 +6751,8 @@ static int btrfs_truncate(struct inode *inode)
 	 * using truncate to replace the contents of the file will
 	 * end up with a zero length file after a crash.
 	 */
-	if (inode->i_size == 0 && BTRFS_I(inode)->ordered_data_close)
+	if (inode->i_size == 0 && test_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
+					   &BTRFS_I(inode)->runtime_flags))
 		btrfs_add_ordered_operation(trans, root, inode);
 
 	while (1) {
@@ -6889,11 +6889,7 @@ struct inode *btrfs_alloc_inode(struct super_block *sb)
 	ei->outstanding_extents = 0;
 	ei->reserved_extents = 0;
 
-	ei->ordered_data_close = 0;
-	ei->orphan_meta_reserved = 0;
-	ei->dummy_inode = 0;
-	ei->in_defrag = 0;
-	ei->delalloc_meta_reserved = 0;
+	ei->runtime_flags = 0;
 	ei->force_compress = BTRFS_COMPRESS_NONE;
 
 	ei->delayed_node = NULL;