btrfs: Catch locking failures in {set,clear,convert}_extent_bit
The *_state functions can only return 0 or -EEXIST. This patch addresses
the cases where those functions returning -EEXIST represent a locking
failure. It handles them by panicking with an appropriate error message.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index a55fbe6..601f23b 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -53,6 +53,12 @@
unsigned int sync_io:1;
};
+static inline struct btrfs_fs_info *
+tree_fs_info(struct extent_io_tree *tree)
+{
+ return btrfs_sb(tree->mapping->host->i_sb);
+}
+
int __init extent_io_init(void)
{
extent_state_cache = kmem_cache_create("extent_state",
@@ -439,6 +445,13 @@
return prealloc;
}
+void extent_io_tree_panic(struct extent_io_tree *tree, int err)
+{
+ btrfs_panic(tree_fs_info(tree), err, "Locking error: "
+ "Extent tree was modified by another "
+ "thread while locked.");
+}
+
/*
* clear some bits on a range in the tree. This may require splitting
* or inserting elements in the tree, so the gfp mask is used to
@@ -542,7 +555,9 @@
prealloc = alloc_extent_state_atomic(prealloc);
BUG_ON(!prealloc);
err = split_state(tree, state, prealloc, start);
- BUG_ON(err == -EEXIST);
+ if (err)
+ extent_io_tree_panic(tree, err);
+
prealloc = NULL;
if (err)
goto out;
@@ -564,7 +579,9 @@
prealloc = alloc_extent_state_atomic(prealloc);
BUG_ON(!prealloc);
err = split_state(tree, state, prealloc, end + 1);
- BUG_ON(err == -EEXIST);
+ if (err)
+ extent_io_tree_panic(tree, err);
+
if (wake)
wake_up(&state->wq);
@@ -742,8 +759,10 @@
prealloc = alloc_extent_state_atomic(prealloc);
BUG_ON(!prealloc);
err = insert_state(tree, prealloc, start, end, &bits);
+ if (err)
+ extent_io_tree_panic(tree, err);
+
prealloc = NULL;
- BUG_ON(err == -EEXIST);
goto out;
}
state = rb_entry(node, struct extent_state, rb_node);
@@ -809,7 +828,9 @@
prealloc = alloc_extent_state_atomic(prealloc);
BUG_ON(!prealloc);
err = split_state(tree, state, prealloc, start);
- BUG_ON(err == -EEXIST);
+ if (err)
+ extent_io_tree_panic(tree, err);
+
prealloc = NULL;
if (err)
goto out;
@@ -846,12 +867,9 @@
*/
err = insert_state(tree, prealloc, start, this_end,
&bits);
- BUG_ON(err == -EEXIST);
- if (err) {
- free_extent_state(prealloc);
- prealloc = NULL;
- goto out;
- }
+ if (err)
+ extent_io_tree_panic(tree, err);
+
cache_state(prealloc, cached_state);
prealloc = NULL;
start = this_end + 1;
@@ -873,7 +891,8 @@
prealloc = alloc_extent_state_atomic(prealloc);
BUG_ON(!prealloc);
err = split_state(tree, state, prealloc, end + 1);
- BUG_ON(err == -EEXIST);
+ if (err)
+ extent_io_tree_panic(tree, err);
set_state_bits(tree, prealloc, &bits);
cache_state(prealloc, cached_state);
@@ -946,7 +965,8 @@
}
err = insert_state(tree, prealloc, start, end, &bits);
prealloc = NULL;
- BUG_ON(err == -EEXIST);
+ if (err)
+ extent_io_tree_panic(tree, err);
goto out;
}
state = rb_entry(node, struct extent_state, rb_node);
@@ -1002,7 +1022,8 @@
goto out;
}
err = split_state(tree, state, prealloc, start);
- BUG_ON(err == -EEXIST);
+ if (err)
+ extent_io_tree_panic(tree, err);
prealloc = NULL;
if (err)
goto out;
@@ -1041,12 +1062,8 @@
*/
err = insert_state(tree, prealloc, start, this_end,
&bits);
- BUG_ON(err == -EEXIST);
- if (err) {
- free_extent_state(prealloc);
- prealloc = NULL;
- goto out;
- }
+ if (err)
+ extent_io_tree_panic(tree, err);
prealloc = NULL;
start = this_end + 1;
goto search_again;
@@ -1065,7 +1082,8 @@
}
err = split_state(tree, state, prealloc, end + 1);
- BUG_ON(err == -EEXIST);
+ if (err)
+ extent_io_tree_panic(tree, err);
set_state_bits(tree, prealloc, &bits);
clear_state_bit(tree, prealloc, &clear_bits, 0);