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btrfs: Catch locking failures in {set,clear,convert}_extent_bit

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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>
This commit is contained in:
Jeff Mahoney 2011-10-03 23:22:32 -04:00 committed by David Sterba
parent 8c34293001
commit c2d904e086
1 changed files with 38 additions and 20 deletions
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58
fs/btrfs/extent_io.c
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@ -53,6 +53,12 @@ struct extent_page_data {
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 @@ alloc_extent_state_atomic(struct extent_state *prealloc)
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 @@ hit_next:
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 @@ hit_next:
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 @@ again:
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 @@ hit_next:
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 @@ hit_next:
*/
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 @@ hit_next:
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 @@ again:
}
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 @@ hit_next:
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 @@ hit_next:
*/
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 @@ hit_next:
}
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);