@@ -439,6 +439,15 @@ static int clear_state_bit(struct extent_io_tree *tree,
return ret;
}
+static struct extent_state *
+alloc_extent_state_atomic(struct extent_state *prealloc)
+{
+ if (!prealloc)
+ prealloc = alloc_extent_state(GFP_ATOMIC);
+
+ return prealloc;
+}
+
/*
* 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
@@ -476,8 +485,7 @@ int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
again:
if (!prealloc && (mask & __GFP_WAIT)) {
prealloc = alloc_extent_state(mask);
- if (!prealloc)
- return -ENOMEM;
+ BUG_ON(!prealloc);
}
spin_lock(&tree->lock);
@@ -529,8 +537,8 @@ hit_next:
*/
if (state->start < start) {
- if (!prealloc)
- prealloc = alloc_extent_state(GFP_ATOMIC);
+ prealloc = alloc_extent_state_atomic(prealloc);
+ BUG_ON(!prealloc);
err = split_state(tree, state, prealloc, start);
BUG_ON(err == -EEXIST);
prealloc = NULL;
@@ -551,8 +559,8 @@ hit_next:
* on the first half
*/
if (state->start <= end && state->end > end) {
- if (!prealloc)
- prealloc = alloc_extent_state(GFP_ATOMIC);
+ prealloc = alloc_extent_state_atomic(prealloc);
+ BUG_ON(!prealloc);
err = split_state(tree, state, prealloc, end + 1);
BUG_ON(err == -EEXIST);
if (wake)
@@ -725,8 +733,7 @@ int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
again:
if (!prealloc && (mask & __GFP_WAIT)) {
prealloc = alloc_extent_state(mask);
- if (!prealloc)
- return -ENOMEM;
+ BUG_ON(!prealloc);
}
spin_lock(&tree->lock);
@@ -743,6 +750,8 @@ again:
*/
node = tree_search(tree, start);
if (!node) {
+ prealloc = alloc_extent_state_atomic(prealloc);
+ BUG_ON(!prealloc);
err = insert_state(tree, prealloc, start, end, &bits);
prealloc = NULL;
BUG_ON(err == -EEXIST);
@@ -811,6 +820,9 @@ hit_next:
err = -EEXIST;
goto out;
}
+
+ prealloc = alloc_extent_state_atomic(prealloc);
+ BUG_ON(!prealloc);
err = split_state(tree, state, prealloc, start);
BUG_ON(err == -EEXIST);
prealloc = NULL;
@@ -841,6 +853,9 @@ hit_next:
this_end = end;
else
this_end = last_start - 1;
+
+ prealloc = alloc_extent_state_atomic(prealloc);
+ BUG_ON(!prealloc);
err = insert_state(tree, prealloc, start, this_end,
&bits);
BUG_ON(err == -EEXIST);
@@ -865,6 +880,9 @@ hit_next:
err = -EEXIST;
goto out;
}
+
+ prealloc = alloc_extent_state_atomic(prealloc);
+ BUG_ON(!prealloc);
err = split_state(tree, state, prealloc, end + 1);
BUG_ON(err == -EEXIST);
It doesn't allocate extent_state and check the result properly: - in set_extent_bit, it doesn't allocate extent_state if the path is not allowed wait - in clear_extent_bit, it doesn't check the result after atomic-ly allocate, we trigger BUG_ON() if it's fail - if allocate fail, we trigger BUG_ON instead of returning -ENOMEM since the return value of clear_extent_bit() is ignored by many callers Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> --- fs/btrfs/extent_io.c | 34 ++++++++++++++++++++++++++-------- 1 files changed, 26 insertions(+), 8 deletions(-)