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path: root/fs/btrfs/free-space-tree.c
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Diffstat (limited to 'fs/btrfs/free-space-tree.c')
-rw-r--r--fs/btrfs/free-space-tree.c70
1 files changed, 30 insertions, 40 deletions
diff --git a/fs/btrfs/free-space-tree.c b/fs/btrfs/free-space-tree.c
index dad0b492a663..1ad2ad384b9e 100644
--- a/fs/btrfs/free-space-tree.c
+++ b/fs/btrfs/free-space-tree.c
@@ -165,11 +165,9 @@ static unsigned long *alloc_bitmap(u32 bitmap_size)
/*
* GFP_NOFS doesn't work with kvmalloc(), but we really can't recurse
- * into the filesystem as the free space bitmap can be modified in the
- * critical section of a transaction commit.
- *
- * TODO: push the memalloc_nofs_{save,restore}() to the caller where we
- * know that recursion is unsafe.
+ * into the filesystem here. All callers hold a transaction handle
+ * open, so if a GFP_KERNEL allocation recurses into the filesystem
+ * and triggers a transaction commit, we would deadlock.
*/
nofs_flag = memalloc_nofs_save();
ret = kvzalloc(bitmap_rounded_size, GFP_KERNEL);
@@ -218,11 +216,8 @@ int btrfs_convert_free_space_to_bitmaps(struct btrfs_trans_handle *trans,
bitmap_size = free_space_bitmap_size(fs_info, block_group->length);
bitmap = alloc_bitmap(bitmap_size);
- if (unlikely(!bitmap)) {
- ret = -ENOMEM;
- btrfs_abort_transaction(trans, ret);
- goto out;
- }
+ if (unlikely(!bitmap))
+ return 0;
start = block_group->start;
end = block_group->start + block_group->length;
@@ -361,11 +356,8 @@ int btrfs_convert_free_space_to_extents(struct btrfs_trans_handle *trans,
bitmap_size = free_space_bitmap_size(fs_info, block_group->length);
bitmap = alloc_bitmap(bitmap_size);
- if (unlikely(!bitmap)) {
- ret = -ENOMEM;
- btrfs_abort_transaction(trans, ret);
- goto out;
- }
+ if (unlikely(!bitmap))
+ return 0;
start = block_group->start;
end = block_group->start + block_group->length;
@@ -841,7 +833,7 @@ int btrfs_remove_from_free_space_tree(struct btrfs_trans_handle *trans,
u64 start, u64 size)
{
struct btrfs_block_group *block_group;
- struct btrfs_path *path;
+ BTRFS_PATH_AUTO_FREE(path);
int ret;
if (!btrfs_fs_compat_ro(trans->fs_info, FREE_SPACE_TREE))
@@ -851,7 +843,7 @@ int btrfs_remove_from_free_space_tree(struct btrfs_trans_handle *trans,
if (unlikely(!path)) {
ret = -ENOMEM;
btrfs_abort_transaction(trans, ret);
- goto out;
+ return ret;
}
block_group = btrfs_lookup_block_group(trans->fs_info, start);
@@ -859,7 +851,7 @@ int btrfs_remove_from_free_space_tree(struct btrfs_trans_handle *trans,
DEBUG_WARN("no block group found for start=%llu", start);
ret = -ENOENT;
btrfs_abort_transaction(trans, ret);
- goto out;
+ return ret;
}
mutex_lock(&block_group->free_space_lock);
@@ -869,8 +861,7 @@ int btrfs_remove_from_free_space_tree(struct btrfs_trans_handle *trans,
btrfs_abort_transaction(trans, ret);
btrfs_put_block_group(block_group);
-out:
- btrfs_free_path(path);
+
return ret;
}
@@ -1023,7 +1014,7 @@ int btrfs_add_to_free_space_tree(struct btrfs_trans_handle *trans,
u64 start, u64 size)
{
struct btrfs_block_group *block_group;
- struct btrfs_path *path;
+ BTRFS_PATH_AUTO_FREE(path);
int ret;
if (!btrfs_fs_compat_ro(trans->fs_info, FREE_SPACE_TREE))
@@ -1033,7 +1024,7 @@ int btrfs_add_to_free_space_tree(struct btrfs_trans_handle *trans,
if (unlikely(!path)) {
ret = -ENOMEM;
btrfs_abort_transaction(trans, ret);
- goto out;
+ return ret;
}
block_group = btrfs_lookup_block_group(trans->fs_info, start);
@@ -1041,7 +1032,7 @@ int btrfs_add_to_free_space_tree(struct btrfs_trans_handle *trans,
DEBUG_WARN("no block group found for start=%llu", start);
ret = -ENOENT;
btrfs_abort_transaction(trans, ret);
- goto out;
+ return ret;
}
mutex_lock(&block_group->free_space_lock);
@@ -1051,8 +1042,7 @@ int btrfs_add_to_free_space_tree(struct btrfs_trans_handle *trans,
btrfs_abort_transaction(trans, ret);
btrfs_put_block_group(block_group);
-out:
- btrfs_free_path(path);
+
return ret;
}
@@ -1106,14 +1096,15 @@ static int populate_free_space_tree(struct btrfs_trans_handle *trans,
* If ret is 1 (no key found), it means this is an empty block group,
* without any extents allocated from it and there's no block group
* item (key BTRFS_BLOCK_GROUP_ITEM_KEY) located in the extent tree
- * because we are using the block group tree feature, so block group
- * items are stored in the block group tree. It also means there are no
- * extents allocated for block groups with a start offset beyond this
- * block group's end offset (this is the last, highest, block group).
+ * because we are using the block group tree feature (so block group
+ * items are stored in the block group tree) or this is a new block
+ * group created in the current transaction and its block group item
+ * was not yet inserted in the extent tree (that happens in
+ * btrfs_create_pending_block_groups() -> insert_block_group_item()).
+ * It also means there are no extents allocated for block groups with a
+ * start offset beyond this block group's end offset (this is the last,
+ * highest, block group).
*/
- if (!btrfs_fs_compat_ro(trans->fs_info, BLOCK_GROUP_TREE))
- ASSERT(ret == 0);
-
start = block_group->start;
end = block_group->start + block_group->length;
while (ret == 0) {
@@ -1465,7 +1456,7 @@ int btrfs_remove_block_group_free_space(struct btrfs_trans_handle *trans,
struct btrfs_block_group *block_group)
{
struct btrfs_root *root = btrfs_free_space_root(block_group);
- struct btrfs_path *path;
+ BTRFS_PATH_AUTO_FREE(path);
struct btrfs_key key, found_key;
struct extent_buffer *leaf;
u64 start, end;
@@ -1484,7 +1475,7 @@ int btrfs_remove_block_group_free_space(struct btrfs_trans_handle *trans,
if (unlikely(!path)) {
ret = -ENOMEM;
btrfs_abort_transaction(trans, ret);
- goto out;
+ return ret;
}
start = block_group->start;
@@ -1498,7 +1489,7 @@ int btrfs_remove_block_group_free_space(struct btrfs_trans_handle *trans,
ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1);
if (unlikely(ret)) {
btrfs_abort_transaction(trans, ret);
- goto out;
+ return ret;
}
leaf = path->nodes[0];
@@ -1529,14 +1520,13 @@ int btrfs_remove_block_group_free_space(struct btrfs_trans_handle *trans,
ret = btrfs_del_items(trans, root, path, path->slots[0], nr);
if (unlikely(ret)) {
btrfs_abort_transaction(trans, ret);
- goto out;
+ return ret;
}
btrfs_release_path(path);
}
ret = 0;
-out:
- btrfs_free_path(path);
+
return ret;
}
@@ -1701,8 +1691,8 @@ int btrfs_load_free_space_tree(struct btrfs_caching_control *caching_ctl)
* Just like caching_thread() doesn't want to deadlock on the extent
* tree, we don't want to deadlock on the free space tree.
*/
- path->skip_locking = 1;
- path->search_commit_root = 1;
+ path->skip_locking = true;
+ path->search_commit_root = true;
path->reada = READA_FORWARD;
info = btrfs_search_free_space_info(NULL, block_group, path, 0);
generated by cgit (git 2.34.1) at 2025-12-04 16:06:07 +0000