[PATCH 1/3] btrfs: handle ENOMEM in btrfs_alloc_tree_block
From: Omar Sandoval <osandov@osandov.com>
Date: 2015-02-17 10:51:34
Also in:
lkml
Subsystem:
btrfs file system, filesystems (vfs and infrastructure), the rest · Maintainers:
Chris Mason, David Sterba, Alexander Viro, Christian Brauner, Linus Torvalds
This is one of the first places to go when memory is tight. Handle it properly rather than with a BUG_ON. Signed-off-by: Omar Sandoval <osandov@osandov.com> --- fs/btrfs/extent-tree.c | 41 ++++++++++++++++++++++++++++------------- 1 file changed, 28 insertions(+), 13 deletions(-)
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index a684086..479df76 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c@@ -7321,7 +7321,7 @@ static void unuse_block_rsv(struct btrfs_fs_info *fs_info, * returns the key for the extent through ins, and a tree buffer for * the first block of the extent through buf. * - * returns the tree buffer or NULL. + * returns the tree buffer or an ERR_PTR on error. */ struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
@@ -7332,6 +7332,7 @@ struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans, struct btrfs_key ins; struct btrfs_block_rsv *block_rsv; struct extent_buffer *buf; + struct btrfs_delayed_extent_op *extent_op; u64 flags = 0; int ret; u32 blocksize = root->nodesize;
@@ -7352,14 +7353,15 @@ struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans, ret = btrfs_reserve_extent(root, blocksize, blocksize, empty_size, hint, &ins, 0, 0); - if (ret) { - unuse_block_rsv(root->fs_info, block_rsv, blocksize); - return ERR_PTR(ret); - } + if (ret) + goto out_unuse; buf = btrfs_init_new_buffer(trans, root, ins.objectid, blocksize, level); - BUG_ON(IS_ERR(buf)); /* -ENOMEM */ + if (IS_ERR(buf)) { + ret = PTR_ERR(buf); + goto out_free_reserved; + } if (root_objectid == BTRFS_TREE_RELOC_OBJECTID) { if (parent == 0)
@@ -7369,9 +7371,11 @@ struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans, BUG_ON(parent > 0); if (root_objectid != BTRFS_TREE_LOG_OBJECTID) { - struct btrfs_delayed_extent_op *extent_op; extent_op = btrfs_alloc_delayed_extent_op(); - BUG_ON(!extent_op); /* -ENOMEM */ + if (!extent_op) { + ret = -ENOMEM; + goto out_free_buf; + } if (key) memcpy(&extent_op->key, key, sizeof(extent_op->key)); else
@@ -7386,13 +7390,24 @@ struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans, extent_op->level = level; ret = btrfs_add_delayed_tree_ref(root->fs_info, trans, - ins.objectid, - ins.offset, parent, root_objectid, - level, BTRFS_ADD_DELAYED_EXTENT, - extent_op, 0); - BUG_ON(ret); /* -ENOMEM */ + ins.objectid, ins.offset, + parent, root_objectid, level, + BTRFS_ADD_DELAYED_EXTENT, + extent_op, 0); + if (ret) + goto out_free_delayed; } return buf; + +out_free_delayed: + btrfs_free_delayed_extent_op(extent_op); +out_free_buf: + free_extent_buffer(buf); +out_free_reserved: + btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 0); +out_unuse: + unuse_block_rsv(root->fs_info, block_rsv, blocksize); + return ERR_PTR(ret); } struct walk_control {
--
2.3.0