[PATCH v2] Btrfs: fix memory leak of block group cache
From: Liu Bo <hidden>
Date: 2016-07-21 00:40:13
Subsystem:
btrfs file system, filesystems (vfs and infrastructure), the rest · Maintainers:
Chris Mason, David Sterba, Alexander Viro, Christian Brauner, Linus Torvalds
While processing delayed refs, we may update block group's statistics
and attach it to cur_trans->dirty_bgs, and later writing dirty block
groups will process the list, which happens during
btrfs_commit_transaction().
For whatever reason, the transaction is aborted and dirty_bgs
is not processed in cleanup_transaction(), we end up with memory leak
of these dirty block group cache.
Since btrfs_start_dirty_block_groups() doesn't make it go to the commit
critical section, this also adds the cleanup work inside it.
Signed-off-by: Liu Bo <redacted>
---
v2: - remove the 'return' when dirty_bgs is empty because there
might be block group in list io_bgs.
- remove unnecessary '\n' in btrfs_err().
- more commit log.
fs/btrfs/disk-io.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++++++
fs/btrfs/disk-io.h | 2 ++
fs/btrfs/extent-tree.c | 2 ++
3 files changed, 75 insertions(+)
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index db53eb8..4c110de 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c@@ -4434,9 +4434,80 @@ again: return 0; } +static void btrfs_cleanup_bg_io(struct btrfs_block_group_cache *cache) +{ + struct inode *inode; + + inode = cache->io_ctl.inode; + if (inode) { + invalidate_inode_pages2(inode->i_mapping); + BTRFS_I(inode)->generation = 0; + cache->io_ctl.inode = NULL; + iput(inode); + } + btrfs_put_block_group(cache); +} + +void btrfs_cleanup_dirty_bgs(struct btrfs_transaction *cur_trans, + struct btrfs_root *root) +{ + struct btrfs_block_group_cache *cache; + + spin_lock(&cur_trans->dirty_bgs_lock); + while (!list_empty(&cur_trans->dirty_bgs)) { + cache = list_first_entry(&cur_trans->dirty_bgs, + struct btrfs_block_group_cache, + dirty_list); + if (!cache) { + btrfs_err(root->fs_info, + "orphan block group dirty_bgs list"); + spin_unlock(&cur_trans->dirty_bgs_lock); + return; + } + + if (!list_empty(&cache->io_list)) { + spin_unlock(&cur_trans->dirty_bgs_lock); + list_del_init(&cache->io_list); + btrfs_cleanup_bg_io(cache); + spin_lock(&cur_trans->dirty_bgs_lock); + } + + list_del_init(&cache->dirty_list); + spin_lock(&cache->lock); + cache->disk_cache_state = BTRFS_DC_ERROR; + spin_unlock(&cache->lock); + + spin_unlock(&cur_trans->dirty_bgs_lock); + btrfs_put_block_group(cache); + spin_lock(&cur_trans->dirty_bgs_lock); + } + spin_unlock(&cur_trans->dirty_bgs_lock); + + while (!list_empty(&cur_trans->io_bgs)) { + cache = list_first_entry(&cur_trans->io_bgs, + struct btrfs_block_group_cache, + io_list); + if (!cache) { + btrfs_err(root->fs_info, + "orphan block group on io_bgs list"); + return; + } + + list_del_init(&cache->io_list); + spin_lock(&cache->lock); + cache->disk_cache_state = BTRFS_DC_ERROR; + spin_unlock(&cache->lock); + btrfs_cleanup_bg_io(cache); + } +} + void btrfs_cleanup_one_transaction(struct btrfs_transaction *cur_trans, struct btrfs_root *root) { + btrfs_cleanup_dirty_bgs(cur_trans, root); + ASSERT(list_empty(&cur_trans->dirty_bgs)); + ASSERT(list_empty(&cur_trans->io_bgs)); + btrfs_destroy_delayed_refs(cur_trans, root); cur_trans->state = TRANS_STATE_COMMIT_START;
diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index acba821..6201663 100644
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h@@ -133,6 +133,8 @@ int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info); int btrfs_add_log_tree(struct btrfs_trans_handle *trans, struct btrfs_root *root); +void btrfs_cleanup_dirty_bgs(struct btrfs_transaction *trans, + struct btrfs_root *root); void btrfs_cleanup_one_transaction(struct btrfs_transaction *trans, struct btrfs_root *root); struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 50bd683..7a35c9d 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c@@ -3698,6 +3698,8 @@ again: goto again; } spin_unlock(&cur_trans->dirty_bgs_lock); + } else if (ret < 0) { + btrfs_cleanup_dirty_bgs(cur_trans, root); } btrfs_free_path(path);
--
2.5.5