From 3612b49598c303cfb22a4b609427f829828e2427 Mon Sep 17 00:00:00 2001 From: Tsutomu Itoh Date: Tue, 25 Jan 2011 02:51:38 +0000 Subject: [PATCH] btrfs: fix return value check of btrfs_join_transaction() The error check of btrfs_join_transaction()/btrfs_join_transaction_nolock() is added, and the mistake of the error check in several places is corrected. For more stable Btrfs, I think that we should reduce BUG_ON(). But, I think that long time is necessary for this. So, I propose this patch as a short-term solution. With this patch: - To more stable Btrfs, the part that should be corrected is clarified. - The panic isn't done by the NULL pointer reference etc. (even if BUG_ON() is increased temporarily) - The error code is returned in the place where the error can be easily returned. As a long-term plan: - BUG_ON() is reduced by using the forced-readonly framework, etc. Signed-off-by: Tsutomu Itoh Signed-off-by: Chris Mason --- fs/btrfs/disk-io.c | 5 +++++ fs/btrfs/extent-tree.c | 2 +- fs/btrfs/inode.c | 24 ++++++++++++++++-------- fs/btrfs/ioctl.c | 2 +- fs/btrfs/relocation.c | 26 +++++++++++++++++++++++--- fs/btrfs/transaction.c | 5 +++++ 6 files changed, 51 insertions(+), 13 deletions(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 2887b8be6fdd..b36eeef19194 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1550,6 +1550,7 @@ static int transaction_kthread(void *arg) spin_unlock(&root->fs_info->new_trans_lock); trans = btrfs_join_transaction(root, 1); + BUG_ON(IS_ERR(trans)); if (transid == trans->transid) { ret = btrfs_commit_transaction(trans, root); BUG_ON(ret); @@ -2464,10 +2465,14 @@ int btrfs_commit_super(struct btrfs_root *root) up_write(&root->fs_info->cleanup_work_sem); trans = btrfs_join_transaction(root, 1); + if (IS_ERR(trans)) + return PTR_ERR(trans); ret = btrfs_commit_transaction(trans, root); BUG_ON(ret); /* run commit again to drop the original snapshot */ trans = btrfs_join_transaction(root, 1); + if (IS_ERR(trans)) + return PTR_ERR(trans); btrfs_commit_transaction(trans, root); ret = btrfs_write_and_wait_transaction(NULL, root); BUG_ON(ret); diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index bcf303204f7f..98ee139885cc 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -7478,7 +7478,7 @@ int btrfs_drop_dead_reloc_roots(struct btrfs_root *root) BUG_ON(reloc_root->commit_root != NULL); while (1) { trans = btrfs_join_transaction(root, 1); - BUG_ON(!trans); + BUG_ON(IS_ERR(trans)); mutex_lock(&root->fs_info->drop_mutex); ret = btrfs_drop_snapshot(trans, reloc_root); diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 2b7d251d6ad1..40fee137dd11 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -416,7 +416,7 @@ again: } if (start == 0) { trans = btrfs_join_transaction(root, 1); - BUG_ON(!trans); + BUG_ON(IS_ERR(trans)); btrfs_set_trans_block_group(trans, inode); trans->block_rsv = &root->fs_info->delalloc_block_rsv; @@ -612,6 +612,7 @@ retry: GFP_NOFS); trans = btrfs_join_transaction(root, 1); + BUG_ON(IS_ERR(trans)); ret = btrfs_reserve_extent(trans, root, async_extent->compressed_size, async_extent->compressed_size, @@ -771,7 +772,7 @@ static noinline int cow_file_range(struct inode *inode, BUG_ON(root == root->fs_info->tree_root); trans = btrfs_join_transaction(root, 1); - BUG_ON(!trans); + BUG_ON(IS_ERR(trans)); btrfs_set_trans_block_group(trans, inode); trans->block_rsv = &root->fs_info->delalloc_block_rsv; @@ -1049,7 +1050,7 @@ static noinline int run_delalloc_nocow(struct inode *inode, } else { trans = btrfs_join_transaction(root, 1); } - BUG_ON(!trans); + BUG_ON(IS_ERR(trans)); cow_start = (u64)-1; cur_offset = start; @@ -1704,7 +1705,7 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end) trans = btrfs_join_transaction_nolock(root, 1); else trans = btrfs_join_transaction(root, 1); - BUG_ON(!trans); + BUG_ON(IS_ERR(trans)); btrfs_set_trans_block_group(trans, inode); trans->block_rsv = &root->fs_info->delalloc_block_rsv; ret = btrfs_update_inode(trans, root, inode); @@ -1721,6 +1722,7 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end) trans = btrfs_join_transaction_nolock(root, 1); else trans = btrfs_join_transaction(root, 1); + BUG_ON(IS_ERR(trans)); btrfs_set_trans_block_group(trans, inode); trans->block_rsv = &root->fs_info->delalloc_block_rsv; @@ -2382,6 +2384,7 @@ void btrfs_orphan_cleanup(struct btrfs_root *root) if (root->orphan_block_rsv || root->orphan_item_inserted) { trans = btrfs_join_transaction(root, 1); + BUG_ON(IS_ERR(trans)); btrfs_end_transaction(trans, root); } @@ -4350,6 +4353,8 @@ int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc) trans = btrfs_join_transaction_nolock(root, 1); else trans = btrfs_join_transaction(root, 1); + if (IS_ERR(trans)) + return PTR_ERR(trans); btrfs_set_trans_block_group(trans, inode); if (nolock) ret = btrfs_end_transaction_nolock(trans, root); @@ -4375,6 +4380,7 @@ void btrfs_dirty_inode(struct inode *inode) return; trans = btrfs_join_transaction(root, 1); + BUG_ON(IS_ERR(trans)); btrfs_set_trans_block_group(trans, inode); ret = btrfs_update_inode(trans, root, inode); @@ -5179,6 +5185,8 @@ again: em = NULL; btrfs_release_path(root, path); trans = btrfs_join_transaction(root, 1); + if (IS_ERR(trans)) + return ERR_CAST(trans); goto again; } map = kmap(page); @@ -5283,8 +5291,8 @@ static struct extent_map *btrfs_new_extent_direct(struct inode *inode, btrfs_drop_extent_cache(inode, start, start + len - 1, 0); trans = btrfs_join_transaction(root, 0); - if (!trans) - return ERR_PTR(-ENOMEM); + if (IS_ERR(trans)) + return ERR_CAST(trans); trans->block_rsv = &root->fs_info->delalloc_block_rsv; @@ -5508,7 +5516,7 @@ static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock, * while we look for nocow cross refs */ trans = btrfs_join_transaction(root, 0); - if (!trans) + if (IS_ERR(trans)) goto must_cow; if (can_nocow_odirect(trans, inode, start, len) == 1) { @@ -5643,7 +5651,7 @@ again: BUG_ON(!ordered); trans = btrfs_join_transaction(root, 1); - if (!trans) { + if (IS_ERR(trans)) { err = -ENOMEM; goto out; } diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index edd82becbb9e..04b4fb9144a9 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -203,7 +203,7 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg) trans = btrfs_join_transaction(root, 1); - BUG_ON(!trans); + BUG_ON(IS_ERR(trans)); ret = btrfs_update_inode(trans, root, inode); BUG_ON(ret); diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c index 045c9c2b2d7e..ea9965430241 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -2147,6 +2147,12 @@ again: } trans = btrfs_join_transaction(rc->extent_root, 1); + if (IS_ERR(trans)) { + if (!err) + btrfs_block_rsv_release(rc->extent_root, + rc->block_rsv, num_bytes); + return PTR_ERR(trans); + } if (!err) { if (num_bytes != rc->merging_rsv_size) { @@ -3222,6 +3228,7 @@ truncate: trans = btrfs_join_transaction(root, 0); if (IS_ERR(trans)) { btrfs_free_path(path); + ret = PTR_ERR(trans); goto out; } @@ -3628,6 +3635,7 @@ int prepare_to_relocate(struct reloc_control *rc) set_reloc_control(rc); trans = btrfs_join_transaction(rc->extent_root, 1); + BUG_ON(IS_ERR(trans)); btrfs_commit_transaction(trans, rc->extent_root); return 0; } @@ -3804,7 +3812,10 @@ static noinline_for_stack int relocate_block_group(struct reloc_control *rc) /* get rid of pinned extents */ trans = btrfs_join_transaction(rc->extent_root, 1); - btrfs_commit_transaction(trans, rc->extent_root); + if (IS_ERR(trans)) + err = PTR_ERR(trans); + else + btrfs_commit_transaction(trans, rc->extent_root); out_free: btrfs_free_block_rsv(rc->extent_root, rc->block_rsv); btrfs_free_path(path); @@ -4125,6 +4136,11 @@ int btrfs_recover_relocation(struct btrfs_root *root) set_reloc_control(rc); trans = btrfs_join_transaction(rc->extent_root, 1); + if (IS_ERR(trans)) { + unset_reloc_control(rc); + err = PTR_ERR(trans); + goto out_free; + } rc->merge_reloc_tree = 1; @@ -4154,9 +4170,13 @@ int btrfs_recover_relocation(struct btrfs_root *root) unset_reloc_control(rc); trans = btrfs_join_transaction(rc->extent_root, 1); - btrfs_commit_transaction(trans, rc->extent_root); -out: + if (IS_ERR(trans)) + err = PTR_ERR(trans); + else + btrfs_commit_transaction(trans, rc->extent_root); +out_free: kfree(rc); +out: while (!list_empty(&reloc_roots)) { reloc_root = list_entry(reloc_roots.next, struct btrfs_root, root_list); diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index bae5c7b8bbe2..3d73c8d93bbb 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -1161,6 +1161,11 @@ int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans, INIT_DELAYED_WORK(&ac->work, do_async_commit); ac->root = root; ac->newtrans = btrfs_join_transaction(root, 0); + if (IS_ERR(ac->newtrans)) { + int err = PTR_ERR(ac->newtrans); + kfree(ac); + return err; + } /* take transaction reference */ mutex_lock(&root->fs_info->trans_mutex);