From: Qu Wenruo Date: Mon, 26 Oct 2015 06:11:18 +0000 (+0800) Subject: btrfs: qgroup: Fix a race in delayed_ref which leads to abort trans X-Git-Tag: v4.4-rc1~82^2~4 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=5846a3c26873;p=karo-tx-linux.git btrfs: qgroup: Fix a race in delayed_ref which leads to abort trans Between btrfs_allocerved_file_extent() and btrfs_add_delayed_qgroup_reserve(), there is a window that delayed_refs are run and delayed ref head maybe freed before btrfs_add_delayed_qgroup_reserve(). This will cause btrfs_dad_delayed_qgroup_reserve() to return -ENOENT, and cause transaction to be aborted. This patch will record qgroup reserve space info into delayed_ref_head at btrfs_add_delayed_ref(), to eliminate the race window. Reported-by: Filipe Manana Signed-off-by: Qu Wenruo Signed-off-by: Chris Mason --- diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 4001585ec434..a2e73f6053a8 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -3430,7 +3430,8 @@ void btrfs_free_tree_block(struct btrfs_trans_handle *trans, int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 root_objectid, u64 owner, - u64 offset, struct btrfs_key *ins); + u64 offset, u64 ram_bytes, + struct btrfs_key *ins); int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 root_objectid, u64 owner, u64 offset, diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c index 1c3588a70ce6..e06dd75ad13f 100644 --- a/fs/btrfs/delayed-ref.c +++ b/fs/btrfs/delayed-ref.c @@ -535,7 +535,8 @@ add_delayed_ref_head(struct btrfs_fs_info *fs_info, struct btrfs_trans_handle *trans, struct btrfs_delayed_ref_node *ref, struct btrfs_qgroup_extent_record *qrecord, - u64 bytenr, u64 num_bytes, int action, int is_data) + u64 bytenr, u64 num_bytes, u64 ref_root, u64 reserved, + int action, int is_data) { struct btrfs_delayed_ref_head *existing; struct btrfs_delayed_ref_head *head_ref = NULL; @@ -544,6 +545,9 @@ add_delayed_ref_head(struct btrfs_fs_info *fs_info, int count_mod = 1; int must_insert_reserved = 0; + /* If reserved is provided, it must be a data extent. */ + BUG_ON(!is_data && reserved); + /* * the head node stores the sum of all the mods, so dropping a ref * should drop the sum in the head node by one. @@ -593,6 +597,11 @@ add_delayed_ref_head(struct btrfs_fs_info *fs_info, /* Record qgroup extent info if provided */ if (qrecord) { + if (ref_root && reserved) { + head_ref->qgroup_ref_root = ref_root; + head_ref->qgroup_reserved = reserved; + } + qrecord->bytenr = bytenr; qrecord->num_bytes = num_bytes; qrecord->old_roots = NULL; @@ -611,6 +620,8 @@ add_delayed_ref_head(struct btrfs_fs_info *fs_info, existing = htree_insert(&delayed_refs->href_root, &head_ref->href_node); if (existing) { + WARN_ON(ref_root && reserved && existing->qgroup_ref_root + && existing->qgroup_reserved); update_existing_head_ref(delayed_refs, &existing->node, ref); /* * we've updated the existing ref, free the newly @@ -777,7 +788,7 @@ int btrfs_add_delayed_tree_ref(struct btrfs_fs_info *fs_info, * the spin lock */ head_ref = add_delayed_ref_head(fs_info, trans, &head_ref->node, record, - bytenr, num_bytes, action, 0); + bytenr, num_bytes, 0, 0, action, 0); add_delayed_tree_ref(fs_info, trans, head_ref, &ref->node, bytenr, num_bytes, parent, ref_root, level, action); @@ -800,7 +811,7 @@ int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info, struct btrfs_trans_handle *trans, u64 bytenr, u64 num_bytes, u64 parent, u64 ref_root, - u64 owner, u64 offset, int action, + u64 owner, u64 offset, u64 reserved, int action, struct btrfs_delayed_extent_op *extent_op) { struct btrfs_delayed_data_ref *ref; @@ -839,7 +850,8 @@ int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info, * the spin lock */ head_ref = add_delayed_ref_head(fs_info, trans, &head_ref->node, record, - bytenr, num_bytes, action, 1); + bytenr, num_bytes, ref_root, reserved, + action, 1); add_delayed_data_ref(fs_info, trans, head_ref, &ref->node, bytenr, num_bytes, parent, ref_root, owner, offset, @@ -894,7 +906,7 @@ int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info, spin_lock(&delayed_refs->lock); add_delayed_ref_head(fs_info, trans, &head_ref->node, NULL, bytenr, - num_bytes, BTRFS_UPDATE_DELAYED_HEAD, + num_bytes, 0, 0, BTRFS_UPDATE_DELAYED_HEAD, extent_op->is_data); spin_unlock(&delayed_refs->lock); diff --git a/fs/btrfs/delayed-ref.h b/fs/btrfs/delayed-ref.h index f9cf2345b864..00ed02cbf3e9 100644 --- a/fs/btrfs/delayed-ref.h +++ b/fs/btrfs/delayed-ref.h @@ -248,7 +248,7 @@ int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info, struct btrfs_trans_handle *trans, u64 bytenr, u64 num_bytes, u64 parent, u64 ref_root, - u64 owner, u64 offset, int action, + u64 owner, u64 offset, u64 reserved, int action, struct btrfs_delayed_extent_op *extent_op); int btrfs_add_delayed_qgroup_reserve(struct btrfs_fs_info *fs_info, struct btrfs_trans_handle *trans, diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index c1f8c7e27a6d..f50c7c2e2b59 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -2087,8 +2087,8 @@ int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans, BTRFS_ADD_DELAYED_REF, NULL); } else { ret = btrfs_add_delayed_data_ref(fs_info, trans, bytenr, - num_bytes, - parent, root_objectid, owner, offset, + num_bytes, parent, root_objectid, + owner, offset, 0, BTRFS_ADD_DELAYED_REF, NULL); } return ret; @@ -6832,8 +6832,8 @@ int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, ret = btrfs_add_delayed_data_ref(fs_info, trans, bytenr, num_bytes, parent, root_objectid, owner, - offset, BTRFS_DROP_DELAYED_REF, - NULL); + offset, 0, + BTRFS_DROP_DELAYED_REF, NULL); } return ret; } @@ -7759,7 +7759,8 @@ static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans, int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 root_objectid, u64 owner, - u64 offset, struct btrfs_key *ins) + u64 offset, u64 ram_bytes, + struct btrfs_key *ins) { int ret; @@ -7768,7 +7769,8 @@ int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans, ret = btrfs_add_delayed_data_ref(root->fs_info, trans, ins->objectid, ins->offset, 0, root_objectid, owner, offset, - BTRFS_ADD_DELAYED_EXTENT, NULL); + ram_bytes, BTRFS_ADD_DELAYED_EXTENT, + NULL); return ret; } diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 6f030c299de8..4439fbb4ff45 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -2127,17 +2127,13 @@ static int insert_reserved_file_extent(struct btrfs_trans_handle *trans, ins.type = BTRFS_EXTENT_ITEM_KEY; ret = btrfs_alloc_reserved_file_extent(trans, root, root->root_key.objectid, - btrfs_ino(inode), file_pos, &ins); - if (ret < 0) - goto out; + btrfs_ino(inode), file_pos, + ram_bytes, &ins); /* - * Release the reserved range from inode dirty range map, and - * move it to delayed ref codes, as now accounting only happens at - * commit_transaction() time. + * Release the reserved range from inode dirty range map, as it is + * already moved into delayed_ref_head */ btrfs_qgroup_release_data(inode, file_pos, ram_bytes); - ret = btrfs_add_delayed_qgroup_reserve(root->fs_info, trans, - root->objectid, disk_bytenr, ram_bytes); out: btrfs_free_path(path);