Please kindly ignore this patch as it did introduce soft lockup when
btrfs_search_slot() returns a spinning path and its callers goes to
sleep before releasing the path.
thanks,
liubo
On Thu, Aug 16, 2018 at 2:07 PM, Liu Bo <bo.liu@xxxxxxxxxxxxxxxxx> wrote:
> As btrfs_clear_path_blocking() turns out to be a major source of lock
> contention, we've kill it and without it btrfs_search_slot() and
> btrfs_search_old_slot() are not able to return a path in spinning
> mode, lets kill leave_spinning, too.
>
> Signed-off-by: Liu Bo <bo.liu@xxxxxxxxxxxxxxxxx>
> ---
> fs/btrfs/backref.c | 3 ---
> fs/btrfs/ctree.c | 16 +++-------------
> fs/btrfs/ctree.h | 1 -
> fs/btrfs/delayed-inode.c | 4 ----
> fs/btrfs/dir-item.c | 1 -
> fs/btrfs/export.c | 1 -
> fs/btrfs/extent-tree.c | 7 -------
> fs/btrfs/extent_io.c | 1 -
> fs/btrfs/file-item.c | 4 ----
> fs/btrfs/free-space-tree.c | 2 --
> fs/btrfs/inode-item.c | 6 ------
> fs/btrfs/inode.c | 8 --------
> fs/btrfs/ioctl.c | 3 ---
> fs/btrfs/qgroup.c | 2 --
> fs/btrfs/super.c | 2 --
> fs/btrfs/tests/qgroup-tests.c | 4 ----
> 16 files changed, 3 insertions(+), 62 deletions(-)
>
> diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
> index ae750b1574a2..70c629b90710 100644
> --- a/fs/btrfs/backref.c
> +++ b/fs/btrfs/backref.c
> @@ -1613,13 +1613,11 @@ char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path,
> s64 bytes_left = ((s64)size) - 1;
> struct extent_buffer *eb = eb_in;
> struct btrfs_key found_key;
> - int leave_spinning = path->leave_spinning;
> struct btrfs_inode_ref *iref;
>
> if (bytes_left >= 0)
> dest[bytes_left] = '\0';
>
> - path->leave_spinning = 1;
> while (1) {
> bytes_left -= name_len;
> if (bytes_left >= 0)
> @@ -1665,7 +1663,6 @@ char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path,
> }
>
> btrfs_release_path(path);
> - path->leave_spinning = leave_spinning;
>
> if (ret)
> return ERR_PTR(ret);
> diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
> index 8b31caa60b0a..d2df7cfbec06 100644
> --- a/fs/btrfs/ctree.c
> +++ b/fs/btrfs/ctree.c
> @@ -2875,14 +2875,10 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root,
> }
> ret = 1;
> done:
> - /*
> - * we don't really know what they plan on doing with the path
> - * from here on, so for now just mark it as blocking
> - */
> - if (!p->leave_spinning)
> - btrfs_set_path_blocking(p);
> if (ret < 0 && !p->skip_release_on_error)
> btrfs_release_path(p);
> +
> + /* path is supposed to be in blocking mode from now on. */
> return ret;
> }
>
> @@ -2987,11 +2983,10 @@ int btrfs_search_old_slot(struct btrfs_root *root, const struct btrfs_key *key,
> }
> ret = 1;
> done:
> - if (!p->leave_spinning)
> - btrfs_set_path_blocking(p);
> if (ret < 0)
> btrfs_release_path(p);
>
> + /* path is supposed to be in blocking mode from now on.*/
> return ret;
> }
>
> @@ -5628,7 +5623,6 @@ int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path,
> struct btrfs_key key;
> u32 nritems;
> int ret;
> - int old_spinning = path->leave_spinning;
> int next_rw_lock = 0;
>
> nritems = btrfs_header_nritems(path->nodes[0]);
> @@ -5643,7 +5637,6 @@ int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path,
> btrfs_release_path(path);
>
> path->keep_locks = 1;
> - path->leave_spinning = 1;
>
> if (time_seq)
> ret = btrfs_search_old_slot(root, &key, path, time_seq);
> @@ -5780,9 +5773,6 @@ int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path,
> ret = 0;
> done:
> unlock_up(path, 0, 1, 0, NULL);
> - path->leave_spinning = old_spinning;
> - if (!old_spinning)
> - btrfs_set_path_blocking(path);
>
> return ret;
> }
> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
> index 1aeed3c0e949..e8bddf21b7f7 100644
> --- a/fs/btrfs/ctree.h
> +++ b/fs/btrfs/ctree.h
> @@ -339,7 +339,6 @@ struct btrfs_path {
> unsigned int search_for_split:1;
> unsigned int keep_locks:1;
> unsigned int skip_locking:1;
> - unsigned int leave_spinning:1;
> unsigned int search_commit_root:1;
> unsigned int need_commit_sem:1;
> unsigned int skip_release_on_error:1;
> diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
> index db9f45082c61..e6fbcdbc313e 100644
> --- a/fs/btrfs/delayed-inode.c
> +++ b/fs/btrfs/delayed-inode.c
> @@ -1138,7 +1138,6 @@ static int __btrfs_run_delayed_items(struct btrfs_trans_handle *trans, int nr)
> path = btrfs_alloc_path();
> if (!path)
> return -ENOMEM;
> - path->leave_spinning = 1;
>
> block_rsv = trans->block_rsv;
> trans->block_rsv = &fs_info->delayed_block_rsv;
> @@ -1203,7 +1202,6 @@ int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
> btrfs_release_delayed_node(delayed_node);
> return -ENOMEM;
> }
> - path->leave_spinning = 1;
>
> block_rsv = trans->block_rsv;
> trans->block_rsv = &delayed_node->root->fs_info->delayed_block_rsv;
> @@ -1248,7 +1246,6 @@ int btrfs_commit_inode_delayed_inode(struct btrfs_inode *inode)
> ret = -ENOMEM;
> goto trans_out;
> }
> - path->leave_spinning = 1;
>
> block_rsv = trans->block_rsv;
> trans->block_rsv = &fs_info->delayed_block_rsv;
> @@ -1317,7 +1314,6 @@ static void btrfs_async_run_delayed_root(struct btrfs_work *work)
> if (!delayed_node)
> break;
>
> - path->leave_spinning = 1;
> root = delayed_node->root;
>
> trans = btrfs_join_transaction(root);
> diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c
> index a678b07fcf01..4f27d6ba2f1e 100644
> --- a/fs/btrfs/dir-item.c
> +++ b/fs/btrfs/dir-item.c
> @@ -127,7 +127,6 @@ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
> path = btrfs_alloc_path();
> if (!path)
> return -ENOMEM;
> - path->leave_spinning = 1;
>
> btrfs_cpu_key_to_disk(&disk_key, location);
>
> diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c
> index 1f3755b3a37a..7f410edd92e4 100644
> --- a/fs/btrfs/export.c
> +++ b/fs/btrfs/export.c
> @@ -245,7 +245,6 @@ static int btrfs_get_name(struct dentry *parent, char *name,
> path = btrfs_alloc_path();
> if (!path)
> return -ENOMEM;
> - path->leave_spinning = 1;
>
> if (ino == BTRFS_FIRST_FREE_OBJECTID) {
> key.objectid = BTRFS_I(inode)->root->root_key.objectid;
> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
> index de6f75f5547b..8d9ca923db93 100644
> --- a/fs/btrfs/extent-tree.c
> +++ b/fs/btrfs/extent-tree.c
> @@ -2116,7 +2116,6 @@ static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
> return -ENOMEM;
>
> path->reada = READA_FORWARD;
> - path->leave_spinning = 1;
> /* this will setup the path even if it fails to insert the back ref */
> ret = insert_inline_extent_backref(trans, path, bytenr, num_bytes,
> parent, root_objectid, owner,
> @@ -2141,7 +2140,6 @@ static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
> btrfs_release_path(path);
>
> path->reada = READA_FORWARD;
> - path->leave_spinning = 1;
> /* now insert the actual backref */
> ret = insert_extent_backref(trans, path, bytenr, parent, root_objectid,
> owner, offset, refs_to_add);
> @@ -2251,7 +2249,6 @@ static int run_delayed_extent_op(struct btrfs_trans_handle *trans,
>
> again:
> path->reada = READA_FORWARD;
> - path->leave_spinning = 1;
> ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 1);
> if (ret < 0) {
> err = ret;
> @@ -6700,7 +6697,6 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
> return -ENOMEM;
>
> path->reada = READA_FORWARD;
> - path->leave_spinning = 1;
>
> is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
> BUG_ON(!is_data && refs_to_drop != 1);
> @@ -6743,7 +6739,6 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
> goto out;
> }
> btrfs_release_path(path);
> - path->leave_spinning = 1;
>
> key.objectid = bytenr;
> key.type = BTRFS_EXTENT_ITEM_KEY;
> @@ -7896,7 +7891,6 @@ static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
> if (!path)
> return -ENOMEM;
>
> - path->leave_spinning = 1;
> ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
> ins, size);
> if (ret) {
> @@ -7985,7 +7979,6 @@ static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
> return -ENOMEM;
> }
>
> - path->leave_spinning = 1;
> ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
> &extent_key, size);
> if (ret) {
> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
> index 628f1aef34b0..481a4bbc49fd 100644
> --- a/fs/btrfs/extent_io.c
> +++ b/fs/btrfs/extent_io.c
> @@ -4444,7 +4444,6 @@ int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
> path = btrfs_alloc_path();
> if (!path)
> return -ENOMEM;
> - path->leave_spinning = 1;
>
> start = round_down(start, btrfs_inode_sectorsize(inode));
> len = round_up(max, btrfs_inode_sectorsize(inode)) - start;
> diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
> index ba74827beb32..8e25953ed901 100644
> --- a/fs/btrfs/file-item.c
> +++ b/fs/btrfs/file-item.c
> @@ -45,7 +45,6 @@ int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
> file_key.offset = pos;
> file_key.type = BTRFS_EXTENT_DATA_KEY;
>
> - path->leave_spinning = 1;
> ret = btrfs_insert_empty_item(trans, root, path, &file_key,
> sizeof(*item));
> if (ret < 0)
> @@ -598,7 +597,6 @@ int btrfs_del_csums(struct btrfs_trans_handle *trans,
> key.offset = end_byte - 1;
> key.type = BTRFS_EXTENT_CSUM_KEY;
>
> - path->leave_spinning = 1;
> ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
> if (ret > 0) {
> if (path->slots[0] == 0)
> @@ -874,10 +872,8 @@ int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
> } else {
> ins_size = csum_size;
> }
> - path->leave_spinning = 1;
> ret = btrfs_insert_empty_item(trans, root, path, &file_key,
> ins_size);
> - path->leave_spinning = 0;
> if (ret < 0)
> goto fail_unlock;
> if (WARN_ON(ret != 0))
> diff --git a/fs/btrfs/free-space-tree.c b/fs/btrfs/free-space-tree.c
> index d6736595ec57..bccc33bb453c 100644
> --- a/fs/btrfs/free-space-tree.c
> +++ b/fs/btrfs/free-space-tree.c
> @@ -1188,8 +1188,6 @@ static int clear_free_space_tree(struct btrfs_trans_handle *trans,
> if (!path)
> return -ENOMEM;
>
> - path->leave_spinning = 1;
> -
> key.objectid = 0;
> key.type = 0;
> key.offset = 0;
> diff --git a/fs/btrfs/inode-item.c b/fs/btrfs/inode-item.c
> index a8956a3c9e05..97a7b4de1033 100644
> --- a/fs/btrfs/inode-item.c
> +++ b/fs/btrfs/inode-item.c
> @@ -129,8 +129,6 @@ static int btrfs_del_inode_extref(struct btrfs_trans_handle *trans,
> if (!path)
> return -ENOMEM;
>
> - path->leave_spinning = 1;
> -
> ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
> if (ret > 0)
> ret = -ENOENT;
> @@ -203,8 +201,6 @@ int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
> if (!path)
> return -ENOMEM;
>
> - path->leave_spinning = 1;
> -
> ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
> if (ret > 0) {
> ret = -ENOENT;
> @@ -278,7 +274,6 @@ static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans,
> if (!path)
> return -ENOMEM;
>
> - path->leave_spinning = 1;
> ret = btrfs_insert_empty_item(trans, root, path, &key,
> ins_len);
> if (ret == -EEXIST) {
> @@ -335,7 +330,6 @@ int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
> if (!path)
> return -ENOMEM;
>
> - path->leave_spinning = 1;
> path->skip_release_on_error = 1;
> ret = btrfs_insert_empty_item(trans, root, path, &key,
> ins_len);
> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> index 9357a19d2bff..8b135a46835f 100644
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -191,7 +191,6 @@ static int insert_inline_extent(struct btrfs_trans_handle *trans,
> key.type = BTRFS_EXTENT_DATA_KEY;
>
> datasize = btrfs_file_extent_calc_inline_size(cur_size);
> - path->leave_spinning = 1;
> ret = btrfs_insert_empty_item(trans, root, path, &key,
> datasize);
> if (ret)
> @@ -2236,7 +2235,6 @@ static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
> ins.offset = file_pos;
> ins.type = BTRFS_EXTENT_DATA_KEY;
>
> - path->leave_spinning = 1;
> ret = btrfs_insert_empty_item(trans, root, path, &ins,
> sizeof(*fi));
> if (ret)
> @@ -2668,7 +2666,6 @@ static noinline int relink_extent_backref(struct btrfs_path *path,
> key.type = BTRFS_EXTENT_DATA_KEY;
> key.offset = start;
>
> - path->leave_spinning = 1;
> if (merge) {
> struct btrfs_file_extent_item *fi;
> u64 extent_len;
> @@ -2739,7 +2736,6 @@ static noinline int relink_extent_backref(struct btrfs_path *path,
> ret = 1;
> out_free_path:
> btrfs_release_path(path);
> - path->leave_spinning = 0;
> btrfs_end_transaction(trans);
> out_unlock:
> unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
> @@ -3833,7 +3829,6 @@ static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
> if (!path)
> return -ENOMEM;
>
> - path->leave_spinning = 1;
> ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
> 1);
> if (ret) {
> @@ -3924,7 +3919,6 @@ static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
> goto out;
> }
>
> - path->leave_spinning = 1;
> di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
> name, name_len, -1);
> if (IS_ERR(di)) {
> @@ -4584,7 +4578,6 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
> goto out;
> }
>
> - path->leave_spinning = 1;
> ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
> if (ret < 0)
> goto out;
> @@ -6300,7 +6293,6 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
> goto fail;
> }
>
> - path->leave_spinning = 1;
> ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
> if (ret != 0)
> goto fail_unlock;
> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> index d3a5d2a41e5f..1de051f529f9 100644
> --- a/fs/btrfs/ioctl.c
> +++ b/fs/btrfs/ioctl.c
> @@ -3899,7 +3899,6 @@ static int btrfs_clone(struct inode *src, struct inode *inode,
> * note the key will change type as we walk through the
> * tree.
> */
> - path->leave_spinning = 1;
> ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
> 0, 0);
> if (ret < 0)
> @@ -3981,7 +3980,6 @@ static int btrfs_clone(struct inode *src, struct inode *inode,
> size);
>
> btrfs_release_path(path);
> - path->leave_spinning = 0;
>
> memcpy(&new_key, &key, sizeof(new_key));
> new_key.objectid = btrfs_ino(BTRFS_I(inode));
> @@ -4371,7 +4369,6 @@ static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
> ret = -ENOMEM;
> goto out;
> }
> - path->leave_spinning = 1;
>
> trans = btrfs_start_transaction(root, 1);
> if (IS_ERR(trans)) {
> diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
> index 4353bb69bb86..58e859593bbb 100644
> --- a/fs/btrfs/qgroup.c
> +++ b/fs/btrfs/qgroup.c
> @@ -844,8 +844,6 @@ static int btrfs_clean_quota_tree(struct btrfs_trans_handle *trans,
> if (!path)
> return -ENOMEM;
>
> - path->leave_spinning = 1;
> -
> key.objectid = 0;
> key.offset = 0;
> key.type = 0;
> diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
> index 6601c9aa5e35..4aa0b4f61ffd 100644
> --- a/fs/btrfs/super.c
> +++ b/fs/btrfs/super.c
> @@ -1015,7 +1015,6 @@ static char *get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info,
> ret = -ENOMEM;
> goto err;
> }
> - path->leave_spinning = 1;
>
> name = kmalloc(PATH_MAX, GFP_KERNEL);
> if (!name) {
> @@ -1143,7 +1142,6 @@ static int get_default_subvol_objectid(struct btrfs_fs_info *fs_info, u64 *objec
> path = btrfs_alloc_path();
> if (!path)
> return -ENOMEM;
> - path->leave_spinning = 1;
>
> /*
> * Find the "default" dir item which points to the root item that we
> diff --git a/fs/btrfs/tests/qgroup-tests.c b/fs/btrfs/tests/qgroup-tests.c
> index 412b910b04cc..91233a0d4d62 100644
> --- a/fs/btrfs/tests/qgroup-tests.c
> +++ b/fs/btrfs/tests/qgroup-tests.c
> @@ -36,7 +36,6 @@ static int insert_normal_tree_ref(struct btrfs_root *root, u64 bytenr,
> return -ENOMEM;
> }
>
> - path->leave_spinning = 1;
> ret = btrfs_insert_empty_item(&trans, root, path, &ins, size);
> if (ret) {
> test_err("couldn't insert ref %d", ret);
> @@ -86,7 +85,6 @@ static int add_tree_ref(struct btrfs_root *root, u64 bytenr, u64 num_bytes,
> return -ENOMEM;
> }
>
> - path->leave_spinning = 1;
> ret = btrfs_search_slot(&trans, root, &key, path, 0, 1);
> if (ret) {
> test_err("couldn't find extent ref");
> @@ -135,7 +133,6 @@ static int remove_extent_item(struct btrfs_root *root, u64 bytenr,
> test_err("couldn't allocate path");
> return -ENOMEM;
> }
> - path->leave_spinning = 1;
>
> ret = btrfs_search_slot(&trans, root, &key, path, -1, 1);
> if (ret) {
> @@ -170,7 +167,6 @@ static int remove_extent_ref(struct btrfs_root *root, u64 bytenr,
> return -ENOMEM;
> }
>
> - path->leave_spinning = 1;
> ret = btrfs_search_slot(&trans, root, &key, path, 0, 1);
> if (ret) {
> test_err("couldn't find extent ref");
> --
> 1.8.3.1
>
