> -----Original Message----- > From: Qu Wenruo [mailto:quwenruo.btrfs@xxxxxxx] > Sent: Thursday, July 05, 2018 5:41 PM > To: Gu, Jinxiang/顾 金香 <gujx@xxxxxxxxxxxxxx>; Qu Wenruo <wqu@xxxxxxxx>; linux-btrfs@xxxxxxxxxxxxxxx > Subject: Re: [PATCH 1/4] btrfs-progs: check: Remove the ability to rebuild root overwritting existing tree blocks > > > > On 2018年07月05日 16:50, Gu, Jinxiang wrote: > > > > > >> -----Original Message----- > >> From: linux-btrfs-owner@xxxxxxxxxxxxxxx [mailto:linux-btrfs-owner@xxxxxxxxxxxxxxx] On Behalf Of Qu Wenruo > >> Sent: Thursday, July 05, 2018 3:37 PM > >> To: linux-btrfs@xxxxxxxxxxxxxxx > >> Subject: [PATCH 1/4] btrfs-progs: check: Remove the ability to rebuild root overwritting existing tree blocks > >> > >> We have function btrfs_fsck_reinit_root() to reinit csum or extent tree. > > > > Nit： > > or fs/file tree > > Nope, btrfs check is only capable of reinit csum or extent tree. Sorry, not fs/file tree. But DATA RELOC TREE. Call stack is reset_balance -> btrfs_fsck_reinit_root, and the root is get by btrfs_read_fs_root(fs_info, &key), which key is (BTRFS_DATA_RELOC_TREE_OBJECTID, BTRFS_ROOT_ITEM_KEY , (u64)-1) > > Thanks, > Qu > > > > >> However this function allows us to let it overwrite existing tree blocks > >> using @overwrite parameter. > >> > >> Such behavior is pretty dangerous while no caller is using this feature > >> explicitly. > >> > >> So just remove @overwrite parameter and allow btrfs_fsck_reinit_root() > >> to error out when it fails to allocate tree block. > >> > >> Signed-off-by: Qu Wenruo <wqu@xxxxxxxx> > >> --- > >> check/main.c | 26 ++++++++------------------ > >> 1 file changed, 8 insertions(+), 18 deletions(-) > >> > >> diff --git a/check/main.c b/check/main.c > >> index 8db300abb825..c8c347236543 100644 > >> --- a/check/main.c > >> +++ b/check/main.c > >> @@ -8379,7 +8379,7 @@ static int do_check_chunks_and_extents(struct btrfs_fs_info *fs_info) > >> } > >> > >> static int btrfs_fsck_reinit_root(struct btrfs_trans_handle *trans, > >> - struct btrfs_root *root, int overwrite) > >> + struct btrfs_root *root) > >> { > >> struct extent_buffer *c; > >> struct extent_buffer *old = root->node; > >> @@ -8389,21 +8389,13 @@ static int btrfs_fsck_reinit_root(struct btrfs_trans_handle *trans, > >> > >> level = 0; > >> > >> - if (overwrite) { > >> - c = old; > >> - extent_buffer_get(c); > >> - goto init; > >> - } > >> c = btrfs_alloc_free_block(trans, root, > >> root->fs_info->nodesize, > >> root->root_key.objectid, > >> &disk_key, level, 0, 0); > >> - if (IS_ERR(c)) { > >> - c = old; > >> - extent_buffer_get(c); > >> - overwrite = 1; > >> - } > >> -init: > >> + if (IS_ERR(c)) > >> + return PTR_ERR(c); > >> + > >> memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header)); > >> btrfs_set_header_level(c, level); > >> btrfs_set_header_bytenr(c, c->start); > >> @@ -8422,9 +8414,7 @@ init: > >> /* > >> * this case can happen in the following case: > >> * > >> - * 1.overwrite previous root. > >> - * > >> - * 2.reinit reloc data root, this is because we skip pin > >> + * reinit reloc data root, this is because we skip pin > >> * down reloc data tree before which means we can allocate > >> * same block bytenr here. > >> */ > >> @@ -8609,7 +8599,7 @@ reinit_data_reloc: > >> goto out; > >> } > >> record_root_in_trans(trans, root); > >> - ret = btrfs_fsck_reinit_root(trans, root, 0); > >> + ret = btrfs_fsck_reinit_root(trans, root); > >> if (ret) > >> goto out; > >> ret = btrfs_make_root_dir(trans, root, BTRFS_FIRST_FREE_OBJECTID); > >> @@ -8675,7 +8665,7 @@ again: > >> } > >> > >> /* Ok we can allocate now, reinit the extent root */ > >> - ret = btrfs_fsck_reinit_root(trans, fs_info->extent_root, 0); > >> + ret = btrfs_fsck_reinit_root(trans, fs_info->extent_root); > >> if (ret) { > >> fprintf(stderr, "extent root initialization failed\n"); > >> /* > >> @@ -9764,7 +9754,7 @@ int cmd_check(int argc, char **argv) > >> > >> if (init_csum_tree) { > >> printf("Reinitialize checksum tree\n"); > >> - ret = btrfs_fsck_reinit_root(trans, info->csum_root, 0); > >> + ret = btrfs_fsck_reinit_root(trans, info->csum_root); > >> if (ret) { > >> error("checksum tree initialization failed: %d", > >> ret); > >> -- > > > > Reviewed-by: Gu Jinxiang <gujx@xxxxxxxxxxxxxx> > > > > > >> 2.18.0 > >> > >> -- > >> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > >> the body of a message to majordomo@xxxxxxxxxxxxxxx > >> More majordomo info at http://vger.kernel.org/majordomo-info.html > >> > > > > > > > > N嫥叉靣笡y氊b瞂千v豝�)藓{.n�+壏{眓谶�)韰骅w*jg� 秹殠娸/侁鋤罐枈�2娹櫒璀�&�)摺玜囤 瓽珴閔�鎗:+v墾 > 妛鑶佶 > > ��.n��������+%������w��{.n�����{����n�r������&��z�ޗ�zf���h���~����������_��+v���)ߣ�
