Messages in this thread | | | Date | Mon, 9 Sep 2019 10:33:55 +0100 | From | Jaegeuk Kim <> | Subject | Re: [PATCH] f2fs: fix to avoid accessing uninitialized field of inode page in is_alive() |
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On 09/09, Chao Yu wrote: > On 2019/9/9 16:37, Jaegeuk Kim wrote: > > On 09/09, Chao Yu wrote: > >> On 2019/9/9 15:58, Chao Yu wrote: > >>> On 2019/9/9 15:44, Jaegeuk Kim wrote: > >>>> On 09/07, Chao Yu wrote: > >>>>> On 2019-9-7 7:48, Jaegeuk Kim wrote: > >>>>>> On 09/06, Chao Yu wrote: > >>>>>>> If inode is newly created, inode page may not synchronize with inode cache, > >>>>>>> so fields like .i_inline or .i_extra_isize could be wrong, in below call > >>>>>>> path, we may access such wrong fields, result in failing to migrate valid > >>>>>>> target block. > >>>>>> > >>>>>> If data is valid, how can we get new inode page? > >>>> > >>>> Let me rephrase the question. If inode is newly created, is this data block > >>>> really valid to move in GC? > >>> > >>> I guess it's valid, let double check that. > >> > >> We can see inode page: > >> > >> - f2fs_create > >> - f2fs_add_link > >> - f2fs_add_dentry > >> - f2fs_init_inode_metadata > >> - f2fs_add_inline_entry > >> - ipage = f2fs_new_inode_page > >> - f2fs_put_page(ipage) <---- after this > > > > Can you print out how many block was assigned to this inode? > > Add log like this: > > if (!test_and_set_bit(segno, SIT_I(sbi)->invalid_segmap)) { > if (is_inode) { > for (i = 0; i < 923 - 50; i++) { > __le32 *base = blkaddr_in_node(node); > unsigned ofs = offset_in_addr(inode); > > printk("i:%u, addr:%x\n", i, > le32_to_cpu(*(base + i))); > } > printk("i_inline: %u\n", inode->i_inline); > } > > It shows: > ... > i:10, addr:e66a > ... > i:46, addr:e66c > i:47, addr:e66d > i:48, addr:e66e > i:49, addr:e66f > i:50, addr:e670 > i:51, addr:e671 > i:52, addr:e672 > i:53, addr:e673 > i:54, addr:e674 > i:55, addr:e675 > i:56, addr:e676 > ... > i:140, addr:2c35 <--- we want to migrate this block, however, without correct > .i_inline and .i_extra_isize value, we can just find i_addr[i:140-6] = NULL_ADDR
So, the theory is the block is indeed valid and the address was updated before write_inode()?
> i:141, addr:2c38 > i:142, addr:2c39 > i:143, addr:2c3b > i:144, addr:2c3e > i:145, addr:2c40 > i:146, addr:2c44 > i:147, addr:2c48 > i:148, addr:2c4a > i:149, addr:2c4c > i:150, addr:2c4f > i:151, addr:2c59 > i:152, addr:2c5d > ... > i:188, addr:e677 > i:189, addr:e678 > i:190, addr:e679 > i:191, addr:e67a > i:192, addr:e67b > i:193, addr:e67c > i:194, addr:e67d > i:195, addr:e67e > i:196, addr:e67f > i:197, addr:e680 > i:198, addr:ffffffff > i:199, addr:ffffffff > i:200, addr:ffffffff > i:201, addr:ffffffff > i:202, addr:ffffffff > i:203, addr:ffffffff > i:204, addr:ffffffff > i:205, addr:ffffffff > i:206, addr:ffffffff > i:207, addr:ffffffff > i:208, addr:ffffffff > i:209, addr:ffffffff > i:210, addr:ffffffff > i:211, addr:ffffffff > i:212, addr:ffffffff > i:213, addr:ffffffff > i:214, addr:ffffffff > i:215, addr:ffffffff > i:216, addr:ffffffff > i:217, addr:ffffffff > i:218, addr:ffffffff > i:219, addr:ffffffff > i:220, addr:ffffffff > i:221, addr:ffffffff > i:222, addr:ffffffff > i:223, addr:ffffffff > i:224, addr:ffffffff > i:225, addr:ffffffff > i:226, addr:ffffffff > i:227, addr:ffffffff > i:228, addr:ffffffff > i:229, addr:ffffffff > i:230, addr:ffffffff > i:231, addr:ffffffff > i:232, addr:ffffffff > i:233, addr:ffffffff > i:234, addr:b032 > i:235, addr:b033 > i:236, addr:b034 > i:237, addr:b035 > i:238, addr:b036 > i:239, addr:b038 > ... > i:283, addr:e681 > ... > i_inline: 0 > > F2FS-fs (zram1): summary nid: 360, ofs: 134, ver: 0 > F2FS-fs (zram1): blkaddr 2c35 (blkaddr in node 0) <-blkaddr in node is NULL_ADDR > F2FS-fs (zram1): expect: seg 14, ofs_in_seg: 53 > F2FS-fs (zram1): real: seg 4294967295, ofs_in_seg: 0 > F2FS-fs (zram1): ofs: 53, 0 > F2FS-fs (zram1): node info ino:360, nid:360, nofs:0 > F2FS-fs (zram1): ofs_in_addr: 0 > F2FS-fs (zram1): end ======== > > > > >> > >>> > >>>> > >>>>> > >>>>> is_alive() > >>>>> { > >>>>> ... > >>>>> node_page = f2fs_get_node_page(sbi, nid); <--- inode page > >>>> > >>>> Aren't we seeing the below version warnings? > >>>> > >>>> if (sum->version != dni->version) { > >>>> f2fs_warn(sbi, "%s: valid data with mismatched node version.", > >>>> __func__); > >>>> set_sbi_flag(sbi, SBI_NEED_FSCK); > >>>> } > >> > >> The version of summary and dni are all zero. > > > > Then, this node was allocated and removed without being flushed. > > > >> > >> summary nid: 613, ofs: 111, ver: 0 > >> blkaddr 2436 (blkaddr in node 0) > >> expect: seg 10, ofs_in_seg: 54 > >> real: seg 4294967295, ofs_in_seg: 0 > >> ofs: 54, 0 > >> node info ino:613, nid:613, nofs:0 > >> ofs_in_addr: 0 > >> > >> Thanks, > >> > >>>> > >>>>> > >>>>> source_blkaddr = datablock_addr(NULL, node_page, ofs_in_node); > >>>> > >>>> So, we're getting this? Does this incur infinite loop in GC? > >>>> > >>>> if (!test_and_set_bit(segno, SIT_I(sbi)->invalid_segmap)) { > >>>> f2fs_err(sbi, "mismatched blkaddr %u (source_blkaddr %u) in seg %u\n", > >>>> f2fs_bug_on(sbi, 1); > >>>> } > >>> > >>> Yes, I only get this with generic/269, rather than "valid data with mismatched > >>> node version.". > > > > Was this block moved as valid? In either way, is_alive() returns false, no? > > How about checking i_blocks to detect the page is initialized in is_alive()? > > > >>> > >>> With this patch, generic/269 won't panic again. > >>> > >>> Thanks, > >>> > >>>> > >>>>> ... > >>>>> } > >>>>> > >>>>> datablock_addr() > >>>>> { > >>>>> ... > >>>>> base = offset_in_addr(&raw_node->i); <--- the base could be wrong here due to > >>>>> accessing uninitialized .i_inline of raw_node->i. > >>>>> ... > >>>>> } > >>>>> > >>>>> Thanks, > >>>>> > >>>>>> > >>>>>>> > >>>>>>> - gc_data_segment > >>>>>>> - is_alive > >>>>>>> - datablock_addr > >>>>>>> - offset_in_addr > >>>>>>> > >>>>>>> Fixes: 7a2af766af15 ("f2fs: enhance on-disk inode structure scalability") > >>>>>>> Signed-off-by: Chao Yu <yuchao0@huawei.com> > >>>>>>> --- > >>>>>>> fs/f2fs/dir.c | 3 +++ > >>>>>>> 1 file changed, 3 insertions(+) > >>>>>>> > >>>>>>> diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c > >>>>>>> index 765f13354d3f..b1840852967e 100644 > >>>>>>> --- a/fs/f2fs/dir.c > >>>>>>> +++ b/fs/f2fs/dir.c > >>>>>>> @@ -479,6 +479,9 @@ struct page *f2fs_init_inode_metadata(struct inode *inode, struct inode *dir, > >>>>>>> if (IS_ERR(page)) > >>>>>>> return page; > >>>>>>> > >>>>>>> + /* synchronize inode page's data from inode cache */ > >>>>>>> + f2fs_update_inode(inode, page); > >>>>>>> + > >>>>>>> if (S_ISDIR(inode->i_mode)) { > >>>>>>> /* in order to handle error case */ > >>>>>>> get_page(page); > >>>>>>> -- > >>>>>>> 2.18.0.rc1 > >>>> . > >>>> > > . > >
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