Messages in this thread | | | Subject | Re: [PATCH] f2fs: fix to avoid accessing uninitialized field of inode page in is_alive() | From | Chao Yu <> | Date | Mon, 9 Sep 2019 19:05:48 +0800 |
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On 2019/9/9 17:33, Jaegeuk Kim wrote: > 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 guess so. :)
Thanks,
> >> 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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