Messages in this thread | | | Date | Mon, 9 Sep 2019 15:37:25 +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 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?
Can we update inode before finally putting ipage?
> >> > >> 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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