Messages in this thread | | | Subject | Re: [PATCH] f2fs: fix to avoid accessing uninitialized field of inode page in is_alive() | From | Chao Yu <> | Date | Tue, 10 Sep 2019 08:59:59 +0800 |
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On 2019/9/9 22:37, Jaegeuk Kim wrote: > 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?
Agreed.
Thanks,
> >>>> >>>> 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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