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Date: Thu, 5 Aug 2021 08:43:01 +0800 From: Chao Yu <chao@...nel.org> To: Jaegeuk Kim <jaegeuk@...nel.org> Cc: linux-f2fs-devel@...ts.sourceforge.net, linux-kernel@...r.kernel.org, Chao Yu <chao.yu@...ux.dev> Subject: Re: [PATCH] f2fs: compress: do sanity check on cluster On 2021/8/5 6:50, Jaegeuk Kim wrote: > On 08/04, Chao Yu wrote: >> On 2021/8/4 10:03, Jaegeuk Kim wrote: >>> On 08/04, Chao Yu wrote: >>>> On 2021/8/4 2:26, Jaegeuk Kim wrote: >>>>> On 08/03, Chao Yu wrote: >>>>>> This patch adds f2fs_sanity_check_cluster() to support doing >>>>>> sanity check on cluster of compressed file, it will be triggered >>>>>> from below two paths: >>>>>> >>>>>> - __f2fs_cluster_blocks() >>>>>> - f2fs_map_blocks(F2FS_GET_BLOCK_FIEMAP) >>>>>> >>>>>> And it can detect below three kind of cluster insanity status. >>>>>> >>>>>> C: COMPRESS_ADDR >>>>>> N: NULL_ADDR or NEW_ADDR >>>>>> V: valid blkaddr >>>>>> *: any value >>>>>> >>>>>> 1. [*|C|*|*] >>>>>> 2. [C|*|C|*] >>>>>> 3. [C|N|N|V] >>>>>> >>>>>> Signed-off-by: Chao Yu <chao@...nel.org> >>>>>> --- >>>>>> fs/f2fs/compress.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++ >>>>>> fs/f2fs/data.c | 21 ++++++++++++------ >>>>>> fs/f2fs/f2fs.h | 1 + >>>>>> 3 files changed, 68 insertions(+), 7 deletions(-) >>>>>> >>>>>> diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c >>>>>> index 455561826c7d..4aa166d3d9bf 100644 >>>>>> --- a/fs/f2fs/compress.c >>>>>> +++ b/fs/f2fs/compress.c >>>>>> @@ -898,6 +898,54 @@ static bool cluster_has_invalid_data(struct compress_ctx *cc) >>>>>> return false; >>>>>> } >>>>>> +bool f2fs_sanity_check_cluster(struct dnode_of_data *dn) >>>>>> +{ >>>>>> + struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode); >>>>>> + unsigned int cluster_size = F2FS_I(dn->inode)->i_cluster_size; >>>>>> + bool compressed = dn->data_blkaddr == COMPRESS_ADDR; >>>>>> + int cluster_end = 0; >>>>>> + int i; >>>>>> + char *reason = ""; >>>>>> + >>>>>> + if (!compressed) >>>>>> + return false; >>>>>> + >>>>>> + /* [..., COMPR_ADDR, ...] */ >>>>>> + if (dn->ofs_in_node % cluster_size) { >>>>>> + reason = "[*|C|*|*]"; >>>>>> + goto out; >>>>>> + } >>>>>> + >>>>>> + for (i = 1; i < cluster_size; i++) { >>>>>> + block_t blkaddr = data_blkaddr(dn->inode, dn->node_page, >>>>>> + dn->ofs_in_node + i); >>>>>> + >>>>>> + /* [COMPR_ADDR, ..., COMPR_ADDR] */ >>>>>> + if (blkaddr == COMPRESS_ADDR) { >>>>>> + reason = "[C|*|C|*]"; >>>>>> + goto out; >>>>>> + } >>>>>> + if (compressed) { >>>>>> + if (!__is_valid_data_blkaddr(blkaddr)) { >>>>>> + if (!cluster_end) >>>>>> + cluster_end = i; >>>>>> + continue; >>>>>> + } >>>>>> + /* [COMPR_ADDR, NULL_ADDR or NEW_ADDR, valid_blkaddr] */ >>>>>> + if (cluster_end) { >>>>>> + reason = "[C|N|N|V]"; >>>>>> + goto out; >>>>>> + } >>>>>> + } >>>>>> + } >>>>>> + return false; >>>>>> +out: >>>>>> + f2fs_warn(sbi, "access invalid cluster, ino:%lu, nid:%u, ofs_in_node:%u, reason:%s", >>>>>> + dn->inode->i_ino, dn->nid, dn->ofs_in_node, reason); >>>>>> + set_sbi_flag(sbi, SBI_NEED_FSCK); >>>>>> + return true; >>>>>> +} >>>>>> + >>>>>> static int __f2fs_cluster_blocks(struct inode *inode, >>>>>> unsigned int cluster_idx, bool compr) >>>>>> { >>>>>> @@ -915,6 +963,11 @@ static int __f2fs_cluster_blocks(struct inode *inode, >>>>>> goto fail; >>>>>> } >>>>>> + if (f2fs_sanity_check_cluster(&dn)) { >>>>>> + ret = -EFSCORRUPTED; >>>>>> + goto fail; >>>>>> + } >>>>>> + >>>>>> if (dn.data_blkaddr == COMPRESS_ADDR) { >>>>>> int i; >>>>>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c >>>>>> index 948083c88d17..75dda2035f68 100644 >>>>>> --- a/fs/f2fs/data.c >>>>>> +++ b/fs/f2fs/data.c >>>>>> @@ -1558,13 +1558,20 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map, >>>>>> } >>>>>> if (flag == F2FS_GET_BLOCK_PRECACHE) >>>>>> goto sync_out; >>>>>> - if (flag == F2FS_GET_BLOCK_FIEMAP && >>>>>> - blkaddr == NULL_ADDR) { >>>>>> - if (map->m_next_pgofs) >>>>>> - *map->m_next_pgofs = pgofs + 1; >>>>>> - goto sync_out; >>>>>> - } >>>>>> - if (flag != F2FS_GET_BLOCK_FIEMAP) { >>>>>> + if (flag == ) { >>>>>> + if (blkaddr == NULL_ADDR) { >>>>>> + if (map->m_next_pgofs) >>>>>> + *map->m_next_pgofs = pgofs + 1; >>>>>> + goto sync_out; >>>>>> + } >>>>>> +#ifdef CONFIG_F2FS_FS_COMPRESSION >>>>>> + if (f2fs_compressed_file(inode) && >>>>>> + f2fs_sanity_check_cluster(&dn)) { >>>>>> + err = -EFSCORRUPTED; >>>>> >>>>> I prefer to give the block map as is instead of giving an error, since this\ >>>> >>>> It looks the policy is not consistent with the one we did in >>>> f2fs_is_valid_blkaddr(). >>> >>> Why FIEMAP only? Do we need to check in other cases likewise >>> f2fs_is_valid_blkaddr()? >> >> Agreed, let me cover all missing pieces. >> >>> >>>> >>>>> takes away to debug the problem from user-land. >>>> >>>> We can debug through "dump.f2fs -i" command? also once f2fs_sanity_check_cluster() >>>> fails, it will print kernel message for further debuging. >>> >>> My concern here is how to debug and get out of this endless fiemap error before >>> recovered. >> >> Got your concern. >> >> For debug purpose, maybe we can add a new ioctl under CONFIG_F2FS_CHECK_FS to dump >> original mapping? or support dump.f2fs -f to dump all blkaddrs of target file? > > How about giving EFSCORRUPTED if CONFIG_F2FS_CHECK_FS is enabled? Sometimes it's Hmm... if original mapping is useful for debuging, shouldn't we return original one if CONFIG_F2FS_CHECK_FS is enabled? since commonly we will enable CONFIG_F2FS_CHECK_FS in eng version of Android to get more debug info. Thanks, > useful to ask fiemap to users. > >> >> Thanks >> >>> >>>> >>>> Thanks, >>>> >>>>> >>>>>> + goto sync_out; >>>>>> + } >>>>>> +#endif >>>>>> + } else { >>>>>> /* for defragment case */ >>>>>> if (map->m_next_pgofs) >>>>>> *map->m_next_pgofs = pgofs + 1; >>>>>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h >>>>>> index 20389b9b3eac..86d416ffad61 100644 >>>>>> --- a/fs/f2fs/f2fs.h >>>>>> +++ b/fs/f2fs/f2fs.h >>>>>> @@ -4060,6 +4060,7 @@ void f2fs_end_read_compressed_page(struct page *page, bool failed, >>>>>> block_t blkaddr); >>>>>> bool f2fs_cluster_is_empty(struct compress_ctx *cc); >>>>>> bool f2fs_cluster_can_merge_page(struct compress_ctx *cc, pgoff_t index); >>>>>> +bool f2fs_sanity_check_cluster(struct dnode_of_data *dn); >>>>>> void f2fs_compress_ctx_add_page(struct compress_ctx *cc, struct page *page); >>>>>> int f2fs_write_multi_pages(struct compress_ctx *cc, >>>>>> int *submitted, >>>>>> -- >>>>>> 2.22.1
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