Messages in this thread |  | | Subject | Re: [f2fs-dev] [PATCH v4] f2fs: Fix indefinite loop in f2fs_gc() | From | Chao Yu <> | Date | Fri, 6 Sep 2019 19:00:32 +0800 |
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Hi Sahitya,
Luckily, I can reproduce this issue with generic/269, and have sent another patch for the issue, could you please check that one?
Thanks,
On 2019/8/7 22:06, Chao Yu wrote: > On 2019-8-7 21:40, Sahitya Tummala wrote: >> Policy - Foreground GC, LFS and greedy GC mode. >> >> Under this policy, f2fs_gc() loops forever to GC as it doesn't have >> enough free segements to proceed and thus it keeps calling gc_more >> for the same victim segment. This can happen if the selected victim >> segment could not be GC'd due to failed blkaddr validity check i.e. >> is_alive() returns false for the blocks set in current validity map. >> >> Fix this by keeping track of such invalid segments and skip those >> segments for selection in get_victim_by_default() to avoid endless >> GC loop under such error scenarios. Currently, add this logic under >> CONFIG_F2FS_CHECK_FS to be able to root cause the issue in debug >> version. >> >> Signed-off-by: Sahitya Tummala <stummala@codeaurora.org> >> --- >> v4: Cover all logic with CONFIG_F2FS_CHECK_FS >> >> fs/f2fs/gc.c | 31 +++++++++++++++++++++++++++++-- >> fs/f2fs/segment.c | 14 +++++++++++++- >> fs/f2fs/segment.h | 3 +++ >> 3 files changed, 45 insertions(+), 3 deletions(-) >> >> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c >> index 8974672..cbcacbd 100644 >> --- a/fs/f2fs/gc.c >> +++ b/fs/f2fs/gc.c >> @@ -382,6 +382,16 @@ static int get_victim_by_default(struct f2fs_sb_info *sbi, >> nsearched++; >> } >> >> +#ifdef CONFIG_F2FS_CHECK_FS >> + /* >> + * skip selecting the invalid segno (that is failed due to block >> + * validity check failure during GC) to avoid endless GC loop in >> + * such cases. >> + */ >> + if (test_bit(segno, sm->invalid_segmap)) >> + goto next; >> +#endif >> + >> secno = GET_SEC_FROM_SEG(sbi, segno); >> >> if (sec_usage_check(sbi, secno)) >> @@ -602,8 +612,15 @@ static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum, >> { >> struct page *node_page; >> nid_t nid; >> - unsigned int ofs_in_node; >> + unsigned int ofs_in_node, segno; >> block_t source_blkaddr; >> + unsigned long offset; >> +#ifdef CONFIG_F2FS_CHECK_FS >> + struct sit_info *sit_i = SIT_I(sbi); >> +#endif >> + >> + segno = GET_SEGNO(sbi, blkaddr); >> + offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr); >> >> nid = le32_to_cpu(sum->nid); >> ofs_in_node = le16_to_cpu(sum->ofs_in_node); >> @@ -627,8 +644,18 @@ static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum, >> source_blkaddr = datablock_addr(NULL, node_page, ofs_in_node); >> f2fs_put_page(node_page, 1); >> >> - if (source_blkaddr != blkaddr) >> + if (source_blkaddr != blkaddr) { >> +#ifdef CONFIG_F2FS_CHECK_FS > > unsigned int segno = GET_SEGNO(sbi, blkaddr); > unsigned int offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr); > > Should be local, otherwise it looks good to me, I think Jaegeuk can help to fix > this while merging. > > Reviewed-by: Chao Yu <yuchao0@huawei.com> > > Thanks, > >> + if (unlikely(check_valid_map(sbi, segno, offset))) { >> + if (!test_and_set_bit(segno, sit_i->invalid_segmap)) { >> + f2fs_err(sbi, "mismatched blkaddr %u (source_blkaddr %u) in seg %u\n", >> + blkaddr, source_blkaddr, segno); >> + f2fs_bug_on(sbi, 1); >> + } >> + } >> +#endif >> return false; >> + } >> return true; >> } >> >> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c >> index a661ac3..ee795b1 100644 >> --- a/fs/f2fs/segment.c >> +++ b/fs/f2fs/segment.c >> @@ -806,6 +806,9 @@ static void __remove_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno, >> enum dirty_type dirty_type) >> { >> struct dirty_seglist_info *dirty_i = DIRTY_I(sbi); >> +#ifdef CONFIG_F2FS_CHECK_FS >> + struct sit_info *sit_i = SIT_I(sbi); >> +#endif >> >> if (test_and_clear_bit(segno, dirty_i->dirty_segmap[dirty_type])) >> dirty_i->nr_dirty[dirty_type]--; >> @@ -817,9 +820,13 @@ static void __remove_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno, >> if (test_and_clear_bit(segno, dirty_i->dirty_segmap[t])) >> dirty_i->nr_dirty[t]--; >> >> - if (get_valid_blocks(sbi, segno, true) == 0) >> + if (get_valid_blocks(sbi, segno, true) == 0) { >> clear_bit(GET_SEC_FROM_SEG(sbi, segno), >> dirty_i->victim_secmap); >> +#ifdef CONFIG_F2FS_CHECK_FS >> + clear_bit(segno, sit_i->invalid_segmap); >> +#endif >> + } >> } >> } >> >> @@ -4015,6 +4022,10 @@ static int build_sit_info(struct f2fs_sb_info *sbi) >> sit_i->sit_bitmap_mir = kmemdup(src_bitmap, bitmap_size, GFP_KERNEL); >> if (!sit_i->sit_bitmap_mir) >> return -ENOMEM; >> + >> + sit_i->invalid_segmap = f2fs_kvzalloc(sbi, bitmap_size, GFP_KERNEL); >> + if (!sit_i->invalid_segmap) >> + return -ENOMEM; >> #endif >> >> /* init SIT information */ >> @@ -4517,6 +4528,7 @@ static void destroy_sit_info(struct f2fs_sb_info *sbi) >> kvfree(sit_i->sit_bitmap); >> #ifdef CONFIG_F2FS_CHECK_FS >> kvfree(sit_i->sit_bitmap_mir); >> + kvfree(sit_i->invalid_segmap); >> #endif >> kvfree(sit_i); >> } >> diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h >> index b746028..9370d53 100644 >> --- a/fs/f2fs/segment.h >> +++ b/fs/f2fs/segment.h >> @@ -229,6 +229,9 @@ struct sit_info { >> char *sit_bitmap; /* SIT bitmap pointer */ >> #ifdef CONFIG_F2FS_CHECK_FS >> char *sit_bitmap_mir; /* SIT bitmap mirror */ >> + >> + /* bitmap of segments to be ignored by GC in case of errors */ >> + unsigned long *invalid_segmap; >> #endif >> unsigned int bitmap_size; /* SIT bitmap size */ >> >> > . >
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