Messages in this thread Patch in this message | | | From | Sahitya Tummala <> | Subject | [PATCH v4] f2fs: Fix indefinite loop in f2fs_gc() | Date | Wed, 7 Aug 2019 19:10:32 +0530 |
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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 + 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 */ -- Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.
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