f2fs: Fix indefinite loop in f2fs_gc()
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>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
[Jaegeuk Kim: fix wrong bitmap size]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 8974672..e88f98d 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))
@@ -627,8 +637,21 @@ 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 long offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
+
+ if (unlikely(check_valid_map(sbi, segno, offset))) {
+ if (!test_and_set_bit(segno, SIT_I(sbi)->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 426d4a5..cc230fc 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -817,9 +817,13 @@ 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(sbi)->invalid_segmap);
+#endif
+ }
}
}
@@ -3946,7 +3950,7 @@ static int build_sit_info(struct f2fs_sb_info *sbi)
struct sit_info *sit_i;
unsigned int sit_segs, start;
char *src_bitmap, *bitmap;
- unsigned int bitmap_size;
+ unsigned int bitmap_size, main_bitmap_size, sit_bitmap_size;
/* allocate memory for SIT information */
sit_i = f2fs_kzalloc(sbi, sizeof(struct sit_info), GFP_KERNEL);
@@ -3962,8 +3966,8 @@ static int build_sit_info(struct f2fs_sb_info *sbi)
if (!sit_i->sentries)
return -ENOMEM;
- bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
- sit_i->dirty_sentries_bitmap = f2fs_kvzalloc(sbi, bitmap_size,
+ main_bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
+ sit_i->dirty_sentries_bitmap = f2fs_kvzalloc(sbi, main_bitmap_size,
GFP_KERNEL);
if (!sit_i->dirty_sentries_bitmap)
return -ENOMEM;
@@ -4012,17 +4016,23 @@ static int build_sit_info(struct f2fs_sb_info *sbi)
sit_segs = le32_to_cpu(raw_super->segment_count_sit) >> 1;
/* setup SIT bitmap from ckeckpoint pack */
- bitmap_size = __bitmap_size(sbi, SIT_BITMAP);
+ sit_bitmap_size = __bitmap_size(sbi, SIT_BITMAP);
src_bitmap = __bitmap_ptr(sbi, SIT_BITMAP);
- sit_i->sit_bitmap = kmemdup(src_bitmap, bitmap_size, GFP_KERNEL);
+ sit_i->sit_bitmap = kmemdup(src_bitmap, sit_bitmap_size, GFP_KERNEL);
if (!sit_i->sit_bitmap)
return -ENOMEM;
#ifdef CONFIG_F2FS_CHECK_FS
- sit_i->sit_bitmap_mir = kmemdup(src_bitmap, bitmap_size, GFP_KERNEL);
+ sit_i->sit_bitmap_mir = kmemdup(src_bitmap,
+ sit_bitmap_size, GFP_KERNEL);
if (!sit_i->sit_bitmap_mir)
return -ENOMEM;
+
+ sit_i->invalid_segmap = f2fs_kvzalloc(sbi,
+ main_bitmap_size, GFP_KERNEL);
+ if (!sit_i->invalid_segmap)
+ return -ENOMEM;
#endif
/* init SIT information */
@@ -4031,7 +4041,7 @@ static int build_sit_info(struct f2fs_sb_info *sbi)
sit_i->sit_base_addr = le32_to_cpu(raw_super->sit_blkaddr);
sit_i->sit_blocks = sit_segs << sbi->log_blocks_per_seg;
sit_i->written_valid_blocks = 0;
- sit_i->bitmap_size = bitmap_size;
+ sit_i->bitmap_size = sit_bitmap_size;
sit_i->dirty_sentries = 0;
sit_i->sents_per_block = SIT_ENTRY_PER_BLOCK;
sit_i->elapsed_time = le64_to_cpu(sbi->ckpt->elapsed_time);
@@ -4514,6 +4524,7 @@ 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 ec4d568..b219009 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -230,6 +230,9 @@ 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 */