Re: [f2fs-dev] [PATCH v2] f2fs: add bug_on when f2fs_gc even fails to get one victim
From: Yunlong Song
Date: Mon Oct 30 2017 - 21:35:24 EST
I think there may be bugs somewhere, since no victim is selected but it
really needs gc.
What is the size of the data image?
On 2017/10/16 11:25, Chao Yu wrote:
On 2017/10/14 20:34, Yunlong Song wrote:
Do you mean check out-of-space test? I have tried that but no bugon.
Yes, test recent f2fs codes with kernel 4.13.0-rc1+ in VM, FYI:
kernel BUG at gc.c:1034!
invalid opcode: 0000 [#1] SMP
Hardware name: Xen HVM domU, BIOS 4.1.2_115-900.260_ 11/06/2015
RIP: 0010:f2fs_gc+0x6e5/0x6f0 [f2fs]
RSP: 0018:ffffc90004af7b40 EFLAGS: 00010202
RAX: ffff8801b0a15940 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff8801b0a15940 RSI: ffff8801978d5f00 RDI: ffff880128148048
RBP: ffffc90004af7c38 R08: ffff8801978d5f00 R09: 0000000000000003
R10: 0000000000000003 R11: ffff8800060703a0 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000001 R15: ffff8801b4279800
FS: 00007f23493cb740(0000) GS:ffff880216f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd05402ff8 CR3: 00000001bffb3000 CR4: 00000000001406e0
Call Trace:
f2fs_balance_fs+0x123/0x140 [f2fs]
f2fs_create+0x130/0x240 [f2fs]
path_openat+0xee7/0x1360
do_filp_open+0x7e/0xd0
do_sys_open+0x115/0x1f0
SyS_open+0x1e/0x20
do_syscall_64+0x6e/0x160
entry_SYSCALL64_slow_path+0x25/0x25
Thanks,
On 2017/10/14 8:17, Chao Yu wrote:
On 2017/10/13 21:31, Yunlong Song wrote:
This can help us to debug on some corner case.
I can hit this bugon with generic/015 of fstest easily, could have a look at
this?
Thanks,
Signed-off-by: Yunlong Song <yunlong.song@xxxxxxxxxx>
Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
---
fs/f2fs/gc.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 197ebf4..2b03202 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -986,6 +986,7 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
.ilist = LIST_HEAD_INIT(gc_list.ilist),
.iroot = RADIX_TREE_INIT(GFP_NOFS),
};
+ bool need_fggc = false;
trace_f2fs_gc_begin(sbi->sb, sync, background,
get_pages(sbi, F2FS_DIRTY_NODES),
@@ -1018,8 +1019,10 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
if (ret)
goto stop;
}
- if (has_not_enough_free_secs(sbi, 0, 0))
+ if (has_not_enough_free_secs(sbi, 0, 0)) {
gc_type = FG_GC;
+ need_fggc = true;
+ }
}
/* f2fs_balance_fs doesn't need to do BG_GC in critical path. */
@@ -1028,6 +1031,7 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
goto stop;
}
if (!__get_victim(sbi, &segno, gc_type)) {
+ f2fs_bug_on(sbi, !total_freed && need_fggc);
ret = -ENODATA;
goto stop;
}
.
.
--
Thanks,
Yunlong Song