From: Zhiguo Niu <[email protected]>
There is bug on issue after atgc feature is enabled in
32bits platform as the following log:
F2FS-fs (dm-x): inconsistent rbtree, cur(3470333575168) next(3320009719808)
------------[ cut here ]------------
kernel BUG at fs/f2fs/gc.c:602!
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM
PC is at get_victim_by_default+0x13c0/0x1498
LR is at f2fs_check_rb_tree_consistence+0xc4/0xd4
....
[<c04d98b0>] (get_victim_by_default) from [<c04d4f44>] (f2fs_gc+0x220/0x6cc)
[<c04d4f44>] (f2fs_gc) from [<c04d4780>] (gc_thread_func+0x2ac/0x708)
[<c04d4780>] (gc_thread_func) from [<c015c774>] (kthread+0x1a8/0x1b4)
[<c015c774>] (kthread) from [<c01010b4>] (ret_from_fork+0x14/0x20)
The reason is the 64bits key in struct rb_entry has __packed attibute
but has not in struct victim_entry, so the wrong key value got by
in f2fs_check_rb_tree_consistence, the following are the memory layouts
of struct rb_entry and struct victim_entry in 32bits platform:
struct rb_entry {
[0] struct rb_node rb_node;
union {
struct {...};
[12] unsigned long long key;
};
}
struct victim_entry {
[0] struct rb_node rb_node;
union {
struct {...};
[16] struct victim_info vi;
};
[32] struct list_head list;
}
This patch fix this inconsistence layout of 64bits key between
struct rb_entry and struct victim_entry.
Signed-off-by: Zhiguo Niu <[email protected]>
---
fs/f2fs/gc.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/f2fs/gc.h b/fs/f2fs/gc.h
index 19b956c2d697..9a03c6502b39 100644
--- a/fs/f2fs/gc.h
+++ b/fs/f2fs/gc.h
@@ -68,7 +68,7 @@ struct victim_entry {
unsigned int segno; /* segment No. */
};
struct victim_info vi; /* victim info */
- };
+ } __packed;
struct list_head list;
};
--
2.17.1
On 2022/11/4 15:40, zhiguo.niu wrote:
> From: Zhiguo Niu <[email protected]>
>
> There is bug on issue after atgc feature is enabled in
> 32bits platform as the following log:
>
> F2FS-fs (dm-x): inconsistent rbtree, cur(3470333575168) next(3320009719808)
> ------------[ cut here ]------------
> kernel BUG at fs/f2fs/gc.c:602!
> Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM
> PC is at get_victim_by_default+0x13c0/0x1498
> LR is at f2fs_check_rb_tree_consistence+0xc4/0xd4
> ....
> [<c04d98b0>] (get_victim_by_default) from [<c04d4f44>] (f2fs_gc+0x220/0x6cc)
> [<c04d4f44>] (f2fs_gc) from [<c04d4780>] (gc_thread_func+0x2ac/0x708)
> [<c04d4780>] (gc_thread_func) from [<c015c774>] (kthread+0x1a8/0x1b4)
> [<c015c774>] (kthread) from [<c01010b4>] (ret_from_fork+0x14/0x20)
>
> The reason is the 64bits key in struct rb_entry has __packed attibute
> but has not in struct victim_entry, so the wrong key value got by
> in f2fs_check_rb_tree_consistence, the following are the memory layouts
> of struct rb_entry and struct victim_entry in 32bits platform:
>
> struct rb_entry {
> [0] struct rb_node rb_node;
> union {
> struct {...};
> [12] unsigned long long key;
> };
> }
> struct victim_entry {
> [0] struct rb_node rb_node;
> union {
> struct {...};
> [16] struct victim_info vi;
> };
> [32] struct list_head list;
> }
Shouldn't we add __packed for struct victim_entry?
>
> This patch fix this inconsistence layout of 64bits key between
> struct rb_entry and struct victim_entry.
>
Fixes: 093749e296e2 ("f2fs: support age threshold based garbage collection")
> Signed-off-by: Zhiguo Niu <[email protected]>
On 2022/11/7 13:04, Zhiguo Niu wrote:
> Dear Chao
>
> Chao Yu <[email protected] <mailto:[email protected]>> 于2022年11月7日周一 09:25写道：
>
> On 2022/11/4 15:40, zhiguo.niu wrote:
> > From: Zhiguo Niu <[email protected] <mailto:[email protected]>>
> >
> > There is bug on issue after atgc feature is enabled in
> > 32bits platform as the following log:
> >
> > F2FS-fs (dm-x): inconsistent rbtree, cur(3470333575168) next(3320009719808)
> > ------------[ cut here ]------------
> > kernel BUG at fs/f2fs/gc.c:602!
> > Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM
> > PC is at get_victim_by_default+0x13c0/0x1498
> > LR is at f2fs_check_rb_tree_consistence+0xc4/0xd4
> > ....
> > [<c04d98b0>] (get_victim_by_default) from [<c04d4f44>] (f2fs_gc+0x220/0x6cc)
> > [<c04d4f44>] (f2fs_gc) from [<c04d4780>] (gc_thread_func+0x2ac/0x708)
> > [<c04d4780>] (gc_thread_func) from [<c015c774>] (kthread+0x1a8/0x1b4)
> > [<c015c774>] (kthread) from [<c01010b4>] (ret_from_fork+0x14/0x20)
> >
> > The reason is the 64bits key in struct rb_entry has __packed attibute
> > but has not in struct victim_entry, so the wrong key value got by
> > in f2fs_check_rb_tree_consistence, the following are the memory layouts
> > of struct rb_entry and struct victim_entry in 32bits platform:
> >
> > struct rb_entry {
> > [0] struct rb_node rb_node;
> > union {
> > struct {...};
> > [12] unsigned long long key;
> > };
> > }
> > struct victim_entry {
> > [0] struct rb_node rb_node;
> > union {
> > struct {...};
> > [16] struct victim_info vi;
> > };
> > [32] struct list_head list;
> > }
>
> Shouldn't we add __packed for struct victim_entry?
>
> I try to keep it consistent with struct rb_entry (__packed is only added to union for 64bits key),
> victim_entry.vi.mtime is used to store the key, and rb_entry.key is used to verify the key,
> so make sure that the memory offsets of the 64 bits key in these two structures are the same.
> Other members of victim_entry, such as list, i think there is no problem because of it storaged and loaded
> are both based on struct victim_entry
I'm not sure, there will be any further update in struct rb_node and
struct list_head later, so, IMO, it will be more safe to add __packed to
align all fields in structure to byte.
Thanks,
>
> >
> > This patch fix this inconsistence layout of 64bits key between
> > struct rb_entry and struct victim_entry.
> >
>
> Fixes: 093749e296e2 ("f2fs: support age threshold based garbage collection")
>
> > Signed-off-by: Zhiguo Niu <[email protected] <mailto:[email protected]>>
>