diff mbox series

Revert "f2fs: stop allocating pinned sections if EAGAIN happens"

Message ID 20240205031415.557879-1-bo.wu@vivo.com
State New
Headers
Series Revert "f2fs: stop allocating pinned sections if EAGAIN happens" |

Commit Message

Wu Bo Feb. 5, 2024, 3:14 a.m. UTC 
  This reverts commit 2e42b7f817acd6e8d78226445eb6fe44fe79c12a.

If the GC victim section has a pinned block when fallocate() trigger
FG_GC, the section is not able to be recycled. And this will return
-EAGAIN cause fallocate() failed, even though there are much spare space
as user see. As the GC policy prone to chose the same victim,
fallocate() may not successed at a long period.

This scenario has been found during Android OTA.

Link: https://lore.kernel.org/linux-f2fs-devel/20231030094024.263707-1-bo.wu@vivo.com/t/#u

CC: stable@vger.kernel.org
Signed-off-by: Wu Bo <bo.wu@vivo.com>
---
 fs/f2fs/file.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Chao Yu Feb. 5, 2024, 3:54 a.m. UTC | #1 
On 2024/2/5 11:14, Wu Bo wrote:
> This reverts commit 2e42b7f817acd6e8d78226445eb6fe44fe79c12a.
> 
> If the GC victim section has a pinned block when fallocate() trigger
> FG_GC, the section is not able to be recycled. And this will return
> -EAGAIN cause fallocate() failed, even though there are much spare space
> as user see. As the GC policy prone to chose the same victim,
> fallocate() may not successed at a long period.
> 
> This scenario has been found during Android OTA.
> 
> Link: https://lore.kernel.org/linux-f2fs-devel/20231030094024.263707-1-bo.wu@vivo.com/t/#u
> 
> CC: stable@vger.kernel.org
> Signed-off-by: Wu Bo <bo.wu@vivo.com>
> ---
>   fs/f2fs/file.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index b58ab1157b7e..19915faccee9 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -1725,7 +1725,7 @@ static int f2fs_expand_inode_data(struct inode *inode, loff_t offset,
>   			f2fs_down_write(&sbi->gc_lock);
>   			stat_inc_gc_call_count(sbi, FOREGROUND);
>   			err = f2fs_gc(sbi, &gc_control);
> -			if (err && err != -ENODATA)
> +			if (err && err != -ENODATA && err != -EAGAIN)
>   				goto out_err;
>   		}

How about calling f2fs_balance_fs() to double check and make sure there is
enough free space for following allocation.

		if (has_not_enough_free_secs(sbi, 0,
			GET_SEC_FROM_SEG(sbi, overprovision_segments(sbi)))) {
			f2fs_down_write(&sbi->gc_lock);
			stat_inc_gc_call_count(sbi, FOREGROUND);
			err = f2fs_gc(sbi, &gc_control);
			if (err == -EAGAIN)
				f2fs_balance_fs(sbi, true);
			if (err && err != -ENODATA)
				goto out_err;
		}

Thanks,

>
Wu Bo Feb. 8, 2024, 8:11 a.m. UTC | #2 
On 2024/2/5 11:54, Chao Yu wrote:
> How about calling f2fs_balance_fs() to double check and make sure 
> there is
> enough free space for following allocation.
>
>         if (has_not_enough_free_secs(sbi, 0,
>             GET_SEC_FROM_SEG(sbi, overprovision_segments(sbi)))) {
>             f2fs_down_write(&sbi->gc_lock);
>             stat_inc_gc_call_count(sbi, FOREGROUND);
>             err = f2fs_gc(sbi, &gc_control);
>             if (err == -EAGAIN)
>                 f2fs_balance_fs(sbi, true);
>             if (err && err != -ENODATA)
>                 goto out_err;
>         }
>
> Thanks,

f2fs_balance_fs() here will not change procedure branch and may just 
trigger another GC.

I'm afraid this is a bit redundant.

>
Chao Yu Feb. 20, 2024, 6:50 a.m. UTC | #3 
On 2024/2/8 16:11, Wu Bo wrote:
> On 2024/2/5 11:54, Chao Yu wrote:
>> How about calling f2fs_balance_fs() to double check and make sure there is
>> enough free space for following allocation.
>>
>>         if (has_not_enough_free_secs(sbi, 0,
>>             GET_SEC_FROM_SEG(sbi, overprovision_segments(sbi)))) {
>>             f2fs_down_write(&sbi->gc_lock);
>>             stat_inc_gc_call_count(sbi, FOREGROUND);
>>             err = f2fs_gc(sbi, &gc_control);
>>             if (err == -EAGAIN)
>>                 f2fs_balance_fs(sbi, true);
>>             if (err && err != -ENODATA)
>>                 goto out_err;
>>         }
>>
>> Thanks,
> 
> f2fs_balance_fs() here will not change procedure branch and may just trigger another GC.
> 
> I'm afraid this is a bit redundant.

Okay.

I guess maybe Jaegeuk has concern which is the reason to commit
2e42b7f817ac ("f2fs: stop allocating pinned sections if EAGAIN happens").

Thanks,

> 
>>
diff mbox series

Patch

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index b58ab1157b7e..19915faccee9 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1725,7 +1725,7 @@  static int f2fs_expand_inode_data(struct inode *inode, loff_t offset,
 			f2fs_down_write(&sbi->gc_lock);
 			stat_inc_gc_call_count(sbi, FOREGROUND);
 			err = f2fs_gc(sbi, &gc_control);
-			if (err && err != -ENODATA)
+			if (err && err != -ENODATA && err != -EAGAIN)
 				goto out_err;
 		}