[PATCH] ext4: increase wait time needed before reuse of deleted inode numbers

[PATCH] ext4: increase wait time needed before reuse of deleted inode numbers

[Theodore Ts'o]

Current wait times have proven to be too short to protect against inode
reuses that lead to metadata inconsistencies.

Now that we will retry the inode allocation if we can't find any
recently deleted inodes, it's a lot safer to increase the recently
deleted time from 5 seconds to a minute.

Google-Bug-Id: 36602237
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---
 fs/ext4/ialloc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 9faaf32be5cc..4b8c9a9bdf0c 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -662,7 +662,7 @@ static int find_group_other(struct super_block *sb, struct inode *parent,
  * block has been written back to disk.  (Yes, these values are
  * somewhat arbitrary...)
  */
-#define RECENTCY_MIN	5
+#define RECENTCY_MIN	60
 #define RECENTCY_DIRTY	300
 
 static int recently_deleted(struct super_block *sb, ext4_group_t group, int ino)
-- 
2.24.1

Re: [PATCH] ext4: increase wait time needed before reuse of deleted inode numbers

[Jan Kara]

On Mon 13-04-20 22:39:25, Theodore Ts'o wrote:
> Current wait times have proven to be too short to protect against inode
> reuses that lead to metadata inconsistencies.
> 
> Now that we will retry the inode allocation if we can't find any
> recently deleted inodes, it's a lot safer to increase the recently
> deleted time from 5 seconds to a minute.
> 
> Google-Bug-Id: 36602237
> Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Looks good to me. You can add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
>  fs/ext4/ialloc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
> index 9faaf32be5cc..4b8c9a9bdf0c 100644
> --- a/fs/ext4/ialloc.c
> +++ b/fs/ext4/ialloc.c
> @@ -662,7 +662,7 @@ static int find_group_other(struct super_block *sb, struct inode *parent,
>   * block has been written back to disk.  (Yes, these values are
>   * somewhat arbitrary...)
>   */
> -#define RECENTCY_MIN	5
> +#define RECENTCY_MIN	60
>  #define RECENTCY_DIRTY	300
>  
>  static int recently_deleted(struct super_block *sb, ext4_group_t group, int ino)
> -- 
> 2.24.1
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR