Re: [PATCH v5 2/3] ext4: set EXT4_STATE_NO_EXPAND in ext4_evict_inode

[Jan Kara]

On Mon 15-06-26 19:53:16, Yun Zhou wrote:
> An inode being evicted will never need its extra isize expanded.  Set
> EXT4_STATE_NO_EXPAND before ext4_mark_inode_dirty() in ext4_evict_inode()
> to make this explicit and prevent any unnecessary work in
> ext4_try_to_expand_extra_isize().
> 
> This also provides defense-in-depth for the s_writepages_rwsem deadlock
> during mount-time orphan cleanup, ensuring the expand path is blocked
> for inodes under eviction regardless of how they are reached.
> 
> Signed-off-by: Yun Zhou <yun.zhou@xxxxxxxxxxxxx>

Looks good. I'd move the setting somewhat earlier (just before
dquot_initialize()) so that it obviously covers all the inode dirtying that
can happen while deleting the inode. But otherwise feel free to add:

Reviewed-by: Jan Kara <jack@xxxxxxx>

								Honza

> ---
>  fs/ext4/inode.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index be1e3eaa4f23..60c91c098fa0 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -264,6 +264,7 @@ void ext4_evict_inode(struct inode *inode)
>  	if (ext4_inode_is_fast_symlink(inode))
>  		memset(EXT4_I(inode)->i_data, 0, sizeof(EXT4_I(inode)->i_data));
>  	inode->i_size = 0;
> +	ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND);
>  	err = ext4_mark_inode_dirty(handle, inode);
>  	if (err) {
>  		ext4_warning(inode->i_sb,
> -- 
> 2.43.0
> 
-- 
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR