Re: [f2fs-dev][PATCH 1/2] f2fs: get rid of kzalloc in __recover_inline_status

From: Jaegeuk Kim
Date: Tue Jan 06 2015 - 14:32:35 EST


Hi Chao,

On Tue, Jan 06, 2015 at 02:28:43PM +0800, Chao Yu wrote:
> We use kzalloc to allocate memory in __recover_inline_status, and use this
> all-zero memory to check the inline date content of inode page by comparing
> them. This is low effective and not needed, let's check inline date content
> directly.
>
> Signed-off-by: Chao Yu <chao2.yu@xxxxxxxxxxx>
> ---
> fs/f2fs/inode.c | 27 +++++++++++----------------
> 1 file changed, 11 insertions(+), 16 deletions(-)
>
> diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
> index 3a8958d..8be0fd5 100644
> --- a/fs/f2fs/inode.c
> +++ b/fs/f2fs/inode.c
> @@ -67,29 +67,25 @@ static void __set_inode_rdev(struct inode *inode, struct f2fs_inode *ri)
> }
> }
>
> -static int __recover_inline_status(struct inode *inode, struct page *ipage)
> +static void __recover_inline_status(struct inode *inode, struct page *ipage)
> {
> void *inline_data = inline_data_addr(ipage);
> + __le32 *start = inline_data;
> + __le32 *end = start + MAX_INLINE_DATA / sizeof(__le32);
> struct f2fs_inode *ri;
> - void *zbuf;
> -
> - zbuf = kzalloc(MAX_INLINE_DATA, GFP_NOFS);
> - if (!zbuf)
> - return -ENOMEM;
> -
> - if (!memcmp(zbuf, inline_data, MAX_INLINE_DATA)) {
> - kfree(zbuf);
> - return 0;
> - }
> - kfree(zbuf);
>
> + while (start < end)
> + if (*start++)
> + goto recover;
> + return;
> +recover:
> f2fs_wait_on_page_writeback(ipage, NODE);
> set_inode_flag(F2FS_I(inode), FI_DATA_EXIST);
>
> ri = F2FS_INODE(ipage);
> set_raw_inline(F2FS_I(inode), ri);
> set_page_dirty(ipage);
> - return 0;
> + return;
> }

I think *goto recovery* is not a good way.

How's like this?
If you don't mind, I'll merge the patch with this.

static void __recover_inline_status(struct inode *inode, struct page *ipage)
{
void *inline_data = inline_data_addr(ipage);
__le32 *start = inline_data;
__le32 *end = start + MAX_INLINE_DATA / sizeof(__le32);

while (start < end) {
if (*start++) {
f2fs_wait_on_page_writeback(ipage, NODE);

set_inode_flag(F2FS_I(inode), FI_DATA_EXIST);
set_raw_inline(F2FS_I(inode), F2FS_INODE(ipage));
set_page_dirty(ipage);
return;
}
}
return;
}

Thanks,

>
> static int do_read_inode(struct inode *inode)
> @@ -98,7 +94,6 @@ static int do_read_inode(struct inode *inode)
> struct f2fs_inode_info *fi = F2FS_I(inode);
> struct page *node_page;
> struct f2fs_inode *ri;
> - int err = 0;
>
> /* Check if ino is within scope */
> if (check_nid_range(sbi, inode->i_ino)) {
> @@ -142,7 +137,7 @@ static int do_read_inode(struct inode *inode)
>
> /* check data exist */
> if (f2fs_has_inline_data(inode) && !f2fs_exist_data(inode))
> - err = __recover_inline_status(inode, node_page);
> + __recover_inline_status(inode, node_page);
>
> /* get rdev by using inline_info */
> __get_inode_rdev(inode, ri);
> @@ -152,7 +147,7 @@ static int do_read_inode(struct inode *inode)
> stat_inc_inline_inode(inode);
> stat_inc_inline_dir(inode);
>
> - return err;
> + return 0;
> }
>
> struct inode *f2fs_iget(struct super_block *sb, unsigned long ino)
> --
> 2.2.1
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