Re: [PATCH 22/31] fs/ntfs: use kmemdup rather than duplicating its implementation

From: Anton Altaparmakov
Date: Wed Sep 23 2015 - 06:30:05 EST


Hi Andrzej,

Thanks for your patch. It looks fine though I don't quite see the point of it to be honest.

It actually adds an additional function call (kmemdup() is not inline) just to save 1 line of source code in the driver and I don't think it improves readability or anything so why bother? What does it gain?

Best regards,

Anton

> On 7 Aug 2015, at 08:59, Andrzej Hajda <a.hajda@xxxxxxxxxxx> wrote:
>
> The patch was generated using fixed coccinelle semantic patch
> scripts/coccinelle/api/memdup.cocci [1].
>
> [1]: http://permalink.gmane.org/gmane.linux.kernel/2014320
>
> Signed-off-by: Andrzej Hajda <a.hajda@xxxxxxxxxxx>
> ---
> fs/ntfs/dir.c | 7 +++----
> 1 file changed, 3 insertions(+), 4 deletions(-)
>
> diff --git a/fs/ntfs/dir.c b/fs/ntfs/dir.c
> index 9e38daf..2b7fef0 100644
> --- a/fs/ntfs/dir.c
> +++ b/fs/ntfs/dir.c
> @@ -1172,14 +1172,13 @@ static int ntfs_readdir(struct file *file, struct dir_context *actor)
> * map the mft record without deadlocking.
> */
> rc = le32_to_cpu(ctx->attr->data.resident.value_length);
> - ir = kmalloc(rc, GFP_NOFS);
> + /* Copy the index root value (it has been verified in read_inode). */
> + ir = kmemdup((u8 *)ctx->attr + le16_to_cpu(ctx->attr->data.resident.value_offset),
> + rc, GFP_NOFS);
> if (unlikely(!ir)) {
> err = -ENOMEM;
> goto err_out;
> }
> - /* Copy the index root value (it has been verified in read_inode). */
> - memcpy(ir, (u8*)ctx->attr +
> - le16_to_cpu(ctx->attr->data.resident.value_offset), rc);
> ntfs_attr_put_search_ctx(ctx);
> unmap_mft_record(ndir);
> ctx = NULL;
> --
> 1.9.1

--
Anton Altaparmakov <anton at tuxera.com> (replace at with @)
Lead in File System Development, Tuxera Inc., http://www.tuxera.com/
Linux NTFS maintainer

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