Re: [PATCH v2] btrfs: use kbasename in btrfsic_mount

From: Andy Shevchenko
Date: Fri Nov 27 2015 - 03:47:00 EST


On Fri, Nov 27, 2015 at 10:42 AM, Rasmus Villemoes
<linux@xxxxxxxxxxxxxxxxxx> wrote:
> This is more readable.
>
> Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>

You missed David's tag.

Anyway, also mine is here

Reviewed-by Andy Shevchenko <andy.shevchenko@xxxxxxxxx>

> ---
> v2: make p const char* (thanks 0day).
>
> Original comment:
>
> I think the following strlcpy may be somewhat fragile since obviously
> ds->name and p overlap. It certainly relies on strlcpy doing a forward
> copy, and since different architectures can have their own strlcpy,
> that's hard to verify (and also won't necessarily continue to hold).
>
> Maybe
>
> if (p != ds->name)
> memmove(ds->name, p, strlen(p)+1);
>
> instead.
>
> fs/btrfs/check-integrity.c | 9 +++------
> 1 file changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c
> index 0340c57bf377..d6fe77c5b4ac 100644
> --- a/fs/btrfs/check-integrity.c
> +++ b/fs/btrfs/check-integrity.c
> @@ -95,6 +95,7 @@
> #include <linux/genhd.h>
> #include <linux/blkdev.h>
> #include <linux/vmalloc.h>
> +#include <linux/string.h>
> #include "ctree.h"
> #include "disk-io.h"
> #include "hash.h"
> @@ -3120,7 +3121,7 @@ int btrfsic_mount(struct btrfs_root *root,
>
> list_for_each_entry(device, dev_head, dev_list) {
> struct btrfsic_dev_state *ds;
> - char *p;
> + const char *p;
>
> if (!device->bdev || !device->name)
> continue;
> @@ -3136,11 +3137,7 @@ int btrfsic_mount(struct btrfs_root *root,
> ds->state = state;
> bdevname(ds->bdev, ds->name);
> ds->name[BDEVNAME_SIZE - 1] = '\0';
> - for (p = ds->name; *p != '\0'; p++);
> - while (p > ds->name && *p != '/')
> - p--;
> - if (*p == '/')
> - p++;
> + p = kbasename(ds->name);
> strlcpy(ds->name, p, sizeof(ds->name));
> btrfsic_dev_state_hashtable_add(ds,
> &btrfsic_dev_state_hashtable);
> --
> 2.6.1
>
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--
With Best Regards,
Andy Shevchenko
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