On Tue, Apr 09, 2019 at 05:34:22PM +0800, Su Yue wrote:
>
>
> On 2019/4/8 9:31 PM, Johannes Thumshirn wrote:
> > Add a 'btrfs inspect-internal csum-dump' command to dump the on-disk
> > checksums of a file.
> >
> > The dump command first uses the FIEMAP ioctl() to get a map of the file's
> > extents and then uses the BTRFS_TREE_SEARCH_V2 ioctl() to get the
> > checksums for these extents.
> >
> > Using FIEMAP instead of the BTRFS_TREE_SEARCH_V2 ioctl() to get the
> > extents allows us to quickly filter out any holes in the file, as this is
> > already done for us in the kernel.
> >
>
> Looks much better than V1. Some comments bellow.
>
Thanks.
[...]
> > + fiemap = calloc(1, sizeof(*fiemap));
> > + if (!fiemap)
> > + return -1;
>
> -ENOMEM is better.
OK.
> > +
> > + fiemap->fm_length = ~0;
> > +
> > + ret = ioctl(fd, FS_IOC_FIEMAP, fiemap);
> > + if (ret)
> > + goto free_fiemap;
> > +
> > + ext_size = fiemap->fm_mapped_extents * sizeof(struct fiemap_extent);
> > +
> > + tmp = realloc(fiemap, sizeof(*fiemap) + ext_size);
> > + if (!tmp)
>
> ret = -ENOMEM;
> else btrfs_get_extent_csum() will return 0.
>
Good catch, thanks
[...]
> > + fd = open(filename, O_RDONLY);
> > + if (fd < 0) {
> > + error("cannot open file %s:%m\n", filename);
>
> error() does break a line, no need of '\n'.
> > + return 1;
>
> -errno is better here.
OK.
--
Johannes Thumshirn SUSE Labs Filesystems
jthumshirn@xxxxxxx +49 911 74053 689
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
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