On 12/04/2015 10:45 AM, J. Bruce Fields wrote:
> On Thu, Dec 03, 2015 at 03:55:35PM -0500, Anna Schumaker wrote:
>> @@ -498,6 +499,22 @@ __be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
>> }
>> #endif
>>
>> +ssize_t nfsd_copy_range(struct file *src, u64 src_pos,
>> + struct file *dst, u64 dst_pos,
>> + u64 count)
>> +{
>> + ssize_t bytes;
>> + u64 limit = 0x10000000;
>
> Why that value? Could I get a comment here?
Whoops! I had a comment there at one point, but I must have deleted it :(. That value is to cap copies to 256MB.
>
>> +
>> + if (count > limit)
>> + count = limit;
>> +
>> + bytes = vfs_copy_file_range(src, src_pos, dst, dst_pos, count, 0);
>
> Sorry, I lost track of the copy discussions: does this only work on
> filesystems with special support, or does it fall back on doing the copy
> by hand? Which filesystems (of the exportable filesystems) support
> this?
The system call falls back on doing the copy by hand if there is no filesystem acceleration.
Anna
>
> --b.
>
>> + if (bytes > 0)
>> + vfs_fsync_range(dst, dst_pos, dst_pos + bytes, 0);
>> + return bytes;
>> +}
>> +
>> __be32 nfsd4_vfs_fallocate(struct svc_rqst *rqstp, struct svc_fh *fhp,
>> struct file *file, loff_t offset, loff_t len,
>> int flags)
> --
> To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
