> On 04 August 2014 at 20:31 Zach Brown <[email protected]> wrote: > > > On Sat, Aug 02, 2014 at 02:24:49PM +0200, Fabian Frederick wrote: > > On Thu, 17 Jul 2014 12:01:52 -0700 > > Zach Brown <[email protected]> wrote: > > > > > > > > @@ -515,7 +515,8 @@ static int write_buf(struct file *filp, const > > > > > > void *buf, > > > > > > u32 len, loff_t *off) > > > > > > > > > > Though this probably wants to be rewritten in terms of kernel_write(). > > > > > That'd give an opportunity to get rid of the sctx->send_off and have > > > > > it > > > > > use f_pos in the filp. > > > > > > > > Do you mean directly call kernel_write from send_cmd/send_header ? > > > > I guess that loop around vfs_write in write_buf is there for something > > > > ... > > > > > > write_buf() could still exist to iterate over the buffer in the case of > > > partial writes but it doesn't need to muck around with set_fs() and > > > forcing casts. > > > > > > - z > > > > Hello Zach, > > > > Here's an untested patch which > > Try testing it. It's easy with virtualization and xfstests. > > You'll find that sending to a file fails because each individual file > write call that makes up a send starts at offset 0 -- at the start of > the file. > > Getting this right means getting the semantics around updating the send > descriptors f_pos right. It requires having a bit of a think about send > semantics and f_pos update locking.
Thanks for those informations Zach, I've tried btrfs test scripts related to ioctl in xfstests (tests/btrfs/025, 035, 052, 055) but was not able to trigger that problem. Do I have to create another script, use some generic one or maybe use big test/scratch devices ? Regards, Fabian > > - z -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
