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From: David Sterba <dave@jikos.cz>
To: Jan Schmidt <list.btrfs@jan-o-sch.net>
Cc: Li Zefan <lizf@cn.fujitsu.com>,
	Chris Mason <chris.mason@oracle.com>,
	"linux-btrfs@vger.kernel.org" <linux-btrfs@vger.kernel.org>
Subject: Re: [PATCH 12/12] Btrfs: Fix file clone when source offset is not 0
Date: Thu, 26 Jan 2012 17:17:45 +0100	[thread overview]
Message-ID: <20120126161745.GM7322@twin.jikos.cz> (raw)
In-Reply-To: <4F215AA0.8040505@jan-o-sch.net>

On Thu, Jan 26, 2012 at 02:52:32PM +0100, Jan Schmidt wrote:
> I was looking at the clone range ioctl and have some remarks:
> 
> On 27.01.2011 09:46, Li Zefan wrote:
> > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> > index f87552a..1b61dab 100644
> > --- a/fs/btrfs/ioctl.c
> > +++ b/fs/btrfs/ioctl.c
> > @@ -1788,7 +1788,10 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
> >  
> >  			memcpy(&new_key, &key, sizeof(new_key));
> >  			new_key.objectid = inode->i_ino;
> > -			new_key.offset = key.offset + destoff - off;
> > +			if (off <= key.offset)
> > +				new_key.offset = key.offset + destoff - off;
> > +			else
> > +				new_key.offset = destoff;
> 						 ^^^^^^^
> 1) This looks spurious to me. What if destoff isn't aligned? That's what
> the "key.offset - off" code above is for. Before the patch, the code
> didn't work at all, I agree. But this fix can only work for aligned
> requests.

Source range and destination offset are accepted iff are aligned:

2300         /* verify the end result is block aligned */
2301         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
2302             !IS_ALIGNED(destoff, bs))
2303                 goto out_unlock;


david

  reply	other threads:[~2012-01-26 16:17 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-01-27  8:42 [PATCH 00/12] Btrfs: Some bug fixes Li Zefan
2011-01-27  8:42 ` [PATCH 01/12] btrfs: Fix threshold calculation for block groups smaller than 1GB Li Zefan
2011-01-27  8:42 ` [PATCH 02/12] btrfs: Add helper function free_bitmap() Li Zefan
2011-01-27  8:43 ` [PATCH 03/12] btrfs: Free fully occupied bitmap in cluster Li Zefan
2011-01-27  8:43 ` [PATCH 04/12] btrfs: Update stats when allocating from a cluster Li Zefan
2011-01-27  8:44 ` [PATCH 05/12] btrfs: Add a helper try_merge_free_space() Li Zefan
2011-01-27  8:44 ` [PATCH 06/12] btrfs: Check mergeable free space when removing a cluster Li Zefan
2011-01-27  8:44 ` [PATCH 07/12] Btrfs: Fix memory leak at umount Li Zefan
2011-01-27  8:44 ` [PATCH 08/12] Btrfs: Fix memory leak on finding existing super Li Zefan
2011-01-27  8:45 ` [PATCH 09/12] Btrfs: Free correct pointer after using strsep Li Zefan
2011-01-27  8:45 ` [PATCH 10/12] Btrfs: Don't return acl info when mounting with noacl option Li Zefan
2011-01-27  8:45 ` [PATCH 11/12] Btrfs: Fix memory leak in writepage fixup work Li Zefan
2011-01-27  8:46 ` [PATCH 12/12] Btrfs: Fix file clone when source offset is not 0 Li Zefan
2012-01-26 13:52   ` Jan Schmidt
2012-01-26 16:17     ` David Sterba [this message]
2012-01-30  6:33     ` Li Zefan
2012-01-30 10:03       ` Jan Schmidt
2012-02-01  9:44         ` Li Zefan
2012-02-02  4:31         ` Yan, Zheng 
2012-02-02 21:00           ` Jan Schmidt
2012-02-02  4:25   ` Yan, Zheng 
2012-02-02  5:31     ` Li Zefan
2012-02-02  6:44       ` Yan, Zheng 
2011-01-30 23:48 ` [PATCH 00/12] Btrfs: Some bug fixes Chris Mason

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