On Fri, Jun 12, 2015 at 08:30:09AM +0800, Chao Yu wrote:
> Hi Jaegeuk,
>
> > -----Original Message-----
> > From: Chao Yu [mailto:[email protected]]
> > Sent: Tuesday, June 09, 2015 10:28 AM
> > To: Jaegeuk Kim; Changman Lee
> > Cc: [email protected]; [email protected]
> > Subject: [f2fs-dev] [PATCH v2] f2fs: do not trim preallocated blocks when
> > truncating after i_size
> >
> > When we perform generic/092 in xfstests, output is like below:
> >
> > XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
> > 0: [0..10239]: data
> > 0: [0..10239]: data
> > -1: [10240..20479]: unwritten
> > +1: [10240..14335]: unwritten
> >
> > This is because with this testcase, we redefine the regulation for
> > truncate in perallocated space past i_size as below:
> >
> > "There was some confused about what the fs was supposed to do when you
> > truncate at i_size with preallocated space past i_size. We decided on the
> > following things.
> >
> > 1) truncate(i_size) will trim all blocks past i_size.
> > 2) truncate(x) where x > i_size will not trim all blocks past i_size.
> > "
> >
> > This method is used in xfs, and then ext4/btrfs will follow the rule.
> >
> > This patch fixes to follow the new rule for f2fs.
> >
> > Signed-off-by: Chao Yu <[email protected]>
> > ---
> > v2:
> > * adjust code style pointed out by Jaegeuk Kim.
> >
> > fs/f2fs/file.c | 15 +++++++--------
> > 1 file changed, 7 insertions(+), 8 deletions(-)
> >
> > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> > index 4d42d66..ec47c4a 100644
> > --- a/fs/f2fs/file.c
> > +++ b/fs/f2fs/file.c
> > @@ -651,16 +651,15 @@ int f2fs_setattr(struct dentry *dentry, struct iattr
> > *attr)
> > f2fs_get_encryption_info(inode))
> > return -EACCES;
> >
> > - if (attr->ia_size != i_size_read(inode)) {
> > - truncate_setsize(inode, attr->ia_size);
> > + truncate_setsize(inode, attr->ia_size);
> > +
> > + /*
> > + * do not trim all preallocated blocks after i_size if target
> > + * size is larger than i_size.
> > + */
> > + if (attr->ia_size <= i_size_read(inode)) {
>
> It's wrong implementation here, because we have set i_size in inode with
> attr->ia_size, so that we will always go into this "truncate smaller size"
> branch.
>
> Please ignore this patch, sorry for my mistake.
>
> Jaegeuk, I'd like to use v1 patch, how do you think?
Oh, I see.
I'll merge v1.
Thank you for pointing out this.
>
> Thanks,
>
> > f2fs_truncate(inode);
> > f2fs_balance_fs(F2FS_I_SB(inode));
> > - } else {
> > - /*
> > - * giving a chance to truncate blocks past EOF which
> > - * are fallocated with FALLOC_FL_KEEP_SIZE.
> > - */
> > - f2fs_truncate(inode);
> > }
> > }
> >
> > --
> > 2.4.2
> >
> >
> >
> > ------------------------------------------------------------------------------
> > _______________________________________________
> > Linux-f2fs-devel mailing list
> > [email protected]
> > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
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