On Wed, May 02, 2012 at 12:11:44PM +0800, Tao Ma wrote:
> Hi zheng,
> On 04/28/2012 11:39 AM, Zheng Liu wrote:
> > From: Zheng Liu <wenqing.lz@xxxxxxxxxx>
> >
> > ext4_file_buffered/direct_write are defined in order to split buffered IO and
> > direct IO in ext4. This patch just refactor some stuff in write path.
> >
> > Signed-off-by: Zheng Liu <wenqing.lz@xxxxxxxxxx>
> > ---
> > fs/ext4/file.c | 66 +++++++++++++++++++++++++++++++++++++------------------
> > 1 files changed, 44 insertions(+), 22 deletions(-)
> >
> > diff --git a/fs/ext4/file.c b/fs/ext4/file.c
> > index cb70f18..e5d6be3 100644
> > --- a/fs/ext4/file.c
> > +++ b/fs/ext4/file.c
> > @@ -89,12 +89,51 @@ ext4_unaligned_aio(struct inode *inode, const struct iovec *iov,
> > return 0;
> > }
> >
> > +static inline ssize_t
> > +ext4_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
> > + unsigned long nr_segs, loff_t pos)
> > +{
> > + return generic_file_aio_write(iocb, iov, nr_segs, pos);
> > +}
> any reason you wrap generic_file_aio_write with a new function? I didn't
> see you use it in the following patch either.
Yes, I don't use it in the following patch. It is defined in order to
be consistent with ext4_file_dio_write and make things clearly.
Regards,
Zheng
>
> Thanks
> Tao
> > +
> > +static ssize_t
> > +ext4_file_dio_write(struct kiocb *iocb, const struct iovec *iov,
> > + unsigned long nr_segs, loff_t pos)
> > +{
> > + struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
> > + int unaligned_aio = 0;
> > + ssize_t ret;
> > +
> > + if (!is_sync_kiocb(iocb))
> > + unaligned_aio = ext4_unaligned_aio(inode, iov, nr_segs, pos);
> > +
> > + /* Unaligned direct AIO must be serialized; see comment above */
> > + if (unaligned_aio) {
> > + static unsigned long unaligned_warn_time;
> > +
> > + /* Warn about this once per day */
> > + if (printk_timed_ratelimit(&unaligned_warn_time, 60*60*24*HZ))
> > + ext4_msg(inode->i_sb, KERN_WARNING,
> > + "Unaligned AIO/DIO on inode %ld by %s; "
> > + "performance will be poor.",
> > + inode->i_ino, current->comm);
> > + mutex_lock(ext4_aio_mutex(inode));
> > + ext4_aiodio_wait(inode);
> > + }
> > +
> > + ret = generic_file_aio_write(iocb, iov, nr_segs, pos);
> > +
> > + if (unaligned_aio)
> > + mutex_unlock(ext4_aio_mutex(inode));
> > +
> > + return ret;
> > +}
> > +
> > static ssize_t
> > ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
> > unsigned long nr_segs, loff_t pos)
> > {
> > struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
> > - int unaligned_aio = 0;
> > int ret;
> >
> > /*
> > @@ -114,29 +153,12 @@ ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
> > nr_segs = iov_shorten((struct iovec *)iov, nr_segs,
> > sbi->s_bitmap_maxbytes - pos);
> > }
> > - } else if (unlikely((iocb->ki_filp->f_flags & O_DIRECT) &&
> > - !is_sync_kiocb(iocb))) {
> > - unaligned_aio = ext4_unaligned_aio(inode, iov, nr_segs, pos);
> > - }
> > -
> > - /* Unaligned direct AIO must be serialized; see comment above */
> > - if (unaligned_aio) {
> > - static unsigned long unaligned_warn_time;
> > -
> > - /* Warn about this once per day */
> > - if (printk_timed_ratelimit(&unaligned_warn_time, 60*60*24*HZ))
> > - ext4_msg(inode->i_sb, KERN_WARNING,
> > - "Unaligned AIO/DIO on inode %ld by %s; "
> > - "performance will be poor.",
> > - inode->i_ino, current->comm);
> > - mutex_lock(ext4_aio_mutex(inode));
> > - ext4_aiodio_wait(inode);
> > }
> >
> > - ret = generic_file_aio_write(iocb, iov, nr_segs, pos);
> > -
> > - if (unaligned_aio)
> > - mutex_unlock(ext4_aio_mutex(inode));
> > + if (unlikely(iocb->ki_filp->f_flags & O_DIRECT))
> > + ret = ext4_file_dio_write(iocb, iov, nr_segs, pos);
> > + else
> > + ret = generic_file_aio_write(iocb, iov, nr_segs, pos);
> >
> > return ret;
> > }
>
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