diff options
| author | Christoph Hellwig <hch@lst.de> | 2016-07-20 11:36:57 +1000 |
|---|---|---|
| committer | Dave Chinner <david@fromorbit.com> | 2016-07-20 11:36:57 +1000 |
| commit | f1285ff0acf9040a39921355d07bd83a3308c402 (patch) | |
| tree | ea0906759f357f47b8c1049615f1f44a7f817d5e /fs/xfs/xfs_file.c | |
| parent | bbc5a740c4f27a9732a3a3decf3186b4bce21108 (diff) | |
xfs: stop using generic_file_read_iter for direct I/O
XFS already implement it's own flushing of the pagecache because it
implements proper synchronization for direct I/O reads. This means
calling generic_file_read_iter for direct I/O is rather useless,
as it doesn't do much but updating the atime and iocb position for
us. This also gets rid of the buffered I/O fallback that isn't used
for XFS.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Diffstat (limited to 'fs/xfs/xfs_file.c')
| -rw-r--r-- | fs/xfs/xfs_file.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index fdb123ffd616..440bb8b5c64d 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -289,12 +289,17 @@ xfs_file_dio_aio_read( struct address_space *mapping = iocb->ki_filp->f_mapping; struct inode *inode = mapping->host; struct xfs_inode *ip = XFS_I(inode); + loff_t isize = i_size_read(inode); size_t count = iov_iter_count(to); + struct iov_iter data; struct xfs_buftarg *target; ssize_t ret = 0; trace_xfs_file_direct_read(ip, count, iocb->ki_pos); + if (!count) + return 0; /* skip atime */ + if (XFS_IS_REALTIME_INODE(ip)) target = ip->i_mount->m_rtdev_targp; else @@ -303,7 +308,7 @@ xfs_file_dio_aio_read( if (!IS_DAX(inode)) { /* DIO must be aligned to device logical sector size */ if ((iocb->ki_pos | count) & target->bt_logical_sectormask) { - if (iocb->ki_pos == i_size_read(inode)) + if (iocb->ki_pos == isize) return 0; return -EINVAL; } @@ -354,9 +359,15 @@ xfs_file_dio_aio_read( xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL); } - ret = generic_file_read_iter(iocb, to); + data = *to; + ret = mapping->a_ops->direct_IO(iocb, &data); + if (ret > 0) { + iocb->ki_pos += ret; + iov_iter_advance(to, ret); + } xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED); + file_accessed(iocb->ki_filp); return ret; } |