From bbc5a740c4f27a9732a3a3decf3186b4bce21108 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 20 Jul 2016 11:35:42 +1000 Subject: [PATCH] xfs: split xfs_file_read_iter into buffered and direct I/O helpers Similar to what we did on the write side a while ago. Signed-off-by: Christoph Hellwig Reviewed-by: Dave Chinner Signed-off-by: Dave Chinner --- fs/xfs/xfs_file.c | 83 ++++++++++++++++++++++++++++++++--------------- 1 file changed, 57 insertions(+), 26 deletions(-) diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 7ec8225b7fd2..fdb123ffd616 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -282,35 +282,33 @@ xfs_file_fsync( } STATIC ssize_t -xfs_file_read_iter( +xfs_file_dio_aio_read( struct kiocb *iocb, struct iov_iter *to) { - struct file *file = iocb->ki_filp; - struct inode *inode = file->f_mapping->host; + struct address_space *mapping = iocb->ki_filp->f_mapping; + struct inode *inode = mapping->host; struct xfs_inode *ip = XFS_I(inode); - struct xfs_mount *mp = ip->i_mount; - size_t size = iov_iter_count(to); + size_t count = iov_iter_count(to); + struct xfs_buftarg *target; ssize_t ret = 0; - loff_t pos = iocb->ki_pos; - XFS_STATS_INC(mp, xs_read_calls); + trace_xfs_file_direct_read(ip, count, iocb->ki_pos); - if ((iocb->ki_flags & IOCB_DIRECT) && !IS_DAX(inode)) { - xfs_buftarg_t *target = - XFS_IS_REALTIME_INODE(ip) ? - mp->m_rtdev_targp : mp->m_ddev_targp; + if (XFS_IS_REALTIME_INODE(ip)) + target = ip->i_mount->m_rtdev_targp; + else + target = ip->i_mount->m_ddev_targp; + + if (!IS_DAX(inode)) { /* DIO must be aligned to device logical sector size */ - if ((pos | size) & target->bt_logical_sectormask) { - if (pos == i_size_read(inode)) + if ((iocb->ki_pos | count) & target->bt_logical_sectormask) { + if (iocb->ki_pos == i_size_read(inode)) return 0; return -EINVAL; } } - if (XFS_FORCED_SHUTDOWN(mp)) - return -EIO; - /* * Locking is a bit tricky here. If we take an exclusive lock for direct * IO, we effectively serialise all new concurrent read IO to this file @@ -322,7 +320,7 @@ xfs_file_read_iter( * serialisation. */ xfs_rw_ilock(ip, XFS_IOLOCK_SHARED); - if ((iocb->ki_flags & IOCB_DIRECT) && inode->i_mapping->nrpages) { + if (mapping->nrpages) { xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED); xfs_rw_ilock(ip, XFS_IOLOCK_EXCL); @@ -337,8 +335,8 @@ xfs_file_read_iter( * flush and reduce the chances of repeated iolock cycles going * forward. */ - if (inode->i_mapping->nrpages) { - ret = filemap_write_and_wait(VFS_I(ip)->i_mapping); + if (mapping->nrpages) { + ret = filemap_write_and_wait(mapping); if (ret) { xfs_rw_iunlock(ip, XFS_IOLOCK_EXCL); return ret; @@ -349,23 +347,56 @@ xfs_file_read_iter( * we fail to invalidate a page, but this should never * happen on XFS. Warn if it does fail. */ - ret = invalidate_inode_pages2(VFS_I(ip)->i_mapping); + ret = invalidate_inode_pages2(mapping); WARN_ON_ONCE(ret); ret = 0; } xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL); } + ret = generic_file_read_iter(iocb, to); + xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED); + + return ret; +} + +STATIC ssize_t +xfs_file_buffered_aio_read( + struct kiocb *iocb, + struct iov_iter *to) +{ + struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp)); + ssize_t ret; + + trace_xfs_file_buffered_read(ip, iov_iter_count(to), iocb->ki_pos); + + xfs_rw_ilock(ip, XFS_IOLOCK_SHARED); + ret = generic_file_read_iter(iocb, to); + xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED); + + return ret; +} + +STATIC ssize_t +xfs_file_read_iter( + struct kiocb *iocb, + struct iov_iter *to) +{ + struct xfs_mount *mp = XFS_I(file_inode(iocb->ki_filp))->i_mount; + ssize_t ret = 0; + + XFS_STATS_INC(mp, xs_read_calls); + + if (XFS_FORCED_SHUTDOWN(mp)) + return -EIO; + if (iocb->ki_flags & IOCB_DIRECT) - trace_xfs_file_direct_read(ip, size, pos); + ret = xfs_file_dio_aio_read(iocb, to); else - trace_xfs_file_buffered_read(ip, size, pos); + ret = xfs_file_buffered_aio_read(iocb, to); - ret = generic_file_read_iter(iocb, to); if (ret > 0) XFS_STATS_ADD(mp, xs_read_bytes, ret); - - xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED); return ret; } @@ -747,7 +778,7 @@ xfs_file_dio_aio_write( end = iocb->ki_pos + count - 1; /* - * See xfs_file_read_iter() for why we do a full-file flush here. + * See xfs_file_dio_aio_read() for why we do a full-file flush here. */ if (mapping->nrpages) { ret = filemap_write_and_wait(VFS_I(ip)->i_mapping); -- 2.20.1