xfs: use iomap for blocksize == PAGE_SIZE readpage and readpages

For file systems with a block size that equals the page size we never do
partial reads, so we can use the buffer_head-less iomap versions of
readpage and readpages without conflicting with the buffer_head structures
create later in write_begin.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 8eb3ba3..85e1a62 100644 (file)
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -1401,6 +1401,8 @@ xfs_vm_readpage(
        struct page             *page)
 {
        trace_xfs_vm_readpage(page->mapping->host, 1);
+       if (i_blocksize(page->mapping->host) == PAGE_SIZE)
+               return iomap_readpage(page, &xfs_iomap_ops);
        return mpage_readpage(page, xfs_get_blocks);
 }
 
@@ -1412,6 +1414,8 @@ xfs_vm_readpages(
        unsigned                nr_pages)
 {
        trace_xfs_vm_readpages(mapping->host, nr_pages);
+       if (i_blocksize(mapping->host) == PAGE_SIZE)
+               return iomap_readpages(mapping, pages, nr_pages, &xfs_iomap_ops);
        return mpage_readpages(mapping, pages, nr_pages, xfs_get_blocks);
 }