Commit a308996e authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Anna Schumaker
Browse files

nfs: split nfs_read_folio 



nfs_read_folio is a bit hard to follow because it mixes highlevel logic
with the actual data read.  Split the latter into a helper and update
the comments to be more accurate.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
parent fada32ed

fs/nfs/read.c

+41 −28
Original line number Diff line number Diff line
@@ -325,18 +325,52 @@ int nfs_read_add_folio(struct nfs_pageio_descriptor *pgio, 
}



/*

 * Read a page over NFS.

 * We read the page synchronously in the following case:

 *  -	The error flag is set for this page. This happens only when a

 *	previous async read operation failed.

 * Actually read a folio over the wire.

 */

static int nfs_do_read_folio(struct file *file, struct folio *folio)

{

	struct inode *inode = file_inode(file);

	struct nfs_pageio_descriptor pgio;

	struct nfs_open_context *ctx;

	int ret;



	ctx = get_nfs_open_context(nfs_file_open_context(file));



	xchg(&ctx->error, 0);

	nfs_pageio_init_read(&pgio, inode, false,

			     &nfs_async_read_completion_ops);



	ret = nfs_read_add_folio(&pgio, ctx, folio);

	if (ret)

		goto out_put;



	nfs_pageio_complete_read(&pgio);

	nfs_update_delegated_atime(inode);

	if (pgio.pg_error < 0) {

		ret = pgio.pg_error;

		goto out_put;

	}



	ret = folio_wait_locked_killable(folio);

	if (!folio_test_uptodate(folio) && !ret)

		ret = xchg(&ctx->error, 0);



out_put:

	put_nfs_open_context(ctx);

	return ret;

}



/*

 * Synchronously read a folio.

 *

 * This is not heavily used as most users to try an asynchronous

 * large read through ->readahead first.

 */

int nfs_read_folio(struct file *file, struct folio *folio)

{

	struct inode *inode = file_inode(file);

	loff_t pos = folio_pos(folio);

	size_t len = folio_size(folio);

	struct nfs_pageio_descriptor pgio;

	struct nfs_open_context *ctx;

	int ret;



	trace_nfs_aop_readpage(inode, pos, len);
@@ -361,29 +395,8 @@ int nfs_read_folio(struct file *file, struct folio *folio) 
		goto out_unlock;



	ret = nfs_netfs_read_folio(file, folio);

	if (!ret)

		goto out;



	ctx = get_nfs_open_context(nfs_file_open_context(file));



	xchg(&ctx->error, 0);

	nfs_pageio_init_read(&pgio, inode, false,

			     &nfs_async_read_completion_ops);



	ret = nfs_read_add_folio(&pgio, ctx, folio);

	if (ret)

		goto out_put;



	nfs_pageio_complete_read(&pgio);

	nfs_update_delegated_atime(inode);

	ret = pgio.pg_error < 0 ? pgio.pg_error : 0;

	if (!ret) {

		ret = folio_wait_locked_killable(folio);

		if (!folio_test_uptodate(folio) && !ret)

			ret = xchg(&ctx->error, 0);

	}

out_put:

	put_nfs_open_context(ctx);

		ret = nfs_do_read_folio(file, folio);

out:

	trace_nfs_aop_readpage_done(inode, pos, len, ret);

	return ret;