[PATCH v21 11/30] coda: Implement splice-read

David Howells
2023-05-20T00:01:36Z

Implement splice-read for coda by passing the request down a layer rather
than going through generic_file_splice_read() which is going to be changed
to assume that ->read_folio() is present on buffered files.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Jan Harkes <jaharkes@cs.cmu.edu>
cc: Christoph Hellwig <hch@lst.de>
cc: Jens Axboe <axboe@kernel.dk>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: John Hubbard <jhubbard@nvidia.com>
cc: David Hildenbrand <david@redhat.com>
cc: Matthew Wilcox <willy@infradead.org>
cc: coda@cs.cmu.edu
cc: codalist@coda.cs.cmu.edu
cc: linux-unionfs@vger.kernel.org
cc: linux-block@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
---

Notes:
ver #17)
- Use vfs_splice_read() helper rather than open-coding checks.

fs/coda/file.c | 29 ++++++++++++++++++++++++++++-
1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/fs/coda/file.c b/fs/coda/file.c
index 3f3c81e6b1ab..12b26bd13564 100644
--- a/fs/coda/file.c
+++ b/fs/coda/file.c
@@ -23,6 +23,7 @@
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/uio.h>
+#include <linux/splice.h>

#include <linux/coda.h>
#include "coda_psdev.h"
@@ -94,6 +95,32 @@ coda_file_write_iter(struct kiocb *iocb, struct iov_iter *to)
return ret;
}

+static ssize_t
+coda_file_splice_read(struct file *coda_file, loff_t *ppos,
+ struct pipe_inode_info *pipe,
+ size_t len, unsigned int flags)
+{
+ struct inode *coda_inode = file_inode(coda_file);
+ struct coda_file_info *cfi = coda_ftoc(coda_file);
+ struct file *in = cfi->cfi_container;
+ loff_t ki_pos = *ppos;
+ ssize_t ret;
+
+ ret = venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode),
+ &cfi->cfi_access_intent,
+ len, ki_pos, CODA_ACCESS_TYPE_READ);
+ if (ret)
+ goto finish_read;
+
+ ret = vfs_splice_read(in, ppos, pipe, len, flags);
+
+finish_read:
+ venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode),
+ &cfi->cfi_access_intent,
+ len, ki_pos, CODA_ACCESS_TYPE_READ_FINISH);
+ return ret;
+}
+
static void
coda_vm_open(struct vm_area_struct *vma)
{
@@ -302,5 +329,5 @@ const struct file_operations coda_file_operations = {
.open = coda_open,
.release = coda_release,
.fsync = coda_fsync,
- .splice_read = generic_file_splice_read,
+ .splice_read = coda_file_splice_read,
};