[PATCH v21 15/30] afs: Provide a splice-read stub

David Howells
2023-05-20T00:01:49Z

Provide a splice_read stub for AFS to call afs_validate() before going into
generic_file_splice_read() so that we're likely to have a callback promise
from the server.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Christoph Hellwig <hch@lst.de>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: Jens Axboe <axboe@kernel.dk>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: linux-fsdevel@vger.kernel.org
cc: linux-block@vger.kernel.org
cc: linux-mm@kvack.org
---
fs/afs/file.c | 20 +++++++++++++++++++-
1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/fs/afs/file.c b/fs/afs/file.c
index 719b31374879..d8a6b09dadf7 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -25,6 +25,9 @@ static void afs_invalidate_folio(struct folio *folio, size_t offset,
static bool afs_release_folio(struct folio *folio, gfp_t gfp_flags);

static ssize_t afs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter);
+static ssize_t afs_file_splice_read(struct file *in, loff_t *ppos,
+ struct pipe_inode_info *pipe,
+ size_t len, unsigned int flags);
static void afs_vm_open(struct vm_area_struct *area);
static void afs_vm_close(struct vm_area_struct *area);
static vm_fault_t afs_vm_map_pages(struct vm_fault *vmf, pgoff_t start_pgoff, pgoff_t end_pgoff);
@@ -36,7 +39,7 @@ const struct file_operations afs_file_operations = {
.read_iter = afs_file_read_iter,
.write_iter = afs_file_write,
.mmap = afs_file_mmap,
- .splice_read = generic_file_splice_read,
+ .splice_read = afs_file_splice_read,
.splice_write = iter_file_splice_write,
.fsync = afs_fsync,
.lock = afs_lock,
@@ -587,3 +590,18 @@ static ssize_t afs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)

return generic_file_read_iter(iocb, iter);
}
+
+static ssize_t afs_file_splice_read(struct file *in, loff_t *ppos,
+ struct pipe_inode_info *pipe,
+ size_t len, unsigned int flags)
+{
+ struct afs_vnode *vnode = AFS_FS_I(file_inode(in));
+ struct afs_file *af = in->private_data;
+ int ret;
+
+ ret = afs_validate(vnode, af->key);
+ if (ret < 0)
+ return ret;
+
+ return generic_file_splice_read(in, ppos, pipe, len, flags);
+}