The nfs_direct_IO() exists to support SWAP IO, but hasn't worked for a
while. We now need a ->swap_rw function which behaves slightly
differently, returning zero for success rather than a byte count.
So modify nfs_direct_IO accordingly, rename it, and use it as the
->swap_rw function.
Note: it still won't work - that will be fixed in later patches.
Signed-off-by: NeilBrown <[email protected]>
---
fs/nfs/direct.c | 23 ++++++++++-------------
fs/nfs/file.c | 5 +----
include/linux/nfs_fs.h | 2 +-
3 files changed, 12 insertions(+), 18 deletions(-)
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index eabfdab543c8..b929dd5b0c3a 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -153,28 +153,25 @@ nfs_direct_count_bytes(struct nfs_direct_req *dreq,
}
/**
- * nfs_direct_IO - NFS address space operation for direct I/O
+ * nfs_swap_rw - NFS address space operation for swap I/O
* @iocb: target I/O control block
* @iter: I/O buffer
*
- * The presence of this routine in the address space ops vector means
- * the NFS client supports direct I/O. However, for most direct IO, we
- * shunt off direct read and write requests before the VFS gets them,
- * so this method is only ever called for swap.
+ * Perform IO to the swap-file. This is much like direct IO.
*/
-ssize_t nfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
+int nfs_swap_rw(struct kiocb *iocb, struct iov_iter *iter)
{
- struct inode *inode = iocb->ki_filp->f_mapping->host;
-
- /* we only support swap file calling nfs_direct_IO */
- if (!IS_SWAPFILE(inode))
- return 0;
+ ssize_t ret;
VM_BUG_ON(iov_iter_count(iter) != PAGE_SIZE);
if (iov_iter_rw(iter) == READ)
- return nfs_file_direct_read(iocb, iter);
- return nfs_file_direct_write(iocb, iter);
+ ret = nfs_file_direct_read(iocb, iter);
+ else
+ ret = nfs_file_direct_write(iocb, iter);
+ if (ret < 0)
+ return ret;
+ return 0;
}
static void nfs_direct_release_pages(struct page **pages, unsigned int npages)
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 4d4750738aeb..91ff9ed05b06 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -489,10 +489,6 @@ static int nfs_swap_activate(struct swap_info_struct *sis, struct file *file,
struct rpc_clnt *clnt = NFS_CLIENT(file->f_mapping->host);
struct inode *inode = file->f_mapping->host;
- if (!file->f_mapping->a_ops->swap_rw)
- /* Cannot support swap */
- return -EINVAL;
-
spin_lock(&inode->i_lock);
blocks = inode->i_blocks;
isize = inode->i_size;
@@ -540,6 +536,7 @@ const struct address_space_operations nfs_file_aops = {
.error_remove_page = generic_error_remove_page,
.swap_activate = nfs_swap_activate,
.swap_deactivate = nfs_swap_deactivate,
+ .swap_rw = nfs_swap_rw,
};
/*
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 00835bacd236..29a5e579f26f 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -509,7 +509,7 @@ static inline const struct cred *nfs_file_cred(struct file *file)
/*
* linux/fs/nfs/direct.c
*/
-extern ssize_t nfs_direct_IO(struct kiocb *, struct iov_iter *);
+extern int nfs_swap_rw(struct kiocb *, struct iov_iter *);
extern ssize_t nfs_file_direct_read(struct kiocb *iocb,
struct iov_iter *iter);
extern ssize_t nfs_file_direct_write(struct kiocb *iocb,
> +extern int nfs_swap_rw(struct kiocb *, struct iov_iter *);
Might be worth to drop the pointless extern while you're at it.
Otherwise looks good:
Reviewed-by: Christoph Hellwig <[email protected]>