/*
* Find an associated nfs write request, and prepare to flush it out
* May return an error if the user signalled nfs_wait_on_request().
*/
static int nfs_page_async_flush(struct nfs_pageio_descriptor *pgio,
struct page *page)
{
struct inode *inode = page->mapping->host;
struct nfs_page *req;
int ret;
spin_lock(&inode->i_lock);
for(;;) {
req = nfs_page_find_request_locked(page);
if (req == NULL) {
spin_unlock(&inode->i_lock);
return 0;
}
if (nfs_set_page_tag_locked(req))
break;
/* Note: If we hold the page lock, as is the case in nfs_writepage,
* then the call to nfs_set_page_tag_locked() will always
* succeed provided that someone hasn't already marked the
* request as dirty (in which case we don't care).
*/
spin_unlock(&inode->i_lock);
ret = nfs_wait_on_request(req);
nfs_release_request(req);
if (ret != 0)
return ret;
spin_lock(&inode->i_lock);
}
if (test_bit(PG_CLEAN, &req->wb_flags)) {
spin_unlock(&inode->i_lock);
BUG();
}
if (nfs_set_page_writeback(page) != 0) {
spin_unlock(&inode->i_lock);
BUG();
}
spin_unlock(&inode->i_lock);
if (!nfs_pageio_add_request(pgio, req)) {
nfs_redirty_request(req);
return pgio->pg_error;
}
return 0;
}
/*
* nfs_pageio_resend - Transfer requests to new descriptor and resend
* @hdr - the pgio header to move request from
* @desc - the pageio descriptor to add requests to
*
* Try to move each request (nfs_page) from @hdr to @desc then attempt
* to send them.
*
* Returns 0 on success and < 0 on error.
*/
int nfs_pageio_resend(struct nfs_pageio_descriptor *desc,
struct nfs_pgio_header *hdr)
{
LIST_HEAD(failed);
desc->pg_dreq = hdr->dreq;
while (!list_empty(&hdr->pages)) {
struct nfs_page *req = nfs_list_entry(hdr->pages.next);
nfs_list_remove_request(req);
if (!nfs_pageio_add_request(desc, req))
nfs_list_add_request(req, &failed);
}
nfs_pageio_complete(desc);
if (!list_empty(&failed)) {
list_move(&failed, &hdr->pages);
return -EIO;
}
return 0;
}
/*
* Find an associated nfs write request, and prepare to flush it out
* May return an error if the user signalled nfs_wait_on_request().
*/
static int nfs_page_async_flush(struct nfs_pageio_descriptor *pgio,
struct page *page)
{
struct nfs_page *req;
int ret = 0;
req = nfs_find_and_lock_request(page);
if (!req)
goto out;
ret = PTR_ERR(req);
if (IS_ERR(req))
goto out;
ret = nfs_set_page_writeback(page);
BUG_ON(ret != 0);
BUG_ON(test_bit(PG_CLEAN, &req->wb_flags));
if (!nfs_pageio_add_request(pgio, req)) {
nfs_redirty_request(req);
ret = pgio->pg_error;
}
out:
return ret;
}
