io_uring: ensure that SQPOLL thread is started for exit
[linux-2.6-microblaze.git] / fs / nfs / read.c
index eb854f1..d2b6dce 100644 (file)
@@ -74,6 +74,24 @@ void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
 }
 EXPORT_SYMBOL_GPL(nfs_pageio_init_read);
 
+static void nfs_pageio_complete_read(struct nfs_pageio_descriptor *pgio,
+                                    struct inode *inode)
+{
+       struct nfs_pgio_mirror *pgm;
+       unsigned long npages;
+
+       nfs_pageio_complete(pgio);
+
+       /* It doesn't make sense to do mirrored reads! */
+       WARN_ON_ONCE(pgio->pg_mirror_count != 1);
+
+       pgm = &pgio->pg_mirrors[0];
+       NFS_I(inode)->read_io += pgm->pg_bytes_written;
+       npages = (pgm->pg_bytes_written + PAGE_SIZE - 1) >> PAGE_SHIFT;
+       nfs_add_stats(inode, NFSIOS_READPAGES, npages);
+}
+
+
 void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio)
 {
        struct nfs_pgio_mirror *mirror;
@@ -114,41 +132,10 @@ static void nfs_readpage_release(struct nfs_page *req, int error)
        nfs_release_request(req);
 }
 
-int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode,
-                      struct page *page)
-{
-       struct nfs_page *new;
-       unsigned int len;
+struct nfs_readdesc {
        struct nfs_pageio_descriptor pgio;
-       struct nfs_pgio_mirror *pgm;
-
-       len = nfs_page_length(page);
-       if (len == 0)
-               return nfs_return_empty_page(page);
-       new = nfs_create_request(ctx, page, 0, len);
-       if (IS_ERR(new)) {
-               unlock_page(page);
-               return PTR_ERR(new);
-       }
-       if (len < PAGE_SIZE)
-               zero_user_segment(page, len, PAGE_SIZE);
-
-       nfs_pageio_init_read(&pgio, inode, false,
-                            &nfs_async_read_completion_ops);
-       if (!nfs_pageio_add_request(&pgio, new)) {
-               nfs_list_remove_request(new);
-               nfs_readpage_release(new, pgio.pg_error);
-       }
-       nfs_pageio_complete(&pgio);
-
-       /* It doesn't make sense to do mirrored reads! */
-       WARN_ON_ONCE(pgio.pg_mirror_count != 1);
-
-       pgm = &pgio.pg_mirrors[0];
-       NFS_I(inode)->read_io += pgm->pg_bytes_written;
-
-       return pgio.pg_error < 0 ? pgio.pg_error : 0;
-}
+       struct nfs_open_context *ctx;
+};
 
 static void nfs_page_group_set_uptodate(struct nfs_page *req)
 {
@@ -171,8 +158,7 @@ static void nfs_read_completion(struct nfs_pgio_header *hdr)
 
                if (test_bit(NFS_IOHDR_EOF, &hdr->flags)) {
                        /* note: regions of the page not covered by a
-                        * request are zeroed in nfs_readpage_async /
-                        * readpage_async_filler */
+                        * request are zeroed in readpage_async_filler */
                        if (bytes > hdr->good_bytes) {
                                /* nothing in this request was good, so zero
                                 * the full extent of the request */
@@ -304,6 +290,38 @@ static void nfs_readpage_result(struct rpc_task *task,
                nfs_readpage_retry(task, hdr);
 }
 
+static int
+readpage_async_filler(void *data, struct page *page)
+{
+       struct nfs_readdesc *desc = data;
+       struct nfs_page *new;
+       unsigned int len;
+       int error;
+
+       len = nfs_page_length(page);
+       if (len == 0)
+               return nfs_return_empty_page(page);
+
+       new = nfs_create_request(desc->ctx, page, 0, len);
+       if (IS_ERR(new))
+               goto out_error;
+
+       if (len < PAGE_SIZE)
+               zero_user_segment(page, len, PAGE_SIZE);
+       if (!nfs_pageio_add_request(&desc->pgio, new)) {
+               nfs_list_remove_request(new);
+               error = desc->pgio.pg_error;
+               nfs_readpage_release(new, error);
+               goto out;
+       }
+       return 0;
+out_error:
+       error = PTR_ERR(new);
+       unlock_page(page);
+out:
+       return error;
+}
+
 /*
  * Read a page over NFS.
  * We read the page synchronously in the following case:
@@ -312,14 +330,13 @@ static void nfs_readpage_result(struct rpc_task *task,
  */
 int nfs_readpage(struct file *file, struct page *page)
 {
-       struct nfs_open_context *ctx;
+       struct nfs_readdesc desc;
        struct inode *inode = page_file_mapping(page)->host;
-       int             error;
+       int ret;
 
        dprintk("NFS: nfs_readpage (%p %ld@%lu)\n",
                page, PAGE_SIZE, page_index(page));
        nfs_inc_stats(inode, NFSIOS_VFSREADPAGE);
-       nfs_add_stats(inode, NFSIOS_READPAGES, 1);
 
        /*
         * Try to flush any pending writes to the file..
@@ -328,93 +345,59 @@ int nfs_readpage(struct file *file, struct page *page)
         * be any new pending writes generated at this point
         * for this page (other pages can be written to).
         */
-       error = nfs_wb_page(inode, page);
-       if (error)
+       ret = nfs_wb_page(inode, page);
+       if (ret)
                goto out_unlock;
        if (PageUptodate(page))
                goto out_unlock;
 
-       error = -ESTALE;
+       ret = -ESTALE;
        if (NFS_STALE(inode))
                goto out_unlock;
 
        if (file == NULL) {
-               error = -EBADF;
-               ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
-               if (ctx == NULL)
+               ret = -EBADF;
+               desc.ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
+               if (desc.ctx == NULL)
                        goto out_unlock;
        } else
-               ctx = get_nfs_open_context(nfs_file_open_context(file));
+               desc.ctx = get_nfs_open_context(nfs_file_open_context(file));
 
        if (!IS_SYNC(inode)) {
-               error = nfs_readpage_from_fscache(ctx, inode, page);
-               if (error == 0)
+               ret = nfs_readpage_from_fscache(desc.ctx, inode, page);
+               if (ret == 0)
                        goto out;
        }
 
-       xchg(&ctx->error, 0);
-       error = nfs_readpage_async(ctx, inode, page);
-       if (!error) {
-               error = wait_on_page_locked_killable(page);
-               if (!PageUptodate(page) && !error)
-                       error = xchg(&ctx->error, 0);
-       }
-out:
-       put_nfs_open_context(ctx);
-       return error;
-out_unlock:
-       unlock_page(page);
-       return error;
-}
-
-struct nfs_readdesc {
-       struct nfs_pageio_descriptor *pgio;
-       struct nfs_open_context *ctx;
-};
-
-static int
-readpage_async_filler(void *data, struct page *page)
-{
-       struct nfs_readdesc *desc = (struct nfs_readdesc *)data;
-       struct nfs_page *new;
-       unsigned int len;
-       int error;
+       xchg(&desc.ctx->error, 0);
+       nfs_pageio_init_read(&desc.pgio, inode, false,
+                            &nfs_async_read_completion_ops);
 
-       len = nfs_page_length(page);
-       if (len == 0)
-               return nfs_return_empty_page(page);
+       ret = readpage_async_filler(&desc, page);
 
-       new = nfs_create_request(desc->ctx, page, 0, len);
-       if (IS_ERR(new))
-               goto out_error;
+       if (!ret)
+               nfs_pageio_complete_read(&desc.pgio, inode);
 
-       if (len < PAGE_SIZE)
-               zero_user_segment(page, len, PAGE_SIZE);
-       if (!nfs_pageio_add_request(desc->pgio, new)) {
-               nfs_list_remove_request(new);
-               error = desc->pgio->pg_error;
-               nfs_readpage_release(new, error);
-               goto out;
+       ret = desc.pgio.pg_error < 0 ? desc.pgio.pg_error : 0;
+       if (!ret) {
+               ret = wait_on_page_locked_killable(page);
+               if (!PageUptodate(page) && !ret)
+                       ret = xchg(&desc.ctx->error, 0);
        }
-       return 0;
-out_error:
-       error = PTR_ERR(new);
-       unlock_page(page);
 out:
-       return error;
+       put_nfs_open_context(desc.ctx);
+       return ret;
+out_unlock:
+       unlock_page(page);
+       return ret;
 }
 
-int nfs_readpages(struct file *filp, struct address_space *mapping,
+int nfs_readpages(struct file *file, struct address_space *mapping,
                struct list_head *pages, unsigned nr_pages)
 {
-       struct nfs_pageio_descriptor pgio;
-       struct nfs_pgio_mirror *pgm;
-       struct nfs_readdesc desc = {
-               .pgio = &pgio,
-       };
+       struct nfs_readdesc desc;
        struct inode *inode = mapping->host;
-       unsigned long npages;
-       int ret = -ESTALE;
+       int ret;
 
        dprintk("NFS: nfs_readpages (%s/%Lu %d)\n",
                        inode->i_sb->s_id,
@@ -422,15 +405,17 @@ int nfs_readpages(struct file *filp, struct address_space *mapping,
                        nr_pages);
        nfs_inc_stats(inode, NFSIOS_VFSREADPAGES);
 
+       ret = -ESTALE;
        if (NFS_STALE(inode))
                goto out;
 
-       if (filp == NULL) {
+       if (file == NULL) {
+               ret = -EBADF;
                desc.ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
                if (desc.ctx == NULL)
-                       return -EBADF;
+                       goto out;
        } else
-               desc.ctx = get_nfs_open_context(nfs_file_open_context(filp));
+               desc.ctx = get_nfs_open_context(nfs_file_open_context(file));
 
        /* attempt to read as many of the pages as possible from the cache
         * - this returns -ENOBUFS immediately if the cookie is negative
@@ -440,20 +425,13 @@ int nfs_readpages(struct file *filp, struct address_space *mapping,
        if (ret == 0)
                goto read_complete; /* all pages were read */
 
-       nfs_pageio_init_read(&pgio, inode, false,
+       nfs_pageio_init_read(&desc.pgio, inode, false,
                             &nfs_async_read_completion_ops);
 
        ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc);
-       nfs_pageio_complete(&pgio);
 
-       /* It doesn't make sense to do mirrored reads! */
-       WARN_ON_ONCE(pgio.pg_mirror_count != 1);
+       nfs_pageio_complete_read(&desc.pgio, inode);
 
-       pgm = &pgio.pg_mirrors[0];
-       NFS_I(inode)->read_io += pgm->pg_bytes_written;
-       npages = (pgm->pg_bytes_written + PAGE_SIZE - 1) >>
-                PAGE_SHIFT;
-       nfs_add_stats(inode, NFSIOS_READPAGES, npages);
 read_complete:
        put_nfs_open_context(desc.ctx);
 out: