diff options
| -rw-r--r-- | fs/splice.c | 74 |
1 files changed, 63 insertions, 11 deletions
diff --git a/fs/splice.c b/fs/splice.c index c47b561edac0..e30743c2c06a 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -240,7 +240,7 @@ __generic_file_splice_read(struct file *in, struct pipe_inode_info *pipe, struct page *pages[PIPE_BUFFERS]; struct page *page; pgoff_t index; - int i; + int i, error; index = in->f_pos >> PAGE_CACHE_SHIFT; offset = in->f_pos & ~PAGE_CACHE_MASK; @@ -260,32 +260,84 @@ __generic_file_splice_read(struct file *in, struct pipe_inode_info *pipe, /* * now fill in the holes */ + error = 0; for (i = 0; i < nr_pages; i++, index++) { +find_page: /* - * no page there, look one up / create it + * lookup the page for this index */ - page = find_or_create_page(mapping, index, - mapping_gfp_mask(mapping)); - if (!page) - break; + page = find_get_page(mapping, index); + if (!page) { + /* + * If in nonblock mode then dont block on + * readpage (we've kicked readahead so there + * will be asynchronous progress): + */ + if (flags & SPLICE_F_NONBLOCK) + break; + + /* + * page didn't exist, allocate one + */ + page = page_cache_alloc_cold(mapping); + if (!page) + break; + + error = add_to_page_cache_lru(page, mapping, index, + mapping_gfp_mask(mapping)); + if (unlikely(error)) { + page_cache_release(page); + break; + } - if (PageUptodate(page)) - unlock_page(page); - else { - int error = mapping->a_ops->readpage(in, page); + goto readpage; + } + + /* + * If the page isn't uptodate, we may need to start io on it + */ + if (!PageUptodate(page)) { + lock_page(page); + + /* + * page was truncated, stop here. if this isn't the + * first page, we'll just complete what we already + * added + */ + if (!page->mapping) { + unlock_page(page); + page_cache_release(page); + break; + } + /* + * page was already under io and is now done, great + */ + if (PageUptodate(page)) { + unlock_page(page); + goto fill_it; + } + +readpage: + /* + * need to read in the page + */ + error = mapping->a_ops->readpage(in, page); if (unlikely(error)) { page_cache_release(page); + if (error == AOP_TRUNCATED_PAGE) + goto find_page; break; } } +fill_it: pages[i] = page; } if (i) return move_to_pipe(pipe, pages, i, offset, len, flags); - return 0; + return error; } /** |