direct-io: submit bio after boundary buffer is added to it

Currently, dio_send_cur_page() submits bio before current page and cached sdio->cur_page is added to the bio if sdio->boundary is set. This is actually wrong because sdio->boundary means the current buffer is the last one before metadata needs to be read. So we should rather submit the bio after the current page is added to it. Signed-off-by: Jan Kara <[email protected]> Reported-by: Kazuya Mio <[email protected]> Tested-by: Kazuya Mio <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
sjhung · Apr 29, 2013 · b1058b9 · b1058b9
1 parent 092c8d4
commit b1058b9
Showing 1 changed file with 11 additions and 17 deletions.
diff --git a/fs/direct-io.c b/fs/direct-io.c
@@ -672,12 +672,6 @@ static inline int dio_send_cur_page(struct dio *dio, struct dio_submit *sdio,
 		if (sdio->final_block_in_bio != sdio->cur_page_block ||
 		    cur_offset != bio_next_offset)
 			dio_bio_submit(dio, sdio);
-		/*
-		 * Submit now if the underlying fs is about to perform a
-		 * metadata read
-		 */
-		else if (sdio->boundary)
-			dio_bio_submit(dio, sdio);
 	}
 
 	if (sdio->bio == NULL) {
@@ -737,16 +731,6 @@ submit_page_section(struct dio *dio, struct dio_submit *sdio, struct page *page,
 	    sdio->cur_page_block +
 	    (sdio->cur_page_len >> sdio->blkbits) == blocknr) {
 		sdio->cur_page_len += len;
-
-		/*
-		 * If sdio->boundary then we want to schedule the IO now to
-		 * avoid metadata seeks.
-		 */
-		if (sdio->boundary) {
-			ret = dio_send_cur_page(dio, sdio, map_bh);
-			page_cache_release(sdio->cur_page);
-			sdio->cur_page = NULL;
-		}
 		goto out;
 	}
 
@@ -758,7 +742,7 @@ submit_page_section(struct dio *dio, struct dio_submit *sdio, struct page *page,
 		page_cache_release(sdio->cur_page);
 		sdio->cur_page = NULL;
 		if (ret)
-			goto out;
+			return ret;
 	}
 
 	page_cache_get(page);		/* It is in dio */
@@ -768,6 +752,16 @@ submit_page_section(struct dio *dio, struct dio_submit *sdio, struct page *page,
 	sdio->cur_page_block = blocknr;
 	sdio->cur_page_fs_offset = sdio->block_in_file << sdio->blkbits;
 out:
+	/*
+	 * If sdio->boundary then we want to schedule the IO now to
+	 * avoid metadata seeks.
+	 */
+	if (sdio->boundary) {
+		ret = dio_send_cur_page(dio, sdio, map_bh);
+		dio_bio_submit(dio, sdio);
+		page_cache_release(sdio->cur_page);
+		sdio->cur_page = NULL;
+	}
 	return ret;
 }