From 8e0ae2a449f996e0ea5ad865d3147ee6758743aa Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@suse.cz>
Date: Fri, 29 Mar 2013 18:05:01 +0100
Subject: [PATCH] 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.
Reported-by: Kazuya Mio <k-mio@sx.jp.nec.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/direct-io.c | 28 +++++++++++-----------------
1 files changed, 11 insertions(+), 17 deletions(-)
@@ -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;
}
--
1.7.1