For pages from kernel AIO, it is required to dirty
them before direct IO.
The idea is borrowd from Dave previous post.
Cc: Zach Brown <zab@xxxxxxxxx>
Cc: Dave Kleikamp <dave.kleikamp@xxxxxxxxxx>
Cc: Benjamin LaHaise <bcrl@xxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: linux-fsdevel@xxxxxxxxxxxxxxx
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxxxxx>
---
fs/direct-io.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/fs/direct-io.c b/fs/direct-io.c
index c311640..f0460e0 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -121,6 +121,7 @@ struct dio {
int page_errors; /* errno from get_user_pages() */
int is_async; /* is IO async ? */
bool defer_completion; /* defer AIO completion to workqueue? */
+ bool should_dirty; /* if page should be dirty */
int io_error; /* IO error in completion path */
unsigned long refcount; /* direct_io_worker() and bios */
struct bio *bio_list; /* singly linked via bi_private */
@@ -392,7 +393,7 @@ static inline void dio_bio_submit(struct dio *dio, struct dio_submit *sdio)
dio->refcount++;
spin_unlock_irqrestore(&dio->bio_lock, flags);
- if (dio->is_async && dio->rw == READ)
+ if (dio->is_async && dio->rw == READ && dio->should_dirty)
bio_set_pages_dirty(bio);
if (sdio->submit_io)
@@ -463,13 +464,14 @@ static int dio_bio_complete(struct dio *dio, struct bio *bio)
if (!uptodate)
dio->io_error = -EIO;
- if (dio->is_async && dio->rw == READ) {
+ if (dio->is_async && dio->rw == READ && dio->should_dirty) {
bio_check_pages_dirty(bio); /* transfers ownership */
} else {
bio_for_each_segment_all(bvec, bio, i) {
struct page *page = bvec->bv_page;
- if (dio->rw == READ && !PageCompound(page))
+ if (dio->rw == READ && !PageCompound(page) &&
+ dio->should_dirty)
set_page_dirty_lock(page);
page_cache_release(page);
}
@@ -1217,6 +1219,7 @@ do_blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
spin_lock_init(&dio->bio_lock);
dio->refcount = 1;
+ dio->should_dirty = !is_kernel_kiocb(iocb);
sdio.iter = iter;
sdio.final_block_in_request =
--
1.7.9.5
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