fs: move guard_bio_eod() after bio_set_op_attrs

Commit Message

Ming Lei Jan. 5, 2020, 1:41 a.m. UTC

Commit 85a8ce62c2ea ("block: add bio_truncate to fix guard_bio_eod")
adds bio_truncate() for handling bio EOD. However, bio_truncate()
doesn't use the passed 'op' parameter from guard_bio_eod's callers.

So bio_trunacate() may retrieve wrong 'op', and zering pages may
not be done for READ bio.

Fixes this issue by moving guard_bio_eod() after bio_set_op_attrs()
in submit_bh_wbc() so that bio_truncate() can always retrieve correct
op info.

Meantime remove the 'op' parameter from guard_bio_eod() because it isn't
used any more.

Cc: Carlos Maiolino <[e-mail]>
Cc: [e-mail]
Fixes: 85a8ce62c2ea ("block: add bio_truncate to fix guard_bio_eod")
Signed-off-by: Ming Lei <[e-mail]>
---
 fs/buffer.c   | 8 ++++----
 fs/internal.h | 2 +-
 fs/mpage.c    | 2 +-
 3 files changed, 6 insertions(+), 6 deletions(-)

Comments

Jens Axboe Jan. 6, 2020, 12:45 a.m. UTC | #1

On 1/4/20 6:41 PM, Ming Lei wrote:
> Commit 85a8ce62c2ea ("block: add bio_truncate to fix guard_bio_eod")
> adds bio_truncate() for handling bio EOD. However, bio_truncate()
> doesn't use the passed 'op' parameter from guard_bio_eod's callers.
> 
> So bio_trunacate() may retrieve wrong 'op', and zering pages may
> not be done for READ bio.
> 
> Fixes this issue by moving guard_bio_eod() after bio_set_op_attrs()
> in submit_bh_wbc() so that bio_truncate() can always retrieve correct
> op info.
> 
> Meantime remove the 'op' parameter from guard_bio_eod() because it isn't
> used any more.

I'll queue this up, since the previous fix went through the block tree.

Patch

diff --git a/fs/buffer.c b/fs/buffer.c
index e94a6619464c..18a87ec8a465 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -3031,7 +3031,7 @@  static void end_bio_bh_io_sync(struct bio *bio)
  * errors, this only handles the "we need to be able to
  * do IO at the final sector" case.
  */
-void guard_bio_eod(int op, struct bio *bio)
+void guard_bio_eod(struct bio *bio)
 {
 	sector_t maxsector;
 	struct hd_struct *part;
@@ -3095,15 +3095,15 @@  static int submit_bh_wbc(int op, int op_flags, struct buffer_head *bh,
 	bio->bi_end_io = end_bio_bh_io_sync;
 	bio->bi_private = bh;
 
-	/* Take care of bh's that straddle the end of the device */
-	guard_bio_eod(op, bio);
-
 	if (buffer_meta(bh))
 		op_flags |= REQ_META;
 	if (buffer_prio(bh))
 		op_flags |= REQ_PRIO;
 	bio_set_op_attrs(bio, op, op_flags);
 
+	/* Take care of bh's that straddle the end of the device */
+	guard_bio_eod(bio);
+
 	if (wbc) {
 		wbc_init_bio(wbc, bio);
 		wbc_account_cgroup_owner(wbc, bh->b_page, bh->b_size);
diff --git a/fs/internal.h b/fs/internal.h
index 4a7da1df573d..e3fa69544b66 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -38,7 +38,7 @@  static inline int __sync_blockdev(struct block_device *bdev, int wait)
 /*
  * buffer.c
  */
-extern void guard_bio_eod(int rw, struct bio *bio);
+extern void guard_bio_eod(struct bio *bio);
 extern int __block_write_begin_int(struct page *page, loff_t pos, unsigned len,
 		get_block_t *get_block, struct iomap *iomap);
 
diff --git a/fs/mpage.c b/fs/mpage.c
index a63620cdb73a..ccba3c4c4479 100644
--- a/fs/mpage.c
+++ b/fs/mpage.c
@@ -62,7 +62,7 @@  static struct bio *mpage_bio_submit(int op, int op_flags, struct bio *bio)
 {
 	bio->bi_end_io = mpage_end_io;
 	bio_set_op_attrs(bio, op, op_flags);
-	guard_bio_eod(op, bio);
+	guard_bio_eod(bio);
 	submit_bio(bio);
 	return NULL;
 }