Linux 4.3 compat: bio_end_io_t / BIO_UPTODATE

Commit torvalds/linux@4246a0b ("block: add a bi_error field to struct bio") dropped the error argument from bio_end_io in favor of newly introduced bio->bi_error. This also replaces bio->bi_flags value BIO_UPTODATE. bio_end_io was a 3 argument function until Linux 2.6.24, which made it a 2 argument function, and now the prototype has changed yet again to a 1 argument function. Fix build breakage caused by 37f9dac on pre 2.6.24 kernels because zvol.c:zvol_request() assumed that bio_endio() was always a 2 argument function. Signed-off-by: Lukas Wunner <[email protected]> Fixes openzfs#3799
l1k · Sep 24, 2015 · 68b5c9b · 68b5c9b
1 parent 4a4809f
commit 68b5c9b
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Showing 4 changed files with 58 additions and 17 deletions.
diff --git a/config/kernel-bio-end-io-t-args.m4 b/config/kernel-bio-end-io-t-args.m4
@@ -6,21 +6,47 @@ dnl # There is no longer any need for a size argument.  This also means
 dnl # that partial IO's are no longer possibe and the end_io callback
 dnl # should not check bi->bi_size.  Finally, the return type was updated
 dnl # to void.
+dnl # Introduced by torvalds/linux@6712ecf8f648118c3363c142196418f89a510b90
+dnl # ("Drop 'size' argument from bio_endio and bi_end_io")
+dnl #
+dnl # 4.3 API change
+dnl # Error argument dropped from bio_end_io in favor of newly introduced
+dnl # bio->bi_error. This also replaces bio->bi_flags value BIO_UPTODATE.
+dnl # Introduced by torvalds/linux@4246a0b63bd8f56a1469b12eafeb875b1041a451
+dnl # ("block: add a bi_error field to struct bio").
 dnl #
 AC_DEFUN([ZFS_AC_KERNEL_BIO_END_IO_T_ARGS], [
-	AC_MSG_CHECKING([whether bio_end_io_t wants 2 args])
+	AC_MSG_CHECKING([whether bio_end_io_t wants 1 arg])
 	ZFS_LINUX_TRY_COMPILE([
 		#include <linux/bio.h>
 
-		void wanted_end_io(struct bio *bio, int x) { return; }
+		void wanted_end_io(struct bio *bio) { return; }
 
 		bio_end_io_t *end_io __attribute__ ((unused)) = wanted_end_io;
 	],[
 	],[
 		AC_MSG_RESULT(yes)
-		AC_DEFINE(HAVE_2ARGS_BIO_END_IO_T, 1,
-		          [bio_end_io_t wants 2 args])
+		AC_DEFINE(HAVE_1ARG_BIO_END_IO_T, 1,
+			  [bio_end_io_t wants 1 arg])
 	],[
 		AC_MSG_RESULT(no)
+		AC_MSG_CHECKING([whether bio_end_io_t wants 2 args])
+		ZFS_LINUX_TRY_COMPILE([
+			#include <linux/bio.h>
+
+			void wanted_end_io(struct bio *bio, int x) { return; }
+
+			bio_end_io_t *end_io __attribute__ ((unused)) =
+				wanted_end_io;
+		],[
+		],[
+			AC_MSG_RESULT(yes)
+			AC_DEFINE(HAVE_2ARGS_BIO_END_IO_T, 1,
+				  [bio_end_io_t wants 2 args])
+		],[
+			AC_MSG_RESULT(no)
+			AC_DEFINE(HAVE_3ARGS_BIO_END_IO_T, 1,
+				  [bio_end_io_t wants 3 args])
+		])
 	])
 ])
diff --git a/include/linux/blkdev_compat.h b/include/linux/blkdev_compat.h
@@ -182,20 +182,27 @@ bio_set_flags_failfast(struct block_device *bdev, int *flags)
 #endif /* DISK_NAME_LEN */
 
 /*
- * 2.6.24 API change,
+ * 2.6.24 and 4.3 API change,
  * The bio_end_io() prototype changed slightly.  These are helper
- * macro's to ensure the prototype and return value are handled.
+ * macro's to ensure the prototype, return value and invocation
+ * are handled.
  */
-#ifdef HAVE_2ARGS_BIO_END_IO_T
+#if   defined(HAVE_1ARG_BIO_END_IO_T)
+#define	BIO_END_IO_PROTO(fn, x, y, z)	static void fn(struct bio *x)
+#define	BIO_END_IO_RETURN(rc)		return
+#define	BIO_END_IO(bio, error)		bio->bi_error = error; bio_endio(bio);
+#elif defined(HAVE_2ARGS_BIO_END_IO_T)
 #define	BIO_END_IO_PROTO(fn, x, y, z)	static void fn(struct bio *x, int z)
 #define	BIO_END_IO_RETURN(rc)		return
-#else
+#define	BIO_END_IO(bio, error)		bio_endio(bio, error);
+#elif defined(HAVE_3ARGS_BIO_END_IO_T)
 #define	BIO_END_IO_PROTO(fn, x, y, z)	static int fn( \
 					    struct bio *x, \
 					    unsigned int y, \
 					    int z)
 #define	BIO_END_IO_RETURN(rc)		return rc
-#endif /* HAVE_2ARGS_BIO_END_IO_T */
+#define	BIO_END_IO(bio, error)		bio_endio(bio, 0, error);
+#endif /* HAVE_1ARG_BIO_END_IO_T */
 
 /*
  * 2.6.38 - 2.6.x API,

diff --git a/module/zfs/vdev_disk.c b/module/zfs/vdev_disk.c
@@ -429,16 +429,21 @@ BIO_END_IO_PROTO(vdev_disk_physio_completion, bio, size, error)
 	dio_request_t *dr = bio->bi_private;
 	int rc;
 
-#ifndef HAVE_2ARGS_BIO_END_IO_T
+#ifdef HAVE_3ARGS_BIO_END_IO_T
 	if (BIO_BI_SIZE(bio))
 		return (1);
-#endif /* HAVE_2ARGS_BIO_END_IO_T */
-
-	if (error == 0 && !test_bit(BIO_UPTODATE, &bio->bi_flags))
-		error = (-EIO);
+#endif
 
-	if (dr->dr_error == 0)
-		dr->dr_error = -error;
+	if (dr->dr_error == 0) {
+#ifdef HAVE_1ARG_BIO_END_IO_T
+		dr->dr_error = -(bio->bi_error);
+#else /* HAVE_2ARGS_BIO_END_IO_T || HAVE_3ARGS_BIO_END_IO_T */
+		if (error)
+			dr->dr_error = -(error);
+		else if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
+			dr->dr_error = EIO;
+#endif
+	}
 
 	/* Drop reference aquired by __vdev_disk_physio */
 	rc = vdev_disk_dio_put(dr);
@@ -627,6 +632,9 @@ vdev_disk_physio(struct block_device *bdev, caddr_t kbuf,
 BIO_END_IO_PROTO(vdev_disk_io_flush_completion, bio, size, rc)
 {
 	zio_t *zio = bio->bi_private;
+#ifdef HAVE_1ARG_BIO_END_IO_T
+	int rc = bio->bi_error;
+#endif
 
 	zio->io_delay = jiffies_64 - zio->io_delay;
 	zio->io_error = -rc;

diff --git a/module/zfs/zvol.c b/module/zfs/zvol.c
@@ -752,7 +752,7 @@ zvol_request(struct request_queue *q, struct bio *bio)
 out2:
 	generic_end_io_acct(rw, &zv->zv_disk->part0, start);
 out1:
-	bio_endio(bio, -error);
+	BIO_END_IO(bio, -error);
 	spl_fstrans_unmark(cookie);
 #ifdef HAVE_MAKE_REQUEST_FN_RET_INT
 	return (0);