]> granicus.if.org Git - zfs/commitdiff
Linux 4.8 compat: Fix removal of bio->bi_rw member
authorBrian Behlendorf <behlendorf1@llnl.gov>
Tue, 9 Aug 2016 18:22:30 +0000 (11:22 -0700)
committerBrian Behlendorf <behlendorf1@llnl.gov>
Thu, 11 Aug 2016 18:19:34 +0000 (11:19 -0700)
All users of bio->bi_rw have been replaced with compatibility wrappers.
This allows the kernel specific logic to be abstracted away, and for
each of the supported cases to be documented with the wrapper.  The
updated interfaces are as follows:

* void blk_queue_set_write_cache(struct request_queue *, bool, bool)
* boolean_t bio_is_flush(struct bio *)
* boolean_t bio_is_fua(struct bio *)
* boolean_t bio_is_discard(struct bio *)
* boolean_t bio_is_secure_erase(struct bio *)
* VDEV_WRITE_FLUSH_FUA

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Closes #4951

config/kernel-bio-op.m4 [new file with mode: 0644]
config/kernel.m4
include/linux/blkdev_compat.h
module/zfs/zvol.c

diff --git a/config/kernel-bio-op.m4 b/config/kernel-bio-op.m4
new file mode 100644 (file)
index 0000000..b4b6995
--- /dev/null
@@ -0,0 +1,67 @@
+dnl #
+dnl # Linux 4.8 API,
+dnl #
+dnl # The bio_op() helper was introduced as a replacement for explicitly
+dnl # checking the bio->bi_rw flags.  The following checks are used to
+dnl # detect if a specific operation is supported.
+dnl #
+AC_DEFUN([ZFS_AC_KERNEL_REQ_OP_DISCARD], [
+       AC_MSG_CHECKING([whether REQ_OP_DISCARD is defined])
+       ZFS_LINUX_TRY_COMPILE([
+               #include <linux/blk_types.h>
+       ],[
+               enum req_op op __attribute__ ((unused)) = REQ_OP_DISCARD;
+       ],[
+               AC_MSG_RESULT(yes)
+               AC_DEFINE(HAVE_REQ_OP_DISCARD, 1,
+                   [REQ_OP_DISCARD is defined])
+       ],[
+               AC_MSG_RESULT(no)
+       ])
+])
+
+AC_DEFUN([ZFS_AC_KERNEL_REQ_OP_SECURE_ERASE], [
+       AC_MSG_CHECKING([whether REQ_OP_SECURE_ERASE is defined])
+       ZFS_LINUX_TRY_COMPILE([
+               #include <linux/blk_types.h>
+       ],[
+               enum req_op op __attribute__ ((unused)) = REQ_OP_SECURE_ERASE;
+       ],[
+               AC_MSG_RESULT(yes)
+               AC_DEFINE(HAVE_REQ_OP_SECURE_DISCARD, 1,
+                   [REQ_OP_SECURE_ERASE is defined])
+       ],[
+               AC_MSG_RESULT(no)
+       ])
+])
+
+
+AC_DEFUN([ZFS_AC_KERNEL_REQ_OP_FLUSH], [
+       AC_MSG_CHECKING([whether REQ_OP_FLUSH is defined])
+       ZFS_LINUX_TRY_COMPILE([
+               #include <linux/blk_types.h>
+       ],[
+               enum req_op op __attribute__ ((unused)) = REQ_OP_FLUSH;
+       ],[
+               AC_MSG_RESULT(yes)
+               AC_DEFINE(HAVE_REQ_OP_FLUSH, 1,
+                   [REQ_OP_FLUSH is defined])
+       ],[
+               AC_MSG_RESULT(no)
+       ])
+])
+
+AC_DEFUN([ZFS_AC_KERNEL_BIO_BI_OPF], [
+       AC_MSG_CHECKING([whether bio->bi_opf is defined])
+       ZFS_LINUX_TRY_COMPILE([
+               #include <linux/bio.h>
+       ],[
+               struct bio bio __attribute__ ((unused));
+               bio.bi_opf = 0;
+       ],[
+               AC_MSG_RESULT(yes)
+               AC_DEFINE(HAVE_BIO_BI_OPF, 1, [bio->bi_opf is defined])
+       ],[
+               AC_MSG_RESULT(no)
+       ])
+])
index 7a207f642050bb5f2021c3793dd3b3d5b094cfca..6cdad2d1adca9a4b6b85b75efcdb16d151abe7cb 100644 (file)
@@ -23,6 +23,10 @@ AC_DEFUN([ZFS_AC_CONFIG_KERNEL], [
        ZFS_AC_KERNEL_BIO_BVEC_ITER
        ZFS_AC_KERNEL_BIO_FAILFAST_DTD
        ZFS_AC_KERNEL_REQ_FAILFAST_MASK
+       ZFS_AC_KERNEL_REQ_OP_DISCARD
+       ZFS_AC_KERNEL_REQ_OP_SECURE_ERASE
+       ZFS_AC_KERNEL_REQ_OP_FLUSH
+       ZFS_AC_KERNEL_BIO_BI_OPF
        ZFS_AC_KERNEL_BIO_END_IO_T_ARGS
        ZFS_AC_KERNEL_BIO_RW_BARRIER
        ZFS_AC_KERNEL_BIO_RW_DISCARD
index 01bfad600ce2c99381bf62ac33b8322c8faa097b..aa7e6b498df8d725ce6fa5e2134c027b815e8fdc 100644 (file)
@@ -37,35 +37,24 @@ typedef unsigned __bitwise__ fmode_t;
 #endif /* HAVE_FMODE_T */
 
 /*
- * 2.6.36 API change,
+ * 4.7 - 4.x API,
+ * The blk_queue_write_cache() interface has replaced blk_queue_flush()
+ * interface.  However, the new interface is GPL-only thus we implement
+ * our own trivial wrapper when the GPL-only version is detected.
+ *
+ * 2.6.36 - 4.6 API,
  * The blk_queue_flush() interface has replaced blk_queue_ordered()
  * interface.  However, while the old interface was available to all the
  * new one is GPL-only.   Thus if the GPL-only version is detected we
- * implement our own trivial helper compatibility funcion.   The hope is
- * that long term this function will be opened up.
- */
-#if defined(HAVE_BLK_QUEUE_FLUSH) && defined(HAVE_BLK_QUEUE_FLUSH_GPL_ONLY)
-#define        blk_queue_flush __blk_queue_flush
-static inline void
-__blk_queue_flush(struct request_queue *q, unsigned int flags)
-{
-       q->flush_flags = flags & (REQ_FLUSH | REQ_FUA);
-}
-#endif /* HAVE_BLK_QUEUE_FLUSH && HAVE_BLK_QUEUE_FLUSH_GPL_ONLY */
-
-/*
- * 4.7 API change,
- * The blk_queue_write_cache() interface has replaced blk_queue_flush()
- * interface.  However, while the new interface is GPL-only. Thus if the
- * GPL-only version is detected we implement our own trivial helper
- * compatibility funcion.
+ * implement our own trivial helper.
+ *
+ * 2.6.x - 2.6.35
+ * Legacy blk_queue_ordered() interface.
  */
-#if defined(HAVE_BLK_QUEUE_WRITE_CACHE) && \
-       defined(HAVE_BLK_QUEUE_WRITE_CACHE_GPL_ONLY)
-#define        blk_queue_write_cache __blk_queue_write_cache
 static inline void
-__blk_queue_write_cache(struct request_queue *q, bool wc, bool fua)
+blk_queue_set_write_cache(struct request_queue *q, bool wc, bool fua)
 {
+#if defined(HAVE_BLK_QUEUE_WRITE_CACHE_GPL_ONLY)
        spin_lock_irq(q->queue_lock);
        if (wc)
                queue_flag_set(QUEUE_FLAG_WC, q);
@@ -76,8 +65,19 @@ __blk_queue_write_cache(struct request_queue *q, bool wc, bool fua)
        else
                queue_flag_clear(QUEUE_FLAG_FUA, q);
        spin_unlock_irq(q->queue_lock);
-}
+#elif defined(HAVE_BLK_QUEUE_WRITE_CACHE)
+       blk_queue_write_cache(q, wc, fua);
+#elif defined(HAVE_BLK_QUEUE_FLUSH_GPL_ONLY)
+       if (wc)
+               q->flush_flags |= REQ_FLUSH;
+       if (fua)
+               q->flush_flags |= REQ_FUA;
+#elif defined(HAVE_BLK_QUEUE_FLUSH)
+       blk_queue_flush(q, (wc ? REQ_FLUSH : 0) | (fua ? REQ_FUA : 0));
+#else
+       blk_queue_ordered(q, QUEUE_ORDERED_DRAIN, NULL);
 #endif
+}
 
 /*
  * Most of the blk_* macros were removed in 2.6.36.  Ostensibly this was
@@ -301,68 +301,121 @@ bio_set_flags_failfast(struct block_device *bdev, int *flags)
  * allow richer semantics to be expressed to the block layer.  It is
  * the block layers responsibility to choose the correct way to
  * implement these semantics.
- *
- * The existence of these flags implies that REQ_FLUSH an REQ_FUA are
- * defined.  Thus we can safely define VDEV_REQ_FLUSH and VDEV_REQ_FUA
- * compatibility macros.
- *
- * Linux 4.8 renamed the REQ_FLUSH to REQ_PREFLUSH but there was no
- * functional change in behavior.
  */
 #ifdef WRITE_FLUSH_FUA
-
 #define        VDEV_WRITE_FLUSH_FUA            WRITE_FLUSH_FUA
-#ifdef REQ_PREFLUSH
-#define        VDEV_REQ_FLUSH                  REQ_PREFLUSH
-#define        VDEV_REQ_FUA                    REQ_FUA
 #else
-#define        VDEV_REQ_FLUSH                  REQ_FLUSH
-#define        VDEV_REQ_FUA                    REQ_FUA
+#define        VDEV_WRITE_FLUSH_FUA            WRITE_BARRIER
 #endif
 
+/*
+ * 4.8 - 4.x API,
+ *   REQ_OP_FLUSH
+ *
+ * 4.8-rc0 - 4.8-rc1,
+ *   REQ_PREFLUSH
+ *
+ * 2.6.36 - 4.7 API,
+ *   REQ_FLUSH
+ *
+ * 2.6.x - 2.6.35 API,
+ *   HAVE_BIO_RW_BARRIER
+ *
+ * Used to determine if a cache flush has been requested.  This check has
+ * been left intentionally broad in order to cover both a legacy flush
+ * and the new preflush behavior introduced in Linux 4.8.  This is correct
+ * in all cases but may have a performance impact for some kernels.  It
+ * has the advantage of minimizing kernel specific changes in the zvol code.
+ */
+static inline boolean_t
+bio_is_flush(struct bio *bio)
+{
+#if defined(HAVE_REQ_OP_FLUSH) && defined(HAVE_BIO_BI_OPF)
+       return ((bio_op(bio) == REQ_OP_FLUSH) || (bio->bi_opf & REQ_PREFLUSH));
+#elif defined(REQ_PREFLUSH) && defined(HAVE_BIO_BI_OPF)
+       return (bio->bi_opf & REQ_PREFLUSH);
+#elif defined(REQ_PREFLUSH) && !defined(HAVE_BIO_BI_OPF)
+       return (bio->bi_rw & REQ_PREFLUSH);
+#elif defined(REQ_FLUSH)
+       return (bio->bi_rw & REQ_FLUSH);
+#elif defined(HAVE_BIO_RW_BARRIER)
+       return (bio->bi_rw & (1 << BIO_RW_BARRIER));
 #else
-
-#define        VDEV_WRITE_FLUSH_FUA            WRITE_BARRIER
-#ifdef HAVE_BIO_RW_BARRIER
-#define        VDEV_REQ_FLUSH                  (1 << BIO_RW_BARRIER)
-#define        VDEV_REQ_FUA                    (1 << BIO_RW_BARRIER)
-#else
-#define        VDEV_REQ_FLUSH                  REQ_HARDBARRIER
-#define        VDEV_REQ_FUA                    REQ_FUA
+#error "Allowing the build will cause flush requests to be ignored. Please "
+       "file an issue report at: https://github.com/zfsonlinux/zfs/issues/new"
 #endif
+}
 
+/*
+ * 4.8 - 4.x API,
+ *   REQ_FUA flag moved to bio->bi_opf
+ *
+ * 2.6.x - 4.7 API,
+ *   REQ_FUA
+ */
+static inline boolean_t
+bio_is_fua(struct bio *bio)
+{
+#if defined(HAVE_BIO_BI_OPF)
+       return (bio->bi_opf & REQ_FUA);
+#elif defined(REQ_FUA)
+       return (bio->bi_rw & REQ_FUA);
+#else
+#error "Allowing the build will cause fua requests to be ignored. Please "
+       "file an issue report at: https://github.com/zfsonlinux/zfs/issues/new"
 #endif
+}
 
 /*
- * 2.6.28 - 2.6.35 API,
- *   BIO_RW_DISCARD
+ * 4.8 - 4.x API,
+ *   REQ_OP_DISCARD
  *
  * 2.6.36 - 4.7 API,
  *   REQ_DISCARD
  *
- * 4.8 - 4.x API,
- *   REQ_OP_DISCARD
+ * 2.6.28 - 2.6.35 API,
+ *   BIO_RW_DISCARD
  *
  * In all cases the normal I/O path is used for discards.  The only
  * difference is how the kernel tags individual I/Os as discards.
  */
-#ifdef QUEUE_FLAG_DISCARD
 static inline boolean_t
 bio_is_discard(struct bio *bio)
 {
-#if defined(HAVE_BIO_RW_DISCARD)
-       return (bio->bi_rw & (1 << BIO_RW_DISCARD));
+#if defined(HAVE_REQ_OP_DISCARD)
+       return (bio_op(bio) == REQ_OP_DISCARD);
 #elif defined(REQ_DISCARD)
        return (bio->bi_rw & REQ_DISCARD);
+#elif defined(HAVE_BIO_RW_DISCARD)
+       return (bio->bi_rw & (1 << BIO_RW_DISCARD));
 #else
-       return (bio_op(bio) == REQ_OP_DISCARD);
+#error "Allowing the build will cause discard requests to become writes "
+       "potentially triggering the DMU_MAX_ACCESS assertion. Please file "
+       "an issue report at: https://github.com/zfsonlinux/zfs/issues/new"
 #endif
 }
+
+/*
+ * 4.8 - 4.x API,
+ *   REQ_OP_SECURE_ERASE
+ *
+ * 2.6.36 - 4.7 API,
+ *   REQ_SECURE
+ *
+ * 2.6.x - 2.6.35 API,
+ *   Unsupported by kernel
+ */
+static inline boolean_t
+bio_is_secure_erase(struct bio *bio)
+{
+#if defined(HAVE_REQ_OP_SECURE_ERASE)
+       return (bio_op(bio) == REQ_OP_SECURE_ERASE);
+#elif defined(REQ_SECURE)
+       return (bio->bi_rw & REQ_SECURE);
 #else
-#error "Allowing the build will cause discard requests to become writes "
-       "potentially triggering the DMU_MAX_ACCESS assertion. Please file a "
-       "an issue report at: https://github.com/zfsonlinux/zfs/issues/new"
+       return (0);
 #endif
+}
 
 /*
  * 2.6.33 API change
index c25b243db3a82b9c6cfd5a36a3c2544dc26ae6a0..bf6d59fba5dd954bbdcbee68156ef44f1c11414c 100644 (file)
@@ -707,20 +707,16 @@ zvol_discard(struct bio *bio)
                return (SET_ERROR(EIO));
 
        /*
-        * Align the request to volume block boundaries when REQ_SECURE is
-        * available, but not requested. If we don't, then this will force
-        * dnode_free_range() to zero out the unaligned parts, which is slow
-        * (read-modify-write) and useless since we are not freeing any space
-        * by doing so. Kernels that do not support REQ_SECURE (2.6.32 through
-        * 2.6.35) will not receive this optimization.
+        * Align the request to volume block boundaries when a secure erase is
+        * not required.  This will prevent dnode_free_range() from zeroing out
+        * the unaligned parts which is slow (read-modify-write) and useless
+        * since we are not freeing any space by doing so.
         */
-#ifdef REQ_SECURE
-       if (!(bio->bi_rw & REQ_SECURE)) {
+       if (!bio_is_secure_erase(bio)) {
                start = P2ROUNDUP(start, zv->zv_volblocksize);
                end = P2ALIGN(end, zv->zv_volblocksize);
                size = end - start;
        }
-#endif
 
        if (start >= end)
                return (0);
@@ -812,7 +808,7 @@ zvol_request(struct request_queue *q, struct bio *bio)
                        goto out2;
                }
 
-               if (bio_is_discard(bio)) {
+               if (bio_is_discard(bio) || bio_is_secure_erase(bio)) {
                        error = zvol_discard(bio);
                        goto out2;
                }
@@ -821,14 +817,14 @@ zvol_request(struct request_queue *q, struct bio *bio)
                 * Some requests are just for flush and nothing else.
                 */
                if (uio.uio_resid == 0) {
-                       if (bio->bi_rw & VDEV_REQ_FLUSH)
+                       if (bio_is_flush(bio))
                                zil_commit(zv->zv_zilog, ZVOL_OBJ);
                        goto out2;
                }
 
                error = zvol_write(zv, &uio,
-                   ((bio->bi_rw & (VDEV_REQ_FUA|VDEV_REQ_FLUSH)) ||
-                   zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS));
+                   bio_is_flush(bio) || bio_is_fua(bio) ||
+                   zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS);
        } else
                error = zvol_read(zv, &uio);
 
@@ -1290,14 +1286,7 @@ zvol_alloc(dev_t dev, const char *name)
                goto out_kmem;
 
        blk_queue_make_request(zv->zv_queue, zvol_request);
-
-#ifdef HAVE_BLK_QUEUE_WRITE_CACHE
-       blk_queue_write_cache(zv->zv_queue, B_TRUE, B_TRUE);
-#elif defined(HAVE_BLK_QUEUE_FLUSH)
-       blk_queue_flush(zv->zv_queue, VDEV_REQ_FLUSH | VDEV_REQ_FUA);
-#else
-       blk_queue_ordered(zv->zv_queue, QUEUE_ORDERED_DRAIN, NULL);
-#endif /* HAVE_BLK_QUEUE_FLUSH */
+       blk_queue_set_write_cache(zv->zv_queue, B_TRUE, B_TRUE);
 
        zv->zv_disk = alloc_disk(ZVOL_MINORS);
        if (zv->zv_disk == NULL)