Linux 3.14 compat: IO acct, global_page_state, etc

generic_start_io_acct/generic_end_io_acct in the master
branch of the linux kernel requires that the request_queue
be provided.

Move the logic from freemem in the spl to arc_free_memory
in arc.c. Do this so we can take advantage of global_page_state
interface checks in zfs.

Upstream kernel replaced struct block_device with
struct gendisk in struct bio. Determine if the
function bio_set_dev exists during configure
and have zfs use that if it exists.

bio_set_dev https://github.com/torvalds/linux/commit/74d4699
global_node_page_state https://github.com/torvalds/linux/commit/75ef718
io acct https://github.com/torvalds/linux/commit/d62e26b

Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Giuseppe Di Natale <[email protected]>
Closes #6635 

3 files changed, 42 insertions, 10 deletions

diff --git a/module/zfs/arc.c b/module/zfs/arc.c
index 75f0af9d5..57bf6b83c 100644
--- a/module/zfs/arc.c
+++ b/module/zfs/arc.c
@@ -4665,6 +4665,24 @@ arc_all_memory(void)
 #endif
 }
 
+#ifdef _KERNEL
+static uint64_t
+arc_free_memory(void)
+{
+#ifdef ZFS_GLOBAL_NODE_PAGE_STATE
+	return (nr_free_pages() +
+	    global_node_page_state(NR_INACTIVE_FILE) +
+	    global_node_page_state(NR_INACTIVE_ANON) +
+	    global_node_page_state(NR_SLAB_RECLAIMABLE));
+#else
+	return (nr_free_pages() +
+	    global_page_state(NR_INACTIVE_FILE) +
+	    global_page_state(NR_INACTIVE_ANON) +
+	    global_page_state(NR_SLAB_RECLAIMABLE));
+#endif
+}
+#endif
+
 typedef enum free_memory_reason_t {
 	FMR_UNKNOWN,
 	FMR_NEEDFREE,
@@ -4701,7 +4719,7 @@ arc_available_memory(void)
 	int64_t lowest = INT64_MAX;
 	free_memory_reason_t r = FMR_UNKNOWN;
 #ifdef _KERNEL
-	uint64_t available_memory = ptob(freemem);
+	uint64_t available_memory = ptob(arc_free_memory());
 	int64_t n;
 #ifdef __linux__
 	pgcnt_t needfree = btop(arc_need_free);
@@ -6904,7 +6922,7 @@ static int
 arc_memory_throttle(uint64_t reserve, uint64_t txg)
 {
 #ifdef _KERNEL
-	uint64_t available_memory = ptob(freemem);
+	uint64_t available_memory = ptob(arc_free_memory());
 	static uint64_t page_load = 0;
 	static uint64_t last_txg = 0;
 #ifdef __linux__
diff --git a/module/zfs/vdev_disk.c b/module/zfs/vdev_disk.c
index c6bb24a33..87cc2c892 100644
--- a/module/zfs/vdev_disk.c
+++ b/module/zfs/vdev_disk.c
@@ -503,6 +503,14 @@ vdev_submit_bio_impl(struct bio *bio)
 #endif
 }
 
+#ifndef HAVE_BIO_SET_DEV
+static inline void
+bio_set_dev(struct bio *bio, struct block_device *bdev)
+{
+	bio->bi_bdev = bdev;
+}
+#endif /* !HAVE_BIO_SET_DEV */
+
 static inline void
 vdev_submit_bio(struct bio *bio)
 {
@@ -585,7 +593,7 @@ retry:
 		/* Matching put called by vdev_disk_physio_completion */
 		vdev_disk_dio_get(dr);
 
-		dr->dr_bio[i]->bi_bdev = bdev;
+		bio_set_dev(dr->dr_bio[i], bdev);
 		BIO_BI_SECTOR(dr->dr_bio[i]) = bio_offset >> 9;
 		dr->dr_bio[i]->bi_end_io = vdev_disk_physio_completion;
 		dr->dr_bio[i]->bi_private = dr;
@@ -659,7 +667,7 @@ vdev_disk_io_flush(struct block_device *bdev, zio_t *zio)
 
 	bio->bi_end_io = vdev_disk_io_flush_completion;
 	bio->bi_private = zio;
-	bio->bi_bdev = bdev;
+	bio_set_dev(bio, bdev);
 	bio_set_flush(bio);
 	vdev_submit_bio(bio);
 	invalidate_bdev(bdev);
diff --git a/module/zfs/zvol.c b/module/zfs/zvol.c
index 1cb03fc7e..fe7dbb371 100644
--- a/module/zfs/zvol.c
+++ b/module/zfs/zvol.c
@@ -761,7 +761,8 @@ zvol_write(void *arg)
 	ASSERT(zv && zv->zv_open_count > 0);
 
 	start_jif = jiffies;
-	generic_start_io_acct(WRITE, bio_sectors(bio), &zv->zv_disk->part0);
+	blk_generic_start_io_acct(zv->zv_queue, WRITE, bio_sectors(bio),
+	    &zv->zv_disk->part0);
 
 	sync = bio_is_fua(bio) || zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS;
 
@@ -794,7 +795,8 @@ zvol_write(void *arg)
 		zil_commit(zv->zv_zilog, ZVOL_OBJ);
 
 	rw_exit(&zv->zv_suspend_lock);
-	generic_end_io_acct(WRITE, &zv->zv_disk->part0, start_jif);
+	blk_generic_end_io_acct(zv->zv_queue, WRITE, &zv->zv_disk->part0,
+	    start_jif);
 	BIO_END_IO(bio, -error);
 	kmem_free(zvr, sizeof (zv_request_t));
 }
@@ -840,7 +842,8 @@ zvol_discard(void *arg)
 	ASSERT(zv && zv->zv_open_count > 0);
 
 	start_jif = jiffies;
-	generic_start_io_acct(WRITE, bio_sectors(bio), &zv->zv_disk->part0);
+	blk_generic_start_io_acct(zv->zv_queue, WRITE, bio_sectors(bio),
+	    &zv->zv_disk->part0);
 
 	sync = bio_is_fua(bio) || zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS;
 
@@ -881,7 +884,8 @@ unlock:
 		zil_commit(zv->zv_zilog, ZVOL_OBJ);
 
 	rw_exit(&zv->zv_suspend_lock);
-	generic_end_io_acct(WRITE, &zv->zv_disk->part0, start_jif);
+	blk_generic_end_io_acct(zv->zv_queue, WRITE, &zv->zv_disk->part0,
+	    start_jif);
 	BIO_END_IO(bio, -error);
 	kmem_free(zvr, sizeof (zv_request_t));
 }
@@ -902,7 +906,8 @@ zvol_read(void *arg)
 	ASSERT(zv && zv->zv_open_count > 0);
 
 	start_jif = jiffies;
-	generic_start_io_acct(READ, bio_sectors(bio), &zv->zv_disk->part0);
+	blk_generic_start_io_acct(zv->zv_queue, READ, bio_sectors(bio),
+	    &zv->zv_disk->part0);
 
 	while (uio.uio_resid > 0 && uio.uio_loffset < volsize) {
 		uint64_t bytes = MIN(uio.uio_resid, DMU_MAX_ACCESS >> 1);
@@ -922,7 +927,8 @@ zvol_read(void *arg)
 	zfs_range_unlock(zvr->rl);
 
 	rw_exit(&zv->zv_suspend_lock);
-	generic_end_io_acct(READ, &zv->zv_disk->part0, start_jif);
+	blk_generic_end_io_acct(zv->zv_queue, READ, &zv->zv_disk->part0,
+	    start_jif);
 	BIO_END_IO(bio, -error);
 	kmem_free(zvr, sizeof (zv_request_t));
 }