blkdev: move blkdev_issue helper functions to separate file

Move blkdev_issue_discard from blk-barrier.c because it is
not barrier related.
Later the file will be populated by other helpers.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

3 files changed, 115 insertions, 105 deletions

diff --git a/block/Makefile b/block/Makefile
index cb2d515ebd6e..0bb499a739cd 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -5,7 +5,7 @@
 obj-$(CONFIG_BLOCK) := elevator.o blk-core.o blk-tag.o blk-sysfs.o \
                         blk-barrier.o blk-settings.o blk-ioc.o blk-map.o \
                         blk-exec.o blk-merge.o blk-softirq.o blk-timeout.o \
-                        blk-iopoll.o ioctl.o genhd.o scsi_ioctl.o
+                        blk-iopoll.o blk-lib.o ioctl.o genhd.o scsi_ioctl.o
 
 obj-$(CONFIG_BLK_DEV_BSG)       += bsg.o
 obj-$(CONFIG_BLK_CGROUP)        += blk-cgroup.o
diff --git a/block/blk-barrier.c b/block/blk-barrier.c
index f11eec9669e4..0d710c9d403b 100644
--- a/block/blk-barrier.c
+++ b/block/blk-barrier.c
@@ -347,107 +347,3 @@ int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
         return ret;
 }
 EXPORT_SYMBOL(blkdev_issue_flush);
-
-static void blkdev_discard_end_io(struct bio *bio, int err)
-{
-        if (err) {
-                if (err == -EOPNOTSUPP)
-                        set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
-                clear_bit(BIO_UPTODATE, &bio->bi_flags);
-        }
-
-        if (bio->bi_private)
-                complete(bio->bi_private);
-        __free_page(bio_page(bio));
-
-        bio_put(bio);
-}
-
-/**
- * blkdev_issue_discard - queue a discard
- * @bdev:       blockdev to issue discard for
- * @sector:     start sector
- * @nr_sects:   number of sectors to discard
- * @gfp_mask:   memory allocation flags (for bio_alloc)
- * @flags:      BLKDEV_IFL_* flags to control behaviour
- *
- * Description:
- *    Issue a discard request for the sectors in question.
- */
-int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
-                sector_t nr_sects, gfp_t gfp_mask, unsigned long flags)
-{
-        DECLARE_COMPLETION_ONSTACK(wait);
-        struct request_queue *q = bdev_get_queue(bdev);
-        int type = flags & BLKDEV_IFL_BARRIER ?
-                DISCARD_BARRIER : DISCARD_NOBARRIER;
-        struct bio *bio;
-        struct page *page;
-        int ret = 0;
-
-        if (!q)
-                return -ENXIO;
-
-        if (!blk_queue_discard(q))
-                return -EOPNOTSUPP;
-
-        while (nr_sects && !ret) {
-                unsigned int sector_size = q->limits.logical_block_size;
-                unsigned int max_discard_sectors =
-                        min(q->limits.max_discard_sectors, UINT_MAX >> 9);
-
-                bio = bio_alloc(gfp_mask, 1);
-                if (!bio)
-                        goto out;
-                bio->bi_sector = sector;
-                bio->bi_end_io = blkdev_discard_end_io;
-                bio->bi_bdev = bdev;
-                if (flags & BLKDEV_IFL_WAIT)
-                        bio->bi_private = &wait;
-
-                /*
-                 * Add a zeroed one-sector payload as that's what
-                 * our current implementations need.  If we'll ever need
-                 * more the interface will need revisiting.
-                 */
-                page = alloc_page(gfp_mask | __GFP_ZERO);
-                if (!page)
-                        goto out_free_bio;
-                if (bio_add_pc_page(q, bio, page, sector_size, 0) < sector_size)
-                        goto out_free_page;
-
-                /*
-                 * And override the bio size - the way discard works we
-                 * touch many more blocks on disk than the actual payload
-                 * length.
-                 */
-                if (nr_sects > max_discard_sectors) {
-                        bio->bi_size = max_discard_sectors << 9;
-                        nr_sects -= max_discard_sectors;
-                        sector += max_discard_sectors;
-                } else {
-                        bio->bi_size = nr_sects << 9;
-                        nr_sects = 0;
-                }
-
-                bio_get(bio);
-                submit_bio(type, bio);
-
-                if (flags & BLKDEV_IFL_WAIT)
-                        wait_for_completion(&wait);
-
-                if (bio_flagged(bio, BIO_EOPNOTSUPP))
-                        ret = -EOPNOTSUPP;
-                else if (!bio_flagged(bio, BIO_UPTODATE))
-                        ret = -EIO;
-                bio_put(bio);
-        }
-        return ret;
-out_free_page:
-        __free_page(page);
-out_free_bio:
-        bio_put(bio);
-out:
-        return -ENOMEM;
-}
-EXPORT_SYMBOL(blkdev_issue_discard);
diff --git a/block/blk-lib.c b/block/blk-lib.c
new file mode 100644
index 000000000000..0dc438812d81
--- /dev/null
+++ b/block/blk-lib.c
@@ -0,0 +1,114 @@
+/*
+ * Functions related to generic helpers functions
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/scatterlist.h>
+
+#include "blk.h"
+
+static void blkdev_discard_end_io(struct bio *bio, int err)
+{
+        if (err) {
+                if (err == -EOPNOTSUPP)
+                        set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
+                clear_bit(BIO_UPTODATE, &bio->bi_flags);
+        }
+
+        if (bio->bi_private)
+                complete(bio->bi_private);
+        __free_page(bio_page(bio));
+
+        bio_put(bio);
+}
+
+/**
+ * blkdev_issue_discard - queue a discard
+ * @bdev:       blockdev to issue discard for
+ * @sector:     start sector
+ * @nr_sects:   number of sectors to discard
+ * @gfp_mask:   memory allocation flags (for bio_alloc)
+ * @flags:      BLKDEV_IFL_* flags to control behaviour
+ *
+ * Description:
+ *    Issue a discard request for the sectors in question.
+ */
+int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
+                sector_t nr_sects, gfp_t gfp_mask, unsigned long flags)
+{
+        DECLARE_COMPLETION_ONSTACK(wait);
+        struct request_queue *q = bdev_get_queue(bdev);
+        int type = flags & BLKDEV_IFL_BARRIER ?
+                DISCARD_BARRIER : DISCARD_NOBARRIER;
+        struct bio *bio;
+        struct page *page;
+        int ret = 0;
+
+        if (!q)
+                return -ENXIO;
+
+        if (!blk_queue_discard(q))
+                return -EOPNOTSUPP;
+
+        while (nr_sects && !ret) {
+                unsigned int sector_size = q->limits.logical_block_size;
+                unsigned int max_discard_sectors =
+                        min(q->limits.max_discard_sectors, UINT_MAX >> 9);
+
+                bio = bio_alloc(gfp_mask, 1);
+                if (!bio)
+                        goto out;
+                bio->bi_sector = sector;
+                bio->bi_end_io = blkdev_discard_end_io;
+                bio->bi_bdev = bdev;
+                if (flags & BLKDEV_IFL_WAIT)
+                        bio->bi_private = &wait;
+
+                /*
+                 * Add a zeroed one-sector payload as that's what
+                 * our current implementations need.  If we'll ever need
+                 * more the interface will need revisiting.
+                 */
+                page = alloc_page(gfp_mask | __GFP_ZERO);
+                if (!page)
+                        goto out_free_bio;
+                if (bio_add_pc_page(q, bio, page, sector_size, 0) < sector_size)
+                        goto out_free_page;
+
+                /*
+                 * And override the bio size - the way discard works we
+                 * touch many more blocks on disk than the actual payload
+                 * length.
+                 */
+                if (nr_sects > max_discard_sectors) {
+                        bio->bi_size = max_discard_sectors << 9;
+                        nr_sects -= max_discard_sectors;
+                        sector += max_discard_sectors;
+                } else {
+                        bio->bi_size = nr_sects << 9;
+                        nr_sects = 0;
+                }
+
+                bio_get(bio);
+                submit_bio(type, bio);
+
+                if (flags & BLKDEV_IFL_WAIT)
+                        wait_for_completion(&wait);
+
+                if (bio_flagged(bio, BIO_EOPNOTSUPP))
+                        ret = -EOPNOTSUPP;
+                else if (!bio_flagged(bio, BIO_UPTODATE))
+                        ret = -EIO;
+                bio_put(bio);
+        }
+        return ret;
+out_free_page:
+        __free_page(page);
+out_free_bio:
+        bio_put(bio);
+out:
+        return -ENOMEM;
+}
+EXPORT_SYMBOL(blkdev_issue_discard);