block: remove BLKDEV_IFL_WAIT

All the blkdev_issue_* helpers can only sanely be used for synchronous
caller.  To issue cache flushes or barriers asynchronously the caller needs
to set up a bio by itself with a completion callback to move the asynchronous
state machine ahead.  So drop the BLKDEV_IFL_WAIT flag that is always
specified when calling blkdev_issue_* and also remove the now unused flags
argument to blkdev_issue_flush and blkdev_issue_zeroout.  For
blkdev_issue_discard we need to keep it for the secure discard flag, which
gains a more descriptive name and loses the bitops vs flag confusion.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

19 files changed, 47 insertions, 71 deletions

diff --git a/block/blk-flush.c b/block/blk-flush.c
index 62b7df9bca9d..54b123d6563e 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -205,7 +205,6 @@ static void bio_end_flush(struct bio *bio, int err)
  * @bdev:       blockdev to issue flush for
  * @gfp_mask:   memory allocation flags (for bio_alloc)
  * @error_sector:       error sector
- * @flags:      BLKDEV_IFL_* flags to control behaviour
  *
  * Description:
  *    Issue a flush for the block device in question. Caller can supply
@@ -214,7 +213,7 @@ static void bio_end_flush(struct bio *bio, int err)
  *    request was pushed in some internal queue for later handling.
  */
 int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
-                sector_t *error_sector, unsigned long flags)
+                sector_t *error_sector)
 {
         DECLARE_COMPLETION_ONSTACK(wait);
         struct request_queue *q;
@@ -240,21 +239,19 @@ int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
         bio = bio_alloc(gfp_mask, 0);
         bio->bi_end_io = bio_end_flush;
         bio->bi_bdev = bdev;
-        if (test_bit(BLKDEV_WAIT, &flags))
-                bio->bi_private = &wait;
+        bio->bi_private = &wait;
 
         bio_get(bio);
         submit_bio(WRITE_FLUSH, bio);
-        if (test_bit(BLKDEV_WAIT, &flags)) {
-                wait_for_completion(&wait);
-                /*
-                 * The driver must store the error location in ->bi_sector, if
-                 * it supports it. For non-stacked drivers, this should be
-                 * copied from blk_rq_pos(rq).
-                 */
-                if (error_sector)
-                        *error_sector = bio->bi_sector;
-        }
+        wait_for_completion(&wait);
+
+        /*
+         * The driver must store the error location in ->bi_sector, if
+         * it supports it. For non-stacked drivers, this should be
+         * copied from blk_rq_pos(rq).
+         */
+        if (error_sector)
+               *error_sector = bio->bi_sector;
 
         if (!bio_flagged(bio, BIO_UPTODATE))
                 ret = -EIO;
diff --git a/block/blk-lib.c b/block/blk-lib.c
index fe2e6ed0f510..1a320d2406b0 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -61,7 +61,7 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
                 max_discard_sectors &= ~(disc_sects - 1);
         }
 
-        if (flags & BLKDEV_IFL_SECURE) {
+        if (flags & BLKDEV_DISCARD_SECURE) {
                 if (!blk_queue_secdiscard(q))
                         return -EOPNOTSUPP;
                 type |= REQ_SECURE;
@@ -77,8 +77,7 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
                 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;
+                bio->bi_private = &wait;
 
                 if (nr_sects > max_discard_sectors) {
                         bio->bi_size = max_discard_sectors << 9;
@@ -92,8 +91,7 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
                 bio_get(bio);
                 submit_bio(type, bio);
 
-                if (flags & BLKDEV_IFL_WAIT)
-                        wait_for_completion(&wait);
+                wait_for_completion(&wait);
 
                 if (bio_flagged(bio, BIO_EOPNOTSUPP))
                         ret = -EOPNOTSUPP;
@@ -139,7 +137,6 @@ static void bio_batch_end_io(struct bio *bio, int err)
  * @sector:     start sector
  * @nr_sects:   number of sectors to write
  * @gfp_mask:   memory allocation flags (for bio_alloc)
- * @flags:      BLKDEV_IFL_* flags to control behaviour
  *
  * Description:
  *  Generate and issue number of bios with zerofiled pages.
@@ -148,7 +145,7 @@ static void bio_batch_end_io(struct bio *bio, int err)
  */
 
 int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
-                        sector_t nr_sects, gfp_t gfp_mask, unsigned long flags)
+                        sector_t nr_sects, gfp_t gfp_mask)
 {
         int ret;
         struct bio *bio;
@@ -174,8 +171,7 @@ submit:
                 bio->bi_sector = sector;
                 bio->bi_bdev   = bdev;
                 bio->bi_end_io = bio_batch_end_io;
-                if (flags & BLKDEV_IFL_WAIT)
-                        bio->bi_private = &bb;
+                bio->bi_private = &bb;
 
                 while (nr_sects != 0) {
                         sz = min((sector_t) PAGE_SIZE >> 9 , nr_sects);
@@ -193,10 +189,9 @@ submit:
                 submit_bio(WRITE, bio);
         }
 
-        if (flags & BLKDEV_IFL_WAIT)
-                /* Wait for bios in-flight */
-                while ( issued != atomic_read(&bb.done))
-                        wait_for_completion(&wait);
+        /* Wait for bios in-flight */
+        while (issued != atomic_read(&bb.done))
+                wait_for_completion(&wait);
 
         if (!test_bit(BIO_UPTODATE, &bb.flags))
                 /* One of bios in the batch was completed with error.*/
diff --git a/block/ioctl.c b/block/ioctl.c
index d8052f0dabd3..cb2b9099862b 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -116,7 +116,7 @@ static int blkdev_reread_part(struct block_device *bdev)
 static int blk_ioctl_discard(struct block_device *bdev, uint64_t start,
                              uint64_t len, int secure)
 {
-        unsigned long flags = BLKDEV_IFL_WAIT;
+        unsigned long flags = 0;
 
         if (start & 511)
                 return -EINVAL;
@@ -128,7 +128,7 @@ static int blk_ioctl_discard(struct block_device *bdev, uint64_t start,
         if (start + len > (bdev->bd_inode->i_size >> 9))
                 return -EINVAL;
         if (secure)
-                flags |= BLKDEV_IFL_SECURE;
+                flags |= BLKDEV_DISCARD_SECURE;
         return blkdev_issue_discard(bdev, start, len, GFP_KERNEL, flags);
 }
 
diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index 352441b0f92f..c2ef476f5711 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -2321,8 +2321,7 @@ static inline void drbd_md_flush(struct drbd_conf *mdev)
         if (test_bit(MD_NO_BARRIER, &mdev->flags))
                 return;
 
-        r = blkdev_issue_flush(mdev->ldev->md_bdev, GFP_KERNEL, NULL,
-                        BLKDEV_IFL_WAIT);
+        r = blkdev_issue_flush(mdev->ldev->md_bdev, GFP_KERNEL, NULL);
         if (r) {
                 set_bit(MD_NO_BARRIER, &mdev->flags);
                 dev_err(DEV, "meta data flush failed with status %d, disabling md-flushes\n", r);
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 081522d3c742..df15e7f0e7b7 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -975,7 +975,7 @@ static enum finish_epoch drbd_flush_after_epoch(struct drbd_conf *mdev, struct d
 
         if (mdev->write_ordering >= WO_bdev_flush && get_ldev(mdev)) {
                 rv = blkdev_issue_flush(mdev->ldev->backing_bdev, GFP_KERNEL,
-                                        NULL, BLKDEV_IFL_WAIT);
+                                        NULL);
                 if (rv) {
                         dev_err(DEV, "local disk flush failed with status %d\n", rv);
                         /* would rather check on EOPNOTSUPP, but that is not reliable.
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 50e8c8582faa..b737451e2e9d 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -370,7 +370,7 @@ int blkdev_fsync(struct file *filp, int datasync)
          */
         mutex_unlock(&bd_inode->i_mutex);
 
-        error = blkdev_issue_flush(bdev, GFP_KERNEL, NULL, BLKDEV_IFL_WAIT);
+        error = blkdev_issue_flush(bdev, GFP_KERNEL, NULL);
         if (error == -EOPNOTSUPP)
                 error = 0;
 
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 43dc9ea9aef6..0b81ecdb101c 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -1695,8 +1695,7 @@ static int remove_extent_backref(struct btrfs_trans_handle *trans,
 static void btrfs_issue_discard(struct block_device *bdev,
                                 u64 start, u64 len)
 {
-        blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL,
-                        BLKDEV_IFL_WAIT);
+        blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL, 0);
 }
 
 static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
diff --git a/fs/ext3/fsync.c b/fs/ext3/fsync.c
index d7e9f74dc3a6..09b13bb34c94 100644
--- a/fs/ext3/fsync.c
+++ b/fs/ext3/fsync.c
@@ -90,7 +90,6 @@ int ext3_sync_file(struct file *file, int datasync)
          * storage
          */
         if (needs_barrier)
-                blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL,
-                                BLKDEV_IFL_WAIT);
+                blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
         return ret;
 }
diff --git a/fs/ext4/fsync.c b/fs/ext4/fsync.c
index 592adf2e546e..3f3ff5ee8f9d 100644
--- a/fs/ext4/fsync.c
+++ b/fs/ext4/fsync.c
@@ -128,10 +128,9 @@ int ext4_sync_file(struct file *file, int datasync)
                     (journal->j_fs_dev != journal->j_dev) &&
                     (journal->j_flags & JBD2_BARRIER))
                         blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL,
-                                        NULL, BLKDEV_IFL_WAIT);
+                                        NULL);
                 ret = jbd2_log_wait_commit(journal, commit_tid);
         } else if (journal->j_flags & JBD2_BARRIER)
-                blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL,
-                        BLKDEV_IFL_WAIT);
+                blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
         return ret;
 }
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index a22bfef3da95..19aa0d44d822 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2566,8 +2566,7 @@ static inline void ext4_issue_discard(struct super_block *sb,
         discard_block = block + ext4_group_first_block_no(sb, block_group);
         trace_ext4_discard_blocks(sb,
                         (unsigned long long) discard_block, count);
-        ret = sb_issue_discard(sb, discard_block, count, GFP_NOFS,
-                               BLKDEV_IFL_WAIT);
+        ret = sb_issue_discard(sb, discard_block, count, GFP_NOFS, 0);
         if (ret == EOPNOTSUPP) {
                 ext4_warning(sb, "discard not supported, disabling");
                 clear_opt(EXT4_SB(sb)->s_mount_opt, DISCARD);
diff --git a/fs/fat/fatent.c b/fs/fat/fatent.c
index f9a0b7ae8648..b47d2c9f4fa1 100644
--- a/fs/fat/fatent.c
+++ b/fs/fat/fatent.c
@@ -578,8 +578,7 @@ int fat_free_clusters(struct inode *inode, int cluster)
                                 sb_issue_discard(sb,
                                         fat_clus_to_blknr(sbi, first_cl),
                                         nr_clus * sbi->sec_per_clus,
-                                        GFP_NOFS,
-                                        BLKDEV_IFL_WAIT);
+                                        GFP_NOFS, 0);
 
                                 first_cl = cluster;
                         }
diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 379316472918..38b3ea1abacc 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -854,7 +854,7 @@ static void gfs2_rgrp_send_discards(struct gfs2_sbd *sdp, u64 offset,
                                 if ((start + nr_sects) != blk) {
                                         rv = blkdev_issue_discard(bdev, start,
                                                             nr_sects, GFP_NOFS,
-                                                            BLKDEV_IFL_WAIT);
+                                                            0);
                                         if (rv)
                                                 goto fail;
                                         nr_sects = 0;
@@ -868,8 +868,7 @@ start_new_extent:
                 }
         }
         if (nr_sects) {
-                rv = blkdev_issue_discard(bdev, start, nr_sects, GFP_NOFS,
-                                         BLKDEV_IFL_WAIT);
+                rv = blkdev_issue_discard(bdev, start, nr_sects, GFP_NOFS, 0);
                 if (rv)
                         goto fail;
         }
diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c
index 5247e7ffdcb4..6571a056e55d 100644
--- a/fs/jbd2/checkpoint.c
+++ b/fs/jbd2/checkpoint.c
@@ -532,8 +532,7 @@ int jbd2_cleanup_journal_tail(journal_t *journal)
          */
         if ((journal->j_fs_dev != journal->j_dev) &&
             (journal->j_flags & JBD2_BARRIER))
-                blkdev_issue_flush(journal->j_fs_dev, GFP_KERNEL, NULL,
-                        BLKDEV_IFL_WAIT);
+                blkdev_issue_flush(journal->j_fs_dev, GFP_KERNEL, NULL);
         if (!(journal->j_flags & JBD2_ABORT))
                 jbd2_journal_update_superblock(journal, 1);
         return 0;
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index f204e27f44d1..cb43c605cfaa 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -684,8 +684,7 @@ start_journal_io:
         if (commit_transaction->t_flushed_data_blocks &&
             (journal->j_fs_dev != journal->j_dev) &&
             (journal->j_flags & JBD2_BARRIER))
-                blkdev_issue_flush(journal->j_fs_dev, GFP_KERNEL, NULL,
-                        BLKDEV_IFL_WAIT);
+                blkdev_issue_flush(journal->j_fs_dev, GFP_KERNEL, NULL);
 
         /* Done it all: now write the commit record asynchronously. */
         if (JBD2_HAS_INCOMPAT_FEATURE(journal,
@@ -810,8 +809,7 @@ wait_for_iobuf:
         if (JBD2_HAS_INCOMPAT_FEATURE(journal,
                                       JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT) &&
             journal->j_flags & JBD2_BARRIER) {
-                blkdev_issue_flush(journal->j_dev, GFP_KERNEL, NULL,
-                                   BLKDEV_IFL_WAIT);
+                blkdev_issue_flush(journal->j_dev, GFP_KERNEL, NULL);
         }
 
         if (err)
diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c
index 400b2caef4d8..d97310f07bef 100644
--- a/fs/nilfs2/the_nilfs.c
+++ b/fs/nilfs2/the_nilfs.c
@@ -774,7 +774,7 @@ int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump,
                         ret = blkdev_issue_discard(nilfs->ns_bdev,
                                                    start * sects_per_block,
                                                    nblocks * sects_per_block,
-                                                   GFP_NOFS, BLKDEV_IFL_WAIT);
+                                                   GFP_NOFS, 0);
                         if (ret < 0)
                                 return ret;
                         nblocks = 0;
@@ -784,7 +784,7 @@ int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump,
                 ret = blkdev_issue_discard(nilfs->ns_bdev,
                                            start * sects_per_block,
                                            nblocks * sects_per_block,
-                                           GFP_NOFS, BLKDEV_IFL_WAIT);
+                                           GFP_NOFS, 0);
         return ret;
 }
 
diff --git a/fs/reiserfs/file.c b/fs/reiserfs/file.c
index 6846371498b6..91f080cc76c8 100644
--- a/fs/reiserfs/file.c
+++ b/fs/reiserfs/file.c
@@ -152,8 +152,7 @@ static int reiserfs_sync_file(struct file *filp, int datasync)
         barrier_done = reiserfs_commit_for_inode(inode);
         reiserfs_write_unlock(inode->i_sb);
         if (barrier_done != 1 && reiserfs_barrier_flush(inode->i_sb))
-                blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL, 
-                        BLKDEV_IFL_WAIT);
+                blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
         if (barrier_done < 0)
                 return barrier_done;
         return (err < 0) ? -EIO : 0;
diff --git a/fs/xfs/linux-2.6/xfs_super.c b/fs/xfs/linux-2.6/xfs_super.c
index 15c35b62ff14..5fa7a30cc3f0 100644
--- a/fs/xfs/linux-2.6/xfs_super.c
+++ b/fs/xfs/linux-2.6/xfs_super.c
@@ -693,8 +693,7 @@ void
 xfs_blkdev_issue_flush(
         xfs_buftarg_t           *buftarg)
 {
-        blkdev_issue_flush(buftarg->bt_bdev, GFP_KERNEL, NULL,
-                        BLKDEV_IFL_WAIT);
+        blkdev_issue_flush(buftarg->bt_bdev, GFP_KERNEL, NULL);
 }
 
 STATIC void
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index cfcb3a610605..accbd0e5c893 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -867,18 +867,14 @@ static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
                 return NULL;
         return bqt->tag_index[tag];
 }
-enum{
-        BLKDEV_WAIT,    /* wait for completion */
-        BLKDEV_SECURE,  /* secure discard */
-};
-#define BLKDEV_IFL_WAIT         (1 << BLKDEV_WAIT)
-#define BLKDEV_IFL_SECURE       (1 << BLKDEV_SECURE)
-extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *,
-                        unsigned long);
+
+#define BLKDEV_DISCARD_SECURE  0x01    /* secure discard */
+
+extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
                 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
-                        sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
+                        sector_t nr_sects, gfp_t gfp_mask);
 static inline int sb_issue_discard(struct super_block *sb, sector_t block,
                 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
 {
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 68cda164dff6..e132e1708acc 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -141,7 +141,7 @@ static int discard_swap(struct swap_info_struct *si)
         nr_blocks = ((sector_t)se->nr_pages - 1) << (PAGE_SHIFT - 9);
         if (nr_blocks) {
                 err = blkdev_issue_discard(si->bdev, start_block,
-                                nr_blocks, GFP_KERNEL, BLKDEV_IFL_WAIT);
+                                nr_blocks, GFP_KERNEL, 0);
                 if (err)
                         return err;
                 cond_resched();
@@ -152,7 +152,7 @@ static int discard_swap(struct swap_info_struct *si)
                 nr_blocks = (sector_t)se->nr_pages << (PAGE_SHIFT - 9);
 
                 err = blkdev_issue_discard(si->bdev, start_block,
-                                nr_blocks, GFP_KERNEL, BLKDEV_IFL_WAIT);
+                                nr_blocks, GFP_KERNEL, 0);
                 if (err)
                         break;
 
@@ -191,7 +191,7 @@ static void discard_swap_cluster(struct swap_info_struct *si,
                         start_block <<= PAGE_SHIFT - 9;
                         nr_blocks <<= PAGE_SHIFT - 9;
                         if (blkdev_issue_discard(si->bdev, start_block,
-                                    nr_blocks, GFP_NOIO, BLKDEV_IFL_WAIT))
+                                    nr_blocks, GFP_NOIO, 0))
                                 break;
                 }