[PATCH 75/78] block: stop using bdget_disk for partition 0

Christoph Hellwig
2020-11-16T15:18:15Z

We can just dereference the point in struct gendisk instead. Also
remove the now unused export.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
block/genhd.c | 1 -
drivers/block/nbd.c | 4 +---
drivers/block/xen-blkfront.c | 20 +++++---------------
drivers/block/zram/zram_drv.c | 25 ++-----------------------
drivers/md/dm.c | 13 ++-----------
drivers/s390/block/dasd_ioctl.c | 5 ++---
6 files changed, 12 insertions(+), 56 deletions(-)

diff --git a/block/genhd.c b/block/genhd.c
index 5dcb8b8902daae..b2a4e68171519a 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -904,7 +904,6 @@ struct block_device *bdget_disk(struct gendisk *disk, int partno)

return bdev;
}
-EXPORT_SYMBOL(bdget_disk);

/*
* print a full list of all partitions - intended for places where the root
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 014683968ce174..92f84ed0ba9eb6 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -1488,12 +1488,10 @@ static int nbd_open(struct block_device *bdev, fmode_t mode)
static void nbd_release(struct gendisk *disk, fmode_t mode)
{
struct nbd_device *nbd = disk->private_data;
- struct block_device *bdev = bdget_disk(disk, 0);

if (test_bit(NBD_RT_DISCONNECT_ON_CLOSE, &nbd->config->runtime_flags) &&
- bdev->bd_openers == 0)
+ disk->part0->bd_openers == 0)
nbd_disconnect_and_put(nbd);
- bdput(bdev);

nbd_config_put(nbd);
nbd_put(nbd);
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 5b1f99ca77b734..c2721ec73d7291 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -2153,7 +2153,7 @@ static void blkfront_closing(struct blkfront_info *info)
}

if (info->gd)
- bdev = bdget_disk(info->gd, 0);
+ bdev = bdgrab(info->gd->part0);

mutex_unlock(&info->mutex);

@@ -2518,7 +2518,7 @@ static int blkfront_remove(struct xenbus_device *xbdev)

disk = info->gd;
if (disk)
- bdev = bdget_disk(disk, 0);
+ bdev = bdgrab(disk->part0);

info->xbdev = NULL;
mutex_unlock(&info->mutex);
@@ -2595,19 +2595,11 @@ static int blkif_open(struct block_device *bdev, fmode_t mode)
static void blkif_release(struct gendisk *disk, fmode_t mode)
{
struct blkfront_info *info = disk->private_data;
- struct block_device *bdev;
struct xenbus_device *xbdev;

mutex_lock(&blkfront_mutex);
-
- bdev = bdget_disk(disk, 0);
-
- if (!bdev) {
- WARN(1, "Block device %s yanked out from us!\n", disk->disk_name);
+ if (disk->part0->bd_openers)
goto out_mutex;
- }
- if (bdev->bd_openers)
- goto out;

/*
* Check if we have been instructed to close. We will have
@@ -2619,7 +2611,7 @@ static void blkif_release(struct gendisk *disk, fmode_t mode)

if (xbdev && xbdev->state == XenbusStateClosing) {
/* pending switch to state closed */
- dev_info(disk_to_dev(bdev->bd_disk), "releasing disk\n");
+ dev_info(disk_to_dev(disk), "releasing disk\n");
xlvbd_release_gendisk(info);
xenbus_frontend_closed(info->xbdev);
}
@@ -2628,14 +2620,12 @@ static void blkif_release(struct gendisk *disk, fmode_t mode)

if (!xbdev) {
/* sudden device removal */
- dev_info(disk_to_dev(bdev->bd_disk), "releasing disk\n");
+ dev_info(disk_to_dev(disk), "releasing disk\n");
xlvbd_release_gendisk(info);
disk->private_data = NULL;
free_info(info);
}

-out:
- bdput(bdev);
out_mutex:
mutex_unlock(&blkfront_mutex);
}
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index e765765263495f..e7a23638e2f181 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -1748,7 +1748,6 @@ static ssize_t reset_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t len)
{
struct zram *zram = dev_to_zram(dev);
- struct block_device *bdev;
unsigned short do_reset;
int ret = 0;

@@ -1758,17 +1757,12 @@ static ssize_t reset_store(struct device *dev,
if (!do_reset)
return -EINVAL;

- bdev = bdget_disk(zram->disk, 0);
- if (!bdev)
- return -ENOMEM;
-
mutex_lock(&zram->disk->mutex);
- if (bdev->bd_openers)
+ if (zram->disk->part0->bd_openers)
ret = -EBUSY;
else
zram_reset_device(zram);
mutex_unlock(&zram->disk->mutex);
- bdput(bdev);

return ret ? ret : len;
}
@@ -1931,24 +1925,9 @@ static int zram_add(void)
return ret;
}

-static bool zram_busy(struct zram *zram)
-{
- struct block_device *bdev;
- bool busy = false;
-
- bdev = bdget_disk(zram->disk, 0);
- if (bdev) {
- if (bdev->bd_openers)
- busy = true;
- bdput(bdev);
- }
-
- return busy;
-}
-
static int zram_remove(struct zram *zram)
{
- if (zram_busy(zram))
+ if (zram->disk->part0->bd_openers)
return -EBUSY;

del_gendisk(zram->disk);
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index ac46f6e41279cc..ec48ccae50dd53 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2375,17 +2375,12 @@ struct dm_table *dm_swap_table(struct mapped_device *md, struct dm_table *table)
*/
static int lock_fs(struct mapped_device *md)
{
- struct block_device *bdev;
int r;

WARN_ON(md->frozen_sb);

- bdev = bdget_disk(md->disk, 0);
- if (!bdev)
- return -ENOMEM;
- md->frozen_sb = freeze_bdev(bdev);
+ md->frozen_sb = freeze_bdev(md->disk->part0);
if (IS_ERR(md->frozen_sb)) {
- bdput(bdev);
r = PTR_ERR(md->frozen_sb);
md->frozen_sb = NULL;
return r;
@@ -2398,14 +2393,10 @@ static int lock_fs(struct mapped_device *md)

static void unlock_fs(struct mapped_device *md)
{
- struct block_device *bdev;
-
if (!test_bit(DMF_FROZEN, &md->flags))
return;

- bdev = md->frozen_sb->s_bdev;
- thaw_bdev(bdev, md->frozen_sb);
- bdput(bdev);
+ thaw_bdev(md->frozen_sb->s_bdev, md->frozen_sb);
md->frozen_sb = NULL;
clear_bit(DMF_FROZEN, &md->flags);
}
diff --git a/drivers/s390/block/dasd_ioctl.c b/drivers/s390/block/dasd_ioctl.c
index 304eba1acf163c..9f642440894655 100644
--- a/drivers/s390/block/dasd_ioctl.c
+++ b/drivers/s390/block/dasd_ioctl.c
@@ -220,9 +220,8 @@ dasd_format(struct dasd_block *block, struct format_data_t *fdata)
* enabling the device later.
*/
if (fdata->start_unit == 0) {
- struct block_device *bdev = bdget_disk(block->gdp, 0);
- bdev->bd_inode->i_blkbits = blksize_bits(fdata->blksize);
- bdput(bdev);
+ block->gdp->part0->bd_inode->i_blkbits =
+ blksize_bits(fdata->blksize);
}

rc = base->discipline->format_device(base, fdata, 1);