Mailing List Archive

[PATCH 16/20] block: stop using bdget_disk for partition 0
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 | 18 +++---------------
drivers/md/dm.c | 8 +-------
drivers/s390/block/dasd_ioctl.c | 5 ++---
6 files changed, 12 insertions(+), 44 deletions(-)

diff --git a/block/genhd.c b/block/genhd.c
index a14e2408e3d4e8..ec41d0f18f5ce1 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -907,7 +907,6 @@ 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 79521e33d30ed5..188e0b47534bcf 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 01757f9578dcb8..56024905bd242c 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -1748,7 +1748,7 @@ 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;
+ struct block_device *bdev = zram->disk->part0;
unsigned short do_reset;
int ret = 0;

@@ -1758,17 +1758,12 @@ 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(&bdev->bd_mutex);
if (bdev->bd_openers)
ret = -EBUSY;
else
zram_reset_device(zram);
mutex_unlock(&bdev->bd_mutex);
- bdput(bdev);

return ret ? ret : len;
}
@@ -1933,15 +1928,8 @@ static int zram_add(void)

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

del_gendisk(zram->disk);
zram_debugfs_unregister(zram);
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index c9438feefe55a3..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;
@@ -2402,7 +2397,6 @@ static void unlock_fs(struct mapped_device *md)
return;

thaw_bdev(md->frozen_sb->s_bdev, md->frozen_sb);
- bdput(md->frozen_sb->s_bdev);
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);
--
2.29.2
Re: [PATCH 16/20] block: stop using bdget_disk for partition 0 [ In reply to ]
On Wed 18-11-20 09:47:56, Christoph Hellwig wrote:
> We can just dereference the point in struct gendisk instead. Also
> remove the now unused export.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Looks good to me. You can add:

Reviewed-by: Jan Kara <jack@suse.cz>

Honza

> ---
> block/genhd.c | 1 -
> drivers/block/nbd.c | 4 +---
> drivers/block/xen-blkfront.c | 20 +++++---------------
> drivers/block/zram/zram_drv.c | 18 +++---------------
> drivers/md/dm.c | 8 +-------
> drivers/s390/block/dasd_ioctl.c | 5 ++---
> 6 files changed, 12 insertions(+), 44 deletions(-)
>
> diff --git a/block/genhd.c b/block/genhd.c
> index a14e2408e3d4e8..ec41d0f18f5ce1 100644
> --- a/block/genhd.c
> +++ b/block/genhd.c
> @@ -907,7 +907,6 @@ 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 79521e33d30ed5..188e0b47534bcf 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 01757f9578dcb8..56024905bd242c 100644
> --- a/drivers/block/zram/zram_drv.c
> +++ b/drivers/block/zram/zram_drv.c
> @@ -1748,7 +1748,7 @@ 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;
> + struct block_device *bdev = zram->disk->part0;
> unsigned short do_reset;
> int ret = 0;
>
> @@ -1758,17 +1758,12 @@ 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(&bdev->bd_mutex);
> if (bdev->bd_openers)
> ret = -EBUSY;
> else
> zram_reset_device(zram);
> mutex_unlock(&bdev->bd_mutex);
> - bdput(bdev);
>
> return ret ? ret : len;
> }
> @@ -1933,15 +1928,8 @@ static int zram_add(void)
>
> static int zram_remove(struct zram *zram)
> {
> - struct block_device *bdev = bdget_disk(zram->disk, 0);
> -
> - if (bdev) {
> - if (bdev->bd_openers) {
> - bdput(bdev);
> - return -EBUSY;
> - }
> - bdput(bdev);
> - }
> + if (zram->disk->part0->bd_openers)
> + return -EBUSY;
>
> del_gendisk(zram->disk);
> zram_debugfs_unregister(zram);
> diff --git a/drivers/md/dm.c b/drivers/md/dm.c
> index c9438feefe55a3..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;
> @@ -2402,7 +2397,6 @@ static void unlock_fs(struct mapped_device *md)
> return;
>
> thaw_bdev(md->frozen_sb->s_bdev, md->frozen_sb);
> - bdput(md->frozen_sb->s_bdev);
> 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);
> --
> 2.29.2
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR