[PATCH 09/29] bcache: Convert to bdev_open_by_path()

Jan Kara
2023-09-27T09:34:57Z

Convert bcache to use bdev_open_by_path() and pass the handle around.

CC: linux-bcache@vger.kernel.org
CC: Coly Li <colyli@suse.de
CC: Kent Overstreet <kent.overstreet@gmail.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Acked-by: Coly Li <colyli@suse.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
drivers/md/bcache/bcache.h | 2 +
drivers/md/bcache/super.c | 78 ++++++++++++++++++++------------------
2 files changed, 43 insertions(+), 37 deletions(-)

diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h
index 5a79bb3c272f..2aa3f2c1f719 100644
--- a/drivers/md/bcache/bcache.h
+++ b/drivers/md/bcache/bcache.h
@@ -299,6 +299,7 @@ struct cached_dev {
struct list_head list;
struct bcache_device disk;
struct block_device *bdev;
+ struct bdev_handle *bdev_handle;

struct cache_sb sb;
struct cache_sb_disk *sb_disk;
@@ -421,6 +422,7 @@ struct cache {

struct kobject kobj;
struct block_device *bdev;
+ struct bdev_handle *bdev_handle;

struct task_struct *alloc_thread;

diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 0ae2b3676293..c11ac86be72b 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -1368,8 +1368,8 @@ static void cached_dev_free(struct closure *cl)
if (dc->sb_disk)
put_page(virt_to_page(dc->sb_disk));

- if (!IS_ERR_OR_NULL(dc->bdev))
- blkdev_put(dc->bdev, dc);
+ if (dc->bdev_handle)
+ bdev_release(dc->bdev_handle);

wake_up(&unregister_wait);

@@ -1444,7 +1444,7 @@ static int cached_dev_init(struct cached_dev *dc, unsigned int block_size)
/* Cached device - bcache superblock */

static int register_bdev(struct cache_sb *sb, struct cache_sb_disk *sb_disk,
- struct block_device *bdev,
+ struct bdev_handle *bdev_handle,
struct cached_dev *dc)
{
const char *err = "cannot allocate memory";
@@ -1452,14 +1452,15 @@ static int register_bdev(struct cache_sb *sb, struct cache_sb_disk *sb_disk,
int ret = -ENOMEM;

memcpy(&dc->sb, sb, sizeof(struct cache_sb));
- dc->bdev = bdev;
+ dc->bdev_handle = bdev_handle;
+ dc->bdev = bdev_handle->bdev;
dc->sb_disk = sb_disk;

if (cached_dev_init(dc, sb->block_size << 9))
goto err;

err = "error creating kobject";
- if (kobject_add(&dc->disk.kobj, bdev_kobj(bdev), "bcache"))
+ if (kobject_add(&dc->disk.kobj, bdev_kobj(dc->bdev), "bcache"))
goto err;
if (bch_cache_accounting_add_kobjs(&dc->accounting, &dc->disk.kobj))
goto err;
@@ -2216,8 +2217,8 @@ void bch_cache_release(struct kobject *kobj)
if (ca->sb_disk)
put_page(virt_to_page(ca->sb_disk));

- if (!IS_ERR_OR_NULL(ca->bdev))
- blkdev_put(ca->bdev, ca);
+ if (ca->bdev_handle)
+ bdev_release(ca->bdev_handle);

kfree(ca);
module_put(THIS_MODULE);
@@ -2337,16 +2338,18 @@ static int cache_alloc(struct cache *ca)
}

static int register_cache(struct cache_sb *sb, struct cache_sb_disk *sb_disk,
- struct block_device *bdev, struct cache *ca)
+ struct bdev_handle *bdev_handle,
+ struct cache *ca)
{
const char *err = NULL; /* must be set for any error case */
int ret = 0;

memcpy(&ca->sb, sb, sizeof(struct cache_sb));
- ca->bdev = bdev;
+ ca->bdev_handle = bdev_handle;
+ ca->bdev = bdev_handle->bdev;
ca->sb_disk = sb_disk;

- if (bdev_max_discard_sectors((bdev)))
+ if (bdev_max_discard_sectors((bdev_handle->bdev)))
ca->discard = CACHE_DISCARD(&ca->sb);

ret = cache_alloc(ca);
@@ -2354,10 +2357,10 @@ static int register_cache(struct cache_sb *sb, struct cache_sb_disk *sb_disk,
/*
* If we failed here, it means ca->kobj is not initialized yet,
* kobject_put() won't be called and there is no chance to
- * call blkdev_put() to bdev in bch_cache_release(). So we
- * explicitly call blkdev_put() here.
+ * call bdev_release() to bdev in bch_cache_release(). So
+ * we explicitly call bdev_release() here.
*/
- blkdev_put(bdev, ca);
+ bdev_release(bdev_handle);
if (ret == -ENOMEM)
err = "cache_alloc(): -ENOMEM";
else if (ret == -EPERM)
@@ -2367,7 +2370,7 @@ static int register_cache(struct cache_sb *sb, struct cache_sb_disk *sb_disk,
goto err;
}

- if (kobject_add(&ca->kobj, bdev_kobj(bdev), "bcache")) {
+ if (kobject_add(&ca->kobj, bdev_kobj(bdev_handle->bdev), "bcache")) {
err = "error calling kobject_add";
ret = -ENOMEM;
goto out;
@@ -2382,14 +2385,14 @@ static int register_cache(struct cache_sb *sb, struct cache_sb_disk *sb_disk,
goto out;
}

- pr_info("registered cache device %pg\n", ca->bdev);
+ pr_info("registered cache device %pg\n", ca->bdev_handle->bdev);

out:
kobject_put(&ca->kobj);

err:
if (err)
- pr_notice("error %pg: %s\n", ca->bdev, err);
+ pr_notice("error %pg: %s\n", ca->bdev_handle->bdev, err);

return ret;
}
@@ -2445,7 +2448,7 @@ struct async_reg_args {
char *path;
struct cache_sb *sb;
struct cache_sb_disk *sb_disk;
- struct block_device *bdev;
+ struct bdev_handle *bdev_handle;
void *holder;
};

@@ -2456,8 +2459,8 @@ static void register_bdev_worker(struct work_struct *work)
container_of(work, struct async_reg_args, reg_work.work);

mutex_lock(&bch_register_lock);
- if (register_bdev(args->sb, args->sb_disk, args->bdev, args->holder)
- < 0)
+ if (register_bdev(args->sb, args->sb_disk, args->bdev_handle,
+ args->holder) < 0)
fail = true;
mutex_unlock(&bch_register_lock);

@@ -2477,7 +2480,8 @@ static void register_cache_worker(struct work_struct *work)
container_of(work, struct async_reg_args, reg_work.work);

/* blkdev_put() will be called in bch_cache_release() */
- if (register_cache(args->sb, args->sb_disk, args->bdev, args->holder))
+ if (register_cache(args->sb, args->sb_disk, args->bdev_handle,
+ args->holder))
fail = true;

if (fail)
@@ -2514,7 +2518,7 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
char *path = NULL;
struct cache_sb *sb;
struct cache_sb_disk *sb_disk;
- struct block_device *bdev, *bdev2;
+ struct bdev_handle *bdev_handle, *bdev_handle2;
void *holder = NULL;
ssize_t ret;
bool async_registration = false;
@@ -2547,15 +2551,15 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,

ret = -EINVAL;
err = "failed to open device";
- bdev = blkdev_get_by_path(strim(path), BLK_OPEN_READ, NULL, NULL);
- if (IS_ERR(bdev))
+ bdev_handle = bdev_open_by_path(strim(path), BLK_OPEN_READ, NULL, NULL);
+ if (IS_ERR(bdev_handle))
goto out_free_sb;

err = "failed to set blocksize";
- if (set_blocksize(bdev, 4096))
+ if (set_blocksize(bdev_handle->bdev, 4096))
goto out_blkdev_put;

- err = read_super(sb, bdev, &sb_disk);
+ err = read_super(sb, bdev_handle->bdev, &sb_disk);
if (err)
goto out_blkdev_put;

@@ -2567,13 +2571,13 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
}

/* Now reopen in exclusive mode with proper holder */
- bdev2 = blkdev_get_by_dev(bdev->bd_dev, BLK_OPEN_READ | BLK_OPEN_WRITE,
- holder, NULL);
- blkdev_put(bdev, NULL);
- bdev = bdev2;
- if (IS_ERR(bdev)) {
- ret = PTR_ERR(bdev);
- bdev = NULL;
+ bdev_handle2 = bdev_open_by_dev(bdev_handle->bdev->bd_dev,
+ BLK_OPEN_READ | BLK_OPEN_WRITE, holder, NULL);
+ bdev_release(bdev_handle);
+ bdev_handle = bdev_handle2;
+ if (IS_ERR(bdev_handle)) {
+ ret = PTR_ERR(bdev_handle);
+ bdev_handle = NULL;
if (ret == -EBUSY) {
dev_t dev;

@@ -2608,7 +2612,7 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
args->path = path;
args->sb = sb;
args->sb_disk = sb_disk;
- args->bdev = bdev;
+ args->bdev_handle = bdev_handle;
args->holder = holder;
register_device_async(args);
/* No wait and returns to user space */
@@ -2617,14 +2621,14 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,

if (SB_IS_BDEV(sb)) {
mutex_lock(&bch_register_lock);
- ret = register_bdev(sb, sb_disk, bdev, holder);
+ ret = register_bdev(sb, sb_disk, bdev_handle, holder);
mutex_unlock(&bch_register_lock);
/* blkdev_put() will be called in cached_dev_free() */
if (ret < 0)
goto out_free_sb;
} else {
/* blkdev_put() will be called in bch_cache_release() */
- ret = register_cache(sb, sb_disk, bdev, holder);
+ ret = register_cache(sb, sb_disk, bdev_handle, holder);
if (ret)
goto out_free_sb;
}
@@ -2640,8 +2644,8 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
out_put_sb_page:
put_page(virt_to_page(sb_disk));
out_blkdev_put:
- if (bdev)
- blkdev_put(bdev, holder);
+ if (bdev_handle)
+ bdev_release(bdev_handle);
out_free_sb:
kfree(sb);
out_free_path:
--
2.35.3