| Message ID | 20210521055116.1053587-7-hch@lst.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [01/26] block: refactor device number setup in __device_add_disk | expand |
On 5/21/21 7:50 AM, Christoph Hellwig wrote: > Convert the brd driver to use the blk_alloc_disk and blk_cleanup_disk > helpers to simplify gendisk and request_queue allocation. This also > allows to remove the request_queue pointer in struct request_queue, > and to simplify the initialization as blk_cleanup_disk can be called > on any disk returned from blk_alloc_disk. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > drivers/block/brd.c | 94 ++++++++++++++++----------------------------- > 1 file changed, 33 insertions(+), 61 deletions(-) > > diff --git a/drivers/block/brd.c b/drivers/block/brd.c > index 7562cf30b14e..95694113e38e 100644 > --- a/drivers/block/brd.c > +++ b/drivers/block/brd.c > @@ -38,9 +38,7 @@ > * device). > */ > struct brd_device { > - int brd_number; > - > - struct request_queue *brd_queue; > + int brd_number; > struct gendisk *brd_disk; > struct list_head brd_list; > > @@ -372,7 +370,7 @@ static LIST_HEAD(brd_devices); > static DEFINE_MUTEX(brd_devices_mutex); > static struct dentry *brd_debugfs_dir; > > -static struct brd_device *brd_alloc(int i) > +static int brd_alloc(int i) > { > struct brd_device *brd; > struct gendisk *disk; > @@ -380,64 +378,55 @@ static struct brd_device *brd_alloc(int i) > > brd = kzalloc(sizeof(*brd), GFP_KERNEL); > if (!brd) > - goto out; > + return -ENOMEM; > brd->brd_number = i; > spin_lock_init(&brd->brd_lock); > INIT_RADIX_TREE(&brd->brd_pages, GFP_ATOMIC); > > - brd->brd_queue = blk_alloc_queue(NUMA_NO_NODE); > - if (!brd->brd_queue) > - goto out_free_dev; > - > snprintf(buf, DISK_NAME_LEN, "ram%d", i); > if (!IS_ERR_OR_NULL(brd_debugfs_dir)) > debugfs_create_u64(buf, 0444, brd_debugfs_dir, > &brd->brd_nr_pages); > > - /* This is so fdisk will align partitions on 4k, because of > - * direct_access API needing 4k alignment, returning a PFN > - * (This is only a problem on very small devices <= 4M, > - * otherwise fdisk will align on 1M. Regardless this call > - * is harmless) > - */ > - blk_queue_physical_block_size(brd->brd_queue, PAGE_SIZE); > - disk = brd->brd_disk = alloc_disk(max_part); > + disk = brd->brd_disk = blk_alloc_disk(NUMA_NO_NODE); > if (!disk) > - goto out_free_queue; > + goto out_free_dev; > + > disk->major = RAMDISK_MAJOR; > disk->first_minor = i * max_part; > + disk->minors = max_part; > disk->fops = &brd_fops; > disk->private_data = brd; > disk->flags = GENHD_FL_EXT_DEVT; > strlcpy(disk->disk_name, buf, DISK_NAME_LEN); > set_capacity(disk, rd_size * 2); > + > + /* > + * This is so fdisk will align partitions on 4k, because of > + * direct_access API needing 4k alignment, returning a PFN > + * (This is only a problem on very small devices <= 4M, > + * otherwise fdisk will align on 1M. Regardless this call > + * is harmless) > + */ > + blk_queue_physical_block_size(disk->queue, PAGE_SIZE); > Maybe converting the comment to refer to 'PAGE_SIZE' instead of 4k while you're at it ... > /* Tell the block layer that this is not a rotational device */ > - blk_queue_flag_set(QUEUE_FLAG_NONROT, brd->brd_queue); > - blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, brd->brd_queue); > + blk_queue_flag_set(QUEUE_FLAG_NONROT, disk->queue); > + blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, disk->queue); > + add_disk(disk); > + list_add_tail(&brd->brd_list, &brd_devices); > > - return brd; > + return 0; > > -out_free_queue: > - blk_cleanup_queue(brd->brd_queue); > out_free_dev: > kfree(brd); > -out: > - return NULL; > -} > - > -static void brd_free(struct brd_device *brd) > -{ > - put_disk(brd->brd_disk); > - blk_cleanup_queue(brd->brd_queue); > - brd_free_pages(brd); > - kfree(brd); > + return -ENOMEM; > } > > static void brd_probe(dev_t dev) > { > - struct brd_device *brd; > int i = MINOR(dev) / max_part; > + struct brd_device *brd; > > mutex_lock(&brd_devices_mutex); > list_for_each_entry(brd, &brd_devices, brd_list) { > @@ -445,13 +434,7 @@ static void brd_probe(dev_t dev) > goto out_unlock; > } > > - brd = brd_alloc(i); > - if (brd) { > - brd->brd_disk->queue = brd->brd_queue; > - add_disk(brd->brd_disk); > - list_add_tail(&brd->brd_list, &brd_devices); > - } > - > + brd_alloc(i); > out_unlock: > mutex_unlock(&brd_devices_mutex); > } > @@ -460,7 +443,9 @@ static void brd_del_one(struct brd_device *brd) > { > list_del(&brd->brd_list); > del_gendisk(brd->brd_disk); > - brd_free(brd); > + blk_cleanup_disk(brd->brd_disk); > + brd_free_pages(brd); > + kfree(brd); > } > > static inline void brd_check_and_reset_par(void) > @@ -485,7 +470,7 @@ static inline void brd_check_and_reset_par(void) > static int __init brd_init(void) > { > struct brd_device *brd, *next; > - int i; > + int err, i; > > /* > * brd module now has a feature to instantiate underlying device > @@ -511,22 +496,11 @@ static int __init brd_init(void) > > mutex_lock(&brd_devices_mutex); > for (i = 0; i < rd_nr; i++) { > - brd = brd_alloc(i); > - if (!brd) > + err = brd_alloc(i); > + if (err) > goto out_free; > - list_add_tail(&brd->brd_list, &brd_devices); > } > > - /* point of no return */ > - > - list_for_each_entry(brd, &brd_devices, brd_list) { > - /* > - * associate with queue just before adding disk for > - * avoiding to mess up failure path > - */ > - brd->brd_disk->queue = brd->brd_queue; > - add_disk(brd->brd_disk); > - } > mutex_unlock(&brd_devices_mutex); > > pr_info("brd: module loaded\n"); > @@ -535,15 +509,13 @@ static int __init brd_init(void) > out_free: > debugfs_remove_recursive(brd_debugfs_dir); > > - list_for_each_entry_safe(brd, next, &brd_devices, brd_list) { > - list_del(&brd->brd_list); > - brd_free(brd); > - } > + list_for_each_entry_safe(brd, next, &brd_devices, brd_list) > + brd_del_one(brd); > mutex_unlock(&brd_devices_mutex); > unregister_blkdev(RAMDISK_MAJOR, "ramdisk"); > > pr_info("brd: module NOT loaded !!!\n"); > - return -ENOMEM; > + return err; > } > > static void __exit brd_exit(void) > Other than that: Reviewed-by: Hannes Reinecke <hare@suse.de> Cheers, Hannes
On Sun, May 23, 2021 at 09:58:48AM +0200, Hannes Reinecke wrote: >> + /* >> + * This is so fdisk will align partitions on 4k, because of >> + * direct_access API needing 4k alignment, returning a PFN >> + * (This is only a problem on very small devices <= 4M, >> + * otherwise fdisk will align on 1M. Regardless this call >> + * is harmless) >> + */ >> + blk_queue_physical_block_size(disk->queue, PAGE_SIZE); >> > > Maybe converting the comment to refer to 'PAGE_SIZE' instead of 4k while > you're at it ... I really do not want to touch these kinds of unrelated things here.
diff --git a/drivers/block/brd.c b/drivers/block/brd.c index 7562cf30b14e..95694113e38e 100644 --- a/drivers/block/brd.c +++ b/drivers/block/brd.c @@ -38,9 +38,7 @@ * device). */ struct brd_device { - int brd_number; - - struct request_queue *brd_queue; + int brd_number; struct gendisk *brd_disk; struct list_head brd_list; @@ -372,7 +370,7 @@ static LIST_HEAD(brd_devices); static DEFINE_MUTEX(brd_devices_mutex); static struct dentry *brd_debugfs_dir; -static struct brd_device *brd_alloc(int i) +static int brd_alloc(int i) { struct brd_device *brd; struct gendisk *disk; @@ -380,64 +378,55 @@ static struct brd_device *brd_alloc(int i) brd = kzalloc(sizeof(*brd), GFP_KERNEL); if (!brd) - goto out; + return -ENOMEM; brd->brd_number = i; spin_lock_init(&brd->brd_lock); INIT_RADIX_TREE(&brd->brd_pages, GFP_ATOMIC); - brd->brd_queue = blk_alloc_queue(NUMA_NO_NODE); - if (!brd->brd_queue) - goto out_free_dev; - snprintf(buf, DISK_NAME_LEN, "ram%d", i); if (!IS_ERR_OR_NULL(brd_debugfs_dir)) debugfs_create_u64(buf, 0444, brd_debugfs_dir, &brd->brd_nr_pages); - /* This is so fdisk will align partitions on 4k, because of - * direct_access API needing 4k alignment, returning a PFN - * (This is only a problem on very small devices <= 4M, - * otherwise fdisk will align on 1M. Regardless this call - * is harmless) - */ - blk_queue_physical_block_size(brd->brd_queue, PAGE_SIZE); - disk = brd->brd_disk = alloc_disk(max_part); + disk = brd->brd_disk = blk_alloc_disk(NUMA_NO_NODE); if (!disk) - goto out_free_queue; + goto out_free_dev; + disk->major = RAMDISK_MAJOR; disk->first_minor = i * max_part; + disk->minors = max_part; disk->fops = &brd_fops; disk->private_data = brd; disk->flags = GENHD_FL_EXT_DEVT; strlcpy(disk->disk_name, buf, DISK_NAME_LEN); set_capacity(disk, rd_size * 2); + + /* + * This is so fdisk will align partitions on 4k, because of + * direct_access API needing 4k alignment, returning a PFN + * (This is only a problem on very small devices <= 4M, + * otherwise fdisk will align on 1M. Regardless this call + * is harmless) + */ + blk_queue_physical_block_size(disk->queue, PAGE_SIZE); /* Tell the block layer that this is not a rotational device */ - blk_queue_flag_set(QUEUE_FLAG_NONROT, brd->brd_queue); - blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, brd->brd_queue); + blk_queue_flag_set(QUEUE_FLAG_NONROT, disk->queue); + blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, disk->queue); + add_disk(disk); + list_add_tail(&brd->brd_list, &brd_devices); - return brd; + return 0; -out_free_queue: - blk_cleanup_queue(brd->brd_queue); out_free_dev: kfree(brd); -out: - return NULL; -} - -static void brd_free(struct brd_device *brd) -{ - put_disk(brd->brd_disk); - blk_cleanup_queue(brd->brd_queue); - brd_free_pages(brd); - kfree(brd); + return -ENOMEM; } static void brd_probe(dev_t dev) { - struct brd_device *brd; int i = MINOR(dev) / max_part; + struct brd_device *brd; mutex_lock(&brd_devices_mutex); list_for_each_entry(brd, &brd_devices, brd_list) { @@ -445,13 +434,7 @@ static void brd_probe(dev_t dev) goto out_unlock; } - brd = brd_alloc(i); - if (brd) { - brd->brd_disk->queue = brd->brd_queue; - add_disk(brd->brd_disk); - list_add_tail(&brd->brd_list, &brd_devices); - } - + brd_alloc(i); out_unlock: mutex_unlock(&brd_devices_mutex); } @@ -460,7 +443,9 @@ static void brd_del_one(struct brd_device *brd) { list_del(&brd->brd_list); del_gendisk(brd->brd_disk); - brd_free(brd); + blk_cleanup_disk(brd->brd_disk); + brd_free_pages(brd); + kfree(brd); } static inline void brd_check_and_reset_par(void) @@ -485,7 +470,7 @@ static inline void brd_check_and_reset_par(void) static int __init brd_init(void) { struct brd_device *brd, *next; - int i; + int err, i; /* * brd module now has a feature to instantiate underlying device @@ -511,22 +496,11 @@ static int __init brd_init(void) mutex_lock(&brd_devices_mutex); for (i = 0; i < rd_nr; i++) { - brd = brd_alloc(i); - if (!brd) + err = brd_alloc(i); + if (err) goto out_free; - list_add_tail(&brd->brd_list, &brd_devices); } - /* point of no return */ - - list_for_each_entry(brd, &brd_devices, brd_list) { - /* - * associate with queue just before adding disk for - * avoiding to mess up failure path - */ - brd->brd_disk->queue = brd->brd_queue; - add_disk(brd->brd_disk); - } mutex_unlock(&brd_devices_mutex); pr_info("brd: module loaded\n"); @@ -535,15 +509,13 @@ static int __init brd_init(void) out_free: debugfs_remove_recursive(brd_debugfs_dir); - list_for_each_entry_safe(brd, next, &brd_devices, brd_list) { - list_del(&brd->brd_list); - brd_free(brd); - } + list_for_each_entry_safe(brd, next, &brd_devices, brd_list) + brd_del_one(brd); mutex_unlock(&brd_devices_mutex); unregister_blkdev(RAMDISK_MAJOR, "ramdisk"); pr_info("brd: module NOT loaded !!!\n"); - return -ENOMEM; + return err; } static void __exit brd_exit(void)
Convert the brd driver to use the blk_alloc_disk and blk_cleanup_disk helpers to simplify gendisk and request_queue allocation. This also allows to remove the request_queue pointer in struct request_queue, and to simplify the initialization as blk_cleanup_disk can be called on any disk returned from blk_alloc_disk. Signed-off-by: Christoph Hellwig <hch@lst.de> --- drivers/block/brd.c | 94 ++++++++++++++++----------------------------- 1 file changed, 33 insertions(+), 61 deletions(-)