| Message ID | 20210521055116.1053587-6-hch@lst.de |
|---|---|
| State | New |
| Headers | show |
| Series | [01/26] block: refactor device number setup in __device_add_disk | expand |
On Fri, May 21, 2021 at 07:50:55AM +0200, Christoph Hellwig wrote: > Add two new APIs to allocate and free a gendisk including the > request_queue for use with BIO based drivers. This is to avoid > boilerplate code in drivers. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > block/genhd.c | 35 +++++++++++++++++++++++++++++++++++ > include/linux/genhd.h | 22 ++++++++++++++++++++++ > 2 files changed, 57 insertions(+) > > diff --git a/block/genhd.c b/block/genhd.c > index e4974af3d729..6d4ce962866d 100644 > --- a/block/genhd.c > +++ b/block/genhd.c > @@ -1302,6 +1302,25 @@ struct gendisk *__alloc_disk_node(int minors, int node_id) > } > EXPORT_SYMBOL(__alloc_disk_node); > > +struct gendisk *__blk_alloc_disk(int node) > +{ > + struct request_queue *q; > + struct gendisk *disk; > + > + q = blk_alloc_queue(node); > + if (!q) > + return NULL; > + > + disk = __alloc_disk_node(0, node); > + if (!disk) { > + blk_cleanup_queue(q); > + return NULL; > + } > + disk->queue = q; > + return disk; > +} > +EXPORT_SYMBOL(__blk_alloc_disk); Its not obvious to me why using this new API requires you then to set minors explicitly to 1, and yet here underneath we see the minors argument passed is 0. Nor is it clear from the documentation. Luis
On 5/21/21 7:50 AM, Christoph Hellwig wrote: > Add two new APIs to allocate and free a gendisk including the > request_queue for use with BIO based drivers. This is to avoid > boilerplate code in drivers. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > block/genhd.c | 35 +++++++++++++++++++++++++++++++++++ > include/linux/genhd.h | 22 ++++++++++++++++++++++ > 2 files changed, 57 insertions(+) > Reviewed-by: Hannes Reinecke <hare@suse.de> Cheers, Hannes -- Dr. Hannes Reinecke Kernel Storage Architect hare@suse.de +49 911 74053 688 SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg HRB 36809 (AG Nürnberg), Geschäftsführer: Felix Imendörffer
On Fri, May 21, 2021 at 05:44:07PM +0000, Luis Chamberlain wrote: > Its not obvious to me why using this new API requires you then to > set minors explicitly to 1, and yet here underneath we see the minors > argument passed is 0. > > Nor is it clear from the documentation. Basically for all new drivers no one should set minors at all, and the dynamic dev_t mechanism does all the work. For converted old drivers minors is set manually instead of being passed an an argument that should be 0 for all new drivers.
diff --git a/block/genhd.c b/block/genhd.c index e4974af3d729..6d4ce962866d 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -1302,6 +1302,25 @@ struct gendisk *__alloc_disk_node(int minors, int node_id) } EXPORT_SYMBOL(__alloc_disk_node); +struct gendisk *__blk_alloc_disk(int node) +{ + struct request_queue *q; + struct gendisk *disk; + + q = blk_alloc_queue(node); + if (!q) + return NULL; + + disk = __alloc_disk_node(0, node); + if (!disk) { + blk_cleanup_queue(q); + return NULL; + } + disk->queue = q; + return disk; +} +EXPORT_SYMBOL(__blk_alloc_disk); + /** * put_disk - decrements the gendisk refcount * @disk: the struct gendisk to decrement the refcount for @@ -1319,6 +1338,22 @@ void put_disk(struct gendisk *disk) } EXPORT_SYMBOL(put_disk); +/** + * blk_cleanup_disk - shutdown a gendisk allocated by blk_alloc_disk + * @disk: gendisk to shutdown + * + * Mark the queue hanging off @disk DYING, drain all pending requests, then mark + * the queue DEAD, destroy and put it and the gendisk structure. + * + * Context: can sleep + */ +void blk_cleanup_disk(struct gendisk *disk) +{ + blk_cleanup_queue(disk->queue); + put_disk(disk); +} +EXPORT_SYMBOL(blk_cleanup_disk); + static void set_disk_ro_uevent(struct gendisk *gd, int ro) { char event[] = "DISK_RO=1"; diff --git a/include/linux/genhd.h b/include/linux/genhd.h index a5443f0b139d..03aa12730634 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -278,6 +278,28 @@ extern void put_disk(struct gendisk *disk); #define alloc_disk(minors) alloc_disk_node(minors, NUMA_NO_NODE) +/** + * blk_alloc_disk - allocate a gendisk structure + * @node_id: numa node to allocate on + * + * Allocate and pre-initialize a gendisk structure for use with BIO based + * drivers. + * + * Context: can sleep + */ +#define blk_alloc_disk(node_id) \ +({ \ + struct gendisk *__disk = __blk_alloc_disk(node_id); \ + static struct lock_class_key __key; \ + \ + if (__disk) \ + lockdep_init_map(&__disk->lockdep_map, \ + "(bio completion)", &__key, 0); \ + __disk; \ +}) +struct gendisk *__blk_alloc_disk(int node); +void blk_cleanup_disk(struct gendisk *disk); + int __register_blkdev(unsigned int major, const char *name, void (*probe)(dev_t devt)); #define register_blkdev(major, name) \
Add two new APIs to allocate and free a gendisk including the request_queue for use with BIO based drivers. This is to avoid boilerplate code in drivers. Signed-off-by: Christoph Hellwig <hch@lst.de> --- block/genhd.c | 35 +++++++++++++++++++++++++++++++++++ include/linux/genhd.h | 22 ++++++++++++++++++++++ 2 files changed, 57 insertions(+)