lightnvm: allow targets to use sysfs

In order to register through the sysfs interface, a driver needs to know
its kobject. On a disk structure, this happens when the partition
information is added (device_add_disk), which for lightnvm takes place
after the target has been initialized. This means that on target
initialization, the kboject has not been created yet.

This patch adds a target function to let targets initialize their own
kboject as a child of the disk kobject.

Signed-off-by: Javier González <javier@cnexlabs.com>
Added exit typedef and passed gendisk instead of void pointer for exit.
Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

2 files changed, 15 insertions, 0 deletions

diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
index b2cd3d6f2a31..9bfe0352d093 100644
--- a/drivers/lightnvm/core.c
+++ b/drivers/lightnvm/core.c
@@ -289,6 +289,9 @@ static int nvm_create_tgt(struct nvm_dev *dev, struct nvm_ioctl_create *create)
         set_capacity(tdisk, tt->capacity(targetdata));
         add_disk(tdisk);
 
+        if (tt->sysfs_init && tt->sysfs_init(tdisk))
+                goto err_sysfs;
+
         t->type = tt;
         t->disk = tdisk;
         t->dev = tgt_dev;
@@ -298,6 +301,9 @@ static int nvm_create_tgt(struct nvm_dev *dev, struct nvm_ioctl_create *create)
         mutex_unlock(&dev->mlock);
 
         return 0;
+err_sysfs:
+        if (tt->exit)
+                tt->exit(targetdata);
 err_init:
         put_disk(tdisk);
 err_queue:
@@ -320,6 +326,9 @@ static void __nvm_remove_target(struct nvm_target *t)
         del_gendisk(tdisk);
         blk_cleanup_queue(q);
 
+        if (tt->sysfs_exit)
+                tt->sysfs_exit(tdisk);
+
         if (tt->exit)
                 tt->exit(tdisk->private_data);
 
diff --git a/include/linux/lightnvm.h b/include/linux/lightnvm.h
index bc282d26017a..ca45e4a088a9 100644
--- a/include/linux/lightnvm.h
+++ b/include/linux/lightnvm.h
@@ -440,6 +440,8 @@ typedef blk_qc_t (nvm_tgt_make_rq_fn)(struct request_queue *, struct bio *);
 typedef sector_t (nvm_tgt_capacity_fn)(void *);
 typedef void *(nvm_tgt_init_fn)(struct nvm_tgt_dev *, struct gendisk *);
 typedef void (nvm_tgt_exit_fn)(void *);
+typedef int (nvm_tgt_sysfs_init_fn)(struct gendisk *);
+typedef void (nvm_tgt_sysfs_exit_fn)(struct gendisk *);
 
 struct nvm_tgt_type {
         const char *name;
@@ -453,6 +455,10 @@ struct nvm_tgt_type {
         nvm_tgt_init_fn *init;
         nvm_tgt_exit_fn *exit;
 
+        /* sysfs */
+        nvm_tgt_sysfs_init_fn *sysfs_init;
+        nvm_tgt_sysfs_exit_fn *sysfs_exit;
+
         /* For internal use */
         struct list_head list;
 };