[PATCH v2 06/15] leds: trigger: blkdev: Add function to get gendisk by name
From: Ian Pilcher <hidden>
Date: 2021-09-09 22:25:36
Also in:
linux-block, lkml
Subsystem:
led subsystem, the rest · Maintainers:
Lee Jones, Pavel Machek, Linus Torvalds
Add ledtrig_blkdev_get_disk() to find block device by name and increment its reference count. (Caller must call put_disk().) Must be built-in to access block_class and disk_type symbols. Signed-off-by: Ian Pilcher <redacted> --- drivers/leds/trigger/ledtrig-blkdev-core.c | 20 ++++++++++++++++++++ drivers/leds/trigger/ledtrig-blkdev.h | 3 +++ 2 files changed, 23 insertions(+)
diff --git a/drivers/leds/trigger/ledtrig-blkdev-core.c b/drivers/leds/trigger/ledtrig-blkdev-core.c
index d7b02e760b06..5fd741aa14a6 100644
--- a/drivers/leds/trigger/ledtrig-blkdev-core.c
+++ b/drivers/leds/trigger/ledtrig-blkdev-core.c@@ -33,3 +33,23 @@ void ledtrig_blkdev_disk_cleanup(struct gendisk *const gd) mutex_unlock(&ledtrig_blkdev_mutex); } + +/* class_find_device() callback. Must be built-in to access disk_type. */ +static int blkdev_match_name(struct device *const dev, const void *const name) +{ + return dev->type == &disk_type + && sysfs_streq(dev_to_disk(dev)->disk_name, name); +} + +/* Must be built-in to access block_class */ +struct gendisk *ledtrig_blkdev_get_disk(const char *const name) +{ + struct device *dev; + + dev = class_find_device(&block_class, NULL, name, blkdev_match_name); + if (dev == NULL) + return NULL; + + return dev_to_disk(dev); +} +EXPORT_SYMBOL_NS_GPL(ledtrig_blkdev_get_disk, LEDTRIG_BLKDEV);
diff --git a/drivers/leds/trigger/ledtrig-blkdev.h b/drivers/leds/trigger/ledtrig-blkdev.h
index b1294da17ba3..a6ff24fad0c2 100644
--- a/drivers/leds/trigger/ledtrig-blkdev.h
+++ b/drivers/leds/trigger/ledtrig-blkdev.h@@ -12,4 +12,7 @@ extern struct mutex ledtrig_blkdev_mutex; extern void (*__ledtrig_blkdev_disk_cleanup)(struct gendisk *gd); +/* Caller must call put_disk() */ +struct gendisk *ledtrig_blkdev_get_disk(const char *const name); + #endif /* __LEDTRIG_BLKDEV_H */
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2.31.1