[PATCH -next 1/5] block: add disk sequence number
From: Matteo Croce <hidden>
Date: 2021-03-15 20:04:10
Also in:
linux-fsdevel, lkml
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
From: Matteo Croce <redacted> Add a sequence number to the disk devices. This number is put in the uevent so userspace can correlate events when a driver reuses a device, like the loop one. Signed-off-by: Matteo Croce <redacted> --- block/genhd.c | 19 +++++++++++++++++++ include/linux/genhd.h | 2 ++ 2 files changed, 21 insertions(+)
diff --git a/block/genhd.c b/block/genhd.c
index 8c8f543572e6..92debcb9e061 100644
--- a/block/genhd.c
+++ b/block/genhd.c@@ -1215,8 +1215,17 @@ static void disk_release(struct device *dev) blk_put_queue(disk->queue); kfree(disk); } + +static int block_uevent(struct device *dev, struct kobj_uevent_env *env) +{ + struct gendisk *disk = dev_to_disk(dev); + + return add_uevent_var(env, "DISKSEQ=%llu", disk->diskseq); +} + struct class block_class = { .name = "block", + .dev_uevent = block_uevent, }; static char *block_devnode(struct device *dev, umode_t *mode,
@@ -1388,6 +1397,8 @@ struct gendisk *__alloc_disk_node(int minors, int node_id) disk_to_dev(disk)->class = &block_class; disk_to_dev(disk)->type = &disk_type; device_initialize(disk_to_dev(disk)); + inc_diskseq(disk); + return disk; out_destroy_part_tbl:
@@ -1938,3 +1949,11 @@ static void disk_release_events(struct gendisk *disk) WARN_ON_ONCE(disk->ev && disk->ev->block != 1); kfree(disk->ev); } + +void inc_diskseq(struct gendisk *disk) +{ + static atomic64_t diskseq; + + disk->diskseq = atomic64_inc_return(&diskseq); +} +EXPORT_SYMBOL_GPL(inc_diskseq);
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index f364619092cc..632141b360d2 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h@@ -167,6 +167,7 @@ struct gendisk { int node_id; struct badblocks *bb; struct lockdep_map lockdep_map; + u64 diskseq; }; /*
@@ -326,6 +327,7 @@ static inline void bd_unlink_disk_holder(struct block_device *bdev, #endif /* CONFIG_SYSFS */ extern struct rw_semaphore bdev_lookup_sem; +extern void inc_diskseq(struct gendisk *disk); dev_t blk_lookup_devt(const char *name, int partno); void blk_request_module(dev_t devt);
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2.30.2