In preparation for the pmem driver attaching to pmem-namespaces emitted
by libnd, convert it to use an ida instead of an always increasing
atomic index. This provides a bit of stability to pmem device names in
the presence of driver re-bind events.
Cc: Christoph Hellwig <h...@lst.de>
Signed-off-by: Dan Williams <dan.j.willi...@intel.com>
---
drivers/block/pmem.c | 22 +++++++++++++++-------
1 file changed, 15 insertions(+), 7 deletions(-)
diff --git a/drivers/block/pmem.c b/drivers/block/pmem.c
index eabf4a8d0085..e3cf9142b172 100644
--- a/drivers/block/pmem.c
+++ b/drivers/block/pmem.c
@@ -34,10 +34,11 @@ struct pmem_device {
phys_addr_t phys_addr;
void *virt_addr;
size_t size;
+ int id;
};
static int pmem_major;
-static atomic_t pmem_index;
+static DEFINE_IDA(pmem_ida);
static void pmem_do_bvec(struct pmem_device *pmem, struct page *page,
unsigned int len, unsigned int off, int rw,
@@ -122,20 +123,26 @@ static struct pmem_device *pmem_alloc(struct device *dev,
struct resource *res)
{
struct pmem_device *pmem;
struct gendisk *disk;
- int idx, err;
+ int err;
err = -ENOMEM;
pmem = kzalloc(sizeof(*pmem), GFP_KERNEL);
if (!pmem)
goto out;
+ pmem->id = ida_simple_get(&pmem_ida, 0, 0, GFP_KERNEL);
+ if (pmem->id < 0) {
+ err = pmem->id;
+ goto out_free_dev;
+ }
+
pmem->phys_addr = res->start;
pmem->size = resource_size(res);
err = -EINVAL;
if (!request_mem_region(pmem->phys_addr, pmem->size, "pmem")) {
dev_warn(dev, "could not reserve region [0x%pa:0x%zx]\n",
&pmem->phys_addr, pmem->size);
- goto out_free_dev;
+ goto out_free_ida;
}
/*
@@ -159,15 +166,13 @@ static struct pmem_device *pmem_alloc(struct device *dev,
struct resource *res)
if (!disk)
goto out_free_queue;
- idx = atomic_inc_return(&pmem_index) - 1;
-
disk->major = pmem_major;
- disk->first_minor = PMEM_MINORS * idx;
+ disk->first_minor = PMEM_MINORS * pmem->id;
disk->fops = &pmem_fops;
disk->private_data = pmem;
disk->queue = pmem->pmem_queue;
disk->flags = GENHD_FL_EXT_DEVT;
- sprintf(disk->disk_name, "pmem%d", idx);
+ sprintf(disk->disk_name, "pmem%d", pmem->id);
disk->driverfs_dev = dev;
set_capacity(disk, pmem->size >> 9);
pmem->pmem_disk = disk;
@@ -182,6 +187,8 @@ out_unmap:
iounmap(pmem->virt_addr);
out_release_region:
release_mem_region(pmem->phys_addr, pmem->size);
+out_free_ida:
+ ida_simple_remove(&pmem_ida, pmem->id);
out_free_dev:
kfree(pmem);
out:
@@ -195,6 +202,7 @@ static void pmem_free(struct pmem_device *pmem)
blk_cleanup_queue(pmem->pmem_queue);
iounmap(pmem->virt_addr);
release_mem_region(pmem->phys_addr, pmem->size);
+ ida_simple_remove(&pmem_ida, pmem->id);
kfree(pmem);
}
--
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