[PATCH 14/15] axonram: Pass attribute group to device_add_disk

Fam Zheng
2016-08-17T07:15:14Z

Previously after device_add_disk returns, the KOBJ_ADD uevent is already
emitted. Adding attributes after that is a poor usage of kobject, and
in practice may result in race conditions with userspace, for
example udev checks availability of certain attributes and initializes
/dev entries conditionally.

device_add_disk can handle adding attribute group better, so use it.
Meanwhile, handle the error of device_add_disk.

Signed-off-by: Fam Zheng <famz@redhat.com>
---
arch/powerpc/sysdev/axonram.c | 23 +++++++++++++++--------
1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/sysdev/axonram.c b/arch/powerpc/sysdev/axonram.c
index 6aef6c2..23109e3 100644
--- a/arch/powerpc/sysdev/axonram.c
+++ b/arch/powerpc/sysdev/axonram.c
@@ -158,6 +158,15 @@ static const struct block_device_operations axon_ram_devops = {
.direct_access = axon_ram_direct_access
};

+static struct attribute *axon_attrs[] = {
+ &dev_attr_ecc.attr,
+ NULL,
+};
+
+static struct attribute_group axon_attr_group = {
+ .attrs = axon_attrs,
+};
+
/**
* axon_ram_probe - probe() method for platform driver
* @device: see platform_driver method
@@ -237,7 +246,12 @@ static int axon_ram_probe(struct platform_device *device)
set_capacity(bank->disk, bank->size >> AXON_RAM_SECTOR_SHIFT);
blk_queue_make_request(bank->disk->queue, axon_ram_make_request);
blk_queue_logical_block_size(bank->disk->queue, AXON_RAM_SECTOR_SIZE);
- device_add_disk(&device->dev, bank->disk, NULL);
+ rc = device_add_disk(&device->dev, bank->disk, &axon_attr_group);
+ if (rc != 0) {
+ dev_err(&device->dev, "Cannot create disk\n");
+ rc = -EFAULT;
+ goto failed;
+ }

bank->irq_id = irq_of_parse_and_map(device->dev.of_node, 0);
if (bank->irq_id == NO_IRQ) {
@@ -255,13 +269,6 @@ static int axon_ram_probe(struct platform_device *device)
goto failed;
}

- rc = device_create_file(&device->dev, &dev_attr_ecc);
- if (rc != 0) {
- dev_err(&device->dev, "Cannot create sysfs file\n");
- rc = -EFAULT;
- goto failed;
- }
-
azfs_minor += bank->disk->minors;

return 0;
--
2.7.4