Swap the calling sequence of krealloc() and __request_region(), call the
latter first. In this way, the value of dev_dax->nr_range does not need to
be considered when __request_region() failed.
Signed-off-by: Zhen Lei <[email protected]>
---
drivers/dax/bus.c | 29 ++++++++++++-----------------
1 file changed, 12 insertions(+), 17 deletions(-)
diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index 27513d311242..1efae11d947a 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -763,23 +763,15 @@ static int alloc_dev_dax_range(struct dev_dax *dev_dax, u64 start,
return 0;
}
- ranges = krealloc(dev_dax->ranges, sizeof(*ranges)
- * (dev_dax->nr_range + 1), GFP_KERNEL);
- if (!ranges)
- return -ENOMEM;
-
alloc = __request_region(res, start, size, dev_name(dev), 0);
- if (!alloc) {
- /*
- * If this was an empty set of ranges nothing else
- * will release @ranges, so do it now.
- */
- if (!dev_dax->nr_range) {
- kfree(ranges);
- ranges = NULL;
- }
- dev_dax->ranges = ranges;
+ if (!alloc)
return -ENOMEM;
+
+ ranges = krealloc(dev_dax->ranges, sizeof(*ranges)
+ * (dev_dax->nr_range + 1), GFP_KERNEL);
+ if (!ranges) {
+ rc = -ENOMEM;
+ goto err;
}
for (i = 0; i < dev_dax->nr_range; i++)
@@ -808,11 +800,14 @@ static int alloc_dev_dax_range(struct dev_dax *dev_dax, u64 start,
dev_dbg(dev, "delete range[%d]: %pa:%pa\n", dev_dax->nr_range - 1,
&alloc->start, &alloc->end);
dev_dax->nr_range--;
- __release_region(res, alloc->start, resource_size(alloc));
- return rc;
+ goto err;
}
return 0;
+
+err:
+ __release_region(res, alloc->start, resource_size(alloc));
+ return rc;
}
static int adjust_dev_dax_range(struct dev_dax *dev_dax, struct resource *res, resource_size_t size)
--
2.26.0.106.g9fadedd
On Fri, Nov 20, 2020 at 1:23 AM Zhen Lei <[email protected]> wrote:
>
> Swap the calling sequence of krealloc() and __request_region(), call the
> latter first. In this way, the value of dev_dax->nr_range does not need to
> be considered when __request_region() failed.
This looks ok, but I think I want to see another cleanup go in first
before this to add a helper for trimming the last range off the set of
ranges:
static void dev_dax_trim_range(struct dev_dax *dev_dax)
{
int i = dev_dax->nr_range - 1;
struct range *range = &dev_dax->ranges[i].range;
struct dax_region *dax_region = dev_dax->region;
dev_dbg(dev, "delete range[%d]: %#llx:%#llx\n", i,
(unsigned long long)range->start,
(unsigned long long)range->end);
__release_region(&dax_region->res, range->start, range_len(range));
if (--dev_dax->nr_range == 0) {
kfree(dev_dax->ranges);
dev_dax->ranges = NULL;
}
}
Care to do a lead in patch with that cleanup, then do this one?
I think that might also cleanup a memory leak report from Jane in
addition to not needing the "goto" as well.
http://lore.kernel.org/r/[email protected]
On 2020/12/18 11:10, Dan Williams wrote:
> On Fri, Nov 20, 2020 at 1:23 AM Zhen Lei <[email protected]> wrote:
>>
>> Swap the calling sequence of krealloc() and __request_region(), call the
>> latter first. In this way, the value of dev_dax->nr_range does not need to
>> be considered when __request_region() failed.
>
> This looks ok, but I think I want to see another cleanup go in first
> before this to add a helper for trimming the last range off the set of
> ranges:
>
> static void dev_dax_trim_range(struct dev_dax *dev_dax)
> {
> int i = dev_dax->nr_range - 1;
> struct range *range = &dev_dax->ranges[i].range;
> struct dax_region *dax_region = dev_dax->region;
>
> dev_dbg(dev, "delete range[%d]: %#llx:%#llx\n", i,
> (unsigned long long)range->start,
> (unsigned long long)range->end);
>
> __release_region(&dax_region->res, range->start, range_len(range));
> if (--dev_dax->nr_range == 0) {
> kfree(dev_dax->ranges);
> dev_dax->ranges = NULL;
> }
> }
>
> Care to do a lead in patch with that cleanup, then do this one?
I don't mind! You can add above helper first. After that, I'll update
and send this patch again.
>
> I think that might also cleanup a memory leak report from Jane in
> addition to not needing the "goto" as well.
>
> http://lore.kernel.org/r/[email protected]
>
> .
>
On 2020/11/20 17:22, Zhen Lei wrote:
> Swap the calling sequence of krealloc() and __request_region(), call the
> latter first. In this way, the value of dev_dax->nr_range does not need to
> be considered when __request_region() failed.
>
> Signed-off-by: Zhen Lei <[email protected]>
> ---
> drivers/dax/bus.c | 29 ++++++++++++-----------------
> 1 file changed, 12 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
> index 27513d311242..1efae11d947a 100644
> --- a/drivers/dax/bus.c
> +++ b/drivers/dax/bus.c
> @@ -763,23 +763,15 @@ static int alloc_dev_dax_range(struct dev_dax *dev_dax, u64 start,
> return 0;
> }
>
> - ranges = krealloc(dev_dax->ranges, sizeof(*ranges)
> - * (dev_dax->nr_range + 1), GFP_KERNEL);
> - if (!ranges)
> - return -ENOMEM;
> -
> alloc = __request_region(res, start, size, dev_name(dev), 0);
> - if (!alloc) {
> - /*
> - * If this was an empty set of ranges nothing else
> - * will release @ranges, so do it now.
> - */
> - if (!dev_dax->nr_range) {
> - kfree(ranges);
> - ranges = NULL;
> - }
> - dev_dax->ranges = ranges;
> + if (!alloc)
> return -ENOMEM;
> +
> + ranges = krealloc(dev_dax->ranges, sizeof(*ranges)
> + * (dev_dax->nr_range + 1), GFP_KERNEL);
> + if (!ranges) {
> + rc = -ENOMEM;
> + goto err;
Hi, Dan Williams:
In fact, after adding the new helper dev_dax_trim_range(), we can
directly call __release_region() and return error code at here. Replace goto.
> }
>
> for (i = 0; i < dev_dax->nr_range; i++)
> @@ -808,11 +800,14 @@ static int alloc_dev_dax_range(struct dev_dax *dev_dax, u64 start,
> dev_dbg(dev, "delete range[%d]: %pa:%pa\n", dev_dax->nr_range - 1,
> &alloc->start, &alloc->end);
> dev_dax->nr_range--;
> - __release_region(res, alloc->start, resource_size(alloc));
> - return rc;
> + goto err;
> }
>
> return 0;
> +
> +err:
> + __release_region(res, alloc->start, resource_size(alloc));
> + return rc;
> }
>
> static int adjust_dev_dax_range(struct dev_dax *dev_dax, struct resource *res, resource_size_t size)
>