ping ? Any comments on this clean up patch ?
On 1/31/2023 9:44 AM, Hou Tao wrote:
> ping ? Any comments on this clean up patch ?
>
> On 1/18/2023 9:16 PM, Hou Tao wrote:
>> ping ?
>>
>> On 12/16/2022 12:23 PM, Hou Tao wrote:
>>> From: Hou Tao <hout...@huawei.com>
>>>
>>> __hash_remove() removes hash_cell with _hash_lock locked, so acquiring
>>> _hash_lock can guarantee no-NULL hc returned from dm_get_mdptr() must
>>> have not been removed and hc->md must still be md.
>>>
>>> __hash_remove() also acquires dm_hash_cells_mutex before setting mdptr
>>> as NULL, so in dm_copy_name_and_uuid() after acquiring
>>> dm_hash_cells_mutex and ensuring returned hc is not NULL, the returned
>>> hc must still be alive and hc->md must still be md.
>>>
>>> So removing these unnecessary hc->md != md checks when using
>>> dm_get_mdptr() with _hash_lock or dm_hash_cells_mutex acquired.
>>>
>>> Signed-off-by: Hou Tao <hout...@huawei.com>
>>> ---
>>> drivers/md/dm-ioctl.c | 6 +++---
>>> 1 file changed, 3 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
>>> index 3bfc1583c20a..2a86524661d1 100644
>>> --- a/drivers/md/dm-ioctl.c
>>> +++ b/drivers/md/dm-ioctl.c
>>> @@ -772,7 +772,7 @@ static struct dm_table *dm_get_inactive_table(struct
>>> mapped_device *md, int *src
>>>
>>> down_read(&_hash_lock);
>>> hc = dm_get_mdptr(md);
>>> - if (!hc || hc->md != md) {
>>> + if (!hc) {
>>> DMERR("device has been removed from the dev hash table.");
>>> goto out;
>>> }
>>> @@ -1476,7 +1476,7 @@ static int table_load(struct file *filp, struct
>>> dm_ioctl *param, size_t param_si
>>> /* stage inactive table */
>>> down_write(&_hash_lock);
>>> hc = dm_get_mdptr(md);
>>> - if (!hc || hc->md != md) {
>>> + if (!hc) {
>>> DMERR("device has been removed from the dev hash table.");
>>> up_write(&_hash_lock);
>>> r = -ENXIO;
>>> @@ -2128,7 +2128,7 @@ int dm_copy_name_and_uuid(struct mapped_device *md,
>>> char *name, char *uuid)
>>>
>>> mutex_lock(&dm_hash_cells_mutex);
>>> hc = dm_get_mdptr(md);
>>> - if (!hc || hc->md != md) {
>>> + if (!hc) {
>>> r = -ENXIO;
>>> goto out;
>>> }
> .
--
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