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dma-buf: remove restriction of IOCTL:DMA_BUF_SET_NAME 

In this patch(https://patchwork.freedesktop.org/patch/310349),
it add a new IOCTL to support dma-buf user to set debug name.

But it also added a limitation of this IOCTL, it needs the
attachments of dmabuf should be empty, otherwise it will fail.

For the original series, the idea was that allowing name change
mid-use could confuse the users about the dma-buf.
However, the rest of the series also makes sure each dma-buf have a unique
inode(https://patchwork.freedesktop.org/patch/310387/), and any accounting
should probably use that, without relying on the name as much.

So, removing this restriction will let dma-buf userspace users to use it
more comfortably and without any side effect.

Signed-off-by: Guangming Cao <Guangming.Cao@mediatek.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211014102551.54983-1-guangming.cao@mediatek.com
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
This commit is contained in:
Guangming Cao 2021-10-14 18:25:51 +08:00 committed by Christian König
parent 099afadc53
commit e73c317efb
1 changed files with 3 additions and 14 deletions
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17
drivers/dma-buf/dma-buf.c
View File

@ -293,10 +293,8 @@ static __poll_t dma_buf_poll(struct file *file, poll_table *poll)
/**
* dma_buf_set_name - Set a name to a specific dma_buf to track the usage.
* The name of the dma-buf buffer can only be set when the dma-buf is not
* attached to any devices. It could theoritically support changing the
* name of the dma-buf if the same piece of memory is used for multiple
* purpose between different devices.
* It could support changing the name of the dma-buf if the same
* piece of memory is used for multiple purpose between different devices.
*
* @dmabuf: [in] dmabuf buffer that will be renamed.
* @buf: [in] A piece of userspace memory that contains the name of
@ -309,25 +307,16 @@ static __poll_t dma_buf_poll(struct file *file, poll_table *poll)
static long dma_buf_set_name(struct dma_buf *dmabuf, const char __user *buf)
{
char *name = strndup_user(buf, DMA_BUF_NAME_LEN);
long ret = 0;
if (IS_ERR(name))
return PTR_ERR(name);
dma_resv_lock(dmabuf->resv, NULL);
if (!list_empty(&dmabuf->attachments)) {
ret = -EBUSY;
kfree(name);
goto out_unlock;
}
spin_lock(&dmabuf->name_lock);
kfree(dmabuf->name);
dmabuf->name = name;
spin_unlock(&dmabuf->name_lock);
out_unlock:
dma_resv_unlock(dmabuf->resv);
return ret;
return 0;
}
static long dma_buf_ioctl(struct file *file,