Re: [PATCH v2] b43: don't save dentries for debugfs

On 2021-05-19 08:42, Greg Kroah-Hartman wrote:

On Wed, May 19, 2021 at 08:04:59AM -0700, Jeff Johnson wrote:

quoted

On 2021-05-18 22:05, Greg Kroah-Hartman wrote:

quoted

On Tue, May 18, 2021 at 03:00:44PM -0700, Jeff Johnson wrote:

quoted

On 2021-05-18 12:29, Jeff Johnson wrote:
Would still like guidance on if there is a recommended way to get a
dentry not associated with debugfs.

What do you exactly mean by "not associated with debugfs"?

And why are you passing a debugfs dentry to relay_open()?  That feels
really wrong and fragile.

I don't know the history but the relay documentation tells us:
"If you want a directory structure to contain your relay files,
you should create it using the host filesystem’s directory
creation function, e.g. debugfs_create_dir()..."

So my guess is that the original implementation followed that
advice.  I see 5 clients of this functionality, and all 5 pass a
dentry returned from debugfs_create_dir():

drivers/gpu/drm/i915/gt/uc/intel_guc_log.c, line 384
drivers/net/wireless/ath/ath10k/spectral.c, line 534
drivers/net/wireless/ath/ath11k/spectral.c, line 902
drivers/net/wireless/ath/ath9k/common-spectral.c, line 1077
kernel/trace/blktrace.c, line 549

Ah, that's just the "parent" dentry for the relayfs file.  That's fine,
not a big deal, debugfs will always provide a way for you to get that 
if
needed.

Unless debugfs is disabled, like on Android, which is the real problem 
I'm
trying to solve.

Jeff
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