On Wed, May 19, 2021 at 08:57:00AM -0700, Jeff Johnson wrote: > On 2021-05-19 08:42, Greg Kroah-Hartman wrote: > > On Wed, May 19, 2021 at 08:04:59AM -0700, Jeff Johnson wrote: > > > On 2021-05-18 22:05, Greg Kroah-Hartman wrote: > > > > On Tue, May 18, 2021 at 03:00:44PM -0700, Jeff Johnson wrote: > > > > > 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. Then use some other filesystem to place your relay file in. A relay file is not a file that userspace should rely on for normal operation, so why do you need it at all? What tools/operation requires access to this file that systems without debugfs support is causing problems on? thanks, greg k-h
