kernel/linux.git/fs/debugfs/internal.h, branch v6.18.21

debugfs_get_aux(): allow storing non-const void *

2025-07-09T11:30:29+00:00

typechecking is up to users, anyway... Signed-off-by: Al Viro Link: https://lore.kernel.org/r/20250702212616.GI3406663@ZenIV Signed-off-by: Greg Kroah-Hartman

debugfs: allow to store an additional opaque pointer at file creation

2025-01-15T12:14:36+00:00

Set by debugfs_create_file_aux(name, mode, parent, data, aux, fops). Plain debugfs_create_file() has it set to NULL. Accessed by debugfs_get_aux(file). Convenience macros for numeric opaque data - debugfs_create_file_aux_num and debugfs_get_aux_num, resp. Signed-off-by: Al Viro Reviewed-by: Christian Brauner Link: https://lore.kernel.org/r/20250112080705.141166-5-viro@zeniv.linux.org.uk Signed-off-by: Greg Kroah-Hartman

debugfs: don't mess with bits in ->d_fsdata

2025-01-15T12:14:35+00:00

The reason we need that crap is the dual use ->d_fsdata has there - it's both holding a debugfs_fsdata reference after the first debugfs_file_get() (actually, after the call of proxy ->open()) *and* it serves as a place to stash a reference to real file_operations from object creation to the first open. Oh, and it's triple use, actually - that stashed reference might be to debugfs_short_fops. Bugger that for a game of solidiers - just put the operations reference into debugfs-private augmentation of inode. And split debugfs_full_file_operations into full and short cases, so that debugfs_get_file() could tell one from another. Voila - ->d_fsdata holds NULL until the first (successful) debugfs_get_file() and a reference to struct debugfs_fsdata afterwards. Signed-off-by: Al Viro Reviewed-by: Christian Brauner Link: https://lore.kernel.org/r/20250112080705.141166-4-viro@zeniv.linux.org.uk Signed-off-by: Greg Kroah-Hartman

debugfs: get rid of dynamically allocation proxy_ops

2025-01-15T12:14:35+00:00

All it takes is having full_proxy_open() collect the information about available methods and store it in debugfs_fsdata. Wrappers are called only after full_proxy_open() has succeeded calling debugfs_get_file(), so they are guaranteed to have ->d_fsdata already pointing to debugfs_fsdata. As the result, they can check if method is absent and bugger off early, without any atomic operations, etc. - same effect as what we'd have from NULL method. Which makes the entire proxy_fops contents unconditional, making it completely pointless - we can just put those methods (unconditionally) into debugfs_full_proxy_file_operations and forget about dynamic allocation, replace_fops, etc. Signed-off-by: Al Viro Reviewed-by: Christian Brauner Link: https://lore.kernel.org/r/20250112080705.141166-3-viro@zeniv.linux.org.uk Signed-off-by: Greg Kroah-Hartman

debugfs: move ->automount into debugfs_inode_info

2025-01-15T12:14:35+00:00

... and don't bother with debugfs_fsdata for those. Life's simpler that way... Signed-off-by: Al Viro Reviewed-by: Christian Brauner Link: https://lore.kernel.org/r/20250112080705.141166-2-viro@zeniv.linux.org.uk Signed-off-by: Greg Kroah-Hartman

debugfs: separate cache for debugfs inodes

2025-01-15T12:14:35+00:00

Embed them into container (struct debugfs_inode_info, with nothing else in it at the moment), set the cache up, etc. Just the infrastructure changes letting us augment debugfs inodes here; adding stuff will come at the next step. Signed-off-by: Al Viro Reviewed-by: Christian Brauner Link: https://lore.kernel.org/r/20250112080705.141166-1-viro@zeniv.linux.org.uk Signed-off-by: Greg Kroah-Hartman

fs: debugfs: differentiate short fops with proxy ops

2025-01-07T15:20:08+00:00

Geert reported that my previous short fops debugfs changes broke m68k, because it only has mandatory alignement of two, so we can't stash the "is it short" information into the pointer (as we already did with the "is it real" bit.) Instead, exploit the fact that debugfs_file_get() called on an already open file will already find that the fsdata is no longer the real fops but rather the allocated data that already distinguishes full/short ops, so only open() needs to be able to distinguish. We can achieve that by using two different open functions. Unfortunately this requires another set of full file ops, increasing the size by 536 bytes (x86-64), but that's still a reasonable trade-off given that only converting some of the wireless stack gained over 28k. This brings the total cost of this to around 1k, for wins of 28k (all x86-64). Reported-and-tested-by: Geert Uytterhoeven Link: https://lore.kernel.org/CAMuHMdWu_9-L2Te101w8hU7H_2yobJFPXSwwUmGHSJfaPWDKiQ@mail.gmail.com Fixes: 8dc6d81c6b2a ("debugfs: add small file operations for most files") Signed-off-by: Johannes Berg Tested-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/20241129121536.30989-2-johannes@sipsolutions.net Signed-off-by: Greg Kroah-Hartman

debugfs: add small file operations for most files

2024-10-23T14:47:01+00:00

As struct file_operations is really big, but (most) debugfs files only use simple_open, read, write and perhaps seek, and don't need anything else, this wastes a lot of space for NULL pointers. Add a struct debugfs_short_fops and some bookkeeping code in debugfs so that users can use that with debugfs_create_file() using _Generic to figure out which function to use. Converting mac80211 to use it where possible saves quite a bit of space: 1010127 205064 1220 1216411 128f9b net/mac80211/mac80211.ko (before) 981199 205064 1220 1187483 121e9b net/mac80211/mac80211.ko (after) ------- -28928 = ~28KiB With a marginal space cost in debugfs: 8701 550 16 9267 2433 fs/debugfs/inode.o (before) 25233 325 32 25590 63f6 fs/debugfs/file.o (before) 8914 558 16 9488 2510 fs/debugfs/inode.o (after) 25380 325 32 25737 6489 fs/debugfs/file.o (after) --------------- +360 +8 (All on x86-64) A simple spatch suggests there are more than 300 instances, not even counting the ones hidden in macros like in mac80211, that could be trivially converted, for additional savings of about 240 bytes for each. Reviewed-by: Greg Kroah-Hartman Link: https://patch.msgid.link/20241022151838.26f9925fb959.Ia80b55e934bbfc45ce0df42a3233d34b35508046@changeid Signed-off-by: Johannes Berg

Revert "debugfs: annotate debugfs handlers vs. removal with lockdep"

2023-12-04T06:43:16+00:00

This reverts commit f4acfcd4deb1 ("debugfs: annotate debugfs handlers vs. removal with lockdep"), it appears to have false positives and really shouldn't have been in the -rc series with the fixes anyway. Signed-off-by: Johannes Berg Link: https://lore.kernel.org/r/20231202114936.fd55431ab160.I911aa53abeeca138126f690d383a89b13eb05667@changeid Signed-off-by: Greg Kroah-Hartman

debugfs: add API to allow debugfs operations cancellation

2023-11-27T10:24:55+00:00

In some cases there might be longer-running hardware accesses in debugfs files, or attempts to acquire locks, and we want to still be able to quickly remove the files. Introduce a cancellations API to use inside the debugfs handler functions to be able to cancel such operations on a per-file basis. Acked-by: Greg Kroah-Hartman Signed-off-by: Johannes Berg