linux/fs/debugfs, branch for-next

fs: debugfs: fix open proxy for unsafe files

2025-01-10T08:41:53Z

In the previous commit referenced below, I had to split the short fops handling into different proxy fops. This necessitated knowing out-of-band whether or not the ops are short or full, when attempting to convert from fops to allocated fsdata. Unfortunately, I only converted full_proxy_open() which is used for the new full_proxy_open_regular() and full_proxy_open_short(), but forgot about the call in open_proxy_open(), used for debugfs_create_file_unsafe(). Fix that, it never has short fops. Fixes: f8f25893a477 ("fs: debugfs: differentiate short fops with proxy ops") Reported-by: Suresh Kumar Kurmi Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-lkp/202501101055.bb8bf3e7-lkp@intel.com Reported-by: Venkat Rao Bagalkote Signed-off-by: Johannes Berg Link: https://lore.kernel.org/r/20250110085826.cd74f3b7a36b.I430c79c82ec3f954c2ff9665753bf6ac9e63eef8@changeid Signed-off-by: Greg Kroah-Hartman

debugfs: fix missing mutex_destroy() in short_fops case

2025-01-07T15:20:11Z

we need that in ->real_fops == NULL, ->short_fops != NULL case Fixes: 8dc6d81c6b2a "debugfs: add small file operations for most files" Signed-off-by: Al Viro Link: https://lore.kernel.org/r/20241229081223.3193228-1-viro@zeniv.linux.org.uk Signed-off-by: Greg Kroah-Hartman

fs: debugfs: differentiate short fops with proxy ops

2025-01-07T15:20:08Z

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

2024-10-23T14:47:01Z

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

[tree-wide] finally take no_llseek out

2024-09-27T15:18:43Z

no_llseek had been defined to NULL two years ago, in commit 868941b14441 ("fs: remove no_llseek") To quote that commit, At -rc1 we'll need do a mechanical removal of no_llseek - git grep -l -w no_llseek | grep -v porting.rst | while read i; do sed -i '/\/d' $i done would do it. Unfortunately, that hadn't been done. Linus, could you do that now, so that we could finally put that thing to rest? All instances are of the form .llseek = no_llseek, so it's obviously safe. Signed-off-by: Al Viro Signed-off-by: Linus Torvalds

debugfs show actual source in /proc/mounts

2024-08-30T06:22:37Z

After its conversion to the new mount API, debugfs displays "none" in /proc/mounts instead of the actual source. Fix this by recognising its "source" mount option. Signed-off-by: Marc Aurèle La France Link: https://lore.kernel.org/r/e439fae2-01da-234b-75b9-2a7951671e27@tuyoix.net Fixes: a20971c18752 ("vfs: Convert debugfs to use the new mount API") Cc: stable@vger.kernel.org # 6.10.x: 49abee5991e1: debugfs: Convert to new uid/gid option parsing helpers Signed-off-by: Christian Brauner

Merge tag 'vfs-6.11.mount.api' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2024-07-15T18:31:32Z

Pull vfs mount API updates from Christian Brauner: - Add a generic helper to parse uid and gid mount options. Currently we open-code the same logic in various filesystems which is error prone, especially since the verification of uid and gid mount options is a sensitive operation in the face of idmappings. Add a generic helper and convert all filesystems over to it. Make sure that filesystems that are mountable in unprivileged containers verify that the specified uid and gid can be represented in the owning namespace of the filesystem. - Convert hostfs to the new mount api. * tag 'vfs-6.11.mount.api' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: fuse: Convert to new uid/gid option parsing helpers fuse: verify {g,u}id mount options correctly fat: Convert to new uid/gid option parsing helpers fat: Convert to new mount api fat: move debug into fat_mount_options vboxsf: Convert to new uid/gid option parsing helpers tracefs: Convert to new uid/gid option parsing helpers smb: client: Convert to new uid/gid option parsing helpers tmpfs: Convert to new uid/gid option parsing helpers ntfs3: Convert to new uid/gid option parsing helpers isofs: Convert to new uid/gid option parsing helpers hugetlbfs: Convert to new uid/gid option parsing helpers ext4: Convert to new uid/gid option parsing helpers exfat: Convert to new uid/gid option parsing helpers efivarfs: Convert to new uid/gid option parsing helpers debugfs: Convert to new uid/gid option parsing helpers autofs: Convert to new uid/gid option parsing helpers fs_parse: add uid & gid option option parsing helpers hostfs: Add const qualifier to host_root in hostfs_fill_super() hostfs: convert hostfs to use the new mount API

debugfs: Convert to new uid/gid option parsing helpers

2024-07-02T04:21:18Z

Convert to new uid/gid option parsing helpers Signed-off-by: Eric Sandeen Link: https://lore.kernel.org/r/b2f44ee0-3cee-49eb-a416-f26a9306eb56@redhat.com Signed-off-by: Christian Brauner

debugfs: continue to ignore unknown mount options

2024-05-28T12:32:42Z

Wolfram reported that debugfs remained empty on some of his boards triggering the message "debugfs: Unknown parameter 'auto'". The root of the issue is that we ignored unknown mount options in the old mount api but we started rejecting unknown mount options in the new mount api. Continue to ignore unknown mount options to not regress userspace. Fixes: a20971c18752 ("vfs: Convert debugfs to use the new mount API") Link: https://lore.kernel.org/r/20240527100618.np2wqiw5mz7as3vk@ninjato Reported-by: Wolfram Sang Tested-by: Wolfram Sang Signed-off-by: Christian Brauner

vfs: Convert debugfs to use the new mount API

2024-03-26T08:04:54Z

Convert the debugfs filesystem to the new internal mount API as the old one will be obsoleted and removed. This allows greater flexibility in communication of mount parameters between userspace, the VFS and the filesystem. See Documentation/filesystems/mount_api.txt for more information. Signed-off-by: David Howells Co-developed-by: Eric Sandeen Signed-off-by: Eric Sandeen [sandeen: forward port to modern kernel, fix remounting] Link: https://lore.kernel.org/r/49d1f108-46e3-443f-85a3-6dd730c5d076@redhat.com cc: Greg Kroah-Hartman cc: Rafael J. Wysocki Signed-off-by: Christian Brauner