kernel/linux.git/fs/debugfs/inode.c, branch v6.6.132

debugfs: fix automount d_fsdata usage

2024-01-20T10:51:37+00:00

[ Upstream commit 0ed04a1847a10297595ac24dc7d46b35fb35f90a ] debugfs_create_automount() stores a function pointer in d_fsdata, but since commit 7c8d469877b1 ("debugfs: add support for more elaborate ->d_fsdata") debugfs_release_dentry() will free it, now conditionally on DEBUGFS_FSDATA_IS_REAL_FOPS_BIT, but that's not set for the function pointer in automount. As a result, removing an automount dentry would attempt to free the function pointer. Luckily, the only user of this (tracing) never removes it. Nevertheless, it's safer if we just handle the fsdata in one way, namely either DEBUGFS_FSDATA_IS_REAL_FOPS_BIT or allocated. Thus, change the automount to allocate it, and use the real_fops in the data to indicate whether or not automount is filled, rather than adding a type tag. At least for now this isn't actually needed, but the next changes will require it. Also check in debugfs_file_get() that it gets only called on regular files, just to make things clearer. Acked-by: Greg Kroah-Hartman Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin

debugfs: convert to ctime accessor functions

2023-07-13T08:28:05+00:00

In later patches, we're going to change how the inode's ctime field is used. Switch to using accessor functions instead of raw accesses of inode->i_ctime. Acked-by: Greg Kroah-Hartman Signed-off-by: Jeff Layton Reviewed-by: Jan Kara Message-Id: <20230705190309.579783-32-jlayton@kernel.org> Signed-off-by: Christian Brauner

Merge tag 'driver-core-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

2023-02-24T20:58:55+00:00

Pull driver core updates from Greg KH: "Here is the large set of driver core changes for 6.3-rc1. There's a lot of changes this development cycle, most of the work falls into two different categories: - fw_devlink fixes and updates. This has gone through numerous review cycles and lots of review and testing by lots of different devices. Hopefully all should be good now, and Saravana will be keeping a watch for any potential regression on odd embedded systems. - driver core changes to work to make struct bus_type able to be moved into read-only memory (i.e. const) The recent work with Rust has pointed out a number of areas in the driver core where we are passing around and working with structures that really do not have to be dynamic at all, and they should be able to be read-only making things safer overall. This is the contuation of that work (started last release with kobject changes) in moving struct bus_type to be constant. We didn't quite make it for this release, but the remaining patches will be finished up for the release after this one, but the groundwork has been laid for this effort. Other than that we have in here: - debugfs memory leak fixes in some subsystems - error path cleanups and fixes for some never-able-to-be-hit codepaths. - cacheinfo rework and fixes - Other tiny fixes, full details are in the shortlog All of these have been in linux-next for a while with no reported problems" [ Geert Uytterhoeven points out that that last sentence isn't true, and that there's a pending report that has a fix that is queued up - Linus ] * tag 'driver-core-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (124 commits) debugfs: drop inline constant formatting for ERR_PTR(-ERROR) OPP: fix error checking in opp_migrate_dentry() debugfs: update comment of debugfs_rename() i3c: fix device.h kernel-doc warnings dma-mapping: no need to pass a bus_type into get_arch_dma_ops() driver core: class: move EXPORT_SYMBOL_GPL() lines to the correct place Revert "driver core: add error handling for devtmpfs_create_node()" Revert "devtmpfs: add debug info to handle()" Revert "devtmpfs: remove return value of devtmpfs_delete_node()" driver core: cpu: don't hand-override the uevent bus_type callback. devtmpfs: remove return value of devtmpfs_delete_node() devtmpfs: add debug info to handle() driver core: add error handling for devtmpfs_create_node() driver core: bus: update my copyright notice driver core: bus: add bus_get_dev_root() function driver core: bus: constify bus_unregister() driver core: bus: constify some internal functions driver core: bus: constify bus_get_kset() driver core: bus: constify bus_register/unregister_notifier() driver core: remove private pointer from struct bus_type ...

debugfs: drop inline constant formatting for ERR_PTR(-ERROR)

2023-02-20T13:14:56+00:00

Stephen Rothwell reported htmldocs warning when merging driver-core tree for linux-next: Documentation/filesystems/api-summary:146: fs/debugfs/inode.c:804: WARNING: Inline literal start-string without end-string. The warning is due to inline constant formatting (``%CONST``) doesn't play nice with complex-name constants like ERR_PTR(-ERROR). Drop the formatting for that constant above to be consistent with similar error constants and also to fix the above warning. Link: https://lore.kernel.org/lkml/20230220163133.481e43d8@canb.auug.org.au/ Fixes: d3002468cb5d5d ("debugfs: update comment of debugfs_rename()") Reported-by: Stephen Rothwell Signed-off-by: Bagas Sanjaya Link: https://lore.kernel.org/r/20230220124721.11657-1-bagasdotme@gmail.com Signed-off-by: Greg Kroah-Hartman

debugfs: update comment of debugfs_rename()

2023-02-16T12:43:05+00:00

Since commit ff9fb72bc077 ("debugfs: return error values, not NULL") changed return value of debugfs_rename() in error cases from %NULL to %ERR_PTR(-ERROR), the comment of debugfs_rename should also be updated so as not to mislead readers. Signed-off-by: Qi Zheng Link: https://lore.kernel.org/r/20230208035634.58095-1-zhengqi.arch@bytedance.com Signed-off-by: Greg Kroah-Hartman

fs: port ->rename() to pass mnt_idmap

2023-01-19T08:24:26+00:00

Convert to struct mnt_idmap. Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner Reviewed-by: Christoph Hellwig Signed-off-by: Christian Brauner (Microsoft)

fs: port ->setattr() to pass mnt_idmap

2023-01-19T08:24:02+00:00

debugfs: Only clobber mode/uid/gid on remount if asked

2022-09-24T12:01:37+00:00

Users may have explicitly configured their debugfs permissions; we shouldn't overwrite those just because a second mount appeared. Only clobber if the options were provided at mount time. Existing behavior: ## Pre-existing status: debugfs is 0755. # chmod 755 /sys/kernel/debug/ # stat -c '%A' /sys/kernel/debug/ drwxr-xr-x ## New mount sets kernel-default permissions: # mount -t debugfs none /mnt/foo # stat -c '%A' /mnt/foo drwx------ ## Unexpected: the original mount changed permissions: # stat -c '%A' /sys/kernel/debug drwx------ New behavior: ## Pre-existing status: debugfs is 0755. # chmod 755 /sys/kernel/debug/ # stat -c '%A' /sys/kernel/debug/ drwxr-xr-x ## New mount inherits existing permissions: # mount -t debugfs none /mnt/foo # stat -c '%A' /mnt/foo drwxr-xr-x ## Expected: old mount is unchanged: # stat -c '%A' /sys/kernel/debug drwxr-xr-x Full test cases are being submitted to LTP. Signed-off-by: Brian Norris Link: https://lore.kernel.org/r/20220912163042.v3.1.Icbd40fce59f55ad74b80e5d435ea233579348a78@changeid Signed-off-by: Greg Kroah-Hartman

debugfs: add debugfs_lookup_and_remove()

2022-09-05T11:02:34+00:00

There is a very common pattern of using debugfs_remove(debufs_lookup(..)) which results in a dentry leak of the dentry that was looked up. Instead of having to open-code the correct pattern of calling dput() on the dentry, create debugfs_lookup_and_remove() to handle this pattern automatically and properly without any memory leaks. Cc: stable Reported-by: Kuyo Chang Tested-by: Kuyo Chang Link: https://lore.kernel.org/r/YxIaQ8cSinDR881k@kroah.com Signed-off-by: Greg Kroah-Hartman

debugfs: Document that debugfs_create functions need not be error checked

2022-02-25T10:56:13+00:00

As talked about in commit b792e64021ec ("drm: no need to check return value of debugfs_create functions"), in many cases we can get away with totally skipping checking the errors of debugfs functions. Let's document that so people don't add new code that needlessly checks these errors. Probably this note could be added to a boatload of functions, but that's a lot of duplication. Let's just add it to the two most frequent ones and hope people will get the idea. Suggested-by: Javier Martinez Canillas Reviewed-by: Javier Martinez Canillas Signed-off-by: Douglas Anderson Link: https://lore.kernel.org/r/20220222154555.1.I26d364db7a007f8995e8f0dac978673bc8e9f5e2@changeid Signed-off-by: Greg Kroah-Hartman