kernel/linux.git/fs/sysfs/group.c, branch v6.6.131

sysfs: Skip empty folders creation

2023-06-15T11:37:53+00:00

Most sysfs attributes are statically defined, the goal with this design being to be able to move all the filesystem description into read-only memory. Anyway, it may be relevant in some cases to populate attributes at run time. This leads to situation where an attribute may or may not be present depending on conditions which are not known at compile time, up to the point where no attribute at all gets added in a folder which then becomes "sometimes" empty. Problem is, providing an attribute group with a name and without .[bin_]attrs members will be loudly refused by the core, leading in most cases to a device registration failure. The simple way to support such situation right now is to dynamically allocate an empty attribute array, which is: * a (small) waste of space * a waste of time * disturbing, to say the least, as an empty sysfs folder will be created anyway. Another (even worse) possibility would be to dynamically overwrite a member of the attribute_group list, hopefully the last, which is also supposed to remain in the read-only section. In order to avoid these hackish situations, while still giving a little bit of flexibility, we might just check the validity of the .[bin_]attrs list and, if empty, just skip the attribute group creation instead of failing. This way, developers will not be tempted to workaround the core with useless allocations or strange writes on supposedly read-only structures. The content of the WARN() message is kept but turned into a debug message in order to help developers understanding why their sysfs folders might now silently fail to be created. Signed-off-by: Miquel Raynal Message-ID: <20230614063018.2419043-3-miquel.raynal@bootlin.com> Signed-off-by: Greg Kroah-Hartman

sysfs: Improve readability by following the kernel coding style

2023-06-15T11:37:50+00:00

The purpose of the if/else block is to select the right sysfs directory entry to be used for the files creation. At a first look when you have the file in front of you, it really seems like the "create_files()" lines right after the block are badly indented and the "else" does not guard. In practice the code is correct but lacks curly brackets to show where the big if/else block actually ends. Add these brackets to comply with the current kernel coding style and to ease the understanding of the whole logic. Signed-off-by: Miquel Raynal Message-ID: <20230614063018.2419043-2-miquel.raynal@bootlin.com> Signed-off-by: Greg Kroah-Hartman

sysfs: split out binary attribute handling from sysfs_add_file_mode_ns

2021-09-14T14:59:46+00:00

Split adding binary attributes into a separate handler instead of overloading sysfs_add_file_mode_ns. Acked-by: Christian Brauner Acked-by: Tejun Heo Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20210913054121.616001-5-hch@lst.de Signed-off-by: Greg Kroah-Hartman

sysfs: Use local reference in compat_only_sysfs_link_entry_to_kobj()

2021-07-21T14:11:42+00:00

As we have just obtained target_kobj->sd into a local variable, and incremented the object's reference count, it is better to use the local variable instead of the original reference. Signed-off-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/20210714151559.2532572-1-geert@linux-m68k.org Signed-off-by: Greg Kroah-Hartman

sysfs: remove redundant __compat_only_sysfs_link_entry_to_kobj fn

2020-04-05T18:34:35+00:00

Commit 9255782f7061 ("sysfs: Wrap __compat_only_sysfs_link_entry_to_kobj function to change the symlink name") made this function a wrapper around a new non-underscored function, which is a bit odd. The normal naming convention is the other way around: the underscored function is the wrappee, and the non-underscored function is the wrapper. There's only one single user (well, two call-sites in that user) of the more limited double underscore version of this function, so just remove the oddly named wrapper entirely and just add the extra NULL argument to the user. I considered just doing that in the merge, but that tends to make history really hard to read. Link: https://lore.kernel.org/lkml/CAHk-=wgkkmNV5tMzQDmPAQuNJBuMcry--Jb+h8H1o4RA3kF7QQ@mail.gmail.com/ Cc: Sourabh Jain Cc: Michael Ellerman Signed-off-by: Linus Torvalds

Merge tag 'powerpc-5.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2020-04-05T18:12:59+00:00

Pull powerpc updates from Michael Ellerman: "Slightly late as I had to rebase mid-week to insert a bug fix: - A large series from Nick for 64-bit to further rework our exception vectors, and rewrite portions of the syscall entry/exit and interrupt return in C. The result is much easier to follow code that is also faster in general. - Cleanup of our ptrace code to split various parts out that had become badly intertwined with #ifdefs over the years. - Changes to our NUMA setup under the PowerVM hypervisor which should hopefully avoid non-sensical topologies which can lead to warnings from the workqueue code and other problems. - MAINTAINERS updates to remove some of our old orphan entries and update the status of others. - Quite a few other small changes and fixes all over the map. Thanks to: Abdul Haleem, afzal mohammed, Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V, Balamuruhan S, Cédric Le Goater, Chen Zhou, Christophe JAILLET, Christophe Leroy, Christoph Hellwig, Clement Courbet, Daniel Axtens, David Gibson, Douglas Miller, Fabiano Rosas, Fangrui Song, Ganesh Goudar, Gautham R. Shenoy, Greg Kroah-Hartman, Greg Kurz, Gustavo Luiz Duarte, Hari Bathini, Ilie Halip, Jan Kara, Joe Lawrence, Joe Perches, Kajol Jain, Larry Finger, Laurentiu Tudor, Leonardo Bras, Libor Pechacek, Madhavan Srinivasan, Mahesh Salgaonkar, Masahiro Yamada, Masami Hiramatsu, Mauricio Faria de Oliveira, Michael Neuling, Michal Suchanek, Mike Rapoport, Nageswara R Sastry, Nathan Chancellor, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Nick Desaulniers, Oliver O'Halloran, Po-Hsu Lin, Pratik Rajesh Sampat, Rasmus Villemoes, Ravi Bangoria, Roman Bolshakov, Sam Bobroff, Sandipan Das, Santosh S, Sedat Dilek, Segher Boessenkool, Shilpasri G Bhat, Sourabh Jain, Srikar Dronamraju, Stephen Rothwell, Tyrel Datwyler, Vaibhav Jain, YueHaibing" * tag 'powerpc-5.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (158 commits) powerpc: Make setjmp/longjmp signature standard powerpc/cputable: Remove unnecessary copy of cpu_spec->oprofile_type powerpc: Suppress .eh_frame generation powerpc: Drop -fno-dwarf2-cfi-asm powerpc/32: drop unused ISA_DMA_THRESHOLD powerpc/powernv: Add documentation for the opal sensor_groups sysfs interfaces selftests/powerpc: Fix try-run when source tree is not writable powerpc/vmlinux.lds: Explicitly retain .gnu.hash powerpc/ptrace: move ptrace_triggered() into hw_breakpoint.c powerpc/ptrace: create ppc_gethwdinfo() powerpc/ptrace: create ptrace_get_debugreg() powerpc/ptrace: split out ADV_DEBUG_REGS related functions. powerpc/ptrace: move register viewing functions out of ptrace.c powerpc/ptrace: split out TRANSACTIONAL_MEM related functions. powerpc/ptrace: split out SPE related functions. powerpc/ptrace: split out ALTIVEC related functions. powerpc/ptrace: split out VSX related functions. powerpc/ptrace: drop PARAMETER_SAVE_AREA_OFFSET powerpc/ptrace: drop unnecessary #ifdefs CONFIG_PPC64 powerpc/ptrace: remove unused header includes ...

sysfs: add sysfs_group{s}_change_owner()

2020-02-27T04:07:25+00:00

Add helpers to change the owner of sysfs groups. This function will be used to correctly account for kobject ownership changes, e.g. when moving network devices between network namespaces. Reviewed-by: Greg Kroah-Hartman Signed-off-by: Christian Brauner Signed-off-by: David S. Miller

sysfs: Wrap __compat_only_sysfs_link_entry_to_kobj function to change the symlink name

2020-02-19T10:07:09+00:00

The __compat_only_sysfs_link_entry_to_kobj function creates a symlink to a kobject but doesn't provide an option to change the symlink file name. This patch adds a wrapper function compat_only_sysfs_link_entry_to_kobj that extends the __compat_only_sysfs_link_entry_to_kobj functionality which allows function caller to customize the symlink name. Signed-off-by: Sourabh Jain [mpe: Fix compile error when CONFIG_SYSFS=n] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20191211160910.21656-3-sourabhjain@linux.ibm.com

treewide: remove redundant IS_ERR() before error code check

2020-02-04T03:05:27+00:00

'PTR_ERR(p) == -E*' is a stronger condition than IS_ERR(p). Hence, IS_ERR(p) is unneeded. The semantic patch that generates this commit is as follows: // @@ expression ptr; constant error_code; @@ -IS_ERR(ptr) && (PTR_ERR(ptr) == - error_code) +PTR_ERR(ptr) == - error_code // Link: http://lkml.kernel.org/r/20200106045833.1725-1-masahiroy@kernel.org Signed-off-by: Masahiro Yamada Cc: Julia Lawall Acked-by: Stephen Boyd [drivers/clk/clk.c] Acked-by: Bartosz Golaszewski [GPIO] Acked-by: Wolfram Sang [drivers/i2c] Acked-by: Rafael J. Wysocki [acpi/scan.c] Acked-by: Rob Herring Cc: Eric Biggers Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

sysfs: Add sysfs_update_groups function

2019-06-03T09:58:20+00:00

Adding sysfs_update_groups function to update multiple groups. sysfs_update_groups - given a directory kobject, create a bunch of attribute groups @kobj: The kobject to update the group on @groups: The attribute groups to update, NULL terminated This function update a bunch of attribute groups. If an error occurs when updating a group, all previously updated groups will be removed together with already existing (not updated) attributes. Signed-off-by: Jiri Olsa Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Greg Kroah-Hartman Cc: Alexander Shishkin Cc: Arnaldo Carvalho de Melo Cc: Linus Torvalds Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Thomas Gleixner Link: https://lkml.kernel.org/r/20190512155518.21468-2-jolsa@kernel.org Signed-off-by: Ingo Molnar