kernel/linux.git/fs/sysfs/mount.c, branch v7.2-rc1

sysfs: remove trivial sysfs_get_tree() wrapper

2026-05-11T21:13:01+00:00

Now that FS_USERNS_MOUNT_RESTRICTED is a file_system_type flag, sysfs_get_tree() is a trivial wrapper around kernfs_get_tree() with no additional logic. Point sysfs_fs_context_ops.get_tree directly at kernfs_get_tree() and remove the wrapper. Link: https://patch.msgid.link/e8ac71fc96ad864c8b58fc0a8e5305550c01db25.1777278334.git.legion@kernel.org Reviewed-by: Aleksa Sarai Signed-off-by: Christian Brauner

fs: move SB_I_USERNS_VISIBLE to FS_USERNS_MOUNT_RESTRICTED

2026-05-11T21:13:01+00:00

Whether a filesystem's mounts need to undergo a visibility check in user namespaces is a static property of the filesystem type, not a runtime property of each superblock instance. Both proc and sysfs always set SB_I_USERNS_VISIBLE on their superblocks unconditionally (sysfs does so on first creation, and subsequent mounts reuse the same superblock). Move this flag from sb->s_iflags (SB_I_USERNS_VISIBLE) to file_system_type->fs_flags (FS_USERNS_MOUNT_RESTRICTED) so the intent is expressed at the filesystem type level where it belongs. All check sites are updated to test sb->s_type->fs_flags instead of sb->s_iflags. The SB_I_NOEXEC and SB_I_NODEV flags remain on the superblock as they are runtime properties set during fill_super. Link: https://patch.msgid.link/72887c5b6204dc3adf5a53104f0be6bd8bc4f6cd.1777278334.git.legion@kernel.org Reviewed-by: Aleksa Sarai Signed-off-by: Christian Brauner

kernfs: pass struct ns_common instead of const void * for namespace tags

2026-04-09T12:36:52+00:00

kernfs has historically used const void * to pass around namespace tags used for directory-level namespace filtering. The only current user of this is sysfs network namespace tagging where struct net pointers are cast to void *. Replace all const void * namespace parameters with const struct ns_common * throughout the kernfs, sysfs, and kobject namespace layers. This includes the kobj_ns_type_operations callbacks, kobject_namespace(), and all sysfs/kernfs APIs that accept or return namespace tags. Passing struct ns_common is needed because various codepaths require access to the underlying namespace. A struct ns_common can always be converted back to the concrete namespace type (e.g., struct net) via container_of() or to_ns_common() in the reverse direction. This is a preparatory change for switching to ns_id-based directory iteration to prevent a KASLR pointer leak through the current use of raw namespace pointers as hash seeds and comparison keys. Signed-off-by: Christian Brauner

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

kernfs: move struct kernfs_root out of the public view.

2022-02-23T14:46:34+00:00

There is no need to have struct kernfs_root be part of kernfs.h for the whole kernel to see and poke around it. Move it internal to kernfs code and provide a helper function, kernfs_root_to_node(), to handle the one field that kernfs users were directly accessing from the structure. Cc: Imran Khan Acked-by: Tejun Heo Link: https://lore.kernel.org/r/20220222070713.3517679-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

docs: filesystems: fix renamed references

2020-04-20T21:45:22+00:00

Some filesystem references got broken by a previous patch series I submitted. Address those. Signed-off-by: Mauro Carvalho Chehab Acked-by: David Sterba # fs/affs/Kconfig Link: https://lore.kernel.org/r/57318c53008dbda7f6f4a5a9e5787f4d37e8565a.1586881715.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet

no need to protect against put_user_ns(NULL)

2019-05-25T21:59:54+00:00

it's a no-op Signed-off-by: Al Viro

fix sysfs_init_fs_context() in !CONFIG_NET_NS case

2019-03-16T13:45:42+00:00

Permission checks on current's netns should be done only when netns are enabled. Reported-by: Dominik Brodowski Fixes: 23bf1b6be9c2 Signed-off-by: Al Viro

kernfs, sysfs, cgroup, intel_rdt: Support fs_context

2019-02-28T08:29:34+00:00

Make kernfs support superblock creation/mount/remount with fs_context. This requires that sysfs, cgroup and intel_rdt, which are built on kernfs, be made to support fs_context also. Notes: (1) A kernfs_fs_context struct is created to wrap fs_context and the kernfs mount parameters are moved in here (or are in fs_context). (2) kernfs_mount{,_ns}() are made into kernfs_get_tree(). The extra namespace tag parameter is passed in the context if desired (3) kernfs_free_fs_context() is provided as a destructor for the kernfs_fs_context struct, but for the moment it does nothing except get called in the right places. (4) sysfs doesn't wrap kernfs_fs_context since it has no parameters to pass, but possibly this should be done anyway in case someone wants to add a parameter in future. (5) A cgroup_fs_context struct is created to wrap kernfs_fs_context and the cgroup v1 and v2 mount parameters are all moved there. (6) cgroup1 parameter parsing error messages are now handled by invalf(), which allows userspace to collect them directly. (7) cgroup1 parameter cleanup is now done in the context destructor rather than in the mount/get_tree and remount functions. Weirdies: (*) cgroup_do_get_tree() calls cset_cgroup_from_root() with locks held, but then uses the resulting pointer after dropping the locks. I'm told this is okay and needs commenting. (*) The cgroup refcount web. This really needs documenting. (*) cgroup2 only has one root? Add a suggestion from Thomas Gleixner in which the RDT enablement code is placed into its own function. [folded a leak fix from Andrey Vagin] Signed-off-by: David Howells cc: Greg Kroah-Hartman cc: Tejun Heo cc: Li Zefan cc: Johannes Weiner cc: cgroups@vger.kernel.org cc: fenghua.yu@intel.com Signed-off-by: Al Viro