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| author | Christian Brauner <brauner@kernel.org> | 2026-06-01 15:56:36 +0200 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2026-06-29 10:38:48 +0200 |
| commit | 67c54d1d730a8b7a43f2560dcea9b7dc95fba1cd (patch) | |
| tree | 2ea97e2319dfa880a0e910da56221b2ca527e859 /include | |
| parent | d114eb8577bd8d6c307ab0a096ae7df93fb7e011 (diff) | |
| download | linux-next-67c54d1d730a8b7a43f2560dcea9b7dc95fba1cd.tar.gz linux-next-67c54d1d730a8b7a43f2560dcea9b7dc95fba1cd.zip | |
fs: add scoped_with_init_fs()
Similar to scoped_with_kernel_creds() allow a temporary override of
current->fs to serve the few places where lookup is performed from
kthread context or needs init's filesytem state.
Link: https://patch.msgid.link/20260601-work-kthread-nullfs-v4-3-77ee053060e0@kernel.org
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/fs_struct.h | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/include/linux/fs_struct.h b/include/linux/fs_struct.h index ade459383f92..e11d0e57168f 100644 --- a/include/linux/fs_struct.h +++ b/include/linux/fs_struct.h @@ -6,6 +6,7 @@ #include <linux/path.h> #include <linux/spinlock.h> #include <linux/seqlock.h> +#include <linux/vfsdebug.h> struct fs_struct { int users; @@ -49,4 +50,34 @@ static inline int current_umask(void) return current->fs->umask; } +/* + * Temporarily use userspace_init_fs for path resolution in kthreads. + * Callers should use scoped_with_init_fs() which automatically + * restores the original fs_struct at scope exit. + */ +static inline struct fs_struct *__override_init_fs(void) +{ + struct fs_struct *fs; + + fs = current->fs; + WRITE_ONCE(current->fs, fs); + return fs; +} + +static inline void __revert_init_fs(struct fs_struct *revert_fs) +{ + VFS_WARN_ON_ONCE(current->fs != revert_fs); + WRITE_ONCE(current->fs, revert_fs); +} + +DEFINE_CLASS(__override_init_fs, + struct fs_struct *, + __revert_init_fs(_T), + __override_init_fs(), void) + +#define scoped_with_init_fs() \ + scoped_class(__override_init_fs, __UNIQUE_ID(label)) + +void __init init_userspace_fs(void); + #endif /* _LINUX_FS_STRUCT_H */ |