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| author | Amir Goldstein <amir73il@gmail.com> | 2023-10-09 17:37:12 +0200 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2023-10-19 11:03:15 +0200 |
| commit | def3ae83da02f87005210fa3d448c5dd37ba4105 (patch) | |
| tree | 3205fda67f49682217cef7e8d09b79a590294a69 /fs/file_table.c | |
| parent | fs: create helper file_user_path() for user displayed mapped file path (diff) | |
| download | linux-def3ae83da02f87005210fa3d448c5dd37ba4105.tar.xz linux-def3ae83da02f87005210fa3d448c5dd37ba4105.zip | |
fs: store real path instead of fake path in backing file f_path
A backing file struct stores two path's, one "real" path that is referring
to f_inode and one "fake" path, which should be displayed to users in
/proc/<pid>/maps.
There is a lot more potential code that needs to know the "real" path, then
code that needs to know the "fake" path.
Instead of code having to request the "real" path with file_real_path(),
store the "real" path in f_path and require code that needs to know the
"fake" path request it with file_user_path().
Replace the file_real_path() helper with a simple const accessor f_path().
After this change, file_dentry() is not expected to observe any files
with overlayfs f_path and real f_inode, so the call to ->d_real() should
not be needed. Leave the ->d_real() call for now and add an assertion
in ovl_d_real() to catch if we made wrong assumptions.
Suggested-by: Miklos Szeredi <miklos@szeredi.hu>
Link: https://lore.kernel.org/r/CAJfpegtt48eXhhjDFA1ojcHPNKj3Go6joryCPtEFAKpocyBsnw@mail.gmail.com/
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20231009153712.1566422-4-amir73il@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'fs/file_table.c')
| -rw-r--r-- | fs/file_table.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/fs/file_table.c b/fs/file_table.c index 08fd1dd6d863..fa92743ba6a9 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -44,10 +44,10 @@ static struct kmem_cache *filp_cachep __read_mostly; static struct percpu_counter nr_files __cacheline_aligned_in_smp; -/* Container for backing file with optional real path */ +/* Container for backing file with optional user path */ struct backing_file { struct file file; - struct path real_path; + struct path user_path; }; static inline struct backing_file *backing_file(struct file *f) @@ -55,11 +55,11 @@ static inline struct backing_file *backing_file(struct file *f) return container_of(f, struct backing_file, file); } -struct path *backing_file_real_path(struct file *f) +struct path *backing_file_user_path(struct file *f) { - return &backing_file(f)->real_path; + return &backing_file(f)->user_path; } -EXPORT_SYMBOL_GPL(backing_file_real_path); +EXPORT_SYMBOL_GPL(backing_file_user_path); static inline void file_free(struct file *f) { @@ -68,7 +68,7 @@ static inline void file_free(struct file *f) percpu_counter_dec(&nr_files); put_cred(f->f_cred); if (unlikely(f->f_mode & FMODE_BACKING)) { - path_put(backing_file_real_path(f)); + path_put(backing_file_user_path(f)); kfree(backing_file(f)); } else { kmem_cache_free(filp_cachep, f); |