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| author | Amir Goldstein <amir73il@gmail.com> | 2023-10-09 18:37:12 +0300 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2023-10-19 11:03:15 +0200 |
| commit | def3ae83da02f87005210fa3d448c5dd37ba4105 (patch) | |
| tree | 3205fda67f49682217cef7e8d09b79a590294a69 /fs/overlayfs | |
| parent | 08582d678fcf11fc86188f0b92239d3d49667d8e (diff) | |
| download | linux-def3ae83da02f87005210fa3d448c5dd37ba4105.tar.gz | |
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/overlayfs')
| -rw-r--r-- | fs/overlayfs/super.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index def266b5e2a33..9f43f0d303ad7 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -34,14 +34,22 @@ static struct dentry *ovl_d_real(struct dentry *dentry, struct dentry *real = NULL, *lower; int err; - /* It's an overlay file */ + /* + * vfs is only expected to call d_real() with NULL from d_real_inode() + * and with overlay inode from file_dentry() on an overlay file. + * + * TODO: remove @inode argument from d_real() API, remove code in this + * function that deals with non-NULL @inode and remove d_real() call + * from file_dentry(). + */ if (inode && d_inode(dentry) == inode) return dentry; + else if (inode) + goto bug; if (!d_is_reg(dentry)) { - if (!inode || inode == d_inode(dentry)) - return dentry; - goto bug; + /* d_real_inode() is only relevant for regular files */ + return dentry; } real = ovl_dentry_upper(dentry); |