diff options
| -rw-r--r-- | fs/file_table.c | 12 | ||||
| -rw-r--r-- | fs/internal.h | 2 | ||||
| -rw-r--r-- | fs/open.c | 23 | ||||
| -rw-r--r-- | fs/overlayfs/super.c | 16 | ||||
| -rw-r--r-- | include/linux/fs.h | 22 | ||||
| -rw-r--r-- | include/linux/fsnotify.h | 3 |
6 files changed, 35 insertions, 43 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); diff --git a/fs/internal.h b/fs/internal.h index 4e93a685bdaa..58e43341aebf 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -101,7 +101,7 @@ static inline void file_put_write_access(struct file *file) put_write_access(file->f_inode); mnt_put_write_access(file->f_path.mnt); if (unlikely(file->f_mode & FMODE_BACKING)) - mnt_put_write_access(backing_file_real_path(file)->mnt); + mnt_put_write_access(backing_file_user_path(file)->mnt); } static inline void put_file_access(struct file *file) diff --git a/fs/open.c b/fs/open.c index fe63e236da22..02dc608d40d8 100644 --- a/fs/open.c +++ b/fs/open.c @@ -881,7 +881,7 @@ static inline int file_get_write_access(struct file *f) if (unlikely(error)) goto cleanup_inode; if (unlikely(f->f_mode & FMODE_BACKING)) { - error = mnt_get_write_access(backing_file_real_path(f)->mnt); + error = mnt_get_write_access(backing_file_user_path(f)->mnt); if (unlikely(error)) goto cleanup_mnt; } @@ -1182,20 +1182,19 @@ EXPORT_SYMBOL_GPL(kernel_file_open); /** * backing_file_open - open a backing file for kernel internal use - * @path: path of the file to open + * @user_path: path that the user reuqested to open * @flags: open flags * @real_path: path of the backing file * @cred: credentials for open * * Open a backing file for a stackable filesystem (e.g., overlayfs). - * @path may be on the stackable filesystem and backing inode on the - * underlying filesystem. In this case, we want to be able to return - * the @real_path of the backing inode. This is done by embedding the - * returned file into a container structure that also stores the path of - * the backing inode on the underlying filesystem, which can be - * retrieved using backing_file_real_path(). + * @user_path may be on the stackable filesystem and @real_path on the + * underlying filesystem. In this case, we want to be able to return the + * @user_path of the stackable filesystem. This is done by embedding the + * returned file into a container structure that also stores the stacked + * file's path, which can be retrieved using backing_file_user_path(). */ -struct file *backing_file_open(const struct path *path, int flags, +struct file *backing_file_open(const struct path *user_path, int flags, const struct path *real_path, const struct cred *cred) { @@ -1206,9 +1205,9 @@ struct file *backing_file_open(const struct path *path, int flags, if (IS_ERR(f)) return f; - f->f_path = *path; - path_get(real_path); - *backing_file_real_path(f) = *real_path; + path_get(user_path); + *backing_file_user_path(f) = *user_path; + f->f_path = *real_path; error = do_dentry_open(f, d_inode(real_path->dentry), NULL); if (error) { fput(f); diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index def266b5e2a3..9f43f0d303ad 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); diff --git a/include/linux/fs.h b/include/linux/fs.h index 057a3bbd4d27..b37dccfb4534 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2492,26 +2492,10 @@ struct file *dentry_open(const struct path *path, int flags, const struct cred *creds); struct file *dentry_create(const struct path *path, int flags, umode_t mode, const struct cred *cred); -struct file *backing_file_open(const struct path *path, int flags, +struct file *backing_file_open(const struct path *user_path, int flags, const struct path *real_path, const struct cred *cred); -struct path *backing_file_real_path(struct file *f); - -/* - * file_real_path - get the path corresponding to f_inode - * - * When opening a backing file for a stackable filesystem (e.g., - * overlayfs) f_path may be on the stackable filesystem and f_inode on - * the underlying filesystem. When the path associated with f_inode is - * needed, this helper should be used instead of accessing f_path - * directly. -*/ -static inline const struct path *file_real_path(struct file *f) -{ - if (unlikely(f->f_mode & FMODE_BACKING)) - return backing_file_real_path(f); - return &f->f_path; -} +struct path *backing_file_user_path(struct file *f); /* * file_user_path - get the path to display for memory mapped file @@ -2524,6 +2508,8 @@ static inline const struct path *file_real_path(struct file *f) */ static inline const struct path *file_user_path(struct file *f) { + if (unlikely(f->f_mode & FMODE_BACKING)) + return backing_file_user_path(f); return &f->f_path; } diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h index ed48e4f1e755..bcb6609b54b3 100644 --- a/include/linux/fsnotify.h +++ b/include/linux/fsnotify.h @@ -96,8 +96,7 @@ static inline int fsnotify_file(struct file *file, __u32 mask) if (file->f_mode & FMODE_NONOTIFY) return 0; - /* Overlayfs internal files have fake f_path */ - path = file_real_path(file); + path = &file->f_path; return fsnotify_parent(path->dentry, mask, path, FSNOTIFY_EVENT_PATH); } |