[PATCH v2 08/92] fs: new helper: simple_rename_timestamp

Jeff Layton
2023-07-05T18:59:09Z

A rename potentially involves updating 4 different inode timestamps. Add
a function that handles the details sanely, and convert the libfs.c
callers to use it.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
fs/libfs.c | 36 +++++++++++++++++++++++++++---------
include/linux/fs.h | 2 ++
2 files changed, 29 insertions(+), 9 deletions(-)

diff --git a/fs/libfs.c b/fs/libfs.c
index a7e56baf8bbd..9ee79668c909 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -692,6 +692,31 @@ int simple_rmdir(struct inode *dir, struct dentry *dentry)
}
EXPORT_SYMBOL(simple_rmdir);

+/**
+ * simple_rename_timestamp - update the various inode timestamps for rename
+ * @old_dir: old parent directory
+ * @old_dentry: dentry that is being renamed
+ * @new_dir: new parent directory
+ * @new_dentry: target for rename
+ *
+ * POSIX mandates that the old and new parent directories have their ctime and
+ * mtime updated, and that inodes of @old_dentry and @new_dentry (if any), have
+ * their ctime updated.
+ */
+void simple_rename_timestamp(struct inode *old_dir, struct dentry *old_dentry,
+ struct inode *new_dir, struct dentry *new_dentry)
+{
+ struct inode *newino = d_inode(new_dentry);
+
+ old_dir->i_mtime = inode_set_ctime_current(old_dir);
+ if (new_dir != old_dir)
+ new_dir->i_mtime = inode_set_ctime_current(new_dir);
+ inode_set_ctime_current(d_inode(old_dentry));
+ if (newino)
+ inode_set_ctime_current(newino);
+}
+EXPORT_SYMBOL_GPL(simple_rename_timestamp);
+
int simple_rename_exchange(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
{
@@ -707,11 +732,7 @@ int simple_rename_exchange(struct inode *old_dir, struct dentry *old_dentry,
inc_nlink(old_dir);
}
}
- old_dir->i_ctime = old_dir->i_mtime =
- new_dir->i_ctime = new_dir->i_mtime =
- d_inode(old_dentry)->i_ctime =
- d_inode(new_dentry)->i_ctime = current_time(old_dir);
-
+ simple_rename_timestamp(old_dir, old_dentry, new_dir, new_dentry);
return 0;
}
EXPORT_SYMBOL_GPL(simple_rename_exchange);
@@ -720,7 +741,6 @@ int simple_rename(struct mnt_idmap *idmap, struct inode *old_dir,
struct dentry *old_dentry, struct inode *new_dir,
struct dentry *new_dentry, unsigned int flags)
{
- struct inode *inode = d_inode(old_dentry);
int they_are_dirs = d_is_dir(old_dentry);

if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
@@ -743,9 +763,7 @@ int simple_rename(struct mnt_idmap *idmap, struct inode *old_dir,
inc_nlink(new_dir);
}

- old_dir->i_ctime = old_dir->i_mtime = new_dir->i_ctime =
- new_dir->i_mtime = inode->i_ctime = current_time(old_dir);
-
+ simple_rename_timestamp(old_dir, old_dentry, new_dir, new_dentry);
return 0;
}
EXPORT_SYMBOL(simple_rename);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index bdfbd11a5811..14e38bd900f1 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2979,6 +2979,8 @@ extern int simple_open(struct inode *inode, struct file *file);
extern int simple_link(struct dentry *, struct inode *, struct dentry *);
extern int simple_unlink(struct inode *, struct dentry *);
extern int simple_rmdir(struct inode *, struct dentry *);
+void simple_rename_timestamp(struct inode *old_dir, struct dentry *old_dentry,
+ struct inode *new_dir, struct dentry *new_dentry);
extern int simple_rename_exchange(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry);
extern int simple_rename(struct mnt_idmap *, struct inode *,
--
2.41.0