[PATCH 2/7] vfs: rename: use common code for dir and non-dir

From: Miklos Szeredi
Date: Tue Oct 01 2013 - 12:00:42 EST


From: Miklos Szeredi <mszeredi@xxxxxxx>

There's actually very little difference between vfs_rename_dir() and
vfs_rename_other() so move both inline into vfs_rename() which still stays
reasonably readable.

Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxx>
---
fs/namei.c | 118 ++++++++++++++++++++-----------------------------------------
1 file changed, 39 insertions(+), 79 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 911aadc..7ec6a12 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3963,19 +3963,38 @@ SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname
* ->i_mutex on parents, which works but leads to some truly excessive
* locking].
*/
-static int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry,
- struct inode *new_dir, struct dentry *new_dentry)
+int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
+ struct inode *new_dir, struct dentry *new_dentry)
{
- int error = 0;
+ int error;
+ const unsigned char *old_name;
+ struct inode *source = old_dentry->d_inode;
struct inode *target = new_dentry->d_inode;
- unsigned max_links = new_dir->i_sb->s_max_links;
+ bool is_dir = S_ISDIR(source->i_mode);
+
+ if (source == target)
+ return 0;
+
+ error = may_delete(old_dir, old_dentry, is_dir);
+ if (error)
+ return error;
+
+ if (!target)
+ error = may_create(new_dir, new_dentry);
+ else
+ error = may_delete(new_dir, new_dentry, is_dir);
+ if (error)
+ return error;
+
+ if (!old_dir->i_op->rename)
+ return -EPERM;

/*
* If we are going to change the parent - check write permissions,
* we'll need to flip '..'.
*/
- if (new_dir != old_dir) {
- error = inode_permission(old_dentry->d_inode, MAY_WRITE);
+ if (is_dir && new_dir != old_dir) {
+ error = inode_permission(source, MAY_WRITE);
if (error)
return error;
}
@@ -3984,6 +4003,7 @@ static int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry,
if (error)
return error;

+ old_name = fsnotify_oldname_init(old_dentry->d_name.name);
dget(new_dentry);
if (target)
mutex_lock(&target->i_mutex);
@@ -3992,96 +4012,36 @@ static int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry,
if (d_mountpoint(old_dentry) || d_mountpoint(new_dentry))
goto out;

- error = -EMLINK;
- if (max_links && !target && new_dir != old_dir &&
- new_dir->i_nlink >= max_links)
- goto out;
+ if (is_dir) {
+ unsigned max_links = new_dir->i_sb->s_max_links;

- if (target)
- shrink_dcache_parent(new_dentry);
- error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry);
- if (error)
- goto out;
+ error = -EMLINK;
+ if (max_links && !target && new_dir != old_dir &&
+ new_dir->i_nlink >= max_links)
+ goto out;

- if (target) {
- target->i_flags |= S_DEAD;
- dont_mount(new_dentry);
+ if (target)
+ shrink_dcache_parent(new_dentry);
}
- if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE))
- d_move(old_dentry, new_dentry);
-out:
- if (target)
- mutex_unlock(&target->i_mutex);
- dput(new_dentry);
- return error;
-}
-
-static int vfs_rename_other(struct inode *old_dir, struct dentry *old_dentry,
- struct inode *new_dir, struct dentry *new_dentry)
-{
- struct inode *target = new_dentry->d_inode;
- int error;
-
- error = security_inode_rename(old_dir, old_dentry, new_dir, new_dentry);
- if (error)
- return error;
-
- dget(new_dentry);
- if (target)
- mutex_lock(&target->i_mutex);
-
- error = -EBUSY;
- if (d_mountpoint(old_dentry)||d_mountpoint(new_dentry))
- goto out;

error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry);
if (error)
goto out;

- if (target)
+ if (target) {
+ if (is_dir)
+ target->i_flags |= S_DEAD;
dont_mount(new_dentry);
+ }
if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE))
d_move(old_dentry, new_dentry);
out:
if (target)
mutex_unlock(&target->i_mutex);
dput(new_dentry);
- return error;
-}
-
-int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
- struct inode *new_dir, struct dentry *new_dentry)
-{
- int error;
- int is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
- const unsigned char *old_name;
-
- if (old_dentry->d_inode == new_dentry->d_inode)
- return 0;
-
- error = may_delete(old_dir, old_dentry, is_dir);
- if (error)
- return error;
-
- if (!new_dentry->d_inode)
- error = may_create(new_dir, new_dentry);
- else
- error = may_delete(new_dir, new_dentry, is_dir);
- if (error)
- return error;
-
- if (!old_dir->i_op->rename)
- return -EPERM;
-
- old_name = fsnotify_oldname_init(old_dentry->d_name.name);
-
- if (is_dir)
- error = vfs_rename_dir(old_dir,old_dentry,new_dir,new_dentry);
- else
- error = vfs_rename_other(old_dir,old_dentry,new_dir,new_dentry);
if (!error)
fsnotify_move(old_dir, new_dir, old_name, is_dir,
- new_dentry->d_inode, old_dentry);
+ target, old_dentry);
fsnotify_oldname_free(old_name);

return error;
--
1.8.1.4

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