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vfs: rename: use common code for dir and non-dir

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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@suse.cz>
Reviewed-by: J. Bruce Fields <bfields@redhat.com>
This commit is contained in:
Miklos Szeredi 2014-04-01 17:08:42 +02:00
parent de22a4c372
commit bc27027a73
1 changed files with 90 additions and 127 deletions
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211
fs/namei.c
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@ -3973,7 +3973,27 @@ SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname
return sys_linkat(AT_FDCWD, oldname, AT_FDCWD, newname, 0); return sys_linkat(AT_FDCWD, oldname, AT_FDCWD, newname, 0);
} }
/* /**
* vfs_rename - rename a filesystem object
* @old_dir: parent of source
* @old_dentry: source
* @new_dir: parent of destination
* @new_dentry: destination
* @delegated_inode: returns an inode needing a delegation break
*
* The caller must hold multiple mutexes--see lock_rename()).
*
* If vfs_rename discovers a delegation in need of breaking at either
* the source or destination, it will return -EWOULDBLOCK and return a
* reference to the inode in delegated_inode. The caller should then
* break the delegation and retry. Because breaking a delegation may
* take a long time, the caller should drop all locks before doing
* so.
*
* Alternatively, a caller may pass NULL for delegated_inode. This may
* be appropriate for callers that expect the underlying filesystem not
* to be NFS exported.
*
* The worst of all namespace operations - renaming directory. "Perverted" * The worst of all namespace operations - renaming directory. "Perverted"
* doesn't even start to describe it. Somebody in UCB had a heck of a trip... * doesn't even start to describe it. Somebody in UCB had a heck of a trip...
* Problems: * Problems:
@ -4001,137 +4021,24 @@ SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname
* ->i_mutex on parents, which works but leads to some truly excessive * ->i_mutex on parents, which works but leads to some truly excessive
* locking]. * locking].
*/ */
static int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
{
int error = 0;
struct inode *target = new_dentry->d_inode;
unsigned max_links = new_dir->i_sb->s_max_links;
/*
* 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 (error)
return 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 = -EMLINK;
if (max_links && !target && new_dir != old_dir &&
new_dir->i_nlink >= max_links)
goto out;
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;
if (target) {
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;
}
static int vfs_rename_other(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry,
struct inode **delegated_inode)
{
struct inode *target = new_dentry->d_inode;
struct inode *source = old_dentry->d_inode;
int error;
error = security_inode_rename(old_dir, old_dentry, new_dir, new_dentry);
if (error)
return error;
dget(new_dentry);
lock_two_nondirectories(source, target);
error = -EBUSY;
if (d_mountpoint(old_dentry)||d_mountpoint(new_dentry))
goto out;
error = try_break_deleg(source, delegated_inode);
if (error)
goto out;
if (target) {
error = try_break_deleg(target, delegated_inode);
if (error)
goto out;
}
error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry);
if (error)
goto out;
if (target)
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:
unlock_two_nondirectories(source, target);
dput(new_dentry);
return error;
}
/**
* vfs_rename - rename a filesystem object
* @old_dir: parent of source
* @old_dentry: source
* @new_dir: parent of destination
* @new_dentry: destination
* @delegated_inode: returns an inode needing a delegation break
*
* The caller must hold multiple mutexes--see lock_rename()).
*
* If vfs_rename discovers a delegation in need of breaking at either
* the source or destination, it will return -EWOULDBLOCK and return a
* reference to the inode in delegated_inode. The caller should then
* break the delegation and retry. Because breaking a delegation may
* take a long time, the caller should drop all locks before doing
* so.
*
* Alternatively, a caller may pass NULL for delegated_inode. This may
* be appropriate for callers that expect the underlying filesystem not
* to be NFS exported.
*/
int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry, struct inode *new_dir, struct dentry *new_dentry,
struct inode **delegated_inode) struct inode **delegated_inode)
{ {
int error; int error;
int is_dir = d_is_dir(old_dentry); bool is_dir = d_is_dir(old_dentry);
const unsigned char *old_name; const unsigned char *old_name;
struct inode *source = old_dentry->d_inode;
struct inode *target = new_dentry->d_inode;
if (old_dentry->d_inode == new_dentry->d_inode) if (source == target)
return 0; return 0;
error = may_delete(old_dir, old_dentry, is_dir); error = may_delete(old_dir, old_dentry, is_dir);
if (error) if (error)
return error; return error;
if (!new_dentry->d_inode) if (!target)
error = may_create(new_dir, new_dentry); error = may_create(new_dir, new_dentry);
else else
error = may_delete(new_dir, new_dentry, is_dir); error = may_delete(new_dir, new_dentry, is_dir);
@ -4141,15 +4048,71 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
if (!old_dir->i_op->rename) if (!old_dir->i_op->rename)
return -EPERM; return -EPERM;
old_name = fsnotify_oldname_init(old_dentry->d_name.name); /*
* If we are going to change the parent - check write permissions,
* we'll need to flip '..'.
*/
if (is_dir && new_dir != old_dir) {
error = inode_permission(source, MAY_WRITE);
if (error)
return error;
}
error = security_inode_rename(old_dir, old_dentry, new_dir, new_dentry);
if (error)
return error;
old_name = fsnotify_oldname_init(old_dentry->d_name.name);
dget(new_dentry);
if (!is_dir)
lock_two_nondirectories(source, target);
else if (target)
mutex_lock(&target->i_mutex);
error = -EBUSY;
if (d_mountpoint(old_dentry) || d_mountpoint(new_dentry))
goto out;
if (is_dir) {
unsigned max_links = new_dir->i_sb->s_max_links;
error = -EMLINK;
if (max_links && !target && new_dir != old_dir &&
new_dir->i_nlink >= max_links)
goto out;
if (target)
shrink_dcache_parent(new_dentry);
} else {
error = try_break_deleg(source, delegated_inode);
if (error)
goto out;
if (target) {
error = try_break_deleg(target, delegated_inode);
if (error)
goto out;
}
}
error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry);
if (error)
goto out;
if (target) {
if (is_dir) if (is_dir)
error = vfs_rename_dir(old_dir,old_dentry,new_dir,new_dentry); target->i_flags |= S_DEAD;
else dont_mount(new_dentry);
error = vfs_rename_other(old_dir,old_dentry,new_dir,new_dentry,delegated_inode); }
if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE))
d_move(old_dentry, new_dentry);
out:
if (!is_dir)
unlock_two_nondirectories(source, target);
else if (target)
mutex_unlock(&target->i_mutex);
dput(new_dentry);
if (!error) if (!error)
fsnotify_move(old_dir, new_dir, old_name, is_dir, fsnotify_move(old_dir, new_dir, old_name, is_dir,
new_dentry->d_inode, old_dentry); target, old_dentry);
fsnotify_oldname_free(old_name); fsnotify_oldname_free(old_name);
return error; return error;