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Date: Fri, 7 Feb 2014 17:49:01 +0100
From: Miklos Szeredi <miklos@...redi.hu>
To: viro@...IV.linux.org.uk, torvalds@...ux-foundation.org
Cc: linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
bfields@...ldses.org, hch@...radead.org, akpm@...ux-foundation.org,
dhowells@...hat.com, zab@...hat.com, jack@...e.cz,
luto@...capital.net, mszeredi@...e.cz
Subject: [PATCH 03/13] vfs: rename: use common code for dir and non-dir
From: Miklos Szeredi <mszeredi@...e.cz>
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@...e.cz>
---
fs/namei.c | 187 +++++++++++++++++++++++++------------------------------------
1 file changed, 75 insertions(+), 112 deletions(-)
diff --git a/fs/namei.c b/fs/namei.c
index 1409090d0913..b6976bd59cbb 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3946,7 +3946,27 @@ SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname
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"
* doesn't even start to describe it. Somebody in UCB had a heck of a trip...
* Problems:
@@ -3974,19 +3994,39 @@ 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,
+ struct inode **delegated_inode)
{
- int error = 0;
+ int error;
+ bool is_dir = d_is_dir(old_dentry);
+ 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;
+
+ 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;
}
@@ -3995,134 +4035,57 @@ 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)
+ 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;
- 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);
+ if (is_dir) {
+ unsigned max_links = new_dir->i_sb->s_max_links;
- 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;
- error = try_break_deleg(source, delegated_inode);
- if (error)
- goto out;
- if (target) {
- error = try_break_deleg(target, delegated_inode);
+ 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 (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:
- unlock_two_nondirectories(source, target);
+ if (!is_dir)
+ unlock_two_nondirectories(source, target);
+ else if (target)
+ mutex_unlock(&target->i_mutex);
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,
- struct inode *new_dir, struct dentry *new_dentry,
- struct inode **delegated_inode)
-{
- int error;
- int is_dir = d_is_dir(old_dentry);
- 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,delegated_inode);
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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