linux-next: manual merge of the userns tree with Linus' tree

From: Stephen Rothwell
Date: Tue Apr 08 2014 - 22:40:44 EST


Hi Eric,

Today's linux-next merge of the userns tree got a conflict in fs/namei.c
between commits from Linus' tree and commits 3dd905eaa258 ("vfs: Don't
allow overwriting mounts in the current mount namespace") and
f43d102a391d ("vfs: Lazily remove mounts on unlinked files and
directories") from the userns tree.

I fixed it up (I used the conflict resolution that you sent to Linus -
see below) and can carry the fix as necessary (no action is required).

--
Cheers,
Stephen Rothwell sfr@xxxxxxxxxxxxxxxx

diff --cc fs/namei.c
index 88339f59efb5,384fcc6a5606..000000000000
--- a/fs/namei.c
+++ b/fs/namei.c
@@@ -4082,33 -4045,17 +4085,33 @@@ int vfs_rename(struct inode *old_dir, s
if (error)
return error;

+ old_name = fsnotify_oldname_init(old_dentry->d_name.name);
dget(new_dentry);
- lock_two_nondirectories(source, target);
+ if (!is_dir || (flags & RENAME_EXCHANGE))
+ lock_two_nondirectories(source, target);
+ else if (target)
+ mutex_lock(&target->i_mutex);

error = -EBUSY;
- if (d_mountpoint(old_dentry) || d_mountpoint(new_dentry))
+ if (is_local_mountpoint(old_dentry) || is_local_mountpoint(new_dentry))
goto out;

- error = try_break_deleg(source, delegated_inode);
- if (error)
- goto out;
- if (target) {
+ if (max_links && new_dir != old_dir) {
+ error = -EMLINK;
+ if (is_dir && !new_is_dir && new_dir->i_nlink >= max_links)
+ goto out;
+ if ((flags & RENAME_EXCHANGE) && !is_dir && new_is_dir &&
+ old_dir->i_nlink >= max_links)
+ goto out;
+ }
+ if (is_dir && !(flags & RENAME_EXCHANGE) && target)
+ shrink_dcache_parent(new_dentry);
+ if (!is_dir) {
+ error = try_break_deleg(source, delegated_inode);
+ if (error)
+ goto out;
+ }
+ if (target && !new_is_dir) {
error = try_break_deleg(target, delegated_inode);
if (error)
goto out;
@@@ -4123,31 -4064,73 +4126,32 @@@
if (error)
goto out;

- if (target) {
+ if (!(flags & RENAME_EXCHANGE) && target) {
+ if (is_dir)
+ target->i_flags |= S_DEAD;
dont_mount(new_dentry);
+ detach_mounts(new_dentry);
}
- if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE))
- d_move(old_dentry, new_dentry);
+ if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE)) {
+ if (!(flags & RENAME_EXCHANGE))
+ d_move(old_dentry, new_dentry);
+ else
+ d_exchange(old_dentry, new_dentry);
+ }
out:
- unlock_two_nondirectories(source, target);
+ if (!is_dir || (flags & RENAME_EXCHANGE))
+ 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_directory(old_dentry) || d_is_autodir(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)
+ if (!error) {
fsnotify_move(old_dir, new_dir, old_name, is_dir,
- new_dentry->d_inode, old_dentry);
+ !(flags & RENAME_EXCHANGE) ? target : NULL, old_dentry);
+ if (flags & RENAME_EXCHANGE) {
+ fsnotify_move(new_dir, old_dir, old_dentry->d_name.name,
+ new_is_dir, NULL, new_dentry);
+ }
+ }
fsnotify_oldname_free(old_name);

return error;

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