In order to add directory delegation support, we need to break delegations on the parent whenever there is going to be a change in the directory.
Rename vfs_mknod as __vfs_mknod, make it static, and add a new delegated_inode parameter. Make do_mknodat call __vfs_mknod and wait synchronously for delegation breaks to complete. Add a new exported vfs_mknod wrapper that calls __vfs_mknod with a NULL delegated_inode pointer. Signed-off-by: Jeff Layton <[email protected]> --- fs/namei.c | 57 +++++++++++++++++++++++++++++++++++---------------------- 1 file changed, 35 insertions(+), 22 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index d4b8330a3eb97e205dc2e71766fed1e45503323b..7bcd898c84138061030f1f8b91273261cdf2a9b4 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -4215,24 +4215,9 @@ inline struct dentry *user_path_create(int dfd, const char __user *pathname, } EXPORT_SYMBOL(user_path_create); -/** - * vfs_mknod - create device node or file - * @idmap: idmap of the mount the inode was found from - * @dir: inode of the parent directory - * @dentry: dentry of the child device node - * @mode: mode of the child device node - * @dev: device number of device to create - * - * Create a device node or file. - * - * If the inode has been found through an idmapped mount the idmap of - * the vfsmount must be passed through @idmap. This function will then take - * care to map the inode according to @idmap before checking permissions. - * On non-idmapped mounts or if permission checking is to be performed on the - * raw inode simply pass @nop_mnt_idmap. - */ -int vfs_mknod(struct mnt_idmap *idmap, struct inode *dir, - struct dentry *dentry, umode_t mode, dev_t dev) +static int __vfs_mknod(struct mnt_idmap *idmap, struct inode *dir, + struct dentry *dentry, umode_t mode, dev_t dev, + struct inode **delegated_inode) { bool is_whiteout = S_ISCHR(mode) && dev == WHITEOUT_DEV; int error = may_create(idmap, dir, dentry); @@ -4256,11 +4241,37 @@ int vfs_mknod(struct mnt_idmap *idmap, struct inode *dir, if (error) return error; + error = try_break_deleg(dir, delegated_inode); + if (error) + return error; + error = dir->i_op->mknod(idmap, dir, dentry, mode, dev); if (!error) fsnotify_create(dir, dentry); return error; } + +/** + * vfs_mknod - create device node or file + * @idmap: idmap of the mount the inode was found from + * @dir: inode of the parent directory + * @dentry: dentry of the child device node + * @mode: mode of the child device node + * @dev: device number of device to create + * + * Create a device node or file. + * + * If the inode has been found through an idmapped mount the idmap of + * the vfsmount must be passed through @idmap. This function will then take + * care to map the inode according to @idmap before checking permissions. + * On non-idmapped mounts or if permission checking is to be performed on the + * raw inode simply pass @nop_mnt_idmap. + */ +int vfs_mknod(struct mnt_idmap *idmap, struct inode *dir, + struct dentry *dentry, umode_t mode, dev_t dev) +{ + return __vfs_mknod(idmap, dir, dentry, mode, dev, NULL); +} EXPORT_SYMBOL(vfs_mknod); static int may_mknod(umode_t mode) @@ -4314,12 +4325,14 @@ static int do_mknodat(int dfd, struct filename *name, umode_t mode, security_path_post_mknod(idmap, dentry); break; case S_IFCHR: case S_IFBLK: - error = vfs_mknod(idmap, path.dentry->d_inode, - dentry, mode, new_decode_dev(dev)); + error = __vfs_mknod(idmap, path.dentry->d_inode, + dentry, mode, new_decode_dev(dev), + &delegated_inode); break; case S_IFIFO: case S_IFSOCK: - error = vfs_mknod(idmap, path.dentry->d_inode, - dentry, mode, 0); + error = __vfs_mknod(idmap, path.dentry->d_inode, + dentry, mode, 0, + &delegated_inode); break; } out2: -- 2.51.0
