Re: [Xen-devel] [PATCHv3 1/2] libfs: allow simple_fill_super() to add symlinks

From: David Vrabel
Date: Mon Jul 11 2016 - 05:38:22 EST


On 28/06/16 19:06, David Vrabel wrote:
> simple_fill_super() will add symlinks if an entry has mode & S_IFLNK.
> The target is provided in the new "link" field.

Can I get an ack for this, please? So it can go into 4.8 via the Xen tree.

David

>
> Signed-off-by: David Vrabel <david.vrabel@xxxxxxxxxx>
> ---
> v2:
> - simplified.
> ---
> fs/libfs.c | 15 +++++++++++++--
> include/linux/fs.h | 2 +-
> 2 files changed, 14 insertions(+), 3 deletions(-)
>
> diff --git a/fs/libfs.c b/fs/libfs.c
> index cedeacb..bbf2d82 100644
> --- a/fs/libfs.c
> +++ b/fs/libfs.c
> @@ -512,9 +512,20 @@ int simple_fill_super(struct super_block *s, unsigned long magic,
> dput(dentry);
> goto out;
> }
> - inode->i_mode = S_IFREG | files->mode;
> + if (files->mode & S_IFLNK) {
> + inode->i_mode = files->mode;
> + inode->i_op = &simple_symlink_inode_operations;
> + inode->i_link = kstrdup(files->link, GFP_KERNEL);
> + if (!inode->i_link) {
> + iput(inode);
> + dput(dentry);
> + goto out;
> + }
> + } else {
> + inode->i_mode = S_IFREG | files->mode;
> + inode->i_fop = files->ops;
> + }
> inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
> - inode->i_fop = files->ops;
> inode->i_ino = i;
> d_add(dentry, inode);
> }
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index dd28814..20c54a2 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -2953,7 +2953,7 @@ extern const struct file_operations simple_dir_operations;
> extern const struct inode_operations simple_dir_inode_operations;
> extern void make_empty_dir_inode(struct inode *inode);
> extern bool is_empty_dir_inode(struct inode *inode);
> -struct tree_descr { char *name; const struct file_operations *ops; int mode; };
> +struct tree_descr { char *name; const struct file_operations *ops; int mode; char *link; };
> struct dentry *d_alloc_name(struct dentry *, const char *);
> extern int simple_fill_super(struct super_block *, unsigned long, struct tree_descr *);
> extern int simple_pin_fs(struct file_system_type *, struct vfsmount **mount, int *count);
>