Add some helpers to hypfs.c to support dynamic directories with a numerical id as name.
The dynamic directory is based on a template specified by the user allowing to use specific access functions and having a predefined set of entries in the directory. Signed-off-by: Juergen Gross <jgr...@suse.com> --- xen/common/hypfs.c | 76 +++++++++++++++++++++++++++++++++++++++++ xen/include/xen/hypfs.h | 14 ++++++++ 2 files changed, 90 insertions(+) diff --git a/xen/common/hypfs.c b/xen/common/hypfs.c index 4c226a06b4..12be2f6d16 100644 --- a/xen/common/hypfs.c +++ b/xen/common/hypfs.c @@ -257,6 +257,82 @@ unsigned int hypfs_getsize(const struct hypfs_entry *entry) return entry->size; } +int hypfs_read_dyndir_id_entry(struct hypfs_entry_dir *template, + unsigned int id, bool is_last, + XEN_GUEST_HANDLE_PARAM(void) *uaddr) +{ + struct xen_hypfs_dirlistentry direntry; + char name[12]; + unsigned int e_namelen, e_len; + + e_namelen = snprintf(name, sizeof(name), "%u", id); + e_len = HYPFS_DIRENTRY_SIZE(e_namelen); + direntry.e.pad = 0; + direntry.e.type = template->e.type; + direntry.e.encoding = template->e.encoding; + direntry.e.content_len = template->e.funcs->getsize(&template->e); + direntry.e.max_write_len = template->e.max_size; + direntry.off_next = is_last ? 0 : e_len; + if ( copy_to_guest(*uaddr, &direntry, 1) ) + return -EFAULT; + if ( copy_to_guest_offset(*uaddr, HYPFS_DIRENTRY_NAME_OFF, name, + e_namelen + 1) ) + return -EFAULT; + + guest_handle_add_offset(*uaddr, e_len); + + return 0; +} + +static struct hypfs_entry *hypfs_dyndir_findentry(struct hypfs_entry_dir *dir, + const char *name, + unsigned int name_len) +{ + struct hypfs_dyndir_id *data; + + data = hypfs_get_dyndata(); + if ( !data ) + return ERR_PTR(-ENOENT); + + /* Use template with original findentry function. */ + return data->template->e.funcs->findentry(data->template, name, name_len); +} + +static int hypfs_read_dyndir(const struct hypfs_entry *entry, + XEN_GUEST_HANDLE_PARAM(void) uaddr) +{ + struct hypfs_dyndir_id *data; + + data = hypfs_get_dyndata(); + if ( !data ) + return -ENOENT; + + /* Use template with original read function. */ + return data->template->e.funcs->read(&data->template->e, uaddr); +} + +struct hypfs_entry *hypfs_gen_dyndir_entry_id(struct hypfs_entry_dir *template, + unsigned int id) +{ + struct hypfs_dyndir_id *data; + + data = hypfs_alloc_dyndata(sizeof(*data), alignof(*data)); + if ( !data ) + return ERR_PTR(-ENOMEM); + + data->template = template; + data->id = id; + snprintf(data->name, sizeof(data->name), "%u", id); + data->dir = *template; + data->dir.e.name = data->name; + data->dir.e.funcs = &data->funcs; + data->funcs = *template->e.funcs; + data->funcs.findentry = hypfs_dyndir_findentry; + data->funcs.read = hypfs_read_dyndir; + + return &data->dir.e; +} + int hypfs_read_dir(const struct hypfs_entry *entry, XEN_GUEST_HANDLE_PARAM(void) uaddr) { diff --git a/xen/include/xen/hypfs.h b/xen/include/xen/hypfs.h index c8999b5381..adfb522496 100644 --- a/xen/include/xen/hypfs.h +++ b/xen/include/xen/hypfs.h @@ -50,6 +50,15 @@ struct hypfs_entry_dir { struct list_head dirlist; }; +struct hypfs_dyndir_id { + struct hypfs_entry_dir dir; /* Modified copy of template. */ + struct hypfs_funcs funcs; /* Dynamic functions. */ + struct hypfs_entry_dir *template; /* Template used. */ + char name[12]; /* Name of hypfs entry. */ + + unsigned int id; /* Numerical id. */ +}; + #define HYPFS_DIRENTRY_NAME_OFF offsetof(struct xen_hypfs_dirlistentry, name) #define HYPFS_DIRENTRY_SIZE(name_len) \ (HYPFS_DIRENTRY_NAME_OFF + \ @@ -150,6 +159,11 @@ struct hypfs_entry *hypfs_dir_findentry(struct hypfs_entry_dir *dir, unsigned int name_len); void *hypfs_alloc_dyndata(unsigned long size, unsigned long align); void *hypfs_get_dyndata(void); +int hypfs_read_dyndir_id_entry(struct hypfs_entry_dir *template, + unsigned int id, bool is_last, + XEN_GUEST_HANDLE_PARAM(void) *uaddr); +struct hypfs_entry *hypfs_gen_dyndir_entry_id(struct hypfs_entry_dir *template, + unsigned int id); #endif #endif /* __XEN_HYPFS_H__ */ -- 2.26.2