From 870823e629ea194e6cf8e82a9694ac62cad49512 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sat, 3 Oct 2015 15:32:37 +0200 Subject: [PATCH] configfs: add show and store methods to struct configfs_attribute Add methods to struct configfs_attribute to directly show and store attributes without adding boilerplate code to every user. In addition to the methods this also adds 3 helper macros to define read/write, read-only and write-only attributes with a single line of code. Signed-off-by: Christoph Hellwig Reviewed-by: Nicholas Bellinger Acked-by: Greg Kroah-Hartman Signed-off-by: Nicholas Bellinger --- fs/configfs/file.c | 17 ++++++++++++----- include/linux/configfs.h | 27 +++++++++++++++++++++++++++ 2 files changed, 39 insertions(+), 5 deletions(-) diff --git a/fs/configfs/file.c b/fs/configfs/file.c index 403269ffcdf3..106ca589e90a 100644 --- a/fs/configfs/file.c +++ b/fs/configfs/file.c @@ -74,7 +74,11 @@ static int fill_read_buffer(struct dentry * dentry, struct configfs_buffer * buf if (!buffer->page) return -ENOMEM; - count = ops->show_attribute(item,attr,buffer->page); + if (ops->show_attribute) + count = ops->show_attribute(item, attr, buffer->page); + else + count = attr->show(item, buffer->page); + buffer->needs_read_fill = 0; BUG_ON(count > (ssize_t)SIMPLE_ATTR_SIZE); if (count >= 0) @@ -173,7 +177,9 @@ flush_write_buffer(struct dentry * dentry, struct configfs_buffer * buffer, size struct config_item * item = to_item(dentry->d_parent); struct configfs_item_operations * ops = buffer->ops; - return ops->store_attribute(item,attr,buffer->page,count); + if (ops->store_attribute) + return ops->store_attribute(item, attr, buffer->page, count); + return attr->store(item, buffer->page, count); } @@ -237,8 +243,8 @@ static int check_perm(struct inode * inode, struct file * file) * and we must have a store method. */ if (file->f_mode & FMODE_WRITE) { - - if (!(inode->i_mode & S_IWUGO) || !ops->store_attribute) + if (!(inode->i_mode & S_IWUGO) || + (!ops->store_attribute && !attr->store)) goto Eaccess; } @@ -248,7 +254,8 @@ static int check_perm(struct inode * inode, struct file * file) * must be a show method for it. */ if (file->f_mode & FMODE_READ) { - if (!(inode->i_mode & S_IRUGO) || !ops->show_attribute) + if (!(inode->i_mode & S_IRUGO) || + (!ops->show_attribute && !attr->show)) goto Eaccess; } diff --git a/include/linux/configfs.h b/include/linux/configfs.h index 63a36e89d0eb..85e9956a86de 100644 --- a/include/linux/configfs.h +++ b/include/linux/configfs.h @@ -125,8 +125,35 @@ struct configfs_attribute { const char *ca_name; struct module *ca_owner; umode_t ca_mode; + ssize_t (*show)(struct config_item *, char *); + ssize_t (*store)(struct config_item *, const char *, size_t); }; +#define CONFIGFS_ATTR(_pfx, _name) \ +static struct configfs_attribute _pfx##attr_##_name = { \ + .ca_name = __stringify(_name), \ + .ca_mode = S_IRUGO | S_IWUSR, \ + .ca_owner = THIS_MODULE, \ + .show = _pfx##_name##_show, \ + .store = _pfx##_name##_store, \ +} + +#define CONFIGFS_ATTR_RO(_pfx, _name) \ +static struct configfs_attribute _pfx##attr_##_name = { \ + .ca_name = __stringify(_name), \ + .ca_mode = S_IRUGO, \ + .ca_owner = THIS_MODULE, \ + .show = _pfx##_name##_show, \ +} + +#define CONFIGFS_ATTR_WO(_pfx, _name) \ +static struct configfs_attribute _pfx##attr_##_name = { \ + .ca_name = __stringify(_name), \ + .ca_mode = S_IWUSR, \ + .ca_owner = THIS_MODULE, \ + .store = _pfx##_name##_store, \ +} + /* * Users often need to create attribute structures for their configurable * attributes, containing a configfs_attribute member and function pointers -- 2.20.1