configfs: implement binary attributes
ConfigFS lacked binary attributes up until now. This patch
introduces support for binary attributes in a somewhat similar
manner of sysfs binary attributes albeit with changes that
fit the configfs usage model.
Problems that configfs binary attributes fix are everything that
requires a binary blob as part of the configuration of a resource,
such as bitstream loading for FPGAs, DTBs for dynamically created
devices etc.
Look at Documentation/filesystems/configfs/configfs.txt for internals
and howto use them.
This patch is against linux-next as of today that contains
Christoph's configfs rework.
Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
[hch: folded a fix from Geert Uytterhoeven <geert+renesas@glider.be>]
[hch: a few tiny updates based on review feedback]
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index a7a1b21..7ae97e8 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -255,6 +255,12 @@
inode->i_fop = &configfs_file_operations;
}
+static void configfs_init_bin_file(struct inode *inode)
+{
+ inode->i_size = 0;
+ inode->i_fop = &configfs_bin_file_operations;
+}
+
static void init_symlink(struct inode * inode)
{
inode->i_op = &configfs_symlink_inode_operations;
@@ -423,7 +429,9 @@
spin_unlock(&configfs_dirent_lock);
error = configfs_create(dentry, (attr->ca_mode & S_IALLUGO) | S_IFREG,
- configfs_init_file);
+ (sd->s_type & CONFIGFS_ITEM_BIN_ATTR) ?
+ configfs_init_bin_file :
+ configfs_init_file);
if (error) {
configfs_put(sd);
return error;
@@ -583,6 +591,7 @@
{
struct config_item_type *t = item->ci_type;
struct configfs_attribute *attr;
+ struct configfs_bin_attribute *bin_attr;
int error = 0;
int i;
@@ -594,6 +603,13 @@
break;
}
}
+ if (t->ct_bin_attrs) {
+ for (i = 0; (bin_attr = t->ct_bin_attrs[i]) != NULL; i++) {
+ error = configfs_create_bin_file(item, bin_attr);
+ if (error)
+ break;
+ }
+ }
if (error)
detach_attrs(item);