sysfs: prepare open path for unified regular / bin file handling
sysfs bin file handling will be merged into the regular file support.
This patch prepares the open path.
This patch updates sysfs_open_file() such that it can handle both
regular and bin files.
This is a preparation and the new bin file path isn't used yet.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 02797a1..417d005 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -610,37 +610,39 @@
struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
struct sysfs_open_file *of;
- const struct sysfs_ops *ops;
+ bool has_read, has_write;
int error = -EACCES;
/* need attr_sd for attr and ops, its parent for kobj */
if (!sysfs_get_active(attr_sd))
return -ENODEV;
- /* every kobject with an attribute needs a ktype assigned */
- ops = sysfs_file_ops(attr_sd);
- if (WARN(!ops, KERN_ERR
- "missing sysfs attribute operations for kobject: %s\n",
- kobject_name(kobj)))
+ if (sysfs_is_bin(attr_sd)) {
+ struct bin_attribute *battr = attr_sd->s_bin_attr.bin_attr;
+
+ has_read = battr->read || battr->mmap;
+ has_write = battr->write || battr->mmap;
+ } else {
+ const struct sysfs_ops *ops = sysfs_file_ops(attr_sd);
+
+ /* every kobject with an attribute needs a ktype assigned */
+ if (WARN(!ops, KERN_ERR
+ "missing sysfs attribute operations for kobject: %s\n",
+ kobject_name(kobj)))
+ goto err_out;
+
+ has_read = ops->show;
+ has_write = ops->store;
+ }
+
+ /* check perms and supported operations */
+ if ((file->f_mode & FMODE_WRITE) &&
+ (!(inode->i_mode & S_IWUGO) || !has_write))
goto err_out;
- /* File needs write support.
- * The inode's perms must say it's ok,
- * and we must have a store method.
- */
- if (file->f_mode & FMODE_WRITE) {
- if (!(inode->i_mode & S_IWUGO) || !ops->store)
- goto err_out;
- }
-
- /* File needs read support.
- * The inode's perms must say it's ok, and we there
- * must be a show method for it.
- */
- if (file->f_mode & FMODE_READ) {
- if (!(inode->i_mode & S_IRUGO) || !ops->show)
- goto err_out;
- }
+ if ((file->f_mode & FMODE_READ) &&
+ (!(inode->i_mode & S_IRUGO) || !has_read))
+ goto err_out;
/* allocate a sysfs_open_file for the file */
error = -ENOMEM;
@@ -653,11 +655,14 @@
of->file = file;
/*
- * Always instantiate seq_file even if read access is not
- * implemented or requested. This unifies private data access and
- * most files are readable anyway.
+ * Always instantiate seq_file even if read access doesn't use
+ * seq_file or is not requested. This unifies private data access
+ * and readable regular files are the vast majority anyway.
*/
- error = single_open(file, sysfs_seq_show, of);
+ if (sysfs_is_bin(attr_sd))
+ error = single_open(file, NULL, of);
+ else
+ error = single_open(file, sysfs_seq_show, of);
if (error)
goto err_free;
@@ -807,6 +812,9 @@
.write = sysfs_write_file,
.llseek = generic_file_llseek,
.mmap = sysfs_bin_mmap,
+ .open = sysfs_open_file,
+ .release = sysfs_release,
+ .poll = sysfs_poll,
};
int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd,