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sysfs: prepare open path for unified regular / bin file handling

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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>
This commit is contained in:
Tejun Heo 2013-10-01 17:42:08 -04:00 committed by Greg Kroah-Hartman
parent 73d9714627
commit 49fe604781
1 changed files with 35 additions and 27 deletions
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62
fs/sysfs/file.c
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@ -610,37 +610,39 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
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 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
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 @@ const struct file_operations sysfs_bin_operations = {
.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,