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path: root/fs/sysfs/bin.c
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Diffstat (limited to 'fs/sysfs/bin.c')
-rw-r--r--fs/sysfs/bin.c95
1 files changed, 62 insertions, 33 deletions
diff --git a/fs/sysfs/bin.c b/fs/sysfs/bin.c
index 5dc47fe5de5..618b8aea6a7 100644
--- a/fs/sysfs/bin.c
+++ b/fs/sysfs/bin.c
@@ -23,6 +23,7 @@
struct bin_buffer {
struct mutex mutex;
void *buffer;
+ int mmapped;
};
static int
@@ -30,12 +31,20 @@ fill_read(struct dentry *dentry, char *buffer, loff_t off, size_t count)
{
struct sysfs_dirent *attr_sd = dentry->d_fsdata;
struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr;
- struct kobject * kobj = to_kobj(dentry->d_parent);
+ struct kobject *kobj = attr_sd->s_parent->s_elem.dir.kobj;
+ int rc;
+
+ /* need attr_sd for attr, its parent for kobj */
+ if (!sysfs_get_active_two(attr_sd))
+ return -ENODEV;
- if (!attr->read)
- return -EIO;
+ rc = -EIO;
+ if (attr->read)
+ rc = attr->read(kobj, buffer, off, count);
- return attr->read(kobj, buffer, off, count);
+ sysfs_put_active_two(attr_sd);
+
+ return rc;
}
static ssize_t
@@ -79,12 +88,20 @@ flush_write(struct dentry *dentry, char *buffer, loff_t offset, size_t count)
{
struct sysfs_dirent *attr_sd = dentry->d_fsdata;
struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr;
- struct kobject *kobj = to_kobj(dentry->d_parent);
+ struct kobject *kobj = attr_sd->s_parent->s_elem.dir.kobj;
+ int rc;
+
+ /* need attr_sd for attr, its parent for kobj */
+ if (!sysfs_get_active_two(attr_sd))
+ return -ENODEV;
- if (!attr->write)
- return -EIO;
+ rc = -EIO;
+ if (attr->write)
+ rc = attr->write(kobj, buffer, offset, count);
- return attr->write(kobj, buffer, offset, count);
+ sysfs_put_active_two(attr_sd);
+
+ return rc;
}
static ssize_t write(struct file *file, const char __user *userbuf,
@@ -124,14 +141,24 @@ static int mmap(struct file *file, struct vm_area_struct *vma)
struct bin_buffer *bb = file->private_data;
struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr;
- struct kobject *kobj = to_kobj(file->f_path.dentry->d_parent);
+ struct kobject *kobj = attr_sd->s_parent->s_elem.dir.kobj;
int rc;
- if (!attr->mmap)
- return -EINVAL;
-
mutex_lock(&bb->mutex);
- rc = attr->mmap(kobj, attr, vma);
+
+ /* need attr_sd for attr, its parent for kobj */
+ if (!sysfs_get_active_two(attr_sd))
+ return -ENODEV;
+
+ rc = -EINVAL;
+ if (attr->mmap)
+ rc = attr->mmap(kobj, attr, vma);
+
+ if (rc == 0 && !bb->mmapped)
+ bb->mmapped = 1;
+ else
+ sysfs_put_active_two(attr_sd);
+
mutex_unlock(&bb->mutex);
return rc;
@@ -139,58 +166,60 @@ static int mmap(struct file *file, struct vm_area_struct *vma)
static int open(struct inode * inode, struct file * file)
{
- struct kobject *kobj = sysfs_get_kobject(file->f_path.dentry->d_parent);
struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr;
struct bin_buffer *bb = NULL;
- int error = -EINVAL;
+ int error;
- if (!kobj || !attr)
- goto Done;
+ /* need attr_sd for attr */
+ if (!sysfs_get_active(attr_sd))
+ return -ENODEV;
- /* Grab the module reference for this attribute if we have one */
+ /* Grab the module reference for this attribute */
error = -ENODEV;
- if (!try_module_get(attr->attr.owner))
- goto Done;
+ if (!try_module_get(attr->attr.owner))
+ goto err_sput;
error = -EACCES;
if ((file->f_mode & FMODE_WRITE) && !(attr->write || attr->mmap))
- goto Error;
+ goto err_mput;
if ((file->f_mode & FMODE_READ) && !(attr->read || attr->mmap))
- goto Error;
+ goto err_mput;
error = -ENOMEM;
bb = kzalloc(sizeof(*bb), GFP_KERNEL);
if (!bb)
- goto Error;
+ goto err_mput;
bb->buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (!bb->buffer)
- goto Error;
+ goto err_mput;
mutex_init(&bb->mutex);
file->private_data = bb;
- error = 0;
- goto Done;
+ /* open succeeded, put active reference and pin attr_sd */
+ sysfs_put_active(attr_sd);
+ sysfs_get(attr_sd);
+ return 0;
- Error:
- kfree(bb);
+ err_mput:
module_put(attr->attr.owner);
- Done:
- if (error)
- kobject_put(kobj);
+ err_sput:
+ sysfs_put_active(attr_sd);
+ kfree(bb);
return error;
}
static int release(struct inode * inode, struct file * file)
{
- struct kobject * kobj = to_kobj(file->f_path.dentry->d_parent);
struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr;
struct bin_buffer *bb = file->private_data;
- kobject_put(kobj);
+ if (bb->mmapped)
+ sysfs_put_active_two(attr_sd);
+ sysfs_put(attr_sd);
module_put(attr->attr.owner);
kfree(bb->buffer);
kfree(bb);