diff options
| -rw-r--r-- | fs/sysfs/bin.c | 64 |
1 files changed, 49 insertions, 15 deletions
diff --git a/fs/sysfs/bin.c b/fs/sysfs/bin.c index 67a0d5030c9..5dc47fe5de5 100644 --- a/fs/sysfs/bin.c +++ b/fs/sysfs/bin.c @@ -20,6 +20,11 @@ #include "sysfs.h" +struct bin_buffer { + struct mutex mutex; + void *buffer; +}; + static int fill_read(struct dentry *dentry, char *buffer, loff_t off, size_t count) { @@ -36,7 +41,7 @@ fill_read(struct dentry *dentry, char *buffer, loff_t off, size_t count) static ssize_t read(struct file *file, char __user *userbuf, size_t bytes, loff_t *off) { - char *buffer = file->private_data; + struct bin_buffer *bb = file->private_data; struct dentry *dentry = file->f_path.dentry; int size = dentry->d_inode->i_size; loff_t offs = *off; @@ -49,17 +54,23 @@ read(struct file *file, char __user *userbuf, size_t bytes, loff_t *off) count = size - offs; } - count = fill_read(dentry, buffer, offs, count); + mutex_lock(&bb->mutex); + + count = fill_read(dentry, bb->buffer, offs, count); if (count < 0) - return count; + goto out_unlock; - if (copy_to_user(userbuf, buffer, count)) - return -EFAULT; + if (copy_to_user(userbuf, bb->buffer, count)) { + count = -EFAULT; + goto out_unlock; + } pr_debug("offs = %lld, *off = %lld, count = %d\n", offs, *off, count); *off = offs + count; + out_unlock: + mutex_unlock(&bb->mutex); return count; } @@ -79,7 +90,7 @@ flush_write(struct dentry *dentry, char *buffer, loff_t offset, size_t count) static ssize_t write(struct file *file, const char __user *userbuf, size_t bytes, loff_t *off) { - char *buffer = file->private_data; + struct bin_buffer *bb = file->private_data; struct dentry *dentry = file->f_path.dentry; int size = dentry->d_inode->i_size; loff_t offs = *off; @@ -92,25 +103,38 @@ static ssize_t write(struct file *file, const char __user *userbuf, count = size - offs; } - if (copy_from_user(buffer, userbuf, count)) - return -EFAULT; + mutex_lock(&bb->mutex); + + if (copy_from_user(bb->buffer, userbuf, count)) { + count = -EFAULT; + goto out_unlock; + } - count = flush_write(dentry, buffer, offs, count); + count = flush_write(dentry, bb->buffer, offs, count); if (count > 0) *off = offs + count; + + out_unlock: + mutex_unlock(&bb->mutex); return count; } 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); + int rc; if (!attr->mmap) return -EINVAL; - return attr->mmap(kobj, attr, vma); + mutex_lock(&bb->mutex); + rc = attr->mmap(kobj, attr, vma); + mutex_unlock(&bb->mutex); + + return rc; } static int open(struct inode * inode, struct file * file) @@ -118,6 +142,7 @@ 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; if (!kobj || !attr) @@ -135,14 +160,22 @@ static int open(struct inode * inode, struct file * file) goto Error; error = -ENOMEM; - file->private_data = kmalloc(PAGE_SIZE, GFP_KERNEL); - if (!file->private_data) + bb = kzalloc(sizeof(*bb), GFP_KERNEL); + if (!bb) goto Error; + bb->buffer = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!bb->buffer) + goto Error; + + mutex_init(&bb->mutex); + file->private_data = bb; + error = 0; - goto Done; + goto Done; Error: + kfree(bb); module_put(attr->attr.owner); Done: if (error) @@ -155,11 +188,12 @@ 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; - u8 * buffer = file->private_data; + struct bin_buffer *bb = file->private_data; kobject_put(kobj); module_put(attr->attr.owner); - kfree(buffer); + kfree(bb->buffer); + kfree(bb); return 0; } |