X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;ds=sidebyside;f=fs%2Fsysfs%2Ffile.c;h=352f966a1174681f0c1e6a5801942b16d8df7d40;hb=6a77f38946aaee1cd85eeec6cf4229b204c15071;hp=159d99f06a3fa50f6cce1ef11242441f57367fbb;hpb=87fc8d1bb10cd459024a742c6a10961fefcef18f;p=linux-2.6.git diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 159d99f06..352f966a1 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -6,18 +6,10 @@ #include #include #include +#include #include "sysfs.h" -static struct file_operations sysfs_file_operations; - -static int init_file(struct inode * inode) -{ - inode->i_size = PAGE_SIZE; - inode->i_fop = &sysfs_file_operations; - return 0; -} - #define to_subsys(k) container_of(k,struct subsystem,kset.kobj) #define to_sattr(a) container_of(a,struct subsys_attribute,attr) @@ -62,12 +54,14 @@ struct sysfs_buffer { loff_t pos; char * page; struct sysfs_ops * ops; + struct semaphore sem; + int needs_read_fill; }; /** * fill_read_buffer - allocate and fill buffer from object. - * @file: file pointer. + * @dentry: dentry pointer. * @buffer: data buffer for file. * * Allocate @buffer->page, if it hasn't been already, then call the @@ -75,10 +69,10 @@ struct sysfs_buffer { * data. * This is called only once, on the file's first read. */ -static int fill_read_buffer(struct file * file, struct sysfs_buffer * buffer) +static int fill_read_buffer(struct dentry * dentry, struct sysfs_buffer * buffer) { - struct attribute * attr = file->f_dentry->d_fsdata; - struct kobject * kobj = file->f_dentry->d_parent->d_fsdata; + struct attribute * attr = to_attr(dentry); + struct kobject * kobj = to_kobj(dentry->d_parent); struct sysfs_ops * ops = buffer->ops; int ret = 0; ssize_t count; @@ -89,6 +83,7 @@ static int fill_read_buffer(struct file * file, struct sysfs_buffer * buffer) return -ENOMEM; count = ops->show(kobj,attr,buffer->page); + buffer->needs_read_fill = 0; BUG_ON(count > (ssize_t)PAGE_SIZE); if (count >= 0) buffer->count = count; @@ -115,6 +110,9 @@ static int flush_read_buffer(struct sysfs_buffer * buffer, char __user * buf, { int error; + if (*ppos > buffer->count) + return 0; + if (count > (buffer->count - *ppos)) count = buffer->count - *ppos; @@ -149,13 +147,17 @@ sysfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos) struct sysfs_buffer * buffer = file->private_data; ssize_t retval = 0; - if (!*ppos) { - if ((retval = fill_read_buffer(file,buffer))) - return retval; + down(&buffer->sem); + if (buffer->needs_read_fill) { + if ((retval = fill_read_buffer(file->f_dentry,buffer))) + goto out; } pr_debug("%s: count = %d, ppos = %lld, buf = %s\n", __FUNCTION__,count,*ppos,buffer->page); - return flush_read_buffer(buffer,buf,count,ppos); + retval = flush_read_buffer(buffer,buf,count,ppos); +out: + up(&buffer->sem); + return retval; } @@ -182,6 +184,7 @@ fill_write_buffer(struct sysfs_buffer * buffer, const char __user * buf, size_t if (count >= PAGE_SIZE) count = PAGE_SIZE - 1; error = copy_from_user(buffer->page,buf,count); + buffer->needs_read_fill = 1; return error ? -EFAULT : count; } @@ -197,10 +200,10 @@ fill_write_buffer(struct sysfs_buffer * buffer, const char __user * buf, size_t */ static int -flush_write_buffer(struct file * file, struct sysfs_buffer * buffer, size_t count) +flush_write_buffer(struct dentry * dentry, struct sysfs_buffer * buffer, size_t count) { - struct attribute * attr = file->f_dentry->d_fsdata; - struct kobject * kobj = file->f_dentry->d_parent->d_fsdata; + struct attribute * attr = to_attr(dentry); + struct kobject * kobj = to_kobj(dentry->d_parent); struct sysfs_ops * ops = buffer->ops; return ops->store(kobj,attr,buffer->page,count); @@ -228,19 +231,22 @@ static ssize_t sysfs_write_file(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { struct sysfs_buffer * buffer = file->private_data; - - count = fill_write_buffer(buffer,buf,count); - if (count > 0) - count = flush_write_buffer(file,buffer,count); - if (count > 0) - *ppos += count; - return count; + ssize_t len; + + down(&buffer->sem); + len = fill_write_buffer(buffer, buf, count); + if (len > 0) + len = flush_write_buffer(file->f_dentry, buffer, len); + if (len > 0) + *ppos += len; + up(&buffer->sem); + return len; } static int check_perm(struct inode * inode, struct file * file) { struct kobject *kobj = sysfs_get_kobject(file->f_dentry->d_parent); - struct attribute * attr = file->f_dentry->d_fsdata; + struct attribute * attr = to_attr(file->f_dentry); struct sysfs_buffer * buffer; struct sysfs_ops * ops = NULL; int error = 0; @@ -296,6 +302,8 @@ static int check_perm(struct inode * inode, struct file * file) buffer = kmalloc(sizeof(struct sysfs_buffer),GFP_KERNEL); if (buffer) { memset(buffer,0,sizeof(struct sysfs_buffer)); + init_MUTEX(&buffer->sem); + buffer->needs_read_fill = 1; buffer->ops = ops; file->private_data = buffer; } else @@ -321,13 +329,15 @@ static int sysfs_open_file(struct inode * inode, struct file * filp) static int sysfs_release(struct inode * inode, struct file * filp) { - struct kobject * kobj = filp->f_dentry->d_parent->d_fsdata; - struct attribute * attr = filp->f_dentry->d_fsdata; + struct kobject * kobj = to_kobj(filp->f_dentry->d_parent); + struct attribute * attr = to_attr(filp->f_dentry); + struct module * owner = attr->owner; struct sysfs_buffer * buffer = filp->private_data; if (kobj) kobject_put(kobj); - module_put(attr->owner); + /* After this point, attr should not be accessed. */ + module_put(owner); if (buffer) { if (buffer->page) @@ -337,7 +347,7 @@ static int sysfs_release(struct inode * inode, struct file * filp) return 0; } -static struct file_operations sysfs_file_operations = { +struct file_operations sysfs_file_operations = { .read = sysfs_read_file, .write = sysfs_write_file, .llseek = generic_file_llseek, @@ -346,23 +356,16 @@ static struct file_operations sysfs_file_operations = { }; -int sysfs_add_file(struct dentry * dir, const struct attribute * attr) +int sysfs_add_file(struct dentry * dir, const struct attribute * attr, int type) { - struct dentry * dentry; - int error; + struct sysfs_dirent * parent_sd = dir->d_fsdata; + umode_t mode = (attr->mode & S_IALLUGO) | S_IFREG; + int error = 0; down(&dir->d_inode->i_sem); - dentry = sysfs_get_dentry(dir,attr->name); - if (!IS_ERR(dentry)) { - error = sysfs_create(dentry, - (attr->mode & S_IALLUGO) | S_IFREG, - init_file); - if (!error) - dentry->d_fsdata = (void *)attr; - dput(dentry); - } else - error = PTR_ERR(dentry); + error = sysfs_make_dirent(parent_sd, NULL, (void *) attr, mode, type); up(&dir->d_inode->i_sem); + return error; } @@ -375,9 +378,10 @@ int sysfs_add_file(struct dentry * dir, const struct attribute * attr) int sysfs_create_file(struct kobject * kobj, const struct attribute * attr) { - if (kobj && attr) - return sysfs_add_file(kobj->dentry,attr); - return -EINVAL; + BUG_ON(!kobj || !kobj->dentry || !attr); + + return sysfs_add_file(kobj->dentry, attr, SYSFS_KOBJ_ATTR); + } @@ -409,7 +413,8 @@ int sysfs_update_file(struct kobject * kobj, const struct attribute * attr) */ dput(victim); res = 0; - } + } else + d_drop(victim); /** * Drop the reference acquired from sysfs_get_dentry() above. @@ -436,7 +441,7 @@ void sysfs_remove_file(struct kobject * kobj, const struct attribute * attr) } -EXPORT_SYMBOL(sysfs_create_file); -EXPORT_SYMBOL(sysfs_remove_file); -EXPORT_SYMBOL(sysfs_update_file); +EXPORT_SYMBOL_GPL(sysfs_create_file); +EXPORT_SYMBOL_GPL(sysfs_remove_file); +EXPORT_SYMBOL_GPL(sysfs_update_file);