diff options
Diffstat (limited to 'fs/sysfs/file.c')
| -rw-r--r-- | fs/sysfs/file.c | 73 |
1 files changed, 16 insertions, 57 deletions
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 27d1785b764..8acf82bba44 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -20,43 +20,6 @@ #include "sysfs.h" -#define to_sattr(a) container_of(a,struct subsys_attribute, attr) - -/* - * Subsystem file operations. - * These operations allow subsystems to have files that can be - * read/written. - */ -static ssize_t -subsys_attr_show(struct kobject * kobj, struct attribute * attr, char * page) -{ - struct kset *kset = to_kset(kobj); - struct subsys_attribute * sattr = to_sattr(attr); - ssize_t ret = -EIO; - - if (sattr->show) - ret = sattr->show(kset, page); - return ret; -} - -static ssize_t -subsys_attr_store(struct kobject * kobj, struct attribute * attr, - const char * page, size_t count) -{ - struct kset *kset = to_kset(kobj); - struct subsys_attribute * sattr = to_sattr(attr); - ssize_t ret = -EIO; - - if (sattr->store) - ret = sattr->store(kset, page, count); - return ret; -} - -static struct sysfs_ops subsys_sysfs_ops = { - .show = subsys_attr_show, - .store = subsys_attr_store, -}; - /* * There's one sysfs_buffer for each open file and one * sysfs_open_dirent for each sysfs_dirent with one or more open @@ -66,7 +29,7 @@ static struct sysfs_ops subsys_sysfs_ops = { * sysfs_dirent->s_attr.open points to sysfs_open_dirent. s_attr.open * is protected by sysfs_open_dirent_lock. */ -static spinlock_t sysfs_open_dirent_lock = SPIN_LOCK_UNLOCKED; +static DEFINE_SPINLOCK(sysfs_open_dirent_lock); struct sysfs_open_dirent { atomic_t refcnt; @@ -119,7 +82,11 @@ static int fill_read_buffer(struct dentry * dentry, struct sysfs_buffer * buffer sysfs_put_active_two(attr_sd); - BUG_ON(count > (ssize_t)PAGE_SIZE); + /* + * The code works fine with PAGE_SIZE return but it's likely to + * indicate truncated result or overflow in normal use cases. + */ + BUG_ON(count >= (ssize_t)PAGE_SIZE); if (count >= 0) { buffer->needs_read_fill = 0; buffer->count = count; @@ -350,31 +317,23 @@ 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_buffer * buffer; - struct sysfs_ops * ops = NULL; - int error; + struct sysfs_buffer *buffer; + struct sysfs_ops *ops; + int error = -EACCES; /* need attr_sd for attr and ops, its parent for kobj */ if (!sysfs_get_active_two(attr_sd)) return -ENODEV; - /* if the kobject has no ktype, then we assume that it is a subsystem - * itself, and use ops for it. - */ - if (kobj->kset && kobj->kset->ktype) - ops = kobj->kset->ktype->sysfs_ops; - else if (kobj->ktype) + /* every kobject with an attribute needs a ktype assigned */ + if (kobj->ktype && kobj->ktype->sysfs_ops) ops = kobj->ktype->sysfs_ops; - else - ops = &subsys_sysfs_ops; - - error = -EACCES; - - /* No sysfs operations, either from having no subsystem, - * or the subsystem have no operations. - */ - if (!ops) + else { + printk(KERN_ERR "missing sysfs attribute operations for " + "kobject: %s\n", kobject_name(kobj)); + WARN_ON(1); goto err_out; + } /* File needs write support. * The inode's perms must say it's ok, |