X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=fs%2Fsysfs%2Ffile.c;h=e7735f643cd1b03eab8560479d6f691e387ce218;hb=d67c6f869c0a7f275689855161c93d714197e052;hp=4045bdcc4b331dbf7f4cdd7c6d781f16021ffbf2;hpb=03bbe082cffc4533f6557bf23f0c672307067246;p=linux-2.6 diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 4045bdcc4b..e7735f643c 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -12,6 +12,8 @@ #include #include +#include +#include #include #include #include @@ -20,43 +22,6 @@ #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 +31,7 @@ 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; @@ -123,7 +88,12 @@ static int fill_read_buffer(struct dentry * dentry, struct sysfs_buffer * buffer * 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 >= (ssize_t)PAGE_SIZE) { + print_symbol("fill_read_buffer: %s returned bad count\n", + (unsigned long)ops->show); + /* Try to struggle along */ + count = PAGE_SIZE - 1; + } if (count >= 0) { buffer->needs_read_fill = 0; buffer->count = count; @@ -159,13 +129,13 @@ sysfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos) ssize_t retval = 0; mutex_lock(&buffer->mutex); - if (buffer->needs_read_fill) { + if (buffer->needs_read_fill || *ppos == 0) { retval = fill_read_buffer(file->f_path.dentry,buffer); if (retval) goto out; } pr_debug("%s: count = %zd, ppos = %lld, buf = %s\n", - __FUNCTION__, count, *ppos, buffer->page); + __func__, count, *ppos, buffer->page); retval = simple_read_from_buffer(buf, count, ppos, buffer->page, buffer->count); out: @@ -354,31 +324,23 @@ 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, @@ -448,8 +410,7 @@ static int sysfs_release(struct inode *inode, struct file *filp) * return POLLERR|POLLPRI, and select will return the fd whether * it is waiting for read, write, or exceptions. * Once poll/select indicates that the value has changed, you - * need to close and re-open the file, as simply seeking and reading - * again will not get new data, or reset the state of 'poll'. + * need to close and re-open the file, or seek to 0 and read again. * Reminder: this only works for attributes which actively support * it, and it is not possible to test an attribute from userspace * to see if it supports poll (Neither 'poll' nor 'select' return @@ -516,11 +477,10 @@ const struct file_operations sysfs_file_operations = { .poll = sysfs_poll, }; - -int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr, - int type) +int sysfs_add_file_mode(struct sysfs_dirent *dir_sd, + const struct attribute *attr, int type, mode_t amode) { - umode_t mode = (attr->mode & S_IALLUGO) | S_IFREG; + umode_t mode = (amode & S_IALLUGO) | S_IFREG; struct sysfs_addrm_cxt acxt; struct sysfs_dirent *sd; int rc; @@ -541,6 +501,13 @@ int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr, } +int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr, + int type) +{ + return sysfs_add_file_mode(dir_sd, attr, type, attr->mode); +} + + /** * sysfs_create_file - create an attribute file for an object. * @kobj: object we're creating for. @@ -568,7 +535,11 @@ int sysfs_add_file_to_group(struct kobject *kobj, struct sysfs_dirent *dir_sd; int error; - dir_sd = sysfs_get_dirent(kobj->sd, group); + if (group) + dir_sd = sysfs_get_dirent(kobj->sd, group); + else + dir_sd = sysfs_get(kobj->sd); + if (!dir_sd) return -ENOENT; @@ -656,7 +627,10 @@ void sysfs_remove_file_from_group(struct kobject *kobj, { struct sysfs_dirent *dir_sd; - dir_sd = sysfs_get_dirent(kobj->sd, group); + if (group) + dir_sd = sysfs_get_dirent(kobj->sd, group); + else + dir_sd = sysfs_get(kobj->sd); if (dir_sd) { sysfs_hash_and_remove(dir_sd, attr->name); sysfs_put(dir_sd);