#include <linux/pagemap.h>
#include <linux/namei.h>
#include <linux/backing-dev.h>
+#include <linux/capability.h>
+#include <linux/errno.h>
+#include "sysfs.h"
+
extern struct super_block * sysfs_sb;
-static struct address_space_operations sysfs_aops = {
+static const struct address_space_operations sysfs_aops = {
.readpage = simple_readpage,
.prepare_write = simple_prepare_write,
.commit_write = simple_commit_write
static struct backing_dev_info sysfs_backing_dev_info = {
.ra_pages = 0, /* No readahead */
- .memory_backed = 1, /* Does not contribute to dirty memory */
+ .capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
+};
+
+static struct inode_operations sysfs_inode_operations ={
+ .setattr = sysfs_setattr,
};
-struct inode * sysfs_new_inode(mode_t mode)
+int sysfs_setattr(struct dentry * dentry, struct iattr * iattr)
+{
+ struct inode * inode = dentry->d_inode;
+ struct sysfs_dirent * sd = dentry->d_fsdata;
+ struct iattr * sd_iattr;
+ unsigned int ia_valid = iattr->ia_valid;
+ int error;
+
+ if (!sd)
+ return -EINVAL;
+
+ sd_iattr = sd->s_iattr;
+
+ error = inode_change_ok(inode, iattr);
+ if (error)
+ return error;
+
+ error = inode_setattr(inode, iattr);
+ if (error)
+ return error;
+
+ if (!sd_iattr) {
+ /* setting attributes for the first time, allocate now */
+ sd_iattr = kzalloc(sizeof(struct iattr), GFP_KERNEL);
+ if (!sd_iattr)
+ return -ENOMEM;
+ /* assign default attributes */
+ sd_iattr->ia_mode = sd->s_mode;
+ sd_iattr->ia_uid = 0;
+ sd_iattr->ia_gid = 0;
+ sd_iattr->ia_atime = sd_iattr->ia_mtime = sd_iattr->ia_ctime = CURRENT_TIME;
+ sd->s_iattr = sd_iattr;
+ }
+
+ /* attributes were changed atleast once in past */
+
+ if (ia_valid & ATTR_UID)
+ sd_iattr->ia_uid = iattr->ia_uid;
+ if (ia_valid & ATTR_GID)
+ sd_iattr->ia_gid = iattr->ia_gid;
+ if (ia_valid & ATTR_ATIME)
+ sd_iattr->ia_atime = timespec_trunc(iattr->ia_atime,
+ inode->i_sb->s_time_gran);
+ if (ia_valid & ATTR_MTIME)
+ sd_iattr->ia_mtime = timespec_trunc(iattr->ia_mtime,
+ inode->i_sb->s_time_gran);
+ if (ia_valid & ATTR_CTIME)
+ sd_iattr->ia_ctime = timespec_trunc(iattr->ia_ctime,
+ inode->i_sb->s_time_gran);
+ if (ia_valid & ATTR_MODE) {
+ umode_t mode = iattr->ia_mode;
+
+ if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
+ mode &= ~S_ISGID;
+ sd_iattr->ia_mode = sd->s_mode = mode;
+ }
+
+ return error;
+}
+
+static inline void set_default_inode_attr(struct inode * inode, mode_t mode)
+{
+ inode->i_mode = mode;
+ inode->i_uid = 0;
+ inode->i_gid = 0;
+ inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+}
+
+static inline void set_inode_attr(struct inode * inode, struct iattr * iattr)
+{
+ inode->i_mode = iattr->ia_mode;
+ inode->i_uid = iattr->ia_uid;
+ inode->i_gid = iattr->ia_gid;
+ inode->i_atime = iattr->ia_atime;
+ inode->i_mtime = iattr->ia_mtime;
+ inode->i_ctime = iattr->ia_ctime;
+}
+
+
+/*
+ * sysfs has a different i_mutex lock order behavior for i_mutex than other
+ * filesystems; sysfs i_mutex is called in many places with subsystem locks
+ * held. At the same time, many of the VFS locking rules do not apply to
+ * sysfs at all (cross directory rename for example). To untangle this mess
+ * (which gives false positives in lockdep), we're giving sysfs inodes their
+ * own class for i_mutex.
+ */
+static struct lock_class_key sysfs_inode_imutex_key;
+
+struct inode * sysfs_new_inode(mode_t mode, struct sysfs_dirent * sd)
{
struct inode * inode = new_inode(sysfs_sb);
if (inode) {
- inode->i_mode = mode;
- inode->i_uid = current->fsuid;
- inode->i_gid = current->fsgid;
- inode->i_blksize = PAGE_CACHE_SIZE;
inode->i_blocks = 0;
- inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
inode->i_mapping->a_ops = &sysfs_aops;
inode->i_mapping->backing_dev_info = &sysfs_backing_dev_info;
+ inode->i_op = &sysfs_inode_operations;
+ lockdep_set_class(&inode->i_mutex, &sysfs_inode_imutex_key);
+
+ if (sd->s_iattr) {
+ /* sysfs_dirent has non-default attributes
+ * get them for the new inode from persistent copy
+ * in sysfs_dirent
+ */
+ set_inode_attr(inode, sd->s_iattr);
+ } else
+ set_default_inode_attr(inode, mode);
}
return inode;
}
struct inode * inode = NULL;
if (dentry) {
if (!dentry->d_inode) {
- if ((inode = sysfs_new_inode(mode))) {
+ struct sysfs_dirent * sd = dentry->d_fsdata;
+ if ((inode = sysfs_new_inode(mode, sd))) {
if (dentry->d_parent && dentry->d_parent->d_inode) {
struct inode *p_inode = dentry->d_parent->d_inode;
p_inode->i_mtime = p_inode->i_ctime = CURRENT_TIME;
error = init(inode);
if (!error) {
d_instantiate(dentry, inode);
- dget(dentry); /* Extra count - pin the dentry in core */
+ if (S_ISDIR(mode))
+ dget(dentry); /* pin only directory dentry in core */
} else
iput(inode);
Done:
return error;
}
-int sysfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
+/*
+ * Get the name for corresponding element represented by the given sysfs_dirent
+ */
+const unsigned char * sysfs_get_name(struct sysfs_dirent *sd)
{
- return sysfs_create(dentry, mode, NULL);
-}
+ struct attribute * attr;
+ struct bin_attribute * bin_attr;
+ struct sysfs_symlink * sl;
-struct dentry * sysfs_get_dentry(struct dentry * parent, const char * name)
-{
- struct qstr qstr;
+ BUG_ON(!sd || !sd->s_element);
+
+ switch (sd->s_type) {
+ case SYSFS_DIR:
+ /* Always have a dentry so use that */
+ return sd->s_dentry->d_name.name;
- qstr.name = name;
- qstr.len = strlen(name);
- qstr.hash = full_name_hash(name,qstr.len);
- return lookup_hash(&qstr,parent);
+ case SYSFS_KOBJ_ATTR:
+ attr = sd->s_element;
+ return attr->name;
+
+ case SYSFS_KOBJ_BIN_ATTR:
+ bin_attr = sd->s_element;
+ return bin_attr->attr.name;
+
+ case SYSFS_KOBJ_LINK:
+ sl = sd->s_element;
+ return sl->link_name;
+ }
+ return NULL;
}
-void sysfs_hash_and_remove(struct dentry * dir, const char * name)
+
+/*
+ * Unhashes the dentry corresponding to given sysfs_dirent
+ * Called with parent inode's i_mutex held.
+ */
+void sysfs_drop_dentry(struct sysfs_dirent * sd, struct dentry * parent)
{
- struct dentry * victim;
-
- down(&dir->d_inode->i_sem);
- victim = sysfs_get_dentry(dir,name);
- if (!IS_ERR(victim)) {
- /* make sure dentry is really there */
- if (victim->d_inode &&
- (victim->d_parent->d_inode == dir->d_inode)) {
- pr_debug("sysfs: Removing %s (%d)\n", victim->d_name.name,
- atomic_read(&victim->d_count));
-
- d_drop(victim);
- /* release the target kobject in case of
- * a symlink
- */
- if (S_ISLNK(victim->d_inode->i_mode))
- kobject_put(victim->d_fsdata);
- simple_unlink(dir->d_inode,victim);
+ struct dentry * dentry = sd->s_dentry;
+
+ if (dentry) {
+ spin_lock(&dcache_lock);
+ spin_lock(&dentry->d_lock);
+ if (!(d_unhashed(dentry) && dentry->d_inode)) {
+ dget_locked(dentry);
+ __d_drop(dentry);
+ spin_unlock(&dentry->d_lock);
+ spin_unlock(&dcache_lock);
+ simple_unlink(parent->d_inode, dentry);
+ } else {
+ spin_unlock(&dentry->d_lock);
+ spin_unlock(&dcache_lock);
}
- /*
- * Drop reference from sysfs_get_dentry() above.
- */
- dput(victim);
}
- up(&dir->d_inode->i_sem);
}
+int sysfs_hash_and_remove(struct dentry * dir, const char * name)
+{
+ struct sysfs_dirent * sd;
+ struct sysfs_dirent * parent_sd;
+ int found = 0;
+ if (!dir)
+ return -ENOENT;
+
+ if (dir->d_inode == NULL)
+ /* no inode means this hasn't been made visible yet */
+ return -ENOENT;
+
+ parent_sd = dir->d_fsdata;
+ mutex_lock(&dir->d_inode->i_mutex);
+ list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
+ if (!sd->s_element)
+ continue;
+ if (!strcmp(sysfs_get_name(sd), name)) {
+ list_del_init(&sd->s_sibling);
+ sysfs_drop_dentry(sd, dir);
+ sysfs_put(sd);
+ found = 1;
+ break;
+ }
+ }
+ mutex_unlock(&dir->d_inode->i_mutex);
+
+ return found ? 0 : -ENOENT;
+}
git://git.onelab.eu / linux-2.6.git / blobdiff