/*
- * dir.c - Operations for sysfs directories.
+ * fs/sysfs/dir.c - sysfs core and dir operation implementation
+ *
+ * Copyright (c) 2001-3 Patrick Mochel
+ * Copyright (c) 2007 SUSE Linux Products GmbH
+ * Copyright (c) 2007 Tejun Heo <teheo@suse.de>
+ *
+ * This file is released under the GPLv2.
+ *
+ * Please see Documentation/filesystems/sysfs.txt for more information.
*/
#undef DEBUG
#include <linux/namei.h>
#include <linux/idr.h>
#include <linux/completion.h>
-#include <asm/semaphore.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/security.h>
#include "sysfs.h"
-DECLARE_RWSEM(sysfs_rename_sem);
-spinlock_t sysfs_lock = SPIN_LOCK_UNLOCKED;
-spinlock_t kobj_sysfs_assoc_lock = SPIN_LOCK_UNLOCKED;
+DEFINE_MUTEX(sysfs_mutex);
+DEFINE_SPINLOCK(sysfs_assoc_lock);
-static spinlock_t sysfs_ino_lock = SPIN_LOCK_UNLOCKED;
+static DEFINE_SPINLOCK(sysfs_ino_lock);
static DEFINE_IDA(sysfs_ino_ida);
/**
* @sd: sysfs_dirent of interest
*
* Link @sd into its sibling list which starts from
- * sd->s_parent->s_children.
+ * sd->s_parent->s_dir.children.
*
* Locking:
- * mutex_lock(sd->s_parent->dentry->d_inode->i_mutex)
+ * mutex_lock(sysfs_mutex)
*/
static void sysfs_link_sibling(struct sysfs_dirent *sd)
{
struct sysfs_dirent *parent_sd = sd->s_parent;
+ struct sysfs_dirent **pos;
BUG_ON(sd->s_sibling);
- sd->s_sibling = parent_sd->s_children;
- parent_sd->s_children = sd;
+
+ /* Store directory entries in order by ino. This allows
+ * readdir to properly restart without having to add a
+ * cursor into the s_dir.children list.
+ */
+ for (pos = &parent_sd->s_dir.children; *pos; pos = &(*pos)->s_sibling) {
+ if (sd->s_ino < (*pos)->s_ino)
+ break;
+ }
+ sd->s_sibling = *pos;
+ *pos = sd;
}
/**
* @sd: sysfs_dirent of interest
*
* Unlink @sd from its sibling list which starts from
- * sd->s_parent->s_children.
+ * sd->s_parent->s_dir.children.
*
* Locking:
- * mutex_lock(sd->s_parent->dentry->d_inode->i_mutex)
+ * mutex_lock(sysfs_mutex)
*/
static void sysfs_unlink_sibling(struct sysfs_dirent *sd)
{
struct sysfs_dirent **pos;
- for (pos = &sd->s_parent->s_children; *pos; pos = &(*pos)->s_sibling) {
+ for (pos = &sd->s_parent->s_dir.children; *pos;
+ pos = &(*pos)->s_sibling) {
if (*pos == sd) {
*pos = sd->s_sibling;
sd->s_sibling = NULL;
* RETURNS:
* Pointer to @sd on success, NULL on failure.
*/
-struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd)
+static struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd)
{
if (unlikely(!sd))
return NULL;
return NULL;
t = atomic_cmpxchg(&sd->s_active, v, v + 1);
- if (likely(t == v))
+ if (likely(t == v)) {
+ rwsem_acquire_read(&sd->dep_map, 0, 1, _RET_IP_);
return sd;
+ }
if (t < 0)
return NULL;
* Put an active reference to @sd. This function is noop if @sd
* is NULL.
*/
-void sysfs_put_active(struct sysfs_dirent *sd)
+static void sysfs_put_active(struct sysfs_dirent *sd)
{
struct completion *cmpl;
int v;
if (unlikely(!sd))
return;
+ rwsem_release(&sd->dep_map, 1, _RET_IP_);
v = atomic_dec_return(&sd->s_active);
if (likely(v != SD_DEACTIVATED_BIAS))
return;
*
* Deny new active references and drain existing ones.
*/
-void sysfs_deactivate(struct sysfs_dirent *sd)
+static void sysfs_deactivate(struct sysfs_dirent *sd)
{
DECLARE_COMPLETION_ONSTACK(wait);
int v;
- BUG_ON(sd->s_sibling);
+ BUG_ON(sd->s_sibling || !(sd->s_flags & SYSFS_FLAG_REMOVED));
sd->s_sibling = (void *)&wait;
+ rwsem_acquire(&sd->dep_map, 0, 0, _RET_IP_);
/* atomic_add_return() is a mb(), put_active() will always see
* the updated sd->s_sibling.
*/
v = atomic_add_return(SD_DEACTIVATED_BIAS, &sd->s_active);
- if (v != SD_DEACTIVATED_BIAS)
+ if (v != SD_DEACTIVATED_BIAS) {
+ lock_contended(&sd->dep_map, _RET_IP_);
wait_for_completion(&wait);
+ }
sd->s_sibling = NULL;
+
+ lock_acquired(&sd->dep_map, _RET_IP_);
+ rwsem_release(&sd->dep_map, 1, _RET_IP_);
}
static int sysfs_alloc_ino(ino_t *pino)
struct sysfs_dirent *parent_sd;
repeat:
+ /* Moving/renaming is always done while holding reference.
+ * sd->s_parent won't change beneath us.
+ */
parent_sd = sd->s_parent;
if (sysfs_type(sd) == SYSFS_KOBJ_LINK)
- sysfs_put(sd->s_elem.symlink.target_sd);
+ sysfs_put(sd->s_symlink.target_sd);
if (sysfs_type(sd) & SYSFS_COPY_NAME)
kfree(sd->s_name);
+ if (sd->s_iattr && sd->s_iattr->ia_secdata)
+ security_release_secctx(sd->s_iattr->ia_secdata,
+ sd->s_iattr->ia_secdata_len);
kfree(sd->s_iattr);
sysfs_free_ino(sd->s_ino);
kmem_cache_free(sysfs_dir_cachep, sd);
goto repeat;
}
-static void sysfs_d_iput(struct dentry * dentry, struct inode * inode)
+static int sysfs_dentry_delete(struct dentry *dentry)
{
- struct sysfs_dirent * sd = dentry->d_fsdata;
+ struct sysfs_dirent *sd = dentry->d_fsdata;
+ return !!(sd->s_flags & SYSFS_FLAG_REMOVED);
+}
- if (sd) {
- /* sd->s_dentry is protected with sysfs_lock. This
- * allows sysfs_drop_dentry() to dereference it.
- */
- spin_lock(&sysfs_lock);
+static int sysfs_dentry_revalidate(struct dentry *dentry, struct nameidata *nd)
+{
+ struct sysfs_dirent *sd = dentry->d_fsdata;
+ int is_dir;
+
+ mutex_lock(&sysfs_mutex);
+
+ /* The sysfs dirent has been deleted */
+ if (sd->s_flags & SYSFS_FLAG_REMOVED)
+ goto out_bad;
+
+ /* The sysfs dirent has been moved? */
+ if (dentry->d_parent->d_fsdata != sd->s_parent)
+ goto out_bad;
+
+ /* The sysfs dirent has been renamed */
+ if (strcmp(dentry->d_name.name, sd->s_name) != 0)
+ goto out_bad;
- /* The dentry might have been deleted or another
- * lookup could have happened updating sd->s_dentry to
- * point the new dentry. Ignore if it isn't pointing
- * to this dentry.
+ mutex_unlock(&sysfs_mutex);
+out_valid:
+ return 1;
+out_bad:
+ /* Remove the dentry from the dcache hashes.
+ * If this is a deleted dentry we use d_drop instead of d_delete
+ * so sysfs doesn't need to cope with negative dentries.
+ *
+ * If this is a dentry that has simply been renamed we
+ * use d_drop to remove it from the dcache lookup on its
+ * old parent. If this dentry persists later when a lookup
+ * is performed at its new name the dentry will be readded
+ * to the dcache hashes.
+ */
+ is_dir = (sysfs_type(sd) == SYSFS_DIR);
+ mutex_unlock(&sysfs_mutex);
+ if (is_dir) {
+ /* If we have submounts we must allow the vfs caches
+ * to lie about the state of the filesystem to prevent
+ * leaks and other nasty things.
*/
- if (sd->s_dentry == dentry)
- sd->s_dentry = NULL;
- spin_unlock(&sysfs_lock);
- sysfs_put(sd);
+ if (have_submounts(dentry))
+ goto out_valid;
+ shrink_dcache_parent(dentry);
}
+ d_drop(dentry);
+ return 0;
+}
+
+static void sysfs_dentry_iput(struct dentry *dentry, struct inode *inode)
+{
+ struct sysfs_dirent * sd = dentry->d_fsdata;
+
+ sysfs_put(sd);
iput(inode);
}
-static struct dentry_operations sysfs_dentry_ops = {
- .d_iput = sysfs_d_iput,
+static const struct dentry_operations sysfs_dentry_ops = {
+ .d_revalidate = sysfs_dentry_revalidate,
+ .d_delete = sysfs_dentry_delete,
+ .d_iput = sysfs_dentry_iput,
};
struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type)
{
char *dup_name = NULL;
- struct sysfs_dirent *sd = NULL;
+ struct sysfs_dirent *sd;
if (type & SYSFS_COPY_NAME) {
name = dup_name = kstrdup(name, GFP_KERNEL);
if (!name)
- goto err_out;
+ return NULL;
}
sd = kmem_cache_zalloc(sysfs_dir_cachep, GFP_KERNEL);
if (!sd)
- goto err_out;
+ goto err_out1;
if (sysfs_alloc_ino(&sd->s_ino))
- goto err_out;
+ goto err_out2;
atomic_set(&sd->s_count, 1);
atomic_set(&sd->s_active, 0);
- atomic_set(&sd->s_event, 1);
+ sysfs_dirent_init_lockdep(sd);
sd->s_name = name;
sd->s_mode = mode;
return sd;
- err_out:
- kfree(dup_name);
+ err_out2:
kmem_cache_free(sysfs_dir_cachep, sd);
+ err_out1:
+ kfree(dup_name);
return NULL;
}
-static void sysfs_attach_dentry(struct sysfs_dirent *sd, struct dentry *dentry)
+/**
+ * sysfs_addrm_start - prepare for sysfs_dirent add/remove
+ * @acxt: pointer to sysfs_addrm_cxt to be used
+ * @parent_sd: parent sysfs_dirent
+ *
+ * This function is called when the caller is about to add or
+ * remove sysfs_dirent under @parent_sd. This function acquires
+ * sysfs_mutex. @acxt is used to keep and pass context to
+ * other addrm functions.
+ *
+ * LOCKING:
+ * Kernel thread context (may sleep). sysfs_mutex is locked on
+ * return.
+ */
+void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
+ struct sysfs_dirent *parent_sd)
{
- dentry->d_op = &sysfs_dentry_ops;
- dentry->d_fsdata = sysfs_get(sd);
-
- /* protect sd->s_dentry against sysfs_d_iput */
- spin_lock(&sysfs_lock);
- sd->s_dentry = dentry;
- spin_unlock(&sysfs_lock);
+ memset(acxt, 0, sizeof(*acxt));
+ acxt->parent_sd = parent_sd;
- d_rehash(dentry);
+ mutex_lock(&sysfs_mutex);
}
-void sysfs_attach_dirent(struct sysfs_dirent *sd,
- struct sysfs_dirent *parent_sd, struct dentry *dentry)
+/**
+ * __sysfs_add_one - add sysfs_dirent to parent without warning
+ * @acxt: addrm context to use
+ * @sd: sysfs_dirent to be added
+ *
+ * Get @acxt->parent_sd and set sd->s_parent to it and increment
+ * nlink of parent inode if @sd is a directory and link into the
+ * children list of the parent.
+ *
+ * This function should be called between calls to
+ * sysfs_addrm_start() and sysfs_addrm_finish() and should be
+ * passed the same @acxt as passed to sysfs_addrm_start().
+ *
+ * LOCKING:
+ * Determined by sysfs_addrm_start().
+ *
+ * RETURNS:
+ * 0 on success, -EEXIST if entry with the given name already
+ * exists.
+ */
+int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
{
- if (dentry)
- sysfs_attach_dentry(sd, dentry);
+ struct sysfs_inode_attrs *ps_iattr;
- if (parent_sd) {
- sd->s_parent = sysfs_get(parent_sd);
- sysfs_link_sibling(sd);
+ if (sysfs_find_dirent(acxt->parent_sd, sd->s_name))
+ return -EEXIST;
+
+ sd->s_parent = sysfs_get(acxt->parent_sd);
+
+ sysfs_link_sibling(sd);
+
+ /* Update timestamps on the parent */
+ ps_iattr = acxt->parent_sd->s_iattr;
+ if (ps_iattr) {
+ struct iattr *ps_iattrs = &ps_iattr->ia_iattr;
+ ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME;
}
+
+ return 0;
}
-/*
+/**
+ * sysfs_pathname - return full path to sysfs dirent
+ * @sd: sysfs_dirent whose path we want
+ * @path: caller allocated buffer
*
- * Return -EEXIST if there is already a sysfs element with the same name for
- * the same parent.
+ * Gives the name "/" to the sysfs_root entry; any path returned
+ * is relative to wherever sysfs is mounted.
*
- * called with parent inode's i_mutex held
+ * XXX: does no error checking on @path size
*/
-int sysfs_dirent_exist(struct sysfs_dirent *parent_sd,
- const unsigned char *new)
+static char *sysfs_pathname(struct sysfs_dirent *sd, char *path)
{
- struct sysfs_dirent * sd;
+ if (sd->s_parent) {
+ sysfs_pathname(sd->s_parent, path);
+ strcat(path, "/");
+ }
+ strcat(path, sd->s_name);
+ return path;
+}
- for (sd = parent_sd->s_children; sd; sd = sd->s_sibling) {
- if (sysfs_type(sd)) {
- if (strcmp(sd->s_name, new))
- continue;
- else
- return -EEXIST;
- }
+/**
+ * sysfs_add_one - add sysfs_dirent to parent
+ * @acxt: addrm context to use
+ * @sd: sysfs_dirent to be added
+ *
+ * Get @acxt->parent_sd and set sd->s_parent to it and increment
+ * nlink of parent inode if @sd is a directory and link into the
+ * children list of the parent.
+ *
+ * This function should be called between calls to
+ * sysfs_addrm_start() and sysfs_addrm_finish() and should be
+ * passed the same @acxt as passed to sysfs_addrm_start().
+ *
+ * LOCKING:
+ * Determined by sysfs_addrm_start().
+ *
+ * RETURNS:
+ * 0 on success, -EEXIST if entry with the given name already
+ * exists.
+ */
+int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
+{
+ int ret;
+
+ ret = __sysfs_add_one(acxt, sd);
+ if (ret == -EEXIST) {
+ char *path = kzalloc(PATH_MAX, GFP_KERNEL);
+ WARN(1, KERN_WARNING
+ "sysfs: cannot create duplicate filename '%s'\n",
+ (path == NULL) ? sd->s_name :
+ strcat(strcat(sysfs_pathname(acxt->parent_sd, path), "/"),
+ sd->s_name));
+ kfree(path);
}
- return 0;
+ return ret;
}
-static int create_dir(struct kobject *kobj, struct dentry *parent,
- const char *name, struct dentry **p_dentry)
+/**
+ * sysfs_remove_one - remove sysfs_dirent from parent
+ * @acxt: addrm context to use
+ * @sd: sysfs_dirent to be removed
+ *
+ * Mark @sd removed and drop nlink of parent inode if @sd is a
+ * directory. @sd is unlinked from the children list.
+ *
+ * This function should be called between calls to
+ * sysfs_addrm_start() and sysfs_addrm_finish() and should be
+ * passed the same @acxt as passed to sysfs_addrm_start().
+ *
+ * LOCKING:
+ * Determined by sysfs_addrm_start().
+ */
+void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
{
- int error;
- umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
- struct dentry *dentry;
- struct inode *inode;
- struct sysfs_dirent *sd;
+ struct sysfs_inode_attrs *ps_iattr;
- mutex_lock(&parent->d_inode->i_mutex);
+ BUG_ON(sd->s_flags & SYSFS_FLAG_REMOVED);
- /* allocate */
- dentry = lookup_one_len(name, parent, strlen(name));
- if (IS_ERR(dentry)) {
- error = PTR_ERR(dentry);
- goto out_unlock;
+ sysfs_unlink_sibling(sd);
+
+ /* Update timestamps on the parent */
+ ps_iattr = acxt->parent_sd->s_iattr;
+ if (ps_iattr) {
+ struct iattr *ps_iattrs = &ps_iattr->ia_iattr;
+ ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME;
}
- error = -EEXIST;
- if (dentry->d_inode)
- goto out_dput;
+ sd->s_flags |= SYSFS_FLAG_REMOVED;
+ sd->s_sibling = acxt->removed;
+ acxt->removed = sd;
+}
- error = -ENOMEM;
- sd = sysfs_new_dirent(name, mode, SYSFS_DIR);
- if (!sd)
- goto out_drop;
- sd->s_elem.dir.kobj = kobj;
+/**
+ * sysfs_addrm_finish - finish up sysfs_dirent add/remove
+ * @acxt: addrm context to finish up
+ *
+ * Finish up sysfs_dirent add/remove. Resources acquired by
+ * sysfs_addrm_start() are released and removed sysfs_dirents are
+ * cleaned up.
+ *
+ * LOCKING:
+ * sysfs_mutex is released.
+ */
+void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt)
+{
+ /* release resources acquired by sysfs_addrm_start() */
+ mutex_unlock(&sysfs_mutex);
- inode = sysfs_get_inode(sd);
- if (!inode)
- goto out_sput;
-
- if (inode->i_state & I_NEW) {
- inode->i_op = &sysfs_dir_inode_operations;
- inode->i_fop = &sysfs_dir_operations;
- /* directory inodes start off with i_nlink == 2 (for ".") */
- inc_nlink(inode);
+ /* kill removed sysfs_dirents */
+ while (acxt->removed) {
+ struct sysfs_dirent *sd = acxt->removed;
+
+ acxt->removed = sd->s_sibling;
+ sd->s_sibling = NULL;
+
+ sysfs_deactivate(sd);
+ unmap_bin_file(sd);
+ sysfs_put(sd);
}
+}
- /* link in */
- error = -EEXIST;
- if (sysfs_dirent_exist(parent->d_fsdata, name))
- goto out_iput;
+/**
+ * sysfs_find_dirent - find sysfs_dirent with the given name
+ * @parent_sd: sysfs_dirent to search under
+ * @name: name to look for
+ *
+ * Look for sysfs_dirent with name @name under @parent_sd.
+ *
+ * LOCKING:
+ * mutex_lock(sysfs_mutex)
+ *
+ * RETURNS:
+ * Pointer to sysfs_dirent if found, NULL if not.
+ */
+struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd,
+ const unsigned char *name)
+{
+ struct sysfs_dirent *sd;
- sysfs_instantiate(dentry, inode);
- inc_nlink(parent->d_inode);
- sysfs_attach_dirent(sd, parent->d_fsdata, dentry);
+ for (sd = parent_sd->s_dir.children; sd; sd = sd->s_sibling)
+ if (!strcmp(sd->s_name, name))
+ return sd;
+ return NULL;
+}
- *p_dentry = dentry;
- error = 0;
- goto out_unlock; /* pin directory dentry in core */
+/**
+ * sysfs_get_dirent - find and get sysfs_dirent with the given name
+ * @parent_sd: sysfs_dirent to search under
+ * @name: name to look for
+ *
+ * Look for sysfs_dirent with name @name under @parent_sd and get
+ * it if found.
+ *
+ * LOCKING:
+ * Kernel thread context (may sleep). Grabs sysfs_mutex.
+ *
+ * RETURNS:
+ * Pointer to sysfs_dirent if found, NULL if not.
+ */
+struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
+ const unsigned char *name)
+{
+ struct sysfs_dirent *sd;
- out_iput:
- iput(inode);
- out_sput:
- sysfs_put(sd);
- out_drop:
- d_drop(dentry);
- out_dput:
- dput(dentry);
- out_unlock:
- mutex_unlock(&parent->d_inode->i_mutex);
- return error;
+ mutex_lock(&sysfs_mutex);
+ sd = sysfs_find_dirent(parent_sd, name);
+ sysfs_get(sd);
+ mutex_unlock(&sysfs_mutex);
+
+ return sd;
}
+EXPORT_SYMBOL_GPL(sysfs_get_dirent);
+
+static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd,
+ const char *name, struct sysfs_dirent **p_sd)
+{
+ umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
+ struct sysfs_addrm_cxt acxt;
+ struct sysfs_dirent *sd;
+ int rc;
+ /* allocate */
+ sd = sysfs_new_dirent(name, mode, SYSFS_DIR);
+ if (!sd)
+ return -ENOMEM;
+ sd->s_dir.kobj = kobj;
-int sysfs_create_subdir(struct kobject * k, const char * n, struct dentry ** d)
+ /* link in */
+ sysfs_addrm_start(&acxt, parent_sd);
+ rc = sysfs_add_one(&acxt, sd);
+ sysfs_addrm_finish(&acxt);
+
+ if (rc == 0)
+ *p_sd = sd;
+ else
+ sysfs_put(sd);
+
+ return rc;
+}
+
+int sysfs_create_subdir(struct kobject *kobj, const char *name,
+ struct sysfs_dirent **p_sd)
{
- return create_dir(k,k->dentry,n,d);
+ return create_dir(kobj, kobj->sd, name, p_sd);
}
/**
* sysfs_create_dir - create a directory for an object.
* @kobj: object we're creating directory for.
- * @shadow_parent: parent parent object.
*/
-
-int sysfs_create_dir(struct kobject * kobj, struct dentry *shadow_parent)
+int sysfs_create_dir(struct kobject * kobj)
{
- struct dentry * dentry = NULL;
- struct dentry * parent;
+ struct sysfs_dirent *parent_sd, *sd;
int error = 0;
BUG_ON(!kobj);
- if (shadow_parent)
- parent = shadow_parent;
- else if (kobj->parent)
- parent = kobj->parent->dentry;
- else if (sysfs_mount && sysfs_mount->mnt_sb)
- parent = sysfs_mount->mnt_sb->s_root;
+ if (kobj->parent)
+ parent_sd = kobj->parent->sd;
else
- return -EFAULT;
+ parent_sd = &sysfs_root;
- error = create_dir(kobj,parent,kobject_name(kobj),&dentry);
+ error = create_dir(kobj, parent_sd, kobject_name(kobj), &sd);
if (!error)
- kobj->dentry = dentry;
+ kobj->sd = sd;
return error;
}
static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
struct nameidata *nd)
{
- struct sysfs_dirent * parent_sd = dentry->d_parent->d_fsdata;
- struct sysfs_dirent * sd;
- struct bin_attribute *bin_attr;
+ struct dentry *ret = NULL;
+ struct sysfs_dirent *parent_sd = dentry->d_parent->d_fsdata;
+ struct sysfs_dirent *sd;
struct inode *inode;
- int found = 0;
- for (sd = parent_sd->s_children; sd; sd = sd->s_sibling) {
- if ((sysfs_type(sd) & SYSFS_NOT_PINNED) &&
- !strcmp(sd->s_name, dentry->d_name.name)) {
- found = 1;
- break;
- }
- }
+ mutex_lock(&sysfs_mutex);
+
+ sd = sysfs_find_dirent(parent_sd, dentry->d_name.name);
/* no such entry */
- if (!found)
- return NULL;
+ if (!sd) {
+ ret = ERR_PTR(-ENOENT);
+ goto out_unlock;
+ }
/* attach dentry and inode */
inode = sysfs_get_inode(sd);
- if (!inode)
- return ERR_PTR(-ENOMEM);
-
- if (inode->i_state & I_NEW) {
- /* initialize inode according to type */
- switch (sysfs_type(sd)) {
- case SYSFS_KOBJ_ATTR:
- inode->i_size = PAGE_SIZE;
- inode->i_fop = &sysfs_file_operations;
- break;
- case SYSFS_KOBJ_BIN_ATTR:
- bin_attr = sd->s_elem.bin_attr.bin_attr;
- inode->i_size = bin_attr->size;
- inode->i_fop = &bin_fops;
- break;
- case SYSFS_KOBJ_LINK:
- inode->i_op = &sysfs_symlink_inode_operations;
- break;
- default:
- BUG();
- }
+ if (!inode) {
+ ret = ERR_PTR(-ENOMEM);
+ goto out_unlock;
}
- sysfs_instantiate(dentry, inode);
- sysfs_attach_dentry(sd, dentry);
+ /* instantiate and hash dentry */
+ ret = d_find_alias(inode);
+ if (!ret) {
+ dentry->d_op = &sysfs_dentry_ops;
+ dentry->d_fsdata = sysfs_get(sd);
+ d_add(dentry, inode);
+ } else {
+ d_move(ret, dentry);
+ iput(inode);
+ }
- return NULL;
+ out_unlock:
+ mutex_unlock(&sysfs_mutex);
+ return ret;
}
const struct inode_operations sysfs_dir_inode_operations = {
.lookup = sysfs_lookup,
+ .permission = sysfs_permission,
.setattr = sysfs_setattr,
+ .getattr = sysfs_getattr,
+ .setxattr = sysfs_setxattr,
};
-static void remove_dir(struct dentry * d)
+static void remove_dir(struct sysfs_dirent *sd)
{
- struct dentry *parent = d->d_parent;
- struct sysfs_dirent *sd = d->d_fsdata;
+ struct sysfs_addrm_cxt acxt;
- mutex_lock(&parent->d_inode->i_mutex);
-
- sysfs_unlink_sibling(sd);
-
- pr_debug(" o %s removing done (%d)\n",d->d_name.name,
- atomic_read(&d->d_count));
-
- mutex_unlock(&parent->d_inode->i_mutex);
-
- sysfs_drop_dentry(sd);
- sysfs_deactivate(sd);
- sysfs_put(sd);
+ sysfs_addrm_start(&acxt, sd->s_parent);
+ sysfs_remove_one(&acxt, sd);
+ sysfs_addrm_finish(&acxt);
}
-void sysfs_remove_subdir(struct dentry * d)
+void sysfs_remove_subdir(struct sysfs_dirent *sd)
{
- remove_dir(d);
+ remove_dir(sd);
}
-static void __sysfs_remove_dir(struct dentry *dentry)
+static void __sysfs_remove_dir(struct sysfs_dirent *dir_sd)
{
- struct sysfs_dirent *removed = NULL;
- struct sysfs_dirent *parent_sd;
+ struct sysfs_addrm_cxt acxt;
struct sysfs_dirent **pos;
- if (!dentry)
+ if (!dir_sd)
return;
- pr_debug("sysfs %s: removing dir\n",dentry->d_name.name);
- mutex_lock(&dentry->d_inode->i_mutex);
- parent_sd = dentry->d_fsdata;
- pos = &parent_sd->s_children;
+ pr_debug("sysfs %s: removing dir\n", dir_sd->s_name);
+ sysfs_addrm_start(&acxt, dir_sd);
+ pos = &dir_sd->s_dir.children;
while (*pos) {
struct sysfs_dirent *sd = *pos;
- if (sysfs_type(sd) && (sysfs_type(sd) & SYSFS_NOT_PINNED)) {
- *pos = sd->s_sibling;
- sd->s_sibling = removed;
- removed = sd;
- } else
+ if (sysfs_type(sd) != SYSFS_DIR)
+ sysfs_remove_one(&acxt, sd);
+ else
pos = &(*pos)->s_sibling;
}
- mutex_unlock(&dentry->d_inode->i_mutex);
+ sysfs_addrm_finish(&acxt);
- while (removed) {
- struct sysfs_dirent *sd = removed;
-
- removed = sd->s_sibling;
- sd->s_sibling = NULL;
-
- sysfs_drop_dentry(sd);
- sysfs_deactivate(sd);
- sysfs_put(sd);
- }
-
- remove_dir(dentry);
+ remove_dir(dir_sd);
}
/**
void sysfs_remove_dir(struct kobject * kobj)
{
- struct dentry *d = kobj->dentry;
+ struct sysfs_dirent *sd = kobj->sd;
- spin_lock(&kobj_sysfs_assoc_lock);
- kobj->dentry = NULL;
- spin_unlock(&kobj_sysfs_assoc_lock);
+ spin_lock(&sysfs_assoc_lock);
+ kobj->sd = NULL;
+ spin_unlock(&sysfs_assoc_lock);
- __sysfs_remove_dir(d);
+ __sysfs_remove_dir(sd);
}
-int sysfs_rename_dir(struct kobject * kobj, struct dentry *new_parent,
- const char *new_name)
+int sysfs_rename(struct sysfs_dirent *sd,
+ struct sysfs_dirent *new_parent_sd, const char *new_name)
{
- struct sysfs_dirent *sd = kobj->dentry->d_fsdata;
- struct sysfs_dirent *parent_sd = new_parent->d_fsdata;
- struct dentry *new_dentry;
- char *dup_name;
+ const char *dup_name = NULL;
int error;
- if (!new_parent)
- return -EFAULT;
-
- down_write(&sysfs_rename_sem);
- mutex_lock(&new_parent->d_inode->i_mutex);
-
- new_dentry = lookup_one_len(new_name, new_parent, strlen(new_name));
- if (IS_ERR(new_dentry)) {
- error = PTR_ERR(new_dentry);
- goto out_unlock;
- }
-
- /* By allowing two different directories with the same
- * d_parent we allow this routine to move between different
- * shadows of the same directory
- */
- error = -EINVAL;
- if (kobj->dentry->d_parent->d_inode != new_parent->d_inode ||
- new_dentry->d_parent->d_inode != new_parent->d_inode ||
- new_dentry == kobj->dentry)
- goto out_dput;
-
- error = -EEXIST;
- if (new_dentry->d_inode)
- goto out_dput;
-
- /* rename kobject and sysfs_dirent */
- error = -ENOMEM;
- new_name = dup_name = kstrdup(new_name, GFP_KERNEL);
- if (!new_name)
- goto out_drop;
-
- error = kobject_set_name(kobj, "%s", new_name);
- if (error)
- goto out_free;
-
- kfree(sd->s_name);
- sd->s_name = new_name;
-
- /* move under the new parent */
- d_add(new_dentry, NULL);
- d_move(kobj->dentry, new_dentry);
-
- sysfs_unlink_sibling(sd);
- sysfs_get(parent_sd);
- sysfs_put(sd->s_parent);
- sd->s_parent = parent_sd;
- sysfs_link_sibling(sd);
+ mutex_lock(&sysfs_mutex);
error = 0;
- goto out_unlock;
+ if ((sd->s_parent == new_parent_sd) &&
+ (strcmp(sd->s_name, new_name) == 0))
+ goto out; /* nothing to rename */
- out_free:
- kfree(dup_name);
- out_drop:
- d_drop(new_dentry);
- out_dput:
- dput(new_dentry);
- out_unlock:
- mutex_unlock(&new_parent->d_inode->i_mutex);
- up_write(&sysfs_rename_sem);
- return error;
-}
+ error = -EEXIST;
+ if (sysfs_find_dirent(new_parent_sd, new_name))
+ goto out;
-int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent)
-{
- struct dentry *old_parent_dentry, *new_parent_dentry, *new_dentry;
- struct sysfs_dirent *new_parent_sd, *sd;
- int error;
+ /* rename sysfs_dirent */
+ if (strcmp(sd->s_name, new_name) != 0) {
+ error = -ENOMEM;
+ new_name = dup_name = kstrdup(new_name, GFP_KERNEL);
+ if (!new_name)
+ goto out;
- old_parent_dentry = kobj->parent ?
- kobj->parent->dentry : sysfs_mount->mnt_sb->s_root;
- new_parent_dentry = new_parent ?
- new_parent->dentry : sysfs_mount->mnt_sb->s_root;
-
- if (old_parent_dentry->d_inode == new_parent_dentry->d_inode)
- return 0; /* nothing to move */
-again:
- mutex_lock(&old_parent_dentry->d_inode->i_mutex);
- if (!mutex_trylock(&new_parent_dentry->d_inode->i_mutex)) {
- mutex_unlock(&old_parent_dentry->d_inode->i_mutex);
- goto again;
+ dup_name = sd->s_name;
+ sd->s_name = new_name;
}
- new_parent_sd = new_parent_dentry->d_fsdata;
- sd = kobj->dentry->d_fsdata;
-
- new_dentry = lookup_one_len(kobj->name, new_parent_dentry,
- strlen(kobj->name));
- if (IS_ERR(new_dentry)) {
- error = PTR_ERR(new_dentry);
- goto out;
- } else
- error = 0;
- d_add(new_dentry, NULL);
- d_move(kobj->dentry, new_dentry);
- dput(new_dentry);
-
/* Remove from old parent's list and insert into new parent's list. */
- sysfs_unlink_sibling(sd);
- sysfs_get(new_parent_sd);
- sysfs_put(sd->s_parent);
- sd->s_parent = new_parent_sd;
- sysfs_link_sibling(sd);
-
-out:
- mutex_unlock(&new_parent_dentry->d_inode->i_mutex);
- mutex_unlock(&old_parent_dentry->d_inode->i_mutex);
+ if (sd->s_parent != new_parent_sd) {
+ sysfs_unlink_sibling(sd);
+ sysfs_get(new_parent_sd);
+ sysfs_put(sd->s_parent);
+ sd->s_parent = new_parent_sd;
+ sysfs_link_sibling(sd);
+ }
+ error = 0;
+ out:
+ mutex_unlock(&sysfs_mutex);
+ kfree(dup_name);
return error;
}
-static int sysfs_dir_open(struct inode *inode, struct file *file)
+int sysfs_rename_dir(struct kobject *kobj, const char *new_name)
{
- struct dentry * dentry = file->f_path.dentry;
- struct sysfs_dirent * parent_sd = dentry->d_fsdata;
- struct sysfs_dirent * sd;
-
- mutex_lock(&dentry->d_inode->i_mutex);
- sd = sysfs_new_dirent("_DIR_", 0, 0);
- if (sd)
- sysfs_attach_dirent(sd, parent_sd, NULL);
- mutex_unlock(&dentry->d_inode->i_mutex);
-
- file->private_data = sd;
- return sd ? 0 : -ENOMEM;
+ return sysfs_rename(kobj->sd, kobj->sd->s_parent, new_name);
}
-static int sysfs_dir_close(struct inode *inode, struct file *file)
+int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent_kobj)
{
- struct dentry * dentry = file->f_path.dentry;
- struct sysfs_dirent * cursor = file->private_data;
-
- mutex_lock(&dentry->d_inode->i_mutex);
- sysfs_unlink_sibling(cursor);
- mutex_unlock(&dentry->d_inode->i_mutex);
+ struct sysfs_dirent *sd = kobj->sd;
+ struct sysfs_dirent *new_parent_sd;
- release_sysfs_dirent(cursor);
+ BUG_ON(!sd->s_parent);
+ new_parent_sd = new_parent_kobj && new_parent_kobj->sd ?
+ new_parent_kobj->sd : &sysfs_root;
- return 0;
+ return sysfs_rename(sd, new_parent_sd, sd->s_name);
}
/* Relationship between s_mode and the DT_xxx types */
{
struct dentry *dentry = filp->f_path.dentry;
struct sysfs_dirent * parent_sd = dentry->d_fsdata;
- struct sysfs_dirent *cursor = filp->private_data;
- struct sysfs_dirent **pos;
+ struct sysfs_dirent *pos;
ino_t ino;
- int i = filp->f_pos;
- switch (i) {
- case 0:
- ino = parent_sd->s_ino;
- if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
- break;
+ if (filp->f_pos == 0) {
+ ino = parent_sd->s_ino;
+ if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) == 0)
filp->f_pos++;
- i++;
- /* fallthrough */
- case 1:
- if (parent_sd->s_parent)
- ino = parent_sd->s_parent->s_ino;
- else
- ino = parent_sd->s_ino;
- if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
- break;
+ }
+ if (filp->f_pos == 1) {
+ if (parent_sd->s_parent)
+ ino = parent_sd->s_parent->s_ino;
+ else
+ ino = parent_sd->s_ino;
+ if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) == 0)
filp->f_pos++;
- i++;
- /* fallthrough */
- default:
- pos = &parent_sd->s_children;
- while (*pos != cursor)
- pos = &(*pos)->s_sibling;
-
- /* unlink cursor */
- *pos = cursor->s_sibling;
-
- if (filp->f_pos == 2)
- pos = &parent_sd->s_children;
-
- for ( ; *pos; pos = &(*pos)->s_sibling) {
- struct sysfs_dirent *next = *pos;
- const char * name;
- int len;
-
- if (!sysfs_type(next))
- continue;
+ }
+ if ((filp->f_pos > 1) && (filp->f_pos < INT_MAX)) {
+ mutex_lock(&sysfs_mutex);
- name = next->s_name;
- len = strlen(name);
- ino = next->s_ino;
+ /* Skip the dentries we have already reported */
+ pos = parent_sd->s_dir.children;
+ while (pos && (filp->f_pos > pos->s_ino))
+ pos = pos->s_sibling;
- if (filldir(dirent, name, len, filp->f_pos, ino,
- dt_type(next)) < 0)
- break;
+ for ( ; pos; pos = pos->s_sibling) {
+ const char * name;
+ int len;
- filp->f_pos++;
- }
+ name = pos->s_name;
+ len = strlen(name);
+ filp->f_pos = ino = pos->s_ino;
- /* put cursor back in */
- cursor->s_sibling = *pos;
- *pos = cursor;
- }
- return 0;
-}
-
-static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin)
-{
- struct dentry * dentry = file->f_path.dentry;
-
- mutex_lock(&dentry->d_inode->i_mutex);
- switch (origin) {
- case 1:
- offset += file->f_pos;
- case 0:
- if (offset >= 0)
+ if (filldir(dirent, name, len, filp->f_pos, ino,
+ dt_type(pos)) < 0)
break;
- default:
- mutex_unlock(&file->f_path.dentry->d_inode->i_mutex);
- return -EINVAL;
- }
- if (offset != file->f_pos) {
- file->f_pos = offset;
- if (file->f_pos >= 2) {
- struct sysfs_dirent *sd = dentry->d_fsdata;
- struct sysfs_dirent *cursor = file->private_data;
- struct sysfs_dirent **pos;
- loff_t n = file->f_pos - 2;
-
- sysfs_unlink_sibling(cursor);
-
- pos = &sd->s_children;
- while (n && *pos) {
- struct sysfs_dirent *next = *pos;
- if (sysfs_type(next))
- n--;
- pos = &(*pos)->s_sibling;
- }
-
- cursor->s_sibling = *pos;
- *pos = cursor;
}
+ if (!pos)
+ filp->f_pos = INT_MAX;
+ mutex_unlock(&sysfs_mutex);
}
- mutex_unlock(&dentry->d_inode->i_mutex);
- return offset;
-}
-
-
-/**
- * sysfs_make_shadowed_dir - Setup so a directory can be shadowed
- * @kobj: object we're creating shadow of.
- */
-
-int sysfs_make_shadowed_dir(struct kobject *kobj,
- void * (*follow_link)(struct dentry *, struct nameidata *))
-{
- struct inode *inode;
- struct inode_operations *i_op;
-
- inode = kobj->dentry->d_inode;
- if (inode->i_op != &sysfs_dir_inode_operations)
- return -EINVAL;
-
- i_op = kmalloc(sizeof(*i_op), GFP_KERNEL);
- if (!i_op)
- return -ENOMEM;
-
- memcpy(i_op, &sysfs_dir_inode_operations, sizeof(*i_op));
- i_op->follow_link = follow_link;
-
- /* Locking of inode->i_op?
- * Since setting i_op is a single word write and they
- * are atomic we should be ok here.
- */
- inode->i_op = i_op;
return 0;
}
-/**
- * sysfs_create_shadow_dir - create a shadow directory for an object.
- * @kobj: object we're creating directory for.
- *
- * sysfs_make_shadowed_dir must already have been called on this
- * directory.
- */
-
-struct dentry *sysfs_create_shadow_dir(struct kobject *kobj)
-{
- struct dentry *dir = kobj->dentry;
- struct inode *inode = dir->d_inode;
- struct dentry *parent = dir->d_parent;
- struct sysfs_dirent *parent_sd = parent->d_fsdata;
- struct dentry *shadow;
- struct sysfs_dirent *sd;
-
- shadow = ERR_PTR(-EINVAL);
- if (!sysfs_is_shadowed_inode(inode))
- goto out;
-
- shadow = d_alloc(parent, &dir->d_name);
- if (!shadow)
- goto nomem;
-
- sd = sysfs_new_dirent("_SHADOW_", inode->i_mode, SYSFS_DIR);
- if (!sd)
- goto nomem;
- sd->s_elem.dir.kobj = kobj;
- /* point to parent_sd but don't attach to it */
- sd->s_parent = sysfs_get(parent_sd);
- sysfs_attach_dirent(sd, NULL, shadow);
-
- d_instantiate(shadow, igrab(inode));
- inc_nlink(inode);
- inc_nlink(parent->d_inode);
-
- dget(shadow); /* Extra count - pin the dentry in core */
-
-out:
- return shadow;
-nomem:
- dput(shadow);
- shadow = ERR_PTR(-ENOMEM);
- goto out;
-}
-
-/**
- * sysfs_remove_shadow_dir - remove an object's directory.
- * @shadow: dentry of shadow directory
- *
- * The only thing special about this is that we remove any files in
- * the directory before we remove the directory, and we've inlined
- * what used to be sysfs_rmdir() below, instead of calling separately.
- */
-
-void sysfs_remove_shadow_dir(struct dentry *shadow)
-{
- __sysfs_remove_dir(shadow);
-}
const struct file_operations sysfs_dir_operations = {
- .open = sysfs_dir_open,
- .release = sysfs_dir_close,
- .llseek = sysfs_dir_lseek,
.read = generic_read_dir,
.readdir = sysfs_readdir,
+ .llseek = generic_file_llseek,
};