/*
- * 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 "sysfs.h"
DEFINE_MUTEX(sysfs_mutex);
-spinlock_t sysfs_assoc_lock = SPIN_LOCK_UNLOCKED;
+DEFINE_MUTEX(sysfs_rename_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(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(sysfs_mutex)
{
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;
}
/**
+ * sysfs_get_dentry - get dentry for the given sysfs_dirent
+ * @sd: sysfs_dirent of interest
+ *
+ * Get dentry for @sd. Dentry is looked up if currently not
+ * present. This function descends from the root looking up
+ * dentry for each step.
+ *
+ * LOCKING:
+ * mutex_lock(sysfs_rename_mutex)
+ *
+ * RETURNS:
+ * Pointer to found dentry on success, ERR_PTR() value on error.
+ */
+struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd)
+{
+ struct dentry *dentry = dget(sysfs_sb->s_root);
+
+ while (dentry->d_fsdata != sd) {
+ struct sysfs_dirent *cur;
+ struct dentry *parent;
+
+ /* find the first ancestor which hasn't been looked up */
+ cur = sd;
+ while (cur->s_parent != dentry->d_fsdata)
+ cur = cur->s_parent;
+
+ /* look it up */
+ parent = dentry;
+ mutex_lock(&parent->d_inode->i_mutex);
+ dentry = lookup_one_noperm(cur->s_name, parent);
+ mutex_unlock(&parent->d_inode->i_mutex);
+ dput(parent);
+
+ if (IS_ERR(dentry))
+ break;
+ }
+ return dentry;
+}
+
+/**
* sysfs_get_active - get an active reference to sysfs_dirent
* @sd: sysfs_dirent to get an active reference to
*
* 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;
* 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;
*
* 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;
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);
kfree(sd->s_iattr);
{
struct sysfs_dirent * sd = dentry->d_fsdata;
- if (sd) {
- /* sd->s_dentry is protected with sysfs_assoc_lock.
- * This allows sysfs_drop_dentry() to dereference it.
- */
- spin_lock(&sysfs_assoc_lock);
-
- /* 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.
- */
- if (sd->s_dentry == dentry)
- sd->s_dentry = NULL;
- spin_unlock(&sysfs_assoc_lock);
- sysfs_put(sd);
- }
+ sysfs_put(sd);
iput(inode);
}
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);
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 int sysfs_ilookup_test(struct inode *inode, void *arg)
+{
+ struct sysfs_dirent *sd = arg;
+ return inode->i_ino == sd->s_ino;
+}
+
/**
- * sysfs_attach_dentry - associate sysfs_dirent with dentry
- * @sd: target sysfs_dirent
- * @dentry: dentry to associate
+ * sysfs_addrm_start - prepare for sysfs_dirent add/remove
+ * @acxt: pointer to sysfs_addrm_cxt to be used
+ * @parent_sd: parent sysfs_dirent
*
- * Associate @sd with @dentry. This is protected by
- * sysfs_assoc_lock to avoid race with sysfs_d_iput().
+ * This function is called when the caller is about to add or
+ * remove sysfs_dirent under @parent_sd. This function acquires
+ * sysfs_mutex, grabs inode for @parent_sd if available and lock
+ * i_mutex of it. @acxt is used to keep and pass context to
+ * other addrm functions.
*
* LOCKING:
- * mutex_lock(sysfs_mutex)
+ * Kernel thread context (may sleep). sysfs_mutex is locked on
+ * return. i_mutex of parent inode is locked on return if
+ * available.
*/
-static void sysfs_attach_dentry(struct sysfs_dirent *sd, struct dentry *dentry)
+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);
+ struct inode *inode;
- /* protect sd->s_dentry against sysfs_d_iput */
- spin_lock(&sysfs_assoc_lock);
- sd->s_dentry = dentry;
- spin_unlock(&sysfs_assoc_lock);
+ memset(acxt, 0, sizeof(*acxt));
+ acxt->parent_sd = parent_sd;
- d_rehash(dentry);
+ /* Lookup parent inode. inode initialization is protected by
+ * sysfs_mutex, so inode existence can be determined by
+ * looking up inode while holding sysfs_mutex.
+ */
+ mutex_lock(&sysfs_mutex);
+
+ inode = ilookup5(sysfs_sb, parent_sd->s_ino, sysfs_ilookup_test,
+ parent_sd);
+ if (inode) {
+ WARN_ON(inode->i_state & I_NEW);
+
+ /* parent inode available */
+ acxt->parent_inode = inode;
+
+ /* sysfs_mutex is below i_mutex in lock hierarchy.
+ * First, trylock i_mutex. If fails, unlock
+ * sysfs_mutex and lock them in order.
+ */
+ if (!mutex_trylock(&inode->i_mutex)) {
+ mutex_unlock(&sysfs_mutex);
+ mutex_lock(&inode->i_mutex);
+ mutex_lock(&sysfs_mutex);
+ }
+ }
}
/**
- * sysfs_attach_dirent - attach sysfs_dirent to its parent and dentry
- * @sd: sysfs_dirent to attach
- * @parent_sd: parent to attach to (optional)
- * @dentry: dentry to be associated to @sd (optional)
+ * __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.
*
- * Attach @sd to @parent_sd and/or @dentry. Both are optional.
+ * 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:
- * mutex_lock(sysfs_mutex)
+ * 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 (sysfs_find_dirent(acxt->parent_sd, sd->s_name))
+ return -EEXIST;
+
+ sd->s_parent = sysfs_get(acxt->parent_sd);
+
+ if (sysfs_type(sd) == SYSFS_DIR && acxt->parent_inode)
+ inc_nlink(acxt->parent_inode);
+
+ acxt->cnt++;
+
+ sysfs_link_sibling(sd);
+
+ return 0;
+}
+
+/**
+ * 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.
*/
-void sysfs_attach_dirent(struct sysfs_dirent *sd,
- struct sysfs_dirent *parent_sd, struct dentry *dentry)
+int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
{
- if (dentry)
- sysfs_attach_dentry(sd, dentry);
+ int ret;
+
+ ret = __sysfs_add_one(acxt, sd);
+ WARN(ret == -EEXIST, KERN_WARNING "sysfs: duplicate filename '%s' "
+ "can not be created\n", sd->s_name);
+ return ret;
+}
- if (parent_sd) {
- sd->s_parent = sysfs_get(parent_sd);
- sysfs_link_sibling(sd);
+/**
+ * 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)
+{
+ BUG_ON(sd->s_flags & SYSFS_FLAG_REMOVED);
+
+ sysfs_unlink_sibling(sd);
+
+ sd->s_flags |= SYSFS_FLAG_REMOVED;
+ sd->s_sibling = acxt->removed;
+ acxt->removed = sd;
+
+ if (sysfs_type(sd) == SYSFS_DIR && acxt->parent_inode)
+ drop_nlink(acxt->parent_inode);
+
+ acxt->cnt++;
+}
+
+/**
+ * sysfs_drop_dentry - drop dentry for the specified sysfs_dirent
+ * @sd: target sysfs_dirent
+ *
+ * Drop dentry for @sd. @sd must have been unlinked from its
+ * parent on entry to this function such that it can't be looked
+ * up anymore.
+ */
+static void sysfs_drop_dentry(struct sysfs_dirent *sd)
+{
+ struct inode *inode;
+ struct dentry *dentry;
+
+ inode = ilookup(sysfs_sb, sd->s_ino);
+ if (!inode)
+ return;
+
+ /* Drop any existing dentries associated with sd.
+ *
+ * For the dentry to be properly freed we need to grab a
+ * reference to the dentry under the dcache lock, unhash it,
+ * and then put it. The playing with the dentry count allows
+ * dput to immediately free the dentry if it is not in use.
+ */
+repeat:
+ spin_lock(&dcache_lock);
+ list_for_each_entry(dentry, &inode->i_dentry, d_alias) {
+ if (d_unhashed(dentry))
+ continue;
+ dget_locked(dentry);
+ spin_lock(&dentry->d_lock);
+ __d_drop(dentry);
+ spin_unlock(&dentry->d_lock);
+ spin_unlock(&dcache_lock);
+ dput(dentry);
+ goto repeat;
+ }
+ spin_unlock(&dcache_lock);
+
+ /* adjust nlink and update timestamp */
+ mutex_lock(&inode->i_mutex);
+
+ inode->i_ctime = CURRENT_TIME;
+ drop_nlink(inode);
+ if (sysfs_type(sd) == SYSFS_DIR)
+ drop_nlink(inode);
+
+ mutex_unlock(&inode->i_mutex);
+
+ iput(inode);
+}
+
+/**
+ * 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. Timestamps on the parent inode are updated.
+ *
+ * LOCKING:
+ * All mutexes acquired by sysfs_addrm_start() are released.
+ */
+void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt)
+{
+ /* release resources acquired by sysfs_addrm_start() */
+ mutex_unlock(&sysfs_mutex);
+ if (acxt->parent_inode) {
+ struct inode *inode = acxt->parent_inode;
+
+ /* if added/removed, update timestamps on the parent */
+ if (acxt->cnt)
+ inode->i_ctime = inode->i_mtime = CURRENT_TIME;
+
+ mutex_unlock(&inode->i_mutex);
+ iput(inode);
+ }
+
+ /* kill removed sysfs_dirents */
+ while (acxt->removed) {
+ struct sysfs_dirent *sd = acxt->removed;
+
+ acxt->removed = sd->s_sibling;
+ sd->s_sibling = NULL;
+
+ sysfs_drop_dentry(sd);
+ sysfs_deactivate(sd);
+ sysfs_put(sd);
}
}
{
struct sysfs_dirent *sd;
- for (sd = parent_sd->s_children; sd; sd = sd->s_sibling)
- if (sysfs_type(sd) && !strcmp(sd->s_name, name))
+ for (sd = parent_sd->s_dir.children; sd; sd = sd->s_sibling)
+ if (!strcmp(sd->s_name, name))
return sd;
return NULL;
}
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)
{
- struct dentry *parent = parent_sd->s_dentry;
- int error;
umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
- struct dentry *dentry;
- struct inode *inode;
+ struct sysfs_addrm_cxt acxt;
struct sysfs_dirent *sd;
-
- mutex_lock(&parent->d_inode->i_mutex);
+ int rc;
/* allocate */
- dentry = lookup_one_len(name, parent, strlen(name));
- if (IS_ERR(dentry)) {
- error = PTR_ERR(dentry);
- goto out_unlock;
- }
-
- error = -EEXIST;
- if (dentry->d_inode)
- goto out_dput;
-
- error = -ENOMEM;
sd = sysfs_new_dirent(name, mode, SYSFS_DIR);
if (!sd)
- goto out_drop;
- sd->s_elem.dir.kobj = kobj;
-
- 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);
- }
+ return -ENOMEM;
+ sd->s_dir.kobj = kobj;
/* link in */
- mutex_lock(&sysfs_mutex);
+ sysfs_addrm_start(&acxt, parent_sd);
+ rc = sysfs_add_one(&acxt, sd);
+ sysfs_addrm_finish(&acxt);
- error = -EEXIST;
- if (sysfs_find_dirent(parent_sd, name)) {
- mutex_unlock(&sysfs_mutex);
- goto out_iput;
- }
-
- sysfs_instantiate(dentry, inode);
- inc_nlink(parent->d_inode);
- sysfs_attach_dirent(sd, parent_sd, dentry);
-
- mutex_unlock(&sysfs_mutex);
-
- *p_sd = sd;
- error = 0;
- goto out_unlock; /* pin directory dentry in core */
+ if (rc == 0)
+ *p_sd = sd;
+ else
+ sysfs_put(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;
+ return rc;
}
int sysfs_create_subdir(struct kobject *kobj, const char *name,
/**
* sysfs_create_dir - create a directory for an object.
* @kobj: object we're creating directory for.
- * @shadow_parent: parent object.
*/
-int sysfs_create_dir(struct kobject *kobj,
- struct sysfs_dirent *shadow_parent_sd)
+int sysfs_create_dir(struct kobject * kobj)
{
struct sysfs_dirent *parent_sd, *sd;
int error = 0;
BUG_ON(!kobj);
- if (shadow_parent_sd)
- parent_sd = shadow_parent_sd;
- else if (kobj->parent)
+ if (kobj->parent)
parent_sd = kobj->parent->sd;
- else if (sysfs_mount && sysfs_mount->mnt_sb)
- parent_sd = sysfs_mount->mnt_sb->s_root->d_fsdata;
else
- return -EFAULT;
+ parent_sd = &sysfs_root;
error = create_dir(kobj, parent_sd, kobject_name(kobj), &sd);
if (!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);
-
- mutex_lock(&sysfs_mutex);
-
- 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 */
+ dentry->d_op = &sysfs_dentry_ops;
+ dentry->d_fsdata = sysfs_get(sd);
+ d_instantiate(dentry, inode);
+ d_rehash(dentry);
+ out_unlock:
mutex_unlock(&sysfs_mutex);
-
- return NULL;
+ return ret;
}
const struct inode_operations sysfs_dir_inode_operations = {
static void remove_dir(struct sysfs_dirent *sd)
{
- mutex_lock(&sysfs_mutex);
- sysfs_unlink_sibling(sd);
- sd->s_flags |= SYSFS_FLAG_REMOVED;
- mutex_unlock(&sysfs_mutex);
-
- pr_debug(" o %s removing done\n", sd->s_name);
+ struct sysfs_addrm_cxt acxt;
- 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 sysfs_dirent *sd)
static void __sysfs_remove_dir(struct sysfs_dirent *dir_sd)
{
- struct sysfs_dirent *removed = NULL;
+ struct sysfs_addrm_cxt acxt;
struct sysfs_dirent **pos;
if (!dir_sd)
return;
pr_debug("sysfs %s: removing dir\n", dir_sd->s_name);
- mutex_lock(&sysfs_mutex);
- pos = &dir_sd->s_children;
+ 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)) {
- sd->s_flags |= SYSFS_FLAG_REMOVED;
- *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(&sysfs_mutex);
-
- 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);
- }
+ sysfs_addrm_finish(&acxt);
remove_dir(dir_sd);
}
__sysfs_remove_dir(sd);
}
-int sysfs_rename_dir(struct kobject *kobj, struct sysfs_dirent *new_parent_sd,
- const char *new_name)
+int sysfs_rename_dir(struct kobject * kobj, const char *new_name)
{
struct sysfs_dirent *sd = kobj->sd;
- struct dentry *new_parent = new_parent_sd->s_dentry;
- struct dentry *new_dentry;
- char *dup_name;
+ struct dentry *parent = NULL;
+ struct dentry *old_dentry = NULL, *new_dentry = NULL;
+ const char *dup_name = NULL;
int error;
- if (!new_parent_sd)
- return -EFAULT;
-
- mutex_lock(&new_parent->d_inode->i_mutex);
+ mutex_lock(&sysfs_rename_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;
+ error = 0;
+ if (strcmp(sd->s_name, new_name) == 0)
+ goto out; /* nothing to rename */
+
+ /* get the original dentry */
+ old_dentry = sysfs_get_dentry(sd);
+ if (IS_ERR(old_dentry)) {
+ error = PTR_ERR(old_dentry);
+ old_dentry = NULL;
+ goto out;
}
- /* 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 (sd->s_parent->s_dentry->d_inode != new_parent->d_inode ||
- new_dentry->d_parent->d_inode != new_parent->d_inode ||
- new_dentry == sd->s_dentry)
- goto out_dput;
+ parent = old_dentry->d_parent;
+
+ /* lock parent and get dentry for new name */
+ mutex_lock(&parent->d_inode->i_mutex);
+ mutex_lock(&sysfs_mutex);
error = -EEXIST;
- if (new_dentry->d_inode)
- goto out_dput;
+ if (sysfs_find_dirent(sd->s_parent, new_name))
+ goto out_unlock;
+
+ error = -ENOMEM;
+ new_dentry = d_alloc_name(parent, new_name);
+ if (!new_dentry)
+ goto out_unlock;
- /* rename kobject and sysfs_dirent */
+ /* rename 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;
+ goto out_unlock;
- kfree(sd->s_name);
+ dup_name = sd->s_name;
sd->s_name = new_name;
- /* move under the new parent */
+ /* rename */
d_add(new_dentry, NULL);
- d_move(sd->s_dentry, new_dentry);
-
- mutex_lock(&sysfs_mutex);
-
- sysfs_unlink_sibling(sd);
- sysfs_get(new_parent_sd);
- sysfs_put(sd->s_parent);
- sd->s_parent = new_parent_sd;
- sysfs_link_sibling(sd);
-
- mutex_unlock(&sysfs_mutex);
+ d_move(old_dentry, new_dentry);
error = 0;
- goto out_unlock;
-
- out_free:
+ out_unlock:
+ mutex_unlock(&sysfs_mutex);
+ mutex_unlock(&parent->d_inode->i_mutex);
kfree(dup_name);
- out_drop:
- d_drop(new_dentry);
- out_dput:
+ dput(old_dentry);
dput(new_dentry);
- out_unlock:
- mutex_unlock(&new_parent->d_inode->i_mutex);
+ out:
+ mutex_unlock(&sysfs_rename_mutex);
return error;
}
-int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent)
+int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent_kobj)
{
- struct dentry *old_parent_dentry, *new_parent_dentry, *new_dentry;
- struct sysfs_dirent *new_parent_sd, *sd;
+ struct sysfs_dirent *sd = kobj->sd;
+ struct sysfs_dirent *new_parent_sd;
+ struct dentry *old_parent, *new_parent = NULL;
+ struct dentry *old_dentry = NULL, *new_dentry = NULL;
int error;
- old_parent_dentry = kobj->parent ?
- kobj->parent->sd->s_dentry : sysfs_mount->mnt_sb->s_root;
- new_parent_dentry = new_parent ?
- new_parent->sd->s_dentry : sysfs_mount->mnt_sb->s_root;
+ mutex_lock(&sysfs_rename_mutex);
+ BUG_ON(!sd->s_parent);
+ new_parent_sd = new_parent_kobj->sd ? new_parent_kobj->sd : &sysfs_root;
+
+ error = 0;
+ if (sd->s_parent == new_parent_sd)
+ goto out; /* nothing to move */
+
+ /* get dentries */
+ old_dentry = sysfs_get_dentry(sd);
+ if (IS_ERR(old_dentry)) {
+ error = PTR_ERR(old_dentry);
+ old_dentry = NULL;
+ goto out;
+ }
+ old_parent = old_dentry->d_parent;
+
+ new_parent = sysfs_get_dentry(new_parent_sd);
+ if (IS_ERR(new_parent)) {
+ error = PTR_ERR(new_parent);
+ new_parent = NULL;
+ goto out;
+ }
- 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);
+ mutex_lock(&old_parent->d_inode->i_mutex);
+ if (!mutex_trylock(&new_parent->d_inode->i_mutex)) {
+ mutex_unlock(&old_parent->d_inode->i_mutex);
goto again;
}
+ mutex_lock(&sysfs_mutex);
- new_parent_sd = new_parent_dentry->d_fsdata;
- sd = kobj->sd;
+ error = -EEXIST;
+ if (sysfs_find_dirent(new_parent_sd, sd->s_name))
+ goto out_unlock;
- 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;
+ error = -ENOMEM;
+ new_dentry = d_alloc_name(new_parent, sd->s_name);
+ if (!new_dentry)
+ goto out_unlock;
+
+ error = 0;
d_add(new_dentry, NULL);
- d_move(sd->s_dentry, new_dentry);
- dput(new_dentry);
+ d_move(old_dentry, new_dentry);
/* Remove from old parent's list and insert into new parent's list. */
- mutex_lock(&sysfs_mutex);
-
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_unlock:
mutex_unlock(&sysfs_mutex);
-out:
- mutex_unlock(&new_parent_dentry->d_inode->i_mutex);
- mutex_unlock(&old_parent_dentry->d_inode->i_mutex);
-
+ mutex_unlock(&new_parent->d_inode->i_mutex);
+ mutex_unlock(&old_parent->d_inode->i_mutex);
+ out:
+ dput(new_parent);
+ dput(old_dentry);
+ dput(new_dentry);
+ mutex_unlock(&sysfs_rename_mutex);
return error;
}
-static int sysfs_dir_open(struct inode *inode, struct file *file)
-{
- struct dentry * dentry = file->f_path.dentry;
- struct sysfs_dirent * parent_sd = dentry->d_fsdata;
- struct sysfs_dirent * sd;
-
- sd = sysfs_new_dirent("_DIR_", 0, 0);
- if (sd) {
- mutex_lock(&sysfs_mutex);
- sysfs_attach_dirent(sd, parent_sd, NULL);
- mutex_unlock(&sysfs_mutex);
- }
-
- file->private_data = sd;
- return sd ? 0 : -ENOMEM;
-}
-
-static int sysfs_dir_close(struct inode *inode, struct file *file)
-{
- struct sysfs_dirent * cursor = file->private_data;
-
- mutex_lock(&sysfs_mutex);
- sysfs_unlink_sibling(cursor);
- mutex_unlock(&sysfs_mutex);
-
- release_sysfs_dirent(cursor);
-
- return 0;
-}
-
/* Relationship between s_mode and the DT_xxx types */
static inline unsigned char dt_type(struct sysfs_dirent *sd)
{
{
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:
- mutex_lock(&sysfs_mutex);
-
- 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;
-
- name = next->s_name;
- len = strlen(name);
- ino = next->s_ino;
-
- if (filldir(dirent, name, len, filp->f_pos, ino,
- dt_type(next)) < 0)
- break;
-
- filp->f_pos++;
- }
+ }
+ if ((filp->f_pos > 1) && (filp->f_pos < INT_MAX)) {
+ mutex_lock(&sysfs_mutex);
- /* put cursor back in */
- cursor->s_sibling = *pos;
- *pos = cursor;
+ /* 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;
- mutex_unlock(&sysfs_mutex);
- }
- return 0;
-}
+ for ( ; pos; pos = pos->s_sibling) {
+ const char * name;
+ int len;
-static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin)
-{
- struct dentry * dentry = file->f_path.dentry;
+ name = pos->s_name;
+ len = strlen(name);
+ filp->f_pos = ino = pos->s_ino;
- 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:
- return -EINVAL;
- }
- if (offset != file->f_pos) {
- mutex_lock(&sysfs_mutex);
-
- 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);
}
-
- 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->sd->s_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 sysfs_dirent *sysfs_create_shadow_dir(struct kobject *kobj)
-{
- struct dentry *dir = kobj->sd->s_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;
-
- sd = 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);
- mutex_lock(&sysfs_mutex);
- sysfs_attach_dirent(sd, NULL, shadow);
- mutex_unlock(&sysfs_mutex);
-
- d_instantiate(shadow, igrab(inode));
- inc_nlink(inode);
- inc_nlink(parent->d_inode);
-
- dget(shadow); /* Extra count - pin the dentry in core */
-
-out:
- return sd;
-nomem:
- dput(shadow);
- sd = ERR_PTR(-ENOMEM);
- goto out;
-}
-
-/**
- * sysfs_remove_shadow_dir - remove an object's directory.
- * @shadow_sd: sysfs_dirent 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 sysfs_dirent *shadow_sd)
-{
- __sysfs_remove_dir(shadow_sd);
-}
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,
};
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff