#include <linux/kobject.h>
#include <linux/namei.h>
#include <linux/idr.h>
+#include <linux/completion.h>
#include <asm/semaphore.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);
+spinlock_t sysfs_assoc_lock = SPIN_LOCK_UNLOCKED;
static spinlock_t sysfs_ino_lock = SPIN_LOCK_UNLOCKED;
static DEFINE_IDA(sysfs_ino_ida);
/**
+ * sysfs_link_sibling - link sysfs_dirent into sibling list
+ * @sd: sysfs_dirent of interest
+ *
+ * Link @sd into its sibling list which starts from
+ * sd->s_parent->s_children.
+ *
+ * Locking:
+ * mutex_lock(sysfs_mutex)
+ */
+void sysfs_link_sibling(struct sysfs_dirent *sd)
+{
+ struct sysfs_dirent *parent_sd = sd->s_parent;
+
+ BUG_ON(sd->s_sibling);
+ sd->s_sibling = parent_sd->s_children;
+ parent_sd->s_children = sd;
+}
+
+/**
+ * sysfs_unlink_sibling - unlink sysfs_dirent from sibling list
+ * @sd: sysfs_dirent of interest
+ *
+ * Unlink @sd from its sibling list which starts from
+ * sd->s_parent->s_children.
+ *
+ * Locking:
+ * mutex_lock(sysfs_mutex)
+ */
+void sysfs_unlink_sibling(struct sysfs_dirent *sd)
+{
+ struct sysfs_dirent **pos;
+
+ for (pos = &sd->s_parent->s_children; *pos; pos = &(*pos)->s_sibling) {
+ if (*pos == sd) {
+ *pos = sd->s_sibling;
+ sd->s_sibling = NULL;
+ break;
+ }
+ }
+}
+
+/**
+ * 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 climbs sysfs_dirent tree till it
+ * reaches a sysfs_dirent with valid dentry attached and descends
+ * down from there looking up dentry for each step.
+ *
+ * LOCKING:
+ * Kernel thread context (may sleep)
+ *
+ * RETURNS:
+ * Pointer to found dentry on success, ERR_PTR() value on error.
+ */
+struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd)
+{
+ struct sysfs_dirent *cur;
+ struct dentry *parent_dentry, *dentry;
+ int i, depth;
+
+ /* Find the first parent which has valid s_dentry and get the
+ * dentry.
+ */
+ mutex_lock(&sysfs_mutex);
+ restart0:
+ spin_lock(&sysfs_assoc_lock);
+ restart1:
+ spin_lock(&dcache_lock);
+
+ dentry = NULL;
+ depth = 0;
+ cur = sd;
+ while (!cur->s_dentry || !cur->s_dentry->d_inode) {
+ if (cur->s_flags & SYSFS_FLAG_REMOVED) {
+ dentry = ERR_PTR(-ENOENT);
+ depth = 0;
+ break;
+ }
+ cur = cur->s_parent;
+ depth++;
+ }
+ if (!IS_ERR(dentry))
+ dentry = dget_locked(cur->s_dentry);
+
+ spin_unlock(&dcache_lock);
+ spin_unlock(&sysfs_assoc_lock);
+
+ /* from the found dentry, look up depth times */
+ while (depth--) {
+ /* find and get depth'th ancestor */
+ for (cur = sd, i = 0; cur && i < depth; i++)
+ cur = cur->s_parent;
+
+ /* This can happen if tree structure was modified due
+ * to move/rename. Restart.
+ */
+ if (i != depth) {
+ dput(dentry);
+ goto restart0;
+ }
+
+ sysfs_get(cur);
+
+ mutex_unlock(&sysfs_mutex);
+
+ /* look it up */
+ parent_dentry = dentry;
+ dentry = lookup_one_len_kern(cur->s_name, parent_dentry,
+ strlen(cur->s_name));
+ dput(parent_dentry);
+
+ if (IS_ERR(dentry)) {
+ sysfs_put(cur);
+ return dentry;
+ }
+
+ mutex_lock(&sysfs_mutex);
+ spin_lock(&sysfs_assoc_lock);
+
+ /* This, again, can happen if tree structure has
+ * changed and we looked up the wrong thing. Restart.
+ */
+ if (cur->s_dentry != dentry) {
+ dput(dentry);
+ sysfs_put(cur);
+ goto restart1;
+ }
+
+ spin_unlock(&sysfs_assoc_lock);
+
+ sysfs_put(cur);
+ }
+
+ mutex_unlock(&sysfs_mutex);
+ return dentry;
+}
+
+/**
* sysfs_get_active - get an active reference to sysfs_dirent
* @sd: sysfs_dirent to get an active reference to
*
*/
struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd)
{
- if (sd) {
- if (unlikely(!down_read_trylock(&sd->s_active)))
- sd = NULL;
+ if (unlikely(!sd))
+ return NULL;
+
+ while (1) {
+ int v, t;
+
+ v = atomic_read(&sd->s_active);
+ if (unlikely(v < 0))
+ return NULL;
+
+ t = atomic_cmpxchg(&sd->s_active, v, v + 1);
+ if (likely(t == v))
+ return sd;
+ if (t < 0)
+ return NULL;
+
+ cpu_relax();
}
- return sd;
}
/**
*/
void sysfs_put_active(struct sysfs_dirent *sd)
{
- if (sd)
- up_read(&sd->s_active);
+ struct completion *cmpl;
+ int v;
+
+ if (unlikely(!sd))
+ return;
+
+ v = atomic_dec_return(&sd->s_active);
+ if (likely(v != SD_DEACTIVATED_BIAS))
+ return;
+
+ /* atomic_dec_return() is a mb(), we'll always see the updated
+ * sd->s_sibling.
+ */
+ cmpl = (void *)sd->s_sibling;
+ complete(cmpl);
}
/**
* sysfs_deactivate - deactivate sysfs_dirent
* @sd: sysfs_dirent to deactivate
*
- * Deny new active references and drain existing ones. s_active
- * will be unlocked when the sysfs_dirent is released.
+ * Deny new active references and drain existing ones.
*/
-void sysfs_deactivate(struct sysfs_dirent *sd)
+static void sysfs_deactivate(struct sysfs_dirent *sd)
{
- down_write_nested(&sd->s_active, SYSFS_S_ACTIVE_DEACTIVATE);
+ DECLARE_COMPLETION_ONSTACK(wait);
+ int v;
+
+ BUG_ON(sd->s_sibling || !(sd->s_flags & SYSFS_FLAG_REMOVED));
+ sd->s_sibling = (void *)&wait;
- /* s_active will be unlocked by the thread doing the final put
- * on @sd. Lie to lockdep.
+ /* atomic_add_return() is a mb(), put_active() will always see
+ * the updated sd->s_sibling.
*/
- rwsem_release(&sd->s_active.dep_map, 1, _RET_IP_);
+ v = atomic_add_return(SD_DEACTIVATED_BIAS, &sd->s_active);
+
+ if (v != SD_DEACTIVATED_BIAS)
+ wait_for_completion(&wait);
+
+ sd->s_sibling = NULL;
}
static int sysfs_alloc_ino(ino_t *pino)
struct sysfs_dirent *parent_sd;
repeat:
- parent_sd = sd->s_parent;
-
- /* If @sd is being released after deletion, s_active is write
- * locked. If @sd is cursor for directory walk or being
- * released prematurely, s_active has no reader or writer.
- *
- * sysfs_deactivate() lies to lockdep that s_active is
- * unlocked immediately. Lie one more time to cover the
- * previous lie.
+ /* Moving/renaming is always done while holding reference.
+ * sd->s_parent won't change beneath us.
*/
- if (!down_write_trylock(&sd->s_active))
- rwsem_acquire(&sd->s_active.dep_map,
- SYSFS_S_ACTIVE_DEACTIVATE, 0, _RET_IP_);
- up_write(&sd->s_active);
+ parent_sd = sd->s_parent;
- if (sd->s_type & SYSFS_KOBJ_LINK)
+ if (sysfs_type(sd) == SYSFS_KOBJ_LINK)
sysfs_put(sd->s_elem.symlink.target_sd);
- if (sd->s_type & SYSFS_COPY_NAME)
+ if (sysfs_type(sd) & SYSFS_COPY_NAME)
kfree(sd->s_name);
kfree(sd->s_iattr);
sysfs_free_ino(sd->s_ino);
struct sysfs_dirent * sd = dentry->d_fsdata;
if (sd) {
- /* sd->s_dentry is protected with sysfs_lock. This
- * allows sysfs_drop_dentry() to dereference it.
+ /* sd->s_dentry is protected with sysfs_assoc_lock.
+ * This allows sysfs_drop_dentry() to dereference it.
*/
- spin_lock(&sysfs_lock);
+ spin_lock(&sysfs_assoc_lock);
/* The dentry might have been deleted or another
* lookup could have happened updating sd->s_dentry to
*/
if (sd->s_dentry == dentry)
sd->s_dentry = NULL;
- spin_unlock(&sysfs_lock);
+ spin_unlock(&sysfs_assoc_lock);
sysfs_put(sd);
}
iput(inode);
goto err_out;
atomic_set(&sd->s_count, 1);
+ atomic_set(&sd->s_active, 0);
atomic_set(&sd->s_event, 1);
- init_rwsem(&sd->s_active);
- INIT_LIST_HEAD(&sd->s_children);
- INIT_LIST_HEAD(&sd->s_sibling);
sd->s_name = name;
sd->s_mode = mode;
- sd->s_type = type;
+ sd->s_flags = type;
return sd;
return NULL;
}
+/**
+ * sysfs_attach_dentry - associate sysfs_dirent with dentry
+ * @sd: target sysfs_dirent
+ * @dentry: dentry to associate
+ *
+ * Associate @sd with @dentry. This is protected by
+ * sysfs_assoc_lock to avoid race with sysfs_d_iput().
+ *
+ * LOCKING:
+ * mutex_lock(sysfs_mutex)
+ */
static void sysfs_attach_dentry(struct sysfs_dirent *sd, struct dentry *dentry)
{
dentry->d_op = &sysfs_dentry_ops;
dentry->d_fsdata = sysfs_get(sd);
/* protect sd->s_dentry against sysfs_d_iput */
- spin_lock(&sysfs_lock);
+ spin_lock(&sysfs_assoc_lock);
sd->s_dentry = dentry;
- spin_unlock(&sysfs_lock);
+ spin_unlock(&sysfs_assoc_lock);
d_rehash(dentry);
}
-void sysfs_attach_dirent(struct sysfs_dirent *sd,
- struct sysfs_dirent *parent_sd, struct dentry *dentry)
+static int sysfs_ilookup_test(struct inode *inode, void *arg)
{
- if (dentry)
- sysfs_attach_dentry(sd, dentry);
-
- if (parent_sd) {
- sd->s_parent = sysfs_get(parent_sd);
- list_add(&sd->s_sibling, &parent_sd->s_children);
- }
+ struct sysfs_dirent *sd = arg;
+ return inode->i_ino == sd->s_ino;
}
-/*
+/**
+ * sysfs_addrm_start - prepare for sysfs_dirent add/remove
+ * @acxt: pointer to sysfs_addrm_cxt to be used
+ * @parent_sd: parent sysfs_dirent
*
- * Return -EEXIST if there is already a sysfs element with the same name for
- * the same parent.
+ * 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.
*
- * called with parent inode's i_mutex held
+ * LOCKING:
+ * Kernel thread context (may sleep). sysfs_mutex is locked on
+ * return. i_mutex of parent inode is locked on return if
+ * available.
*/
-int sysfs_dirent_exist(struct sysfs_dirent *parent_sd,
- const unsigned char *new)
+void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
+ struct sysfs_dirent *parent_sd)
{
- struct sysfs_dirent * sd;
+ struct inode *inode;
- list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
- if (sd->s_type) {
- if (strcmp(sd->s_name, new))
- continue;
- else
- return -EEXIST;
+ memset(acxt, 0, sizeof(*acxt));
+ acxt->parent_sd = parent_sd;
+
+ /* Lookup parent inode. inode initialization and I_NEW
+ * clearing are protected by sysfs_mutex. By grabbing it and
+ * looking up with _nowait variant, inode state can be
+ * determined reliably.
+ */
+ mutex_lock(&sysfs_mutex);
+
+ inode = ilookup5_nowait(sysfs_sb, parent_sd->s_ino, sysfs_ilookup_test,
+ parent_sd);
+
+ if (inode && !(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);
}
- }
+ } else
+ iput(inode);
+}
- 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. @sd is NOT
+ * linked into the children list of the parent. The caller
+ * should invoke sysfs_link_sibling() after this function
+ * completes if @sd needs to be on 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_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
+{
+ sd->s_parent = sysfs_get(acxt->parent_sd);
+
+ if (sysfs_type(sd) == SYSFS_DIR && acxt->parent_inode)
+ inc_nlink(acxt->parent_inode);
+
+ acxt->cnt++;
}
-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 added
+ *
+ * Mark @sd removed and drop nlink of parent inode if @sd is a
+ * directory. @sd is NOT unlinked from the children list of the
+ * parent. The caller is repsonsible for removing @sd from the
+ * children list before calling this function.
+ *
+ * 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;
+ BUG_ON(sd->s_sibling || (sd->s_flags & SYSFS_FLAG_REMOVED));
+
+ 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.
+ *
+ * @sd->s_dentry which is protected with sysfs_assoc_lock points
+ * to the currently associated dentry but we're not holding a
+ * reference to it and racing with dput(). Grab dcache_lock and
+ * verify dentry before dropping it. If @sd->s_dentry is NULL or
+ * dput() beats us, no need to bother.
+ */
+static void sysfs_drop_dentry(struct sysfs_dirent *sd)
+{
+ struct dentry *dentry = NULL;
struct inode *inode;
- struct sysfs_dirent *sd;
- mutex_lock(&parent->d_inode->i_mutex);
+ /* We're not holding a reference to ->s_dentry dentry but the
+ * field will stay valid as long as sysfs_assoc_lock is held.
+ */
+ spin_lock(&sysfs_assoc_lock);
+ spin_lock(&dcache_lock);
+
+ /* drop dentry if it's there and dput() didn't kill it yet */
+ if (sd->s_dentry && sd->s_dentry->d_inode) {
+ dentry = dget_locked(sd->s_dentry);
+ spin_lock(&dentry->d_lock);
+ __d_drop(dentry);
+ spin_unlock(&dentry->d_lock);
+ }
- /* allocate */
- dentry = lookup_one_len(name, parent, strlen(name));
- if (IS_ERR(dentry)) {
- error = PTR_ERR(dentry);
- goto out_unlock;
+ spin_unlock(&dcache_lock);
+ spin_unlock(&sysfs_assoc_lock);
+
+ /* dentries for shadowed inodes are pinned, unpin */
+ if (dentry && sysfs_is_shadowed_inode(dentry->d_inode))
+ dput(dentry);
+ dput(dentry);
+
+ /* adjust nlink and update timestamp */
+ inode = ilookup(sysfs_sb, sd->s_ino);
+ if (inode) {
+ 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);
}
+}
- error = -EEXIST;
- if (dentry->d_inode)
- goto out_dput;
+/**
+ * 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.
+ *
+ * RETURNS:
+ * Number of added/removed sysfs_dirents since sysfs_addrm_start().
+ */
+int 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;
- error = -ENOMEM;
- sd = sysfs_new_dirent(name, mode, SYSFS_DIR);
- if (!sd)
- goto out_drop;
- sd->s_elem.dir.kobj = kobj;
+ /* if added/removed, update timestamps on the parent */
+ if (acxt->cnt)
+ inode->i_ctime = inode->i_mtime = CURRENT_TIME;
- inode = sysfs_get_inode(sd);
- if (!inode)
- goto out_sput;
+ mutex_unlock(&inode->i_mutex);
+ iput(inode);
+ }
- 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_drop_dentry(sd);
+ sysfs_deactivate(sd);
+ sysfs_put(sd);
}
- /* link in */
- error = -EEXIST;
- if (sysfs_dirent_exist(parent->d_fsdata, name))
- goto out_iput;
+ return acxt->cnt;
+}
- sysfs_instantiate(dentry, inode);
- inc_nlink(parent->d_inode);
- sysfs_attach_dirent(sd, parent->d_fsdata, dentry);
+/**
+ * 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;
- *p_dentry = dentry;
- error = 0;
- goto out_unlock; /* pin directory dentry in core */
+ for (sd = parent_sd->s_children; sd; sd = sd->s_sibling)
+ if (sysfs_type(sd) && !strcmp(sd->s_name, name))
+ return sd;
+ return NULL;
+}
- 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;
+/**
+ * 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;
+
+ mutex_lock(&sysfs_mutex);
+ sd = sysfs_find_dirent(parent_sd, name);
+ sysfs_get(sd);
+ mutex_unlock(&sysfs_mutex);
+
+ return sd;
}
+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 sysfs_create_subdir(struct kobject * k, const char * n, struct dentry ** d)
+ /* allocate */
+ sd = sysfs_new_dirent(name, mode, SYSFS_DIR);
+ if (!sd)
+ return -ENOMEM;
+ sd->s_elem.dir.kobj = kobj;
+
+ /* link in */
+ sysfs_addrm_start(&acxt, parent_sd);
+ if (!sysfs_find_dirent(parent_sd, name)) {
+ sysfs_add_one(&acxt, sd);
+ sysfs_link_sibling(sd);
+ }
+ if (sysfs_addrm_finish(&acxt)) {
+ *p_sd = sd;
+ return 0;
+ }
+
+ sysfs_put(sd);
+ return -EEXIST;
+}
+
+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.
+ * @shadow_parent: parent object.
*/
-
-int sysfs_create_dir(struct kobject * kobj, struct dentry *shadow_parent)
+int sysfs_create_dir(struct kobject *kobj,
+ struct sysfs_dirent *shadow_parent_sd)
{
- 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;
+ if (shadow_parent_sd)
+ parent_sd = shadow_parent_sd;
else if (kobj->parent)
- parent = kobj->parent->dentry;
+ parent_sd = kobj->parent->sd;
else if (sysfs_mount && sysfs_mount->mnt_sb)
- parent = sysfs_mount->mnt_sb->s_root;
+ parent_sd = sysfs_mount->mnt_sb->s_root->d_fsdata;
else
return -EFAULT;
- 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 int sysfs_count_nlink(struct sysfs_dirent *sd)
+{
+ struct sysfs_dirent *child;
+ int nr = 0;
+
+ for (child = sd->s_children; child; child = child->s_sibling)
+ if (sysfs_type(child) == SYSFS_DIR)
+ nr++;
+ return nr + 2;
+}
+
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 inode *inode;
int found = 0;
- list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
- if ((sd->s_type & SYSFS_NOT_PINNED) &&
+ for (sd = parent_sd->s_children; sd; sd = sd->s_sibling) {
+ if (sysfs_type(sd) &&
!strcmp(sd->s_name, dentry->d_name.name)) {
found = 1;
break;
if (!inode)
return ERR_PTR(-ENOMEM);
+ mutex_lock(&sysfs_mutex);
+
if (inode->i_state & I_NEW) {
/* initialize inode according to type */
- if (sd->s_type & SYSFS_KOBJ_ATTR) {
+ switch (sysfs_type(sd)) {
+ case SYSFS_DIR:
+ inode->i_op = &sysfs_dir_inode_operations;
+ inode->i_fop = &sysfs_dir_operations;
+ inode->i_nlink = sysfs_count_nlink(sd);
+ break;
+ case SYSFS_KOBJ_ATTR:
inode->i_size = PAGE_SIZE;
inode->i_fop = &sysfs_file_operations;
- } else if (sd->s_type & SYSFS_KOBJ_BIN_ATTR) {
- struct bin_attribute *bin_attr =
- sd->s_elem.bin_attr.bin_attr;
+ 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;
- } else if (sd->s_type & SYSFS_KOBJ_LINK)
+ break;
+ case SYSFS_KOBJ_LINK:
inode->i_op = &sysfs_symlink_inode_operations;
+ break;
+ default:
+ BUG();
+ }
}
sysfs_instantiate(dentry, inode);
sysfs_attach_dentry(sd, dentry);
+ mutex_unlock(&sysfs_mutex);
+
return NULL;
}
.setattr = sysfs_setattr,
};
-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;
-
- mutex_lock(&parent->d_inode->i_mutex);
-
- list_del_init(&sd->s_sibling);
-
- pr_debug(" o %s removing done (%d)\n",d->d_name.name,
- atomic_read(&d->d_count));
+ struct sysfs_addrm_cxt acxt;
- 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_unlink_sibling(sd);
+ 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)
{
- LIST_HEAD(removed);
- struct sysfs_dirent * parent_sd;
- struct sysfs_dirent * sd, * tmp;
+ 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;
- list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) {
- if (!sd->s_type || !(sd->s_type & SYSFS_NOT_PINNED))
- continue;
- list_move(&sd->s_sibling, &removed);
- }
- mutex_unlock(&dentry->d_inode->i_mutex);
-
- list_for_each_entry_safe(sd, tmp, &removed, s_sibling) {
- list_del_init(&sd->s_sibling);
- sysfs_drop_dentry(sd);
- sysfs_deactivate(sd);
- sysfs_put(sd);
+ pr_debug("sysfs %s: removing dir\n", dir_sd->s_name);
+ sysfs_addrm_start(&acxt, dir_sd);
+ pos = &dir_sd->s_children;
+ while (*pos) {
+ struct sysfs_dirent *sd = *pos;
+
+ if (sysfs_type(sd) && sysfs_type(sd) != SYSFS_DIR) {
+ *pos = sd->s_sibling;
+ sd->s_sibling = NULL;
+ sysfs_remove_one(&acxt, sd);
+ } else
+ pos = &(*pos)->s_sibling;
}
+ sysfs_addrm_finish(&acxt);
- 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,
+int sysfs_rename_dir(struct kobject *kobj, 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;
+ struct sysfs_dirent *sd = kobj->sd;
+ struct dentry *new_parent = NULL;
+ struct dentry *old_dentry = NULL, *new_dentry = NULL;
+ const char *dup_name = NULL;
int error;
- if (!new_parent)
- return -EFAULT;
+ /* get dentries */
+ old_dentry = sysfs_get_dentry(sd);
+ if (IS_ERR(old_dentry)) {
+ error = PTR_ERR(old_dentry);
+ goto out_dput;
+ }
- down_write(&sysfs_rename_sem);
+ new_parent = sysfs_get_dentry(new_parent_sd);
+ if (IS_ERR(new_parent)) {
+ error = PTR_ERR(new_parent);
+ goto out_dput;
+ }
+
+ /* lock new_parent and get dentry for new name */
mutex_lock(&new_parent->d_inode->i_mutex);
new_dentry = lookup_one_len(new_name, new_parent, strlen(new_name));
* shadows of the same directory
*/
error = -EINVAL;
- if (kobj->dentry->d_parent->d_inode != new_parent->d_inode ||
+ if (old_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;
+ old_dentry == new_dentry)
+ goto out_unlock;
error = -EEXIST;
if (new_dentry->d_inode)
- goto out_dput;
+ goto out_unlock;
/* rename kobject and sysfs_dirent */
error = -ENOMEM;
error = kobject_set_name(kobj, "%s", new_name);
if (error)
- goto out_free;
+ goto out_drop;
- kfree(sd->s_name);
+ dup_name = sd->s_name;
sd->s_name = new_name;
/* move under the new parent */
d_add(new_dentry, NULL);
- d_move(kobj->dentry, new_dentry);
+ d_move(sd->s_dentry, new_dentry);
+
+ mutex_lock(&sysfs_mutex);
- list_del_init(&sd->s_sibling);
- sysfs_get(parent_sd);
+ sysfs_unlink_sibling(sd);
+ sysfs_get(new_parent_sd);
sysfs_put(sd->s_parent);
- sd->s_parent = parent_sd;
- list_add(&sd->s_sibling, &parent_sd->s_children);
+ sd->s_parent = new_parent_sd;
+ sysfs_link_sibling(sd);
+
+ mutex_unlock(&sysfs_mutex);
error = 0;
goto out_unlock;
- 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);
+ out_dput:
+ kfree(dup_name);
+ dput(new_parent);
+ dput(old_dentry);
+ dput(new_dentry);
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->dentry : sysfs_mount->mnt_sb->s_root;
- new_parent_dentry = new_parent ?
- new_parent->dentry : sysfs_mount->mnt_sb->s_root;
+ BUG_ON(!sd->s_parent);
+ new_parent_sd = new_parent_kobj->sd ? new_parent_kobj->sd : &sysfs_root;
- if (old_parent_dentry->d_inode == new_parent_dentry->d_inode)
- return 0; /* nothing to move */
+ /* get dentries */
+ old_dentry = sysfs_get_dentry(sd);
+ if (IS_ERR(old_dentry)) {
+ error = PTR_ERR(old_dentry);
+ goto out_dput;
+ }
+ old_parent = sd->s_parent->s_dentry;
+
+ new_parent = sysfs_get_dentry(new_parent_sd);
+ if (IS_ERR(new_parent)) {
+ error = PTR_ERR(new_parent);
+ goto out_dput;
+ }
+
+ if (old_parent->d_inode == new_parent->d_inode) {
+ error = 0;
+ goto out_dput; /* 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;
}
- 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));
+ new_dentry = lookup_one_len(kobj->name, new_parent, strlen(kobj->name));
if (IS_ERR(new_dentry)) {
error = PTR_ERR(new_dentry);
- goto out;
+ goto out_unlock;
} else
error = 0;
d_add(new_dentry, NULL);
- d_move(kobj->dentry, new_dentry);
+ d_move(sd->s_dentry, new_dentry);
dput(new_dentry);
/* Remove from old parent's list and insert into new parent's list. */
- list_del_init(&sd->s_sibling);
+ mutex_lock(&sysfs_mutex);
+
+ sysfs_unlink_sibling(sd);
sysfs_get(new_parent_sd);
sysfs_put(sd->s_parent);
sd->s_parent = new_parent_sd;
- list_add(&sd->s_sibling, &new_parent_sd->s_children);
+ sysfs_link_sibling(sd);
-out:
- mutex_unlock(&new_parent_dentry->d_inode->i_mutex);
- mutex_unlock(&old_parent_dentry->d_inode->i_mutex);
+ mutex_unlock(&sysfs_mutex);
+ out_unlock:
+ mutex_unlock(&new_parent->d_inode->i_mutex);
+ mutex_unlock(&old_parent->d_inode->i_mutex);
+ out_dput:
+ dput(new_parent);
+ dput(old_dentry);
+ dput(new_dentry);
return error;
}
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);
+ if (sd) {
+ mutex_lock(&sysfs_mutex);
+ sd->s_parent = sysfs_get(parent_sd);
+ sysfs_link_sibling(sd);
+ mutex_unlock(&sysfs_mutex);
+ }
file->private_data = sd;
return sd ? 0 : -ENOMEM;
static int sysfs_dir_close(struct inode *inode, struct file *file)
{
- struct dentry * dentry = file->f_path.dentry;
struct sysfs_dirent * cursor = file->private_data;
- mutex_lock(&dentry->d_inode->i_mutex);
- list_del_init(&cursor->s_sibling);
- mutex_unlock(&dentry->d_inode->i_mutex);
+ mutex_lock(&sysfs_mutex);
+ sysfs_unlink_sibling(cursor);
+ mutex_unlock(&sysfs_mutex);
release_sysfs_dirent(cursor);
struct dentry *dentry = filp->f_path.dentry;
struct sysfs_dirent * parent_sd = dentry->d_fsdata;
struct sysfs_dirent *cursor = filp->private_data;
- struct list_head *p, *q = &cursor->s_sibling;
+ struct sysfs_dirent **pos;
ino_t ino;
int i = 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)
- list_move(q, &parent_sd->s_children);
+ pos = &parent_sd->s_children;
- for (p=q->next; p!= &parent_sd->s_children; p=p->next) {
- struct sysfs_dirent *next;
+ for ( ; *pos; pos = &(*pos)->s_sibling) {
+ struct sysfs_dirent *next = *pos;
const char * name;
int len;
- next = list_entry(p, struct sysfs_dirent,
- s_sibling);
- if (!next->s_type)
+ if (!sysfs_type(next))
continue;
name = next->s_name;
if (filldir(dirent, name, len, filp->f_pos, ino,
dt_type(next)) < 0)
- return 0;
+ break;
- list_move(q, p);
- p = q;
filp->f_pos++;
}
+
+ /* put cursor back in */
+ cursor->s_sibling = *pos;
+ *pos = cursor;
+
+ mutex_unlock(&sysfs_mutex);
}
return 0;
}
{
struct dentry * dentry = file->f_path.dentry;
- mutex_lock(&dentry->d_inode->i_mutex);
switch (origin) {
case 1:
offset += file->f_pos;
if (offset >= 0)
break;
default:
- mutex_unlock(&file->f_path.dentry->d_inode->i_mutex);
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 list_head *p;
+ struct sysfs_dirent **pos;
loff_t n = file->f_pos - 2;
- list_del(&cursor->s_sibling);
- p = sd->s_children.next;
- while (n && p != &sd->s_children) {
- struct sysfs_dirent *next;
- next = list_entry(p, struct sysfs_dirent,
- s_sibling);
- if (next->s_type)
+ sysfs_unlink_sibling(cursor);
+
+ pos = &sd->s_children;
+ while (n && *pos) {
+ struct sysfs_dirent *next = *pos;
+ if (sysfs_type(next))
n--;
- p = p->next;
+ pos = &(*pos)->s_sibling;
}
- list_add_tail(&cursor->s_sibling, p);
+
+ cursor->s_sibling = *pos;
+ *pos = cursor;
}
+
+ mutex_unlock(&sysfs_mutex);
}
- mutex_unlock(&dentry->d_inode->i_mutex);
+
return offset;
}
int sysfs_make_shadowed_dir(struct kobject *kobj,
void * (*follow_link)(struct dentry *, struct nameidata *))
{
+ struct dentry *dentry;
struct inode *inode;
struct inode_operations *i_op;
- inode = kobj->dentry->d_inode;
- if (inode->i_op != &sysfs_dir_inode_operations)
+ /* get dentry for @kobj->sd, dentry of a shadowed dir is pinned */
+ dentry = sysfs_get_dentry(kobj->sd);
+ if (IS_ERR(dentry))
+ return PTR_ERR(dentry);
+
+ inode = dentry->d_inode;
+ if (inode->i_op != &sysfs_dir_inode_operations) {
+ dput(dentry);
return -EINVAL;
+ }
i_op = kmalloc(sizeof(*i_op), GFP_KERNEL);
if (!i_op)
* directory.
*/
-struct dentry *sysfs_create_shadow_dir(struct kobject *kobj)
+struct sysfs_dirent *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 *parent_sd = kobj->sd->s_parent;
+ struct dentry *dir, *parent, *shadow;
+ struct inode *inode;
struct sysfs_dirent *sd;
+ struct sysfs_addrm_cxt acxt;
- shadow = ERR_PTR(-EINVAL);
- if (!sysfs_is_shadowed_inode(inode))
+ dir = sysfs_get_dentry(kobj->sd);
+ if (IS_ERR(dir)) {
+ sd = (void *)dir;
goto out;
+ }
+ parent = dir->d_parent;
+
+ inode = dir->d_inode;
+ sd = ERR_PTR(-EINVAL);
+ if (!sysfs_is_shadowed_inode(inode))
+ goto out_dput;
shadow = d_alloc(parent, &dir->d_name);
if (!shadow)
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);
+ sysfs_addrm_start(&acxt, parent_sd);
+
+ /* add but don't link into children list */
+ sysfs_add_one(&acxt, sd);
+
+ /* attach and instantiate dentry */
+ sysfs_attach_dentry(sd, shadow);
d_instantiate(shadow, igrab(inode));
- inc_nlink(inode);
- inc_nlink(parent->d_inode);
+ inc_nlink(inode); /* tj: synchronization? */
+
+ sysfs_addrm_finish(&acxt);
dget(shadow); /* Extra count - pin the dentry in core */
-out:
- return shadow;
-nomem:
+ goto out_dput;
+
+ nomem:
dput(shadow);
- shadow = ERR_PTR(-ENOMEM);
- goto out;
+ sd = ERR_PTR(-ENOMEM);
+ out_dput:
+ dput(dir);
+ out:
+ return sd;
}
/**
* sysfs_remove_shadow_dir - remove an object's directory.
- * @shadow: dentry of shadow 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 dentry *shadow)
+void sysfs_remove_shadow_dir(struct sysfs_dirent *shadow_sd)
{
- __sysfs_remove_dir(shadow);
+ __sysfs_remove_dir(shadow_sd);
}
const struct file_operations sysfs_dir_operations = {
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff