#include <linux/module.h>
#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);
+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
+ *
+ * Get an active reference of @sd. This function is noop if @sd
+ * is NULL.
+ *
+ * RETURNS:
+ * Pointer to @sd on success, NULL on failure.
+ */
+struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd)
+{
+ 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();
+ }
+}
+
+/**
+ * sysfs_put_active - put an active reference to sysfs_dirent
+ * @sd: sysfs_dirent to put an active reference to
+ *
+ * Put an active reference to @sd. This function is noop if @sd
+ * is NULL.
+ */
+void sysfs_put_active(struct sysfs_dirent *sd)
+{
+ 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_get_active_two - get active references to sysfs_dirent and parent
+ * @sd: sysfs_dirent of interest
+ *
+ * Get active reference to @sd and its parent. Parent's active
+ * reference is grabbed first. This function is noop if @sd is
+ * NULL.
+ *
+ * RETURNS:
+ * Pointer to @sd on success, NULL on failure.
+ */
+struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd)
+{
+ if (sd) {
+ if (sd->s_parent && unlikely(!sysfs_get_active(sd->s_parent)))
+ return NULL;
+ if (unlikely(!sysfs_get_active(sd))) {
+ sysfs_put_active(sd->s_parent);
+ return NULL;
+ }
+ }
+ return sd;
+}
+
+/**
+ * sysfs_put_active_two - put active references to sysfs_dirent and parent
+ * @sd: sysfs_dirent of interest
+ *
+ * Put active references to @sd and its parent. This function is
+ * noop if @sd is NULL.
+ */
+void sysfs_put_active_two(struct sysfs_dirent *sd)
+{
+ if (sd) {
+ sysfs_put_active(sd);
+ sysfs_put_active(sd->s_parent);
+ }
+}
+
+/**
+ * sysfs_deactivate - deactivate sysfs_dirent
+ * @sd: sysfs_dirent to deactivate
+ *
+ * Deny new active references and drain existing ones.
+ */
+static void sysfs_deactivate(struct sysfs_dirent *sd)
+{
+ DECLARE_COMPLETION_ONSTACK(wait);
+ int v;
+
+ BUG_ON(sd->s_sibling || !(sd->s_flags & SYSFS_FLAG_REMOVED));
+ sd->s_sibling = (void *)&wait;
+
+ /* 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)
+ wait_for_completion(&wait);
+
+ sd->s_sibling = NULL;
+}
+
+static int sysfs_alloc_ino(ino_t *pino)
+{
+ int ino, rc;
+
+ retry:
+ spin_lock(&sysfs_ino_lock);
+ rc = ida_get_new_above(&sysfs_ino_ida, 2, &ino);
+ spin_unlock(&sysfs_ino_lock);
+
+ if (rc == -EAGAIN) {
+ if (ida_pre_get(&sysfs_ino_ida, GFP_KERNEL))
+ goto retry;
+ rc = -ENOMEM;
+ }
+
+ *pino = ino;
+ return rc;
+}
+
+static void sysfs_free_ino(ino_t ino)
+{
+ spin_lock(&sysfs_ino_lock);
+ ida_remove(&sysfs_ino_ida, ino);
+ spin_unlock(&sysfs_ino_lock);
+}
+
+void release_sysfs_dirent(struct sysfs_dirent * sd)
+{
+ 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);
+ if (sysfs_type(sd) & SYSFS_COPY_NAME)
+ kfree(sd->s_name);
+ kfree(sd->s_iattr);
+ sysfs_free_ino(sd->s_ino);
+ kmem_cache_free(sysfs_dir_cachep, sd);
+
+ sd = parent_sd;
+ if (sd && atomic_dec_and_test(&sd->s_count))
+ goto repeat;
+}
static void sysfs_d_iput(struct dentry * dentry, struct inode * inode)
{
struct sysfs_dirent * sd = dentry->d_fsdata;
if (sd) {
- BUG_ON(sd->s_dentry != dentry);
- sd->s_dentry = NULL;
+ /* 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);
}
iput(inode);
.d_iput = sysfs_d_iput,
};
-/*
- * Allocates a new sysfs_dirent and links it to the parent sysfs_dirent
- */
-static struct sysfs_dirent * sysfs_new_dirent(struct sysfs_dirent * parent_sd,
- void * element)
+struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type)
{
- struct sysfs_dirent * sd;
+ char *dup_name = NULL;
+ struct sysfs_dirent *sd = NULL;
+
+ if (type & SYSFS_COPY_NAME) {
+ name = dup_name = kstrdup(name, GFP_KERNEL);
+ if (!name)
+ goto err_out;
+ }
- sd = kmem_cache_alloc(sysfs_dir_cachep, GFP_KERNEL);
+ sd = kmem_cache_zalloc(sysfs_dir_cachep, GFP_KERNEL);
if (!sd)
- return NULL;
+ goto err_out;
+
+ if (sysfs_alloc_ino(&sd->s_ino))
+ goto err_out;
- memset(sd, 0, sizeof(*sd));
atomic_set(&sd->s_count, 1);
- INIT_LIST_HEAD(&sd->s_children);
- list_add(&sd->s_sibling, &parent_sd->s_children);
- sd->s_element = element;
+ atomic_set(&sd->s_active, 0);
+ atomic_set(&sd->s_event, 1);
+
+ sd->s_name = name;
+ sd->s_mode = mode;
+ sd->s_flags = type;
return sd;
+
+ err_out:
+ kfree(dup_name);
+ kmem_cache_free(sysfs_dir_cachep, sd);
+ return NULL;
}
/**
+ * sysfs_attach_dentry - associate sysfs_dirent with dentry
+ * @sd: target sysfs_dirent
+ * @dentry: dentry to associate
*
- * Return -EEXIST if there is already a sysfs element with the same name for
- * the same parent.
+ * Associate @sd with @dentry. This is protected by
+ * sysfs_assoc_lock to avoid race with sysfs_d_iput().
*
- * called with parent inode's i_mutex held
+ * LOCKING:
+ * mutex_lock(sysfs_mutex)
*/
-int sysfs_dirent_exist(struct sysfs_dirent *parent_sd,
- const unsigned char *new)
+static void sysfs_attach_dentry(struct sysfs_dirent *sd, struct dentry *dentry)
{
- struct sysfs_dirent * sd;
+ dentry->d_op = &sysfs_dentry_ops;
+ dentry->d_fsdata = sysfs_get(sd);
- list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
- if (sd->s_element) {
- const unsigned char *existing = sysfs_get_name(sd);
- if (strcmp(existing, new))
- continue;
- else
- return -EEXIST;
- }
- }
+ /* protect sd->s_dentry against sysfs_d_iput */
+ spin_lock(&sysfs_assoc_lock);
+ sd->s_dentry = dentry;
+ spin_unlock(&sysfs_assoc_lock);
- return 0;
+ d_rehash(dentry);
+}
+
+static int sysfs_ilookup_test(struct inode *inode, void *arg)
+{
+ 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
+ *
+ * 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:
+ * Kernel thread context (may sleep). sysfs_mutex is locked on
+ * return. i_mutex of parent inode is locked on return if
+ * available.
+ */
+void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
+ struct sysfs_dirent *parent_sd)
+{
+ struct inode *inode;
+
+ memset(acxt, 0, sizeof(*acxt));
+ acxt->parent_sd = parent_sd;
-int sysfs_make_dirent(struct sysfs_dirent * parent_sd, struct dentry * dentry,
- void * element, umode_t mode, int type)
+ /* 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);
+}
+
+/**
+ * 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)
{
- struct sysfs_dirent * sd;
+ sd->s_parent = sysfs_get(acxt->parent_sd);
- sd = sysfs_new_dirent(parent_sd, element);
- if (!sd)
- return -ENOMEM;
+ if (sysfs_type(sd) == SYSFS_DIR && acxt->parent_inode)
+ inc_nlink(acxt->parent_inode);
- sd->s_mode = mode;
- sd->s_type = type;
- sd->s_dentry = dentry;
- if (dentry) {
- dentry->d_fsdata = sysfs_get(sd);
- dentry->d_op = &sysfs_dentry_ops;
+ acxt->cnt++;
+}
+
+/**
+ * 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)
+{
+ 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;
+
+ /* 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);
}
- return 0;
+ 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);
+ }
}
-static int init_dir(struct inode * 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.
+ *
+ * RETURNS:
+ * Number of added/removed sysfs_dirents since sysfs_addrm_start().
+ */
+int sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt)
{
- inode->i_op = &sysfs_dir_inode_operations;
- inode->i_fop = &sysfs_dir_operations;
+ /* release resources acquired by sysfs_addrm_start() */
+ mutex_unlock(&sysfs_mutex);
+ if (acxt->parent_inode) {
+ struct inode *inode = acxt->parent_inode;
- /* directory inodes start off with i_nlink == 2 (for "." entry) */
- inode->i_nlink++;
- return 0;
+ /* 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);
+ }
+
+ return acxt->cnt;
}
-static int init_file(struct inode * inode)
+/**
+ * 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)
{
- inode->i_size = PAGE_SIZE;
- inode->i_fop = &sysfs_file_operations;
- return 0;
+ struct sysfs_dirent *sd;
+
+ for (sd = parent_sd->s_children; sd; sd = sd->s_sibling)
+ if (sysfs_type(sd) && !strcmp(sd->s_name, name))
+ return sd;
+ return NULL;
}
-static int init_symlink(struct inode * inode)
+/**
+ * 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)
{
- inode->i_op = &sysfs_symlink_inode_operations;
- return 0;
+ 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 * k, struct dentry * p,
- const char * n, struct dentry ** d)
+static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd,
+ const char *name, struct sysfs_dirent **p_sd)
{
- int error;
umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
+ struct sysfs_addrm_cxt acxt;
+ struct sysfs_dirent *sd;
- mutex_lock(&p->d_inode->i_mutex);
- *d = lookup_one_len(n, p, strlen(n));
- if (!IS_ERR(*d)) {
- if (sysfs_dirent_exist(p->d_fsdata, n))
- error = -EEXIST;
- else
- error = sysfs_make_dirent(p->d_fsdata, *d, k, mode,
- SYSFS_DIR);
- if (!error) {
- error = sysfs_create(*d, mode, init_dir);
- if (!error) {
- p->d_inode->i_nlink++;
- (*d)->d_op = &sysfs_dentry_ops;
- d_rehash(*d);
- }
- }
- if (error && (error != -EEXIST)) {
- struct sysfs_dirent *sd = (*d)->d_fsdata;
- if (sd) {
- list_del_init(&sd->s_sibling);
- sysfs_put(sd);
- }
- d_drop(*d);
- }
- dput(*d);
- } else
- error = PTR_ERR(*d);
- mutex_unlock(&p->d_inode->i_mutex);
- return error;
-}
+ /* 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 * k, const char * n, struct dentry ** d)
+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.
- * @parent: parent parent object.
* @kobj: object we're creating directory for.
+ * @shadow_parent: parent object.
*/
-
-int sysfs_create_dir(struct kobject * kobj)
+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 (kobj->parent)
- parent = kobj->parent->dentry;
+ if (shadow_parent_sd)
+ parent_sd = shadow_parent_sd;
+ else if (kobj->parent)
+ 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;
}
-/* attaches attribute's sysfs_dirent to the dentry corresponding to the
- * attribute file
- */
-static int sysfs_attach_attr(struct sysfs_dirent * sd, struct dentry * dentry)
+static int sysfs_count_nlink(struct sysfs_dirent *sd)
{
- struct attribute * attr = NULL;
- struct bin_attribute * bin_attr = NULL;
- int (* init) (struct inode *) = NULL;
- int error = 0;
-
- if (sd->s_type & SYSFS_KOBJ_BIN_ATTR) {
- bin_attr = sd->s_element;
- attr = &bin_attr->attr;
- } else {
- attr = sd->s_element;
- init = init_file;
- }
-
- dentry->d_fsdata = sysfs_get(sd);
- sd->s_dentry = dentry;
- error = sysfs_create(dentry, (attr->mode & S_IALLUGO) | S_IFREG, init);
- if (error) {
- sysfs_put(sd);
- return error;
- }
-
- if (bin_attr) {
- dentry->d_inode->i_size = bin_attr->size;
- dentry->d_inode->i_fop = &bin_fops;
- }
- dentry->d_op = &sysfs_dentry_ops;
- d_rehash(dentry);
-
- return 0;
-}
-
-static int sysfs_attach_link(struct sysfs_dirent * sd, struct dentry * dentry)
-{
- int err = 0;
-
- dentry->d_fsdata = sysfs_get(sd);
- sd->s_dentry = dentry;
- err = sysfs_create(dentry, S_IFLNK|S_IRWXUGO, init_symlink);
- if (!err) {
- dentry->d_op = &sysfs_dentry_ops;
- d_rehash(dentry);
- } else
- sysfs_put(sd);
+ struct sysfs_dirent *child;
+ int nr = 0;
- return err;
+ 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 sysfs_dirent * parent_sd = dentry->d_parent->d_fsdata;
struct sysfs_dirent * sd;
- int err = 0;
+ struct bin_attribute *bin_attr;
+ struct inode *inode;
+ int found = 0;
+
+ 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;
+ }
+ }
- list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
- if (sd->s_type & SYSFS_NOT_PINNED) {
- const unsigned char * name = sysfs_get_name(sd);
+ /* no such entry */
+ if (!found)
+ return NULL;
- if (strcmp(name, dentry->d_name.name))
- continue;
+ /* attach dentry and inode */
+ inode = sysfs_get_inode(sd);
+ if (!inode)
+ return ERR_PTR(-ENOMEM);
- if (sd->s_type & SYSFS_KOBJ_LINK)
- err = sysfs_attach_link(sd, dentry);
- else
- err = sysfs_attach_attr(sd, dentry);
+ mutex_lock(&sysfs_mutex);
+
+ if (inode->i_state & I_NEW) {
+ /* initialize inode according to type */
+ 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;
+ 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();
}
}
- return ERR_PTR(err);
+ sysfs_instantiate(dentry, inode);
+ sysfs_attach_dentry(sd, dentry);
+
+ mutex_unlock(&sysfs_mutex);
+
+ return NULL;
}
-struct inode_operations sysfs_dir_inode_operations = {
+const struct inode_operations sysfs_dir_inode_operations = {
.lookup = sysfs_lookup,
.setattr = sysfs_setattr,
};
-static void remove_dir(struct dentry * d)
+static void remove_dir(struct sysfs_dirent *sd)
{
- struct dentry * parent = dget(d->d_parent);
- struct sysfs_dirent * sd;
-
- mutex_lock(&parent->d_inode->i_mutex);
- d_delete(d);
- sd = d->d_fsdata;
- list_del_init(&sd->s_sibling);
- sysfs_put(sd);
- if (d->d_inode)
- simple_rmdir(parent->d_inode,d);
-
- 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);
- dput(parent);
+ 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 sysfs_dirent *dir_sd)
+{
+ struct sysfs_addrm_cxt acxt;
+ struct sysfs_dirent **pos;
+
+ if (!dir_sd)
+ return;
+
+ 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(dir_sd);
+}
+
/**
* sysfs_remove_dir - remove an object's directory.
- * @kobj: object.
+ * @kobj: object.
*
- * The only thing special about this is that we remove any files in
+ * 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_dir(struct kobject * kobj)
{
- struct dentry * dentry = dget(kobj->dentry);
- struct sysfs_dirent * parent_sd;
- struct sysfs_dirent * sd, * tmp;
+ struct sysfs_dirent *sd = kobj->sd;
- if (!dentry)
- return;
+ spin_lock(&sysfs_assoc_lock);
+ kobj->sd = NULL;
+ spin_unlock(&sysfs_assoc_lock);
- 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_element || !(sd->s_type & SYSFS_NOT_PINNED))
- continue;
- list_del_init(&sd->s_sibling);
- sysfs_drop_dentry(sd, dentry);
- sysfs_put(sd);
+ __sysfs_remove_dir(sd);
+}
+
+int sysfs_rename_dir(struct kobject *kobj, struct sysfs_dirent *new_parent_sd,
+ const char *new_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;
+
+ /* get dentries */
+ old_dentry = sysfs_get_dentry(sd);
+ if (IS_ERR(old_dentry)) {
+ error = PTR_ERR(old_dentry);
+ goto out_dput;
}
- mutex_unlock(&dentry->d_inode->i_mutex);
- remove_dir(dentry);
- /**
- * Drop reference from dget() on entrance.
+ 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));
+ 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
*/
- dput(dentry);
- kobj->dentry = NULL;
+ error = -EINVAL;
+ if (old_dentry->d_parent->d_inode != new_parent->d_inode ||
+ new_dentry->d_parent->d_inode != new_parent->d_inode ||
+ old_dentry == new_dentry)
+ goto out_unlock;
+
+ error = -EEXIST;
+ if (new_dentry->d_inode)
+ goto out_unlock;
+
+ /* 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_drop;
+
+ dup_name = sd->s_name;
+ sd->s_name = new_name;
+
+ /* move under the new parent */
+ 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);
+
+ error = 0;
+ goto out_unlock;
+
+ out_drop:
+ d_drop(new_dentry);
+ out_unlock:
+ mutex_unlock(&new_parent->d_inode->i_mutex);
+ out_dput:
+ kfree(dup_name);
+ dput(new_parent);
+ dput(old_dentry);
+ dput(new_dentry);
+ return error;
}
-int sysfs_rename_dir(struct kobject * kobj, const char *new_name)
+int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent_kobj)
{
- int error = 0;
- struct dentry * new_dentry, * parent;
-
- if (!strcmp(kobject_name(kobj), new_name))
- return -EINVAL;
+ 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;
- if (!kobj->parent)
- return -EINVAL;
+ BUG_ON(!sd->s_parent);
+ new_parent_sd = new_parent_kobj->sd ? new_parent_kobj->sd : &sysfs_root;
- down_write(&sysfs_rename_sem);
- parent = kobj->parent->dentry;
+ /* 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;
- mutex_lock(&parent->d_inode->i_mutex);
+ new_parent = sysfs_get_dentry(new_parent_sd);
+ if (IS_ERR(new_parent)) {
+ error = PTR_ERR(new_parent);
+ goto out_dput;
+ }
- new_dentry = lookup_one_len(new_name, parent, strlen(new_name));
- if (!IS_ERR(new_dentry)) {
- if (!new_dentry->d_inode) {
- error = kobject_set_name(kobj, "%s", new_name);
- if (!error) {
- d_add(new_dentry, NULL);
- d_move(kobj->dentry, new_dentry);
- }
- else
- d_drop(new_dentry);
- } else
- error = -EEXIST;
- dput(new_dentry);
+ if (old_parent->d_inode == new_parent->d_inode) {
+ error = 0;
+ goto out_dput; /* nothing to move */
+ }
+again:
+ 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_unlock(&parent->d_inode->i_mutex);
- up_write(&sysfs_rename_sem);
+ new_dentry = lookup_one_len(kobj->name, new_parent, strlen(kobj->name));
+ if (IS_ERR(new_dentry)) {
+ error = PTR_ERR(new_dentry);
+ goto out_unlock;
+ } else
+ error = 0;
+ d_add(new_dentry, NULL);
+ d_move(sd->s_dentry, new_dentry);
+ dput(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);
+
+ 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;
}
static int sysfs_dir_open(struct inode *inode, struct file *file)
{
- struct dentry * dentry = file->f_dentry;
+ 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);
- file->private_data = sysfs_new_dirent(parent_sd, NULL);
- mutex_unlock(&dentry->d_inode->i_mutex);
-
- return file->private_data ? 0 : -ENOMEM;
+ sd = sysfs_new_dirent("_DIR_", 0, 0);
+ 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_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);
static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
{
- struct dentry *dentry = filp->f_dentry;
+ 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;
switch (i) {
case 0:
- ino = dentry->d_inode->i_ino;
+ ino = parent_sd->s_ino;
if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
break;
filp->f_pos++;
i++;
/* fallthrough */
case 1:
- ino = parent_ino(dentry);
+ 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;
filp->f_pos++;
i++;
/* fallthrough */
default:
- if (filp->f_pos == 2) {
- list_del(q);
- list_add(q, &parent_sd->s_children);
- }
- for (p=q->next; p!= &parent_sd->s_children; p=p->next) {
- struct sysfs_dirent *next;
+ 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;
- next = list_entry(p, struct sysfs_dirent,
- s_sibling);
- if (!next->s_element)
+ if (!sysfs_type(next))
continue;
- name = sysfs_get_name(next);
+ name = next->s_name;
len = strlen(name);
- if (next->s_dentry)
- ino = next->s_dentry->d_inode->i_ino;
- else
- ino = iunique(sysfs_sb, 2);
+ ino = next->s_ino;
if (filldir(dirent, name, len, filp->f_pos, ino,
dt_type(next)) < 0)
- return 0;
+ break;
- list_del(q);
- list_add(q, p);
- p = q;
filp->f_pos++;
}
+
+ /* put cursor back in */
+ cursor->s_sibling = *pos;
+ *pos = cursor;
+
+ mutex_unlock(&sysfs_mutex);
}
return 0;
}
static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin)
{
- struct dentry * dentry = file->f_dentry;
+ 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_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_element)
+ 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;
}
-struct file_operations sysfs_dir_operations = {
+
+/**
+ * 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 dentry *dentry;
+ struct inode *inode;
+ struct inode_operations *i_op;
+
+ /* 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)
+ 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 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;
+
+ 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)
+ goto nomem;
+
+ sd = sysfs_new_dirent("_SHADOW_", inode->i_mode, SYSFS_DIR);
+ if (!sd)
+ goto nomem;
+ sd->s_elem.dir.kobj = kobj;
+
+ 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); /* tj: synchronization? */
+
+ sysfs_addrm_finish(&acxt);
+
+ dget(shadow); /* Extra count - pin the dentry in core */
+
+ goto out_dput;
+
+ nomem:
+ dput(shadow);
+ sd = ERR_PTR(-ENOMEM);
+ out_dput:
+ dput(dir);
+ out:
+ return sd;
+}
+
+/**
+ * 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,
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff