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Diffstat (limited to 'fs/configfs/dir.c')
-rw-r--r--fs/configfs/dir.c271
1 files changed, 131 insertions, 140 deletions
diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index 8e48b52205a..668dcabc569 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -53,29 +53,31 @@ DEFINE_SPINLOCK(configfs_dirent_lock);
static void configfs_d_iput(struct dentry * dentry,
struct inode * inode)
{
- struct configfs_dirent * sd = dentry->d_fsdata;
+ struct configfs_dirent *sd = dentry->d_fsdata;
if (sd) {
- BUG_ON(sd->s_dentry != dentry);
- sd->s_dentry = NULL;
+ /* Coordinate with configfs_readdir */
+ spin_lock(&configfs_dirent_lock);
+ /* Coordinate with configfs_attach_attr where will increase
+ * sd->s_count and update sd->s_dentry to new allocated one.
+ * Only set sd->dentry to null when this dentry is the only
+ * sd owner.
+ * If not do so, configfs_d_iput may run just after
+ * configfs_attach_attr and set sd->s_dentry to null
+ * even it's still in use.
+ */
+ if (atomic_read(&sd->s_count) <= 2)
+ sd->s_dentry = NULL;
+
+ spin_unlock(&configfs_dirent_lock);
configfs_put(sd);
}
iput(inode);
}
-/*
- * We _must_ delete our dentries on last dput, as the chain-to-parent
- * behavior is required to clear the parents of default_groups.
- */
-static int configfs_d_delete(struct dentry *dentry)
-{
- return 1;
-}
-
-static const struct dentry_operations configfs_dentry_ops = {
+const struct dentry_operations configfs_dentry_ops = {
.d_iput = configfs_d_iput,
- /* simple_delete_dentry() isn't exported */
- .d_delete = configfs_d_delete,
+ .d_delete = always_delete_dentry,
};
#ifdef CONFIG_LOCKDEP
@@ -232,10 +234,8 @@ int configfs_make_dirent(struct configfs_dirent * parent_sd,
sd->s_mode = mode;
sd->s_dentry = dentry;
- if (dentry) {
+ if (dentry)
dentry->d_fsdata = configfs_get(sd);
- dentry->d_op = &configfs_dentry_ops;
- }
return 0;
}
@@ -263,11 +263,13 @@ static int init_symlink(struct inode * inode)
return 0;
}
-static int create_dir(struct config_item * k, struct dentry * p,
- struct dentry * d)
+static int create_dir(struct config_item *k, struct dentry *d)
{
int error;
umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
+ struct dentry *p = d->d_parent;
+
+ BUG_ON(!k);
error = configfs_dirent_exists(p->d_fsdata, d->d_name.name);
if (!error)
@@ -278,7 +280,6 @@ static int create_dir(struct config_item * k, struct dentry * p,
error = configfs_create(d, mode, init_dir);
if (!error) {
inc_nlink(p->d_inode);
- (d)->d_op = &configfs_dentry_ops;
} else {
struct configfs_dirent *sd = d->d_fsdata;
if (sd) {
@@ -304,19 +305,7 @@ static int create_dir(struct config_item * k, struct dentry * p,
static int configfs_create_dir(struct config_item * item, struct dentry *dentry)
{
- struct dentry * parent;
- int error = 0;
-
- BUG_ON(!item);
-
- if (item->ci_parent)
- parent = item->ci_parent->ci_dentry;
- else if (configfs_mount && configfs_mount->mnt_sb)
- parent = configfs_mount->mnt_sb->s_root;
- else
- return -EFAULT;
-
- error = create_dir(item,parent,dentry);
+ int error = create_dir(item, dentry);
if (!error)
item->ci_dentry = dentry;
return error;
@@ -371,9 +360,7 @@ int configfs_create_link(struct configfs_symlink *sl,
CONFIGFS_ITEM_LINK);
if (!err) {
err = configfs_create(dentry, mode, init_symlink);
- if (!err)
- dentry->d_op = &configfs_dentry_ops;
- else {
+ if (err) {
struct configfs_dirent *sd = dentry->d_fsdata;
if (sd) {
spin_lock(&configfs_dirent_lock);
@@ -399,8 +386,7 @@ static void remove_dir(struct dentry * d)
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));
+ pr_debug(" o %s removing done (%d)\n",d->d_name.name, d_count(d));
dput(parent);
}
@@ -439,8 +425,11 @@ static int configfs_attach_attr(struct configfs_dirent * sd, struct dentry * den
struct configfs_attribute * attr = sd->s_element;
int error;
+ spin_lock(&configfs_dirent_lock);
dentry->d_fsdata = configfs_get(sd);
sd->s_dentry = dentry;
+ spin_unlock(&configfs_dirent_lock);
+
error = configfs_create(dentry, (attr->ca_mode & S_IALLUGO) | S_IFREG,
configfs_init_file);
if (error) {
@@ -448,7 +437,6 @@ static int configfs_attach_attr(struct configfs_dirent * sd, struct dentry * den
return error;
}
- dentry->d_op = &configfs_dentry_ops;
d_rehash(dentry);
return 0;
@@ -456,7 +444,7 @@ static int configfs_attach_attr(struct configfs_dirent * sd, struct dentry * den
static struct dentry * configfs_lookup(struct inode *dir,
struct dentry *dentry,
- struct nameidata *nd)
+ unsigned int flags)
{
struct configfs_dirent * parent_sd = dentry->d_parent->d_fsdata;
struct configfs_dirent * sd;
@@ -493,7 +481,10 @@ static struct dentry * configfs_lookup(struct inode *dir,
* If it doesn't exist and it isn't a NOT_PINNED item,
* it must be negative.
*/
- return simple_lookup(dir, dentry, nd);
+ if (dentry->d_name.len > NAME_MAX)
+ return ERR_PTR(-ENAMETOOLONG);
+ d_add(dentry, NULL);
+ return NULL;
}
out:
@@ -645,6 +636,7 @@ static void detach_groups(struct config_group *group)
configfs_detach_group(sd->s_element);
child->d_inode->i_flags |= S_DEAD;
+ dont_mount(child);
mutex_unlock(&child->d_inode->i_mutex);
@@ -670,19 +662,15 @@ static int create_default_group(struct config_group *parent_group,
struct config_group *group)
{
int ret;
- struct qstr name;
struct configfs_dirent *sd;
/* We trust the caller holds a reference to parent */
struct dentry *child, *parent = parent_group->cg_item.ci_dentry;
if (!group->cg_item.ci_name)
group->cg_item.ci_name = group->cg_item.ci_namebuf;
- name.name = group->cg_item.ci_name;
- name.len = strlen(name.name);
- name.hash = full_name_hash(name.name, name.len);
ret = -ENOMEM;
- child = d_alloc(parent, &name);
+ child = d_alloc_name(parent, group->cg_item.ci_name);
if (child) {
d_add(child, NULL);
@@ -692,7 +680,8 @@ static int create_default_group(struct config_group *parent_group,
sd = child->d_fsdata;
sd->s_type |= CONFIGFS_USET_DEFAULT;
} else {
- d_delete(child);
+ BUG_ON(child->d_inode);
+ d_drop(child);
dput(child);
}
}
@@ -840,6 +829,7 @@ static int configfs_attach_item(struct config_item *parent_item,
mutex_lock(&dentry->d_inode->i_mutex);
configfs_remove_dir(item);
dentry->d_inode->i_flags |= S_DEAD;
+ dont_mount(dentry);
mutex_unlock(&dentry->d_inode->i_mutex);
d_delete(dentry);
}
@@ -882,6 +872,7 @@ static int configfs_attach_group(struct config_item *parent_item,
if (ret) {
configfs_detach_item(item);
dentry->d_inode->i_flags |= S_DEAD;
+ dont_mount(dentry);
}
configfs_adjust_dir_dirent_depth_after_populate(sd);
mutex_unlock(&dentry->d_inode->i_mutex);
@@ -949,9 +940,9 @@ static void client_drop_item(struct config_item *parent_item,
#ifdef DEBUG
static void configfs_dump_one(struct configfs_dirent *sd, int level)
{
- printk(KERN_INFO "%*s\"%s\":\n", level, " ", configfs_get_name(sd));
+ pr_info("%*s\"%s\":\n", level, " ", configfs_get_name(sd));
-#define type_print(_type) if (sd->s_type & _type) printk(KERN_INFO "%*s %s\n", level, " ", #_type);
+#define type_print(_type) if (sd->s_type & _type) pr_info("%*s %s\n", level, " ", #_type);
type_print(CONFIGFS_ROOT);
type_print(CONFIGFS_DIR);
type_print(CONFIGFS_ITEM_ATTR);
@@ -991,7 +982,7 @@ static int configfs_dump(struct configfs_dirent *sd, int level)
* This describes these functions and their helpers.
*
* Allow another kernel system to depend on a config_item. If this
- * happens, the item cannot go away until the dependant can live without
+ * happens, the item cannot go away until the dependent can live without
* it. The idea is to give client modules as simple an interface as
* possible. When a system asks them to depend on an item, they just
* call configfs_depend_item(). If the item is live and the client
@@ -1044,10 +1035,11 @@ static int configfs_dump(struct configfs_dirent *sd, int level)
static int configfs_depend_prep(struct dentry *origin,
struct config_item *target)
{
- struct configfs_dirent *child_sd, *sd = origin->d_fsdata;
+ struct configfs_dirent *child_sd, *sd;
int ret = 0;
- BUG_ON(!origin || !sd);
+ BUG_ON(!origin || !origin->d_fsdata);
+ sd = origin->d_fsdata;
if (sd->s_element == target) /* Boo-yah */
goto out;
@@ -1076,23 +1068,24 @@ int configfs_depend_item(struct configfs_subsystem *subsys,
int ret;
struct configfs_dirent *p, *root_sd, *subsys_sd = NULL;
struct config_item *s_item = &subsys->su_group.cg_item;
+ struct dentry *root;
/*
* Pin the configfs filesystem. This means we can safely access
* the root of the configfs filesystem.
*/
- ret = configfs_pin_fs();
- if (ret)
- return ret;
+ root = configfs_pin_fs();
+ if (IS_ERR(root))
+ return PTR_ERR(root);
/*
* Next, lock the root directory. We're going to check that the
* subsystem is really registered, and so we need to lock out
* configfs_[un]register_subsystem().
*/
- mutex_lock(&configfs_sb->s_root->d_inode->i_mutex);
+ mutex_lock(&root->d_inode->i_mutex);
- root_sd = configfs_sb->s_root->d_fsdata;
+ root_sd = root->d_fsdata;
list_for_each_entry(p, &root_sd->s_children, s_sibling) {
if (p->s_type & CONFIGFS_DIR) {
@@ -1126,7 +1119,7 @@ int configfs_depend_item(struct configfs_subsystem *subsys,
out_unlock_dirent_lock:
spin_unlock(&configfs_dirent_lock);
out_unlock_fs:
- mutex_unlock(&configfs_sb->s_root->d_inode->i_mutex);
+ mutex_unlock(&root->d_inode->i_mutex);
/*
* If we succeeded, the fs is pinned via other methods. If not,
@@ -1167,7 +1160,7 @@ void configfs_undepend_item(struct configfs_subsystem *subsys,
}
EXPORT_SYMBOL(configfs_undepend_item);
-static int configfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+static int configfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
int ret = 0;
int module_got = 0;
@@ -1180,11 +1173,6 @@ static int configfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
struct module *subsys_owner = NULL, *new_item_owner = NULL;
char *name;
- if (dentry->d_parent == configfs_sb->s_root) {
- ret = -EPERM;
- goto out;
- }
-
sd = dentry->d_parent->d_fsdata;
/*
@@ -1356,9 +1344,6 @@ static int configfs_rmdir(struct inode *dir, struct dentry *dentry)
struct module *subsys_owner = NULL, *dead_item_owner = NULL;
int ret;
- if (dentry->d_parent == configfs_sb->s_root)
- return -EPERM;
-
sd = dentry->d_fsdata;
if (sd->s_type & CONFIGFS_USET_DEFAULT)
return -EPERM;
@@ -1456,6 +1441,11 @@ const struct inode_operations configfs_dir_inode_operations = {
.setattr = configfs_setattr,
};
+const struct inode_operations configfs_root_inode_operations = {
+ .lookup = configfs_lookup,
+ .setattr = configfs_setattr,
+};
+
#if 0
int configfs_rename_dir(struct config_item * item, const char *new_name)
{
@@ -1540,80 +1530,83 @@ static inline unsigned char dt_type(struct configfs_dirent *sd)
return (sd->s_mode >> 12) & 15;
}
-static int configfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
+static int configfs_readdir(struct file *file, struct dir_context *ctx)
{
- struct dentry *dentry = filp->f_path.dentry;
+ struct dentry *dentry = file->f_path.dentry;
+ struct super_block *sb = dentry->d_sb;
struct configfs_dirent * parent_sd = dentry->d_fsdata;
- struct configfs_dirent *cursor = filp->private_data;
+ struct configfs_dirent *cursor = file->private_data;
struct list_head *p, *q = &cursor->s_sibling;
- ino_t ino;
- int i = filp->f_pos;
+ ino_t ino = 0;
- switch (i) {
- case 0:
- ino = dentry->d_inode->i_ino;
- if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
- break;
- filp->f_pos++;
- i++;
- /* fallthrough */
- case 1:
- ino = parent_ino(dentry);
- if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
- break;
- filp->f_pos++;
- i++;
- /* fallthrough */
- default:
- if (filp->f_pos == 2) {
- spin_lock(&configfs_dirent_lock);
- list_move(q, &parent_sd->s_children);
- spin_unlock(&configfs_dirent_lock);
- }
- for (p=q->next; p!= &parent_sd->s_children; p=p->next) {
- struct configfs_dirent *next;
- const char * name;
- int len;
+ if (!dir_emit_dots(file, ctx))
+ return 0;
+ if (ctx->pos == 2) {
+ spin_lock(&configfs_dirent_lock);
+ list_move(q, &parent_sd->s_children);
+ spin_unlock(&configfs_dirent_lock);
+ }
+ for (p = q->next; p != &parent_sd->s_children; p = p->next) {
+ struct configfs_dirent *next;
+ const char *name;
+ int len;
+ struct inode *inode = NULL;
+
+ next = list_entry(p, struct configfs_dirent, s_sibling);
+ if (!next->s_element)
+ continue;
- next = list_entry(p, struct configfs_dirent,
- s_sibling);
- if (!next->s_element)
- continue;
+ name = configfs_get_name(next);
+ len = strlen(name);
- name = configfs_get_name(next);
- len = strlen(name);
- if (next->s_dentry)
- ino = next->s_dentry->d_inode->i_ino;
- else
- ino = iunique(configfs_sb, 2);
+ /*
+ * We'll have a dentry and an inode for
+ * PINNED items and for open attribute
+ * files. We lock here to prevent a race
+ * with configfs_d_iput() clearing
+ * s_dentry before calling iput().
+ *
+ * Why do we go to the trouble? If
+ * someone has an attribute file open,
+ * the inode number should match until
+ * they close it. Beyond that, we don't
+ * care.
+ */
+ spin_lock(&configfs_dirent_lock);
+ dentry = next->s_dentry;
+ if (dentry)
+ inode = dentry->d_inode;
+ if (inode)
+ ino = inode->i_ino;
+ spin_unlock(&configfs_dirent_lock);
+ if (!inode)
+ ino = iunique(sb, 2);
- if (filldir(dirent, name, len, filp->f_pos, ino,
- dt_type(next)) < 0)
- return 0;
+ if (!dir_emit(ctx, name, len, ino, dt_type(next)))
+ return 0;
- spin_lock(&configfs_dirent_lock);
- list_move(q, p);
- spin_unlock(&configfs_dirent_lock);
- p = q;
- filp->f_pos++;
- }
+ spin_lock(&configfs_dirent_lock);
+ list_move(q, p);
+ spin_unlock(&configfs_dirent_lock);
+ p = q;
+ ctx->pos++;
}
return 0;
}
-static loff_t configfs_dir_lseek(struct file * file, loff_t offset, int origin)
+static loff_t configfs_dir_lseek(struct file *file, loff_t offset, int whence)
{
struct dentry * dentry = file->f_path.dentry;
mutex_lock(&dentry->d_inode->i_mutex);
- switch (origin) {
+ switch (whence) {
case 1:
offset += file->f_pos;
case 0:
if (offset >= 0)
break;
default:
- mutex_unlock(&file->f_path.dentry->d_inode->i_mutex);
+ mutex_unlock(&file_inode(file)->i_mutex);
return -EINVAL;
}
if (offset != file->f_pos) {
@@ -1648,43 +1641,39 @@ const struct file_operations configfs_dir_operations = {
.release = configfs_dir_close,
.llseek = configfs_dir_lseek,
.read = generic_read_dir,
- .readdir = configfs_readdir,
+ .iterate = configfs_readdir,
};
int configfs_register_subsystem(struct configfs_subsystem *subsys)
{
int err;
struct config_group *group = &subsys->su_group;
- struct qstr name;
struct dentry *dentry;
+ struct dentry *root;
struct configfs_dirent *sd;
- err = configfs_pin_fs();
- if (err)
- return err;
+ root = configfs_pin_fs();
+ if (IS_ERR(root))
+ return PTR_ERR(root);
if (!group->cg_item.ci_name)
group->cg_item.ci_name = group->cg_item.ci_namebuf;
- sd = configfs_sb->s_root->d_fsdata;
+ sd = root->d_fsdata;
link_group(to_config_group(sd->s_element), group);
- mutex_lock_nested(&configfs_sb->s_root->d_inode->i_mutex,
- I_MUTEX_PARENT);
-
- name.name = group->cg_item.ci_name;
- name.len = strlen(name.name);
- name.hash = full_name_hash(name.name, name.len);
+ mutex_lock_nested(&root->d_inode->i_mutex, I_MUTEX_PARENT);
err = -ENOMEM;
- dentry = d_alloc(configfs_sb->s_root, &name);
+ dentry = d_alloc_name(root, group->cg_item.ci_name);
if (dentry) {
d_add(dentry, NULL);
err = configfs_attach_group(sd->s_element, &group->cg_item,
dentry);
if (err) {
- d_delete(dentry);
+ BUG_ON(dentry->d_inode);
+ d_drop(dentry);
dput(dentry);
} else {
spin_lock(&configfs_dirent_lock);
@@ -1693,7 +1682,7 @@ int configfs_register_subsystem(struct configfs_subsystem *subsys)
}
}
- mutex_unlock(&configfs_sb->s_root->d_inode->i_mutex);
+ mutex_unlock(&root->d_inode->i_mutex);
if (err) {
unlink_group(group);
@@ -1707,29 +1696,31 @@ void configfs_unregister_subsystem(struct configfs_subsystem *subsys)
{
struct config_group *group = &subsys->su_group;
struct dentry *dentry = group->cg_item.ci_dentry;
+ struct dentry *root = dentry->d_sb->s_root;
- if (dentry->d_parent != configfs_sb->s_root) {
- printk(KERN_ERR "configfs: Tried to unregister non-subsystem!\n");
+ if (dentry->d_parent != root) {
+ pr_err("Tried to unregister non-subsystem!\n");
return;
}
- mutex_lock_nested(&configfs_sb->s_root->d_inode->i_mutex,
+ mutex_lock_nested(&root->d_inode->i_mutex,
I_MUTEX_PARENT);
mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD);
mutex_lock(&configfs_symlink_mutex);
spin_lock(&configfs_dirent_lock);
if (configfs_detach_prep(dentry, NULL)) {
- printk(KERN_ERR "configfs: Tried to unregister non-empty subsystem!\n");
+ pr_err("Tried to unregister non-empty subsystem!\n");
}
spin_unlock(&configfs_dirent_lock);
mutex_unlock(&configfs_symlink_mutex);
configfs_detach_group(&group->cg_item);
dentry->d_inode->i_flags |= S_DEAD;
+ dont_mount(dentry);
mutex_unlock(&dentry->d_inode->i_mutex);
d_delete(dentry);
- mutex_unlock(&configfs_sb->s_root->d_inode->i_mutex);
+ mutex_unlock(&root->d_inode->i_mutex);
dput(dentry);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-09 19:06:38 +0000