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-rw-r--r--fs/configfs/dir.c306
1 files changed, 167 insertions, 139 deletions
diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index 92112915de8e..cf7b7e1d5bd7 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -22,7 +22,6 @@
#include <linux/configfs.h>
#include "configfs_internal.h"
-DECLARE_RWSEM(configfs_rename_sem);
/*
* Protects mutations of configfs_dirent linkage together with proper i_mutex
* Also protects mutations of symlinks linkage to target configfs_dirent
@@ -151,11 +150,38 @@ configfs_adjust_dir_dirent_depth_after_populate(struct configfs_dirent *sd)
#endif /* CONFIG_LOCKDEP */
+static struct configfs_fragment *new_fragment(void)
+{
+ struct configfs_fragment *p;
+
+ p = kmalloc(sizeof(struct configfs_fragment), GFP_KERNEL);
+ if (p) {
+ atomic_set(&p->frag_count, 1);
+ init_rwsem(&p->frag_sem);
+ p->frag_dead = false;
+ }
+ return p;
+}
+
+void put_fragment(struct configfs_fragment *frag)
+{
+ if (frag && atomic_dec_and_test(&frag->frag_count))
+ kfree(frag);
+}
+
+struct configfs_fragment *get_fragment(struct configfs_fragment *frag)
+{
+ if (likely(frag))
+ atomic_inc(&frag->frag_count);
+ return frag;
+}
+
/*
* Allocates a new configfs_dirent and links it to the parent configfs_dirent
*/
static struct configfs_dirent *configfs_new_dirent(struct configfs_dirent *parent_sd,
- void *element, int type)
+ void *element, int type,
+ struct configfs_fragment *frag)
{
struct configfs_dirent * sd;
@@ -164,7 +190,6 @@ static struct configfs_dirent *configfs_new_dirent(struct configfs_dirent *paren
return ERR_PTR(-ENOMEM);
atomic_set(&sd->s_count, 1);
- INIT_LIST_HEAD(&sd->s_links);
INIT_LIST_HEAD(&sd->s_children);
sd->s_element = element;
sd->s_type = type;
@@ -175,6 +200,7 @@ static struct configfs_dirent *configfs_new_dirent(struct configfs_dirent *paren
kmem_cache_free(configfs_dir_cachep, sd);
return ERR_PTR(-ENOENT);
}
+ sd->s_frag = get_fragment(frag);
list_add(&sd->s_sibling, &parent_sd->s_children);
spin_unlock(&configfs_dirent_lock);
@@ -209,11 +235,11 @@ static int configfs_dirent_exists(struct configfs_dirent *parent_sd,
int configfs_make_dirent(struct configfs_dirent * parent_sd,
struct dentry * dentry, void * element,
- umode_t mode, int type)
+ umode_t mode, int type, struct configfs_fragment *frag)
{
struct configfs_dirent * sd;
- sd = configfs_new_dirent(parent_sd, element, type);
+ sd = configfs_new_dirent(parent_sd, element, type, frag);
if (IS_ERR(sd))
return PTR_ERR(sd);
@@ -225,30 +251,16 @@ int configfs_make_dirent(struct configfs_dirent * parent_sd,
return 0;
}
-static void init_dir(struct inode * inode)
+static void configfs_remove_dirent(struct dentry *dentry)
{
- inode->i_op = &configfs_dir_inode_operations;
- inode->i_fop = &configfs_dir_operations;
-
- /* directory inodes start off with i_nlink == 2 (for "." entry) */
- inc_nlink(inode);
-}
-
-static void configfs_init_file(struct inode * inode)
-{
- inode->i_size = PAGE_SIZE;
- inode->i_fop = &configfs_file_operations;
-}
-
-static void configfs_init_bin_file(struct inode *inode)
-{
- inode->i_size = 0;
- inode->i_fop = &configfs_bin_file_operations;
-}
+ struct configfs_dirent *sd = dentry->d_fsdata;
-static void init_symlink(struct inode * inode)
-{
- inode->i_op = &configfs_symlink_inode_operations;
+ if (!sd)
+ return;
+ spin_lock(&configfs_dirent_lock);
+ list_del_init(&sd->s_sibling);
+ spin_unlock(&configfs_dirent_lock);
+ configfs_put(sd);
}
/**
@@ -260,11 +272,13 @@ static void init_symlink(struct inode * inode)
* until it is validated by configfs_dir_set_ready()
*/
-static int configfs_create_dir(struct config_item *item, struct dentry *dentry)
+static int configfs_create_dir(struct config_item *item, struct dentry *dentry,
+ struct configfs_fragment *frag)
{
int error;
umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
struct dentry *p = dentry->d_parent;
+ struct inode *inode;
BUG_ON(!item);
@@ -273,25 +287,30 @@ static int configfs_create_dir(struct config_item *item, struct dentry *dentry)
return error;
error = configfs_make_dirent(p->d_fsdata, dentry, item, mode,
- CONFIGFS_DIR | CONFIGFS_USET_CREATING);
+ CONFIGFS_DIR | CONFIGFS_USET_CREATING,
+ frag);
if (unlikely(error))
return error;
configfs_set_dir_dirent_depth(p->d_fsdata, dentry->d_fsdata);
- error = configfs_create(dentry, mode, init_dir);
- if (!error) {
- inc_nlink(d_inode(p));
- item->ci_dentry = dentry;
- } else {
- struct configfs_dirent *sd = dentry->d_fsdata;
- if (sd) {
- spin_lock(&configfs_dirent_lock);
- list_del_init(&sd->s_sibling);
- spin_unlock(&configfs_dirent_lock);
- configfs_put(sd);
- }
- }
- return error;
+ inode = configfs_create(dentry, mode);
+ if (IS_ERR(inode))
+ goto out_remove;
+
+ inode->i_op = &configfs_dir_inode_operations;
+ inode->i_fop = &configfs_dir_operations;
+ /* directory inodes start off with i_nlink == 2 (for "." entry) */
+ inc_nlink(inode);
+ d_instantiate(dentry, inode);
+ /* already hashed */
+ dget(dentry); /* pin directory dentries in core */
+ inc_nlink(d_inode(p));
+ item->ci_dentry = dentry;
+ return 0;
+
+out_remove:
+ configfs_remove_dirent(dentry);
+ return PTR_ERR(inode);
}
/*
@@ -332,40 +351,40 @@ int configfs_dirent_is_ready(struct configfs_dirent *sd)
return ret;
}
-int configfs_create_link(struct configfs_symlink *sl,
- struct dentry *parent,
- struct dentry *dentry)
+int configfs_create_link(struct configfs_dirent *target, struct dentry *parent,
+ struct dentry *dentry, char *body)
{
int err = 0;
umode_t mode = S_IFLNK | S_IRWXUGO;
+ struct configfs_dirent *p = parent->d_fsdata;
+ struct inode *inode;
- err = configfs_make_dirent(parent->d_fsdata, dentry, sl, mode,
- CONFIGFS_ITEM_LINK);
- if (!err) {
- err = configfs_create(dentry, mode, init_symlink);
- if (err) {
- struct configfs_dirent *sd = dentry->d_fsdata;
- if (sd) {
- spin_lock(&configfs_dirent_lock);
- list_del_init(&sd->s_sibling);
- spin_unlock(&configfs_dirent_lock);
- configfs_put(sd);
- }
- }
- }
- return err;
+ err = configfs_make_dirent(p, dentry, target, mode, CONFIGFS_ITEM_LINK,
+ p->s_frag);
+ if (err)
+ return err;
+
+ inode = configfs_create(dentry, mode);
+ if (IS_ERR(inode))
+ goto out_remove;
+
+ inode->i_link = body;
+ inode->i_op = &configfs_symlink_inode_operations;
+ d_instantiate(dentry, inode);
+ dget(dentry); /* pin link dentries in core */
+ return 0;
+
+out_remove:
+ configfs_remove_dirent(dentry);
+ return PTR_ERR(inode);
}
static void remove_dir(struct dentry * d)
{
struct dentry * parent = dget(d->d_parent);
- struct configfs_dirent * sd;
- sd = d->d_fsdata;
- spin_lock(&configfs_dirent_lock);
- list_del_init(&sd->s_sibling);
- spin_unlock(&configfs_dirent_lock);
- configfs_put(sd);
+ configfs_remove_dirent(d);
+
if (d_really_is_positive(d))
simple_rmdir(d_inode(parent),d);
@@ -406,20 +425,27 @@ static void configfs_remove_dir(struct config_item * item)
static int configfs_attach_attr(struct configfs_dirent * sd, struct dentry * dentry)
{
struct configfs_attribute * attr = sd->s_element;
- int error;
+ struct inode *inode;
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,
- (sd->s_type & CONFIGFS_ITEM_BIN_ATTR) ?
- configfs_init_bin_file :
- configfs_init_file);
- if (error)
+ inode = configfs_create(dentry, (attr->ca_mode & S_IALLUGO) | S_IFREG);
+ if (IS_ERR(inode)) {
configfs_put(sd);
- return error;
+ return PTR_ERR(inode);
+ }
+ if (sd->s_type & CONFIGFS_ITEM_BIN_ATTR) {
+ inode->i_size = 0;
+ inode->i_fop = &configfs_bin_file_operations;
+ } else {
+ inode->i_size = PAGE_SIZE;
+ inode->i_fop = &configfs_file_operations;
+ }
+ d_add(dentry, inode);
+ return 0;
}
static struct dentry * configfs_lookup(struct inode *dir,
@@ -489,7 +515,7 @@ static int configfs_detach_prep(struct dentry *dentry, struct dentry **wait)
parent_sd->s_type |= CONFIGFS_USET_DROPPING;
ret = -EBUSY;
- if (!list_empty(&parent_sd->s_links))
+ if (parent_sd->s_links)
goto out;
ret = 0;
@@ -599,7 +625,8 @@ static int populate_attrs(struct config_item *item)
static int configfs_attach_group(struct config_item *parent_item,
struct config_item *item,
- struct dentry *dentry);
+ struct dentry *dentry,
+ struct configfs_fragment *frag);
static void configfs_detach_group(struct config_item *item);
static void detach_groups(struct config_group *group)
@@ -647,7 +674,8 @@ static void detach_groups(struct config_group *group)
* try using vfs_mkdir. Just a thought.
*/
static int create_default_group(struct config_group *parent_group,
- struct config_group *group)
+ struct config_group *group,
+ struct configfs_fragment *frag)
{
int ret;
struct configfs_dirent *sd;
@@ -663,7 +691,7 @@ static int create_default_group(struct config_group *parent_group,
d_add(child, NULL);
ret = configfs_attach_group(&parent_group->cg_item,
- &group->cg_item, child);
+ &group->cg_item, child, frag);
if (!ret) {
sd = child->d_fsdata;
sd->s_type |= CONFIGFS_USET_DEFAULT;
@@ -677,13 +705,14 @@ static int create_default_group(struct config_group *parent_group,
return ret;
}
-static int populate_groups(struct config_group *group)
+static int populate_groups(struct config_group *group,
+ struct configfs_fragment *frag)
{
struct config_group *new_group;
int ret = 0;
list_for_each_entry(new_group, &group->default_groups, group_entry) {
- ret = create_default_group(group, new_group);
+ ret = create_default_group(group, new_group, frag);
if (ret) {
detach_groups(group);
break;
@@ -797,11 +826,12 @@ static void link_group(struct config_group *parent_group, struct config_group *g
*/
static int configfs_attach_item(struct config_item *parent_item,
struct config_item *item,
- struct dentry *dentry)
+ struct dentry *dentry,
+ struct configfs_fragment *frag)
{
int ret;
- ret = configfs_create_dir(item, dentry);
+ ret = configfs_create_dir(item, dentry, frag);
if (!ret) {
ret = populate_attrs(item);
if (ret) {
@@ -831,12 +861,13 @@ static void configfs_detach_item(struct config_item *item)
static int configfs_attach_group(struct config_item *parent_item,
struct config_item *item,
- struct dentry *dentry)
+ struct dentry *dentry,
+ struct configfs_fragment *frag)
{
int ret;
struct configfs_dirent *sd;
- ret = configfs_attach_item(parent_item, item, dentry);
+ ret = configfs_attach_item(parent_item, item, dentry, frag);
if (!ret) {
sd = dentry->d_fsdata;
sd->s_type |= CONFIGFS_USET_DIR;
@@ -852,7 +883,7 @@ static int configfs_attach_group(struct config_item *parent_item,
*/
inode_lock_nested(d_inode(dentry), I_MUTEX_CHILD);
configfs_adjust_dir_dirent_depth_before_populate(sd);
- ret = populate_groups(to_config_group(item));
+ ret = populate_groups(to_config_group(item), frag);
if (ret) {
configfs_detach_item(item);
d_inode(dentry)->i_flags |= S_DEAD;
@@ -1247,6 +1278,7 @@ static int configfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode
struct configfs_dirent *sd;
const struct config_item_type *type;
struct module *subsys_owner = NULL, *new_item_owner = NULL;
+ struct configfs_fragment *frag;
char *name;
sd = dentry->d_parent->d_fsdata;
@@ -1265,6 +1297,12 @@ static int configfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode
goto out;
}
+ frag = new_fragment();
+ if (!frag) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
/* Get a working ref for the duration of this function */
parent_item = configfs_get_config_item(dentry->d_parent);
type = parent_item->ci_type;
@@ -1367,9 +1405,9 @@ static int configfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode
spin_unlock(&configfs_dirent_lock);
if (group)
- ret = configfs_attach_group(parent_item, item, dentry);
+ ret = configfs_attach_group(parent_item, item, dentry, frag);
else
- ret = configfs_attach_item(parent_item, item, dentry);
+ ret = configfs_attach_item(parent_item, item, dentry, frag);
spin_lock(&configfs_dirent_lock);
sd->s_type &= ~CONFIGFS_USET_IN_MKDIR;
@@ -1406,6 +1444,7 @@ out_put:
* reference.
*/
config_item_put(parent_item);
+ put_fragment(frag);
out:
return ret;
@@ -1417,6 +1456,7 @@ static int configfs_rmdir(struct inode *dir, struct dentry *dentry)
struct config_item *item;
struct configfs_subsystem *subsys;
struct configfs_dirent *sd;
+ struct configfs_fragment *frag;
struct module *subsys_owner = NULL, *dead_item_owner = NULL;
int ret;
@@ -1474,6 +1514,16 @@ static int configfs_rmdir(struct inode *dir, struct dentry *dentry)
}
} while (ret == -EAGAIN);
+ frag = sd->s_frag;
+ if (down_write_killable(&frag->frag_sem)) {
+ spin_lock(&configfs_dirent_lock);
+ configfs_detach_rollback(dentry);
+ spin_unlock(&configfs_dirent_lock);
+ return -EINTR;
+ }
+ frag->frag_dead = true;
+ up_write(&frag->frag_sem);
+
/* Get a working ref for the duration of this function */
item = configfs_get_config_item(dentry);
@@ -1523,44 +1573,6 @@ const struct inode_operations configfs_root_inode_operations = {
.setattr = configfs_setattr,
};
-#if 0
-int configfs_rename_dir(struct config_item * item, const char *new_name)
-{
- int error = 0;
- struct dentry * new_dentry, * parent;
-
- if (!strcmp(config_item_name(item), new_name))
- return -EINVAL;
-
- if (!item->parent)
- return -EINVAL;
-
- down_write(&configfs_rename_sem);
- parent = item->parent->dentry;
-
- inode_lock(d_inode(parent));
-
- new_dentry = lookup_one_len(new_name, parent, strlen(new_name));
- if (!IS_ERR(new_dentry)) {
- if (d_really_is_negative(new_dentry)) {
- error = config_item_set_name(item, "%s", new_name);
- if (!error) {
- d_add(new_dentry, NULL);
- d_move(item->dentry, new_dentry);
- }
- else
- d_delete(new_dentry);
- } else
- error = -EEXIST;
- dput(new_dentry);
- }
- inode_unlock(d_inode(parent));
- up_write(&configfs_rename_sem);
-
- return error;
-}
-#endif
-
static int configfs_dir_open(struct inode *inode, struct file *file)
{
struct dentry * dentry = file->f_path.dentry;
@@ -1574,7 +1586,7 @@ static int configfs_dir_open(struct inode *inode, struct file *file)
*/
err = -ENOENT;
if (configfs_dirent_is_ready(parent_sd)) {
- file->private_data = configfs_new_dirent(parent_sd, NULL, 0);
+ file->private_data = configfs_new_dirent(parent_sd, NULL, 0, NULL);
if (IS_ERR(file->private_data))
err = PTR_ERR(file->private_data);
else
@@ -1732,8 +1744,13 @@ int configfs_register_group(struct config_group *parent_group,
{
struct configfs_subsystem *subsys = parent_group->cg_subsys;
struct dentry *parent;
+ struct configfs_fragment *frag;
int ret;
+ frag = new_fragment();
+ if (!frag)
+ return -ENOMEM;
+
mutex_lock(&subsys->su_mutex);
link_group(parent_group, group);
mutex_unlock(&subsys->su_mutex);
@@ -1741,7 +1758,7 @@ int configfs_register_group(struct config_group *parent_group,
parent = parent_group->cg_item.ci_dentry;
inode_lock_nested(d_inode(parent), I_MUTEX_PARENT);
- ret = create_default_group(parent_group, group);
+ ret = create_default_group(parent_group, group, frag);
if (ret)
goto err_out;
@@ -1749,12 +1766,14 @@ int configfs_register_group(struct config_group *parent_group,
configfs_dir_set_ready(group->cg_item.ci_dentry->d_fsdata);
spin_unlock(&configfs_dirent_lock);
inode_unlock(d_inode(parent));
+ put_fragment(frag);
return 0;
err_out:
inode_unlock(d_inode(parent));
mutex_lock(&subsys->su_mutex);
unlink_group(group);
mutex_unlock(&subsys->su_mutex);
+ put_fragment(frag);
return ret;
}
EXPORT_SYMBOL(configfs_register_group);
@@ -1770,16 +1789,12 @@ void configfs_unregister_group(struct config_group *group)
struct configfs_subsystem *subsys = group->cg_subsys;
struct dentry *dentry = group->cg_item.ci_dentry;
struct dentry *parent = group->cg_item.ci_parent->ci_dentry;
+ struct configfs_dirent *sd = dentry->d_fsdata;
+ struct configfs_fragment *frag = sd->s_frag;
- mutex_lock(&subsys->su_mutex);
- if (!group->cg_item.ci_parent->ci_group) {
- /*
- * The parent has already been unlinked and detached
- * due to a rmdir.
- */
- goto unlink_group;
- }
- mutex_unlock(&subsys->su_mutex);
+ down_write(&frag->frag_sem);
+ frag->frag_dead = true;
+ up_write(&frag->frag_sem);
inode_lock_nested(d_inode(parent), I_MUTEX_PARENT);
spin_lock(&configfs_dirent_lock);
@@ -1796,7 +1811,6 @@ void configfs_unregister_group(struct config_group *group)
dput(dentry);
mutex_lock(&subsys->su_mutex);
-unlink_group:
unlink_group(group);
mutex_unlock(&subsys->su_mutex);
}
@@ -1853,10 +1867,17 @@ int configfs_register_subsystem(struct configfs_subsystem *subsys)
struct dentry *dentry;
struct dentry *root;
struct configfs_dirent *sd;
+ struct configfs_fragment *frag;
+
+ frag = new_fragment();
+ if (!frag)
+ return -ENOMEM;
root = configfs_pin_fs();
- if (IS_ERR(root))
+ if (IS_ERR(root)) {
+ put_fragment(frag);
return PTR_ERR(root);
+ }
if (!group->cg_item.ci_name)
group->cg_item.ci_name = group->cg_item.ci_namebuf;
@@ -1872,7 +1893,7 @@ int configfs_register_subsystem(struct configfs_subsystem *subsys)
d_add(dentry, NULL);
err = configfs_attach_group(sd->s_element, &group->cg_item,
- dentry);
+ dentry, frag);
if (err) {
BUG_ON(d_inode(dentry));
d_drop(dentry);
@@ -1890,6 +1911,7 @@ int configfs_register_subsystem(struct configfs_subsystem *subsys)
unlink_group(group);
configfs_release_fs();
}
+ put_fragment(frag);
return err;
}
@@ -1899,12 +1921,18 @@ 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;
+ struct configfs_dirent *sd = dentry->d_fsdata;
+ struct configfs_fragment *frag = sd->s_frag;
if (dentry->d_parent != root) {
pr_err("Tried to unregister non-subsystem!\n");
return;
}
+ down_write(&frag->frag_sem);
+ frag->frag_dead = true;
+ up_write(&frag->frag_sem);
+
inode_lock_nested(d_inode(root),
I_MUTEX_PARENT);
inode_lock_nested(d_inode(dentry), I_MUTEX_CHILD);