* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mfasheh/ocfs2:
[PATCH] ocfs2: Release mutex in error handling code
[PATCH] ocfs2: Fix oops when racing files truncates with writes into an mmap region
[PATCH 2/2] ocfs2: Fix race between mount and recovery
[PATCH 1/2] ocfs2: Add counter in struct ocfs2_dinode to track journal replays
[PATCH] configfs: Convenience macros for attribute definition.
[PATCH] configfs: Pin configfs subsystems separately from new config_items.
[PATCH] configfs: Fix open directory making rmdir() fail
[PATCH] configfs: Lock new directory inodes before removing on cleanup after failure
[PATCH] configfs: Prevent userspace from creating new entries under attaching directories
[PATCH] configfs: Fix failing symlink() making rmdir() fail
[PATCH] configfs: Fix symlink() to a removing item
[PATCH] configfs: Include linux/err.h in linux/configfs.h
[An Example]
The best example of these basic concepts is the simple_children
-subsystem/group and the simple_child item in configfs_example.c It
-shows a trivial object displaying and storing an attribute, and a simple
-group creating and destroying these children.
+subsystem/group and the simple_child item in configfs_example_explicit.c
+and configfs_example_macros.c. It shows a trivial object displaying and
+storing an attribute, and a simple group creating and destroying these
+children.
+
+The only difference between configfs_example_explicit.c and
+configfs_example_macros.c is how the attributes of the childless item
+are defined. The childless item has extended attributes, each with
+their own show()/store() operation. This follows a convention commonly
+used in sysfs. configfs_example_explicit.c creates these attributes
+by explicitly defining the structures involved. Conversely
+configfs_example_macros.c uses some convenience macros from configfs.h
+to define the attributes. These macros are similar to their sysfs
+counterparts.
[Hierarchy Navigation and the Subsystem Mutex]
/*
* vim: noexpandtab ts=8 sts=0 sw=8:
*
- * configfs_example.c - This file is a demonstration module containing
- * a number of configfs subsystems.
+ * configfs_example_explicit.c - This file is a demonstration module
+ * containing a number of configfs subsystems. It explicitly defines
+ * each structure without using the helper macros defined in
+ * configfs.h.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
if (!simple_child)
return ERR_PTR(-ENOMEM);
-
config_item_init_type_name(&simple_child->item, name,
&simple_child_type);
};
static ssize_t simple_children_attr_show(struct config_item *item,
- struct configfs_attribute *attr,
- char *page)
+ struct configfs_attribute *attr,
+ char *page)
{
return sprintf(page,
"[02-simple-children]\n"
}
static struct configfs_item_operations simple_children_item_ops = {
- .release = simple_children_release,
+ .release = simple_children_release,
.show_attribute = simple_children_attr_show,
};
if (!simple_children)
return ERR_PTR(-ENOMEM);
-
config_group_init_type_name(&simple_children->group, name,
&simple_children_type);
};
static ssize_t group_children_attr_show(struct config_item *item,
- struct configfs_attribute *attr,
- char *page)
+ struct configfs_attribute *attr,
+ char *page)
{
return sprintf(page,
"[03-group-children]\n"
--- /dev/null
+/*
+ * vim: noexpandtab ts=8 sts=0 sw=8:
+ *
+ * configfs_example_macros.c - This file is a demonstration module
+ * containing a number of configfs subsystems. It uses the helper
+ * macros defined by configfs.h
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ *
+ * Based on sysfs:
+ * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
+ *
+ * configfs Copyright (C) 2005 Oracle. All rights reserved.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include <linux/configfs.h>
+
+
+
+/*
+ * 01-childless
+ *
+ * This first example is a childless subsystem. It cannot create
+ * any config_items. It just has attributes.
+ *
+ * Note that we are enclosing the configfs_subsystem inside a container.
+ * This is not necessary if a subsystem has no attributes directly
+ * on the subsystem. See the next example, 02-simple-children, for
+ * such a subsystem.
+ */
+
+struct childless {
+ struct configfs_subsystem subsys;
+ int showme;
+ int storeme;
+};
+
+static inline struct childless *to_childless(struct config_item *item)
+{
+ return item ? container_of(to_configfs_subsystem(to_config_group(item)), struct childless, subsys) : NULL;
+}
+
+CONFIGFS_ATTR_STRUCT(childless);
+#define CHILDLESS_ATTR(_name, _mode, _show, _store) \
+struct childless_attribute childless_attr_##_name = __CONFIGFS_ATTR(_name, _mode, _show, _store)
+#define CHILDLESS_ATTR_RO(_name, _show) \
+struct childless_attribute childless_attr_##_name = __CONFIGFS_ATTR_RO(_name, _show);
+
+static ssize_t childless_showme_read(struct childless *childless,
+ char *page)
+{
+ ssize_t pos;
+
+ pos = sprintf(page, "%d\n", childless->showme);
+ childless->showme++;
+
+ return pos;
+}
+
+static ssize_t childless_storeme_read(struct childless *childless,
+ char *page)
+{
+ return sprintf(page, "%d\n", childless->storeme);
+}
+
+static ssize_t childless_storeme_write(struct childless *childless,
+ const char *page,
+ size_t count)
+{
+ unsigned long tmp;
+ char *p = (char *) page;
+
+ tmp = simple_strtoul(p, &p, 10);
+ if (!p || (*p && (*p != '\n')))
+ return -EINVAL;
+
+ if (tmp > INT_MAX)
+ return -ERANGE;
+
+ childless->storeme = tmp;
+
+ return count;
+}
+
+static ssize_t childless_description_read(struct childless *childless,
+ char *page)
+{
+ return sprintf(page,
+"[01-childless]\n"
+"\n"
+"The childless subsystem is the simplest possible subsystem in\n"
+"configfs. It does not support the creation of child config_items.\n"
+"It only has a few attributes. In fact, it isn't much different\n"
+"than a directory in /proc.\n");
+}
+
+CHILDLESS_ATTR_RO(showme, childless_showme_read);
+CHILDLESS_ATTR(storeme, S_IRUGO | S_IWUSR, childless_storeme_read,
+ childless_storeme_write);
+CHILDLESS_ATTR_RO(description, childless_description_read);
+
+static struct configfs_attribute *childless_attrs[] = {
+ &childless_attr_showme.attr,
+ &childless_attr_storeme.attr,
+ &childless_attr_description.attr,
+ NULL,
+};
+
+CONFIGFS_ATTR_OPS(childless);
+static struct configfs_item_operations childless_item_ops = {
+ .show_attribute = childless_attr_show,
+ .store_attribute = childless_attr_store,
+};
+
+static struct config_item_type childless_type = {
+ .ct_item_ops = &childless_item_ops,
+ .ct_attrs = childless_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
+static struct childless childless_subsys = {
+ .subsys = {
+ .su_group = {
+ .cg_item = {
+ .ci_namebuf = "01-childless",
+ .ci_type = &childless_type,
+ },
+ },
+ },
+};
+
+
+/* ----------------------------------------------------------------- */
+
+/*
+ * 02-simple-children
+ *
+ * This example merely has a simple one-attribute child. Note that
+ * there is no extra attribute structure, as the child's attribute is
+ * known from the get-go. Also, there is no container for the
+ * subsystem, as it has no attributes of its own.
+ */
+
+struct simple_child {
+ struct config_item item;
+ int storeme;
+};
+
+static inline struct simple_child *to_simple_child(struct config_item *item)
+{
+ return item ? container_of(item, struct simple_child, item) : NULL;
+}
+
+static struct configfs_attribute simple_child_attr_storeme = {
+ .ca_owner = THIS_MODULE,
+ .ca_name = "storeme",
+ .ca_mode = S_IRUGO | S_IWUSR,
+};
+
+static struct configfs_attribute *simple_child_attrs[] = {
+ &simple_child_attr_storeme,
+ NULL,
+};
+
+static ssize_t simple_child_attr_show(struct config_item *item,
+ struct configfs_attribute *attr,
+ char *page)
+{
+ ssize_t count;
+ struct simple_child *simple_child = to_simple_child(item);
+
+ count = sprintf(page, "%d\n", simple_child->storeme);
+
+ return count;
+}
+
+static ssize_t simple_child_attr_store(struct config_item *item,
+ struct configfs_attribute *attr,
+ const char *page, size_t count)
+{
+ struct simple_child *simple_child = to_simple_child(item);
+ unsigned long tmp;
+ char *p = (char *) page;
+
+ tmp = simple_strtoul(p, &p, 10);
+ if (!p || (*p && (*p != '\n')))
+ return -EINVAL;
+
+ if (tmp > INT_MAX)
+ return -ERANGE;
+
+ simple_child->storeme = tmp;
+
+ return count;
+}
+
+static void simple_child_release(struct config_item *item)
+{
+ kfree(to_simple_child(item));
+}
+
+static struct configfs_item_operations simple_child_item_ops = {
+ .release = simple_child_release,
+ .show_attribute = simple_child_attr_show,
+ .store_attribute = simple_child_attr_store,
+};
+
+static struct config_item_type simple_child_type = {
+ .ct_item_ops = &simple_child_item_ops,
+ .ct_attrs = simple_child_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
+
+struct simple_children {
+ struct config_group group;
+};
+
+static inline struct simple_children *to_simple_children(struct config_item *item)
+{
+ return item ? container_of(to_config_group(item), struct simple_children, group) : NULL;
+}
+
+static struct config_item *simple_children_make_item(struct config_group *group, const char *name)
+{
+ struct simple_child *simple_child;
+
+ simple_child = kzalloc(sizeof(struct simple_child), GFP_KERNEL);
+ if (!simple_child)
+ return ERR_PTR(-ENOMEM);
+
+ config_item_init_type_name(&simple_child->item, name,
+ &simple_child_type);
+
+ simple_child->storeme = 0;
+
+ return &simple_child->item;
+}
+
+static struct configfs_attribute simple_children_attr_description = {
+ .ca_owner = THIS_MODULE,
+ .ca_name = "description",
+ .ca_mode = S_IRUGO,
+};
+
+static struct configfs_attribute *simple_children_attrs[] = {
+ &simple_children_attr_description,
+ NULL,
+};
+
+static ssize_t simple_children_attr_show(struct config_item *item,
+ struct configfs_attribute *attr,
+ char *page)
+{
+ return sprintf(page,
+"[02-simple-children]\n"
+"\n"
+"This subsystem allows the creation of child config_items. These\n"
+"items have only one attribute that is readable and writeable.\n");
+}
+
+static void simple_children_release(struct config_item *item)
+{
+ kfree(to_simple_children(item));
+}
+
+static struct configfs_item_operations simple_children_item_ops = {
+ .release = simple_children_release,
+ .show_attribute = simple_children_attr_show,
+};
+
+/*
+ * Note that, since no extra work is required on ->drop_item(),
+ * no ->drop_item() is provided.
+ */
+static struct configfs_group_operations simple_children_group_ops = {
+ .make_item = simple_children_make_item,
+};
+
+static struct config_item_type simple_children_type = {
+ .ct_item_ops = &simple_children_item_ops,
+ .ct_group_ops = &simple_children_group_ops,
+ .ct_attrs = simple_children_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
+static struct configfs_subsystem simple_children_subsys = {
+ .su_group = {
+ .cg_item = {
+ .ci_namebuf = "02-simple-children",
+ .ci_type = &simple_children_type,
+ },
+ },
+};
+
+
+/* ----------------------------------------------------------------- */
+
+/*
+ * 03-group-children
+ *
+ * This example reuses the simple_children group from above. However,
+ * the simple_children group is not the subsystem itself, it is a
+ * child of the subsystem. Creation of a group in the subsystem creates
+ * a new simple_children group. That group can then have simple_child
+ * children of its own.
+ */
+
+static struct config_group *group_children_make_group(struct config_group *group, const char *name)
+{
+ struct simple_children *simple_children;
+
+ simple_children = kzalloc(sizeof(struct simple_children),
+ GFP_KERNEL);
+ if (!simple_children)
+ return ERR_PTR(-ENOMEM);
+
+ config_group_init_type_name(&simple_children->group, name,
+ &simple_children_type);
+
+ return &simple_children->group;
+}
+
+static struct configfs_attribute group_children_attr_description = {
+ .ca_owner = THIS_MODULE,
+ .ca_name = "description",
+ .ca_mode = S_IRUGO,
+};
+
+static struct configfs_attribute *group_children_attrs[] = {
+ &group_children_attr_description,
+ NULL,
+};
+
+static ssize_t group_children_attr_show(struct config_item *item,
+ struct configfs_attribute *attr,
+ char *page)
+{
+ return sprintf(page,
+"[03-group-children]\n"
+"\n"
+"This subsystem allows the creation of child config_groups. These\n"
+"groups are like the subsystem simple-children.\n");
+}
+
+static struct configfs_item_operations group_children_item_ops = {
+ .show_attribute = group_children_attr_show,
+};
+
+/*
+ * Note that, since no extra work is required on ->drop_item(),
+ * no ->drop_item() is provided.
+ */
+static struct configfs_group_operations group_children_group_ops = {
+ .make_group = group_children_make_group,
+};
+
+static struct config_item_type group_children_type = {
+ .ct_item_ops = &group_children_item_ops,
+ .ct_group_ops = &group_children_group_ops,
+ .ct_attrs = group_children_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
+static struct configfs_subsystem group_children_subsys = {
+ .su_group = {
+ .cg_item = {
+ .ci_namebuf = "03-group-children",
+ .ci_type = &group_children_type,
+ },
+ },
+};
+
+/* ----------------------------------------------------------------- */
+
+/*
+ * We're now done with our subsystem definitions.
+ * For convenience in this module, here's a list of them all. It
+ * allows the init function to easily register them. Most modules
+ * will only have one subsystem, and will only call register_subsystem
+ * on it directly.
+ */
+static struct configfs_subsystem *example_subsys[] = {
+ &childless_subsys.subsys,
+ &simple_children_subsys,
+ &group_children_subsys,
+ NULL,
+};
+
+static int __init configfs_example_init(void)
+{
+ int ret;
+ int i;
+ struct configfs_subsystem *subsys;
+
+ for (i = 0; example_subsys[i]; i++) {
+ subsys = example_subsys[i];
+
+ config_group_init(&subsys->su_group);
+ mutex_init(&subsys->su_mutex);
+ ret = configfs_register_subsystem(subsys);
+ if (ret) {
+ printk(KERN_ERR "Error %d while registering subsystem %s\n",
+ ret,
+ subsys->su_group.cg_item.ci_namebuf);
+ goto out_unregister;
+ }
+ }
+
+ return 0;
+
+out_unregister:
+ for (; i >= 0; i--) {
+ configfs_unregister_subsystem(example_subsys[i]);
+ }
+
+ return ret;
+}
+
+static void __exit configfs_example_exit(void)
+{
+ int i;
+
+ for (i = 0; example_subsys[i]; i++) {
+ configfs_unregister_subsystem(example_subsys[i]);
+ }
+}
+
+module_init(configfs_example_init);
+module_exit(configfs_example_exit);
+MODULE_LICENSE("GPL");
#define CONFIGFS_USET_DEFAULT 0x0080
#define CONFIGFS_USET_DROPPING 0x0100
#define CONFIGFS_USET_IN_MKDIR 0x0200
+#define CONFIGFS_USET_CREATING 0x0400
#define CONFIGFS_NOT_PINNED (CONFIGFS_ITEM_ATTR)
+extern struct mutex configfs_symlink_mutex;
extern spinlock_t configfs_dirent_lock;
extern struct vfsmount * configfs_mount;
extern int configfs_create_file(struct config_item *, const struct configfs_attribute *);
extern int configfs_make_dirent(struct configfs_dirent *,
struct dentry *, void *, umode_t, int);
+extern int configfs_dirent_is_ready(struct configfs_dirent *);
extern int configfs_add_file(struct dentry *, const struct configfs_attribute *, int);
extern void configfs_hash_and_remove(struct dentry * dir, const char * name);
error = configfs_dirent_exists(p->d_fsdata, d->d_name.name);
if (!error)
error = configfs_make_dirent(p->d_fsdata, d, k, mode,
- CONFIGFS_DIR);
+ CONFIGFS_DIR | CONFIGFS_USET_CREATING);
if (!error) {
error = configfs_create(d, mode, init_dir);
if (!error) {
* configfs_create_dir - create a directory for an config_item.
* @item: config_itemwe're creating directory for.
* @dentry: config_item's dentry.
+ *
+ * Note: user-created entries won't be allowed under this new directory
+ * until it is validated by configfs_dir_set_ready()
*/
static int configfs_create_dir(struct config_item * item, struct dentry *dentry)
return error;
}
+/*
+ * Allow userspace to create new entries under a new directory created with
+ * configfs_create_dir(), and under all of its chidlren directories recursively.
+ * @sd configfs_dirent of the new directory to validate
+ *
+ * Caller must hold configfs_dirent_lock.
+ */
+static void configfs_dir_set_ready(struct configfs_dirent *sd)
+{
+ struct configfs_dirent *child_sd;
+
+ sd->s_type &= ~CONFIGFS_USET_CREATING;
+ list_for_each_entry(child_sd, &sd->s_children, s_sibling)
+ if (child_sd->s_type & CONFIGFS_USET_CREATING)
+ configfs_dir_set_ready(child_sd);
+}
+
+/*
+ * Check that a directory does not belong to a directory hierarchy being
+ * attached and not validated yet.
+ * @sd configfs_dirent of the directory to check
+ *
+ * @return non-zero iff the directory was validated
+ *
+ * Note: takes configfs_dirent_lock, so the result may change from false to true
+ * in two consecutive calls, but never from true to false.
+ */
+int configfs_dirent_is_ready(struct configfs_dirent *sd)
+{
+ int ret;
+
+ spin_lock(&configfs_dirent_lock);
+ ret = !(sd->s_type & CONFIGFS_USET_CREATING);
+ spin_unlock(&configfs_dirent_lock);
+
+ return ret;
+}
+
int configfs_create_link(struct configfs_symlink *sl,
struct dentry *parent,
struct dentry *dentry)
* 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 configfs_rmdir() below, instead of calling separately.
+ *
+ * Caller holds the mutex of the item's inode
*/
static void configfs_remove_dir(struct config_item * item)
struct configfs_dirent * parent_sd = dentry->d_parent->d_fsdata;
struct configfs_dirent * sd;
int found = 0;
- int err = 0;
+ int err;
+
+ /*
+ * Fake invisibility if dir belongs to a group/default groups hierarchy
+ * being attached
+ *
+ * This forbids userspace to read/write attributes of items which may
+ * not complete their initialization, since the dentries of the
+ * attributes won't be instantiated.
+ */
+ err = -ENOENT;
+ if (!configfs_dirent_is_ready(parent_sd))
+ goto out;
list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
if (sd->s_type & CONFIGFS_NOT_PINNED) {
return simple_lookup(dir, dentry, nd);
}
+out:
return ERR_PTR(err);
}
struct configfs_dirent *sd;
int ret;
+ /* Mark that we're trying to drop the group */
+ parent_sd->s_type |= CONFIGFS_USET_DROPPING;
+
ret = -EBUSY;
if (!list_empty(&parent_sd->s_links))
goto out;
ret = 0;
list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
- if (sd->s_type & CONFIGFS_NOT_PINNED)
+ if (!sd->s_element ||
+ (sd->s_type & CONFIGFS_NOT_PINNED))
continue;
if (sd->s_type & CONFIGFS_USET_DEFAULT) {
/* Abort if racing with mkdir() */
*wait_mutex = &sd->s_dentry->d_inode->i_mutex;
return -EAGAIN;
}
- /* Mark that we're trying to drop the group */
- sd->s_type |= CONFIGFS_USET_DROPPING;
/*
* Yup, recursive. If there's a problem, blame
struct configfs_dirent *parent_sd = dentry->d_fsdata;
struct configfs_dirent *sd;
- list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
- if (sd->s_type & CONFIGFS_USET_DEFAULT) {
+ parent_sd->s_type &= ~CONFIGFS_USET_DROPPING;
+
+ list_for_each_entry(sd, &parent_sd->s_children, s_sibling)
+ if (sd->s_type & CONFIGFS_USET_DEFAULT)
configfs_detach_rollback(sd->s_dentry);
- sd->s_type &= ~CONFIGFS_USET_DROPPING;
- }
- }
}
static void detach_attrs(struct config_item * item)
static int populate_groups(struct config_group *group)
{
struct config_group *new_group;
- struct dentry *dentry = group->cg_item.ci_dentry;
int ret = 0;
int i;
if (group->default_groups) {
- /*
- * FYI, we're faking mkdir here
- * I'm not sure we need this semaphore, as we're called
- * from our parent's mkdir. That holds our parent's
- * i_mutex, so afaik lookup cannot continue through our
- * parent to find us, let alone mess with our tree.
- * That said, taking our i_mutex is closer to mkdir
- * emulation, and shouldn't hurt.
- */
- mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD);
-
for (i = 0; group->default_groups[i]; i++) {
new_group = group->default_groups[i];
ret = create_default_group(group, new_group);
- if (ret)
+ if (ret) {
+ detach_groups(group);
break;
+ }
}
-
- mutex_unlock(&dentry->d_inode->i_mutex);
}
- if (ret)
- detach_groups(group);
-
return ret;
}
if (!ret) {
ret = populate_attrs(item);
if (ret) {
+ /*
+ * We are going to remove an inode and its dentry but
+ * the VFS may already have hit and used them. Thus,
+ * we must lock them as rmdir() would.
+ */
+ mutex_lock(&dentry->d_inode->i_mutex);
configfs_remove_dir(item);
+ dentry->d_inode->i_flags |= S_DEAD;
+ mutex_unlock(&dentry->d_inode->i_mutex);
d_delete(dentry);
}
}
return ret;
}
+/* Caller holds the mutex of the item's inode */
static void configfs_detach_item(struct config_item *item)
{
detach_attrs(item);
sd = dentry->d_fsdata;
sd->s_type |= CONFIGFS_USET_DIR;
+ /*
+ * FYI, we're faking mkdir in populate_groups()
+ * We must lock the group's inode to avoid races with the VFS
+ * which can already hit the inode and try to add/remove entries
+ * under it.
+ *
+ * We must also lock the inode to remove it safely in case of
+ * error, as rmdir() would.
+ */
+ mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD);
ret = populate_groups(to_config_group(item));
if (ret) {
configfs_detach_item(item);
- d_delete(dentry);
+ dentry->d_inode->i_flags |= S_DEAD;
}
+ mutex_unlock(&dentry->d_inode->i_mutex);
+ if (ret)
+ d_delete(dentry);
}
return ret;
}
+/* Caller holds the mutex of the group's inode */
static void configfs_detach_group(struct config_item *item)
{
detach_groups(to_config_group(item));
struct configfs_subsystem *subsys;
struct configfs_dirent *sd;
struct config_item_type *type;
- struct module *owner = NULL;
+ struct module *subsys_owner = NULL, *new_item_owner = NULL;
char *name;
if (dentry->d_parent == configfs_sb->s_root) {
}
sd = dentry->d_parent->d_fsdata;
+
+ /*
+ * Fake invisibility if dir belongs to a group/default groups hierarchy
+ * being attached
+ */
+ if (!configfs_dirent_is_ready(sd)) {
+ ret = -ENOENT;
+ goto out;
+ }
+
if (!(sd->s_type & CONFIGFS_USET_DIR)) {
ret = -EPERM;
goto out;
goto out_put;
}
+ /*
+ * The subsystem may belong to a different module than the item
+ * being created. We don't want to safely pin the new item but
+ * fail to pin the subsystem it sits under.
+ */
+ if (!subsys->su_group.cg_item.ci_type) {
+ ret = -EINVAL;
+ goto out_put;
+ }
+ subsys_owner = subsys->su_group.cg_item.ci_type->ct_owner;
+ if (!try_module_get(subsys_owner)) {
+ ret = -EINVAL;
+ goto out_put;
+ }
+
name = kmalloc(dentry->d_name.len + 1, GFP_KERNEL);
if (!name) {
ret = -ENOMEM;
- goto out_put;
+ goto out_subsys_put;
}
snprintf(name, dentry->d_name.len + 1, "%s", dentry->d_name.name);
kfree(name);
if (ret) {
/*
- * If item == NULL, then link_obj() was never called.
+ * If ret != 0, then link_obj() was never called.
* There are no extra references to clean up.
*/
- goto out_put;
+ goto out_subsys_put;
}
/*
goto out_unlink;
}
- owner = type->ct_owner;
- if (!try_module_get(owner)) {
+ new_item_owner = type->ct_owner;
+ if (!try_module_get(new_item_owner)) {
ret = -EINVAL;
goto out_unlink;
}
spin_lock(&configfs_dirent_lock);
sd->s_type &= ~CONFIGFS_USET_IN_MKDIR;
+ if (!ret)
+ configfs_dir_set_ready(dentry->d_fsdata);
spin_unlock(&configfs_dirent_lock);
out_unlink:
mutex_unlock(&subsys->su_mutex);
if (module_got)
- module_put(owner);
+ module_put(new_item_owner);
}
+out_subsys_put:
+ if (ret)
+ module_put(subsys_owner);
+
out_put:
/*
* link_obj()/link_group() took a reference from child->parent,
struct config_item *item;
struct configfs_subsystem *subsys;
struct configfs_dirent *sd;
- struct module *owner = NULL;
+ struct module *subsys_owner = NULL, *dead_item_owner = NULL;
int ret;
if (dentry->d_parent == configfs_sb->s_root)
return -EINVAL;
}
+ /* configfs_mkdir() shouldn't have allowed this */
+ BUG_ON(!subsys->su_group.cg_item.ci_type);
+ subsys_owner = subsys->su_group.cg_item.ci_type->ct_owner;
+
+ /*
+ * Ensure that no racing symlink() will make detach_prep() fail while
+ * the new link is temporarily attached
+ */
+ mutex_lock(&configfs_symlink_mutex);
spin_lock(&configfs_dirent_lock);
do {
struct mutex *wait_mutex;
if (ret) {
configfs_detach_rollback(dentry);
spin_unlock(&configfs_dirent_lock);
+ mutex_unlock(&configfs_symlink_mutex);
if (ret != -EAGAIN) {
config_item_put(parent_item);
return ret;
mutex_lock(wait_mutex);
mutex_unlock(wait_mutex);
+ mutex_lock(&configfs_symlink_mutex);
spin_lock(&configfs_dirent_lock);
}
} while (ret == -EAGAIN);
spin_unlock(&configfs_dirent_lock);
+ mutex_unlock(&configfs_symlink_mutex);
/* Get a working ref for the duration of this function */
item = configfs_get_config_item(dentry);
config_item_put(parent_item);
if (item->ci_type)
- owner = item->ci_type->ct_owner;
+ dead_item_owner = item->ci_type->ct_owner;
if (sd->s_type & CONFIGFS_USET_DIR) {
configfs_detach_group(item);
/* Drop our reference from above */
config_item_put(item);
- module_put(owner);
+ module_put(dead_item_owner);
+ module_put(subsys_owner);
return 0;
}
{
struct dentry * dentry = file->f_path.dentry;
struct configfs_dirent * parent_sd = dentry->d_fsdata;
+ int err;
mutex_lock(&dentry->d_inode->i_mutex);
- file->private_data = configfs_new_dirent(parent_sd, NULL);
+ /*
+ * Fake invisibility if dir belongs to a group/default groups hierarchy
+ * being attached
+ */
+ err = -ENOENT;
+ if (configfs_dirent_is_ready(parent_sd)) {
+ file->private_data = configfs_new_dirent(parent_sd, NULL);
+ if (IS_ERR(file->private_data))
+ err = PTR_ERR(file->private_data);
+ else
+ err = 0;
+ }
mutex_unlock(&dentry->d_inode->i_mutex);
- return IS_ERR(file->private_data) ? PTR_ERR(file->private_data) : 0;
-
+ return err;
}
static int configfs_dir_close(struct inode *inode, struct file *file)
if (err) {
d_delete(dentry);
dput(dentry);
+ } else {
+ spin_lock(&configfs_dirent_lock);
+ configfs_dir_set_ready(dentry->d_fsdata);
+ spin_unlock(&configfs_dirent_lock);
}
}
mutex_lock_nested(&configfs_sb->s_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");
}
spin_unlock(&configfs_dirent_lock);
+ mutex_unlock(&configfs_symlink_mutex);
configfs_detach_group(&group->cg_item);
dentry->d_inode->i_flags |= S_DEAD;
mutex_unlock(&dentry->d_inode->i_mutex);
#include <linux/configfs.h>
#include "configfs_internal.h"
+/* Protects attachments of new symlinks */
+DEFINE_MUTEX(configfs_symlink_mutex);
+
static int item_depth(struct config_item * item)
{
struct config_item * p = item;
struct configfs_symlink *sl;
int ret;
+ ret = -ENOENT;
+ if (!configfs_dirent_is_ready(target_sd))
+ goto out;
ret = -ENOMEM;
sl = kmalloc(sizeof(struct configfs_symlink), GFP_KERNEL);
if (sl) {
sl->sl_target = config_item_get(item);
spin_lock(&configfs_dirent_lock);
+ if (target_sd->s_type & CONFIGFS_USET_DROPPING) {
+ spin_unlock(&configfs_dirent_lock);
+ config_item_put(item);
+ kfree(sl);
+ return -ENOENT;
+ }
list_add(&sl->sl_list, &target_sd->s_links);
spin_unlock(&configfs_dirent_lock);
ret = configfs_create_link(sl, parent_item->ci_dentry,
}
}
+out:
return ret;
}
{
int ret;
struct nameidata nd;
+ struct configfs_dirent *sd;
struct config_item *parent_item;
struct config_item *target_item;
struct config_item_type *type;
if (dentry->d_parent == configfs_sb->s_root)
goto out;
+ sd = dentry->d_parent->d_fsdata;
+ /*
+ * Fake invisibility if dir belongs to a group/default groups hierarchy
+ * being attached
+ */
+ ret = -ENOENT;
+ if (!configfs_dirent_is_ready(sd))
+ goto out;
+
parent_item = configfs_get_config_item(dentry->d_parent);
type = parent_item->ci_type;
+ ret = -EPERM;
if (!type || !type->ct_item_ops ||
!type->ct_item_ops->allow_link)
goto out_put;
ret = type->ct_item_ops->allow_link(parent_item, target_item);
if (!ret) {
+ mutex_lock(&configfs_symlink_mutex);
ret = create_link(parent_item, target_item, dentry);
+ mutex_unlock(&configfs_symlink_mutex);
if (ret && type->ct_item_ops->drop_link)
type->ct_item_ops->drop_link(parent_item,
target_item);
for(i = 0; i < wc->w_num_pages; i++) {
tmppage = wc->w_pages[i];
- if (ocfs2_should_order_data(inode))
- walk_page_buffers(wc->w_handle, page_buffers(tmppage),
- from, to, NULL,
- ocfs2_journal_dirty_data);
-
- block_commit_write(tmppage, from, to);
+ if (page_has_buffers(tmppage)) {
+ if (ocfs2_should_order_data(inode))
+ walk_page_buffers(wc->w_handle,
+ page_buffers(tmppage),
+ from, to, NULL,
+ ocfs2_journal_dirty_data);
+
+ block_commit_write(tmppage, from, to);
+ }
}
}
to = PAGE_CACHE_SIZE;
}
- if (ocfs2_should_order_data(inode))
- walk_page_buffers(wc->w_handle, page_buffers(tmppage),
- from, to, NULL,
- ocfs2_journal_dirty_data);
-
- block_commit_write(tmppage, from, to);
+ if (page_has_buffers(tmppage)) {
+ if (ocfs2_should_order_data(inode))
+ walk_page_buffers(wc->w_handle,
+ page_buffers(tmppage),
+ from, to, NULL,
+ ocfs2_journal_dirty_data);
+ block_commit_write(tmppage, from, to);
+ }
}
out_write_size:
out_rw_unlock:
ocfs2_rw_unlock(inode, 1);
- mutex_unlock(&inode->i_mutex);
out:
+ mutex_unlock(&inode->i_mutex);
return ret;
}
static int ocfs2_commit_cache(struct ocfs2_super *osb);
static int ocfs2_wait_on_mount(struct ocfs2_super *osb);
static int ocfs2_journal_toggle_dirty(struct ocfs2_super *osb,
- int dirty);
+ int dirty, int replayed);
static int ocfs2_trylock_journal(struct ocfs2_super *osb,
int slot_num);
static int ocfs2_recover_orphans(struct ocfs2_super *osb,
return status;
}
+static void ocfs2_bump_recovery_generation(struct ocfs2_dinode *di)
+{
+ le32_add_cpu(&(di->id1.journal1.ij_recovery_generation), 1);
+}
+
+static u32 ocfs2_get_recovery_generation(struct ocfs2_dinode *di)
+{
+ return le32_to_cpu(di->id1.journal1.ij_recovery_generation);
+}
+
static int ocfs2_journal_toggle_dirty(struct ocfs2_super *osb,
- int dirty)
+ int dirty, int replayed)
{
int status;
unsigned int flags;
flags &= ~OCFS2_JOURNAL_DIRTY_FL;
fe->id1.journal1.ij_flags = cpu_to_le32(flags);
+ if (replayed)
+ ocfs2_bump_recovery_generation(fe);
+
status = ocfs2_write_block(osb, bh, journal->j_inode);
if (status < 0)
mlog_errno(status);
* Do not toggle if flush was unsuccessful otherwise
* will leave dirty metadata in a "clean" journal
*/
- status = ocfs2_journal_toggle_dirty(osb, 0);
+ status = ocfs2_journal_toggle_dirty(osb, 0, 0);
if (status < 0)
mlog_errno(status);
}
}
}
-int ocfs2_journal_load(struct ocfs2_journal *journal, int local)
+int ocfs2_journal_load(struct ocfs2_journal *journal, int local, int replayed)
{
int status = 0;
struct ocfs2_super *osb;
ocfs2_clear_journal_error(osb->sb, journal->j_journal, osb->slot_num);
- status = ocfs2_journal_toggle_dirty(osb, 1);
+ status = ocfs2_journal_toggle_dirty(osb, 1, replayed);
if (status < 0) {
mlog_errno(status);
goto done;
goto bail;
}
- status = ocfs2_journal_toggle_dirty(journal->j_osb, 0);
+ status = ocfs2_journal_toggle_dirty(journal->j_osb, 0, 0);
if (status < 0)
mlog_errno(status);
spin_unlock(&osb->osb_lock);
mlog(0, "All nodes recovered\n");
+ /* Refresh all journal recovery generations from disk */
+ status = ocfs2_check_journals_nolocks(osb);
+ status = (status == -EROFS) ? 0 : status;
+ if (status < 0)
+ mlog_errno(status);
+
ocfs2_super_unlock(osb, 1);
/* We always run recovery on our own orphan dir - the dead
mlog_exit_void();
}
+static int ocfs2_read_journal_inode(struct ocfs2_super *osb,
+ int slot_num,
+ struct buffer_head **bh,
+ struct inode **ret_inode)
+{
+ int status = -EACCES;
+ struct inode *inode = NULL;
+
+ BUG_ON(slot_num >= osb->max_slots);
+
+ inode = ocfs2_get_system_file_inode(osb, JOURNAL_SYSTEM_INODE,
+ slot_num);
+ if (!inode || is_bad_inode(inode)) {
+ mlog_errno(status);
+ goto bail;
+ }
+ SET_INODE_JOURNAL(inode);
+
+ status = ocfs2_read_block(osb, OCFS2_I(inode)->ip_blkno, bh, 0, inode);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+ status = 0;
+
+bail:
+ if (inode) {
+ if (status || !ret_inode)
+ iput(inode);
+ else
+ *ret_inode = inode;
+ }
+ return status;
+}
+
/* Does the actual journal replay and marks the journal inode as
* clean. Will only replay if the journal inode is marked dirty. */
static int ocfs2_replay_journal(struct ocfs2_super *osb,
struct ocfs2_dinode *fe;
journal_t *journal = NULL;
struct buffer_head *bh = NULL;
+ u32 slot_reco_gen;
- inode = ocfs2_get_system_file_inode(osb, JOURNAL_SYSTEM_INODE,
- slot_num);
- if (inode == NULL) {
- status = -EACCES;
+ status = ocfs2_read_journal_inode(osb, slot_num, &bh, &inode);
+ if (status) {
mlog_errno(status);
goto done;
}
- if (is_bad_inode(inode)) {
- status = -EACCES;
- iput(inode);
- inode = NULL;
- mlog_errno(status);
+
+ fe = (struct ocfs2_dinode *)bh->b_data;
+ slot_reco_gen = ocfs2_get_recovery_generation(fe);
+ brelse(bh);
+ bh = NULL;
+
+ /*
+ * As the fs recovery is asynchronous, there is a small chance that
+ * another node mounted (and recovered) the slot before the recovery
+ * thread could get the lock. To handle that, we dirty read the journal
+ * inode for that slot to get the recovery generation. If it is
+ * different than what we expected, the slot has been recovered.
+ * If not, it needs recovery.
+ */
+ if (osb->slot_recovery_generations[slot_num] != slot_reco_gen) {
+ mlog(0, "Slot %u already recovered (old/new=%u/%u)\n", slot_num,
+ osb->slot_recovery_generations[slot_num], slot_reco_gen);
+ osb->slot_recovery_generations[slot_num] = slot_reco_gen;
+ status = -EBUSY;
goto done;
}
- SET_INODE_JOURNAL(inode);
+
+ /* Continue with recovery as the journal has not yet been recovered */
status = ocfs2_inode_lock_full(inode, &bh, 1, OCFS2_META_LOCK_RECOVERY);
if (status < 0) {
fe = (struct ocfs2_dinode *) bh->b_data;
flags = le32_to_cpu(fe->id1.journal1.ij_flags);
+ slot_reco_gen = ocfs2_get_recovery_generation(fe);
if (!(flags & OCFS2_JOURNAL_DIRTY_FL)) {
mlog(0, "No recovery required for node %d\n", node_num);
+ /* Refresh recovery generation for the slot */
+ osb->slot_recovery_generations[slot_num] = slot_reco_gen;
goto done;
}
flags &= ~OCFS2_JOURNAL_DIRTY_FL;
fe->id1.journal1.ij_flags = cpu_to_le32(flags);
+ /* Increment recovery generation to indicate successful recovery */
+ ocfs2_bump_recovery_generation(fe);
+ osb->slot_recovery_generations[slot_num] =
+ ocfs2_get_recovery_generation(fe);
+
status = ocfs2_write_block(osb, bh, inode);
if (status < 0)
mlog_errno(status);
status = ocfs2_replay_journal(osb, node_num, slot_num);
if (status < 0) {
+ if (status == -EBUSY) {
+ mlog(0, "Skipping recovery for slot %u (node %u) "
+ "as another node has recovered it\n", slot_num,
+ node_num);
+ status = 0;
+ goto done;
+ }
mlog_errno(status);
goto done;
}
{
unsigned int node_num;
int status, i;
+ struct buffer_head *bh = NULL;
+ struct ocfs2_dinode *di;
/* This is called with the super block cluster lock, so we
* know that the slot map can't change underneath us. */
spin_lock(&osb->osb_lock);
for (i = 0; i < osb->max_slots; i++) {
+ /* Read journal inode to get the recovery generation */
+ status = ocfs2_read_journal_inode(osb, i, &bh, NULL);
+ if (status) {
+ mlog_errno(status);
+ goto bail;
+ }
+ di = (struct ocfs2_dinode *)bh->b_data;
+ osb->slot_recovery_generations[i] =
+ ocfs2_get_recovery_generation(di);
+ brelse(bh);
+ bh = NULL;
+
+ mlog(0, "Slot %u recovery generation is %u\n", i,
+ osb->slot_recovery_generations[i]);
+
if (i == osb->slot_num)
continue;
return 0;
}
-/* Look for a dirty journal without taking any cluster locks. Used for
- * hard readonly access to determine whether the file system journals
- * require recovery. */
+/* Reads all the journal inodes without taking any cluster locks. Used
+ * for hard readonly access to determine whether any journal requires
+ * recovery. Also used to refresh the recovery generation numbers after
+ * a journal has been recovered by another node.
+ */
int ocfs2_check_journals_nolocks(struct ocfs2_super *osb)
{
int ret = 0;
unsigned int slot;
- struct buffer_head *di_bh;
+ struct buffer_head *di_bh = NULL;
struct ocfs2_dinode *di;
- struct inode *journal = NULL;
+ int journal_dirty = 0;
for(slot = 0; slot < osb->max_slots; slot++) {
- journal = ocfs2_get_system_file_inode(osb,
- JOURNAL_SYSTEM_INODE,
- slot);
- if (!journal || is_bad_inode(journal)) {
- ret = -EACCES;
- mlog_errno(ret);
- goto out;
- }
-
- di_bh = NULL;
- ret = ocfs2_read_block(osb, OCFS2_I(journal)->ip_blkno, &di_bh,
- 0, journal);
- if (ret < 0) {
+ ret = ocfs2_read_journal_inode(osb, slot, &di_bh, NULL);
+ if (ret) {
mlog_errno(ret);
goto out;
}
di = (struct ocfs2_dinode *) di_bh->b_data;
+ osb->slot_recovery_generations[slot] =
+ ocfs2_get_recovery_generation(di);
+
if (le32_to_cpu(di->id1.journal1.ij_flags) &
OCFS2_JOURNAL_DIRTY_FL)
- ret = -EROFS;
+ journal_dirty = 1;
brelse(di_bh);
- if (ret)
- break;
+ di_bh = NULL;
}
out:
- if (journal)
- iput(journal);
-
+ if (journal_dirty)
+ ret = -EROFS;
return ret;
}
void ocfs2_journal_shutdown(struct ocfs2_super *osb);
int ocfs2_journal_wipe(struct ocfs2_journal *journal,
int full);
-int ocfs2_journal_load(struct ocfs2_journal *journal, int local);
+int ocfs2_journal_load(struct ocfs2_journal *journal, int local,
+ int replayed);
int ocfs2_check_journals_nolocks(struct ocfs2_super *osb);
void ocfs2_recovery_thread(struct ocfs2_super *osb,
int node_num);
struct ocfs2_slot_info *slot_info;
+ u32 *slot_recovery_generations;
+
spinlock_t node_map_lock;
u64 root_blkno;
struct { /* Info for journal system
inodes */
__le32 ij_flags; /* Mounted, version, etc. */
- __le32 ij_pad;
+ __le32 ij_recovery_generation; /* Incremented when the
+ journal is recovered
+ after an unclean
+ shutdown */
} journal1;
} id1; /* Inode type dependant 1 */
/*C0*/ union {
}
mlog(0, "max_slots for this device: %u\n", osb->max_slots);
+ osb->slot_recovery_generations =
+ kcalloc(osb->max_slots, sizeof(*osb->slot_recovery_generations),
+ GFP_KERNEL);
+ if (!osb->slot_recovery_generations) {
+ status = -ENOMEM;
+ mlog_errno(status);
+ goto bail;
+ }
+
init_waitqueue_head(&osb->osb_wipe_event);
osb->osb_orphan_wipes = kcalloc(osb->max_slots,
sizeof(*osb->osb_orphan_wipes),
local = ocfs2_mount_local(osb);
/* will play back anything left in the journal. */
- status = ocfs2_journal_load(osb->journal, local);
+ status = ocfs2_journal_load(osb->journal, local, dirty);
if (status < 0) {
mlog(ML_ERROR, "ocfs2 journal load failed! %d\n", status);
goto finally;
ocfs2_free_slot_info(osb);
kfree(osb->osb_orphan_wipes);
+ kfree(osb->slot_recovery_generations);
/* FIXME
* This belongs in journal shutdown, but because we have to
* allocate osb->journal at the start of ocfs2_initalize_osb(),
#include <linux/list.h>
#include <linux/kref.h>
#include <linux/mutex.h>
+#include <linux/err.h>
#include <asm/atomic.h>
/*
* Users often need to create attribute structures for their configurable
* attributes, containing a configfs_attribute member and function pointers
- * for the show() and store() operations on that attribute. They can use
- * this macro (similar to sysfs' __ATTR) to make defining attributes easier.
+ * for the show() and store() operations on that attribute. If they don't
+ * need anything else on the extended attribute structure, they can use
+ * this macro to define it The argument _item is the name of the
+ * config_item structure.
+ */
+#define CONFIGFS_ATTR_STRUCT(_item) \
+struct _item##_attribute { \
+ struct configfs_attribute attr; \
+ ssize_t (*show)(struct _item *, char *); \
+ ssize_t (*store)(struct _item *, const char *, size_t); \
+}
+
+/*
+ * With the extended attribute structure, users can use this macro
+ * (similar to sysfs' __ATTR) to make defining attributes easier.
+ * An example:
+ * #define MYITEM_ATTR(_name, _mode, _show, _store) \
+ * struct myitem_attribute childless_attr_##_name = \
+ * __CONFIGFS_ATTR(_name, _mode, _show, _store)
*/
#define __CONFIGFS_ATTR(_name, _mode, _show, _store) \
{ \
.show = _show, \
.store = _store, \
}
+/* Here is a readonly version, only requiring a show() operation */
+#define __CONFIGFS_ATTR_RO(_name, _show) \
+{ \
+ .attr = { \
+ .ca_name = __stringify(_name), \
+ .ca_mode = 0444, \
+ .ca_owner = THIS_MODULE, \
+ }, \
+ .show = _show, \
+}
+
+/*
+ * With these extended attributes, the simple show_attribute() and
+ * store_attribute() operations need to call the show() and store() of the
+ * attributes. This is a common pattern, so we provide a macro to define
+ * them. The argument _item is the name of the config_item structure.
+ * This macro expects the attributes to be named "struct <name>_attribute"
+ * and the function to_<name>() to exist;
+ */
+#define CONFIGFS_ATTR_OPS(_item) \
+static ssize_t _item##_attr_show(struct config_item *item, \
+ struct configfs_attribute *attr, \
+ char *page) \
+{ \
+ struct _item *_item = to_##_item(item); \
+ struct _item##_attribute *_item##_attr = \
+ container_of(attr, struct _item##_attribute, attr); \
+ ssize_t ret = 0; \
+ \
+ if (_item##_attr->show) \
+ ret = _item##_attr->show(_item, page); \
+ return ret; \
+} \
+static ssize_t _item##_attr_store(struct config_item *item, \
+ struct configfs_attribute *attr, \
+ const char *page, size_t count) \
+{ \
+ struct _item *_item = to_##_item(item); \
+ struct _item##_attribute *_item##_attr = \
+ container_of(attr, struct _item##_attribute, attr); \
+ ssize_t ret = -EINVAL; \
+ \
+ if (_item##_attr->store) \
+ ret = _item##_attr->store(_item, page, count); \
+ return ret; \
+}
/*
* If allow_link() exists, the item can symlink(2) out to other
git.openpandora.org / pandora-kernel.git / commitdiff