linux-stable/include/linux/configfs.h

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/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* configfs.h - definitions for the device driver filesystem
*
* Based on sysfs:
* sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
*
* Based on kobject.h:
* Copyright (c) 2002-2003 Patrick Mochel
* Copyright (c) 2002-2003 Open Source Development Labs
*
* configfs Copyright (C) 2005 Oracle. All rights reserved.
*
* Please read Documentation/filesystems/configfs.rst before using
* the configfs interface, ESPECIALLY the parts about reference counts and
* item destructors.
*/
#ifndef _CONFIGFS_H_
#define _CONFIGFS_H_
#include <linux/stat.h> /* S_IRUGO */
#include <linux/types.h> /* ssize_t */
#include <linux/list.h> /* struct list_head */
#include <linux/kref.h> /* struct kref */
#include <linux/mutex.h> /* struct mutex */
#define CONFIGFS_ITEM_NAME_LEN 20
struct module;
struct configfs_item_operations;
struct configfs_group_operations;
struct configfs_attribute;
struct configfs_bin_attribute;
struct configfs_subsystem;
struct config_item {
char *ci_name;
char ci_namebuf[CONFIGFS_ITEM_NAME_LEN];
struct kref ci_kref;
struct list_head ci_entry;
struct config_item *ci_parent;
struct config_group *ci_group;
const struct config_item_type *ci_type;
struct dentry *ci_dentry;
};
extern __printf(2, 3)
int config_item_set_name(struct config_item *, const char *, ...);
static inline char *config_item_name(struct config_item * item)
{
return item->ci_name;
}
extern void config_item_init_type_name(struct config_item *item,
const char *name,
const struct config_item_type *type);
extern struct config_item *config_item_get(struct config_item *);
extern struct config_item *config_item_get_unless_zero(struct config_item *);
extern void config_item_put(struct config_item *);
struct config_item_type {
struct module *ct_owner;
struct configfs_item_operations *ct_item_ops;
struct configfs_group_operations *ct_group_ops;
struct configfs_attribute **ct_attrs;
struct configfs_bin_attribute **ct_bin_attrs;
};
/**
* group - a group of config_items of a specific type, belonging
* to a specific subsystem.
*/
struct config_group {
struct config_item cg_item;
struct list_head cg_children;
struct configfs_subsystem *cg_subsys;
struct list_head default_groups;
struct list_head group_entry;
};
extern void config_group_init(struct config_group *group);
extern void config_group_init_type_name(struct config_group *group,
const char *name,
const struct config_item_type *type);
static inline struct config_group *to_config_group(struct config_item *item)
{
return item ? container_of(item,struct config_group,cg_item) : NULL;
}
static inline struct config_group *config_group_get(struct config_group *group)
{
return group ? to_config_group(config_item_get(&group->cg_item)) : NULL;
}
static inline void config_group_put(struct config_group *group)
{
config_item_put(&group->cg_item);
}
extern struct config_item *config_group_find_item(struct config_group *,
const char *);
static inline void configfs_add_default_group(struct config_group *new_group,
struct config_group *group)
{
list_add_tail(&new_group->group_entry, &group->default_groups);
}
struct configfs_attribute {
const char *ca_name;
struct module *ca_owner;
umode_t ca_mode;
ssize_t (*show)(struct config_item *, char *);
ssize_t (*store)(struct config_item *, const char *, size_t);
};
#define CONFIGFS_ATTR(_pfx, _name) \
static struct configfs_attribute _pfx##attr_##_name = { \
.ca_name = __stringify(_name), \
.ca_mode = S_IRUGO | S_IWUSR, \
.ca_owner = THIS_MODULE, \
.show = _pfx##_name##_show, \
.store = _pfx##_name##_store, \
}
#define CONFIGFS_ATTR_RO(_pfx, _name) \
static struct configfs_attribute _pfx##attr_##_name = { \
.ca_name = __stringify(_name), \
.ca_mode = S_IRUGO, \
.ca_owner = THIS_MODULE, \
.show = _pfx##_name##_show, \
}
#define CONFIGFS_ATTR_WO(_pfx, _name) \
static struct configfs_attribute _pfx##attr_##_name = { \
.ca_name = __stringify(_name), \
.ca_mode = S_IWUSR, \
.ca_owner = THIS_MODULE, \
.store = _pfx##_name##_store, \
}
struct file;
struct vm_area_struct;
struct configfs_bin_attribute {
struct configfs_attribute cb_attr; /* std. attribute */
void *cb_private; /* for user */
size_t cb_max_size; /* max core size */
ssize_t (*read)(struct config_item *, void *, size_t);
ssize_t (*write)(struct config_item *, const void *, size_t);
};
#define CONFIGFS_BIN_ATTR(_pfx, _name, _priv, _maxsz) \
static struct configfs_bin_attribute _pfx##attr_##_name = { \
.cb_attr = { \
.ca_name = __stringify(_name), \
.ca_mode = S_IRUGO | S_IWUSR, \
.ca_owner = THIS_MODULE, \
}, \
.cb_private = _priv, \
.cb_max_size = _maxsz, \
.read = _pfx##_name##_read, \
.write = _pfx##_name##_write, \
}
#define CONFIGFS_BIN_ATTR_RO(_pfx, _name, _priv, _maxsz) \
static struct configfs_bin_attribute _pfx##attr_##_name = { \
.cb_attr = { \
.ca_name = __stringify(_name), \
.ca_mode = S_IRUGO, \
.ca_owner = THIS_MODULE, \
}, \
.cb_private = _priv, \
.cb_max_size = _maxsz, \
.read = _pfx##_name##_read, \
}
#define CONFIGFS_BIN_ATTR_WO(_pfx, _name, _priv, _maxsz) \
static struct configfs_bin_attribute _pfx##attr_##_name = { \
.cb_attr = { \
.ca_name = __stringify(_name), \
.ca_mode = S_IWUSR, \
.ca_owner = THIS_MODULE, \
}, \
.cb_private = _priv, \
.cb_max_size = _maxsz, \
.write = _pfx##_name##_write, \
}
/*
* If allow_link() exists, the item can symlink(2) out to other
* items. If the item is a group, it may support mkdir(2).
* Groups supply one of make_group() and make_item(). If the
* group supports make_group(), one can create group children. If it
* supports make_item(), one can create config_item children. make_group()
* and make_item() return ERR_PTR() on errors. If it has
* default_groups on group->default_groups, it has automatically created
* group children. default_groups may coexist alongsize make_group() or
* make_item(), but if the group wishes to have only default_groups
* children (disallowing mkdir(2)), it need not provide either function.
*/
struct configfs_item_operations {
void (*release)(struct config_item *);
int (*allow_link)(struct config_item *src, struct config_item *target);
void (*drop_link)(struct config_item *src, struct config_item *target);
};
struct configfs_group_operations {
struct config_item *(*make_item)(struct config_group *group, const char *name);
struct config_group *(*make_group)(struct config_group *group, const char *name);
void (*disconnect_notify)(struct config_group *group, struct config_item *item);
void (*drop_item)(struct config_group *group, struct config_item *item);
};
struct configfs_subsystem {
struct config_group su_group;
struct mutex su_mutex;
};
static inline struct configfs_subsystem *to_configfs_subsystem(struct config_group *group)
{
return group ?
container_of(group, struct configfs_subsystem, su_group) :
NULL;
}
int configfs_register_subsystem(struct configfs_subsystem *subsys);
void configfs_unregister_subsystem(struct configfs_subsystem *subsys);
configfs: allow dynamic group creation This patchset introduces IIO software triggers, offers a way of configuring them via configfs and adds the IIO hrtimer based interrupt source to be used with software triggers. The architecture is now split in 3 parts, to remove all IIO trigger specific parts from IIO configfs core: (1) IIO configfs - creates the root of the IIO configfs subsys. (2) IIO software triggers - software trigger implementation, dynamically creating /config/iio/triggers group. (3) IIO hrtimer trigger - is the first interrupt source for software triggers (with syfs to follow). Each trigger type can implement its own set of attributes. Lockdep seems to be happy with the locking in configfs patch. This patch (of 5): We don't want to hardcode default groups at subsystem creation time. We export: * configfs_register_group * configfs_unregister_group to allow drivers to programatically create/destroy groups later, after module init time. This is needed for IIO configfs support. (akpm: the other 4 patches to be merged via the IIO tree) Signed-off-by: Daniel Baluta <daniel.baluta@intel.com> Suggested-by: Lars-Peter Clausen <lars@metafoo.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Joel Becker <jlbec@evilplan.org> Cc: Hartmut Knaack <knaack.h@gmx.de> Cc: Octavian Purdila <octavian.purdila@intel.com> Cc: Paul Bolle <pebolle@tiscali.nl> Cc: Adriana Reus <adriana.reus@intel.com> Cc: Cristina Opriceana <cristina.opriceana@gmail.com> Cc: Peter Meerwald <pmeerw@pmeerw.net> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-20 23:56:53 +00:00
int configfs_register_group(struct config_group *parent_group,
struct config_group *group);
void configfs_unregister_group(struct config_group *group);
void configfs_remove_default_groups(struct config_group *group);
configfs: allow dynamic group creation This patchset introduces IIO software triggers, offers a way of configuring them via configfs and adds the IIO hrtimer based interrupt source to be used with software triggers. The architecture is now split in 3 parts, to remove all IIO trigger specific parts from IIO configfs core: (1) IIO configfs - creates the root of the IIO configfs subsys. (2) IIO software triggers - software trigger implementation, dynamically creating /config/iio/triggers group. (3) IIO hrtimer trigger - is the first interrupt source for software triggers (with syfs to follow). Each trigger type can implement its own set of attributes. Lockdep seems to be happy with the locking in configfs patch. This patch (of 5): We don't want to hardcode default groups at subsystem creation time. We export: * configfs_register_group * configfs_unregister_group to allow drivers to programatically create/destroy groups later, after module init time. This is needed for IIO configfs support. (akpm: the other 4 patches to be merged via the IIO tree) Signed-off-by: Daniel Baluta <daniel.baluta@intel.com> Suggested-by: Lars-Peter Clausen <lars@metafoo.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Joel Becker <jlbec@evilplan.org> Cc: Hartmut Knaack <knaack.h@gmx.de> Cc: Octavian Purdila <octavian.purdila@intel.com> Cc: Paul Bolle <pebolle@tiscali.nl> Cc: Adriana Reus <adriana.reus@intel.com> Cc: Cristina Opriceana <cristina.opriceana@gmail.com> Cc: Peter Meerwald <pmeerw@pmeerw.net> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-20 23:56:53 +00:00
struct config_group *
configfs_register_default_group(struct config_group *parent_group,
const char *name,
const struct config_item_type *item_type);
configfs: allow dynamic group creation This patchset introduces IIO software triggers, offers a way of configuring them via configfs and adds the IIO hrtimer based interrupt source to be used with software triggers. The architecture is now split in 3 parts, to remove all IIO trigger specific parts from IIO configfs core: (1) IIO configfs - creates the root of the IIO configfs subsys. (2) IIO software triggers - software trigger implementation, dynamically creating /config/iio/triggers group. (3) IIO hrtimer trigger - is the first interrupt source for software triggers (with syfs to follow). Each trigger type can implement its own set of attributes. Lockdep seems to be happy with the locking in configfs patch. This patch (of 5): We don't want to hardcode default groups at subsystem creation time. We export: * configfs_register_group * configfs_unregister_group to allow drivers to programatically create/destroy groups later, after module init time. This is needed for IIO configfs support. (akpm: the other 4 patches to be merged via the IIO tree) Signed-off-by: Daniel Baluta <daniel.baluta@intel.com> Suggested-by: Lars-Peter Clausen <lars@metafoo.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Joel Becker <jlbec@evilplan.org> Cc: Hartmut Knaack <knaack.h@gmx.de> Cc: Octavian Purdila <octavian.purdila@intel.com> Cc: Paul Bolle <pebolle@tiscali.nl> Cc: Adriana Reus <adriana.reus@intel.com> Cc: Cristina Opriceana <cristina.opriceana@gmail.com> Cc: Peter Meerwald <pmeerw@pmeerw.net> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-20 23:56:53 +00:00
void configfs_unregister_default_group(struct config_group *group);
/* These functions can sleep and can alloc with GFP_KERNEL */
/* WARNING: These cannot be called underneath configfs callbacks!! */
int configfs_depend_item(struct configfs_subsystem *subsys,
struct config_item *target);
void configfs_undepend_item(struct config_item *target);
fs: configfs: Add unlocked version of configfs_depend_item() This change is necessary for the SCSI target usb gadget composed with configfs. In this case configfs will be used for two different purposes: to compose a usb gadget and to configure the target part. If an instance of tcm function is created in $CONFIGFS_ROOT/usb_gadget/<gadget>/functions a tpg can be created in $CONFIGFS_ROOT/target/usb_gadget/<wwn>/, but after a tpg is created the tcm function must not be removed until its corresponding tpg is gone. While the configfs_depend/undepend_item() are meant exactly for creating this kind of dependencies, they are not suitable if the other kernel subsystem happens to be another subsystem in configfs, so this patch adds unlocked versions meant for configfs callbacks. Above description has been provided by: Andrzej Pietrasiewicz <andrzej.p@samsung.com> In configfs_depend_item() we have to consider two possible cases: 1) When we are called to depend another item in the same subsystem as caller In this case we should skip locking configfs root as we know that configfs is in valid state and our subsystem will not be unregistered during this call. 2) When we are called to depend item in different subsystem than our caller In this case we are also sure that configfs is in valid state but we have to lock root of configfs to avoid unregistration of target's subsystem. As it is other than caller's subsystem, there may be nothing what protects us against unregistration of that subsystem. Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-12-11 15:06:12 +00:00
/*
* These functions can sleep and can alloc with GFP_KERNEL
* NOTE: These should be called only underneath configfs callbacks.
* NOTE: First parameter is a caller's subsystem, not target's.
* WARNING: These cannot be called on newly created item
* (in make_group()/make_item() callback)
*/
int configfs_depend_item_unlocked(struct configfs_subsystem *caller_subsys,
struct config_item *target);
static inline void configfs_undepend_item_unlocked(struct config_item *target)
{
configfs_undepend_item(target);
}
#endif /* _CONFIGFS_H_ */