Commit f66241cb authored by Douglas Fuller's avatar Douglas Fuller Committed by Ilya Dryomov

libceph: support for advisory locking on RADOS objects

This patch adds support for rados lock, unlock and break lock.

Based heavily on code by Mike Christie <michaelc@cs.wisc.edu>.
Signed-off-by: default avatarDouglas Fuller <dfuller@redhat.com>
Signed-off-by: default avatarIlya Dryomov <idryomov@gmail.com>
Reviewed-by: default avatarMike Christie <mchristi@redhat.com>
Reviewed-by: default avatarAlex Elder <elder@linaro.org>
parent 428a7158
#ifndef _LINUX_CEPH_CLS_LOCK_CLIENT_H
#define _LINUX_CEPH_CLS_LOCK_CLIENT_H
#include <linux/ceph/osd_client.h>
enum ceph_cls_lock_type {
CEPH_CLS_LOCK_NONE = 0,
CEPH_CLS_LOCK_EXCLUSIVE = 1,
CEPH_CLS_LOCK_SHARED = 2,
};
int ceph_cls_lock(struct ceph_osd_client *osdc,
struct ceph_object_id *oid,
struct ceph_object_locator *oloc,
char *lock_name, u8 type, char *cookie,
char *tag, char *desc, u8 flags);
int ceph_cls_unlock(struct ceph_osd_client *osdc,
struct ceph_object_id *oid,
struct ceph_object_locator *oloc,
char *lock_name, char *cookie);
int ceph_cls_break_lock(struct ceph_osd_client *osdc,
struct ceph_object_id *oid,
struct ceph_object_locator *oloc,
char *lock_name, char *cookie,
struct ceph_entity_name *locker);
#endif
......@@ -5,6 +5,7 @@ obj-$(CONFIG_CEPH_LIB) += libceph.o
libceph-y := ceph_common.o messenger.o msgpool.o buffer.o pagelist.o \
mon_client.o \
cls_lock_client.o \
osd_client.o osdmap.o crush/crush.o crush/mapper.o crush/hash.o \
debugfs.o \
auth.o auth_none.o \
......
#include <linux/ceph/ceph_debug.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/ceph/cls_lock_client.h>
#include <linux/ceph/decode.h>
/**
* ceph_cls_lock - grab rados lock for object
* @oid, @oloc: object to lock
* @lock_name: the name of the lock
* @type: lock type (CEPH_CLS_LOCK_EXCLUSIVE or CEPH_CLS_LOCK_SHARED)
* @cookie: user-defined identifier for this instance of the lock
* @tag: user-defined tag
* @desc: user-defined lock description
* @flags: lock flags
*
* All operations on the same lock should use the same tag.
*/
int ceph_cls_lock(struct ceph_osd_client *osdc,
struct ceph_object_id *oid,
struct ceph_object_locator *oloc,
char *lock_name, u8 type, char *cookie,
char *tag, char *desc, u8 flags)
{
int lock_op_buf_size;
int name_len = strlen(lock_name);
int cookie_len = strlen(cookie);
int tag_len = strlen(tag);
int desc_len = strlen(desc);
void *p, *end;
struct page *lock_op_page;
struct timespec mtime;
int ret;
lock_op_buf_size = name_len + sizeof(__le32) +
cookie_len + sizeof(__le32) +
tag_len + sizeof(__le32) +
desc_len + sizeof(__le32) +
sizeof(struct ceph_timespec) +
/* flag and type */
sizeof(u8) + sizeof(u8) +
CEPH_ENCODING_START_BLK_LEN;
if (lock_op_buf_size > PAGE_SIZE)
return -E2BIG;
lock_op_page = alloc_page(GFP_NOIO);
if (!lock_op_page)
return -ENOMEM;
p = page_address(lock_op_page);
end = p + lock_op_buf_size;
/* encode cls_lock_lock_op struct */
ceph_start_encoding(&p, 1, 1,
lock_op_buf_size - CEPH_ENCODING_START_BLK_LEN);
ceph_encode_string(&p, end, lock_name, name_len);
ceph_encode_8(&p, type);
ceph_encode_string(&p, end, cookie, cookie_len);
ceph_encode_string(&p, end, tag, tag_len);
ceph_encode_string(&p, end, desc, desc_len);
/* only support infinite duration */
memset(&mtime, 0, sizeof(mtime));
ceph_encode_timespec(p, &mtime);
p += sizeof(struct ceph_timespec);
ceph_encode_8(&p, flags);
dout("%s lock_name %s type %d cookie %s tag %s desc %s flags 0x%x\n",
__func__, lock_name, type, cookie, tag, desc, flags);
ret = ceph_osdc_call(osdc, oid, oloc, "lock", "lock",
CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK,
lock_op_page, lock_op_buf_size, NULL, NULL);
dout("%s: status %d\n", __func__, ret);
__free_page(lock_op_page);
return ret;
}
EXPORT_SYMBOL(ceph_cls_lock);
/**
* ceph_cls_unlock - release rados lock for object
* @oid, @oloc: object to lock
* @lock_name: the name of the lock
* @cookie: user-defined identifier for this instance of the lock
*/
int ceph_cls_unlock(struct ceph_osd_client *osdc,
struct ceph_object_id *oid,
struct ceph_object_locator *oloc,
char *lock_name, char *cookie)
{
int unlock_op_buf_size;
int name_len = strlen(lock_name);
int cookie_len = strlen(cookie);
void *p, *end;
struct page *unlock_op_page;
int ret;
unlock_op_buf_size = name_len + sizeof(__le32) +
cookie_len + sizeof(__le32) +
CEPH_ENCODING_START_BLK_LEN;
if (unlock_op_buf_size > PAGE_SIZE)
return -E2BIG;
unlock_op_page = alloc_page(GFP_NOIO);
if (!unlock_op_page)
return -ENOMEM;
p = page_address(unlock_op_page);
end = p + unlock_op_buf_size;
/* encode cls_lock_unlock_op struct */
ceph_start_encoding(&p, 1, 1,
unlock_op_buf_size - CEPH_ENCODING_START_BLK_LEN);
ceph_encode_string(&p, end, lock_name, name_len);
ceph_encode_string(&p, end, cookie, cookie_len);
dout("%s lock_name %s cookie %s\n", __func__, lock_name, cookie);
ret = ceph_osdc_call(osdc, oid, oloc, "lock", "unlock",
CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK,
unlock_op_page, unlock_op_buf_size, NULL, NULL);
dout("%s: status %d\n", __func__, ret);
__free_page(unlock_op_page);
return ret;
}
EXPORT_SYMBOL(ceph_cls_unlock);
/**
* ceph_cls_break_lock - release rados lock for object for specified client
* @oid, @oloc: object to lock
* @lock_name: the name of the lock
* @cookie: user-defined identifier for this instance of the lock
* @locker: current lock owner
*/
int ceph_cls_break_lock(struct ceph_osd_client *osdc,
struct ceph_object_id *oid,
struct ceph_object_locator *oloc,
char *lock_name, char *cookie,
struct ceph_entity_name *locker)
{
int break_op_buf_size;
int name_len = strlen(lock_name);
int cookie_len = strlen(cookie);
struct page *break_op_page;
void *p, *end;
int ret;
break_op_buf_size = name_len + sizeof(__le32) +
cookie_len + sizeof(__le32) +
sizeof(u8) + sizeof(__le64) +
CEPH_ENCODING_START_BLK_LEN;
if (break_op_buf_size > PAGE_SIZE)
return -E2BIG;
break_op_page = alloc_page(GFP_NOIO);
if (!break_op_page)
return -ENOMEM;
p = page_address(break_op_page);
end = p + break_op_buf_size;
/* encode cls_lock_break_op struct */
ceph_start_encoding(&p, 1, 1,
break_op_buf_size - CEPH_ENCODING_START_BLK_LEN);
ceph_encode_string(&p, end, lock_name, name_len);
ceph_encode_copy(&p, locker, sizeof(*locker));
ceph_encode_string(&p, end, cookie, cookie_len);
dout("%s lock_name %s cookie %s locker %s%llu\n", __func__, lock_name,
cookie, ENTITY_NAME(*locker));
ret = ceph_osdc_call(osdc, oid, oloc, "lock", "break_lock",
CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK,
break_op_page, break_op_buf_size, NULL, NULL);
dout("%s: status %d\n", __func__, ret);
__free_page(break_op_page);
return ret;
}
EXPORT_SYMBOL(ceph_cls_break_lock);
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