mirror of
https://git.proxmox.com/git/mirror_zfs
synced 2025-08-05 13:11:01 +00:00
d88895a069
struct zvol_state contains a dummy znode, which is around 1KB on x64, only for zfs_range_lock. But in reality, other than z_range_lock and z_range_avl, zfs_range_lock only need znode on regular file, which means we add 1KB on a structure and gain nothing. In this patch, we remove the dummy znode for zvol_state. In order to do that, we also need to refactor zfs_range_lock a bit. We move z_range_lock and z_range_avl pair out of znode_t to form zfs_rlock_t. This new struct replaces znode_t as the main handle inside the range lock functions. We also add pointers to z_size, z_blksz, and z_max_blksz so range lock code doesn't depend on znode_t. This allows non-ZPL consumers like Lustre to use the range locks with their equivalent znode_t structure. Signed-off-by: Chunwei Chen <david.chen@osnexus.com> Signed-off-by: Boris Protopopov <boris.protopopov@actifio.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #4510
116 lines
3.3 KiB
C
116 lines
3.3 KiB
C
/*
|
|
* CDDL HEADER START
|
|
*
|
|
* The contents of this file are subject to the terms of the
|
|
* Common Development and Distribution License (the "License").
|
|
* You may not use this file except in compliance with the License.
|
|
*
|
|
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
|
|
* or http://www.opensolaris.org/os/licensing.
|
|
* See the License for the specific language governing permissions
|
|
* and limitations under the License.
|
|
*
|
|
* When distributing Covered Code, include this CDDL HEADER in each
|
|
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
|
|
* If applicable, add the following below this CDDL HEADER, with the
|
|
* fields enclosed by brackets "[]" replaced with your own identifying
|
|
* information: Portions Copyright [yyyy] [name of copyright owner]
|
|
*
|
|
* CDDL HEADER END
|
|
*/
|
|
/*
|
|
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
|
|
* Use is subject to license terms.
|
|
*/
|
|
|
|
#ifndef _SYS_FS_ZFS_RLOCK_H
|
|
#define _SYS_FS_ZFS_RLOCK_H
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
#ifdef _KERNEL
|
|
|
|
#include <sys/list.h>
|
|
#include <sys/avl.h>
|
|
#include <sys/condvar.h>
|
|
|
|
typedef enum {
|
|
RL_READER,
|
|
RL_WRITER,
|
|
RL_APPEND
|
|
} rl_type_t;
|
|
|
|
typedef struct zfs_rlock {
|
|
kmutex_t zr_mutex; /* protects changes to zr_avl */
|
|
avl_tree_t zr_avl; /* avl tree of range locks */
|
|
uint64_t *zr_size; /* points to znode->z_size */
|
|
uint_t *zr_blksz; /* points to znode->z_blksz */
|
|
uint64_t *zr_max_blksz; /* points to zsb->z_max_blksz */
|
|
} zfs_rlock_t;
|
|
|
|
typedef struct rl {
|
|
zfs_rlock_t *r_zrl;
|
|
avl_node_t r_node; /* avl node link */
|
|
uint64_t r_off; /* file range offset */
|
|
uint64_t r_len; /* file range length */
|
|
uint_t r_cnt; /* range reference count in tree */
|
|
rl_type_t r_type; /* range type */
|
|
kcondvar_t r_wr_cv; /* cv for waiting writers */
|
|
kcondvar_t r_rd_cv; /* cv for waiting readers */
|
|
uint8_t r_proxy; /* acting for original range */
|
|
uint8_t r_write_wanted; /* writer wants to lock this range */
|
|
uint8_t r_read_wanted; /* reader wants to lock this range */
|
|
list_node_t rl_node; /* used for deferred release */
|
|
} rl_t;
|
|
|
|
/*
|
|
* Lock a range (offset, length) as either shared (RL_READER)
|
|
* or exclusive (RL_WRITER or RL_APPEND). RL_APPEND is a special type that
|
|
* is converted to RL_WRITER that specified to lock from the start of the
|
|
* end of file. Returns the range lock structure.
|
|
*/
|
|
rl_t *zfs_range_lock(zfs_rlock_t *zrl, uint64_t off, uint64_t len,
|
|
rl_type_t type);
|
|
|
|
/* Unlock range and destroy range lock structure. */
|
|
void zfs_range_unlock(rl_t *rl);
|
|
|
|
/*
|
|
* Reduce range locked as RW_WRITER from whole file to specified range.
|
|
* Asserts the whole file was previously locked.
|
|
*/
|
|
void zfs_range_reduce(rl_t *rl, uint64_t off, uint64_t len);
|
|
|
|
/*
|
|
* AVL comparison function used to order range locks
|
|
* Locks are ordered on the start offset of the range.
|
|
*/
|
|
int zfs_range_compare(const void *arg1, const void *arg2);
|
|
|
|
static inline void
|
|
zfs_rlock_init(zfs_rlock_t *zrl)
|
|
{
|
|
mutex_init(&zrl->zr_mutex, NULL, MUTEX_DEFAULT, NULL);
|
|
avl_create(&zrl->zr_avl, zfs_range_compare,
|
|
sizeof (rl_t), offsetof(rl_t, r_node));
|
|
zrl->zr_size = NULL;
|
|
zrl->zr_blksz = NULL;
|
|
zrl->zr_max_blksz = NULL;
|
|
}
|
|
|
|
static inline void
|
|
zfs_rlock_destroy(zfs_rlock_t *zrl)
|
|
{
|
|
avl_destroy(&zrl->zr_avl);
|
|
mutex_destroy(&zrl->zr_mutex);
|
|
}
|
|
#endif /* _KERNEL */
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif /* _SYS_FS_ZFS_RLOCK_H */
|