linux_dsm_epyc7002/fs/xfs/xfs_trans_priv.h
Jie Liu 8d1d40832b xfs: Simplify xfs_ail_min() with list_first_entry_or_null()
At xfs_ail_min(), we do check if the AIL list is empty or not before
returning the first item in it with list_empty() and list_first_entry().

This can be simplified a bit with a new list operation routine that is
the list_first_entry_or_null() which has been introduced by:

commit 6d7581e62f
    list: introduce list_first_entry_or_null

v2: make xfs_ail_min() as a static inline function and move it to
    xfs_trans_priv.h as per Dave Chinner's comments.

Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-23 12:57:43 -05:00

164 lines
4.9 KiB
C

/*
* Copyright (c) 2000,2002,2005 Silicon Graphics, Inc.
* All Rights Reserved.
*
* 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.
*
* This program is distributed in the hope that it would 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 the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef __XFS_TRANS_PRIV_H__
#define __XFS_TRANS_PRIV_H__
struct xfs_log_item;
struct xfs_log_item_desc;
struct xfs_mount;
struct xfs_trans;
struct xfs_ail;
struct xfs_log_vec;
void xfs_trans_init(struct xfs_mount *);
int xfs_trans_roll(struct xfs_trans **, struct xfs_inode *);
void xfs_trans_add_item(struct xfs_trans *, struct xfs_log_item *);
void xfs_trans_del_item(struct xfs_log_item *);
void xfs_trans_free_items(struct xfs_trans *tp, xfs_lsn_t commit_lsn,
int flags);
void xfs_trans_unreserve_and_mod_sb(struct xfs_trans *tp);
void xfs_trans_committed_bulk(struct xfs_ail *ailp, struct xfs_log_vec *lv,
xfs_lsn_t commit_lsn, int aborted);
/*
* AIL traversal cursor.
*
* Rather than using a generation number for detecting changes in the ail, use
* a cursor that is protected by the ail lock. The aild cursor exists in the
* struct xfs_ail, but other traversals can declare it on the stack and link it
* to the ail list.
*
* When an object is deleted from or moved int the AIL, the cursor list is
* searched to see if the object is a designated cursor item. If it is, it is
* deleted from the cursor so that the next time the cursor is used traversal
* will return to the start.
*
* This means a traversal colliding with a removal will cause a restart of the
* list scan, rather than any insertion or deletion anywhere in the list. The
* low bit of the item pointer is set if the cursor has been invalidated so
* that we can tell the difference between invalidation and reaching the end
* of the list to trigger traversal restarts.
*/
struct xfs_ail_cursor {
struct list_head list;
struct xfs_log_item *item;
};
/*
* Private AIL structures.
*
* Eventually we need to drive the locking in here as well.
*/
struct xfs_ail {
struct xfs_mount *xa_mount;
struct task_struct *xa_task;
struct list_head xa_ail;
xfs_lsn_t xa_target;
xfs_lsn_t xa_target_prev;
struct list_head xa_cursors;
spinlock_t xa_lock;
xfs_lsn_t xa_last_pushed_lsn;
int xa_log_flush;
struct list_head xa_buf_list;
wait_queue_head_t xa_empty;
};
/*
* From xfs_trans_ail.c
*/
void xfs_trans_ail_update_bulk(struct xfs_ail *ailp,
struct xfs_ail_cursor *cur,
struct xfs_log_item **log_items, int nr_items,
xfs_lsn_t lsn) __releases(ailp->xa_lock);
/*
* Return a pointer to the first item in the AIL. If the AIL is empty, then
* return NULL.
*/
static inline struct xfs_log_item *
xfs_ail_min(
struct xfs_ail *ailp)
{
return list_first_entry_or_null(&ailp->xa_ail, struct xfs_log_item,
li_ail);
}
static inline void
xfs_trans_ail_update(
struct xfs_ail *ailp,
struct xfs_log_item *lip,
xfs_lsn_t lsn) __releases(ailp->xa_lock)
{
xfs_trans_ail_update_bulk(ailp, NULL, &lip, 1, lsn);
}
void xfs_trans_ail_delete_bulk(struct xfs_ail *ailp,
struct xfs_log_item **log_items, int nr_items,
int shutdown_type)
__releases(ailp->xa_lock);
static inline void
xfs_trans_ail_delete(
struct xfs_ail *ailp,
xfs_log_item_t *lip,
int shutdown_type) __releases(ailp->xa_lock)
{
xfs_trans_ail_delete_bulk(ailp, &lip, 1, shutdown_type);
}
void xfs_ail_push(struct xfs_ail *, xfs_lsn_t);
void xfs_ail_push_all(struct xfs_ail *);
void xfs_ail_push_all_sync(struct xfs_ail *);
struct xfs_log_item *xfs_ail_min(struct xfs_ail *ailp);
xfs_lsn_t xfs_ail_min_lsn(struct xfs_ail *ailp);
struct xfs_log_item * xfs_trans_ail_cursor_first(struct xfs_ail *ailp,
struct xfs_ail_cursor *cur,
xfs_lsn_t lsn);
struct xfs_log_item * xfs_trans_ail_cursor_last(struct xfs_ail *ailp,
struct xfs_ail_cursor *cur,
xfs_lsn_t lsn);
struct xfs_log_item * xfs_trans_ail_cursor_next(struct xfs_ail *ailp,
struct xfs_ail_cursor *cur);
void xfs_trans_ail_cursor_done(struct xfs_ail *ailp,
struct xfs_ail_cursor *cur);
#if BITS_PER_LONG != 64
static inline void
xfs_trans_ail_copy_lsn(
struct xfs_ail *ailp,
xfs_lsn_t *dst,
xfs_lsn_t *src)
{
ASSERT(sizeof(xfs_lsn_t) == 8); /* don't lock if it shrinks */
spin_lock(&ailp->xa_lock);
*dst = *src;
spin_unlock(&ailp->xa_lock);
}
#else
static inline void
xfs_trans_ail_copy_lsn(
struct xfs_ail *ailp,
xfs_lsn_t *dst,
xfs_lsn_t *src)
{
ASSERT(sizeof(xfs_lsn_t) == 8);
*dst = *src;
}
#endif
#endif /* __XFS_TRANS_PRIV_H__ */