linux/fs/xfs/xfs_log.h
Darrick J. Wong ed1575daf7 xfs: expose the log push threshold
Separate the computation of the log push threshold and the push logic in
xlog_grant_push_ail.  This enables higher level code to determine (for
example) that it is holding on to a logged intent item and the log is so
busy that it is more than 75% full.  In that case, it would be desirable
to move the log item towards the head to release the tail, which we will
cover in the next patch.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2020-10-07 08:40:29 -07:00

147 lines
4.2 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
* All Rights Reserved.
*/
#ifndef __XFS_LOG_H__
#define __XFS_LOG_H__
struct xfs_cil_ctx;
struct xfs_log_vec {
struct xfs_log_vec *lv_next; /* next lv in build list */
int lv_niovecs; /* number of iovecs in lv */
struct xfs_log_iovec *lv_iovecp; /* iovec array */
struct xfs_log_item *lv_item; /* owner */
char *lv_buf; /* formatted buffer */
int lv_bytes; /* accounted space in buffer */
int lv_buf_len; /* aligned size of buffer */
int lv_size; /* size of allocated lv */
};
#define XFS_LOG_VEC_ORDERED (-1)
static inline void *
xlog_prepare_iovec(struct xfs_log_vec *lv, struct xfs_log_iovec **vecp,
uint type)
{
struct xfs_log_iovec *vec = *vecp;
if (vec) {
ASSERT(vec - lv->lv_iovecp < lv->lv_niovecs);
vec++;
} else {
vec = &lv->lv_iovecp[0];
}
vec->i_type = type;
vec->i_addr = lv->lv_buf + lv->lv_buf_len;
ASSERT(IS_ALIGNED((unsigned long)vec->i_addr, sizeof(uint64_t)));
*vecp = vec;
return vec->i_addr;
}
/*
* We need to make sure the next buffer is naturally aligned for the biggest
* basic data type we put into it. We already accounted for this padding when
* sizing the buffer.
*
* However, this padding does not get written into the log, and hence we have to
* track the space used by the log vectors separately to prevent log space hangs
* due to inaccurate accounting (i.e. a leak) of the used log space through the
* CIL context ticket.
*/
static inline void
xlog_finish_iovec(struct xfs_log_vec *lv, struct xfs_log_iovec *vec, int len)
{
lv->lv_buf_len += round_up(len, sizeof(uint64_t));
lv->lv_bytes += len;
vec->i_len = len;
}
static inline void *
xlog_copy_iovec(struct xfs_log_vec *lv, struct xfs_log_iovec **vecp,
uint type, void *data, int len)
{
void *buf;
buf = xlog_prepare_iovec(lv, vecp, type);
memcpy(buf, data, len);
xlog_finish_iovec(lv, *vecp, len);
return buf;
}
/*
* By comparing each component, we don't have to worry about extra
* endian issues in treating two 32 bit numbers as one 64 bit number
*/
static inline xfs_lsn_t _lsn_cmp(xfs_lsn_t lsn1, xfs_lsn_t lsn2)
{
if (CYCLE_LSN(lsn1) != CYCLE_LSN(lsn2))
return (CYCLE_LSN(lsn1)<CYCLE_LSN(lsn2))? -999 : 999;
if (BLOCK_LSN(lsn1) != BLOCK_LSN(lsn2))
return (BLOCK_LSN(lsn1)<BLOCK_LSN(lsn2))? -999 : 999;
return 0;
}
#define XFS_LSN_CMP(x,y) _lsn_cmp(x,y)
/*
* Flags to xfs_log_force()
*
* XFS_LOG_SYNC: Synchronous force in-core log to disk
*/
#define XFS_LOG_SYNC 0x1
/* Log manager interfaces */
struct xfs_mount;
struct xlog_in_core;
struct xlog_ticket;
struct xfs_log_item;
struct xfs_item_ops;
struct xfs_trans;
int xfs_log_force(struct xfs_mount *mp, uint flags);
int xfs_log_force_lsn(struct xfs_mount *mp, xfs_lsn_t lsn, uint flags,
int *log_forced);
int xfs_log_mount(struct xfs_mount *mp,
struct xfs_buftarg *log_target,
xfs_daddr_t start_block,
int num_bblocks);
int xfs_log_mount_finish(struct xfs_mount *mp);
void xfs_log_mount_cancel(struct xfs_mount *);
xfs_lsn_t xlog_assign_tail_lsn(struct xfs_mount *mp);
xfs_lsn_t xlog_assign_tail_lsn_locked(struct xfs_mount *mp);
void xfs_log_space_wake(struct xfs_mount *mp);
void xfs_log_release_iclog(struct xlog_in_core *iclog);
int xfs_log_reserve(struct xfs_mount *mp,
int length,
int count,
struct xlog_ticket **ticket,
uint8_t clientid,
bool permanent);
int xfs_log_regrant(struct xfs_mount *mp, struct xlog_ticket *tic);
void xfs_log_unmount(struct xfs_mount *mp);
int xfs_log_force_umount(struct xfs_mount *mp, int logerror);
struct xlog_ticket *xfs_log_ticket_get(struct xlog_ticket *ticket);
void xfs_log_ticket_put(struct xlog_ticket *ticket);
void xfs_log_commit_cil(struct xfs_mount *mp, struct xfs_trans *tp,
xfs_lsn_t *commit_lsn, bool regrant);
void xlog_cil_process_committed(struct list_head *list);
bool xfs_log_item_in_current_chkpt(struct xfs_log_item *lip);
void xfs_log_work_queue(struct xfs_mount *mp);
void xfs_log_quiesce(struct xfs_mount *mp);
bool xfs_log_check_lsn(struct xfs_mount *, xfs_lsn_t);
bool xfs_log_in_recovery(struct xfs_mount *);
xfs_lsn_t xlog_grant_push_threshold(struct xlog *log, int need_bytes);
#endif /* __XFS_LOG_H__ */