#if defined(DEBUG)
STATIC void xlog_verify_dest_ptr(xlog_t *log, char *ptr);
-STATIC void xlog_verify_grant_head(xlog_t *log, int equals);
STATIC void xlog_verify_grant_tail(struct log *log);
STATIC void xlog_verify_iclog(xlog_t *log, xlog_in_core_t *iclog,
int count, boolean_t syncing);
xfs_lsn_t tail_lsn);
#else
#define xlog_verify_dest_ptr(a,b)
-#define xlog_verify_grant_head(a,b)
#define xlog_verify_grant_tail(a)
#define xlog_verify_iclog(a,b,c,d)
#define xlog_verify_tail_lsn(a,b,c)
atomic64_t *head,
int bytes)
{
- int cycle, space;
+ int64_t head_val = atomic64_read(head);
+ int64_t new, old;
- xlog_crack_grant_head(head, &cycle, &space);
+ do {
+ int cycle, space;
- space -= bytes;
- if (space < 0) {
- space += log->l_logsize;
- cycle--;
- }
+ xlog_crack_grant_head_val(head_val, &cycle, &space);
- xlog_assign_grant_head(head, cycle, space);
+ space -= bytes;
+ if (space < 0) {
+ space += log->l_logsize;
+ cycle--;
+ }
+
+ old = head_val;
+ new = xlog_assign_grant_head_val(cycle, space);
+ head_val = atomic64_cmpxchg(head, old, new);
+ } while (head_val != old);
}
static void
atomic64_t *head,
int bytes)
{
- int tmp;
- int cycle, space;
+ int64_t head_val = atomic64_read(head);
+ int64_t new, old;
- xlog_crack_grant_head(head, &cycle, &space);
+ do {
+ int tmp;
+ int cycle, space;
- tmp = log->l_logsize - space;
- if (tmp > bytes)
- space += bytes;
- else {
- space = bytes - tmp;
- cycle++;
- }
+ xlog_crack_grant_head_val(head_val, &cycle, &space);
- xlog_assign_grant_head(head, cycle, space);
+ tmp = log->l_logsize - space;
+ if (tmp > bytes)
+ space += bytes;
+ else {
+ space = bytes - tmp;
+ cycle++;
+ }
+
+ old = head_val;
+ new = xlog_assign_grant_head_val(cycle, space);
+ head_val = atomic64_cmpxchg(head, old, new);
+ } while (head_val != old);
}
static void
trace_xfs_log_reserve(log, internal_ticket);
- spin_lock(&log->l_grant_lock);
xlog_grant_push_ail(log, internal_ticket->t_unit_res);
- spin_unlock(&log->l_grant_lock);
retval = xlog_regrant_write_log_space(log, internal_ticket);
} else {
/* may sleep if need to allocate more tickets */
trace_xfs_log_reserve(log, internal_ticket);
- spin_lock(&log->l_grant_lock);
xlog_grant_push_ail(log,
(internal_ticket->t_unit_res *
internal_ticket->t_cnt));
- spin_unlock(&log->l_grant_lock);
retval = xlog_grant_log_space(log, internal_ticket);
}
log->l_xbuf = bp;
spin_lock_init(&log->l_icloglock);
- spin_lock_init(&log->l_grant_lock);
init_waitqueue_head(&log->l_flush_wait);
/* log record size must be multiple of BBSIZE; see xlog_rec_header_t */
kmem_free(iclog);
}
spinlock_destroy(&log->l_icloglock);
- spinlock_destroy(&log->l_grant_lock);
xfs_buf_free(log->l_xbuf);
out_free_log:
kmem_free(log);
roundoff < BBTOB(1)));
/* move grant heads by roundoff in sync */
- spin_lock(&log->l_grant_lock);
xlog_grant_add_space(log, &log->l_grant_reserve_head, roundoff);
xlog_grant_add_space(log, &log->l_grant_write_head, roundoff);
- spin_unlock(&log->l_grant_lock);
/* put cycle number in every block */
xlog_pack_data(log, iclog, roundoff);
iclog = next_iclog;
}
spinlock_destroy(&log->l_icloglock);
- spinlock_destroy(&log->l_grant_lock);
xfs_buf_free(log->l_xbuf);
log->l_mp->m_log = NULL;
}
/* we've got enough space */
- spin_lock(&log->l_grant_lock);
xlog_grant_add_space(log, &log->l_grant_reserve_head, need_bytes);
xlog_grant_add_space(log, &log->l_grant_write_head, need_bytes);
trace_xfs_log_grant_exit(log, tic);
- xlog_verify_grant_head(log, 1);
xlog_verify_grant_tail(log);
- spin_unlock(&log->l_grant_lock);
return 0;
error_return_unlocked:
}
/* we've got enough space */
- spin_lock(&log->l_grant_lock);
xlog_grant_add_space(log, &log->l_grant_write_head, need_bytes);
trace_xfs_log_regrant_write_exit(log, tic);
- xlog_verify_grant_head(log, 1);
xlog_verify_grant_tail(log);
- spin_unlock(&log->l_grant_lock);
return 0;
if (ticket->t_cnt > 0)
ticket->t_cnt--;
- spin_lock(&log->l_grant_lock);
xlog_grant_sub_space(log, &log->l_grant_reserve_head,
ticket->t_curr_res);
xlog_grant_sub_space(log, &log->l_grant_write_head,
trace_xfs_log_regrant_reserve_sub(log, ticket);
- xlog_verify_grant_head(log, 1);
-
/* just return if we still have some of the pre-reserved space */
- if (ticket->t_cnt > 0) {
- spin_unlock(&log->l_grant_lock);
+ if (ticket->t_cnt > 0)
return;
- }
xlog_grant_add_space(log, &log->l_grant_reserve_head,
ticket->t_unit_res);
trace_xfs_log_regrant_reserve_exit(log, ticket);
- xlog_verify_grant_head(log, 0);
- spin_unlock(&log->l_grant_lock);
ticket->t_curr_res = ticket->t_unit_res;
xlog_tic_reset_res(ticket);
} /* xlog_regrant_reserve_log_space */
if (ticket->t_cnt > 0)
ticket->t_cnt--;
- spin_lock(&log->l_grant_lock);
trace_xfs_log_ungrant_enter(log, ticket);
trace_xfs_log_ungrant_sub(log, ticket);
trace_xfs_log_ungrant_exit(log, ticket);
- xlog_verify_grant_head(log, 1);
- spin_unlock(&log->l_grant_lock);
xfs_log_move_tail(log->l_mp, 1);
} /* xlog_ungrant_log_space */
xlog_panic("xlog_verify_dest_ptr: invalid ptr");
}
-STATIC void
-xlog_verify_grant_head(xlog_t *log, int equals)
-{
- int reserve_cycle, reserve_space;
- int write_cycle, write_space;
-
- xlog_crack_grant_head(&log->l_grant_reserve_head,
- &reserve_cycle, &reserve_space);
- xlog_crack_grant_head(&log->l_grant_write_head,
- &write_cycle, &write_space);
-
- if (reserve_cycle == write_cycle) {
- if (equals)
- ASSERT(reserve_space >= write_space);
- else
- ASSERT(reserve_space > write_space);
- } else {
- ASSERT(reserve_cycle - 1 == write_cycle);
- ASSERT(write_space >= reserve_space);
- }
-}
-
STATIC void
xlog_verify_grant_tail(
struct log *log)
int l_curr_block; /* current logical log block */
int l_prev_block; /* previous logical log block */
- /* The following block of fields are changed while holding grant_lock */
- spinlock_t l_grant_lock ____cacheline_aligned_in_smp;
-
/*
* l_last_sync_lsn and l_tail_lsn are atomics so they can be set and
* read without needing to hold specific locks. To avoid operations
}
/*
- * When we crack the grrant head, we sample it first so that the value will not
+ * When we crack the grant head, we sample it first so that the value will not
* change while we are cracking it into the component values. This means we
* will always get consistent component values to work from.
*/
static inline void
-xlog_crack_grant_head(atomic64_t *head, int *cycle, int *space)
+xlog_crack_grant_head_val(int64_t val, int *cycle, int *space)
{
- int64_t val = atomic64_read(head);
-
*cycle = val >> 32;
*space = val & 0xffffffff;
}
+static inline void
+xlog_crack_grant_head(atomic64_t *head, int *cycle, int *space)
+{
+ xlog_crack_grant_head_val(atomic64_read(head), cycle, space);
+}
+
+static inline int64_t
+xlog_assign_grant_head_val(int cycle, int space)
+{
+ return ((int64_t)cycle << 32) | space;
+}
+
static inline void
xlog_assign_grant_head(atomic64_t *head, int cycle, int space)
{
- atomic64_set(head, ((int64_t)cycle << 32) | space);
+ atomic64_set(head, xlog_assign_grant_head_val(cycle, space));
}
/*