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yaml
---
r: 229062
b: refs/heads/master
c: d0eb2f3
h: refs/heads/master
v: v3
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Dave Chinner authored and Dave Chinner committed Dec 21, 2010
1 parent d00ef98 commit b40fa24
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Showing 3 changed files with 50 additions and 78 deletions.
2 changes: 1 addition & 1 deletion [refs]
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Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 3f16b9850743b702380f098ab5e0308cd6af1792
refs/heads/master: d0eb2f38b250b7d6c993adf81b0e4ded0565497e
103 changes: 34 additions & 69 deletions trunk/fs/xfs/xfs_log.c
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Original file line number Diff line number Diff line change
Expand Up @@ -81,15 +81,13 @@ STATIC void xlog_ungrant_log_space(xlog_t *log,

#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);
STATIC void xlog_verify_tail_lsn(xlog_t *log, xlog_in_core_t *iclog,
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)
Expand All @@ -103,17 +101,24 @@ xlog_grant_sub_space(
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
Expand All @@ -122,20 +127,27 @@ xlog_grant_add_space(
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
Expand Down Expand Up @@ -318,9 +330,7 @@ xfs_log_reserve(

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 */
Expand All @@ -334,11 +344,9 @@ xfs_log_reserve(

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);
}

Expand Down Expand Up @@ -1057,7 +1065,6 @@ xlog_alloc_log(xfs_mount_t *mp,
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 */
Expand Down Expand Up @@ -1135,7 +1142,6 @@ xlog_alloc_log(xfs_mount_t *mp,
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);
Expand Down Expand Up @@ -1331,10 +1337,8 @@ xlog_sync(xlog_t *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);
Expand Down Expand Up @@ -1455,7 +1459,6 @@ xlog_dealloc_log(xlog_t *log)
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;
Expand Down Expand Up @@ -2574,13 +2577,10 @@ xlog_grant_log_space(xlog_t *log,
}

/* 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:
Expand Down Expand Up @@ -2694,12 +2694,9 @@ xlog_regrant_write_log_space(xlog_t *log,
}

/* 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;


Expand Down Expand Up @@ -2737,7 +2734,6 @@ xlog_regrant_reserve_log_space(xlog_t *log,
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,
Expand All @@ -2747,21 +2743,15 @@ xlog_regrant_reserve_log_space(xlog_t *log,

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 */
Expand Down Expand Up @@ -2790,7 +2780,6 @@ xlog_ungrant_log_space(xlog_t *log,
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);

Expand All @@ -2809,8 +2798,6 @@ xlog_ungrant_log_space(xlog_t *log,

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 */

Expand Down Expand Up @@ -3428,28 +3415,6 @@ xlog_verify_dest_ptr(
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)
Expand Down
23 changes: 15 additions & 8 deletions trunk/fs/xfs/xfs_log_priv.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -510,9 +510,6 @@ typedef struct 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
Expand Down Expand Up @@ -599,23 +596,33 @@ xlog_assign_atomic_lsn(atomic64_t *lsn, uint cycle, uint block)
}

/*
* 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));
}

/*
Expand Down

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