[PATCH 27/34] xfs: use wait queues directly for the log wait queues

Dave Chinner
2010-12-21T07:28:23Z

The log grant queues are one of the few places left using sv_t
constructs for waiting. Given we are touching this code, we should
convert them to plain wait queues. While there, convert all the
other sv_t users in the log code as well.

Seeing as this removes the last users of the sv_t type, remove the
header file defining the wrapper and the fragments that still
reference it.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
fs/xfs/linux-2.6/sv.h | 59 --------------------------------------
fs/xfs/linux-2.6/xfs_linux.h | 1 -
fs/xfs/quota/xfs_dquot.c | 1 -
fs/xfs/xfs_log.c | 64 ++++++++++++++++++-----------------------
fs/xfs/xfs_log_cil.c | 8 ++--
fs/xfs/xfs_log_priv.h | 25 +++++++++++++---
6 files changed, 52 insertions(+), 106 deletions(-)
delete mode 100644 fs/xfs/linux-2.6/sv.h

diff --git a/fs/xfs/linux-2.6/sv.h b/fs/xfs/linux-2.6/sv.h
deleted file mode 100644
index 4dfc7c3..0000000
--- a/fs/xfs/linux-2.6/sv.h
+++ /dev/null
@@ -1,59 +0,0 @@
-/*
- * 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_SUPPORT_SV_H__
-#define __XFS_SUPPORT_SV_H__
-
-#include <linux/wait.h>
-#include <linux/sched.h>
-#include <linux/spinlock.h>
-
-/*
- * Synchronisation variables.
- *
- * (Parameters "pri", "svf" and "rts" are not implemented)
- */
-
-typedef struct sv_s {
- wait_queue_head_t waiters;
-} sv_t;
-
-static inline void _sv_wait(sv_t *sv, spinlock_t *lock)
-{
- DECLARE_WAITQUEUE(wait, current);
-
- add_wait_queue_exclusive(&sv->waiters, &wait);
- __set_current_state(TASK_UNINTERRUPTIBLE);
- spin_unlock(lock);
-
- schedule();
-
- remove_wait_queue(&sv->waiters, &wait);
-}
-
-#define sv_init(sv,flag,name) \
- init_waitqueue_head(&(sv)->waiters)
-#define sv_destroy(sv) \
- /*NOTHING*/
-#define sv_wait(sv, pri, lock, s) \
- _sv_wait(sv, lock)
-#define sv_signal(sv) \
- wake_up(&(sv)->waiters)
-#define sv_broadcast(sv) \
- wake_up_all(&(sv)->waiters)
-
-#endif /* __XFS_SUPPORT_SV_H__ */
diff --git a/fs/xfs/linux-2.6/xfs_linux.h b/fs/xfs/linux-2.6/xfs_linux.h
index 9fa4f2a..ccebd86 100644
--- a/fs/xfs/linux-2.6/xfs_linux.h
+++ b/fs/xfs/linux-2.6/xfs_linux.h
@@ -37,7 +37,6 @@

#include <kmem.h>
#include <mrlock.h>
-#include <sv.h>
#include <time.h>

#include <support/debug.h>
diff --git a/fs/xfs/quota/xfs_dquot.c b/fs/xfs/quota/xfs_dquot.c
index faf8e1a..d22aa31 100644
--- a/fs/xfs/quota/xfs_dquot.c
+++ b/fs/xfs/quota/xfs_dquot.c
@@ -149,7 +149,6 @@ xfs_qm_dqdestroy(
ASSERT(list_empty(&dqp->q_freelist));

mutex_destroy(&dqp->q_qlock);
- sv_destroy(&dqp->q_pinwait);
kmem_zone_free(xfs_Gqm->qm_dqzone, dqp);

atomic_dec(&xfs_Gqm->qm_totaldquots);
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index 6bba8b4..cc0504e 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -547,8 +547,8 @@ xfs_log_unmount_write(xfs_mount_t *mp)
if (!(iclog->ic_state == XLOG_STATE_ACTIVE ||
iclog->ic_state == XLOG_STATE_DIRTY)) {
if (!XLOG_FORCED_SHUTDOWN(log)) {
- sv_wait(&iclog->ic_force_wait, PMEM,
- &log->l_icloglock, s);
+ xlog_wait(&iclog->ic_force_wait,
+ &log->l_icloglock);
} else {
spin_unlock(&log->l_icloglock);
}
@@ -588,8 +588,8 @@ xfs_log_unmount_write(xfs_mount_t *mp)
|| iclog->ic_state == XLOG_STATE_DIRTY
|| iclog->ic_state == XLOG_STATE_IOERROR) ) {

- sv_wait(&iclog->ic_force_wait, PMEM,
- &log->l_icloglock, s);
+ xlog_wait(&iclog->ic_force_wait,
+ &log->l_icloglock);
} else {
spin_unlock(&log->l_icloglock);
}
@@ -700,7 +700,7 @@ xfs_log_move_tail(xfs_mount_t *mp,
break;
tail_lsn = 0;
free_bytes -= tic->t_unit_res;
- sv_signal(&tic->t_wait);
+ wake_up(&tic->t_wait);
}
}

@@ -719,7 +719,7 @@ xfs_log_move_tail(xfs_mount_t *mp,
break;
tail_lsn = 0;
free_bytes -= need_bytes;
- sv_signal(&tic->t_wait);
+ wake_up(&tic->t_wait);
}
}
spin_unlock(&log->l_grant_lock);
@@ -1060,7 +1060,7 @@ xlog_alloc_log(xfs_mount_t *mp,

spin_lock_init(&log->l_icloglock);
spin_lock_init(&log->l_grant_lock);
- sv_init(&log->l_flush_wait, 0, "flush_wait");
+ init_waitqueue_head(&log->l_flush_wait);

/* log record size must be multiple of BBSIZE; see xlog_rec_header_t */
ASSERT((XFS_BUF_SIZE(bp) & BBMASK) == 0);
@@ -1116,8 +1116,8 @@ xlog_alloc_log(xfs_mount_t *mp,

ASSERT(XFS_BUF_ISBUSY(iclog->ic_bp));
ASSERT(XFS_BUF_VALUSEMA(iclog->ic_bp) <= 0);
- sv_init(&iclog->ic_force_wait, SV_DEFAULT, "iclog-force");
- sv_init(&iclog->ic_write_wait, SV_DEFAULT, "iclog-write");
+ init_waitqueue_head(&iclog->ic_force_wait);
+ init_waitqueue_head(&iclog->ic_write_wait);

iclogp = &iclog->ic_next;
}
@@ -1132,11 +1132,8 @@ xlog_alloc_log(xfs_mount_t *mp,
out_free_iclog:
for (iclog = log->l_iclog; iclog; iclog = prev_iclog) {
prev_iclog = iclog->ic_next;
- if (iclog->ic_bp) {
- sv_destroy(&iclog->ic_force_wait);
- sv_destroy(&iclog->ic_write_wait);
+ if (iclog->ic_bp)
xfs_buf_free(iclog->ic_bp);
- }
kmem_free(iclog);
}
spinlock_destroy(&log->l_icloglock);
@@ -1453,8 +1450,6 @@ xlog_dealloc_log(xlog_t *log)

iclog = log->l_iclog;
for (i=0; i<log->l_iclog_bufs; i++) {
- sv_destroy(&iclog->ic_force_wait);
- sv_destroy(&iclog->ic_write_wait);
xfs_buf_free(iclog->ic_bp);
next_iclog = iclog->ic_next;
kmem_free(iclog);
@@ -2261,7 +2256,7 @@ xlog_state_do_callback(
xlog_state_clean_log(log);

/* wake up threads waiting in xfs_log_force() */
- sv_broadcast(&iclog->ic_force_wait);
+ wake_up_all(&iclog->ic_force_wait);

iclog = iclog->ic_next;
} while (first_iclog != iclog);
@@ -2308,7 +2303,7 @@ xlog_state_do_callback(
spin_unlock(&log->l_icloglock);

if (wake)
- sv_broadcast(&log->l_flush_wait);
+ wake_up_all(&log->l_flush_wait);
}

@@ -2359,7 +2354,7 @@ xlog_state_done_syncing(
* iclog buffer, we wake them all, one will get to do the
* I/O, the others get to wait for the result.
*/
- sv_broadcast(&iclog->ic_write_wait);
+ wake_up_all(&iclog->ic_write_wait);
spin_unlock(&log->l_icloglock);
xlog_state_do_callback(log, aborted, iclog); /* also cleans log */
} /* xlog_state_done_syncing */
@@ -2408,7 +2403,7 @@ restart:
XFS_STATS_INC(xs_log_noiclogs);

/* Wait for log writes to have flushed */
- sv_wait(&log->l_flush_wait, 0, &log->l_icloglock, 0);
+ xlog_wait(&log->l_flush_wait, &log->l_icloglock);
goto restart;
}

@@ -2523,7 +2518,8 @@ xlog_grant_log_space(xlog_t *log,
goto error_return;

XFS_STATS_INC(xs_sleep_logspace);
- sv_wait(&tic->t_wait, PINOD|PLTWAIT, &log->l_grant_lock, s);
+ xlog_wait(&tic->t_wait, &log->l_grant_lock);
+
/*
* If we got an error, and the filesystem is shutting down,
* we'll catch it down below. So just continue...
@@ -2552,7 +2548,7 @@ redo:
spin_lock(&log->l_grant_lock);

XFS_STATS_INC(xs_sleep_logspace);
- sv_wait(&tic->t_wait, PINOD|PLTWAIT, &log->l_grant_lock, s);
+ xlog_wait(&tic->t_wait, &log->l_grant_lock);

spin_lock(&log->l_grant_lock);
if (XLOG_FORCED_SHUTDOWN(log))
@@ -2635,7 +2631,7 @@ xlog_regrant_write_log_space(xlog_t *log,
if (free_bytes < ntic->t_unit_res)
break;
free_bytes -= ntic->t_unit_res;
- sv_signal(&ntic->t_wait);
+ wake_up(&ntic->t_wait);
}

if (ntic != list_first_entry(&log->l_writeq,
@@ -2650,8 +2646,7 @@ xlog_regrant_write_log_space(xlog_t *log,
spin_lock(&log->l_grant_lock);

XFS_STATS_INC(xs_sleep_logspace);
- sv_wait(&tic->t_wait, PINOD|PLTWAIT,
- &log->l_grant_lock, s);
+ xlog_wait(&tic->t_wait, &log->l_grant_lock);

/* If we're shutting down, this tic is already
* off the queue */
@@ -2677,8 +2672,7 @@ redo:

XFS_STATS_INC(xs_sleep_logspace);
trace_xfs_log_regrant_write_sleep2(log, tic);
-
- sv_wait(&tic->t_wait, PINOD|PLTWAIT, &log->l_grant_lock, s);
+ xlog_wait(&tic->t_wait, &log->l_grant_lock);

/* If we're shutting down, this tic is already off the queue */
spin_lock(&log->l_grant_lock);
@@ -3029,7 +3023,7 @@ maybe_sleep:
return XFS_ERROR(EIO);
}
XFS_STATS_INC(xs_log_force_sleep);
- sv_wait(&iclog->ic_force_wait, PINOD, &log->l_icloglock, s);
+ xlog_wait(&iclog->ic_force_wait, &log->l_icloglock);
/*
* No need to grab the log lock here since we're
* only deciding whether or not to return EIO
@@ -3147,8 +3141,8 @@ try_again:

XFS_STATS_INC(xs_log_force_sleep);

- sv_wait(&iclog->ic_prev->ic_write_wait,
- PSWP, &log->l_icloglock, s);
+ xlog_wait(&iclog->ic_prev->ic_write_wait,
+ &log->l_icloglock);
if (log_flushed)
*log_flushed = 1;
already_slept = 1;
@@ -3176,7 +3170,7 @@ try_again:
return XFS_ERROR(EIO);
}
XFS_STATS_INC(xs_log_force_sleep);
- sv_wait(&iclog->ic_force_wait, PSWP, &log->l_icloglock, s);
+ xlog_wait(&iclog->ic_force_wait, &log->l_icloglock);
/*
* No need to grab the log lock here since we're
* only deciding whether or not to return EIO
@@ -3251,10 +3245,8 @@ xfs_log_ticket_put(
xlog_ticket_t *ticket)
{
ASSERT(atomic_read(&ticket->t_ref) > 0);
- if (atomic_dec_and_test(&ticket->t_ref)) {
- sv_destroy(&ticket->t_wait);
+ if (atomic_dec_and_test(&ticket->t_ref))
kmem_zone_free(xfs_log_ticket_zone, ticket);
- }
}

xlog_ticket_t *
@@ -3387,7 +3379,7 @@ xlog_ticket_alloc(
tic->t_trans_type = 0;
if (xflags & XFS_LOG_PERM_RESERV)
tic->t_flags |= XLOG_TIC_PERM_RESERV;
- sv_init(&tic->t_wait, SV_DEFAULT, "logtick");
+ init_waitqueue_head(&tic->t_wait);

xlog_tic_reset_res(tic);

@@ -3719,10 +3711,10 @@ xfs_log_force_umount(
* action is protected by the GRANTLOCK.
*/
list_for_each_entry(tic, &log->l_reserveq, t_queue)
- sv_signal(&tic->t_wait);
+ wake_up(&tic->t_wait);

list_for_each_entry(tic, &log->l_writeq, t_queue)
- sv_signal(&tic->t_wait);
+ wake_up(&tic->t_wait);
spin_unlock(&log->l_grant_lock);

if (!(log->l_iclog->ic_state & XLOG_STATE_IOERROR)) {
diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c
index f36f1a2..9dc8125 100644
--- a/fs/xfs/xfs_log_cil.c
+++ b/fs/xfs/xfs_log_cil.c
@@ -61,7 +61,7 @@ xlog_cil_init(
INIT_LIST_HEAD(&cil->xc_committing);
spin_lock_init(&cil->xc_cil_lock);
init_rwsem(&cil->xc_ctx_lock);
- sv_init(&cil->xc_commit_wait, SV_DEFAULT, "cilwait");
+ init_waitqueue_head(&cil->xc_commit_wait);

INIT_LIST_HEAD(&ctx->committing);
INIT_LIST_HEAD(&ctx->busy_extents);
@@ -563,7 +563,7 @@ restart:
* It is still being pushed! Wait for the push to
* complete, then start again from the beginning.
*/
- sv_wait(&cil->xc_commit_wait, 0, &cil->xc_cil_lock, 0);
+ xlog_wait(&cil->xc_commit_wait, &cil->xc_cil_lock);
goto restart;
}
}
@@ -587,7 +587,7 @@ restart:
*/
spin_lock(&cil->xc_cil_lock);
ctx->commit_lsn = commit_lsn;
- sv_broadcast(&cil->xc_commit_wait);
+ wake_up_all(&cil->xc_commit_wait);
spin_unlock(&cil->xc_cil_lock);

/* release the hounds! */
@@ -752,7 +752,7 @@ restart:
* It is still being pushed! Wait for the push to
* complete, then start again from the beginning.
*/
- sv_wait(&cil->xc_commit_wait, 0, &cil->xc_cil_lock, 0);
+ xlog_wait(&cil->xc_commit_wait, &cil->xc_cil_lock);
goto restart;
}
if (ctx->sequence != sequence)
diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h
index 2f74c80..e2bb276 100644
--- a/fs/xfs/xfs_log_priv.h
+++ b/fs/xfs/xfs_log_priv.h
@@ -241,7 +241,7 @@ typedef struct xlog_res {
} xlog_res_t;

typedef struct xlog_ticket {
- sv_t t_wait; /* ticket wait queue : 20 */
+ wait_queue_head_t t_wait; /* ticket wait queue */
struct list_head t_queue; /* reserve/write queue */
xlog_tid_t t_tid; /* transaction identifier : 4 */
atomic_t t_ref; /* ticket reference count : 4 */
@@ -349,8 +349,8 @@ typedef union xlog_in_core2 {
* and move everything else out to subsequent cachelines.
*/
typedef struct xlog_in_core {
- sv_t ic_force_wait;
- sv_t ic_write_wait;
+ wait_queue_head_t ic_force_wait;
+ wait_queue_head_t ic_write_wait;
struct xlog_in_core *ic_next;
struct xlog_in_core *ic_prev;
struct xfs_buf *ic_bp;
@@ -417,7 +417,7 @@ struct xfs_cil {
struct xfs_cil_ctx *xc_ctx;
struct rw_semaphore xc_ctx_lock;
struct list_head xc_committing;
- sv_t xc_commit_wait;
+ wait_queue_head_t xc_commit_wait;
xfs_lsn_t xc_current_sequence;
};

@@ -499,7 +499,7 @@ typedef struct log {
int l_logBBsize; /* size of log in BB chunks */

/* The following block of fields are changed while holding icloglock */
- sv_t l_flush_wait ____cacheline_aligned_in_smp;
+ wait_queue_head_t l_flush_wait ____cacheline_aligned_in_smp;
/* waiting for iclog flush */
int l_covered_state;/* state of "covering disk
* log entries" */
@@ -602,6 +602,21 @@ xlog_cil_force(struct log *log)
*/
#define XLOG_UNMOUNT_REC_TYPE (-1U)

+/*
+ * Wrapper function for waiting on a wait queue serialised against wakeups
+ * by a spinlock. This matches the semantics of all the wait queues used in the
+ * log code.
+ */
+static inline void xlog_wait(wait_queue_head_t *wq, spinlock_t *lock)
+{
+ DECLARE_WAITQUEUE(wait, current);
+
+ add_wait_queue_exclusive(wq, &wait);
+ __set_current_state(TASK_UNINTERRUPTIBLE);
+ spin_unlock(lock);
+ schedule();
+ remove_wait_queue(wq, &wait);
+}
#endif /* __KERNEL__ */

#endif /* __XFS_LOG_PRIV_H__ */