提交 bc3048e3 编写于 作者: P Peter Leckie 提交者: Lachlan McIlroy

[XFS] Clean up dquot pincount code.

This is a code cleanup and optimization that removes a per mount point
spinlock from the quota code and cleans up the code.

The patch changes the pincount from being an int protected by a spinlock
to an atomic_t allowing the pincount to be manipulated without holding the
spinlock.

This cleanup also protects against random wakup's of both the aild and
xfssyncd by reevaluating the pincount after been woken. Two latter patches
will address the Spurious wakeups.

SGI-PV: 986789

SGI-Modid: xfs-linux-melb:xfs-kern:32215a
Signed-off-by: NPeter Leckie <pleckie@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NDonald Douwsma <donaldd@sgi.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
上级 d112f298
......@@ -101,7 +101,7 @@ xfs_qm_dqinit(
if (brandnewdquot) {
dqp->dq_flnext = dqp->dq_flprev = dqp;
mutex_init(&dqp->q_qlock);
sv_init(&dqp->q_pinwait, SV_DEFAULT, "pdq");
init_waitqueue_head(&dqp->q_pinwait);
/*
* Because we want to use a counting completion, complete
......@@ -131,7 +131,7 @@ xfs_qm_dqinit(
dqp->q_res_bcount = 0;
dqp->q_res_icount = 0;
dqp->q_res_rtbcount = 0;
dqp->q_pincount = 0;
atomic_set(&dqp->q_pincount, 0);
dqp->q_hash = NULL;
ASSERT(dqp->dq_flnext == dqp->dq_flprev);
......@@ -1489,7 +1489,7 @@ xfs_qm_dqpurge(
"xfs_qm_dqpurge: dquot %p flush failed", dqp);
xfs_dqflock(dqp);
}
ASSERT(dqp->q_pincount == 0);
ASSERT(atomic_read(&dqp->q_pincount) == 0);
ASSERT(XFS_FORCED_SHUTDOWN(mp) ||
!(dqp->q_logitem.qli_item.li_flags & XFS_LI_IN_AIL));
......
......@@ -83,8 +83,8 @@ typedef struct xfs_dquot {
xfs_qcnt_t q_res_rtbcount;/* total realtime blks used+reserved */
mutex_t q_qlock; /* quota lock */
struct completion q_flush; /* flush completion queue */
uint q_pincount; /* pin count for this dquot */
sv_t q_pinwait; /* sync var for pinning */
atomic_t q_pincount; /* dquot pin count */
wait_queue_head_t q_pinwait; /* dquot pinning wait queue */
#ifdef XFS_DQUOT_TRACE
struct ktrace *q_trace; /* trace header structure */
#endif
......
......@@ -88,25 +88,22 @@ xfs_qm_dquot_logitem_format(
/*
* Increment the pin count of the given dquot.
* This value is protected by pinlock spinlock in the xQM structure.
*/
STATIC void
xfs_qm_dquot_logitem_pin(
xfs_dq_logitem_t *logitem)
{
xfs_dquot_t *dqp;
xfs_dquot_t *dqp = logitem->qli_dquot;
dqp = logitem->qli_dquot;
ASSERT(XFS_DQ_IS_LOCKED(dqp));
spin_lock(&(XFS_DQ_TO_QINF(dqp)->qi_pinlock));
dqp->q_pincount++;
spin_unlock(&(XFS_DQ_TO_QINF(dqp)->qi_pinlock));
atomic_inc(dqp->q_pincount);
}
/*
* Decrement the pin count of the given dquot, and wake up
* anyone in xfs_dqwait_unpin() if the count goes to 0. The
* dquot must have been previously pinned with a call to xfs_dqpin().
* dquot must have been previously pinned with a call to
* xfs_qm_dquot_logitem_pin().
*/
/* ARGSUSED */
STATIC void
......@@ -114,16 +111,11 @@ xfs_qm_dquot_logitem_unpin(
xfs_dq_logitem_t *logitem,
int stale)
{
xfs_dquot_t *dqp;
xfs_dquot_t *dqp = logitem->qli_dquot;
dqp = logitem->qli_dquot;
ASSERT(dqp->q_pincount > 0);
spin_lock(&(XFS_DQ_TO_QINF(dqp)->qi_pinlock));
dqp->q_pincount--;
if (dqp->q_pincount == 0) {
sv_broadcast(&dqp->q_pinwait);
}
spin_unlock(&(XFS_DQ_TO_QINF(dqp)->qi_pinlock));
ASSERT(atomic_read(&dqp->q_pincount) > 0);
if (atomic_dec_and_test(&dqp->q_pincount))
wake_up(&dqp->q_pinwait);
}
/* ARGSUSED */
......@@ -193,21 +185,14 @@ xfs_qm_dqunpin_wait(
xfs_dquot_t *dqp)
{
ASSERT(XFS_DQ_IS_LOCKED(dqp));
if (dqp->q_pincount == 0) {
if (atomic_read(&dqp->q_pincount) == 0)
return;
}
/*
* Give the log a push so we don't wait here too long.
*/
xfs_log_force(dqp->q_mount, (xfs_lsn_t)0, XFS_LOG_FORCE);
spin_lock(&(XFS_DQ_TO_QINF(dqp)->qi_pinlock));
if (dqp->q_pincount == 0) {
spin_unlock(&(XFS_DQ_TO_QINF(dqp)->qi_pinlock));
return;
}
sv_wait(&(dqp->q_pinwait), PINOD,
&(XFS_DQ_TO_QINF(dqp)->qi_pinlock), s);
wait_event(dqp->q_pinwait, (atomic_read(&dqp->q_pincount) == 0));
}
/*
......@@ -310,7 +295,7 @@ xfs_qm_dquot_logitem_trylock(
uint retval;
dqp = qip->qli_dquot;
if (dqp->q_pincount > 0)
if (atomic_read(&dqp->q_pincount) > 0)
return (XFS_ITEM_PINNED);
if (! xfs_qm_dqlock_nowait(dqp))
......
......@@ -1137,7 +1137,6 @@ xfs_qm_init_quotainfo(
return error;
}
spin_lock_init(&qinf->qi_pinlock);
xfs_qm_list_init(&qinf->qi_dqlist, "mpdqlist", 0);
qinf->qi_dqreclaims = 0;
......@@ -1234,7 +1233,6 @@ xfs_qm_destroy_quotainfo(
*/
xfs_qm_rele_quotafs_ref(mp);
spinlock_destroy(&qi->qi_pinlock);
xfs_qm_list_destroy(&qi->qi_dqlist);
if (qi->qi_uquotaip) {
......
......@@ -106,7 +106,6 @@ typedef struct xfs_qm {
typedef struct xfs_quotainfo {
xfs_inode_t *qi_uquotaip; /* user quota inode */
xfs_inode_t *qi_gquotaip; /* group quota inode */
spinlock_t qi_pinlock; /* dquot pinning lock */
xfs_dqlist_t qi_dqlist; /* all dquots in filesys */
int qi_dqreclaims; /* a change here indicates
a removal in the dqlist */
......
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