Author: avg
Date: Tue Nov 26 20:09:43 2013
New Revision: 258665
URL: http://svnweb.freebsd.org/changeset/base/258665
Log:
4347 ZPL can use dmu_tx_assign(TXG_WAIT)
illumos/illumos-gate@e722410c49fe67cbf0f639cbcc288bd6cbcf7dd1
Modified:
vendor-sys/illumos/dist/uts/common/fs/zfs/zfs_dir.c
vendor-sys/illumos/dist/uts/common/fs/zfs/zfs_vnops.c
vendor-sys/illumos/dist/uts/common/fs/zfs/zfs_znode.c
Modified: vendor-sys/illumos/dist/uts/common/fs/zfs/zfs_dir.c
==============================================================================
--- vendor-sys/illumos/dist/uts/common/fs/zfs/zfs_dir.c Tue Nov 26 20:03:25
2013 (r258664)
+++ vendor-sys/illumos/dist/uts/common/fs/zfs/zfs_dir.c Tue Nov 26 20:09:43
2013 (r258665)
@@ -937,7 +937,6 @@ zfs_make_xattrdir(znode_t *zp, vattr_t *
return (SET_ERROR(EDQUOT));
}
-top:
tx = dmu_tx_create(zfsvfs->z_os);
dmu_tx_hold_sa_create(tx, acl_ids.z_aclp->z_acl_bytes +
ZFS_SA_BASE_ATTR_SIZE);
@@ -946,13 +945,8 @@ top:
fuid_dirtied = zfsvfs->z_fuid_dirty;
if (fuid_dirtied)
zfs_fuid_txhold(zfsvfs, tx);
- error = dmu_tx_assign(tx, TXG_NOWAIT);
+ error = dmu_tx_assign(tx, TXG_WAIT);
if (error) {
- if (error == ERESTART) {
- dmu_tx_wait(tx);
- dmu_tx_abort(tx);
- goto top;
- }
zfs_acl_ids_free(&acl_ids);
dmu_tx_abort(tx);
return (error);
Modified: vendor-sys/illumos/dist/uts/common/fs/zfs/zfs_vnops.c
==============================================================================
--- vendor-sys/illumos/dist/uts/common/fs/zfs/zfs_vnops.c Tue Nov 26
20:03:25 2013 (r258664)
+++ vendor-sys/illumos/dist/uts/common/fs/zfs/zfs_vnops.c Tue Nov 26
20:09:43 2013 (r258665)
@@ -111,11 +111,18 @@
* (3) All range locks must be grabbed before calling dmu_tx_assign(),
* as they can span dmu_tx_assign() calls.
*
- * (4) Always pass TXG_NOWAIT as the second argument to
dmu_tx_assign().
- * This is critical because we don't want to block while holding locks.
- * Note, in particular, that if a lock is sometimes acquired before
- * the tx assigns, and sometimes after (e.g. z_lock), then failing to
- * use a non-blocking assign can deadlock the system. The scenario:
+ * (4) If ZPL locks are held, pass TXG_NOWAIT as the second argument to
+ * dmu_tx_assign(). This is critical because we don't want to block
+ * while holding locks.
+ *
+ * If no ZPL locks are held (aside from ZFS_ENTER()), use TXG_WAIT. This
+ * reduces lock contention and CPU usage when we must wait (note that if
+ * throughput is constrained by the storage, nearly every transaction
+ * must wait).
+ *
+ * Note, in particular, that if a lock is sometimes acquired before
+ * the tx assigns, and sometimes after (e.g. z_lock), then failing
+ * to use a non-blocking assign can deadlock the system. The scenario:
*
* Thread A has grabbed a lock before calling dmu_tx_assign().
* Thread B is in an already-assigned tx, and blocks for this lock.
@@ -728,7 +735,6 @@ zfs_write(vnode_t *vp, uio_t *uio, int i
while (n > 0) {
abuf = NULL;
woff = uio->uio_loffset;
-again:
if (zfs_owner_overquota(zfsvfs, zp, B_FALSE) ||
zfs_owner_overquota(zfsvfs, zp, B_TRUE)) {
if (abuf != NULL)
@@ -780,13 +786,8 @@ again:
dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
dmu_tx_hold_write(tx, zp->z_id, woff, MIN(n, max_blksz));
zfs_sa_upgrade_txholds(tx, zp);
- error = dmu_tx_assign(tx, TXG_NOWAIT);
+ error = dmu_tx_assign(tx, TXG_WAIT);
if (error) {
- if (error == ERESTART) {
- dmu_tx_wait(tx);
- dmu_tx_abort(tx);
- goto again;
- }
dmu_tx_abort(tx);
if (abuf != NULL)
dmu_return_arcbuf(abuf);
@@ -3043,12 +3044,9 @@ top:
zfs_sa_upgrade_txholds(tx, zp);
- err = dmu_tx_assign(tx, TXG_NOWAIT);
- if (err) {
- if (err == ERESTART)
- dmu_tx_wait(tx);
+ err = dmu_tx_assign(tx, TXG_WAIT);
+ if (err)
goto out;
- }
count = 0;
/*
@@ -4140,19 +4138,13 @@ zfs_putapage(vnode_t *vp, page_t *pp, u_
err = SET_ERROR(EDQUOT);
goto out;
}
-top:
tx = dmu_tx_create(zfsvfs->z_os);
dmu_tx_hold_write(tx, zp->z_id, off, len);
dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
zfs_sa_upgrade_txholds(tx, zp);
- err = dmu_tx_assign(tx, TXG_NOWAIT);
+ err = dmu_tx_assign(tx, TXG_WAIT);
if (err != 0) {
- if (err == ERESTART) {
- dmu_tx_wait(tx);
- dmu_tx_abort(tx);
- goto top;
- }
dmu_tx_abort(tx);
goto out;
}
Modified: vendor-sys/illumos/dist/uts/common/fs/zfs/zfs_znode.c
==============================================================================
--- vendor-sys/illumos/dist/uts/common/fs/zfs/zfs_znode.c Tue Nov 26
20:03:25 2013 (r258664)
+++ vendor-sys/illumos/dist/uts/common/fs/zfs/zfs_znode.c Tue Nov 26
20:09:43 2013 (r258665)
@@ -1469,7 +1469,6 @@ zfs_extend(znode_t *zp, uint64_t end)
zfs_range_unlock(rl);
return (0);
}
-top:
tx = dmu_tx_create(zfsvfs->z_os);
dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
zfs_sa_upgrade_txholds(tx, zp);
@@ -1489,13 +1488,8 @@ top:
newblksz = 0;
}
- error = dmu_tx_assign(tx, TXG_NOWAIT);
+ error = dmu_tx_assign(tx, TXG_WAIT);
if (error) {
- if (error == ERESTART) {
- dmu_tx_wait(tx);
- dmu_tx_abort(tx);
- goto top;
- }
dmu_tx_abort(tx);
zfs_range_unlock(rl);
return (error);
@@ -1592,17 +1586,11 @@ zfs_trunc(znode_t *zp, uint64_t end)
zfs_range_unlock(rl);
return (error);
}
-top:
tx = dmu_tx_create(zfsvfs->z_os);
dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
zfs_sa_upgrade_txholds(tx, zp);
- error = dmu_tx_assign(tx, TXG_NOWAIT);
+ error = dmu_tx_assign(tx, TXG_WAIT);
if (error) {
- if (error == ERESTART) {
- dmu_tx_wait(tx);
- dmu_tx_abort(tx);
- goto top;
- }
dmu_tx_abort(tx);
zfs_range_unlock(rl);
return (error);
@@ -1709,13 +1697,8 @@ log:
tx = dmu_tx_create(zfsvfs->z_os);
dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
zfs_sa_upgrade_txholds(tx, zp);
- error = dmu_tx_assign(tx, TXG_NOWAIT);
+ error = dmu_tx_assign(tx, TXG_WAIT);
if (error) {
- if (error == ERESTART) {
- dmu_tx_wait(tx);
- dmu_tx_abort(tx);
- goto log;
- }
dmu_tx_abort(tx);
return (error);
}
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