From a169a625a6d57ae0a92147cfde0da69235b2d4f1 Mon Sep 17 00:00:00 2001 From: Matthew Ahrens Date: Thu, 22 Aug 2013 09:51:47 -0800 Subject: Illumos #4046 4046 dsl_dataset_t ds_dir->dd_lock is highly contended Reviewed by: Eric Schrock Reviewed by: George Wilson Approved by: Garrett D'Amore References: https://www.illumos.org/issues/4046 illumos/illumos-gate@b62969f868a827f0823a084bc0af9c7d8b76c659 Ported-by: Richard Yao Signed-off-by: Brian Behlendorf Issue #1775 Porting notes: 1. This commit removed dsl_dataset_namelen in Illumos, but that appears to have been removed from ZFSOnLinux in an earlier commit. --- module/zfs/dsl_dir.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) (limited to 'module/zfs/dsl_dir.c') diff --git a/module/zfs/dsl_dir.c b/module/zfs/dsl_dir.c index c1b518241..44795f344 100644 --- a/module/zfs/dsl_dir.c +++ b/module/zfs/dsl_dir.c @@ -846,11 +846,21 @@ dsl_dir_diduse_space(dsl_dir_t *dd, dd_used_t type, int64_t used, int64_t compressed, int64_t uncompressed, dmu_tx_t *tx) { int64_t accounted_delta; + + /* + * dsl_dataset_set_refreservation_sync_impl() calls this with + * dd_lock held, so that it can atomically update + * ds->ds_reserved and the dsl_dir accounting, so that + * dsl_dataset_check_quota() can see dataset and dir accounting + * consistently. + */ boolean_t needlock = !MUTEX_HELD(&dd->dd_lock); ASSERT(dmu_tx_is_syncing(tx)); ASSERT(type < DD_USED_NUM); + dmu_buf_will_dirty(dd->dd_dbuf, tx); + if (needlock) mutex_enter(&dd->dd_lock); accounted_delta = parent_delta(dd, dd->dd_phys->dd_used_bytes, used); @@ -859,7 +869,6 @@ dsl_dir_diduse_space(dsl_dir_t *dd, dd_used_t type, dd->dd_phys->dd_compressed_bytes >= -compressed); ASSERT(uncompressed >= 0 || dd->dd_phys->dd_uncompressed_bytes >= -uncompressed); - dmu_buf_will_dirty(dd->dd_dbuf, tx); dd->dd_phys->dd_used_bytes += used; dd->dd_phys->dd_uncompressed_bytes += uncompressed; dd->dd_phys->dd_compressed_bytes += compressed; @@ -894,8 +903,6 @@ void dsl_dir_transfer_space(dsl_dir_t *dd, int64_t delta, dd_used_t oldtype, dd_used_t newtype, dmu_tx_t *tx) { - boolean_t needlock = !MUTEX_HELD(&dd->dd_lock); - ASSERT(dmu_tx_is_syncing(tx)); ASSERT(oldtype < DD_USED_NUM); ASSERT(newtype < DD_USED_NUM); @@ -903,17 +910,15 @@ dsl_dir_transfer_space(dsl_dir_t *dd, int64_t delta, if (delta == 0 || !(dd->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN)) return; - if (needlock) - mutex_enter(&dd->dd_lock); + dmu_buf_will_dirty(dd->dd_dbuf, tx); + mutex_enter(&dd->dd_lock); ASSERT(delta > 0 ? dd->dd_phys->dd_used_breakdown[oldtype] >= delta : dd->dd_phys->dd_used_breakdown[newtype] >= -delta); ASSERT(dd->dd_phys->dd_used_bytes >= ABS(delta)); - dmu_buf_will_dirty(dd->dd_dbuf, tx); dd->dd_phys->dd_used_breakdown[oldtype] -= delta; dd->dd_phys->dd_used_breakdown[newtype] += delta; - if (needlock) - mutex_exit(&dd->dd_lock); + mutex_exit(&dd->dd_lock); } typedef struct dsl_dir_set_qr_arg { -- cgit v1.2.3