diff options
author | Anand Avati <avati@redhat.com> | 2013-04-04 19:35:11 -0700 |
---|---|---|
committer | Anand Avati <avati@redhat.com> | 2013-04-05 17:47:16 -0700 |
commit | 6f6744730e34fa8a161b5f7f2a8ad3f8a7fc30fa (patch) | |
tree | a0de6ae7d951a09f4f888e5ed8abe130cb6730f9 /xlators/cluster/afr/src | |
parent | 862b1164525b8a6d4f8d49b3049093847533f819 (diff) |
afr: let eager-locking do its own overlap checks
Today there is a non-obvious dependence of eager-locking on
write-behind. The reason is that eager-locking works as long
as the inheriting transaction has no overlaps with any of the
transactions already in progress. While write-behind provides
non-overlapping writes as a side-effect most of times (and only
guarantees it when strict-write-ordering option is enabled,
which is not on by default) eager-lock needs the behavior
as a guarantee. This is leading to complex and unwanted checks
for the presence of write-behind in the graph, for the simple
task of checking for overlaps.
This patch removes the interdependence between eager-locking
and write-behind by making eager-locking do its own overlap checks
with in-progress writes.
Change-Id: Iccba1185aeb5f1e7f060089c895a62840787133f
BUG: 912581
Signed-off-by: Anand Avati <avati@redhat.com>
Reviewed-on: http://review.gluster.org/4782
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>
Diffstat (limited to 'xlators/cluster/afr/src')
-rw-r--r-- | xlators/cluster/afr/src/afr-common.c | 7 | ||||
-rw-r--r-- | xlators/cluster/afr/src/afr-transaction.c | 78 | ||||
-rw-r--r-- | xlators/cluster/afr/src/afr.h | 4 |
3 files changed, 87 insertions, 2 deletions
diff --git a/xlators/cluster/afr/src/afr-common.c b/xlators/cluster/afr/src/afr-common.c index 89d964056a0..a9acb409490 100644 --- a/xlators/cluster/afr/src/afr-common.c +++ b/xlators/cluster/afr/src/afr-common.c @@ -2520,6 +2520,8 @@ __afr_fd_ctx_set (xlator_t *this, fd_t *fd) INIT_LIST_HEAD (&fd_ctx->entries); fd_ctx->call_child = -1; + INIT_LIST_HEAD (&fd_ctx->eager_locked); + ret = __fd_ctx_set (fd, this, (uint64_t)(long) fd_ctx); if (ret) gf_log (this->name, GF_LOG_DEBUG, @@ -4086,8 +4088,9 @@ afr_transaction_local_init (afr_local_t *local, xlator_t *this) AFR_NUM_CHANGE_LOGS); if (!local->transaction.txn_changelog) goto out; - if (local->fd && (local->transaction.type == AFR_DATA_TRANSACTION)) - local->transaction.eager_lock_on = priv->eager_lock; + + INIT_LIST_HEAD (&local->transaction.eager_locked); + ret = 0; out: return ret; diff --git a/xlators/cluster/afr/src/afr-transaction.c b/xlators/cluster/afr/src/afr-transaction.c index 502e1ed496f..644544abcc7 100644 --- a/xlators/cluster/afr/src/afr-transaction.c +++ b/xlators/cluster/afr/src/afr-transaction.c @@ -1647,6 +1647,17 @@ afr_transaction_resume (call_frame_t *frame, xlator_t *this) int_lock = &local->internal_lock; priv = this->private; + if (local->transaction.eager_lock_on) { + /* We don't need to retain "local" in the + fd list anymore, writes to all subvols + are finished by now */ + LOCK (&local->fd->lock); + { + list_del_init (&local->transaction.eager_locked); + } + UNLOCK (&local->fd->lock); + } + afr_restore_lk_owner (frame); if (__fop_changelog_needed (frame, this)) { @@ -1681,6 +1692,71 @@ afr_transaction_fop_failed (call_frame_t *frame, xlator_t *this, int child_index child_index, local->transaction.type); } + + +static gf_boolean_t +afr_locals_overlap (afr_local_t *local1, afr_local_t *local2) +{ + uint64_t start1 = local1->transaction.start; + uint64_t start2 = local2->transaction.start; + uint64_t end1 = 0; + uint64_t end2 = 0; + + if (local1->transaction.len) + end1 = start1 + local1->transaction.len - 1; + else + end1 = ULLONG_MAX; + + if (local2->transaction.len) + end2 = start2 + local2->transaction.len - 1; + else + end2 = ULLONG_MAX; + + return ((end1 >= start2) && (end2 >= start1)); +} + + +void +afr_transaction_eager_lock_init (afr_local_t *local, xlator_t *this) +{ + afr_private_t *priv = NULL; + afr_fd_ctx_t *fdctx = NULL; + afr_local_t *each = NULL; + + priv = this->private; + + if (!local->fd) + return; + + if (local->transaction.type != AFR_DATA_TRANSACTION) + return; + + if (!priv->eager_lock) + return; + + fdctx = afr_fd_ctx_get (local->fd, this); + if (!fdctx) + return; + + LOCK (&local->fd->lock); + { + list_for_each_entry (each, &fdctx->eager_locked, + transaction.eager_locked) { + if (afr_locals_overlap (each, local)) { + local->transaction.eager_lock_on = _gf_false; + goto unlock; + } + } + + local->transaction.eager_lock_on = _gf_true; + list_add_tail (&local->transaction.eager_locked, + &fdctx->eager_locked); + } +unlock: + UNLOCK (&local->fd->lock); +} + + int afr_transaction (call_frame_t *frame, xlator_t *this, afr_transaction_type type) { @@ -1700,6 +1776,8 @@ afr_transaction (call_frame_t *frame, xlator_t *this, afr_transaction_type type) goto out; } + afr_transaction_eager_lock_init (local, this); + if (local->fd && local->transaction.eager_lock_on) afr_set_lk_owner (frame, this, local->fd); else diff --git a/xlators/cluster/afr/src/afr.h b/xlators/cluster/afr/src/afr.h index 24bd20f136b..387ed12ec2f 100644 --- a/xlators/cluster/afr/src/afr.h +++ b/xlators/cluster/afr/src/afr.h @@ -677,6 +677,7 @@ typedef struct _afr_local { of the transaction frame */ call_stub_t *resume_stub; + struct list_head eager_locked; int32_t **txn_changelog;//changelog after pre+post ops unsigned char *pre_op; @@ -744,6 +745,9 @@ typedef struct { (i.e, without O_SYNC or O_DSYNC) */ gf_boolean_t witnessed_unstable_write; + + /* list of frames currently in progress */ + struct list_head eager_locked; } afr_fd_ctx_t; |