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authorDave Chinner <dchinner@redhat.com>2021-08-11 04:00:43 +0300
committerDarrick J. Wong <djwong@kernel.org>2021-08-16 22:09:30 +0300
commitcaa80090d17c89d0caca1dcb4c8a9cdef5335e71 (patch)
tree6455ca8369d70e9a5e8bff85cc42beb93556b9e3 /fs/xfs/xfs_log_cil.c
parentbf034bc827807ac15affa051e6a94b03f93b1a03 (diff)
downloadlinux-caa80090d17c89d0caca1dcb4c8a9cdef5335e71.tar.xz
xfs: attach iclog callbacks in xlog_cil_set_ctx_write_state()
Now that we have a mechanism to guarantee that the callbacks attached to an iclog are owned by the context that attaches them until they drop their reference to the iclog via xlog_state_release_iclog(), we can attach callbacks to the iclog at any time we have an active reference to the iclog. xlog_state_get_iclog_space() always guarantees that the commit record will fit in the iclog it returns, so we can move this IO callback setting to xlog_cil_set_ctx_write_state(), record the commit iclog in the context and remove the need for the commit iclog to be returned by xlog_write() altogether. This, in turn, allows us to move the wakeup for ordered commit record writes up into xlog_cil_set_ctx_write_state(), too, because we have been guaranteed that this commit record will be physically located in the iclog before any waiting commit record at a higher sequence number will be granted iclog space. This further cleans up the post commit record write processing in the CIL push code, especially as xlog_state_release_iclog() will now clean up the context when shutdown errors occur. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Diffstat (limited to 'fs/xfs/xfs_log_cil.c')
-rw-r--r--fs/xfs/xfs_log_cil.c94
1 files changed, 52 insertions, 42 deletions
diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c
index 38917c97a582..ae6449fd5cf2 100644
--- a/fs/xfs/xfs_log_cil.c
+++ b/fs/xfs/xfs_log_cil.c
@@ -646,11 +646,41 @@ xlog_cil_set_ctx_write_state(
xfs_lsn_t lsn = be64_to_cpu(iclog->ic_header.h_lsn);
ASSERT(!ctx->commit_lsn);
- spin_lock(&cil->xc_push_lock);
- if (!ctx->start_lsn)
+ if (!ctx->start_lsn) {
+ spin_lock(&cil->xc_push_lock);
ctx->start_lsn = lsn;
- else
- ctx->commit_lsn = lsn;
+ spin_unlock(&cil->xc_push_lock);
+ return;
+ }
+
+ /*
+ * Take a reference to the iclog for the context so that we still hold
+ * it when xlog_write is done and has released it. This means the
+ * context controls when the iclog is released for IO.
+ */
+ atomic_inc(&iclog->ic_refcnt);
+
+ /*
+ * xlog_state_get_iclog_space() guarantees there is enough space in the
+ * iclog for an entire commit record, so we can attach the context
+ * callbacks now. This needs to be done before we make the commit_lsn
+ * visible to waiters so that checkpoints with commit records in the
+ * same iclog order their IO completion callbacks in the same order that
+ * the commit records appear in the iclog.
+ */
+ spin_lock(&cil->xc_log->l_icloglock);
+ list_add_tail(&ctx->iclog_entry, &iclog->ic_callbacks);
+ spin_unlock(&cil->xc_log->l_icloglock);
+
+ /*
+ * Now we can record the commit LSN and wake anyone waiting for this
+ * sequence to have the ordered commit record assigned to a physical
+ * location in the log.
+ */
+ spin_lock(&cil->xc_push_lock);
+ ctx->commit_iclog = iclog;
+ ctx->commit_lsn = lsn;
+ wake_up_all(&cil->xc_commit_wait);
spin_unlock(&cil->xc_push_lock);
}
@@ -707,8 +737,7 @@ restart:
*/
static int
xlog_cil_write_commit_record(
- struct xfs_cil_ctx *ctx,
- struct xlog_in_core **iclog)
+ struct xfs_cil_ctx *ctx)
{
struct xlog *log = ctx->cil->xc_log;
struct xfs_log_iovec reg = {
@@ -725,8 +754,7 @@ xlog_cil_write_commit_record(
if (xlog_is_shutdown(log))
return -EIO;
- error = xlog_write(log, ctx, &vec, ctx->ticket, iclog,
- XLOG_COMMIT_TRANS);
+ error = xlog_write(log, ctx, &vec, ctx->ticket, XLOG_COMMIT_TRANS);
if (error)
xfs_force_shutdown(log->l_mp, SHUTDOWN_LOG_IO_ERROR);
return error;
@@ -756,7 +784,6 @@ xlog_cil_push_work(
struct xfs_log_vec *lv;
struct xfs_cil_ctx *ctx;
struct xfs_cil_ctx *new_ctx;
- struct xlog_in_core *commit_iclog;
struct xlog_ticket *tic;
int num_iovecs;
int error = 0;
@@ -945,7 +972,7 @@ xlog_cil_push_work(
*/
wait_for_completion(&bdev_flush);
- error = xlog_write(log, ctx, &lvhdr, tic, NULL, XLOG_START_TRANS);
+ error = xlog_write(log, ctx, &lvhdr, tic, XLOG_START_TRANS);
if (error)
goto out_abort_free_ticket;
@@ -953,37 +980,13 @@ xlog_cil_push_work(
if (error)
goto out_abort_free_ticket;
- error = xlog_cil_write_commit_record(ctx, &commit_iclog);
+ error = xlog_cil_write_commit_record(ctx);
if (error)
goto out_abort_free_ticket;
xfs_log_ticket_ungrant(log, tic);
/*
- * Once we attach the ctx to the iclog, it is effectively owned by the
- * iclog and we can only use it while we still have an active reference
- * to the iclog. i.e. once we call xlog_state_release_iclog() we can no
- * longer safely reference the ctx.
- */
- spin_lock(&log->l_icloglock);
- if (xlog_is_shutdown(log)) {
- spin_unlock(&log->l_icloglock);
- goto out_abort;
- }
- ASSERT_ALWAYS(commit_iclog->ic_state == XLOG_STATE_ACTIVE ||
- commit_iclog->ic_state == XLOG_STATE_WANT_SYNC);
- list_add_tail(&ctx->iclog_entry, &commit_iclog->ic_callbacks);
-
- /*
- * now the checkpoint commit is complete and we've attached the
- * callbacks to the iclog we can assign the commit LSN to the context
- * and wake up anyone who is waiting for the commit to complete.
- */
- spin_lock(&cil->xc_push_lock);
- wake_up_all(&cil->xc_commit_wait);
- spin_unlock(&cil->xc_push_lock);
-
- /*
* If the checkpoint spans multiple iclogs, wait for all previous iclogs
* to complete before we submit the commit_iclog. We can't use state
* checks for this - ACTIVE can be either a past completed iclog or a
@@ -995,17 +998,18 @@ xlog_cil_push_work(
* iclog header lsn and compare it to the commit lsn to determine if we
* need to wait on iclogs or not.
*/
+ spin_lock(&log->l_icloglock);
if (ctx->start_lsn != ctx->commit_lsn) {
xfs_lsn_t plsn;
- plsn = be64_to_cpu(commit_iclog->ic_prev->ic_header.h_lsn);
+ plsn = be64_to_cpu(ctx->commit_iclog->ic_prev->ic_header.h_lsn);
if (plsn && XFS_LSN_CMP(plsn, ctx->commit_lsn) < 0) {
/*
* Waiting on ic_force_wait orders the completion of
* iclogs older than ic_prev. Hence we only need to wait
* on the most recent older iclog here.
*/
- xlog_wait_on_iclog(commit_iclog->ic_prev);
+ xlog_wait_on_iclog(ctx->commit_iclog->ic_prev);
spin_lock(&log->l_icloglock);
}
@@ -1013,7 +1017,7 @@ xlog_cil_push_work(
* We need to issue a pre-flush so that the ordering for this
* checkpoint is correctly preserved down to stable storage.
*/
- commit_iclog->ic_flags |= XLOG_ICL_NEED_FLUSH;
+ ctx->commit_iclog->ic_flags |= XLOG_ICL_NEED_FLUSH;
}
/*
@@ -1021,8 +1025,8 @@ xlog_cil_push_work(
* journal IO vs metadata writeback IO is correctly ordered on stable
* storage.
*/
- commit_iclog->ic_flags |= XLOG_ICL_NEED_FUA;
- xlog_state_release_iclog(log, commit_iclog, preflush_tail_lsn);
+ ctx->commit_iclog->ic_flags |= XLOG_ICL_NEED_FUA;
+ xlog_state_release_iclog(log, ctx->commit_iclog, preflush_tail_lsn);
/* Not safe to reference ctx now! */
@@ -1037,9 +1041,15 @@ out_skip:
out_abort_free_ticket:
xfs_log_ticket_ungrant(log, tic);
-out_abort:
ASSERT(xlog_is_shutdown(log));
- xlog_cil_committed(ctx);
+ if (!ctx->commit_iclog) {
+ xlog_cil_committed(ctx);
+ return;
+ }
+ spin_lock(&log->l_icloglock);
+ xlog_state_release_iclog(log, ctx->commit_iclog, 0);
+ /* Not safe to reference ctx now! */
+ spin_unlock(&log->l_icloglock);
}
/*