Merge branch 'xfs-misc-fixes-2-for-3.16' into for-next

[sagit-ice-cold/kernel_xiaomi_msm8998.git] / fs / xfs / xfs_log_cil.c

diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c
index de835da..b3425b3 100644 (file)
--- a/fs/xfs/xfs_log_cil.c
+++ b/fs/xfs/xfs_log_cil.c
@@ -386,7 +386,15 @@ xlog_cil_committed(
        xfs_extent_busy_clear(mp, &ctx->busy_extents,
                             (mp->m_flags & XFS_MOUNT_DISCARD) && !abort);
 
+       /*
+        * If we are aborting the commit, wake up anyone waiting on the
+        * committing list.  If we don't, then a shutdown we can leave processes
+        * waiting in xlog_cil_force_lsn() waiting on a sequence commit that
+        * will never happen because we aborted it.
+        */
        spin_lock(&ctx->cil->xc_push_lock);
+       if (abort)
+               wake_up_all(&ctx->cil->xc_commit_wait);
        list_del(&ctx->committing);
        spin_unlock(&ctx->cil->xc_push_lock);
 
@@ -565,8 +573,18 @@ restart:
        spin_lock(&cil->xc_push_lock);
        list_for_each_entry(new_ctx, &cil->xc_committing, committing) {
                /*
+                * Avoid getting stuck in this loop because we were woken by the
+                * shutdown, but then went back to sleep once already in the
+                * shutdown state.
+                */
+               if (XLOG_FORCED_SHUTDOWN(log)) {
+                       spin_unlock(&cil->xc_push_lock);
+                       goto out_abort_free_ticket;
+               }
+
+               /*
                 * Higher sequences will wait for this one so skip them.
-                * Don't wait for own own sequence, either.
+                * Don't wait for our own sequence, either.
                 */
                if (new_ctx->sequence >= ctx->sequence)
                        continue;
@@ -811,6 +829,13 @@ restart:
         */
        spin_lock(&cil->xc_push_lock);
        list_for_each_entry(ctx, &cil->xc_committing, committing) {
+               /*
+                * Avoid getting stuck in this loop because we were woken by the
+                * shutdown, but then went back to sleep once already in the
+                * shutdown state.
+                */
+               if (XLOG_FORCED_SHUTDOWN(log))
+                       goto out_shutdown;
                if (ctx->sequence > sequence)
                        continue;
                if (!ctx->commit_lsn) {
@@ -834,14 +859,12 @@ restart:
         * push sequence after the above wait loop and the CIL still contains
         * dirty objects.
         *
-        * When the push occurs, it will empty the CIL and
-        * atomically increment the currect sequence past the push sequence and
-        * move it into the committing list. Of course, if the CIL is clean at
-        * the time of the push, it won't have pushed the CIL at all, so in that
-        * case we should try the push for this sequence again from the start
-        * just in case.
+        * When the push occurs, it will empty the CIL and atomically increment
+        * the currect sequence past the push sequence and move it into the
+        * committing list. Of course, if the CIL is clean at the time of the
+        * push, it won't have pushed the CIL at all, so in that case we should
+        * try the push for this sequence again from the start just in case.
         */
-
        if (sequence == cil->xc_current_sequence &&
            !list_empty(&cil->xc_cil)) {
                spin_unlock(&cil->xc_push_lock);
@@ -850,6 +873,17 @@ restart:
 
        spin_unlock(&cil->xc_push_lock);
        return commit_lsn;
+
+       /*
+        * We detected a shutdown in progress. We need to trigger the log force
+        * to pass through it's iclog state machine error handling, even though
+        * we are already in a shutdown state. Hence we can't return
+        * NULLCOMMITLSN here as that has special meaning to log forces (i.e.
+        * LSN is already stable), so we return a zero LSN instead.
+        */
+out_shutdown:
+       spin_unlock(&cil->xc_push_lock);
+       return 0;
 }
 
 /*