[PATCH 28/29] xfs: support nowait semantics for xc_ctx_lock in xlog_cil_commit()

Hao Xu
2023-08-25T14:06:45Z

Apply trylock logic for xc_ctx_lock in xlog_cil_commit() in nowait
case and error out -EAGAIN for xlog_cil_commit().

Signed-off-by: Hao Xu <howeyxu@tencent.com>
---
fs/xfs/xfs_log_cil.c | 12 ++++++++++--
fs/xfs/xfs_log_priv.h | 2 +-
fs/xfs/xfs_trans.c | 4 +++-
3 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c
index b31830ee36dd..6d054359bbb5 100644
--- a/fs/xfs/xfs_log_cil.c
+++ b/fs/xfs/xfs_log_cil.c
@@ -1613,7 +1613,7 @@ xlog_cil_process_intents(
* background commit, returns without it held once background commits are
* allowed again.
*/
-void
+int
xlog_cil_commit(
struct xlog *log,
struct xfs_trans *tp,
@@ -1623,6 +1623,7 @@ xlog_cil_commit(
struct xfs_cil *cil = log->l_cilp;
struct xfs_log_item *lip, *next;
uint32_t released_space = 0;
+ bool nowait = tp->t_flags & XFS_TRANS_NOWAIT;

/*
* Do all necessary memory allocation before we lock the CIL.
@@ -1632,7 +1633,12 @@ xlog_cil_commit(
xlog_cil_alloc_shadow_bufs(log, tp);

/* lock out background commit */
- down_read(&cil->xc_ctx_lock);
+ if (nowait) {
+ if (!down_read_trylock(&cil->xc_ctx_lock))
+ return -EAGAIN;
+ } else {
+ down_read(&cil->xc_ctx_lock);
+ }

if (tp->t_flags & XFS_TRANS_HAS_INTENT_DONE)
released_space = xlog_cil_process_intents(cil, tp);
@@ -1668,6 +1674,8 @@ xlog_cil_commit(

/* xlog_cil_push_background() releases cil->xc_ctx_lock */
xlog_cil_push_background(log);
+
+ return 0;
}

/*
diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h
index 41edaa0ae869..eb7a1241deab 100644
--- a/fs/xfs/xfs_log_priv.h
+++ b/fs/xfs/xfs_log_priv.h
@@ -580,7 +580,7 @@ int xlog_cil_init(struct xlog *log);
void xlog_cil_init_post_recovery(struct xlog *log);
void xlog_cil_destroy(struct xlog *log);
bool xlog_cil_empty(struct xlog *log);
-void xlog_cil_commit(struct xlog *log, struct xfs_trans *tp,
+int xlog_cil_commit(struct xlog *log, struct xfs_trans *tp,
xfs_csn_t *commit_seq, bool regrant);
void xlog_cil_set_ctx_write_state(struct xfs_cil_ctx *ctx,
struct xlog_in_core *iclog);
diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
index f1f84a3dd456..e5beda636a37 100644
--- a/fs/xfs/xfs_trans.c
+++ b/fs/xfs/xfs_trans.c
@@ -1037,7 +1037,9 @@ __xfs_trans_commit(
xfs_trans_apply_sb_deltas(tp);
xfs_trans_apply_dquot_deltas(tp);

- xlog_cil_commit(log, tp, &commit_seq, regrant);
+ error = xlog_cil_commit(log, tp, &commit_seq, regrant);
+ if (error)
+ goto out_unreserve;

xfs_trans_free(tp);

--
2.25.1