From: Nadav Amit <[email protected]> Small refactoring to reduce the number of locations in which locks are released in userfaultfd_ctx_read(), as this makes the understanding of the code and its changes harder.
No functional change intended. Cc: Jens Axboe <[email protected]> Cc: Andrea Arcangeli <[email protected]> Cc: Peter Xu <[email protected]> Cc: Alexander Viro <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Signed-off-by: Nadav Amit <[email protected]> --- fs/userfaultfd.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index 4fe07c1a44c6..fedf7c1615d5 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -1039,6 +1039,7 @@ static ssize_t userfaultfd_ctx_read(struct userfaultfd_ctx *ctx, int no_wait, set_current_state(TASK_INTERRUPTIBLE); spin_lock(&ctx->fault_pending_wqh.lock); uwq = find_userfault(ctx); + ret = -EAGAIN; if (uwq) { /* * Use a seqcount to repeat the lockless check @@ -1077,11 +1078,11 @@ static ssize_t userfaultfd_ctx_read(struct userfaultfd_ctx *ctx, int no_wait, /* careful to always initialize msg if ret == 0 */ *msg = uwq->msg; - spin_unlock(&ctx->fault_pending_wqh.lock); ret = 0; - break; } spin_unlock(&ctx->fault_pending_wqh.lock); + if (!ret) + break; spin_lock(&ctx->event_wqh.lock); uwq = find_userfault_evt(ctx); @@ -1099,17 +1100,14 @@ static ssize_t userfaultfd_ctx_read(struct userfaultfd_ctx *ctx, int no_wait, * reference on it. */ userfaultfd_ctx_get(fork_nctx); - spin_unlock(&ctx->event_wqh.lock); - ret = 0; - break; + } else { + userfaultfd_event_complete(ctx, uwq); } - - userfaultfd_event_complete(ctx, uwq); - spin_unlock(&ctx->event_wqh.lock); ret = 0; - break; } spin_unlock(&ctx->event_wqh.lock); + if (!ret) + break; if (signal_pending(current)) { ret = -ERESTARTSYS; -- 2.25.1
