From 880cbc5da3f8041dd92cba31d5a8baa0c90049bc Mon Sep 17 00:00:00 2001
From: Ziye Yang <ziye.yang@intel.com>
Date: Thu, 9 May 2019 22:13:41 +0800
Subject: [PATCH] blobfs: fix the semphore usage issue in spdk_file_read

We need to move sub_reads++ statement earlier. Otherwise if
the read fails, the sem_wait(&channel->sem) call number
is not correct.

Signed-off-by: Ziye Yang <ziye.yang@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/453788 (master)

(cherry picked from commit bc1495b0f0270d7cbf7a9e64c1bea757b4056c9f)
Change-Id: I05281a74bef78e4f80ce8d202b47849d1e6c2009
Signed-off-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/457285
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
---
 lib/blobfs/blobfs.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/blobfs/blobfs.c b/lib/blobfs/blobfs.c
index ecf165bb6..be646dae2 100644
--- a/lib/blobfs/blobfs.c
+++ b/lib/blobfs/blobfs.c
@@ -2456,6 +2456,8 @@ spdk_file_read(struct spdk_file *file, struct spdk_fs_thread_ctx *ctx,
 		if (length > (final_offset - offset)) {
 			length = final_offset - offset;
 		}
+
+		sub_reads++;
 		rc = __file_read(file, payload, offset, length, channel);
 		if (rc == 0) {
 			final_length += length;
@@ -2464,7 +2466,6 @@ spdk_file_read(struct spdk_file *file, struct spdk_fs_thread_ctx *ctx,
 		}
 		payload += length;
 		offset += length;
-		sub_reads++;
 	}
 	pthread_spin_unlock(&file->lock);
 	while (sub_reads-- > 0) {