[lustre-devel] [PATCH] staging: lustre: grab the cld->cld_lock mutex unconditionally

[Cihangir Akturk]

Instead of using the locked variable as a helper to determine the state
of the mutex cld->cld_lock, expand the scope of the recover_cld variable
and assign to the cld->cld_recover variable depending on whether the
value of the recover_cld variable is valid or not.

As a bonus, code size is slightly reduced.

before:
text    data     bss     dec     hex filename
26188    2256    4208   32652    7f8c drivers/staging/lustre/lustre/mgc/mgc_request.o

after:
text    data     bss     dec     hex filename
26140    2256    4208   32604    7f5c drivers/staging/lustre/lustre/mgc/mgc_request.o

Additionally silences the following warning reported by coccinelle:

drivers/staging/lustre/lustre/mgc/mgc_request.c:359:2-12: second lock on
line 365

Signed-off-by: Cihangir Akturk <cakturk at gmail.com>
---
 drivers/staging/lustre/lustre/mgc/mgc_request.c | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/drivers/staging/lustre/lustre/mgc/mgc_request.c b/drivers/staging/lustre/lustre/mgc/mgc_request.c
index eee0b66..6718474 100644
--- a/drivers/staging/lustre/lustre/mgc/mgc_request.c
+++ b/drivers/staging/lustre/lustre/mgc/mgc_request.c
@@ -288,7 +288,7 @@ config_log_add(struct obd_device *obd, char *logname,
 	struct config_llog_data *cld;
 	struct config_llog_data *sptlrpc_cld;
 	struct config_llog_data *params_cld;
-	bool locked = false;
+	struct config_llog_data *recover_cld = ERR_PTR(-EINVAL);
 	char			seclogname[32];
 	char			*ptr;
 	int			rc;
@@ -338,8 +338,6 @@ config_log_add(struct obd_device *obd, char *logname,
 
 	LASSERT(lsi->lsi_lmd);
 	if (!(lsi->lsi_lmd->lmd_flags & LMD_FLG_NOIR)) {
-		struct config_llog_data *recover_cld;
-
 		ptr = strrchr(seclogname, '-');
 		if (ptr) {
 			*ptr = 0;
@@ -355,14 +353,11 @@ config_log_add(struct obd_device *obd, char *logname,
 			rc = PTR_ERR(recover_cld);
 			goto out_cld;
 		}
-
-		mutex_lock(&cld->cld_lock);
-		locked = true;
-		cld->cld_recover = recover_cld;
 	}
 
-	if (!locked)
-		mutex_lock(&cld->cld_lock);
+	mutex_lock(&cld->cld_lock);
+	if (!IS_ERR(recover_cld))
+		cld->cld_recover = recover_cld;
 	cld->cld_params = params_cld;
 	cld->cld_sptlrpc = sptlrpc_cld;
 	mutex_unlock(&cld->cld_lock);
-- 
2.7.4