[PATCH v2] staging: lustre: fix lock imbalance

[Joshua Clayton]

nrs_resource_put_safe() might hold a lock one one struct
while operating on the other.
There are 2 levels of structures.
Use nrs_policy_put(), which has locking baked in.

sparse gives the following warning:
drivers/staging/lustre//lustre/ptlrpc/nrs.c:498:39:
warning: context imbalance in 'nrs_resource_put_safe' -
  different lock contexts for basic block

Signed-off-by: Joshua Clayton 
---
changed for v2:
- remove unused nrs variable

 drivers/staging/lustre/lustre/ptlrpc/nrs.c | 14 ++
 1 file changed, 2 insertions(+), 12 deletions(-)

diff --git a/drivers/staging/lustre/lustre/ptlrpc/nrs.c 
b/drivers/staging/lustre/lustre/ptlrpc/nrs.c
index 7044e1f..57acf8c 100644
--- a/drivers/staging/lustre/lustre/ptlrpc/nrs.c
+++ b/drivers/staging/lustre/lustre/ptlrpc/nrs.c
@@ -482,7 +482,6 @@ static void nrs_resource_get_safe(struct ptlrpc_nrs *nrs,
 static void nrs_resource_put_safe(struct ptlrpc_nrs_resource **resp)
 {
struct ptlrpc_nrs_policy *pols[NRS_RES_MAX];
-   struct ptlrpc_nrs *nrs = NULL;
int i;
 
for (i = 0; i < NRS_RES_MAX; i++) {
@@ -496,18 +495,9 @@ static void nrs_resource_put_safe(struct 
ptlrpc_nrs_resource **resp)
}
 
for (i = 0; i < NRS_RES_MAX; i++) {
-   if (pols[i] == NULL)
-   continue;
-
-   if (nrs == NULL) {
-   nrs = pols[i]->pol_nrs;
-   spin_lock(>nrs_lock);
-   }
-   nrs_policy_put_locked(pols[i]);
+   if (pols[i])
+   nrs_policy_put(pols[i]);
}
-
-   if (nrs != NULL)
-   spin_unlock(>nrs_lock);
 }
 
 /**
-- 
2.6.4

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[PATCH v2] staging: lustre: fix lock imbalance

[Joshua Clayton]

nrs_resource_put_safe() might hold a lock one one struct
while operating on the other.
There are 2 levels of structures.
Use nrs_policy_put(), which has locking baked in.

sparse gives the following warning:
drivers/staging/lustre//lustre/ptlrpc/nrs.c:498:39:
warning: context imbalance in 'nrs_resource_put_safe' -
  different lock contexts for basic block

Signed-off-by: Joshua Clayton 
---
changed for v2:
- remove unused nrs variable

 drivers/staging/lustre/lustre/ptlrpc/nrs.c | 14 ++
 1 file changed, 2 insertions(+), 12 deletions(-)

diff --git a/drivers/staging/lustre/lustre/ptlrpc/nrs.c 
b/drivers/staging/lustre/lustre/ptlrpc/nrs.c
index 7044e1f..57acf8c 100644
--- a/drivers/staging/lustre/lustre/ptlrpc/nrs.c
+++ b/drivers/staging/lustre/lustre/ptlrpc/nrs.c
@@ -482,7 +482,6 @@ static void nrs_resource_get_safe(struct ptlrpc_nrs *nrs,
 static void nrs_resource_put_safe(struct ptlrpc_nrs_resource **resp)
 {
struct ptlrpc_nrs_policy *pols[NRS_RES_MAX];
-   struct ptlrpc_nrs *nrs = NULL;
int i;
 
for (i = 0; i < NRS_RES_MAX; i++) {
@@ -496,18 +495,9 @@ static void nrs_resource_put_safe(struct 
ptlrpc_nrs_resource **resp)
}
 
for (i = 0; i < NRS_RES_MAX; i++) {
-   if (pols[i] == NULL)
-   continue;
-
-   if (nrs == NULL) {
-   nrs = pols[i]->pol_nrs;
-   spin_lock(>nrs_lock);
-   }
-   nrs_policy_put_locked(pols[i]);
+   if (pols[i])
+   nrs_policy_put(pols[i]);
}
-
-   if (nrs != NULL)
-   spin_unlock(>nrs_lock);
 }
 
 /**
-- 
2.6.4

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