LU-16890 obd: OBD_FREE_PRE() to ignore NULL pointers

This patch modifies OBD_FREE_PRE() to not LASSERT
when null pointer is passed as the kfree() function
accepts NULL as no-op.

This is first set of patch that modifies the definitions.
Subsequent set will modify the callers to accept this
case.

As as example:

This caller will now be change to:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
char *test;
OBD_ALLOC(test, 32);
...
OBD_FREE(test, 32);

Previously the caller used to be:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
char *test;
OBD_ALLOC(test, 32);
...
if (test)
	OBD_FREE(test, 32);

Test-Parameters: trivial
Signed-off-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Change-Id: I735c8210e30f58da19ede4c87c07186108b35b99
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/51332
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Neil Brown <neilb@suse.de>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Oleg Drokin <green@whamcloud.com>

diff --git a/lustre/include/obd_support.h b/lustre/include/obd_support.h
index 6dd4c59..5ca93d3 100644 (file)
--- a/lustre/include/obd_support.h
+++ b/lustre/include/obd_support.h
@@ -45,8 +45,8 @@
 /* global variables */
 extern struct lprocfs_stats *obd_memory;
 enum {
-        OBD_MEMORY_STAT = 0,
-        OBD_STATS_NUM,
+       OBD_MEMORY_STAT = 0,
+       OBD_STATS_NUM,
 };
 
 extern unsigned int obd_debug_peer_on_timeout;
@@ -54,7 +54,7 @@ extern unsigned int obd_dump_on_timeout;
 extern unsigned int obd_dump_on_eviction;
 extern unsigned int obd_lbug_on_eviction;
 /* obd_timeout should only be used for recovery, not for
-   networking / disk / timings affected by load (use Adaptive Timeouts) */
+ * networking / disk / timings affected by load (use Adaptive Timeouts) */
 extern unsigned int obd_timeout;          /* seconds */
 extern unsigned int ldlm_timeout;         /* seconds */
 extern unsigned int ping_interval;       /* seconds */
@@ -544,7 +544,7 @@ extern char obd_jobid_var[];
 #define OBD_FAIL_MGS_LDLM_REPLY_NET     0x90d
 #define OBD_FAIL_MGS_WRITE_TARGET_DELAY         0x90e
 
-#define OBD_FAIL_QUOTA_DQACQ_NET                       0xA01
+#define OBD_FAIL_QUOTA_DQACQ_NET         0xA01
 #define OBD_FAIL_QUOTA_EDQUOT            0xA02
 #define OBD_FAIL_QUOTA_DELAY_REINT       0xA03
 #define OBD_FAIL_QUOTA_RECOVERABLE_ERR   0xA04
@@ -707,7 +707,7 @@ extern char obd_jobid_var[];
 /* FLR */
 #define OBD_FAIL_FLR_LV_DELAY                  0x1A01
 #define OBD_FAIL_FLR_LV_INC                    0x1A02 /* unused since 2.15 */
-#define OBD_FAIL_FLR_RANDOM_PICK_MIRROR        0x1A03
+#define OBD_FAIL_FLR_RANDOM_PICK_MIRROR                0x1A03
 
 /* DT */
 #define OBD_FAIL_DT_DECLARE_ATTR_GET           0x2000
@@ -798,14 +798,14 @@ extern __u64 obd_max_alloc;
 
 static inline void obd_memory_add(long size)
 {
-        obd_alloc += size;
-        if (obd_alloc > obd_max_alloc)
-                obd_max_alloc = obd_alloc;
+       obd_alloc += size;
+       if (obd_alloc > obd_max_alloc)
+               obd_max_alloc = obd_alloc;
 }
 
 static inline void obd_memory_sub(long size)
 {
-        obd_alloc -= size;
+       obd_alloc -= size;
 }
 
 #define obd_memory_sum() (obd_alloc)
@@ -824,9 +824,12 @@ static inline void obd_memory_sub(long size)
 
 /* message format here needs to match regexp in lustre/tests/leak_finder.pl */
 #define OBD_FREE_PRE(ptr, size, name)                                  \
-       LASSERT(ptr);                                                   \
-       obd_memory_sub(size);                                           \
-       LIBCFS_MEM_MSG(ptr, size, name)
+do {                                                                   \
+       if (likely(ptr)) {                                              \
+               obd_memory_sub(size);                                   \
+               LIBCFS_MEM_MSG(ptr, size, name);                        \
+       }                                                               \
+} while (0)
 
 #else /* !OBD_DEBUG_MEMUSAGE */
 
@@ -899,7 +902,7 @@ do {                                                                          \
                OBD_ALLOC_GFP(ptr, size, GFP_NOFS | __GFP_NOWARN |            \
                              (((size) > PAGE_SIZE) ? __GFP_NORETRY : 0));    \
        if (ptr == NULL)                                                      \
-                OBD_VMALLOC(ptr, size);                                       \
+               OBD_VMALLOC(ptr, size);                                       \
 } while (0)
 
 #define OBD_ALLOC_PTR_ARRAY_LARGE(ptr, n)                              \
@@ -929,10 +932,12 @@ do {                                                                            \
 
 #define OBD_FREE(ptr, size)                                                  \
 do {                                                                         \
-       OBD_FREE_PRE(ptr, size, "kfreed");                                    \
-       POISON(ptr, 0x5a, size);                                              \
-       kfree(ptr);                                                           \
-       POISON_PTR(ptr);                                                      \
+       if (likely(ptr)) {                                                    \
+               OBD_FREE_PRE(ptr, size, "kfreed");                            \
+               POISON(ptr, 0x5a, size);                                      \
+               kfree(ptr);                                                   \
+               POISON_PTR(ptr);                                              \
+       }                                                                     \
 } while (0)
 
 #define OBD_FREE_LARGE(ptr, size)                                            \
@@ -955,9 +960,9 @@ do {                                                                              \
  * love to assert on that, but slab.c keeps kmem_cache_s all to itself. */
 #define OBD_SLAB_FREE_RTN0(ptr, slab)                                         \
 ({                                                                            \
-       kmem_cache_free((slab), (ptr));                                    \
-        (ptr) = NULL;                                                         \
-        0;                                                                    \
+       kmem_cache_free((slab), (ptr));                                       \
+       (ptr) = NULL;                                                         \
+       0;                                                                    \
 })
 
 #define __OBD_SLAB_ALLOC_VERBOSE(ptr, slab, cptab, cpt, size, type)          \
@@ -979,11 +984,13 @@ do {                                                                            \
 #define OBD_FREE_PTR_ARRAY(ptr, n) OBD_FREE(ptr, (n) * sizeof(*(ptr)))
 
 #define OBD_SLAB_FREE(ptr, slab, size)                                        \
-do {                                                                          \
-        OBD_FREE_PRE(ptr, size, "slab-freed");                                \
-       POISON(ptr, 0x5a, size);                                              \
-       kmem_cache_free(slab, ptr);                                        \
-        POISON_PTR(ptr);                                                      \
+do {                                                                         \
+       if (likely(ptr)) {                                                    \
+               OBD_FREE_PRE(ptr, size, "slab-freed");                        \
+               POISON(ptr, 0x5a, size);                                      \
+               kmem_cache_free(slab, ptr);                                   \
+               POISON_PTR(ptr);                                              \
+       }                                                                     \
 } while(0)
 
 #define OBD_SLAB_ALLOC(ptr, slab, size)                                              \
@@ -1001,7 +1008,7 @@ do {                                                                          \
 #define OBD_SLAB_ALLOC_PTR_GFP(ptr, slab, flags)                             \
        OBD_SLAB_ALLOC_GFP(ptr, slab, sizeof(*(ptr)), flags)
 
-#define OBD_SLAB_CPT_ALLOC_PTR_GFP(ptr, slab, cptab, cpt, flags)                     \
+#define OBD_SLAB_CPT_ALLOC_PTR_GFP(ptr, slab, cptab, cpt, flags)             \
        OBD_SLAB_CPT_ALLOC_GFP(ptr, slab, cptab, cpt, sizeof(*(ptr)), flags)
 
 #define OBD_SLAB_FREE_PTR(ptr, slab)                                         \