[Libvirt-cim] [PATCH V6 07/20] DevicePool, reimplement get_diskpool_config with libvirt

Wenchao Xia xiawenc at linux.vnet.ibm.com
Mon Mar 25 09:52:47 UTC 2013


  Original implemetion may return pools with NULL name if
some pool disappear between two libvirt pool API call. And
originally it return the number of pools and negative value
when error happens, but caller of this function consider
number = 0 as error.
  As a fix, this patch changed the function prototype, it do
not return the pool number anymore, it returns 0 on success
and negative on fail now. Code for checking the risk of returning
pools with NULL name is also added.
  Other small fixes are: return false in get_disk_parent() when
strdup() fail, set member to NULL in parse_diskpool_line() after
free, removed the duplicated macro declaration in Virt_DevicePool.c
file for VIR_USE_LIBVIRT_STORAGE, refined the code in
get_diskpool_config() when VIR_USE_LIBVIRT_STORAGE == 0.

Signed-off-by: Wenchao Xia <xiawenc at linux.vnet.ibm.com>
---
 src/Virt_DevicePool.c |  220 ++++++++++++++++++++++++++++++++-----------------
 src/Virt_DevicePool.h |    4 +
 2 files changed, 149 insertions(+), 75 deletions(-)

diff --git a/src/Virt_DevicePool.c b/src/Virt_DevicePool.c
index 08677e2..a8dc9cd 100644
--- a/src/Virt_DevicePool.c
+++ b/src/Virt_DevicePool.c
@@ -51,21 +51,30 @@ struct tmp_disk_pool {
         bool primordial;
 };
 
+static void free_diskpool(struct tmp_disk_pool *pools, int count)
+{
+        int i;
+
+        if (pools == NULL) {
+                return;
+        }
+
+        for (i = 0; i < count; i++) {
+                free(pools[i].tag);
+                free(pools[i].path);
+        }
+
+        free(pools);
+}
+
 /*
- * Right now, detect support and use it, if available.
- * Later, this can be a configure option if needed
+ * If fail, *_pools will be freed and set to NULL, and *_count will be set to
+ * zero.
  */
-#if LIBVIR_VERSION_NUMBER > 4000
-# define VIR_USE_LIBVIRT_STORAGE 1
-#else
-# define VIR_USE_LIBVIRT_STORAGE 0
-#endif
-
 static bool get_disk_parent(struct tmp_disk_pool **_pools,
                             int *_count)
 {
         struct tmp_disk_pool *pools = NULL;
-        int ret = false;
         int count;
 
         count = *_count;
@@ -74,23 +83,31 @@ static bool get_disk_parent(struct tmp_disk_pool **_pools,
         pools = realloc(pools, (count + 1) * (sizeof(*pools)));
         if (pools == NULL) {
                 CU_DEBUG("Failed to alloc new pool");
-                goto out;
+                pools = *_pools;
+                goto fail;
         }
 
-        pools[count].tag = strdup("0");
         pools[count].path = NULL;
         pools[count].primordial = true;
+        pools[count].tag = strdup("0");
+        if (pools[count].tag == NULL) {
+                count++;
+                goto fail;
+        }
         count++;
 
         *_count = count;
         *_pools = pools;
-        ret = true;
+        return true;
 
- out:
-        return ret;
+ fail:
+        free_diskpool(pools, count);
+        /* old pool is invalid, update it */
+        *_count = 0;
+        *_pools = NULL;
+        return false;
 }
 
-
 #if VIR_USE_LIBVIRT_STORAGE
 int get_disk_pool(virStoragePoolPtr poolptr, struct virt_pool **pool)
 {
@@ -117,52 +134,80 @@ int get_disk_pool(virStoragePoolPtr poolptr, struct virt_pool **pool)
         return ret;
 }
 
+/*
+ * return 0 on success, negative on fail, *pools and *_count will be set
+ * only on success .
+ */
 static int get_diskpool_config(virConnectPtr conn,
-                               struct tmp_disk_pool **_pools)
+                               struct tmp_disk_pool **_pools,
+                               int *_count)
 {
-        int count = 0;
+        int count = 0, realcount = 0;
         int i;
         char ** names = NULL;
         struct tmp_disk_pool *pools = NULL;
+        int ret = 0;
 
         count = virConnectNumOfStoragePools(conn);
-        if (count <= 0)
+        if (count < 0) {
+                ret = count;
                 goto out;
+        } else if (count == 0) {
+                goto set_parent;
+        }
 
         names = calloc(count, sizeof(char *));
         if (names == NULL) {
                 CU_DEBUG("Failed to alloc space for %i pool names", count);
-                count = 0;
+                ret = -1;
                 goto out;
         }
 
-        if (virConnectListStoragePools(conn, names, count) == -1) {
-                CU_DEBUG("Failed to get storage pools");
-                count = 0;
-                goto out;
+        realcount = virConnectListStoragePools(conn, names, count);
+        if (realcount < 0) {
+                CU_DEBUG("Failed to get storage pools, return %d.", realcount);
+                ret = realcount;
+                goto free_names;
+        }
+        if (realcount == 0) {
+                CU_DEBUG("Zero pools got, but prelist is %d.", count);
+                goto set_parent;
         }
 
-        pools = calloc(count, sizeof(*pools));
+        pools = calloc(realcount, sizeof(*pools));
         if (pools == NULL) {
-                CU_DEBUG("Failed to alloc space for %i pool structs", count);
-                goto out;
+                CU_DEBUG("Failed to alloc space for %i pool structs",
+                         realcount);
+                ret = -2;
+                goto free_names;
         }
 
-        for (i = 0; i < count; i++) {
-                pools[i].tag = strdup(names[i]);
+        for (i = 0; i < realcount; i++) {
+                pools[i].tag = names[i];
+                names[i] = NULL;
                 pools[i].primordial = false;
         }
 
- out:
-        for (i = 0; i < count; i++)
-                free(names[i]);
-        free(names);
-
-        get_disk_parent(&pools, &count);
+ set_parent:
+        if (!get_disk_parent(&pools, &realcount)) {
+                CU_DEBUG("Failed in adding parentpool.");
+                ret = -4;
+                /* pools is already freed in get_disk_parent().*/
+                goto free_names;
+        }
 
+        /* succeed */
         *_pools = pools;
+        *_count = realcount;
+
+ free_names:
+        for (i = 0; i < count; i++) {
+                free(names[i]);
+        }
+        free(names);
 
-        return count;
+ out:
+        return ret;
 }
 
 static bool diskpool_set_capacity(virConnectPtr conn,
@@ -279,8 +324,8 @@ static bool _diskpool_is_member(virConnectPtr conn,
         return result;
 }
 #else
-static int parse_diskpool_line(struct tmp_disk_pool *pool,
-                               const char *line)
+static bool parse_diskpool_line(struct tmp_disk_pool *pool,
+                                const char *line)
 {
         int ret;
 
@@ -288,48 +333,81 @@ static int parse_diskpool_line(struct tmp_disk_pool *pool,
         if (ret != 2) {
                 free(pool->tag);
                 free(pool->path);
+                pool->tag = NULL;
+                pool->path = NULL;
         }
         pool->primordial = false;
 
         return (ret == 2);
 }
 
+/*
+ * return 0 on success, negative on fail, *pools and *_count will be set
+ * only on success .
+ */
 static int get_diskpool_config(virConnectPtr conn,
-                               struct tmp_disk_pool **_pools)
+                               struct tmp_disk_pool **_pools,
+                               int *_count)
 {
         const char *path = DISK_POOL_CONFIG;
         FILE *config;
         char *line = NULL;
         size_t len = 0;
-        int count = 0;
-        struct tmp_disk_pool *pools = NULL;
+        int count = 0, ret = 0;
+        struct tmp_disk_pool *pools = NULL, *new_pools = NULL, *pool = NULL;
 
         config = fopen(path, "r");
         if (config == NULL) {
                 CU_DEBUG("Failed to open %s: %m", path);
-                return 0;
+                ret = -1;
+                goto out;
         }
 
+        pool = calloc(1, sizeof(*pool));
+        if (!pool) {
+                CU_DEBUG("Failed to calloc pool");
+                ret = -2;
+                goto close;
+        }
+
+        /* *line will be automatically freed by getline() */
         while (getline(&line, &len, config) > 0) {
-                pools = realloc(pools,
-                                (count + 1) * (sizeof(*pools)));
-                if (pools == NULL) {
-                        CU_DEBUG("Failed to alloc new pool");
-                        goto out;
+                if (parse_diskpool_line(pool, line)) {
+                        new_pools = realloc(pools,
+                                           (count + 1) * (sizeof(*pools)));
+                        if (new_pools == NULL) {
+                                CU_DEBUG("Failed to alloc new pool");
+                                ret = -3;
+                                goto free_pools;
+                        }
+                        pools = new_pools;
+                        pools[count] = *pool;
+                        memset(pool, 0, sizeof(*pool));
+                        count++;
                 }
+        }
 
-                if (parse_diskpool_line(&pools[count], line))
-                        count++;
+        if (!get_disk_parent(&pools, &count)) {
+                CU_DEBUG("Failed in adding parentpool.");
+                ret = -4;
+                /* pools is already freed by get_disk_parent() */
+                goto clean;
         }
 
+        /* succeed */
+        *_pools = pools;
+        *_count = count;
+        goto clean;
 
-        get_disk_parent(&pools, &count);
- out:
+ free_pools:
+        free_diskpool(pools, count);
+ clean:
         free(line);
-        *_pools = pools;
+        free_diskpool(pool, 1);
+ close:
         fclose(config);
-
-        return count;
+ out:
+        return ret;
 }
 
 static bool diskpool_set_capacity(virConnectPtr conn,
@@ -367,39 +445,23 @@ static bool diskpool_set_capacity(virConnectPtr conn,
 }
 
 static bool _diskpool_is_member(virConnectPtr conn,
-                                const struct disk_pool *pool,
+                                const struct tmp_disk_pool *pool,
                                 const char *file)
 {
         return STARTS_WITH(file, pool->path);
 }
 #endif
 
-static void free_diskpool(struct tmp_disk_pool *pools, int count)
-{
-        int i;
-
-        if (pools == NULL)
-                return;
-
-        for (i = 0; i < count; i++) {
-                free(pools[i].tag);
-                free(pools[i].path);
-        }
-
-        free(pools);
-}
-
 static char *_diskpool_member_of(virConnectPtr conn,
                                  const char *file)
 {
         struct tmp_disk_pool *pools = NULL;
         int count;
-        int i;
+        int i, ret;
         char *pool = NULL;
 
-        count = get_diskpool_config(conn, &pools);
-        if (count == 0) {
-                free(pools);
+        ret = get_diskpool_config(conn, &pools, &count);
+        if (ret < 0) {
                 return NULL;
         }
 
@@ -1088,9 +1150,17 @@ static CMPIStatus diskpool_instance(virConnectPtr conn,
         CMPIStatus s = {CMPI_RC_OK, NULL};
         struct tmp_disk_pool *pools = NULL;
         int count = 0;
-        int i;
+        int i, ret;
 
-        count = get_diskpool_config(conn, &pools);
+        ret = get_diskpool_config(conn, &pools, &count);
+        if (ret < 0) {
+                CU_DEBUG("Failed to get diskpool config, return is %d.", ret);
+                cu_statusf(broker, &s,
+                           CMPI_RC_ERR_FAILED,
+                           "Failed to get diskpool config, return is %d.",
+                           ret);
+                return s;
+        }
         if ((id == NULL) && (count == 0)) {
                 CU_DEBUG("No defined DiskPools");
                 free(pools);
diff --git a/src/Virt_DevicePool.h b/src/Virt_DevicePool.h
index d160bf1..6b44863 100644
--- a/src/Virt_DevicePool.h
+++ b/src/Virt_DevicePool.h
@@ -28,6 +28,10 @@
 
 #include "pool_parsing.h"
 
+/*
+ * Right now, detect support and use it, if available.
+ * Later, this can be a configure option if needed
+ */
 #if LIBVIR_VERSION_NUMBER > 4000
 # define VIR_USE_LIBVIRT_STORAGE 1
 #else
-- 
1.7.1





More information about the Libvirt-cim mailing list