[sheepdog] [PATCH v2] using xmalloc() to allocate sd_inode instead of using memory on stack

[Robin Dong]

'struct sd_inode' may be very large, so putting it on stack is not safe.

Signed-off-by: Robin Dong <sanbai at taobao.com>
---
v1-->v2:
  1. change size of xmalloc() to SD_INODE_HEADER_SIZE in vid_to_name_tag()

 dog/common.c    | 15 ++++++++-------
 dog/vdi.c       | 17 +++++++++--------
 sheep/http/kv.c |  8 +++++---
 3 files changed, 22 insertions(+), 18 deletions(-)

diff --git a/dog/common.c b/dog/common.c
index 4be1afd..13eabd2 100644
--- a/dog/common.c
+++ b/dog/common.c
@@ -132,7 +132,7 @@ int parse_vdi(vdi_parser_func_t func, size_t size, void *data)
 {
 	int ret;
 	unsigned long nr;
-	static struct sd_inode i;
+	struct sd_inode *i = xmalloc(sizeof(*i));
 	struct sd_req req;
 	struct sd_rsp *rsp = (struct sd_rsp *)&req;
 	static DECLARE_BITMAP(vdi_inuse, SD_NR_VDIS);
@@ -156,20 +156,20 @@ int parse_vdi(vdi_parser_func_t func, size_t size, void *data)
 		oid = vid_to_vdi_oid(nr);
 
 		/* for B-tree inode, we also need sd_index_header */
-		ret = dog_read_object(oid, &i, SD_INODE_HEADER_SIZE +
+		ret = dog_read_object(oid, i, SD_INODE_HEADER_SIZE +
 				      sizeof(struct sd_index_header), 0, true);
 		if (ret != SD_RES_SUCCESS) {
 			sd_err("Failed to read inode header");
 			continue;
 		}
 
-		if (i.name[0] == '\0') /* this VDI has been deleted */
+		if (i->name[0] == '\0') /* this VDI has been deleted */
 			continue;
 
 		if (size > SD_INODE_HEADER_SIZE) {
-			rlen = sd_inode_get_meta_size(&i, size);
+			rlen = sd_inode_get_meta_size(i, size);
 			ret = dog_read_object(oid,
-					((char *)&i) + SD_INODE_HEADER_SIZE,
+					((char *)i) + SD_INODE_HEADER_SIZE,
 					      rlen, SD_INODE_HEADER_SIZE, true);
 
 			if (ret != SD_RES_SUCCESS) {
@@ -178,11 +178,12 @@ int parse_vdi(vdi_parser_func_t func, size_t size, void *data)
 			}
 		}
 
-		snapid = vdi_is_snapshot(&i) ? i.snap_id : 0;
-		func(i.vdi_id, i.name, i.tag, snapid, 0, &i, data);
+		snapid = vdi_is_snapshot(i) ? i->snap_id : 0;
+		func(i->vdi_id, i->name, i->tag, snapid, 0, i, data);
 	}
 
 out:
+	free(i);
 	return ret;
 }
 
diff --git a/dog/vdi.c b/dog/vdi.c
index 09a87b2..999d4be 100644
--- a/dog/vdi.c
+++ b/dog/vdi.c
@@ -2153,18 +2153,19 @@ out:
 
 static int vid_to_name_tag(uint32_t vid, char *name, char *tag)
 {
-	struct sd_inode inode;
+	struct sd_inode *inode = xmalloc(SD_INODE_HEADER_SIZE);
 	int ret;
 
-	ret = dog_read_object(vid_to_vdi_oid(vid), &inode, SD_INODE_HEADER_SIZE,
-			     0, true);
+	ret = dog_read_object(vid_to_vdi_oid(vid), inode, SD_INODE_HEADER_SIZE,
+			      0, true);
 	if (ret != SD_RES_SUCCESS)
-		return ret;
-
-	pstrcpy(name, SD_MAX_VDI_LEN, inode.name);
-	pstrcpy(tag, SD_MAX_VDI_TAG_LEN, inode.tag);
+		goto out;
 
-	return SD_RES_SUCCESS;
+	pstrcpy(name, SD_MAX_VDI_LEN, inode->name);
+	pstrcpy(tag, SD_MAX_VDI_TAG_LEN, inode->tag);
+out:
+	free(inode);
+	return ret;
 }
 
 static int vdi_cache_info(int argc, char **argv)
diff --git a/sheep/http/kv.c b/sheep/http/kv.c
index 6f648e3..9ac328c 100644
--- a/sheep/http/kv.c
+++ b/sheep/http/kv.c
@@ -586,7 +586,7 @@ out:
 
 int kv_iterate_bucket(const char *account, bucket_iter_cb cb, void *opaque)
 {
-	struct sd_inode account_inode;
+	struct sd_inode *account_inode;
 	struct bucket_iterater_arg arg = {opaque, cb, 0, 0, 0};
 	uint32_t account_vid;
 	uint64_t oid;
@@ -598,18 +598,20 @@ int kv_iterate_bucket(const char *account, bucket_iter_cb cb, void *opaque)
 		return ret;
 	}
 
+	account_inode = xmalloc(sizeof(*account_inode));
 	oid = vid_to_vdi_oid(account_vid);
 	sys->cdrv->lock(account_vid);
-	ret = sd_read_object(oid, (char *)&account_inode,
+	ret = sd_read_object(oid, (char *)account_inode,
 			     sizeof(struct sd_inode), 0);
 	if (ret != SD_RES_SUCCESS) {
 		sd_err("Failed to read account inode header %s", account);
 		goto out;
 	}
 
-	sd_inode_index_walk(&account_inode, bucket_iterater, &arg);
+	sd_inode_index_walk(account_inode, bucket_iterater, &arg);
 out:
 	sys->cdrv->unlock(account_vid);
+	free(account_inode);
 	return ret;
 }
 
-- 
1.7.12.4