[Qemu-devel] [PATCH v5 0/2] Fix dump_error to return error message

[Qemu-devel] [PATCH v5 0/2] Fix dump_error to return error message

[zhanghailiang]

Hi,

In original code, Function dump_error ignores its second parameter which contains
error reason, it is better to return the error message to the caller.

Here we use error_setg to return the error info to caller.
And at the same time, we turn functions like write_elf64_note() to void,
Because functions shouldn't return an error code _and_ an Error object.
After this modification the code will be more clean. 

V4 -> V5:
- Turn functions like write_elf64_note() to void (advised by Luiz Capitulino)
V3 -> V4:
- Adjust the errp argument to the end 
- Remove trailing '.' in error messages
V2 -> V3:
- Drop the '\n' in the message when call dump_error(comment of Eric Blake) 
V1 -> V2:
- Return the error reason to the caller which suggested by Luiz Capitulino.

zhanghailiang (2):
  dump: let dump_error return error info to caller
  dump: Don't return error code when return an Error object

 dump.c | 333 +++++++++++++++++++++++++++--------------------------------------
 1 file changed, 138 insertions(+), 195 deletions(-)

-- 
1.7.12.4

[Qemu-devel] [PATCH v5 1/2] dump: let dump_error return error info to caller

[zhanghailiang]

The second parameter of dump_error is unused, but one purpose of
using this function is to report the error info.

Use error_set to return the error info to the caller.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
---
 dump.c | 165 ++++++++++++++++++++++++++++++++---------------------------------
 1 file changed, 82 insertions(+), 83 deletions(-)

diff --git a/dump.c b/dump.c
index 71d3e94..07d2300 100644
--- a/dump.c
+++ b/dump.c
@@ -81,9 +81,10 @@ static int dump_cleanup(DumpState *s)
     return 0;
 }
 
-static void dump_error(DumpState *s, const char *reason)
+static void dump_error(DumpState *s, const char *reason, Error **errp)
 {
     dump_cleanup(s);
+    error_setg(errp, "%s", reason);
 }
 
 static int fd_write_vmcore(const void *buf, size_t size, void *opaque)
@@ -99,7 +100,7 @@ static int fd_write_vmcore(const void *buf, size_t size, void *opaque)
     return 0;
 }
 
-static int write_elf64_header(DumpState *s)
+static int write_elf64_header(DumpState *s, Error **errp)
 {
     Elf64_Ehdr elf_header;
     int ret;
@@ -126,14 +127,14 @@ static int write_elf64_header(DumpState *s)
 
     ret = fd_write_vmcore(&elf_header, sizeof(elf_header), s);
     if (ret < 0) {
-        dump_error(s, "dump: failed to write elf header.\n");
+        dump_error(s, "dump: failed to write elf header", errp);
         return -1;
     }
 
     return 0;
 }
 
-static int write_elf32_header(DumpState *s)
+static int write_elf32_header(DumpState *s, Error **errp)
 {
     Elf32_Ehdr elf_header;
     int ret;
@@ -160,7 +161,7 @@ static int write_elf32_header(DumpState *s)
 
     ret = fd_write_vmcore(&elf_header, sizeof(elf_header), s);
     if (ret < 0) {
-        dump_error(s, "dump: failed to write elf header.\n");
+        dump_error(s, "dump: failed to write elf header", errp);
         return -1;
     }
 
@@ -169,7 +170,7 @@ static int write_elf32_header(DumpState *s)
 
 static int write_elf64_load(DumpState *s, MemoryMapping *memory_mapping,
                             int phdr_index, hwaddr offset,
-                            hwaddr filesz)
+                            hwaddr filesz, Error **errp)
 {
     Elf64_Phdr phdr;
     int ret;
@@ -186,7 +187,7 @@ static int write_elf64_load(DumpState *s, MemoryMapping *memory_mapping,
 
     ret = fd_write_vmcore(&phdr, sizeof(Elf64_Phdr), s);
     if (ret < 0) {
-        dump_error(s, "dump: failed to write program header table.\n");
+        dump_error(s, "dump: failed to write program header table", errp);
         return -1;
     }
 
@@ -195,7 +196,7 @@ static int write_elf64_load(DumpState *s, MemoryMapping *memory_mapping,
 
 static int write_elf32_load(DumpState *s, MemoryMapping *memory_mapping,
                             int phdr_index, hwaddr offset,
-                            hwaddr filesz)
+                            hwaddr filesz, Error **errp)
 {
     Elf32_Phdr phdr;
     int ret;
@@ -212,14 +213,14 @@ static int write_elf32_load(DumpState *s, MemoryMapping *memory_mapping,
 
     ret = fd_write_vmcore(&phdr, sizeof(Elf32_Phdr), s);
     if (ret < 0) {
-        dump_error(s, "dump: failed to write program header table.\n");
+        dump_error(s, "dump: failed to write program header table", errp);
         return -1;
     }
 
     return 0;
 }
 
-static int write_elf64_note(DumpState *s)
+static int write_elf64_note(DumpState *s, Error **errp)
 {
     Elf64_Phdr phdr;
     hwaddr begin = s->memory_offset - s->note_size;
@@ -235,7 +236,7 @@ static int write_elf64_note(DumpState *s)
 
     ret = fd_write_vmcore(&phdr, sizeof(Elf64_Phdr), s);
     if (ret < 0) {
-        dump_error(s, "dump: failed to write program header table.\n");
+        dump_error(s, "dump: failed to write program header table", errp);
         return -1;
     }
 
@@ -247,7 +248,8 @@ static inline int cpu_index(CPUState *cpu)
     return cpu->cpu_index + 1;
 }
 
-static int write_elf64_notes(WriteCoreDumpFunction f, DumpState *s)
+static int write_elf64_notes(WriteCoreDumpFunction f, DumpState *s,
+                             Error **errp)
 {
     CPUState *cpu;
     int ret;
@@ -257,7 +259,7 @@ static int write_elf64_notes(WriteCoreDumpFunction f, DumpState *s)
         id = cpu_index(cpu);
         ret = cpu_write_elf64_note(f, cpu, id, s);
         if (ret < 0) {
-            dump_error(s, "dump: failed to write elf notes.\n");
+            dump_error(s, "dump: failed to write elf notes", errp);
             return -1;
         }
     }
@@ -265,7 +267,7 @@ static int write_elf64_notes(WriteCoreDumpFunction f, DumpState *s)
     CPU_FOREACH(cpu) {
         ret = cpu_write_elf64_qemunote(f, cpu, s);
         if (ret < 0) {
-            dump_error(s, "dump: failed to write CPU status.\n");
+            dump_error(s, "dump: failed to write CPU status", errp);
             return -1;
         }
     }
@@ -273,7 +275,7 @@ static int write_elf64_notes(WriteCoreDumpFunction f, DumpState *s)
     return 0;
 }
 
-static int write_elf32_note(DumpState *s)
+static int write_elf32_note(DumpState *s, Error **errp)
 {
     hwaddr begin = s->memory_offset - s->note_size;
     Elf32_Phdr phdr;
@@ -289,14 +291,15 @@ static int write_elf32_note(DumpState *s)
 
     ret = fd_write_vmcore(&phdr, sizeof(Elf32_Phdr), s);
     if (ret < 0) {
-        dump_error(s, "dump: failed to write program header table.\n");
+        dump_error(s, "dump: failed to write program header table", errp);
         return -1;
     }
 
     return 0;
 }
 
-static int write_elf32_notes(WriteCoreDumpFunction f, DumpState *s)
+static int write_elf32_notes(WriteCoreDumpFunction f, DumpState *s,
+                             Error **errp)
 {
     CPUState *cpu;
     int ret;
@@ -306,7 +309,7 @@ static int write_elf32_notes(WriteCoreDumpFunction f, DumpState *s)
         id = cpu_index(cpu);
         ret = cpu_write_elf32_note(f, cpu, id, s);
         if (ret < 0) {
-            dump_error(s, "dump: failed to write elf notes.\n");
+            dump_error(s, "dump: failed to write elf notes", errp);
             return -1;
         }
     }
@@ -314,7 +317,7 @@ static int write_elf32_notes(WriteCoreDumpFunction f, DumpState *s)
     CPU_FOREACH(cpu) {
         ret = cpu_write_elf32_qemunote(f, cpu, s);
         if (ret < 0) {
-            dump_error(s, "dump: failed to write CPU status.\n");
+            dump_error(s, "dump: failed to write CPU status", errp);
             return -1;
         }
     }
@@ -322,7 +325,7 @@ static int write_elf32_notes(WriteCoreDumpFunction f, DumpState *s)
     return 0;
 }
 
-static int write_elf_section(DumpState *s, int type)
+static int write_elf_section(DumpState *s, int type, Error **errp)
 {
     Elf32_Shdr shdr32;
     Elf64_Shdr shdr64;
@@ -344,20 +347,20 @@ static int write_elf_section(DumpState *s, int type)
 
     ret = fd_write_vmcore(&shdr, shdr_size, s);
     if (ret < 0) {
-        dump_error(s, "dump: failed to write section header table.\n");
+        dump_error(s, "dump: failed to write section header table", errp);
         return -1;
     }
 
     return 0;
 }
 
-static int write_data(DumpState *s, void *buf, int length)
+static int write_data(DumpState *s, void *buf, int length, Error **errp)
 {
     int ret;
 
     ret = fd_write_vmcore(buf, length, s);
     if (ret < 0) {
-        dump_error(s, "dump: failed to save memory.\n");
+        dump_error(s, "dump: failed to save memory", errp);
         return -1;
     }
 
@@ -366,14 +369,14 @@ static int write_data(DumpState *s, void *buf, int length)
 
 /* write the memroy to vmcore. 1 page per I/O. */
 static int write_memory(DumpState *s, GuestPhysBlock *block, ram_addr_t start,
-                        int64_t size)
+                        int64_t size, Error **errp)
 {
     int64_t i;
     int ret;
 
     for (i = 0; i < size / TARGET_PAGE_SIZE; i++) {
         ret = write_data(s, block->host_addr + start + i * TARGET_PAGE_SIZE,
-                         TARGET_PAGE_SIZE);
+                         TARGET_PAGE_SIZE, errp);
         if (ret < 0) {
             return ret;
         }
@@ -381,7 +384,7 @@ static int write_memory(DumpState *s, GuestPhysBlock *block, ram_addr_t start,
 
     if ((size % TARGET_PAGE_SIZE) != 0) {
         ret = write_data(s, block->host_addr + start + i * TARGET_PAGE_SIZE,
-                         size % TARGET_PAGE_SIZE);
+                         size % TARGET_PAGE_SIZE, errp);
         if (ret < 0) {
             return ret;
         }
@@ -452,7 +455,7 @@ static void get_offset_range(hwaddr phys_addr,
     }
 }
 
-static int write_elf_loads(DumpState *s)
+static int write_elf_loads(DumpState *s, Error **errp)
 {
     hwaddr offset, filesz;
     MemoryMapping *memory_mapping;
@@ -472,10 +475,10 @@ static int write_elf_loads(DumpState *s)
                          s, &offset, &filesz);
         if (s->dump_info.d_class == ELFCLASS64) {
             ret = write_elf64_load(s, memory_mapping, phdr_index++, offset,
-                                   filesz);
+                                   filesz, errp);
         } else {
             ret = write_elf32_load(s, memory_mapping, phdr_index++, offset,
-                                   filesz);
+                                   filesz, errp);
         }
 
         if (ret < 0) {
@@ -491,7 +494,7 @@ static int write_elf_loads(DumpState *s)
 }
 
 /* write elf header, PT_NOTE and elf note to vmcore. */
-static int dump_begin(DumpState *s)
+static int dump_begin(DumpState *s, Error **errp)
 {
     int ret;
 
@@ -521,9 +524,9 @@ static int dump_begin(DumpState *s)
 
     /* write elf header to vmcore */
     if (s->dump_info.d_class == ELFCLASS64) {
-        ret = write_elf64_header(s);
+        ret = write_elf64_header(s, errp);
     } else {
-        ret = write_elf32_header(s);
+        ret = write_elf32_header(s, errp);
     }
     if (ret < 0) {
         return -1;
@@ -531,47 +534,47 @@ static int dump_begin(DumpState *s)
 
     if (s->dump_info.d_class == ELFCLASS64) {
         /* write PT_NOTE to vmcore */
-        if (write_elf64_note(s) < 0) {
+        if (write_elf64_note(s, errp) < 0) {
             return -1;
         }
 
         /* write all PT_LOAD to vmcore */
-        if (write_elf_loads(s) < 0) {
+        if (write_elf_loads(s, errp) < 0) {
             return -1;
         }
 
         /* write section to vmcore */
         if (s->have_section) {
-            if (write_elf_section(s, 1) < 0) {
+            if (write_elf_section(s, 1, errp) < 0) {
                 return -1;
             }
         }
 
         /* write notes to vmcore */
-        if (write_elf64_notes(fd_write_vmcore, s) < 0) {
+        if (write_elf64_notes(fd_write_vmcore, s, errp) < 0) {
             return -1;
         }
 
     } else {
         /* write PT_NOTE to vmcore */
-        if (write_elf32_note(s) < 0) {
+        if (write_elf32_note(s, errp) < 0) {
             return -1;
         }
 
         /* write all PT_LOAD to vmcore */
-        if (write_elf_loads(s) < 0) {
+        if (write_elf_loads(s, errp) < 0) {
             return -1;
         }
 
         /* write section to vmcore */
         if (s->have_section) {
-            if (write_elf_section(s, 0) < 0) {
+            if (write_elf_section(s, 0, errp) < 0) {
                 return -1;
             }
         }
 
         /* write notes to vmcore */
-        if (write_elf32_notes(fd_write_vmcore, s) < 0) {
+        if (write_elf32_notes(fd_write_vmcore, s, errp) < 0) {
             return -1;
         }
     }
@@ -614,7 +617,7 @@ static int get_next_block(DumpState *s, GuestPhysBlock *block)
 }
 
 /* write all memory to vmcore */
-static int dump_iterate(DumpState *s)
+static int dump_iterate(DumpState *s, Error **errp)
 {
     GuestPhysBlock *block;
     int64_t size;
@@ -630,7 +633,7 @@ static int dump_iterate(DumpState *s)
                 size -= block->target_end - (s->begin + s->length);
             }
         }
-        ret = write_memory(s, block, s->start, size);
+        ret = write_memory(s, block, s->start, size, errp);
         if (ret == -1) {
             return ret;
         }
@@ -643,16 +646,16 @@ static int dump_iterate(DumpState *s)
     }
 }
 
-static int create_vmcore(DumpState *s)
+static int create_vmcore(DumpState *s, Error **errp)
 {
     int ret;
 
-    ret = dump_begin(s);
+    ret = dump_begin(s, errp);
     if (ret < 0) {
         return -1;
     }
 
-    ret = dump_iterate(s);
+    ret = dump_iterate(s, errp);
     if (ret < 0) {
         return -1;
     }
@@ -738,7 +741,7 @@ static int buf_write_note(const void *buf, size_t size, void *opaque)
 }
 
 /* write common header, sub header and elf note to vmcore */
-static int create_header32(DumpState *s)
+static int create_header32(DumpState *s, Error **errp)
 {
     int ret = 0;
     DiskDumpHeader32 *dh = NULL;
@@ -784,7 +787,7 @@ static int create_header32(DumpState *s)
     dh->status = cpu_to_dump32(s, status);
 
     if (write_buffer(s->fd, 0, dh, size) < 0) {
-        dump_error(s, "dump: failed to write disk dump header.\n");
+        dump_error(s, "dump: failed to write disk dump header", errp);
         ret = -1;
         goto out;
     }
@@ -804,7 +807,7 @@ static int create_header32(DumpState *s)
 
     if (write_buffer(s->fd, DISKDUMP_HEADER_BLOCKS *
                      block_size, kh, size) < 0) {
-        dump_error(s, "dump: failed to write kdump sub header.\n");
+        dump_error(s, "dump: failed to write kdump sub header", errp);
         ret = -1;
         goto out;
     }
@@ -814,14 +817,14 @@ static int create_header32(DumpState *s)
     s->note_buf_offset = 0;
 
     /* use s->note_buf to store notes temporarily */
-    if (write_elf32_notes(buf_write_note, s) < 0) {
+    if (write_elf32_notes(buf_write_note, s, errp) < 0) {
         ret = -1;
         goto out;
     }
 
     if (write_buffer(s->fd, offset_note, s->note_buf,
                      s->note_size) < 0) {
-        dump_error(s, "dump: failed to write notes");
+        dump_error(s, "dump: failed to write notes", errp);
         ret = -1;
         goto out;
     }
@@ -843,7 +846,7 @@ out:
 }
 
 /* write common header, sub header and elf note to vmcore */
-static int create_header64(DumpState *s)
+static int create_header64(DumpState *s, Error **errp)
 {
     int ret = 0;
     DiskDumpHeader64 *dh = NULL;
@@ -889,7 +892,7 @@ static int create_header64(DumpState *s)
     dh->status = cpu_to_dump32(s, status);
 
     if (write_buffer(s->fd, 0, dh, size) < 0) {
-        dump_error(s, "dump: failed to write disk dump header.\n");
+        dump_error(s, "dump: failed to write disk dump header", errp);
         ret = -1;
         goto out;
     }
@@ -909,7 +912,7 @@ static int create_header64(DumpState *s)
 
     if (write_buffer(s->fd, DISKDUMP_HEADER_BLOCKS *
                      block_size, kh, size) < 0) {
-        dump_error(s, "dump: failed to write kdump sub header.\n");
+        dump_error(s, "dump: failed to write kdump sub header", errp);
         ret = -1;
         goto out;
     }
@@ -919,14 +922,14 @@ static int create_header64(DumpState *s)
     s->note_buf_offset = 0;
 
     /* use s->note_buf to store notes temporarily */
-    if (write_elf64_notes(buf_write_note, s) < 0) {
+    if (write_elf64_notes(buf_write_note, s, errp) < 0) {
         ret = -1;
         goto out;
     }
 
     if (write_buffer(s->fd, offset_note, s->note_buf,
                      s->note_size) < 0) {
-        dump_error(s, "dump: failed to write notes");
+        dump_error(s, "dump: failed to write notes", errp);
         ret = -1;
         goto out;
     }
@@ -947,12 +950,12 @@ out:
     return ret;
 }
 
-static int write_dump_header(DumpState *s)
+static int write_dump_header(DumpState *s, Error **errp)
 {
     if (s->dump_info.d_class == ELFCLASS32) {
-        return create_header32(s);
+        return create_header32(s, errp);
     } else {
-        return create_header64(s);
+        return create_header64(s, errp);
     }
 }
 
@@ -1066,7 +1069,7 @@ static bool get_next_page(GuestPhysBlock **blockptr, uint64_t *pfnptr,
     return true;
 }
 
-static int write_dump_bitmap(DumpState *s)
+static int write_dump_bitmap(DumpState *s, Error **errp)
 {
     int ret = 0;
     uint64_t last_pfn, pfn;
@@ -1087,7 +1090,7 @@ static int write_dump_bitmap(DumpState *s)
     while (get_next_page(&block_iter, &pfn, NULL, s)) {
         ret = set_dump_bitmap(last_pfn, pfn, true, dump_bitmap_buf, s);
         if (ret < 0) {
-            dump_error(s, "dump: failed to set dump_bitmap.\n");
+            dump_error(s, "dump: failed to set dump_bitmap", errp);
             ret = -1;
             goto out;
         }
@@ -1105,7 +1108,7 @@ static int write_dump_bitmap(DumpState *s)
         ret = set_dump_bitmap(last_pfn, last_pfn + PFN_BUFBITMAP, false,
                               dump_bitmap_buf, s);
         if (ret < 0) {
-            dump_error(s, "dump: failed to sync dump_bitmap.\n");
+            dump_error(s, "dump: failed to sync dump_bitmap", errp);
             ret = -1;
             goto out;
         }
@@ -1197,7 +1200,7 @@ static inline bool is_zero_page(const uint8_t *buf, size_t page_size)
     return buffer_is_zero(buf, page_size);
 }
 
-static int write_dump_pages(DumpState *s)
+static int write_dump_pages(DumpState *s, Error **errp)
 {
     int ret = 0;
     DataCache page_desc, page_data;
@@ -1241,7 +1244,7 @@ static int write_dump_pages(DumpState *s)
     ret = write_cache(&page_data, buf, TARGET_PAGE_SIZE, false);
     g_free(buf);
     if (ret < 0) {
-        dump_error(s, "dump: failed to write page data(zero page).\n");
+        dump_error(s, "dump: failed to write page data (zero page)", errp);
         goto out;
     }
 
@@ -1257,7 +1260,7 @@ static int write_dump_pages(DumpState *s)
             ret = write_cache(&page_desc, &pd_zero, sizeof(PageDescriptor),
                               false);
             if (ret < 0) {
-                dump_error(s, "dump: failed to write page desc.\n");
+                dump_error(s, "dump: failed to write page desc", errp);
                 goto out;
             }
         } else {
@@ -1282,7 +1285,7 @@ static int write_dump_pages(DumpState *s)
 
                 ret = write_cache(&page_data, buf_out, size_out, false);
                 if (ret < 0) {
-                    dump_error(s, "dump: failed to write page data.\n");
+                    dump_error(s, "dump: failed to write page data", errp);
                     goto out;
                 }
 #ifdef CONFIG_LZO
@@ -1295,7 +1298,7 @@ static int write_dump_pages(DumpState *s)
 
                 ret = write_cache(&page_data, buf_out, size_out, false);
                 if (ret < 0) {
-                    dump_error(s, "dump: failed to write page data.\n");
+                    dump_error(s, "dump: failed to write page data", errp);
                     goto out;
                 }
 #endif
@@ -1309,7 +1312,7 @@ static int write_dump_pages(DumpState *s)
 
                 ret = write_cache(&page_data, buf_out, size_out, false);
                 if (ret < 0) {
-                    dump_error(s, "dump: failed to write page data.\n");
+                    dump_error(s, "dump: failed to write page data", errp);
                     goto out;
                 }
 #endif
@@ -1324,7 +1327,7 @@ static int write_dump_pages(DumpState *s)
 
                 ret = write_cache(&page_data, buf, TARGET_PAGE_SIZE, false);
                 if (ret < 0) {
-                    dump_error(s, "dump: failed to write page data.\n");
+                    dump_error(s, "dump: failed to write page data", errp);
                     goto out;
                 }
             }
@@ -1336,7 +1339,7 @@ static int write_dump_pages(DumpState *s)
 
             ret = write_cache(&page_desc, &pd, sizeof(PageDescriptor), false);
             if (ret < 0) {
-                dump_error(s, "dump: failed to write page desc.\n");
+                dump_error(s, "dump: failed to write page desc", errp);
                 goto out;
             }
         }
@@ -1344,12 +1347,12 @@ static int write_dump_pages(DumpState *s)
 
     ret = write_cache(&page_desc, NULL, 0, true);
     if (ret < 0) {
-        dump_error(s, "dump: failed to sync cache for page_desc.\n");
+        dump_error(s, "dump: failed to sync cache for page_desc", errp);
         goto out;
     }
     ret = write_cache(&page_data, NULL, 0, true);
     if (ret < 0) {
-        dump_error(s, "dump: failed to sync cache for page_data.\n");
+        dump_error(s, "dump: failed to sync cache for page_data", errp);
         goto out;
     }
 
@@ -1366,7 +1369,7 @@ out:
     return ret;
 }
 
-static int create_kdump_vmcore(DumpState *s)
+static int create_kdump_vmcore(DumpState *s, Error **errp)
 {
     int ret;
 
@@ -1394,28 +1397,28 @@ static int create_kdump_vmcore(DumpState *s)
 
     ret = write_start_flat_header(s->fd);
     if (ret < 0) {
-        dump_error(s, "dump: failed to write start flat header.\n");
+        dump_error(s, "dump: failed to write start flat header", errp);
         return -1;
     }
 
-    ret = write_dump_header(s);
+    ret = write_dump_header(s, errp);
     if (ret < 0) {
         return -1;
     }
 
-    ret = write_dump_bitmap(s);
+    ret = write_dump_bitmap(s, errp);
     if (ret < 0) {
         return -1;
     }
 
-    ret = write_dump_pages(s);
+    ret = write_dump_pages(s, errp);
     if (ret < 0) {
         return -1;
     }
 
     ret = write_end_flat_header(s->fd);
     if (ret < 0) {
-        dump_error(s, "dump: failed to write end flat header.\n");
+        dump_error(s, "dump: failed to write end flat header", errp);
         return -1;
     }
 
@@ -1699,13 +1702,9 @@ void qmp_dump_guest_memory(bool paging, const char *file, bool has_begin,
     }
 
     if (has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
-        if (create_kdump_vmcore(s) < 0) {
-            error_set(errp, QERR_IO_ERROR);
-        }
+        create_kdump_vmcore(s, errp);
     } else {
-        if (create_vmcore(s) < 0) {
-            error_set(errp, QERR_IO_ERROR);
-        }
+        create_vmcore(s, errp);
     }
 
     g_free(s);
-- 
1.7.12.4

[Qemu-devel] [PATCH v5 2/2] dump: Don't return error code when return an Error object

[zhanghailiang]

Functions shouldn't return an error code and an Error object at the same time.
Turn all these functions that returning Error object to void.
We also judge if a function success or fail by reference to the *errp.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
---
 dump.c | 244 +++++++++++++++++++++++++----------------------------------------
 1 file changed, 94 insertions(+), 150 deletions(-)

diff --git a/dump.c b/dump.c
index 07d2300..b2ed846 100644
--- a/dump.c
+++ b/dump.c
@@ -100,7 +100,7 @@ static int fd_write_vmcore(const void *buf, size_t size, void *opaque)
     return 0;
 }
 
-static int write_elf64_header(DumpState *s, Error **errp)
+static void write_elf64_header(DumpState *s, Error **errp)
 {
     Elf64_Ehdr elf_header;
     int ret;
@@ -128,13 +128,10 @@ static int write_elf64_header(DumpState *s, Error **errp)
     ret = fd_write_vmcore(&elf_header, sizeof(elf_header), s);
     if (ret < 0) {
         dump_error(s, "dump: failed to write elf header", errp);
-        return -1;
     }
-
-    return 0;
 }
 
-static int write_elf32_header(DumpState *s, Error **errp)
+static void write_elf32_header(DumpState *s, Error **errp)
 {
     Elf32_Ehdr elf_header;
     int ret;
@@ -162,13 +159,10 @@ static int write_elf32_header(DumpState *s, Error **errp)
     ret = fd_write_vmcore(&elf_header, sizeof(elf_header), s);
     if (ret < 0) {
         dump_error(s, "dump: failed to write elf header", errp);
-        return -1;
     }
-
-    return 0;
 }
 
-static int write_elf64_load(DumpState *s, MemoryMapping *memory_mapping,
+static void write_elf64_load(DumpState *s, MemoryMapping *memory_mapping,
                             int phdr_index, hwaddr offset,
                             hwaddr filesz, Error **errp)
 {
@@ -188,13 +182,10 @@ static int write_elf64_load(DumpState *s, MemoryMapping *memory_mapping,
     ret = fd_write_vmcore(&phdr, sizeof(Elf64_Phdr), s);
     if (ret < 0) {
         dump_error(s, "dump: failed to write program header table", errp);
-        return -1;
     }
-
-    return 0;
 }
 
-static int write_elf32_load(DumpState *s, MemoryMapping *memory_mapping,
+static void write_elf32_load(DumpState *s, MemoryMapping *memory_mapping,
                             int phdr_index, hwaddr offset,
                             hwaddr filesz, Error **errp)
 {
@@ -214,13 +205,10 @@ static int write_elf32_load(DumpState *s, MemoryMapping *memory_mapping,
     ret = fd_write_vmcore(&phdr, sizeof(Elf32_Phdr), s);
     if (ret < 0) {
         dump_error(s, "dump: failed to write program header table", errp);
-        return -1;
     }
-
-    return 0;
 }
 
-static int write_elf64_note(DumpState *s, Error **errp)
+static void write_elf64_note(DumpState *s, Error **errp)
 {
     Elf64_Phdr phdr;
     hwaddr begin = s->memory_offset - s->note_size;
@@ -237,10 +225,7 @@ static int write_elf64_note(DumpState *s, Error **errp)
     ret = fd_write_vmcore(&phdr, sizeof(Elf64_Phdr), s);
     if (ret < 0) {
         dump_error(s, "dump: failed to write program header table", errp);
-        return -1;
     }
-
-    return 0;
 }
 
 static inline int cpu_index(CPUState *cpu)
@@ -248,7 +233,7 @@ static inline int cpu_index(CPUState *cpu)
     return cpu->cpu_index + 1;
 }
 
-static int write_elf64_notes(WriteCoreDumpFunction f, DumpState *s,
+static void write_elf64_notes(WriteCoreDumpFunction f, DumpState *s,
                              Error **errp)
 {
     CPUState *cpu;
@@ -260,7 +245,7 @@ static int write_elf64_notes(WriteCoreDumpFunction f, DumpState *s,
         ret = cpu_write_elf64_note(f, cpu, id, s);
         if (ret < 0) {
             dump_error(s, "dump: failed to write elf notes", errp);
-            return -1;
+            return;
         }
     }
 
@@ -268,14 +253,12 @@ static int write_elf64_notes(WriteCoreDumpFunction f, DumpState *s,
         ret = cpu_write_elf64_qemunote(f, cpu, s);
         if (ret < 0) {
             dump_error(s, "dump: failed to write CPU status", errp);
-            return -1;
+            return;
         }
     }
-
-    return 0;
 }
 
-static int write_elf32_note(DumpState *s, Error **errp)
+static void write_elf32_note(DumpState *s, Error **errp)
 {
     hwaddr begin = s->memory_offset - s->note_size;
     Elf32_Phdr phdr;
@@ -292,13 +275,10 @@ static int write_elf32_note(DumpState *s, Error **errp)
     ret = fd_write_vmcore(&phdr, sizeof(Elf32_Phdr), s);
     if (ret < 0) {
         dump_error(s, "dump: failed to write program header table", errp);
-        return -1;
     }
-
-    return 0;
 }
 
-static int write_elf32_notes(WriteCoreDumpFunction f, DumpState *s,
+static void write_elf32_notes(WriteCoreDumpFunction f, DumpState *s,
                              Error **errp)
 {
     CPUState *cpu;
@@ -310,7 +290,7 @@ static int write_elf32_notes(WriteCoreDumpFunction f, DumpState *s,
         ret = cpu_write_elf32_note(f, cpu, id, s);
         if (ret < 0) {
             dump_error(s, "dump: failed to write elf notes", errp);
-            return -1;
+            return;
         }
     }
 
@@ -318,14 +298,12 @@ static int write_elf32_notes(WriteCoreDumpFunction f, DumpState *s,
         ret = cpu_write_elf32_qemunote(f, cpu, s);
         if (ret < 0) {
             dump_error(s, "dump: failed to write CPU status", errp);
-            return -1;
+            return;
         }
     }
-
-    return 0;
 }
 
-static int write_elf_section(DumpState *s, int type, Error **errp)
+static void write_elf_section(DumpState *s, int type, Error **errp)
 {
     Elf32_Shdr shdr32;
     Elf64_Shdr shdr64;
@@ -348,49 +326,42 @@ static int write_elf_section(DumpState *s, int type, Error **errp)
     ret = fd_write_vmcore(&shdr, shdr_size, s);
     if (ret < 0) {
         dump_error(s, "dump: failed to write section header table", errp);
-        return -1;
+        return;
     }
-
-    return 0;
 }
 
-static int write_data(DumpState *s, void *buf, int length, Error **errp)
+static void write_data(DumpState *s, void *buf, int length, Error **errp)
 {
     int ret;
 
     ret = fd_write_vmcore(buf, length, s);
     if (ret < 0) {
         dump_error(s, "dump: failed to save memory", errp);
-        return -1;
+        return;
     }
-
-    return 0;
 }
 
 /* write the memroy to vmcore. 1 page per I/O. */
-static int write_memory(DumpState *s, GuestPhysBlock *block, ram_addr_t start,
+static void write_memory(DumpState *s, GuestPhysBlock *block, ram_addr_t start,
                         int64_t size, Error **errp)
 {
     int64_t i;
-    int ret;
 
     for (i = 0; i < size / TARGET_PAGE_SIZE; i++) {
-        ret = write_data(s, block->host_addr + start + i * TARGET_PAGE_SIZE,
+        write_data(s, block->host_addr + start + i * TARGET_PAGE_SIZE,
                          TARGET_PAGE_SIZE, errp);
-        if (ret < 0) {
-            return ret;
+        if (*errp) {
+            return;
         }
     }
 
     if ((size % TARGET_PAGE_SIZE) != 0) {
-        ret = write_data(s, block->host_addr + start + i * TARGET_PAGE_SIZE,
+        write_data(s, block->host_addr + start + i * TARGET_PAGE_SIZE,
                          size % TARGET_PAGE_SIZE, errp);
-        if (ret < 0) {
-            return ret;
+        if (*errp) {
+            return;
         }
     }
-
-    return 0;
 }
 
 /* get the memory's offset and size in the vmcore */
@@ -455,12 +426,11 @@ static void get_offset_range(hwaddr phys_addr,
     }
 }
 
-static int write_elf_loads(DumpState *s, Error **errp)
+static void write_elf_loads(DumpState *s, Error **errp)
 {
     hwaddr offset, filesz;
     MemoryMapping *memory_mapping;
     uint32_t phdr_index = 1;
-    int ret;
     uint32_t max_index;
 
     if (s->have_section) {
@@ -474,29 +444,26 @@ static int write_elf_loads(DumpState *s, Error **errp)
                          memory_mapping->length,
                          s, &offset, &filesz);
         if (s->dump_info.d_class == ELFCLASS64) {
-            ret = write_elf64_load(s, memory_mapping, phdr_index++, offset,
+            write_elf64_load(s, memory_mapping, phdr_index++, offset,
                                    filesz, errp);
         } else {
-            ret = write_elf32_load(s, memory_mapping, phdr_index++, offset,
+            write_elf32_load(s, memory_mapping, phdr_index++, offset,
                                    filesz, errp);
         }
 
-        if (ret < 0) {
-            return -1;
+        if (*errp) {
+            return;
         }
 
         if (phdr_index >= max_index) {
             break;
         }
     }
-
-    return 0;
 }
 
 /* write elf header, PT_NOTE and elf note to vmcore. */
-static int dump_begin(DumpState *s, Error **errp)
+static void dump_begin(DumpState *s, Error **errp)
 {
-    int ret;
 
     /*
      * the vmcore's format is:
@@ -524,62 +491,68 @@ static int dump_begin(DumpState *s, Error **errp)
 
     /* write elf header to vmcore */
     if (s->dump_info.d_class == ELFCLASS64) {
-        ret = write_elf64_header(s, errp);
+        write_elf64_header(s, errp);
     } else {
-        ret = write_elf32_header(s, errp);
+        write_elf32_header(s, errp);
     }
-    if (ret < 0) {
-        return -1;
+    if (*errp) {
+        return;
     }
 
     if (s->dump_info.d_class == ELFCLASS64) {
         /* write PT_NOTE to vmcore */
-        if (write_elf64_note(s, errp) < 0) {
-            return -1;
+        write_elf64_note(s, errp);
+        if (*errp) {
+            return;
         }
 
         /* write all PT_LOAD to vmcore */
-        if (write_elf_loads(s, errp) < 0) {
-            return -1;
+        write_elf_loads(s, errp);
+        if (*errp) {
+            return;
         }
 
         /* write section to vmcore */
         if (s->have_section) {
-            if (write_elf_section(s, 1, errp) < 0) {
-                return -1;
+            write_elf_section(s, 1, errp);
+            if (*errp) {
+                return;
             }
         }
 
         /* write notes to vmcore */
-        if (write_elf64_notes(fd_write_vmcore, s, errp) < 0) {
-            return -1;
+        write_elf64_notes(fd_write_vmcore, s, errp);
+        if (*errp) {
+            return;
         }
 
     } else {
         /* write PT_NOTE to vmcore */
-        if (write_elf32_note(s, errp) < 0) {
-            return -1;
+        write_elf32_note(s, errp);
+        if (*errp) {
+            return;
         }
 
         /* write all PT_LOAD to vmcore */
-        if (write_elf_loads(s, errp) < 0) {
-            return -1;
+        write_elf_loads(s, errp);
+        if (*errp) {
+            return;
         }
 
         /* write section to vmcore */
         if (s->have_section) {
-            if (write_elf_section(s, 0, errp) < 0) {
-                return -1;
+            write_elf_section(s, 0, errp);
+            if (*errp) {
+                return;
             }
         }
 
         /* write notes to vmcore */
-        if (write_elf32_notes(fd_write_vmcore, s, errp) < 0) {
-            return -1;
+        write_elf32_notes(fd_write_vmcore, s, errp);
+        if (*errp) {
+            return;
         }
     }
-
-    return 0;
 }
 
 /* write PT_LOAD to vmcore */
@@ -617,7 +590,7 @@ static int get_next_block(DumpState *s, GuestPhysBlock *block)
 }
 
 /* write all memory to vmcore */
-static int dump_iterate(DumpState *s, Error **errp)
+static void dump_iterate(DumpState *s, Error **errp)
 {
     GuestPhysBlock *block;
     int64_t size;
@@ -633,34 +606,27 @@ static int dump_iterate(DumpState *s, Error **errp)
                 size -= block->target_end - (s->begin + s->length);
             }
         }
-        ret = write_memory(s, block, s->start, size, errp);
-        if (ret == -1) {
-            return ret;
+        write_memory(s, block, s->start, size, errp);
+        if (*errp) {
+            return;
         }
 
         ret = get_next_block(s, block);
         if (ret == 1) {
             dump_completed(s);
-            return 0;
         }
     }
 }
 
-static int create_vmcore(DumpState *s, Error **errp)
+static void create_vmcore(DumpState *s, Error **errp)
 {
-    int ret;
-
-    ret = dump_begin(s, errp);
-    if (ret < 0) {
-        return -1;
-    }
 
-    ret = dump_iterate(s, errp);
-    if (ret < 0) {
-        return -1;
+    dump_begin(s, errp);
+    if (*errp) {
+        return;
     }
 
-    return 0;
+    dump_iterate(s, errp);
 }
 
 static int write_start_flat_header(int fd)
@@ -741,9 +707,8 @@ static int buf_write_note(const void *buf, size_t size, void *opaque)
 }
 
 /* write common header, sub header and elf note to vmcore */
-static int create_header32(DumpState *s, Error **errp)
+static void create_header32(DumpState *s, Error **errp)
 {
-    int ret = 0;
     DiskDumpHeader32 *dh = NULL;
     KdumpSubHeader32 *kh = NULL;
     size_t size;
@@ -788,7 +753,6 @@ static int create_header32(DumpState *s, Error **errp)
 
     if (write_buffer(s->fd, 0, dh, size) < 0) {
         dump_error(s, "dump: failed to write disk dump header", errp);
-        ret = -1;
         goto out;
     }
 
@@ -808,7 +772,6 @@ static int create_header32(DumpState *s, Error **errp)
     if (write_buffer(s->fd, DISKDUMP_HEADER_BLOCKS *
                      block_size, kh, size) < 0) {
         dump_error(s, "dump: failed to write kdump sub header", errp);
-        ret = -1;
         goto out;
     }
 
@@ -817,15 +780,14 @@ static int create_header32(DumpState *s, Error **errp)
     s->note_buf_offset = 0;
 
     /* use s->note_buf to store notes temporarily */
-    if (write_elf32_notes(buf_write_note, s, errp) < 0) {
-        ret = -1;
+    write_elf32_notes(buf_write_note, s, errp);
+    if (*errp) {
         goto out;
     }
 
     if (write_buffer(s->fd, offset_note, s->note_buf,
                      s->note_size) < 0) {
         dump_error(s, "dump: failed to write notes", errp);
-        ret = -1;
         goto out;
     }
 
@@ -841,14 +803,11 @@ out:
     g_free(dh);
     g_free(kh);
     g_free(s->note_buf);
-
-    return ret;
 }
 
 /* write common header, sub header and elf note to vmcore */
-static int create_header64(DumpState *s, Error **errp)
+static void create_header64(DumpState *s, Error **errp)
 {
-    int ret = 0;
     DiskDumpHeader64 *dh = NULL;
     KdumpSubHeader64 *kh = NULL;
     size_t size;
@@ -893,7 +852,6 @@ static int create_header64(DumpState *s, Error **errp)
 
     if (write_buffer(s->fd, 0, dh, size) < 0) {
         dump_error(s, "dump: failed to write disk dump header", errp);
-        ret = -1;
         goto out;
     }
 
@@ -913,7 +871,6 @@ static int create_header64(DumpState *s, Error **errp)
     if (write_buffer(s->fd, DISKDUMP_HEADER_BLOCKS *
                      block_size, kh, size) < 0) {
         dump_error(s, "dump: failed to write kdump sub header", errp);
-        ret = -1;
         goto out;
     }
 
@@ -922,15 +879,14 @@ static int create_header64(DumpState *s, Error **errp)
     s->note_buf_offset = 0;
 
     /* use s->note_buf to store notes temporarily */
-    if (write_elf64_notes(buf_write_note, s, errp) < 0) {
-        ret = -1;
+    write_elf64_notes(buf_write_note, s, errp);
+    if (*errp) {
         goto out;
     }
 
     if (write_buffer(s->fd, offset_note, s->note_buf,
                      s->note_size) < 0) {
         dump_error(s, "dump: failed to write notes", errp);
-        ret = -1;
         goto out;
     }
 
@@ -946,16 +902,14 @@ out:
     g_free(dh);
     g_free(kh);
     g_free(s->note_buf);
-
-    return ret;
 }
 
-static int write_dump_header(DumpState *s, Error **errp)
+static void write_dump_header(DumpState *s, Error **errp)
 {
     if (s->dump_info.d_class == ELFCLASS32) {
-        return create_header32(s, errp);
+        create_header32(s, errp);
     } else {
-        return create_header64(s, errp);
+        create_header64(s, errp);
     }
 }
 
@@ -1069,7 +1023,7 @@ static bool get_next_page(GuestPhysBlock **blockptr, uint64_t *pfnptr,
     return true;
 }
 
-static int write_dump_bitmap(DumpState *s, Error **errp)
+static void write_dump_bitmap(DumpState *s, Error **errp)
 {
     int ret = 0;
     uint64_t last_pfn, pfn;
@@ -1091,7 +1045,6 @@ static int write_dump_bitmap(DumpState *s, Error **errp)
         ret = set_dump_bitmap(last_pfn, pfn, true, dump_bitmap_buf, s);
         if (ret < 0) {
             dump_error(s, "dump: failed to set dump_bitmap", errp);
-            ret = -1;
             goto out;
         }
 
@@ -1109,7 +1062,6 @@ static int write_dump_bitmap(DumpState *s, Error **errp)
                               dump_bitmap_buf, s);
         if (ret < 0) {
             dump_error(s, "dump: failed to sync dump_bitmap", errp);
-            ret = -1;
             goto out;
         }
     }
@@ -1119,8 +1071,6 @@ static int write_dump_bitmap(DumpState *s, Error **errp)
 
 out:
     g_free(dump_bitmap_buf);
-
-    return ret;
 }
 
 static void prepare_data_cache(DataCache *data_cache, DumpState *s,
@@ -1200,7 +1150,7 @@ static inline bool is_zero_page(const uint8_t *buf, size_t page_size)
     return buffer_is_zero(buf, page_size);
 }
 
-static int write_dump_pages(DumpState *s, Error **errp)
+static void write_dump_pages(DumpState *s, Error **errp)
 {
     int ret = 0;
     DataCache page_desc, page_data;
@@ -1365,11 +1315,9 @@ out:
 #endif
 
     g_free(buf_out);
-
-    return ret;
 }
 
-static int create_kdump_vmcore(DumpState *s, Error **errp)
+static void create_kdump_vmcore(DumpState *s, Error **errp)
 {
     int ret;
 
@@ -1398,33 +1346,31 @@ static int create_kdump_vmcore(DumpState *s, Error **errp)
     ret = write_start_flat_header(s->fd);
     if (ret < 0) {
         dump_error(s, "dump: failed to write start flat header", errp);
-        return -1;
+        return;
     }
 
-    ret = write_dump_header(s, errp);
-    if (ret < 0) {
-        return -1;
+    write_dump_header(s, errp);
+    if (*errp) {
+        return;
     }
 
-    ret = write_dump_bitmap(s, errp);
-    if (ret < 0) {
-        return -1;
+    write_dump_bitmap(s, errp);
+    if (*errp) {
+        return;
     }
 
-    ret = write_dump_pages(s, errp);
-    if (ret < 0) {
-        return -1;
+    write_dump_pages(s, errp);
+    if (*errp) {
+        return;
     }
 
     ret = write_end_flat_header(s->fd);
     if (ret < 0) {
         dump_error(s, "dump: failed to write end flat header", errp);
-        return -1;
+        return;
     }
 
     dump_completed(s);
-
-    return 0;
 }
 
 static ram_addr_t get_start_block(DumpState *s)
@@ -1463,7 +1409,7 @@ static void get_max_mapnr(DumpState *s)
     s->max_mapnr = paddr_to_pfn(last_block->target_end);
 }
 
-static int dump_init(DumpState *s, int fd, bool has_format,
+static void dump_init(DumpState *s, int fd, bool has_format,
                      DumpGuestMemoryFormat format, bool paging, bool has_filter,
                      int64_t begin, int64_t length, Error **errp)
 {
@@ -1570,7 +1516,7 @@ static int dump_init(DumpState *s, int fd, bool has_format,
             s->flag_compress = 0;
         }
 
-        return 0;
+        return;
     }
 
     if (s->has_filter) {
@@ -1619,11 +1565,10 @@ static int dump_init(DumpState *s, int fd, bool has_format,
         }
     }
 
-    return 0;
+    return;
 
 cleanup:
     dump_cleanup(s);
-    return -1;
 }
 
 void qmp_dump_guest_memory(bool paging, const char *file, bool has_begin,
@@ -1634,7 +1579,6 @@ void qmp_dump_guest_memory(bool paging, const char *file, bool has_begin,
     const char *p;
     int fd = -1;
     DumpState *s;
-    int ret;
 
     /*
      * kdump-compressed format need the whole memory dumped, so paging or
@@ -1694,9 +1638,9 @@ void qmp_dump_guest_memory(bool paging, const char *file, bool has_begin,
 
     s = g_malloc0(sizeof(DumpState));
 
-    ret = dump_init(s, fd, has_format, format, paging, has_begin,
+    dump_init(s, fd, has_format, format, paging, has_begin,
                     begin, length, errp);
-    if (ret < 0) {
+    if (*errp) {
         g_free(s);
         return;
     }
-- 
1.7.12.4

Re: [Qemu-devel] [PATCH v5 2/2] dump: Don't return error code when return an Error object

[Markus Armbruster]

zhanghailiang <zhang.zhanghailiang@huawei.com> writes:

> Functions shouldn't return an error code and an Error object at the same time.
> Turn all these functions that returning Error object to void.
> We also judge if a function success or fail by reference to the *errp.
>
> Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
> ---
>  dump.c | 244 +++++++++++++++++++++++++----------------------------------------
>  1 file changed, 94 insertions(+), 150 deletions(-)
>
> diff --git a/dump.c b/dump.c
> index 07d2300..b2ed846 100644
> --- a/dump.c
> +++ b/dump.c
[...]
>  /* write the memroy to vmcore. 1 page per I/O. */
> -static int write_memory(DumpState *s, GuestPhysBlock *block, ram_addr_t start,
> +static void write_memory(DumpState *s, GuestPhysBlock *block, ram_addr_t start,
>                          int64_t size, Error **errp)
>  {
>      int64_t i;
> -    int ret;
>  
>      for (i = 0; i < size / TARGET_PAGE_SIZE; i++) {
> -        ret = write_data(s, block->host_addr + start + i * TARGET_PAGE_SIZE,
> +        write_data(s, block->host_addr + start + i * TARGET_PAGE_SIZE,
>                           TARGET_PAGE_SIZE, errp);

Please fix up indentation of arguments.

> -        if (ret < 0) {
> -            return ret;
> +        if (*errp) {
> +            return;

This breaks when a caller choses to ignore errors by passing a null
argument for errp.

For static functions that may be okay.  But in general, we support null
arguments by coding like this:

    Error *local_err = NULL;
    int64_t i;

    for (i = 0; i < size / TARGET_PAGE_SIZE; i++) {
        write_data(s, block->host_addr + start + i * TARGET_PAGE_SIZE,
                   TARGET_PAGE_SIZE, &local_err);
        if (local_err) {
            error_propagate(errp, local_err);
            return;
        }
    }

I feel it's better to stick to this convention.

More of the same elsewhere.

>          }
>      }
[...]

Re: [Qemu-devel] [PATCH v5 2/2] dump: Don't return error code when return an Error object

[zhanghailiang]

On 2014/9/17 0:24, Markus Armbruster wrote:
> zhanghailiang <zhang.zhanghailiang@huawei.com> writes:
>
>> Functions shouldn't return an error code and an Error object at the same time.
>> Turn all these functions that returning Error object to void.
>> We also judge if a function success or fail by reference to the *errp.
>>
>> Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
>> ---
>>   dump.c | 244 +++++++++++++++++++++++++----------------------------------------
>>   1 file changed, 94 insertions(+), 150 deletions(-)
>>
>> diff --git a/dump.c b/dump.c
>> index 07d2300..b2ed846 100644
>> --- a/dump.c
>> +++ b/dump.c
> [...]
>>   /* write the memroy to vmcore. 1 page per I/O. */
>> -static int write_memory(DumpState *s, GuestPhysBlock *block, ram_addr_t start,
>> +static void write_memory(DumpState *s, GuestPhysBlock *block, ram_addr_t start,
>>                           int64_t size, Error **errp)
>>   {
>>       int64_t i;
>> -    int ret;
>>
>>       for (i = 0; i < size / TARGET_PAGE_SIZE; i++) {
>> -        ret = write_data(s, block->host_addr + start + i * TARGET_PAGE_SIZE,
>> +        write_data(s, block->host_addr + start + i * TARGET_PAGE_SIZE,
>>                            TARGET_PAGE_SIZE, errp);
>
> Please fix up indentation of arguments.
>

OK.

>> -        if (ret < 0) {
>> -            return ret;
>> +        if (*errp) {
>> +            return;
>
> This breaks when a caller choses to ignore errors by passing a null
> argument for errp.
>
> For static functions that may be okay.  But in general, we support null
> arguments by coding like this:
>
>      Error *local_err = NULL;
>      int64_t i;
>
>      for (i = 0; i < size / TARGET_PAGE_SIZE; i++) {
>          write_data(s, block->host_addr + start + i * TARGET_PAGE_SIZE,
>                     TARGET_PAGE_SIZE, &local_err);
>          if (local_err) {
>              error_propagate(errp, local_err);
>              return;
>          }
>      }
>
> I feel it's better to stick to this convention.
>
> More of the same elsewhere.
>

OK, will do it, Thanks.

>>           }
>>       }
> [...]
>
> .
>