async file I/O API

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@2075 c046a42c-6fe2-441c-8c8c-71466251a162

Changelog

@@ -1,3 +1,8 @@
+version 0.8.3:
+
+  - Support for relative paths in backing files for disk images
+  - Async file I/O API
+
 version 0.8.2:
 
   - ACPI support

Makefile

@@ -25,14 +25,22 @@ else
 DOCS=
 endif
 
+ifndef CONFIG_DARWIN
+ifndef CONFIG_WIN32
+ifndef CONFIG_SOLARIS
+LIBS+=-lrt
+endif
+endif
+endif
+
 all: $(TOOLS) $(DOCS) recurse-all
 
 subdir-%: dyngen$(EXESUF)
 	$(MAKE) -C $(subst subdir-,,$@) all
 
 recurse-all: $(patsubst %,subdir-%, $(TARGET_DIRS))
-        
-qemu-img$(EXESUF): qemu-img.c block.c block-cow.c block-qcow.c aes.c block-vmdk.c block-cloop.c block-dmg.c block-bochs.c block-vpc.c block-vvfat.c
+
+qemu-img$(EXESUF): qemu-img.c block.c block-raw.c block-cow.c block-qcow.c aes.c block-vmdk.c block-cloop.c block-dmg.c block-bochs.c block-vpc.c block-vvfat.c
 	$(CC) -DQEMU_TOOL $(CFLAGS) $(LDFLAGS) $(DEFINES) -o $@ $^ -lz $(LIBS)
 
 dyngen$(EXESUF): dyngen.c

Makefile.target

@@ -289,7 +289,8 @@ ifeq ($(ARCH),alpha)
 endif
 
 # must use static linking to avoid leaving stuff in virtual address space
-VL_OBJS=vl.o osdep.o block.o readline.o monitor.o pci.o console.o loader.o
+VL_OBJS=vl.o osdep.o readline.o monitor.o pci.o console.o loader.o
+VL_OBJS+=block.o block-raw.o
 VL_OBJS+=block-cow.o block-qcow.o aes.o block-vmdk.o block-cloop.o block-dmg.o block-bochs.o block-vpc.o block-vvfat.o
 ifdef CONFIG_WIN32
 VL_OBJS+=tap-win32.o

block-bochs.c

@@ -85,15 +85,15 @@ static int bochs_probe(const uint8_t *buf, int buf_size, const char *filename)
     return 0;
 }
 
-static int bochs_open(BlockDriverState *bs, const char *filename)
+static int bochs_open(BlockDriverState *bs, const char *filename, int flags)
 {
     BDRVBochsState *s = bs->opaque;
     int fd, i;
     struct bochs_header bochs;
 
-    fd = open(filename, O_RDWR | O_BINARY | O_LARGEFILE);
+    fd = open(filename, O_RDWR | O_BINARY);
     if (fd < 0) {
-        fd = open(filename, O_RDONLY | O_BINARY | O_LARGEFILE);
+        fd = open(filename, O_RDONLY | O_BINARY);
         if (fd < 0)
             return -1;
     }

block-cloop.c

@@ -50,14 +50,14 @@ static int cloop_probe(const uint8_t *buf, int buf_size, const char *filename)
     return 0;
 }
 
-static int cloop_open(BlockDriverState *bs, const char *filename)
+static int cloop_open(BlockDriverState *bs, const char *filename, int flags)
 {
     BDRVCloopState *s = bs->opaque;
     uint32_t offsets_size,max_compressed_block_size=1,i;
 
-    s->fd = open(filename, O_RDONLY | O_BINARY | O_LARGEFILE);
+    s->fd = open(filename, O_RDONLY | O_BINARY);
     if (s->fd < 0)
-        return -1;
+        return -errno;
     bs->read_only = 1;
 
     /* read header */

block-cow.c

@@ -62,7 +62,7 @@ static int cow_probe(const uint8_t *buf, int buf_size, const char *filename)
         return 0;
 }
 
-static int cow_open(BlockDriverState *bs, const char *filename)
+static int cow_open(BlockDriverState *bs, const char *filename, int flags)
 {
     BDRVCowState *s = bs->opaque;
     int fd;
@@ -93,22 +93,6 @@ static int cow_open(BlockDriverState *bs, const char *filename)
     pstrcpy(bs->backing_file, sizeof(bs->backing_file), 
             cow_header.backing_file);
 
-#if 0
-    if (cow_header.backing_file[0] != '\0') {
-        if (stat(cow_header.backing_file, &st) != 0) {
-            fprintf(stderr, "%s: could not find original disk image '%s'\n", filename, cow_header.backing_file);
-            goto fail;
-        }
-        if (st.st_mtime != be32_to_cpu(cow_header.mtime)) {
-            fprintf(stderr, "%s: original raw disk image '%s' does not match saved timestamp\n", filename, cow_header.backing_file);
-            goto fail;
-            }
-        fd = open(cow_header.backing_file, O_RDONLY | O_LARGEFILE);
-        if (fd < 0)
-            goto fail;
-        bs->fd = fd;
-    }
-#endif
     /* mmap the bitmap */
     s->cow_bitmap_size = ((bs->total_sectors + 7) >> 3) + sizeof(cow_header);
     s->cow_bitmap_addr = mmap(get_mmap_addr(s->cow_bitmap_size), 
@@ -179,8 +163,15 @@ static int cow_read(BlockDriverState *bs, int64_t sector_num,
             if (ret != n * 512) 
                 return -1;
         } else {
+            if (bs->backing_hd) {
+                /* read from the base image */
+                ret = bdrv_read(bs->backing_hd, sector_num, buf, n);
+                if (ret < 0)
+                    return -1;
+            } else {
             memset(buf, 0, n * 512);
         }
+        }
         nb_sectors -= n;
         sector_num += n;
         buf += n * 512;
@@ -220,26 +211,31 @@ static int cow_create(const char *filename, int64_t image_sectors,
     if (flags)
         return -ENOTSUP;
 
-    cow_fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE, 
+    cow_fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 
               0644);
     if (cow_fd < 0)
         return -1;
     memset(&cow_header, 0, sizeof(cow_header));
     cow_header.magic = cpu_to_be32(COW_MAGIC);
     cow_header.version = cpu_to_be32(COW_VERSION);
     if (image_filename) {
+        /* Note: if no file, we put a dummy mtime */
+        cow_header.mtime = cpu_to_be32(0);
+
         fd = open(image_filename, O_RDONLY | O_BINARY);
         if (fd < 0) {
             close(cow_fd);
-            return -1;
+            goto mtime_fail;
         }
         if (fstat(fd, &st) != 0) {
             close(fd);
-            return -1;
+            goto mtime_fail;
         }
         close(fd);
         cow_header.mtime = cpu_to_be32(st.st_mtime);
-        realpath(image_filename, cow_header.backing_file);
+    mtime_fail:
+        pstrcpy(cow_header.backing_file, sizeof(cow_header.backing_file),
+                image_filename);
     }
     cow_header.sectorsize = cpu_to_be32(512);
     cow_header.size = cpu_to_be64(image_sectors * 512);

block-dmg.c

@@ -73,16 +73,16 @@ static off_t read_uint32(int fd)
 	return be32_to_cpu(buffer);
 }
 
-static int dmg_open(BlockDriverState *bs, const char *filename)
+static int dmg_open(BlockDriverState *bs, const char *filename, int flags)
 {
     BDRVDMGState *s = bs->opaque;
     off_t info_begin,info_end,last_in_offset,last_out_offset;
     uint32_t count;
     uint32_t max_compressed_size=1,max_sectors_per_chunk=1,i;
 
-    s->fd = open(filename, O_RDONLY | O_BINARY | O_LARGEFILE);
+    s->fd = open(filename, O_RDONLY | O_BINARY);
     if (s->fd < 0)
-        return -1;
+        return -errno;
     bs->read_only = 1;
     s->n_chunks = 0;
     s->offsets = s->lengths = s->sectors = s->sectorcounts = 0;
@@ -93,7 +93,7 @@ static int dmg_open(BlockDriverState *bs, const char *filename)
 	close(s->fd);
 	/* open raw instead */
 	bs->drv=&bdrv_raw;
-	return bs->drv->bdrv_open(bs,filename);
+	return bs->drv->bdrv_open(bs, filename, flags);
     }
     info_begin=read_off(s->fd);
     if(info_begin==0)