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[Qemu-block] [PATCH v6 06/25] block: bdrv_get_full_backing_filename_from
From: |
Max Reitz |
Subject: |
[Qemu-block] [PATCH v6 06/25] block: bdrv_get_full_backing_filename_from_...'s ret. val. |
Date: |
Fri, 29 Sep 2017 18:53:28 +0200 |
Make bdrv_get_full_backing_filename_from_filename() return an allocated
string instead of placing the result in a caller-provided buffer.
Signed-off-by: Max Reitz <address@hidden>
---
include/block/block.h | 7 +++----
block.c | 51 +++++++++++++++++++++++++++++++++++----------------
block/vmdk.c | 9 ++++-----
3 files changed, 42 insertions(+), 25 deletions(-)
diff --git a/include/block/block.h b/include/block/block.h
index a6ab70fb5e..3002236967 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -484,10 +484,9 @@ void bdrv_get_backing_filename(BlockDriverState *bs,
char *filename, int filename_size);
void bdrv_get_full_backing_filename(BlockDriverState *bs,
char *dest, size_t sz, Error **errp);
-void bdrv_get_full_backing_filename_from_filename(const char *backed,
- const char *backing,
- char *dest, size_t sz,
- Error **errp);
+char *bdrv_get_full_backing_filename_from_filename(const char *backed,
+ const char *backing,
+ Error **errp);
int path_has_protocol(const char *path);
int path_is_absolute(const char *path);
diff --git a/block.c b/block.c
index 32e8437107..4ca56983bb 100644
--- a/block.c
+++ b/block.c
@@ -283,20 +283,28 @@ int bdrv_set_read_only(BlockDriverState *bs, bool
read_only, Error **errp)
return 0;
}
-void bdrv_get_full_backing_filename_from_filename(const char *backed,
- const char *backing,
- char *dest, size_t sz,
- Error **errp)
+/* If @backing is empty, this function returns NULL without setting
+ * @errp. In all other cases, NULL will only be returned with @errp
+ * set.
+ *
+ * Therefore, a return value of NULL without @errp set means that
+ * there is no backing file; if @errp is set, there is one but its
+ * absolute filename cannot be generated.
+ */
+char *bdrv_get_full_backing_filename_from_filename(const char *backed,
+ const char *backing,
+ Error **errp)
{
- if (backing[0] == '\0' || path_has_protocol(backing) ||
- path_is_absolute(backing))
- {
- pstrcpy(dest, sz, backing);
+ if (backing[0] == '\0') {
+ return NULL;
+ } else if (path_has_protocol(backing) || path_is_absolute(backing)) {
+ return g_strdup(backing);
} else if (backed[0] == '\0' || strstart(backed, "json:", NULL)) {
error_setg(errp, "Cannot use relative backing file names for '%s'",
backed);
+ return NULL;
} else {
- path_combine_deprecated(dest, sz, backed, backing);
+ return path_combine(backed, backing);
}
}
@@ -304,9 +312,20 @@ void bdrv_get_full_backing_filename(BlockDriverState *bs,
char *dest, size_t sz,
Error **errp)
{
char *backed = bs->exact_filename[0] ? bs->exact_filename : bs->filename;
+ char *full_name;
+ Error *local_error = NULL;
- bdrv_get_full_backing_filename_from_filename(backed, bs->backing_file,
- dest, sz, errp);
+ full_name = bdrv_get_full_backing_filename_from_filename(backed,
+ bs->backing_file,
+ &local_error);
+ if (full_name) {
+ pstrcpy(dest, sz, full_name);
+ g_free(full_name);
+ } else if (local_error) {
+ error_propagate(errp, local_error);
+ } else if (sz > 0) {
+ *dest = '\0';
+ }
}
void bdrv_register(BlockDriver *bdrv)
@@ -4509,17 +4528,17 @@ void bdrv_img_create(const char *filename, const char
*fmt,
size = qemu_opt_get_size(opts, BLOCK_OPT_SIZE, 0);
if (backing_file && !(flags & BDRV_O_NO_BACKING)) {
BlockDriverState *bs;
- char *full_backing = g_new0(char, PATH_MAX);
+ char *full_backing;
int back_flags;
QDict *backing_options = NULL;
- bdrv_get_full_backing_filename_from_filename(filename, backing_file,
- full_backing, PATH_MAX,
- &local_err);
+ full_backing =
+ bdrv_get_full_backing_filename_from_filename(filename,
backing_file,
+ &local_err);
if (local_err) {
- g_free(full_backing);
goto out;
}
+ assert(full_backing);
/* backing files always opened read-only */
back_flags = flags;
diff --git a/block/vmdk.c b/block/vmdk.c
index 5397a4345e..c1dbcfe133 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -2001,16 +2001,15 @@ static int vmdk_create(const char *filename, QemuOpts
*opts, Error **errp)
}
if (backing_file) {
BlockBackend *blk;
- char *full_backing = g_new0(char, PATH_MAX);
- bdrv_get_full_backing_filename_from_filename(filename, backing_file,
- full_backing, PATH_MAX,
- &local_err);
+ char *full_backing =
+ bdrv_get_full_backing_filename_from_filename(filename,
backing_file,
+ &local_err);
if (local_err) {
- g_free(full_backing);
error_propagate(errp, local_err);
ret = -ENOENT;
goto exit;
}
+ assert(full_backing);
blk = blk_new_open(full_backing, NULL, NULL,
BDRV_O_NO_BACKING, errp);
--
2.13.6
- [Qemu-block] [PATCH v6 00/25] block: Fix some filename generation issues, Max Reitz, 2017/09/29
- [Qemu-block] [PATCH v6 01/25] block/mirror: Small absolute-paths simplification, Max Reitz, 2017/09/29
- [Qemu-block] [PATCH v6 02/25] block: Use children list in bdrv_refresh_filename, Max Reitz, 2017/09/29
- [Qemu-block] [PATCH v6 03/25] block: Add BDS.backing_overridden, Max Reitz, 2017/09/29
- [Qemu-block] [PATCH v6 04/25] block: Respect backing bs in bdrv_refresh_filename, Max Reitz, 2017/09/29
- [Qemu-block] [PATCH v6 05/25] block: Make path_combine() return the path, Max Reitz, 2017/09/29
- [Qemu-block] [PATCH v6 06/25] block: bdrv_get_full_backing_filename_from_...'s ret. val.,
Max Reitz <=
- [Qemu-block] [PATCH v6 07/25] block: bdrv_get_full_backing_filename's ret. val., Max Reitz, 2017/09/29
- [Qemu-block] [PATCH v6 08/25] block: Add bdrv_make_absolute_filename(), Max Reitz, 2017/09/29
- [Qemu-block] [PATCH v6 09/25] block: Fix bdrv_find_backing_image(), Max Reitz, 2017/09/29
- [Qemu-block] [PATCH v6 10/25] block: Add bdrv_dirname(), Max Reitz, 2017/09/29
- [Qemu-block] [PATCH v6 11/25] blkverify: Make bdrv_dirname() return NULL, Max Reitz, 2017/09/29
- [Qemu-block] [PATCH v6 12/25] quorum: Make bdrv_dirname() return NULL, Max Reitz, 2017/09/29
- [Qemu-block] [PATCH v6 13/25] block/nbd: Make bdrv_dirname() return NULL, Max Reitz, 2017/09/29
- [Qemu-block] [PATCH v6 14/25] block/nfs: Implement bdrv_dirname(), Max Reitz, 2017/09/29
- [Qemu-block] [PATCH v6 15/25] block: Use bdrv_dirname() for relative filenames, Max Reitz, 2017/09/29
- [Qemu-block] [PATCH v6 16/25] block: Add 'base-directory' BDS option, Max Reitz, 2017/09/29