diff options
| -rw-r--r-- | block.c | 19 | ||||
| -rw-r--r-- | block/qcow.c | 7 | ||||
| -rw-r--r-- | block/qcow2.c | 10 | ||||
| -rw-r--r-- | block/qed.c | 7 | ||||
| -rw-r--r-- | block/vmdk.c | 6 | ||||
| -rw-r--r-- | include/block/block_int.h | 4 |
6 files changed, 44 insertions, 9 deletions
@@ -2361,6 +2361,7 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, char *bdref_key_dot; const char *reference = NULL; int ret = 0; + bool implicit_backing = false; BlockDriverState *backing_hd; QDict *options; QDict *tmp_parent_options = NULL; @@ -2396,6 +2397,16 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, qobject_unref(options); goto free_exit; } else { + if (qdict_size(options) == 0) { + /* If the user specifies options that do not modify the + * backing file's behavior, we might still consider it the + * implicit backing file. But it's easier this way, and + * just specifying some of the backing BDS's options is + * only possible with -drive anyway (otherwise the QAPI + * schema forces the user to specify everything). */ + implicit_backing = !strcmp(bs->auto_backing_file, bs->backing_file); + } + bdrv_get_full_backing_filename(bs, backing_filename, PATH_MAX, &local_err); if (local_err) { @@ -2429,6 +2440,12 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, } bdrv_set_aio_context(backing_hd, bdrv_get_aio_context(bs)); + if (implicit_backing) { + bdrv_refresh_filename(backing_hd); + pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file), + backing_hd->filename); + } + /* Hook up the backing file link; drop our reference, bs owns the * backing_hd reference now */ bdrv_set_backing_hd(bs, backing_hd, &local_err); @@ -3848,6 +3865,8 @@ int bdrv_change_backing_file(BlockDriverState *bs, if (ret == 0) { pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: ""); pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: ""); + pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file), + backing_file ?: ""); } return ret; } diff --git a/block/qcow.c b/block/qcow.c index 0a235bf..d47515d 100644 --- a/block/qcow.c +++ b/block/qcow.c @@ -31,6 +31,7 @@ #include "qemu/module.h" #include "qemu/option.h" #include "qemu/bswap.h" +#include "qemu/cutils.h" #include <zlib.h> #include "qapi/qmp/qdict.h" #include "qapi/qmp/qstring.h" @@ -295,11 +296,13 @@ static int qcow_open(BlockDriverState *bs, QDict *options, int flags, goto fail; } ret = bdrv_pread(bs->file, header.backing_file_offset, - bs->backing_file, len); + bs->auto_backing_file, len); if (ret < 0) { goto fail; } - bs->backing_file[len] = '\0'; + bs->auto_backing_file[len] = '\0'; + pstrcpy(bs->backing_file, sizeof(bs->backing_file), + bs->auto_backing_file); } /* Disable migration when qcow images are used */ diff --git a/block/qcow2.c b/block/qcow2.c index 65a54c9..3826ce7 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -1474,13 +1474,15 @@ static int coroutine_fn qcow2_do_open(BlockDriverState *bs, QDict *options, goto fail; } ret = bdrv_pread(bs->file, header.backing_file_offset, - bs->backing_file, len); + bs->auto_backing_file, len); if (ret < 0) { error_setg_errno(errp, -ret, "Could not read backing file name"); goto fail; } - bs->backing_file[len] = '\0'; - s->image_backing_file = g_strdup(bs->backing_file); + bs->auto_backing_file[len] = '\0'; + pstrcpy(bs->backing_file, sizeof(bs->backing_file), + bs->auto_backing_file); + s->image_backing_file = g_strdup(bs->auto_backing_file); } /* Internal snapshots */ @@ -2518,6 +2520,8 @@ static int qcow2_change_backing_file(BlockDriverState *bs, return -EINVAL; } + pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file), + backing_file ?: ""); pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: ""); pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: ""); diff --git a/block/qed.c b/block/qed.c index 1280870..81a1bed 100644 --- a/block/qed.c +++ b/block/qed.c @@ -454,11 +454,14 @@ static int coroutine_fn bdrv_qed_do_open(BlockDriverState *bs, QDict *options, } ret = qed_read_string(bs->file, s->header.backing_filename_offset, - s->header.backing_filename_size, bs->backing_file, - sizeof(bs->backing_file)); + s->header.backing_filename_size, + bs->auto_backing_file, + sizeof(bs->auto_backing_file)); if (ret < 0) { return ret; } + pstrcpy(bs->backing_file, sizeof(bs->backing_file), + bs->auto_backing_file); if (s->header.features & QED_F_BACKING_FORMAT_NO_PROBE) { pstrcpy(bs->backing_format, sizeof(bs->backing_format), "raw"); diff --git a/block/vmdk.c b/block/vmdk.c index 117dc6a..464b718 100644 --- a/block/vmdk.c +++ b/block/vmdk.c @@ -386,12 +386,14 @@ static int vmdk_parent_open(BlockDriverState *bs) ret = -EINVAL; goto out; } - if ((end_name - p_name) > sizeof(bs->backing_file) - 1) { + if ((end_name - p_name) > sizeof(bs->auto_backing_file) - 1) { ret = -EINVAL; goto out; } - pstrcpy(bs->backing_file, end_name - p_name + 1, p_name); + pstrcpy(bs->auto_backing_file, end_name - p_name + 1, p_name); + pstrcpy(bs->backing_file, sizeof(bs->backing_file), + bs->auto_backing_file); } out: diff --git a/include/block/block_int.h b/include/block/block_int.h index 8437df8..dd7276c 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -702,6 +702,10 @@ struct BlockDriverState { char filename[PATH_MAX]; char backing_file[PATH_MAX]; /* if non zero, the image is a diff of this file image */ + /* The backing filename indicated by the image header; if we ever + * open this file, then this is replaced by the resulting BDS's + * filename (i.e. after a bdrv_refresh_filename() run). */ + char auto_backing_file[PATH_MAX]; char backing_format[16]; /* if non-zero and backing_file exists */ QDict *full_open_options; |