diff options
Diffstat (limited to 'block')
| -rw-r--r-- | block/qcow2.c | 29 | ||||
| -rw-r--r-- | block/qcow2.h | 6 |
2 files changed, 28 insertions, 7 deletions
diff --git a/block/qcow2.c b/block/qcow2.c index 32bdf756ca..316a8db22b 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -140,6 +140,7 @@ static int qcow2_read_extensions(BlockDriverState *bs, uint64_t start_offset, return 3; } bs->backing_format[ext.len] = '\0'; + s->image_backing_format = g_strdup(bs->backing_format); #ifdef DEBUG_EXT printf("Qcow2: Got format extension %s\n", bs->backing_format); #endif @@ -884,6 +885,7 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags, goto fail; } bs->backing_file[len] = '\0'; + s->image_backing_file = g_strdup(bs->backing_file); } /* Internal snapshots */ @@ -1457,6 +1459,9 @@ static void qcow2_close(BlockDriverState *bs) g_free(s->unknown_header_fields); cleanup_unknown_header_ext(bs); + g_free(s->image_backing_file); + g_free(s->image_backing_format); + g_free(s->cluster_cache); qemu_vfree(s->cluster_data); qcow2_refcount_close(bs); @@ -1622,9 +1627,10 @@ int qcow2_update_header(BlockDriverState *bs) } /* Backing file format header extension */ - if (*bs->backing_format) { + if (s->image_backing_format) { ret = header_ext_add(buf, QCOW2_EXT_MAGIC_BACKING_FORMAT, - bs->backing_format, strlen(bs->backing_format), + s->image_backing_format, + strlen(s->image_backing_format), buflen); if (ret < 0) { goto fail; @@ -1682,8 +1688,8 @@ int qcow2_update_header(BlockDriverState *bs) buflen -= ret; /* Backing file name */ - if (*bs->backing_file) { - size_t backing_file_len = strlen(bs->backing_file); + if (s->image_backing_file) { + size_t backing_file_len = strlen(s->image_backing_file); if (buflen < backing_file_len) { ret = -ENOSPC; @@ -1691,7 +1697,7 @@ int qcow2_update_header(BlockDriverState *bs) } /* Using strncpy is ok here, since buf is not NUL-terminated. */ - strncpy(buf, bs->backing_file, buflen); + strncpy(buf, s->image_backing_file, buflen); header->backing_file_offset = cpu_to_be64(buf - ((char*) header)); header->backing_file_size = cpu_to_be32(backing_file_len); @@ -1712,9 +1718,17 @@ fail: static int qcow2_change_backing_file(BlockDriverState *bs, const char *backing_file, const char *backing_fmt) { + BDRVQcowState *s = bs->opaque; + pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: ""); pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: ""); + g_free(s->image_backing_file); + g_free(s->image_backing_format); + + s->image_backing_file = backing_file ? g_strdup(bs->backing_file) : NULL; + s->image_backing_format = backing_fmt ? g_strdup(bs->backing_format) : NULL; + return qcow2_update_header(bs); } @@ -2751,8 +2765,9 @@ static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts, } if (backing_file || backing_format) { - ret = qcow2_change_backing_file(bs, backing_file ?: bs->backing_file, - backing_format ?: bs->backing_format); + ret = qcow2_change_backing_file(bs, + backing_file ?: s->image_backing_file, + backing_format ?: s->image_backing_format); if (ret < 0) { return ret; } diff --git a/block/qcow2.h b/block/qcow2.h index aa6d367818..422b825138 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -283,6 +283,12 @@ typedef struct BDRVQcowState { QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext; QTAILQ_HEAD (, Qcow2DiscardRegion) discards; bool cache_discards; + + /* Backing file path and format as stored in the image (this is not the + * effective path/format, which may be the result of a runtime option + * override) */ + char *image_backing_file; + char *image_backing_format; } BDRVQcowState; struct QCowAIOCB; |