Revision b1b1d783 block.c
| b/block.c | ||
|---|---|---|
| 3123 | 3123 |
return -ENOTSUP; |
| 3124 | 3124 |
} |
| 3125 | 3125 |
|
| 3126 |
/* backing_file can either be relative, or absolute, or a protocol. If it is |
|
| 3127 |
* relative, it must be relative to the chain. So, passing in bs->filename |
|
| 3128 |
* from a BDS as backing_file should not be done, as that may be relative to |
|
| 3129 |
* the CWD rather than the chain. */ |
|
| 3126 | 3130 |
BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, |
| 3127 | 3131 |
const char *backing_file) |
| 3128 | 3132 |
{
|
| 3129 |
if (!bs->drv) {
|
|
| 3133 |
char *filename_full = NULL; |
|
| 3134 |
char *backing_file_full = NULL; |
|
| 3135 |
char *filename_tmp = NULL; |
|
| 3136 |
int is_protocol = 0; |
|
| 3137 |
BlockDriverState *curr_bs = NULL; |
|
| 3138 |
BlockDriverState *retval = NULL; |
|
| 3139 |
|
|
| 3140 |
if (!bs || !bs->drv || !backing_file) {
|
|
| 3130 | 3141 |
return NULL; |
| 3131 | 3142 |
} |
| 3132 | 3143 |
|
| 3133 |
if (bs->backing_hd) {
|
|
| 3134 |
if (strcmp(bs->backing_file, backing_file) == 0) {
|
|
| 3135 |
return bs->backing_hd; |
|
| 3144 |
filename_full = g_malloc(PATH_MAX); |
|
| 3145 |
backing_file_full = g_malloc(PATH_MAX); |
|
| 3146 |
filename_tmp = g_malloc(PATH_MAX); |
|
| 3147 |
|
|
| 3148 |
is_protocol = path_has_protocol(backing_file); |
|
| 3149 |
|
|
| 3150 |
for (curr_bs = bs; curr_bs->backing_hd; curr_bs = curr_bs->backing_hd) {
|
|
| 3151 |
|
|
| 3152 |
/* If either of the filename paths is actually a protocol, then |
|
| 3153 |
* compare unmodified paths; otherwise make paths relative */ |
|
| 3154 |
if (is_protocol || path_has_protocol(curr_bs->backing_file)) {
|
|
| 3155 |
if (strcmp(backing_file, curr_bs->backing_file) == 0) {
|
|
| 3156 |
retval = curr_bs->backing_hd; |
|
| 3157 |
break; |
|
| 3158 |
} |
|
| 3136 | 3159 |
} else {
|
| 3137 |
return bdrv_find_backing_image(bs->backing_hd, backing_file); |
|
| 3160 |
/* If not an absolute filename path, make it relative to the current |
|
| 3161 |
* image's filename path */ |
|
| 3162 |
path_combine(filename_tmp, PATH_MAX, curr_bs->filename, |
|
| 3163 |
backing_file); |
|
| 3164 |
|
|
| 3165 |
/* We are going to compare absolute pathnames */ |
|
| 3166 |
if (!realpath(filename_tmp, filename_full)) {
|
|
| 3167 |
continue; |
|
| 3168 |
} |
|
| 3169 |
|
|
| 3170 |
/* We need to make sure the backing filename we are comparing against |
|
| 3171 |
* is relative to the current image filename (or absolute) */ |
|
| 3172 |
path_combine(filename_tmp, PATH_MAX, curr_bs->filename, |
|
| 3173 |
curr_bs->backing_file); |
|
| 3174 |
|
|
| 3175 |
if (!realpath(filename_tmp, backing_file_full)) {
|
|
| 3176 |
continue; |
|
| 3177 |
} |
|
| 3178 |
|
|
| 3179 |
if (strcmp(backing_file_full, filename_full) == 0) {
|
|
| 3180 |
retval = curr_bs->backing_hd; |
|
| 3181 |
break; |
|
| 3182 |
} |
|
| 3138 | 3183 |
} |
| 3139 | 3184 |
} |
| 3140 | 3185 |
|
| 3141 |
return NULL; |
|
| 3186 |
g_free(filename_full); |
|
| 3187 |
g_free(backing_file_full); |
|
| 3188 |
g_free(filename_tmp); |
|
| 3189 |
return retval; |
|
| 3142 | 3190 |
} |
| 3143 | 3191 |
|
| 3144 | 3192 |
int bdrv_get_backing_file_depth(BlockDriverState *bs) |
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