diff options
Diffstat (limited to 'blockdev.c')
| -rw-r--r-- | blockdev.c | 126 |
1 files changed, 119 insertions, 7 deletions
diff --git a/blockdev.c b/blockdev.c index 69b7c2a8c5..48bd9a37bc 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1871,14 +1871,17 @@ static void block_job_cb(void *opaque, int ret) bdrv_put_ref_bh_schedule(bs); } -void qmp_block_stream(const char *device, bool has_base, - const char *base, bool has_speed, int64_t speed, +void qmp_block_stream(const char *device, + bool has_base, const char *base, + bool has_backing_file, const char *backing_file, + bool has_speed, int64_t speed, bool has_on_error, BlockdevOnError on_error, Error **errp) { BlockDriverState *bs; BlockDriverState *base_bs = NULL; Error *local_err = NULL; + const char *base_name = NULL; if (!has_on_error) { on_error = BLOCKDEV_ON_ERROR_REPORT; @@ -1894,15 +1897,27 @@ void qmp_block_stream(const char *device, bool has_base, return; } - if (base) { + if (has_base) { base_bs = bdrv_find_backing_image(bs, base); if (base_bs == NULL) { error_set(errp, QERR_BASE_NOT_FOUND, base); return; } + base_name = base; + } + + /* if we are streaming the entire chain, the result will have no backing + * file, and specifying one is therefore an error */ + if (base_bs == NULL && has_backing_file) { + error_setg(errp, "backing file specified, but streaming the " + "entire chain"); + return; } - stream_start(bs, base_bs, base, has_speed ? speed : 0, + /* backing_file string overrides base bs filename */ + base_name = has_backing_file ? backing_file : base_name; + + stream_start(bs, base_bs, base_name, has_speed ? speed : 0, on_error, block_job_cb, bs, &local_err); if (local_err) { error_propagate(errp, local_err); @@ -1913,7 +1928,9 @@ void qmp_block_stream(const char *device, bool has_base, } void qmp_block_commit(const char *device, - bool has_base, const char *base, const char *top, + bool has_base, const char *base, + bool has_top, const char *top, + bool has_backing_file, const char *backing_file, bool has_speed, int64_t speed, Error **errp) { @@ -1932,6 +1949,11 @@ void qmp_block_commit(const char *device, /* drain all i/o before commits */ bdrv_drain_all(); + /* Important Note: + * libvirt relies on the DeviceNotFound error class in order to probe for + * live commit feature versions; for this to work, we must make sure to + * perform the device lookup before any generic errors that may occur in a + * scenario in which all optional arguments are omitted. */ bs = bdrv_find(device); if (!bs) { error_set(errp, QERR_DEVICE_NOT_FOUND, device); @@ -1945,7 +1967,7 @@ void qmp_block_commit(const char *device, /* default top_bs is the active layer */ top_bs = bs; - if (top) { + if (has_top && top) { if (strcmp(bs->filename, top) != 0) { top_bs = bdrv_find_backing_image(bs, top); } @@ -1967,12 +1989,23 @@ void qmp_block_commit(const char *device, return; } + /* Do not allow attempts to commit an image into itself */ + if (top_bs == base_bs) { + error_setg(errp, "cannot commit an image into itself"); + return; + } + if (top_bs == bs) { + if (has_backing_file) { + error_setg(errp, "'backing-file' specified," + " but 'top' is the active layer"); + return; + } commit_active_start(bs, base_bs, speed, on_error, block_job_cb, bs, &local_err); } else { commit_start(bs, base_bs, top_bs, speed, on_error, block_job_cb, bs, - &local_err); + has_backing_file ? backing_file : NULL, &local_err); } if (local_err != NULL) { error_propagate(errp, local_err); @@ -2355,6 +2388,85 @@ void qmp_block_job_complete(const char *device, Error **errp) block_job_complete(job, errp); } +void qmp_change_backing_file(const char *device, + const char *image_node_name, + const char *backing_file, + Error **errp) +{ + BlockDriverState *bs = NULL; + BlockDriverState *image_bs = NULL; + Error *local_err = NULL; + bool ro; + int open_flags; + int ret; + + /* find the top layer BDS of the chain */ + bs = bdrv_find(device); + if (!bs) { + error_set(errp, QERR_DEVICE_NOT_FOUND, device); + return; + } + + image_bs = bdrv_lookup_bs(NULL, image_node_name, &local_err); + if (local_err) { + error_propagate(errp, local_err); + return; + } + + if (!image_bs) { + error_setg(errp, "image file not found"); + return; + } + + if (bdrv_find_base(image_bs) == image_bs) { + error_setg(errp, "not allowing backing file change on an image " + "without a backing file"); + return; + } + + /* even though we are not necessarily operating on bs, we need it to + * determine if block ops are currently prohibited on the chain */ + if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_CHANGE, errp)) { + return; + } + + /* final sanity check */ + if (!bdrv_chain_contains(bs, image_bs)) { + error_setg(errp, "'%s' and image file are not in the same chain", + device); + return; + } + + /* if not r/w, reopen to make r/w */ + open_flags = image_bs->open_flags; + ro = bdrv_is_read_only(image_bs); + + if (ro) { + bdrv_reopen(image_bs, open_flags | BDRV_O_RDWR, &local_err); + if (local_err) { + error_propagate(errp, local_err); + return; + } + } + + ret = bdrv_change_backing_file(image_bs, backing_file, + image_bs->drv ? image_bs->drv->format_name : ""); + + if (ret < 0) { + error_setg_errno(errp, -ret, "Could not change backing file to '%s'", + backing_file); + /* don't exit here, so we can try to restore open flags if + * appropriate */ + } + + if (ro) { + bdrv_reopen(image_bs, open_flags, &local_err); + if (local_err) { + error_propagate(errp, local_err); /* will preserve prior errp */ + } + } +} + void qmp_blockdev_add(BlockdevOptions *options, Error **errp) { QmpOutputVisitor *ov = qmp_output_visitor_new(); |