From 72daa72eeecb6b2ee06ab7d836ac3aa01ad7e6df Mon Sep 17 00:00:00 2001 From: Max Reitz Date: Fri, 20 Dec 2013 19:28:08 +0100 Subject: [PATCH] block: Allow reference for bdrv_file_open() Allow specifying a reference to an existing block device (by name) for bdrv_file_open() instead of a filename and/or options. Signed-off-by: Max Reitz Reviewed-by: Kevin Wolf Signed-off-by: Kevin Wolf --- block.c | 25 ++++++++++++++++++++++--- block/blkdebug.c | 2 +- block/blkverify.c | 2 +- block/cow.c | 3 ++- block/qcow.c | 3 ++- block/qcow2.c | 2 +- block/qed.c | 4 ++-- block/sheepdog.c | 4 ++-- block/vhdx.c | 2 +- block/vmdk.c | 8 ++++---- include/block/block.h | 3 ++- qemu-io.c | 2 +- 12 files changed, 41 insertions(+), 19 deletions(-) diff --git a/block.c b/block.c index 64e7d220c6..1e53b3dffd 100644 --- a/block.c +++ b/block.c @@ -858,9 +858,10 @@ free_and_fail: * dictionary, it needs to use QINCREF() before calling bdrv_file_open. */ int bdrv_file_open(BlockDriverState **pbs, const char *filename, - QDict *options, int flags, Error **errp) + const char *reference, QDict *options, int flags, + Error **errp) { - BlockDriverState *bs; + BlockDriverState *bs = NULL; BlockDriver *drv; const char *drvname; bool allow_protocol_prefix = false; @@ -872,6 +873,24 @@ int bdrv_file_open(BlockDriverState **pbs, const char *filename, options = qdict_new(); } + if (reference) { + if (filename || qdict_size(options)) { + error_setg(errp, "Cannot reference an existing block device with " + "additional options or a new filename"); + return -EINVAL; + } + QDECREF(options); + + bs = bdrv_find(reference); + if (!bs) { + error_setg(errp, "Cannot find block device '%s'", reference); + return -ENODEV; + } + bdrv_ref(bs); + *pbs = bs; + return 0; + } + bs = bdrv_new(""); bs->options = options; options = qdict_clone_shallow(options); @@ -1124,7 +1143,7 @@ int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options, qdict_extract_subqdict(options, &file_options, "file."); - ret = bdrv_file_open(&file, filename, file_options, + ret = bdrv_file_open(&file, filename, NULL, file_options, bdrv_open_flags(bs, flags | BDRV_O_UNMAP), &local_err); if (ret < 0) { goto fail; diff --git a/block/blkdebug.c b/block/blkdebug.c index 0bf3bb518a..21a4931594 100644 --- a/block/blkdebug.c +++ b/block/blkdebug.c @@ -403,7 +403,7 @@ static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags, goto fail; } - ret = bdrv_file_open(&bs->file, filename, NULL, flags, &local_err); + ret = bdrv_file_open(&bs->file, filename, NULL, NULL, flags, &local_err); if (ret < 0) { error_propagate(errp, local_err); goto fail; diff --git a/block/blkverify.c b/block/blkverify.c index 1c1637f55e..e15ac4ca69 100644 --- a/block/blkverify.c +++ b/block/blkverify.c @@ -141,7 +141,7 @@ static int blkverify_open(BlockDriverState *bs, QDict *options, int flags, goto fail; } - ret = bdrv_file_open(&bs->file, raw, NULL, flags, &local_err); + ret = bdrv_file_open(&bs->file, raw, NULL, NULL, flags, &local_err); if (ret < 0) { error_propagate(errp, local_err); goto fail; diff --git a/block/cow.c b/block/cow.c index dc15e46b6c..7fc0b12163 100644 --- a/block/cow.c +++ b/block/cow.c @@ -351,7 +351,8 @@ static int cow_create(const char *filename, QEMUOptionParameter *options, return ret; } - ret = bdrv_file_open(&cow_bs, filename, NULL, BDRV_O_RDWR, &local_err); + ret = bdrv_file_open(&cow_bs, filename, NULL, NULL, BDRV_O_RDWR, + &local_err); if (ret < 0) { qerror_report_err(local_err); error_free(local_err); diff --git a/block/qcow.c b/block/qcow.c index c470e05f60..948b0c5601 100644 --- a/block/qcow.c +++ b/block/qcow.c @@ -691,7 +691,8 @@ static int qcow_create(const char *filename, QEMUOptionParameter *options, return ret; } - ret = bdrv_file_open(&qcow_bs, filename, NULL, BDRV_O_RDWR, &local_err); + ret = bdrv_file_open(&qcow_bs, filename, NULL, NULL, BDRV_O_RDWR, + &local_err); if (ret < 0) { qerror_report_err(local_err); error_free(local_err); diff --git a/block/qcow2.c b/block/qcow2.c index 8ec9db10f8..e15a4dd057 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -1483,7 +1483,7 @@ static int qcow2_create2(const char *filename, int64_t total_size, return ret; } - ret = bdrv_file_open(&bs, filename, NULL, BDRV_O_RDWR, &local_err); + ret = bdrv_file_open(&bs, filename, NULL, NULL, BDRV_O_RDWR, &local_err); if (ret < 0) { error_propagate(errp, local_err); return ret; diff --git a/block/qed.c b/block/qed.c index 450a1fa2e9..0dd5c5859e 100644 --- a/block/qed.c +++ b/block/qed.c @@ -563,8 +563,8 @@ static int qed_create(const char *filename, uint32_t cluster_size, return ret; } - ret = bdrv_file_open(&bs, filename, NULL, BDRV_O_RDWR | BDRV_O_CACHE_WB, - &local_err); + ret = bdrv_file_open(&bs, filename, NULL, NULL, + BDRV_O_RDWR | BDRV_O_CACHE_WB, &local_err); if (ret < 0) { qerror_report_err(local_err); error_free(local_err); diff --git a/block/sheepdog.c b/block/sheepdog.c index 6088fa5571..2ce3d9b9fb 100644 --- a/block/sheepdog.c +++ b/block/sheepdog.c @@ -1534,7 +1534,7 @@ static int sd_prealloc(const char *filename) Error *local_err = NULL; int ret; - ret = bdrv_file_open(&bs, filename, NULL, BDRV_O_RDWR, &local_err); + ret = bdrv_file_open(&bs, filename, NULL, NULL, BDRV_O_RDWR, &local_err); if (ret < 0) { qerror_report_err(local_err); error_free(local_err); @@ -1695,7 +1695,7 @@ static int sd_create(const char *filename, QEMUOptionParameter *options, goto out; } - ret = bdrv_file_open(&bs, backing_file, NULL, 0, &local_err); + ret = bdrv_file_open(&bs, backing_file, NULL, NULL, 0, &local_err); if (ret < 0) { qerror_report_err(local_err); error_free(local_err); diff --git a/block/vhdx.c b/block/vhdx.c index 1995778945..9ee0a612ff 100644 --- a/block/vhdx.c +++ b/block/vhdx.c @@ -1797,7 +1797,7 @@ static int vhdx_create(const char *filename, QEMUOptionParameter *options, goto exit; } - ret = bdrv_file_open(&bs, filename, NULL, BDRV_O_RDWR, &local_err); + ret = bdrv_file_open(&bs, filename, NULL, NULL, BDRV_O_RDWR, &local_err); if (ret < 0) { error_propagate(errp, local_err); goto exit; diff --git a/block/vmdk.c b/block/vmdk.c index 22b99b04ac..599a928545 100644 --- a/block/vmdk.c +++ b/block/vmdk.c @@ -769,8 +769,8 @@ static int vmdk_parse_extents(const char *desc, BlockDriverState *bs, path_combine(extent_path, sizeof(extent_path), desc_file_path, fname); - ret = bdrv_file_open(&extent_file, extent_path, NULL, bs->open_flags, - errp); + ret = bdrv_file_open(&extent_file, extent_path, NULL, NULL, + bs->open_flags, errp); if (ret) { return ret; } @@ -1469,7 +1469,7 @@ static int vmdk_create_extent(const char *filename, int64_t filesize, goto exit; } - ret = bdrv_file_open(&bs, filename, NULL, BDRV_O_RDWR, &local_err); + ret = bdrv_file_open(&bs, filename, NULL, NULL, BDRV_O_RDWR, &local_err); if (ret < 0) { error_propagate(errp, local_err); goto exit; @@ -1807,7 +1807,7 @@ static int vmdk_create(const char *filename, QEMUOptionParameter *options, goto exit; } } - ret = bdrv_file_open(&new_bs, filename, NULL, BDRV_O_RDWR, &local_err); + ret = bdrv_file_open(&new_bs, filename, NULL, NULL, BDRV_O_RDWR, &local_err); if (ret < 0) { error_setg_errno(errp, -ret, "Could not write description"); goto exit; diff --git a/include/block/block.h b/include/block/block.h index 36efaeac2d..e2b2a15f9a 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -184,7 +184,8 @@ void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top); int bdrv_parse_cache_flags(const char *mode, int *flags); int bdrv_parse_discard_flags(const char *mode, int *flags); int bdrv_file_open(BlockDriverState **pbs, const char *filename, - QDict *options, int flags, Error **errp); + const char *reference, QDict *options, int flags, + Error **errp); int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp); int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options, int flags, BlockDriver *drv, Error **errp); diff --git a/qemu-io.c b/qemu-io.c index fdc46a97e8..bfb773e70f 100644 --- a/qemu-io.c +++ b/qemu-io.c @@ -59,7 +59,7 @@ static int openfile(char *name, int flags, int growable, QDict *opts) } if (growable) { - if (bdrv_file_open(&qemuio_bs, name, opts, flags, &local_err)) { + if (bdrv_file_open(&qemuio_bs, name, NULL, opts, flags, &local_err)) { fprintf(stderr, "%s: can't open device %s: %s\n", progname, name, error_get_pretty(local_err)); error_free(local_err); -- 2.34.1