diff options
| -rw-r--r-- | qemu-img.c | 33 | ||||
| -rw-r--r-- | qemu-img.texi | 7 |
2 files changed, 36 insertions, 4 deletions
diff --git a/qemu-img.c b/qemu-img.c index 1b741956bc..28022145d5 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -24,6 +24,7 @@ #include "qemu/osdep.h" #include "qemu-version.h" #include "qapi/error.h" +#include "qapi/util.h" #include "qapi-visit.h" #include "qapi/qobject-output-visitor.h" #include "qapi/qmp/qerror.h" @@ -62,6 +63,7 @@ enum { OPTION_NO_DRAIN = 262, OPTION_TARGET_IMAGE_OPTS = 263, OPTION_SIZE = 264, + OPTION_PREALLOCATION = 265, }; typedef enum OutputFormat { @@ -3408,9 +3410,10 @@ static int img_resize(int argc, char **argv) Error *err = NULL; int c, ret, relative; const char *filename, *fmt, *size; - int64_t n, total_size; + int64_t n, total_size, current_size; bool quiet = false; BlockBackend *blk = NULL; + PreallocMode prealloc = PREALLOC_MODE_OFF; QemuOpts *param; static QemuOptsList resize_options = { @@ -3444,6 +3447,7 @@ static int img_resize(int argc, char **argv) {"help", no_argument, 0, 'h'}, {"object", required_argument, 0, OPTION_OBJECT}, {"image-opts", no_argument, 0, OPTION_IMAGE_OPTS}, + {"preallocation", required_argument, 0, OPTION_PREALLOCATION}, {0, 0, 0, 0} }; c = getopt_long(argc, argv, ":f:hq", @@ -3478,6 +3482,15 @@ static int img_resize(int argc, char **argv) case OPTION_IMAGE_OPTS: image_opts = true; break; + case OPTION_PREALLOCATION: + prealloc = qapi_enum_parse(PreallocMode_lookup, optarg, + PREALLOC_MODE__MAX, PREALLOC_MODE__MAX, + NULL); + if (prealloc == PREALLOC_MODE__MAX) { + error_report("Invalid preallocation mode '%s'", optarg); + return 1; + } + break; } } if (optind != argc - 1) { @@ -3526,8 +3539,16 @@ static int img_resize(int argc, char **argv) goto out; } + current_size = blk_getlength(blk); + if (current_size < 0) { + error_report("Failed to inquire current image length: %s", + strerror(-current_size)); + ret = -1; + goto out; + } + if (relative) { - total_size = blk_getlength(blk) + n * relative; + total_size = current_size + n * relative; } else { total_size = n; } @@ -3537,7 +3558,13 @@ static int img_resize(int argc, char **argv) goto out; } - ret = blk_truncate(blk, total_size, PREALLOC_MODE_OFF, &err); + if (total_size <= current_size && prealloc != PREALLOC_MODE_OFF) { + error_report("Preallocation can only be used for growing images"); + ret = -1; + goto out; + } + + ret = blk_truncate(blk, total_size, prealloc, &err); if (!ret) { qprintf(quiet, "Image resized.\n"); } else { diff --git a/qemu-img.texi b/qemu-img.texi index a2f45199d2..f11f6036ad 100644 --- a/qemu-img.texi +++ b/qemu-img.texi @@ -529,7 +529,7 @@ qemu-img rebase -b base.img diff.qcow2 At this point, @code{modified.img} can be discarded, since @code{base.img + diff.qcow2} contains the same information. -@item resize @var{filename} [+ | -]@var{size} +@item resize [--preallocation=@var{prealloc}] @var{filename} [+ | -]@var{size} Change the disk image as if it had been created with @var{size}. @@ -541,6 +541,11 @@ After using this command to grow a disk image, you must use file system and partitioning tools inside the VM to actually begin using the new space on the device. +When growing an image, the @code{--preallocation} option may be used to specify +how the additional image area should be allocated on the host. See the format +description in the @code{NOTES} section which values are allowed. Using this +option may result in slightly more data being allocated than necessary. + @item amend [-p] [-f @var{fmt}] [-t @var{cache}] -o @var{options} @var{filename} Amends the image format specific @var{options} for the image file |