diff options
author | Hu Tao <hutao@cn.fujitsu.com> | 2014-09-10 17:05:49 +0800 |
---|---|---|
committer | Kevin Wolf <kwolf@redhat.com> | 2014-09-12 15:43:06 +0200 |
commit | 0e4271b711a8ea766d29824c844e268b91ac3ae5 (patch) | |
tree | 8d00320ff6821eca68094864906838f3f4f5a6fe | |
parent | 06247428be8037b3739280f82cb29efe8397695f (diff) |
qcow2: Add falloc and full preallocation option
preallocation=falloc allocates disk space by posix_fallocate(),
preallocation=full allocates disk space by writing zeros to disk.
Both modes imply preallocation=metadata.
Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
-rw-r--r-- | block/qcow2.c | 63 | ||||
-rw-r--r-- | qemu-doc.texi | 8 | ||||
-rw-r--r-- | qemu-img.texi | 8 | ||||
-rw-r--r-- | tests/qemu-iotests/082.out | 54 |
4 files changed, 90 insertions, 43 deletions
diff --git a/block/qcow2.c b/block/qcow2.c index 2d68b51f14..0daf25cb58 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -1772,6 +1772,56 @@ static int qcow2_create2(const char *filename, int64_t total_size, Error *local_err = NULL; int ret; + if (prealloc == PREALLOC_MODE_FULL || prealloc == PREALLOC_MODE_FALLOC) { + int64_t meta_size = 0; + uint64_t nreftablee, nrefblocke, nl1e, nl2e; + int64_t aligned_total_size = align_offset(total_size, cluster_size); + + /* header: 1 cluster */ + meta_size += cluster_size; + + /* total size of L2 tables */ + nl2e = aligned_total_size / cluster_size; + nl2e = align_offset(nl2e, cluster_size / sizeof(uint64_t)); + meta_size += nl2e * sizeof(uint64_t); + + /* total size of L1 tables */ + nl1e = nl2e * sizeof(uint64_t) / cluster_size; + nl1e = align_offset(nl1e, cluster_size / sizeof(uint64_t)); + meta_size += nl1e * sizeof(uint64_t); + + /* total size of refcount blocks + * + * note: every host cluster is reference-counted, including metadata + * (even refcount blocks are recursively included). + * Let: + * a = total_size (this is the guest disk size) + * m = meta size not including refcount blocks and refcount tables + * c = cluster size + * y1 = number of refcount blocks entries + * y2 = meta size including everything + * then, + * y1 = (y2 + a)/c + * y2 = y1 * sizeof(u16) + y1 * sizeof(u16) * sizeof(u64) / c + m + * we can get y1: + * y1 = (a + m) / (c - sizeof(u16) - sizeof(u16) * sizeof(u64) / c) + */ + nrefblocke = (aligned_total_size + meta_size + cluster_size) / + (cluster_size - sizeof(uint16_t) - + 1.0 * sizeof(uint16_t) * sizeof(uint64_t) / cluster_size); + nrefblocke = align_offset(nrefblocke, cluster_size / sizeof(uint16_t)); + meta_size += nrefblocke * sizeof(uint16_t); + + /* total size of refcount tables */ + nreftablee = nrefblocke * sizeof(uint16_t) / cluster_size; + nreftablee = align_offset(nreftablee, cluster_size / sizeof(uint64_t)); + meta_size += nreftablee * sizeof(uint64_t); + + qemu_opt_set_number(opts, BLOCK_OPT_SIZE, + aligned_total_size + meta_size); + qemu_opt_set(opts, BLOCK_OPT_PREALLOC, PreallocMode_lookup[prealloc]); + } + ret = bdrv_create_file(filename, opts, &local_err); if (ret < 0) { error_propagate(errp, local_err); @@ -1877,7 +1927,7 @@ static int qcow2_create2(const char *filename, int64_t total_size, } /* And if we're supposed to preallocate metadata, do that now */ - if (prealloc == PREALLOC_MODE_METADATA) { + if (prealloc != PREALLOC_MODE_OFF) { BDRVQcowState *s = bs->opaque; qemu_co_mutex_lock(&s->lock); ret = preallocate(bs); @@ -1958,14 +2008,6 @@ static int qcow2_create(const char *filename, QemuOpts *opts, Error **errp) flags |= BLOCK_FLAG_LAZY_REFCOUNTS; } - if (prealloc != PREALLOC_MODE_OFF && - prealloc != PREALLOC_MODE_METADATA) { - ret = -EINVAL; - error_setg(errp, "Unsupported preallocate mode: %s", - PreallocMode_lookup[prealloc]); - goto finish; - } - if (backing_file && prealloc != PREALLOC_MODE_OFF) { error_setg(errp, "Backing file and preallocation cannot be used at " "the same time"); @@ -2526,7 +2568,8 @@ static QemuOptsList qcow2_create_opts = { { .name = BLOCK_OPT_PREALLOC, .type = QEMU_OPT_STRING, - .help = "Preallocation mode (allowed values: off, metadata)" + .help = "Preallocation mode (allowed values: off, metadata, " + "falloc, full)" }, { .name = BLOCK_OPT_LAZY_REFCOUNTS, diff --git a/qemu-doc.texi b/qemu-doc.texi index 1f289d6a08..ef3be72ae2 100644 --- a/qemu-doc.texi +++ b/qemu-doc.texi @@ -584,9 +584,11 @@ sizes can improve the image file size whereas larger cluster sizes generally provide better performance. @item preallocation -Preallocation mode (allowed values: off, metadata). An image with preallocated -metadata is initially larger but can improve performance when the image needs -to grow. +Preallocation mode (allowed values: @code{off}, @code{metadata}, @code{falloc}, +@code{full}). An image with preallocated metadata is initially larger but can +improve performance when the image needs to grow. @code{falloc} and @code{full} +preallocations are like the same options of @code{raw} format, but sets up +metadata also. @item lazy_refcounts If this option is set to @code{on}, reference count updates are postponed with diff --git a/qemu-img.texi b/qemu-img.texi index d64d05edda..50d2cca7a0 100644 --- a/qemu-img.texi +++ b/qemu-img.texi @@ -476,9 +476,11 @@ sizes can improve the image file size whereas larger cluster sizes generally provide better performance. @item preallocation -Preallocation mode (allowed values: off, metadata). An image with preallocated -metadata is initially larger but can improve performance when the image needs -to grow. +Preallocation mode (allowed values: @code{off}, @code{metadata}, @code{falloc}, +@code{full}). An image with preallocated metadata is initially larger but can +improve performance when the image needs to grow. @code{falloc} and @code{full} +preallocations are like the same options of @code{raw} format, but sets up +metadata also. @item lazy_refcounts If this option is set to @code{on}, reference count updates are postponed with diff --git a/tests/qemu-iotests/082.out b/tests/qemu-iotests/082.out index 413e7ef391..90c21c893b 100644 --- a/tests/qemu-iotests/082.out +++ b/tests/qemu-iotests/082.out @@ -64,7 +64,7 @@ backing_file File name of a base image backing_fmt Image format of the base image encryption Encrypt the image cluster_size qcow2 cluster size -preallocation Preallocation mode (allowed values: off, metadata) +preallocation Preallocation mode (allowed values: off, metadata, falloc, full) lazy_refcounts Postpone refcount updates nocow Turn off copy-on-write (valid only on btrfs) @@ -76,7 +76,7 @@ backing_file File name of a base image backing_fmt Image format of the base image encryption Encrypt the image cluster_size qcow2 cluster size -preallocation Preallocation mode (allowed values: off, metadata) +preallocation Preallocation mode (allowed values: off, metadata, falloc, full) lazy_refcounts Postpone refcount updates nocow Turn off copy-on-write (valid only on btrfs) @@ -88,7 +88,7 @@ backing_file File name of a base image backing_fmt Image format of the base image encryption Encrypt the image cluster_size qcow2 cluster size -preallocation Preallocation mode (allowed values: off, metadata) +preallocation Preallocation mode (allowed values: off, metadata, falloc, full) lazy_refcounts Postpone refcount updates nocow Turn off copy-on-write (valid only on btrfs) @@ -100,7 +100,7 @@ backing_file File name of a base image backing_fmt Image format of the base image encryption Encrypt the image cluster_size qcow2 cluster size -preallocation Preallocation mode (allowed values: off, metadata) +preallocation Preallocation mode (allowed values: off, metadata, falloc, full) lazy_refcounts Postpone refcount updates nocow Turn off copy-on-write (valid only on btrfs) @@ -112,7 +112,7 @@ backing_file File name of a base image backing_fmt Image format of the base image encryption Encrypt the image cluster_size qcow2 cluster size -preallocation Preallocation mode (allowed values: off, metadata) +preallocation Preallocation mode (allowed values: off, metadata, falloc, full) lazy_refcounts Postpone refcount updates nocow Turn off copy-on-write (valid only on btrfs) @@ -124,7 +124,7 @@ backing_file File name of a base image backing_fmt Image format of the base image encryption Encrypt the image cluster_size qcow2 cluster size -preallocation Preallocation mode (allowed values: off, metadata) +preallocation Preallocation mode (allowed values: off, metadata, falloc, full) lazy_refcounts Postpone refcount updates nocow Turn off copy-on-write (valid only on btrfs) @@ -136,7 +136,7 @@ backing_file File name of a base image backing_fmt Image format of the base image encryption Encrypt the image cluster_size qcow2 cluster size -preallocation Preallocation mode (allowed values: off, metadata) +preallocation Preallocation mode (allowed values: off, metadata, falloc, full) lazy_refcounts Postpone refcount updates nocow Turn off copy-on-write (valid only on btrfs) @@ -148,7 +148,7 @@ backing_file File name of a base image backing_fmt Image format of the base image encryption Encrypt the image cluster_size qcow2 cluster size -preallocation Preallocation mode (allowed values: off, metadata) +preallocation Preallocation mode (allowed values: off, metadata, falloc, full) lazy_refcounts Postpone refcount updates nocow Turn off copy-on-write (valid only on btrfs) @@ -175,7 +175,7 @@ backing_file File name of a base image backing_fmt Image format of the base image encryption Encrypt the image cluster_size qcow2 cluster size -preallocation Preallocation mode (allowed values: off, metadata) +preallocation Preallocation mode (allowed values: off, metadata, falloc, full) lazy_refcounts Postpone refcount updates Testing: create -o help @@ -253,7 +253,7 @@ backing_file File name of a base image backing_fmt Image format of the base image encryption Encrypt the image cluster_size qcow2 cluster size -preallocation Preallocation mode (allowed values: off, metadata) +preallocation Preallocation mode (allowed values: off, metadata, falloc, full) lazy_refcounts Postpone refcount updates nocow Turn off copy-on-write (valid only on btrfs) @@ -265,7 +265,7 @@ backing_file File name of a base image backing_fmt Image format of the base image encryption Encrypt the image cluster_size qcow2 cluster size -preallocation Preallocation mode (allowed values: off, metadata) +preallocation Preallocation mode (allowed values: off, metadata, falloc, full) lazy_refcounts Postpone refcount updates nocow Turn off copy-on-write (valid only on btrfs) @@ -277,7 +277,7 @@ backing_file File name of a base image backing_fmt Image format of the base image encryption Encrypt the image cluster_size qcow2 cluster size -preallocation Preallocation mode (allowed values: off, metadata) +preallocation Preallocation mode (allowed values: off, metadata, falloc, full) lazy_refcounts Postpone refcount updates nocow Turn off copy-on-write (valid only on btrfs) @@ -289,7 +289,7 @@ backing_file File name of a base image backing_fmt Image format of the base image encryption Encrypt the image cluster_size qcow2 cluster size -preallocation Preallocation mode (allowed values: off, metadata) +preallocation Preallocation mode (allowed values: off, metadata, falloc, full) lazy_refcounts Postpone refcount updates nocow Turn off copy-on-write (valid only on btrfs) @@ -301,7 +301,7 @@ backing_file File name of a base image backing_fmt Image format of the base image encryption Encrypt the image cluster_size qcow2 cluster size -preallocation Preallocation mode (allowed values: off, metadata) +preallocation Preallocation mode (allowed values: off, metadata, falloc, full) lazy_refcounts Postpone refcount updates nocow Turn off copy-on-write (valid only on btrfs) @@ -313,7 +313,7 @@ backing_file File name of a base image backing_fmt Image format of the base image encryption Encrypt the image cluster_size qcow2 cluster size -preallocation Preallocation mode (allowed values: off, metadata) +preallocation Preallocation mode (allowed values: off, metadata, falloc, full) lazy_refcounts Postpone refcount updates nocow Turn off copy-on-write (valid only on btrfs) @@ -325,7 +325,7 @@ backing_file File name of a base image backing_fmt Image format of the base image encryption Encrypt the image cluster_size qcow2 cluster size -preallocation Preallocation mode (allowed values: off, metadata) +preallocation Preallocation mode (allowed values: off, metadata, falloc, full) lazy_refcounts Postpone refcount updates nocow Turn off copy-on-write (valid only on btrfs) @@ -337,7 +337,7 @@ backing_file File name of a base image backing_fmt Image format of the base image encryption Encrypt the image cluster_size qcow2 cluster size -preallocation Preallocation mode (allowed values: off, metadata) +preallocation Preallocation mode (allowed values: off, metadata, falloc, full) lazy_refcounts Postpone refcount updates nocow Turn off copy-on-write (valid only on btrfs) @@ -364,7 +364,7 @@ backing_file File name of a base image backing_fmt Image format of the base image encryption Encrypt the image cluster_size qcow2 cluster size -preallocation Preallocation mode (allowed values: off, metadata) +preallocation Preallocation mode (allowed values: off, metadata, falloc, full) lazy_refcounts Postpone refcount updates Testing: convert -o help @@ -431,7 +431,7 @@ backing_file File name of a base image backing_fmt Image format of the base image encryption Encrypt the image cluster_size qcow2 cluster size -preallocation Preallocation mode (allowed values: off, metadata) +preallocation Preallocation mode (allowed values: off, metadata, falloc, full) lazy_refcounts Postpone refcount updates nocow Turn off copy-on-write (valid only on btrfs) @@ -443,7 +443,7 @@ backing_file File name of a base image backing_fmt Image format of the base image encryption Encrypt the image cluster_size qcow2 cluster size -preallocation Preallocation mode (allowed values: off, metadata) +preallocation Preallocation mode (allowed values: off, metadata, falloc, full) lazy_refcounts Postpone refcount updates nocow Turn off copy-on-write (valid only on btrfs) @@ -455,7 +455,7 @@ backing_file File name of a base image backing_fmt Image format of the base image encryption Encrypt the image cluster_size qcow2 cluster size -preallocation Preallocation mode (allowed values: off, metadata) +preallocation Preallocation mode (allowed values: off, metadata, falloc, full) lazy_refcounts Postpone refcount updates nocow Turn off copy-on-write (valid only on btrfs) @@ -467,7 +467,7 @@ backing_file File name of a base image backing_fmt Image format of the base image encryption Encrypt the image cluster_size qcow2 cluster size -preallocation Preallocation mode (allowed values: off, metadata) +preallocation Preallocation mode (allowed values: off, metadata, falloc, full) lazy_refcounts Postpone refcount updates nocow Turn off copy-on-write (valid only on btrfs) @@ -479,7 +479,7 @@ backing_file File name of a base image backing_fmt Image format of the base image encryption Encrypt the image cluster_size qcow2 cluster size -preallocation Preallocation mode (allowed values: off, metadata) +preallocation Preallocation mode (allowed values: off, metadata, falloc, full) lazy_refcounts Postpone refcount updates nocow Turn off copy-on-write (valid only on btrfs) @@ -491,7 +491,7 @@ backing_file File name of a base image backing_fmt Image format of the base image encryption Encrypt the image cluster_size qcow2 cluster size -preallocation Preallocation mode (allowed values: off, metadata) +preallocation Preallocation mode (allowed values: off, metadata, falloc, full) lazy_refcounts Postpone refcount updates nocow Turn off copy-on-write (valid only on btrfs) @@ -503,7 +503,7 @@ backing_file File name of a base image backing_fmt Image format of the base image encryption Encrypt the image cluster_size qcow2 cluster size -preallocation Preallocation mode (allowed values: off, metadata) +preallocation Preallocation mode (allowed values: off, metadata, falloc, full) lazy_refcounts Postpone refcount updates nocow Turn off copy-on-write (valid only on btrfs) @@ -515,7 +515,7 @@ backing_file File name of a base image backing_fmt Image format of the base image encryption Encrypt the image cluster_size qcow2 cluster size -preallocation Preallocation mode (allowed values: off, metadata) +preallocation Preallocation mode (allowed values: off, metadata, falloc, full) lazy_refcounts Postpone refcount updates nocow Turn off copy-on-write (valid only on btrfs) @@ -544,7 +544,7 @@ backing_file File name of a base image backing_fmt Image format of the base image encryption Encrypt the image cluster_size qcow2 cluster size -preallocation Preallocation mode (allowed values: off, metadata) +preallocation Preallocation mode (allowed values: off, metadata, falloc, full) lazy_refcounts Postpone refcount updates Testing: convert -o help |