From 709f197b2ddcfdb0a0a5f486f7ad96e23bdd51b7 Mon Sep 17 00:00:00 2001 From: Uri Lublin <uril@redhat.com> Date: Mon, 30 Mar 2009 23:15:44 +0300 Subject: [PATCH 03/12] Revert "qcow2 format: keep 'num_free_bytes', and show it upon 'info blockstats' (Uri Lublin)" This reverts commit 69f6850da20d243515479add9ba182075c317b55. Was not accepted upstream. Using an alternative solution with watermark and asynchronous notification. Signed-off-by: Uri Lublin <uril@redhat.com> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com> Bugzilla: 489964 RH-Upstream-status: not-applicable Acked-by: Eduardo Habkost <ehabkost@redhat.com> Acked-by: Dor Laor <dlaor@redhat.com> --- qemu/block-qcow2.c | 36 ++++++++---------------------------- qemu/block.c | 5 ++--- qemu/block.h | 1 - 3 files changed, 10 insertions(+), 32 deletions(-) diff --git a/qemu/block-qcow2.c b/qemu/block-qcow2.c index b58203c..9175c9d 100644 --- a/qemu/block-qcow2.c +++ b/qemu/block-qcow2.c @@ -145,7 +145,6 @@ typedef struct BDRVQcowState { AES_CBC_CIPHER aes_decrypt_cipher; int64_t highest_alloc; /* highest cluester allocated (in clusters) */ - int64_t nc_free; /* num of free clusters below highest_alloc */ uint64_t snapshots_offset; int snapshots_size; @@ -174,7 +173,7 @@ static void free_clusters(BlockDriverState *bs, #ifdef DEBUG_ALLOC static void check_refcounts(BlockDriverState *bs); #endif -static void scan_refcount(BlockDriverState *bs, int64_t *high, int64_t *free); +static void scan_refcount(BlockDriverState *bs, int64_t *high); static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename) @@ -284,7 +283,7 @@ static int qcow_open(BlockDriverState *bs, const char *filename, int flags) if (refcount_init(bs) < 0) goto fail; - scan_refcount(bs, &s->highest_alloc, &s->nc_free); + scan_refcount(bs, &s->highest_alloc); /* read the backing file name */ if (header.backing_file_offset != 0) { @@ -1684,7 +1683,6 @@ static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) bdi->vm_state_offset = (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits); bdi->highest_alloc = s->highest_alloc << s->cluster_bits; - bdi->num_free_bytes = s->nc_free << s->cluster_bits; return 0; } @@ -2219,35 +2217,25 @@ static int load_refcount_block(BlockDriverState *bs, return 0; } -static void scan_refcount(BlockDriverState *bs, int64_t *high, int64_t *free) +static void scan_refcount(BlockDriverState *bs, int64_t *high) { BDRVQcowState *s = bs->opaque; - int64_t refcnt_index, cluster_index, cluster_end, h = 0, f = 0; - int64_t tail = 0; /* do not count last consecutive free entries */ + int64_t refcnt_index, cluster_index, cluster_end, h = 0; for (refcnt_index=0; refcnt_index < s->refcount_table_size; refcnt_index++){ if (s->refcount_table[refcnt_index] == 0) { - f += 1 << (s->cluster_bits - REFCOUNT_SHIFT); - tail += 1 << (s->cluster_bits - REFCOUNT_SHIFT); continue; } cluster_index = refcnt_index << (s->cluster_bits - REFCOUNT_SHIFT); cluster_end = (refcnt_index + 1) << (s->cluster_bits - REFCOUNT_SHIFT); for ( ; cluster_index < cluster_end; cluster_index++) { - if (get_refcount(bs, cluster_index) == 0) { - f++; - tail++; - } - else { + if (get_refcount(bs, cluster_index) == 0) + /* do nothing -- reserved for free counting */; + else h = cluster_index; - tail = 0; - } } } - f -= tail; - if (free) - *free = f; if (high) *high = (h+1); } @@ -2293,10 +2281,8 @@ retry: (s->free_cluster_index - nb_clusters) << s->cluster_bits); #endif - if (s->highest_alloc < s->free_cluster_index) { - s->nc_free += (s->free_cluster_index - s->highest_alloc); + if (s->highest_alloc < s->free_cluster_index) s->highest_alloc = s->free_cluster_index; - } return (s->free_cluster_index - nb_clusters) << s->cluster_bits; } @@ -2473,12 +2459,6 @@ static int update_cluster_refcount(BlockDriverState *bs, block_index = cluster_index & ((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); refcount = be16_to_cpu(s->refcount_block_cache[block_index]); - - if (refcount == 1 && addend == -1) - s->nc_free += 1; - else if (refcount == 0 && addend == 1) - s->nc_free -= 1; - refcount += addend; if (refcount < 0 || refcount > 0xffff) return -EINVAL; diff --git a/qemu/block.c b/qemu/block.c index 05cd742..7f24866 100644 --- a/qemu/block.c +++ b/qemu/block.c @@ -1177,9 +1177,8 @@ void bdrv_info_stats (void) bs->rd_bytes, bs->wr_bytes, bs->rd_ops, bs->wr_ops); if (bdrv_get_info(bs, &bdi) == 0) - term_printf(" high=%" PRId64 - " bytes_free=%" PRId64, - bdi.highest_alloc, bdi.num_free_bytes); + term_printf(" high=%" PRIu64, + bdi.highest_alloc); term_printf("\n"); } } diff --git a/qemu/block.h b/qemu/block.h index 1390693..403065b 100644 --- a/qemu/block.h +++ b/qemu/block.h @@ -26,7 +26,6 @@ typedef struct BlockDriverInfo { /* offset at which the VM state can be saved (0 if not possible) */ int64_t vm_state_offset; int64_t highest_alloc; /* highest allocated block offset (in bytes) */ - int64_t num_free_bytes; /* below highest_alloc */ } BlockDriverInfo; typedef struct QEMUSnapshotInfo { -- 1.6.1