From 59c0cb7830be68080c6a0d1449253b954350e57d Mon Sep 17 00:00:00 2001 From: Max Reitz Date: Tue, 10 Feb 2015 15:28:51 -0500 Subject: [PATCH] qcow2: More helpers for refcount modification Add helper functions for getting and setting refcounts in a refcount array for any possible refcount order, and choose the correct one during refcount initialization. Signed-off-by: Max Reitz Reviewed-by: Eric Blake Reviewed-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- block/qcow2-refcount.c | 121 ++++++++++++++++++++++++++++++++++++++++- 1 file changed, 119 insertions(+), 2 deletions(-) diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c index c0c1313ddb..dc8d186a82 100644 --- a/block/qcow2-refcount.c +++ b/block/qcow2-refcount.c @@ -32,10 +32,49 @@ static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs, int64_t offset, int64_t length, uint64_t addend, bool decrease, enum qcow2_discard_type type); +static uint64_t get_refcount_ro0(const void *refcount_array, uint64_t index); +static uint64_t get_refcount_ro1(const void *refcount_array, uint64_t index); +static uint64_t get_refcount_ro2(const void *refcount_array, uint64_t index); +static uint64_t get_refcount_ro3(const void *refcount_array, uint64_t index); static uint64_t get_refcount_ro4(const void *refcount_array, uint64_t index); +static uint64_t get_refcount_ro5(const void *refcount_array, uint64_t index); +static uint64_t get_refcount_ro6(const void *refcount_array, uint64_t index); +static void set_refcount_ro0(void *refcount_array, uint64_t index, + uint64_t value); +static void set_refcount_ro1(void *refcount_array, uint64_t index, + uint64_t value); +static void set_refcount_ro2(void *refcount_array, uint64_t index, + uint64_t value); +static void set_refcount_ro3(void *refcount_array, uint64_t index, + uint64_t value); static void set_refcount_ro4(void *refcount_array, uint64_t index, uint64_t value); +static void set_refcount_ro5(void *refcount_array, uint64_t index, + uint64_t value); +static void set_refcount_ro6(void *refcount_array, uint64_t index, + uint64_t value); + + +static Qcow2GetRefcountFunc *const get_refcount_funcs[] = { + &get_refcount_ro0, + &get_refcount_ro1, + &get_refcount_ro2, + &get_refcount_ro3, + &get_refcount_ro4, + &get_refcount_ro5, + &get_refcount_ro6 +}; + +static Qcow2SetRefcountFunc *const set_refcount_funcs[] = { + &set_refcount_ro0, + &set_refcount_ro1, + &set_refcount_ro2, + &set_refcount_ro3, + &set_refcount_ro4, + &set_refcount_ro5, + &set_refcount_ro6 +}; /*********************************************************/ @@ -47,8 +86,10 @@ int qcow2_refcount_init(BlockDriverState *bs) unsigned int refcount_table_size2, i; int ret; - s->get_refcount = &get_refcount_ro4; - s->set_refcount = &set_refcount_ro4; + assert(s->refcount_order >= 0 && s->refcount_order <= 6); + + s->get_refcount = get_refcount_funcs[s->refcount_order]; + s->set_refcount = set_refcount_funcs[s->refcount_order]; assert(s->refcount_table_size <= INT_MAX / sizeof(uint64_t)); refcount_table_size2 = s->refcount_table_size * sizeof(uint64_t); @@ -80,6 +121,59 @@ void qcow2_refcount_close(BlockDriverState *bs) } +static uint64_t get_refcount_ro0(const void *refcount_array, uint64_t index) +{ + return (((const uint8_t *)refcount_array)[index / 8] >> (index % 8)) & 0x1; +} + +static void set_refcount_ro0(void *refcount_array, uint64_t index, + uint64_t value) +{ + assert(!(value >> 1)); + ((uint8_t *)refcount_array)[index / 8] &= ~(0x1 << (index % 8)); + ((uint8_t *)refcount_array)[index / 8] |= value << (index % 8); +} + +static uint64_t get_refcount_ro1(const void *refcount_array, uint64_t index) +{ + return (((const uint8_t *)refcount_array)[index / 4] >> (2 * (index % 4))) + & 0x3; +} + +static void set_refcount_ro1(void *refcount_array, uint64_t index, + uint64_t value) +{ + assert(!(value >> 2)); + ((uint8_t *)refcount_array)[index / 4] &= ~(0x3 << (2 * (index % 4))); + ((uint8_t *)refcount_array)[index / 4] |= value << (2 * (index % 4)); +} + +static uint64_t get_refcount_ro2(const void *refcount_array, uint64_t index) +{ + return (((const uint8_t *)refcount_array)[index / 2] >> (4 * (index % 2))) + & 0xf; +} + +static void set_refcount_ro2(void *refcount_array, uint64_t index, + uint64_t value) +{ + assert(!(value >> 4)); + ((uint8_t *)refcount_array)[index / 2] &= ~(0xf << (4 * (index % 2))); + ((uint8_t *)refcount_array)[index / 2] |= value << (4 * (index % 2)); +} + +static uint64_t get_refcount_ro3(const void *refcount_array, uint64_t index) +{ + return ((const uint8_t *)refcount_array)[index]; +} + +static void set_refcount_ro3(void *refcount_array, uint64_t index, + uint64_t value) +{ + assert(!(value >> 8)); + ((uint8_t *)refcount_array)[index] = value; +} + static uint64_t get_refcount_ro4(const void *refcount_array, uint64_t index) { return be16_to_cpu(((const uint16_t *)refcount_array)[index]); @@ -92,6 +186,29 @@ static void set_refcount_ro4(void *refcount_array, uint64_t index, ((uint16_t *)refcount_array)[index] = cpu_to_be16(value); } +static uint64_t get_refcount_ro5(const void *refcount_array, uint64_t index) +{ + return be32_to_cpu(((const uint32_t *)refcount_array)[index]); +} + +static void set_refcount_ro5(void *refcount_array, uint64_t index, + uint64_t value) +{ + assert(!(value >> 32)); + ((uint32_t *)refcount_array)[index] = cpu_to_be32(value); +} + +static uint64_t get_refcount_ro6(const void *refcount_array, uint64_t index) +{ + return be64_to_cpu(((const uint64_t *)refcount_array)[index]); +} + +static void set_refcount_ro6(void *refcount_array, uint64_t index, + uint64_t value) +{ + ((uint64_t *)refcount_array)[index] = cpu_to_be64(value); +} + static int load_refcount_block(BlockDriverState *bs, int64_t refcount_block_offset,