From 9f708e7644414c113b7652ac3ffc7757ad82b450 Mon Sep 17 00:00:00 2001 From: Jeffrey Cody Date: Thu, 10 Jul 2014 23:24:17 +0200 Subject: [PATCH 17/44] block: vhdx - update log guid in header, and first write tracker RH-Author: Jeffrey Cody Message-id: <34949d25967359c10dea8e66dcb1716d8639423e.1405033137.git.jcody@redhat.com> Patchwork-id: 59753 O-Subject: [RHEL6-6 qemu-kvm PATCH v2 08/24] block: vhdx - update log guid in header, and first write tracker Bugzilla: 1063559 RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Fam Zheng RH-Acked-by: Markus Armbruster Allow tracking of first file write in the VHDX image, as well as the ability to update the GUID in the header. This is in preparation for log support. Signed-off-by: Jeff Cody Signed-off-by: Stefan Hajnoczi (cherry picked from commit c3906c5e8281b37a526c706596af8575d6ac00d3) --- block/vhdx.c | 30 ++++++++++++++++++++++++------ block/vhdx.h | 6 ++++++ 2 files changed, 30 insertions(+), 6 deletions(-) Signed-off-by: Miroslav Rezanina --- block/vhdx.c | 30 ++++++++++++++++++++++++------ block/vhdx.h | 6 ++++++ 2 files changed, 30 insertions(+), 6 deletions(-) diff --git a/block/vhdx.c b/block/vhdx.c index 4bfadd9..5742541 100644 --- a/block/vhdx.c +++ b/block/vhdx.c @@ -231,7 +231,7 @@ static int vhdx_probe(const uint8_t *buf, int buf_size, const char *filename) * - non-current header is updated with largest sequence number */ static int vhdx_update_header(BlockDriverState *bs, BDRVVHDXState *s, - bool generate_data_write_guid) + bool generate_data_write_guid, MSGUID *log_guid) { int ret = 0; int hdr_idx = 0; @@ -263,6 +263,11 @@ static int vhdx_update_header(BlockDriverState *bs, BDRVVHDXState *s, vhdx_guid_generate(&inactive_header->data_write_guid); } + /* update the log guid if present */ + if (log_guid) { + inactive_header->log_guid = *log_guid; + } + /* the header checksum is not over just the packed size of VHDXHeader, * but rather over the entire 'reserved' range for the header, which is * 4KB (VHDX_HEADER_SIZE). */ @@ -295,16 +300,16 @@ exit: * The VHDX spec calls for header updates to be performed twice, so that both * the current and non-current header have valid info */ -static int vhdx_update_headers(BlockDriverState *bs, BDRVVHDXState *s, - bool generate_data_write_guid) +int vhdx_update_headers(BlockDriverState *bs, BDRVVHDXState *s, + bool generate_data_write_guid, MSGUID *log_guid) { int ret; - ret = vhdx_update_header(bs, s, generate_data_write_guid); + ret = vhdx_update_header(bs, s, generate_data_write_guid, log_guid); if (ret < 0) { return ret; } - ret = vhdx_update_header(bs, s, generate_data_write_guid); + ret = vhdx_update_header(bs, s, generate_data_write_guid, log_guid); return ret; } @@ -799,6 +804,7 @@ static int vhdx_open(BlockDriverState *bs, int flags) s->bat = NULL; + s->first_visible_write = true; qemu_co_mutex_init(&s->lock); @@ -879,7 +885,7 @@ static int vhdx_open(BlockDriverState *bs, int flags) } if (flags & BDRV_O_RDWR) { - ret = vhdx_update_headers(bs, s, false); + ret = vhdx_update_headers(bs, s, false, NULL); if (ret < 0) { goto fail; } @@ -1025,6 +1031,18 @@ exit: +/* Per the spec, on the first write of guest-visible data to the file the + * data write guid must be updated in the header */ +int vhdx_user_visible_write(BlockDriverState *bs, BDRVVHDXState *s) +{ + int ret = 0; + if (s->first_visible_write) { + s->first_visible_write = false; + ret = vhdx_update_headers(bs, s, true, NULL); + } + return ret; +} + static coroutine_fn int vhdx_co_writev(BlockDriverState *bs, int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) { diff --git a/block/vhdx.h b/block/vhdx.h index 2689ef7..d7949f4 100644 --- a/block/vhdx.h +++ b/block/vhdx.h @@ -368,6 +368,7 @@ typedef struct BDRVVHDXState { VHDXBatEntry *bat; uint64_t bat_offset; + bool first_visible_write; MSGUID session_guid; VHDXLogEntries log; @@ -380,6 +381,9 @@ typedef struct BDRVVHDXState { void vhdx_guid_generate(MSGUID *guid); +int vhdx_update_headers(BlockDriverState *bs, BDRVVHDXState *s, bool rw, + MSGUID *log_guid); + uint32_t vhdx_update_checksum(uint8_t *buf, size_t size, int crc_offset); uint32_t vhdx_checksum_calc(uint32_t crc, uint8_t *buf, size_t size, int crc_offset); @@ -409,4 +413,6 @@ void vhdx_log_data_le_export(VHDXLogDataSector *d); void vhdx_log_entry_hdr_le_import(VHDXLogEntryHeader *hdr); void vhdx_log_entry_hdr_le_export(VHDXLogEntryHeader *hdr); +int vhdx_user_visible_write(BlockDriverState *bs, BDRVVHDXState *s); + #endif -- 1.7.1