From bf5b16fa401633475d21d69c66532f5b29e8433d Mon Sep 17 00:00:00 2001 From: Alberto Faria Date: Tue, 5 Jul 2022 17:15:09 +0100 Subject: [PATCH] block: Make blk_{pread,pwrite}() return 0 on success They currently return the value of their 'bytes' parameter on success. Make them return 0 instead, for consistency with other I/O functions and in preparation to implement them using generated_co_wrapper. This also makes it clear that short reads/writes are not possible. Signed-off-by: Alberto Faria Message-Id: <20220705161527.1054072-2-afaria@redhat.com> Reviewed-by: Hanna Reitz Signed-off-by: Hanna Reitz --- block.c | 8 +++++--- block/block-backend.c | 7 ++----- block/qcow.c | 6 +++--- hw/block/m25p80.c | 2 +- hw/misc/mac_via.c | 4 ++-- hw/misc/sifive_u_otp.c | 2 +- hw/nvram/eeprom_at24c.c | 8 ++++---- hw/nvram/spapr_nvram.c | 14 +++++++------- hw/ppc/pnv_pnor.c | 2 +- qemu-img.c | 25 +++++++++---------------- qemu-io-cmds.c | 18 ++++++++++++------ tests/unit/test-block-iothread.c | 4 ++-- 12 files changed, 49 insertions(+), 51 deletions(-) diff --git a/block.c b/block.c index 2c00dddd80..0fd830e2e2 100644 --- a/block.c +++ b/block.c @@ -1045,14 +1045,16 @@ static int find_image_format(BlockBackend *file, const char *filename, return ret; } - drv = bdrv_probe_all(buf, ret, filename); + drv = bdrv_probe_all(buf, sizeof(buf), filename); if (!drv) { error_setg(errp, "Could not determine image format: No compatible " "driver found"); - ret = -ENOENT; + *pdrv = NULL; + return -ENOENT; } + *pdrv = drv; - return ret; + return 0; } /** diff --git a/block/block-backend.c b/block/block-backend.c index f425b00793..4c5e130615 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -1573,19 +1573,16 @@ int blk_pread(BlockBackend *blk, int64_t offset, void *buf, int bytes) ret = blk_do_preadv(blk, offset, bytes, &qiov, 0); blk_dec_in_flight(blk); - return ret < 0 ? ret : bytes; + return ret; } int blk_pwrite(BlockBackend *blk, int64_t offset, const void *buf, int bytes, BdrvRequestFlags flags) { - int ret; QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes); IO_OR_GS_CODE(); - ret = blk_pwritev_part(blk, offset, bytes, &qiov, 0, flags); - - return ret < 0 ? ret : bytes; + return blk_pwritev_part(blk, offset, bytes, &qiov, 0, flags); } int64_t blk_getlength(BlockBackend *blk) diff --git a/block/qcow.c b/block/qcow.c index c646d6b16d..25a43353c1 100644 --- a/block/qcow.c +++ b/block/qcow.c @@ -891,14 +891,14 @@ static int coroutine_fn qcow_co_create(BlockdevCreateOptions *opts, /* write all the data */ ret = blk_pwrite(qcow_blk, 0, &header, sizeof(header), 0); - if (ret != sizeof(header)) { + if (ret < 0) { goto exit; } if (qcow_opts->has_backing_file) { ret = blk_pwrite(qcow_blk, sizeof(header), qcow_opts->backing_file, backing_filename_len, 0); - if (ret != backing_filename_len) { + if (ret < 0) { goto exit; } } @@ -908,7 +908,7 @@ static int coroutine_fn qcow_co_create(BlockdevCreateOptions *opts, i++) { ret = blk_pwrite(qcow_blk, header_size + BDRV_SECTOR_SIZE * i, tmp, BDRV_SECTOR_SIZE, 0); - if (ret != BDRV_SECTOR_SIZE) { + if (ret < 0) { g_free(tmp); goto exit; } diff --git a/hw/block/m25p80.c b/hw/block/m25p80.c index 3045dda53b..755134313d 100644 --- a/hw/block/m25p80.c +++ b/hw/block/m25p80.c @@ -1532,7 +1532,7 @@ static void m25p80_realize(SSIPeripheral *ss, Error **errp) trace_m25p80_binding(s); s->storage = blk_blockalign(s->blk, s->size); - if (blk_pread(s->blk, 0, s->storage, s->size) != s->size) { + if (blk_pread(s->blk, 0, s->storage, s->size) < 0) { error_setg(errp, "failed to read the initial flash content"); return; } diff --git a/hw/misc/mac_via.c b/hw/misc/mac_via.c index 525e38ce93..c32325dcaf 100644 --- a/hw/misc/mac_via.c +++ b/hw/misc/mac_via.c @@ -1029,8 +1029,8 @@ static void mos6522_q800_via1_realize(DeviceState *dev, Error **errp) return; } - len = blk_pread(v1s->blk, 0, v1s->PRAM, sizeof(v1s->PRAM)); - if (len != sizeof(v1s->PRAM)) { + ret = blk_pread(v1s->blk, 0, v1s->PRAM, sizeof(v1s->PRAM)); + if (ret < 0) { error_setg(errp, "can't read PRAM contents"); return; } diff --git a/hw/misc/sifive_u_otp.c b/hw/misc/sifive_u_otp.c index 6d5f84e6c2..535acde08b 100644 --- a/hw/misc/sifive_u_otp.c +++ b/hw/misc/sifive_u_otp.c @@ -240,7 +240,7 @@ static void sifive_u_otp_realize(DeviceState *dev, Error **errp) return; } - if (blk_pread(s->blk, 0, s->fuse, filesize) != filesize) { + if (blk_pread(s->blk, 0, s->fuse, filesize) < 0) { error_setg(errp, "failed to read the initial flash content"); return; } diff --git a/hw/nvram/eeprom_at24c.c b/hw/nvram/eeprom_at24c.c index d695f6ae89..8fd9f97eee 100644 --- a/hw/nvram/eeprom_at24c.c +++ b/hw/nvram/eeprom_at24c.c @@ -64,8 +64,8 @@ int at24c_eeprom_event(I2CSlave *s, enum i2c_event event) case I2C_START_RECV: DPRINTK("clear\n"); if (ee->blk && ee->changed) { - int len = blk_pwrite(ee->blk, 0, ee->mem, ee->rsize, 0); - if (len != ee->rsize) { + int ret = blk_pwrite(ee->blk, 0, ee->mem, ee->rsize, 0); + if (ret < 0) { ERR(TYPE_AT24C_EE " : failed to write backing file\n"); } @@ -165,9 +165,9 @@ void at24c_eeprom_reset(DeviceState *state) memset(ee->mem, 0, ee->rsize); if (ee->blk) { - int len = blk_pread(ee->blk, 0, ee->mem, ee->rsize); + int ret = blk_pread(ee->blk, 0, ee->mem, ee->rsize); - if (len != ee->rsize) { + if (ret < 0) { ERR(TYPE_AT24C_EE " : Failed initial sync with backing file\n"); } diff --git a/hw/nvram/spapr_nvram.c b/hw/nvram/spapr_nvram.c index 18b43be7f6..59d2e7b705 100644 --- a/hw/nvram/spapr_nvram.c +++ b/hw/nvram/spapr_nvram.c @@ -103,7 +103,7 @@ static void rtas_nvram_store(PowerPCCPU *cpu, SpaprMachineState *spapr, { SpaprNvram *nvram = spapr->nvram; hwaddr offset, buffer, len; - int alen; + int ret; void *membuf; if ((nargs != 3) || (nret != 2)) { @@ -128,9 +128,9 @@ static void rtas_nvram_store(PowerPCCPU *cpu, SpaprMachineState *spapr, membuf = cpu_physical_memory_map(buffer, &len, false); - alen = len; + ret = 0; if (nvram->blk) { - alen = blk_pwrite(nvram->blk, offset, membuf, len, 0); + ret = blk_pwrite(nvram->blk, offset, membuf, len, 0); } assert(nvram->buf); @@ -138,8 +138,8 @@ static void rtas_nvram_store(PowerPCCPU *cpu, SpaprMachineState *spapr, cpu_physical_memory_unmap(membuf, len, 0, len); - rtas_st(rets, 0, (alen < len) ? RTAS_OUT_HW_ERROR : RTAS_OUT_SUCCESS); - rtas_st(rets, 1, (alen < 0) ? 0 : alen); + rtas_st(rets, 0, (ret < 0) ? RTAS_OUT_HW_ERROR : RTAS_OUT_SUCCESS); + rtas_st(rets, 1, (ret < 0) ? 0 : len); } static void spapr_nvram_realize(SpaprVioDevice *dev, Error **errp) @@ -179,9 +179,9 @@ static void spapr_nvram_realize(SpaprVioDevice *dev, Error **errp) } if (nvram->blk) { - int alen = blk_pread(nvram->blk, 0, nvram->buf, nvram->size); + ret = blk_pread(nvram->blk, 0, nvram->buf, nvram->size); - if (alen != nvram->size) { + if (ret < 0) { error_setg(errp, "can't read spapr-nvram contents"); return; } diff --git a/hw/ppc/pnv_pnor.c b/hw/ppc/pnv_pnor.c index 83ecccca28..1fb748afef 100644 --- a/hw/ppc/pnv_pnor.c +++ b/hw/ppc/pnv_pnor.c @@ -99,7 +99,7 @@ static void pnv_pnor_realize(DeviceState *dev, Error **errp) s->storage = blk_blockalign(s->blk, s->size); - if (blk_pread(s->blk, 0, s->storage, s->size) != s->size) { + if (blk_pread(s->blk, 0, s->storage, s->size) < 0) { error_setg(errp, "failed to read the initial flash content"); return; } diff --git a/qemu-img.c b/qemu-img.c index 4cf4d2423d..2dc07e5ac3 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -5120,30 +5120,23 @@ static int img_dd(int argc, char **argv) in.buf = g_new(uint8_t, in.bsz); for (out_pos = 0; in_pos < size; block_count++) { - int in_ret, out_ret; + int bytes = (in_pos + in.bsz > size) ? size - in_pos : in.bsz; - if (in_pos + in.bsz > size) { - in_ret = blk_pread(blk1, in_pos, in.buf, size - in_pos); - } else { - in_ret = blk_pread(blk1, in_pos, in.buf, in.bsz); - } - if (in_ret < 0) { + ret = blk_pread(blk1, in_pos, in.buf, bytes); + if (ret < 0) { error_report("error while reading from input image file: %s", - strerror(-in_ret)); - ret = -1; + strerror(-ret)); goto out; } - in_pos += in_ret; + in_pos += bytes; - out_ret = blk_pwrite(blk2, out_pos, in.buf, in_ret, 0); - - if (out_ret < 0) { + ret = blk_pwrite(blk2, out_pos, in.buf, bytes, 0); + if (ret < 0) { error_report("error while writing to output image file: %s", - strerror(-out_ret)); - ret = -1; + strerror(-ret)); goto out; } - out_pos += out_ret; + out_pos += bytes; } out: diff --git a/qemu-io-cmds.c b/qemu-io-cmds.c index 2f0d8ac25a..443f22c732 100644 --- a/qemu-io-cmds.c +++ b/qemu-io-cmds.c @@ -541,28 +541,34 @@ fail: static int do_pread(BlockBackend *blk, char *buf, int64_t offset, int64_t bytes, int64_t *total) { + int ret; + if (bytes > INT_MAX) { return -ERANGE; } - *total = blk_pread(blk, offset, (uint8_t *)buf, bytes); - if (*total < 0) { - return *total; + ret = blk_pread(blk, offset, (uint8_t *)buf, bytes); + if (ret < 0) { + return ret; } + *total = bytes; return 1; } static int do_pwrite(BlockBackend *blk, char *buf, int64_t offset, int64_t bytes, int flags, int64_t *total) { + int ret; + if (bytes > INT_MAX) { return -ERANGE; } - *total = blk_pwrite(blk, offset, (uint8_t *)buf, bytes, flags); - if (*total < 0) { - return *total; + ret = blk_pwrite(blk, offset, (uint8_t *)buf, bytes, flags); + if (ret < 0) { + return ret; } + *total = bytes; return 1; } diff --git a/tests/unit/test-block-iothread.c b/tests/unit/test-block-iothread.c index a5c163af7e..3c1a3f64a2 100644 --- a/tests/unit/test-block-iothread.c +++ b/tests/unit/test-block-iothread.c @@ -117,7 +117,7 @@ static void test_sync_op_blk_pread(BlockBackend *blk) /* Success */ ret = blk_pread(blk, 0, buf, sizeof(buf)); - g_assert_cmpint(ret, ==, 512); + g_assert_cmpint(ret, ==, 0); /* Early error: Negative offset */ ret = blk_pread(blk, -2, buf, sizeof(buf)); @@ -131,7 +131,7 @@ static void test_sync_op_blk_pwrite(BlockBackend *blk) /* Success */ ret = blk_pwrite(blk, 0, buf, sizeof(buf), 0); - g_assert_cmpint(ret, ==, 512); + g_assert_cmpint(ret, ==, 0); /* Early error: Negative offset */ ret = blk_pwrite(blk, -2, buf, sizeof(buf), 0);