From 353a5d84b25c335b259f37c4f43dad96e6d60ba8 Mon Sep 17 00:00:00 2001 From: Alberto Faria Date: Thu, 9 Jun 2022 16:27:37 +0100 Subject: [PATCH] block: Make bdrv_{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. The few callers that rely on the previous behavior are adjusted accordingly by hand. Signed-off-by: Alberto Faria Reviewed-by: Paolo Bonzini Reviewed-by: Stefan Hajnoczi Message-Id: <20220609152744.3891847-4-afaria@redhat.com> Reviewed-by: Hanna Reitz Signed-off-by: Hanna Reitz --- block/cloop.c | 2 +- block/crypto.c | 4 ++-- block/dmg.c | 10 +++++----- block/io.c | 10 ++-------- block/qcow.c | 2 +- block/qcow2.c | 4 ++-- block/qed.c | 7 +------ block/vdi.c | 2 +- block/vmdk.c | 5 ++--- tests/unit/test-block-iothread.c | 4 ++-- 10 files changed, 19 insertions(+), 31 deletions(-) diff --git a/block/cloop.c b/block/cloop.c index 9a2334495e..40b146e714 100644 --- a/block/cloop.c +++ b/block/cloop.c @@ -222,7 +222,7 @@ static inline int cloop_read_block(BlockDriverState *bs, int block_num) ret = bdrv_pread(bs->file, s->offsets[block_num], bytes, s->compressed_block, 0); - if (ret != bytes) { + if (ret < 0) { return -1; } diff --git a/block/crypto.c b/block/crypto.c index deec7fae2f..e7f5c4e31a 100644 --- a/block/crypto.c +++ b/block/crypto.c @@ -70,7 +70,7 @@ static ssize_t block_crypto_read_func(QCryptoBlock *block, error_setg_errno(errp, -ret, "Could not read encryption header"); return ret; } - return ret; + return buflen; } static ssize_t block_crypto_write_func(QCryptoBlock *block, @@ -88,7 +88,7 @@ static ssize_t block_crypto_write_func(QCryptoBlock *block, error_setg_errno(errp, -ret, "Could not write encryption header"); return ret; } - return ret; + return buflen; } diff --git a/block/dmg.c b/block/dmg.c index 5a460c3eb1..98db18d82a 100644 --- a/block/dmg.c +++ b/block/dmg.c @@ -390,7 +390,7 @@ static int dmg_read_plist_xml(BlockDriverState *bs, DmgHeaderState *ds, buffer = g_malloc(info_length + 1); buffer[info_length] = '\0'; ret = bdrv_pread(bs->file, info_begin, info_length, buffer, 0); - if (ret != info_length) { + if (ret < 0) { ret = -EINVAL; goto fail; } @@ -611,7 +611,7 @@ static inline int dmg_read_chunk(BlockDriverState *bs, uint64_t sector_num) * inflated. */ ret = bdrv_pread(bs->file, s->offsets[chunk], s->lengths[chunk], s->compressed_chunk, 0); - if (ret != s->lengths[chunk]) { + if (ret < 0) { return -1; } @@ -637,7 +637,7 @@ static inline int dmg_read_chunk(BlockDriverState *bs, uint64_t sector_num) * inflated. */ ret = bdrv_pread(bs->file, s->offsets[chunk], s->lengths[chunk], s->compressed_chunk, 0); - if (ret != s->lengths[chunk]) { + if (ret < 0) { return -1; } @@ -658,7 +658,7 @@ static inline int dmg_read_chunk(BlockDriverState *bs, uint64_t sector_num) * inflated. */ ret = bdrv_pread(bs->file, s->offsets[chunk], s->lengths[chunk], s->compressed_chunk, 0); - if (ret != s->lengths[chunk]) { + if (ret < 0) { return -1; } @@ -674,7 +674,7 @@ static inline int dmg_read_chunk(BlockDriverState *bs, uint64_t sector_num) case UDRW: /* copy */ ret = bdrv_pread(bs->file, s->offsets[chunk], s->lengths[chunk], s->uncompressed_chunk, 0); - if (ret != s->lengths[chunk]) { + if (ret < 0) { return -1; } break; diff --git a/block/io.c b/block/io.c index d4a39b5569..86b5e8b471 100644 --- a/block/io.c +++ b/block/io.c @@ -1100,7 +1100,6 @@ int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags) int bdrv_pread(BdrvChild *child, int64_t offset, int64_t bytes, void *buf, BdrvRequestFlags flags) { - int ret; QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes); IO_CODE(); @@ -1108,9 +1107,7 @@ int bdrv_pread(BdrvChild *child, int64_t offset, int64_t bytes, void *buf, return -EINVAL; } - ret = bdrv_preadv(child, offset, bytes, &qiov, flags); - - return ret < 0 ? ret : bytes; + return bdrv_preadv(child, offset, bytes, &qiov, flags); } /* Return no. of bytes on success or < 0 on error. Important errors are: @@ -1122,7 +1119,6 @@ int bdrv_pread(BdrvChild *child, int64_t offset, int64_t bytes, void *buf, int bdrv_pwrite(BdrvChild *child, int64_t offset, int64_t bytes, const void *buf, BdrvRequestFlags flags) { - int ret; QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes); IO_CODE(); @@ -1130,9 +1126,7 @@ int bdrv_pwrite(BdrvChild *child, int64_t offset, int64_t bytes, return -EINVAL; } - ret = bdrv_pwritev(child, offset, bytes, &qiov, flags); - - return ret < 0 ? ret : bytes; + return bdrv_pwritev(child, offset, bytes, &qiov, flags); } /* diff --git a/block/qcow.c b/block/qcow.c index c94524b814..c646d6b16d 100644 --- a/block/qcow.c +++ b/block/qcow.c @@ -597,7 +597,7 @@ static int decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset) csize &= (s->cluster_size - 1); BLKDBG_EVENT(bs->file, BLKDBG_READ_COMPRESSED); ret = bdrv_pread(bs->file, coffset, csize, s->cluster_data, 0); - if (ret != csize) + if (ret < 0) return -1; if (decompress_buffer(s->cluster_cache, s->cluster_size, s->cluster_data, csize) < 0) { diff --git a/block/qcow2.c b/block/qcow2.c index 5493e6b847..d5a1e8bc43 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -113,7 +113,7 @@ static ssize_t qcow2_crypto_hdr_read_func(QCryptoBlock *block, size_t offset, error_setg_errno(errp, -ret, "Could not read encryption header"); return -1; } - return ret; + return buflen; } @@ -174,7 +174,7 @@ static ssize_t qcow2_crypto_hdr_write_func(QCryptoBlock *block, size_t offset, error_setg_errno(errp, -ret, "Could not read encryption header"); return -1; } - return ret; + return buflen; } static QDict* diff --git a/block/qed.c b/block/qed.c index ba93e99570..55da91eb72 100644 --- a/block/qed.c +++ b/block/qed.c @@ -87,14 +87,9 @@ static void qed_header_cpu_to_le(const QEDHeader *cpu, QEDHeader *le) int qed_write_header_sync(BDRVQEDState *s) { QEDHeader le; - int ret; qed_header_cpu_to_le(&s->header, &le); - ret = bdrv_pwrite(s->bs->file, 0, sizeof(le), &le, 0); - if (ret != sizeof(le)) { - return ret; - } - return 0; + return bdrv_pwrite(s->bs->file, 0, sizeof(le), &le, 0); } /** diff --git a/block/vdi.c b/block/vdi.c index 9ef55a117a..a0be2a23b9 100644 --- a/block/vdi.c +++ b/block/vdi.c @@ -730,7 +730,7 @@ nonallocating_write: n_sectors * SECTOR_SIZE, base, 0); } - return ret < 0 ? ret : 0; + return ret; } static int coroutine_fn vdi_co_do_create(BlockdevCreateOptions *create_options, diff --git a/block/vmdk.c b/block/vmdk.c index aacea1095f..332565c80f 100644 --- a/block/vmdk.c +++ b/block/vmdk.c @@ -473,7 +473,6 @@ static int vmdk_parent_open(BlockDriverState *bs) if (ret < 0) { goto out; } - ret = 0; p_name = strstr(desc, "parentFileNameHint"); if (p_name != NULL) { @@ -905,7 +904,7 @@ static char *vmdk_read_desc(BdrvChild *file, uint64_t desc_offset, Error **errp) g_free(buf); return NULL; } - buf[ret] = 0; + buf[size] = 0; return buf; } @@ -1630,7 +1629,7 @@ static int get_cluster_offset(BlockDriverState *bs, l2_size_bytes, l2_table, 0 - ) != l2_size_bytes) { + ) < 0) { return VMDK_ERROR; } diff --git a/tests/unit/test-block-iothread.c b/tests/unit/test-block-iothread.c index 49fb1ef1ea..a5c163af7e 100644 --- a/tests/unit/test-block-iothread.c +++ b/tests/unit/test-block-iothread.c @@ -89,7 +89,7 @@ static void test_sync_op_pread(BdrvChild *c) /* Success */ ret = bdrv_pread(c, 0, sizeof(buf), buf, 0); - g_assert_cmpint(ret, ==, 512); + g_assert_cmpint(ret, ==, 0); /* Early error: Negative offset */ ret = bdrv_pread(c, -2, sizeof(buf), buf, 0); @@ -103,7 +103,7 @@ static void test_sync_op_pwrite(BdrvChild *c) /* Success */ ret = bdrv_pwrite(c, 0, sizeof(buf), buf, 0); - g_assert_cmpint(ret, ==, 512); + g_assert_cmpint(ret, ==, 0); /* Early error: Negative offset */ ret = bdrv_pwrite(c, -2, sizeof(buf), buf, 0);