From 3d661c8ab18ad2013992c622ab307422ace891a2 Mon Sep 17 00:00:00 2001 From: Yury Kotov Date: Mon, 22 Apr 2019 13:34:20 +0300 Subject: [PATCH] migration: Add error_desc for file channel errors Currently, there is no information about error if outgoing migration was failed because of file channel errors. Example (QMP session): -> { "execute": "migrate", "arguments": { "uri": "exec:head -c 1" }} <- { "return": {} } ... -> { "execute": "query-migrate" } <- { "return": { "status": "failed" }} // There is not error's description And even in the QEMU's output there is nothing. This patch 1) Adds errp for the most of QEMUFileOps 2) Adds qemu_file_get_error_obj/qemu_file_set_error_obj 3) And finally using of qemu_file_get_error_obj in migration.c And now, the status for the mentioned fail will be: -> { "execute": "query-migrate" } <- { "return": { "status": "failed", "error-desc": "Unable to write to command: Broken pipe" }} Signed-off-by: Yury Kotov Message-Id: <20190422103420.15686-1-yury-kotov@yandex-team.ru> Reviewed-by: Dr. David Alan Gilbert Signed-off-by: Dr. David Alan Gilbert --- migration/migration.c | 10 +++++-- migration/qemu-file-channel.c | 30 +++++++++++---------- migration/qemu-file.c | 63 ++++++++++++++++++++++++++++++++++--------- migration/qemu-file.h | 15 +++++++---- migration/savevm.c | 6 ++--- 5 files changed, 88 insertions(+), 36 deletions(-) diff --git a/migration/migration.c b/migration/migration.c index 8a607fe1e2..28342969ea 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -2963,6 +2963,7 @@ static MigThrError migration_detect_error(MigrationState *s) { int ret; int state = s->state; + Error *local_error = NULL; if (state == MIGRATION_STATUS_CANCELLING || state == MIGRATION_STATUS_CANCELLED) { @@ -2971,13 +2972,18 @@ static MigThrError migration_detect_error(MigrationState *s) } /* Try to detect any file errors */ - ret = qemu_file_get_error(s->to_dst_file); - + ret = qemu_file_get_error_obj(s->to_dst_file, &local_error); if (!ret) { /* Everything is fine */ + assert(!local_error); return MIG_THR_ERR_NONE; } + if (local_error) { + migrate_set_error(s, local_error); + error_free(local_error); + } + if (state == MIGRATION_STATUS_POSTCOPY_ACTIVE && ret == -EIO) { /* * For postcopy, we allow the network to be down for a diff --git a/migration/qemu-file-channel.c b/migration/qemu-file-channel.c index 8e639eb496..c382ea2d78 100644 --- a/migration/qemu-file-channel.c +++ b/migration/qemu-file-channel.c @@ -33,7 +33,8 @@ static ssize_t channel_writev_buffer(void *opaque, struct iovec *iov, int iovcnt, - int64_t pos) + int64_t pos, + Error **errp) { QIOChannel *ioc = QIO_CHANNEL(opaque); ssize_t done = 0; @@ -47,7 +48,7 @@ static ssize_t channel_writev_buffer(void *opaque, while (nlocal_iov > 0) { ssize_t len; - len = qio_channel_writev(ioc, local_iov, nlocal_iov, NULL); + len = qio_channel_writev(ioc, local_iov, nlocal_iov, errp); if (len == QIO_CHANNEL_ERR_BLOCK) { if (qemu_in_coroutine()) { qio_channel_yield(ioc, G_IO_OUT); @@ -57,7 +58,6 @@ static ssize_t channel_writev_buffer(void *opaque, continue; } if (len < 0) { - /* XXX handle Error objects */ done = -EIO; goto cleanup; } @@ -75,13 +75,14 @@ static ssize_t channel_writev_buffer(void *opaque, static ssize_t channel_get_buffer(void *opaque, uint8_t *buf, int64_t pos, - size_t size) + size_t size, + Error **errp) { QIOChannel *ioc = QIO_CHANNEL(opaque); ssize_t ret; do { - ret = qio_channel_read(ioc, (char *)buf, size, NULL); + ret = qio_channel_read(ioc, (char *)buf, size, errp); if (ret < 0) { if (ret == QIO_CHANNEL_ERR_BLOCK) { if (qemu_in_coroutine()) { @@ -90,7 +91,6 @@ static ssize_t channel_get_buffer(void *opaque, qio_channel_wait(ioc, G_IO_IN); } } else { - /* XXX handle Error * object */ return -EIO; } } @@ -100,18 +100,20 @@ static ssize_t channel_get_buffer(void *opaque, } -static int channel_close(void *opaque) +static int channel_close(void *opaque, Error **errp) { + int ret; QIOChannel *ioc = QIO_CHANNEL(opaque); - qio_channel_close(ioc, NULL); + ret = qio_channel_close(ioc, errp); object_unref(OBJECT(ioc)); - return 0; + return ret; } static int channel_shutdown(void *opaque, bool rd, - bool wr) + bool wr, + Error **errp) { QIOChannel *ioc = QIO_CHANNEL(opaque); @@ -125,8 +127,7 @@ static int channel_shutdown(void *opaque, } else { mode = QIO_CHANNEL_SHUTDOWN_WRITE; } - if (qio_channel_shutdown(ioc, mode, NULL) < 0) { - /* XXX handler Error * object */ + if (qio_channel_shutdown(ioc, mode, errp) < 0) { return -EIO; } } @@ -135,11 +136,12 @@ static int channel_shutdown(void *opaque, static int channel_set_blocking(void *opaque, - bool enabled) + bool enabled, + Error **errp) { QIOChannel *ioc = QIO_CHANNEL(opaque); - if (qio_channel_set_blocking(ioc, enabled, NULL) < 0) { + if (qio_channel_set_blocking(ioc, enabled, errp) < 0) { return -1; } return 0; diff --git a/migration/qemu-file.c b/migration/qemu-file.c index 0431585502..c04a7a891b 100644 --- a/migration/qemu-file.c +++ b/migration/qemu-file.c @@ -28,6 +28,7 @@ #include "migration.h" #include "qemu-file.h" #include "trace.h" +#include "qapi/error.h" #define IO_BUF_SIZE 32768 #define MAX_IOV_SIZE MIN(IOV_MAX, 64) @@ -51,6 +52,7 @@ struct QEMUFile { unsigned int iovcnt; int last_error; + Error *last_error_obj; }; /* @@ -62,7 +64,7 @@ int qemu_file_shutdown(QEMUFile *f) if (!f->ops->shut_down) { return -ENOSYS; } - return f->ops->shut_down(f->opaque, true, true); + return f->ops->shut_down(f->opaque, true, true, NULL); } /* @@ -107,24 +109,55 @@ void qemu_file_set_hooks(QEMUFile *f, const QEMUFileHooks *hooks) } /* - * Get last error for stream f + * Get last error for stream f with optional Error* * * Return negative error value if there has been an error on previous * operations, return 0 if no error happened. + * Optional, it returns Error* in errp, but it may be NULL even if return value + * is not 0. * */ -int qemu_file_get_error(QEMUFile *f) +int qemu_file_get_error_obj(QEMUFile *f, Error **errp) { + if (errp) { + *errp = f->last_error_obj ? error_copy(f->last_error_obj) : NULL; + } return f->last_error; } -void qemu_file_set_error(QEMUFile *f, int ret) +/* + * Set the last error for stream f with optional Error* + */ +void qemu_file_set_error_obj(QEMUFile *f, int ret, Error *err) { - if (f->last_error == 0) { + if (f->last_error == 0 && ret) { f->last_error = ret; + error_propagate(&f->last_error_obj, err); + } else if (err) { + error_report_err(err); } } +/* + * Get last error for stream f + * + * Return negative error value if there has been an error on previous + * operations, return 0 if no error happened. + * + */ +int qemu_file_get_error(QEMUFile *f) +{ + return qemu_file_get_error_obj(f, NULL); +} + +/* + * Set the last error for stream f + */ +void qemu_file_set_error(QEMUFile *f, int ret) +{ + qemu_file_set_error_obj(f, ret, NULL); +} + bool qemu_file_is_writable(QEMUFile *f) { return f->ops->writev_buffer; @@ -176,6 +209,7 @@ void qemu_fflush(QEMUFile *f) { ssize_t ret = 0; ssize_t expect = 0; + Error *local_error = NULL; if (!qemu_file_is_writable(f)) { return; @@ -183,7 +217,8 @@ void qemu_fflush(QEMUFile *f) if (f->iovcnt > 0) { expect = iov_size(f->iov, f->iovcnt); - ret = f->ops->writev_buffer(f->opaque, f->iov, f->iovcnt, f->pos); + ret = f->ops->writev_buffer(f->opaque, f->iov, f->iovcnt, f->pos, + &local_error); qemu_iovec_release_ram(f); } @@ -195,7 +230,7 @@ void qemu_fflush(QEMUFile *f) * data set we requested, so sanity check that. */ if (ret != expect) { - qemu_file_set_error(f, ret < 0 ? ret : -EIO); + qemu_file_set_error_obj(f, ret < 0 ? ret : -EIO, local_error); } f->buf_index = 0; f->iovcnt = 0; @@ -283,6 +318,7 @@ static ssize_t qemu_fill_buffer(QEMUFile *f) { int len; int pending; + Error *local_error = NULL; assert(!qemu_file_is_writable(f)); @@ -294,14 +330,16 @@ static ssize_t qemu_fill_buffer(QEMUFile *f) f->buf_size = pending; len = f->ops->get_buffer(f->opaque, f->buf + pending, f->pos, - IO_BUF_SIZE - pending); + IO_BUF_SIZE - pending, &local_error); if (len > 0) { f->buf_size += len; f->pos += len; } else if (len == 0) { - qemu_file_set_error(f, -EIO); + qemu_file_set_error_obj(f, -EIO, local_error); } else if (len != -EAGAIN) { - qemu_file_set_error(f, len); + qemu_file_set_error_obj(f, len, local_error); + } else { + error_free(local_error); } return len; @@ -327,7 +365,7 @@ int qemu_fclose(QEMUFile *f) ret = qemu_file_get_error(f); if (f->ops->close) { - int ret2 = f->ops->close(f->opaque); + int ret2 = f->ops->close(f->opaque, NULL); if (ret >= 0) { ret = ret2; } @@ -338,6 +376,7 @@ int qemu_fclose(QEMUFile *f) if (f->last_error) { ret = f->last_error; } + error_free(f->last_error_obj); g_free(f); trace_qemu_file_fclose(); return ret; @@ -783,6 +822,6 @@ void qemu_put_counted_string(QEMUFile *f, const char *str) void qemu_file_set_blocking(QEMUFile *f, bool block) { if (f->ops->set_blocking) { - f->ops->set_blocking(f->opaque, block); + f->ops->set_blocking(f->opaque, block, NULL); } } diff --git a/migration/qemu-file.h b/migration/qemu-file.h index 13baf896bd..eb886db65f 100644 --- a/migration/qemu-file.h +++ b/migration/qemu-file.h @@ -32,7 +32,8 @@ * bytes actually read should be returned. */ typedef ssize_t (QEMUFileGetBufferFunc)(void *opaque, uint8_t *buf, - int64_t pos, size_t size); + int64_t pos, size_t size, + Error **errp); /* Close a file * @@ -41,7 +42,7 @@ typedef ssize_t (QEMUFileGetBufferFunc)(void *opaque, uint8_t *buf, * The meaning of return value on success depends on the specific back-end being * used. */ -typedef int (QEMUFileCloseFunc)(void *opaque); +typedef int (QEMUFileCloseFunc)(void *opaque, Error **errp); /* Called to return the OS file descriptor associated to the QEMUFile. */ @@ -49,14 +50,15 @@ typedef int (QEMUFileGetFD)(void *opaque); /* Called to change the blocking mode of the file */ -typedef int (QEMUFileSetBlocking)(void *opaque, bool enabled); +typedef int (QEMUFileSetBlocking)(void *opaque, bool enabled, Error **errp); /* * This function writes an iovec to file. The handler must write all * of the data or return a negative errno value. */ typedef ssize_t (QEMUFileWritevBufferFunc)(void *opaque, struct iovec *iov, - int iovcnt, int64_t pos); + int iovcnt, int64_t pos, + Error **errp); /* * This function provides hooks around different @@ -97,7 +99,8 @@ typedef QEMUFile *(QEMURetPathFunc)(void *opaque); * Existing blocking reads/writes must be woken * Returns 0 on success, -err on error */ -typedef int (QEMUFileShutdownFunc)(void *opaque, bool rd, bool wr); +typedef int (QEMUFileShutdownFunc)(void *opaque, bool rd, bool wr, + Error **errp); typedef struct QEMUFileOps { QEMUFileGetBufferFunc *get_buffer; @@ -149,6 +152,8 @@ void qemu_update_position(QEMUFile *f, size_t size); void qemu_file_reset_rate_limit(QEMUFile *f); void qemu_file_set_rate_limit(QEMUFile *f, int64_t new_rate); int64_t qemu_file_get_rate_limit(QEMUFile *f); +int qemu_file_get_error_obj(QEMUFile *f, Error **errp); +void qemu_file_set_error_obj(QEMUFile *f, int ret, Error *err); void qemu_file_set_error(QEMUFile *f, int ret); int qemu_file_shutdown(QEMUFile *f); QEMUFile *qemu_file_get_return_path(QEMUFile *f); diff --git a/migration/savevm.c b/migration/savevm.c index 79ed44d475..a2a5f89b75 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -124,7 +124,7 @@ static struct mig_cmd_args { /* savevm/loadvm support */ static ssize_t block_writev_buffer(void *opaque, struct iovec *iov, int iovcnt, - int64_t pos) + int64_t pos, Error **errp) { int ret; QEMUIOVector qiov; @@ -139,12 +139,12 @@ static ssize_t block_writev_buffer(void *opaque, struct iovec *iov, int iovcnt, } static ssize_t block_get_buffer(void *opaque, uint8_t *buf, int64_t pos, - size_t size) + size_t size, Error **errp) { return bdrv_load_vmstate(opaque, buf, pos, size); } -static int bdrv_fclose(void *opaque) +static int bdrv_fclose(void *opaque, Error **errp) { return bdrv_flush(opaque); } -- 2.11.4.GIT