diff options
Diffstat (limited to 'block.c')
| -rw-r--r-- | block.c | 351 |
1 files changed, 208 insertions, 143 deletions
@@ -26,8 +26,10 @@ #include "trace.h" #include "monitor.h" #include "block_int.h" +#include "blockjob.h" #include "module.h" #include "qjson.h" +#include "sysemu.h" #include "qemu-coroutine.h" #include "qmp-commands.h" #include "qemu-timer.h" @@ -1386,7 +1388,8 @@ void bdrv_set_dev_ops(BlockDriverState *bs, const BlockDevOps *ops, } void bdrv_emit_qmp_error_event(const BlockDriverState *bdrv, - BlockQMPEventAction action, int is_read) + enum MonitorEvent ev, + BlockErrorAction action, bool is_read) { QObject *data; const char *action_str; @@ -1409,7 +1412,7 @@ void bdrv_emit_qmp_error_event(const BlockDriverState *bdrv, bdrv->device_name, action_str, is_read ? "read" : "write"); - monitor_protocol_event(QEVENT_BLOCK_IO_ERROR, data); + monitor_protocol_event(ev, data); qobject_decref(data); } @@ -1503,7 +1506,7 @@ int bdrv_commit(BlockDriverState *bs) int n, ro, open_flags; int ret = 0; uint8_t *buf; - char filename[1024]; + char filename[PATH_MAX]; if (!drv) return -ENOMEDIUM; @@ -1517,7 +1520,8 @@ int bdrv_commit(BlockDriverState *bs) } ro = bs->backing_hd->read_only; - strncpy(filename, bs->backing_hd->filename, sizeof(filename)); + /* Use pstrcpy (not strncpy): filename must be NUL-terminated. */ + pstrcpy(filename, sizeof(filename), bs->backing_hd->filename); open_flags = bs->backing_hd->open_flags; if (ro) { @@ -1724,6 +1728,149 @@ int bdrv_change_backing_file(BlockDriverState *bs, return ret; } +/* + * Finds the image layer in the chain that has 'bs' as its backing file. + * + * active is the current topmost image. + * + * Returns NULL if bs is not found in active's image chain, + * or if active == bs. + */ +BlockDriverState *bdrv_find_overlay(BlockDriverState *active, + BlockDriverState *bs) +{ + BlockDriverState *overlay = NULL; + BlockDriverState *intermediate; + + assert(active != NULL); + assert(bs != NULL); + + /* if bs is the same as active, then by definition it has no overlay + */ + if (active == bs) { + return NULL; + } + + intermediate = active; + while (intermediate->backing_hd) { + if (intermediate->backing_hd == bs) { + overlay = intermediate; + break; + } + intermediate = intermediate->backing_hd; + } + + return overlay; +} + +typedef struct BlkIntermediateStates { + BlockDriverState *bs; + QSIMPLEQ_ENTRY(BlkIntermediateStates) entry; +} BlkIntermediateStates; + + +/* + * Drops images above 'base' up to and including 'top', and sets the image + * above 'top' to have base as its backing file. + * + * Requires that the overlay to 'top' is opened r/w, so that the backing file + * information in 'bs' can be properly updated. + * + * E.g., this will convert the following chain: + * bottom <- base <- intermediate <- top <- active + * + * to + * + * bottom <- base <- active + * + * It is allowed for bottom==base, in which case it converts: + * + * base <- intermediate <- top <- active + * + * to + * + * base <- active + * + * Error conditions: + * if active == top, that is considered an error + * + */ +int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top, + BlockDriverState *base) +{ + BlockDriverState *intermediate; + BlockDriverState *base_bs = NULL; + BlockDriverState *new_top_bs = NULL; + BlkIntermediateStates *intermediate_state, *next; + int ret = -EIO; + + QSIMPLEQ_HEAD(states_to_delete, BlkIntermediateStates) states_to_delete; + QSIMPLEQ_INIT(&states_to_delete); + + if (!top->drv || !base->drv) { + goto exit; + } + + new_top_bs = bdrv_find_overlay(active, top); + + if (new_top_bs == NULL) { + /* we could not find the image above 'top', this is an error */ + goto exit; + } + + /* special case of new_top_bs->backing_hd already pointing to base - nothing + * to do, no intermediate images */ + if (new_top_bs->backing_hd == base) { + ret = 0; + goto exit; + } + + intermediate = top; + + /* now we will go down through the list, and add each BDS we find + * into our deletion queue, until we hit the 'base' + */ + while (intermediate) { + intermediate_state = g_malloc0(sizeof(BlkIntermediateStates)); + intermediate_state->bs = intermediate; + QSIMPLEQ_INSERT_TAIL(&states_to_delete, intermediate_state, entry); + + if (intermediate->backing_hd == base) { + base_bs = intermediate->backing_hd; + break; + } + intermediate = intermediate->backing_hd; + } + if (base_bs == NULL) { + /* something went wrong, we did not end at the base. safely + * unravel everything, and exit with error */ + goto exit; + } + + /* success - we can delete the intermediate states, and link top->base */ + ret = bdrv_change_backing_file(new_top_bs, base_bs->filename, + base_bs->drv ? base_bs->drv->format_name : ""); + if (ret) { + goto exit; + } + new_top_bs->backing_hd = base_bs; + + + QSIMPLEQ_FOREACH_SAFE(intermediate_state, &states_to_delete, entry, next) { + /* so that bdrv_close() does not recursively close the chain */ + intermediate_state->bs->backing_hd = NULL; + bdrv_delete(intermediate_state->bs); + } + ret = 0; + +exit: + QSIMPLEQ_FOREACH_SAFE(intermediate_state, &states_to_delete, entry, next) { + g_free(intermediate_state); + } + return ret; +} + + static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset, size_t size) { @@ -2330,18 +2477,51 @@ void bdrv_set_io_limits(BlockDriverState *bs, bs->io_limits_enabled = bdrv_io_limits_enabled(bs); } -void bdrv_set_on_error(BlockDriverState *bs, BlockErrorAction on_read_error, - BlockErrorAction on_write_error) +void bdrv_set_on_error(BlockDriverState *bs, BlockdevOnError on_read_error, + BlockdevOnError on_write_error) { bs->on_read_error = on_read_error; bs->on_write_error = on_write_error; } -BlockErrorAction bdrv_get_on_error(BlockDriverState *bs, int is_read) +BlockdevOnError bdrv_get_on_error(BlockDriverState *bs, bool is_read) { return is_read ? bs->on_read_error : bs->on_write_error; } +BlockErrorAction bdrv_get_error_action(BlockDriverState *bs, bool is_read, int error) +{ + BlockdevOnError on_err = is_read ? bs->on_read_error : bs->on_write_error; + + switch (on_err) { + case BLOCKDEV_ON_ERROR_ENOSPC: + return (error == ENOSPC) ? BDRV_ACTION_STOP : BDRV_ACTION_REPORT; + case BLOCKDEV_ON_ERROR_STOP: + return BDRV_ACTION_STOP; + case BLOCKDEV_ON_ERROR_REPORT: + return BDRV_ACTION_REPORT; + case BLOCKDEV_ON_ERROR_IGNORE: + return BDRV_ACTION_IGNORE; + default: + abort(); + } +} + +/* This is done by device models because, while the block layer knows + * about the error, it does not know whether an operation comes from + * the device or the block layer (from a job, for example). + */ +void bdrv_error_action(BlockDriverState *bs, BlockErrorAction action, + bool is_read, int error) +{ + assert(error >= 0); + bdrv_emit_qmp_error_event(bs, QEVENT_BLOCK_IO_ERROR, action, is_read); + if (action == BDRV_ACTION_STOP) { + vm_stop(RUN_STATE_IO_ERROR); + bdrv_iostatus_set_err(bs, error); + } +} + int bdrv_is_read_only(BlockDriverState *bs) { return bs->read_only; @@ -2974,6 +3154,22 @@ int bdrv_get_backing_file_depth(BlockDriverState *bs) return 1 + bdrv_get_backing_file_depth(bs->backing_hd); } +BlockDriverState *bdrv_find_base(BlockDriverState *bs) +{ + BlockDriverState *curr_bs = NULL; + + if (!bs) { + return NULL; + } + + curr_bs = bs; + + while (curr_bs->backing_hd) { + curr_bs = curr_bs->backing_hd; + } + return curr_bs; +} + #define NB_SUFFIXES 4 char *get_human_readable_size(char *buf, int buf_size, int64_t size) @@ -4049,9 +4245,9 @@ void bdrv_iostatus_enable(BlockDriverState *bs) bool bdrv_iostatus_is_enabled(const BlockDriverState *bs) { return (bs->iostatus_enabled && - (bs->on_write_error == BLOCK_ERR_STOP_ENOSPC || - bs->on_write_error == BLOCK_ERR_STOP_ANY || - bs->on_read_error == BLOCK_ERR_STOP_ANY)); + (bs->on_write_error == BLOCKDEV_ON_ERROR_ENOSPC || + bs->on_write_error == BLOCKDEV_ON_ERROR_STOP || + bs->on_read_error == BLOCKDEV_ON_ERROR_STOP)); } void bdrv_iostatus_disable(BlockDriverState *bs) @@ -4066,14 +4262,10 @@ void bdrv_iostatus_reset(BlockDriverState *bs) } } -/* XXX: Today this is set by device models because it makes the implementation - quite simple. However, the block layer knows about the error, so it's - possible to implement this without device models being involved */ void bdrv_iostatus_set_err(BlockDriverState *bs, int error) { - if (bdrv_iostatus_is_enabled(bs) && - bs->iostatus == BLOCK_DEVICE_IO_STATUS_OK) { - assert(error >= 0); + assert(bdrv_iostatus_is_enabled(bs)); + if (bs->iostatus == BLOCK_DEVICE_IO_STATUS_OK) { bs->iostatus = error == ENOSPC ? BLOCK_DEVICE_IO_STATUS_NOSPACE : BLOCK_DEVICE_IO_STATUS_FAILED; } @@ -4247,130 +4439,3 @@ out: return ret; } - -void *block_job_create(const BlockJobType *job_type, BlockDriverState *bs, - int64_t speed, BlockDriverCompletionFunc *cb, - void *opaque, Error **errp) -{ - BlockJob *job; - - if (bs->job || bdrv_in_use(bs)) { - error_set(errp, QERR_DEVICE_IN_USE, bdrv_get_device_name(bs)); - return NULL; - } - bdrv_set_in_use(bs, 1); - - job = g_malloc0(job_type->instance_size); - job->job_type = job_type; - job->bs = bs; - job->cb = cb; - job->opaque = opaque; - job->busy = true; - bs->job = job; - - /* Only set speed when necessary to avoid NotSupported error */ - if (speed != 0) { - Error *local_err = NULL; - - block_job_set_speed(job, speed, &local_err); - if (error_is_set(&local_err)) { - bs->job = NULL; - g_free(job); - bdrv_set_in_use(bs, 0); - error_propagate(errp, local_err); - return NULL; - } - } - return job; -} - -void block_job_complete(BlockJob *job, int ret) -{ - BlockDriverState *bs = job->bs; - - assert(bs->job == job); - job->cb(job->opaque, ret); - bs->job = NULL; - g_free(job); - bdrv_set_in_use(bs, 0); -} - -void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp) -{ - Error *local_err = NULL; - - if (!job->job_type->set_speed) { - error_set(errp, QERR_NOT_SUPPORTED); - return; - } - job->job_type->set_speed(job, speed, &local_err); - if (error_is_set(&local_err)) { - error_propagate(errp, local_err); - return; - } - - job->speed = speed; -} - -void block_job_cancel(BlockJob *job) -{ - job->cancelled = true; - if (job->co && !job->busy) { - qemu_coroutine_enter(job->co, NULL); - } -} - -bool block_job_is_cancelled(BlockJob *job) -{ - return job->cancelled; -} - -struct BlockCancelData { - BlockJob *job; - BlockDriverCompletionFunc *cb; - void *opaque; - bool cancelled; - int ret; -}; - -static void block_job_cancel_cb(void *opaque, int ret) -{ - struct BlockCancelData *data = opaque; - - data->cancelled = block_job_is_cancelled(data->job); - data->ret = ret; - data->cb(data->opaque, ret); -} - -int block_job_cancel_sync(BlockJob *job) -{ - struct BlockCancelData data; - BlockDriverState *bs = job->bs; - - assert(bs->job == job); - - /* Set up our own callback to store the result and chain to - * the original callback. - */ - data.job = job; - data.cb = job->cb; - data.opaque = job->opaque; - data.ret = -EINPROGRESS; - job->cb = block_job_cancel_cb; - job->opaque = &data; - block_job_cancel(job); - while (data.ret == -EINPROGRESS) { - qemu_aio_wait(); - } - return (data.cancelled && data.ret == 0) ? -ECANCELED : data.ret; -} - -void block_job_sleep_ns(BlockJob *job, QEMUClock *clock, int64_t ns) -{ - /* Check cancellation *before* setting busy = false, too! */ - if (!block_job_is_cancelled(job)) { - job->busy = false; - co_sleep_ns(clock, ns); - job->busy = true; - } -} |