diff options
Diffstat (limited to 'src/server/image.c')
| -rw-r--r-- | src/server/image.c | 136 |
1 files changed, 135 insertions, 1 deletions
diff --git a/src/server/image.c b/src/server/image.c index 3583f86..5a9e15b 100644 --- a/src/server/image.c +++ b/src/server/image.c @@ -55,6 +55,8 @@ static dnbd3_cache_map_t* image_loadCacheMap(const char * const imagePath, const static uint32_t* image_loadCrcList(const char * const imagePath, const int64_t fileSize, uint32_t *masterCrc); static bool image_checkRandomBlocks(dnbd3_image_t *image, const int count, int fromFd); static void* closeUnusedFds(void*); +static void* saveAllCacheMaps(void*); +static bool saveCacheMap(dnbd3_image_t *image); static void allocCacheMap(dnbd3_image_t *image, bool complete); static void cmfree(ref *ref) @@ -73,6 +75,7 @@ void image_serverStartup() mutex_init( &remoteCloneLock, LOCK_REMOTE_CLONE ); mutex_init( &reloadLock, LOCK_RELOAD ); server_addJob( &closeUnusedFds, NULL, 10, 900 ); + server_addJob( &saveAllCacheMaps, NULL, 9, 20 ); } /** @@ -160,6 +163,8 @@ void image_updateCachemap(dnbd3_image_t *image, uint64_t start, uint64_t end, co integrity_check( image, block, false ); } } + } else if ( !set ) { + image->mapDirty = true; } ref_put( &cache->reference ); } @@ -624,6 +629,7 @@ static dnbd3_image_t* image_free(dnbd3_image_t *image) // this will get called again when the uplink is done. if ( !uplink_shutdown( image ) ) return NULL; + saveCacheMap( image ); mutex_lock( &image->lock ); ref_setref( &image->ref_cacheMap, NULL ); free( image->crc32 ); @@ -1830,6 +1836,135 @@ static void* closeUnusedFds(void* nix UNUSED) return NULL; } +#define IMGCOUNT 5 +static void* saveAllCacheMaps(void* nix UNUSED) +{ + static ticks nextSave; + dnbd3_image_t *list[IMGCOUNT]; + int count = 0; + declare_now; + bool full = timing_reached( &nextSave, &now ); + mutex_lock( &imageListLock ); + for ( int i = 0; i < _num_images; ++i ) { + dnbd3_image_t * const image = _images[i]; + if ( image->mapDirty ) { + // Flag is set if integrity checker found a problem - save out + image->users++; + list[count++] = image; + image->mapDirty = false; + } else { + // Otherwise, consider longer timeout and byte count limits of uplink + dnbd3_uplink_t *uplink = ref_get_uplink( &image->uplinkref ); + if ( uplink != NULL ) { + assert( uplink->bytesReceivedLastSave <= uplink->bytesReceived ); + uint64_t diff = uplink->bytesReceived - uplink->bytesReceivedLastSave; + if ( diff > CACHE_MAP_MAX_UNSAVED_BYTES + || ( full && diff != 0 ) ) { + image->users++; + list[count++] = image; + uplink->bytesReceivedLastSave = uplink->bytesReceived; + } + ref_put( &uplink->reference ); + } + } + if ( count == IMGCOUNT ) + break; + } + mutex_unlock( &imageListLock ); + if ( full && count < IMGCOUNT ) { + // Only update nextSave once we handled all images in the list + timing_addSeconds( &nextSave, &now, CACHE_MAP_MAX_SAVE_DELAY ); + } + for ( int i = 0; i < count; ++i ) { + saveCacheMap( list[i] ); + image_release( list[i] ); + } + return NULL; +} +#undef IMGCOUNT + +/** + * Saves the cache map of the given image. + * Return true on success. + * @param image the image + */ +static bool saveCacheMap(dnbd3_image_t *image) +{ + if ( !_isProxy ) + return true; // Nothing to do + dnbd3_cache_map_t *cache = ref_get_cachemap( image ); + if ( cache == NULL ) + return true; // Nothing to do + // Check if we're a "hybrid proxy", i.e. there are only some namespaces (directories) + // for which we have any upstream servers configured. If there's none, don't touch + // the cache map on disk. + if ( !altservers_imageHasAltServers( image->name ) ) { + ref_put( &cache->reference ); + return true; // Nothing to do + } + + logadd( LOG_DEBUG2, "Saving cache map of %s:%d", image->name, (int)image->rid ); + const size_t size = IMGSIZE_TO_MAPBYTES(image->virtualFilesize); + char mapfile[strlen( image->path ) + 4 + 1]; + strcpy( mapfile, image->path ); + strcat( mapfile, ".map" ); + + int fd = open( mapfile, O_WRONLY | O_CREAT, 0644 ); + if ( fd == -1 ) { + const int err = errno; + ref_put( &cache->reference ); + logadd( LOG_WARNING, "Could not open file to write cache map to disk (errno=%d) file %s", err, mapfile ); + return false; + } + + // On Linux we could use readFd, but in general it's not guaranteed to work + int imgFd = open( image->path, O_WRONLY ); + if ( imgFd == -1 ) { + logadd( LOG_WARNING, "Cannot open %s for fsync(): errno=%d", image->path, errno ); + } else { + if ( fsync( imgFd ) == -1 ) { + logadd( LOG_ERROR, "fsync() on image file %s failed with errno %d. Resetting cache map.", image->path, errno ); + dnbd3_cache_map_t *old = image_loadCacheMap(image->path, image->virtualFilesize); + const int mapSize = IMGSIZE_TO_MAPBYTES( image->virtualFilesize ); + if ( old == NULL ) { + // Could not load old map. FS might be toast. + logadd( LOG_ERROR, "Cannot load old cache map. Setting all zero." ); + memset( cache->map, 0, mapSize ); + } else { + // AND the maps together to be safe + for ( int i = 0; i < mapSize; ++i ) { + cache->map[i] &= old->map[i]; + } + old->reference.free( &old->reference ); + } + } + close( imgFd ); + } + + // Write current map to file + size_t done = 0; + while ( done < size ) { + const ssize_t ret = write( fd, cache->map + done, size - done ); + if ( ret == -1 ) { + if ( errno == EINTR ) continue; + logadd( LOG_WARNING, "Could not write cache map (errno=%d) file %s", errno, mapfile ); + break; + } + if ( ret <= 0 ) { + logadd( LOG_WARNING, "Unexpected return value %d for write() to %s", (int)ret, mapfile ); + break; + } + done += (size_t)ret; + } + ref_put( &cache->reference ); + if ( fsync( fd ) == -1 ) { + logadd( LOG_WARNING, "fsync() on image map %s failed with errno %d", mapfile, errno ); + } + close( fd ); + // TODO fsync on parent directory + return true; +} + static void allocCacheMap(dnbd3_image_t *image, bool complete) { const uint8_t val = complete ? 0xff : 0; @@ -1846,4 +1981,3 @@ static void allocCacheMap(dnbd3_image_t *image, bool complete) } mutex_unlock( &image->lock ); } - |