X-Git-Url: http://git.vrable.net/?p=bluesky.git;a=blobdiff_plain;f=bluesky%2Flog.c;h=ccc9a7a712bafc698ae17dfcc87cff6b50f2e2e9;hp=6d5c5908972afea4ac9e1d8f7657d06d3fd07216;hb=b52abd849493636b81dda8c752a60834f1a6b91f;hpb=5cc2d7413ae0dd76a16d798dcf060effe70cb3f9 diff --git a/bluesky/log.c b/bluesky/log.c index 6d5c590..ccc9a7a 100644 --- a/bluesky/log.c +++ b/bluesky/log.c @@ -34,13 +34,25 @@ * only incompletely written out before a crash, which should only happen for * log records that were not considered committed). */ -// Rough size limit for a log segment. This is not a firm limit and there are -// no absolute guarantees on the size of a log segment. -#define LOG_SEGMENT_SIZE (1 << 22) - #define HEADER_MAGIC 0x676f4c0a #define FOOTER_MAGIC 0x2e435243 +static size_t readbuf(int fd, char *buf, size_t len) +{ + size_t total_bytes = 0; + while (len > 0) { + ssize_t bytes = read(fd, buf, len); + if (bytes < 0 && errno == EINTR) + continue; + g_assert(bytes >= 0); + if (bytes == 0) + break; + buf += bytes; + len -= bytes; + } + return total_bytes; +} + static void writebuf(int fd, const char *buf, size_t len) { while (len > 0) { @@ -413,6 +425,7 @@ BlueSkyCacheFile *bluesky_cachefile_lookup(BlueSkyFS *fs, g_mutex_lock(map->lock); map->cond = g_cond_new(); map->filename = g_strdup(logname); + map->log_dir = clouddir; map->log_seq = log_seq; map->log = log; g_atomic_int_set(&map->mapcount, 0); @@ -426,14 +439,16 @@ BlueSkyCacheFile *bluesky_cachefile_lookup(BlueSkyFS *fs, ftruncate(fd, 5 << 20); // FIXME close(fd); } - - // If the log file is stored in the cloud, we may need to fetch it - if (clouddir >= 0 && start_fetch) - cloudlog_fetch_start(map); } else { g_mutex_lock(map->lock); } + + /* If the log file is stored in the cloud and has not been fully fetched, + * we may need to initiate a fetch now. */ + if (clouddir >= 0 && start_fetch && !map->complete && !map->fetching) + cloudlog_fetch_start(map); + g_mutex_unlock(log->mmap_lock); if (map != NULL) g_atomic_int_inc(&map->refcount); @@ -463,12 +478,15 @@ static void cloudlog_partial_fetch_start(BlueSkyCacheFile *cachefile, size_t offset, size_t length) { g_atomic_int_inc(&cachefile->refcount); - g_print("Starting fetch of %s from cloud\n", cachefile->filename); + if (bluesky_verbose) + g_print("Starting partial fetch of %s from cloud (%zd + %zd)\n", + cachefile->filename, offset, length); BlueSkyStoreAsync *async = bluesky_store_async_new(cachefile->fs->store); async->op = STORE_OP_GET; async->key = g_strdup(cachefile->filename); async->start = offset; async->len = length; + async->profile = bluesky_profile_get(); bluesky_store_async_add_notifier(async, (GFunc)cloudlog_partial_fetch_complete, cachefile); @@ -479,11 +497,18 @@ static void cloudlog_partial_fetch_start(BlueSkyCacheFile *cachefile, static void cloudlog_partial_fetch_complete(BlueSkyStoreAsync *async, BlueSkyCacheFile *cachefile) { - g_print("Partial fetch of %s from cloud complete, status = %d\n", - async->key, async->result); + if (bluesky_verbose || async->result != 0) + g_print("Fetch of %s from cloud complete, status = %d\n", + async->key, async->result); g_mutex_lock(cachefile->lock); if (async->result >= 0) { + if (async->len == 0) { + if (bluesky_verbose) + g_print("Complete object was fetched.\n"); + cachefile->complete = TRUE; + } + /* Descrypt items fetched and write valid items out to the local log, * but only if they do not overlap existing objects. This will protect * against an attack by the cloud provider where one valid object is @@ -492,9 +517,11 @@ static void cloudlog_partial_fetch_complete(BlueSkyStoreAsync *async, BlueSkyRangeset *items = bluesky_rangeset_new(); int fd = openat(cachefile->log->dirfd, cachefile->filename, O_WRONLY); if (fd >= 0) { + gboolean allow_unauth; async->data = bluesky_string_dup(async->data); + allow_unauth = cachefile->log_dir == BLUESKY_CLOUD_DIR_CLEANER; bluesky_cloudlog_decrypt(async->data->data, async->data->len, - cachefile->fs->keys, items); + cachefile->fs->keys, items, allow_unauth); uint64_t item_offset = 0; while (TRUE) { const BlueSkyRangesetItem *item; @@ -522,8 +549,10 @@ static void cloudlog_partial_fetch_complete(BlueSkyStoreAsync *async, g_warning("Unable to open and write to cache file %s: %m", cachefile->filename); } + + bluesky_rangeset_free(items); } else { - g_print("Error fetching from cloud, retrying...\n"); + g_print("Error fetching %s from cloud, retrying...\n", async->key); cloudlog_partial_fetch_start(cachefile, async->start, async->len); } @@ -546,10 +575,12 @@ static void cloudlog_fetch_start(BlueSkyCacheFile *cachefile) { g_atomic_int_inc(&cachefile->refcount); cachefile->fetching = TRUE; - g_print("Starting fetch of %s from cloud\n", cachefile->filename); + if (bluesky_verbose) + g_print("Starting fetch of %s from cloud\n", cachefile->filename); BlueSkyStoreAsync *async = bluesky_store_async_new(cachefile->fs->store); async->op = STORE_OP_GET; async->key = g_strdup(cachefile->filename); + async->profile = bluesky_profile_get(); bluesky_store_async_add_notifier(async, (GFunc)cloudlog_partial_fetch_complete, cachefile); @@ -557,6 +588,57 @@ static void cloudlog_fetch_start(BlueSkyCacheFile *cachefile) bluesky_store_async_unref(async); } +/* Map and return a read-only version of a byte range from a cached file. The + * CacheFile object must be locked. */ +BlueSkyRCStr *bluesky_cachefile_map_raw(BlueSkyCacheFile *cachefile, + off_t offset, size_t size) +{ + cachefile->atime = bluesky_get_current_time(); + + /* Easy case: the needed data is already in memory */ + if (cachefile->addr != NULL && offset + size <= cachefile->len) + return bluesky_string_new_from_mmap(cachefile, offset, size); + + int fd = openat(cachefile->log->dirfd, cachefile->filename, O_RDONLY); + if (fd < 0) { + fprintf(stderr, "Error opening logfile %s: %m\n", + cachefile->filename); + return NULL; + } + + off_t length = lseek(fd, 0, SEEK_END); + if (offset + size > length) { + close(fd); + return NULL; + } + + /* File is not mapped in memory. Map the entire file in, then return a + * pointer to just the required data. */ + if (cachefile->addr == NULL) { + cachefile->addr = (const char *)mmap(NULL, length, PROT_READ, + MAP_SHARED, fd, 0); + cachefile->len = length; + g_atomic_int_inc(&cachefile->refcount); + + close(fd); + return bluesky_string_new_from_mmap(cachefile, offset, size); + } + + /* Otherwise, the file was mapped in but doesn't cover the data we need. + * This shouldn't happen much, if at all, but if it does just read the data + * we need directly from the file. We lose memory-management benefits of + * using mmapped data, but otherwise this works. */ + char *buf = g_malloc(size); + size_t actual_size = readbuf(fd, buf, size); + close(fd); + if (actual_size != size) { + g_free(buf); + return NULL; + } else { + return bluesky_string_new(buf, size); + } +} + /* The arguments are mostly straightforward. log_dir is -1 for access from the * journal, and non-negative for access to a cloud log segment. map_data * should be TRUE for the case that are mapping just the data of an item where @@ -565,12 +647,12 @@ static void cloudlog_fetch_start(BlueSkyCacheFile *cachefile) BlueSkyRCStr *bluesky_log_map_object(BlueSkyCloudLog *item, gboolean map_data) { BlueSkyFS *fs = item->fs; - BlueSkyLog *log = fs->log; BlueSkyCacheFile *map = NULL; BlueSkyRCStr *str = NULL; int location = 0; size_t file_offset = 0, file_size = 0; - gboolean range_request = TRUE; + gboolean range_request = bluesky_options.full_segment_fetches + ? FALSE : TRUE; if (page_size == 0) { page_size = getpagesize(); @@ -622,7 +704,7 @@ BlueSkyRCStr *bluesky_log_map_object(BlueSkyCloudLog *item, gboolean map_data) file_offset); } if (range_request) { - uint64_t start = 0, length = 0, end; + uint64_t start = file_offset, length = file_size, end; if (map->prefetches != NULL) bluesky_rangeset_get_extents(map->prefetches, &start, &length); @@ -639,30 +721,12 @@ BlueSkyRCStr *bluesky_log_map_object(BlueSkyCloudLog *item, gboolean map_data) } else if (rangeitem->start == file_offset && rangeitem->length == file_size) { if (bluesky_verbose) - g_print("Item now available.\n"); + g_print("Item %zd now available.\n", file_offset); break; } } } - if (map->addr == NULL) { - int fd = openat(log->dirfd, map->filename, O_RDONLY); - - if (fd < 0) { - fprintf(stderr, "Error opening logfile %s: %m\n", map->filename); - goto exit2; - } - - off_t length = lseek(fd, 0, SEEK_END); - map->addr = (const char *)mmap(NULL, length, PROT_READ, MAP_SHARED, - fd, 0); - map->len = length; - - g_atomic_int_inc(&map->refcount); - - close(fd); - } - if (map_data) { if (location == CLOUDLOG_JOURNAL) file_offset += sizeof(struct log_header); @@ -671,8 +735,7 @@ BlueSkyRCStr *bluesky_log_map_object(BlueSkyCloudLog *item, gboolean map_data) file_size = item->data_size; } - str = bluesky_string_new_from_mmap(map, file_offset, file_size); - map->atime = bluesky_get_current_time(); + str = bluesky_cachefile_map_raw(map, file_offset, file_size); exit2: bluesky_cachefile_unref(map); @@ -689,7 +752,7 @@ void bluesky_mmap_unref(BlueSkyCacheFile *mmap) if (g_atomic_int_dec_and_test(&mmap->mapcount)) { g_mutex_lock(mmap->lock); - if (g_atomic_int_get(&mmap->mapcount) == 0) { + if (mmap->addr != NULL && g_atomic_int_get(&mmap->mapcount) == 0) { if (bluesky_verbose) g_print("Unmapped log segment %d...\n", mmap->log_seq); munmap((void *)mmap->addr, mmap->len); @@ -698,6 +761,7 @@ void bluesky_mmap_unref(BlueSkyCacheFile *mmap) } g_mutex_unlock(mmap->lock); } + g_assert(g_atomic_int_get(&mmap->mapcount) >= 0); } /******************************* JOURNAL REPLAY *******************************