commit a5a5e96bf510fb6fe4cd26e36d06a7060a59e29d Author: David Sorber Date: Wed Mar 21 09:56:22 2018 -0400 Adding FUSE readdir() example that I posted to the FUSE dev list. diff --git a/software/FUSE_example/readdir_test.cc b/software/FUSE_example/readdir_test.cc new file mode 100644 index 0000000..b7d3bad --- /dev/null +++ b/software/FUSE_example/readdir_test.cc @@ -0,0 +1,443 @@ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +#include + +// The things we do for decent logging... +#define LOG(level, msg) {\ + std::time_t __now = std::chrono::system_clock::to_time_t(std::chrono::system_clock::now());\ + char tsstr[100];\ + std::strftime(tsstr, sizeof(tsstr), "%a %b %d %T", std::localtime(&__now));\ + std::cerr << tsstr << "|" << level << "|" << __FILE__ << ":" << __LINE__ \ + << "|" << msg << std::endl; } +#define ERROR(msg) LOG("ERROR", msg) +#define DEBUG(msg) LOG("DEBUG", msg) + + +/****************************************************************************** + * Hardcoded file system data for testing purposes + *****************************************************************************/ +typedef std::tuple EntryAttrs; + +std::map fs_data = +{ + std::pair{".", std::make_tuple(16893, 1000, 1000, 0, 1497357835, 1497357835, 1497357835)}, + std::pair{"..", std::make_tuple(16893, 1000, 1000, 0, 1497357835, 1497357835, 1497357835)}, + std::pair{"0001.bin", std::make_tuple(33188, 1000, 1000, 168593714, 1513688527, 1496839609, 1496839608)}, + std::pair{"0002.bin", std::make_tuple(33188, 1000, 1000, 22593382637, 1513688527, 1496857810, 1496857765)}, + std::pair{"0003.bin", std::make_tuple(33188, 1000, 0, 0, 1513688528, 1511787445, 1496859394)}, + std::pair{"0004.bin", std::make_tuple(33188, 1000, 0, 4204, 1513688528, 1510043263, 1496859394)}, + std::pair{"0005.bin", std::make_tuple(33188, 1000, 1000, 473253720, 1513688528, 1497007653, 1497007652)}, + std::pair{"0006.bin", std::make_tuple(33188, 1000, 0, 77563049, 1513688528, 1497017377, 1497007822)}, + std::pair{"0007.bin", std::make_tuple(33188, 1000, 1000, 22593382637, 1513688528, 1497351617, 1497351587)}, + std::pair{"0008.bin", std::make_tuple(33204, 1000, 1000, 15, 1516107258, 1516107258, 1497357863)}, + std::pair{"0009.bin", std::make_tuple(33204, 1000, 1000, 1, 1516107258, 1516107258, 1497357863)}, + std::pair{"0010.bin", std::make_tuple(33204, 1000, 1000, 536870912, 1516201822, 1497357867, 1497357865)}, + std::pair{"0011.bin", std::make_tuple(33204, 1000, 1000, 549, 1516107859, 1497357867, 1497357867)}, + std::pair{"0012.bin", std::make_tuple(33204, 1000, 1000, 22593382637, 1516201816, 1497357956, 1497357871)}, + std::pair{"0013.bin", std::make_tuple(33204, 1000, 1000, 1046, 1516109117, 1497357981, 1497357981)}, + std::pair{"0014.bin", std::make_tuple(33204, 1000, 1000, 68157440, 1516107747, 1516107741, 1497357983)}, + std::pair{"0015.bin", std::make_tuple(33204, 1000, 1000, 6892667, 1516109116, 1497357992, 1497357992)}, + std::pair{"0016.bin", std::make_tuple(33204, 1000, 1000, 6892667, 1497357992, 1497357992, 1497357992)}, + std::pair{"0017.bin", std::make_tuple(33204, 1000, 1000, 1046, 1513688532, 1497357993, 1497357993)}, + std::pair{"0018.bin", std::make_tuple(33204, 1000, 1000, 202375168, 1513688532, 1497358008, 1497358007)}, + std::pair{"0019.bin", std::make_tuple(33204, 1000, 1000, 536870912, 1516107330, 1497358016, 1497358013)}, + std::pair{"0020.bin", std::make_tuple(33204, 1000, 1000, 268435456, 1516107336, 1497358020, 1497358019)}, + std::pair{"0021.bin", std::make_tuple(33204, 1000, 1000, 8144, 1516107593, 1497358031, 1497358030)}, + std::pair{"0022.bin", std::make_tuple(33204, 1000, 1000, 4775, 1516107734, 1497358046, 1497358046)}, + std::pair{"0023.bin", std::make_tuple(33204, 1000, 1000, 481, 1516107371, 1497358047, 1497358047)}, + std::pair{"0024.bin", std::make_tuple(33204, 1000, 1000, 526201714, 1497358048, 1497358049, 1497358048)}, + std::pair{"0025.bin", std::make_tuple(33204, 1000, 1000, 4725659, 1516108145, 1497358050, 1497358049)}, + std::pair{"0026.bin", std::make_tuple(33204, 1000, 1000, 4461205, 1516108145, 1497358050, 1497358050)}, + std::pair{"0027.bin", std::make_tuple(33204, 1000, 1000, 4670395, 1516108145, 1497358050, 1497358050)}, + std::pair{"0028.bin", std::make_tuple(33204, 1000, 1000, 4627799, 1516108145, 1497358050, 1497358050)}, + std::pair{"0029.bin", std::make_tuple(33204, 1000, 1000, 4588549, 1516108145, 1497358050, 1497358050)}, + std::pair{"0030.bin", std::make_tuple(33204, 1000, 1000, 4586073, 1516108145, 1497358050, 1497358050)}, + std::pair{"0031.bin", std::make_tuple(33204, 1000, 1000, 4537877, 1516108145, 1497358050, 1497358050)}, + std::pair{"0032.bin", std::make_tuple(33204, 1000, 1000, 4481762, 1516108145, 1497358050, 1497358050)}, + std::pair{"0033.bin", std::make_tuple(33204, 1000, 1000, 4529771, 1516108145, 1497358050, 1497358050)}, + std::pair{"0034.bin", std::make_tuple(33204, 1000, 1000, 4715336, 1516108145, 1497358050, 1497358050)}, + std::pair{"0035.bin", std::make_tuple(33204, 1000, 1000, 4696289, 1516108145, 1497358050, 1497358050)}, + std::pair{"0036.bin", std::make_tuple(33204, 1000, 1000, 4528268, 1516108145, 1497358050, 1497358050)}, + std::pair{"0037.bin", std::make_tuple(33204, 1000, 1000, 4539782, 1516108145, 1497358050, 1497358050)}, + std::pair{"0038.bin", std::make_tuple(33204, 1000, 1000, 4653329, 1516108145, 1497358050, 1497358050)}, + std::pair{"0039.bin", std::make_tuple(33204, 1000, 1000, 4521595, 1516108145, 1497358050, 1497358050)}, + std::pair{"0040.bin", std::make_tuple(33204, 1000, 1000, 4660637, 1516108145, 1497358050, 1497358050)}, + std::pair{"0041.bin", std::make_tuple(33204, 1000, 1000, 4581008, 1516108145, 1497358050, 1497358050)}, + std::pair{"0042.bin", std::make_tuple(33204, 1000, 1000, 4578016, 1516108145, 1497358050, 1497358050)}, + std::pair{"0043.bin", std::make_tuple(33204, 1000, 1000, 4753460, 1516108145, 1497358050, 1497358050)}, + std::pair{"0044.bin", std::make_tuple(33204, 1000, 1000, 4559827, 1516108145, 1497358050, 1497358050)}, + std::pair{"0045.bin", std::make_tuple(33204, 1000, 1000, 4586278, 1516108145, 1497358050, 1497358050)}, + std::pair{"0046.bin", std::make_tuple(33204, 1000, 1000, 4622489, 1516108145, 1497358050, 1497358050)}, + std::pair{"0047.bin", std::make_tuple(33204, 1000, 1000, 4392706, 1516108145, 1497358051, 1497358050)}, + std::pair{"0048.bin", std::make_tuple(33204, 1000, 1000, 4592057, 1516108145, 1497358051, 1497358051)}, + std::pair{"0049.bin", std::make_tuple(33204, 1000, 1000, 4692335, 1516108145, 1497358051, 1497358051)}, + std::pair{"0050.bin", std::make_tuple(33204, 1000, 1000, 4641344, 1516108145, 1497358051, 1497358051)}, + std::pair{"0051.bin", std::make_tuple(33204, 1000, 1000, 4519803, 1516108145, 1497358051, 1497358051)}, + std::pair{"0052.bin", std::make_tuple(33204, 1000, 1000, 4580694, 1516108145, 1497358051, 1497358051)}, + std::pair{"0053.bin", std::make_tuple(33204, 1000, 1000, 4562114, 1516108145, 1497358051, 1497358051)}, + std::pair{"0054.bin", std::make_tuple(33204, 1000, 1000, 4537820, 1516108145, 1497358051, 1497358051)}, + std::pair{"0055.bin", std::make_tuple(33204, 1000, 1000, 4523996, 1516108145, 1497358051, 1497358051)}, + std::pair{"0056.bin", std::make_tuple(33204, 1000, 1000, 4680014, 1516108145, 1497358051, 1497358051)}, + std::pair{"0057.bin", std::make_tuple(33204, 1000, 1000, 4496418, 1516108145, 1497358051, 1497358051)}, + std::pair{"0058.bin", std::make_tuple(33204, 1000, 1000, 4804784, 1516108145, 1497358051, 1497358051)}, + std::pair{"0059.bin", std::make_tuple(33204, 1000, 1000, 4510851, 1516108145, 1497358051, 1497358051)}, + std::pair{"0060.bin", std::make_tuple(33204, 1000, 1000, 4651723, 1516108145, 1497358051, 1497358051)}, + std::pair{"0061.bin", std::make_tuple(33204, 1000, 1000, 4582348, 1516108145, 1497358051, 1497358051)}, + std::pair{"0062.bin", std::make_tuple(33204, 1000, 1000, 4556271, 1516108145, 1497358051, 1497358051)}, + std::pair{"0063.bin", std::make_tuple(33204, 1000, 1000, 4416323, 1516108145, 1497358051, 1497358051)}, + std::pair{"0064.bin", std::make_tuple(33204, 1000, 1000, 4584588, 1516108145, 1497358051, 1497358051)}, + std::pair{"0065.bin", std::make_tuple(33204, 1000, 1000, 4617515, 1516108145, 1497358051, 1497358051)}, + std::pair{"0066.bin", std::make_tuple(33204, 1000, 1000, 4738641, 1516108145, 1497358052, 1497358051)}, + std::pair{"0067.bin", std::make_tuple(33204, 1000, 1000, 4521443, 1516108145, 1497358052, 1497358052)}, + std::pair{"0068.bin", std::make_tuple(33204, 1000, 1000, 4857734, 1516108145, 1497358052, 1497358052)}, + std::pair{"0069.bin", std::make_tuple(33204, 1000, 1000, 4653949, 1516108145, 1497358052, 1497358052)}, + std::pair{"0070.bin", std::make_tuple(33204, 1000, 1000, 4709419, 1516108145, 1497358052, 1497358052)}, + std::pair{"0071.bin", std::make_tuple(33204, 1000, 1000, 4390969, 1516108145, 1497358052, 1497358052)}, + std::pair{"0072.bin", std::make_tuple(33204, 1000, 1000, 4444072, 1516108145, 1497358052, 1497358052)}, + std::pair{"0073.bin", std::make_tuple(33204, 1000, 1000, 4320725, 1516108145, 1497358052, 1497358052)}, + std::pair{"0074.bin", std::make_tuple(33204, 1000, 1000, 4819829, 1516108145, 1497358052, 1497358052)}, + std::pair{"0075.bin", std::make_tuple(33204, 1000, 1000, 4686232, 1516108145, 1497358052, 1497358052)}, + std::pair{"0076.bin", std::make_tuple(33204, 1000, 1000, 4749938, 1516108145, 1497358052, 1497358052)}, + std::pair{"0077.bin", std::make_tuple(33204, 1000, 1000, 4694213, 1516108145, 1497358052, 1497358052)}, + std::pair{"0078.bin", std::make_tuple(33204, 1000, 1000, 4698242, 1516108145, 1497358052, 1497358052)}, + std::pair{"0079.bin", std::make_tuple(33204, 1000, 1000, 4794803, 1516108145, 1497358052, 1497358052)}, + std::pair{"0080.bin", std::make_tuple(33204, 1000, 1000, 4606039, 1516108145, 1497358052, 1497358052)}, + std::pair{"0081.bin", std::make_tuple(33204, 1000, 1000, 4399879, 1516108145, 1497358052, 1497358052)}, + std::pair{"0082.bin", std::make_tuple(33204, 1000, 1000, 4816006, 1516108145, 1497358052, 1497358052)}, + std::pair{"0083.bin", std::make_tuple(33204, 1000, 1000, 4663708, 1516108145, 1497358052, 1497358052)}, + std::pair{"0084.bin", std::make_tuple(33204, 1000, 1000, 4879173, 1516108145, 1497358052, 1497358052)}, + std::pair{"0085.bin", std::make_tuple(33204, 1000, 1000, 4871831, 1516108145, 1497358052, 1497358052)}, + std::pair{"0086.bin", std::make_tuple(33204, 1000, 1000, 4563574, 1516108145, 1497358052, 1497358052)}, + std::pair{"0087.bin", std::make_tuple(33204, 1000, 1000, 4847954, 1516108145, 1497358052, 1497358052)}, + std::pair{"0088.bin", std::make_tuple(33204, 1000, 1000, 4878237, 1516108145, 1497358052, 1497358052)}, + std::pair{"0089.bin", std::make_tuple(33204, 1000, 1000, 4812806, 1516108145, 1497358052, 1497358052)}, + std::pair{"0090.bin", std::make_tuple(33204, 1000, 1000, 4701756, 1516108145, 1497358052, 1497358052)}, + std::pair{"0091.bin", std::make_tuple(33204, 1000, 1000, 4418793, 1516108145, 1497358052, 1497358052)}, + std::pair{"0092.bin", std::make_tuple(33204, 1000, 1000, 4860231, 1516108145, 1497358052, 1497358052)}, + std::pair{"0093.bin", std::make_tuple(33204, 1000, 1000, 4404407, 1516108145, 1497358052, 1497358052)}, + std::pair{"0094.bin", std::make_tuple(33204, 1000, 1000, 4356939, 1516108145, 1497358052, 1497358052)}, + std::pair{"0095.bin", std::make_tuple(33204, 1000, 1000, 4517704, 1516108145, 1497358052, 1497358052)}, + std::pair{"0096.bin", std::make_tuple(33204, 1000, 1000, 4411777, 1516108145, 1497358052, 1497358052)}, + std::pair{"0097.bin", std::make_tuple(33204, 1000, 1000, 4597873, 1516108145, 1497358052, 1497358052)}, + std::pair{"0098.bin", std::make_tuple(33204, 1000, 1000, 4458429, 1516108145, 1497358052, 1497358052)}, + std::pair{"0099.bin", std::make_tuple(33204, 1000, 1000, 4776084, 1516108145, 1497358052, 1497358052)}, + std::pair{"0100.bin", std::make_tuple(33204, 1000, 1000, 4762316, 1516108145, 1497358053, 1497358053)}, +}; + + + +// Globals +const std::string mountpoint("/mnt/readdir"); +const uint32_t BLK_SIZE = 512; + +struct fuse_args* p_fuseArgv = nullptr; +struct fuse* p_fuseInstance = nullptr; +struct fuse_loop_config loop_config; +struct fuse_operations operations; +std::thread* p_fuseEventThread = nullptr; +struct sigaction exit_act; +std::vector> readdir_cache; + +// FUSE operation functions +void* test_init(struct fuse_conn_info* info, fuse_config* config) +{ + // Disable ATOMIC_O_TRUNC, which is enabled by default + info->want &= (~FUSE_CAP_ATOMIC_O_TRUNC); + + // Enable FUSE_CAP_READDIRPLUS to get better performance with readdir on + // large directories + info->want |= FUSE_CAP_READDIRPLUS; + info->want |= FUSE_CAP_READDIRPLUS_AUTO; + + // Disable FUSE_CAP_AUTO_INVAL_DATA because it checks file attributes after + // each read request which slows things way down... + info->want &= (~FUSE_CAP_AUTO_INVAL_DATA); + + // Make sure asynchronous reads are enabled + info->want |= FUSE_CAP_ASYNC_READ; + + // None of these really seem to do anything... but we can dream + info->max_read = 0; // no limit but the kernel will limit anyway + info->max_readahead = 1073741824; // 1GB + info->max_write = 1073741824; // 1GB + + // Set attr timeout to 3600 seconds (60m/1hr) to effectively enable + // attribute caching. + config->attr_timeout = 3600; + + DEBUG("FS (FUSE) Initialized."); + + return nullptr; +} + +// Helper function +inline void __populate_stat_buf( + struct stat& stat_buf, + std::pair& entry) +{ + stat_buf.st_mode = (mode_t) std::get<0>(entry.second); + stat_buf.st_uid = (uid_t) std::get<1>(entry.second); + stat_buf.st_gid = (gid_t) std::get<2>(entry.second); + stat_buf.st_size = (off64_t) std::get<3>(entry.second); + stat_buf.st_ctime = (time_t) std::get<4>(entry.second); + stat_buf.st_atime = (time_t) std::get<5>(entry.second); + stat_buf.st_mtime = (time_t) std::get<6>(entry.second); + stat_buf.st_blksize = BLK_SIZE; + stat_buf.st_blocks = (stat_buf.st_size / stat_buf.st_blksize); + + return; +} + +int test_getattr( + const char* path, + struct stat* ss, + struct fuse_file_info* /* info */) +{ + DEBUG("GETATTR: " << path); + + std::string path_str(path); + if (path_str == "/") + { + path_str = "."; + } + else + { + // Strip on leading slash + path_str = path_str.substr(1); + } + + // Find the directory entry + auto iter = fs_data.find(path_str); + if (iter == fs_data.end()) + { + DEBUG("GETATTR: returning ENOENT"); + return -ENOENT; + } + + // Populate the stat buffer + __populate_stat_buf(*ss, *iter); + + return 0; +} + +int test_readdir( + const char* path, + void* buf, + fuse_fill_dir_t filler, + off_t offset, + struct fuse_file_info* /* info */, + fuse_readdir_flags flags) +{ + DEBUG("READDIR (offset: " << offset << " flags: " << flags << "): " << path); + + bool readdir_plus = (flags & FUSE_READDIR_PLUS); + + if (offset == 0) + { + struct stat stat_buf; + std::memset(&stat_buf, 0, sizeof(struct stat)); + + // Iterate over the directory contents + for (auto& iter : fs_data) + { + __populate_stat_buf(stat_buf, iter); + + if (iter.first == "." || iter.first == "..") + { + stat_buf.st_ino = 17; // must be nonzero for these entries to appear + } + + // If readdir plus populate the cache otherwise just call filler + if (readdir_plus) + { + readdir_cache.emplace_back(iter.first, stat_buf); + } + else + { + // "regular" readdir + filler(buf, iter.first.c_str(), &stat_buf, 0, (fuse_fill_dir_flags)0); + } + } + + if (! readdir_plus) + { + return 0; + } + } + + // readdir plus fill in entries + for (off_t offset_idx = offset; offset_idx < readdir_cache.size(); ++offset_idx) + { + if (filler(buf, readdir_cache[offset_idx].first.c_str(), + &readdir_cache[offset_idx].second, offset_idx + 1, + FUSE_FILL_DIR_PLUS)) + { + break; + } + } + + // Clear readdir cache + if (offset == readdir_cache.size()) + { + DEBUG("freeing readdir cache"); + readdir_cache.clear(); + } + + return 0; +} + +void run() +{ + if (p_fuseInstance == nullptr) + { + ERROR("FUSE instance pointer is null"); + return; + } + + std::memset(&loop_config, 0, sizeof(struct fuse_loop_config)); + loop_config.clone_fd = 1; + loop_config.max_idle_threads = 10; + + DEBUG("about to call fuse_loop_mt()"); + fuse_loop_mt(p_fuseInstance, &loop_config); + DEBUG("fuse_loop_mt() returned"); +} + +void stop(int signum) +{ + DEBUG("handler triggered"); + if (p_fuseInstance != nullptr) + { + fuse_exit(p_fuseInstance); + } +} + +// g++ -std=c++11 -O3 -o readdir_test readdir_test.cc -lfuse3 -DFUSE_USE_VERSION=32 +int main(int argc, char** argv) +{ + std::cout << "Readdir Test FS\n" << std::endl; + + // Make sure the mountpoint exists and is a directory + struct stat stat_buf; + int rc = stat(mountpoint.c_str(), &stat_buf); + if (rc != 0) + { + ERROR("mountpoint: " << mountpoint << " " <join(); + DEBUG("FUSE thread stopping..."); + + // Clean up + if (p_fuseInstance != nullptr) + { + fuse_unmount(p_fuseInstance); + fuse_destroy(p_fuseInstance); + } + DEBUG("FUSE unmounted and destroyed"); + + delete p_fuseArgv; + delete p_fuseEventThread; + + return 0; +} \ No newline at end of file