diff options
Diffstat (limited to 'erts/emulator/nifs/common/prim_file_nif.c')
| -rw-r--r-- | erts/emulator/nifs/common/prim_file_nif.c | 1298 |
1 files changed, 1298 insertions, 0 deletions
diff --git a/erts/emulator/nifs/common/prim_file_nif.c b/erts/emulator/nifs/common/prim_file_nif.c new file mode 100644 index 0000000000..a78ee62677 --- /dev/null +++ b/erts/emulator/nifs/common/prim_file_nif.c @@ -0,0 +1,1298 @@ +/* + * %CopyrightBegin% + * + * Copyright Ericsson 2017-2018. All Rights Reserved. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + * %CopyrightEnd% + */ + +#define STATIC_ERLANG_NIF 1 + +#include "erl_nif.h" +#include "config.h" +#include "sys.h" + +#ifdef VALGRIND +# include <valgrind/memcheck.h> +#endif + +#include "erl_driver.h" +#include "prim_file_nif.h" + +/* NIF interface declarations */ +static int load(ErlNifEnv *env, void** priv_data, ERL_NIF_TERM load_info); +static int upgrade(ErlNifEnv *env, void** priv_data, void** old_priv_data, ERL_NIF_TERM load_info); +static void unload(ErlNifEnv *env, void* priv_data); + +static ErlNifResourceType *efile_resource_type; + +static ERL_NIF_TERM am_close; + +static ERL_NIF_TERM am_ok; +static ERL_NIF_TERM am_error; +static ERL_NIF_TERM am_continue; + +static ERL_NIF_TERM am_file_info; + +/* File modes */ +static ERL_NIF_TERM am_read; +static ERL_NIF_TERM am_write; +static ERL_NIF_TERM am_exclusive; +static ERL_NIF_TERM am_append; +static ERL_NIF_TERM am_sync; +static ERL_NIF_TERM am_skip_type_check; + +/* enum efile_access_t; read and write are defined above.*/ +static ERL_NIF_TERM am_read_write; +static ERL_NIF_TERM am_none; + +/* enum efile_advise_t */ +static ERL_NIF_TERM am_normal; +static ERL_NIF_TERM am_random; +static ERL_NIF_TERM am_sequential; +static ERL_NIF_TERM am_will_need; +static ERL_NIF_TERM am_dont_need; +static ERL_NIF_TERM am_no_reuse; + +/* enum efile_filetype_t */ +static ERL_NIF_TERM am_device; +static ERL_NIF_TERM am_directory; +static ERL_NIF_TERM am_regular; +static ERL_NIF_TERM am_symlink; +static ERL_NIF_TERM am_other; + +/* enum efile_seek_t, 'eof' marker. */ +static ERL_NIF_TERM am_bof; +static ERL_NIF_TERM am_cur; +static ERL_NIF_TERM am_eof; + +static ERL_NIF_TERM read_info_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM set_permissions_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM set_owner_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM set_time_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); + +static ERL_NIF_TERM read_link_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM list_dir_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); + +static ERL_NIF_TERM make_hard_link_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM make_soft_link_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM rename_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM make_dir_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM del_file_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM del_dir_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM get_device_cwd_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM get_cwd_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM set_cwd_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); + +static ERL_NIF_TERM read_file_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); + +static ERL_NIF_TERM open_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM close_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); + +/* Internal ops */ +static ERL_NIF_TERM delayed_close_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM get_handle_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM altname_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); + +/* All file handle operations are passed through a wrapper that handles state + * transitions, marking it as busy during the course of the operation, and + * closing on completion if the owner died in the middle of an operation. + * + * This is pretty ugly but required as there's no way to tell when it's safe to + * asynchronously close a file; the event could have fired just before landing + * in a system call which will fail with EBADF at best or alias a newly opened + * fd at worst. + * + * The old driver got away with enqueueing the close operation on the same + * async queue as all of its other operations, but since dirty schedulers use a + * single global queue there's no natural way to schedule an asynchronous close + * "behind" other operations. + * + * The states may transition as follows: + * + * IDLE -> + * BUSY (file_handle_wrapper) | + * CLOSED (owner_death_callback) + * + * BUSY -> + * IDLE (file_handle_wrapper) + * CLOSED (close_nif_impl) + * CLOSE_PENDING (owner_death_callback) + * + * CLOSE_PENDING -> + * CLOSED (file_handle_wrapper) + * + * Should the owner of a file die, we can't close it immediately as that could + * potentially block a normal scheduler. When entering the CLOSED state from + * owner_death_callback, we will instead send a message to the erts_prim_file + * process that will then close the file through delayed_close_nif. */ + +typedef ERL_NIF_TERM (*file_op_impl_t)(efile_data_t *d, ErlNifEnv *env, + int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM file_handle_wrapper(file_op_impl_t operation, ErlNifEnv *env, + int argc, const ERL_NIF_TERM argv[]); + +#define WRAP_FILE_HANDLE_EXPORT(name) \ + static ERL_NIF_TERM name ## _impl (efile_data_t *d, ErlNifEnv *env, \ + int argc, const ERL_NIF_TERM argv[]);\ + static ERL_NIF_TERM name(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { \ + return file_handle_wrapper( name ## _impl , env, argc, argv); \ + } + +WRAP_FILE_HANDLE_EXPORT(read_nif) +WRAP_FILE_HANDLE_EXPORT(write_nif) +WRAP_FILE_HANDLE_EXPORT(pread_nif) +WRAP_FILE_HANDLE_EXPORT(pwrite_nif) +WRAP_FILE_HANDLE_EXPORT(seek_nif) +WRAP_FILE_HANDLE_EXPORT(sync_nif) +WRAP_FILE_HANDLE_EXPORT(truncate_nif) +WRAP_FILE_HANDLE_EXPORT(allocate_nif) +WRAP_FILE_HANDLE_EXPORT(advise_nif) +WRAP_FILE_HANDLE_EXPORT(get_handle_nif) +WRAP_FILE_HANDLE_EXPORT(ipread_s32bu_p32bu_nif) + +static ErlNifFunc nif_funcs[] = { + /* File handle ops */ + {"open_nif", 2, open_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"close_nif", 1, close_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"read_nif", 2, read_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"write_nif", 2, write_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"pread_nif", 3, pread_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"pwrite_nif", 3, pwrite_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"seek_nif", 3, seek_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"sync_nif", 2, sync_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"truncate_nif", 1, truncate_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"allocate_nif", 3, allocate_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"advise_nif", 4, advise_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + + /* Filesystem ops */ + {"make_hard_link_nif", 2, make_hard_link_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"make_soft_link_nif", 2, make_soft_link_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"rename_nif", 2, rename_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"read_info_nif", 2, read_info_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"set_permissions_nif", 2, set_permissions_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"set_owner_nif", 3, set_owner_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"set_time_nif", 4, set_time_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"read_link_nif", 1, read_link_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"list_dir_nif", 1, list_dir_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"make_dir_nif", 1, make_dir_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"del_file_nif", 1, del_file_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"del_dir_nif", 1, del_dir_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"get_device_cwd_nif", 1, get_device_cwd_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"set_cwd_nif", 1, set_cwd_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"get_cwd_nif", 0, get_cwd_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + + /* These operations are equivalent to chained calls of other operations, + * but have been moved down to avoid excessive rescheduling. */ + {"ipread_s32bu_p32bu_nif", 3, ipread_s32bu_p32bu_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"read_file_nif", 1, read_file_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + + /* Internal ops. */ + {"get_handle_nif", 1, get_handle_nif}, + {"delayed_close_nif", 1, delayed_close_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"altname_nif", 1, altname_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, +}; + +ERL_NIF_INIT(prim_file, nif_funcs, load, NULL, upgrade, unload) + +static ErlNifPid erts_prim_file_pid; + +static void owner_death_callback(ErlNifEnv* env, void* obj, ErlNifPid* pid, ErlNifMonitor* mon); + +static int load(ErlNifEnv *env, void** priv_data, ERL_NIF_TERM prim_file_pid) +{ + ErlNifResourceTypeInit callbacks; + + if(!enif_get_local_pid(env, prim_file_pid, &erts_prim_file_pid)) { + ASSERT(!"bad pid passed to prim_file_nif"); + } + + am_close = enif_make_atom(env, "close"); + + am_ok = enif_make_atom(env, "ok"); + am_error = enif_make_atom(env, "error"); + am_continue = enif_make_atom(env, "continue"); + + am_read = enif_make_atom(env, "read"); + am_write = enif_make_atom(env, "write"); + am_exclusive = enif_make_atom(env, "exclusive"); + am_append = enif_make_atom(env, "append"); + am_sync = enif_make_atom(env, "sync"); + am_skip_type_check = enif_make_atom(env, "skip_type_check"); + + am_read_write = enif_make_atom(env, "read_write"); + am_none = enif_make_atom(env, "none"); + + am_normal = enif_make_atom(env, "normal"); + am_random = enif_make_atom(env, "random"); + am_sequential = enif_make_atom(env, "sequential"); + am_will_need = enif_make_atom(env, "will_need"); + am_dont_need = enif_make_atom(env, "dont_need"); + am_no_reuse = enif_make_atom(env, "no_reuse"); + + am_device = enif_make_atom(env, "device"); + am_directory = enif_make_atom(env, "directory"); + am_regular = enif_make_atom(env, "regular"); + am_symlink = enif_make_atom(env, "symlink"); + am_other = enif_make_atom(env, "other"); + + am_file_info = enif_make_atom(env, "file_info"); + + am_bof = enif_make_atom(env, "bof"); + am_cur = enif_make_atom(env, "cur"); + am_eof = enif_make_atom(env, "eof"); + + callbacks.down = owner_death_callback; + callbacks.dtor = NULL; + callbacks.stop = NULL; + + efile_resource_type = enif_open_resource_type_x(env, "efile", &callbacks, + ERL_NIF_RT_CREATE, NULL); + + *priv_data = NULL; + + return 0; +} + +static void unload(ErlNifEnv *env, void* priv_data) +{ + +} + +static int upgrade(ErlNifEnv *env, void** priv_data, void** old_priv_data, ERL_NIF_TERM load_info) +{ + if(*old_priv_data != NULL) { + return -1; /* Don't know how to do that */ + } + if(*priv_data != NULL) { + return -1; /* Don't know how to do that */ + } + if(load(env, priv_data, load_info)) { + return -1; + } + return 0; +} + +static ERL_NIF_TERM posix_error_to_tuple(ErlNifEnv *env, posix_errno_t posix_errno) { + ERL_NIF_TERM error = enif_make_atom(env, erl_errno_id(posix_errno)); + return enif_make_tuple2(env, am_error, error); +} + +static int get_file_data(ErlNifEnv *env, ERL_NIF_TERM opaque, efile_data_t **d) { + return enif_get_resource(env, opaque, efile_resource_type, (void **)d); +} + +static ERL_NIF_TERM file_handle_wrapper(file_op_impl_t operation, ErlNifEnv *env, + int argc, const ERL_NIF_TERM argv[]) { + + efile_data_t *d; + + enum efile_state_t previous_state; + ERL_NIF_TERM result; + + if(argc < 1 || !get_file_data(env, argv[0], &d)) { + return enif_make_badarg(env); + } + + previous_state = erts_atomic32_cmpxchg_acqb(&d->state, + EFILE_STATE_BUSY, EFILE_STATE_IDLE); + + if(previous_state == EFILE_STATE_IDLE) { + result = operation(d, env, argc - 1, &argv[1]); + + previous_state = erts_atomic32_cmpxchg_relb(&d->state, + EFILE_STATE_IDLE, EFILE_STATE_BUSY); + + ASSERT(previous_state != EFILE_STATE_IDLE); + + if(previous_state == EFILE_STATE_CLOSE_PENDING) { + /* This is the only point where a change from CLOSE_PENDING is + * possible, and we're running synchronously, so we can't race with + * anything else here. */ + posix_errno_t ignored; + + erts_atomic32_set_acqb(&d->state, EFILE_STATE_CLOSED); + efile_close(d, &ignored); + } + } else { + /* CLOSE_PENDING should be impossible at this point since it requires + * a transition from BUSY; the only valid state here is CLOSED. */ + ASSERT(previous_state == EFILE_STATE_CLOSED); + + result = posix_error_to_tuple(env, EINVAL); + } + + return result; +} + +/* This is a special close operation used by the erts_prim_file process for + * cleaning up orphaned files. It differs from the ordinary close_nif in that + * it only works for files that have already entered the CLOSED state. */ +static ERL_NIF_TERM delayed_close_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t ignored; + efile_data_t *d; + + ASSERT(argc == 1); + if(!get_file_data(env, argv[0], &d)) { + return enif_make_badarg(env); + } + + ASSERT(erts_atomic32_read_acqb(&d->state) == EFILE_STATE_CLOSED); + efile_close(d, &ignored); + + return am_ok; +} + +static void owner_death_callback(ErlNifEnv* env, void* obj, ErlNifPid* pid, ErlNifMonitor* mon) { + efile_data_t *d = (efile_data_t*)obj; + + (void)env; + (void)pid; + (void)mon; + + for(;;) { + enum efile_state_t previous_state; + + previous_state = erts_atomic32_cmpxchg_acqb(&d->state, + EFILE_STATE_CLOSED, EFILE_STATE_IDLE); + + switch(previous_state) { + case EFILE_STATE_IDLE: + { + /* We cannot close the file here as that could block a normal + * scheduler, so we tell erts_prim_file to do it for us. + * + * This can in turn become a bottleneck (especially in cases + * like NFS failure), but it's less problematic than blocking + * thread progress. */ + ERL_NIF_TERM message, file_ref; + + file_ref = enif_make_resource(env, d); + message = enif_make_tuple2(env, am_close, file_ref); + + if(!enif_send(env, &erts_prim_file_pid, NULL, message)) { + ERTS_INTERNAL_ERROR("Failed to defer prim_file close."); + } + + return; + } + case EFILE_STATE_CLOSE_PENDING: + case EFILE_STATE_CLOSED: + /* We're either already closed or managed to mark ourselves for + * closure in the previous iteration. */ + return; + case EFILE_STATE_BUSY: + /* Schedule ourselves to be closed once the current operation + * finishes, retrying the [IDLE -> CLOSED] transition in case we + * narrowly passed the [BUSY -> IDLE] one. */ + erts_atomic32_cmpxchg_nob(&d->state, + EFILE_STATE_CLOSE_PENDING, EFILE_STATE_BUSY); + break; + } + } +} + +static ERL_NIF_TERM efile_filetype_to_atom(enum efile_filetype_t type) { + switch(type) { + case EFILE_FILETYPE_DEVICE: return am_device; + case EFILE_FILETYPE_DIRECTORY: return am_directory; + case EFILE_FILETYPE_REGULAR: return am_regular; + case EFILE_FILETYPE_SYMLINK: return am_symlink; + case EFILE_FILETYPE_OTHER: return am_other; + } + + return am_other; +} + +static ERL_NIF_TERM efile_access_to_atom(enum efile_access_t type) { + if(type & EFILE_ACCESS_READ && !(type & EFILE_ACCESS_WRITE)) { + return am_read; + } else if(type & EFILE_ACCESS_WRITE && !(type & EFILE_ACCESS_READ)) { + return am_write; + } else if(type & EFILE_ACCESS_READ_WRITE) { + return am_read_write; + } + + return am_none; +} + +static enum efile_modes_t efile_translate_modelist(ErlNifEnv *env, ERL_NIF_TERM list) { + enum efile_modes_t modes; + ERL_NIF_TERM head, tail; + + modes = 0; + + while(enif_get_list_cell(env, list, &head, &tail)) { + if(enif_is_identical(head, am_read)) { + modes |= EFILE_MODE_READ; + } else if(enif_is_identical(head, am_write)) { + modes |= EFILE_MODE_WRITE; + } else if(enif_is_identical(head, am_exclusive)) { + modes |= EFILE_MODE_EXCLUSIVE; + } else if(enif_is_identical(head, am_append)) { + modes |= EFILE_MODE_APPEND; + } else if(enif_is_identical(head, am_sync)) { + modes |= EFILE_MODE_SYNC; + } else if(enif_is_identical(head, am_skip_type_check)) { + modes |= EFILE_MODE_SKIP_TYPE_CHECK; + } else { + /* Modes like 'raw', 'ram', 'delayed_writes' etc are handled + * further up the chain. */ + } + + list = tail; + } + + if(modes & (EFILE_MODE_APPEND | EFILE_MODE_EXCLUSIVE)) { + /* 'append' and 'exclusive' are documented as "open for writing." */ + modes |= EFILE_MODE_WRITE; + } else if(!(modes & EFILE_MODE_READ_WRITE)) { + /* Defaulting to read if !(W|R) is undocumented, but specifically + * tested against in file_SUITE. */ + modes |= EFILE_MODE_READ; + } + + return modes; +} + +static ERL_NIF_TERM open_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + efile_data_t *d; + + ErlNifPid controlling_process; + enum efile_modes_t modes; + ERL_NIF_TERM result; + efile_path_t path; + + if(argc != 2 || !enif_is_list(env, argv[1])) { + return enif_make_badarg(env); + } + + modes = efile_translate_modelist(env, argv[1]); + + if((posix_errno = efile_marshal_path(env, argv[0], &path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_open(&path, modes, efile_resource_type, &d))) { + return posix_error_to_tuple(env, posix_errno); + } + + enif_self(env, &controlling_process); + + if(enif_monitor_process(env, d, &controlling_process, &d->monitor)) { + /* We need to close the file manually as we haven't registered a + * destructor. */ + posix_errno_t ignored; + + erts_atomic32_set_acqb(&d->state, EFILE_STATE_CLOSED); + efile_close(d, &ignored); + + return posix_error_to_tuple(env, EINVAL); + } + + /* Note that we do not call enif_release_resource at this point. While it's + * normally safe to leave resource management to the GC, efile_close is a + * blocking operation which must not be done in the GC callback, and we + * can't defer it as the resource is gone as soon as it returns. + * + * We instead keep the resource alive until efile_close is called, after + * which it's safe to leave things to the GC. If the controlling process + * were to die before the user had a chance to close their file, the above + * monitor will tell the erts_prim_file process to close it for them. */ + result = enif_make_resource(env, d); + + return enif_make_tuple2(env, am_ok, result); +} + +static ERL_NIF_TERM close_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + enum efile_state_t previous_state; + efile_data_t *d; + + ASSERT(argc == 1); + if(!get_file_data(env, argv[0], &d)) { + return enif_make_badarg(env); + } + + previous_state = erts_atomic32_cmpxchg_acqb(&d->state, + EFILE_STATE_CLOSED, EFILE_STATE_IDLE); + + if(previous_state == EFILE_STATE_IDLE) { + posix_errno_t error; + + enif_demonitor_process(env, d, &d->monitor); + + if(!efile_close(d, &error)) { + return posix_error_to_tuple(env, error); + } + + return am_ok; + } else { + /* CLOSE_PENDING should be impossible at this point since it requires + * a transition from BUSY; the only valid state here is CLOSED. */ + ASSERT(previous_state == EFILE_STATE_CLOSED); + + return posix_error_to_tuple(env, EINVAL); + } +} + +static ERL_NIF_TERM read_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + Sint64 bytes_read, block_size; + SysIOVec read_vec[1]; + ErlNifBinary result; + + if(argc != 1 || !enif_is_number(env, argv[0])) { + return enif_make_badarg(env); + } + + if(!enif_get_int64(env, argv[0], &block_size) || block_size < 0) { + return posix_error_to_tuple(env, EINVAL); + } + + if(!enif_alloc_binary(block_size, &result)) { + return posix_error_to_tuple(env, ENOMEM); + } + + read_vec[0].iov_base = result.data; + read_vec[0].iov_len = result.size; + + bytes_read = efile_readv(d, read_vec, 1); + ASSERT(bytes_read <= block_size); + + if(bytes_read < 0) { + enif_release_binary(&result); + return posix_error_to_tuple(env, d->posix_errno); + } else if(bytes_read == 0) { + enif_release_binary(&result); + return am_eof; + } + + if(bytes_read < block_size && !enif_realloc_binary(&result, bytes_read)) { + ERTS_INTERNAL_ERROR("Failed to shrink read result."); + } + + return enif_make_tuple2(env, am_ok, enif_make_binary(env, &result)); +} + +static ERL_NIF_TERM write_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + ErlNifIOVec vec, *input = &vec; + Sint64 bytes_written; + ERL_NIF_TERM tail; + + if(argc != 1 || !enif_inspect_iovec(env, 64, argv[0], &tail, &input)) { + return enif_make_badarg(env); + } + + bytes_written = efile_writev(d, input->iov, input->iovcnt); + + if(bytes_written < 0) { + return posix_error_to_tuple(env, d->posix_errno); + } + + if(!enif_is_empty_list(env, tail)) { + ASSERT(bytes_written > 0); + return enif_make_tuple2(env, am_continue, tail); + } + + return am_ok; +} + +static ERL_NIF_TERM pread_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + Sint64 bytes_read, block_size, offset; + SysIOVec read_vec[1]; + ErlNifBinary result; + + if(argc != 2 || !enif_is_number(env, argv[0]) + || !enif_is_number(env, argv[1])) { + return enif_make_badarg(env); + } + + if(!enif_get_int64(env, argv[0], &offset) || + !enif_get_int64(env, argv[1], &block_size) || + (offset < 0 || block_size < 0)) { + return posix_error_to_tuple(env, EINVAL); + } + + if(!enif_alloc_binary(block_size, &result)) { + return posix_error_to_tuple(env, ENOMEM); + } + + read_vec[0].iov_base = result.data; + read_vec[0].iov_len = result.size; + + bytes_read = efile_preadv(d, offset, read_vec, 1); + + if(bytes_read < 0) { + enif_release_binary(&result); + return posix_error_to_tuple(env, d->posix_errno); + } else if(bytes_read == 0) { + enif_release_binary(&result); + return am_eof; + } + + if(bytes_read < block_size && !enif_realloc_binary(&result, bytes_read)) { + ERTS_INTERNAL_ERROR("Failed to shrink pread result."); + } + + return enif_make_tuple2(env, am_ok, enif_make_binary(env, &result)); +} + +static ERL_NIF_TERM pwrite_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + ErlNifIOVec vec, *input = &vec; + Sint64 bytes_written, offset; + ERL_NIF_TERM tail; + + if(argc != 2 || !enif_is_number(env, argv[0]) + || !enif_inspect_iovec(env, 64, argv[1], &tail, &input)) { + return enif_make_badarg(env); + } + + if(!enif_get_int64(env, argv[0], &offset) || offset < 0) { + return posix_error_to_tuple(env, EINVAL); + } + + bytes_written = efile_pwritev(d, offset, input->iov, input->iovcnt); + + if(bytes_written < 0) { + return posix_error_to_tuple(env, d->posix_errno); + } + + if(!enif_is_empty_list(env, tail)) { + ASSERT(bytes_written > 0); + return enif_make_tuple3(env, am_continue, + enif_make_int64(env, bytes_written), tail); + } + + return am_ok; +} + +static ERL_NIF_TERM seek_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + Sint64 new_position, offset; + enum efile_seek_t seek; + + if(argc != 2 || !enif_get_int64(env, argv[1], &offset)) { + return enif_make_badarg(env); + } + + if(enif_is_identical(argv[0], am_bof)) { + seek = EFILE_SEEK_BOF; + } else if(enif_is_identical(argv[0], am_cur)) { + seek = EFILE_SEEK_CUR; + } else if(enif_is_identical(argv[0], am_eof)) { + seek = EFILE_SEEK_EOF; + } else { + return enif_make_badarg(env); + } + + if(!efile_seek(d, seek, offset, &new_position)) { + return posix_error_to_tuple(env, d->posix_errno); + } + + return enif_make_tuple2(env, am_ok, enif_make_uint64(env, new_position)); +} + +static ERL_NIF_TERM sync_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + int data_only; + + if(argc != 1 || !enif_get_int(env, argv[0], &data_only)) { + return enif_make_badarg(env); + } + + if(!efile_sync(d, data_only)) { + return posix_error_to_tuple(env, d->posix_errno); + } + + return am_ok; +} + +static ERL_NIF_TERM truncate_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + if(argc != 0) { + return enif_make_badarg(env); + } + + if(!efile_truncate(d)) { + return posix_error_to_tuple(env, d->posix_errno); + } + + return am_ok; +} + +static ERL_NIF_TERM allocate_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + Sint64 offset, length; + + if(argc != 2 || !enif_is_number(env, argv[0]) + || !enif_is_number(env, argv[1])) { + return enif_make_badarg(env); + } + + if(!enif_get_int64(env, argv[0], &offset) || + !enif_get_int64(env, argv[1], &length) || + (offset < 0 || length < 0)) { + return posix_error_to_tuple(env, EINVAL); + } + + if(!efile_allocate(d, offset, length)) { + return posix_error_to_tuple(env, d->posix_errno); + } + + return am_ok; +} + +static ERL_NIF_TERM advise_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + enum efile_advise_t advise; + Sint64 offset, length; + + if(argc != 3 || !enif_is_number(env, argv[0]) + || !enif_is_number(env, argv[1])) { + return enif_make_badarg(env); + } + + if(!enif_get_int64(env, argv[0], &offset) || + !enif_get_int64(env, argv[1], &length) || + (offset < 0 || length < 0)) { + return posix_error_to_tuple(env, EINVAL); + } + + if(enif_is_identical(argv[2], am_normal)) { + advise = EFILE_ADVISE_NORMAL; + } else if(enif_is_identical(argv[2], am_random)) { + advise = EFILE_ADVISE_RANDOM; + } else if(enif_is_identical(argv[2], am_sequential)) { + advise = EFILE_ADVISE_SEQUENTIAL; + } else if(enif_is_identical(argv[2], am_will_need)) { + advise = EFILE_ADVISE_WILL_NEED; + } else if(enif_is_identical(argv[2], am_dont_need)) { + advise = EFILE_ADVISE_DONT_NEED; + } else if(enif_is_identical(argv[2], am_no_reuse)) { + advise = EFILE_ADVISE_NO_REUSE; + } else { + /* The tests check for EINVAL instead of badarg. Sigh. */ + return posix_error_to_tuple(env, EINVAL); + } + + if(!efile_advise(d, offset, length, advise)) { + return posix_error_to_tuple(env, d->posix_errno); + } + + return am_ok; +} + +/* This undocumented function reads a pointer and then reads the data block + * described by said pointer. It was reverse-engineered from the old + * implementation so while all tests pass it may not be entirely correct. Our + * current understanding is as follows: + * + * Pointer layout: + * + * <<Size:1/integer-unit:32, Offset:1/integer-unit:32>> + * + * Where Offset is the -absolute- address to the data block. + * + * *) If we fail to read the pointer block in its entirety, we return eof. + * *) If the provided max_payload_size is larger than Size, we return eof. + * *) If we fail to read any data whatsoever at Offset, we return + * {ok, {Size, Offset, eof}} + * *) Otherwise, we return {ok, {Size, Offset, Data}}. Note that the size + * of Data may be smaller than Size if we encounter EOF before we could + * read the entire block. + * + * On errors we'll return {error, posix()} regardless of whether they + * happened before or after reading the pointer block. */ +static ERL_NIF_TERM ipread_s32bu_p32bu_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + Sint64 payload_offset, payload_size; + + SysIOVec read_vec[1]; + Sint64 bytes_read; + + ErlNifBinary payload; + + if(argc != 2 || !enif_is_number(env, argv[0]) + || !enif_is_number(env, argv[1])) { + return enif_make_badarg(env); + } + + { + Sint64 max_payload_size, pointer_offset; + unsigned char pointer_block[8]; + + if(!enif_get_int64(env, argv[0], &pointer_offset) || + !enif_get_int64(env, argv[1], &max_payload_size) || + (pointer_offset < 0 || max_payload_size >= 1u << 31)) { + return posix_error_to_tuple(env, EINVAL); + } + + read_vec[0].iov_base = pointer_block; + read_vec[0].iov_len = sizeof(pointer_block); + + bytes_read = efile_preadv(d, pointer_offset, read_vec, 1); + + if(bytes_read < 0) { + return posix_error_to_tuple(env, d->posix_errno); + } else if(bytes_read < sizeof(pointer_block)) { + return am_eof; + } + + payload_size = (Uint32)get_int32(&pointer_block[0]); + payload_offset = (Uint32)get_int32(&pointer_block[4]); + + if(payload_size > max_payload_size) { + return am_eof; + } + } + + if(!enif_alloc_binary(payload_size, &payload)) { + return posix_error_to_tuple(env, ENOMEM); + } + + read_vec[0].iov_base = payload.data; + read_vec[0].iov_len = payload.size; + + bytes_read = efile_preadv(d, payload_offset, read_vec, 1); + + if(bytes_read < 0) { + enif_release_binary(&payload); + return posix_error_to_tuple(env, d->posix_errno); + } else if(bytes_read == 0) { + enif_release_binary(&payload); + + return enif_make_tuple2(env, am_ok, + enif_make_tuple3(env, + enif_make_uint(env, payload_size), + enif_make_uint(env, payload_offset), + am_eof)); + } + + if(bytes_read < payload.size && !enif_realloc_binary(&payload, bytes_read)) { + ERTS_INTERNAL_ERROR("Failed to shrink ipread payload."); + } + + return enif_make_tuple2(env, am_ok, + enif_make_tuple3(env, + enif_make_uint(env, payload_size), + enif_make_uint(env, payload_offset), + enif_make_binary(env, &payload))); +} + +static ERL_NIF_TERM get_handle_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + if(argc != 0) { + return enif_make_badarg(env); + } + + return efile_get_handle(env, d); +} + +static ERL_NIF_TERM read_info_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + efile_fileinfo_t info = {0}; + efile_path_t path; + int follow_links; + + if(argc != 2 || !enif_get_int(env, argv[1], &follow_links)) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_marshal_path(env, argv[0], &path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_read_info(&path, follow_links, &info))) { + return posix_error_to_tuple(env, posix_errno); + } + + /* #file_info as declared in file.hrl */ + return enif_make_tuple(env, 14, + am_file_info, + enif_make_uint64(env, info.size), + efile_filetype_to_atom(info.type), + efile_access_to_atom(info.access), + enif_make_int64(env, MAX(EFILE_MIN_FILETIME, info.a_time)), + enif_make_int64(env, MAX(EFILE_MIN_FILETIME, info.m_time)), + enif_make_int64(env, MAX(EFILE_MIN_FILETIME, info.c_time)), + enif_make_uint(env, info.mode), + enif_make_uint(env, info.links), + enif_make_uint(env, info.major_device), + enif_make_uint(env, info.minor_device), + enif_make_uint(env, info.inode), + enif_make_uint(env, info.uid), + enif_make_uint(env, info.gid) + ); +} + +static ERL_NIF_TERM set_permissions_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + efile_path_t path; + unsigned int permissions; + + if(argc != 2 || !enif_get_uint(env, argv[1], &permissions)) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_marshal_path(env, argv[0], &path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_set_permissions(&path, permissions))) { + return posix_error_to_tuple(env, posix_errno); + } + + return am_ok; +} + +static ERL_NIF_TERM set_owner_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + efile_path_t path; + int uid, gid; + + if(argc != 3 || !enif_get_int(env, argv[1], &uid) + || !enif_get_int(env, argv[2], &gid)) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_marshal_path(env, argv[0], &path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_set_owner(&path, uid, gid))) { + return posix_error_to_tuple(env, posix_errno); + } + + return am_ok; +} + +static ERL_NIF_TERM set_time_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + Sint64 accessed, modified, created; + efile_path_t path; + + if(argc != 4 || !enif_get_int64(env, argv[1], &accessed) + || !enif_get_int64(env, argv[2], &modified) + || !enif_get_int64(env, argv[3], &created)) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_marshal_path(env, argv[0], &path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_set_time(&path, accessed, modified, created))) { + return posix_error_to_tuple(env, posix_errno); + } + + return am_ok; +} + +static ERL_NIF_TERM read_link_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + efile_path_t path; + ERL_NIF_TERM result; + + if(argc != 1) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_marshal_path(env, argv[0], &path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_read_link(env, &path, &result))) { + return posix_error_to_tuple(env, posix_errno); + } + + return enif_make_tuple2(env, am_ok, result); +} + +static ERL_NIF_TERM list_dir_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + efile_path_t path; + ERL_NIF_TERM result; + + if(argc != 1) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_marshal_path(env, argv[0], &path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_list_dir(env, &path, &result))) { + return posix_error_to_tuple(env, posix_errno); + } + + return enif_make_tuple2(env, am_ok, result); +} + +static ERL_NIF_TERM rename_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + efile_path_t existing_path, new_path; + + if(argc != 2) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_marshal_path(env, argv[0], &existing_path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_marshal_path(env, argv[1], &new_path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_rename(&existing_path, &new_path))) { + return posix_error_to_tuple(env, posix_errno); + } + + return am_ok; +} + +static ERL_NIF_TERM make_hard_link_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + efile_path_t existing_path, new_path; + + if(argc != 2) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_marshal_path(env, argv[0], &existing_path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_marshal_path(env, argv[1], &new_path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_make_hard_link(&existing_path, &new_path))) { + return posix_error_to_tuple(env, posix_errno); + } + + return am_ok; +} + +static ERL_NIF_TERM make_soft_link_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + efile_path_t existing_path, new_path; + + if(argc != 2) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_marshal_path(env, argv[0], &existing_path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_marshal_path(env, argv[1], &new_path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_make_soft_link(&existing_path, &new_path))) { + return posix_error_to_tuple(env, posix_errno); + } + + return am_ok; +} + +static ERL_NIF_TERM make_dir_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + efile_path_t path; + + if(argc != 1) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_marshal_path(env, argv[0], &path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_make_dir(&path))) { + return posix_error_to_tuple(env, posix_errno); + } + + return am_ok; +} + +static ERL_NIF_TERM del_file_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + efile_path_t path; + + if(argc != 1) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_marshal_path(env, argv[0], &path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_del_file(&path))) { + return posix_error_to_tuple(env, posix_errno); + } + + return am_ok; +} + +static ERL_NIF_TERM del_dir_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + efile_path_t path; + + if(argc != 1) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_marshal_path(env, argv[0], &path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_del_dir(&path))) { + return posix_error_to_tuple(env, posix_errno); + } + + return am_ok; +} + +static ERL_NIF_TERM get_device_cwd_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + ERL_NIF_TERM result; + int device_index; + + if(argc != 1 || !enif_get_int(env, argv[0], &device_index)) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_get_device_cwd(env, device_index, &result))) { + return posix_error_to_tuple(env, posix_errno); + } + + return enif_make_tuple2(env, am_ok, result); +} + +static ERL_NIF_TERM get_cwd_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + ERL_NIF_TERM result; + + if(argc != 0) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_get_cwd(env, &result))) { + return posix_error_to_tuple(env, posix_errno); + } + + return enif_make_tuple2(env, am_ok, result); +} + +static ERL_NIF_TERM set_cwd_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + efile_path_t path; + + if(argc != 1) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_marshal_path(env, argv[0], &path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_set_cwd(&path))) { + return posix_error_to_tuple(env, posix_errno); + } + + return am_ok; +} + +/** @brief Reads an entire file into \c result, stopping after \c size bytes or + * EOF. It will read until EOF if size is 0. */ +static posix_errno_t read_file(efile_data_t *d, size_t size, ErlNifBinary *result) { + size_t initial_buffer_size; + ssize_t bytes_read; + + if(size == 0) { + initial_buffer_size = 16 << 10; + } else { + initial_buffer_size = size; + } + + if(!enif_alloc_binary(initial_buffer_size, result)) { + return ENOMEM; + } + + bytes_read = 0; + + for(;;) { + ssize_t block_bytes_read; + SysIOVec read_vec[1]; + + read_vec[0].iov_base = result->data + bytes_read; + read_vec[0].iov_len = result->size - bytes_read; + + block_bytes_read = efile_readv(d, read_vec, 1); + + if(block_bytes_read < 0) { + enif_release_binary(result); + return d->posix_errno; + } + + bytes_read += block_bytes_read; + + if(block_bytes_read < (result->size - bytes_read)) { + /* EOF */ + break; + } else if(bytes_read == size) { + break; + } + + if(!enif_realloc_binary(result, bytes_read * 2)) { + enif_release_binary(result); + return ENOMEM; + } + } + + /* The file may have shrunk since we queried its size, so we have to do + * this even when the size is known. */ + if(bytes_read < result->size && !enif_realloc_binary(result, bytes_read)) { + ERTS_INTERNAL_ERROR("Failed to shrink read_file result."); + } + + return 0; +} + +static ERL_NIF_TERM read_file_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno, ignored; + + efile_fileinfo_t info = {0}; + efile_path_t path; + efile_data_t *d; + + ErlNifBinary result; + + if(argc != 1) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_marshal_path(env, argv[0], &path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_read_info(&path, 1, &info))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_open(&path, EFILE_MODE_READ, efile_resource_type, &d))) { + return posix_error_to_tuple(env, posix_errno); + } + + posix_errno = read_file(d, info.size, &result); + + erts_atomic32_set_acqb(&d->state, EFILE_STATE_CLOSED); + efile_close(d, &ignored); + + if(posix_errno) { + return posix_error_to_tuple(env, posix_errno); + } + + return enif_make_tuple2(env, am_ok, enif_make_binary(env, &result)); +} + +static ERL_NIF_TERM altname_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + efile_path_t path; + ERL_NIF_TERM result; + + if(argc != 1) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_marshal_path(env, argv[0], &path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_altname(env, &path, &result))) { + return posix_error_to_tuple(env, posix_errno); + } + + return enif_make_tuple2(env, am_ok, result); +} |