file: copy_file_range

Author: RomaniukVadim

erts/emulator/nifs/common/prim_file_nif.c

@@ -102,6 +102,9 @@ static ERL_NIF_TERM read_file_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM a
 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[]);
 
+static ERL_NIF_TERM copy_file_available_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM copy_file_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
+
 static ERL_NIF_TERM file_desc_to_ref_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
 
 /* Internal ops */
@@ -185,6 +188,8 @@ static ErlNifFunc nif_funcs[] = {
     {"allocate_nif", 3, allocate_nif, ERL_NIF_DIRTY_JOB_IO_BOUND},
     {"advise_nif", 4, advise_nif, ERL_NIF_DIRTY_JOB_IO_BOUND},
     {"read_handle_info_nif", 1, read_handle_info_nif, ERL_NIF_DIRTY_JOB_IO_BOUND},
+    {"copy_file_available_nif", 0, copy_file_available_nif, ERL_NIF_DIRTY_JOB_IO_BOUND},
+    {"copy_file_nif", 3, copy_file_nif, ERL_NIF_DIRTY_JOB_IO_BOUND},
 
     /* Filesystem ops */
     {"make_hard_link_nif", 2, make_hard_link_nif, ERL_NIF_DIRTY_JOB_IO_BOUND},
@@ -1399,3 +1404,76 @@ static ERL_NIF_TERM altname_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM arg
 
     return enif_make_tuple2(env, am_ok, result);
 }
+
+static ERL_NIF_TERM copy_file_available_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]) {
+    off64_t ret;
+
+    ret = syscall(SYS_copy_file_range, -1, NULL, -1, NULL, 0, 0);
+
+    if (ret == -1 && errno == ENOSYS) {
+        return enif_make_atom(env, "false");
+    } else {
+        return enif_make_atom(env, "true");
+    }
+}
+
+static ERL_NIF_TERM copy_file_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]) {
+    posix_errno_t posix_errno, ignored;
+    efile_data_t *d_in, *d_out;
+    off64_t ret = 0, len;
+    efile_fileinfo_t info = {0};
+    efile_path_t file_path_in, file_path_out;
+    char atom_name[256];
+
+    ASSERT(argc == 2);
+
+    if ((posix_errno = efile_marshal_path(env, argv[0], &file_path_in))) {
+        return posix_error_to_tuple(env, posix_errno);
+    }
+
+    if ((posix_errno = efile_marshal_path(env, argv[1], &file_path_out))) {
+        return posix_error_to_tuple(env, posix_errno);
+    }
+
+    /* We need to open Source file in order to get file size*/
+    if (posix_errno = efile_open(&file_path_in, EFILE_MODE_READ, efile_resource_type, &d_in)) {
+        return posix_error_to_tuple(env, posix_errno);
+    }
+
+    if ((posix_errno = efile_read_handle_info(d_in, &info))) {
+        /* In error case we should close Source file */
+        erts_atomic32_set_acqb(&d_in->state, EFILE_STATE_CLOSED);
+        efile_close(d_in, &ignored);
+        return posix_error_to_tuple(env, posix_errno);
+    }
+
+    len = (off64_t)info.size;
+
+    if (len < 0) {
+       return enif_make_badarg(env);
+    }
+
+    if ((posix_errno = efile_open(&file_path_out, EFILE_MODE_WRITE, efile_resource_type, &d_out))) {
+        erts_atomic32_set_acqb(&d_in->state, EFILE_STATE_CLOSED);
+        efile_close(d_in, &ignored);
+        return posix_error_to_tuple(env, posix_errno);
+    }
+
+    /* Copy file contents using SYS_copy_file_range syscall */
+    if ((posix_errno = efile_copy_file_range(d_in, d_out, len, &ret))) {
+        erts_atomic32_set_acqb(&d_in->state, EFILE_STATE_CLOSED);
+        efile_close(d_in, &ignored);
+        erts_atomic32_set_acqb(&d_out->state, EFILE_STATE_CLOSED);
+        efile_close(d_out, &ignored);
+        return posix_error_to_tuple(env, posix_errno);
+    }
+    
+    /* Close file descriptors
+     * Closing without moving the file into CLOSED state will crash the debug emulator.*/
+    erts_atomic32_set_acqb(&d_in->state, EFILE_STATE_CLOSED);
+    efile_close(d_in, &ignored);
+    erts_atomic32_set_acqb(&d_out->state, EFILE_STATE_CLOSED);
+    efile_close(d_out, &ignored);
+
+    return enif_make_tuple2(env, enif_make_atom(env, "ok"), enif_make_uint(env, (unsigned int)ret));
+}

erts/emulator/nifs/common/prim_file_nif.h

@@ -177,6 +177,8 @@ posix_errno_t efile_from_fd(int fd,
                             ErlNifResourceType *nif_type,
                             efile_data_t **d);
 
+posix_errno_t efile_copy_file_range(efile_data_t *d_in, efile_data_t *d_out, off64_t length, off64_t *result);
+
 /** @brief Closes a file. The file must have entered the CLOSED state prior to
  * calling this to prevent double close.
  *

erts/emulator/nifs/unix/unix_prim_file.c

@@ -1085,3 +1085,26 @@ posix_errno_t efile_altname(ErlNifEnv *env, const efile_path_t *path, ERL_NIF_TE
 
     return ENOTSUP;
 }
+
+
+posix_errno_t efile_copy_file_range(efile_data_t *d_in, efile_data_t *d_out, off64_t length, off64_t *result) {
+    efile_unix_t *u_in = (efile_unix_t*)d_in;
+    efile_unix_t *u_out = (efile_unix_t*)d_out;
+    off64_t ret;
+
+    ASSERT(u_in->fd != -1);
+    ASSERT(u_out->fd != -1);
+
+    /* Perform the unix copy file range syscall */ 
+    ret = syscall(SYS_copy_file_range, u_in->fd, NULL, u_out->fd, NULL, length, 0);
+
+    if (ret < 0) {
+        return errno;
+    }
+
+    if (result != NULL) {
+        (*result) = ret;
+    }
+
+    return 0;
+}

erts/preloaded/ebin/prim_file.beam

@@ -24,7 +24,8 @@
 -export([open/2, close/1,
          sync/1, datasync/1, truncate/1, advise/4, allocate/3,
          read_line/1, read/2, write/2, position/2,
-         pread/2, pread/3, pwrite/2, pwrite/3]).
+         pread/2, pread/3, pwrite/2, pwrite/3,
+         copy_file_available/0, copy_file/2]).
 
 %% OTP internal.
 
@@ -73,7 +74,8 @@
        del_dir_nif/1, get_device_cwd_nif/1, set_cwd_nif/1, get_cwd_nif/0,
        ipread_s32bu_p32bu_nif/3, read_file_nif/1,
        get_handle_nif/1, delayed_close_nif/1, altname_nif/1,
-       file_desc_to_ref_nif/1]).
+       file_desc_to_ref_nif/1, copy_file_available_nif/0,
+       copy_file_nif/2]).
 
 -type prim_file_name() :: string() | unicode:unicode_binary().
 -type prim_file_name_error() :: 'error' | 'ignore' | 'warning'.
@@ -126,6 +128,13 @@ copy(#file_descriptor{module = ?MODULE} = Source,
     %% XXX Should be moved down to the driver for optimization.
     file:copy_opened(Source, Dest, Length).
 
+%% Returns {error, Reason} | {ok, BytesCopied}
+%% Using unix syscall copy_file_range(2)
+copy_file(Source, Destination) ->
+    copy_file_nif(encode_path(Source), encode_path(Destination)).
+copy_file_available() ->
+    copy_file_available_nif().
+
 open(Name, Modes) ->
     %% The try/catch pattern seen here is used throughout the file to adhere to
     %% the public file interface, which has leaked through for ages because of
@@ -529,6 +538,10 @@ delayed_close_nif(_FileRef) ->
     erlang:nif_error(undef).
 read_handle_info_nif(_FileRef) ->
     erlang:nif_error(undef).
+copy_file_available_nif() ->
+     erlang:nif_error(undef).
+copy_file_nif(_Name,_Dest) ->
+     erlang:nif_error(undef).
 
 %%
 %% Quality-of-life helpers

erts/preloaded/src/prim_file.erl

@@ -151,7 +151,7 @@ MODULES = \
 	raw_file_io_deflate \
 	raw_file_io_delayed \
 	raw_file_io_list \
-	wrap_log_reader
+	wrap_log_reader 
 
 HRL_FILES= ../include/file.hrl ../include/inet.hrl ../include/inet_sctp.hrl \
 	../include/dist.hrl ../include/dist_util.hrl \