transmission/libtransmission/file-posix.c

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/*
* This file Copyright (C) 2013-2014 Mnemosyne LLC
*
* It may be used under the GNU GPL versions 2 or 3
* or any future license endorsed by Mnemosyne LLC.
*
* $Id$
*/
#if defined (HAVE_MKDTEMP) && (!defined (_XOPEN_SOURCE) || _XOPEN_SOURCE < 700)
#undef _XOPEN_SOURCE
#define _XOPEN_SOURCE 700
#elif (defined (HAVE_POSIX_FADVISE) || defined (HAVE_POSIX_FALLOCATE)) && (!defined (_XOPEN_SOURCE) || _XOPEN_SOURCE < 600)
#undef _XOPEN_SOURCE
#define _XOPEN_SOURCE 600
#endif
#if (defined (HAVE_FALLOCATE64) || defined (HAVE_CANONICALIZE_FILE_NAME)) && !defined (_GNU_SOURCE)
#define _GNU_SOURCE
#endif
#if defined (__APPLE__) && !defined (_DARWIN_C_SOURCE)
#define _DARWIN_C_SOURCE
#endif
#include <assert.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h> /* O_LARGEFILE, posix_fadvise (), [posix_]fallocate () */
#include <libgen.h> /* basename (), dirname () */
#include <limits.h> /* PATH_MAX */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h> /* mmap (), munmap () */
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h> /* lseek (), write (), ftruncate (), pread (), pwrite (), pathconf (), etc */
#ifdef HAVE_XFS_XFS_H
#include <xfs/xfs.h>
#endif
#include "transmission.h"
#include "file.h"
#include "log.h"
#include "platform.h"
#include "utils.h"
#ifndef O_LARGEFILE
#define O_LARGEFILE 0
#endif
#ifndef O_BINARY
#define O_BINARY 0
#endif
#ifndef O_SEQUENTIAL
#define O_SEQUENTIAL 0
#endif
#ifndef O_CLOEXEC
#define O_CLOEXEC 0
#endif
#ifndef PATH_MAX
#define PATH_MAX 4096
#endif
/* don't use pread/pwrite on old versions of uClibc because they're buggy.
* https://trac.transmissionbt.com/ticket/3826 */
#ifdef __UCLIBC__
#define TR_UCLIBC_CHECK_VERSION(major,minor,micro) \
(__UCLIBC_MAJOR__ > (major) || \
(__UCLIBC_MAJOR__ == (major) && __UCLIBC_MINOR__ > (minor)) || \
(__UCLIBC_MAJOR__ == (major) && __UCLIBC_MINOR__ == (minor) && \
__UCLIBC_SUBLEVEL__ >= (micro)))
#if !TR_UCLIBC_CHECK_VERSION (0,9,28)
#undef HAVE_PREAD
#undef HAVE_PWRITE
#endif
#endif
#ifdef __APPLE__
#ifndef HAVE_PREAD
#define HAVE_PREAD
#endif
#ifndef HAVE_PWRITE
#define HAVE_PWRITE
#endif
#ifndef HAVE_MKDTEMP
#define HAVE_MKDTEMP
#endif
#endif
static void
set_system_error (tr_error ** error,
int code)
{
if (error == NULL)
return;
tr_error_set_literal (error, code, tr_strerror (code));
}
static void
set_system_error_if_file_found (tr_error ** error,
int code)
{
if (code != ENOENT)
set_system_error (error, code);
}
static void
stat_to_sys_path_info (const struct stat * sb,
tr_sys_path_info * info)
{
if (S_ISREG (sb->st_mode))
info->type = TR_SYS_PATH_IS_FILE;
else if (S_ISDIR (sb->st_mode))
info->type = TR_SYS_PATH_IS_DIRECTORY;
else
info->type = TR_SYS_PATH_IS_OTHER;
info->size = (uint64_t) sb->st_size;
info->last_modified_at = sb->st_mtime;
}
static void
set_file_for_single_pass (tr_sys_file_t handle)
{
/* Set hints about the lookahead buffer and caching. It's okay
for these to fail silently, so don't let them affect errno */
const int err = errno;
if (handle == TR_BAD_SYS_FILE)
return;
#ifdef HAVE_POSIX_FADVISE
posix_fadvise (handle, 0, 0, POSIX_FADV_SEQUENTIAL);
#endif
#ifdef __APPLE__
fcntl (handle, F_RDAHEAD, 1);
fcntl (handle, F_NOCACHE, 1);
#endif
errno = err;
}
#ifndef HAVE_MKDIRP
static bool
create_path (const char * path_in,
int permissions,
tr_error ** error)
{
char * p;
char * pp;
bool done;
int tmperr;
int rv;
struct stat sb;
char * path;
/* make a temporary copy of path */
path = tr_strdup (path_in);
/* walk past the root */
p = path;
while (*p == TR_PATH_DELIMITER)
++p;
pp = p;
done = false;
while ((p = strchr (pp, TR_PATH_DELIMITER)) || (p = strchr (pp, '\0')))
{
if (!*p)
done = true;
else
*p = '\0';
tmperr = errno;
rv = stat (path, &sb);
errno = tmperr;
if (rv)
{
tr_error * my_error = NULL;
/* Folder doesn't exist yet */
if (!tr_sys_dir_create (path, 0, permissions, &my_error))
{
tr_logAddError (_ ("Couldn't create \"%1$s\": %2$s"), path, my_error->message);
tr_free (path);
tr_error_propagate (error, &my_error);
return false;
}
}
else if ((sb.st_mode & S_IFMT) != S_IFDIR)
{
/* Node exists but isn't a folder */
char * const buf = tr_strdup_printf (_ ("File \"%s\" is in the way"), path);
tr_logAddError (_ ("Couldn't create \"%1$s\": %2$s"), path_in, buf);
tr_free (buf);
tr_free (path);
set_system_error (error, ENOTDIR);
return false;
}
if (done)
break;
*p = TR_PATH_DELIMITER;
p++;
pp = p;
}
tr_free (path);
return true;
}
#endif
bool
tr_sys_path_exists (const char * path,
tr_error ** error)
{
bool ret;
assert (path != NULL);
ret = access (path, F_OK) != -1;
if (!ret)
set_system_error_if_file_found (error, errno);
return ret;
}
bool
tr_sys_path_get_info (const char * path,
int flags,
tr_sys_path_info * info,
tr_error ** error)
{
bool ret;
struct stat sb;
assert (path != NULL);
assert (info != NULL);
if ((flags & TR_SYS_PATH_NO_FOLLOW) == 0)
ret = stat (path, &sb) != -1;
else
ret = lstat (path, &sb) != -1;
if (ret)
stat_to_sys_path_info (&sb, info);
else
set_system_error (error, errno);
return ret;
}
bool
tr_sys_path_is_same (const char * path1,
const char * path2,
tr_error ** error)
{
bool ret = false;
struct stat sb1, sb2;
assert (path1 != NULL);
assert (path2 != NULL);
if (stat (path1, &sb1) != -1 && stat (path2, &sb2) != -1)
ret = sb1.st_dev == sb2.st_dev && sb1.st_ino == sb2.st_ino;
else
set_system_error_if_file_found (error, errno);
return ret;
}
char *
tr_sys_path_resolve (const char * path,
tr_error ** error)
{
char * ret = NULL;
char * tmp = NULL;
assert (path != NULL);
#if defined (HAVE_CANONICALIZE_FILE_NAME)
ret = canonicalize_file_name (path);
#endif
#if defined (_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 200809L
/* Better safe than sorry: realpath () officially supports NULL as destination
starting off POSIX.1-2008. */
if (ret == NULL)
ret = realpath (path, NULL);
#endif
if (ret == NULL)
{
tmp = tr_new (char, PATH_MAX);
ret = realpath (path, tmp);
if (ret != NULL)
ret = tr_strdup (ret);
}
if (ret == NULL)
set_system_error (error, errno);
tr_free (tmp);
return ret;
}
char *
tr_sys_path_basename (const char * path,
tr_error ** error)
{
char * ret = NULL;
char * tmp;
assert (path != NULL);
tmp = tr_strdup (path);
ret = basename (tmp);
if (ret != NULL)
ret = tr_strdup (ret);
else
set_system_error (error, errno);
tr_free (tmp);
return ret;
}
char *
tr_sys_path_dirname (const char * path,
tr_error ** error)
{
char * ret = NULL;
char * tmp;
assert (path != NULL);
tmp = tr_strdup (path);
ret = dirname (tmp);
if (ret != NULL)
ret = tr_strdup (ret);
else
set_system_error (error, errno);
tr_free (tmp);
return ret;
}
bool
tr_sys_path_rename (const char * src_path,
const char * dst_path,
tr_error ** error)
{
bool ret;
assert (src_path != NULL);
assert (dst_path != NULL);
ret = rename (src_path, dst_path) != -1;
if (!ret)
set_system_error (error, errno);
return ret;
}
bool
tr_sys_path_remove (const char * path,
tr_error ** error)
{
bool ret;
assert (path != NULL);
ret = remove (path) != -1;
if (!ret)
set_system_error (error, errno);
return ret;
}
tr_sys_file_t
tr_sys_file_get_std (tr_std_sys_file_t std_file,
tr_error ** error)
{
tr_sys_file_t ret = TR_BAD_SYS_FILE;
switch (std_file)
{
case TR_STD_SYS_FILE_IN:
ret = STDIN_FILENO;
break;
case TR_STD_SYS_FILE_OUT:
ret = STDOUT_FILENO;
break;
case TR_STD_SYS_FILE_ERR:
ret = STDERR_FILENO;
break;
default:
assert (0 && "Unknown standard file");
set_system_error (error, EINVAL);
}
return ret;
}
tr_sys_file_t
tr_sys_file_open (const char * path,
int flags,
int permissions,
tr_error ** error)
{
tr_sys_file_t ret;
int native_flags = 0;
assert (path != NULL);
assert ((flags & (TR_SYS_FILE_READ | TR_SYS_FILE_WRITE)) != 0);
if ((flags & (TR_SYS_FILE_READ | TR_SYS_FILE_WRITE)) == (TR_SYS_FILE_READ | TR_SYS_FILE_WRITE))
native_flags |= O_RDWR;
else if (flags & TR_SYS_FILE_READ)
native_flags |= O_RDONLY;
else if (flags & TR_SYS_FILE_WRITE)
native_flags |= O_WRONLY;
native_flags |=
(flags & TR_SYS_FILE_CREATE ? O_CREAT : 0) |
(flags & TR_SYS_FILE_CREATE_NEW ? O_CREAT | O_EXCL : 0) |
(flags & TR_SYS_FILE_APPEND ? O_APPEND : 0) |
(flags & TR_SYS_FILE_TRUNCATE ? O_TRUNC : 0) |
(flags & TR_SYS_FILE_SEQUENTIAL ? O_SEQUENTIAL : 0) |
O_BINARY | O_LARGEFILE | O_CLOEXEC;
ret = open (path, native_flags, permissions);
if (ret != TR_BAD_SYS_FILE)
{
if (flags & TR_SYS_FILE_SEQUENTIAL)
set_file_for_single_pass (ret);
}
else
{
set_system_error (error, errno);
}
return ret;
}
tr_sys_file_t
tr_sys_file_open_temp (char * path_template,
tr_error ** error)
{
tr_sys_file_t ret;
assert (path_template != NULL);
ret = mkstemp (path_template);
if (ret == TR_BAD_SYS_FILE)
set_system_error (error, errno);
set_file_for_single_pass (ret);
return ret;
}
bool
tr_sys_file_close (tr_sys_file_t handle,
tr_error ** error)
{
bool ret;
assert (handle != TR_BAD_SYS_FILE);
ret = close (handle) != -1;
if (!ret)
set_system_error (error, errno);
return ret;
}
bool
tr_sys_file_get_info (tr_sys_file_t handle,
tr_sys_path_info * info,
tr_error ** error)
{
bool ret;
struct stat sb;
assert (handle != TR_BAD_SYS_FILE);
assert (info != NULL);
ret = fstat (handle, &sb) != -1;
if (ret)
stat_to_sys_path_info (&sb, info);
else
set_system_error (error, errno);
return ret;
}
bool
tr_sys_file_seek (tr_sys_file_t handle,
int64_t offset,
tr_seek_origin_t origin,
uint64_t * new_offset,
tr_error ** error)
{
bool ret = false;
off_t my_new_offset;
TR_STATIC_ASSERT (TR_SEEK_SET == SEEK_SET, "values should match");
TR_STATIC_ASSERT (TR_SEEK_CUR == SEEK_CUR, "values should match");
TR_STATIC_ASSERT (TR_SEEK_END == SEEK_END, "values should match");
TR_STATIC_ASSERT (sizeof (*new_offset) >= sizeof (my_new_offset), "");
assert (handle != TR_BAD_SYS_FILE);
assert (origin == TR_SEEK_SET || origin == TR_SEEK_CUR || origin == TR_SEEK_END);
my_new_offset = lseek (handle, offset, origin);
if (my_new_offset != -1)
{
if (new_offset != NULL)
*new_offset = my_new_offset;
ret = true;
}
else
{
set_system_error (error, errno);
}
return ret;
}
bool
tr_sys_file_read (tr_sys_file_t handle,
void * buffer,
uint64_t size,
uint64_t * bytes_read,
tr_error ** error)
{
bool ret = false;
ssize_t my_bytes_read;
TR_STATIC_ASSERT (sizeof (*bytes_read) >= sizeof (my_bytes_read), "");
assert (handle != TR_BAD_SYS_FILE);
assert (buffer != NULL || size == 0);
my_bytes_read = read (handle, buffer, size);
if (my_bytes_read != -1)
{
if (bytes_read != NULL)
*bytes_read = my_bytes_read;
ret = true;
}
else
{
set_system_error (error, errno);
}
return ret;
}
bool
tr_sys_file_read_at (tr_sys_file_t handle,
void * buffer,
uint64_t size,
uint64_t offset,
uint64_t * bytes_read,
tr_error ** error)
{
bool ret = false;
ssize_t my_bytes_read;
TR_STATIC_ASSERT (sizeof (*bytes_read) >= sizeof (my_bytes_read), "");
assert (handle != TR_BAD_SYS_FILE);
assert (buffer != NULL || size == 0);
/* seek requires signed offset, so it should be in mod range */
assert (offset < UINT64_MAX / 2);
#ifdef HAVE_PREAD
my_bytes_read = pread (handle, buffer, size, offset);
#else
if (lseek (handle, offset, SEEK_SET) != -1)
my_bytes_read = read (handle, buffer, size);
else
my_bytes_read = -1;
#endif
if (my_bytes_read != -1)
{
if (bytes_read != NULL)
*bytes_read = my_bytes_read;
ret = true;
}
else
{
set_system_error (error, errno);
}
return ret;
}
bool
tr_sys_file_write (tr_sys_file_t handle,
const void * buffer,
uint64_t size,
uint64_t * bytes_written,
tr_error ** error)
{
bool ret = false;
ssize_t my_bytes_written;
TR_STATIC_ASSERT (sizeof (*bytes_written) >= sizeof (my_bytes_written), "");
assert (handle != TR_BAD_SYS_FILE);
assert (buffer != NULL || size == 0);
my_bytes_written = write (handle, buffer, size);
if (my_bytes_written != -1)
{
if (bytes_written != NULL)
*bytes_written = my_bytes_written;
ret = true;
}
else
{
set_system_error (error, errno);
}
return ret;
}
bool
tr_sys_file_write_at (tr_sys_file_t handle,
const void * buffer,
uint64_t size,
uint64_t offset,
uint64_t * bytes_written,
tr_error ** error)
{
bool ret = false;
ssize_t my_bytes_written;
TR_STATIC_ASSERT (sizeof (*bytes_written) >= sizeof (my_bytes_written), "");
assert (handle != TR_BAD_SYS_FILE);
assert (buffer != NULL || size == 0);
/* seek requires signed offset, so it should be in mod range */
assert (offset < UINT64_MAX / 2);
#ifdef HAVE_PWRITE
my_bytes_written = pwrite (handle, buffer, size, offset);
#else
if (lseek (handle, offset, SEEK_SET) != -1)
my_bytes_written = write (handle, buffer, size);
else
my_bytes_written = -1;
#endif
if (my_bytes_written != -1)
{
if (bytes_written != NULL)
*bytes_written = my_bytes_written;
ret = true;
}
else
{
set_system_error (error, errno);
}
return ret;
}
bool
tr_sys_file_flush (tr_sys_file_t handle,
tr_error ** error)
{
bool ret;
assert (handle != TR_BAD_SYS_FILE);
ret = fsync (handle) != -1;
if (!ret)
set_system_error (error, errno);
return ret;
}
bool
tr_sys_file_truncate (tr_sys_file_t handle,
uint64_t size,
tr_error ** error)
{
bool ret;
assert (handle != TR_BAD_SYS_FILE);
ret = ftruncate (handle, size) != -1;
if (!ret)
set_system_error (error, errno);
return ret;
}
bool
tr_sys_file_prefetch (tr_sys_file_t handle,
uint64_t offset,
uint64_t size,
tr_error ** error)
{
bool ret = false;
#if defined (HAVE_POSIX_FADVISE)
int code;
assert (handle != TR_BAD_SYS_FILE);
assert (size > 0);
code = posix_fadvise (handle, offset, size, POSIX_FADV_WILLNEED);
if (code == 0)
ret = true;
else
set_system_error (error, code);
#elif defined (__APPLE__)
struct radvisory radv;
assert (handle != TR_BAD_SYS_FILE);
assert (size > 0);
radv.ra_offset = offset;
radv.ra_count = size;
ret = fcntl (handle, F_RDADVISE, &radv) != -1;
if (!ret)
set_system_error (error, errno);
#endif
return ret;
}
bool
tr_sys_file_preallocate (tr_sys_file_t handle,
uint64_t size,
int flags,
tr_error ** error)
{
bool ret = false;
assert (handle != TR_BAD_SYS_FILE);
errno = 0;
#ifdef HAVE_FALLOCATE64
/* fallocate64 is always preferred, so try it first */
ret = fallocate64 (handle, 0, 0, size) != -1;
if (ret || errno == ENOSPC)
goto out;
#endif
if ((flags & TR_SYS_FILE_PREALLOC_SPARSE) == 0)
{
int code = errno;
#ifdef HAVE_XFS_XFS_H
if (platform_test_xfs_fd (handle))
{
xfs_flock64_t fl;
fl.l_whence = 0;
fl.l_start = 0;
fl.l_len = size;
ret = xfsctl (NULL, handle, XFS_IOC_RESVSP64, &fl) != -1;
if (ret)
ret = ftruncate (handle, size) != -1;
code = errno;
if (ret || code == ENOSPC)
goto non_sparse_out;
}
#endif
#ifdef __APPLE__
{
fstore_t fst;
fst.fst_flags = F_ALLOCATEALL;
fst.fst_posmode = F_PEOFPOSMODE;
fst.fst_offset = 0;
fst.fst_length = size;
fst.fst_bytesalloc = 0;
ret = fcntl (handle, F_PREALLOCATE, &fst) != -1;
if (ret)
ret = ftruncate (handle, size) != -1;
code = errno;
if (ret || code == ENOSPC)
goto non_sparse_out;
}
#endif
#ifdef HAVE_POSIX_FALLOCATE
code = posix_fallocate (handle, 0, size);
ret = code == 0;
#endif
non_sparse_out:
errno = code;
}
out:
if (!ret)
set_system_error (error, errno);
return ret;
}
void *
tr_sys_file_map_for_reading (tr_sys_file_t handle,
uint64_t offset,
uint64_t size,
tr_error ** error)
{
void * ret;
assert (handle != TR_BAD_SYS_FILE);
assert (size > 0);
ret = mmap (NULL, size, PROT_READ, MAP_SHARED, handle, offset);
if (ret == MAP_FAILED)
{
set_system_error (error, errno);
ret = NULL;
}
return ret;
}
bool
tr_sys_file_unmap (const void * address,
uint64_t size,
tr_error ** error)
{
bool ret;
assert (address != NULL);
assert (size > 0);
ret = munmap ((void *) address, size) != -1;
if (!ret)
set_system_error (error, errno);
return ret;
}
char *
tr_sys_dir_get_current (tr_error ** error)
{
char * ret;
ret = getcwd (NULL, 0);
if (ret == NULL && (errno == EINVAL || errno == ERANGE))
{
size_t size = PATH_MAX;
char * tmp = NULL;
do
{
tmp = tr_renew (char, tmp, size);
if (tmp == NULL)
break;
ret = getcwd (tmp, size);
size += 2048;
}
while (ret == NULL && errno == ERANGE);
if (ret == NULL)
{
const int err = errno;
tr_free (tmp);
errno = err;
}
}
if (ret == NULL)
set_system_error (error, errno);
return ret;
}
bool
tr_sys_dir_create (const char * path,
int flags,
int permissions,
tr_error ** error)
{
bool ret;
tr_error * my_error = NULL;
assert (path != NULL);
if ((flags & TR_SYS_DIR_CREATE_PARENTS) != 0)
#ifdef HAVE_MKDIRP
ret = mkdirp (path, permissions) != -1;
#else
ret = create_path (path, permissions, &my_error);
#endif
else
ret = mkdir (path, permissions) != -1;
if (!ret && errno == EEXIST)
{
struct stat sb;
if (stat (path, &sb) != -1 && S_ISDIR (sb.st_mode))
{
tr_error_clear (&my_error);
ret = true;
}
else
{
errno = EEXIST;
}
}
if (!ret)
{
if (my_error != NULL)
tr_error_propagate (error, &my_error);
else
set_system_error (error, errno);
}
return ret;
}
bool
tr_sys_dir_create_temp (char * path_template,
tr_error ** error)
{
bool ret;
assert (path_template != NULL);
#ifdef HAVE_MKDTEMP
ret = mkdtemp (path_template) != NULL;
#else
ret = mktemp (path_template) != NULL && mkdir (path_template, 0700) != -1;
#endif
if (!ret)
set_system_error (error, errno);
return ret;
}
tr_sys_dir_t
tr_sys_dir_open (const char * path,
tr_error ** error)
{
tr_sys_dir_t ret;
#ifndef __clang__
/* Clang gives "static_assert expression is not an integral constant expression" error */
TR_STATIC_ASSERT (TR_BAD_SYS_DIR == NULL, "values should match");
#endif
assert (path != NULL);
ret = opendir (path);
if (ret == TR_BAD_SYS_DIR)
set_system_error (error, errno);
return ret;
}
const char *
tr_sys_dir_read_name (tr_sys_dir_t handle,
tr_error ** error)
{
const char * ret = NULL;
struct dirent * entry;
assert (handle != TR_BAD_SYS_DIR);
errno = 0;
entry = readdir (handle);
if (entry != NULL)
ret = entry->d_name;
else if (errno != 0)
set_system_error (error, errno);
return ret;
}
bool
tr_sys_dir_close (tr_sys_dir_t handle,
tr_error ** error)
{
bool ret;
assert (handle != TR_BAD_SYS_DIR);
ret = closedir (handle) != -1;
if (!ret)
set_system_error (error, errno);
return ret;
}