mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-04 10:50:07 +00:00
905ae44c77
This generic implementation already expects a getdents API which is Linux specific. It also allows simplify it by assuming _DIRENT_HAVE_D_RECLEN and _DIRENT_HAVE_D_OFF support. The readdir are also expanded on each required implementation, futher fixes and improvements will make parametrize the implementation more complex. Checked on x86_64-linux-gnu, i686-linux-gnu, and with a build for all affected ABIs.
171 lines
4.3 KiB
C
171 lines
4.3 KiB
C
/* Read a directory. Linux LFS version.
|
|
Copyright (C) 1997-2020 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, see
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
/* When _DIRENT_MATCHES_DIRENT64 is defined we can alias 'readdir64' to
|
|
'readdir'. However the function signatures are not equal due
|
|
different return types, so we need to suppress {__}readdir so weak
|
|
and strong alias do not throw conflicting types errors. */
|
|
#define readdir __no_readdir_decl
|
|
#define __readdir __no___readdir_decl
|
|
#include <dirent.h>
|
|
#undef __readdir
|
|
#undef readdir
|
|
|
|
/* Read a directory entry from DIRP. */
|
|
struct dirent64 *
|
|
__readdir64 (DIR *dirp)
|
|
{
|
|
struct dirent64 *dp;
|
|
int saved_errno = errno;
|
|
|
|
#if IS_IN (libc)
|
|
__libc_lock_lock (dirp->lock);
|
|
#endif
|
|
|
|
do
|
|
{
|
|
size_t reclen;
|
|
|
|
if (dirp->offset >= dirp->size)
|
|
{
|
|
/* We've emptied out our buffer. Refill it. */
|
|
|
|
size_t maxread = dirp->allocation;
|
|
ssize_t bytes;
|
|
|
|
bytes = __getdents64 (dirp->fd, dirp->data, maxread);
|
|
if (bytes <= 0)
|
|
{
|
|
/* On some systems getdents fails with ENOENT when the
|
|
open directory has been rmdir'd already. POSIX.1
|
|
requires that we treat this condition like normal EOF. */
|
|
if (bytes < 0 && errno == ENOENT)
|
|
bytes = 0;
|
|
|
|
/* Don't modifiy errno when reaching EOF. */
|
|
if (bytes == 0)
|
|
__set_errno (saved_errno);
|
|
dp = NULL;
|
|
break;
|
|
}
|
|
dirp->size = (size_t) bytes;
|
|
|
|
/* Reset the offset into the buffer. */
|
|
dirp->offset = 0;
|
|
}
|
|
|
|
dp = (struct dirent64 *) &dirp->data[dirp->offset];
|
|
|
|
reclen = dp->d_reclen;
|
|
|
|
dirp->offset += reclen;
|
|
|
|
dirp->filepos = dp->d_off;
|
|
|
|
/* Skip deleted files. */
|
|
} while (dp->d_ino == 0);
|
|
|
|
#if IS_IN (libc)
|
|
__libc_lock_unlock (dirp->lock);
|
|
#endif
|
|
|
|
return dp;
|
|
}
|
|
libc_hidden_def (__readdir64)
|
|
|
|
#if _DIRENT_MATCHES_DIRENT64
|
|
strong_alias (__readdir64, __readdir)
|
|
weak_alias (__readdir64, readdir64)
|
|
weak_alias (__readdir64, readdir)
|
|
#else
|
|
/* The compat code expects the 'struct direct' with d_ino being a __ino_t
|
|
instead of __ino64_t. */
|
|
# include <shlib-compat.h>
|
|
# if IS_IN(rtld)
|
|
weak_alias (__readdir64, readdir64)
|
|
# else
|
|
versioned_symbol (libc, __readdir64, readdir64, GLIBC_2_2);
|
|
# endif
|
|
# if SHLIB_COMPAT(libc, GLIBC_2_1, GLIBC_2_2)
|
|
# include <olddirent.h>
|
|
|
|
attribute_compat_text_section
|
|
struct __old_dirent64 *
|
|
__old_readdir64 (DIR *dirp)
|
|
{
|
|
struct __old_dirent64 *dp;
|
|
int saved_errno = errno;
|
|
|
|
#if IS_IN (libc)
|
|
__libc_lock_lock (dirp->lock);
|
|
#endif
|
|
|
|
do
|
|
{
|
|
size_t reclen;
|
|
|
|
if (dirp->offset >= dirp->size)
|
|
{
|
|
/* We've emptied out our buffer. Refill it. */
|
|
|
|
size_t maxread = dirp->allocation;
|
|
ssize_t bytes;
|
|
|
|
bytes = __old_getdents64 (dirp->fd, dirp->data, maxread);
|
|
if (bytes <= 0)
|
|
{
|
|
/* On some systems getdents fails with ENOENT when the
|
|
open directory has been rmdir'd already. POSIX.1
|
|
requires that we treat this condition like normal EOF. */
|
|
if (bytes < 0 && errno == ENOENT)
|
|
bytes = 0;
|
|
|
|
/* Don't modifiy errno when reaching EOF. */
|
|
if (bytes == 0)
|
|
__set_errno (saved_errno);
|
|
dp = NULL;
|
|
break;
|
|
}
|
|
dirp->size = (size_t) bytes;
|
|
|
|
/* Reset the offset into the buffer. */
|
|
dirp->offset = 0;
|
|
}
|
|
|
|
dp = (struct __old_dirent64 *) &dirp->data[dirp->offset];
|
|
|
|
reclen = dp->d_reclen;
|
|
|
|
dirp->offset += reclen;
|
|
|
|
dirp->filepos = dp->d_off;
|
|
|
|
/* Skip deleted files. */
|
|
} while (dp->d_ino == 0);
|
|
|
|
#if IS_IN (libc)
|
|
__libc_lock_unlock (dirp->lock);
|
|
#endif
|
|
|
|
return dp;
|
|
}
|
|
libc_hidden_def (__old_readdir64)
|
|
compat_symbol (libc, __old_readdir64, readdir64, GLIBC_2_1);
|
|
# endif /* SHLIB_COMPAT(libc, GLIBC_2_1, GLIBC_2_2) */
|
|
#endif /* _DIRENT_MATCHES_DIRENT64 */
|