diff --git a/dirent/tst-seekdir.c b/dirent/tst-seekdir.c index dcdd699b09..187eda7584 100644 --- a/dirent/tst-seekdir.c +++ b/dirent/tst-seekdir.c @@ -41,6 +41,14 @@ do_test (void) if (i == 400) break; } + if (i < 3) + { + /* Non-lfs opendir skips entries that can not be represented (for + instance if d_off is not an offset but rather an internal filesystem + representation. For this case there is no point in continue the + testcase. */ + return 77; + } printf ("going back past 4-th entry...\n"); diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile index f298878e8f..33708f910b 100644 --- a/sysdeps/unix/sysv/linux/Makefile +++ b/sysdeps/unix/sysv/linux/Makefile @@ -465,6 +465,7 @@ ifeq ($(subdir),dirent) sysdep_routines += getdirentries getdirentries64 tests += \ tst-getdents64 \ + tst-opendir-nolfs \ tst-readdir64-compat \ # tests endif # $(subdir) == dirent diff --git a/sysdeps/unix/sysv/linux/alpha/bits/dirent.h b/sysdeps/unix/sysv/linux/alpha/bits/dirent.h index c8a0cfe93f..586d75586a 100644 --- a/sysdeps/unix/sysv/linux/alpha/bits/dirent.h +++ b/sysdeps/unix/sysv/linux/alpha/bits/dirent.h @@ -54,4 +54,7 @@ struct dirent64 /* Inform libc code that these two types are effectively identical. */ #define _DIRENT_MATCHES_DIRENT64 1 +/* alpha 'long int' is enough to handle off64_t. */ +#define _DIRENT_OFFSET_TRANSLATION 0 + #endif /* bits/dirent.h */ diff --git a/sysdeps/unix/sysv/linux/bits/dirent.h b/sysdeps/unix/sysv/linux/bits/dirent.h index ab34d986ff..bb02dcb70a 100644 --- a/sysdeps/unix/sysv/linux/bits/dirent.h +++ b/sysdeps/unix/sysv/linux/bits/dirent.h @@ -57,3 +57,7 @@ struct dirent64 #else # define _DIRENT_MATCHES_DIRENT64 0 #endif + +/* The telldir function returns long int, which may not be large enough to + store off64_t values. In this case, translation is required. */ +#define _DIRENT_OFFSET_TRANSLATION (LONG_WIDTH < 64) diff --git a/sysdeps/unix/sysv/linux/closedir.c b/sysdeps/unix/sysv/linux/closedir.c index f1c2608642..9585a6ca3a 100644 --- a/sysdeps/unix/sysv/linux/closedir.c +++ b/sysdeps/unix/sysv/linux/closedir.c @@ -47,6 +47,10 @@ __closedir (DIR *dirp) __libc_lock_fini (dirp->lock); #endif +#if _DIRENT_OFFSET_TRANSLATION + dirstream_loc_clear (&dirp->locs); +#endif + free ((void *) dirp); return __close_nocancel (fd); diff --git a/sysdeps/unix/sysv/linux/dirstream.h b/sysdeps/unix/sysv/linux/dirstream.h index adcf8234f1..8f58a1c3a6 100644 --- a/sysdeps/unix/sysv/linux/dirstream.h +++ b/sysdeps/unix/sysv/linux/dirstream.h @@ -22,6 +22,7 @@ #include #include +#include /* Directory stream type. @@ -38,13 +39,16 @@ struct __dirstream size_t size; /* Total valid data in the block. */ size_t offset; /* Current offset into the block. */ - off_t filepos; /* Position of next entry to read. */ + off64_t filepos; /* Position of next entry to read. */ int errcode; /* Delayed error code. */ #if !defined __OFF_T_MATCHES_OFF64_T || !defined __INO_T_MATCHES_INO64_T struct dirent tdp; #endif +#if _DIRENT_OFFSET_TRANSLATION + struct dirstream_loc_t locs; /* off64_t to long int map for telldir. */ +#endif /* Directory block. We must make sure that this block starts at an address that is aligned adequately enough to store diff --git a/sysdeps/unix/sysv/linux/opendir.c b/sysdeps/unix/sysv/linux/opendir.c index 4336196a4d..3e2caabb9d 100644 --- a/sysdeps/unix/sysv/linux/opendir.c +++ b/sysdeps/unix/sysv/linux/opendir.c @@ -129,6 +129,9 @@ __alloc_dir (int fd, bool close_fd, int flags, dirp->offset = 0; dirp->filepos = 0; dirp->errcode = 0; +#if _DIRENT_OFFSET_TRANSLATION + dirstream_loc_init (&dirp->locs); +#endif return dirp; } diff --git a/sysdeps/unix/sysv/linux/readdir.c b/sysdeps/unix/sysv/linux/readdir.c index cd0ccaf33a..7a7f484c36 100644 --- a/sysdeps/unix/sysv/linux/readdir.c +++ b/sysdeps/unix/sysv/linux/readdir.c @@ -36,6 +36,15 @@ dirstream_entry (struct __dirstream *ds, const struct dirent64 *dp64) if (dp64->d_reclen - offsetof (struct dirent64, d_name) > NAME_MAX) return false; + /* telldir can not return an error, so preallocate the map if the entry can + not be packed directly. */ + if (telldir_need_dirstream (dp64->d_off)) + { + dirstream_loc_add (&ds->locs, dp64->d_off); + if (dirstream_loc_has_failed (&ds->locs)) + return false; + } + ds->filepos = dp64->d_off; ds->tdp.d_off = dp64->d_off; @@ -76,7 +85,7 @@ __readdir_unlocked (DIR *dirp) /* Reset the offset into the buffer. */ dirp->offset = 0; - } + } struct dirent64 *dp64 = (struct dirent64 *) &dirp->data[dirp->offset]; dirp->offset += dp64->d_reclen; diff --git a/sysdeps/unix/sysv/linux/rewinddir.c b/sysdeps/unix/sysv/linux/rewinddir.c index c0fb7aa765..1b158a584f 100644 --- a/sysdeps/unix/sysv/linux/rewinddir.c +++ b/sysdeps/unix/sysv/linux/rewinddir.c @@ -33,6 +33,11 @@ __rewinddir (DIR *dirp) dirp->offset = 0; dirp->size = 0; dirp->errcode = 0; + +#ifndef __LP64__ + dirstream_loc_clear (&dirp->locs); +#endif + #if IS_IN (libc) __libc_lock_unlock (dirp->lock); #endif diff --git a/sysdeps/unix/sysv/linux/seekdir.c b/sysdeps/unix/sysv/linux/seekdir.c index 939ccc4447..30cce691a4 100644 --- a/sysdeps/unix/sysv/linux/seekdir.c +++ b/sysdeps/unix/sysv/linux/seekdir.c @@ -22,14 +22,39 @@ #include /* Seek to position POS in DIRP. */ -/* XXX should be __seekdir ? */ void seekdir (DIR *dirp, long int pos) { + off64_t filepos; + __libc_lock_lock (dirp->lock); - (void) __lseek (dirp->fd, pos, SEEK_SET); - dirp->size = 0; - dirp->offset = 0; - dirp->filepos = pos; + +#if _DIRENT_OFFSET_TRANSLATION + union dirstream_packed dsp = { .l = pos }; + if (dsp.p.is_packed == 1) + filepos = dsp.p.info; + else + { + size_t index = dsp.p.info; + + if (index >= dirstream_loc_size (&dirp->locs)) + { + __libc_lock_unlock (dirp->lock); + return; + } + filepos = *dirstream_loc_at (&dirp->locs, index); + } +#else + filepos = pos; +#endif + + if (dirp->filepos != filepos) + { + __lseek64 (dirp->fd, filepos, SEEK_SET); + dirp->filepos = filepos; + dirp->offset = 0; + dirp->size = 0; + } + __libc_lock_unlock (dirp->lock); } diff --git a/sysdeps/unix/sysv/linux/telldir.c b/sysdeps/unix/sysv/linux/telldir.c index 1e5c129e9f..c3ef14f3da 100644 --- a/sysdeps/unix/sysv/linux/telldir.c +++ b/sysdeps/unix/sysv/linux/telldir.c @@ -15,9 +15,11 @@ License along with the GNU C Library; if not, see . */ +#include #include #include +#include /* Return the current position of DIRP. */ long int @@ -26,7 +28,40 @@ telldir (DIR *dirp) long int ret; __libc_lock_lock (dirp->lock); + +#if _DIRENT_OFFSET_TRANSLATION + /* If the directory position fits in the packet structure, returns it. + Otherwise, check if the position is already been recorded in the + dynamic array. If not, add the new record. */ + + union dirstream_packed dsp; + + if (!telldir_need_dirstream (dirp->filepos)) + { + dsp.p.is_packed = 1; + dsp.p.info = dirp->filepos; + } + else + { + dsp.l = -1; + + size_t i; + for (i = 0; i < dirstream_loc_size (&dirp->locs); i++) + if (*dirstream_loc_at (&dirp->locs, i) == dirp->filepos) + break; + /* It should be pre-allocated on readdir. */ + assert (i != dirstream_loc_size (&dirp->locs)); + + dsp.p.is_packed = 0; + /* This assignment might overflow, however most likely ENOME would + happen long before. */ + dsp.p.info = i; + } + + ret = dsp.l; +#else ret = dirp->filepos; +#endif __libc_lock_unlock (dirp->lock); return ret; diff --git a/sysdeps/unix/sysv/linux/telldir.h b/sysdeps/unix/sysv/linux/telldir.h new file mode 100644 index 0000000000..758bcb0eb3 --- /dev/null +++ b/sysdeps/unix/sysv/linux/telldir.h @@ -0,0 +1,65 @@ +/* Linux internal telldir definitions. + Copyright (C) 2023 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 + . */ + +#ifndef _TELLDIR_H +#define _TELLDIR_H 1 + +#if _DIRENT_OFFSET_TRANSLATION +/* On platforms where 'long int' is smaller than 'off64_t' this is how the + returned value is encoded and returned by 'telldir'. If the directory + offset can be enconded in 31 bits it is returned in the 'info' member + with 'is_packed' set to 1. + + Otherwise, the 'info' member describes an index in a dynamic array at + 'DIR' structure. */ + +union dirstream_packed +{ + long int l; + struct + { + unsigned long int is_packed:1; + unsigned long int info:31; + } p; +}; + +_Static_assert (sizeof (long int) == sizeof (union dirstream_packed), + "sizeof (long int) != sizeof (union dirstream_packed)"); + +/* telldir maintains a list of offsets that describe the obtained diretory + position if it can fit this information in the returned 'dirstream_packed' + struct. */ + +# define DYNARRAY_STRUCT dirstream_loc_t +# define DYNARRAY_ELEMENT off64_t +# define DYNARRAY_PREFIX dirstream_loc_ +# include + +static __always_inline bool +telldir_need_dirstream (__off64_t d_off) +{ + return d_off >= 1UL << 31; +} +#else + +_Static_assert (sizeof (long int) == sizeof (off64_t), + "sizeof (long int) != sizeof (off64_t)"); + +#endif /* __LP64__ */ + +#endif /* _TELLDIR_H */ diff --git a/sysdeps/unix/sysv/linux/tst-opendir-nolfs.c b/sysdeps/unix/sysv/linux/tst-opendir-nolfs.c new file mode 100644 index 0000000000..52e18171a7 --- /dev/null +++ b/sysdeps/unix/sysv/linux/tst-opendir-nolfs.c @@ -0,0 +1,146 @@ +/* Check multiple telldir and seekdir. + Copyright (C) 2023 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 + . */ + +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +/* Some filesystems returns an arbitrary value for d_off direnty entry (ext4 + for instance, where the value is an internal hash key). The idea of create + a large number of file is to try trigger a overflow d_off value in a entry + to check if telldir/seekdir does work corretly in such case. */ +static const char *dirname; +/* The 2 extra files are '.' and '..'. */ +static const size_t nfiles = (1<<14) + 2; + +static inline bool +in_ino_t_range (ino64_t v) +{ + ino_t s = v; + return s == v; +} + +static inline bool +in_off_t_range (off64_t v) +{ + off_t s = v; + return s == v; +} + +static void +do_prepare (int argc, char *argv[]) +{ + dirname = support_create_temp_directory ("tst-opendir-nolfs-"); + + for (size_t i = 0; i < nfiles - 2; i++) + { + int fd = create_temp_file_in_dir ("tempfile.", dirname, NULL); + TEST_VERIFY_EXIT (fd > 0); + close (fd); + } +} +#define PREPARE do_prepare + +static int +do_test (void) +{ + DIR *dirp = opendir (dirname); + TEST_VERIFY_EXIT (dirp != NULL); + + long int *tdirp = xmalloc (nfiles * sizeof (long int)); + struct dirent **ddirp = xmalloc (nfiles * sizeof (struct dirent *)); + + /* For non-LFS, the entry is skipped if it can not be converted. */ + int count = 0; + for (; count < nfiles; count++) + { + tdirp[count] = telldir (dirp); + struct dirent *dp = readdir (dirp); + if (dp == NULL) + break; + ddirp[count] = xmalloc (dp->d_reclen); + memcpy (ddirp[count], dp, dp->d_reclen); + } + + closedir (dirp); + + /* Check against the getdents64 syscall. */ + int fd = xopen (dirname, O_RDONLY | O_DIRECTORY, 0); + int i = 0; + while (true) + { + struct + { + char buffer[1024]; + struct dirent64 pad; + } data; + + ssize_t ret = getdents64 (fd, &data.buffer, sizeof (data.buffer)); + if (ret < 0) + FAIL_EXIT1 ("getdents64: %m"); + if (ret == 0) + break; + + char *current = data.buffer; + char *end = data.buffer + ret; + while (current != end) + { + struct dirent64 entry; + memcpy (&entry, current, sizeof (entry)); + /* Truncate overlong strings. */ + entry.d_name[sizeof (entry.d_name) - 1] = '\0'; + TEST_VERIFY (strlen (entry.d_name) < sizeof (entry.d_name) - 1); + + if (in_ino_t_range (entry.d_ino) && in_off_t_range (entry.d_off)) + { + TEST_COMPARE_STRING (entry.d_name, ddirp[i]->d_name); + TEST_COMPARE (entry.d_ino, ddirp[i]->d_ino); + TEST_COMPARE (entry.d_off, ddirp[i]->d_off); + TEST_COMPARE (entry.d_type, ddirp[i]->d_type); + + /* Offset zero is reserved for the first entry. */ + TEST_VERIFY (entry.d_off != 0); + + TEST_VERIFY_EXIT (entry.d_reclen <= end - current); + i++; + } + + current += entry.d_reclen; + } + } + + /* direntries_read has been called more than once. */ + TEST_COMPARE (count, i); + + free (tdirp); + for (int i = 0; i < count; i++) + free (ddirp[i]); + free (ddirp); + + return 0; +} + +#include