X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Ffts.c;h=d4f7db21cb7a051582869e1c638bf52dad98d4ae;hb=671c9011cb6944a63f0d15f60252c31bf0ee8e9b;hp=fc6bbd37b72293c75bebc828380b81f5cf044744;hpb=83f57af124f0a11a0f491b90f4ac4910893f0dd0;p=gnulib.git
diff --git a/lib/fts.c b/lib/fts.c
index fc6bbd37b..d4f7db21c 100644
--- a/lib/fts.c
+++ b/lib/fts.c
@@ -1,11 +1,11 @@
/* Traverse a file hierarchy.
- Copyright (C) 2004, 2005, 2006 Free Software Foundation, Inc.
+ Copyright (C) 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
- This program is free software; you can redistribute it and/or modify
+ This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2, or (at your option)
- any later version.
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -13,8 +13,7 @@
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software Foundation,
- Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+ along with this program. If not, see . */
/*-
* Copyright (c) 1990, 1993, 1994
@@ -74,6 +73,7 @@ static char sccsid[] = "@(#)fts.c 8.6 (Berkeley) 8/14/94";
# include "lstat.h"
# include "openat.h"
# include "unistd--.h"
+# include "same-inode.h"
#endif
#include
@@ -93,6 +93,29 @@ static char sccsid[] = "@(#)fts.c 8.6 (Berkeley) 8/14/94";
enum
{
+ NOT_AN_INODE_NUMBER = 0
+};
+
+#ifdef D_INO_IN_DIRENT
+# define D_INO(dp) (dp)->d_ino
+#else
+/* Some systems don't have inodes, so fake them to avoid lots of ifdefs. */
+# define D_INO(dp) NOT_AN_INODE_NUMBER
+#endif
+
+/* If there are more than this many entries in a directory,
+ and the conditions mentioned below are satisfied, then sort
+ the entries on inode number before any further processing. */
+#ifndef FTS_INODE_SORT_DIR_ENTRIES_THRESHOLD
+# define FTS_INODE_SORT_DIR_ENTRIES_THRESHOLD 10000
+#endif
+enum
+{
+ _FTS_INODE_SORT_DIR_ENTRIES_THRESHOLD = FTS_INODE_SORT_DIR_ENTRIES_THRESHOLD
+};
+
+enum Fts_stat
+{
FTS_NO_STAT_REQUIRED = 1,
FTS_STAT_REQUIRED = 2
};
@@ -120,7 +143,7 @@ enum
#endif
#ifndef __attribute__
-# if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 8) || __STRICT_ANSI__
+# if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 8)
# define __attribute__(x) /* empty */
# endif
#endif
@@ -137,6 +160,18 @@ enum
# define HAVE_OPENAT_SUPPORT 0
#endif
+#ifdef NDEBUG
+# define fts_assert(expr) ((void) 0)
+#else
+# define fts_assert(expr) \
+ do \
+ { \
+ if (!(expr)) \
+ abort (); \
+ } \
+ while (false)
+#endif
+
static FTSENT *fts_alloc (FTS *, const char *, size_t) internal_function;
static FTSENT *fts_build (FTS *, int) internal_function;
static void fts_lfree (FTSENT *) internal_function;
@@ -149,14 +184,13 @@ static unsigned short int fts_stat (FTS *, FTSENT *, bool) internal_function;
static int fts_safe_changedir (FTS *, FTSENT *, int, const char *)
internal_function;
-#if _LGPL_PACKAGE
+#if GNULIB_FTS
+# include "fts-cycle.c"
+#else
static bool enter_dir (FTS *fts, FTSENT *ent) { return true; }
static void leave_dir (FTS *fts, FTSENT *ent) {}
static bool setup_dir (FTS *fts) { return true; }
static void free_dir (FTS *fts) {}
-#else
-# include "fcntl--.h"
-# include "fts-cycle.c"
#endif
#ifndef MAX
@@ -178,17 +212,21 @@ static void free_dir (FTS *fts) {}
#define ISSET(opt) (sp->fts_options & (opt))
#define SET(opt) (sp->fts_options |= (opt))
-#define RESTORE_INITIAL_CWD(sp) FCHDIR (sp, (ISSET (FTS_CWDFD) \
- ? AT_FDCWD \
- : sp->fts_rfd))
+/* FIXME: make this a function */
+#define RESTORE_INITIAL_CWD(sp) \
+ (fd_ring_clear (&((sp)->fts_fd_ring)), \
+ FCHDIR ((sp), (ISSET (FTS_CWDFD) ? AT_FDCWD : (sp)->fts_rfd)))
-#define FCHDIR(sp, fd) (!ISSET(FTS_NOCHDIR) \
- && (ISSET(FTS_CWDFD) \
- ? (cwd_advance_fd (sp, fd), 0) \
- : fchdir(fd)))
+/* FIXME: FTS_NOCHDIR is now misnamed.
+ Call it FTS_USE_FULL_RELATIVE_FILE_NAMES instead. */
+#define FCHDIR(sp, fd) \
+ (!ISSET(FTS_NOCHDIR) && (ISSET(FTS_CWDFD) \
+ ? (cwd_advance_fd ((sp), (fd), true), 0) \
+ : fchdir (fd)))
/* fts_build flags */
+/* FIXME: make this an enum */
#define BCHILD 1 /* fts_children */
#define BNAMES 2 /* fts_children, names only */
#define BREAD 3 /* fts_read */
@@ -197,10 +235,13 @@ static void free_dir (FTS *fts) {}
# include
# include
# include
+# include "getcwdat.h"
bool fts_debug = false;
-# define Dprintf(x) do { if (fts_debug) printf x; } while (0)
+# define Dprintf(x) do { if (fts_debug) printf x; } while (false)
#else
# define Dprintf(x)
+# define fd_ring_check(x)
+# define fd_ring_print(a, b, c)
#endif
#define LEAVE_DIR(Fts, Ent, Tag) \
@@ -208,17 +249,28 @@ bool fts_debug = false;
{ \
Dprintf ((" %s-leaving: %s\n", Tag, (Ent)->fts_path)); \
leave_dir (Fts, Ent); \
+ fd_ring_check (Fts); \
} \
while (false)
+static void
+fd_ring_clear (I_ring *fd_ring)
+{
+ while ( ! i_ring_empty (fd_ring))
+ {
+ int fd = i_ring_pop (fd_ring);
+ if (0 <= fd)
+ close (fd);
+ }
+}
+
/* Overload the fts_statp->st_size member (otherwise unused, when
fts_info is FTS_NSOK) to indicate whether fts_read should stat
this entry or not. */
static void
fts_set_stat_required (FTSENT *p, bool required)
{
- if (p->fts_info != FTS_NSOK)
- abort ();
+ fts_assert (p->fts_info == FTS_NSOK);
p->fts_statp->st_size = (required
? FTS_STAT_REQUIRED
: FTS_NO_STAT_REQUIRED);
@@ -245,19 +297,34 @@ opendirat (int fd, char const *dir)
return dirp;
}
-/* Virtual fchdir. Advance SP's working directory
- file descriptor, SP->fts_cwd_fd, to FD, and close
- the previous one, ignoring any error. */
+/* Virtual fchdir. Advance SP's working directory file descriptor,
+ SP->fts_cwd_fd, to FD, and push the previous value onto the fd_ring.
+ CHDIR_DOWN_ONE is true if FD corresponds to an entry in the directory
+ open on sp->fts_cwd_fd; i.e., to move the working directory one level
+ down. */
static void
internal_function
-cwd_advance_fd (FTS *sp, int fd)
+cwd_advance_fd (FTS *sp, int fd, bool chdir_down_one)
{
int old = sp->fts_cwd_fd;
- if (old == fd && old != AT_FDCWD)
- abort ();
+ fts_assert (old != fd || old == AT_FDCWD);
+
+ if (chdir_down_one)
+ {
+ /* Push "old" onto the ring.
+ If the displaced file descriptor is non-negative, close it. */
+ int prev_fd_in_slot = i_ring_push (&sp->fts_fd_ring, old);
+ fd_ring_print (sp, stderr, "post-push");
+ if (0 <= prev_fd_in_slot)
+ close (prev_fd_in_slot); /* ignore any close failure */
+ }
+ else if ( ! ISSET (FTS_NOCHDIR))
+ {
+ if (0 <= old)
+ close (old); /* ignore any close failure */
+ }
+
sp->fts_cwd_fd = fd;
- if (0 <= old)
- close (old); /* ignore any close failure */
}
/* Open the directory DIR if possible, and return a file
@@ -449,6 +516,7 @@ fts_open (char * const *argv,
&& (sp->fts_rfd = diropen (sp, ".")) < 0)
SET(FTS_NOCHDIR);
+ i_ring_init (&sp->fts_fd_ring, -1);
return (sp);
mem3: fts_lfree(root);
@@ -480,7 +548,6 @@ fts_load (FTS *sp, register FTSENT *p)
p->fts_namelen = len;
}
p->fts_accpath = p->fts_path = sp->fts_path;
- sp->fts_dev = p->fts_statp->st_dev;
}
int
@@ -522,6 +589,7 @@ fts_close (FTS *sp)
close(sp->fts_rfd);
}
+ fd_ring_clear (&sp->fts_fd_ring);
free_dir (sp);
/* Free up the stream pointer. */
@@ -639,7 +707,7 @@ fts_read (register FTS *sp)
/* If fts_build's call to fts_safe_changedir failed
because it was not able to fchdir into a
subdirectory, tell the caller. */
- if (p->fts_errno)
+ if (p->fts_errno && p->fts_info != FTS_DNR)
p->fts_info = FTS_ERR;
LEAVE_DIR (sp, p, "2");
return (p);
@@ -652,6 +720,7 @@ fts_read (register FTS *sp)
/* Move to the next node on this level. */
next: tmp = p;
if ((p = p->fts_link) != NULL) {
+ sp->fts_cur = p;
free(tmp);
/*
@@ -662,7 +731,6 @@ next: tmp = p;
if (p->fts_level == FTS_ROOTLEVEL) {
if (RESTORE_INITIAL_CWD(sp)) {
SET(FTS_STOP);
- sp->fts_cur = p;
return (NULL);
}
fts_load(sp, p);
@@ -692,23 +760,23 @@ name: t = sp->fts_path + NAPPEND(p->fts_parent);
*t++ = '/';
memmove(t, p->fts_name, p->fts_namelen + 1);
check_for_dir:
+ sp->fts_cur = p;
if (p->fts_info == FTS_NSOK)
{
- switch (p->fts_statp->st_size)
- {
- case FTS_STAT_REQUIRED:
- p->fts_info = fts_stat(sp, p, false);
- break;
- case FTS_NO_STAT_REQUIRED:
- break;
- default:
- abort ();
- }
+ if (p->fts_statp->st_size == FTS_STAT_REQUIRED)
+ p->fts_info = fts_stat(sp, p, false);
+ else
+ fts_assert (p->fts_statp->st_size == FTS_NO_STAT_REQUIRED);
}
- sp->fts_cur = p;
+
if (p->fts_info == FTS_D)
{
- Dprintf ((" %s-entering: %s\n", sp, p->fts_path));
+ /* Now that P->fts_statp is guaranteed to be valid,
+ if this is a command-line directory, record its
+ device number, to be used for FTS_XDEV. */
+ if (p->fts_level == FTS_ROOTLEVEL)
+ sp->fts_dev = p->fts_statp->st_dev;
+ Dprintf ((" entering: %s\n", p->fts_path));
if (! enter_dir (sp, p))
{
__set_errno (ENOMEM);
@@ -720,6 +788,7 @@ check_for_dir:
/* Move up to the parent node. */
p = tmp->fts_parent;
+ sp->fts_cur = p;
free(tmp);
if (p->fts_level == FTS_ROOTPARENTLEVEL) {
@@ -732,8 +801,7 @@ check_for_dir:
return (sp->fts_cur = NULL);
}
- if (p->fts_info == FTS_NSOK)
- abort ();
+ fts_assert (p->fts_info != FTS_NSOK);
/* NUL terminate the file name. */
sp->fts_path[p->fts_pathlen] = '\0';
@@ -766,7 +834,6 @@ check_for_dir:
p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP;
if (p->fts_errno == 0)
LEAVE_DIR (sp, p, "3");
- sp->fts_cur = p;
return ISSET(FTS_STOP) ? NULL : p;
}
@@ -851,7 +918,7 @@ fts_children (register FTS *sp, int instr)
sp->fts_child = fts_build(sp, instr);
if (ISSET(FTS_CWDFD))
{
- cwd_advance_fd (sp, fd);
+ cwd_advance_fd (sp, fd, true);
}
else
{
@@ -867,6 +934,63 @@ fts_children (register FTS *sp, int instr)
return (sp->fts_child);
}
+#if defined __linux__ \
+ && HAVE_SYS_VFS_H && HAVE_FSTATFS && HAVE_STRUCT_STATFS_F_TYPE
+
+#include
+
+/* Linux-specific constants from coreutils' src/fs.h */
+# define S_MAGIC_TMPFS 0x1021994
+# define S_MAGIC_NFS 0x6969
+
+/* Return false if it is easy to determine the file system type of
+ the directory on which DIR_FD is open, and sorting dirents on
+ inode numbers is known not to improve traversal performance with
+ that type of file system. Otherwise, return true. */
+static bool
+dirent_inode_sort_may_be_useful (int dir_fd)
+{
+ /* Skip the sort only if we can determine efficiently
+ that skipping it is the right thing to do.
+ The cost of performing an unnecessary sort is negligible,
+ while the cost of *not* performing it can be O(N^2) with
+ a very large constant. */
+ struct statfs fs_buf;
+
+ /* If fstatfs fails, assume sorting would be useful. */
+ if (fstatfs (dir_fd, &fs_buf) != 0)
+ return true;
+
+ /* FIXME: what about when f_type is not an integral type?
+ deal with that if/when it's encountered. */
+ switch (fs_buf.f_type)
+ {
+ case S_MAGIC_TMPFS:
+ case S_MAGIC_NFS:
+ /* On a file system of any of these types, sorting
+ is unnecessary, and hence wasteful. */
+ return false;
+
+ default:
+ return true;
+ }
+}
+#else
+static bool dirent_inode_sort_may_be_useful (int dir_fd) { return true; }
+#endif
+
+/* A comparison function to sort on increasing inode number.
+ For some file system types, sorting either way makes a huge
+ performance difference for a directory with very many entries,
+ but sorting on increasing values is slightly better than sorting
+ on decreasing values. The difference is in the 5% range. */
+static int
+fts_compare_ino (struct _ftsent const **a, struct _ftsent const **b)
+{
+ return (a[0]->fts_statp->st_ino < b[0]->fts_statp->st_ino ? -1
+ : b[0]->fts_statp->st_ino < a[0]->fts_statp->st_ino ? 1 : 0);
+}
+
/*
* This is the tricky part -- do not casually change *anything* in here. The
* idea is to build the linked list of entries that are used by fts_children
@@ -1008,6 +1132,8 @@ fts_build (register FTS *sp, int type)
/* Read the directory, attaching each entry to the `link' pointer. */
doadjust = false;
for (head = tail = NULL, nitems = 0; dirp && (dp = readdir(dirp));) {
+ bool is_dir;
+
if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name))
continue;
@@ -1044,7 +1170,7 @@ mem1: saved_errno = errno;
new_len = len + _D_EXACT_NAMLEN (dp);
if (new_len < len) {
/*
- * In the unlikely even that we would end up
+ * In the unlikely event that we would end up
* with a file name longer than SIZE_MAX, free up
* the current structure and the structures already
* allocated, then error out with ENAMETOOLONG.
@@ -1065,6 +1191,9 @@ mem1: saved_errno = errno;
if (dp->d_type == DT_WHT)
p->fts_flags |= FTS_ISW;
#endif
+ /* Store dirent.d_ino, in case we need to sort
+ entries before processing them. */
+ p->fts_statp->st_ino = D_INO (dp);
/* Build a file name for fts_stat to stat. */
if (ISSET(FTS_NOCHDIR)) {
@@ -1073,7 +1202,6 @@ mem1: saved_errno = errno;
} else
p->fts_accpath = p->fts_name;
- bool is_dir;
if (sp->fts_compar == NULL || ISSET(FTS_DEFER_STAT)) {
/* Record what fts_read will have to do with this
entry. In many cases, it will simply fts_stat it,
@@ -1161,6 +1289,19 @@ mem1: saved_errno = errno;
return (NULL);
}
+ /* If there are many entries, no sorting function has been specified,
+ and this file system is of a type that may be slow with a large
+ number of entries, then sort the directory entries on increasing
+ inode numbers. */
+ if (nitems > _FTS_INODE_SORT_DIR_ENTRIES_THRESHOLD
+ && !sp->fts_compar
+ && ISSET (FTS_CWDFD)
+ && dirent_inode_sort_may_be_useful (sp->fts_cwd_fd)) {
+ sp->fts_compar = fts_compare_ino;
+ head = fts_sort (sp, head, nitems);
+ sp->fts_compar = NULL;
+ }
+
/* Sort the entries. */
if (sp->fts_compar && nitems > 1)
head = fts_sort(sp, head, nitems);
@@ -1228,6 +1369,87 @@ fts_cross_check (FTS const *sp)
}
}
}
+
+static bool
+same_fd (int fd1, int fd2)
+{
+ struct stat sb1, sb2;
+ return (fstat (fd1, &sb1) == 0
+ && fstat (fd2, &sb2) == 0
+ && SAME_INODE (sb1, sb2));
+}
+
+static void
+fd_ring_print (FTS const *sp, FILE *stream, char const *msg)
+{
+ I_ring const *fd_ring = &sp->fts_fd_ring;
+ unsigned int i = fd_ring->fts_front;
+ char *cwd = getcwdat (sp->fts_cwd_fd, NULL, 0);
+ fprintf (stream, "=== %s ========== %s\n", msg, cwd);
+ free (cwd);
+ if (i_ring_empty (fd_ring))
+ return;
+
+ while (true)
+ {
+ int fd = fd_ring->fts_fd_ring[i];
+ if (fd < 0)
+ fprintf (stream, "%d: %d:\n", i, fd);
+ else
+ {
+ char *wd = getcwdat (fd, NULL, 0);
+ fprintf (stream, "%d: %d: %s\n", i, fd, wd);
+ free (wd);
+ }
+ if (i == fd_ring->fts_back)
+ break;
+ i = (i + I_RING_SIZE - 1) % I_RING_SIZE;
+ }
+}
+
+/* Ensure that each file descriptor on the fd_ring matches a
+ parent, grandparent, etc. of the current working directory. */
+static void
+fd_ring_check (FTS const *sp)
+{
+ if (!fts_debug)
+ return;
+
+ /* Make a writable copy. */
+ I_ring fd_w = sp->fts_fd_ring;
+
+ int cwd_fd = sp->fts_cwd_fd;
+ cwd_fd = dup (cwd_fd);
+ char *dot = getcwdat (cwd_fd, NULL, 0);
+ error (0, 0, "===== check ===== cwd: %s", dot);
+ free (dot);
+ while ( ! i_ring_empty (&fd_w))
+ {
+ int fd = i_ring_pop (&fd_w);
+ if (0 <= fd)
+ {
+ int parent_fd = openat (cwd_fd, "..", O_RDONLY);
+ if (parent_fd < 0)
+ {
+ // Warn?
+ break;
+ }
+ if (!same_fd (fd, parent_fd))
+ {
+ char *cwd = getcwdat (fd, NULL, 0);
+ error (0, errno, "ring : %s", cwd);
+ char *c2 = getcwdat (parent_fd, NULL, 0);
+ error (0, errno, "parent: %s", c2);
+ free (cwd);
+ free (c2);
+ fts_assert (0);
+ }
+ close (cwd_fd);
+ cwd_fd = parent_fd;
+ }
+ }
+ close (cwd_fd);
+}
#endif
static unsigned short int
@@ -1278,7 +1500,7 @@ err: memset(sbp, 0, sizeof(struct stat));
return (p->fts_level == FTS_ROOTLEVEL ? FTS_D : FTS_DOT);
}
-#if _LGPL_PACKAGE
+#if !GNULIB_FTS
{
/*
* Cycle detection is done by brute force when the directory
@@ -1349,7 +1571,7 @@ fts_sort (FTS *sp, FTSENT *head, register size_t nitems)
* 40 so don't realloc one entry at a time.
*/
if (nitems > sp->fts_nitems) {
- struct _ftsent **a;
+ FTSENT **a;
sp->fts_nitems = nitems + 40;
if (SIZE_MAX / sizeof *a < sp->fts_nitems
@@ -1503,23 +1725,52 @@ internal_function
fts_safe_changedir (FTS *sp, FTSENT *p, int fd, char const *dir)
{
int ret;
+ bool is_dotdot = dir && STREQ (dir, "..");
+ int newfd;
+
+ /* This clause handles the unusual case in which FTS_NOCHDIR
+ is specified, along with FTS_CWDFD. In that case, there is
+ no need to change even the virtual cwd file descriptor.
+ However, if FD is non-negative, we do close it here. */
+ if (ISSET (FTS_NOCHDIR))
+ {
+ if (ISSET (FTS_CWDFD) && 0 <= fd)
+ close (fd);
+ return 0;
+ }
- int newfd = fd;
- if (ISSET(FTS_NOCHDIR)) {
- if (ISSET(FTS_CWDFD) && 0 <= fd)
- close (fd);
- return (0);
- }
- if (fd < 0 && (newfd = diropen (sp, dir)) < 0)
- return (-1);
+ if (fd < 0 && is_dotdot && ISSET (FTS_CWDFD))
+ {
+ /* When possible, skip the diropen and subsequent fstat+dev/ino
+ comparison. I.e., when changing to parent directory
+ (chdir ("..")), use a file descriptor from the ring and
+ save the overhead of diropen+fstat, as well as avoiding
+ failure when we lack "x" access to the virtual cwd. */
+ if ( ! i_ring_empty (&sp->fts_fd_ring))
+ {
+ int parent_fd;
+ fd_ring_print (sp, stderr, "pre-pop");
+ parent_fd = i_ring_pop (&sp->fts_fd_ring);
+ is_dotdot = true;
+ if (0 <= parent_fd)
+ {
+ fd = parent_fd;
+ dir = NULL;
+ }
+ }
+ }
- /* The following dev/inode check is necessary if we're doing
- a `logical' traversal (through symlinks, a la chown -L),
- if the system lacks O_NOFOLLOW support, or if we're changing
- to "..". In the latter case, O_NOFOLLOW can't help. In
- general (when the target is not ".."), diropen's use of
- O_NOFOLLOW ensures we don't mistakenly follow a symlink,
- so we can avoid the expense of this fstat. */
+ newfd = fd;
+ if (fd < 0 && (newfd = diropen (sp, dir)) < 0)
+ return -1;
+
+ /* The following dev/inode check is necessary if we're doing a
+ `logical' traversal (through symlinks, a la chown -L), if the
+ system lacks O_NOFOLLOW support, or if we're changing to ".."
+ (but not via a popped file descriptor). When changing to the
+ name "..", O_NOFOLLOW can't help. In general, when the target is
+ not "..", diropen's use of O_NOFOLLOW ensures we don't mistakenly
+ follow a symlink, so we can avoid the expense of this fstat. */
if (ISSET(FTS_LOGICAL) || ! HAVE_WORKING_O_NOFOLLOW
|| (dir && STREQ (dir, "..")))
{
@@ -1540,7 +1791,7 @@ fts_safe_changedir (FTS *sp, FTSENT *p, int fd, char const *dir)
if (ISSET(FTS_CWDFD))
{
- cwd_advance_fd (sp, newfd);
+ cwd_advance_fd (sp, newfd, ! is_dotdot);
return 0;
}
@@ -1552,5 +1803,5 @@ bail:
(void)close(newfd);
__set_errno (oerrno);
}
- return (ret);
+ return ret;
}