# include "lstat.h"
# include "openat.h"
# include "unistd--.h"
+# include "same-inode.h"
#endif
#include <dirent.h>
#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 */
# include <inttypes.h>
# include <stdint.h>
# include <stdio.h>
+# 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) \
{ \
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. */
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 ();
+
+ 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
&& (sp->fts_rfd = diropen (sp, ".")) < 0)
SET(FTS_NOCHDIR);
+ i_ring_init (&sp->fts_fd_ring, -1);
return (sp);
mem3: fts_lfree(root);
close(sp->fts_rfd);
}
+ fd_ring_clear (&sp->fts_fd_ring);
free_dir (sp);
/* Free up the stream pointer. */
sp->fts_child = fts_build(sp, instr);
if (ISSET(FTS_CWDFD))
{
- cwd_advance_fd (sp, fd);
+ cwd_advance_fd (sp, fd, true);
}
else
{
}
}
}
+
+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);
+ abort ();
+ }
+ close (cwd_fd);
+ cwd_fd = parent_fd;
+ }
+ }
+ close (cwd_fd);
+}
#endif
static unsigned short int
fts_safe_changedir (FTS *sp, FTSENT *p, int fd, char const *dir)
{
int ret;
-
- int newfd = fd;
+ 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);
- }
- if (fd < 0 && (newfd = diropen (sp, dir)) < 0)
- return (-1);
+ if (ISSET (FTS_NOCHDIR))
+ {
+ if (ISSET (FTS_CWDFD) && 0 <= fd)
+ close (fd);
+ return 0;
+ }
- /* 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. */
+ 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))
+ {
+ fd_ring_print (sp, stderr, "pre-pop");
+ int parent_fd = i_ring_pop (&sp->fts_fd_ring);
+ is_dotdot = true;
+ if (0 <= parent_fd)
+ {
+ fd = parent_fd;
+ dir = NULL;
+ }
+ }
+ }
+
+ 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, "..")))
{
if (ISSET(FTS_CWDFD))
{
- cwd_advance_fd (sp, newfd);
+ cwd_advance_fd (sp, newfd, ! is_dotdot);
return 0;
}
(void)close(newfd);
__set_errno (oerrno);
}
- return (ret);
+ return ret;
}
--- /dev/null
+/* definitions for a simple ring buffer
+ Copyright (C) 2006 Free Software Foundation, Inc.
+
+ 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.
+
+ This program 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 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. */
+
+#include <stdbool.h>
+#include "verify.h"
+
+enum { I_RING_SIZE = 4 };
+verify (1 <= I_RING_SIZE);
+
+/* When ir_empty is true, the ring is empty.
+ Otherwise, ir_data[B..F] are defined, where B..F is the contiguous
+ range of indices, modulo I_RING_SIZE, from back to front, inclusive.
+ Undefined elements of ir_data are always set to ir_default_val.
+ Popping from an empty ring aborts.
+ Pushing onto a full ring returns the displaced value.
+ An empty ring has F==B and ir_empty == true.
+ A ring with one entry still has F==B, but now ir_empty == false. */
+struct I_ring
+{
+ int ir_data[I_RING_SIZE];
+ int ir_default_val;
+ unsigned int ir_front;
+ unsigned int ir_back;
+ bool ir_empty;
+};
+typedef struct I_ring I_ring;
+
+void i_ring_init (I_ring *ir, int ir_default_val);
+int i_ring_push (I_ring *ir, int val);
+int i_ring_pop (I_ring *ir);
+bool i_ring_empty (I_ring const *ir);
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