+2020-04-15 Paul Eggert <eggert@cs.ucla.edu>
+
+ fts: remove NOSTAT_LEAF_OPTIMIZATION
+ It caused ‘find’ and ‘du’ to dump core, and it was useful
+ only for obsolescent Linux filesystems anyway. Problem reported in:
+ https://lists.gnu.org/r/bug-gnulib/2020-04/msg00068.html
+ Quite possibly there is still a serious underlying fts bug with
+ tight-loop-check and mutating file systems, but if so this patch
+ should cause the bug to be triggered less often.
+ * lib/fts.c (enum leaf_optimization): Remove
+ NOSTAT_LEAF_OPTIMIZATION, as it’s problematic.
+ (S_MAGIC_REISERFS, S_MAGIC_XFS): Remove; no longer needed.
+ (leaf_optimization): Remove special cases for ReiserFS and XFS.
+ (fts_read): Remove NOSTAT_LEAF_OPTIMIZATION code.
+ * lib/fts_.h (struct _ftsent.fts_n_dirs_remaining):
+ Remove. All uses removed.
+
2020-04-13 Bastien Roucariès <rouca@debian.org>
explicit_bzero: Improve code style.
if ((parent = fts_alloc(sp, "", 0)) == NULL)
goto mem2;
parent->fts_level = FTS_ROOTPARENTLEVEL;
- parent->fts_n_dirs_remaining = -1;
}
/* The classic fts implementation would call fts_stat with
}
/* Minimum link count of a traditional Unix directory. When leaf
- optimization is OK and MIN_DIR_NLINK <= st_nlink, then st_nlink is
- an upper bound on the number of subdirectories (counting "." and
- ".."). */
+ optimization is OK and a directory's st_nlink == MIN_DIR_NLINK,
+ then the directory has no subdirectories. */
enum { MIN_DIR_NLINK = 2 };
/* Whether leaf optimization is OK for a directory. */
/* st_nlink is not reliable for this directory's subdirectories. */
NO_LEAF_OPTIMIZATION,
- /* Leaf optimization is OK, but is not useful for avoiding stat calls. */
- OK_LEAF_OPTIMIZATION,
-
- /* Leaf optimization is not only OK: it is useful for avoiding
- stat calls, because dirent.d_type does not work. */
- NOSTAT_LEAF_OPTIMIZATION
+ /* st_nlink == 2 means the directory lacks subdirectories. */
+ OK_LEAF_OPTIMIZATION
};
#if (defined __linux__ || defined __ANDROID__) \
# define S_MAGIC_CIFS 0xFF534D42
# define S_MAGIC_NFS 0x6969
# define S_MAGIC_PROC 0x9FA0
-# define S_MAGIC_REISERFS 0x52654973
# define S_MAGIC_TMPFS 0x1021994
-# define S_MAGIC_XFS 0x58465342
# ifdef HAVE___FSWORD_T
typedef __fsword_t fsword;
}
/* Given an FTS entry P for a directory with descriptor DIR_FD,
- return true if it is both useful and valid to apply leaf optimization.
- The optimization is useful only for file systems that lack usable
- dirent.d_type info. The optimization is valid if an st_nlink value
- of at least MIN_DIR_NLINK is an upper bound on the number of
- subdirectories of D, counting "." and ".." as subdirectories.
+ return whether it is valid to apply leaf optimization.
+ The optimization is valid if a directory's st_nlink value equal
+ to MIN_DIR_NLINK means the directory has no subdirectories.
DIR_FD is negative if unavailable. */
static enum leaf_optimization
leaf_optimization (FTSENT const *p, int dir_fd)
{
switch (filesystem_type (p, dir_fd))
{
- /* List here the file system types that may lack usable dirent.d_type
- info, yet for which the optimization does apply. */
- case S_MAGIC_REISERFS:
- case S_MAGIC_XFS: /* XFS lacked it until 2013-08-22 commit. */
- return NOSTAT_LEAF_OPTIMIZATION;
-
case 0:
/* Leaf optimization is unsafe if the file system type is unknown. */
FALLTHROUGH;
if (p->fts_info == FTS_NSOK)
{
if (p->fts_statp->st_size == FTS_STAT_REQUIRED)
- {
- FTSENT *parent = p->fts_parent;
- if (parent->fts_n_dirs_remaining == 0
- && ISSET(FTS_NOSTAT)
- && ISSET(FTS_PHYSICAL)
- && (leaf_optimization (parent, sp->fts_cwd_fd)
- == NOSTAT_LEAF_OPTIMIZATION))
- {
- /* nothing more needed */
- }
- else
- {
- p->fts_info = fts_stat(sp, p, false);
- if (S_ISDIR(p->fts_statp->st_mode)
- && p->fts_level != FTS_ROOTLEVEL
- && 0 < parent->fts_n_dirs_remaining
- && parent->fts_n_dirs_remaining != (nlink_t) -1)
- parent->fts_n_dirs_remaining--;
- }
- }
+ p->fts_info = fts_stat(sp, p, false);
else
fts_assert (p->fts_statp->st_size == FTS_NO_STAT_REQUIRED);
}
}
if (S_ISDIR(sbp->st_mode)) {
- p->fts_n_dirs_remaining
- = ((sbp->st_nlink < MIN_DIR_NLINK
- || p->fts_level <= FTS_ROOTLEVEL)
- ? -1
- : sbp->st_nlink - (ISSET (FTS_SEEDOT) ? 0 : MIN_DIR_NLINK));
if (ISDOT(p->fts_name)) {
/* Command-line "." and ".." are real directories. */
return (p->fts_level == FTS_ROOTLEVEL ? FTS_D : FTS_DOT);