X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Ffts_.h;h=42e06c9876fad60c375b5472f127798432a74fde;hb=5131be5b019b1110cd597012b63e48886aaaafc7;hp=954ba569ba01407f57b678c6e01d81c304008589;hpb=c2546905a0f3958439581290d150c9ae4ae52a50;p=gnulib.git

diff --git a/lib/fts_.h b/lib/fts_.h
index 954ba569b..42e06c987 100644
--- a/lib/fts_.h
+++ b/lib/fts_.h
@@ -71,7 +71,7 @@ typedef struct {
 	struct _ftsent *fts_child;	/* linked list of children */
 	struct _ftsent **fts_array;	/* sort array */
 	dev_t fts_dev;			/* starting device # */
-	char *fts_path;			/* path for this descent */
+	char *fts_path;			/* file name for this descent */
 	int fts_rfd;			/* fd for root */
 	size_t fts_pathlen;		/* sizeof(path) */
 	size_t fts_nitems;			/* elements in the sort array */
@@ -88,7 +88,8 @@ typedef struct {
 # define FTS_WHITEOUT	0x0080		/* return whiteout information */
 
   /* There are two ways to detect cycles.
-     The lazy way, with which one may process a directory that is a
+     The lazy way (which works only with FTS_PHYSICAL),
+     with which one may process a directory that is a
      part of the cycle several times before detecting the cycle.
      The `tight' way, whereby fts uses more memory (proportional
      to number of `active' directories, aka distance from root
@@ -96,7 +97,19 @@ typedef struct {
      to detect any cycle right away.  For example, du must use
      this option to avoid counting disk space in a cycle multiple
      times, but chown -R need not.
-     The default is to use the constant-memory lazy way. */
+     The default is to use the constant-memory lazy way, when possible
+     (see below).
+
+     However, with FTS_LOGICAL (when following symlinks, e.g., chown -L)
+     using lazy cycle detection is inadequate.  For example, traversing
+     a directory containing a symbolic link to a peer directory, it is
+     possible to encounter the same directory twice even though there
+     is no cycle:
+     dir
+     ...
+     slink -> dir
+     So, when FTS_LOGICAL is selected, we have to use a different
+     mode of cycle detection: FTS_TIGHT_CYCLE_CHECK.  */
 # define FTS_TIGHT_CYCLE_CHECK	0x0100
 
 # define FTS_OPTIONMASK	0x01ff		/* valid user option mask */
@@ -135,8 +148,8 @@ typedef struct _ftsent {
 	struct _ftsent *fts_link;	/* next file in directory */
 	long fts_number;	        /* local numeric value */
 	void *fts_pointer;	        /* local address value */
-	char *fts_accpath;		/* access path */
-	char *fts_path;			/* root path; == fts_fts->fts_path */
+	char *fts_accpath;		/* access file name */
+	char *fts_path;			/* root name; == fts_fts->fts_path */
 	int fts_errno;			/* errno for this node */
 	int fts_symfd;			/* fd for symlink */
 	size_t fts_pathlen;		/* strlen(fts_path) */