From: Michael Orlitzky <michael@orlitzky.com>
Date: Mon, 26 Feb 2018 02:35:02 +0000 (-0500)
Subject: Allow apply_default_acl() to take a stat pointer for its path argument.
X-Git-Tag: v0.1.0~22
X-Git-Url: https://gitweb.michael.orlitzky.com/?p=apply-default-acl.git;a=commitdiff_plain;h=df929bebddb9852c8e50481169e2fd1b5a01faf6

Allow apply_default_acl() to take a stat pointer for its path argument.

When operating recursively, nftw has already called stat() on the path
that it feeds to apply_default_acl(). Rather than re-stat it, we can
now pass a stat struct pointer in as the second argument to
apply_default_acl(). When not operating recursively, you just pass it
NULL instead, and apply_default_acl() will do the fstat as before.
---

diff --git a/src/apply-default-acl.c b/src/apply-default-acl.c
index 1d59030..c4d0c3b 100644
--- a/src/apply-default-acl.c
+++ b/src/apply-default-acl.c
@@ -534,6 +534,10 @@ int wipe_acls(int fd) {
  * @param path
  *   The path whose ACL we would like to reset to its default.
  *
+ * @param sp
+ *   A pointer to a stat structure for @c path, or @c NULL if you don't
+ *   have one handy.
+ *
  * @param no_exec_mask
  *   The value (either true or false) of the --no-exec-mask flag.
  *
@@ -543,7 +547,9 @@ int wipe_acls(int fd) {
  *     or the parent of @c path is not a directory.
  *   - @c ACL_ERROR - Unexpected library error.
  */
-int apply_default_acl(const char* path, bool no_exec_mask) {
+int apply_default_acl(const char* path,
+		      const struct stat* sp,
+		      bool no_exec_mask) {
 
   if (path == NULL) {
     errno = EINVAL;
@@ -595,16 +601,24 @@ int apply_default_acl(const char* path, bool no_exec_mask) {
    * race condition here, but the window is as small as possible
    * between when we open the file descriptor (look above) and when we
    * fstat it.
+   *
+   * Note: we only need to call fstat ourselves if we weren't passed a
+   * valid pointer to a stat structure (nftw does that).
   */
-  struct stat s;
-  if (fstat(fd, &s) == -1) {
-    perror("apply_default_acl (fstat)");
-    goto cleanup;
+  if (sp == NULL) {
+    struct stat s;
+    if (fstat(fd, &s) == -1) {
+      perror("apply_default_acl (fstat)");
+      goto cleanup;
+    }
+
+    sp = &s;
   }
-  if (!S_ISDIR(s.st_mode)) {
+
+  if (!S_ISDIR(sp->st_mode)) {
     /* If it's not a directory, make sure it's a regular,
        non-hard-linked file. */
-    if (!S_ISREG(s.st_mode) || s.st_nlink != 1) {
+    if (!S_ISREG(sp->st_mode) || sp->st_nlink != 1) {
       result = ACL_FAILURE;
       goto cleanup;
     }
@@ -619,7 +633,7 @@ int apply_default_acl(const char* path, bool no_exec_mask) {
 
   if (!no_exec_mask) {
     /* Never mask the execute bit on directories. */
-    int ace_result = any_can_execute(fd) || S_ISDIR(s.st_mode);
+    int ace_result = any_can_execute(fd) || S_ISDIR(sp->st_mode);
 
     if (ace_result == ACL_ERROR) {
       perror("apply_default_acl (any_can_execute)");
@@ -791,11 +805,11 @@ void usage(const char* program_name) {
  *
  */
 int apply_default_acl_nftw(const char *target,
-			   const struct stat *s,
+			   const struct stat *sp,
 			   int info,
 			   struct FTW *ftw) {
 
-  if (apply_default_acl(target, false)) {
+  if (apply_default_acl(target, sp, false)) {
     return FTW_CONTINUE;
   }
   else {
@@ -813,11 +827,11 @@ int apply_default_acl_nftw(const char *target,
  *
  */
 int apply_default_acl_nftw_x(const char *target,
-			     const struct stat *s,
+			     const struct stat *sp,
 			     int info,
 			     struct FTW *ftw) {
 
-  if (apply_default_acl(target, true)) {
+  if (apply_default_acl(target, sp, true)) {
     return FTW_CONTINUE;
   }
   else {
@@ -854,7 +868,7 @@ int apply_default_acl_nftw_x(const char *target,
 bool apply_default_acl_recursive(const char *target, bool no_exec_mask) {
 
   if (!is_path_directory(target)) {
-    return apply_default_acl(target, no_exec_mask);
+    return apply_default_acl(target, NULL, no_exec_mask);
   }
 
   int max_levels = 256;
@@ -956,7 +970,7 @@ int main(int argc, char* argv[]) {
     }
     else {
       /* It's either a normal file, or we're not operating recursively. */
-      reapp_result = apply_default_acl(target, no_exec_mask);
+      reapp_result = apply_default_acl(target, NULL, no_exec_mask);
     }
 
     if (!reapp_result) {