[hackers] [sbase] libutil/recurse: Use a single path buffer, and directory fd || Michael Forney

From: <git_AT_suckless.org>
Date: Thu, 5 Mar 2020 10:22:41 +0100 (CET)

commit edbcc223ea9ef9c3f039352f787af0644d816ee7
Author: Michael Forney <mforney_AT_mforney.org>
AuthorDate: Sun Dec 22 13:53:46 2019 -0800
Commit: Michael Forney <mforney_AT_mforney.org>
CommitDate: Thu Mar 5 00:45:53 2020 -0800

    libutil/recurse: Use a single path buffer, and directory fd
    
    This way, we don't use PATH_MAX bytes on the stack per path component,
    and don't have to keep copying the complete path around.

diff --git a/chgrp.c b/chgrp.c
index 04b2dd0..d336c88 100644
--- a/chgrp.c
+++ b/chgrp.c
_AT_@ -14,18 +14,17 @@ static gid_t gid = -1;
 static int ret = 0;
 
 static void
-chgrp(const char *path, struct stat *st, void *data, struct recursor *r)
+chgrp(int dirfd, const char *name, struct stat *st, void *data, struct recursor *r)
 {
         int flags = 0;
 
         if ((r->maxdepth == 0 && r->follow == 'P') || (r->follow == 'H' && r->depth) || (hflag && !(r->depth)))
                 flags |= AT_SYMLINK_NOFOLLOW;
-
- if (fchownat(AT_FDCWD, path, -1, gid, flags) < 0) {
- weprintf("chown %s:", path);
+ if (fchownat(dirfd, name, -1, gid, flags) < 0) {
+ weprintf("chown %s:", r->path);
                 ret = 1;
         } else if (S_ISDIR(st->st_mode)) {
- recurse(path, NULL, r);
+ recurse(dirfd, name, NULL, r);
         }
 }
 
_AT_@ -71,7 +70,7 @@ main(int argc, char *argv[])
         }
 
         for (argc--, argv++; *argv; argc--, argv++)
- recurse(*argv, NULL, &r);
+ recurse(AT_FDCWD, *argv, NULL, &r);
 
         return ret || recurse_status;
 }
diff --git a/chmod.c b/chmod.c
index 7b9afe8..554959f 100644
--- a/chmod.c
+++ b/chmod.c
_AT_@ -1,4 +1,5 @@
 /* See LICENSE file for copyright and license details. */
+#include <fcntl.h>
 #include <sys/stat.h>
 
 #include "fs.h"
_AT_@ -9,16 +10,16 @@ static mode_t mask = 0;
 static int ret = 0;
 
 static void
-chmodr(const char *path, struct stat *st, void *data, struct recursor *r)
+chmodr(int dirfd, const char *name, struct stat *st, void *data, struct recursor *r)
 {
         mode_t m;
 
         m = parsemode(modestr, st->st_mode, mask);
- if (!S_ISLNK(st->st_mode) && chmod(path, m) < 0) {
- weprintf("chmod %s:", path);
+ if (!S_ISLNK(st->st_mode) && fchmodat(dirfd, name, m, 0) < 0) {
+ weprintf("chmod %s:", r->path);
                 ret = 1;
         } else if (S_ISDIR(st->st_mode)) {
- recurse(path, NULL, r);
+ recurse(dirfd, name, NULL, r);
         }
 }
 
_AT_@ -71,7 +72,7 @@ done:
                 usage();
 
         for (--argc, ++argv; *argv; argc--, argv++)
- recurse(*argv, NULL, &r);
+ recurse(AT_FDCWD, *argv, NULL, &r);
 
         return ret || recurse_status;
 }
diff --git a/chown.c b/chown.c
index dcd4914..3aaedef 100644
--- a/chown.c
+++ b/chown.c
_AT_@ -17,18 +17,18 @@ static gid_t gid = -1;
 static int ret = 0;
 
 static void
-chownpwgr(const char *path, struct stat *st, void *data, struct recursor *r)
+chownpwgr(int dirfd, const char *name, struct stat *st, void *data, struct recursor *r)
 {
         int flags = 0;
 
         if ((r->maxdepth == 0 && r->follow == 'P') || (r->follow == 'H' && r->depth) || (hflag && !(r->depth)))
                 flags |= AT_SYMLINK_NOFOLLOW;
 
- if (fchownat(AT_FDCWD, path, uid, gid, flags) < 0) {
- weprintf("chown %s:", path);
+ if (fchownat(dirfd, name, uid, gid, flags) < 0) {
+ weprintf("chown %s:", r->path);
                 ret = 1;
         } else if (S_ISDIR(st->st_mode)) {
- recurse(path, NULL, r);
+ recurse(dirfd, name, NULL, r);
         }
 }
 
_AT_@ -99,7 +99,7 @@ main(int argc, char *argv[])
                 usage();
 
         for (argc--, argv++; *argv; argc--, argv++)
- recurse(*argv, NULL, &r);
+ recurse(AT_FDCWD, *argv, NULL, &r);
 
         return ret || recurse_status;
 }
diff --git a/du.c b/du.c
index 4ceac66..fa6a8d6 100644
--- a/du.c
+++ b/du.c
_AT_@ -3,6 +3,7 @@
 #include <sys/types.h>
 
 #include <errno.h>
+#include <fcntl.h>
 #include <limits.h>
 #include <stdint.h>
 #include <stdlib.h>
_AT_@ -35,19 +36,19 @@ nblks(blkcnt_t blocks)
 }
 
 static void
-du(const char *path, struct stat *st, void *data, struct recursor *r)
+du(int dirfd, const char *path, struct stat *st, void *data, struct recursor *r)
 {
         off_t *total = data, subtotal;
 
         subtotal = nblks(st->st_blocks);
         if (S_ISDIR(st->st_mode))
- recurse(path, &subtotal, r);
+ recurse(dirfd, path, &subtotal, r);
         *total += subtotal;
 
         if (!r->depth)
- printpath(*total, path);
+ printpath(*total, r->path);
         else if (!sflag && r->depth <= maxdepth && (S_ISDIR(st->st_mode) || aflag))
- printpath(subtotal, path);
+ printpath(subtotal, r->path);
 }
 
 static void
_AT_@ -104,11 +105,11 @@ main(int argc, char *argv[])
                 blksize = 1024;
 
         if (!argc) {
- recurse(".", &n, &r);
+ recurse(AT_FDCWD, ".", &n, &r);
         } else {
                 for (; *argv; argc--, argv++) {
                         n = 0;
- recurse(*argv, &n, &r);
+ recurse(AT_FDCWD, *argv, &n, &r);
                 }
         }
 
diff --git a/fs.h b/fs.h
index 15ae5f4..00ecd3b 100644
--- a/fs.h
+++ b/fs.h
_AT_@ -1,4 +1,5 @@
 /* See LICENSE file for copyright and license details. */
+#include <limits.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 
_AT_@ -9,7 +10,9 @@ struct history {
 };
 
 struct recursor {
- void (*fn)(const char *, struct stat *st, void *, struct recursor *);
+ void (*fn)(int, const char *, struct stat *, void *, struct recursor *);
+ char path[PATH_MAX];
+ size_t pathlen;
         struct history *hist;
         int depth;
         int maxdepth;
_AT_@ -37,7 +40,7 @@ extern int rm_status;
 
 extern int recurse_status;
 
-void recurse(const char *, void *, struct recursor *);
+void recurse(int, const char *, void *, struct recursor *);
 
 int cp(const char *, const char *, int);
-void rm(const char *, struct stat *st, void *, struct recursor *);
+void rm(int, const char *, struct stat *st, void *, struct recursor *);
diff --git a/libutil/recurse.c b/libutil/recurse.c
index e150fb9..e21d815 100644
--- a/libutil/recurse.c
+++ b/libutil/recurse.c
_AT_@ -16,27 +16,30 @@
 int recurse_status = 0;
 
 void
-recurse(const char *path, void *data, struct recursor *r)
+recurse(int dirfd, const char *name, void *data, struct recursor *r)
 {
         struct dirent *d;
         struct history *new, *h;
         struct stat st, dst;
         DIR *dp;
- char subpath[PATH_MAX];
- int flags = 0;
+ int flags = 0, fd;
+ size_t pathlen = r->pathlen;
+
+ if (dirfd == AT_FDCWD)
+ pathlen = estrlcpy(r->path, name, sizeof(r->path));
 
         if (r->follow == 'P' || (r->follow == 'H' && r->depth))
                 flags |= AT_SYMLINK_NOFOLLOW;
 
- if (fstatat(AT_FDCWD, path, &st, flags) < 0) {
+ if (fstatat(dirfd, name, &st, flags) < 0) {
                 if (!(r->flags & SILENT)) {
- weprintf("stat %s:", path);
+ weprintf("stat %s:", r->path);
                         recurse_status = 1;
                 }
                 return;
         }
         if (!S_ISDIR(st.st_mode)) {
- r->fn(path, &st, data, r);
+ r->fn(dirfd, name, &st, data, r);
                 return;
         }
 
_AT_@ -51,35 +54,39 @@ recurse(const char *path, void *data, struct recursor *r)
                         return;
 
         if (!r->depth && (r->flags & DIRFIRST))
- r->fn(path, &st, data, r);
+ r->fn(dirfd, name, &st, data, r);
 
         if (!r->maxdepth || r->depth + 1 < r->maxdepth) {
- if (!(dp = opendir(path))) {
+ fd = openat(dirfd, name, O_RDONLY | O_CLOEXEC | O_DIRECTORY);
+ if (fd < 0) {
+ weprintf("open %s:", r->path);
+ recurse_status = 1;
+ }
+ if (!(dp = fdopendir(fd))) {
                         if (!(r->flags & SILENT)) {
- weprintf("opendir %s:", path);
+ weprintf("fdopendir:");
                                 recurse_status = 1;
                         }
                         return;
                 }
+ if (r->path[pathlen - 1] != '/')
+ pathlen += estrlcpy(r->path + pathlen, "/", sizeof(r->path) - pathlen);
+ if (r->follow == 'H')
+ flags |= AT_SYMLINK_NOFOLLOW;
                 while ((d = readdir(dp))) {
- if (r->follow == 'H')
- flags |= AT_SYMLINK_NOFOLLOW;
                         if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
                                 continue;
- estrlcpy(subpath, path, sizeof(subpath));
- if (path[strlen(path) - 1] != '/')
- estrlcat(subpath, "/", sizeof(subpath));
- estrlcat(subpath, d->d_name, sizeof(subpath));
- if (fstatat(AT_FDCWD, subpath, &dst, flags) < 0) {
+ r->pathlen = pathlen + estrlcpy(r->path + pathlen, d->d_name, sizeof(r->path) - pathlen);
+ if (fstatat(fd, d->d_name, &dst, flags) < 0) {
                                 if (!(r->flags & SILENT)) {
- weprintf("stat %s:", subpath);
+ weprintf("stat %s:", r->path);
                                         recurse_status = 1;
                                 }
                         } else if ((r->flags & SAMEDEV) && dst.st_dev != st.st_dev) {
                                 continue;
                         } else {
                                 r->depth++;
- r->fn(subpath, &dst, data, r);
+ r->fn(fd, d->d_name, &dst, data, r);
                                 r->depth--;
                         }
                 }
_AT_@ -88,7 +95,7 @@ recurse(const char *path, void *data, struct recursor *r)
 
         if (!r->depth) {
                 if (!(r->flags & DIRFIRST))
- r->fn(path, &st, data, r);
+ r->fn(dirfd, name, &st, data, r);
 
                 while (r->hist) {
                         h = r->hist;
diff --git a/libutil/rm.c b/libutil/rm.c
index 11c20fb..8d4be08 100644
--- a/libutil/rm.c
+++ b/libutil/rm.c
_AT_@ -2,6 +2,7 @@
 #include <sys/stat.h>
 
 #include <errno.h>
+#include <fcntl.h>
 #include <stdio.h>
 #include <unistd.h>
 
_AT_@ -11,20 +12,20 @@
 int rm_status = 0;
 
 void
-rm(const char *path, struct stat *st, void *data, struct recursor *r)
+rm(int dirfd, const char *name, struct stat *st, void *data, struct recursor *r)
 {
         if (!r->maxdepth && S_ISDIR(st->st_mode)) {
- recurse(path, NULL, r);
+ recurse(dirfd, name, NULL, r);
 
- if (rmdir(path) < 0) {
+ if (unlinkat(dirfd, name, AT_REMOVEDIR) < 0) {
                         if (!(r->flags & SILENT))
- weprintf("rmdir %s:", path);
+ weprintf("rmdir %s:", r->path);
                         if (!((r->flags & SILENT) && errno == ENOENT))
                                 rm_status = 1;
                 }
- } else if (unlink(path) < 0) {
+ } else if (unlinkat(dirfd, name, 0) < 0) {
                 if (!(r->flags & SILENT))
- weprintf("unlink %s:", path);
+ weprintf("unlink %s:", r->path);
                 if (!((r->flags & SILENT) && errno == ENOENT))
                         rm_status = 1;
         }
diff --git a/mv.c b/mv.c
index 2cf98d1..c93f72d 100644
--- a/mv.c
+++ b/mv.c
_AT_@ -2,6 +2,7 @@
 #include <sys/stat.h>
 
 #include <errno.h>
+#include <fcntl.h>
 #include <stdio.h>
 
 #include "fs.h"
_AT_@ -21,7 +22,7 @@ mv(const char *s1, const char *s2, int depth)
                 cp_aflag = cp_rflag = cp_pflag = 1;
                 cp_follow = 'P';
                 cp(s1, s2, depth);
- recurse(s1, NULL, &r);
+ recurse(AT_FDCWD, s1, NULL, &r);
                 return (mv_status = cp_status || rm_status);
         }
         mv_status = 1;
diff --git a/rm.c b/rm.c
index 42bc022..b776d0f 100644
--- a/rm.c
+++ b/rm.c
_AT_@ -1,4 +1,6 @@
 /* See LICENSE file for copyright and license details. */
+#include <fcntl.h>
+
 #include "fs.h"
 #include "util.h"
 
_AT_@ -34,7 +36,7 @@ main(int argc, char *argv[])
         }
 
         for (; *argv; argc--, argv++)
- recurse(*argv, NULL, &r);
+ recurse(AT_FDCWD, *argv, NULL, &r);
 
         return rm_status || recurse_status;
 }
diff --git a/tar.c b/tar.c
index f9158c2..603e544 100644
--- a/tar.c
+++ b/tar.c
_AT_@ -368,14 +368,14 @@ print(char *fname, ssize_t l, char b[BLKSIZ])
 }
 
 static void
-c(const char *path, struct stat *st, void *data, struct recursor *r)
+c(int dirfd, const char *name, struct stat *st, void *data, struct recursor *r)
 {
- archive(path);
+ archive(r->path);
         if (vflag)
- puts(path);
+ puts(r->path);
 
         if (S_ISDIR(st->st_mode))
- recurse(path, NULL, r);
+ recurse(dirfd, name, NULL, r);
 }
 
 static void
_AT_@ -578,7 +578,7 @@ main(int argc, char *argv[])
                 if (chdir(dir) < 0)
                         eprintf("chdir %s:", dir);
                 for (; *argv; argc--, argv++)
- recurse(*argv, NULL, &r);
+ recurse(AT_FDCWD, *argv, NULL, &r);
                 break;
         case 't':
         case 'x':
Received on Thu Mar 05 2020 - 10:22:41 CET

This archive was generated by hypermail 2.3.0 : Thu Mar 05 2020 - 10:24:36 CET