summaryrefslogtreecommitdiffstats
path: root/contrib/spd_readdir.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 15:49:25 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 15:49:25 +0000
commit464df1d5e5ab1322e2dd0a7796939fff1aeefa9a (patch)
tree6a403684e0978f0287d7f0ec0e5aab1fd31a59e1 /contrib/spd_readdir.c
parentInitial commit. (diff)
downloade2fsprogs-464df1d5e5ab1322e2dd0a7796939fff1aeefa9a.tar.xz
e2fsprogs-464df1d5e5ab1322e2dd0a7796939fff1aeefa9a.zip
Adding upstream version 1.47.0.upstream/1.47.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'contrib/spd_readdir.c')
-rw-r--r--contrib/spd_readdir.c458
1 files changed, 458 insertions, 0 deletions
diff --git a/contrib/spd_readdir.c b/contrib/spd_readdir.c
new file mode 100644
index 0000000..8345fa1
--- /dev/null
+++ b/contrib/spd_readdir.c
@@ -0,0 +1,458 @@
+/*
+ * readdir accelerator
+ *
+ * (C) Copyright 2003, 2004, 2008 by Theodore Ts'o.
+ *
+ * 2008-06-08 Modified by Ross Boylan <RossBoylan stanfordalumni org>
+ * Added support for readdir_r and readdir64_r calls. Note
+ * this has not been tested on anything other than GNU/Linux i386,
+ * and that the regular readdir wrapper will take slightly more
+ * space than Ted's original since it now includes a lock.
+ *
+ * Compile using the command:
+ *
+ * gcc -o spd_readdir.so -shared -fpic spd_readdir.c -ldl
+ *
+ * Use it by setting the LD_PRELOAD environment variable:
+ *
+ * export LD_PRELOAD=/usr/local/sbin/spd_readdir.so
+ *
+ * %Begin-Header%
+ * This file may be redistributed under the terms of the GNU Public
+ * License.
+ * %End-Header%
+ *
+ */
+
+#define ALLOC_STEPSIZE 100
+#define MAX_DIRSIZE 0
+
+#define DEBUG
+/* Util we autoconfiscate spd_readdir... */
+#define HAVE___SECURE_GETENV 1
+#define HAVE_PRCTL 1
+#define HAVE_SYS_PRCTL_H 1
+
+#ifdef DEBUG
+#define DEBUG_DIR(x) {if (do_debug) { x; }}
+#else
+#define DEBUG_DIR(x)
+#endif
+
+#define _GNU_SOURCE
+#define __USE_LARGEFILE64
+
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <stdlib.h>
+#include <string.h>
+#include <dirent.h>
+#include <errno.h>
+#include <dlfcn.h>
+#ifdef HAVE_SYS_PRCTL_H
+#include <sys/prctl.h>
+#else
+#define PR_GET_DUMPABLE 3
+#endif
+#include <pthread.h>
+
+struct dirent_s {
+ unsigned long long d_ino;
+ long long d_off;
+ unsigned short int d_reclen;
+ unsigned char d_type;
+ char *d_name;
+};
+
+struct dir_s {
+ DIR *dir;
+ pthread_mutex_t lock; /* Mutex lock for this structure. */
+ int num;
+ int max;
+ struct dirent_s *dp;
+ int pos;
+ int direct;
+ struct dirent ret_dir;
+ struct dirent64 ret_dir64;
+};
+
+static int (*real_closedir)(DIR *dir) = 0;
+static DIR *(*real_opendir)(const char *name) = 0;
+static DIR *(*real_fdopendir)(int fd) = 0;
+static void *(*real_rewinddir)(DIR *dirp) = 0;
+static struct dirent *(*real_readdir)(DIR *dir) = 0;
+static int (*real_readdir_r)(DIR *dir, struct dirent *entry,
+ struct dirent **result) = 0;
+static struct dirent64 *(*real_readdir64)(DIR *dir) = 0;
+static int (*real_readdir64_r)(DIR *dir, struct dirent64 *entry,
+ struct dirent64 **result) = 0;
+static off_t (*real_telldir)(DIR *dir) = 0;
+static void (*real_seekdir)(DIR *dir, off_t offset) = 0;
+static int (*real_dirfd)(DIR *dir) = 0;
+static unsigned long max_dirsize = MAX_DIRSIZE;
+static int num_open = 0;
+#ifdef DEBUG
+static int do_debug = 0;
+#endif
+
+static char *safe_getenv(const char *arg)
+{
+ if ((getuid() != geteuid()) || (getgid() != getegid()))
+ return NULL;
+#if HAVE_PRCTL
+ if (prctl(PR_GET_DUMPABLE, 0, 0, 0, 0) == 0)
+ return NULL;
+#else
+#if (defined(linux) && defined(SYS_prctl))
+ if (syscall(SYS_prctl, PR_GET_DUMPABLE, 0, 0, 0, 0) == 0)
+ return NULL;
+#endif
+#endif
+
+#if HAVE___SECURE_GETENV
+ return __secure_getenv(arg);
+#else
+ return getenv(arg);
+#endif
+}
+
+static void setup_ptr()
+{
+ char *cp;
+
+ real_opendir = dlsym(RTLD_NEXT, "opendir");
+ real_fdopendir = dlsym(RTLD_NEXT, "fdopendir");
+ real_closedir = dlsym(RTLD_NEXT, "closedir");
+ real_rewinddir = dlsym(RTLD_NEXT, "rewinddir");
+ real_readdir = dlsym(RTLD_NEXT, "readdir");
+ real_readdir_r = dlsym(RTLD_NEXT, "readdir_r");
+ real_readdir64 = dlsym(RTLD_NEXT, "readdir64");
+ real_readdir64_r = dlsym(RTLD_NEXT, "readdir64_r");
+ real_telldir = dlsym(RTLD_NEXT, "telldir");
+ real_seekdir = dlsym(RTLD_NEXT, "seekdir");
+ real_dirfd = dlsym(RTLD_NEXT, "dirfd");
+ if ((cp = safe_getenv("SPD_READDIR_MAX_SIZE")) != NULL) {
+ max_dirsize = atol(cp);
+ }
+#ifdef DEBUG
+ if (safe_getenv("SPD_READDIR_DEBUG")) {
+ printf("initialized!\n");
+ do_debug++;
+ }
+#endif
+}
+
+static void free_cached_dir(struct dir_s *dirstruct)
+{
+ int i;
+
+ pthread_mutex_destroy(&(dirstruct->lock));
+
+ if (!dirstruct->dp)
+ return;
+
+ for (i=0; i < dirstruct->num; i++) {
+ free(dirstruct->dp[i].d_name);
+ }
+ free(dirstruct->dp);
+ dirstruct->dp = 0;
+ dirstruct->max = dirstruct->num = 0;
+}
+
+static int ino_cmp(const void *a, const void *b)
+{
+ const struct dirent_s *ds_a = (const struct dirent_s *) a;
+ const struct dirent_s *ds_b = (const struct dirent_s *) b;
+ ino_t i_a, i_b;
+
+ i_a = ds_a->d_ino;
+ i_b = ds_b->d_ino;
+
+ if (ds_a->d_name[0] == '.') {
+ if (ds_a->d_name[1] == 0)
+ i_a = 0;
+ else if ((ds_a->d_name[1] == '.') && (ds_a->d_name[2] == 0))
+ i_a = 1;
+ }
+ if (ds_b->d_name[0] == '.') {
+ if (ds_b->d_name[1] == 0)
+ i_b = 0;
+ else if ((ds_b->d_name[1] == '.') && (ds_b->d_name[2] == 0))
+ i_b = 1;
+ }
+
+ return (i_a - i_b);
+}
+
+static struct dir_s *alloc_dirstruct(DIR *dir)
+{
+ struct dir_s *dirstruct;
+ static pthread_mutexattr_t mutexattr;
+ mutexattr.__align = PTHREAD_MUTEX_RECURSIVE;
+
+ dirstruct = malloc(sizeof(struct dir_s));
+ if (dirstruct)
+ memset(dirstruct, 0, sizeof(struct dir_s));
+ dirstruct->dir = dir;
+ pthread_mutex_init(&(dirstruct->lock), &mutexattr);
+ return dirstruct;
+}
+
+static void cache_dirstruct(struct dir_s *dirstruct)
+{
+ struct dirent_s *ds, *dnew;
+ struct dirent64 *d;
+
+ while ((d = (*real_readdir64)(dirstruct->dir)) != NULL) {
+ if (dirstruct->num >= dirstruct->max) {
+ dirstruct->max += ALLOC_STEPSIZE;
+ DEBUG_DIR(printf("Reallocating to size %d\n",
+ dirstruct->max));
+ dnew = realloc(dirstruct->dp,
+ dirstruct->max * sizeof(struct dir_s));
+ if (!dnew)
+ goto nomem;
+ dirstruct->dp = dnew;
+ }
+ ds = &dirstruct->dp[dirstruct->num++];
+ ds->d_ino = d->d_ino;
+ ds->d_off = d->d_off;
+ ds->d_reclen = d->d_reclen;
+ ds->d_type = d->d_type;
+ if ((ds->d_name = malloc(strlen(d->d_name)+1)) == NULL) {
+ dirstruct->num--;
+ goto nomem;
+ }
+ strcpy(ds->d_name, d->d_name);
+ DEBUG_DIR(printf("readdir: %lu %s\n",
+ (unsigned long) d->d_ino, d->d_name));
+ }
+ qsort(dirstruct->dp, dirstruct->num, sizeof(struct dirent_s), ino_cmp);
+ return;
+nomem:
+ DEBUG_DIR(printf("No memory, backing off to direct readdir\n"));
+ free_cached_dir(dirstruct);
+ dirstruct->direct = 1;
+}
+
+DIR *opendir(const char *name)
+{
+ DIR *dir;
+ struct dir_s *dirstruct;
+ struct stat st;
+
+ if (!real_opendir)
+ setup_ptr();
+
+ DEBUG_DIR(printf("Opendir(%s) (%d open)\n", name, num_open++));
+ dir = (*real_opendir)(name);
+ if (!dir)
+ return NULL;
+
+ dirstruct = alloc_dirstruct(dir);
+ if (!dirstruct) {
+ (*real_closedir)(dir);
+ errno = -ENOMEM;
+ return NULL;
+ }
+
+ if (max_dirsize && (stat(name, &st) == 0) &&
+ (st.st_size > max_dirsize)) {
+ DEBUG_DIR(printf("Directory size %ld, using direct readdir\n",
+ st.st_size));
+ dirstruct->direct = 1;
+ return (DIR *) dirstruct;
+ }
+
+ cache_dirstruct(dirstruct);
+ return ((DIR *) dirstruct);
+}
+
+DIR *fdopendir(int fd)
+{
+ DIR *dir;
+ struct dir_s *dirstruct;
+ struct stat st;
+
+ if (!real_fdopendir)
+ setup_ptr();
+
+ DEBUG_DIR(printf("fdopendir(%d) (%d open)\n", fd, num_open++));
+ dir = (*real_fdopendir)(fd);
+ if (!dir)
+ return NULL;
+
+ dirstruct = alloc_dirstruct(dir);
+ if (!dirstruct) {
+ (*real_closedir)(dir);
+ errno = -ENOMEM;
+ return NULL;
+ }
+
+ if (max_dirsize && (fstat(fd, &st) == 0) &&
+ (st.st_size > max_dirsize)) {
+ DEBUG_DIR(printf("Directory size %ld, using direct readdir\n",
+ st.st_size));
+ dirstruct->dir = dir;
+ dirstruct->direct = 1;
+ return (DIR *) dirstruct;
+ }
+
+ cache_dirstruct(dirstruct);
+ return ((DIR *) dirstruct);
+}
+
+int closedir(DIR *dir)
+{
+ struct dir_s *dirstruct = (struct dir_s *) dir;
+
+ DEBUG_DIR(printf("Closedir (%d open)\n", --num_open));
+ if (dirstruct->dir)
+ (*real_closedir)(dirstruct->dir);
+
+ free_cached_dir(dirstruct);
+ free(dirstruct);
+ return 0;
+}
+
+struct dirent *readdir(DIR *dir)
+{
+ struct dir_s *dirstruct = (struct dir_s *) dir;
+ struct dirent_s *ds;
+
+ if (dirstruct->direct)
+ return (*real_readdir)(dirstruct->dir);
+
+ if (dirstruct->pos >= dirstruct->num)
+ return NULL;
+
+ ds = &dirstruct->dp[dirstruct->pos++];
+ dirstruct->ret_dir.d_ino = ds->d_ino;
+ dirstruct->ret_dir.d_off = ds->d_off;
+ dirstruct->ret_dir.d_reclen = ds->d_reclen;
+ dirstruct->ret_dir.d_type = ds->d_type;
+ strncpy(dirstruct->ret_dir.d_name, ds->d_name,
+ sizeof(dirstruct->ret_dir.d_name));
+
+ return (&dirstruct->ret_dir);
+}
+
+int readdir_r(DIR *dir, struct dirent *entry, struct dirent **result)
+{
+ struct dir_s *dirstruct = (struct dir_s *) dir;
+ struct dirent_s *ds;
+
+ if (dirstruct->direct)
+ return (*real_readdir_r)(dirstruct->dir, entry, result);
+
+ pthread_mutex_lock(&(dirstruct->lock));
+ if (dirstruct->pos >= dirstruct->num) {
+ *result = NULL;
+ } else {
+ ds = &dirstruct->dp[dirstruct->pos++];
+ entry->d_ino = ds->d_ino;
+ entry->d_off = ds->d_off;
+ entry->d_reclen = ds->d_reclen;
+ entry->d_type = ds->d_type;
+ strncpy(entry->d_name, ds->d_name, sizeof(entry->d_name));
+ *result = entry;
+ }
+ pthread_mutex_unlock(&(dirstruct->lock));
+ return 0;
+}
+
+struct dirent64 *readdir64(DIR *dir)
+{
+ struct dir_s *dirstruct = (struct dir_s *) dir;
+ struct dirent_s *ds;
+
+ if (dirstruct->direct)
+ return (*real_readdir64)(dirstruct->dir);
+
+ if (dirstruct->pos >= dirstruct->num)
+ return NULL;
+
+ ds = &dirstruct->dp[dirstruct->pos++];
+ dirstruct->ret_dir64.d_ino = ds->d_ino;
+ dirstruct->ret_dir64.d_off = ds->d_off;
+ dirstruct->ret_dir64.d_reclen = ds->d_reclen;
+ dirstruct->ret_dir64.d_type = ds->d_type;
+ strncpy(dirstruct->ret_dir64.d_name, ds->d_name,
+ sizeof(dirstruct->ret_dir64.d_name));
+
+ return (&dirstruct->ret_dir64);
+}
+
+int readdir64_r (DIR *__restrict dir,
+ struct dirent64 *__restrict entry,
+ struct dirent64 **__restrict result)
+{
+ struct dir_s *dirstruct = (struct dir_s *) dir;
+ struct dirent_s *ds;
+
+ if (dirstruct->direct)
+ return (*real_readdir64_r)(dir, entry, result);
+ pthread_mutex_lock(&(dirstruct->lock));
+ if (dirstruct->pos >= dirstruct->num) {
+ *result = NULL;
+ } else {
+ ds = &dirstruct->dp[dirstruct->pos++];
+ entry->d_ino = ds->d_ino;
+ entry->d_off = ds->d_off;
+ entry->d_reclen = ds->d_reclen;
+ entry->d_type = ds->d_type;
+ strncpy(entry->d_name, ds->d_name,
+ sizeof(entry->d_name));
+ *result = entry;
+ }
+ pthread_mutex_unlock(&(dirstruct->lock));
+ return 0;
+}
+
+off_t telldir(DIR *dir)
+{
+ struct dir_s *dirstruct = (struct dir_s *) dir;
+
+ if (dirstruct->direct)
+ return (*real_telldir)(dirstruct->dir);
+
+ return ((off_t) dirstruct->pos);
+}
+
+void seekdir(DIR *dir, off_t offset)
+{
+ struct dir_s *dirstruct = (struct dir_s *) dir;
+
+ if (dirstruct->direct) {
+ (*real_seekdir)(dirstruct->dir, offset);
+ return;
+ }
+
+ dirstruct->pos = offset;
+}
+
+void rewinddir(DIR *dir)
+{
+ struct dir_s *dirstruct = (struct dir_s *) dir;
+
+ (*real_rewinddir)(dirstruct->dir);
+ if (dirstruct->direct)
+ return;
+
+ pthread_mutex_lock(&(dirstruct->lock));
+ dirstruct->pos = 0;
+ free_cached_dir(dirstruct);
+ cache_dirstruct(dirstruct);
+ pthread_mutex_unlock(&(dirstruct->lock));
+}
+
+int dirfd(DIR *dir)
+{
+ struct dir_s *dirstruct = (struct dir_s *) dir;
+ int fd = (*real_dirfd)(dirstruct->dir);
+
+ DEBUG_DIR(printf("dirfd %d, %p\n", fd, real_dirfd));
+ return fd;
+}