Hello
When using readdir() on a directory with many files or long file names
it can happen that it returns the same file name twice. Attached is
a program that demonstrates this.
I have traced this problem back to linux-2.6.10-rc1-bk18 and all kernels
after this one are effected. linux-2.6.10-rc1-bk17 is still okay. If I
reverse the following patch in linux-2.6.10-rc1-bk18, readdir() works
again correctly:
diff -Nru linux-2.6.10-rc1-bk17/fs/ext3/dir.c linux-2.6.10-rc1-bk18/fs/ext3/dir.c
--- linux-2.6.10-rc1-bk17/fs/ext3/dir.c 2004-10-18 23:54:30.000000000 +0200
+++ linux-2.6.10-rc1-bk18/fs/ext3/dir.c 2004-12-05 16:44:21.000000000 +0100
@@ -418,7 +418,7 @@
get_dtype(sb, fname->file_type));
if (error) {
filp->f_pos = curr_pos;
- info->extra_fname = fname->next;
+ info->extra_fname = fname;
return error;
}
fname = fname->next;
@@ -457,9 +457,12 @@
* If there are any leftover names on the hash collision
* chain, return them first.
*/
- if (info->extra_fname &&
- call_filldir(filp, dirent, filldir, info->extra_fname))
- goto finished;
+ if (info->extra_fname) {
+ if(call_filldir(filp, dirent, filldir, info->extra_fname))
+ goto finished;
+ else
+ goto next_entry;
+ }
if (!info->curr_node)
info->curr_node = rb_first(&info->root);
@@ -492,7 +495,7 @@
info->curr_minor_hash = fname->minor_hash;
if (call_filldir(filp, dirent, filldir, fname))
break;
-
+next_entry:
info->curr_node = rb_next(info->curr_node);
if (!info->curr_node) {
if (info->next_hash == ~0) {
Regards,
Holger
PS: Please CC me since I am not on this list.#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include <fcntl.h>
#include <errno.h>
int
main(int argc, char *argv[])
{
int fd, filename_length, i, j, no_of_files;
char pathname[256], *ptr,
prevname[256],
to_pathname[256], *to_ptr;
DIR *dp;
struct dirent *p_dir;
struct stat stat_buf;
if (argc != 3)
{
fprintf(stderr, "Usage: %s <no. of files> <filename length>\n", argv[0]);
exit(1);
}
else
{
no_of_files = atoi(argv[1]);
filename_length = atoi(argv[2]);
}
/* Create necessary dirs. */
(void)mkdir("testbugdir", S_IRUSR|S_IWUSR|S_IXUSR);
(void)mkdir("testbugdir/input", S_IRUSR|S_IWUSR|S_IXUSR);
(void)mkdir("testbugdir/output", S_IRUSR|S_IWUSR|S_IXUSR);
/* Create input files. */
strcpy(pathname, "testbugdir/input/");
ptr = pathname + strlen(pathname);
for (i = 0; i < no_of_files; i++)
{
sprintf(ptr, "%0*d", filename_length, i);
if ((fd = open(pathname, O_RDWR|O_CREAT|O_TRUNC, S_IRUSR|S_IWUSR)) == -1)
{
fprintf(stderr, "open() error %s : %s\n", pathname, strerror(errno));
exit(1);
}
close(fd);
}
/* Move input files to output. */
strcpy(to_pathname, "testbugdir/output/");
to_ptr = to_pathname + strlen(to_pathname);
*ptr = '\0';
if ((dp = opendir(pathname)) == NULL)
{
fprintf(stderr, "opendir() error (%s) : %s\n",
pathname, strerror(errno));
exit(1);
}
prevname[0] = '\0';
while ((p_dir = readdir(dp)) != NULL)
{
if (p_dir->d_name[0] == '.')
{
continue;
}
if (strcmp(prevname, p_dir->d_name) == 0)
{
fprintf(stderr, "BUG: %s appears twice!\n", p_dir->d_name);
}
strcpy(prevname, p_dir->d_name);
strcpy(ptr, p_dir->d_name);
if (stat(pathname, &stat_buf) < 0)
{
fprintf(stderr, "stat() error (%s) : %s\n",
pathname, strerror(errno));
continue;
}
strcpy(to_ptr, p_dir->d_name);
if (rename(pathname, to_pathname) == -1)
{
fprintf(stderr, "rename() error (file %d) : %s\n",
pathname, strerror(errno));
}
}
(void)closedir(dp);
/* Remove everyting. */
*to_ptr = '\0';
if ((dp = opendir(to_pathname)) == NULL)
{
fprintf(stderr, "opendir() error (%s) : %s\n",
to_pathname, strerror(errno));
exit(1);
}
prevname[0] = '\0';
while ((p_dir = readdir(dp)) != NULL)
{
if (p_dir->d_name[0] == '.')
{
continue;
}
if (strcmp(prevname, p_dir->d_name) == 0)
{
fprintf(stderr, "BUG: %s appears twice!\n", p_dir->d_name);
}
strcpy(prevname, p_dir->d_name);
strcpy(to_ptr, p_dir->d_name);
if (unlink(to_pathname) == -1)
{
fprintf(stderr, "unlink() error (%s) : %s\n",
to_pathname, strerror(errno));
continue;
}
}
(void)closedir(dp);
if (rmdir("testbugdir/input") == -1)
{
fprintf(stderr, "rmdir() error (testbugdir/input) : %s\n",
strerror(errno));
}
if (rmdir("testbugdir/output") == -1)
{
fprintf(stderr, "rmdir() error (testbugdir/output) : %s\n",
strerror(errno));
}
if (rmdir("testbugdir") == -1)
{
fprintf(stderr, "rmdir() error (testbugdir) : %s\n", strerror(errno));
}
exit(0);
}
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