> > What would be the next steps for this investigation ?
> >
>
> I need to find some time and to debug the reason for 9p open failure
> so we can make sure the problem is in 9p code and report more details
> of the bug to 9p maintainers, but since a simple reproducer exists,
> they can also try to reproduce the issue right now.
FWIW, the attached reproducer mimics git clone rename_over pattern closer.
It reproduces fanotify_read() errors sometimes, not always,
with either CLOSE_WRITE or OPEN_PERM | CLOSE_WRITE.
maybe CLOSE_WRITE alone has better odds - I'm not sure.
Thanks,
Amir.
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <errno.h>
#include <pthread.h>
void *thread(void *ptr)
{
char filename[10] = {};
const char *new_filename = "config";
const char *content = "Hello, this is a test with file rename operation.\n";
char buffer[100];
int fd;
ssize_t bytes_read;
int counter=0;
fprintf(stderr,"Thread %ld started\n", (long)ptr);
sprintf(filename,"config.%ld", (long)ptr);
retry:
// Create a new file and write to it
fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0644);
if (fd == -1) {
perror("Failed to create file");
return NULL;
}
if (write(fd, content, strlen(content)) == -1) {
perror("Failed to write to file");
close(fd);
return NULL;
}
close(fd);
// Rename the file
if (rename(filename, new_filename) != 0) {
perror("Failed to rename file");
return NULL;
}
fd = open(new_filename, O_RDONLY);
if (fd == -1) {
perror("Failed to open renamed file");
return NULL;
}
bytes_read = read(fd, buffer, sizeof(buffer) - 1);
if (bytes_read == -1) {
perror("Failed to read from file");
close(fd);
return NULL;
}
buffer[bytes_read] = '\0'; // Null-terminate the buffer
close(fd);
// Open the renamed file and read the content
if (counter++ < 100)
goto retry;
printf("File saved %d iterations\n", counter);
// Print the content
printf("Content of %s:\n%s", new_filename, buffer);
return ptr;
}
int main() {
pthread_t th[10];
long i;
for (i = 0; i < 10; i++)
pthread_create(&th[i], NULL, *thread, (void *)i);
for (i = 0; i < 10; i++)
pthread_join(th[i] ,NULL);
return EXIT_SUCCESS;
}
