Messages in this thread Patch in this message | | | Date | Thu, 08 Dec 2005 19:44:41 +0300 | From | Valentine Barshak <> | Subject | [PATCH] posix_fadvise bug (unexpected success on FIFO/pipe) |
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Hello, all. I have the following problem with posix_fadvise : the system call succeeds on a pipe or FIFO, although it has to fail with ESPIPE (EINVAL on linux) return value. Looks like a kernel bug. I've attached a small test for posix_fadvise and a patch for linux kernel 2.6.14 that fixes the problem. The patch makes posix_fadvise return ESPIPE on FIFO/pipe in order to be fully POSIX-compliant. Please, take a look at these. Thanks. #define _GNU_SOURCE #include <stdio.h> #include <unistd.h> #include <stdlib.h> #include <fcntl.h> #include <sys/stat.h> #include <sys/types.h> #include <errno.h>
int main() { int retval, fd;
if (mkfifo("fifo", 0666) < 0) { printf("create fifo error\n"); return 1; } fd = open("fifo", O_RDWR); if (fd < 0) { printf("open fifo error\n"); remove("fifo"); return 1; } retval = posix_fadvise(fd, 0, 0, POSIX_FADV_NORMAL); if (retval) { printf("Expected fail - The fd argument is associated with a pipe or FIFO.\n"); if (retval != ESPIPE) printf("Unexpected ERRNO %d (Expected %d)\n", retval, ESPIPE); } else printf("Unexpected success - The fd argument is associated with a pipe or FIFO.\n");
close(fd); remove("fifo");
if (retval) return 0; return 1; } --- a/mm/fadvise.c 2005-10-10 22:54:29.000000000 +0400 +++ b/mm/fadvise.c 2005-12-06 23:04:19.980711464 +0300 @@ -37,6 +37,11 @@ if (!file) return -EBADF; + if (S_ISFIFO(file->f_dentry->d_inode->i_mode)) { + ret = -ESPIPE; + goto out; + } + mapping = file->f_mapping; if (!mapping || len < 0) { ret = -EINVAL;
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