Hi, A quick google search shows that the sus v3 version of mkdir(2) has reference to EMLINK error http://www.opengroup.org/onlinepubs/000095399/functions/mkdir.html " [EMLINK] The link count of the parent directory would exceed {LINK_MAX}. " Please let me know your opinion on this. Best Regards, Maxin B. John On Mon, Jun 21, 2010 at 9:18 PM, Maxin John <maxin.john@xxxxxxxxx> wrote: > Dear Michael, > > While executing the below given program in ext3 file system, I came > across the EMLINK error in mkdir(2) syscall. > > # cat test_max_directories.c > > #include <stdio.h> > #include <sys/stat.h> > #include <fcntl.h> > #include <stdlib.h> > #include <errno.h> > > int main() > { > char dirname[50]; > int i; > /* The max number of subdirectories in one directory for ext3 is 32000 */ > int limit = 32001; > > for (i = 0; i < limit; i++) { > sprintf(dirname, "testdir%d", i); > if ((mkdir(dirname, 00777)) == -1) { > perror("Error in creating directory!"); > printf("errno = %d\n", errno); > exit(1); > } > } > return 0; > } > > > # ./a.out > Error in creating directory!: Too many links > errno = 29 > > An strace of this execution shows that the mkdir(2) call generates an > EMLINK error when it reaches the limit of maximum number of sub > directories in one directory > > #strace ./a.out > ----------------------------------- > ..... > mkdir("testdir31998", 0777) = -1 EMLINK (Too many links) > dup(2) = 3 > fcntl64(3, F_GETFL) = 0x8002 (flags O_RDWR|O_LARGEFILE) > brk(0) = 0x804a000 > brk(0x806b000) = 0x806b000 > fstat64(3, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 2), ...}) = 0 > mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, > 0) = 0xb7f71000 > _llseek(3, 0, 0xbffc3078, SEEK_CUR) = -1 ESPIPE (Illegal seek) > write(3, "Error in creating directory!: To"..., 45Error in creating > directory!: Too many links > ) = 45 > close(3) = 0 > munmap(0xb7f71000, 4096) = 0 > fstat64(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 2), ...}) = 0 > mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, > 0) = 0xb7f71000 > write(1, "errno = 29\n", 11errno = 29 > ) = 11 > exit_group(1) = ? > Process 16246 detached > ----------------------------------- > > However, reference to EMLINK is not present in the mkdir(2) man page. > The following patch adds the EMLINK error in the man page of mkdir(2). > > Kindly let me know if there are any issues. > > Best Regards, > Maxin B. John > www.maxinbjohn.info > > Signed-off-by: Maxin B. John <maxinbjohn@xxxxxxxxx> > > ------- > > diff --git a/man2/mkdir.2 b/man2/mkdir.2 > index e6cb28c..d01bafd 100644 > --- a/man2/mkdir.2 > +++ b/man2/mkdir.2 > @@ -73,6 +73,10 @@ is a symbolic link, dangling or not. > Too many symbolic links were encountered in resolving > .IR pathname . > .TP > +.B EMLINK > +The new directory cannot be created because the number of sub directories > +in a directory is limited to LINK_MAX defined by the file system. > +.TP > .B ENAMETOOLONG > .IR pathname " was too long." > .TP > > ------- > -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
