ping ... On Thu, Jun 24, 2010 at 10:22 AM, Maxin John <maxin.john@xxxxxxxxx> wrote: > 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
