Created attachment 8391 [details]
Build configuration.

Created attachment 8392 [details]
Runtime configuration.

Created attachment 8393 [details]
'strace' showing leak

Zoom-in on handle-leak syscalls
===============================


Good system:

open("log", O_RDONLY|O_DIRECTORY)       = 28
fstat(28, {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
fstat(28, {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
fcntl(28, F_GETFL)                      = 0x18000 (flags O_RDONLY|O_LARGEFILE|O_DIRECTORY)
fcntl(28, F_SETFD, FD_CLOEXEC)          = 0
getdents(28, /* 184 entries */, 32768)  = 5880
getdents(28, /* 0 entries */, 32768)    = 0
close(28)                               = 0

open(".", O_RDONLY|O_DIRECTORY)         = 28
fstat(28, {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
close(28)                               = 0

open("log", O_RDONLY|O_DIRECTORY)       = 28
fstat(28, {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
fstat(28, {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
fcntl(28, F_GETFL)                      = 0x18000 (flags O_RDONLY|O_LARGEFILE|O_DIRECTORY)
fcntl(28, F_SETFD, FD_CLOEXEC)          = 0
getdents(28, /* 184 entries */, 32768)  = 5880
getdents(28, /* 0 entries */, 32768)    = 0
close(28)                               = 0


Bad system:

open("log", O_RDONLY|O_NONBLOCK|O_LARGEFILE|O_DIRECTORY) = 509
fstat64(509, {st_mode=S_IFDIR|0751, st_size=4096, ...}) = 0
fcntl64(509, F_SETFD, FD_CLOEXEC)       = 0
getdents64(509, /* 129 entries */, 4096) = 4072
getdents64(509, /* 46 entries */, 4096) = 1488
getdents64(509, /* 0 entries */, 4096)  = 0
close(509)                              = 0

open(".", O_RDONLY|O_LARGEFILE|O_DIRECTORY) = 509
fstat64(509, {st_mode=S_IFDIR|0751, st_size=4096, ...}) = 0
close(509)                              = 0

open("log", O_RDONLY|O_LARGEFILE|O_DIRECTORY) = 509
fstat64(509, {st_mode=S_IFDIR|0751, st_size=4096, ...}) = 0

To narrow it down further, copied the 32-bit
'smbd' daemon binary along with required
shared libraries from the CentOS 4 system
to the CentOS 5 system and ran the test
scenario.

The file handle leak remains when running
under the more current 2.6.18-308.24.1.el5
kernel and 2.5-81.el5_8.7 glibc.

In particular this eliminates the older
2.3.4 'glibc' as the culprit and indicates
the bug will reproduce on any system when
the attached config.h file is used during
compilation.



32-bit libraries copied with 'smbd'

libcap.so.1 (CentOS 4)
libpopt.so.0 (CentOS 4)
libtalloc.so.2 (Samba)
libtdb.so.1 (Samba)
libwbclient.so (Samba)

32-bit libraries present on 64-bit CentOS 5 system

linux-gate.so.1
libcrypt.so.1
libresolv.so.2
libnsl.so.1
libdl.so.2
librt.so.1
libc.so.6
/lib/ld-linux.so.2
libpthread.so.0

OCD took over and I nailed the cause down to

  #undef HAVE_FDOPENDIR

1) compiled it CentOS 5 64-bit with
lightly adapted 'config.h' from 32-bit
CentOS 4 system.  Reproduces bug.

2) on a hunch tweaked

   #undef HAVE_FDOPENDIR

to

   #define HAVE_FDOPENDIR 1

and now it works with no file
handle leaks.

Suspect problem lies at

   dir.c line 590

where a guess is that the "Ugly hack. . .ENOSYS" in

   void dptr_CloseDir(files_struct *fsp)

is not operating as intended.

Created attachment 8396 [details]
fix patch

fixed

Hack wasn't ugly enough ;-)

The question is -- why did configure not find fdopendir?

Well originally the subject of this bug was

   "[Bug 9551] file handle leak under RHEL/CentOS 4.9 32-bit"

I forgot to include this in the body text and
once the exact cause was determined, accidently
erased the information.  It does appears again
buried in the middle.

'autoconf' made the decision based on the
lack of 'fdopendir()' in 'glibc' version
2.3.4, which is what comes with RHEL 4
/ CentOS 4.

You will notice that the fix is  a one-line
tweak where the author was thinking the
right thought but his fingers left out a
fragment.  Happens to me often enough.

I see the section of code in question was
rewritten somewhere between 3.6.10 and
3.6.24, and that the revised code is not
susceptible to the problem.

Marking it closed/resolved.