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lsfd: use constants defined in asm/fctl.h flags field of a fdinfo

Close #1709.

The original code decoded the field using constants defined in
/usr/include/fcntl.h. The constants defined in /usr/include/fcntl.h
was suitable for passing to the kernel as a part of arguments of
system calls like open(2). However, they were not suitable for
decoding the field.

Let's think about decoding 0300000 in

    $ cat /proc/157067/fdinfo/3
    pos:	0
    flags:	0300000
    $ lsfd -p 157067 -o+flags -Q -Q 'ASSOC == "3"'
    COMMAND       PID USER ASSOC MODE TYPE SOURCE MNTID INODE NAME               FLAGS
    test_mkfds 125128  jet     3  r--  DIR   dm-0    96    96 /    ???????????????????

The decoded string is printed at ???????????????????.

Quoted from /usr/include/bits/fcntl-linux.h:

    #ifndef __O_LARGEFILE
    # define __O_LARGEFILE	0100000
    #endif
    #ifndef __O_DIRECTORY
    # define __O_DIRECTORY	0200000
    #endif
    #ifndef __O_TMPFILE
    # define __O_TMPFILE   (020000000 | __O_DIRECTORY)
    #endif
    ...
    #ifdef __USE_XOPEN2K8
    # define O_DIRECTORY	__O_DIRECTORY	/* Must be a directory.  */
    ...
    #endif
    ...
    #ifdef __USE_LARGEFILE64
    # define O_LARGEFILE __O_LARGEFILE
    #endif

With these constants, 0300000 is decoded as "directory,_tmpfile" or
"largefile,directory,_tmpfile".

Unexpectedly the decoded string has "_tmpfile".
It has "largefile" only when we define __USE_LARGEFILE64 when building
lsfd though it should have "largefile" always.

Quoted from /usr/include/asm-generic/fcntl.h:

    #ifndef O_LARGEFILE
    #define O_LARGEFILE	00100000
    #endif
    #ifndef O_DIRECTORY
    #define O_DIRECTORY	00200000	/* must be a directory */
    #endif
    #ifndef __O_TMPFILE
    #define __O_TMPFILE	020000000
    #endif

The decoded string is "largefile,directory". It doesn't depend on
__USE_LARGEFILE64.

This change adds lsfd-decode-file-flags.c, a new small and isolated
source file, in which lsfd_decode_file_flags(), the function for
decoding the field is defined.

include/c.h includes /usr/include/fcntl.h. Almost all lsfd related
source files includes include/c.h indirectly. On the other hand,
lsfd-decode-file-flags.c includes only /usr/include/asm-generic/fcntl.h
or /usr/include/asm/fcntl.h. So the function can decode the field
expectedly.

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
pull/1714/head
Masatake YAMATO 2 months ago
parent
commit
908ac36f27
  1. 2
      configure.ac
  2. 2
      meson.build
  3. 1
      misc-utils/Makemodule.am
  4. 148
      misc-utils/lsfd-decode-file-flags.c
  5. 86
      misc-utils/lsfd-file.c
  6. 1
      misc-utils/meson.build
  7. 2
      tests/expected/lsfd/mkfds-directory

2
configure.ac

@ -291,6 +291,8 @@ AC_CHECK_HEADERS([linux/compiler.h linux/blkpg.h linux/major.h], [], [], [
#endif
])
AC_CHECK_HEADERS([ \
asm-generic/fcntl.h \
asm/fcntl.h \
asm/io.h \
byteswap.h \
endian.h \

2
meson.build

@ -151,6 +151,8 @@ headers = '''
unistd.h
utmp.h
utmpx.h
asm-generic/fcntl.h
asm/fcntl.h
asm/io.h
linux/blkzoned.h
linux/capability.h

1
misc-utils/Makemodule.am

@ -258,6 +258,7 @@ lsfd_SOURCES = \
misc-utils/lsfd-filter.c \
misc-utils/lsfd-counter.h \
misc-utils/lsfd-counter.c \
misc-utils/lsfd-decode-file-flags.c \
misc-utils/lsfd-file.c \
misc-utils/lsfd-cdev.c \
misc-utils/lsfd-bdev.c \

148
misc-utils/lsfd-decode-file-flags.c

@ -0,0 +1,148 @@
/*
* lsfd(1) - list file descriptors
*
* Copyright (C) 2022 Red Hat, Inc. All rights reserved.
* Written by Masatake YAMATO <yamato@redhat.com>
*
* Very generally based on lsof(8) by Victor A. Abell <abe@purdue.edu>
* It supports multiple OSes. lsfd specializes to Linux.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it would be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/* lsfd_decode_file_flags() is for decoding `flags' field of
* /proc/$pid/fdinfo/$fd. Bits of the field have name defined
* in fctl.h.
* A system on which lsfd is built may have multiple
* fctl.h files:
*
* - /usr/include/asm-generic/fcntl.h (a part of Linux kernel)
* - /usr/include/asm/fcntl.h (a part of Linux kernel)
* - /usr/include/fcntl.h (a part of glibc)
* - /usr/include/bits/fcntl.h (a part of glibc)
*
* For decoding purpose, /usr/include/asm-generic/fcntl.h or
* /usr/include/asm/fcntl.h is needed.
*
* /usr/include/bits/fcntl.h and /usr/include/fcntl.h are
* not suitable for decoding. They should not be included.
* /usr/include/fcntl.h includes /usr/include/bits/fcntl.h.
*/
#ifdef HAVE_ASM_GENERIC_FCNTL_H
#include <asm-generic/fcntl.h>
#elif HAVE_ASM_FCNTL_H
#include <asm/fcntl.h>
#else
#error "kernel's fcntl.h is not available"
#endif
#include <stddef.h> /* for size_t */
struct ul_buffer;
void lsfd_decode_file_flags(struct ul_buffer *buf, int flags);
/* We cannot include buffer.h because buffer.h includes
* /usr/include/fcntl.h indirectly. */
extern int ul_buffer_is_empty(struct ul_buffer *buf);
extern int ul_buffer_append_data(struct ul_buffer *buf, const char *data, size_t sz);
extern int ul_buffer_append_string(struct ul_buffer *buf, const char *str);
void lsfd_decode_file_flags(struct ul_buffer *buf, int flags)
{
#define SET_FLAG_FULL(L,s) \
do { \
if (flags & (L)) { \
if (!ul_buffer_is_empty(buf)) \
ul_buffer_append_data(buf, ",", 1); \
ul_buffer_append_string(buf, #s); \
} \
} while (0)
#define SET_FLAG(L,s) SET_FLAG_FULL(O_##L,s)
#ifdef O_WRONLY
SET_FLAG(WRONLY,wronly);
#endif
#ifdef O_RDWR
SET_FLAG(RDWR,rdwr);
#endif
#ifdef O_CREAT
SET_FLAG(CREAT,creat);
#endif
#ifdef O_EXCL
SET_FLAG(EXCL,excl);
#endif
#ifdef O_NOCTTY
SET_FLAG(NOCTTY,noctty);
#endif
#ifdef O_APPEND
SET_FLAG(APPEND,append);
#endif
#ifdef O_NONBLOCK
SET_FLAG(NONBLOCK,nonblock);
#endif
#ifdef O_DSYNC
SET_FLAG(DSYNC,dsync);
#endif
#ifdef O_FASYNC
SET_FLAG(FASYNC,fasync);
#endif
#ifdef O_DIRECT
SET_FLAG(DIRECT,direct);
#endif
#ifdef O_LARGEFILE
SET_FLAG(LARGEFILE,largefile);
#endif
#ifdef O_DIRECTORY
SET_FLAG(DIRECTORY,directory);
#endif
#ifdef O_FOLLOW
SET_FLAG(FOLLOW,follow);
#endif
#ifdef O_NOATIME
SET_FLAG(NOATIME,noatime);
#endif
#ifdef O_CLOEXEC
SET_FLAG(CLOEXEC,cloexec);
#endif
#ifdef __O_SYNC
SET_FLAG_FULL(__O_SYNC,_sync);
#endif
#ifdef O_PATH
SET_FLAG(PATH,path);
#endif
#ifdef __O_TMPFILE
SET_FLAG_FULL(__O_TMPFILE,_tmpfile);
#endif
}

86
misc-utils/lsfd-file.c

@ -78,92 +78,10 @@ static const char *strftype(mode_t ftype)
}
}
/* See /usr/include/asm-generic/fcntl.h */
extern void lsfd_decode_file_flags(struct ul_buffer *buf, int flags);
static void file_fill_flags_buf(struct ul_buffer *buf, int flags)
{
#define SET_FLAG_FULL(L,s) \
do { \
if (flags & (L)) { \
if (!ul_buffer_is_empty(buf)) \
ul_buffer_append_data(buf, ",", 1); \
ul_buffer_append_string(buf, #s); \
} \
} while (0)
#define SET_FLAG(L,s) SET_FLAG_FULL(O_##L,s)
#ifdef O_WRONLY
SET_FLAG(WRONLY,wronly);
#endif
#ifdef O_RDWR
SET_FLAG(RDWR,rdwr);
#endif
#ifdef O_CREAT
SET_FLAG(CREAT,creat);
#endif
#ifdef O_EXCL
SET_FLAG(EXCL,excl);
#endif
#ifdef O_NOCTTY
SET_FLAG(NOCTTY,noctty);
#endif
#ifdef O_APPEND
SET_FLAG(APPEND,append);
#endif
#ifdef O_NONBLOCK
SET_FLAG(NONBLOCK,nonblock);
#endif
#ifdef O_DSYNC
SET_FLAG(DSYNC,dsync);
#endif
#ifdef O_FASYNC
SET_FLAG(FASYNC,fasync);
#endif
#ifdef O_DIRECT
SET_FLAG(DIRECT,direct);
#endif
#ifdef O_LARGEFILE
SET_FLAG(LARGEFILE,largefile);
#endif
#ifdef O_DIRECTORY
SET_FLAG(DIRECTORY,directory);
#endif
#ifdef O_FOLLOW
SET_FLAG(FOLLOW,follow);
#endif
#ifdef O_NOATIME
SET_FLAG(NOATIME,noatime);
#endif
#ifdef O_CLOEXEC
SET_FLAG(CLOEXEC,cloexec);
#endif
#ifdef __O_SYNC
SET_FLAG_FULL(__O_SYNC,_sync);
#endif
#ifdef O_PATH
SET_FLAG(PATH,path);
#endif
#ifdef __O_TMPFILE
SET_FLAG_FULL(__O_TMPFILE,_tmpfile);
#endif
lsfd_decode_file_flags(buf, flags);
}
#define does_file_has_fdinfo_alike(file) \

1
misc-utils/meson.build

@ -46,6 +46,7 @@ lsfd_sources = files (
'lsfd-filter.c',
'lsfd-counter.h',
'lsfd-counter.c',
'lsfd-decode-file-flags.c',
'lsfd-file.c',
'lsfd-cdev.c',
'lsfd-bdev.c',

2
tests/expected/lsfd/mkfds-directory

@ -1,4 +1,4 @@
3 r-- DIR directory,_tmpfile /
3 r-- DIR directory /
ASSOC,MODE,TYPE,FLAGS,NAME: 0
PID[RUN]: 0
PID[STR]: 0

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