[PATCH 11/18] flag parameters: inotify_init

From: Ulrich Drepper
Date: Sun May 04 2008 - 23:47:07 EST


This patch introduces the new syscall inotify_init1 (note: the 1 stands
for the one parameter the syscall takes, as opposed to no parameter before).
The values excepted for this parameter are function-specific and defined
in the inotify.h header. In this patch CLOEXEC support is introduced.

The following test must be adjusted for architectures other than x86 and
x86-64 and in case the syscall numbers changed.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/syscall.h>

#ifndef __NR_inotify_init1
# ifdef __x86_64__
# define __NR_inotify_init1 294
# elif defined __i386__
# define __NR_inotify_init1 332
# else
# error "need __NR_inotify_init1"
# endif
#endif

#define IN_CLOEXEC (1 << 0)

int
main (void)
{
int fd;
fd = syscall (__NR_inotify_init1, 0);
if (fd == -1)
{
puts ("inotify_init1(0) failed");
return 1;
}
int coe = fcntl (fd, F_GETFD);
if (coe == -1)
{
puts ("fcntl failed");
return 1;
}
if (coe & FD_CLOEXEC)
{
puts ("inotify_init1(0) set close-on-exit");
return 1;
}
close (fd);

fd = syscall (__NR_inotify_init1, IN_CLOEXEC);
if (fd == -1)
{
puts ("inotify_init1(IN_CLOEXEC) failed");
return 1;
}
coe = fcntl (fd, F_GETFD);
if (coe == -1)
{
puts ("fcntl failed");
return 1;
}
if ((coe & FD_CLOEXEC) == 0)
{
puts ("inotify_init1(O_CLOEXEC) does not set close-on-exit");
return 1;
}
close (fd);

puts ("OK");

return 0;
}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


arch/x86/ia32/ia32entry.S | 1 +
arch/x86/kernel/syscall_table_32.S | 1 +
fs/inotify_user.c | 20 ++++++++++++++++++--
include/asm-x86/unistd_32.h | 1 +
include/asm-x86/unistd_64.h | 2 ++
include/linux/inotify.h | 3 +++
include/linux/syscalls.h | 1 +
7 files changed, 27 insertions(+), 2 deletions(-)


Signed-off-by: Ulrich Drepper <drepper@xxxxxxxxxx>

diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S
index b5e329d..37e4992 100644
--- a/arch/x86/ia32/ia32entry.S
+++ b/arch/x86/ia32/ia32entry.S
@@ -736,4 +736,5 @@ ia32_sys_call_table:
.quad sys_epoll_create2
.quad sys_dup3 /* 330 */
.quad sys_pipe2
+ .quad sys_inotify_init1
ia32_syscall_end:
diff --git a/arch/x86/kernel/syscall_table_32.S b/arch/x86/kernel/syscall_table_32.S
index adff556..f59aba5 100644
--- a/arch/x86/kernel/syscall_table_32.S
+++ b/arch/x86/kernel/syscall_table_32.S
@@ -331,3 +331,4 @@ ENTRY(sys_call_table)
.long sys_epoll_create2
.long sys_dup3 /* 330 */
.long sys_pipe2
+ .long sys_inotify_init1
diff --git a/fs/inotify_user.c b/fs/inotify_user.c
index 6676c06..4bb4c54 100644
--- a/fs/inotify_user.c
+++ b/fs/inotify_user.c
@@ -32,6 +32,7 @@
#include <linux/inotify.h>
#include <linux/syscalls.h>
#include <linux/magic.h>
+#include <linux/flagsremap.h>

#include <asm/ioctls.h>

@@ -566,15 +567,25 @@ static const struct inotify_operations inotify_user_ops = {
.destroy_watch = free_inotify_user_watch,
};

-asmlinkage long sys_inotify_init(void)
+static const struct flags_rmap inotify_file_flags_remap[] = {
+ { IN_CLOEXEC, O_CLOEXEC },
+};
+
+asmlinkage long sys_inotify_init1(int flags)
{
struct inotify_device *dev;
struct inotify_handle *ih;
struct user_struct *user;
struct file *filp;
int fd, ret;
+ int fflags;
+
+ if (flags_remap(inotify_file_flags_remap,
+ ARRAY_SIZE(inotify_file_flags_remap),
+ flags, &fflags) != 0)
+ return -EINVAL;

- fd = get_unused_fd();
+ fd = get_unused_fd_flags(fflags);
if (fd < 0)
return fd;

@@ -638,6 +649,11 @@ out_put_fd:
return ret;
}

+asmlinkage long sys_inotify_init(void)
+{
+ return sys_inotify_init1(0);
+}
+
asmlinkage long sys_inotify_add_watch(int fd, const char __user *path, u32 mask)
{
struct inode *inode;
diff --git a/include/asm-x86/unistd_32.h b/include/asm-x86/unistd_32.h
index 8317d94..b3daf50 100644
--- a/include/asm-x86/unistd_32.h
+++ b/include/asm-x86/unistd_32.h
@@ -337,6 +337,7 @@
#define __NR_epoll_create2 329
#define __NR_dup3 330
#define __NR_pipe2 331
+#define __NR_inotify_init1 332

#ifdef __KERNEL__

diff --git a/include/asm-x86/unistd_64.h b/include/asm-x86/unistd_64.h
index fe26e36..5ef6778 100644
--- a/include/asm-x86/unistd_64.h
+++ b/include/asm-x86/unistd_64.h
@@ -651,6 +651,8 @@ __SYSCALL(__NR_fallocate, sys_fallocate)
__SYSCALL(__NR_dup3, sys_dup3)
#define __NR_pipe2 293
__SYSCALL(__NR_pipe2, sys_pipe2)
+#define __NR_inotify_init1 294
+__SYSCALL(__NR_inotify_init1, sys_inotify_init1)


#ifndef __NO_STUBS
diff --git a/include/linux/inotify.h b/include/linux/inotify.h
index 742b917..af30cfd 100644
--- a/include/linux/inotify.h
+++ b/include/linux/inotify.h
@@ -63,6 +63,9 @@ struct inotify_event {
IN_MOVED_TO | IN_DELETE | IN_CREATE | IN_DELETE_SELF | \
IN_MOVE_SELF)

+/* Flags for sys_inotify_init1. */
+#define IN_CLOEXEC (1 << 0)
+
#ifdef __KERNEL__

#include <linux/dcache.h>
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 0522f36..aeb2df8 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -547,6 +547,7 @@ asmlinkage long sys_get_mempolicy(int __user *policy,
unsigned long addr, unsigned long flags);

asmlinkage long sys_inotify_init(void);
+asmlinkage long sys_inotify_init1(int flags);
asmlinkage long sys_inotify_add_watch(int fd, const char __user *path,
u32 mask);
asmlinkage long sys_inotify_rm_watch(int fd, u32 wd);
--
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