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authorAl Viro <viro@zeniv.linux.org.uk>2008-07-30 04:13:04 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2008-08-01 11:25:23 -0400
commit1027abe8827b47f7e9c4ed6514fde3d44f79963c (patch)
treebe6aba7e46176534cc71622de53a8bcbf28a06c4 /fs/fcntl.c
parenta1bc6eb4b499ae67ada9a01660010580b6569403 (diff)
downloadlinux-linaro-1027abe8827b47f7e9c4ed6514fde3d44f79963c.tar.gz
[PATCH] merge locate_fd() and get_unused_fd()
New primitive: alloc_fd(start, flags). get_unused_fd() and get_unused_fd_flags() become wrappers on top of it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/fcntl.c')
-rw-r--r--fs/fcntl.c87
1 files changed, 14 insertions, 73 deletions
diff --git a/fs/fcntl.c b/fs/fcntl.c
index 61d62513681..2e40799daad 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -49,73 +49,6 @@ static int get_close_on_exec(unsigned int fd)
return res;
}
-/*
- * locate_fd finds a free file descriptor in the open_fds fdset,
- * expanding the fd arrays if necessary. Must be called with the
- * file_lock held for write.
- */
-
-static int locate_fd(unsigned int orig_start, int cloexec)
-{
- struct files_struct *files = current->files;
- unsigned int newfd;
- unsigned int start;
- int error;
- struct fdtable *fdt;
-
- spin_lock(&files->file_lock);
-repeat:
- fdt = files_fdtable(files);
- /*
- * Someone might have closed fd's in the range
- * orig_start..fdt->next_fd
- */
- start = orig_start;
- if (start < files->next_fd)
- start = files->next_fd;
-
- newfd = start;
- if (start < fdt->max_fds)
- newfd = find_next_zero_bit(fdt->open_fds->fds_bits,
- fdt->max_fds, start);
-
- error = expand_files(files, newfd);
- if (error < 0)
- goto out;
-
- /*
- * If we needed to expand the fs array we
- * might have blocked - try again.
- */
- if (error)
- goto repeat;
-
- if (start <= files->next_fd)
- files->next_fd = newfd + 1;
-
- FD_SET(newfd, fdt->open_fds);
- if (cloexec)
- FD_SET(newfd, fdt->close_on_exec);
- else
- FD_CLR(newfd, fdt->close_on_exec);
- error = newfd;
-
-out:
- spin_unlock(&files->file_lock);
- return error;
-}
-
-static int dupfd(struct file *file, unsigned int start, int cloexec)
-{
- int fd = locate_fd(start, cloexec);
- if (fd >= 0)
- fd_install(fd, file);
- else
- fput(file);
-
- return fd;
-}
-
asmlinkage long sys_dup3(unsigned int oldfd, unsigned int newfd, int flags)
{
int err = -EBADF;
@@ -194,10 +127,15 @@ asmlinkage long sys_dup2(unsigned int oldfd, unsigned int newfd)
asmlinkage long sys_dup(unsigned int fildes)
{
int ret = -EBADF;
- struct file * file = fget(fildes);
-
- if (file)
- ret = dupfd(file, 0, 0);
+ struct file *file = fget(fildes);
+
+ if (file) {
+ ret = get_unused_fd();
+ if (ret >= 0)
+ fd_install(ret, file);
+ else
+ fput(file);
+ }
return ret;
}
@@ -322,8 +260,11 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
case F_DUPFD_CLOEXEC:
if (arg >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
break;
- get_file(filp);
- err = dupfd(filp, arg, cmd == F_DUPFD_CLOEXEC);
+ err = alloc_fd(arg, cmd == F_DUPFD_CLOEXEC ? O_CLOEXEC : 0);
+ if (err >= 0) {
+ get_file(filp);
+ fd_install(err, filp);
+ }
break;
case F_GETFD:
err = get_close_on_exec(fd) ? FD_CLOEXEC : 0;