take purely descriptor-related stuff from fcntl.c to file.c
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro
parent
6a6d27de34
commit
fe17f22d7f
131
fs/fcntl.c
131
fs/fcntl.c
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@ -26,127 +26,6 @@
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#include <asm/siginfo.h>
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#include <asm/uaccess.h>
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void set_close_on_exec(unsigned int fd, int flag)
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{
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struct files_struct *files = current->files;
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struct fdtable *fdt;
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spin_lock(&files->file_lock);
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fdt = files_fdtable(files);
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if (flag)
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__set_close_on_exec(fd, fdt);
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else
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__clear_close_on_exec(fd, fdt);
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spin_unlock(&files->file_lock);
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}
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static bool get_close_on_exec(unsigned int fd)
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{
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struct files_struct *files = current->files;
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struct fdtable *fdt;
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bool res;
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rcu_read_lock();
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fdt = files_fdtable(files);
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res = close_on_exec(fd, fdt);
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rcu_read_unlock();
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return res;
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}
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SYSCALL_DEFINE3(dup3, unsigned int, oldfd, unsigned int, newfd, int, flags)
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{
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int err = -EBADF;
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struct file * file, *tofree;
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struct files_struct * files = current->files;
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struct fdtable *fdt;
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if ((flags & ~O_CLOEXEC) != 0)
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return -EINVAL;
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if (unlikely(oldfd == newfd))
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return -EINVAL;
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if (newfd >= rlimit(RLIMIT_NOFILE))
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return -EMFILE;
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spin_lock(&files->file_lock);
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err = expand_files(files, newfd);
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file = fcheck(oldfd);
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if (unlikely(!file))
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goto Ebadf;
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if (unlikely(err < 0)) {
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if (err == -EMFILE)
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goto Ebadf;
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goto out_unlock;
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}
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/*
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* We need to detect attempts to do dup2() over allocated but still
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* not finished descriptor. NB: OpenBSD avoids that at the price of
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* extra work in their equivalent of fget() - they insert struct
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* file immediately after grabbing descriptor, mark it larval if
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* more work (e.g. actual opening) is needed and make sure that
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* fget() treats larval files as absent. Potentially interesting,
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* but while extra work in fget() is trivial, locking implications
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* and amount of surgery on open()-related paths in VFS are not.
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* FreeBSD fails with -EBADF in the same situation, NetBSD "solution"
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* deadlocks in rather amusing ways, AFAICS. All of that is out of
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* scope of POSIX or SUS, since neither considers shared descriptor
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* tables and this condition does not arise without those.
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*/
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err = -EBUSY;
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fdt = files_fdtable(files);
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tofree = fdt->fd[newfd];
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if (!tofree && fd_is_open(newfd, fdt))
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goto out_unlock;
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get_file(file);
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rcu_assign_pointer(fdt->fd[newfd], file);
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__set_open_fd(newfd, fdt);
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if (flags & O_CLOEXEC)
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__set_close_on_exec(newfd, fdt);
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else
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__clear_close_on_exec(newfd, fdt);
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spin_unlock(&files->file_lock);
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if (tofree)
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filp_close(tofree, files);
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return newfd;
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Ebadf:
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err = -EBADF;
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out_unlock:
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spin_unlock(&files->file_lock);
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return err;
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}
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SYSCALL_DEFINE2(dup2, unsigned int, oldfd, unsigned int, newfd)
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{
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if (unlikely(newfd == oldfd)) { /* corner case */
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struct files_struct *files = current->files;
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int retval = oldfd;
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rcu_read_lock();
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if (!fcheck_files(files, oldfd))
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retval = -EBADF;
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rcu_read_unlock();
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return retval;
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}
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return sys_dup3(oldfd, newfd, 0);
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}
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SYSCALL_DEFINE1(dup, unsigned int, fildes)
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{
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int ret = -EBADF;
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struct file *file = fget_raw(fildes);
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if (file) {
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ret = get_unused_fd();
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if (ret >= 0)
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fd_install(ret, file);
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else
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fput(file);
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}
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return ret;
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}
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#define SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | O_DIRECT | O_NOATIME)
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static int setfl(int fd, struct file * filp, unsigned long arg)
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@ -376,14 +255,10 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
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switch (cmd) {
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case F_DUPFD:
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err = f_dupfd(arg, filp, 0);
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break;
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case F_DUPFD_CLOEXEC:
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if (arg >= rlimit(RLIMIT_NOFILE))
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break;
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err = alloc_fd(arg, cmd == F_DUPFD_CLOEXEC ? O_CLOEXEC : 0);
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if (err >= 0) {
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get_file(filp);
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fd_install(err, filp);
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}
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err = f_dupfd(arg, filp, FD_CLOEXEC);
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break;
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case F_GETFD:
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err = get_close_on_exec(fd) ? FD_CLOEXEC : 0;
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132
fs/file.c
132
fs/file.c
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@ -6,6 +6,7 @@
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* Manage the dynamic fd arrays in the process files_struct.
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*/
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#include <linux/syscalls.h>
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#include <linux/export.h>
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#include <linux/fs.h>
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#include <linux/mm.h>
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@ -794,3 +795,134 @@ struct file *fget_raw_light(unsigned int fd, int *fput_needed)
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return file;
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}
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void set_close_on_exec(unsigned int fd, int flag)
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{
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struct files_struct *files = current->files;
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struct fdtable *fdt;
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spin_lock(&files->file_lock);
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fdt = files_fdtable(files);
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if (flag)
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__set_close_on_exec(fd, fdt);
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else
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__clear_close_on_exec(fd, fdt);
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spin_unlock(&files->file_lock);
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}
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bool get_close_on_exec(unsigned int fd)
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{
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struct files_struct *files = current->files;
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struct fdtable *fdt;
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bool res;
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rcu_read_lock();
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fdt = files_fdtable(files);
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res = close_on_exec(fd, fdt);
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rcu_read_unlock();
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return res;
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}
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SYSCALL_DEFINE3(dup3, unsigned int, oldfd, unsigned int, newfd, int, flags)
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{
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int err = -EBADF;
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struct file * file, *tofree;
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struct files_struct * files = current->files;
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struct fdtable *fdt;
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if ((flags & ~O_CLOEXEC) != 0)
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return -EINVAL;
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if (newfd >= rlimit(RLIMIT_NOFILE))
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return -EMFILE;
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spin_lock(&files->file_lock);
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err = expand_files(files, newfd);
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file = fcheck(oldfd);
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if (unlikely(!file))
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goto Ebadf;
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if (unlikely(err < 0)) {
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if (err == -EMFILE)
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goto Ebadf;
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goto out_unlock;
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}
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/*
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* We need to detect attempts to do dup2() over allocated but still
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* not finished descriptor. NB: OpenBSD avoids that at the price of
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* extra work in their equivalent of fget() - they insert struct
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* file immediately after grabbing descriptor, mark it larval if
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* more work (e.g. actual opening) is needed and make sure that
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* fget() treats larval files as absent. Potentially interesting,
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* but while extra work in fget() is trivial, locking implications
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* and amount of surgery on open()-related paths in VFS are not.
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* FreeBSD fails with -EBADF in the same situation, NetBSD "solution"
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* deadlocks in rather amusing ways, AFAICS. All of that is out of
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* scope of POSIX or SUS, since neither considers shared descriptor
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* tables and this condition does not arise without those.
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*/
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err = -EBUSY;
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fdt = files_fdtable(files);
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tofree = fdt->fd[newfd];
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if (!tofree && fd_is_open(newfd, fdt))
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goto out_unlock;
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get_file(file);
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rcu_assign_pointer(fdt->fd[newfd], file);
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__set_open_fd(newfd, fdt);
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if (flags & O_CLOEXEC)
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__set_close_on_exec(newfd, fdt);
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else
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__clear_close_on_exec(newfd, fdt);
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spin_unlock(&files->file_lock);
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if (tofree)
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filp_close(tofree, files);
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return newfd;
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Ebadf:
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err = -EBADF;
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out_unlock:
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spin_unlock(&files->file_lock);
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return err;
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}
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SYSCALL_DEFINE2(dup2, unsigned int, oldfd, unsigned int, newfd)
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{
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if (unlikely(newfd == oldfd)) { /* corner case */
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struct files_struct *files = current->files;
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int retval = oldfd;
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rcu_read_lock();
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if (!fcheck_files(files, oldfd))
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retval = -EBADF;
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rcu_read_unlock();
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return retval;
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}
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return sys_dup3(oldfd, newfd, 0);
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}
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SYSCALL_DEFINE1(dup, unsigned int, fildes)
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{
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int ret = -EBADF;
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struct file *file = fget_raw(fildes);
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if (file) {
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ret = get_unused_fd();
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if (ret >= 0)
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fd_install(ret, file);
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else
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fput(file);
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}
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return ret;
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}
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int f_dupfd(unsigned int from, struct file *file, unsigned flags)
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{
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int err;
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if (from >= rlimit(RLIMIT_NOFILE))
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return -EINVAL;
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err = alloc_fd(from, flags);
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if (err >= 0) {
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get_file(file);
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fd_install(err, file);
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}
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return err;
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}
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@ -30,7 +30,9 @@ extern struct file *fget(unsigned int fd);
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extern struct file *fget_light(unsigned int fd, int *fput_needed);
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extern struct file *fget_raw(unsigned int fd);
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extern struct file *fget_raw_light(unsigned int fd, int *fput_needed);
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extern int f_dupfd(unsigned int from, struct file *file, unsigned flags);
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extern void set_close_on_exec(unsigned int fd, int flag);
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extern bool get_close_on_exec(unsigned int fd);
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extern void put_filp(struct file *);
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extern int alloc_fd(unsigned start, unsigned flags);
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extern int get_unused_fd_flags(unsigned flags);
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