diff options
| -rw-r--r-- | fs/fcntl.c | 87 | ||||
| -rw-r--r-- | fs/file.c | 61 | ||||
| -rw-r--r-- | fs/open.c | 56 | ||||
| -rw-r--r-- | include/linux/file.h | 3 |
4 files changed, 77 insertions, 130 deletions
@@ -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; @@ -6,6 +6,7 @@ * Manage the dynamic fd arrays in the process files_struct. */ +#include <linux/module.h> #include <linux/fs.h> #include <linux/mm.h> #include <linux/time.h> @@ -432,3 +433,63 @@ struct files_struct init_files = { }, .file_lock = __SPIN_LOCK_UNLOCKED(init_task.file_lock), }; + +/* + * allocate a file descriptor, mark it busy. + */ +int alloc_fd(unsigned start, unsigned flags) +{ + struct files_struct *files = current->files; + unsigned int fd; + int error; + struct fdtable *fdt; + + spin_lock(&files->file_lock); +repeat: + fdt = files_fdtable(files); + fd = start; + if (fd < files->next_fd) + fd = files->next_fd; + + if (fd < fdt->max_fds) + fd = find_next_zero_bit(fdt->open_fds->fds_bits, + fdt->max_fds, fd); + + error = expand_files(files, fd); + 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 = fd + 1; + + FD_SET(fd, fdt->open_fds); + if (flags & O_CLOEXEC) + FD_SET(fd, fdt->close_on_exec); + else + FD_CLR(fd, fdt->close_on_exec); + error = fd; +#if 1 + /* Sanity check */ + if (rcu_dereference(fdt->fd[fd]) != NULL) { + printk(KERN_WARNING "alloc_fd: slot %d not NULL!\n", fd); + rcu_assign_pointer(fdt->fd[fd], NULL); + } +#endif + +out: + spin_unlock(&files->file_lock); + return error; +} + +int get_unused_fd(void) +{ + return alloc_fd(0, 0); +} +EXPORT_SYMBOL(get_unused_fd); @@ -963,62 +963,6 @@ struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags) } EXPORT_SYMBOL(dentry_open); -/* - * Find an empty file descriptor entry, and mark it busy. - */ -int get_unused_fd_flags(int flags) -{ - struct files_struct * files = current->files; - int fd, error; - struct fdtable *fdt; - - spin_lock(&files->file_lock); - -repeat: - fdt = files_fdtable(files); - fd = find_next_zero_bit(fdt->open_fds->fds_bits, fdt->max_fds, - files->next_fd); - - /* Do we need to expand the fd array or fd set? */ - error = expand_files(files, fd); - if (error < 0) - goto out; - - if (error) { - /* - * If we needed to expand the fs array we - * might have blocked - try again. - */ - goto repeat; - } - - FD_SET(fd, fdt->open_fds); - if (flags & O_CLOEXEC) - FD_SET(fd, fdt->close_on_exec); - else - FD_CLR(fd, fdt->close_on_exec); - files->next_fd = fd + 1; -#if 1 - /* Sanity check */ - if (fdt->fd[fd] != NULL) { - printk(KERN_WARNING "get_unused_fd: slot %d not NULL!\n", fd); - fdt->fd[fd] = NULL; - } -#endif - error = fd; - -out: - spin_unlock(&files->file_lock); - return error; -} - -int get_unused_fd(void) -{ - return get_unused_fd_flags(0); -} - -EXPORT_SYMBOL(get_unused_fd); - static void __put_unused_fd(struct files_struct *files, unsigned int fd) { struct fdtable *fdt = files_fdtable(files); diff --git a/include/linux/file.h b/include/linux/file.h index 27c64bd..a20259e 100644 --- a/include/linux/file.h +++ b/include/linux/file.h @@ -34,8 +34,9 @@ extern struct file *fget(unsigned int fd); extern struct file *fget_light(unsigned int fd, int *fput_needed); extern void set_close_on_exec(unsigned int fd, int flag); extern void put_filp(struct file *); +extern int alloc_fd(unsigned start, unsigned flags); extern int get_unused_fd(void); -extern int get_unused_fd_flags(int flags); +#define get_unused_fd_flags(flags) alloc_fd(0, (flags)) extern void put_unused_fd(unsigned int fd); extern void fd_install(unsigned int fd, struct file *file); |
