X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=fs%2Ffcntl.c;h=921b556c5452551e0a401d89f1b24ffe346485ea;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=59d27068674cece3dc12ad6cc7a771eef30559f7;hpb=cee37fe97739d85991964371c1f3a745c00dd236;p=linux-2.6.git diff --git a/fs/fcntl.c b/fs/fcntl.c index 59d270686..921b556c5 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include @@ -16,6 +17,7 @@ #include #include #include +#include #include #include @@ -25,21 +27,25 @@ void fastcall set_close_on_exec(unsigned int fd, int flag) { struct files_struct *files = current->files; + struct fdtable *fdt; spin_lock(&files->file_lock); + fdt = files_fdtable(files); if (flag) - FD_SET(fd, files->close_on_exec); + FD_SET(fd, fdt->close_on_exec); else - FD_CLR(fd, files->close_on_exec); + FD_CLR(fd, fdt->close_on_exec); spin_unlock(&files->file_lock); } -static inline int get_close_on_exec(unsigned int fd) +static int get_close_on_exec(unsigned int fd) { struct files_struct *files = current->files; + struct fdtable *fdt; int res; - spin_lock(&files->file_lock); - res = FD_ISSET(fd, files->close_on_exec); - spin_unlock(&files->file_lock); + rcu_read_lock(); + fdt = files_fdtable(files); + res = FD_ISSET(fd, fdt->close_on_exec); + rcu_read_unlock(); return res; } @@ -55,24 +61,26 @@ static int locate_fd(struct files_struct *files, unsigned int newfd; unsigned int start; int error; + struct fdtable *fdt; error = -EINVAL; if (orig_start >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur) goto out; repeat: + fdt = files_fdtable(files); /* * Someone might have closed fd's in the range - * orig_start..files->next_fd + * orig_start..fdt->next_fd */ start = orig_start; if (start < files->next_fd) start = files->next_fd; newfd = start; - if (start < files->max_fdset) { - newfd = find_next_zero_bit(files->open_fds->fds_bits, - files->max_fdset, start); + if (start < fdt->max_fdset) { + newfd = find_next_zero_bit(fdt->open_fds->fds_bits, + fdt->max_fdset, start); } error = -EMFILE; @@ -92,25 +100,33 @@ repeat: if (error) goto repeat; + /* + * We reacquired files_lock, so we are safe as long as + * we reacquire the fdtable pointer and use it while holding + * the lock, no one can free it during that time. + */ if (start <= files->next_fd) files->next_fd = newfd + 1; - + error = newfd; out: return error; } -static int dupfd(struct file *file, unsigned int start) +int dupfd(struct file *file, unsigned int start) { struct files_struct * files = current->files; + struct fdtable *fdt; int fd; spin_lock(&files->file_lock); fd = locate_fd(files, file, start); if (fd >= 0) { - FD_SET(fd, files->open_fds); - FD_CLR(fd, files->close_on_exec); + /* locate_fd() may have expanded fdtable, load the ptr */ + fdt = files_fdtable(files); + FD_SET(fd, fdt->open_fds); + FD_CLR(fd, fdt->close_on_exec); spin_unlock(&files->file_lock); vx_openfd_inc(fd); fd_install(fd, file); @@ -122,11 +138,14 @@ static int dupfd(struct file *file, unsigned int start) return fd; } +EXPORT_SYMBOL_GPL(dupfd); + asmlinkage long sys_dup2(unsigned int oldfd, unsigned int newfd) { int err = -EBADF; struct file * file, *tofree; struct files_struct * files = current->files; + struct fdtable *fdt; spin_lock(&files->file_lock); if (!(file = fcheck(oldfd))) @@ -152,13 +171,14 @@ asmlinkage long sys_dup2(unsigned int oldfd, unsigned int newfd) /* Yes. It's a race. In user space. Nothing sane to do */ err = -EBUSY; - tofree = files->fd[newfd]; - if (!tofree && FD_ISSET(newfd, files->open_fds)) + fdt = files_fdtable(files); + tofree = fdt->fd[newfd]; + if (!tofree && FD_ISSET(newfd, fdt->open_fds)) goto out_fput; - files->fd[newfd] = file; - FD_SET(newfd, files->open_fds); - FD_CLR(newfd, files->close_on_exec); + rcu_assign_pointer(fdt->fd[newfd], file); + FD_SET(newfd, fdt->open_fds); + FD_CLR(newfd, fdt->close_on_exec); spin_unlock(&files->file_lock); if (tofree) @@ -196,8 +216,11 @@ static int setfl(int fd, struct file * filp, unsigned long arg) struct inode * inode = filp->f_dentry->d_inode; int error = 0; - /* O_APPEND cannot be cleared if the file is marked as append-only */ - if (!(arg & O_APPEND) && IS_APPEND(inode)) + /* + * O_APPEND cannot be cleared if the file is marked as append-only + * and the file is open for write. + */ + if (((arg ^ filp->f_flags) & O_APPEND) && IS_APPEND(inode)) return -EPERM; /* O_NOATIME can only be set by the owner or superuser */ @@ -295,7 +318,7 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg, break; case F_SETLK: case F_SETLKW: - err = fcntl_setlk(filp, cmd, (struct flock __user *) arg); + err = fcntl_setlk(fd, filp, cmd, (struct flock __user *) arg); break; case F_GETOWN: /* @@ -383,7 +406,8 @@ asmlinkage long sys_fcntl64(unsigned int fd, unsigned int cmd, unsigned long arg break; case F_SETLK64: case F_SETLKW64: - err = fcntl_setlk64(filp, cmd, (struct flock64 __user *) arg); + err = fcntl_setlk64(fd, filp, cmd, + (struct flock64 __user *) arg); break; default: err = do_fcntl(fd, cmd, arg, filp); @@ -397,7 +421,7 @@ out: /* Table to convert sigio signal codes into poll band bitmaps */ -static long band_table[NSIGPOLL] = { +static const long band_table[NSIGPOLL] = { POLLIN | POLLRDNORM, /* POLL_IN */ POLLOUT | POLLWRNORM | POLLWRBAND, /* POLL_OUT */ POLLIN | POLLRDNORM | POLLMSG, /* POLL_MSG */ @@ -438,18 +462,17 @@ static void send_sigio_to_task(struct task_struct *p, /* Make sure we are called with one of the POLL_* reasons, otherwise we could leak kernel stack into userspace. */ - if ((reason & __SI_MASK) != __SI_POLL) - BUG(); + BUG_ON((reason & __SI_MASK) != __SI_POLL); if (reason - POLL_IN >= NSIGPOLL) si.si_band = ~0L; else si.si_band = band_table[reason - POLL_IN]; si.si_fd = fd; - if (!send_group_sig_info(fown->signum, &si, p)) + if (!group_send_sig_info(fown->signum, &si, p)) break; /* fall-through: fall back on the old plain SIGIO signal */ case 0: - send_group_sig_info(SIGIO, SEND_SIG_PRIV, p); + group_send_sig_info(SIGIO, SEND_SIG_PRIV, p); } } @@ -483,7 +506,7 @@ static void send_sigurg_to_task(struct task_struct *p, struct fown_struct *fown) { if (sigio_perm(p, fown, SIGURG)) - send_group_sig_info(SIGURG, SEND_SIG_PRIV, p); + group_send_sig_info(SIGURG, SEND_SIG_PRIV, p); } int send_sigurg(struct fown_struct *fown) @@ -516,7 +539,7 @@ int send_sigurg(struct fown_struct *fown) } static DEFINE_RWLOCK(fasync_lock); -static kmem_cache_t *fasync_cache; +static kmem_cache_t *fasync_cache __read_mostly; /* * fasync_helper() is used by some character device drivers (mainly mice)