diff options
Diffstat (limited to 'fs/open.c')
-rw-r--r-- | fs/open.c | 217 |
1 files changed, 68 insertions, 149 deletions
diff --git a/fs/open.c b/fs/open.c index d6c79a0dffc..1e914b397e1 100644 --- a/fs/open.c +++ b/fs/open.c @@ -397,10 +397,10 @@ SYSCALL_DEFINE1(fchdir, unsigned int, fd) { struct file *file; struct inode *inode; - int error; + int error, fput_needed; error = -EBADF; - file = fget(fd); + file = fget_raw_light(fd, &fput_needed); if (!file) goto out; @@ -414,7 +414,7 @@ SYSCALL_DEFINE1(fchdir, unsigned int, fd) if (!error) set_fs_pwd(current->fs, &file->f_path); out_putf: - fput(file); + fput_light(file, fput_needed); out: return error; } @@ -537,25 +537,6 @@ static int chown_common(struct path *path, uid_t user, gid_t group) return error; } -SYSCALL_DEFINE3(chown, const char __user *, filename, uid_t, user, gid_t, group) -{ - struct path path; - int error; - - error = user_path(filename, &path); - if (error) - goto out; - error = mnt_want_write(path.mnt); - if (error) - goto out_release; - error = chown_common(&path, user, group); - mnt_drop_write(path.mnt); -out_release: - path_put(&path); -out: - return error; -} - SYSCALL_DEFINE5(fchownat, int, dfd, const char __user *, filename, uid_t, user, gid_t, group, int, flag) { @@ -583,23 +564,15 @@ out: return error; } -SYSCALL_DEFINE3(lchown, const char __user *, filename, uid_t, user, gid_t, group) +SYSCALL_DEFINE3(chown, const char __user *, filename, uid_t, user, gid_t, group) { - struct path path; - int error; + return sys_fchownat(AT_FDCWD, filename, user, group, 0); +} - error = user_lpath(filename, &path); - if (error) - goto out; - error = mnt_want_write(path.mnt); - if (error) - goto out_release; - error = chown_common(&path, user, group); - mnt_drop_write(path.mnt); -out_release: - path_put(&path); -out: - return error; +SYSCALL_DEFINE3(lchown, const char __user *, filename, uid_t, user, gid_t, group) +{ + return sys_fchownat(AT_FDCWD, filename, user, group, + AT_SYMLINK_NOFOLLOW); } SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group) @@ -667,10 +640,9 @@ int open_check_o_direct(struct file *f) return 0; } -static struct file *do_dentry_open(struct dentry *dentry, struct vfsmount *mnt, - struct file *f, - int (*open)(struct inode *, struct file *), - const struct cred *cred) +static int do_dentry_open(struct file *f, + int (*open)(struct inode *, struct file *), + const struct cred *cred) { static const struct file_operations empty_fops = {}; struct inode *inode; @@ -682,9 +654,9 @@ static struct file *do_dentry_open(struct dentry *dentry, struct vfsmount *mnt, if (unlikely(f->f_flags & O_PATH)) f->f_mode = FMODE_PATH; - inode = dentry->d_inode; + inode = f->f_path.dentry->d_inode; if (f->f_mode & FMODE_WRITE) { - error = __get_file_write_access(inode, mnt); + error = __get_file_write_access(inode, f->f_path.mnt); if (error) goto cleanup_file; if (!special_file(inode->i_mode)) @@ -692,14 +664,12 @@ static struct file *do_dentry_open(struct dentry *dentry, struct vfsmount *mnt, } f->f_mapping = inode->i_mapping; - f->f_path.dentry = dentry; - f->f_path.mnt = mnt; f->f_pos = 0; file_sb_list_add(f, inode->i_sb); if (unlikely(f->f_mode & FMODE_PATH)) { f->f_op = &empty_fops; - return f; + return 0; } f->f_op = fops_get(inode->i_fop); @@ -726,10 +696,11 @@ static struct file *do_dentry_open(struct dentry *dentry, struct vfsmount *mnt, file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping); - return f; + return 0; cleanup_all: fops_put(f->f_op); + file_sb_list_del(f); if (f->f_mode & FMODE_WRITE) { put_write_access(inode); if (!special_file(inode->i_mode)) { @@ -740,124 +711,62 @@ cleanup_all: * here, so just reset the state. */ file_reset_write(f); - mnt_drop_write(mnt); + mnt_drop_write(f->f_path.mnt); } } - file_sb_list_del(f); - f->f_path.dentry = NULL; - f->f_path.mnt = NULL; cleanup_file: - dput(dentry); - mntput(mnt); - return ERR_PTR(error); -} - -static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt, - struct file *f, - int (*open)(struct inode *, struct file *), - const struct cred *cred) -{ - struct file *res = do_dentry_open(dentry, mnt, f, open, cred); - if (!IS_ERR(res)) { - int error = open_check_o_direct(f); - if (error) { - fput(res); - res = ERR_PTR(error); - } - } else { - put_filp(f); - } - return res; + path_put(&f->f_path); + f->f_path.mnt = NULL; + f->f_path.dentry = NULL; + return error; } /** - * lookup_instantiate_filp - instantiates the open intent filp - * @nd: pointer to nameidata + * finish_open - finish opening a file + * @od: opaque open data * @dentry: pointer to dentry * @open: open callback * - * Helper for filesystems that want to use lookup open intents and pass back - * a fully instantiated struct file to the caller. - * This function is meant to be called from within a filesystem's - * lookup method. - * Beware of calling it for non-regular files! Those ->open methods might block - * (e.g. in fifo_open), leaving you with parent locked (and in case of fifo, - * leading to a deadlock, as nobody can open that fifo anymore, because - * another process to open fifo will block on locked parent when doing lookup). - * Note that in case of error, nd->intent.open.file is destroyed, but the - * path information remains valid. + * This can be used to finish opening a file passed to i_op->atomic_open(). + * * If the open callback is set to NULL, then the standard f_op->open() * filesystem callback is substituted. */ -struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry, - int (*open)(struct inode *, struct file *)) +int finish_open(struct file *file, struct dentry *dentry, + int (*open)(struct inode *, struct file *), + int *opened) { - const struct cred *cred = current_cred(); + int error; + BUG_ON(*opened & FILE_OPENED); /* once it's opened, it's opened */ - if (IS_ERR(nd->intent.open.file)) - goto out; - if (IS_ERR(dentry)) - goto out_err; - nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->path.mnt), - nd->intent.open.file, - open, cred); -out: - return nd->intent.open.file; -out_err: - release_open_intent(nd); - nd->intent.open.file = ERR_CAST(dentry); - goto out; + mntget(file->f_path.mnt); + file->f_path.dentry = dget(dentry); + + error = do_dentry_open(file, open, current_cred()); + if (!error) + *opened |= FILE_OPENED; + + return error; } -EXPORT_SYMBOL_GPL(lookup_instantiate_filp); +EXPORT_SYMBOL(finish_open); /** - * nameidata_to_filp - convert a nameidata to an open filp. - * @nd: pointer to nameidata - * @flags: open flags + * finish_no_open - finish ->atomic_open() without opening the file + * + * @od: opaque open data + * @dentry: dentry or NULL (as returned from ->lookup()) * - * Note that this function destroys the original nameidata + * This can be used to set the result of a successful lookup in ->atomic_open(). + * The filesystem's atomic_open() method shall return NULL after calling this. */ -struct file *nameidata_to_filp(struct nameidata *nd) +int finish_no_open(struct file *file, struct dentry *dentry) { - const struct cred *cred = current_cred(); - struct file *filp; - - /* Pick up the filp from the open intent */ - filp = nd->intent.open.file; - - /* Has the filesystem initialised the file for us? */ - if (filp->f_path.dentry != NULL) { - nd->intent.open.file = NULL; - } else { - struct file *res; - - path_get(&nd->path); - res = do_dentry_open(nd->path.dentry, nd->path.mnt, - filp, NULL, cred); - if (!IS_ERR(res)) { - int error; - - nd->intent.open.file = NULL; - BUG_ON(res != filp); - - error = open_check_o_direct(filp); - if (error) { - fput(filp); - filp = ERR_PTR(error); - } - } else { - /* Allow nd->intent.open.file to be recycled */ - filp = res; - } - } - return filp; + file->f_path.dentry = dentry; + return 1; } +EXPORT_SYMBOL(finish_no_open); -/* - * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an - * error. - */ -struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags, +struct file *dentry_open(const struct path *path, int flags, const struct cred *cred) { int error; @@ -866,18 +775,28 @@ struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags, validate_creds(cred); /* We must always pass in a valid mount pointer. */ - BUG_ON(!mnt); + BUG_ON(!path->mnt); error = -ENFILE; f = get_empty_filp(); - if (f == NULL) { - dput(dentry); - mntput(mnt); + if (f == NULL) return ERR_PTR(error); - } f->f_flags = flags; - return __dentry_open(dentry, mnt, f, NULL, cred); + f->f_path = *path; + path_get(&f->f_path); + error = do_dentry_open(f, NULL, cred); + if (!error) { + error = open_check_o_direct(f); + if (error) { + fput(f); + f = ERR_PTR(error); + } + } else { + put_filp(f); + f = ERR_PTR(error); + } + return f; } EXPORT_SYMBOL(dentry_open); |