Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932708AbWJGF4h (ORCPT ); Sat, 7 Oct 2006 01:56:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932605AbWJGF4f (ORCPT ); Sat, 7 Oct 2006 01:56:35 -0400 Received: from filer.fsl.cs.sunysb.edu ([130.245.126.2]:12209 "EHLO filer.fsl.cs.sunysb.edu") by vger.kernel.org with ESMTP id S932708AbWJGF43 (ORCPT ); Sat, 7 Oct 2006 01:56:29 -0400 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [PATCH 8 of 23] Unionfs: Directory file operations Message-Id: <9ebbf55159847712027e.1160197647@thor.fsl.cs.sunysb.edu> In-Reply-To: Date: Sat, 07 Oct 2006 01:07:27 -0400 From: Josef "Jeff" Sipek To: linux-kernel@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, torvalds@osdl.org, akpm@osdl.org, hch@infradead.org, viro@ftp.linux.org.uk Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7501 Lines: 287 From: Josef "Jeff" Sipek This patch provides directory file operations. Signed-off-by: Josef "Jeff" Sipek Signed-off-by: David Quigley Signed-off-by: Erez Zadok --- 1 file changed, 263 insertions(+) fs/unionfs/dirfops.c | 263 ++++++++++++++++++++++++++++++++++++++++++++++++++ diff -r b699f4b2c3a5 -r 9ebbf5515984 fs/unionfs/dirfops.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/fs/unionfs/dirfops.c Sat Oct 07 00:46:18 2006 -0400 @@ -0,0 +1,263 @@ +/* + * Copyright (c) 2003-2006 Erez Zadok + * Copyright (c) 2003-2006 Charles P. Wright + * Copyright (c) 2005-2006 Josef 'Jeff' Sipek + * Copyright (c) 2005-2006 Junjiro Okajima + * Copyright (c) 2005 Arun M. Krishnakumar + * Copyright (c) 2004-2006 David P. Quigley + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair + * Copyright (c) 2003 Puja Gupta + * Copyright (c) 2003 Harikesavan Krishnan + * Copyright (c) 2003-2006 Stony Brook University + * Copyright (c) 2003-2006 The Research Foundation of State University of New York + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include "union.h" + +/* Make sure our rdstate is playing by the rules. */ +static void verify_rdstate_offset(struct unionfs_dir_state *rdstate) +{ + BUG_ON(rdstate->uds_offset >= DIREOF); + BUG_ON(rdstate->uds_cookie >= MAXRDCOOKIE); +} + +struct unionfs_getdents_callback { + struct unionfs_dir_state *rdstate; + void *dirent; + int entries_written; + int filldir_called; + int filldir_error; + filldir_t filldir; + struct super_block *sb; +}; + +/* copied from generic filldir in fs/readir.c */ +static int unionfs_filldir(void *dirent, const char *name, int namelen, + loff_t offset, u64 ino, unsigned int d_type) +{ + struct unionfs_getdents_callback *buf = dirent; + struct filldir_node *found = NULL; + int err = 0; + int is_wh_entry = 0; + + buf->filldir_called++; + + if ((namelen > UNIONFS_WHLEN) && !strncmp(name, UNIONFS_WHPFX, UNIONFS_WHLEN)) { + name += UNIONFS_WHLEN; + namelen -= UNIONFS_WHLEN; + is_wh_entry = 1; + } + + found = find_filldir_node(buf->rdstate, name, namelen); + + if (found) + goto out; + + /* if 'name' isn't a whiteout, filldir it. */ + if (!is_wh_entry) { + off_t pos = rdstate2offset(buf->rdstate); + u64 unionfs_ino = ino; + + if (!err) { + err = buf->filldir(buf->dirent, name, namelen, pos, + unionfs_ino, d_type); + buf->rdstate->uds_offset++; + verify_rdstate_offset(buf->rdstate); + } + } + /* If we did fill it, stuff it in our hash, otherwise return an error */ + if (err) { + buf->filldir_error = err; + goto out; + } + buf->entries_written++; + if ((err = add_filldir_node(buf->rdstate, name, namelen, + buf->rdstate->uds_bindex, is_wh_entry))) + buf->filldir_error = err; + +out: + return err; +} + +static int unionfs_readdir(struct file *file, void *dirent, filldir_t filldir) +{ + int err = 0; + struct file *hidden_file = NULL; + struct inode *inode = NULL; + struct unionfs_getdents_callback buf; + struct unionfs_dir_state *uds; + int bend; + loff_t offset; + + if ((err = unionfs_file_revalidate(file, 0))) + goto out; + + inode = file->f_dentry->d_inode; + + uds = ftopd(file)->rdstate; + if (!uds) { + if (file->f_pos == DIREOF) { + goto out; + } else if (file->f_pos > 0) { + uds = find_rdstate(inode, file->f_pos); + if (!uds) { + err = -ESTALE; + goto out; + } + ftopd(file)->rdstate = uds; + } else { + init_rdstate(file); + uds = ftopd(file)->rdstate; + } + } + bend = fbend(file); + + while (uds->uds_bindex <= bend) { + hidden_file = ftohf_index(file, uds->uds_bindex); + if (!hidden_file) { + uds->uds_bindex++; + uds->uds_dirpos = 0; + continue; + } + + /* prepare callback buffer */ + buf.filldir_called = 0; + buf.filldir_error = 0; + buf.entries_written = 0; + buf.dirent = dirent; + buf.filldir = filldir; + buf.rdstate = uds; + buf.sb = inode->i_sb; + + /* Read starting from where we last left off. */ + offset = vfs_llseek(hidden_file, uds->uds_dirpos, 0); + if (offset < 0) { + err = offset; + goto out; + } + err = vfs_readdir(hidden_file, unionfs_filldir, &buf); + /* Save the position for when we continue. */ + + offset = vfs_llseek(hidden_file, 0, 1); + if (offset < 0) { + err = offset; + goto out; + } + uds->uds_dirpos = offset; + + /* Copy the atime. */ + fist_copy_attr_atime(inode, hidden_file->f_dentry->d_inode); + + if (err < 0) + goto out; + + if (buf.filldir_error) + break; + + if (!buf.entries_written) { + uds->uds_bindex++; + uds->uds_dirpos = 0; + } + } + + if (!buf.filldir_error && uds->uds_bindex >= bend) { + /* Save the number of hash entries for next time. */ + itopd(inode)->uii_hashsize = uds->uds_hashentries; + free_rdstate(uds); + ftopd(file)->rdstate = NULL; + file->f_pos = DIREOF; + } else + file->f_pos = rdstate2offset(uds); + +out: + return err; +} + +/* This is not meant to be a generic repositioning function. If you do + * things that aren't supported, then we return EINVAL. + * + * What is allowed: + * (1) seeking to the same position that you are currently at + * This really has no effect, but returns where you are. + * (2) seeking to the end of the file, if you've read everything + * This really has no effect, but returns where you are. + * (3) seeking to the beginning of the file + * This throws out all state, and lets you begin again. + */ +static loff_t unionfs_dir_llseek(struct file *file, loff_t offset, int origin) +{ + struct unionfs_dir_state *rdstate; + loff_t err; + + if ((err = unionfs_file_revalidate(file, 0))) + goto out; + + rdstate = ftopd(file)->rdstate; + + /* We let users seek to their current position, but not anywhere else. */ + if (!offset) { + switch (origin) { + case SEEK_SET: + if (rdstate) { + free_rdstate(rdstate); + ftopd(file)->rdstate = NULL; + } + init_rdstate(file); + err = 0; + break; + case SEEK_CUR: + err = file->f_pos; + break; + case SEEK_END: + /* Unsupported, because we would break everything. */ + err = -EINVAL; + break; + } + } else { + switch (origin) { + case SEEK_SET: + if (rdstate) { + if (offset == rdstate2offset(rdstate)) + err = offset; + else if (file->f_pos == DIREOF) + err = DIREOF; + else + err = -EINVAL; + } else { + if ((rdstate = find_rdstate(file->f_dentry->d_inode, + offset))) { + ftopd(file)->rdstate = rdstate; + err = rdstate->uds_offset; + } else + err = -EINVAL; + } + break; + case SEEK_CUR: + case SEEK_END: + /* Unsupported, because we would break everything. */ + err = -EINVAL; + break; + } + } + +out: + return err; +} + +/* Trimmed directory options, we shouldn't pass everything down since + * we don't want to operate on partial directories. + */ +struct file_operations unionfs_dir_fops = { + .llseek = unionfs_dir_llseek, + .read = generic_read_dir, + .readdir = unionfs_readdir, + .unlocked_ioctl = unionfs_ioctl, + .open = unionfs_open, + .release = unionfs_file_release, + .flush = unionfs_flush, +}; + - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/