Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030525AbXAHEWS (ORCPT ); Sun, 7 Jan 2007 23:22:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030519AbXAHETY (ORCPT ); Sun, 7 Jan 2007 23:19:24 -0500 Received: from filer.fsl.cs.sunysb.edu ([130.245.126.2]:50454 "EHLO filer.fsl.cs.sunysb.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030525AbXAHETJ (ORCPT ); Sun, 7 Jan 2007 23:19:09 -0500 From: "Josef 'Jeff' Sipek" To: linux-kernel@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, hch@infradead.org, viro@ftp.linux.org.uk, torvalds@osdl.org, akpm@osdl.org, mhalcrow@us.ibm.com, Josef "Jeff" Sipek , David Quigley , Erez Zadok Subject: [PATCH 05/24] Unionfs: Copyup Functionality Date: Sun, 7 Jan 2007 23:12:57 -0500 Message-Id: <11682295971184-git-send-email-jsipek@cs.sunysb.edu> X-Mailer: git-send-email 1.4.4.2 In-Reply-To: <1168229596580-git-send-email-jsipek@cs.sunysb.edu> References: <1168229596580-git-send-email-jsipek@cs.sunysb.edu> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 18950 Lines: 702 From: Josef "Jeff" Sipek This patch contains the functions used to perform copyup operations in unionfs. Signed-off-by: Josef "Jeff" Sipek Signed-off-by: David Quigley Signed-off-by: Erez Zadok --- fs/unionfs/copyup.c | 677 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 677 insertions(+), 0 deletions(-) diff --git a/fs/unionfs/copyup.c b/fs/unionfs/copyup.c new file mode 100644 index 0000000..ad70b24 --- /dev/null +++ b/fs/unionfs/copyup.c @@ -0,0 +1,677 @@ +/* + * 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" + +/* Determine the mode based on the copyup flags, and the existing dentry. */ +static int copyup_permissions(struct super_block *sb, + struct dentry *old_hidden_dentry, + struct dentry *new_hidden_dentry) +{ + struct inode *i = old_hidden_dentry->d_inode; + struct iattr newattrs; + int err; + + newattrs.ia_atime = i->i_atime; + newattrs.ia_mtime = i->i_mtime; + newattrs.ia_ctime = i->i_ctime; + + newattrs.ia_gid = i->i_gid; + newattrs.ia_uid = i->i_uid; + + newattrs.ia_mode = i->i_mode; + + newattrs.ia_valid = ATTR_CTIME | ATTR_ATIME | ATTR_MTIME | + ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_FORCE | + ATTR_GID | ATTR_UID | ATTR_MODE; + + err = notify_change(new_hidden_dentry, &newattrs); + + return err; +} + +int copyup_dentry(struct inode *dir, struct dentry *dentry, + int bstart, int new_bindex, + struct file **copyup_file, loff_t len) +{ + return copyup_named_dentry(dir, dentry, bstart, new_bindex, + dentry->d_name.name, + dentry->d_name.len, copyup_file, len); +} + +/* create the new device/file/directory - use copyup_permission to copyup + * times, and mode + * + * if the object being copied up is a regular file, the file is only created, + * the contents have to be copied up separately + */ +static inline int __copyup_ndentry(struct dentry *old_hidden_dentry, + struct dentry *new_hidden_dentry, + struct dentry *new_hidden_parent_dentry, + char *symbuf) +{ + int err = 0; + umode_t old_mode = old_hidden_dentry->d_inode->i_mode; + struct sioq_args args; + + if (S_ISDIR(old_mode)) { + args.mkdir.parent = new_hidden_parent_dentry->d_inode; + args.mkdir.dentry = new_hidden_dentry; + args.mkdir.mode = old_mode; + + run_sioq(__unionfs_mkdir, &args); + err = args.err; + } else if (S_ISLNK(old_mode)) { + args.symlink.parent = new_hidden_parent_dentry->d_inode; + args.symlink.dentry = new_hidden_dentry; + args.symlink.symbuf = symbuf; + args.symlink.mode = old_mode; + + run_sioq(__unionfs_symlink, &args); + err = args.err; + } else if (S_ISBLK(old_mode) || S_ISCHR(old_mode) || + S_ISFIFO(old_mode) || S_ISSOCK(old_mode)) { + args.mknod.parent = new_hidden_parent_dentry->d_inode; + args.mknod.dentry = new_hidden_dentry; + args.mknod.mode = old_mode; + args.mknod.dev = old_hidden_dentry->d_inode->i_rdev; + + run_sioq(__unionfs_mknod, &args); + err = args.err; + } else if (S_ISREG(old_mode)) { + args.create.parent = new_hidden_parent_dentry->d_inode; + args.create.dentry = new_hidden_dentry; + args.create.mode = old_mode; + args.create.nd = NULL; + + run_sioq(__unionfs_create, &args); + err = args.err; + } else { + printk(KERN_ERR "Unknown inode type %d\n", + old_mode); + BUG(); + } + + return err; +} + +static inline int __copyup_reg_data(struct dentry *dentry, + struct dentry *new_hidden_dentry, + int new_bindex, + struct dentry *old_hidden_dentry, + int old_bindex, + struct file **copyup_file, + loff_t len) +{ + struct super_block *sb = dentry->d_sb; + struct file *input_file; + struct file *output_file; + mm_segment_t old_fs; + char *buf = NULL; + ssize_t read_bytes, write_bytes; + loff_t size; + int err = 0; + + /* open old file */ + mntget(unionfs_lower_mnt_idx(dentry, old_bindex)); + branchget(sb, old_bindex); + input_file = dentry_open(old_hidden_dentry, + unionfs_lower_mnt_idx(dentry, old_bindex), + O_RDONLY | O_LARGEFILE); + if (IS_ERR(input_file)) { + dput(old_hidden_dentry); + err = PTR_ERR(input_file); + goto out; + } + if (!input_file->f_op || !input_file->f_op->read) { + err = -EINVAL; + goto out_close_in; + } + + /* open new file */ + dget(new_hidden_dentry); + mntget(unionfs_lower_mnt_idx(dentry, new_bindex)); + branchget(sb, new_bindex); + output_file = dentry_open(new_hidden_dentry, + unionfs_lower_mnt_idx(dentry, new_bindex), + O_WRONLY | O_LARGEFILE); + if (IS_ERR(output_file)) { + err = PTR_ERR(output_file); + goto out_close_in2; + } + if (!output_file->f_op || !output_file->f_op->write) { + err = -EINVAL; + goto out_close_out; + } + + /* allocating a buffer */ + buf = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!buf) { + err = -ENOMEM; + goto out_close_out; + } + + input_file->f_pos = 0; + output_file->f_pos = 0; + + old_fs = get_fs(); + set_fs(KERNEL_DS); + + size = len; + err = 0; + do { + if (len >= PAGE_SIZE) + size = PAGE_SIZE; + else if ((len < PAGE_SIZE) && (len > 0)) + size = len; + + len -= PAGE_SIZE; + + read_bytes = + input_file->f_op->read(input_file, + (char __user *)buf, size, + &input_file->f_pos); + if (read_bytes <= 0) { + err = read_bytes; + break; + } + + write_bytes = + output_file->f_op->write(output_file, + (char __user *)buf, + read_bytes, + &output_file->f_pos); + if ((write_bytes < 0) || (write_bytes < read_bytes)) { + err = write_bytes; + break; + } + } while ((read_bytes > 0) && (len > 0)); + + set_fs(old_fs); + + kfree(buf); + + if (err) + goto out_close_out; + if (copyup_file) { + *copyup_file = output_file; + goto out_close_in; + } + +out_close_out: + fput(output_file); + +out_close_in2: + branchput(sb, new_bindex); + +out_close_in: + fput(input_file); + +out: + branchput(sb, old_bindex); + + return err; +} + +/* dput the lower references for old and new dentry & clear a lower dentry + * pointer + */ +static inline void __clear(struct dentry *dentry, + struct dentry *old_hidden_dentry, + int old_bstart, int old_bend, + struct dentry *new_hidden_dentry, + int new_bindex) +{ + /* get rid of the hidden dentry and all its traces */ + unionfs_set_lower_dentry_idx(dentry, new_bindex, NULL); + set_dbstart(dentry, old_bstart); + set_dbend(dentry, old_bend); + + dput(new_hidden_dentry); + dput(old_hidden_dentry); +} + +/* copy up a dentry to a file of specified name */ +int copyup_named_dentry(struct inode *dir, struct dentry *dentry, + int bstart, int new_bindex, const char *name, + int namelen, struct file **copyup_file, loff_t len) +{ + struct dentry *new_hidden_dentry; + struct dentry *old_hidden_dentry = NULL; + struct super_block *sb; + int err = 0; + int old_bindex; + int old_bstart; + int old_bend; + struct dentry *new_hidden_parent_dentry = NULL; + mm_segment_t oldfs; + char *symbuf = NULL; + + verify_locked(dentry); + + old_bindex = bstart; + old_bstart = dbstart(dentry); + old_bend = dbend(dentry); + + BUG_ON(new_bindex < 0); + BUG_ON(new_bindex >= old_bindex); + + sb = dir->i_sb; + + unionfs_read_lock(sb); + + if ((err = is_robranch_super(sb, new_bindex))) { + dput(old_hidden_dentry); + goto out; + } + + /* Create the directory structure above this dentry. */ + new_hidden_dentry = create_parents_named(dir, dentry, name, new_bindex); + if (IS_ERR(new_hidden_dentry)) { + dput(old_hidden_dentry); + err = PTR_ERR(new_hidden_dentry); + goto out; + } + + old_hidden_dentry = unionfs_lower_dentry_idx(dentry, old_bindex); + dget(old_hidden_dentry); + + /* For symlinks, we must read the link before we lock the directory. */ + if (S_ISLNK(old_hidden_dentry->d_inode->i_mode)) { + + symbuf = kmalloc(PATH_MAX, GFP_KERNEL); + if (!symbuf) { + __clear(dentry, old_hidden_dentry, + old_bstart, old_bend, + new_hidden_dentry, new_bindex); + err = -ENOMEM; + goto out_free; + } + + oldfs = get_fs(); + set_fs(KERNEL_DS); + err = old_hidden_dentry->d_inode->i_op->readlink( + old_hidden_dentry, + (char __user *)symbuf, + PATH_MAX); + set_fs(oldfs); + if (err) { + __clear(dentry, old_hidden_dentry, + old_bstart, old_bend, + new_hidden_dentry, new_bindex); + goto out_free; + } + symbuf[err] = '\0'; + } + + /* Now we lock the parent, and create the object in the new branch. */ + new_hidden_parent_dentry = lock_parent(new_hidden_dentry); + + /* create the new inode */ + err = __copyup_ndentry(old_hidden_dentry, new_hidden_dentry, + new_hidden_parent_dentry, symbuf); + + if (err) { + __clear(dentry, old_hidden_dentry, + old_bstart, old_bend, + new_hidden_dentry, new_bindex); + goto out_unlock; + } + + /* We actually copyup the file here. */ + if (S_ISREG(old_hidden_dentry->d_inode->i_mode)) + err = __copyup_reg_data(dentry, new_hidden_dentry, new_bindex, + old_hidden_dentry, old_bindex, copyup_file, len); + if (err) + goto out_unlink; + + /* Set permissions. */ + if ((err = copyup_permissions(sb, old_hidden_dentry, new_hidden_dentry))) + goto out_unlink; + + /* do not allow files getting deleted to be reinterposed */ + if (!d_deleted(dentry)) + unionfs_reinterpose(dentry); + + goto out_unlock; + /****/ + +out_unlink: + /* copyup failed, because we possibly ran out of space or + * quota, or something else happened so let's unlink; we don't + * really care about the return value of vfs_unlink + */ + vfs_unlink(new_hidden_parent_dentry->d_inode, new_hidden_dentry); + + if (copyup_file) { + /* need to close the file */ + + fput(*copyup_file); + branchput(sb, new_bindex); + } + + /* + * TODO: should we reset the error to something like -EIO? + * + * If we don't reset, the user may get some non-sensical errors, but + * on the other hand, if we reset to EIO, we guarantee that the user + * will get a "confusing" error message. + */ + +out_unlock: + unlock_dir(new_hidden_parent_dentry); + +out_free: + kfree(symbuf); + +out: + unionfs_read_unlock(sb); + + return err; +} + +/* This function creates a copy of a file represented by 'file' which currently + * resides in branch 'bstart' to branch 'new_bindex.' The copy will be named + * "name". + */ +int copyup_named_file(struct inode *dir, struct file *file, char *name, + int bstart, int new_bindex, loff_t len) +{ + int err = 0; + struct file *output_file = NULL; + + err = copyup_named_dentry(dir, file->f_dentry, bstart, + new_bindex, name, strlen(name), &output_file, + len); + if (!err) { + fbstart(file) = new_bindex; + unionfs_set_lower_file_idx(file, new_bindex, output_file); + } + + return err; +} + +/* This function creates a copy of a file represented by 'file' which currently + * resides in branch 'bstart' to branch 'new_bindex'. + */ +int copyup_file(struct inode *dir, struct file *file, int bstart, + int new_bindex, loff_t len) +{ + int err = 0; + struct file *output_file = NULL; + + err = copyup_dentry(dir, file->f_dentry, bstart, new_bindex, + &output_file, len); + if (!err) { + fbstart(file) = new_bindex; + unionfs_set_lower_file_idx(file, new_bindex, output_file); + } + + return err; +} + +/* This function replicates the directory structure upto given dentry + * in the bindex branch. Can create directory structure recursively to the right + * also. + */ +struct dentry *create_parents(struct inode *dir, struct dentry *dentry, + int bindex) +{ + return create_parents_named(dir, dentry, dentry->d_name.name, bindex); +} + +static inline void __cleanup_dentry(struct dentry * dentry, int bindex, + int old_bstart, int old_bend) +{ + int loop_start; + int loop_end; + int new_bstart = -1; + int new_bend = -1; + int i; + + loop_start = min(old_bstart, bindex); + loop_end = max(old_bend, bindex); + + /* This loop sets the bstart and bend for the new dentry by + * traversing from left to right. It also dputs all negative + * dentries except bindex + */ + for (i = loop_start; i <= loop_end; i++) { + if (!unionfs_lower_dentry_idx(dentry, i)) + continue; + + if (i == bindex) { + new_bend = i; + if (new_bstart < 0) + new_bstart = i; + continue; + } + + if (!unionfs_lower_dentry_idx(dentry, i)->d_inode) { + dput(unionfs_lower_dentry_idx(dentry, i)); + unionfs_set_lower_dentry_idx(dentry, i, NULL); + } else { + if (new_bstart < 0) + new_bstart = i; + new_bend = i; + } + } + + if (new_bstart < 0) + new_bstart = bindex; + if (new_bend < 0) + new_bend = bindex; + set_dbstart(dentry, new_bstart); + set_dbend(dentry, new_bend); + +} + +/* set lower inode ptr and update bstart & bend if necessary */ +static inline void __set_inode(struct dentry * upper, struct dentry * lower, + int bindex) +{ + unionfs_set_lower_inode_idx(upper->d_inode, bindex, + igrab(lower->d_inode)); + if (likely(ibstart(upper->d_inode) > bindex)) + ibstart(upper->d_inode) = bindex; + if (likely(ibend(upper->d_inode) < bindex)) + ibend(upper->d_inode) = bindex; + +} + +/* set lower dentry ptr and update bstart & bend if necessary */ +static inline void __set_dentry(struct dentry * upper, struct dentry * lower, + int bindex) +{ + unionfs_set_lower_dentry_idx(upper, bindex, lower); + if (likely(dbstart(upper) > bindex)) + set_dbstart(upper, bindex); + if (likely(dbend(upper) < bindex)) + set_dbend(upper, bindex); +} + +/* This function replicates the directory structure upto given dentry + * in the bindex branch. + */ +struct dentry *create_parents_named(struct inode *dir, struct dentry *dentry, + const char *name, int bindex) +{ + int err; + struct dentry *child_dentry; + struct dentry *parent_dentry; + struct dentry *hidden_parent_dentry = NULL; + struct dentry *hidden_dentry = NULL; + const char *childname; + unsigned int childnamelen; + + int old_kmalloc_size; + int kmalloc_size; + int num_dentry; + int count; + + int old_bstart; + int old_bend; + struct dentry **path = NULL; + struct dentry **tmp_path; + struct super_block *sb; + + verify_locked(dentry); + + /* There is no sense allocating any less than the minimum. */ + kmalloc_size = malloc_sizes[0].cs_size; + num_dentry = kmalloc_size / sizeof(struct dentry *); + + if ((err = is_robranch_super(dir->i_sb, bindex))) { + hidden_dentry = ERR_PTR(err); + goto out; + } + + old_bstart = dbstart(dentry); + old_bend = dbend(dentry); + + hidden_dentry = ERR_PTR(-ENOMEM); + path = kzalloc(kmalloc_size, GFP_KERNEL); + if (!path) + goto out; + + /* assume the negative dentry of unionfs as the parent dentry */ + parent_dentry = dentry; + + count = 0; + /* This loop finds the first parent that exists in the given branch. + * We start building the directory structure from there. At the end + * of the loop, the following should hold: + * - child_dentry is the first nonexistent child + * - parent_dentry is the first existent parent + * - path[0] is the = deepest child + * - path[count] is the first child to create + */ + do { + child_dentry = parent_dentry; + + /* find the parent directory dentry in unionfs */ + parent_dentry = child_dentry->d_parent; + lock_dentry(parent_dentry); + + /* find out the hidden_parent_dentry in the given branch */ + hidden_parent_dentry = unionfs_lower_dentry_idx(parent_dentry, bindex); + + /* store the child dentry */ + path[count++] = child_dentry; + + /* grow path table */ + if (count == num_dentry) { + old_kmalloc_size = kmalloc_size; + kmalloc_size *= 2; + num_dentry = kmalloc_size / sizeof(struct dentry *); + + tmp_path = kzalloc(kmalloc_size, GFP_KERNEL); + if (!tmp_path) { + hidden_dentry = ERR_PTR(-ENOMEM); + goto out; + } + memcpy(tmp_path, path, old_kmalloc_size); + kfree(path); + path = tmp_path; + tmp_path = NULL; + } + + } while (!hidden_parent_dentry); + count--; + + sb = dentry->d_sb; + + /* This is basically while(child_dentry != dentry). This loop is + * horrible to follow and should be replaced with cleaner code. + */ + while (1) { + /* get hidden parent dir in the current branch */ + hidden_parent_dentry = unionfs_lower_dentry_idx(parent_dentry, bindex); + unlock_dentry(parent_dentry); + + /* init the values to lookup */ + childname = child_dentry->d_name.name; + childnamelen = child_dentry->d_name.len; + + if (child_dentry != dentry) { + /* lookup child in the underlying file system */ + hidden_dentry = + lookup_one_len(childname, hidden_parent_dentry, + childnamelen); + if (IS_ERR(hidden_dentry)) + goto out; + } else { + + /* is the name a whiteout of the childname ? + * lookup the whiteout child in the underlying file system + */ + hidden_dentry = + lookup_one_len(name, hidden_parent_dentry, + strlen(name)); + if (IS_ERR(hidden_dentry)) + goto out; + + /* Replace the current dentry (if any) with the new one. */ + dput(unionfs_lower_dentry_idx(dentry, bindex)); + unionfs_set_lower_dentry_idx(dentry, bindex, hidden_dentry); + + __cleanup_dentry(dentry, bindex, old_bstart, old_bend); + break; + } + + if (hidden_dentry->d_inode) { + /* since this already exists we dput to avoid + * multiple references on the same dentry + */ + dput(hidden_dentry); + } else { + struct sioq_args args; + + /* its a negative dentry, create a new dir */ + hidden_parent_dentry = lock_parent(hidden_dentry); + + args.mkdir.parent = hidden_parent_dentry->d_inode; + args.mkdir.dentry = hidden_dentry; + args.mkdir.mode = child_dentry->d_inode->i_mode; + + run_sioq(__unionfs_mkdir, &args); + err = args.err; + + if (!err) + err = copyup_permissions(dir->i_sb, + child_dentry, hidden_dentry); + unlock_dir(hidden_parent_dentry); + if (err) { + dput(hidden_dentry); + hidden_dentry = ERR_PTR(err); + goto out; + } + + } + + __set_inode(child_dentry, hidden_dentry, bindex); + __set_dentry(child_dentry, hidden_dentry, bindex); + + parent_dentry = child_dentry; + child_dentry = path[--count]; + } +out: + kfree(path); + return hidden_dentry; +} + -- 1.4.4.2 - 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/