Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936337AbWLDMgN (ORCPT ); Mon, 4 Dec 2006 07:36:13 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S936365AbWLDMgK (ORCPT ); Mon, 4 Dec 2006 07:36:10 -0500 Received: from filer.fsl.cs.sunysb.edu ([130.245.126.2]:5855 "EHLO filer.fsl.cs.sunysb.edu") by vger.kernel.org with ESMTP id S936337AbWLDMf2 (ORCPT ); Mon, 4 Dec 2006 07:35:28 -0500 From: "Josef 'Jeff' Sipek" To: linux-kernel@vger.kernel.org Cc: torvalds@osdl.org, akpm@osdl.org, hch@infradead.org, viro@ftp.linux.org.uk, linux-fsdevel@vger.kernel.org, mhalcrow@us.ibm.com, Josef "Jeff" Sipek Subject: [PATCH 31/35] Unionfs: Internal include file Date: Mon, 4 Dec 2006 07:31:04 -0500 Message-Id: <11652354721688-git-send-email-jsipek@cs.sunysb.edu> X-Mailer: git-send-email 1.4.3.3 In-Reply-To: <1165235468365-git-send-email-jsipek@cs.sunysb.edu> References: <1165235468365-git-send-email-jsipek@cs.sunysb.edu> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 15741 Lines: 506 From: Josef "Jeff" Sipek This patch contains an internal Unionfs include file. The include file is specific to kernel code only, and therefore is separate from include/linux/unionfs.h. Signed-off-by: Josef "Jeff" Sipek Signed-off-by: David Quigley Signed-off-by: Erez Zadok --- fs/unionfs/union.h | 479 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 479 insertions(+), 0 deletions(-) diff --git a/fs/unionfs/union.h b/fs/unionfs/union.h new file mode 100644 index 0000000..ff0b814 --- /dev/null +++ b/fs/unionfs/union.h @@ -0,0 +1,479 @@ +/* + * Copyright (c) 2003-2006 Erez Zadok + * Copyright (c) 2003-2006 Charles P. Wright + * Copyright (c) 2005-2006 Josef Sipek + * 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. + */ + +#ifndef _UNION_H_ +#define _UNION_H_ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +/* the file system name */ +#define UNIONFS_NAME "unionfs" + +/* unionfs file systems superblock magic */ +#define UNIONFS_SUPER_MAGIC 0xf15f083d + +/* unionfs root inode number */ +#define UNIONFS_ROOT_INO 1 + +/* Mount time flags */ +#define MOUNT_FLAG(sb) (UNIONFS_SB(sb)->mount_flag) + +/* number of characters while generating unique temporary file names */ +#define UNIONFS_TMPNAM_LEN 12 + +/* number of times we try to get a unique temporary file name */ +#define GET_TMPNAM_MAX_RETRY 5 + +/* Operations vectors defined in specific files. */ +extern struct file_operations unionfs_main_fops; +extern struct file_operations unionfs_dir_fops; +extern struct inode_operations unionfs_main_iops; +extern struct inode_operations unionfs_dir_iops; +extern struct inode_operations unionfs_symlink_iops; +extern struct super_operations unionfs_sops; +extern struct dentry_operations unionfs_dops; + +/* How long should an entry be allowed to persist */ +#define RDCACHE_JIFFIES 5*HZ + +/* file private data. */ +struct unionfs_file_info { + int bstart; + int bend; + atomic_t generation; + + struct unionfs_dir_state *rdstate; + struct file **lower_files; +}; + +/* unionfs inode data in memory */ +struct unionfs_inode_info { + int bstart; + int bend; + atomic_t generation; + int stale; + /* Stuff for readdir over NFS. */ + spinlock_t rdlock; + struct list_head readdircache; + int rdcount; + int hashsize; + int cookie; + + /* The hidden inodes */ + struct inode **lower_inodes; + /* to keep track of reads/writes for unlinks before closes */ + atomic_t totalopens; + + struct inode vfs_inode; +}; + +/* unionfs dentry data in memory */ +struct unionfs_dentry_info { + /* The semaphore is used to lock the dentry as soon as we get into a + * unionfs function from the VFS. Our lock ordering is that children + * go before their parents. */ + struct semaphore sem; + int bstart; + int bend; + int bopaque; + int bcount; + atomic_t generation; + struct path *lower_paths; +}; + +/* These are the pointers to our various objects. */ +struct unionfs_data { + struct super_block *sb; + struct vfsmount *hidden_mnt; + atomic_t sbcount; + int branchperms; +}; + +/* unionfs super-block data in memory */ +struct unionfs_sb_info { + int bend; + + atomic_t generation; + unsigned long mount_flag; + struct rw_semaphore rwsem; + + struct unionfs_data *data; +}; + +/* + * structure for making the linked list of entries by readdir on left branch + * to compare with entries on right branch + */ +struct filldir_node { + struct list_head file_list; /* list for directory entries */ + char *name; /* name entry */ + int hash; /* name hash */ + int namelen; /* name len since name is not 0 terminated */ + int bindex; /* we can check for duplicate whiteouts and files in the same branch in order to return -EIO. */ + int whiteout; /* is this a whiteout entry? */ + char iname[DNAME_INLINE_LEN_MIN]; /* Inline name, so we don't need to separately kmalloc small ones */ +}; + +/* Directory hash table. */ +struct unionfs_dir_state { + unsigned int cookie; /* The cookie, which is based off of rdversion */ + unsigned int offset; /* The entry we have returned. */ + int bindex; + loff_t dirpos; /* The offset within the lower level directory. */ + int size; /* How big is the hash table? */ + int hashentries; /* How many entries have been inserted? */ + unsigned long access; + /* This cache list is used when the inode keeps us around. */ + struct list_head cache; + struct list_head list[0]; +}; + +/* include miscellaneous macros */ +#include "fanout.h" +#include "sioq.h" + +/* Cache creation/deletion routines. */ +void destroy_filldir_cache(void); +int init_filldir_cache(void); +int init_inode_cache(void); +void destroy_inode_cache(void); +int init_dentry_cache(void); +void destroy_dentry_cache(void); + +/* Initialize and free readdir-specific state. */ +int init_rdstate(struct file *file); +struct unionfs_dir_state *alloc_rdstate(struct inode *inode, int bindex); +struct unionfs_dir_state *find_rdstate(struct inode *inode, loff_t fpos); +void free_rdstate(struct unionfs_dir_state *state); +int add_filldir_node(struct unionfs_dir_state *rdstate, const char *name, + int namelen, int bindex, int whiteout); +struct filldir_node *find_filldir_node(struct unionfs_dir_state *rdstate, + const char *name, int namelen); + +struct dentry **alloc_new_dentries(int objs); +struct unionfs_data *alloc_new_data(int objs); + +/* We can only use 32-bits of offset for rdstate --- blech! */ +#define DIREOF (0xfffff) +#define RDOFFBITS 20 /* This is the number of bits in DIREOF. */ +#define MAXRDCOOKIE (0xfff) +/* Turn an rdstate into an offset. */ +static inline off_t rdstate2offset(struct unionfs_dir_state *buf) +{ + off_t tmp; + tmp = ((buf->cookie & MAXRDCOOKIE) << RDOFFBITS) + | (buf->offset & DIREOF); + return tmp; +} + +#define unionfs_read_lock(sb) down_read(&UNIONFS_SB(sb)->rwsem) +#define unionfs_read_unlock(sb) up_read(&UNIONFS_SB(sb)->rwsem) +#define unionfs_write_lock(sb) down_write(&UNIONFS_SB(sb)->rwsem) +#define unionfs_write_unlock(sb) up_write(&UNIONFS_SB(sb)->rwsem) + +/* The double lock function needs to go after the debugmacros, so that + * dtopd is defined. */ +static inline void double_lock_dentry(struct dentry *d1, struct dentry *d2) +{ + if (d2 < d1) { + struct dentry *tmp = d1; + d1 = d2; + d2 = tmp; + } + lock_dentry(d1); + lock_dentry(d2); +} + +extern int new_dentry_private_data(struct dentry *dentry); +void free_dentry_private_data(struct unionfs_dentry_info *udi); +void update_bstart(struct dentry *dentry); + +/* + * EXTERNALS: + */ +/* replicates the directory structure upto given dentry in given branch */ +extern struct dentry *create_parents(struct inode *dir, struct dentry *dentry, + int bindex); +struct dentry *create_parents_named(struct inode *dir, struct dentry *dentry, + const char *name, int bindex); + +/* check if two branches overlap */ +extern int is_branch_overlap(struct dentry *dent1, struct dentry *dent2); + +/* partial lookup */ +extern int unionfs_partial_lookup(struct dentry *dentry); + +/* Pass an unionfs dentry and an index and it will try to create a whiteout in branch 'index'. + On error, it will proceed to a branch to the left */ +extern int create_whiteout(struct dentry *dentry, int start); +/* copies a file from dbstart to newbindex branch */ +extern int copyup_file(struct inode *dir, struct file *file, int bstart, + int newbindex, loff_t size); +extern int copyup_named_file(struct inode *dir, struct file *file, + char *name, int bstart, int new_bindex, + loff_t len); +/* copies a dentry from dbstart to newbindex branch */ +extern int copyup_dentry(struct inode *dir, struct dentry *dentry, int bstart, + int new_bindex, struct file **copyup_file, loff_t len); +extern 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); + +extern int remove_whiteouts(struct dentry *dentry, struct dentry *hidden_dentry, + int bindex); + +extern int do_delete_whiteouts(struct dentry *dentry, int bindex, + struct unionfs_dir_state *namelist); + +/* Is this directory empty: 0 if it is empty, -ENOTEMPTY if not. */ +extern int check_empty(struct dentry *dentry, + struct unionfs_dir_state **namelist); +/* Delete whiteouts from this directory in branch bindex. */ +extern int delete_whiteouts(struct dentry *dentry, int bindex, + struct unionfs_dir_state *namelist); + +/* Re-lookup a hidden dentry. */ +extern int unionfs_refresh_hidden_dentry(struct dentry *dentry, int bindex); + +extern void unionfs_reinterpose(struct dentry *this_dentry); +extern struct super_block *unionfs_duplicate_super(struct super_block *sb); + +/* Locking functions. */ +extern int unionfs_setlk(struct file *file, int cmd, struct file_lock *fl); +extern int unionfs_getlk(struct file *file, struct file_lock *fl); + +/* Common file operations. */ +extern int unionfs_file_revalidate(struct file *file, int willwrite); +extern int unionfs_open(struct inode *inode, struct file *file); +extern int unionfs_file_release(struct inode *inode, struct file *file); +extern int unionfs_flush(struct file *file, fl_owner_t id); +extern long unionfs_ioctl(struct file *file, unsigned int cmd, + unsigned long arg); + +/* Inode operations */ +extern int unionfs_rename(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry); +int unionfs_unlink(struct inode *dir, struct dentry *dentry); +int unionfs_rmdir(struct inode *dir, struct dentry *dentry); + +int unionfs_d_revalidate(struct dentry *dentry, struct nameidata *nd); + +/* The values for unionfs_interpose's flag. */ +#define INTERPOSE_DEFAULT 0 +#define INTERPOSE_LOOKUP 1 +#define INTERPOSE_REVAL 2 +#define INTERPOSE_REVAL_NEG 3 +#define INTERPOSE_PARTIAL 4 + +extern int unionfs_interpose(struct dentry *this_dentry, struct super_block *sb, + int flag); + +/* Branch management ioctls. */ +int unionfs_ioctl_incgen(struct file *file, unsigned int cmd, + unsigned long arg); +int unionfs_ioctl_queryfile(struct file *file, unsigned int cmd, + unsigned long arg); + +/* Verify that a branch is valid. */ +int check_branch(struct nameidata *nd); + +/* The root directory is unhashed, but isn't deleted. */ +static inline int d_deleted(struct dentry *d) +{ + return d_unhashed(d) && (d != d->d_sb->s_root); +} + +/* returns the sum of the n_link values of all the underlying inodes of the + * passed inode */ +static inline int unionfs_get_nlinks(struct inode *inode) +{ + int sum_nlinks = 0; + int dirs = 0; + int bindex; + struct inode *hidden_inode; + + /* don't bother to do all the work since we're unlinked */ + if (inode->i_nlink == 0) + return 0; + + if (!S_ISDIR(inode->i_mode)) + return unionfs_lower_inode(inode)->i_nlink; + + for (bindex = ibstart(inode); bindex <= ibend(inode); bindex++) { + hidden_inode = unionfs_lower_inode_idx(inode, bindex); + if (!hidden_inode || !S_ISDIR(hidden_inode->i_mode)) + continue; + BUG_ON(hidden_inode->i_nlink < 0); + + /* A deleted directory. */ + if (hidden_inode->i_nlink == 0) + continue; + dirs++; + /* A broken directory (e.g., squashfs). */ + if (hidden_inode->i_nlink == 1) + sum_nlinks += 2; + else + sum_nlinks += (hidden_inode->i_nlink - 2); + } + + if (!dirs) + return 0; + return sum_nlinks + 2; +} + +struct dentry *unionfs_lookup_backend(struct dentry *dentry, struct nameidata *nd, int lookupmode); +int is_stale_inode(struct inode *inode); +void make_stale_inode(struct inode *inode); + +#define IS_SET(sb, check_flag) (check_flag & MOUNT_FLAG(sb)) + +/* unionfs_permission, check if we should bypass error to facilitate copyup */ +#define IS_COPYUP_ERR(err) ((err) == -EROFS) + +/* unionfs_open, check if we need to copyup the file */ +#define OPEN_WRITE_FLAGS (O_WRONLY | O_RDWR | O_APPEND) +#define IS_WRITE_FLAG(flag) ((flag) & (OPEN_WRITE_FLAGS)) + +static inline int branchperms(struct super_block *sb, int index) +{ + BUG_ON(index < 0); + + return UNIONFS_SB(sb)->data[index].branchperms; +} + +static inline int set_branchperms(struct super_block *sb, int index, int perms) +{ + BUG_ON(index < 0); + + UNIONFS_SB(sb)->data[index].branchperms = perms; + + return perms; +} + +/* Is this file on a read-only branch? */ +static inline int is_robranch_super(struct super_block *sb, int index) +{ + return (!(branchperms(sb, index) & MAY_WRITE)) ? -EROFS : 0; +} + +/* Is this file on a read-only branch? */ +static inline int is_robranch_idx(struct dentry *dentry, int index) +{ + int err = 0; + + BUG_ON(index < 0); + + if ((!(branchperms(dentry->d_sb, index) & MAY_WRITE)) || + IS_RDONLY(unionfs_lower_dentry_idx(dentry, index)->d_inode)) + err = -EROFS; + + return err; +} + +static inline int is_robranch(struct dentry *dentry) +{ + int index; + + index = UNIONFS_D(dentry)->bstart; + BUG_ON(index < 0); + + return is_robranch_idx(dentry, index); +} + +/* What do we use for whiteouts. */ +#define UNIONFS_WHPFX ".wh." +#define UNIONFS_WHLEN 4 +/* If a directory contains this file, then it is opaque. We start with the + * .wh. flag so that it is blocked by lookup. + */ +#define UNIONFS_DIR_OPAQUE_NAME "__dir_opaque" +#define UNIONFS_DIR_OPAQUE UNIONFS_WHPFX UNIONFS_DIR_OPAQUE_NAME + +/* construct whiteout filename */ +static inline char *alloc_whname(const char *name, int len) +{ + char *buf; + + buf = kmalloc(len + UNIONFS_WHLEN + 1, GFP_KERNEL); + if (!buf) + return ERR_PTR(-ENOMEM); + + strcpy(buf, UNIONFS_WHPFX); + strlcat(buf, name, len + UNIONFS_WHLEN + 1); + + return buf; +} + +#define VALID_MOUNT_FLAGS (0) + +/* + * MACROS: + */ + +#ifndef DEFAULT_POLLMASK +#define DEFAULT_POLLMASK (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM) +#endif + +/* + * EXTERNALS: + */ + +/* These two functions are here because it is kind of daft to copy and paste the + * contents of the two functions to 32+ places in unionfs + */ +static inline struct dentry *lock_parent(struct dentry *dentry) +{ + struct dentry *dir = dget(dentry->d_parent); + + mutex_lock(&dir->d_inode->i_mutex); + return dir; +} + +static inline void unlock_dir(struct dentry *dir) +{ + mutex_unlock(&dir->d_inode->i_mutex); + dput(dir); +} + +extern int make_dir_opaque(struct dentry *dir, int bindex); + +#endif /* not _UNION_H_ */ + -- 1.4.3.3 - 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/