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73422811d2
This patch adds an -oexpose_privroot option to allow access to the privroot. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
305 lines
8.7 KiB
C
305 lines
8.7 KiB
C
/*
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* Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
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*/
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#include <linux/string.h>
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#include <linux/errno.h>
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#include <linux/fs.h>
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#include <linux/reiserfs_fs.h>
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#include <linux/stat.h>
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#include <linux/buffer_head.h>
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#include <asm/uaccess.h>
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extern const struct reiserfs_key MIN_KEY;
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static int reiserfs_readdir(struct file *, void *, filldir_t);
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static int reiserfs_dir_fsync(struct file *filp, struct dentry *dentry,
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int datasync);
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const struct file_operations reiserfs_dir_operations = {
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.read = generic_read_dir,
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.readdir = reiserfs_readdir,
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.fsync = reiserfs_dir_fsync,
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.ioctl = reiserfs_ioctl,
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#ifdef CONFIG_COMPAT
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.compat_ioctl = reiserfs_compat_ioctl,
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#endif
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};
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static int reiserfs_dir_fsync(struct file *filp, struct dentry *dentry,
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int datasync)
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{
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struct inode *inode = dentry->d_inode;
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int err;
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reiserfs_write_lock(inode->i_sb);
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err = reiserfs_commit_for_inode(inode);
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reiserfs_write_unlock(inode->i_sb);
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if (err < 0)
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return err;
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return 0;
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}
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#define store_ih(where,what) copy_item_head (where, what)
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static inline bool is_privroot_deh(struct dentry *dir,
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struct reiserfs_de_head *deh)
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{
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struct dentry *privroot = REISERFS_SB(dir->d_sb)->priv_root;
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if (reiserfs_expose_privroot(dir->d_sb))
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return 0;
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return (dir == dir->d_parent && privroot->d_inode &&
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deh->deh_objectid == INODE_PKEY(privroot->d_inode)->k_objectid);
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}
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int reiserfs_readdir_dentry(struct dentry *dentry, void *dirent,
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filldir_t filldir, loff_t *pos)
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{
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struct inode *inode = dentry->d_inode;
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struct cpu_key pos_key; /* key of current position in the directory (key of directory entry) */
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INITIALIZE_PATH(path_to_entry);
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struct buffer_head *bh;
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int item_num, entry_num;
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const struct reiserfs_key *rkey;
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struct item_head *ih, tmp_ih;
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int search_res;
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char *local_buf;
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loff_t next_pos;
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char small_buf[32]; /* avoid kmalloc if we can */
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struct reiserfs_dir_entry de;
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int ret = 0;
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reiserfs_write_lock(inode->i_sb);
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reiserfs_check_lock_depth(inode->i_sb, "readdir");
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/* form key for search the next directory entry using f_pos field of
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file structure */
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make_cpu_key(&pos_key, inode, *pos ?: DOT_OFFSET, TYPE_DIRENTRY, 3);
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next_pos = cpu_key_k_offset(&pos_key);
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path_to_entry.reada = PATH_READA;
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while (1) {
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research:
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/* search the directory item, containing entry with specified key */
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search_res =
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search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry,
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&de);
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if (search_res == IO_ERROR) {
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// FIXME: we could just skip part of directory which could
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// not be read
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ret = -EIO;
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goto out;
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}
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entry_num = de.de_entry_num;
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bh = de.de_bh;
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item_num = de.de_item_num;
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ih = de.de_ih;
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store_ih(&tmp_ih, ih);
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/* we must have found item, that is item of this directory, */
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RFALSE(COMP_SHORT_KEYS(&(ih->ih_key), &pos_key),
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"vs-9000: found item %h does not match to dir we readdir %K",
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ih, &pos_key);
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RFALSE(item_num > B_NR_ITEMS(bh) - 1,
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"vs-9005 item_num == %d, item amount == %d",
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item_num, B_NR_ITEMS(bh));
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/* and entry must be not more than number of entries in the item */
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RFALSE(I_ENTRY_COUNT(ih) < entry_num,
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"vs-9010: entry number is too big %d (%d)",
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entry_num, I_ENTRY_COUNT(ih));
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if (search_res == POSITION_FOUND
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|| entry_num < I_ENTRY_COUNT(ih)) {
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/* go through all entries in the directory item beginning from the entry, that has been found */
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struct reiserfs_de_head *deh =
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B_I_DEH(bh, ih) + entry_num;
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for (; entry_num < I_ENTRY_COUNT(ih);
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entry_num++, deh++) {
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int d_reclen;
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char *d_name;
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off_t d_off;
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ino_t d_ino;
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if (!de_visible(deh))
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/* it is hidden entry */
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continue;
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d_reclen = entry_length(bh, ih, entry_num);
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d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh);
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if (d_reclen <= 0 ||
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d_name + d_reclen > bh->b_data + bh->b_size) {
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/* There is corrupted data in entry,
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* We'd better stop here */
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pathrelse(&path_to_entry);
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ret = -EIO;
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goto out;
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}
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if (!d_name[d_reclen - 1])
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d_reclen = strlen(d_name);
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if (d_reclen >
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REISERFS_MAX_NAME(inode->i_sb->
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s_blocksize)) {
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/* too big to send back to VFS */
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continue;
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}
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/* Ignore the .reiserfs_priv entry */
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if (is_privroot_deh(dentry, deh))
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continue;
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d_off = deh_offset(deh);
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*pos = d_off;
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d_ino = deh_objectid(deh);
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if (d_reclen <= 32) {
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local_buf = small_buf;
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} else {
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local_buf = kmalloc(d_reclen,
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GFP_NOFS);
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if (!local_buf) {
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pathrelse(&path_to_entry);
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ret = -ENOMEM;
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goto out;
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}
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if (item_moved(&tmp_ih, &path_to_entry)) {
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kfree(local_buf);
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goto research;
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}
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}
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// Note, that we copy name to user space via temporary
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// buffer (local_buf) because filldir will block if
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// user space buffer is swapped out. At that time
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// entry can move to somewhere else
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memcpy(local_buf, d_name, d_reclen);
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if (filldir
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(dirent, local_buf, d_reclen, d_off, d_ino,
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DT_UNKNOWN) < 0) {
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if (local_buf != small_buf) {
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kfree(local_buf);
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}
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goto end;
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}
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if (local_buf != small_buf) {
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kfree(local_buf);
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}
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// next entry should be looked for with such offset
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next_pos = deh_offset(deh) + 1;
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if (item_moved(&tmp_ih, &path_to_entry)) {
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goto research;
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}
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} /* for */
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}
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if (item_num != B_NR_ITEMS(bh) - 1)
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// end of directory has been reached
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goto end;
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/* item we went through is last item of node. Using right
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delimiting key check is it directory end */
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rkey = get_rkey(&path_to_entry, inode->i_sb);
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if (!comp_le_keys(rkey, &MIN_KEY)) {
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/* set pos_key to key, that is the smallest and greater
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that key of the last entry in the item */
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set_cpu_key_k_offset(&pos_key, next_pos);
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continue;
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}
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if (COMP_SHORT_KEYS(rkey, &pos_key)) {
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// end of directory has been reached
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goto end;
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}
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/* directory continues in the right neighboring block */
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set_cpu_key_k_offset(&pos_key,
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le_key_k_offset(KEY_FORMAT_3_5, rkey));
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} /* while */
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end:
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*pos = next_pos;
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pathrelse(&path_to_entry);
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reiserfs_check_path(&path_to_entry);
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out:
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reiserfs_write_unlock(inode->i_sb);
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return ret;
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}
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static int reiserfs_readdir(struct file *file, void *dirent, filldir_t filldir)
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{
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struct dentry *dentry = file->f_path.dentry;
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return reiserfs_readdir_dentry(dentry, dirent, filldir, &file->f_pos);
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}
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/* compose directory item containing "." and ".." entries (entries are
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not aligned to 4 byte boundary) */
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/* the last four params are LE */
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void make_empty_dir_item_v1(char *body, __le32 dirid, __le32 objid,
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__le32 par_dirid, __le32 par_objid)
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{
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struct reiserfs_de_head *deh;
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memset(body, 0, EMPTY_DIR_SIZE_V1);
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deh = (struct reiserfs_de_head *)body;
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/* direntry header of "." */
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put_deh_offset(&(deh[0]), DOT_OFFSET);
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/* these two are from make_le_item_head, and are are LE */
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deh[0].deh_dir_id = dirid;
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deh[0].deh_objectid = objid;
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deh[0].deh_state = 0; /* Endian safe if 0 */
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put_deh_location(&(deh[0]), EMPTY_DIR_SIZE_V1 - strlen("."));
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mark_de_visible(&(deh[0]));
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/* direntry header of ".." */
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put_deh_offset(&(deh[1]), DOT_DOT_OFFSET);
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/* key of ".." for the root directory */
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/* these two are from the inode, and are are LE */
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deh[1].deh_dir_id = par_dirid;
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deh[1].deh_objectid = par_objid;
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deh[1].deh_state = 0; /* Endian safe if 0 */
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put_deh_location(&(deh[1]), deh_location(&(deh[0])) - strlen(".."));
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mark_de_visible(&(deh[1]));
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/* copy ".." and "." */
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memcpy(body + deh_location(&(deh[0])), ".", 1);
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memcpy(body + deh_location(&(deh[1])), "..", 2);
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}
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/* compose directory item containing "." and ".." entries */
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void make_empty_dir_item(char *body, __le32 dirid, __le32 objid,
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__le32 par_dirid, __le32 par_objid)
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{
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struct reiserfs_de_head *deh;
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memset(body, 0, EMPTY_DIR_SIZE);
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deh = (struct reiserfs_de_head *)body;
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/* direntry header of "." */
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put_deh_offset(&(deh[0]), DOT_OFFSET);
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/* these two are from make_le_item_head, and are are LE */
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deh[0].deh_dir_id = dirid;
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deh[0].deh_objectid = objid;
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deh[0].deh_state = 0; /* Endian safe if 0 */
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put_deh_location(&(deh[0]), EMPTY_DIR_SIZE - ROUND_UP(strlen(".")));
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mark_de_visible(&(deh[0]));
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/* direntry header of ".." */
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put_deh_offset(&(deh[1]), DOT_DOT_OFFSET);
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/* key of ".." for the root directory */
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/* these two are from the inode, and are are LE */
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deh[1].deh_dir_id = par_dirid;
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deh[1].deh_objectid = par_objid;
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deh[1].deh_state = 0; /* Endian safe if 0 */
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put_deh_location(&(deh[1]),
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deh_location(&(deh[0])) - ROUND_UP(strlen("..")));
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mark_de_visible(&(deh[1]));
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/* copy ".." and "." */
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memcpy(body + deh_location(&(deh[0])), ".", 1);
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memcpy(body + deh_location(&(deh[1])), "..", 2);
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}
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