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346 lines
9.0 KiB
346 lines
9.0 KiB
/* |
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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 "reiserfs.h" |
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#include <linux/stat.h> |
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#include <linux/buffer_head.h> |
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#include <linux/slab.h> |
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#include <linux/uaccess.h> |
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extern const struct reiserfs_key MIN_KEY; |
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static int reiserfs_readdir(struct file *, struct dir_context *); |
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static int reiserfs_dir_fsync(struct file *filp, loff_t start, loff_t end, |
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int datasync); |
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const struct file_operations reiserfs_dir_operations = { |
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.llseek = generic_file_llseek, |
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.read = generic_read_dir, |
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.iterate_shared = reiserfs_readdir, |
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.fsync = reiserfs_dir_fsync, |
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.unlocked_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, loff_t start, loff_t end, |
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int datasync) |
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{ |
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struct inode *inode = filp->f_mapping->host; |
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int err; |
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err = file_write_and_wait_range(filp, start, end); |
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if (err) |
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return err; |
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inode_lock(inode); |
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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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inode_unlock(inode); |
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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 inode *dir, struct reiserfs_de_head *deh) |
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{ |
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struct dentry *privroot = REISERFS_SB(dir->i_sb)->priv_root; |
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return (d_really_is_positive(privroot) && |
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deh->deh_objectid == INODE_PKEY(d_inode(privroot))->k_objectid); |
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} |
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int reiserfs_readdir_inode(struct inode *inode, struct dir_context *ctx) |
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{ |
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/* key of current position in the directory (key of directory entry) */ |
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struct cpu_key pos_key; |
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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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int depth; |
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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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/* |
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* form key for search the next directory entry using |
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* f_pos field of file structure |
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*/ |
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make_cpu_key(&pos_key, inode, ctx->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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/* |
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* search the directory item, containing entry with |
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* specified key |
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*/ |
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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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/* |
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* FIXME: we could just skip part of directory |
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* which could not be read |
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*/ |
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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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/* |
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* and entry must be not more than number of entries |
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* in the item |
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*/ |
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RFALSE(ih_entry_count(ih) < entry_num, |
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"vs-9010: entry number is too big %d (%d)", |
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entry_num, ih_entry_count(ih)); |
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/* |
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* go through all entries in the directory item beginning |
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* from the entry, that has been found |
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*/ |
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if (search_res == POSITION_FOUND |
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|| entry_num < ih_entry_count(ih)) { |
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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 < ih_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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ino_t d_ino; |
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loff_t cur_pos = deh_offset(deh); |
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/* it is hidden entry */ |
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if (!de_visible(deh)) |
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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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/* |
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* There is corrupted data in entry, |
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* We'd better stop here |
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*/ |
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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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/* too big to send back to VFS */ |
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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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continue; |
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} |
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/* Ignore the .reiserfs_priv entry */ |
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if (is_privroot_deh(inode, deh)) |
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continue; |
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ctx->pos = deh_offset(deh); |
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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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/* |
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* Note, that we copy name to user space via |
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* temporary buffer (local_buf) because |
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* filldir will block if user space buffer is |
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* swapped out. At that time entry can move to |
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* somewhere else |
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*/ |
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memcpy(local_buf, d_name, d_reclen); |
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/* |
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* Since filldir might sleep, we can release |
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* the write lock here for other waiters |
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*/ |
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depth = reiserfs_write_unlock_nested(inode->i_sb); |
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if (!dir_emit |
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(ctx, local_buf, d_reclen, d_ino, |
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DT_UNKNOWN)) { |
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reiserfs_write_lock_nested(inode->i_sb, depth); |
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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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reiserfs_write_lock_nested(inode->i_sb, depth); |
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if (local_buf != small_buf) { |
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kfree(local_buf); |
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} |
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/* deh_offset(deh) may be invalid now. */ |
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next_pos = cur_pos + 1; |
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if (item_moved(&tmp_ih, &path_to_entry)) { |
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set_cpu_key_k_offset(&pos_key, |
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next_pos); |
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goto research; |
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} |
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} /* for */ |
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} |
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/* end of directory has been reached */ |
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if (item_num != B_NR_ITEMS(bh) - 1) |
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goto end; |
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/* |
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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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*/ |
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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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/* |
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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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*/ |
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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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/* end of directory has been reached */ |
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if (COMP_SHORT_KEYS(rkey, &pos_key)) { |
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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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ctx->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, struct dir_context *ctx) |
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{ |
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return reiserfs_readdir_inode(file_inode(file), ctx); |
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} |
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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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*/ |
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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 *dot, *dotdot; |
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memset(body, 0, EMPTY_DIR_SIZE_V1); |
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dot = (struct reiserfs_de_head *)body; |
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dotdot = dot + 1; |
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/* direntry header of "." */ |
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put_deh_offset(dot, DOT_OFFSET); |
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/* these two are from make_le_item_head, and are LE */ |
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dot->deh_dir_id = dirid; |
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dot->deh_objectid = objid; |
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dot->deh_state = 0; /* Endian safe if 0 */ |
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put_deh_location(dot, EMPTY_DIR_SIZE_V1 - strlen(".")); |
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mark_de_visible(dot); |
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/* direntry header of ".." */ |
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put_deh_offset(dotdot, 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 LE */ |
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dotdot->deh_dir_id = par_dirid; |
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dotdot->deh_objectid = par_objid; |
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dotdot->deh_state = 0; /* Endian safe if 0 */ |
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put_deh_location(dotdot, deh_location(dot) - strlen("..")); |
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mark_de_visible(dotdot); |
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/* copy ".." and "." */ |
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memcpy(body + deh_location(dot), ".", 1); |
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memcpy(body + deh_location(dotdot), "..", 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 *dot, *dotdot; |
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memset(body, 0, EMPTY_DIR_SIZE); |
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dot = (struct reiserfs_de_head *)body; |
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dotdot = dot + 1; |
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/* direntry header of "." */ |
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put_deh_offset(dot, DOT_OFFSET); |
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/* these two are from make_le_item_head, and are LE */ |
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dot->deh_dir_id = dirid; |
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dot->deh_objectid = objid; |
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dot->deh_state = 0; /* Endian safe if 0 */ |
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put_deh_location(dot, EMPTY_DIR_SIZE - ROUND_UP(strlen("."))); |
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mark_de_visible(dot); |
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/* direntry header of ".." */ |
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put_deh_offset(dotdot, 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 LE */ |
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dotdot->deh_dir_id = par_dirid; |
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dotdot->deh_objectid = par_objid; |
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dotdot->deh_state = 0; /* Endian safe if 0 */ |
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put_deh_location(dotdot, deh_location(dot) - ROUND_UP(strlen(".."))); |
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mark_de_visible(dotdot); |
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/* copy ".." and "." */ |
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memcpy(body + deh_location(dot), ".", 1); |
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memcpy(body + deh_location(dotdot), "..", 2); |
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}
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