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144 lines
3.4 KiB
144 lines
3.4 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* linux/fs/affs/dir.c |
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* |
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* (c) 1996 Hans-Joachim Widmaier - Rewritten |
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* |
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* (C) 1993 Ray Burr - Modified for Amiga FFS filesystem. |
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* |
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* (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem. |
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* |
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* (C) 1991 Linus Torvalds - minix filesystem |
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* |
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* affs directory handling functions |
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* |
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*/ |
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#include <linux/iversion.h> |
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#include "affs.h" |
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static int affs_readdir(struct file *, struct dir_context *); |
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const struct file_operations affs_dir_operations = { |
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.read = generic_read_dir, |
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.llseek = generic_file_llseek, |
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.iterate_shared = affs_readdir, |
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.fsync = affs_file_fsync, |
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}; |
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/* |
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* directories can handle most operations... |
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*/ |
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const struct inode_operations affs_dir_inode_operations = { |
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.create = affs_create, |
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.lookup = affs_lookup, |
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.link = affs_link, |
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.unlink = affs_unlink, |
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.symlink = affs_symlink, |
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.mkdir = affs_mkdir, |
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.rmdir = affs_rmdir, |
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.rename = affs_rename2, |
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.setattr = affs_notify_change, |
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}; |
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static int |
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affs_readdir(struct file *file, struct dir_context *ctx) |
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{ |
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struct inode *inode = file_inode(file); |
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struct super_block *sb = inode->i_sb; |
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struct buffer_head *dir_bh = NULL; |
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struct buffer_head *fh_bh = NULL; |
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unsigned char *name; |
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int namelen; |
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u32 i; |
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int hash_pos; |
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int chain_pos; |
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u32 ino; |
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int error = 0; |
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pr_debug("%s(ino=%lu,f_pos=%llx)\n", __func__, inode->i_ino, ctx->pos); |
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if (ctx->pos < 2) { |
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file->private_data = (void *)0; |
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if (!dir_emit_dots(file, ctx)) |
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return 0; |
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} |
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affs_lock_dir(inode); |
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chain_pos = (ctx->pos - 2) & 0xffff; |
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hash_pos = (ctx->pos - 2) >> 16; |
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if (chain_pos == 0xffff) { |
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affs_warning(sb, "readdir", "More than 65535 entries in chain"); |
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chain_pos = 0; |
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hash_pos++; |
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ctx->pos = ((hash_pos << 16) | chain_pos) + 2; |
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} |
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dir_bh = affs_bread(sb, inode->i_ino); |
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if (!dir_bh) |
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goto out_unlock_dir; |
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/* If the directory hasn't changed since the last call to readdir(), |
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* we can jump directly to where we left off. |
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*/ |
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ino = (u32)(long)file->private_data; |
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if (ino && inode_eq_iversion(inode, file->f_version)) { |
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pr_debug("readdir() left off=%d\n", ino); |
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goto inside; |
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} |
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ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]); |
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for (i = 0; ino && i < chain_pos; i++) { |
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fh_bh = affs_bread(sb, ino); |
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if (!fh_bh) { |
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affs_error(sb, "readdir","Cannot read block %d", i); |
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error = -EIO; |
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goto out_brelse_dir; |
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} |
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ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain); |
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affs_brelse(fh_bh); |
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fh_bh = NULL; |
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} |
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if (ino) |
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goto inside; |
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hash_pos++; |
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for (; hash_pos < AFFS_SB(sb)->s_hashsize; hash_pos++) { |
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ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]); |
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if (!ino) |
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continue; |
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ctx->pos = (hash_pos << 16) + 2; |
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inside: |
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do { |
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fh_bh = affs_bread(sb, ino); |
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if (!fh_bh) { |
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affs_error(sb, "readdir", |
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"Cannot read block %d", ino); |
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break; |
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} |
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namelen = min(AFFS_TAIL(sb, fh_bh)->name[0], |
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(u8)AFFSNAMEMAX); |
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name = AFFS_TAIL(sb, fh_bh)->name + 1; |
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pr_debug("readdir(): dir_emit(\"%.*s\", ino=%u), hash=%d, f_pos=%llx\n", |
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namelen, name, ino, hash_pos, ctx->pos); |
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if (!dir_emit(ctx, name, namelen, ino, DT_UNKNOWN)) |
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goto done; |
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ctx->pos++; |
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ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain); |
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affs_brelse(fh_bh); |
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fh_bh = NULL; |
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} while (ino); |
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} |
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done: |
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file->f_version = inode_query_iversion(inode); |
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file->private_data = (void *)(long)ino; |
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affs_brelse(fh_bh); |
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out_brelse_dir: |
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affs_brelse(dir_bh); |
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out_unlock_dir: |
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affs_unlock_dir(inode); |
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return error; |
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}
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