From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- fs/efs/dir.c | 103 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 103 insertions(+) create mode 100644 fs/efs/dir.c (limited to 'fs/efs/dir.c') diff --git a/fs/efs/dir.c b/fs/efs/dir.c new file mode 100644 index 0000000000..f892ac7c2a --- /dev/null +++ b/fs/efs/dir.c @@ -0,0 +1,103 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * dir.c + * + * Copyright (c) 1999 Al Smith + */ + +#include +#include "efs.h" + +static int efs_readdir(struct file *, struct dir_context *); + +const struct file_operations efs_dir_operations = { + .llseek = generic_file_llseek, + .read = generic_read_dir, + .iterate_shared = efs_readdir, +}; + +const struct inode_operations efs_dir_inode_operations = { + .lookup = efs_lookup, +}; + +static int efs_readdir(struct file *file, struct dir_context *ctx) +{ + struct inode *inode = file_inode(file); + efs_block_t block; + int slot; + + if (inode->i_size & (EFS_DIRBSIZE-1)) + pr_warn("%s(): directory size not a multiple of EFS_DIRBSIZE\n", + __func__); + + /* work out where this entry can be found */ + block = ctx->pos >> EFS_DIRBSIZE_BITS; + + /* each block contains at most 256 slots */ + slot = ctx->pos & 0xff; + + /* look at all blocks */ + while (block < inode->i_blocks) { + struct efs_dir *dirblock; + struct buffer_head *bh; + + /* read the dir block */ + bh = sb_bread(inode->i_sb, efs_bmap(inode, block)); + + if (!bh) { + pr_err("%s(): failed to read dir block %d\n", + __func__, block); + break; + } + + dirblock = (struct efs_dir *) bh->b_data; + + if (be16_to_cpu(dirblock->magic) != EFS_DIRBLK_MAGIC) { + pr_err("%s(): invalid directory block\n", __func__); + brelse(bh); + break; + } + + for (; slot < dirblock->slots; slot++) { + struct efs_dentry *dirslot; + efs_ino_t inodenum; + const char *nameptr; + int namelen; + + if (dirblock->space[slot] == 0) + continue; + + dirslot = (struct efs_dentry *) (((char *) bh->b_data) + EFS_SLOTAT(dirblock, slot)); + + inodenum = be32_to_cpu(dirslot->inode); + namelen = dirslot->namelen; + nameptr = dirslot->name; + pr_debug("%s(): block %d slot %d/%d: inode %u, name \"%s\", namelen %u\n", + __func__, block, slot, dirblock->slots-1, + inodenum, nameptr, namelen); + if (!namelen) + continue; + /* found the next entry */ + ctx->pos = (block << EFS_DIRBSIZE_BITS) | slot; + + /* sanity check */ + if (nameptr - (char *) dirblock + namelen > EFS_DIRBSIZE) { + pr_warn("directory entry %d exceeds directory block\n", + slot); + continue; + } + + /* copy filename and data in dirslot */ + if (!dir_emit(ctx, nameptr, namelen, inodenum, DT_UNKNOWN)) { + brelse(bh); + return 0; + } + } + brelse(bh); + + slot = 0; + block++; + } + ctx->pos = (block << EFS_DIRBSIZE_BITS) | slot; + return 0; +} -- cgit v1.2.3