mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-04 03:14:02 +08:00
7aa123a0dc
* sanity checks belong before risky operation, not after it * don't quit as soon as we'd found an entry Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
102 lines
2.4 KiB
C
102 lines
2.4 KiB
C
/*
|
|
* dir.c
|
|
*
|
|
* Copyright (c) 1999 Al Smith
|
|
*/
|
|
|
|
#include <linux/buffer_head.h>
|
|
#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 = 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))
|
|
printk(KERN_WARNING "EFS: WARNING: readdir(): directory size not a multiple of EFS_DIRBSIZE\n");
|
|
|
|
/* 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) {
|
|
printk(KERN_ERR "EFS: readdir(): failed to read dir block %d\n", block);
|
|
break;
|
|
}
|
|
|
|
dirblock = (struct efs_dir *) bh->b_data;
|
|
|
|
if (be16_to_cpu(dirblock->magic) != EFS_DIRBLK_MAGIC) {
|
|
printk(KERN_ERR "EFS: readdir(): invalid directory block\n");
|
|
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;
|
|
|
|
#ifdef DEBUG
|
|
printk(KERN_DEBUG "EFS: readdir(): block %d slot %d/%d: inode %u, name \"%s\", namelen %u\n", block, slot, dirblock->slots-1, inodenum, nameptr, namelen);
|
|
#endif
|
|
if (!namelen)
|
|
continue;
|
|
/* found the next entry */
|
|
ctx->pos = (block << EFS_DIRBSIZE_BITS) | slot;
|
|
|
|
/* sanity check */
|
|
if (nameptr - (char *) dirblock + namelen > EFS_DIRBSIZE) {
|
|
printk(KERN_WARNING "EFS: 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;
|
|
}
|
|
|