linux/fs/nilfs2/alloc.h
Ryusuke Konishi f41e355f8b nilfs2: fix incorrect inode allocation from reserved inodes
If the bitmap block that manages the inode allocation status is corrupted,
nilfs_ifile_create_inode() may allocate a new inode from the reserved
inode area where it should not be allocated.

Previous fix commit d325dc6eb7 ("nilfs2: fix use-after-free bug of
struct nilfs_root"), fixed the problem that reserved inodes with inode
numbers less than NILFS_USER_INO (=11) were incorrectly reallocated due to
bitmap corruption, but since the start number of non-reserved inodes is
read from the super block and may change, in which case inode allocation
may occur from the extended reserved inode area.

If that happens, access to that inode will cause an IO error, causing the
file system to degrade to an error state.

Fix this potential issue by adding a wraparound option to the common
metadata object allocation routine and by modifying
nilfs_ifile_create_inode() to disable the option so that it only allocates
inodes with inode numbers greater than or equal to the inode number read
in "nilfs->ns_first_ino", regardless of the bitmap status of reserved
inodes.

Link: https://lkml.kernel.org/r/20240623051135.4180-4-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03 19:30:16 -07:00

98 lines
3.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Persistent object (dat entry/disk inode) allocator/deallocator
*
* Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
*
* Originally written by Koji Sato.
* Two allocators were unified by Ryusuke Konishi and Amagai Yoshiji.
*/
#ifndef _NILFS_ALLOC_H
#define _NILFS_ALLOC_H
#include <linux/types.h>
#include <linux/buffer_head.h>
#include <linux/fs.h>
/**
* nilfs_palloc_entries_per_group - get the number of entries per group
* @inode: inode of metadata file using this allocator
*
* The number of entries per group is defined by the number of bits
* that a bitmap block can maintain.
*/
static inline unsigned long
nilfs_palloc_entries_per_group(const struct inode *inode)
{
return 1UL << (inode->i_blkbits + 3 /* log2(8 = CHAR_BITS) */);
}
int nilfs_palloc_init_blockgroup(struct inode *, unsigned int);
int nilfs_palloc_get_entry_block(struct inode *, __u64, int,
struct buffer_head **);
void *nilfs_palloc_block_get_entry(const struct inode *, __u64,
const struct buffer_head *, void *);
int nilfs_palloc_count_max_entries(struct inode *, u64, u64 *);
/**
* nilfs_palloc_req - persistent allocator request and reply
* @pr_entry_nr: entry number (vblocknr or inode number)
* @pr_desc_bh: buffer head of the buffer containing block group descriptors
* @pr_bitmap_bh: buffer head of the buffer containing a block group bitmap
* @pr_entry_bh: buffer head of the buffer containing translation entries
*/
struct nilfs_palloc_req {
__u64 pr_entry_nr;
struct buffer_head *pr_desc_bh;
struct buffer_head *pr_bitmap_bh;
struct buffer_head *pr_entry_bh;
};
int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
struct nilfs_palloc_req *req, bool wrap);
void nilfs_palloc_commit_alloc_entry(struct inode *,
struct nilfs_palloc_req *);
void nilfs_palloc_abort_alloc_entry(struct inode *, struct nilfs_palloc_req *);
void nilfs_palloc_commit_free_entry(struct inode *, struct nilfs_palloc_req *);
int nilfs_palloc_prepare_free_entry(struct inode *, struct nilfs_palloc_req *);
void nilfs_palloc_abort_free_entry(struct inode *, struct nilfs_palloc_req *);
int nilfs_palloc_freev(struct inode *, __u64 *, size_t);
#define nilfs_set_bit_atomic ext2_set_bit_atomic
#define nilfs_clear_bit_atomic ext2_clear_bit_atomic
#define nilfs_find_next_zero_bit find_next_zero_bit_le
#define nilfs_find_next_bit find_next_bit_le
/**
* struct nilfs_bh_assoc - block offset and buffer head association
* @blkoff: block offset
* @bh: buffer head
*/
struct nilfs_bh_assoc {
unsigned long blkoff;
struct buffer_head *bh;
};
/**
* struct nilfs_palloc_cache - persistent object allocator cache
* @lock: cache protecting lock
* @prev_desc: blockgroup descriptors cache
* @prev_bitmap: blockgroup bitmap cache
* @prev_entry: translation entries cache
*/
struct nilfs_palloc_cache {
spinlock_t lock;
struct nilfs_bh_assoc prev_desc;
struct nilfs_bh_assoc prev_bitmap;
struct nilfs_bh_assoc prev_entry;
};
void nilfs_palloc_setup_cache(struct inode *inode,
struct nilfs_palloc_cache *cache);
void nilfs_palloc_clear_cache(struct inode *inode);
void nilfs_palloc_destroy_cache(struct inode *inode);
#endif /* _NILFS_ALLOC_H */