linux-stable/fs/minix/itree_v1.c
Eric Biggers 0a12c4a806 fs/minix: fix block limit check for V1 filesystems
The minix filesystem reads its maximum file size from its on-disk
superblock.  This value isn't necessarily a multiple of the block size.
When it's not, the V1 block mapping code doesn't allow mapping the last
possible block.  Commit 6ed6a722f9 ("minixfs: fix block limit check")
fixed this in the V2 mapping code.  Fix it in the V1 mapping code too.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Qiujun Huang <anenbupt@gmail.com>
Link: http://lkml.kernel.org/r/20200628060846.682158-6-ebiggers@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-12 10:58:00 -07:00

67 lines
1.4 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/buffer_head.h>
#include <linux/slab.h>
#include "minix.h"
enum {DEPTH = 3, DIRECT = 7}; /* Only double indirect */
typedef u16 block_t; /* 16 bit, host order */
static inline unsigned long block_to_cpu(block_t n)
{
return n;
}
static inline block_t cpu_to_block(unsigned long n)
{
return n;
}
static inline block_t *i_data(struct inode *inode)
{
return (block_t *)minix_i(inode)->u.i1_data;
}
static int block_to_path(struct inode * inode, long block, int offsets[DEPTH])
{
int n = 0;
if (block < 0) {
printk("MINIX-fs: block_to_path: block %ld < 0 on dev %pg\n",
block, inode->i_sb->s_bdev);
} else if ((u64)block * BLOCK_SIZE >= inode->i_sb->s_maxbytes) {
if (printk_ratelimit())
printk("MINIX-fs: block_to_path: "
"block %ld too big on dev %pg\n",
block, inode->i_sb->s_bdev);
} else if (block < 7) {
offsets[n++] = block;
} else if ((block -= 7) < 512) {
offsets[n++] = 7;
offsets[n++] = block;
} else {
block -= 512;
offsets[n++] = 8;
offsets[n++] = block>>9;
offsets[n++] = block & 511;
}
return n;
}
#include "itree_common.c"
int V1_minix_get_block(struct inode * inode, long block,
struct buffer_head *bh_result, int create)
{
return get_block(inode, block, bh_result, create);
}
void V1_minix_truncate(struct inode * inode)
{
truncate(inode);
}
unsigned V1_minix_blocks(loff_t size, struct super_block *sb)
{
return nblocks(size, sb);
}