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fs/adfs: bigdir: extract directory validation

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Extract the directory validation from the directory reading function as
we will want to re-use this code.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Russell King 2019-12-09 11:10:57 +00:00 committed by Al Viro
parent 0db35a02a1
commit 6674ecab90
1 changed files with 31 additions and 10 deletions
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41
fs/adfs/dir_fplus.c
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@ -16,6 +16,30 @@ static unsigned int adfs_fplus_offset(const struct adfs_bigdirheader *h,
pos * sizeof(struct adfs_bigdirentry);
}
static int adfs_fplus_validate_header(const struct adfs_bigdirheader *h)
{
unsigned int size = le32_to_cpu(h->bigdirsize);
if (h->bigdirversion[0] != 0 || h->bigdirversion[1] != 0 ||
h->bigdirversion[2] != 0 ||
h->bigdirstartname != cpu_to_le32(BIGDIRSTARTNAME) ||
size & 2047)
return -EIO;
return 0;
}
static int adfs_fplus_validate_tail(const struct adfs_bigdirheader *h,
const struct adfs_bigdirtail *t)
{
if (t->bigdirendname != cpu_to_le32(BIGDIRENDNAME) ||
t->bigdirendmasseq != h->startmasseq ||
t->reserved[0] != 0 || t->reserved[1] != 0)
return -EIO;
return 0;
}
static int adfs_fplus_read(struct super_block *sb, u32 indaddr,
unsigned int size, struct adfs_dir *dir)
{
@ -30,6 +54,11 @@ static int adfs_fplus_read(struct super_block *sb, u32 indaddr,
return ret;
dir->bighead = h = (void *)dir->bhs[0]->b_data;
if (adfs_fplus_validate_header(h)) {
adfs_error(sb, "dir %06x has malformed header", indaddr);
goto out;
}
dirsize = le32_to_cpu(h->bigdirsize);
if (dirsize != size) {
adfs_msg(sb, KERN_WARNING,
@ -37,13 +66,6 @@ static int adfs_fplus_read(struct super_block *sb, u32 indaddr,
indaddr, dirsize, size);
}
if (h->bigdirversion[0] != 0 || h->bigdirversion[1] != 0 ||
h->bigdirversion[2] != 0 || size & 2047 ||
h->bigdirstartname != cpu_to_le32(BIGDIRSTARTNAME)) {
adfs_error(sb, "dir %06x has malformed header", indaddr);
goto out;
}
/* Read remaining buffers */
ret = adfs_dir_read_buffers(sb, indaddr, dirsize, dir);
if (ret)
@ -52,9 +74,8 @@ static int adfs_fplus_read(struct super_block *sb, u32 indaddr,
dir->bigtail = t = (struct adfs_bigdirtail *)
(dir->bhs[dir->nr_buffers - 1]->b_data + (sb->s_blocksize - 8));
if (t->bigdirendname != cpu_to_le32(BIGDIRENDNAME) ||
t->bigdirendmasseq != h->startmasseq ||
t->reserved[0] != 0 || t->reserved[1] != 0) {
ret = adfs_fplus_validate_tail(h, t);
if (ret) {
adfs_error(sb, "dir %06x has malformed tail", indaddr);
goto out;
}