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fs/adfs: newdir: factor out directory format validation 

We have two locations where we validate the new directory format, so
factor this out to a helper.

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 11:10:27 +00:00 committed by Al Viro
parent 016936b321
commit ffc8df347e
1 changed files with 20 additions and 28 deletions
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48
fs/adfs/dir_f.c
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@ -121,6 +121,21 @@ adfs_dir_checkbyte(const struct adfs_dir *dir)
return (dircheck ^ (dircheck >> 8) ^ (dircheck >> 16) ^ (dircheck >> 24)) & 0xff;
}
static int adfs_f_validate(struct adfs_dir *dir)
{
struct adfs_dirheader *head = dir->dirhead;
struct adfs_newdirtail *tail = dir->newtail;
if (head->startmasseq != tail->endmasseq ||
(memcmp(&head->startname, "Nick", 4) &&
memcmp(&head->startname, "Hugo", 4)) ||
memcmp(&head->startname, &tail->endname, 4) ||
adfs_dir_checkbyte(dir) != tail->dircheckbyte)
return -EIO;
return 0;
}
/* Read and check that a directory is valid */
static int adfs_dir_read(struct super_block *sb, u32 indaddr,
unsigned int size, struct adfs_dir *dir)
@ -142,15 +157,7 @@ static int adfs_dir_read(struct super_block *sb, u32 indaddr,
dir->dirhead = bufoff(dir->bh, 0);
dir->newtail = bufoff(dir->bh, 2007);
if (dir->dirhead->startmasseq != dir->newtail->endmasseq ||
memcmp(&dir->dirhead->startname, &dir->newtail->endname, 4))
goto bad_dir;
if (memcmp(&dir->dirhead->startname, "Nick", 4) &&
memcmp(&dir->dirhead->startname, "Hugo", 4))
goto bad_dir;
if (adfs_dir_checkbyte(dir) != dir->newtail->dircheckbyte)
if (adfs_f_validate(dir))
goto bad_dir;
return 0;
@ -327,7 +334,7 @@ adfs_f_update(struct adfs_dir *dir, struct object_info *obj)
ret = adfs_dir_find_entry(dir, obj->indaddr);
if (ret < 0) {
adfs_error(dir->sb, "unable to locate entry to update");
goto out;
return ret;
}
__adfs_dir_put(dir, ret, obj);
@ -344,26 +351,11 @@ adfs_f_update(struct adfs_dir *dir, struct object_info *obj)
*/
dir->newtail->dircheckbyte = ret;
#if 1
if (dir->dirhead->startmasseq != dir->newtail->endmasseq ||
memcmp(&dir->dirhead->startname, &dir->newtail->endname, 4))
goto bad_dir;
ret = adfs_f_validate(dir);
if (ret)
adfs_error(dir->sb, "whoops! I broke a directory!");
if (memcmp(&dir->dirhead->startname, "Nick", 4) &&
memcmp(&dir->dirhead->startname, "Hugo", 4))
goto bad_dir;
if (adfs_dir_checkbyte(dir) != dir->newtail->dircheckbyte)
goto bad_dir;
#endif
ret = 0;
out:
return ret;
#if 1
bad_dir:
adfs_error(dir->sb, "whoops! I broke a directory!");
return -EIO;
#endif
}
const struct adfs_dir_ops adfs_f_dir_ops = {