V3 minixfs: add missing directory type checking
There are a few places in the Minix FS code where the "inode" field of a
minix_dir_entry is used without checking first to see if the dirent is
really a minix3_dir_entry. The inode number in a V1/V2 dirent is 16 bits,
whereas that in a V3 dirent is 32 bits.
Accessing it as a 16 bit field when it really should be accessed as a 32
bit field probably kinda sorta works on a little-endian machine, but leads
to some rather odd behaviour on big-endian machines.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Doug Graham <dgraham@nortel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/minix/dir.c b/fs/minix/dir.c
index d407e7a..6198731 100644
--- a/fs/minix/dir.c
+++ b/fs/minix/dir.c
@@ -308,14 +308,18 @@
struct inode *inode = (struct inode*)mapping->host;
char *kaddr = page_address(page);
loff_t pos = page_offset(page) + (char*)de - kaddr;
- unsigned len = minix_sb(inode->i_sb)->s_dirsize;
+ struct minix_sb_info *sbi = minix_sb(inode->i_sb);
+ unsigned len = sbi->s_dirsize;
int err;
lock_page(page);
err = __minix_write_begin(NULL, mapping, pos, len,
AOP_FLAG_UNINTERRUPTIBLE, &page, NULL);
if (err == 0) {
- de->inode = 0;
+ if (sbi->s_version == MINIX_V3)
+ ((minix3_dirent *) de)->inode = 0;
+ else
+ de->inode = 0;
err = dir_commit_chunk(page, pos, len);
} else {
unlock_page(page);
@@ -440,7 +444,10 @@
err = __minix_write_begin(NULL, mapping, pos, sbi->s_dirsize,
AOP_FLAG_UNINTERRUPTIBLE, &page, NULL);
if (err == 0) {
- de->inode = inode->i_ino;
+ if (sbi->s_version == MINIX_V3)
+ ((minix3_dirent *) de)->inode = inode->i_ino;
+ else
+ de->inode = inode->i_ino;
err = dir_commit_chunk(page, pos, sbi->s_dirsize);
} else {
unlock_page(page);
@@ -470,7 +477,14 @@
ino_t res = 0;
if (de) {
- res = de->inode;
+ struct address_space *mapping = page->mapping;
+ struct inode *inode = mapping->host;
+ struct minix_sb_info *sbi = minix_sb(inode->i_sb);
+
+ if (sbi->s_version == MINIX_V3)
+ res = ((minix3_dirent *) de)->inode;
+ else
+ res = de->inode;
dir_put_page(page);
}
return res;