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V3 minixfs: add missing directory type checking

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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>
This commit is contained in:
Doug Graham 2009-09-22 16:48:00 -07:00 committed by Linus Torvalds
parent 532f649f14
commit 9f6c133393
1 changed files with 18 additions and 4 deletions
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22
fs/minix/dir.c
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@ -308,14 +308,18 @@ int minix_delete_entry(struct minix_dir_entry *de, struct page *page)
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 @@ void minix_set_link(struct minix_dir_entry *de, struct page *page,
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 minix_inode_by_name(struct dentry *dentry)
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;