From 9f6c1333938c5d93da8be8f29f3b5469a3c00f95 Mon Sep 17 00:00:00 2001 From: Doug Graham Date: Tue, 22 Sep 2009 16:48:00 -0700 Subject: [PATCH] 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/minix/dir.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) diff --git a/fs/minix/dir.c b/fs/minix/dir.c index d407e7a0b6fe..6198731d7fcd 100644 --- a/fs/minix/dir.c +++ b/fs/minix/dir.c @@ -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; -- 2.34.1