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Commit 7a262f7c authored by Aneesh Kumar K.V's avatar Aneesh Kumar K.V Committed by Theodore Ts'o
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ext4: Validate extent details only when read from the disk 



Make sure we validate extent details only when read from the disk.

Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: default avatarThiemo Nagel <thiemo.nagel@ph.tum.de>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent 56b19868

fs/ext4/ext4_extents.h

+1 −0
Original line number Diff line number Diff line
@@ -241,5 +241,6 @@ extern int ext4_ext_search_left(struct inode *, struct ext4_ext_path *, 
extern int ext4_ext_search_right(struct inode *, struct ext4_ext_path *,

						ext4_lblk_t *, ext4_fsblk_t *);

extern void ext4_ext_drop_refs(struct ext4_ext_path *);

extern int ext4_ext_check_inode(struct inode *inode);

#endif /* _EXT4_EXTENTS */

fs/ext4/extents.c

+18 −7
Original line number Diff line number Diff line
@@ -429,6 +429,11 @@ corrupted: 
#define ext4_ext_check(inode, eh, depth)	\

	__ext4_ext_check(__func__, inode, eh, depth)



int ext4_ext_check_inode(struct inode *inode)

{

	return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode));

}



#ifdef EXT_DEBUG

static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)

{
@@ -631,9 +636,6 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block, 


	eh = ext_inode_hdr(inode);

	depth = ext_depth(inode);

	if (ext4_ext_check(inode, eh, depth))

		return ERR_PTR(-EIO);





	/* account possible depth increase */

	if (!path) {
@@ -649,6 +651,8 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block, 
	i = depth;

	/* walk through the tree */

	while (i) {

		int need_to_validate = 0;



		ext_debug("depth %d: num %d, max %d\n",

			  ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
@@ -657,10 +661,17 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block, 
		path[ppos].p_depth = i;

		path[ppos].p_ext = NULL;



		bh = sb_bread(inode->i_sb, path[ppos].p_block);

		if (!bh)

		bh = sb_getblk(inode->i_sb, path[ppos].p_block);

		if (unlikely(!bh))

			goto err;



		if (!bh_uptodate_or_lock(bh)) {

			if (bh_submit_read(bh) < 0) {

				put_bh(bh);

				goto err;

			}

			/* validate the extent entries */

			need_to_validate = 1;

		}

		eh = ext_block_hdr(bh);

		ppos++;

		BUG_ON(ppos > depth);
@@ -668,7 +679,7 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block, 
		path[ppos].p_hdr = eh;

		i--;



		if (ext4_ext_check(inode, eh, i))

		if (need_to_validate && ext4_ext_check(inode, eh, i))

			goto err;

	}

fs/ext4/inode.c

+10 −0
Original line number Diff line number Diff line
@@ -4345,6 +4345,16 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino) 
			(__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32;

	}



	if (ei->i_flags & EXT4_EXTENTS_FL) {

		/* Validate extent which is part of inode */

		ret = ext4_ext_check_inode(inode);

		if (ret) {

			brelse(bh);

			goto bad_inode;

		}



	}



	if (S_ISREG(inode->i_mode)) {

		inode->i_op = &ext4_file_inode_operations;

		inode->i_fop = &ext4_file_operations;