Commit 40b163f1 authored by Darrick J. Wong's avatar Darrick J. Wong Committed by Theodore Ts'o
Browse files

ext4: check inline directory before converting 



Before converting an inline directory to a regular directory, check
the directory entries to make sure they're not obviously broken.
This helps us to avoid a BUG_ON if one of the dirents is trashed.

Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Reviewed-by: default avatarAndreas Dilger <adilger@dilger.ca>
parent 6e263146

fs/ext4/dir.c

+25 −0
Original line number Diff line number Diff line
@@ -571,6 +571,31 @@ static int ext4_release_dir(struct inode *inode, struct file *filp) 
	return 0;

}



int ext4_check_all_de(struct inode *dir, struct buffer_head *bh, void *buf,

		      int buf_size)

{

	struct ext4_dir_entry_2 *de;

	int nlen, rlen;

	unsigned int offset = 0;

	char *top;



	de = (struct ext4_dir_entry_2 *)buf;

	top = buf + buf_size;

	while ((char *) de < top) {

		if (ext4_check_dir_entry(dir, NULL, de, bh,

					 buf, buf_size, offset))

			return -EIO;

		nlen = EXT4_DIR_REC_LEN(de->name_len);

		rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);

		de = (struct ext4_dir_entry_2 *)((char *)de + rlen);

		offset += rlen;

	}

	if ((char *) de > top)

		return -EIO;



	return 0;

}



const struct file_operations ext4_dir_operations = {

	.llseek		= ext4_dir_llseek,

	.read		= generic_read_dir,

fs/ext4/ext4.h

+2 −0
Original line number Diff line number Diff line
@@ -2028,6 +2028,8 @@ static inline unsigned char get_dtype(struct super_block *sb, int filetype) 


	return ext4_filetype_table[filetype];

}

extern int ext4_check_all_de(struct inode *dir, struct buffer_head *bh,

			     void *buf, int buf_size);



/* fsync.c */

extern int ext4_sync_file(struct file *, loff_t, loff_t, int);

fs/ext4/inline.c

+12 −0
Original line number Diff line number Diff line
@@ -1172,6 +1172,18 @@ static int ext4_convert_inline_data_nolock(handle_t *handle, 
	if (error < 0)

		goto out;



	/*

	 * Make sure the inline directory entries pass checks before we try to

	 * convert them, so that we avoid touching stuff that needs fsck.

	 */

	if (S_ISDIR(inode->i_mode)) {

		error = ext4_check_all_de(inode, iloc->bh,

					buf + EXT4_INLINE_DOTDOT_SIZE,

					inline_size - EXT4_INLINE_DOTDOT_SIZE);

		if (error)

			goto out;

	}



	error = ext4_destroy_inline_data_nolock(handle, inode);

	if (error)

		goto out;

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