ext4: don't verify checksums of dx non-leaf nodes during fallback scan (c6af8803) · Commits · 戴 / test

During a directory entry lookup of a hashed directory, if the hash-based lookup functions fail and we fall back to a linear scan, don't try to verify the dirent checksum on the internal nodes of the hash tree because they don't store a checksum in a hidden dirent like the leaf nodes do. Reported-by:

George Spelvin <linux@horizon.com> Signed-off-by:

Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by:

"Theodore Ts'o" <tytso@mit.edu>

fs/ext4/namei.c

+17 −0

Original line number	Diff line number	Diff line
		@@ -1146,6 +1146,21 @@ static inline int search_dirblock(struct buffer_head *bh,
		return 0;
		}

		static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
		struct ext4_dir_entry *de)
		{
		struct super_block *sb = dir->i_sb;

		if (!is_dx(dir))
		return 0;
		if (block == 0)
		return 1;
		if (de->inode == 0 &&
		ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
		sb->s_blocksize)
		return 1;
		return 0;
		}

		/*
		* ext4_find_entry()
		@@ -1246,6 +1261,8 @@ restart:
		goto next;
		}
		if (!buffer_verified(bh) &&
		!is_dx_internal_node(dir, block,
		(struct ext4_dir_entry *)bh->b_data) &&
		!ext4_dirent_csum_verify(dir,
		(struct ext4_dir_entry *)bh->b_data)) {
		EXT4_ERROR_INODE(dir, "checksumming directory "

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