udf: Fix directory corruption after extent merging (4651c590) · Commits · 戴 / test

If udf_bread() called from udf_add_entry() managed to merge created extent to an already existing one (or if previous extents could be merged), the code truncating the last extent to proper size would just overwrite the freshly allocated extent with an extent that used to be in that place. This obviously results in a directory corruption. Fix the problem by properly reloading the last extent. Signed-off-by:

Jan Kara <jack@suse.cz>

fs/udf/namei.c

+10 −6

Original line number	Diff line number	Diff line
		@@ -471,15 +471,19 @@ add:
		f_pos >> dir->i_sb->s_blocksize_bits, 1, err);
		if (!fibh->ebh)
		goto out_err;
		/* Extents could have been merged, invalidate our position */
		brelse(epos.bh);
		epos.bh = NULL;
		epos.block = dinfo->i_location;
		epos.offset = udf_file_entry_alloc_offset(dir);

		if (!fibh->soffset) {
		if (udf_next_aext(dir, &epos, &eloc, &elen, 1) ==
		(EXT_RECORDED_ALLOCATED >> 30)) {
		/* Find the freshly allocated block */
		while (udf_next_aext(dir, &epos, &eloc, &elen, 1) ==
		(EXT_RECORDED_ALLOCATED >> 30))
		;
		block = eloc.logicalBlockNum + ((elen - 1) >>
		dir->i_sb->s_blocksize_bits);
		} else
		block++;

		brelse(fibh->sbh);
		fibh->sbh = fibh->ebh;
		fi = (struct fileIdentDesc *)(fibh->sbh->b_data);

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