Commit 38fb6d0e authored by Icenowy Zheng's avatar Icenowy Zheng Committed by Jaegeuk Kim
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f2fs: use EINVAL for superblock with invalid magic 



The kernel mount_block_root() function expects -EACESS or -EINVAL for a
unmountable filesystem when trying to mount the root with different
filesystem types.

However, in 5.3-rc1 the behavior when F2FS code cannot find valid block
changed to return -EFSCORRUPTED(-EUCLEAN), and this error code makes
mount_block_root() fail when trying to probe F2FS.

When the magic number of the superblock mismatches, it has a high
probability that it's just not a F2FS. In this case return -EINVAL seems
to be a better result, and this return value can make mount_block_root()
probing work again.

Return -EINVAL when the superblock has magic mismatch, -EFSCORRUPTED in
other cases (the magic matches but the superblock cannot be recognized).

Fixes: 10f966bb ("f2fs: use generic EFSBADCRC/EFSCORRUPTED")
Signed-off-by: default avatarIcenowy Zheng <icenowy@aosc.io>
Reviewed-by: default avatarChao Yu <yuchao0@huawei.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent 543b8c46

fs/f2fs/super.c

+24 −24
Original line number Diff line number Diff line
@@ -2422,6 +2422,12 @@ static int sanity_check_raw_super(struct f2fs_sb_info *sbi, 
	size_t crc_offset = 0;

	__u32 crc = 0;



	if (le32_to_cpu(raw_super->magic) != F2FS_SUPER_MAGIC) {

		f2fs_info(sbi, "Magic Mismatch, valid(0x%x) - read(0x%x)",

			  F2FS_SUPER_MAGIC, le32_to_cpu(raw_super->magic));

		return -EINVAL;

	}



	/* Check checksum_offset and crc in superblock */

	if (__F2FS_HAS_FEATURE(raw_super, F2FS_FEATURE_SB_CHKSUM)) {

		crc_offset = le32_to_cpu(raw_super->checksum_offset);
@@ -2429,26 +2435,20 @@ static int sanity_check_raw_super(struct f2fs_sb_info *sbi, 
			offsetof(struct f2fs_super_block, crc)) {

			f2fs_info(sbi, "Invalid SB checksum offset: %zu",

				  crc_offset);

			return 1;

			return -EFSCORRUPTED;

		}

		crc = le32_to_cpu(raw_super->crc);

		if (!f2fs_crc_valid(sbi, crc, raw_super, crc_offset)) {

			f2fs_info(sbi, "Invalid SB checksum value: %u", crc);

			return 1;

			return -EFSCORRUPTED;

		}

	}



	if (F2FS_SUPER_MAGIC != le32_to_cpu(raw_super->magic)) {

		f2fs_info(sbi, "Magic Mismatch, valid(0x%x) - read(0x%x)",

			  F2FS_SUPER_MAGIC, le32_to_cpu(raw_super->magic));

		return 1;

	}



	/* Currently, support only 4KB page cache size */

	if (F2FS_BLKSIZE != PAGE_SIZE) {

		f2fs_info(sbi, "Invalid page_cache_size (%lu), supports only 4KB",

			  PAGE_SIZE);

		return 1;

		return -EFSCORRUPTED;

	}



	/* Currently, support only 4KB block size */
@@ -2456,14 +2456,14 @@ static int sanity_check_raw_super(struct f2fs_sb_info *sbi, 
	if (blocksize != F2FS_BLKSIZE) {

		f2fs_info(sbi, "Invalid blocksize (%u), supports only 4KB",

			  blocksize);

		return 1;

		return -EFSCORRUPTED;

	}



	/* check log blocks per segment */

	if (le32_to_cpu(raw_super->log_blocks_per_seg) != 9) {

		f2fs_info(sbi, "Invalid log blocks per segment (%u)",

			  le32_to_cpu(raw_super->log_blocks_per_seg));

		return 1;

		return -EFSCORRUPTED;

	}



	/* Currently, support 512/1024/2048/4096 bytes sector size */
@@ -2473,7 +2473,7 @@ static int sanity_check_raw_super(struct f2fs_sb_info *sbi, 
				F2FS_MIN_LOG_SECTOR_SIZE) {

		f2fs_info(sbi, "Invalid log sectorsize (%u)",

			  le32_to_cpu(raw_super->log_sectorsize));

		return 1;

		return -EFSCORRUPTED;

	}

	if (le32_to_cpu(raw_super->log_sectors_per_block) +

		le32_to_cpu(raw_super->log_sectorsize) !=
@@ -2481,7 +2481,7 @@ static int sanity_check_raw_super(struct f2fs_sb_info *sbi, 
		f2fs_info(sbi, "Invalid log sectors per block(%u) log sectorsize(%u)",

			  le32_to_cpu(raw_super->log_sectors_per_block),

			  le32_to_cpu(raw_super->log_sectorsize));

		return 1;

		return -EFSCORRUPTED;

	}



	segment_count = le32_to_cpu(raw_super->segment_count);
@@ -2495,7 +2495,7 @@ static int sanity_check_raw_super(struct f2fs_sb_info *sbi, 
	if (segment_count > F2FS_MAX_SEGMENT ||

				segment_count < F2FS_MIN_SEGMENTS) {

		f2fs_info(sbi, "Invalid segment count (%u)", segment_count);

		return 1;

		return -EFSCORRUPTED;

	}



	if (total_sections > segment_count ||
@@ -2503,25 +2503,25 @@ static int sanity_check_raw_super(struct f2fs_sb_info *sbi, 
			segs_per_sec > segment_count || !segs_per_sec) {

		f2fs_info(sbi, "Invalid segment/section count (%u, %u x %u)",

			  segment_count, total_sections, segs_per_sec);

		return 1;

		return -EFSCORRUPTED;

	}



	if ((segment_count / segs_per_sec) < total_sections) {

		f2fs_info(sbi, "Small segment_count (%u < %u * %u)",

			  segment_count, segs_per_sec, total_sections);

		return 1;

		return -EFSCORRUPTED;

	}



	if (segment_count > (le64_to_cpu(raw_super->block_count) >> 9)) {

		f2fs_info(sbi, "Wrong segment_count / block_count (%u > %llu)",

			  segment_count, le64_to_cpu(raw_super->block_count));

		return 1;

		return -EFSCORRUPTED;

	}



	if (secs_per_zone > total_sections || !secs_per_zone) {

		f2fs_info(sbi, "Wrong secs_per_zone / total_sections (%u, %u)",

			  secs_per_zone, total_sections);

		return 1;

		return -EFSCORRUPTED;

	}

	if (le32_to_cpu(raw_super->extension_count) > F2FS_MAX_EXTENSION ||

			raw_super->hot_ext_count > F2FS_MAX_EXTENSION ||
@@ -2531,7 +2531,7 @@ static int sanity_check_raw_super(struct f2fs_sb_info *sbi, 
			  le32_to_cpu(raw_super->extension_count),

			  raw_super->hot_ext_count,

			  F2FS_MAX_EXTENSION);

		return 1;

		return -EFSCORRUPTED;

	}



	if (le32_to_cpu(raw_super->cp_payload) >
@@ -2539,7 +2539,7 @@ static int sanity_check_raw_super(struct f2fs_sb_info *sbi, 
		f2fs_info(sbi, "Insane cp_payload (%u > %u)",

			  le32_to_cpu(raw_super->cp_payload),

			  blocks_per_seg - F2FS_CP_PACKS);

		return 1;

		return -EFSCORRUPTED;

	}



	/* check reserved ino info */
@@ -2550,12 +2550,12 @@ static int sanity_check_raw_super(struct f2fs_sb_info *sbi, 
			  le32_to_cpu(raw_super->node_ino),

			  le32_to_cpu(raw_super->meta_ino),

			  le32_to_cpu(raw_super->root_ino));

		return 1;

		return -EFSCORRUPTED;

	}



	/* check CP/SIT/NAT/SSA/MAIN_AREA area boundary */

	if (sanity_check_area_boundary(sbi, bh))

		return 1;

		return -EFSCORRUPTED;



	return 0;

}
@@ -2872,10 +2872,10 @@ static int read_raw_super_block(struct f2fs_sb_info *sbi, 
		}



		/* sanity checking of raw super */

		if (sanity_check_raw_super(sbi, bh)) {

		err = sanity_check_raw_super(sbi, bh);

		if (err) {

			f2fs_err(sbi, "Can't find valid F2FS filesystem in %dth superblock",

				 block + 1);

			err = -EFSCORRUPTED;

			brelse(bh);

			continue;

		}

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