ext4: call out CRC and corruption errors with specific error codes

Instead of overloading EIO for CRC errors and corrupt structures,
return the same error codes that XFS returns for the same issues.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/balloc.c

@@ -203,7 +203,7 @@ static int ext4_init_block_bitmap(struct super_block *sb,
 					   count);
 		}
 		set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state);
-		return -EIO;
+		return -EFSBADCRC;
 	}
 	memset(bh->b_data, 0, sb->s_blocksize);
 

fs/ext4/block_validity.c

@@ -234,7 +234,7 @@ int ext4_check_blockref(const char *function, unsigned int line,
 			es->s_last_error_block = cpu_to_le64(blk);
 			ext4_error_inode(inode, function, line, blk,
 					 "invalid block");
-			return -EIO;
+			return -EFSCORRUPTED;
 		}
 	}
 	return 0;

fs/ext4/dir.c

@@ -621,14 +621,14 @@ int ext4_check_all_de(struct inode *dir, struct buffer_head *bh, void *buf,
 	while ((char *) de < top) {
 		if (ext4_check_dir_entry(dir, NULL, de, bh,
 					 buf, buf_size, offset))
-			return -EIO;
+			return -EFSCORRUPTED;
 		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 -EFSCORRUPTED;
 
 	return 0;
 }

fs/ext4/ext4.h

@@ -3064,4 +3064,7 @@ extern void ext4_resize_end(struct super_block *sb);
 
 #endif	/* __KERNEL__ */
 
+#define EFSBADCRC	EBADMSG		/* Bad CRC detected */
+#define EFSCORRUPTED	EUCLEAN		/* Filesystem is corrupted */
+
 #endif	/* _EXT4_H */

fs/ext4/extents.c

@@ -442,7 +442,7 @@ static int __ext4_ext_check(const char *function, unsigned int line,
 			    int depth, ext4_fsblk_t pblk)
 {
 	const char *error_msg;
-	int max = 0;
+	int max = 0, err = -EFSCORRUPTED;
 
 	if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
 		error_msg = "invalid magic";
@@ -473,6 +473,7 @@ static int __ext4_ext_check(const char *function, unsigned int line,
 	if (ext_depth(inode) != depth &&
 	    !ext4_extent_block_csum_verify(inode, eh)) {
 		error_msg = "extent tree corrupted";
+		err = -EFSBADCRC;
 		goto corrupted;
 	}
 	return 0;
@@ -485,7 +486,7 @@ static int __ext4_ext_check(const char *function, unsigned int line,
 			 le16_to_cpu(eh->eh_magic),
 			 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max),
 			 max, le16_to_cpu(eh->eh_depth), depth);
-	return -EIO;
+	return err;
 }
 
 #define ext4_ext_check(inode, eh, depth, pblk)			\
@@ -910,7 +911,7 @@ ext4_find_extent(struct inode *inode, ext4_lblk_t block,
 			put_bh(bh);
 			EXT4_ERROR_INODE(inode,
 					 "ppos %d > depth %d", ppos, depth);
-			ret = -EIO;
+			ret = -EFSCORRUPTED;
 			goto err;
 		}
 		path[ppos].p_bh = bh;
@@ -959,7 +960,7 @@ static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
 		EXT4_ERROR_INODE(inode,
 				 "logical %d == ei_block %d!",
 				 logical, le32_to_cpu(curp->p_idx->ei_block));
-		return -EIO;
+		return -EFSCORRUPTED;
 	}
 
 	if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries)
@@ -968,7 +969,7 @@ static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
 				 "eh_entries %d >= eh_max %d!",
 				 le16_to_cpu(curp->p_hdr->eh_entries),
 				 le16_to_cpu(curp->p_hdr->eh_max));
-		return -EIO;
+		return -EFSCORRUPTED;
 	}
 
 	if (logical > le32_to_cpu(curp->p_idx->ei_block)) {
@@ -992,7 +993,7 @@ static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
 
 	if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) {
 		EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!");
-		return -EIO;
+		return -EFSCORRUPTED;
 	}
 
 	ix->ei_block = cpu_to_le32(logical);
@@ -1001,7 +1002,7 @@ static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
 
 	if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) {
 		EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!");
-		return -EIO;
+		return -EFSCORRUPTED;
 	}
 
 	err = ext4_ext_dirty(handle, inode, curp);
@@ -1042,7 +1043,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
 	 * border from split point */
 	if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) {
 		EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!");
-		return -EIO;
+		return -EFSCORRUPTED;
 	}
 	if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {
 		border = path[depth].p_ext[1].ee_block;
@@ -1086,7 +1087,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
 	newblock = ablocks[--a];
 	if (unlikely(newblock == 0)) {
 		EXT4_ERROR_INODE(inode, "newblock == 0!");
-		err = -EIO;
+		err = -EFSCORRUPTED;
 		goto cleanup;
 	}
 	bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
@@ -1112,7 +1113,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
 		EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!",
 				 path[depth].p_hdr->eh_entries,
 				 path[depth].p_hdr->eh_max);
-		err = -EIO;
+		err = -EFSCORRUPTED;
 		goto cleanup;
 	}
 	/* start copy from next extent */
@@ -1151,7 +1152,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
 	k = depth - at - 1;
 	if (unlikely(k < 0)) {
 		EXT4_ERROR_INODE(inode, "k %d < 0!", k);
-		err = -EIO;
+		err = -EFSCORRUPTED;
 		goto cleanup;
 	}
 	if (k)
@@ -1191,7 +1192,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
 			EXT4_ERROR_INODE(inode,
 					 "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!",
 					 le32_to_cpu(path[i].p_ext->ee_block));
-			err = -EIO;
+			err = -EFSCORRUPTED;
 			goto cleanup;
 		}
 		/* start copy indexes */
@@ -1425,7 +1426,7 @@ static int ext4_ext_search_left(struct inode *inode,
 
 	if (unlikely(path == NULL)) {
 		EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
-		return -EIO;
+		return -EFSCORRUPTED;
 	}
 	depth = path->p_depth;
 	*phys = 0;
@@ -1444,7 +1445,7 @@ static int ext4_ext_search_left(struct inode *inode,
 			EXT4_ERROR_INODE(inode,
 					 "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!",
 					 *logical, le32_to_cpu(ex->ee_block));
-			return -EIO;
+			return -EFSCORRUPTED;
 		}
 		while (--depth >= 0) {
 			ix = path[depth].p_idx;
@@ -1455,7 +1456,7 @@ static int ext4_ext_search_left(struct inode *inode,
 				  EXT_FIRST_INDEX(path[depth].p_hdr) != NULL ?
 		le32_to_cpu(EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block) : 0,
 				  depth);
-				return -EIO;
+				return -EFSCORRUPTED;
 			}
 		}
 		return 0;
@@ -1465,7 +1466,7 @@ static int ext4_ext_search_left(struct inode *inode,
 		EXT4_ERROR_INODE(inode,
 				 "logical %d < ee_block %d + ee_len %d!",
 				 *logical, le32_to_cpu(ex->ee_block), ee_len);
-		return -EIO;
+		return -EFSCORRUPTED;
 	}
 
 	*logical = le32_to_cpu(ex->ee_block) + ee_len - 1;
@@ -1495,7 +1496,7 @@ static int ext4_ext_search_right(struct inode *inode,
 
 	if (unlikely(path == NULL)) {
 		EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
-		return -EIO;
+		return -EFSCORRUPTED;
 	}
 	depth = path->p_depth;
 	*phys = 0;
@@ -1514,7 +1515,7 @@ static int ext4_ext_search_right(struct inode *inode,
 			EXT4_ERROR_INODE(inode,
 					 "first_extent(path[%d].p_hdr) != ex",
 					 depth);
-			return -EIO;
+			return -EFSCORRUPTED;
 		}
 		while (--depth >= 0) {
 			ix = path[depth].p_idx;
@@ -1522,7 +1523,7 @@ static int ext4_ext_search_right(struct inode *inode,
 				EXT4_ERROR_INODE(inode,
 						 "ix != EXT_FIRST_INDEX *logical %d!",
 						 *logical);
-				return -EIO;
+				return -EFSCORRUPTED;
 			}
 		}
 		goto found_extent;
@@ -1532,7 +1533,7 @@ static int ext4_ext_search_right(struct inode *inode,
 		EXT4_ERROR_INODE(inode,
 				 "logical %d < ee_block %d + ee_len %d!",
 				 *logical, le32_to_cpu(ex->ee_block), ee_len);
-		return -EIO;
+		return -EFSCORRUPTED;
 	}
 
 	if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) {
@@ -1670,7 +1671,7 @@ static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
 	if (unlikely(ex == NULL || eh == NULL)) {
 		EXT4_ERROR_INODE(inode,
 				 "ex %p == NULL or eh %p == NULL", ex, eh);
-		return -EIO;
+		return -EFSCORRUPTED;
 	}
 
 	if (depth == 0) {
@@ -1938,14 +1939,14 @@ int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
 		mb_flags |= EXT4_MB_DELALLOC_RESERVED;
 	if (unlikely(ext4_ext_get_actual_len(newext) == 0)) {
 		EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0");
-		return -EIO;
+		return -EFSCORRUPTED;
 	}
 	depth = ext_depth(inode);
 	ex = path[depth].p_ext;
 	eh = path[depth].p_hdr;
 	if (unlikely(path[depth].p_hdr == NULL)) {
 		EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
-		return -EIO;
+		return -EFSCORRUPTED;
 	}
 
 	/* try to insert block into found extent and return */
@@ -2172,7 +2173,7 @@ static int ext4_fill_fiemap_extents(struct inode *inode,
 		if (unlikely(path[depth].p_hdr == NULL)) {
 			up_read(&EXT4_I(inode)->i_data_sem);
 			EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
-			err = -EIO;
+			err = -EFSCORRUPTED;
 			break;
 		}
 		ex = path[depth].p_ext;
@@ -2241,7 +2242,7 @@ static int ext4_fill_fiemap_extents(struct inode *inode,
 
 		if (unlikely(es.es_len == 0)) {
 			EXT4_ERROR_INODE(inode, "es.es_len == 0");
-			err = -EIO;
+			err = -EFSCORRUPTED;
 			break;
 		}
 
@@ -2264,7 +2265,7 @@ static int ext4_fill_fiemap_extents(struct inode *inode,
 						 "next extent == %u, next "
 						 "delalloc extent = %u",
 						 next, next_del);
-				err = -EIO;
+				err = -EFSCORRUPTED;
 				break;
 			}
 		}
@@ -2363,7 +2364,7 @@ static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
 	leaf = ext4_idx_pblock(path->p_idx);
 	if (unlikely(path->p_hdr->eh_entries == 0)) {
 		EXT4_ERROR_INODE(inode, "path->p_hdr->eh_entries == 0");
-		return -EIO;
+		return -EFSCORRUPTED;
 	}
 	err = ext4_ext_get_access(handle, inode, path);
 	if (err)
@@ -2612,7 +2613,7 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
 	eh = path[depth].p_hdr;
 	if (unlikely(path[depth].p_hdr == NULL)) {
 		EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
-		return -EIO;
+		return -EFSCORRUPTED;
 	}
 	/* find where to start removing */
 	ex = path[depth].p_ext;
@@ -2666,7 +2667,7 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
 					 "on extent %u:%u",
 					 start, end, ex_ee_block,
 					 ex_ee_block + ex_ee_len - 1);
-			err = -EIO;
+			err = -EFSCORRUPTED;
 			goto out;
 		} else if (a != ex_ee_block) {
 			/* remove tail of the extent */
@@ -2841,7 +2842,7 @@ int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
 				EXT4_ERROR_INODE(inode,
 						 "path[%d].p_hdr == NULL",
 						 depth);
-				err = -EIO;
+				err = -EFSCORRUPTED;
 			}
 			goto out;
 		}
@@ -2920,7 +2921,7 @@ int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
 		i = 0;
 
 		if (ext4_ext_check(inode, path[0].p_hdr, depth, 0)) {
-			err = -EIO;
+			err = -EFSCORRUPTED;
 			goto out;
 		}
 	}
@@ -2978,7 +2979,7 @@ int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
 			 * Should be a no-op if we did IO above. */
 			cond_resched();
 			if (WARN_ON(i + 1 > depth)) {
-				err = -EIO;
+				err = -EFSCORRUPTED;
 				break;
 			}
 			path[i + 1].p_bh = bh;
@@ -3345,7 +3346,7 @@ static int ext4_split_extent(handle_t *handle,
 	if (!ex) {
 		EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
 				 (unsigned long) map->m_lblk);
-		return -EIO;
+		return -EFSCORRUPTED;
 	}
 	unwritten = ext4_ext_is_unwritten(ex);
 	split_flag1 = 0;
@@ -3973,7 +3974,7 @@ convert_initialized_extent(handle_t *handle, struct inode *inode,
 		if (!ex) {
 			EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
 					 (unsigned long) map->m_lblk);
-			return -EIO;
+			return -EFSCORRUPTED;
 		}
 	}
 
@@ -4311,7 +4312,7 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
 				 "lblock: %lu, depth: %d pblock %lld",
 				 (unsigned long) map->m_lblk, depth,
 				 path[depth].p_block);
-		err = -EIO;
+		err = -EFSCORRUPTED;
 		goto out2;
 	}
 
@@ -5274,7 +5275,7 @@ ext4_ext_shift_path_extents(struct ext4_ext_path *path, ext4_lblk_t shift,
 		if (depth == path->p_depth) {
 			ex_start = path[depth].p_ext;
 			if (!ex_start)
-				return -EIO;
+				return -EFSCORRUPTED;
 
 			ex_last = EXT_LAST_EXTENT(path[depth].p_hdr);
 
@@ -5414,7 +5415,7 @@ ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
 		if (!extent) {
 			EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
 					 (unsigned long) *iterator);
-			return -EIO;
+			return -EFSCORRUPTED;
 		}
 		if (SHIFT == SHIFT_LEFT && *iterator >
 		    le32_to_cpu(extent->ee_block)) {

fs/ext4/ialloc.c

@@ -1116,6 +1116,7 @@ struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
 	/* Error cases - e2fsck has already cleaned up for us */
 	if (ino > max_ino) {
 		ext4_warning(sb, "bad orphan ino %lu!  e2fsck was run?", ino);
+		err = -EFSCORRUPTED;
 		goto error;
 	}
 

fs/ext4/indirect.c

@@ -566,7 +566,7 @@ int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
 				       EXT4_FEATURE_RO_COMPAT_BIGALLOC)) {
 		EXT4_ERROR_INODE(inode, "Can't allocate blocks for "
 				 "non-extent mapped inodes with bigalloc");
-		return -EUCLEAN;
+		return -EFSCORRUPTED;
 	}
 
 	/* Set up for the direct block allocation */

fs/ext4/inode.c

@@ -378,7 +378,7 @@ static int __check_block_validity(struct inode *inode, const char *func,
 				 "lblock %lu mapped to illegal pblock "
 				 "(length %d)", (unsigned long) map->m_lblk,
 				 map->m_len);
-		return -EIO;
+		return -EFSCORRUPTED;
 	}
 	return 0;
 }
@@ -480,7 +480,7 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode,
 
 	/* We can handle the block number less than EXT_MAX_BLOCKS */
 	if (unlikely(map->m_lblk >= EXT_MAX_BLOCKS))
-		return -EIO;
+		return -EFSCORRUPTED;
 
 	/* Lookup extent status tree firstly */
 	if (ext4_es_lookup_extent(inode, map->m_lblk, &es)) {
@@ -3863,7 +3863,7 @@ static int __ext4_get_inode_loc(struct inode *inode,
 
 	iloc->bh = NULL;
 	if (!ext4_valid_inum(sb, inode->i_ino))
-		return -EIO;
+		return -EFSCORRUPTED;
 
 	iloc->block_group = (inode->i_ino - 1) / EXT4_INODES_PER_GROUP(sb);
 	gdp = ext4_get_group_desc(sb, iloc->block_group, NULL);
@@ -4111,7 +4111,7 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
 			EXT4_ERROR_INODE(inode, "bad extra_isize (%u != %u)",
 				EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize,
 				EXT4_INODE_SIZE(inode->i_sb));
-			ret = -EIO;
+			ret = -EFSCORRUPTED;
 			goto bad_inode;
 		}
 	} else
@@ -4131,7 +4131,7 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
 
 	if (!ext4_inode_csum_verify(inode, raw_inode, ei)) {
 		EXT4_ERROR_INODE(inode, "checksum invalid");
-		ret = -EIO;
+		ret = -EFSBADCRC;
 		goto bad_inode;
 	}
 
@@ -4246,7 +4246,7 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
 	    !ext4_data_block_valid(EXT4_SB(sb), ei->i_file_acl, 1)) {
 		EXT4_ERROR_INODE(inode, "bad extended attribute block %llu",
 				 ei->i_file_acl);
-		ret = -EIO;
+		ret = -EFSCORRUPTED;
 		goto bad_inode;
 	} else if (!ext4_has_inline_data(inode)) {
 		if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
@@ -4297,7 +4297,7 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
 	} else if (ino == EXT4_BOOT_LOADER_INO) {
 		make_bad_inode(inode);
 	} else {
-		ret = -EIO;
+		ret = -EFSCORRUPTED;
 		EXT4_ERROR_INODE(inode, "bogus i_mode (%o)", inode->i_mode);
 		goto bad_inode;
 	}
@@ -4315,7 +4315,7 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
 struct inode *ext4_iget_normal(struct super_block *sb, unsigned long ino)
 {
 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
-		return ERR_PTR(-EIO);
+		return ERR_PTR(-EFSCORRUPTED);
 	return ext4_iget(sb, ino);
 }
 

fs/ext4/mmp.c

@@ -98,10 +98,12 @@ static int read_mmp_block(struct super_block *sb, struct buffer_head **bh,
 	}
 
 	mmp = (struct mmp_struct *)((*bh)->b_data);
-	if (le32_to_cpu(mmp->mmp_magic) == EXT4_MMP_MAGIC &&
-	    ext4_mmp_csum_verify(sb, mmp))
+	if (le32_to_cpu(mmp->mmp_magic) != EXT4_MMP_MAGIC)
+		ret = -EFSCORRUPTED;
+	else if (!ext4_mmp_csum_verify(sb, mmp))
+		ret = -EFSBADCRC;
+	else
 		return 0;
-	ret = -EINVAL;
 
 warn_exit:
 	ext4_warning(sb, "Error %d while reading MMP block %llu",

fs/ext4/namei.c

@@ -109,7 +109,7 @@ static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
 	if (!bh) {
 		ext4_error_inode(inode, func, line, block,
 				 "Directory hole found");
-		return ERR_PTR(-EIO);
+		return ERR_PTR(-EFSCORRUPTED);
 	}
 	dirent = (struct ext4_dir_entry *) bh->b_data;
 	/* Determine whether or not we have an index block */
@@ -124,7 +124,7 @@ static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
 	if (!is_dx_block && type == INDEX) {
 		ext4_error_inode(inode, func, line, block,
 		       "directory leaf block found instead of index block");
-		return ERR_PTR(-EIO);
+		return ERR_PTR(-EFSCORRUPTED);
 	}
 	if (!ext4_has_metadata_csum(inode->i_sb) ||
 	    buffer_verified(bh))
@@ -142,7 +142,7 @@ static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
 			ext4_error_inode(inode, func, line, block,
 					 "Directory index failed checksum");
 			brelse(bh);
-			return ERR_PTR(-EIO);
+			return ERR_PTR(-EFSBADCRC);
 		}
 	}
 	if (!is_dx_block) {
@@ -152,7 +152,7 @@ static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
 			ext4_error_inode(inode, func, line, block,
 					 "Directory block failed checksum");
 			brelse(bh);
-			return ERR_PTR(-EIO);
+			return ERR_PTR(-EFSBADCRC);
 		}
 	}
 	return bh;
@@ -1570,19 +1570,19 @@ static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsi
 		brelse(bh);
 		if (!ext4_valid_inum(dir->i_sb, ino)) {
 			EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
-			return ERR_PTR(-EIO);
+			return ERR_PTR(-EFSCORRUPTED);
 		}
 		if (unlikely(ino == dir->i_ino)) {
 			EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir",
 					 dentry);
-			return ERR_PTR(-EIO);
+			return ERR_PTR(-EFSCORRUPTED);
 		}
 		inode = ext4_iget_normal(dir->i_sb, ino);
 		if (inode == ERR_PTR(-ESTALE)) {
 			EXT4_ERROR_INODE(dir,
 					 "deleted inode referenced: %u",
 					 ino);
-			return ERR_PTR(-EIO);
+			return ERR_PTR(-EFSCORRUPTED);
 		}
 		if (!IS_ERR(inode) && ext4_encrypted_inode(dir) &&
 		    (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
@@ -1619,7 +1619,7 @@ struct dentry *ext4_get_parent(struct dentry *child)
 	if (!ext4_valid_inum(d_inode(child)->i_sb, ino)) {
 		EXT4_ERROR_INODE(d_inode(child),
 				 "bad parent inode number: %u", ino);
-		return ERR_PTR(-EIO);
+		return ERR_PTR(-EFSCORRUPTED);
 	}
 
 	return d_obtain_alias(ext4_iget_normal(d_inode(child)->i_sb, ino));
@@ -1807,7 +1807,7 @@ int ext4_find_dest_de(struct inode *dir, struct inode *inode,
 	while ((char *) de <= top) {
 		if (ext4_check_dir_entry(dir, NULL, de, bh,
 					 buf, buf_size, offset)) {
-			res = -EIO;
+			res = -EFSCORRUPTED;
 			goto return_result;
 		}
 		/* Provide crypto context and crypto buffer to ext4 match */
@@ -1967,7 +1967,7 @@ static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
 	if ((char *) de >= (((char *) root) + blocksize)) {
 		EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
 		brelse(bh);
-		return -EIO;
+		return -EFSCORRUPTED;
 	}
 	len = ((char *) root) + (blocksize - csum_size) - (char *) de;
 
@@ -2315,7 +2315,7 @@ int ext4_generic_delete_entry(handle_t *handle,
 	while (i < buf_size - csum_size) {
 		if (ext4_check_dir_entry(dir, NULL, de, bh,
 					 bh->b_data, bh->b_size, i))
-			return -EIO;
+			return -EFSCORRUPTED;
 		if (de == de_del)  {
 			if (pde)
 				pde->rec_len = ext4_rec_len_to_disk(
@@ -2934,7 +2934,7 @@ static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
 
 	inode = d_inode(dentry);
 
-	retval = -EIO;
+	retval = -EFSCORRUPTED;
 	if (le32_to_cpu(de->inode) != inode->i_ino)
 		goto end_rmdir;
 
@@ -3008,7 +3008,7 @@ static int ext4_unlink(struct inode *dir, struct dentry *dentry)
 
 	inode = d_inode(dentry);
 
-	retval = -EIO;
+	retval = -EFSCORRUPTED;
 	if (le32_to_cpu(de->inode) != inode->i_ino)
 		goto end_unlink;
 
@@ -3310,7 +3310,7 @@ static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent)
 	if (!ent->dir_bh)
 		return retval;
 	if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
-		return -EIO;
+		return -EFSCORRUPTED;
 	BUFFER_TRACE(ent->dir_bh, "get_write_access");
 	return ext4_journal_get_write_access(handle, ent->dir_bh);
 }

fs/ext4/super.c

@@ -490,6 +490,12 @@ const char *ext4_decode_error(struct super_block *sb, int errno,
 	char *errstr = NULL;
 
 	switch (errno) {
+	case -EFSCORRUPTED:
+		errstr = "Corrupt filesystem";
+		break;
+	case -EFSBADCRC:
+		errstr = "Filesystem failed CRC";
+		break;
 	case -EIO:
 		errstr = "IO failure";
 		break;
@@ -3192,6 +3198,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
 			 "invalid superblock checksum.  Run e2fsck?");
 		silent = 1;
+		ret = -EFSBADCRC;
 		goto cantfind_ext4;
 	}
 
@@ -3612,6 +3619,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 	}
 	if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
+		ret = -EFSCORRUPTED;
 		goto failed_mount2;
 	}
 
@@ -4664,7 +4672,7 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
 		g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
 					       le16_to_cpu(gdp->bg_checksum));
-					err = -EINVAL;
+					err = -EFSBADCRC;
 					goto restore_opts;
 				}
 			}

fs/ext4/symlink.c

@@ -57,7 +57,7 @@ static const char *ext4_encrypted_follow_link(struct dentry *dentry, void **cook
 	     sizeof(struct ext4_encrypted_symlink_data) - 1) >
 	    max_size) {
 		/* Symlink data on the disk is corrupted */
-		res = -EIO;
+		res = -EFSCORRUPTED;
 		goto errout;
 	}
 	plen = (cstr.len < EXT4_FNAME_CRYPTO_DIGEST_SIZE*2) ?

fs/ext4/xattr.c

@@ -195,7 +195,7 @@ ext4_xattr_check_names(struct ext4_xattr_entry *entry, void *end,
 	while (!IS_LAST_ENTRY(e)) {
 		struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(e);
 		if ((void *)next >= end)
-			return -EIO;
+			return -EFSCORRUPTED;
 		e = next;
 	}
 
@@ -205,7 +205,7 @@ ext4_xattr_check_names(struct ext4_xattr_entry *entry, void *end,
 		     (void *)e + sizeof(__u32) ||
 		     value_start + le16_to_cpu(entry->e_value_offs) +
 		    le32_to_cpu(entry->e_value_size) > end))
-			return -EIO;
+			return -EFSCORRUPTED;
 		entry = EXT4_XATTR_NEXT(entry);
 	}
 
@@ -222,9 +222,9 @@ ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh)
 
 	if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) ||
 	    BHDR(bh)->h_blocks != cpu_to_le32(1))
-		return -EIO;
+		return -EFSCORRUPTED;
 	if (!ext4_xattr_block_csum_verify(inode, bh->b_blocknr, BHDR(bh)))
-		return -EIO;
+		return -EFSBADCRC;
 	error = ext4_xattr_check_names(BFIRST(bh), bh->b_data + bh->b_size,
 				       bh->b_data);
 	if (!error)
@@ -239,7 +239,7 @@ ext4_xattr_check_entry(struct ext4_xattr_entry *entry, size_t size)
 
 	if (entry->e_value_block != 0 || value_size > size ||
 	    le16_to_cpu(entry->e_value_offs) + value_size > size)
-		return -EIO;
+		return -EFSCORRUPTED;
 	return 0;
 }
 
@@ -266,7 +266,7 @@ ext4_xattr_find_entry(struct ext4_xattr_entry **pentry, int name_index,
 	}
 	*pentry = entry;
 	if (!cmp && ext4_xattr_check_entry(entry, size))
-			return -EIO;
+		return -EFSCORRUPTED;
 	return cmp ? -ENODATA : 0;
 }
 
@@ -297,13 +297,13 @@ ext4_xattr_block_get(struct inode *inode, int name_index, const char *name,
 bad_block:
 		EXT4_ERROR_INODE(inode, "bad block %llu",
 				 EXT4_I(inode)->i_file_acl);
-		error = -EIO;
+		error = -EFSCORRUPTED;
 		goto cleanup;
 	}
 	ext4_xattr_cache_insert(ext4_mb_cache, bh);
 	entry = BFIRST(bh);
 	error = ext4_xattr_find_entry(&entry, name_index, name, bh->b_size, 1);
-	if (error == -EIO)
+	if (error == -EFSCORRUPTED)
 		goto bad_block;
 	if (error)
 		goto cleanup;
@@ -445,7 +445,7 @@ ext4_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size)
 	if (ext4_xattr_check_block(inode, bh)) {
 		EXT4_ERROR_INODE(inode, "bad block %llu",
 				 EXT4_I(inode)->i_file_acl);
-		error = -EIO;
+		error = -EFSCORRUPTED;
 		goto cleanup;
 	}
 	ext4_xattr_cache_insert(ext4_mb_cache, bh);
@@ -751,7 +751,7 @@ ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i,
 		if (ext4_xattr_check_block(inode, bs->bh)) {
 			EXT4_ERROR_INODE(inode, "bad block %llu",
 					 EXT4_I(inode)->i_file_acl);
-			error = -EIO;
+			error = -EFSCORRUPTED;
 			goto cleanup;
 		}
 		/* Find the named attribute. */
@@ -811,7 +811,7 @@ ext4_xattr_block_set(handle_t *handle, struct inode *inode,
 					bs->bh);
 			}
 			unlock_buffer(bs->bh);
-			if (error == -EIO)
+			if (error == -EFSCORRUPTED)
 				goto bad_block;
 			if (!error)
 				error = ext4_handle_dirty_xattr_block(handle,
@@ -855,7 +855,7 @@ ext4_xattr_block_set(handle_t *handle, struct inode *inode,
 	}
 
 	error = ext4_xattr_set_entry(i, s);
-	if (error == -EIO)
+	if (error == -EFSCORRUPTED)
 		goto bad_block;
 	if (error)
 		goto cleanup;
@@ -1314,7 +1314,7 @@ int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
 		if (ext4_xattr_check_block(inode, bh)) {
 			EXT4_ERROR_INODE(inode, "bad block %llu",
 					 EXT4_I(inode)->i_file_acl);
-			error = -EIO;
+			error = -EFSCORRUPTED;
 			goto cleanup;
 		}
 		base = BHDR(bh);
@@ -1579,7 +1579,7 @@ ext4_xattr_cmp(struct ext4_xattr_header *header1,
 		    memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
 			return 1;
 		if (entry1->e_value_block != 0 || entry2->e_value_block != 0)
-			return -EIO;
+			return -EFSCORRUPTED;
 		if (memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
 			   (char *)header2 + le16_to_cpu(entry2->e_value_offs),
 			   le32_to_cpu(entry1->e_value_size)))

fs/jbd2/journal.c

@@ -1558,6 +1558,7 @@ static int journal_get_superblock(journal_t *journal)
 	/* Check superblock checksum */
 	if (!jbd2_superblock_csum_verify(journal, sb)) {
 		printk(KERN_ERR "JBD2: journal checksum error\n");
+		err = -EFSBADCRC;
 		goto out;
 	}
 
@@ -1649,7 +1650,7 @@ int jbd2_journal_load(journal_t *journal)
 		printk(KERN_ERR "JBD2: journal transaction %u on %s "
 		       "is corrupt.\n", journal->j_failed_commit,
 		       journal->j_devname);
-		return -EIO;
+		return -EFSCORRUPTED;
 	}
 
 	/* OK, we've finished with the dynamic journal bits:

fs/jbd2/recovery.c

@@ -140,7 +140,7 @@ static int jread(struct buffer_head **bhp, journal_t *journal,
 
 	if (offset >= journal->j_maxlen) {
 		printk(KERN_ERR "JBD2: corrupted journal superblock\n");
-		return -EIO;
+		return -EFSCORRUPTED;
 	}
 
 	err = jbd2_journal_bmap(journal, offset, &blocknr);
@@ -527,7 +527,7 @@ static int do_one_pass(journal_t *journal,
 				printk(KERN_ERR "JBD2: Invalid checksum "
 				       "recovering block %lu in log\n",
 				       next_log_block);
-				err = -EIO;
+				err = -EFSBADCRC;
 				brelse(bh);
 				goto failed;
 			}
@@ -602,7 +602,7 @@ static int do_one_pass(journal_t *journal,
 						journal, tag, obh->b_data,
 						be32_to_cpu(tmp->h_sequence))) {
 						brelse(obh);
-						success = -EIO;
+						success = -EFSBADCRC;
 						printk(KERN_ERR "JBD2: Invalid "
 						       "checksum recovering "
 						       "block %llu in log\n",
@@ -851,7 +851,7 @@ static int scan_revoke_records(journal_t *journal, struct buffer_head *bh,
 	rcount = be32_to_cpu(header->r_count);
 
 	if (!jbd2_revoke_block_csum_verify(journal, header))
-		return -EINVAL;
+		return -EFSBADCRC;
 
 	if (jbd2_journal_has_csum_v2or3(journal))
 		csum_size = sizeof(struct jbd2_journal_revoke_tail);

include/linux/jbd2.h

@@ -1449,4 +1449,7 @@ static inline tid_t  jbd2_get_latest_transaction(journal_t *journal)
 
 #endif	/* __KERNEL__ */
 
+#define EFSBADCRC	EBADMSG		/* Bad CRC detected */
+#define EFSCORRUPTED	EUCLEAN		/* Filesystem is corrupted */
+
 #endif	/* _LINUX_JBD2_H */