Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 fixes from Ted Ts'o:
 "Various bug fixes for ext4.  The most serious of them fixes a security
  bug (CVE-2012-4508) which leads to stale data exposure when we have
  fallocate racing against writes to files undergoing delayed
  allocation.  We also have two fixes for the metadata checksum feature,
  the most serious of which can cause the superblock to have a invalid
  checksum after a power failure."

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: Avoid underflow in ext4_trim_fs()
  ext4: Checksum the block bitmap properly with bigalloc enabled
  ext4: fix undefined bit shift result in ext4_fill_flex_info
  ext4: fix metadata checksum calculation for the superblock
  ext4: race-condition protection for ext4_convert_unwritten_extents_endio
  ext4: serialize fallocate with ext4_convert_unwritten_extents

9 files changed, 74 insertions, 45 deletions

diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index 1b5089067d0..cf1821784a1 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -174,8 +174,7 @@ void ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh,
 		ext4_free_inodes_set(sb, gdp, 0);
 		ext4_itable_unused_set(sb, gdp, 0);
 		memset(bh->b_data, 0xff, sb->s_blocksize);
-		ext4_block_bitmap_csum_set(sb, block_group, gdp, bh,
-					   EXT4_BLOCKS_PER_GROUP(sb) / 8);
+		ext4_block_bitmap_csum_set(sb, block_group, gdp, bh);
 		return;
 	}
 	memset(bh->b_data, 0, sb->s_blocksize);
@@ -212,8 +211,7 @@ void ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh,
 	 */
 	ext4_mark_bitmap_end(num_clusters_in_group(sb, block_group),
 			     sb->s_blocksize * 8, bh->b_data);
-	ext4_block_bitmap_csum_set(sb, block_group, gdp, bh,
-				   EXT4_BLOCKS_PER_GROUP(sb) / 8);
+	ext4_block_bitmap_csum_set(sb, block_group, gdp, bh);
 	ext4_group_desc_csum_set(sb, block_group, gdp);
 }
 
@@ -350,7 +348,7 @@ void ext4_validate_block_bitmap(struct super_block *sb,
 		return;
 	}
 	if (unlikely(!ext4_block_bitmap_csum_verify(sb, block_group,
-			desc, bh, EXT4_BLOCKS_PER_GROUP(sb) / 8))) {
+			desc, bh))) {
 		ext4_unlock_group(sb, block_group);
 		ext4_error(sb, "bg %u: bad block bitmap checksum", block_group);
 		return;
diff --git a/fs/ext4/bitmap.c b/fs/ext4/bitmap.c
index 5c2d1813ebe..3285aa5a706 100644
--- a/fs/ext4/bitmap.c
+++ b/fs/ext4/bitmap.c
@@ -58,11 +58,12 @@ void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
 
 int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
 				  struct ext4_group_desc *gdp,
-				  struct buffer_head *bh, int sz)
+				  struct buffer_head *bh)
 {
 	__u32 hi;
 	__u32 provided, calculated;
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	int sz = EXT4_CLUSTERS_PER_GROUP(sb) / 8;
 
 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
@@ -84,8 +85,9 @@ int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
 
 void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
 				struct ext4_group_desc *gdp,
-				struct buffer_head *bh, int sz)
+				struct buffer_head *bh)
 {
+	int sz = EXT4_CLUSTERS_PER_GROUP(sb) / 8;
 	__u32 csum;
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
 
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 3ab2539b7b2..3c20de1d59d 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1882,10 +1882,10 @@ int ext4_inode_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
 				  struct buffer_head *bh, int sz);
 void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
 				struct ext4_group_desc *gdp,
-				struct buffer_head *bh, int sz);
+				struct buffer_head *bh);
 int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
 				  struct ext4_group_desc *gdp,
-				  struct buffer_head *bh, int sz);
+				  struct buffer_head *bh);
 
 /* balloc.c */
 extern void ext4_validate_block_bitmap(struct super_block *sb,
@@ -2063,8 +2063,7 @@ extern int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count);
 extern int ext4_calculate_overhead(struct super_block *sb);
 extern int ext4_superblock_csum_verify(struct super_block *sb,
 				       struct ext4_super_block *es);
-extern void ext4_superblock_csum_set(struct super_block *sb,
-				     struct ext4_super_block *es);
+extern void ext4_superblock_csum_set(struct super_block *sb);
 extern void *ext4_kvmalloc(size_t size, gfp_t flags);
 extern void *ext4_kvzalloc(size_t size, gfp_t flags);
 extern void ext4_kvfree(void *ptr);
diff --git a/fs/ext4/ext4_jbd2.c b/fs/ext4/ext4_jbd2.c
index bfa65b49d42..b4323ba846b 100644
--- a/fs/ext4/ext4_jbd2.c
+++ b/fs/ext4/ext4_jbd2.c
@@ -143,17 +143,13 @@ int __ext4_handle_dirty_super(const char *where, unsigned int line,
 	struct buffer_head *bh = EXT4_SB(sb)->s_sbh;
 	int err = 0;
 
+	ext4_superblock_csum_set(sb);
 	if (ext4_handle_valid(handle)) {
-		ext4_superblock_csum_set(sb,
-				(struct ext4_super_block *)bh->b_data);
 		err = jbd2_journal_dirty_metadata(handle, bh);
 		if (err)
 			ext4_journal_abort_handle(where, line, __func__,
 						  bh, handle, err);
-	} else {
-		ext4_superblock_csum_set(sb,
-				(struct ext4_super_block *)bh->b_data);
+	} else
 		mark_buffer_dirty(bh);
-	}
 	return err;
 }
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 1c94cca35ed..7011ac96720 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -52,6 +52,9 @@
 #define EXT4_EXT_MARK_UNINIT1	0x2  /* mark first half uninitialized */
 #define EXT4_EXT_MARK_UNINIT2	0x4  /* mark second half uninitialized */
 
+#define EXT4_EXT_DATA_VALID1	0x8  /* first half contains valid data */
+#define EXT4_EXT_DATA_VALID2	0x10 /* second half contains valid data */
+
 static __le32 ext4_extent_block_csum(struct inode *inode,
 				     struct ext4_extent_header *eh)
 {
@@ -2914,6 +2917,9 @@ static int ext4_split_extent_at(handle_t *handle,
 	unsigned int ee_len, depth;
 	int err = 0;
 
+	BUG_ON((split_flag & (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2)) ==
+	       (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2));
+
 	ext_debug("ext4_split_extents_at: inode %lu, logical"
 		"block %llu\n", inode->i_ino, (unsigned long long)split);
 
@@ -2972,7 +2978,14 @@ static int ext4_split_extent_at(handle_t *handle,
 
 	err = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
 	if (err == -ENOSPC && (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
-		err = ext4_ext_zeroout(inode, &orig_ex);
+		if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) {
+			if (split_flag & EXT4_EXT_DATA_VALID1)
+				err = ext4_ext_zeroout(inode, ex2);
+			else
+				err = ext4_ext_zeroout(inode, ex);
+		} else
+			err = ext4_ext_zeroout(inode, &orig_ex);
+
 		if (err)
 			goto fix_extent_len;
 		/* update the extent length and mark as initialized */
@@ -3025,12 +3038,13 @@ static int ext4_split_extent(handle_t *handle,
 	uninitialized = ext4_ext_is_uninitialized(ex);
 
 	if (map->m_lblk + map->m_len < ee_block + ee_len) {
-		split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT ?
-			      EXT4_EXT_MAY_ZEROOUT : 0;
+		split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT;
 		flags1 = flags | EXT4_GET_BLOCKS_PRE_IO;
 		if (uninitialized)
 			split_flag1 |= EXT4_EXT_MARK_UNINIT1 |
 				       EXT4_EXT_MARK_UNINIT2;
+		if (split_flag & EXT4_EXT_DATA_VALID2)
+			split_flag1 |= EXT4_EXT_DATA_VALID1;
 		err = ext4_split_extent_at(handle, inode, path,
 				map->m_lblk + map->m_len, split_flag1, flags1);
 		if (err)
@@ -3043,8 +3057,8 @@ static int ext4_split_extent(handle_t *handle,
 		return PTR_ERR(path);
 
 	if (map->m_lblk >= ee_block) {
-		split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT ?
-			      EXT4_EXT_MAY_ZEROOUT : 0;
+		split_flag1 = split_flag & (EXT4_EXT_MAY_ZEROOUT |
+					    EXT4_EXT_DATA_VALID2);
 		if (uninitialized)
 			split_flag1 |= EXT4_EXT_MARK_UNINIT1;
 		if (split_flag & EXT4_EXT_MARK_UNINIT2)
@@ -3323,26 +3337,47 @@ static int ext4_split_unwritten_extents(handle_t *handle,
 
 	split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
 	split_flag |= EXT4_EXT_MARK_UNINIT2;
-
+	if (flags & EXT4_GET_BLOCKS_CONVERT)
+		split_flag |= EXT4_EXT_DATA_VALID2;
 	flags |= EXT4_GET_BLOCKS_PRE_IO;
 	return ext4_split_extent(handle, inode, path, map, split_flag, flags);
 }
 
 static int ext4_convert_unwritten_extents_endio(handle_t *handle,
-					      struct inode *inode,
-					      struct ext4_ext_path *path)
+						struct inode *inode,
+						struct ext4_map_blocks *map,
+						struct ext4_ext_path *path)
 {
 	struct ext4_extent *ex;
+	ext4_lblk_t ee_block;
+	unsigned int ee_len;
 	int depth;
 	int err = 0;
 
 	depth = ext_depth(inode);
 	ex = path[depth].p_ext;
+	ee_block = le32_to_cpu(ex->ee_block);
+	ee_len = ext4_ext_get_actual_len(ex);
 
 	ext_debug("ext4_convert_unwritten_extents_endio: inode %lu, logical"
 		"block %llu, max_blocks %u\n", inode->i_ino,
-		(unsigned long long)le32_to_cpu(ex->ee_block),
-		ext4_ext_get_actual_len(ex));
+		  (unsigned long long)ee_block, ee_len);
+
+	/* If extent is larger than requested then split is required */
+	if (ee_block != map->m_lblk || ee_len > map->m_len) {
+		err = ext4_split_unwritten_extents(handle, inode, map, path,
+						   EXT4_GET_BLOCKS_CONVERT);
+		if (err < 0)
+			goto out;
+		ext4_ext_drop_refs(path);
+		path = ext4_ext_find_extent(inode, map->m_lblk, path);
+		if (IS_ERR(path)) {
+			err = PTR_ERR(path);
+			goto out;
+		}
+		depth = ext_depth(inode);
+		ex = path[depth].p_ext;
+	}
 
 	err = ext4_ext_get_access(handle, inode, path + depth);
 	if (err)
@@ -3652,7 +3687,7 @@ ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
 	}
 	/* IO end_io complete, convert the filled extent to written */
 	if ((flags & EXT4_GET_BLOCKS_CONVERT)) {
-		ret = ext4_convert_unwritten_extents_endio(handle, inode,
+		ret = ext4_convert_unwritten_extents_endio(handle, inode, map,
 							path);
 		if (ret >= 0) {
 			ext4_update_inode_fsync_trans(handle, inode, 1);
@@ -4428,6 +4463,9 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
 	 */
 	if (len <= EXT_UNINIT_MAX_LEN << blkbits)
 		flags |= EXT4_GET_BLOCKS_NO_NORMALIZE;
+
+	/* Prevent race condition between unwritten */
+	ext4_flush_unwritten_io(inode);
 retry:
 	while (ret >= 0 && ret < max_blocks) {
 		map.m_lblk = map.m_lblk + ret;
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index fa36372f3fd..4facdd29a35 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -762,9 +762,7 @@ got:
 			ext4_free_group_clusters_set(sb, gdp,
 				ext4_free_clusters_after_init(sb, group, gdp));
 			ext4_block_bitmap_csum_set(sb, group, gdp,
-						   block_bitmap_bh,
-						   EXT4_BLOCKS_PER_GROUP(sb) /
-						   8);
+						   block_bitmap_bh);
 			ext4_group_desc_csum_set(sb, group, gdp);
 		}
 		ext4_unlock_group(sb, group);
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index f8b27bf80ac..526e5535860 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2805,8 +2805,7 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
 	}
 	len = ext4_free_group_clusters(sb, gdp) - ac->ac_b_ex.fe_len;
 	ext4_free_group_clusters_set(sb, gdp, len);
-	ext4_block_bitmap_csum_set(sb, ac->ac_b_ex.fe_group, gdp, bitmap_bh,
-				   EXT4_BLOCKS_PER_GROUP(sb) / 8);
+	ext4_block_bitmap_csum_set(sb, ac->ac_b_ex.fe_group, gdp, bitmap_bh);
 	ext4_group_desc_csum_set(sb, ac->ac_b_ex.fe_group, gdp);
 
 	ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
@@ -4666,8 +4665,7 @@ do_more:
 
 	ret = ext4_free_group_clusters(sb, gdp) + count_clusters;
 	ext4_free_group_clusters_set(sb, gdp, ret);
-	ext4_block_bitmap_csum_set(sb, block_group, gdp, bitmap_bh,
-				   EXT4_BLOCKS_PER_GROUP(sb) / 8);
+	ext4_block_bitmap_csum_set(sb, block_group, gdp, bitmap_bh);
 	ext4_group_desc_csum_set(sb, block_group, gdp);
 	ext4_unlock_group(sb, block_group);
 	percpu_counter_add(&sbi->s_freeclusters_counter, count_clusters);
@@ -4811,8 +4809,7 @@ int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
 	mb_free_blocks(NULL, &e4b, bit, count);
 	blk_free_count = blocks_freed + ext4_free_group_clusters(sb, desc);
 	ext4_free_group_clusters_set(sb, desc, blk_free_count);
-	ext4_block_bitmap_csum_set(sb, block_group, desc, bitmap_bh,
-				   EXT4_BLOCKS_PER_GROUP(sb) / 8);
+	ext4_block_bitmap_csum_set(sb, block_group, desc, bitmap_bh);
 	ext4_group_desc_csum_set(sb, block_group, desc);
 	ext4_unlock_group(sb, block_group);
 	percpu_counter_add(&sbi->s_freeclusters_counter,
@@ -4993,8 +4990,9 @@ int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range)
 	minlen = EXT4_NUM_B2C(EXT4_SB(sb),
 			      range->minlen >> sb->s_blocksize_bits);
 
-	if (unlikely(minlen > EXT4_CLUSTERS_PER_GROUP(sb)) ||
-	    unlikely(start >= max_blks))
+	if (minlen > EXT4_CLUSTERS_PER_GROUP(sb) ||
+	    start >= max_blks ||
+	    range->len < sb->s_blocksize)
 		return -EINVAL;
 	if (end >= max_blks)
 		end = max_blks - 1;
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index 7a75e108696..47bf06a2765 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -1212,8 +1212,7 @@ static int ext4_set_bitmap_checksums(struct super_block *sb,
 	bh = ext4_get_bitmap(sb, group_data->block_bitmap);
 	if (!bh)
 		return -EIO;
-	ext4_block_bitmap_csum_set(sb, group, gdp, bh,
-				   EXT4_BLOCKS_PER_GROUP(sb) / 8);
+	ext4_block_bitmap_csum_set(sb, group, gdp, bh);
 	brelse(bh);
 
 	return 0;
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 7265a036747..80928f71685 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -143,9 +143,10 @@ int ext4_superblock_csum_verify(struct super_block *sb,
 	return es->s_checksum == ext4_superblock_csum(sb, es);
 }
 
-void ext4_superblock_csum_set(struct super_block *sb,
-			      struct ext4_super_block *es)
+void ext4_superblock_csum_set(struct super_block *sb)
 {
+	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
+
 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 		EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 		return;
@@ -1963,7 +1964,7 @@ static int ext4_fill_flex_info(struct super_block *sb)
 		sbi->s_log_groups_per_flex = 0;
 		return 1;
 	}
-	groups_per_flex = 1 << sbi->s_log_groups_per_flex;
+	groups_per_flex = 1U << sbi->s_log_groups_per_flex;
 
 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
 	if (err)
@@ -4381,7 +4382,7 @@ static int ext4_commit_super(struct super_block *sb, int sync)
 		cpu_to_le32(percpu_counter_sum_positive(
 				&EXT4_SB(sb)->s_freeinodes_counter));
 	BUFFER_TRACE(sbh, "marking dirty");
-	ext4_superblock_csum_set(sb, es);
+	ext4_superblock_csum_set(sb);
 	mark_buffer_dirty(sbh);
 	if (sync) {
 		error = sync_dirty_buffer(sbh);