ext4: avoid running out of journal credits when appending to an inline file

Use a separate journal transaction if it turns out that we need to
convert an inline file to use an data block.  Otherwise we could end
up failing due to not having journal credits.

This addresses CVE-2018-10883.

https://bugzilla.kernel.org/show_bug.cgi?id=200071

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org

1 files changed, 1 insertions, 37 deletions

diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index d79115d8d716..851bc552d849 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -887,11 +887,11 @@ retry_journal:
 	flags |= AOP_FLAG_NOFS;
 
 	if (ret == -ENOSPC) {
+		ext4_journal_stop(handle);
 		ret = ext4_da_convert_inline_data_to_extent(mapping,
 							    inode,
 							    flags,
 							    fsdata);
-		ext4_journal_stop(handle);
 		if (ret == -ENOSPC &&
 		    ext4_should_retry_alloc(inode->i_sb, &retries))
 			goto retry_journal;
@@ -1891,42 +1891,6 @@ out:
 	return (error < 0 ? error : 0);
 }
 
-/*
- * Called during xattr set, and if we can sparse space 'needed',
- * just create the extent tree evict the data to the outer block.
- *
- * We use jbd2 instead of page cache to move data to the 1st block
- * so that the whole transaction can be committed as a whole and
- * the data isn't lost because of the delayed page cache write.
- */
-int ext4_try_to_evict_inline_data(handle_t *handle,
-				  struct inode *inode,
-				  int needed)
-{
-	int error;
-	struct ext4_xattr_entry *entry;
-	struct ext4_inode *raw_inode;
-	struct ext4_iloc iloc;
-
-	error = ext4_get_inode_loc(inode, &iloc);
-	if (error)
-		return error;
-
-	raw_inode = ext4_raw_inode(&iloc);
-	entry = (struct ext4_xattr_entry *)((void *)raw_inode +
-					    EXT4_I(inode)->i_inline_off);
-	if (EXT4_XATTR_LEN(entry->e_name_len) +
-	    EXT4_XATTR_SIZE(le32_to_cpu(entry->e_value_size)) < needed) {
-		error = -ENOSPC;
-		goto out;
-	}
-
-	error = ext4_convert_inline_data_nolock(handle, inode, &iloc);
-out:
-	brelse(iloc.bh);
-	return error;
-}
-
 int ext4_inline_data_truncate(struct inode *inode, int *has_inline)
 {
 	handle_t *handle;