Commit b5b18160 authored by Jan Kara's avatar Jan Kara Committed by Theodore Ts'o
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ext4: fix mmap write protection for data=journal mode 



Commit afb585a9 "ext4: data=journal: write-protect pages on
j_submit_inode_data_buffers()") added calls ext4_jbd2_inode_add_write()
to track inode ranges whose mappings need to get write-protected during
transaction commits.  However the added calls use wrong start of a range
(0 instead of page offset) and so write protection is not necessarily
effective.  Use correct range start to fix the problem.

Fixes: afb585a9 ("ext4: data=journal: write-protect pages on j_submit_inode_data_buffers()")
Signed-off-by: default avatarJan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20201027132751.29858-1-jack@suse.cz


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent ea4b01d9

fs/ext4/inode.c

+3 −2
Original line number Diff line number Diff line
@@ -1918,7 +1918,7 @@ static int __ext4_journalled_writepage(struct page *page, 
	}

	if (ret == 0)

		ret = err;

	err = ext4_jbd2_inode_add_write(handle, inode, 0, len);

	err = ext4_jbd2_inode_add_write(handle, inode, page_offset(page), len);

	if (ret == 0)

		ret = err;

	EXT4_I(inode)->i_datasync_tid = handle->h_transaction->t_tid;
@@ -6159,7 +6159,8 @@ vm_fault_t ext4_page_mkwrite(struct vm_fault *vmf) 
			if (ext4_walk_page_buffers(handle, page_buffers(page),

					0, len, NULL, write_end_fn))

				goto out_error;

			if (ext4_jbd2_inode_add_write(handle, inode, 0, len))

			if (ext4_jbd2_inode_add_write(handle, inode,

						      page_offset(page), len))

				goto out_error;

			ext4_set_inode_state(inode, EXT4_STATE_JDATA);

		} else {