static int mpage_submit_page(struct mpage_da_data *mpd, struct page *page)
{
int len;
- loff_t size = i_size_read(mpd->inode);
+ loff_t size;
int err;
BUG_ON(page->index != mpd->first_page);
+ clear_page_dirty_for_io(page);
+ /*
+ * We have to be very careful here! Nothing protects writeback path
+ * against i_size changes and the page can be writeably mapped into
+ * page tables. So an application can be growing i_size and writing
+ * data through mmap while writeback runs. clear_page_dirty_for_io()
+ * write-protects our page in page tables and the page cannot get
+ * written to again until we release page lock. So only after
+ * clear_page_dirty_for_io() we are safe to sample i_size for
+ * ext4_bio_write_page() to zero-out tail of the written page. We rely
+ * on the barrier provided by TestClearPageDirty in
+ * clear_page_dirty_for_io() to make sure i_size is really sampled only
+ * after page tables are updated.
+ */
+ size = i_size_read(mpd->inode);
if (page->index == size >> PAGE_SHIFT)
len = size & ~PAGE_MASK;
else
len = PAGE_SIZE;
- clear_page_dirty_for_io(page);
err = ext4_bio_write_page(&mpd->io_submit, page, len, mpd->wbc, false);
if (!err)
mpd->wbc->nr_to_write--;
get_block_func = ext4_dio_get_block_unwritten_async;
dio_flags = DIO_LOCKING;
}
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
- BUG_ON(ext4_encrypted_inode(inode) && S_ISREG(inode->i_mode));
-#endif
ret = __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev, iter,
get_block_func, ext4_end_io_dio, NULL,
dio_flags);
*/
inode_lock_shared(inode);
ret = filemap_write_and_wait_range(mapping, iocb->ki_pos,
- iocb->ki_pos + count);
+ iocb->ki_pos + count - 1);
if (ret)
goto out_unlock;
ret = __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev,
inode->i_mtime = inode->i_ctime = current_time(inode);
ext4_mark_inode_dirty(handle, inode);
+ if (ret >= 0)
+ ext4_update_inode_fsync_trans(handle, inode, 1);
out_stop:
ext4_journal_stop(handle);
out_dio:
/* No extended attributes present */
if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR) ||
header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) {
- memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE, 0,
- new_extra_isize);
+ memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE +
+ EXT4_I(inode)->i_extra_isize, 0,
+ new_extra_isize - EXT4_I(inode)->i_extra_isize);
EXT4_I(inode)->i_extra_isize = new_extra_isize;
return 0;
}