Btrfs: add missing inode item update in fallocate() (3d850dd4) · Commits · 戴 / test

If we fallocate(), without the keep size flag, into an area already covered by an extent previously fallocated, we were updating the inode's i_size but we weren't updating the inode item in the fs/subvol tree. A following umount + mount would result in a loss of the inode's size (and an fsync would miss too the fact that the inode changed). Reproducer: $ mkfs.btrfs -f /dev/sdd $ mount /dev/sdd /mnt $ fallocate -n -l 1M /mnt/foobar $ fallocate -l 512K /mnt/foobar $ umount /mnt $ mount /dev/sdd /mnt $ od -t x1 /mnt/foobar 0000000 The expected result is: $ od -t x1 /mnt/foobar 0000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 2000000 A test case for fstests follows soon. Signed-off-by:

Filipe Manana <fdmanana@suse.com> Reviewed-by:

Liu Bo <bo.li.liu@oracle.com> Signed-off-by:

Chris Mason <clm@fb.com>

fs/btrfs/file.c

+20 −9

Original line number	Diff line number	Diff line
		@@ -2669,23 +2669,34 @@ static long btrfs_fallocate(struct file *file, int mode,
		1 << inode->i_blkbits,
		offset + len,
		&alloc_hint);

		if (ret < 0) {
		free_extent_map(em);
		break;
		}
		} else if (actual_end > inode->i_size &&
		!(mode & FALLOC_FL_KEEP_SIZE)) {
		struct btrfs_trans_handle *trans;

		/*
		* We didn't need to allocate any more space, but we
		* still extended the size of the file so we need to
		* update i_size.
		* update i_size and the inode item.
		*/
		trans = btrfs_start_transaction(root, 1);
		if (IS_ERR(trans)) {
		ret = PTR_ERR(trans);
		} else {
		inode->i_ctime = CURRENT_TIME;
		i_size_write(inode, actual_end);
		btrfs_ordered_update_i_size(inode, actual_end, NULL);
		btrfs_ordered_update_i_size(inode, actual_end,
		NULL);
		ret = btrfs_update_inode(trans, root, inode);
		if (ret)
		btrfs_end_transaction(trans, root);
		else
		ret = btrfs_end_transaction(trans,
		root);
		}
		}
		free_extent_map(em);
		if (ret < 0)
		break;

		cur_offset = last_byte;
		if (cur_offset >= alloc_end) {

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