From: Filipe Manana <[email protected]> As of the 4.3 kernel release, the fitrim ioctl can now discard any region of a disk that is not part of a chunk/block group, including the MBR (master boot record). Fix this by not allowing to trim/discard any region in the device starting with an offset not greater than min(alloc_start_mount_option, 1Mb), just as we did for space allocated to chunks/block groups.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=109341 Fixes: 499f377f49f0 (btrfs: iterate over unused chunk space in FITRIM) Cc: [email protected] # 4.3+ Signed-off-by: Filipe Manana <[email protected]> --- fs/btrfs/extent-tree.c | 7 +++---- fs/btrfs/volumes.c | 38 ++++++++++++++------------------------ fs/btrfs/volumes.h | 5 +---- 3 files changed, 18 insertions(+), 32 deletions(-) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index cf8983e..7af2f03 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -9482,8 +9482,8 @@ int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr) */ if (device->total_bytes > device->bytes_used + min_free && !device->is_tgtdev_for_dev_replace) { - ret = find_free_dev_extent(trans, device, min_free, - &dev_offset, NULL); + ret = find_free_dev_extent(trans->transaction, device, + min_free, &dev_offset, NULL); if (!ret) dev_nr++; @@ -10677,8 +10677,7 @@ static int btrfs_trim_free_extents(struct btrfs_device *device, atomic_inc(&trans->use_count); spin_unlock(&fs_info->trans_lock); - ret = find_free_dev_extent_start(trans, device, minlen, start, - &start, &len); + ret = find_free_dev_extent(trans, device, minlen, &start, &len); if (trans) btrfs_put_transaction(trans); diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index a114b7b..207f077 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -1222,10 +1222,9 @@ again: /* - * find_free_dev_extent_start - find free space in the specified device + * find_free_dev_extent - find free space in the specified device * @device: the device which we search the free space in * @num_bytes: the size of the free space that we need - * @search_start: the position from which to begin the search * @start: store the start of the free space. * @len: the size of the free space. that we find, or the size * of the max free space if we don't find suitable free space @@ -1242,9 +1241,9 @@ again: * But if we don't find suitable free space, it is used to store the size of * the max free space. */ -int find_free_dev_extent_start(struct btrfs_transaction *transaction, - struct btrfs_device *device, u64 num_bytes, - u64 search_start, u64 *start, u64 *len) +int find_free_dev_extent(struct btrfs_transaction *transaction, + struct btrfs_device *device, u64 num_bytes, + u64 *start, u64 *len) { struct btrfs_key key; struct btrfs_root *root = device->dev_root; @@ -1258,6 +1257,15 @@ int find_free_dev_extent_start(struct btrfs_transaction *transaction, int ret; int slot; struct extent_buffer *l; + u64 search_start; + + /* FIXME use last free of some kind */ + + /* + * we don't want to overwrite the superblock on the drive (nor the MBR + * sector), so we make sure to start at an offset of at least 1MB + */ + search_start = max(root->fs_info->alloc_start, 1024ull * 1024); path = btrfs_alloc_path(); if (!path) @@ -1394,24 +1402,6 @@ out: return ret; } -int find_free_dev_extent(struct btrfs_trans_handle *trans, - struct btrfs_device *device, u64 num_bytes, - u64 *start, u64 *len) -{ - struct btrfs_root *root = device->dev_root; - u64 search_start; - - /* FIXME use last free of some kind */ - - /* - * we don't want to overwrite the superblock on the drive, - * so we make sure to start at an offset of at least 1MB - */ - search_start = max(root->fs_info->alloc_start, 1024ull * 1024); - return find_free_dev_extent_start(trans->transaction, device, - num_bytes, search_start, start, len); -} - static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans, struct btrfs_device *device, u64 start, u64 *dev_extent_len) @@ -4597,7 +4587,7 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans, if (total_avail == 0) continue; - ret = find_free_dev_extent(trans, device, + ret = find_free_dev_extent(trans->transaction, device, max_stripe_size * dev_stripes, &dev_offset, &max_avail); if (ret && ret != -ENOSPC) diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index 6a4375a..9db9261 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -472,10 +472,7 @@ int btrfs_cancel_balance(struct btrfs_fs_info *fs_info); int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info); int btrfs_check_uuid_tree(struct btrfs_fs_info *fs_info); int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset); -int find_free_dev_extent_start(struct btrfs_transaction *transaction, - struct btrfs_device *device, u64 num_bytes, - u64 search_start, u64 *start, u64 *max_avail); -int find_free_dev_extent(struct btrfs_trans_handle *trans, +int find_free_dev_extent(struct btrfs_transaction *transaction, struct btrfs_device *device, u64 num_bytes, u64 *start, u64 *max_avail); void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index); -- 2.1.3 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
