On Sun, Jul 16, 2023 at 11:52:48PM -0400, Sweet Tea Dorminy wrote:
> This change actually saves and loads the extent contexts created and
> freed by the last change.
>
> Signed-off-by: Sweet Tea Dorminy <sweettea-kernel@xxxxxxxxxx>
> ---
> fs/btrfs/file-item.c | 21 ++++++++++++++++
> fs/btrfs/fscrypt.c | 36 +++++++++++++++++++++++++++
> fs/btrfs/fscrypt.h | 6 +++++
> fs/btrfs/inode.c | 44 ++++++++++++++++++++++++++++++---
> fs/btrfs/tree-log.c | 24 ++++++++++++++++--
> include/uapi/linux/btrfs_tree.h | 5 ++++
> 6 files changed, 130 insertions(+), 6 deletions(-)
>
> diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
> index 8095fc2e7ca1..ccc2d12faba3 100644
> --- a/fs/btrfs/file-item.c
> +++ b/fs/btrfs/file-item.c
> @@ -1302,6 +1302,27 @@ void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode,
>
> ctxsize = btrfs_file_extent_ctxsize_from_item(leaf, path);
> ASSERT(ctxsize == btrfs_file_extent_encryption_ctxsize(leaf, fi));
> +
> +#ifdef CONFIG_FS_ENCRYPTION
> + if (ctxsize) {
> + u8 context[FSCRYPT_SET_CONTEXT_MAX_SIZE];
> + int res;
> + unsigned int nofs_flag;
> +
> + read_extent_buffer(leaf, context,
> + (unsigned long)fi->fscrypt_context,
> + ctxsize);
> + nofs_flag = memalloc_nofs_save();
> + res = fscrypt_load_extent_info(&inode->vfs_inode,
> + context, ctxsize,
> + &em->fscrypt_info);
> + memalloc_nofs_restore(nofs_flag);
> + if (res)
> + btrfs_err(fs_info,
> + "Unable to load fscrypt info: %d",
> + res);
> + }
> +#endif /* CONFIG_FS_ENCRYPTION */
> } else if (type == BTRFS_FILE_EXTENT_INLINE) {
> em->block_start = EXTENT_MAP_INLINE;
> em->start = extent_start;
> diff --git a/fs/btrfs/fscrypt.c b/fs/btrfs/fscrypt.c
> index 6875108f4363..30dab7d06589 100644
> --- a/fs/btrfs/fscrypt.c
> +++ b/fs/btrfs/fscrypt.c
> @@ -166,6 +166,41 @@ static bool btrfs_fscrypt_empty_dir(struct inode *inode)
> return inode->i_size == BTRFS_EMPTY_DIR_SIZE;
> }
>
> +int btrfs_fscrypt_get_extent_info(const struct inode *inode,
> + u64 lblk_num,
> + struct fscrypt_info **info_ptr,
> + u64 *extent_offset,
> + u64 *extent_length)
> +{
> + u64 offset = lblk_num << inode->i_blkbits;
> + struct extent_map *em;
> +
> + /* Since IO must be in progress on this extent, this must succeed */
> + em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, offset, PAGE_SIZE);
> + if (!em)
> + return -EINVAL;
> +
> + if (em->block_start == EXTENT_MAP_HOLE) {
> + btrfs_info(BTRFS_I(inode)->root->fs_info,
> + "extent context requested for block %llu of inode %lu without an extent",
> + lblk_num, inode->i_ino);
> + free_extent_map(em);
> + return -ENOENT;
> + }
> +
> + *info_ptr = em->fscrypt_info;
> +
> + if (extent_offset)
> + *extent_offset
> + = (offset - em->start) >> inode->i_blkbits;
> +
> + if (extent_length)
> + *extent_length = em->len >> inode->i_blkbits;
> +
> + free_extent_map(em);
> + return 0;
> +}
> +
> static struct block_device **btrfs_fscrypt_get_devices(struct super_block *sb,
> unsigned int *num_devs)
> {
> @@ -206,6 +241,7 @@ const struct fscrypt_operations btrfs_fscrypt_ops = {
> .get_context = btrfs_fscrypt_get_context,
> .set_context = btrfs_fscrypt_set_context,
> .empty_dir = btrfs_fscrypt_empty_dir,
> + .get_extent_info = btrfs_fscrypt_get_extent_info,
> .get_devices = btrfs_fscrypt_get_devices,
> .key_prefix = "btrfs:"
> };
> diff --git a/fs/btrfs/fscrypt.h b/fs/btrfs/fscrypt.h
> index 2d405d54cbc7..1cab721a64e5 100644
> --- a/fs/btrfs/fscrypt.h
> +++ b/fs/btrfs/fscrypt.h
> @@ -50,6 +50,12 @@ static inline bool btrfs_fscrypt_match_name(struct fscrypt_name *fname,
> }
> #endif /* CONFIG_FS_ENCRYPTION */
>
> +int btrfs_fscrypt_get_extent_info(const struct inode *inode,
> + u64 lblk_num,
> + struct fscrypt_info **info_ptr,
> + u64 *extent_offset,
> + u64 *extent_length);
> +
> extern const struct fscrypt_operations btrfs_fscrypt_ops;
>
> #endif /* BTRFS_FSCRYPT_H */
> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> index 83098779dad2..92a193785a21 100644
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -3036,17 +3036,46 @@ static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
> u64 num_bytes = btrfs_stack_file_extent_num_bytes(stack_fi);
> u64 ram_bytes = btrfs_stack_file_extent_ram_bytes(stack_fi);
> struct btrfs_drop_extents_args drop_args = { 0 };
> - size_t fscrypt_context_size =
> - btrfs_stack_file_extent_encryption(stack_fi) ?
> - FSCRYPT_SET_CONTEXT_MAX_SIZE : 0;
> + size_t fscrypt_context_size = 0;
> +#ifdef CONFIG_FS_ENCRYPTION
> + u8 context[FSCRYPT_SET_CONTEXT_MAX_SIZE];
> +#endif /* CONFIG_FS_ENCRYPTION */
> +
> int ret;
>
> path = btrfs_alloc_path();
> if (!path)
> return -ENOMEM;
>
> +#ifdef CONFIG_FS_ENCRYPTION
> + if (IS_ENCRYPTED(&inode->vfs_inode)) {
> + u8 encryption;
> + struct fscrypt_info *fscrypt_info;
> + u64 lblk_num = file_pos >> root->fs_info->sectorsize_bits;
> +
> + ret = btrfs_fscrypt_get_extent_info(&inode->vfs_inode,
> + lblk_num, &fscrypt_info,
> + NULL, NULL);
> + if (ret) {
> + btrfs_err(root->fs_info, "No fscrypt context found");
> + goto out;
> + }
> +
> + fscrypt_context_size =
> + fscrypt_set_extent_context(fscrypt_info, context,
> + FSCRYPT_SET_CONTEXT_MAX_SIZE);
> + if (fscrypt_context_size < 0) {
> + ret = fscrypt_context_size;
> + goto out;
> + }
> + encryption = btrfs_pack_encryption(BTRFS_ENCRYPTION_FSCRYPT,
> + fscrypt_context_size);
> + btrfs_set_stack_file_extent_encryption(stack_fi, encryption);
> + }
> +#endif /* CONFIG_FS_ENCRYPTION */
Make this into a helper so we're not cluttering the normal code path with the
ifdefs.
> +
> /*
> - * we may be replacing one extent in the tree with another.
> + * We may be replacing one extent in the tree with another.
> * The new extent is pinned in the extent map, and we don't want
> * to drop it from the cache until it is completely in the btree.
> *
> @@ -3079,6 +3108,13 @@ static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
> btrfs_item_ptr_offset(leaf, path->slots[0]),
> sizeof(struct btrfs_file_extent_item));
>
> +#ifdef CONFIG_FS_ENCRYPTION
> + write_extent_buffer(leaf, context,
> + btrfs_item_ptr_offset(leaf, path->slots[0]) +
> + sizeof(struct btrfs_file_extent_item),
> + fscrypt_context_size);
> +#endif /* CONFIG_FS_ENCRYPTION */
> +
> btrfs_mark_buffer_dirty(leaf);
> btrfs_release_path(path);
>
> diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
> index 82c91097672b..f0ad281170c5 100644
> --- a/fs/btrfs/tree-log.c
> +++ b/fs/btrfs/tree-log.c
> @@ -4634,8 +4634,22 @@ static int log_one_extent(struct btrfs_trans_handle *trans,
> u64 extent_offset = em->start - em->orig_start;
> u64 block_len;
> int ret;
> - u8 encryption = btrfs_pack_encryption(IS_ENCRYPTED(&inode->vfs_inode) ?
> - BTRFS_ENCRYPTION_FSCRYPT : 0, 0);
> + u8 encryption = 0;
> + size_t fscrypt_context_size = 0;
> +#ifdef CONFIG_FS_ENCRYPTION
> + u8 context[FSCRYPT_SET_CONTEXT_MAX_SIZE];
> +
> + if (em->fscrypt_info) {
> + fscrypt_context_size =
> + fscrypt_set_extent_context(em->fscrypt_info, context,
> + FSCRYPT_SET_CONTEXT_MAX_SIZE);
> + if (fscrypt_context_size < 0)
> + return fscrypt_context_size;
> +
> + encryption = btrfs_pack_encryption(BTRFS_ENCRYPTION_FSCRYPT,
> + fscrypt_context_size);
> + }
Same here, looks like this can be it's own helper, and the code above can use
this helper and do the other thing it needs to. Thanks,
Josef
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