[PATCH v4 32/46] btrfs: setup fscrypt_extent_info for new extents

Josef Bacik
2023-12-01T22:12:39Z

New extents for encrypted inodes must have a fscrypt_extent_info, which
has the necessary keys and does all the registration at the block layer
for them. This is passed through all of the infrastructure we've
previously added to make sure the context gets saved properly with the
file extents.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
fs/btrfs/inode.c | 34 +++++++++++++++++++++++++++++++++-
1 file changed, 33 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index dc24f11016d9..60d016da1fce 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7434,6 +7434,16 @@ static struct extent_map *create_io_em(struct btrfs_inode *inode,
if (fscrypt_info) {
em->encryption_type = BTRFS_ENCRYPTION_FSCRYPT;
em->fscrypt_info = fscrypt_get_extent_info(fscrypt_info);
+ } else if (IS_ENCRYPTED(&inode->vfs_inode)) {
+ struct fscrypt_extent_info *fscrypt_info;
+
+ em->encryption_type = BTRFS_ENCRYPTION_FSCRYPT;
+ fscrypt_info = fscrypt_prepare_new_extent(&inode->vfs_inode);
+ if (IS_ERR(fscrypt_info)) {
+ free_extent_map(em);
+ return ERR_CAST(fscrypt_info);
+ }
+ em->fscrypt_info = fscrypt_info;
} else {
em->encryption_type = BTRFS_ENCRYPTION_NONE;
}
@@ -9831,6 +9841,9 @@ static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
if (trans)
own_trans = false;
while (num_bytes > 0) {
+ struct fscrypt_extent_info *fscrypt_info = NULL;
+ int encryption_type = BTRFS_ENCRYPTION_NONE;
+
cur_bytes = min_t(u64, num_bytes, SZ_256M);
cur_bytes = max(cur_bytes, min_size);
/*
@@ -9845,6 +9858,20 @@ static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
if (ret)
break;

+ if (IS_ENCRYPTED(inode)) {
+ fscrypt_info = fscrypt_prepare_new_extent(inode);
+ if (IS_ERR(fscrypt_info)) {
+ btrfs_dec_block_group_reservations(fs_info,
+ ins.objectid);
+ btrfs_free_reserved_extent(fs_info,
+ ins.objectid,
+ ins.offset, 0);
+ ret = PTR_ERR(fscrypt_info);
+ break;
+ }
+ encryption_type = BTRFS_ENCRYPTION_FSCRYPT;
+ }
+
/*
* We've reserved this space, and thus converted it from
* ->bytes_may_use to ->bytes_reserved. Any error that happens
@@ -9856,7 +9883,8 @@ static int __btrfs_prealloc_file_range(struct inode *inode, int mode,

last_alloc = ins.offset;
trans = insert_prealloc_file_extent(trans, BTRFS_I(inode),
- &ins, NULL, cur_offset);
+ &ins, fscrypt_info,
+ cur_offset);
/*
* Now that we inserted the prealloc extent we can finally
* decrement the number of reservations in the block group.
@@ -9866,6 +9894,7 @@ static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
btrfs_dec_block_group_reservations(fs_info, ins.objectid);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
+ fscrypt_put_extent_info(fscrypt_info);
btrfs_free_reserved_extent(fs_info, ins.objectid,
ins.offset, 0);
break;
@@ -9873,6 +9902,7 @@ static int __btrfs_prealloc_file_range(struct inode *inode, int mode,

em = alloc_extent_map();
if (!em) {
+ fscrypt_put_extent_info(fscrypt_info);
btrfs_drop_extent_map_range(BTRFS_I(inode), cur_offset,
cur_offset + ins.offset - 1, false);
btrfs_set_inode_full_sync(BTRFS_I(inode));
@@ -9888,6 +9918,8 @@ static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
em->ram_bytes = ins.offset;
set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
em->generation = trans->transid;
+ em->fscrypt_info = fscrypt_info;
+ em->encryption_type = encryption_type;

ret = btrfs_replace_extent_map_range(BTRFS_I(inode), em, true);
free_extent_map(em);
--
2.41.0