From: Sweet Tea Dorminy <sweettea-ker...@dorminy.me>

Each extent_map will end up with a pointer to its associated
fscrypt_info if any, which should have the same lifetime as the
extent_map. We are also going to need to track the encryption_type for
the file extent items.  Add the fscrypt_info to the extent_map, and the
subsequent code for transferring it in the split and merge cases, as
well as the code necessary to free them.  A future patch will add the
code to load them as appropriate.

Signed-off-by: Sweet Tea Dorminy <sweettea-ker...@dorminy.me>
Signed-off-by: Josef Bacik <jo...@toxicpanda.com>
---
 fs/btrfs/extent_map.c | 32 +++++++++++++++++++++++++++++---
 fs/btrfs/extent_map.h |  2 ++
 fs/btrfs/file-item.c  |  1 +
 fs/btrfs/inode.c      |  1 +
 4 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index af5ff6b10865..8c8023388758 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -61,6 +61,7 @@ struct extent_map *alloc_extent_map(void)
 
 static void __free_extent_map(struct extent_map *em)
 {
+       fscrypt_put_extent_info(em->fscrypt_info);
        if (test_bit(EXTENT_FLAG_FS_MAPPING, &em->flags))
                kfree(em->map_lookup);
        kmem_cache_free(extent_map_cache, em);
@@ -103,12 +104,24 @@ void free_extent_map_safe(struct extent_map_tree *tree,
        if (!em)
                return;
 
-       if (refcount_dec_and_test(&em->refs)) {
-               WARN_ON(extent_map_in_tree(em));
-               WARN_ON(!list_empty(&em->list));
+       if (!refcount_dec_and_test(&em->refs))
+               return;
+
+       WARN_ON(extent_map_in_tree(em));
+       WARN_ON(!list_empty(&em->list));
+
+       /*
+        * We could take a lock freeing the fscrypt_info, so add this to the
+        * list of freed_extents to be freed later.
+        */
+       if (em->fscrypt_info) {
                list_add_tail(&em->free_list, &tree->freed_extents);
                set_bit(EXTENT_MAP_TREE_PENDING_FREES, &tree->flags);
+               return;
        }
+
+       /* Nothing scary here, just free the object. */
+       __free_extent_map(em);
 }
 
 /*
@@ -274,6 +287,12 @@ static int mergable_maps(struct extent_map *prev, struct 
extent_map *next)
        if (!list_empty(&prev->list) || !list_empty(&next->list))
                return 0;
 
+       /*
+        * Don't merge adjacent encrypted maps.
+        */
+       if (prev->fscrypt_info || next->fscrypt_info)
+               return 0;
+
        ASSERT(next->block_start != EXTENT_MAP_DELALLOC &&
               prev->block_start != EXTENT_MAP_DELALLOC);
 
@@ -884,6 +903,8 @@ void btrfs_drop_extent_map_range(struct btrfs_inode *inode, 
u64 start, u64 end,
                        split->generation = gen;
                        split->flags = flags;
                        split->compress_type = em->compress_type;
+                       split->fscrypt_info =
+                               fscrypt_get_extent_info(em->fscrypt_info);
                        replace_extent_mapping(em_tree, em, split, modified);
                        free_extent_map(split);
                        split = split2;
@@ -925,6 +946,8 @@ void btrfs_drop_extent_map_range(struct btrfs_inode *inode, 
u64 start, u64 end,
                                split->orig_block_len = 0;
                        }
 
+                       split->fscrypt_info =
+                               fscrypt_get_extent_info(em->fscrypt_info);
                        if (extent_map_in_tree(em)) {
                                replace_extent_mapping(em_tree, em, split,
                                                       modified);
@@ -1087,6 +1110,7 @@ int split_extent_map(struct btrfs_inode *inode, u64 
start, u64 len, u64 pre,
        split_pre->flags = flags;
        split_pre->compress_type = em->compress_type;
        split_pre->generation = em->generation;
+       split_pre->fscrypt_info = fscrypt_get_extent_info(em->fscrypt_info);
 
        replace_extent_mapping(em_tree, em, split_pre, 1);
 
@@ -1106,6 +1130,8 @@ int split_extent_map(struct btrfs_inode *inode, u64 
start, u64 len, u64 pre,
        split_mid->flags = flags;
        split_mid->compress_type = em->compress_type;
        split_mid->generation = em->generation;
+       split_mid->fscrypt_info = fscrypt_get_extent_info(em->fscrypt_info);
+
        add_extent_mapping(em_tree, split_mid, 1);
 
        /* Once for us */
diff --git a/fs/btrfs/extent_map.h b/fs/btrfs/extent_map.h
index 2093720271ea..2d618e61ceb5 100644
--- a/fs/btrfs/extent_map.h
+++ b/fs/btrfs/extent_map.h
@@ -50,10 +50,12 @@ struct extent_map {
         */
        u64 generation;
        unsigned long flags;
+       struct fscrypt_extent_info *fscrypt_info;
        /* Used for chunk mappings, flag EXTENT_FLAG_FS_MAPPING must be set */
        struct map_lookup *map_lookup;
        refcount_t refs;
        unsigned int compress_type;
+       unsigned int encryption_type;
        struct list_head list;
        struct list_head free_list;
 };
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 45cae356e89b..26f35c1baedc 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -1305,6 +1305,7 @@ void btrfs_extent_item_to_extent_map(struct btrfs_inode 
*inode,
                        if (type == BTRFS_FILE_EXTENT_PREALLOC)
                                set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
                }
+               em->encryption_type = btrfs_file_extent_encryption(leaf, fi);
        } else if (type == BTRFS_FILE_EXTENT_INLINE) {
                em->block_start = EXTENT_MAP_INLINE;
                em->start = extent_start;
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 9cb8b82ff8be..19087fd68cfe 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7348,6 +7348,7 @@ static struct extent_map *create_io_em(struct btrfs_inode 
*inode, u64 start,
                set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
                em->compress_type = compress_type;
        }
+       em->encryption_type = BTRFS_ENCRYPTION_NONE;
 
        ret = btrfs_replace_extent_map_range(inode, em, true);
        if (ret) {
-- 
2.41.0

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