Commit 084158b5 authored by Liu Bo's avatar Liu Bo Committed by Stefan Bader

Btrfs: memset to avoid stale content in btree leaf

BugLink: https://bugs.launchpad.net/bugs/1818237

commit 851cd173 upstream.

This is an additional patch to
"Btrfs: memset to avoid stale content in btree node block".

This uses memset to initialize the unused space in a leaf to avoid
potential stale content, which may be incurred by pushing items
between sibling leaves.
Signed-off-by: default avatarLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarBen Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarJuerg Haefliger <juergh@canonical.com>
Signed-off-by: default avatarKhalid Elmously <khalid.elmously@canonical.com>
parent ac2d2805
...@@ -1726,20 +1726,6 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans, ...@@ -1726,20 +1726,6 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
return err; return err;
} }
/*
* The leaf data grows from end-to-front in the node.
* this returns the address of the start of the last item,
* which is the stop of the leaf data stack
*/
static inline unsigned int leaf_data_end(struct btrfs_root *root,
struct extent_buffer *leaf)
{
u32 nr = btrfs_header_nritems(leaf);
if (nr == 0)
return BTRFS_LEAF_DATA_SIZE(root);
return btrfs_item_offset_nr(leaf, nr - 1);
}
/* /*
* search for key in the extent_buffer. The items start at offset p, * search for key in the extent_buffer. The items start at offset p,
......
...@@ -3158,6 +3158,21 @@ static inline unsigned long btrfs_leaf_data(struct extent_buffer *l) ...@@ -3158,6 +3158,21 @@ static inline unsigned long btrfs_leaf_data(struct extent_buffer *l)
return offsetof(struct btrfs_leaf, items); return offsetof(struct btrfs_leaf, items);
} }
/*
* The leaf data grows from end-to-front in the node.
* this returns the address of the start of the last item,
* which is the stop of the leaf data stack
*/
static inline unsigned int leaf_data_end(struct btrfs_root *root,
struct extent_buffer *leaf)
{
u32 nr = btrfs_header_nritems(leaf);
if (nr == 0)
return BTRFS_LEAF_DATA_SIZE(root);
return btrfs_item_offset_nr(leaf, nr - 1);
}
/* struct btrfs_file_extent_item */ /* struct btrfs_file_extent_item */
BTRFS_SETGET_FUNCS(file_extent_type, struct btrfs_file_extent_item, type, 8); BTRFS_SETGET_FUNCS(file_extent_type, struct btrfs_file_extent_item, type, 8);
BTRFS_SETGET_STACK_FUNCS(stack_file_extent_disk_bytenr, BTRFS_SETGET_STACK_FUNCS(stack_file_extent_disk_bytenr,
......
...@@ -3847,8 +3847,10 @@ static noinline_for_stack int write_one_eb(struct extent_buffer *eb, ...@@ -3847,8 +3847,10 @@ static noinline_for_stack int write_one_eb(struct extent_buffer *eb,
struct block_device *bdev = fs_info->fs_devices->latest_bdev; struct block_device *bdev = fs_info->fs_devices->latest_bdev;
struct extent_io_tree *tree = &BTRFS_I(fs_info->btree_inode)->io_tree; struct extent_io_tree *tree = &BTRFS_I(fs_info->btree_inode)->io_tree;
u64 offset = eb->start; u64 offset = eb->start;
u32 nritems;
unsigned long i, num_pages; unsigned long i, num_pages;
unsigned long bio_flags = 0; unsigned long bio_flags = 0;
unsigned long start, end;
int rw = (epd->sync_io ? WRITE_SYNC : WRITE) | REQ_META; int rw = (epd->sync_io ? WRITE_SYNC : WRITE) | REQ_META;
int ret = 0; int ret = 0;
...@@ -3858,15 +3860,21 @@ static noinline_for_stack int write_one_eb(struct extent_buffer *eb, ...@@ -3858,15 +3860,21 @@ static noinline_for_stack int write_one_eb(struct extent_buffer *eb,
if (btrfs_header_owner(eb) == BTRFS_TREE_LOG_OBJECTID) if (btrfs_header_owner(eb) == BTRFS_TREE_LOG_OBJECTID)
bio_flags = EXTENT_BIO_TREE_LOG; bio_flags = EXTENT_BIO_TREE_LOG;
/* set btree node beyond nritems with 0 to avoid stale content */ /* set btree blocks beyond nritems with 0 to avoid stale content. */
if (btrfs_header_level(eb) > 0) {
u32 nritems;
unsigned long end;
nritems = btrfs_header_nritems(eb); nritems = btrfs_header_nritems(eb);
if (btrfs_header_level(eb) > 0) {
end = btrfs_node_key_ptr_offset(nritems); end = btrfs_node_key_ptr_offset(nritems);
memset_extent_buffer(eb, 0, end, eb->len - end); memset_extent_buffer(eb, 0, end, eb->len - end);
} else {
/*
* leaf:
* header 0 1 2 .. N ... data_N .. data_2 data_1 data_0
*/
start = btrfs_item_nr_offset(nritems);
end = btrfs_leaf_data(eb) +
leaf_data_end(fs_info->tree_root, eb);
memset_extent_buffer(eb, 0, start, end - start);
} }
for (i = 0; i < num_pages; i++) { for (i = 0; i < num_pages; i++) {
......
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