[U-Boot] [PATCH] fs: btrfs: Fix cache alignment bugs

[Marek Behún]

Tested-by: Marek Behún <marek.behun at nic.cz>

On Sat, 22 Sep 2018 04:13:35 +0200
Marek Vasut <marex at denx.de> wrote:

> The btrfs implementation passes cache-unaligned buffers into the
> block layer, which triggers cache alignment problems down in the
> block device drivers. Align the buffers to prevent this.
> 
> Signed-off-by: Marek Vasut <marex at denx.de>
> Cc: Marek Behun <marek.behun at nic.cz>
> ---
>  fs/btrfs/ctree.c     | 24 +++++++++++++-----------
>  fs/btrfs/extent-io.c |  3 ++-
>  fs/btrfs/super.c     |  3 ++-
>  3 files changed, 17 insertions(+), 13 deletions(-)
> 
> diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
> index 4da36a9bc7..18b47d92fe 100644
> --- a/fs/btrfs/ctree.c
> +++ b/fs/btrfs/ctree.c
> @@ -7,6 +7,7 @@
>  
>  #include "btrfs.h"
>  #include <malloc.h>
> +#include <memalign.h>
>  
>  int btrfs_comp_keys(struct btrfs_key *a, struct btrfs_key *b)
>  {
> @@ -105,23 +106,24 @@ void btrfs_free_path(struct btrfs_path *p)
>  
>  static int read_tree_node(u64 physical, union btrfs_tree_node **buf)
>  {
> -	struct btrfs_header hdr;
> -	unsigned long size, offset = sizeof(hdr);
> +	ALLOC_CACHE_ALIGN_BUFFER(struct btrfs_header, hdr,
> +				 sizeof(struct btrfs_header));
> +	unsigned long size, offset = sizeof(*hdr);
>  	union btrfs_tree_node *res;
>  	u32 i;
>  
> -	if (!btrfs_devread(physical, sizeof(hdr), &hdr))
> +	if (!btrfs_devread(physical, sizeof(*hdr), hdr))
>  		return -1;
>  
> -	btrfs_header_to_cpu(&hdr);
> +	btrfs_header_to_cpu(hdr);
>  
> -	if (hdr.level)
> +	if (hdr->level)
>  		size = sizeof(struct btrfs_node)
> -		       + hdr.nritems * sizeof(struct btrfs_key_ptr);
> +		       + hdr->nritems * sizeof(struct btrfs_key_ptr);
>  	else
>  		size = btrfs_info.sb.nodesize;
>  
> -	res = malloc(size);
> +	res = malloc_cache_aligned(size);
>  	if (!res) {
>  		debug("%s: malloc failed\n", __func__);
>  		return -1;
> @@ -133,12 +135,12 @@ static int read_tree_node(u64 physical, union
> btrfs_tree_node **buf) return -1;
>  	}
>  
> -	res->header = hdr;
> -	if (hdr.level)
> -		for (i = 0; i < hdr.nritems; ++i)
> +	memcpy(&res->header, hdr, sizeof(*hdr));
> +	if (hdr->level)
> +		for (i = 0; i < hdr->nritems; ++i)
>  			btrfs_key_ptr_to_cpu(&res->node.ptrs[i]);
>  	else
> -		for (i = 0; i < hdr.nritems; ++i)
> +		for (i = 0; i < hdr->nritems; ++i)
>  			btrfs_item_to_cpu(&res->leaf.items[i]);
>  
>  	*buf = res;
> diff --git a/fs/btrfs/extent-io.c b/fs/btrfs/extent-io.c
> index 7263f41644..66d0e1c7d6 100644
> --- a/fs/btrfs/extent-io.c
> +++ b/fs/btrfs/extent-io.c
> @@ -7,6 +7,7 @@
>  
>  #include "btrfs.h"
>  #include <malloc.h>
> +#include <memalign.h>
>  
>  u64 btrfs_read_extent_inline(struct btrfs_path *path,
>  			     struct btrfs_file_extent_item *extent,
> u64 offset, @@ -89,7 +90,7 @@ u64 btrfs_read_extent_reg(struct
> btrfs_path *path, return size;
>  	}
>  
> -	cbuf = malloc(dlen > size ? clen + dlen : clen);
> +	cbuf = malloc_cache_aligned(dlen > size ? clen + dlen :
> clen); if (!cbuf)
>  		return -1ULL;
>  
> diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
> index e680caa56a..7aaf8f9b0d 100644
> --- a/fs/btrfs/super.c
> +++ b/fs/btrfs/super.c
> @@ -6,6 +6,7 @@
>   */
>  
>  #include "btrfs.h"
> +#include <memalign.h>
>  
>  #define BTRFS_SUPER_FLAG_SUPP
> (BTRFS_HEADER_FLAG_WRITTEN	\ | BTRFS_HEADER_FLAG_RELOC	\
> @@ -179,7 +180,7 @@ int btrfs_read_superblock(void)
>  		0x4000000000ull,
>  		0x4000000000000ull
>  	};
> -	char raw_sb[BTRFS_SUPER_INFO_SIZE];
> +	ALLOC_CACHE_ALIGN_BUFFER(char, raw_sb,
> BTRFS_SUPER_INFO_SIZE); struct btrfs_super_block *sb = (struct
> btrfs_super_block *) raw_sb; u64 dev_total_bytes;
>  	int i;