Commit c778df14 authored by David Sterba's avatar David Sterba
Browse files

btrfs: compression: inline alloc_workspace 



Replace indirect calls to alloc_workspace by switch and calls to the
specific callbacks. This is mainly to get rid of the indirection due to
spectre vulnerability mitigations.

Reviewed-by: default avatarJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: default avatarNikolay Borisov <nborisov@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 5907a9bb

fs/btrfs/compression.c

+18 −3
Original line number Diff line number Diff line
@@ -912,7 +912,6 @@ fail: 


const struct btrfs_compress_op btrfs_heuristic_compress = {

	.workspace_manager = &heuristic_wsm,

	.alloc_workspace = alloc_heuristic_ws,

	.free_workspace = free_heuristic_ws,

};
@@ -924,6 +923,22 @@ static const struct btrfs_compress_op * const btrfs_compress_op[] = { 
	&btrfs_zstd_compress,

};



static struct list_head *alloc_workspace(int type, unsigned int level)

{

	switch (type) {

	case BTRFS_COMPRESS_NONE: return alloc_heuristic_ws(level);

	case BTRFS_COMPRESS_ZLIB: return zlib_alloc_workspace(level);

	case BTRFS_COMPRESS_LZO:  return lzo_alloc_workspace(level);

	case BTRFS_COMPRESS_ZSTD: return zstd_alloc_workspace(level);

	default:

		/*

		 * This can't happen, the type is validated several times

		 * before we get here.

		 */

		BUG();

	}

}



static void btrfs_init_workspace_manager(int type)

{

	const struct btrfs_compress_op *ops = btrfs_compress_op[type];
@@ -941,7 +956,7 @@ static void btrfs_init_workspace_manager(int type) 
	 * Preallocate one workspace for each compression type so we can

	 * guarantee forward progress in the worst case

	 */

	workspace = wsm->ops->alloc_workspace(0);

	workspace = alloc_workspace(type, 0);

	if (IS_ERR(workspace)) {

		pr_warn(

	"BTRFS: cannot preallocate compression workspace, will try later\n");
@@ -1020,7 +1035,7 @@ again: 
	 * context of btrfs_compress_bio/btrfs_compress_pages

	 */

	nofs_flag = memalloc_nofs_save();

	workspace = wsm->ops->alloc_workspace(level);

	workspace = alloc_workspace(type, level);

	memalloc_nofs_restore(nofs_flag);



	if (IS_ERR(workspace)) {

fs/btrfs/compression.h

+0 −2
Original line number Diff line number Diff line
@@ -124,8 +124,6 @@ struct list_head *btrfs_get_workspace(int type, unsigned int level); 
void btrfs_put_workspace(struct workspace_manager *wsm, struct list_head *ws);



struct btrfs_compress_op {

	struct list_head *(*alloc_workspace)(unsigned int level);



	void (*free_workspace)(struct list_head *workspace);



	struct workspace_manager *workspace_manager;

fs/btrfs/lzo.c

+0 −1
Original line number Diff line number Diff line
@@ -484,7 +484,6 @@ out: 


const struct btrfs_compress_op btrfs_lzo_compress = {

	.workspace_manager	= &wsm,

	.alloc_workspace	= lzo_alloc_workspace,

	.free_workspace		= lzo_free_workspace,

	.max_level		= 1,

	.default_level		= 1,

fs/btrfs/zlib.c

+0 −1
Original line number Diff line number Diff line
@@ -400,7 +400,6 @@ next: 


const struct btrfs_compress_op btrfs_zlib_compress = {

	.workspace_manager	= &wsm,

	.alloc_workspace	= zlib_alloc_workspace,

	.free_workspace		= zlib_free_workspace,

	.max_level		= 9,

	.default_level		= BTRFS_ZLIB_DEFAULT_LEVEL,

fs/btrfs/zstd.c

+0 −1
Original line number Diff line number Diff line
@@ -708,7 +708,6 @@ finish: 
const struct btrfs_compress_op btrfs_zstd_compress = {

	/* ZSTD uses own workspace manager */

	.workspace_manager = NULL,

	.alloc_workspace = zstd_alloc_workspace,

	.free_workspace = zstd_free_workspace,

	.max_level	= ZSTD_BTRFS_MAX_LEVEL,

	.default_level	= ZSTD_BTRFS_DEFAULT_LEVEL,

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