Commit 1e002351 authored by David Sterba's avatar David Sterba
Browse files

btrfs: compression: inline free_workspace 



Replace indirect calls to free_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 a3bbd2a9

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,

	.free_workspace = free_heuristic_ws,

};



static const struct btrfs_compress_op * const btrfs_compress_op[] = {
@@ -939,6 +938,22 @@ static struct list_head *alloc_workspace(int type, unsigned int level) 
	}

}



static void free_workspace(int type, struct list_head *ws)

{

	switch (type) {

	case BTRFS_COMPRESS_NONE: return free_heuristic_ws(ws);

	case BTRFS_COMPRESS_ZLIB: return zlib_free_workspace(ws);

	case BTRFS_COMPRESS_LZO:  return lzo_free_workspace(ws);

	case BTRFS_COMPRESS_ZSTD: return zstd_free_workspace(ws);

	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];
@@ -976,7 +991,7 @@ static void btrfs_cleanup_workspace_manager(int type) 
	while (!list_empty(&wsman->idle_ws)) {

		ws = wsman->idle_ws.next;

		list_del(ws);

		wsman->ops->free_workspace(ws);

		free_workspace(type, ws);

		atomic_dec(&wsman->total_ws);

	}

}
@@ -1111,7 +1126,7 @@ void btrfs_put_workspace(int type, struct list_head *ws) 
	}

	spin_unlock(ws_lock);



	wsm->ops->free_workspace(ws);

	free_workspace(type, ws);

	atomic_dec(total_ws);

wake:

	cond_wake_up(ws_wait);

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(int type, struct list_head *ws);



struct btrfs_compress_op {

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



	struct workspace_manager *workspace_manager;

	/* Maximum level supported by the compression algorithm */

	unsigned int max_level;

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,

	.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,

	.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,

	.free_workspace = zstd_free_workspace,

	.max_level	= ZSTD_BTRFS_MAX_LEVEL,

	.default_level	= ZSTD_BTRFS_DEFAULT_LEVEL,

};

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