Btrfs: use kmalloc instead of stack for backref_ctx (35075bb0) · Commits · 戴 / test

fs/btrfs/send.c

+18 −11

Original line number	Diff line number	Diff line
		@@ -1149,7 +1149,7 @@ static int find_extent_clone(struct send_ctx *sctx,
		u64 extent_item_pos;
		struct btrfs_file_extent_item *fi;
		struct extent_buffer *eb = path->nodes[0];
		struct backref_ctx backref_ctx;
		struct backref_ctx *backref_ctx = NULL;
		struct clone_root *cur_clone_root;
		struct btrfs_key found_key;
		struct btrfs_path *tmp_path;
		@@ -1159,6 +1159,12 @@ static int find_extent_clone(struct send_ctx *sctx,
		if (!tmp_path)
		return -ENOMEM;

		backref_ctx = kmalloc(sizeof(*backref_ctx), GFP_NOFS);
		if (!backref_ctx) {
		ret = -ENOMEM;
		goto out;
		}

		if (data_offset >= ino_size) {
		/*
		* There may be extents that lie behind the file's size.
		@@ -1206,12 +1212,12 @@ static int find_extent_clone(struct send_ctx *sctx,
		cur_clone_root->found_refs = 0;
		}

		backref_ctx.sctx = sctx;
		backref_ctx.found = 0;
		backref_ctx.cur_objectid = ino;
		backref_ctx.cur_offset = data_offset;
		backref_ctx.found_itself = 0;
		backref_ctx.extent_len = num_bytes;
		backref_ctx->sctx = sctx;
		backref_ctx->found = 0;
		backref_ctx->cur_objectid = ino;
		backref_ctx->cur_offset = data_offset;
		backref_ctx->found_itself = 0;
		backref_ctx->extent_len = num_bytes;

		/*
		* The last extent of a file may be too large due to page alignment.
		@@ -1219,7 +1225,7 @@ static int find_extent_clone(struct send_ctx *sctx,
		* __iterate_backrefs work.
		*/
		if (data_offset + num_bytes >= ino_size)
		backref_ctx.extent_len = ino_size - data_offset;
		backref_ctx->extent_len = ino_size - data_offset;

		/*
		* Now collect all backrefs.
		@@ -1227,11 +1233,11 @@ static int find_extent_clone(struct send_ctx *sctx,
		extent_item_pos = logical - found_key.objectid;
		ret = iterate_extent_inodes(sctx->send_root->fs_info,
		found_key.objectid, extent_item_pos, 1,
		__iterate_backrefs, &backref_ctx);
		__iterate_backrefs, backref_ctx);
		if (ret < 0)
		goto out;

		if (!backref_ctx.found_itself) {
		if (!backref_ctx->found_itself) {
		/* found a bug in backref code? */
		ret = -EIO;
		printk(KERN_ERR "btrfs: ERROR did not find backref in "
		@@ -1246,7 +1252,7 @@ verbose_printk(KERN_DEBUG "btrfs: find_extent_clone: data_offset=%llu, "
		"num_bytes=%llu, logical=%llu\n",
		data_offset, ino, num_bytes, logical);

		if (!backref_ctx.found)
		if (!backref_ctx->found)
		verbose_printk("btrfs: no clones found\n");

		cur_clone_root = NULL;
		@@ -1271,6 +1277,7 @@ verbose_printk(KERN_DEBUG "btrfs: find_extent_clone: data_offset=%llu, "

		out:
		btrfs_free_path(tmp_path);
		kfree(backref_ctx);
		return ret;
		}

Admin message