diff options
| -rw-r--r-- | fs/btrfs/ctree.c | 6 | ||||
| -rw-r--r-- | fs/btrfs/ctree.h | 1 | ||||
| -rw-r--r-- | fs/btrfs/send.c | 48 |
3 files changed, 39 insertions, 16 deletions
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 9d89c1648e8e..1bcfcdb23cf4 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -2769,9 +2769,13 @@ again: * the commit roots are read only * so we always do read locks */ + if (p->need_commit_sem) + down_read(&root->fs_info->commit_root_sem); b = root->commit_root; extent_buffer_get(b); level = btrfs_header_level(b); + if (p->need_commit_sem) + up_read(&root->fs_info->commit_root_sem); if (!p->skip_locking) btrfs_tree_read_lock(b); } else { @@ -5436,6 +5440,7 @@ int btrfs_compare_trees(struct btrfs_root *left_root, * the right if possible or go up and right. */ + down_read(&left_root->fs_info->commit_root_sem); left_level = btrfs_header_level(left_root->commit_root); left_root_level = left_level; left_path->nodes[left_level] = left_root->commit_root; @@ -5445,6 +5450,7 @@ int btrfs_compare_trees(struct btrfs_root *left_root, right_root_level = right_level; right_path->nodes[right_level] = right_root->commit_root; extent_buffer_get(right_path->nodes[right_level]); + up_read(&left_root->fs_info->commit_root_sem); if (left_level == 0) btrfs_item_key_to_cpu(left_path->nodes[left_level], diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 4253ab257c9c..d8a669ed5506 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -609,6 +609,7 @@ struct btrfs_path { unsigned int skip_locking:1; unsigned int leave_spinning:1; unsigned int search_commit_root:1; + unsigned int need_commit_sem:1; }; /* diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index 6b5f13659317..ab34a23838ef 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -493,6 +493,7 @@ static struct btrfs_path *alloc_path_for_send(void) return NULL; path->search_commit_root = 1; path->skip_locking = 1; + path->need_commit_sem = 1; return path; } @@ -771,29 +772,22 @@ out: /* * Helper function to retrieve some fields from an inode item. */ -static int get_inode_info(struct btrfs_root *root, - u64 ino, u64 *size, u64 *gen, - u64 *mode, u64 *uid, u64 *gid, - u64 *rdev) +static int __get_inode_info(struct btrfs_root *root, struct btrfs_path *path, + u64 ino, u64 *size, u64 *gen, u64 *mode, u64 *uid, + u64 *gid, u64 *rdev) { int ret; struct btrfs_inode_item *ii; struct btrfs_key key; - struct btrfs_path *path; - - path = alloc_path_for_send(); - if (!path) - return -ENOMEM; key.objectid = ino; key.type = BTRFS_INODE_ITEM_KEY; key.offset = 0; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); - if (ret < 0) - goto out; if (ret) { - ret = -ENOENT; - goto out; + if (ret > 0) + ret = -ENOENT; + return ret; } ii = btrfs_item_ptr(path->nodes[0], path->slots[0], @@ -811,7 +805,22 @@ static int get_inode_info(struct btrfs_root *root, if (rdev) *rdev = btrfs_inode_rdev(path->nodes[0], ii); -out: + return ret; +} + +static int get_inode_info(struct btrfs_root *root, + u64 ino, u64 *size, u64 *gen, + u64 *mode, u64 *uid, u64 *gid, + u64 *rdev) +{ + struct btrfs_path *path; + int ret; + + path = alloc_path_for_send(); + if (!path) + return -ENOMEM; + ret = __get_inode_info(root, path, ino, size, gen, mode, uid, gid, + rdev); btrfs_free_path(path); return ret; } @@ -1085,6 +1094,7 @@ out: struct backref_ctx { struct send_ctx *sctx; + struct btrfs_path *path; /* number of total found references */ u64 found; @@ -1155,8 +1165,9 @@ static int __iterate_backrefs(u64 ino, u64 offset, u64 root, void *ctx_) * There are inodes that have extents that lie behind its i_size. Don't * accept clones from these extents. */ - ret = get_inode_info(found->root, ino, &i_size, NULL, NULL, NULL, NULL, - NULL); + ret = __get_inode_info(found->root, bctx->path, ino, &i_size, NULL, NULL, + NULL, NULL, NULL); + btrfs_release_path(bctx->path); if (ret < 0) return ret; @@ -1235,12 +1246,17 @@ static int find_extent_clone(struct send_ctx *sctx, if (!tmp_path) return -ENOMEM; + /* We only use this path under the commit sem */ + tmp_path->need_commit_sem = 0; + backref_ctx = kmalloc(sizeof(*backref_ctx), GFP_NOFS); if (!backref_ctx) { ret = -ENOMEM; goto out; } + backref_ctx->path = tmp_path; + if (data_offset >= ino_size) { /* * There may be extents that lie behind the file's size. |