diff options
| -rw-r--r-- | fs/btrfs/backref.c | 109 | ||||
| -rw-r--r-- | fs/btrfs/backref.h | 3 | ||||
| -rw-r--r-- | fs/btrfs/extent_io.c | 40 |
3 files changed, 116 insertions, 36 deletions
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c index 4de97926939e..6829dc5aa657 100644 --- a/fs/btrfs/backref.c +++ b/fs/btrfs/backref.c @@ -25,6 +25,9 @@ #include "delayed-ref.h" #include "locking.h" +/* Just an arbitrary number so we can be sure this happened */ +#define BACKREF_FOUND_SHARED 6 + struct extent_inode_elem { u64 inum; u64 offset; @@ -377,7 +380,8 @@ out: static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info, struct btrfs_path *path, u64 time_seq, struct list_head *head, - const u64 *extent_item_pos, u64 total_refs) + const u64 *extent_item_pos, u64 total_refs, + u64 root_objectid) { int err; int ret = 0; @@ -402,6 +406,10 @@ static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info, continue; if (ref->count == 0) continue; + if (root_objectid && ref->root_id != root_objectid) { + ret = BACKREF_FOUND_SHARED; + goto out; + } err = __resolve_indirect_ref(fs_info, path, time_seq, ref, parents, extent_item_pos, total_refs); @@ -561,7 +569,8 @@ static void __merge_refs(struct list_head *head, int mode) * smaller or equal that seq to the list */ static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq, - struct list_head *prefs, u64 *total_refs) + struct list_head *prefs, u64 *total_refs, + u64 inum) { struct btrfs_delayed_extent_op *extent_op = head->extent_op; struct rb_node *n = &head->node.rb_node; @@ -625,6 +634,16 @@ static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq, key.objectid = ref->objectid; key.type = BTRFS_EXTENT_DATA_KEY; key.offset = ref->offset; + + /* + * Found a inum that doesn't match our known inum, we + * know it's shared. + */ + if (inum && ref->objectid != inum) { + ret = BACKREF_FOUND_SHARED; + break; + } + ret = __add_prelim_ref(prefs, ref->root, &key, 0, 0, node->bytenr, node->ref_mod * sgn, GFP_ATOMIC); @@ -659,7 +678,7 @@ static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq, static int __add_inline_refs(struct btrfs_fs_info *fs_info, struct btrfs_path *path, u64 bytenr, int *info_level, struct list_head *prefs, - u64 *total_refs) + u64 *total_refs, u64 inum) { int ret = 0; int slot; @@ -744,6 +763,12 @@ static int __add_inline_refs(struct btrfs_fs_info *fs_info, dref); key.type = BTRFS_EXTENT_DATA_KEY; key.offset = btrfs_extent_data_ref_offset(leaf, dref); + + if (inum && key.objectid != inum) { + ret = BACKREF_FOUND_SHARED; + break; + } + root = btrfs_extent_data_ref_root(leaf, dref); ret = __add_prelim_ref(prefs, root, &key, 0, 0, bytenr, count, GFP_NOFS); @@ -765,7 +790,7 @@ static int __add_inline_refs(struct btrfs_fs_info *fs_info, */ static int __add_keyed_refs(struct btrfs_fs_info *fs_info, struct btrfs_path *path, u64 bytenr, - int info_level, struct list_head *prefs) + int info_level, struct list_head *prefs, u64 inum) { struct btrfs_root *extent_root = fs_info->extent_root; int ret; @@ -827,6 +852,12 @@ static int __add_keyed_refs(struct btrfs_fs_info *fs_info, dref); key.type = BTRFS_EXTENT_DATA_KEY; key.offset = btrfs_extent_data_ref_offset(leaf, dref); + + if (inum && key.objectid != inum) { + ret = BACKREF_FOUND_SHARED; + break; + } + root = btrfs_extent_data_ref_root(leaf, dref); ret = __add_prelim_ref(prefs, root, &key, 0, 0, bytenr, count, GFP_NOFS); @@ -854,7 +885,8 @@ static int __add_keyed_refs(struct btrfs_fs_info *fs_info, static int find_parent_nodes(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info, u64 bytenr, u64 time_seq, struct ulist *refs, - struct ulist *roots, const u64 *extent_item_pos) + struct ulist *roots, const u64 *extent_item_pos, + u64 root_objectid, u64 inum) { struct btrfs_key key; struct btrfs_path *path; @@ -929,7 +961,8 @@ again: } spin_unlock(&delayed_refs->lock); ret = __add_delayed_refs(head, time_seq, - &prefs_delayed, &total_refs); + &prefs_delayed, &total_refs, + inum); mutex_unlock(&head->mutex); if (ret) goto out; @@ -951,11 +984,11 @@ again: key.type == BTRFS_METADATA_ITEM_KEY)) { ret = __add_inline_refs(fs_info, path, bytenr, &info_level, &prefs, - &total_refs); + &total_refs, inum); if (ret) goto out; ret = __add_keyed_refs(fs_info, path, bytenr, - info_level, &prefs); + info_level, &prefs, inum); if (ret) goto out; } @@ -971,7 +1004,8 @@ again: __merge_refs(&prefs, 1); ret = __resolve_indirect_refs(fs_info, path, time_seq, &prefs, - extent_item_pos, total_refs); + extent_item_pos, total_refs, + root_objectid); if (ret) goto out; @@ -981,6 +1015,11 @@ again: ref = list_first_entry(&prefs, struct __prelim_ref, list); WARN_ON(ref->count < 0); if (roots && ref->count && ref->root_id && ref->parent == 0) { + if (root_objectid && ref->root_id != root_objectid) { + ret = BACKREF_FOUND_SHARED; + goto out; + } + /* no parent == root of tree */ ret = ulist_add(roots, ref->root_id, 0, GFP_NOFS); if (ret < 0) @@ -1087,7 +1126,7 @@ static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans, return -ENOMEM; ret = find_parent_nodes(trans, fs_info, bytenr, - time_seq, *leafs, NULL, extent_item_pos); + time_seq, *leafs, NULL, extent_item_pos, 0, 0); if (ret < 0 && ret != -ENOENT) { free_leaf_list(*leafs); return ret; @@ -1130,7 +1169,7 @@ static int __btrfs_find_all_roots(struct btrfs_trans_handle *trans, ULIST_ITER_INIT(&uiter); while (1) { ret = find_parent_nodes(trans, fs_info, bytenr, - time_seq, tmp, *roots, NULL); + time_seq, tmp, *roots, NULL, 0, 0); if (ret < 0 && ret != -ENOENT) { ulist_free(tmp); ulist_free(*roots); @@ -1161,6 +1200,54 @@ int btrfs_find_all_roots(struct btrfs_trans_handle *trans, return ret; } +int btrfs_check_shared(struct btrfs_trans_handle *trans, + struct btrfs_fs_info *fs_info, u64 root_objectid, + u64 inum, u64 bytenr) +{ + struct ulist *tmp = NULL; + struct ulist *roots = NULL; + struct ulist_iterator uiter; + struct ulist_node *node; + struct seq_list elem = {}; + int ret = 0; + + tmp = ulist_alloc(GFP_NOFS); + roots = ulist_alloc(GFP_NOFS); + if (!tmp || !roots) { + ulist_free(tmp); + ulist_free(roots); + return -ENOMEM; + } + + if (trans) + btrfs_get_tree_mod_seq(fs_info, &elem); + else + down_read(&fs_info->commit_root_sem); + ULIST_ITER_INIT(&uiter); + while (1) { + ret = find_parent_nodes(trans, fs_info, bytenr, elem.seq, tmp, + roots, NULL, root_objectid, inum); + if (ret == BACKREF_FOUND_SHARED) { + ret = 1; + break; + } + if (ret < 0 && ret != -ENOENT) + break; + node = ulist_next(tmp, &uiter); + if (!node) + break; + bytenr = node->val; + cond_resched(); + } + if (trans) + btrfs_put_tree_mod_seq(fs_info, &elem); + else + up_read(&fs_info->commit_root_sem); + ulist_free(tmp); + ulist_free(roots); + return ret; +} + /* * this makes the path point to (inum INODE_ITEM ioff) */ diff --git a/fs/btrfs/backref.h b/fs/btrfs/backref.h index 86fc20fec282..2a1ac6bfc724 100644 --- a/fs/btrfs/backref.h +++ b/fs/btrfs/backref.h @@ -71,6 +71,9 @@ int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid, u64 start_off, struct btrfs_path *path, struct btrfs_inode_extref **ret_extref, u64 *found_off); +int btrfs_check_shared(struct btrfs_trans_handle *trans, + struct btrfs_fs_info *fs_info, u64 root_objectid, + u64 inum, u64 bytenr); int __init btrfs_prelim_ref_init(void); void btrfs_prelim_ref_exit(void); diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index d70feb545066..d5e71d4646dd 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -4169,19 +4169,6 @@ static struct extent_map *get_extent_skip_holes(struct inode *inode, return NULL; } -static noinline int count_ext_ref(u64 inum, u64 offset, u64 root_id, void *ctx) -{ - unsigned long cnt = *((unsigned long *)ctx); - - cnt++; - *((unsigned long *)ctx) = cnt; - - /* Now we're sure that the extent is shared. */ - if (cnt > 1) - return 1; - return 0; -} - int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, __u64 start, __u64 len, get_extent_t *get_extent) { @@ -4198,6 +4185,7 @@ int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, struct extent_map *em = NULL; struct extent_state *cached_state = NULL; struct btrfs_path *path; + struct btrfs_root *root = BTRFS_I(inode)->root; int end = 0; u64 em_start = 0; u64 em_len = 0; @@ -4218,8 +4206,8 @@ int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, * lookup the last file extent. We're not using i_size here * because there might be preallocation past i_size */ - ret = btrfs_lookup_file_extent(NULL, BTRFS_I(inode)->root, - path, btrfs_ino(inode), -1, 0); + ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode), -1, + 0); if (ret < 0) { btrfs_free_path(path); return ret; @@ -4312,25 +4300,27 @@ int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, } else if (em->block_start == EXTENT_MAP_DELALLOC) { flags |= (FIEMAP_EXTENT_DELALLOC | FIEMAP_EXTENT_UNKNOWN); - } else { - unsigned long ref_cnt = 0; + } else if (fieinfo->fi_extents_max) { + u64 bytenr = em->block_start - + (em->start - em->orig_start); disko = em->block_start + offset_in_extent; /* * As btrfs supports shared space, this information * can be exported to userspace tools via - * flag FIEMAP_EXTENT_SHARED. + * flag FIEMAP_EXTENT_SHARED. If fi_extents_max == 0 + * then we're just getting a count and we can skip the + * lookup stuff. */ - ret = iterate_inodes_from_logical( - em->block_start, - BTRFS_I(inode)->root->fs_info, - path, count_ext_ref, &ref_cnt); - if (ret < 0 && ret != -ENOENT) + ret = btrfs_check_shared(NULL, root->fs_info, + root->objectid, + btrfs_ino(inode), bytenr); + if (ret < 0) goto out_free; - - if (ref_cnt > 1) + if (ret) flags |= FIEMAP_EXTENT_SHARED; + ret = 0; } if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) flags |= FIEMAP_EXTENT_ENCODED; |