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Diffstat (limited to 'fs/btrfs/inode-item.c')
-rw-r--r--fs/btrfs/inode-item.c242
1 files changed, 234 insertions, 8 deletions
diff --git a/fs/btrfs/inode-item.c b/fs/btrfs/inode-item.c
index 72ce3c173d6..2be38df703c 100644
--- a/fs/btrfs/inode-item.c
+++ b/fs/btrfs/inode-item.c
@@ -18,7 +18,9 @@
#include "ctree.h"
#include "disk-io.h"
+#include "hash.h"
#include "transaction.h"
+#include "print-tree.h"
static int find_name_in_backref(struct btrfs_path *path, const char *name,
int name_len, struct btrfs_inode_ref **ref_ret)
@@ -49,10 +51,149 @@ static int find_name_in_backref(struct btrfs_path *path, const char *name,
return 0;
}
+int btrfs_find_name_in_ext_backref(struct btrfs_path *path, u64 ref_objectid,
+ const char *name, int name_len,
+ struct btrfs_inode_extref **extref_ret)
+{
+ struct extent_buffer *leaf;
+ struct btrfs_inode_extref *extref;
+ unsigned long ptr;
+ unsigned long name_ptr;
+ u32 item_size;
+ u32 cur_offset = 0;
+ int ref_name_len;
+
+ leaf = path->nodes[0];
+ item_size = btrfs_item_size_nr(leaf, path->slots[0]);
+ ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
+
+ /*
+ * Search all extended backrefs in this item. We're only
+ * looking through any collisions so most of the time this is
+ * just going to compare against one buffer. If all is well,
+ * we'll return success and the inode ref object.
+ */
+ while (cur_offset < item_size) {
+ extref = (struct btrfs_inode_extref *) (ptr + cur_offset);
+ name_ptr = (unsigned long)(&extref->name);
+ ref_name_len = btrfs_inode_extref_name_len(leaf, extref);
+
+ if (ref_name_len == name_len &&
+ btrfs_inode_extref_parent(leaf, extref) == ref_objectid &&
+ (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)) {
+ if (extref_ret)
+ *extref_ret = extref;
+ return 1;
+ }
+
+ cur_offset += ref_name_len + sizeof(*extref);
+ }
+ return 0;
+}
+
+/* Returns NULL if no extref found */
+struct btrfs_inode_extref *
+btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ const char *name, int name_len,
+ u64 inode_objectid, u64 ref_objectid, int ins_len,
+ int cow)
+{
+ int ret;
+ struct btrfs_key key;
+ struct btrfs_inode_extref *extref;
+
+ key.objectid = inode_objectid;
+ key.type = BTRFS_INODE_EXTREF_KEY;
+ key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
+
+ ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
+ if (ret < 0)
+ return ERR_PTR(ret);
+ if (ret > 0)
+ return NULL;
+ if (!btrfs_find_name_in_ext_backref(path, ref_objectid, name, name_len, &extref))
+ return NULL;
+ return extref;
+}
+
+static int btrfs_del_inode_extref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ const char *name, int name_len,
+ u64 inode_objectid, u64 ref_objectid,
+ u64 *index)
+{
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ struct btrfs_inode_extref *extref;
+ struct extent_buffer *leaf;
+ int ret;
+ int del_len = name_len + sizeof(*extref);
+ unsigned long ptr;
+ unsigned long item_start;
+ u32 item_size;
+
+ key.objectid = inode_objectid;
+ btrfs_set_key_type(&key, BTRFS_INODE_EXTREF_KEY);
+ key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ path->leave_spinning = 1;
+
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret > 0)
+ ret = -ENOENT;
+ if (ret < 0)
+ goto out;
+
+ /*
+ * Sanity check - did we find the right item for this name?
+ * This should always succeed so error here will make the FS
+ * readonly.
+ */
+ if (!btrfs_find_name_in_ext_backref(path, ref_objectid,
+ name, name_len, &extref)) {
+ btrfs_std_error(root->fs_info, -ENOENT);
+ ret = -EROFS;
+ goto out;
+ }
+
+ leaf = path->nodes[0];
+ item_size = btrfs_item_size_nr(leaf, path->slots[0]);
+ if (index)
+ *index = btrfs_inode_extref_index(leaf, extref);
+
+ if (del_len == item_size) {
+ /*
+ * Common case only one ref in the item, remove the
+ * whole item.
+ */
+ ret = btrfs_del_item(trans, root, path);
+ goto out;
+ }
+
+ ptr = (unsigned long)extref;
+ item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
+
+ memmove_extent_buffer(leaf, ptr, ptr + del_len,
+ item_size - (ptr + del_len - item_start));
+
+ btrfs_truncate_item(root, path, item_size - del_len, 1);
+
+out:
+ btrfs_free_path(path);
+
+ return ret;
+}
+
int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
- struct btrfs_root *root,
- const char *name, int name_len,
- u64 inode_objectid, u64 ref_objectid, u64 *index)
+ struct btrfs_root *root,
+ const char *name, int name_len,
+ u64 inode_objectid, u64 ref_objectid, u64 *index)
{
struct btrfs_path *path;
struct btrfs_key key;
@@ -63,6 +204,7 @@ int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
u32 item_size;
u32 sub_item_len;
int ret;
+ int search_ext_refs = 0;
int del_len = name_len + sizeof(*ref);
key.objectid = inode_objectid;
@@ -78,12 +220,14 @@ int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret > 0) {
ret = -ENOENT;
+ search_ext_refs = 1;
goto out;
} else if (ret < 0) {
goto out;
}
if (!find_name_in_backref(path, name, name_len, &ref)) {
ret = -ENOENT;
+ search_ext_refs = 1;
goto out;
}
leaf = path->nodes[0];
@@ -101,14 +245,84 @@ int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
item_size - (ptr + sub_item_len - item_start));
- ret = btrfs_truncate_item(trans, root, path,
- item_size - sub_item_len, 1);
- BUG_ON(ret);
+ btrfs_truncate_item(root, path, item_size - sub_item_len, 1);
+out:
+ btrfs_free_path(path);
+
+ if (search_ext_refs) {
+ /*
+ * No refs were found, or we could not find the
+ * name in our ref array. Find and remove the extended
+ * inode ref then.
+ */
+ return btrfs_del_inode_extref(trans, root, name, name_len,
+ inode_objectid, ref_objectid, index);
+ }
+
+ return ret;
+}
+
+/*
+ * btrfs_insert_inode_extref() - Inserts an extended inode ref into a tree.
+ *
+ * The caller must have checked against BTRFS_LINK_MAX already.
+ */
+static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ const char *name, int name_len,
+ u64 inode_objectid, u64 ref_objectid, u64 index)
+{
+ struct btrfs_inode_extref *extref;
+ int ret;
+ int ins_len = name_len + sizeof(*extref);
+ unsigned long ptr;
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ struct extent_buffer *leaf;
+ struct btrfs_item *item;
+
+ key.objectid = inode_objectid;
+ key.type = BTRFS_INODE_EXTREF_KEY;
+ key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ path->leave_spinning = 1;
+ ret = btrfs_insert_empty_item(trans, root, path, &key,
+ ins_len);
+ if (ret == -EEXIST) {
+ if (btrfs_find_name_in_ext_backref(path, ref_objectid,
+ name, name_len, NULL))
+ goto out;
+
+ btrfs_extend_item(root, path, ins_len);
+ ret = 0;
+ }
+ if (ret < 0)
+ goto out;
+
+ leaf = path->nodes[0];
+ item = btrfs_item_nr(path->slots[0]);
+ ptr = (unsigned long)btrfs_item_ptr(leaf, path->slots[0], char);
+ ptr += btrfs_item_size(leaf, item) - ins_len;
+ extref = (struct btrfs_inode_extref *)ptr;
+
+ btrfs_set_inode_extref_name_len(path->nodes[0], extref, name_len);
+ btrfs_set_inode_extref_index(path->nodes[0], extref, index);
+ btrfs_set_inode_extref_parent(path->nodes[0], extref, ref_objectid);
+
+ ptr = (unsigned long)&extref->name;
+ write_extent_buffer(path->nodes[0], name, ptr, name_len);
+ btrfs_mark_buffer_dirty(path->nodes[0]);
+
out:
btrfs_free_path(path);
return ret;
}
+/* Will return 0, -ENOMEM, -EMLINK, or -EEXIST or anything from the CoW path */
int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
const char *name, int name_len,
@@ -139,8 +353,7 @@ int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
goto out;
old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
- ret = btrfs_extend_item(trans, root, path, ins_len);
- BUG_ON(ret);
+ btrfs_extend_item(root, path, ins_len);
ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_ref);
ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size);
@@ -164,6 +377,19 @@ int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
out:
btrfs_free_path(path);
+
+ if (ret == -EMLINK) {
+ struct btrfs_super_block *disk_super = root->fs_info->super_copy;
+ /* We ran out of space in the ref array. Need to
+ * add an extended ref. */
+ if (btrfs_super_incompat_flags(disk_super)
+ & BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
+ ret = btrfs_insert_inode_extref(trans, root, name,
+ name_len,
+ inode_objectid,
+ ref_objectid, index);
+ }
+
return ret;
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-09 06:56:06 +0000