On Mon, Aug 20, 2012 at 02:29:17PM -0600, Mark Fasheh wrote:
>
> Testing wise, the basic namespace operations work well (link, unlink, etc).
> The rest has gotten less debugging (and I really don't have a great way of
> testing the code in tree-log.c) Attached to this e-mail are btrfs-progs
> patches which make testing of the changes possible.
Hi Mark,
I hit a few problems testing this, so I have the patch below that I plan
on folding into your commits (to keep bisect from crashing in tree log).
Just let me know if this is a problem, or if you see any bugs in there.
I'm still doing a last round of checks on it, but I wanted to send along
early for comments.
The biggest change in here is to always check the ref_objectid when
returning a backref. Hash collisions mean we may return a ref for a
completely different parent id otherwise. I think I caught all the
places missing that logic, but please double check me.
Other than that I went through and fixed up bugs in
tree-log.c. __add_inode_ref had a bunch of cut and paste errors, and you
carefully preserved a huge use-after-free bug in the original
add_inode_ref.
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 6f2e7e6..50dcd0f 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3231,7 +3231,8 @@ btrfs_lookup_inode_extref(struct btrfs_trans_handle
*trans,
u64 inode_objectid, u64 ref_objectid, int ins_len,
int cow);
-int btrfs_find_name_in_ext_backref(struct btrfs_path *path, const char *name,
+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);
diff --git a/fs/btrfs/inode-item.c b/fs/btrfs/inode-item.c
index ad11b30..48b8fda 100644
--- a/fs/btrfs/inode-item.c
+++ b/fs/btrfs/inode-item.c
@@ -51,8 +51,8 @@ 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, const char *name,
- int name_len,
+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;
@@ -78,8 +78,9 @@ int btrfs_find_name_in_ext_backref(struct btrfs_path *path,
const char *name,
name_ptr = (unsigned long)(&extref->name);
ref_name_len = btrfs_inode_extref_name_len(leaf, extref);
- if (ref_name_len == name_len
- && (memcmp_extent_buffer(leaf, name, name_ptr, name_len) ==
0)) {
+ 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;
@@ -138,7 +139,7 @@ btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
return ERR_PTR(ret);
if (ret > 0)
return NULL;
- if (!btrfs_find_name_in_ext_backref(path, name, name_len, &extref))
+ if (!btrfs_find_name_in_ext_backref(path, ref_objectid, name, name_len,
&extref))
return NULL;
return extref;
}
@@ -218,7 +219,8 @@ int btrfs_del_inode_extref(struct btrfs_trans_handle *trans,
* This should always succeed so error here will make the FS
* readonly.
*/
- if (!btrfs_find_name_in_ext_backref(path, name, name_len, &extref)) {
+ 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;
@@ -355,7 +357,8 @@ static int btrfs_insert_inode_extref(struct
btrfs_trans_handle *trans,
ret = btrfs_insert_empty_item(trans, root, path, &key,
ins_len);
if (ret == -EEXIST) {
- if (btrfs_find_name_in_ext_backref(path, name, name_len, NULL))
+ if (btrfs_find_name_in_ext_backref(path, ref_objectid,
+ name, name_len, NULL))
goto out;
btrfs_extend_item(trans, root, path, ins_len);
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index baf8be2..1d7b348 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -745,6 +745,7 @@ out:
*/
static noinline int backref_in_log(struct btrfs_root *log,
struct btrfs_key *key,
+ u64 ref_objectid,
char *name, int namelen)
{
struct btrfs_path *path;
@@ -768,7 +769,8 @@ static noinline int backref_in_log(struct btrfs_root *log,
ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
if (key->type == BTRFS_INODE_EXTREF_KEY) {
- if (btrfs_find_name_in_ext_backref(path, name, namelen, NULL))
+ if (btrfs_find_name_in_ext_backref(path, ref_objectid,
+ name, namelen, NULL))
match = 1;
goto out;
@@ -813,6 +815,7 @@ static inline int __add_inode_ref(struct btrfs_trans_handle
*trans,
struct btrfs_key search_key;
struct btrfs_inode_extref *extref;
+again:
/* Search old style refs */
search_key.objectid = inode_objectid;
search_key.type = BTRFS_INODE_REF_KEY;
@@ -848,7 +851,9 @@ static inline int __add_inode_ref(struct btrfs_trans_handle
*trans,
(unsigned long)(victim_ref + 1),
victim_name_len);
- if (!backref_in_log(log_root, &search_key, victim_name,
+ if (!backref_in_log(log_root, &search_key,
+ parent_objectid,
+ victim_name,
victim_name_len)) {
btrfs_inc_nlink(inode);
btrfs_release_path(path);
@@ -856,9 +861,14 @@ static inline int __add_inode_ref(struct
btrfs_trans_handle *trans,
ret = btrfs_unlink_inode(trans, root, dir,
inode, victim_name,
victim_name_len);
+ BUG_ON(ret);
btrfs_run_delayed_items(trans, root);
+ kfree(victim_name);
+ *search_done = 1;
+ goto again;
}
kfree(victim_name);
+
ptr = (unsigned long)(victim_ref + 1) + victim_name_len;
}
BUG_ON(ret);
@@ -889,16 +899,23 @@ static inline int __add_inode_ref(struct
btrfs_trans_handle *trans,
while (cur_offset < item_size) {
extref = (struct btrfs_inode_extref *)base + cur_offset;
- victim_name_len = btrfs_inode_extref_name_len(eb,
extref);
- victim_name = kmalloc(namelen, GFP_NOFS);
- leaf = path->nodes[0];
- read_extent_buffer(eb, name, (unsigned
long)&extref->name, namelen);
+ victim_name_len = btrfs_inode_extref_name_len(leaf,
extref);
+
+ if (btrfs_inode_extref_parent(leaf, extref) !=
parent_objectid)
+ goto next;
+
+ victim_name = kmalloc(victim_name_len, GFP_NOFS);
+ read_extent_buffer(leaf, victim_name, (unsigned
long)&extref->name,
+ victim_name_len);
search_key.objectid = inode_objectid;
search_key.type = BTRFS_INODE_EXTREF_KEY;
search_key.offset = btrfs_extref_hash(parent_objectid,
- name, namelen);
- if (!backref_in_log(log_root, &search_key, victim_name,
+ victim_name,
+ victim_name_len);
+ ret = 0;
+ if (!backref_in_log(log_root, &search_key,
+ parent_objectid, victim_name,
victim_name_len)) {
ret = -ENOENT;
victim_parent = read_one_inode(root,
@@ -912,16 +929,22 @@ static inline int __add_inode_ref(struct
btrfs_trans_handle *trans,
inode,
victim_name,
victim_name_len);
+ btrfs_run_delayed_items(trans, root);
}
+ BUG_ON(ret);
iput(victim_parent);
+ kfree(victim_name);
+ *search_done = 1;
+ goto again;
}
kfree(victim_name);
BUG_ON(ret);
-
+next:
cur_offset += victim_name_len + sizeof(*extref);
}
*search_done = 1;
}
+ btrfs_release_path(path);
/* look for a conflicting sequence number */
di = btrfs_lookup_dir_index_item(trans, root, path, btrfs_ino(dir),
@@ -1158,6 +1181,7 @@ static int count_inode_extrefs(struct btrfs_root *root,
}
offset++;
+ btrfs_release_path(path);
}
btrfs_release_path(path);
@@ -1248,11 +1272,16 @@ static noinline int fixup_inode_link_count(struct
btrfs_trans_handle *trans,
nlink = ret;
ret = count_inode_extrefs(root, inode, path);
+ if (ret == -ENOENT)
+ ret = 0;
+
if (ret < 0)
goto out;
nlink += ret;
+ ret = 0;
+
if (nlink != inode->i_nlink) {
set_nlink(inode, nlink);
btrfs_update_inode(trans, root, inode);
--
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