Btrfs: finish off inode indexing in dirs, add overflows

Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 61d7b4738af67e8632f011616d5538bf322514f7..794f7e4f1c0785d09ae80f00d050d4967e0bd6ad 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -270,6 +270,10 @@ struct btrfs_root {
 #define BTRFS_KEY_TYPE_MAX     256
 #define BTRFS_KEY_TYPE_MASK    (BTRFS_KEY_TYPE_MAX - 1)
 
+#define BTRFS_KEY_OVERFLOW_MAX 128
+#define BTRFS_KEY_OVERFLOW_SHIFT 8
+#define BTRFS_KEY_OVERFLOW_MASK (0x7FULL << BTRFS_KEY_OVERFLOW_SHIFT)
+
 /*
  * inode items have the data typically returned from stat and store other
  * info about object characteristics.  There is one for every file and dir in
@@ -588,6 +592,19 @@ static inline void btrfs_set_disk_key_flags(struct btrfs_disk_key *disk,
        disk->flags = cpu_to_le32(val);
 }
 
+static inline u32 btrfs_key_overflow(struct btrfs_key *key)
+{
+       u32 over = key->flags & BTRFS_KEY_OVERFLOW_MASK;
+       return over >> BTRFS_KEY_OVERFLOW_SHIFT;
+}
+
+static inline void btrfs_set_key_overflow(struct btrfs_key *key, u32 over)
+{
+       BUG_ON(over > BTRFS_KEY_OVERFLOW_MAX);
+       over = over << BTRFS_KEY_OVERFLOW_SHIFT;
+       key->flags = (key->flags & ~((u64)BTRFS_KEY_OVERFLOW_MASK)) | over;
+}
+
 static inline u32 btrfs_key_type(struct btrfs_key *key)
 {
        return key->flags & BTRFS_KEY_TYPE_MASK;
@@ -612,6 +629,22 @@ static inline void btrfs_set_disk_key_type(struct btrfs_disk_key *key, u32 type)
        btrfs_set_disk_key_flags(key, flags);
 }
 
+static inline u32 btrfs_disk_key_overflow(struct btrfs_disk_key *key)
+{
+       u32 over = le32_to_cpu(key->flags) & BTRFS_KEY_OVERFLOW_MASK;
+       return over >> BTRFS_KEY_OVERFLOW_SHIFT;
+}
+
+static inline void btrfs_set_disK_key_overflow(struct btrfs_disk_key *key,
+                                              u32 over)
+{
+       u32 flags = btrfs_disk_key_flags(key);
+       BUG_ON(over > BTRFS_KEY_OVERFLOW_MAX);
+       over = over << BTRFS_KEY_OVERFLOW_SHIFT;
+       flags = (flags & ~((u64)BTRFS_KEY_OVERFLOW_MASK)) | over;
+       btrfs_set_disk_key_flags(key, flags);
+}
+
 static inline u64 btrfs_header_blocknr(struct btrfs_header *h)
 {
        return le64_to_cpu(h->blocknr);

diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c
index 62d0c0916a73c2e5f229a4381e96ef028ae55009..b1629a5d73c8bad2baef3b596db41910f6b14e66 100644 (file)
--- a/fs/btrfs/dir-item.c
+++ b/fs/btrfs/dir-item.c
@@ -4,6 +4,26 @@
 #include "hash.h"
 #include "transaction.h"
 
+int insert_with_overflow(struct btrfs_trans_handle *trans, struct btrfs_root
+                           *root, struct btrfs_path *path, struct btrfs_key
+                           *cpu_key, u32 data_size)
+{
+       int overflow;
+       int ret;
+
+       ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
+       overflow = btrfs_key_overflow(cpu_key);
+
+       while(ret == -EEXIST && overflow < BTRFS_KEY_OVERFLOW_MAX) {
+               overflow++;
+               btrfs_set_key_overflow(cpu_key, overflow);
+               btrfs_release_path(root, path);
+               ret = btrfs_insert_empty_item(trans, root, path, cpu_key,
+                                             data_size);
+       }
+       return ret;
+}
+
 int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
                          *root, const char *name, int name_len, u64 dir, u64
                          objectid, u8 type)
@@ -23,7 +43,7 @@ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
        path = btrfs_alloc_path();
        btrfs_init_path(path);
        data_size = sizeof(*dir_item) + name_len;
-       ret = btrfs_insert_empty_item(trans, root, path, &key, data_size);
+       ret = insert_with_overflow(trans, root, path, &key, data_size);
        if (ret)
                goto out;
 
@@ -41,7 +61,7 @@ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
 
        btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
        key.offset = objectid;
-       ret = btrfs_insert_empty_item(trans, root, path, &key, data_size);
+       ret = insert_with_overflow(trans, root, path, &key, data_size);
        // FIXME clear the dirindex bit
        if (ret)
                goto out;
@@ -70,14 +90,40 @@ int btrfs_lookup_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
        struct btrfs_key key;
        int ins_len = mod < 0 ? -1 : 0;
        int cow = mod != 0;
+       struct btrfs_disk_key *found_key;
+       struct btrfs_leaf *leaf;
 
        key.objectid = dir;
        key.flags = 0;
        btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
+       btrfs_set_key_overflow(&key, BTRFS_KEY_OVERFLOW_MAX - 1);
        ret = btrfs_name_hash(name, name_len, &key.offset);
        BUG_ON(ret);
-       ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
-       return ret;
+       while(1) {
+               ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
+               if (ret < 0)
+                       return ret;
+               if (ret > 0) {
+                       if (path->slots[0] == 0)
+                               return 1;
+                       path->slots[0]--;
+               }
+               leaf = btrfs_buffer_leaf(path->nodes[0]);
+               found_key = &leaf->items[path->slots[0]].key;
+
+               if (btrfs_disk_key_objectid(found_key) != dir ||
+                   btrfs_disk_key_type(found_key) != BTRFS_DIR_ITEM_KEY ||
+                   btrfs_disk_key_offset(found_key) != key.offset)
+                       return 1;
+
+               if (btrfs_match_dir_item_name(root, path, name, name_len))
+                       return 0;
+
+               if (btrfs_disk_key_overflow(found_key) == 0)
+                       return 1;
+               btrfs_release_path(root, path);
+       }
+       return 1;
 }
 
 int btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
@@ -89,13 +135,31 @@ int btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
        struct btrfs_key key;
        int ins_len = mod < 0 ? -1 : 0;
        int cow = mod != 0;
+       struct btrfs_disk_key *found_key;
+       struct btrfs_leaf *leaf;
 
        key.objectid = dir;
        key.flags = 0;
        btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
+       btrfs_set_key_overflow(&key, BTRFS_KEY_OVERFLOW_MAX - 1);
        key.offset = objectid;
        ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
-       return ret;
+       if (ret < 0)
+               return ret;
+       if (ret > 0) {
+               if (path->slots[0] == 0)
+                       return 1;
+               path->slots[0]--;
+       }
+       leaf = btrfs_buffer_leaf(path->nodes[0]);
+       found_key = &leaf->items[path->slots[0]].key;
+
+       if (btrfs_disk_key_objectid(found_key) != dir ||
+           btrfs_disk_key_type(found_key) != BTRFS_DIR_INDEX_KEY)
+               return 1;
+       if (btrfs_disk_key_offset(found_key) == objectid)
+               return 0;
+       return 1;
 }
 
 int btrfs_match_dir_item_name(struct btrfs_root *root,

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index d776b29a1676f3099ec2c15272fbea797465cbe6..4fd2b168b2c46ce85c3f826e453ca1084d9592a9 100644 (file)
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -486,19 +486,18 @@ static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
                        continue;
                if (btrfs_disk_key_offset(&item->key) < filp->f_pos)
                        continue;
-
+               filp->f_pos = btrfs_disk_key_offset(&item->key);
                advance = 1;
                di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
                over = filldir(dirent, (const char *)(di + 1),
                               btrfs_dir_name_len(di),
                               btrfs_disk_key_offset(&item->key),
                               btrfs_dir_objectid(di), d_type);
-               if (over) {
-                       filp->f_pos = btrfs_disk_key_offset(&item->key);
-                       break;
-               }
-               filp->f_pos = btrfs_disk_key_offset(&item->key) + 1;
+               if (over)
+                       goto nopos;
        }
+       filp->f_pos++;
+nopos:
        ret = 0;
 err:
        btrfs_release_path(root, path);