Btrfs: working file_write, reorganized key flags
authorChris Mason <chris.mason@oracle.com>
Wed, 18 Apr 2007 20:15:28 +0000 (16:15 -0400)
committerDavid Woodhouse <dwmw2@hera.kernel.org>
Wed, 18 Apr 2007 20:15:28 +0000 (16:15 -0400)
Signed-off-by: Chris Mason <chris.mason@oracle.com>
fs/btrfs/ctree.c
fs/btrfs/ctree.h
fs/btrfs/dir-item.c
fs/btrfs/extent-tree.c
fs/btrfs/file-item.c
fs/btrfs/print-tree.c
fs/btrfs/super.c

index 5c160c23677318d8b57ab616effc2f61db0261b5..4efcd1bd63e5fb58c6bd60db5f3072a1f55dbee3 100644 (file)
@@ -893,7 +893,11 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
        }
 
        left_nritems = btrfs_header_nritems(&left->header);
-       for (i = left_nritems - 1; i >= 0; i--) {
+       if (left_nritems == 0) {
+               btrfs_block_release(root, right_buf);
+               return 1;
+       }
+       for (i = left_nritems - 1; i >= 1; i--) {
                item = left->items + i;
                if (path->slots[0] == i)
                        push_space += data_size + sizeof(*item);
@@ -907,6 +911,8 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
                btrfs_block_release(root, right_buf);
                return 1;
        }
+       if (push_items == left_nritems)
+               WARN_ON(1);
        right_nritems = btrfs_header_nritems(&right->header);
        /* push left to right */
        push_space = btrfs_item_end(left->items + left_nritems - push_items);
@@ -943,6 +949,7 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
 
        btrfs_mark_buffer_dirty(left_buf);
        btrfs_mark_buffer_dirty(right_buf);
+
        btrfs_memcpy(root, upper_node, &upper_node->ptrs[slot + 1].key,
                &right->items[0].key, sizeof(struct btrfs_disk_key));
        btrfs_mark_buffer_dirty(upper);
@@ -1004,7 +1011,12 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
                return 1;
        }
 
-       for (i = 0; i < btrfs_header_nritems(&right->header); i++) {
+       if (btrfs_header_nritems(&right->header) == 0) {
+               btrfs_block_release(root, t);
+               return 1;
+       }
+
+       for (i = 0; i < btrfs_header_nritems(&right->header) - 1; i++) {
                item = right->items + i;
                if (path->slots[0] == i)
                        push_space += data_size + sizeof(*item);
@@ -1018,6 +1030,8 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
                btrfs_block_release(root, t);
                return 1;
        }
+       if (push_items == btrfs_header_nritems(&right->header))
+               WARN_ON(1);
        /* push data from right to left */
        btrfs_memcpy(root, left, left->items +
                     btrfs_header_nritems(&left->header),
@@ -1064,7 +1078,6 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
 
        btrfs_mark_buffer_dirty(t);
        btrfs_mark_buffer_dirty(right_buf);
-
        wret = fixup_low_keys(trans, root, path, &right->items[0].key, 1);
        if (wret)
                ret = wret;
@@ -1181,6 +1194,12 @@ static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
                                path->nodes[0] = right_buffer;
                                path->slots[0] = 0;
                                path->slots[1] -= 1;
+                               if (path->slots[1] == 0) {
+                                       wret = fixup_low_keys(trans, root,
+                                                  path, &disk_key, 1);
+                                       if (wret)
+                                               ret = wret;
+                               }
                                return ret;
                        }
                        mid = slot;
@@ -1241,6 +1260,11 @@ static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
                          path->slots[1], 1);
        if (wret)
                ret = wret;
+       if (path->slots[1] == 0) {
+               wret = fixup_low_keys(trans, root, path, &disk_key, 1);
+               if (wret)
+                       ret = wret;
+       }
        btrfs_block_release(root, path->nodes[0]);
        path->nodes[0] = right_buffer;
        path->slots[0] = 0;
index d75a4d5bc0102c6467f0aae09d7e8e008a873ce3..8a329d3901a2b80a11bbef3d92fcdaf7c9ccfc0a 100644 (file)
@@ -282,11 +282,12 @@ struct btrfs_root {
 
 /* the lower bits in the key flags defines the item type */
 #define BTRFS_KEY_TYPE_MAX     256
-#define BTRFS_KEY_TYPE_MASK    (BTRFS_KEY_TYPE_MAX - 1)
+#define BTRFS_KEY_TYPE_SHIFT   24
+#define BTRFS_KEY_TYPE_MASK    (((u32)BTRFS_KEY_TYPE_MAX - 1) << \
+                                 BTRFS_KEY_TYPE_SHIFT)
 
 #define BTRFS_KEY_OVERFLOW_MAX 128
-#define BTRFS_KEY_OVERFLOW_SHIFT 8
-#define BTRFS_KEY_OVERFLOW_MASK (0x7FULL << BTRFS_KEY_OVERFLOW_SHIFT)
+#define BTRFS_KEY_OVERFLOW_MASK ((u32)BTRFS_KEY_OVERFLOW_MAX - 1)
 
 /*
  * inode items have the data typically returned from stat and store other
@@ -586,56 +587,55 @@ 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)
+static inline u32 btrfs_disk_key_type(struct btrfs_disk_key *key)
 {
-       u32 over = key->flags & BTRFS_KEY_OVERFLOW_MASK;
-       return over >> BTRFS_KEY_OVERFLOW_SHIFT;
+       return le32_to_cpu(key->flags) >> BTRFS_KEY_TYPE_SHIFT;
 }
 
-static inline void btrfs_set_key_overflow(struct btrfs_key *key, u32 over)
+static inline void btrfs_set_disk_key_type(struct btrfs_disk_key *key,
+                                              u32 val)
 {
-       BUG_ON(over >= BTRFS_KEY_OVERFLOW_MAX);
-       over = over << BTRFS_KEY_OVERFLOW_SHIFT;
-       key->flags = (key->flags & ~((u64)BTRFS_KEY_OVERFLOW_MASK)) | over;
+       u32 flags = btrfs_disk_key_flags(key);
+       BUG_ON(val >= BTRFS_KEY_TYPE_MAX);
+       val = val << BTRFS_KEY_TYPE_SHIFT;
+       flags = (flags & ~BTRFS_KEY_TYPE_MASK) | val;
+       btrfs_set_disk_key_flags(key, flags);
 }
 
 static inline u32 btrfs_key_type(struct btrfs_key *key)
 {
-       return key->flags & BTRFS_KEY_TYPE_MASK;
+       return key->flags >> BTRFS_KEY_TYPE_SHIFT;
 }
 
-static inline u32 btrfs_disk_key_type(struct btrfs_disk_key *key)
+static inline void btrfs_set_key_type(struct btrfs_key *key, u32 val)
 {
-       return le32_to_cpu(key->flags) & BTRFS_KEY_TYPE_MASK;
+       BUG_ON(val >= BTRFS_KEY_TYPE_MAX);
+       val = val << BTRFS_KEY_TYPE_SHIFT;
+       key->flags = (key->flags & ~(BTRFS_KEY_TYPE_MASK)) | val;
 }
 
-static inline void btrfs_set_key_type(struct btrfs_key *key, u32 type)
+static inline u32 btrfs_key_overflow(struct btrfs_key *key)
 {
-       BUG_ON(type >= BTRFS_KEY_TYPE_MAX);
-       key->flags = (key->flags & ~((u64)BTRFS_KEY_TYPE_MASK)) | type;
+       return key->flags & BTRFS_KEY_OVERFLOW_MASK;
 }
 
-static inline void btrfs_set_disk_key_type(struct btrfs_disk_key *key, u32 type)
+static inline void btrfs_set_key_overflow(struct btrfs_key *key, u32 over)
 {
-       u32 flags = btrfs_disk_key_flags(key);
-       BUG_ON(type >= BTRFS_KEY_TYPE_MAX);
-       flags = (flags & ~((u64)BTRFS_KEY_TYPE_MASK)) | type;
-       btrfs_set_disk_key_flags(key, flags);
+       BUG_ON(over >= BTRFS_KEY_OVERFLOW_MAX);
+       key->flags = (key->flags & ~BTRFS_KEY_OVERFLOW_MASK) | over;
 }
 
 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;
+       return le32_to_cpu(key->flags) & BTRFS_KEY_OVERFLOW_MASK;
 }
 
-static inline void btrfs_set_disK_key_overflow(struct btrfs_disk_key *key,
+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;
+       flags = (flags & ~BTRFS_KEY_OVERFLOW_MASK) | over;
        btrfs_set_disk_key_flags(key, flags);
 }
 
index cd4137a8b87e77f5bfaeed0f093e2e7f940163fd..a43deb72648625104cbd5d14c35fa4846d0e0db0 100644 (file)
@@ -58,30 +58,6 @@ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
 
        btrfs_memcpy(root, path->nodes[0]->b_data, name_ptr, name, name_len);
        btrfs_mark_buffer_dirty(path->nodes[0]);
-
-       /* FIXME, use some real flag for selecting the extra index */
-       if (root == root->fs_info->tree_root)
-               goto out;
-
-       btrfs_release_path(root, path);
-
-       btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
-       key.offset = location->objectid;
-       ret = insert_with_overflow(trans, root, path, &key, data_size);
-       // FIXME clear the dirindex bit
-       if (ret)
-               goto out;
-
-       dir_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
-                                 path->slots[0],
-                                 struct btrfs_dir_item);
-       btrfs_cpu_key_to_disk(&dir_item->location, location);
-       btrfs_set_dir_type(dir_item, type);
-       btrfs_set_dir_flags(dir_item, 0);
-       btrfs_set_dir_name_len(dir_item, name_len);
-       name_ptr = (char *)(dir_item + 1);
-       btrfs_memcpy(root, path->nodes[0]->b_data, name_ptr, name, name_len);
-       btrfs_mark_buffer_dirty(path->nodes[0]);
 out:
        btrfs_release_path(root, path);
        btrfs_free_path(path);
@@ -135,52 +111,6 @@ int btrfs_lookup_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
        return 1;
 }
 
-int btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
-                               struct btrfs_root *root,
-                               struct btrfs_path *path, u64 dir,
-                               u64 objectid, int mod)
-{
-       int ret;
-       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;
-       int overflow = 0;
-
-       key.objectid = dir;
-       key.flags = 0;
-       btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
-       key.offset = objectid;
-
-       while(1) {
-               btrfs_set_key_overflow(&key, overflow);
-               ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
-               if (ret < 0)
-                       return ret;
-               if (ret > 0) {
-                       if (overflow >= BTRFS_KEY_OVERFLOW_MAX)
-                               return 1;
-                       overflow++;
-                       btrfs_set_key_overflow(&key, overflow);
-                       btrfs_release_path(root, path);
-                       continue;
-               } else {
-                       /* found */
-                       break;
-               }
-       }
-       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,
                              struct btrfs_path *path,
                              const char *name, int name_len)
index 2cee9df001f66587eb4bf8035f2b179bb448feb2..cb04a70eb7e843de939a11f5c4d5cd286ece5d18 100644 (file)
@@ -35,8 +35,10 @@ int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
        key.offset = num_blocks;
        ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
                                0, 1);
-       if (ret != 0)
+       if (ret != 0) {
+printk("can't find block %Lu %Lu\n", blocknr, num_blocks);
                BUG();
+       }
        BUG_ON(ret != 0);
        l = btrfs_buffer_leaf(path->nodes[0]);
        item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
index ff8f3339c684faa7436cab4c9265b7ed902d8379..8cc3c1d15412309de185f34c85d63783012fc475 100644 (file)
@@ -4,7 +4,7 @@
 #include "transaction.h"
 
 #define MAX_CSUM_ITEMS(r) ((((BTRFS_LEAF_DATA_SIZE(r) - \
-                                sizeof(struct btrfs_item)) / \
+                                sizeof(struct btrfs_item) * 2) / \
                                sizeof(struct btrfs_csum_item)) - 1))
 int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
                               struct btrfs_root *root,
@@ -19,11 +19,6 @@ int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
        path = btrfs_alloc_path();
        BUG_ON(!path);
        btrfs_init_path(path);
-       /*
-       ret = btrfs_alloc_extent(trans, root, num_blocks, hint_block,
-                                (u64)-1, &ins);
-                                */
-       BUG_ON(ret);
        file_key.objectid = objectid;
        file_key.offset = pos;
        file_key.flags = 0;
@@ -40,6 +35,7 @@ int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
        btrfs_set_file_extent_num_blocks(item, num_blocks);
        btrfs_set_file_extent_generation(item, trans->transid);
        btrfs_mark_buffer_dirty(path->nodes[0]);
+
        btrfs_release_path(root, path);
        btrfs_free_path(path);
        return 0;
@@ -57,6 +53,7 @@ struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
        struct btrfs_csum_item *item;
        struct btrfs_leaf *leaf;
        u64 csum_offset = 0;
+       int csums_in_item;
 
        file_key.objectid = objectid;
        file_key.offset = offset;
@@ -79,9 +76,11 @@ struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
                }
                csum_offset = (offset - found_key.offset) >>
                                root->fs_info->sb->s_blocksize_bits;
-               if (csum_offset >=
-                   btrfs_item_size(leaf->items + path->slots[0]) /
-                   sizeof(struct btrfs_csum_item)) {
+               csums_in_item = btrfs_item_size(leaf->items + path->slots[0]);
+               csums_in_item /= sizeof(struct btrfs_csum_item);
+
+               if (csum_offset >= csums_in_item) {
+                       ret = -EFBIG;
                        goto fail;
                }
        }
@@ -128,16 +127,36 @@ int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
 
        path = btrfs_alloc_path();
        BUG_ON(!path);
-       btrfs_init_path(path);
 
-       item = btrfs_lookup_csum(trans, root, path, objectid, offset, 0);
-       if (!IS_ERR(item))
-               goto found;
-       btrfs_release_path(root, path);
        file_key.objectid = objectid;
        file_key.offset = offset;
        file_key.flags = 0;
        btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
+
+       item = btrfs_lookup_csum(trans, root, path, objectid, offset, 1);
+       if (!IS_ERR(item))
+               goto found;
+       ret = PTR_ERR(item);
+       if (ret == -EFBIG) {
+               u32 item_size;
+               /* we found one, but it isn't big enough yet */
+               leaf = btrfs_buffer_leaf(path->nodes[0]);
+               item_size = btrfs_item_size(leaf->items + path->slots[0]);
+               if ((item_size / sizeof(struct btrfs_csum_item)) >=
+                   MAX_CSUM_ITEMS(root)) {
+                       /* already at max size, make a new one */
+                       goto insert;
+               }
+       } else {
+               /* we didn't find a csum item, insert one */
+               goto insert;
+       }
+
+       /*
+        * at this point, we know the tree has an item, but it isn't big
+        * enough yet to put our csum in.  Grow it
+        */
+       btrfs_release_path(root, path);
        ret = btrfs_search_slot(trans, root, &file_key, path,
                                sizeof(struct btrfs_csum_item), 1);
        if (ret < 0)
@@ -146,7 +165,6 @@ int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
                BUG();
        }
        if (path->slots[0] == 0) {
-               btrfs_release_path(root, path);
                goto insert;
        }
        path->slots[0]--;
@@ -157,29 +175,36 @@ int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
        if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
            found_key.objectid != objectid ||
            csum_offset >= MAX_CSUM_ITEMS(root)) {
-               btrfs_release_path(root, path);
+               WARN_ON(1);
                goto insert;
        }
        if (csum_offset >= btrfs_item_size(leaf->items + path->slots[0]) /
            sizeof(struct btrfs_csum_item)) {
-               ret = btrfs_extend_item(trans, root, path,
-                                       sizeof(struct btrfs_csum_item));
+               u32 diff = (csum_offset + 1) * sizeof(struct btrfs_csum_item);
+               diff = diff - btrfs_item_size(leaf->items + path->slots[0]);
+               WARN_ON(diff != sizeof(struct btrfs_csum_item));
+               ret = btrfs_extend_item(trans, root, path, diff);
                BUG_ON(ret);
                goto csum;
        }
 
 insert:
+       btrfs_release_path(root, path);
        csum_offset = 0;
        ret = btrfs_insert_empty_item(trans, root, path, &file_key,
                                      sizeof(struct btrfs_csum_item));
-       if (ret != 0 && ret != -EEXIST)
+       if (ret != 0) {
+               printk("at insert for %Lu %u %Lu ret is %d\n", file_key.objectid, file_key.flags, file_key.offset, ret);
+               WARN_ON(1);
                goto fail;
+       }
 csum:
        item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
                              struct btrfs_csum_item);
        ret = 0;
        item += csum_offset;
 found:
+       btrfs_check_bounds(item->csum, BTRFS_CSUM_SIZE, path->nodes[0]->b_data, root->fs_info->sb->s_blocksize);
        ret = btrfs_csum_data(root, data, len, item->csum);
        btrfs_mark_buffer_dirty(path->nodes[0]);
 fail:
@@ -210,6 +235,9 @@ int btrfs_csum_verify_file_block(struct btrfs_root *root,
        item = btrfs_lookup_csum(NULL, root, path, objectid, offset, 0);
        if (IS_ERR(item)) {
                ret = PTR_ERR(item);
+               /* a csum that isn't present is a preallocated region. */
+               if (ret == -ENOENT || ret == -EFBIG)
+                       ret = 1;
                goto fail;
        }
 
index 0732a2fbb23a9894e3bf3a8fa96b050449b80dd8..1e7038b070aea3eda3b7c7f877f46d1ba4e798a1 100644 (file)
@@ -19,7 +19,7 @@ void btrfs_print_leaf(struct btrfs_root *root, struct btrfs_leaf *l)
        for (i = 0 ; i < nr ; i++) {
                item = l->items + i;
                type = btrfs_disk_key_type(&item->key);
-               printk("\titem %d key (%Lu %u %Lu) itemoff %d itemsize %d\n",
+               printk("\titem %d key (%Lu %x %Lu) itemoff %d itemsize %d\n",
                        i,
                        btrfs_disk_key_objectid(&item->key),
                        btrfs_disk_key_flags(&item->key),
index b2a2220d13524fd5270af67de5f5869f3c7a7a48..583cd87a62e248736244decf82cdca414a035500 100644 (file)
@@ -150,11 +150,6 @@ static int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
        BUG_ON(ret);
 
        btrfs_release_path(root, path);
-       ret = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
-                                         objectid, -1);
-       BUG_ON(ret);
-       ret = btrfs_del_item(trans, root, path);
-       BUG_ON(ret);
        dentry->d_inode->i_ctime = dir->i_ctime;
 err:
        btrfs_release_path(root, path);
@@ -329,8 +324,9 @@ static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
                        extent_start = btrfs_file_extent_disk_blocknr(fi);
                        extent_num_blocks =
                                btrfs_file_extent_disk_num_blocks(fi);
+                       /* FIXME blocksize != 4096 */
                        inode->i_blocks -=
-                               btrfs_file_extent_num_blocks(fi) >> 9;
+                               btrfs_file_extent_num_blocks(fi) << 3;
                        found_extent = 1;
                } else {
                        found_extent = 0;
@@ -562,7 +558,7 @@ static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
                if (btrfs_disk_key_objectid(&item->key) != key.objectid)
                        break;
                if (btrfs_disk_key_type(&item->key) != key_type)
-                       continue;
+                       break;
                if (btrfs_disk_key_offset(&item->key) < filp->f_pos)
                        continue;
                filp->f_pos = btrfs_disk_key_offset(&item->key);
@@ -1285,29 +1281,27 @@ static int drop_extents(struct btrfs_trans_handle *trans,
        struct btrfs_path *path;
        u64 search_start = start;
        int bookend;
-
        path = btrfs_alloc_path();
        if (!path)
                return -ENOMEM;
-search_again:
-       ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
-                                      search_start, -1);
-       if (ret < 0)
-               goto out;
-       if (ret > 0) {
-               if (path->slots[0] == 0) {
-                       ret = -ENOENT;
+       while(1) {
+               btrfs_release_path(root, path);
+               ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
+                                              search_start, -1);
+               if (ret < 0)
                        goto out;
+               if (ret > 0) {
+                       if (path->slots[0] == 0) {
+                               ret = -ENOENT;
+                               goto out;
+                       }
+                       path->slots[0]--;
                }
-               path->slots[0]--;
-       }
-       while(1) {
                keep = 0;
                bookend = 0;
                leaf = btrfs_buffer_leaf(path->nodes[0]);
                slot = path->slots[0];
                btrfs_disk_key_to_cpu(&key, &leaf->items[slot].key);
-
                extent = btrfs_item_ptr(leaf, slot,
                                        struct btrfs_file_extent_item);
                extent_end = key.offset +
@@ -1318,7 +1312,10 @@ search_again:
                        goto out;
                }
                if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
-                       goto next_leaf;
+                       goto out;
+               if (search_start >= extent_end)
+                       goto out;
+               search_start = extent_end;
 
                if (end < extent_end && end >= key.offset) {
                        memcpy(&old, extent, sizeof(old));
@@ -1331,10 +1328,13 @@ search_again:
 
                if (start > key.offset) {
                        u64 new_num;
+                       u64 old_num;
                        /* truncate existing extent */
                        keep = 1;
                        WARN_ON(start & (root->blocksize - 1));
                        new_num = (start - key.offset) >> inode->i_blkbits;
+                       old_num = btrfs_file_extent_num_blocks(extent);
+                       inode->i_blocks -= (old_num - new_num) << 3;
                        btrfs_set_file_extent_num_blocks(extent, new_num);
                        mark_buffer_dirty(path->nodes[0]);
                }
@@ -1344,13 +1344,11 @@ search_again:
                        disk_blocknr = btrfs_file_extent_disk_blocknr(extent);
                        disk_num_blocks =
                                btrfs_file_extent_disk_num_blocks(extent);
-                       search_start = key.offset +
-                               (btrfs_file_extent_num_blocks(extent) <<
-                               inode->i_blkbits);
                        ret = btrfs_del_item(trans, root, path);
                        BUG_ON(ret);
+                       inode->i_blocks -=
+                               btrfs_file_extent_num_blocks(extent) << 3;
                        btrfs_release_path(root, path);
-
                        ret = btrfs_free_extent(trans, root, disk_blocknr,
                                                disk_num_blocks, 0);
 
@@ -1360,7 +1358,7 @@ search_again:
                                goto out;
                        }
                        if (!bookend)
-                               goto search_again;
+                               continue;
                }
                if (bookend) {
                        /* create bookend */
@@ -1395,21 +1393,12 @@ search_again:
                        btrfs_set_file_extent_generation(extent,
                                    btrfs_file_extent_generation(&old));
                        btrfs_mark_buffer_dirty(path->nodes[0]);
+                       inode->i_blocks +=
+                               btrfs_file_extent_num_blocks(extent) << 3;
                        ret = 0;
                        goto out;
                }
-next_leaf:
-               if (slot >= btrfs_header_nritems(&leaf->header) - 1) {
-                       ret = btrfs_next_leaf(root, path);
-                       if (ret) {
-                               ret = 0;
-                               goto out;
-                       }
-               } else {
-                       path->slots[0]++;
-               }
        }
-
 out:
        btrfs_free_path(path);
        return ret;
@@ -1445,15 +1434,6 @@ static int prepare_pages(struct btrfs_root *root,
                }
                offset = pos & (PAGE_CACHE_SIZE -1);
                this_write = min(PAGE_CACHE_SIZE - offset, write_bytes);
-#if 0
-               if ((pages[i]->index == first_index ||
-                   pages[i]->index == last_index) && pos < isize &&
-                   !PageUptodate(pages[i])) {
-                       ret = mpage_readpage(pages[i], btrfs_get_block);
-                       BUG_ON(ret);
-                       lock_page(pages[i]);
-               }
-#endif
                create_empty_buffers(pages[i], root->fs_info->sb->s_blocksize,
                                     (1 << BH_Uptodate));
                head = page_buffers(pages[i]);
@@ -1494,6 +1474,7 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
        struct inode *inode = file->f_path.dentry->d_inode;
        struct btrfs_root *root = BTRFS_I(inode)->root;
        struct page *pages[8];
+       struct page *pinned[2] = { NULL, NULL };
        unsigned long first_index;
        unsigned long last_index;
        u64 start_pos;
@@ -1505,14 +1486,6 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
        if (file->f_flags & O_DIRECT)
                return -EINVAL;
        pos = *ppos;
-
-       start_pos = pos & ~(root->blocksize - 1);
-       /* FIXME */
-       if (start_pos != pos)
-               return -EINVAL;
-       num_blocks = (count + pos - start_pos + root->blocksize - 1) >>
-                       inode->i_blkbits;
-
        vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
        current->backing_dev_info = inode->i_mapping->backing_dev_info;
        err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
@@ -1524,10 +1497,37 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
        if (err)
                goto out;
        file_update_time(file);
+
+       start_pos = pos & ~((u64)PAGE_CACHE_SIZE - 1);
+       num_blocks = (count + pos - start_pos + root->blocksize - 1) >>
+                       inode->i_blkbits;
+
        mutex_lock(&inode->i_mutex);
        first_index = pos >> PAGE_CACHE_SHIFT;
        last_index = (pos + count) >> PAGE_CACHE_SHIFT;
 
+       if ((first_index << PAGE_CACHE_SHIFT) < inode->i_size &&
+           (pos & (PAGE_CACHE_SIZE - 1))) {
+               pinned[0] = grab_cache_page(inode->i_mapping, first_index);
+               if (!PageUptodate(pinned[0])) {
+                       ret = mpage_readpage(pinned[0], btrfs_get_block);
+                       BUG_ON(ret);
+               } else {
+                       unlock_page(pinned[0]);
+               }
+       }
+       if (first_index != last_index &&
+           (last_index << PAGE_CACHE_SHIFT) < inode->i_size &&
+           (count & (PAGE_CACHE_SIZE - 1))) {
+               pinned[1] = grab_cache_page(inode->i_mapping, last_index);
+               if (!PageUptodate(pinned[1])) {
+                       ret = mpage_readpage(pinned[1], btrfs_get_block);
+                       BUG_ON(ret);
+               } else {
+                       unlock_page(pinned[1]);
+               }
+       }
+
        mutex_lock(&root->fs_info->fs_mutex);
        trans = btrfs_start_transaction(root, 1);
        if (!trans) {
@@ -1535,11 +1535,14 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
                mutex_unlock(&root->fs_info->fs_mutex);
                goto out_unlock;
        }
+       /* FIXME blocksize != 4096 */
+       inode->i_blocks += num_blocks << 3;
        if (start_pos < inode->i_size) {
+               /* FIXME blocksize != pagesize */
                ret = drop_extents(trans, root, inode,
                                   start_pos,
                                   (pos + count + root->blocksize -1) &
-                                  ~(root->blocksize - 1));
+                                  ~((u64)root->blocksize - 1));
        }
        ret = btrfs_alloc_extent(trans, root, num_blocks, 1,
                                 (u64)-1, &ins);
@@ -1585,8 +1588,13 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
 out_unlock:
        mutex_unlock(&inode->i_mutex);
 out:
+       if (pinned[0])
+               page_cache_release(pinned[0]);
+       if (pinned[1])
+               page_cache_release(pinned[1]);
        *ppos = pos;
        current->backing_dev_info = NULL;
+       mark_inode_dirty(inode);
        return num_written ? num_written : err;
 }