Btrfs: early work to file_write in big extents

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

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index e2fc6f0..6b76fd9 100644 (file)
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -1249,6 +1249,60 @@ static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
        return ret;
 }
 
+int btrfs_extend_item(struct btrfs_trans_handle *trans, struct btrfs_root
+                     *root, struct btrfs_path *path, u32 data_size)
+{
+       int ret = 0;
+       int slot;
+       int slot_orig;
+       struct btrfs_leaf *leaf;
+       struct buffer_head *leaf_buf;
+       u32 nritems;
+       unsigned int data_end;
+       unsigned int old_data;
+       unsigned int old_size;
+       int i;
+
+       slot_orig = path->slots[0];
+       leaf_buf = path->nodes[0];
+       leaf = btrfs_buffer_leaf(leaf_buf);
+
+       nritems = btrfs_header_nritems(&leaf->header);
+       data_end = leaf_data_end(root, leaf);
+
+       if (btrfs_leaf_free_space(root, leaf) < data_size)
+               BUG();
+       slot = path->slots[0];
+       old_data = btrfs_item_end(leaf->items + slot);
+
+       BUG_ON(slot < 0);
+       BUG_ON(slot >= nritems);
+
+       /*
+        * item0..itemN ... dataN.offset..dataN.size .. data0.size
+        */
+       /* first correct the data pointers */
+       for (i = slot; i < nritems; i++) {
+               u32 ioff = btrfs_item_offset(leaf->items + i);
+               btrfs_set_item_offset(leaf->items + i,
+                                     ioff - data_size);
+       }
+       /* shift the data */
+       btrfs_memmove(root, leaf, btrfs_leaf_data(leaf) +
+                     data_end - data_size, btrfs_leaf_data(leaf) +
+                     data_end, old_data - data_end);
+       data_end = old_data;
+       old_size = btrfs_item_size(leaf->items + slot);
+       btrfs_set_item_size(leaf->items + slot, old_size + data_size);
+       btrfs_mark_buffer_dirty(leaf_buf);
+
+       ret = 0;
+       if (btrfs_leaf_free_space(root, leaf) < 0)
+               BUG();
+       check_leaf(root, path, 0);
+       return ret;
+}
+
 /*
  * Given a key and some data, insert an item into the tree.
  * This does all the path init required, making room in the tree if needed.

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index ef3583c..796f19d 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -227,6 +227,7 @@ struct btrfs_file_extent_item {
 } __attribute__ ((__packed__));
 
 struct btrfs_csum_item {
+       __le64 extent_offset;
        u8 csum[BTRFS_CSUM_SIZE];
 } __attribute__ ((__packed__));
 
@@ -924,6 +925,17 @@ static inline void btrfs_set_file_extent_num_blocks(struct
        e->num_blocks = cpu_to_le64(val);
 }
 
+static inline u64 btrfs_csum_extent_offset(struct btrfs_csum_item *c)
+{
+       return le64_to_cpu(c->extent_offset);
+}
+
+static inline void btrfs_set_csum_extent_offset(struct btrfs_csum_item *c,
+                                               u64 val)
+{
+       c->extent_offset = cpu_to_le64(val);
+}
+
 static inline u16 btrfs_device_pathlen(struct btrfs_device_item *d)
 {
        return le16_to_cpu(d->pathlen);
@@ -1002,6 +1014,8 @@ int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, struct
                               btrfs_root *root);
 /* ctree.c */
+int btrfs_extend_item(struct btrfs_trans_handle *trans, struct btrfs_root
+                     *root, struct btrfs_path *path, u32 data_size);
 int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
                      *root, struct btrfs_key *key, struct btrfs_path *p, int
                      ins_len, int cow);
@@ -1071,6 +1085,7 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
 int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
                          struct btrfs_root *root,
                          u64 objectid, u64 offset,
+                         u64 extent_offset,
                          char *data, size_t len);
 int btrfs_csum_verify_file_block(struct btrfs_root *root,
                                 u64 objectid, u64 offset,

diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index d9fd7f4..93d42d6 100644 (file)
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -3,6 +3,9 @@
 #include "disk-io.h"
 #include "transaction.h"
 
+#define MAX_CSUM_ITEMS(r) ((((BTRFS_LEAF_DATA_SIZE(r) - \
+                                sizeof(struct btrfs_item)) / \
+                               sizeof(struct btrfs_csum_item)) - 1))
 int btrfs_alloc_file_extent(struct btrfs_trans_handle *trans,
                               struct btrfs_root *root,
                               u64 objectid, u64 offset,
@@ -43,6 +46,54 @@ int btrfs_alloc_file_extent(struct btrfs_trans_handle *trans,
        return 0;
 }
 
+static struct btrfs_csum_item *__lookup_csum_item(struct btrfs_root *root,
+                                                 struct btrfs_path *path,
+                                                 u64 objectid, u64 offset)
+{
+       int ret;
+       struct btrfs_key file_key;
+       struct btrfs_key found_key;
+       struct btrfs_csum_item *item;
+       struct btrfs_leaf *leaf;
+       u64 csum_offset = 0;
+
+       file_key.objectid = objectid;
+       file_key.offset = offset;
+       file_key.flags = 0;
+       btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
+       ret = btrfs_search_slot(NULL, root, &file_key, path, 0, 0);
+       if (ret < 0)
+               goto fail;
+       leaf = btrfs_buffer_leaf(path->nodes[0]);
+       if (ret > 0) {
+               ret = 1;
+               if (path->slots[0] == 0)
+                       goto fail;
+               path->slots[0]--;
+               btrfs_disk_key_to_cpu(&found_key,
+                                     &leaf->items[path->slots[0]].key);
+               if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
+                   found_key.objectid != objectid) {
+                       goto fail;
+               }
+               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)) {
+                       goto fail;
+               }
+       }
+       item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
+       item += csum_offset;
+       return item;
+fail:
+       if (ret > 0)
+               ret = -EIO;
+       return ERR_PTR(ret);
+}
+
+
 int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
                             struct btrfs_root *root,
                             struct btrfs_path *path, u64 objectid,
@@ -52,11 +103,16 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
        struct btrfs_key file_key;
        int ins_len = mod < 0 ? -1 : 0;
        int cow = mod != 0;
+       struct btrfs_csum_item *csum_item;
 
+       csum_item = __lookup_csum_item(root, path, objectid, offset);
+       if (IS_ERR(csum_item))
+               return PTR_ERR(csum_item);
        file_key.objectid = objectid;
-       file_key.offset = offset;
+       file_key.offset = btrfs_csum_extent_offset(csum_item);
        file_key.flags = 0;
        btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
+       btrfs_release_path(root, path);
        ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
        return ret;
 }
@@ -64,12 +120,16 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
 int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
                          struct btrfs_root *root,
                          u64 objectid, u64 offset,
+                         u64 extent_offset,
                          char *data, size_t len)
 {
        int ret;
        struct btrfs_key file_key;
+       struct btrfs_key found_key;
        struct btrfs_path *path;
        struct btrfs_csum_item *item;
+       struct btrfs_leaf *leaf;
+       u64 csum_offset;
 
        path = btrfs_alloc_path();
        BUG_ON(!path);
@@ -78,14 +138,50 @@ int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
        file_key.offset = offset;
        file_key.flags = 0;
        btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
+       ret = btrfs_search_slot(trans, root, &file_key, path,
+                               sizeof(struct btrfs_csum_item), 1);
+       if (ret < 0)
+               goto fail;
+       if (ret == 0) {
+               csum_offset = 0;
+               goto csum;
+       }
+       if (path->slots[0] == 0) {
+               btrfs_release_path(root, path);
+               goto insert;
+       }
+       path->slots[0]--;
+       leaf = btrfs_buffer_leaf(path->nodes[0]);
+       btrfs_disk_key_to_cpu(&found_key, &leaf->items[path->slots[0]].key);
+       csum_offset = (offset - found_key.offset) >>
+                       root->fs_info->sb->s_blocksize_bits;
+       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);
+               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));
+               BUG_ON(ret);
+               goto csum;
+       }
+
+insert:
+       csum_offset = 0;
        ret = btrfs_insert_empty_item(trans, root, path, &file_key,
-                                     BTRFS_CSUM_SIZE);
+                                     sizeof(struct btrfs_csum_item));
        if (ret != 0 && ret != -EEXIST)
                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;
        ret = btrfs_csum_data(root, data, len, item->csum);
+       btrfs_set_csum_extent_offset(item, extent_offset);
        btrfs_mark_buffer_dirty(path->nodes[0]);
 fail:
        btrfs_release_path(root, path);
@@ -111,12 +207,13 @@ int btrfs_csum_verify_file_block(struct btrfs_root *root,
        file_key.flags = 0;
        btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
        mutex_lock(&root->fs_info->fs_mutex);
-       ret = btrfs_search_slot(NULL, root, &file_key, path, 0, 0);
-       if (ret)
+
+       item = __lookup_csum_item(root, path, objectid, offset);
+       if (IS_ERR(item)) {
+               ret = PTR_ERR(item);
                goto fail;
-       item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
-                             struct btrfs_csum_item);
-       ret = 0;
+       }
+
        ret = btrfs_csum_data(root, data, len, result);
        WARN_ON(ret);
        if (memcmp(result, item->csum, BTRFS_CSUM_SIZE))

diff --cc fs/btrfs/super.c
Simple merge