Merge Btrfs into fs/btrfs
[pandora-kernel.git] / fs / btrfs / file-item.c
index 5230a44..6dbe88b 100644 (file)
-#include <linux/module.h>
+/*
+ * Copyright (C) 2007 Oracle.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/bio.h>
+#include <linux/pagemap.h>
+#include <linux/highmem.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
+#include "print-tree.h"
 
-int btrfs_alloc_file_extent(struct btrfs_trans_handle *trans,
-                              struct btrfs_root *root,
-                              u64 objectid, u64 offset,
-                              u64 num_blocks, u64 hint_block,
-                              u64 *result)
+#define MAX_CSUM_ITEMS(r) ((((BTRFS_LEAF_DATA_SIZE(r) - \
+                              sizeof(struct btrfs_item) * 2) / \
+                              BTRFS_CRC32_SIZE) - 1))
+int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
+                            struct btrfs_root *root,
+                            u64 objectid, u64 pos,
+                            u64 disk_offset, u64 disk_num_bytes,
+                            u64 num_bytes, u64 offset)
 {
-       struct btrfs_key ins;
        int ret = 0;
        struct btrfs_file_extent_item *item;
        struct btrfs_key file_key;
-       struct btrfs_path path;
+       struct btrfs_path *path;
+       struct extent_buffer *leaf;
 
-       btrfs_init_path(&path);
-       ret = btrfs_alloc_extent(trans, root, num_blocks, hint_block,
-                                (u64)-1, objectid, &ins);
-       BUG_ON(ret);
+       path = btrfs_alloc_path();
+       BUG_ON(!path);
        file_key.objectid = objectid;
-       file_key.offset = offset;
-       file_key.flags = 0;
+       file_key.offset = pos;
        btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
 
-       ret = btrfs_insert_empty_item(trans, root, &path, &file_key,
+       ret = btrfs_insert_empty_item(trans, root, path, &file_key,
                                      sizeof(*item));
+       if (ret < 0)
+               goto out;
        BUG_ON(ret);
-       item = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0],
+       leaf = path->nodes[0];
+       item = btrfs_item_ptr(leaf, path->slots[0],
                              struct btrfs_file_extent_item);
-       btrfs_set_file_extent_disk_blocknr(item, ins.objectid);
-       btrfs_set_file_extent_disk_num_blocks(item, ins.offset);
-       btrfs_set_file_extent_offset(item, 0);
-       btrfs_set_file_extent_num_blocks(item, ins.offset);
-       btrfs_set_file_extent_generation(item, trans->transid);
-       mark_buffer_dirty(path.nodes[0]);
-       *result = ins.objectid;
-       btrfs_release_path(root, &path);
-       return 0;
+       btrfs_set_file_extent_disk_bytenr(leaf, item, disk_offset);
+       btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes);
+       btrfs_set_file_extent_offset(leaf, item, offset);
+       btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
+       btrfs_set_file_extent_generation(leaf, item, trans->transid);
+       btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
+       btrfs_mark_buffer_dirty(leaf);
+out:
+       btrfs_free_path(path);
+       return ret;
+}
+
+struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
+                                         struct btrfs_root *root,
+                                         struct btrfs_path *path,
+                                         u64 objectid, u64 offset,
+                                         int cow)
+{
+       int ret;
+       struct btrfs_key file_key;
+       struct btrfs_key found_key;
+       struct btrfs_csum_item *item;
+       struct extent_buffer *leaf;
+       u64 csum_offset = 0;
+       int csums_in_item;
+
+       file_key.objectid = objectid;
+       file_key.offset = offset;
+       btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
+       ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
+       if (ret < 0)
+               goto fail;
+       leaf = path->nodes[0];
+       if (ret > 0) {
+               ret = 1;
+               if (path->slots[0] == 0)
+                       goto fail;
+               path->slots[0]--;
+               btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+               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;
+               csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
+               csums_in_item /= BTRFS_CRC32_SIZE;
+
+               if (csum_offset >= csums_in_item) {
+                       ret = -EFBIG;
+                       goto fail;
+               }
+       }
+       item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
+       item = (struct btrfs_csum_item *)((unsigned char *)item +
+                                         csum_offset * BTRFS_CRC32_SIZE);
+       return item;
+fail:
+       if (ret > 0)
+               ret = -ENOENT;
+       return ERR_PTR(ret);
 }
 
+
 int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
                             struct btrfs_root *root,
                             struct btrfs_path *path, u64 objectid,
@@ -52,8 +129,384 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
 
        file_key.objectid = objectid;
        file_key.offset = offset;
-       file_key.flags = 0;
        btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
        ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
        return ret;
 }
+
+int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode,
+                         struct bio *bio)
+{
+       u32 sum;
+       struct bio_vec *bvec = bio->bi_io_vec;
+       int bio_index = 0;
+       u64 offset;
+       u64 item_start_offset = 0;
+       u64 item_last_offset = 0;
+       u32 diff;
+       int ret;
+       struct btrfs_path *path;
+       struct btrfs_csum_item *item = NULL;
+       struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+
+       path = btrfs_alloc_path();
+       if (bio->bi_size > PAGE_CACHE_SIZE * 8)
+               path->reada = 2;
+
+       WARN_ON(bio->bi_vcnt <= 0);
+
+       while(bio_index < bio->bi_vcnt) {
+               offset = page_offset(bvec->bv_page) + bvec->bv_offset;
+               ret = btrfs_find_ordered_sum(inode, offset, &sum);
+               if (ret == 0)
+                       goto found;
+
+               if (!item || offset < item_start_offset ||
+                   offset >= item_last_offset) {
+                       struct btrfs_key found_key;
+                       u32 item_size;
+
+                       if (item)
+                               btrfs_release_path(root, path);
+                       item = btrfs_lookup_csum(NULL, root, path,
+                                                inode->i_ino, offset, 0);
+                       if (IS_ERR(item)) {
+                               ret = PTR_ERR(item);
+                               if (ret == -ENOENT || ret == -EFBIG)
+                                       ret = 0;
+                               sum = 0;
+                               printk("no csum found for inode %lu start "
+                                      "%llu\n", inode->i_ino,
+                                      (unsigned long long)offset);
+                               item = NULL;
+                               goto found;
+                       }
+                       btrfs_item_key_to_cpu(path->nodes[0], &found_key,
+                                             path->slots[0]);
+
+                       item_start_offset = found_key.offset;
+                       item_size = btrfs_item_size_nr(path->nodes[0],
+                                                      path->slots[0]);
+                       item_last_offset = item_start_offset +
+                               (item_size / BTRFS_CRC32_SIZE) *
+                               root->sectorsize;
+                       item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+                                             struct btrfs_csum_item);
+               }
+               /*
+                * this byte range must be able to fit inside
+                * a single leaf so it will also fit inside a u32
+                */
+               diff = offset - item_start_offset;
+               diff = diff / root->sectorsize;
+               diff = diff * BTRFS_CRC32_SIZE;
+
+               read_extent_buffer(path->nodes[0], &sum,
+                                  ((unsigned long)item) + diff,
+                                  BTRFS_CRC32_SIZE);
+found:
+               set_state_private(io_tree, offset, sum);
+               bio_index++;
+               bvec++;
+       }
+       btrfs_free_path(path);
+       return 0;
+}
+
+int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
+                      struct bio *bio)
+{
+       struct btrfs_ordered_sum *sums;
+       struct btrfs_sector_sum *sector_sum;
+       struct btrfs_ordered_extent *ordered;
+       char *data;
+       struct bio_vec *bvec = bio->bi_io_vec;
+       int bio_index = 0;
+       unsigned long total_bytes = 0;
+       unsigned long this_sum_bytes = 0;
+       u64 offset;
+
+       WARN_ON(bio->bi_vcnt <= 0);
+       sums = kzalloc(btrfs_ordered_sum_size(root, bio->bi_size), GFP_NOFS);
+       if (!sums)
+               return -ENOMEM;
+
+       sector_sum = sums->sums;
+       sums->file_offset = page_offset(bvec->bv_page) + bvec->bv_offset;
+       sums->len = bio->bi_size;
+       INIT_LIST_HEAD(&sums->list);
+       ordered = btrfs_lookup_ordered_extent(inode, sums->file_offset);
+       BUG_ON(!ordered);
+
+       while(bio_index < bio->bi_vcnt) {
+               offset = page_offset(bvec->bv_page) + bvec->bv_offset;
+               if (offset >= ordered->file_offset + ordered->len ||
+                   offset < ordered->file_offset) {
+                       unsigned long bytes_left;
+                       sums->len = this_sum_bytes;
+                       this_sum_bytes = 0;
+                       btrfs_add_ordered_sum(inode, ordered, sums);
+                       btrfs_put_ordered_extent(ordered);
+
+                       bytes_left = bio->bi_size - total_bytes;
+
+                       sums = kzalloc(btrfs_ordered_sum_size(root, bytes_left),
+                                      GFP_NOFS);
+                       BUG_ON(!sums);
+                       sector_sum = sums->sums;
+                       sums->len = bytes_left;
+                       sums->file_offset = offset;
+                       ordered = btrfs_lookup_ordered_extent(inode,
+                                                     sums->file_offset);
+                       BUG_ON(!ordered);
+               }
+
+               data = kmap_atomic(bvec->bv_page, KM_USER0);
+               sector_sum->sum = ~(u32)0;
+               sector_sum->sum = btrfs_csum_data(root,
+                                                 data + bvec->bv_offset,
+                                                 sector_sum->sum,
+                                                 bvec->bv_len);
+               kunmap_atomic(data, KM_USER0);
+               btrfs_csum_final(sector_sum->sum,
+                                (char *)&sector_sum->sum);
+               sector_sum->offset = page_offset(bvec->bv_page) +
+                       bvec->bv_offset;
+
+               sector_sum++;
+               bio_index++;
+               total_bytes += bvec->bv_len;
+               this_sum_bytes += bvec->bv_len;
+               bvec++;
+       }
+       this_sum_bytes = 0;
+       btrfs_add_ordered_sum(inode, ordered, sums);
+       btrfs_put_ordered_extent(ordered);
+       return 0;
+}
+
+int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
+                          struct btrfs_root *root, struct inode *inode,
+                          struct btrfs_ordered_sum *sums)
+{
+       u64 objectid = inode->i_ino;
+       u64 offset;
+       int ret;
+       struct btrfs_key file_key;
+       struct btrfs_key found_key;
+       u64 next_offset;
+       u64 total_bytes = 0;
+       int found_next;
+       struct btrfs_path *path;
+       struct btrfs_csum_item *item;
+       struct btrfs_csum_item *item_end;
+       struct extent_buffer *leaf = NULL;
+       u64 csum_offset;
+       struct btrfs_sector_sum *sector_sum;
+       u32 nritems;
+       u32 ins_size;
+       char *eb_map;
+       char *eb_token;
+       unsigned long map_len;
+       unsigned long map_start;
+
+       path = btrfs_alloc_path();
+       BUG_ON(!path);
+       sector_sum = sums->sums;
+again:
+       next_offset = (u64)-1;
+       found_next = 0;
+       offset = sector_sum->offset;
+       file_key.objectid = objectid;
+       file_key.offset = offset;
+       btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
+
+       mutex_lock(&BTRFS_I(inode)->csum_mutex);
+       item = btrfs_lookup_csum(trans, root, path, objectid, offset, 1);
+       if (!IS_ERR(item)) {
+               leaf = path->nodes[0];
+               ret = 0;
+               goto found;
+       }
+       ret = PTR_ERR(item);
+       if (ret == -EFBIG) {
+               u32 item_size;
+               /* we found one, but it isn't big enough yet */
+               leaf = path->nodes[0];
+               item_size = btrfs_item_size_nr(leaf, path->slots[0]);
+               if ((item_size / BTRFS_CRC32_SIZE) >= MAX_CSUM_ITEMS(root)) {
+                       /* already at max size, make a new one */
+                       goto insert;
+               }
+       } else {
+               int slot = path->slots[0] + 1;
+               /* we didn't find a csum item, insert one */
+               nritems = btrfs_header_nritems(path->nodes[0]);
+               if (path->slots[0] >= nritems - 1) {
+                       ret = btrfs_next_leaf(root, path);
+                       if (ret == 1)
+                               found_next = 1;
+                       if (ret != 0)
+                               goto insert;
+                       slot = 0;
+               }
+               btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
+               if (found_key.objectid != objectid ||
+                   found_key.type != BTRFS_CSUM_ITEM_KEY) {
+                       found_next = 1;
+                       goto insert;
+               }
+               next_offset = found_key.offset;
+               found_next = 1;
+               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,
+                               BTRFS_CRC32_SIZE, 1);
+       if (ret < 0)
+               goto fail_unlock;
+       if (ret == 0) {
+               BUG();
+       }
+       if (path->slots[0] == 0) {
+               goto insert;
+       }
+       path->slots[0]--;
+       leaf = path->nodes[0];
+       btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+       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)) {
+               goto insert;
+       }
+       if (csum_offset >= btrfs_item_size_nr(leaf, path->slots[0]) /
+           BTRFS_CRC32_SIZE) {
+               u32 diff = (csum_offset + 1) * BTRFS_CRC32_SIZE;
+               diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
+               if (diff != BTRFS_CRC32_SIZE)
+                       goto insert;
+               ret = btrfs_extend_item(trans, root, path, diff);
+               BUG_ON(ret);
+               goto csum;
+       }
+
+insert:
+       btrfs_release_path(root, path);
+       csum_offset = 0;
+       if (found_next) {
+               u64 tmp = min((u64)i_size_read(inode), next_offset);
+               tmp -= offset & ~((u64)root->sectorsize -1);
+               tmp >>= root->fs_info->sb->s_blocksize_bits;
+               tmp = max((u64)1, tmp);
+               tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root));
+               ins_size = BTRFS_CRC32_SIZE * tmp;
+       } else {
+               ins_size = BTRFS_CRC32_SIZE;
+       }
+       ret = btrfs_insert_empty_item(trans, root, path, &file_key,
+                                     ins_size);
+       if (ret < 0)
+               goto fail_unlock;
+       if (ret != 0) {
+               WARN_ON(1);
+               goto fail_unlock;
+       }
+csum:
+       leaf = path->nodes[0];
+       item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
+       ret = 0;
+       item = (struct btrfs_csum_item *)((unsigned char *)item +
+                                         csum_offset * BTRFS_CRC32_SIZE);
+found:
+       item_end = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
+       item_end = (struct btrfs_csum_item *)((unsigned char *)item_end +
+                                     btrfs_item_size_nr(leaf, path->slots[0]));
+       eb_token = NULL;
+       mutex_unlock(&BTRFS_I(inode)->csum_mutex);
+       cond_resched();
+next_sector:
+
+       if (!eb_token ||
+          (unsigned long)item  + BTRFS_CRC32_SIZE >= map_start + map_len) {
+               int err;
+
+               if (eb_token)
+                       unmap_extent_buffer(leaf, eb_token, KM_USER1);
+               eb_token = NULL;
+               err = map_private_extent_buffer(leaf, (unsigned long)item,
+                                               BTRFS_CRC32_SIZE,
+                                               &eb_token, &eb_map,
+                                               &map_start, &map_len, KM_USER1);
+               if (err)
+                       eb_token = NULL;
+       }
+       if (eb_token) {
+               memcpy(eb_token + ((unsigned long)item & (PAGE_CACHE_SIZE - 1)),
+                      &sector_sum->sum, BTRFS_CRC32_SIZE);
+       } else {
+               write_extent_buffer(leaf, &sector_sum->sum,
+                                   (unsigned long)item, BTRFS_CRC32_SIZE);
+       }
+
+       total_bytes += root->sectorsize;
+       sector_sum++;
+       if (total_bytes < sums->len) {
+               item = (struct btrfs_csum_item *)((char *)item +
+                                                 BTRFS_CRC32_SIZE);
+               if (item < item_end && offset + PAGE_CACHE_SIZE ==
+                   sector_sum->offset) {
+                           offset = sector_sum->offset;
+                       goto next_sector;
+               }
+       }
+       if (eb_token) {
+               unmap_extent_buffer(leaf, eb_token, KM_USER1);
+               eb_token = NULL;
+       }
+       btrfs_mark_buffer_dirty(path->nodes[0]);
+       cond_resched();
+       if (total_bytes < sums->len) {
+               btrfs_release_path(root, path);
+               goto again;
+       }
+out:
+       btrfs_free_path(path);
+       return ret;
+
+fail_unlock:
+       mutex_unlock(&BTRFS_I(inode)->csum_mutex);
+       goto out;
+}
+
+int btrfs_csum_truncate(struct btrfs_trans_handle *trans,
+                       struct btrfs_root *root, struct btrfs_path *path,
+                       u64 isize)
+{
+       struct btrfs_key key;
+       struct extent_buffer *leaf = path->nodes[0];
+       int slot = path->slots[0];
+       int ret;
+       u32 new_item_size;
+       u64 new_item_span;
+       u64 blocks;
+
+       btrfs_item_key_to_cpu(leaf, &key, slot);
+       if (isize <= key.offset)
+               return 0;
+       new_item_span = isize - key.offset;
+       blocks = (new_item_span + root->sectorsize - 1) >>
+               root->fs_info->sb->s_blocksize_bits;
+       new_item_size = blocks * BTRFS_CRC32_SIZE;
+       if (new_item_size >= btrfs_item_size_nr(leaf, slot))
+               return 0;
+       ret = btrfs_truncate_item(trans, root, path, new_item_size, 1);
+       BUG_ON(ret);
+       return ret;
+}