Btrfs: Add support for online device removal

[safe/jmp/linux-2.6] / fs / btrfs / file-item.c

diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 614176e..f537eb4 100644 (file)
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -16,6 +16,9 @@
  * 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"
@@ -25,10 +28,10 @@
                               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 offset, u64 disk_num_bytes,
-                              u64 num_bytes)
+                            struct btrfs_root *root,
+                            u64 objectid, u64 pos,
+                            u64 disk_offset, u64 disk_num_bytes,
+                            u64 num_bytes, u64 offset)
 {
        int ret = 0;
        struct btrfs_file_extent_item *item;
@@ -50,9 +53,9 @@ int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
        leaf = path->nodes[0];
        item = btrfs_item_ptr(leaf, path->slots[0],
                              struct btrfs_file_extent_item);
-       btrfs_set_file_extent_disk_bytenr(leaf, item, offset);
+       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, 0);
+       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);
@@ -131,28 +134,65 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
        return ret;
 }
 
-int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
-                         struct btrfs_root *root,
-                         struct inode *inode,
-                         u64 objectid, u64 offset,
-                         char *data, size_t len)
+int btrfs_csum_one_bio(struct btrfs_root *root,
+                      struct bio *bio, char **sums_ret)
 {
+       u32 *sums;
+       char *data;
+       struct bio_vec *bvec = bio->bi_io_vec;
+       int bio_index = 0;
+
+       sums = kmalloc(bio->bi_vcnt * BTRFS_CRC32_SIZE, GFP_NOFS);
+       if (!sums)
+               return -ENOMEM;
+       *sums_ret = (char *)sums;
+
+       while(bio_index < bio->bi_vcnt) {
+               data = kmap_atomic(bvec->bv_page, KM_USER0);
+               *sums = ~(u32)0;
+               *sums = btrfs_csum_data(root, data + bvec->bv_offset,
+                                       *sums, bvec->bv_len);
+               kunmap_atomic(data, KM_USER0);
+               btrfs_csum_final(*sums, (char *)sums);
+               sums++;
+               bio_index++;
+               bvec++;
+       }
+       return 0;
+}
+
+int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
+                          struct btrfs_root *root, struct inode *inode,
+                          struct bio *bio, char *sums)
+{
+       u64 objectid = inode->i_ino;
+       u64 offset;
        int ret;
        struct btrfs_key file_key;
        struct btrfs_key found_key;
-       u64 next_offset = (u64)-1;
-       int found_next = 0;
+       u64 next_offset;
+       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;
-       u32 csum_result = ~(u32)0;
+       u32 *sums32 = (u32 *)sums;
        u32 nritems;
        u32 ins_size;
+       int bio_index = 0;
+       struct bio_vec *bvec = bio->bi_io_vec;
+       char *eb_map;
+       char *eb_token;
+       unsigned long map_len;
+       unsigned long map_start;
 
        path = btrfs_alloc_path();
        BUG_ON(!path);
-
+again:
+       next_offset = (u64)-1;
+       found_next = 0;
+       offset = page_offset(bvec->bv_page) + bvec->bv_offset;
        file_key.objectid = objectid;
        file_key.offset = offset;
        btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
@@ -259,13 +299,55 @@ csum:
        item = (struct btrfs_csum_item *)((unsigned char *)item +
                                          csum_offset * BTRFS_CRC32_SIZE);
 found:
-       csum_result = btrfs_csum_data(root, data, csum_result, len);
-       btrfs_csum_final(csum_result, (char *)&csum_result);
-       write_extent_buffer(leaf, &csum_result, (unsigned long)item,
-                           BTRFS_CRC32_SIZE);
+       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;
+next_bvec:
+
+       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)),
+                      sums32, BTRFS_CRC32_SIZE);
+       } else {
+               write_extent_buffer(leaf, sums32, (unsigned long)item,
+                                   BTRFS_CRC32_SIZE);
+       }
+       bio_index++;
+       bvec++;
+       sums32++;
+       if (bio_index < bio->bi_vcnt) {
+               item = (struct btrfs_csum_item *)((char *)item +
+                                                 BTRFS_CRC32_SIZE);
+               if (item < item_end && offset + PAGE_CACHE_SIZE ==
+                   page_offset(bvec->bv_page)) {
+                       offset = page_offset(bvec->bv_page);
+                       goto next_bvec;
+               }
+       }
+       if (eb_token) {
+               unmap_extent_buffer(leaf, eb_token, KM_USER1);
+               eb_token = NULL;
+       }
        btrfs_mark_buffer_dirty(path->nodes[0]);
+       if (bio_index < bio->bi_vcnt) {
+               btrfs_release_path(root, path);
+               goto again;
+       }
 fail:
-       btrfs_release_path(root, path);
        btrfs_free_path(path);
        return ret;
 }