Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
[linux-2.6-microblaze.git] / fs / btrfs / file-item.c
index 40daf1a..1545c22 100644 (file)
  * Finally new_i_size should only be set in the case of truncate where we're not
  * ready to use i_size_read() as the limiter yet.
  */
-void btrfs_inode_safe_disk_i_size_write(struct inode *inode, u64 new_i_size)
+void btrfs_inode_safe_disk_i_size_write(struct btrfs_inode *inode, u64 new_i_size)
 {
-       struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
+       struct btrfs_fs_info *fs_info = inode->root->fs_info;
        u64 start, end, i_size;
        int ret;
 
-       i_size = new_i_size ?: i_size_read(inode);
+       i_size = new_i_size ?: i_size_read(&inode->vfs_inode);
        if (btrfs_fs_incompat(fs_info, NO_HOLES)) {
-               BTRFS_I(inode)->disk_i_size = i_size;
+               inode->disk_i_size = i_size;
                return;
        }
 
-       spin_lock(&BTRFS_I(inode)->lock);
-       ret = find_contiguous_extent_bit(&BTRFS_I(inode)->file_extent_tree, 0,
-                                        &start, &end, EXTENT_DIRTY);
+       spin_lock(&inode->lock);
+       ret = find_contiguous_extent_bit(&inode->file_extent_tree, 0, &start,
+                                        &end, EXTENT_DIRTY);
        if (!ret && start == 0)
                i_size = min(i_size, end + 1);
        else
                i_size = 0;
-       BTRFS_I(inode)->disk_i_size = i_size;
-       spin_unlock(&BTRFS_I(inode)->lock);
+       inode->disk_i_size = i_size;
+       spin_unlock(&inode->lock);
 }
 
 /**
@@ -238,12 +238,117 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
        return ret;
 }
 
+/*
+ * Find checksums for logical bytenr range [disk_bytenr, disk_bytenr + len) and
+ * estore the result to @dst.
+ *
+ * Return >0 for the number of sectors we found.
+ * Return 0 for the range [disk_bytenr, disk_bytenr + sectorsize) has no csum
+ * for it. Caller may want to try next sector until one range is hit.
+ * Return <0 for fatal error.
+ */
+static int search_csum_tree(struct btrfs_fs_info *fs_info,
+                           struct btrfs_path *path, u64 disk_bytenr,
+                           u64 len, u8 *dst)
+{
+       struct btrfs_csum_item *item = NULL;
+       struct btrfs_key key;
+       const u32 sectorsize = fs_info->sectorsize;
+       const u32 csum_size = fs_info->csum_size;
+       u32 itemsize;
+       int ret;
+       u64 csum_start;
+       u64 csum_len;
+
+       ASSERT(IS_ALIGNED(disk_bytenr, sectorsize) &&
+              IS_ALIGNED(len, sectorsize));
+
+       /* Check if the current csum item covers disk_bytenr */
+       if (path->nodes[0]) {
+               item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+                                     struct btrfs_csum_item);
+               btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
+               itemsize = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
+
+               csum_start = key.offset;
+               csum_len = (itemsize / csum_size) * sectorsize;
+
+               if (in_range(disk_bytenr, csum_start, csum_len))
+                       goto found;
+       }
+
+       /* Current item doesn't contain the desired range, search again */
+       btrfs_release_path(path);
+       item = btrfs_lookup_csum(NULL, fs_info->csum_root, path, disk_bytenr, 0);
+       if (IS_ERR(item)) {
+               ret = PTR_ERR(item);
+               goto out;
+       }
+       btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
+       itemsize = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
+
+       csum_start = key.offset;
+       csum_len = (itemsize / csum_size) * sectorsize;
+       ASSERT(in_range(disk_bytenr, csum_start, csum_len));
+
+found:
+       ret = (min(csum_start + csum_len, disk_bytenr + len) -
+                  disk_bytenr) >> fs_info->sectorsize_bits;
+       read_extent_buffer(path->nodes[0], dst, (unsigned long)item,
+                       ret * csum_size);
+out:
+       if (ret == -ENOENT)
+               ret = 0;
+       return ret;
+}
+
+/*
+ * Locate the file_offset of @cur_disk_bytenr of a @bio.
+ *
+ * Bio of btrfs represents read range of
+ * [bi_sector << 9, bi_sector << 9 + bi_size).
+ * Knowing this, we can iterate through each bvec to locate the page belong to
+ * @cur_disk_bytenr and get the file offset.
+ *
+ * @inode is used to determine if the bvec page really belongs to @inode.
+ *
+ * Return 0 if we can't find the file offset
+ * Return >0 if we find the file offset and restore it to @file_offset_ret
+ */
+static int search_file_offset_in_bio(struct bio *bio, struct inode *inode,
+                                    u64 disk_bytenr, u64 *file_offset_ret)
+{
+       struct bvec_iter iter;
+       struct bio_vec bvec;
+       u64 cur = bio->bi_iter.bi_sector << SECTOR_SHIFT;
+       int ret = 0;
+
+       bio_for_each_segment(bvec, bio, iter) {
+               struct page *page = bvec.bv_page;
+
+               if (cur > disk_bytenr)
+                       break;
+               if (cur + bvec.bv_len <= disk_bytenr) {
+                       cur += bvec.bv_len;
+                       continue;
+               }
+               ASSERT(in_range(disk_bytenr, cur, bvec.bv_len));
+               if (page->mapping && page->mapping->host &&
+                   page->mapping->host == inode) {
+                       ret = 1;
+                       *file_offset_ret = page_offset(page) + bvec.bv_offset +
+                                          disk_bytenr - cur;
+                       break;
+               }
+       }
+       return ret;
+}
+
 /**
- * btrfs_lookup_bio_sums - Look up checksums for a bio.
+ * Lookup the checksum for the read bio in csum tree.
+ *
  * @inode: inode that the bio is for.
  * @bio: bio to look up.
- * @offset: Unless (u64)-1, look up checksums for this offset in the file.
- *          If (u64)-1, use the page offsets from the bio instead.
  * @dst: Buffer of size nblocks * btrfs_super_csum_size() used to return
  *       checksum (nblocks = bio->bi_iter.bi_size / fs_info->sectorsize). If
  *       NULL, the checksum buffer is allocated and returned in
@@ -251,34 +356,40 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
  *
  * Return: BLK_STS_RESOURCE if allocating memory fails, BLK_STS_OK otherwise.
  */
-blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
-                                  u64 offset, u8 *dst)
+blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, u8 *dst)
 {
        struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
-       struct bio_vec bvec;
-       struct bvec_iter iter;
-       struct btrfs_csum_item *item = NULL;
        struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
        struct btrfs_path *path;
-       const bool page_offsets = (offset == (u64)-1);
+       const u32 sectorsize = fs_info->sectorsize;
+       const u32 csum_size = fs_info->csum_size;
+       u32 orig_len = bio->bi_iter.bi_size;
+       u64 orig_disk_bytenr = bio->bi_iter.bi_sector << SECTOR_SHIFT;
+       u64 cur_disk_bytenr;
        u8 *csum;
-       u64 item_start_offset = 0;
-       u64 item_last_offset = 0;
-       u64 disk_bytenr;
-       u64 page_bytes_left;
-       u32 diff;
-       int nblocks;
+       const unsigned int nblocks = orig_len >> fs_info->sectorsize_bits;
        int count = 0;
-       const u32 csum_size = fs_info->csum_size;
 
        if (!fs_info->csum_root || (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
                return BLK_STS_OK;
 
+       /*
+        * This function is only called for read bio.
+        *
+        * This means two things:
+        * - All our csums should only be in csum tree
+        *   No ordered extents csums, as ordered extents are only for write
+        *   path.
+        * - No need to bother any other info from bvec
+        *   Since we're looking up csums, the only important info is the
+        *   disk_bytenr and the length, which can be extracted from bi_iter
+        *   directly.
+        */
+       ASSERT(bio_op(bio) == REQ_OP_READ);
        path = btrfs_alloc_path();
        if (!path)
                return BLK_STS_RESOURCE;
 
-       nblocks = bio->bi_iter.bi_size >> fs_info->sectorsize_bits;
        if (!dst) {
                struct btrfs_io_bio *btrfs_bio = btrfs_io_bio(bio);
 
@@ -297,7 +408,11 @@ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
                csum = dst;
        }
 
-       if (bio->bi_iter.bi_size > PAGE_SIZE * 8)
+       /*
+        * If requested number of sectors is larger than one leaf can contain,
+        * kick the readahead for csum tree.
+        */
+       if (nblocks > fs_info->csums_per_leaf)
                path->reada = READA_FORWARD;
 
        /*
@@ -311,85 +426,62 @@ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
                path->skip_locking = 1;
        }
 
-       disk_bytenr = (u64)bio->bi_iter.bi_sector << 9;
+       for (cur_disk_bytenr = orig_disk_bytenr;
+            cur_disk_bytenr < orig_disk_bytenr + orig_len;
+            cur_disk_bytenr += (count * sectorsize)) {
+               u64 search_len = orig_disk_bytenr + orig_len - cur_disk_bytenr;
+               unsigned int sector_offset;
+               u8 *csum_dst;
 
-       bio_for_each_segment(bvec, bio, iter) {
-               page_bytes_left = bvec.bv_len;
-               if (count)
-                       goto next;
+               /*
+                * Although both cur_disk_bytenr and orig_disk_bytenr is u64,
+                * we're calculating the offset to the bio start.
+                *
+                * Bio size is limited to UINT_MAX, thus unsigned int is large
+                * enough to contain the raw result, not to mention the right
+                * shifted result.
+                */
+               ASSERT(cur_disk_bytenr - orig_disk_bytenr < UINT_MAX);
+               sector_offset = (cur_disk_bytenr - orig_disk_bytenr) >>
+                               fs_info->sectorsize_bits;
+               csum_dst = csum + sector_offset * csum_size;
 
-               if (page_offsets)
-                       offset = page_offset(bvec.bv_page) + bvec.bv_offset;
-               count = btrfs_find_ordered_sum(BTRFS_I(inode), offset,
-                                              disk_bytenr, csum, nblocks);
-               if (count)
-                       goto found;
+               count = search_csum_tree(fs_info, path, cur_disk_bytenr,
+                                        search_len, csum_dst);
+               if (count <= 0) {
+                       /*
+                        * Either we hit a critical error or we didn't find
+                        * the csum.
+                        * Either way, we put zero into the csums dst, and skip
+                        * to the next sector.
+                        */
+                       memset(csum_dst, 0, csum_size);
+                       count = 1;
 
-               if (!item || disk_bytenr < item_start_offset ||
-                   disk_bytenr >= item_last_offset) {
-                       struct btrfs_key found_key;
-                       u32 item_size;
-
-                       if (item)
-                               btrfs_release_path(path);
-                       item = btrfs_lookup_csum(NULL, fs_info->csum_root,
-                                                path, disk_bytenr, 0);
-                       if (IS_ERR(item)) {
-                               count = 1;
-                               memset(csum, 0, csum_size);
-                               if (BTRFS_I(inode)->root->root_key.objectid ==
-                                   BTRFS_DATA_RELOC_TREE_OBJECTID) {
-                                       set_extent_bits(io_tree, offset,
-                                               offset + fs_info->sectorsize - 1,
+                       /*
+                        * For data reloc inode, we need to mark the range
+                        * NODATASUM so that balance won't report false csum
+                        * error.
+                        */
+                       if (BTRFS_I(inode)->root->root_key.objectid ==
+                           BTRFS_DATA_RELOC_TREE_OBJECTID) {
+                               u64 file_offset;
+                               int ret;
+
+                               ret = search_file_offset_in_bio(bio, inode,
+                                               cur_disk_bytenr, &file_offset);
+                               if (ret)
+                                       set_extent_bits(io_tree, file_offset,
+                                               file_offset + sectorsize - 1,
                                                EXTENT_NODATASUM);
-                               } else {
-                                       btrfs_info_rl(fs_info,
-                                                  "no csum found for inode %llu start %llu",
-                                              btrfs_ino(BTRFS_I(inode)), offset);
-                               }
-                               item = NULL;
-                               btrfs_release_path(path);
-                               goto found;
+                       } else {
+                               btrfs_warn_rl(fs_info,
+                       "csum hole found for disk bytenr range [%llu, %llu)",
+                               cur_disk_bytenr, cur_disk_bytenr + sectorsize);
                        }
-                       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 / csum_size) *
-                               fs_info->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 = disk_bytenr - item_start_offset;
-               diff = diff >> fs_info->sectorsize_bits;
-               diff = diff * csum_size;
-               count = min_t(int, nblocks, (item_last_offset - disk_bytenr) >>
-                                           fs_info->sectorsize_bits);
-               read_extent_buffer(path->nodes[0], csum,
-                                  ((unsigned long)item) + diff,
-                                  csum_size * count);
-found:
-               csum += count * csum_size;
-               nblocks -= count;
-next:
-               while (count > 0) {
-                       count--;
-                       disk_bytenr += fs_info->sectorsize;
-                       offset += fs_info->sectorsize;
-                       page_bytes_left -= fs_info->sectorsize;
-                       if (!page_bytes_left)
-                               break; /* move to next bio */
                }
        }
 
-       WARN_ON_ONCE(count);
        btrfs_free_path(path);
        return BLK_STS_OK;
 }
@@ -556,7 +648,7 @@ blk_status_t btrfs_csum_one_bio(struct btrfs_inode *inode, struct bio *bio,
        else
                offset = 0; /* shut up gcc */
 
-       sums->bytenr = (u64)bio->bi_iter.bi_sector << 9;
+       sums->bytenr = bio->bi_iter.bi_sector << 9;
        index = 0;
 
        shash->tfm = fs_info->csum_shash;
@@ -595,7 +687,7 @@ blk_status_t btrfs_csum_one_bio(struct btrfs_inode *inode, struct bio *bio,
                                ordered = btrfs_lookup_ordered_extent(inode,
                                                                offset);
                                ASSERT(ordered); /* Logic error */
-                               sums->bytenr = ((u64)bio->bi_iter.bi_sector << 9)
+                               sums->bytenr = (bio->bi_iter.bi_sector << 9)
                                        + total_bytes;
                                index = 0;
                        }