Btrfs: sparse files!

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

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 3330004..e8f7411 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1180,6 +1180,7 @@ int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
 int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
                               struct btrfs_root *root,
                               u64 objectid, u64 pos, u64 offset,
+                              u64 disk_num_blocks,
                               u64 num_blocks);
 int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
                             struct btrfs_root *root,

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index e3c6bfe..a366415 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -443,6 +443,7 @@ int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
        buf_leaf = btrfs_buffer_leaf(buf);
        for (i = 0; i < btrfs_header_nritems(&buf_node->header); i++) {
                if (leaf) {
+                       u64 disk_blocknr;
                        key = &buf_leaf->items[i].key;
                        if (btrfs_disk_key_type(key) != BTRFS_EXTENT_DATA_KEY)
                                continue;
@@ -451,8 +452,10 @@ int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                        if (btrfs_file_extent_type(fi) ==
                            BTRFS_FILE_EXTENT_INLINE)
                                continue;
-                       ret = btrfs_inc_extent_ref(trans, root,
-                                   btrfs_file_extent_disk_blocknr(fi),
+                       disk_blocknr = btrfs_file_extent_disk_blocknr(fi);
+                       if (disk_blocknr == 0)
+                               continue;
+                       ret = btrfs_inc_extent_ref(trans, root, disk_blocknr,
                                    btrfs_file_extent_disk_num_blocks(fi));
                        BUG_ON(ret);
                } else {
@@ -1248,6 +1251,7 @@ static int drop_leaf_ref(struct btrfs_trans_handle *trans,
        leaf = btrfs_buffer_leaf(cur);
        nritems = btrfs_header_nritems(&leaf->header);
        for (i = 0; i < nritems; i++) {
+               u64 disk_blocknr;
                key = &leaf->items[i].key;
                if (btrfs_disk_key_type(key) != BTRFS_EXTENT_DATA_KEY)
                        continue;
@@ -1258,8 +1262,10 @@ static int drop_leaf_ref(struct btrfs_trans_handle *trans,
                 * FIXME make sure to insert a trans record that
                 * repeats the snapshot del on crash
                 */
-               ret = btrfs_free_extent(trans, root,
-                                       btrfs_file_extent_disk_blocknr(fi),
+               disk_blocknr = btrfs_file_extent_disk_blocknr(fi);
+               if (disk_blocknr == 0)
+                       continue;
+               ret = btrfs_free_extent(trans, root, disk_blocknr,
                                        btrfs_file_extent_disk_num_blocks(fi),
                                        0);
                BUG_ON(ret);

diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index a66709e..7990b57 100644 (file)
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -9,7 +9,8 @@
 int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
                               struct btrfs_root *root,
                               u64 objectid, u64 pos,
-                              u64 offset, u64 num_blocks)
+                              u64 offset, u64 disk_num_blocks,
+                              u64 num_blocks)
 {
        int ret = 0;
        struct btrfs_file_extent_item *item;
@@ -30,7 +31,7 @@ int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
        item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
                              struct btrfs_file_extent_item);
        btrfs_set_file_extent_disk_blocknr(item, offset);
-       btrfs_set_file_extent_disk_num_blocks(item, num_blocks);
+       btrfs_set_file_extent_disk_num_blocks(item, disk_num_blocks);
        btrfs_set_file_extent_offset(item, 0);
        btrfs_set_file_extent_num_blocks(item, num_blocks);
        btrfs_set_file_extent_generation(item, trans->transid);
@@ -176,14 +177,14 @@ 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)) {
-               WARN_ON(1);
                goto insert;
        }
        if (csum_offset >= btrfs_item_size(leaf->items + path->slots[0]) /
            BTRFS_CRC32_SIZE) {
                u32 diff = (csum_offset + 1) * BTRFS_CRC32_SIZE;
                diff = diff - btrfs_item_size(leaf->items + path->slots[0]);
-               WARN_ON(diff != BTRFS_CRC32_SIZE);
+               if (diff != BTRFS_CRC32_SIZE)
+                       goto insert;
                ret = btrfs_extend_item(trans, root, path, diff);
                BUG_ON(ret);
                goto csum;
@@ -241,7 +242,7 @@ int btrfs_csum_verify_file_block(struct btrfs_root *root,
                ret = PTR_ERR(item);
                /* a csum that isn't present is a preallocated region. */
                if (ret == -ENOENT || ret == -EFBIG)
-                       ret = 1;
+                       ret = -ENOENT;
                goto fail;
        }
 

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index c1a0add..5b87c4e 100644 (file)
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -17,6 +17,7 @@
 #include "transaction.h"
 #include "btrfs_inode.h"
 #include "ioctl.h"
+#include "print-tree.h"
 
 struct btrfs_iget_args {
        u64 ino;
@@ -421,14 +422,17 @@ static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
                                            struct btrfs_file_extent_item);
                        if (btrfs_file_extent_type(fi) !=
                            BTRFS_FILE_EXTENT_INLINE) {
+                               u64 num_dec;
                                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) << 3;
-                               found_extent = 1;
+                               num_dec = btrfs_file_extent_num_blocks(fi) << 3;
+                               if (extent_start != 0) {
+                                       found_extent = 1;
+                                       inode->i_blocks -= num_dec;
+                               }
                        }
                }
                ret = btrfs_del_item(trans, root, path);
@@ -448,6 +452,43 @@ error:
        return ret;
 }
 
+static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
+{
+       struct inode *inode = dentry->d_inode;
+       int err;
+
+       err = inode_change_ok(inode, attr);
+       if (err)
+               return err;
+
+       if (S_ISREG(inode->i_mode) &&
+           attr->ia_valid & ATTR_SIZE && attr->ia_size > inode->i_size) {
+               struct btrfs_trans_handle *trans;
+               struct btrfs_root *root = BTRFS_I(inode)->root;
+               u64 mask = root->blocksize - 1;
+               u64 pos = (inode->i_size + mask) & ~mask;
+               u64 hole_size;
+
+               if (attr->ia_size < pos)
+                       goto out;
+               hole_size = (attr->ia_size - pos + mask) & ~mask;
+               hole_size >>= inode->i_blkbits;
+
+               mutex_lock(&root->fs_info->fs_mutex);
+               trans = btrfs_start_transaction(root, 1);
+               btrfs_set_trans_block_group(trans, inode);
+               err = btrfs_insert_file_extent(trans, root, inode->i_ino,
+                                              pos, 0, 0, hole_size);
+               BUG_ON(err);
+               btrfs_end_transaction(trans, root);
+               mutex_unlock(&root->fs_info->fs_mutex);
+       }
+
+       err = inode_setattr(inode, attr);
+
+out:
+       return err;
+}
 static void btrfs_delete_inode(struct inode *inode)
 {
        struct btrfs_trans_handle *trans;
@@ -1169,8 +1210,10 @@ static int btrfs_get_block_lock(struct inode *inode, sector_t iblock,
        if (found_type == BTRFS_FILE_EXTENT_REG) {
                extent_start = extent_start >> inode->i_blkbits;
                extent_end = extent_start + btrfs_file_extent_num_blocks(item);
+               err = 0;
+               if (blocknr == 0)
+                       goto out;
                if (iblock >= extent_start && iblock < extent_end) {
-                       err = 0;
                        btrfs_map_bh_to_logical(root, result, blocknr +
                                                iblock - extent_start);
                        goto out;
@@ -1591,7 +1634,7 @@ static int dirty_and_release_pages(struct btrfs_trans_handle *trans,
                                     ptr, bh->b_data, offset + write_bytes);
                        mark_buffer_dirty(path->nodes[0]);
                        btrfs_free_path(path);
-               } else {
+               } else if (buffer_mapped(bh)) {
                        btrfs_csum_file_block(trans, root, inode->i_ino,
                                      pages[i]->index << PAGE_CACHE_SHIFT,
                                      kmap(pages[i]), PAGE_CACHE_SIZE);
@@ -1693,15 +1736,24 @@ static int drop_extents(struct btrfs_trans_handle *trans,
                        goto out;
                }
 
-               search_start = extent_end;
+               if (found_inline) {
+                       u64 mask = root->blocksize - 1;
+                       search_start = (extent_end + mask) & ~mask;
+               } else
+                       search_start = extent_end;
 
                if (end < extent_end && end >= key.offset) {
                        if (found_extent) {
+                               u64 disk_blocknr =
+                                       btrfs_file_extent_disk_blocknr(extent);
+                               u64 disk_num_blocks =
+                                     btrfs_file_extent_disk_num_blocks(extent);
                                memcpy(&old, extent, sizeof(old));
-                               ret = btrfs_inc_extent_ref(trans, root,
-                                     btrfs_file_extent_disk_blocknr(&old),
-                                     btrfs_file_extent_disk_num_blocks(&old));
-                               BUG_ON(ret);
+                               if (disk_blocknr != 0) {
+                                       ret = btrfs_inc_extent_ref(trans, root,
+                                                disk_blocknr, disk_num_blocks);
+                                       BUG_ON(ret);
+                               }
                        }
                        WARN_ON(found_inline);
                        bookend = 1;
@@ -1719,7 +1771,10 @@ static int drop_extents(struct btrfs_trans_handle *trans,
                                old_num = btrfs_file_extent_num_blocks(extent);
                                *hint_block =
                                        btrfs_file_extent_disk_blocknr(extent);
-                               inode->i_blocks -= (old_num - new_num) << 3;
+                               if (btrfs_file_extent_disk_blocknr(extent)) {
+                                       inode->i_blocks -=
+                                               (old_num - new_num) << 3;
+                               }
                                btrfs_set_file_extent_num_blocks(extent,
                                                                 new_num);
                                mark_buffer_dirty(path->nodes[0]);
@@ -1745,7 +1800,7 @@ static int drop_extents(struct btrfs_trans_handle *trans,
                        BUG_ON(ret);
                        btrfs_release_path(root, path);
                        extent = NULL;
-                       if (found_extent) {
+                       if (found_extent && disk_blocknr != 0) {
                                inode->i_blocks -= extent_num_blocks << 3;
                                ret = btrfs_free_extent(trans, root,
                                                        disk_blocknr,
@@ -1785,18 +1840,19 @@ static int drop_extents(struct btrfs_trans_handle *trans,
                                    btrfs_file_extent_offset(&old) +
                                    ((end - key.offset) >> inode->i_blkbits));
                        WARN_ON(btrfs_file_extent_num_blocks(&old) <
-                               (end - key.offset) >> inode->i_blkbits);
+                               (extent_end - end) >> inode->i_blkbits);
                        btrfs_set_file_extent_num_blocks(extent,
-                                   btrfs_file_extent_num_blocks(&old) -
-                                   ((end - key.offset) >> inode->i_blkbits));
+                                   (extent_end - end) >> inode->i_blkbits);
 
                        btrfs_set_file_extent_type(extent,
                                                   BTRFS_FILE_EXTENT_REG);
                        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;
+                       if (btrfs_file_extent_disk_blocknr(&old) != 0) {
+                               inode->i_blocks +=
+                                     btrfs_file_extent_num_blocks(extent) << 3;
+                       }
                        ret = 0;
                        goto out;
                }
@@ -1960,6 +2016,21 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
                                   ~((u64)root->blocksize - 1), &hint_block);
                BUG_ON(ret);
        }
+       if (inode->i_size < start_pos) {
+               u64 last_pos_in_file;
+               u64 hole_size;
+               u64 mask = root->blocksize - 1;
+               last_pos_in_file = (inode->i_size + mask) & ~mask;
+               hole_size = (start_pos - last_pos_in_file + mask) & ~mask;
+               hole_size >>= inode->i_blkbits;
+               if (last_pos_in_file < start_pos) {
+                       ret = btrfs_insert_file_extent(trans, root,
+                                                      inode->i_ino,
+                                                      last_pos_in_file,
+                                                      0, 0, hole_size);
+               }
+               BUG_ON(ret);
+       }
        if (inode->i_size >= PAGE_CACHE_SIZE || pos + count < inode->i_size ||
            pos + count - start_pos > BTRFS_MAX_INLINE_DATA_SIZE(root)) {
                ret = btrfs_alloc_extent(trans, root, inode->i_ino,
@@ -1967,7 +2038,8 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
                                         &ins, 1);
                BUG_ON(ret);
                ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
-                                      start_pos, ins.objectid, ins.offset);
+                                      start_pos, ins.objectid, ins.offset,
+                                      ins.offset);
                BUG_ON(ret);
        } else {
                ins.offset = 0;
@@ -2044,10 +2116,13 @@ static int btrfs_read_actor(read_descriptor_t *desc, struct page *page,
                                  page->index << PAGE_CACHE_SHIFT,
                                  kmap(page), PAGE_CACHE_SIZE);
                if (ret) {
-                       printk("failed to verify ino %lu page %lu\n",
-                              page->mapping->host->i_ino,
-                              page->index);
-                       memset(page_address(page), 0, PAGE_CACHE_SIZE);
+                       if (ret != -ENOENT) {
+                               printk("failed to verify ino %lu page %lu\n",
+                                      page->mapping->host->i_ino,
+                                      page->index);
+                               memset(page_address(page), 0, PAGE_CACHE_SIZE);
+                               flush_dcache_page(page);
+                       }
                }
                SetPageChecked(page);
                kunmap(page);
@@ -2759,6 +2834,7 @@ static struct inode_operations btrfs_dir_inode_operations = {
        .rmdir          = btrfs_rmdir,
        .rename         = btrfs_rename,
        .symlink        = btrfs_symlink,
+       .setattr        = btrfs_setattr,
 };
 
 static struct inode_operations btrfs_dir_ro_inode_operations = {
@@ -2788,6 +2864,7 @@ static struct address_space_operations btrfs_symlink_aops = {
 static struct inode_operations btrfs_file_inode_operations = {
        .truncate       = btrfs_truncate,
        .getattr        = btrfs_getattr,
+       .setattr        = btrfs_setattr,
 };
 
 static struct file_operations btrfs_file_operations = {