3 files changed, 214 insertions, 32 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index e8f741167c6b..756ea9d0123b 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1198,5 +1198,8 @@ struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
                                           struct btrfs_path *path,
                                           u64 objectid, u64 offset,
                                           int cow);
+int btrfs_csum_truncate(struct btrfs_trans_handle *trans,
+                        struct btrfs_root *root, struct btrfs_path *path,
+                        u64 isize);
 /* super.c */
 #endif
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 7990b5742114..0782e924ddeb 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -2,6 +2,7 @@
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
+#include "print-tree.h"
 
 #define MAX_CSUM_ITEMS(r) ((((BTRFS_LEAF_DATA_SIZE(r) - \
                                sizeof(struct btrfs_item) * 2) / \
@@ -27,6 +28,10 @@ int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
 
         ret = btrfs_insert_empty_item(trans, root, path, &file_key,
                                       sizeof(*item));
+        if (ret) {
+printk("failed to insert %Lu %Lu ret %d\n", objectid, pos, ret);
+btrfs_print_leaf(root, btrfs_buffer_leaf(path->nodes[0]));
+        }
         BUG_ON(ret);
         item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
                               struct btrfs_file_extent_item);
@@ -218,6 +223,31 @@ fail:
         return ret;
 }
 
+int btrfs_csum_truncate(struct btrfs_trans_handle *trans,
+                        struct btrfs_root *root, struct btrfs_path *path,
+                        u64 isize)
+{
+        struct btrfs_key key;
+        struct btrfs_leaf *leaf = btrfs_buffer_leaf(path->nodes[0]);
+        int slot = path->slots[0];
+        int ret;
+        u32 new_item_size;
+        u64 new_item_span;
+        u64 blocks;
+
+        btrfs_disk_key_to_cpu(&key, &leaf->items[slot].key);
+        if (isize <= key.offset)
+                return 0;
+        new_item_span = isize - key.offset;
+        blocks = (new_item_span + root->blocksize - 1) / root->blocksize;
+        new_item_size = blocks * BTRFS_CRC32_SIZE;
+        if (new_item_size >= btrfs_item_size(leaf->items + slot))
+                return 0;
+        ret = btrfs_truncate_item(trans, root, path, new_item_size);
+        BUG_ON(ret);
+        return ret;
+}
+
 int btrfs_csum_verify_file_block(struct btrfs_root *root,
                                  u64 objectid, u64 offset,
                                  char *data, size_t len)
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 5b87c4e9d491..0eb64d6eaf9d 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -36,6 +36,13 @@ static struct address_space_operations btrfs_aops;
 static struct address_space_operations btrfs_symlink_aops;
 static struct file_operations btrfs_file_operations;
 
+static int drop_extents(struct btrfs_trans_handle *trans,
+                          struct btrfs_root *root,
+                          struct inode *inode,
+                          u64 start, u64 end, u64 *hint_block);
+static int btrfs_get_block(struct inode *inode, sector_t iblock,
+                           struct buffer_head *result, int create);
+
 static void btrfs_read_locked_inode(struct inode *inode)
 {
         struct btrfs_path *path;
@@ -381,10 +388,12 @@ static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
         struct btrfs_disk_key *found_key;
         u32 found_type;
         struct btrfs_leaf *leaf;
-        struct btrfs_file_extent_item *fi = NULL;
+        struct btrfs_file_extent_item *fi;
         u64 extent_start = 0;
         u64 extent_num_blocks = 0;
+        u64 item_end = 0;
         int found_extent;
+        int del_item;
 
         path = btrfs_alloc_path();
         BUG_ON(!path);
@@ -394,6 +403,7 @@ static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
         key.flags = (u32)-1;
         while(1) {
                 btrfs_init_path(path);
+                fi = NULL;
                 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
                 if (ret < 0) {
                         goto error;
@@ -413,16 +423,52 @@ static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
                     found_type != BTRFS_DIR_INDEX_KEY &&
                     found_type != BTRFS_EXTENT_DATA_KEY)
                         break;
-                if (btrfs_disk_key_offset(found_key) < inode->i_size)
-                        break;
-                found_extent = 0;
-                if (btrfs_disk_key_type(found_key) == BTRFS_EXTENT_DATA_KEY) {
+                item_end = btrfs_disk_key_offset(found_key);
+                if (found_type == BTRFS_EXTENT_DATA_KEY) {
                         fi = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
                                             path->slots[0],
                                             struct btrfs_file_extent_item);
                         if (btrfs_file_extent_type(fi) !=
                             BTRFS_FILE_EXTENT_INLINE) {
-                                u64 num_dec;
+                                item_end += btrfs_file_extent_num_blocks(fi) <<
+                                                inode->i_blkbits;
+                        }
+                }
+                if (found_type == BTRFS_CSUM_ITEM_KEY) {
+                        ret = btrfs_csum_truncate(trans, root, path,
+                                                  inode->i_size);
+                        BUG_ON(ret);
+                }
+                if (item_end < inode->i_size) {
+                        if (found_type) {
+                                btrfs_set_key_type(&key, found_type - 1);
+                                continue;
+                        }
+                        break;
+                }
+                if (btrfs_disk_key_offset(found_key) >= inode->i_size)
+                        del_item = 1;
+                else
+                        del_item = 0;
+                found_extent = 0;
+
+                if (found_type == BTRFS_EXTENT_DATA_KEY &&
+                           btrfs_file_extent_type(fi) !=
+                           BTRFS_FILE_EXTENT_INLINE) {
+                        u64 num_dec;
+                        if (!del_item) {
+                                u64 orig_num_blocks =
+                                        btrfs_file_extent_num_blocks(fi);
+                                extent_num_blocks = inode->i_size -
+                                        btrfs_disk_key_offset(found_key) +
+                                        root->blocksize - 1;
+                                extent_num_blocks >>= inode->i_blkbits;
+                                btrfs_set_file_extent_num_blocks(fi,
+                                                         extent_num_blocks);
+                                inode->i_blocks -= (orig_num_blocks -
+                                        extent_num_blocks) << 3;
+                                mark_buffer_dirty(path->nodes[0]);
+                        } else {
                                 extent_start =
                                         btrfs_file_extent_disk_blocknr(fi);
                                 extent_num_blocks =
@@ -435,8 +481,12 @@ static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
                                 }
                         }
                 }
-                ret = btrfs_del_item(trans, root, path);
-                BUG_ON(ret);
+                if (del_item) {
+                        ret = btrfs_del_item(trans, root, path);
+                        BUG_ON(ret);
+                } else {
+                        break;
+                }
                 btrfs_release_path(root, path);
                 if (found_extent) {
                         ret = btrfs_free_extent(trans, root, extent_start,
@@ -452,6 +502,68 @@ error:
         return ret;
 }
 
+static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
+{
+        struct inode *inode = mapping->host;
+        unsigned blocksize = 1 << inode->i_blkbits;
+        pgoff_t index = from >> PAGE_CACHE_SHIFT;
+        unsigned offset = from & (PAGE_CACHE_SIZE-1);
+        struct page *page;
+        char *kaddr;
+        int ret = 0;
+        struct btrfs_root *root = BTRFS_I(inode)->root;
+        u64 alloc_hint;
+        struct btrfs_key ins;
+        struct btrfs_trans_handle *trans;
+
+        if ((offset & (blocksize - 1)) == 0)
+                goto out;
+
+        ret = -ENOMEM;
+        page = grab_cache_page(mapping, index);
+        if (!page)
+                goto out;
+
+        if (!PageUptodate(page)) {
+                ret = mpage_readpage(page, btrfs_get_block);
+                lock_page(page);
+                if (!PageUptodate(page)) {
+                        ret = -EIO;
+                        goto out;
+                }
+        }
+        mutex_lock(&root->fs_info->fs_mutex);
+        trans = btrfs_start_transaction(root, 1);
+        btrfs_set_trans_block_group(trans, inode);
+
+        ret = drop_extents(trans, root, inode, page->index << PAGE_CACHE_SHIFT,
+                           (page->index + 1) << PAGE_CACHE_SHIFT, &alloc_hint);
+        BUG_ON(ret);
+        ret = btrfs_alloc_extent(trans, root, inode->i_ino, 1,
+                                 alloc_hint, (u64)-1, &ins, 1);
+        BUG_ON(ret);
+        ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
+                                       page->index << PAGE_CACHE_SHIFT,
+                                       ins.objectid, 1, 1);
+        BUG_ON(ret);
+        SetPageChecked(page);
+        kaddr = kmap(page);
+        memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
+        flush_dcache_page(page);
+        btrfs_csum_file_block(trans, root, inode->i_ino,
+                              page->index << PAGE_CACHE_SHIFT,
+                              kaddr, PAGE_CACHE_SIZE);
+        kunmap(page);
+        btrfs_end_transaction(trans, root);
+        mutex_unlock(&root->fs_info->fs_mutex);
+
+        set_page_dirty(page);
+        unlock_page(page);
+        page_cache_release(page);
+out:
+        return ret;
+}
+
 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
 {
         struct inode *inode = dentry->d_inode;
@@ -469,8 +581,11 @@ static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
                 u64 pos = (inode->i_size + mask) & ~mask;
                 u64 hole_size;
 
-                if (attr->ia_size < pos)
+                if (attr->ia_size <= pos)
                         goto out;
+
+                btrfs_truncate_page(inode->i_mapping, inode->i_size);
+
                 hole_size = (attr->ia_size - pos + mask) & ~mask;
                 hole_size >>= inode->i_blkbits;
 
@@ -483,10 +598,9 @@ static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
                 btrfs_end_transaction(trans, root);
                 mutex_unlock(&root->fs_info->fs_mutex);
         }
-
+out:
         err = inode_setattr(inode, attr);
 
-out:
         return err;
 }
 static void btrfs_delete_inode(struct inode *inode)
@@ -1161,17 +1275,30 @@ static int btrfs_get_block_lock(struct inode *inode, sector_t iblock,
         u64 extent_end = 0;
         u64 objectid = inode->i_ino;
         u32 found_type;
+        u64 alloc_hint = 0;
         struct btrfs_path *path;
         struct btrfs_root *root = BTRFS_I(inode)->root;
         struct btrfs_file_extent_item *item;
         struct btrfs_leaf *leaf;
         struct btrfs_disk_key *found_key;
+        struct btrfs_trans_handle *trans = NULL;
 
         path = btrfs_alloc_path();
         BUG_ON(!path);
         btrfs_init_path(path);
         if (create) {
                 WARN_ON(1);
+                /* this almost but not quite works */
+                trans = btrfs_start_transaction(root, 1);
+                if (!trans) {
+                        err = -ENOMEM;
+                        goto out;
+                }
+                ret = drop_extents(trans, root, inode,
+                                   iblock << inode->i_blkbits,
+                                   (iblock + 1) << inode->i_blkbits,
+                                   &alloc_hint);
+                BUG_ON(ret);
         }
 
         ret = btrfs_lookup_file_extent(NULL, root, path,
@@ -1185,7 +1312,7 @@ static int btrfs_get_block_lock(struct inode *inode, sector_t iblock,
         if (ret != 0) {
                 if (path->slots[0] == 0) {
                         btrfs_release_path(root, path);
-                        goto out;
+                        goto not_found;
                 }
                 path->slots[0]--;
         }
@@ -1203,7 +1330,7 @@ static int btrfs_get_block_lock(struct inode *inode, sector_t iblock,
             found_type != BTRFS_EXTENT_DATA_KEY) {
                 extent_end = 0;
                 extent_start = 0;
-                goto out;
+                goto not_found;
         }
         found_type = btrfs_file_extent_type(item);
         extent_start = btrfs_disk_key_offset(&leaf->items[path->slots[0]].key);
@@ -1211,7 +1338,7 @@ static int btrfs_get_block_lock(struct inode *inode, sector_t iblock,
                 extent_start = extent_start >> inode->i_blkbits;
                 extent_end = extent_start + btrfs_file_extent_num_blocks(item);
                 err = 0;
-                if (blocknr == 0)
+                if (btrfs_file_extent_disk_blocknr(item) == 0)
                         goto out;
                 if (iblock >= extent_start && iblock < extent_end) {
                         btrfs_map_bh_to_logical(root, result, blocknr +
@@ -1227,7 +1354,7 @@ static int btrfs_get_block_lock(struct inode *inode, sector_t iblock,
                 extent_end = (extent_start + size) >> inode->i_blkbits;
                 extent_start >>= inode->i_blkbits;
                 if (iblock < extent_start || iblock > extent_end) {
-                        goto out;
+                        goto not_found;
                 }
                 ptr = btrfs_file_extent_inline_start(item);
                 map = kmap(result->b_page);
@@ -1239,7 +1366,24 @@ static int btrfs_get_block_lock(struct inode *inode, sector_t iblock,
                 SetPageChecked(result->b_page);
                 btrfs_map_bh_to_logical(root, result, 0);
         }
+not_found:
+        if (create) {
+                struct btrfs_key ins;
+                ret = btrfs_alloc_extent(trans, root, inode->i_ino,
+                                         1, alloc_hint, (u64)-1,
+                                         &ins, 1);
+                BUG_ON(ret);
+                ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
+                                               iblock << inode->i_blkbits,
+                                               ins.objectid, ins.offset,
+                                               ins.offset);
+                BUG_ON(ret);
+                SetPageChecked(result->b_page);
+                btrfs_map_bh_to_logical(root, result, ins.objectid);
+        }
 out:
+        if (trans)
+                err = btrfs_end_transaction(trans, root);
         btrfs_free_path(path);
         return err;
 }
@@ -1258,7 +1402,7 @@ static int btrfs_get_block(struct inode *inode, sector_t iblock,
 static int btrfs_prepare_write(struct file *file, struct page *page,
                                unsigned from, unsigned to)
 {
-        return nobh_prepare_write(page, from, to, btrfs_get_block);
+        return block_prepare_write(page, from, to, btrfs_get_block);
 }
 
 static void btrfs_write_super(struct super_block *sb)
@@ -1500,12 +1644,13 @@ static void btrfs_truncate(struct inode *inode)
         if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
                 return;
 
-        nobh_truncate_page(inode->i_mapping, inode->i_size);
+        btrfs_truncate_page(inode->i_mapping, inode->i_size);
 
-        /* FIXME, add redo link to tree so we don't leak on crash */
         mutex_lock(&root->fs_info->fs_mutex);
         trans = btrfs_start_transaction(root, 1);
         btrfs_set_trans_block_group(trans, inode);
+
+        /* FIXME, add redo link to tree so we don't leak on crash */
         ret = btrfs_truncate_in_trans(trans, root, inode);
         BUG_ON(ret);
         btrfs_update_inode(trans, root, inode);
@@ -1515,10 +1660,6 @@ static void btrfs_truncate(struct inode *inode)
         btrfs_btree_balance_dirty(root);
 }
 
-/*
- * Make sure any changes to nobh_commit_write() are reflected in
- * nobh_truncate_page(), since it doesn't call commit_write().
- */
 static int btrfs_commit_write(struct file *file, struct page *page,
                               unsigned from, unsigned to)
 {
@@ -1528,6 +1669,7 @@ static int btrfs_commit_write(struct file *file, struct page *page,
 
         SetPageUptodate(page);
         bh = page_buffers(page);
+        set_buffer_uptodate(bh);
         if (buffer_mapped(bh) && bh->b_blocknr != 0) {
                 set_page_dirty(page);
         }
@@ -1972,8 +2114,7 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
         first_index = pos >> PAGE_CACHE_SHIFT;
         last_index = (pos + count) >> PAGE_CACHE_SHIFT;
 
-        if ((first_index << PAGE_CACHE_SHIFT) < inode->i_size &&
-            (pos & (PAGE_CACHE_SIZE - 1))) {
+        if ((pos & (PAGE_CACHE_SIZE - 1))) {
                 pinned[0] = grab_cache_page(inode->i_mapping, first_index);
                 if (!PageUptodate(pinned[0])) {
                         ret = mpage_readpage(pinned[0], btrfs_get_block);
@@ -1983,10 +2124,7 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
                         unlock_page(pinned[0]);
                 }
         }
-        if (first_index != last_index &&
-            (last_index << PAGE_CACHE_SHIFT) < inode->i_size &&
-            pos + count < inode->i_size &&
-            (count & (PAGE_CACHE_SIZE - 1))) {
+        if ((pos + count) & (PAGE_CACHE_SIZE - 1)) {
                 pinned[1] = grab_cache_page(inode->i_mapping, last_index);
                 if (!PageUptodate(pinned[1])) {
                         ret = mpage_readpage(pinned[1], btrfs_get_block);
@@ -2110,23 +2248,34 @@ static int btrfs_read_actor(read_descriptor_t *desc, struct page *page,
         if (!PageChecked(page)) {
                 /* FIXME, do it per block */
                 struct btrfs_root *root = BTRFS_I(inode)->root;
+                int ret;
+                struct buffer_head *bh;
+
+                if (page_has_buffers(page)) {
+                        bh = page_buffers(page);
+                        if (!buffer_mapped(bh)) {
+                                SetPageChecked(page);
+                                goto checked;
+                        }
+                }
 
-                int ret = btrfs_csum_verify_file_block(root,
+                ret = btrfs_csum_verify_file_block(root,
                                   page->mapping->host->i_ino,
                                   page->index << PAGE_CACHE_SHIFT,
                                   kmap(page), PAGE_CACHE_SIZE);
                 if (ret) {
                         if (ret != -ENOENT) {
-                                printk("failed to verify ino %lu page %lu\n",
+                                printk("failed to verify ino %lu page %lu ret %d\n",
                                        page->mapping->host->i_ino,
-                                       page->index);
-                                memset(page_address(page), 0, PAGE_CACHE_SIZE);
+                                       page->index, ret);
+                                memset(page_address(page), 1, PAGE_CACHE_SIZE);
                                 flush_dcache_page(page);
                         }
                 }
                 SetPageChecked(page);
                 kunmap(page);
         }
+checked:
         /*
          * Faults on the destination of a read are common, so do it before
          * taking the kmap.