5 files changed, 34 insertions, 4 deletions

diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index 0b2e623cf421..1b9ec1ab1f68 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -49,9 +49,6 @@ struct btrfs_inode {
          */
         struct extent_io_tree io_failure_tree;
 
-        /* held while inserting checksums to avoid races */
-        struct mutex csum_mutex;
-
         /* held while inesrting or deleting extents from files */
         struct mutex extent_mutex;
 
@@ -79,6 +76,9 @@ struct btrfs_inode {
          */
         u64 generation;
 
+        /* sequence number for NFS changes */
+        u64 sequence;
+
         /*
          * transid of the trans_handle that last modified this inode
          */
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 242b961ae6de..f72b43819349 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -196,6 +196,12 @@ struct btrfs_dev_item {
         /* expected generation for this device */
         __le64 generation;
 
+        /*
+         * starting byte of this partition on the device,
+         * to allowr for stripe alignment in the future
+         */
+        __le64 start_offset;
+
         /* grouping information for allocation decisions */
         __le32 dev_group;
 
@@ -311,6 +317,9 @@ struct btrfs_super_block {
         __le64 root;
         __le64 chunk_root;
         __le64 log_root;
+
+        /* this will help find the new super based on the log root */
+        __le64 log_root_transid;
         __le64 total_bytes;
         __le64 bytes_used;
         __le64 root_dir_objectid;
@@ -329,7 +338,11 @@ struct btrfs_super_block {
         u8 chunk_root_level;
         u8 log_root_level;
         struct btrfs_dev_item dev_item;
+
         char label[BTRFS_LABEL_SIZE];
+
+        /* future expansion */
+        __le64 reserved[32];
         u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE];
 } __attribute__ ((__packed__));
 
@@ -463,6 +476,14 @@ struct btrfs_inode_item {
         __le64 rdev;
         __le64 flags;
 
+        /* modification sequence number for NFS */
+        __le64 sequence;
+
+        /*
+         * a little future expansion, for more than this we can
+         * just grow the inode item and version it
+         */
+        __le64 reserved[4];
         struct btrfs_timespec atime;
         struct btrfs_timespec ctime;
         struct btrfs_timespec mtime;
@@ -1001,6 +1022,8 @@ BTRFS_SETGET_FUNCS(device_total_bytes, struct btrfs_dev_item, total_bytes, 64);
 BTRFS_SETGET_FUNCS(device_bytes_used, struct btrfs_dev_item, bytes_used, 64);
 BTRFS_SETGET_FUNCS(device_io_align, struct btrfs_dev_item, io_align, 32);
 BTRFS_SETGET_FUNCS(device_io_width, struct btrfs_dev_item, io_width, 32);
+BTRFS_SETGET_FUNCS(device_start_offset, struct btrfs_dev_item,
+                   start_offset, 64);
 BTRFS_SETGET_FUNCS(device_sector_size, struct btrfs_dev_item, sector_size, 32);
 BTRFS_SETGET_FUNCS(device_id, struct btrfs_dev_item, devid, 64);
 BTRFS_SETGET_FUNCS(device_group, struct btrfs_dev_item, dev_group, 32);
@@ -1135,6 +1158,7 @@ BTRFS_SETGET_FUNCS(inode_ref_index, struct btrfs_inode_ref, index, 64);
 
 /* struct btrfs_inode_item */
 BTRFS_SETGET_FUNCS(inode_generation, struct btrfs_inode_item, generation, 64);
+BTRFS_SETGET_FUNCS(inode_sequence, struct btrfs_inode_item, sequence, 64);
 BTRFS_SETGET_FUNCS(inode_transid, struct btrfs_inode_item, transid, 64);
 BTRFS_SETGET_FUNCS(inode_size, struct btrfs_inode_item, size, 64);
 BTRFS_SETGET_FUNCS(inode_nbytes, struct btrfs_inode_item, nbytes, 64);
@@ -1519,6 +1543,8 @@ BTRFS_SETGET_STACK_FUNCS(super_chunk_root_level, struct btrfs_super_block,
                          chunk_root_level, 8);
 BTRFS_SETGET_STACK_FUNCS(super_log_root, struct btrfs_super_block,
                          log_root, 64);
+BTRFS_SETGET_STACK_FUNCS(super_log_root_transid, struct btrfs_super_block,
+                         log_root_transid, 64);
 BTRFS_SETGET_STACK_FUNCS(super_log_root_level, struct btrfs_super_block,
                          log_root_level, 8);
 BTRFS_SETGET_STACK_FUNCS(super_total_bytes, struct btrfs_super_block,
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 1c9243560eab..b5a6a2b6f668 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1055,6 +1055,7 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
         pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL);
 
         mutex_lock(&inode->i_mutex);
+        BTRFS_I(inode)->sequence++;
         first_index = pos >> PAGE_CACHE_SHIFT;
         last_index = (pos + count) >> PAGE_CACHE_SHIFT;
 
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index c03d847b8c4e..932d8c0b2c05 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1963,6 +1963,7 @@ void btrfs_read_locked_inode(struct inode *inode)
 
         inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
         BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
+        BTRFS_I(inode)->sequence = btrfs_inode_sequence(leaf, inode_item);
         inode->i_generation = BTRFS_I(inode)->generation;
         inode->i_rdev = 0;
         rdev = btrfs_inode_rdev(leaf, inode_item);
@@ -2043,6 +2044,7 @@ static void fill_inode_item(struct btrfs_trans_handle *trans,
 
         btrfs_set_inode_nbytes(leaf, item, inode_get_bytes(inode));
         btrfs_set_inode_generation(leaf, item, BTRFS_I(inode)->generation);
+        btrfs_set_inode_sequence(leaf, item, BTRFS_I(inode)->sequence);
         btrfs_set_inode_transid(leaf, item, trans->transid);
         btrfs_set_inode_rdev(leaf, item, inode->i_rdev);
         btrfs_set_inode_flags(leaf, item, BTRFS_I(inode)->flags);
@@ -2945,6 +2947,7 @@ static noinline void init_btrfs_i(struct inode *inode)
         bi->i_default_acl = NULL;
 
         bi->generation = 0;
+        bi->sequence = 0;
         bi->last_trans = 0;
         bi->logged_trans = 0;
         bi->delalloc_bytes = 0;
@@ -2959,7 +2962,6 @@ static noinline void init_btrfs_i(struct inode *inode)
                              inode->i_mapping, GFP_NOFS);
         INIT_LIST_HEAD(&BTRFS_I(inode)->delalloc_inodes);
         btrfs_ordered_inode_tree_init(&BTRFS_I(inode)->ordered_tree);
-        mutex_init(&BTRFS_I(inode)->csum_mutex);
         mutex_init(&BTRFS_I(inode)->extent_mutex);
         mutex_init(&BTRFS_I(inode)->log_mutex);
 }
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 825364fae690..4d210a731d40 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -890,6 +890,7 @@ int btrfs_add_device(struct btrfs_trans_handle *trans,
         btrfs_set_device_group(leaf, dev_item, 0);
         btrfs_set_device_seek_speed(leaf, dev_item, 0);
         btrfs_set_device_bandwidth(leaf, dev_item, 0);
+        btrfs_set_device_start_offset(leaf, dev_item, 0);
 
         ptr = (unsigned long)btrfs_device_uuid(dev_item);
         write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);