Btrfs: i386 fixes from axboe

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

5 files changed, 59 insertions, 5 deletions

diff --git a/fs/btrfs/INSTALL b/fs/btrfs/INSTALL
new file mode 100644
index 000000000000..e83ff6e8c8d5
--- /dev/null
+++ b/fs/btrfs/INSTALL
@@ -0,0 +1,51 @@
+Install Instructions
+
+Btrfs puts snapshots and subvolumes into the root directory of the FS.  This
+directory can only be changed by btrfsctl right now, and normal filesystem
+operations do not work on it.  The default subvolume is called 'default',
+and you can create files and directories in mount_point/default
+
+Btrfs uses the crypto manager interface in the kernel for file and
+metadata checksums.  You need to compile the kernel with:
+
+CONFIG_CRYPTO=y
+CONFIG_CRYPTO_MANAGER=m
+CONFIG_CRYPTO_CRC32C=m
+
+cryptomanager and crc32c can be static as well.  Once your kernel is
+setup, typing make in the btrfs module sources will build against the
+running kernel.  When the build is complete:
+
+modprobe crc32c
+modprobe cryptomgr
+insmod btrfs.ko
+
+The Btrfs utility programs require libuuid to build.  This can be found
+in the e2fsprogs sources, and is usually available as libuuid or
+e2fsprogs-devel from various distros.
+
+Building the utilities is just make ; make install.  The programs go
+into /usr/local/bin.  The commands available are:
+
+mkfs.btrfs: create a filesystem
+
+btrfsctl: control program to create snapshots and subvolumes:
+
+        mount /dev/sda2 /mnt
+        btrfsctl -s new_subvol_name /mnt
+        btrfsctl -s snapshot_of_default /mnt/default
+        btrfsctl -s snapshot_of_new_subvol /mnt/new_subvol_name
+        btrfsctl -s snapshot_of_a_snapshot /mnt/snapshot_of_new_subvol
+        ls /mnt
+        default snapshot_of_a_snapshot snapshot_of_new_subvol
+        new_subvol_name snapshot_of_default
+
+        Snapshots and subvolumes cannot be deleted right now, but you can
+        rm -rf all the files and directories inside them.
+
+btrfsck: do a limited check of the FS extent trees.</li>
+
+debug-tree: print all of the FS metadata in text form.  Example:
+
+        debug-tree /dev/sda2 >& big_output_file
+
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 8c68a64c0ceb..b0ebba6f2e46 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -106,7 +106,7 @@ struct buffer_head *btrfs_find_create_tree_block(struct btrfs_root *root,
         int err;
         u64 first_block = index << (PAGE_CACHE_SHIFT - blockbits);
 
-        page = grab_cache_page(mapping, index);
+        page = find_or_create_page(mapping, index, GFP_NOFS);
         if (!page)
                 return NULL;
 
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 566e526b60ff..83836fb3d4e9 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -112,7 +112,7 @@ static int dirty_and_release_pages(struct btrfs_trans_handle *trans,
                 if (buffer_mapped(bh) && bh->b_blocknr == 0) {
                         struct btrfs_key key;
                         struct btrfs_path *path;
-                        char *ptr;
+                        char *ptr, *kaddr;
                         u32 datasize;
 
                         /* create an inline extent, and copy the data in */
@@ -135,8 +135,11 @@ static int dirty_and_release_pages(struct btrfs_trans_handle *trans,
                         btrfs_set_file_extent_type(ei,
                                                    BTRFS_FILE_EXTENT_INLINE);
                         ptr = btrfs_file_extent_inline_start(ei);
+                        kaddr = kmap_atomic(bh->b_page, KM_USER0);
                         btrfs_memcpy(root, path->nodes[0]->b_data,
-                                     ptr, bh->b_data, offset + write_bytes);
+                                     ptr, kaddr + bh_offset(bh),
+                                     offset + write_bytes);
+                        kunmap_atomic(kaddr, KM_USER0);
                         mark_buffer_dirty(path->nodes[0]);
                         btrfs_free_path(path);
                 } else if (buffer_mapped(bh)) {
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 46f869d6d0fb..d3d5a4cdb6af 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1754,6 +1754,7 @@ static int create_subvol(struct btrfs_root *root, char *name, int namelen)
                                 BTRFS_I(dir)->block_group, S_IFDIR | 0700);
         inode->i_op = &btrfs_dir_inode_operations;
         inode->i_fop = &btrfs_dir_file_operations;
+        new_root->inode = inode;
 
         ret = btrfs_make_empty_dir(trans, new_root, new_dirid, new_dirid);
         BUG_ON(ret);
@@ -1766,8 +1767,6 @@ static int create_subvol(struct btrfs_root *root, char *name, int namelen)
         ret = btrfs_commit_transaction(trans, new_root);
         BUG_ON(ret);
 
-        iput(inode);
-
         mutex_unlock(&root->fs_info->fs_mutex);
         btrfs_btree_balance_dirty(root);
         return 0;
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 30914521cf01..cd4f1d140385 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -18,6 +18,7 @@
 
 #include <linux/module.h>
 #include <linux/fs.h>
+#include <linux/sched.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"