Btrfs: Support for online FS resize (grow and shrink)
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 5f5b7b8..f6a2011 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2346,7 +2346,7 @@
return ret;
}
-static unsigned long force_ra(struct address_space *mapping,
+unsigned long btrfs_force_ra(struct address_space *mapping,
struct file_ra_state *ra, struct file *file,
pgoff_t offset, pgoff_t last_index)
{
@@ -2372,6 +2372,8 @@
unsigned long ra_index = 0;
u64 page_start;
u64 page_end;
+ u64 delalloc_start;
+ u64 existing_delalloc;
unsigned long i;
int ret;
@@ -2385,8 +2387,9 @@
last_index = inode->i_size >> PAGE_CACHE_SHIFT;
for (i = 0; i <= last_index; i++) {
if (i == ra_index) {
- ra_index = force_ra(inode->i_mapping, &file->f_ra,
- file, ra_index, last_index);
+ ra_index = btrfs_force_ra(inode->i_mapping,
+ &file->f_ra,
+ file, ra_index, last_index);
}
page = grab_cache_page(inode->i_mapping, i);
if (!page)
@@ -2404,8 +2407,19 @@
page_end = page_start + PAGE_CACHE_SIZE - 1;
lock_extent(em_tree, page_start, page_end, GFP_NOFS);
+ delalloc_start = page_start;
+ existing_delalloc =
+ count_range_bits(&BTRFS_I(inode)->extent_tree,
+ &delalloc_start, page_end,
+ PAGE_CACHE_SIZE, EXTENT_DELALLOC);
set_extent_delalloc(em_tree, page_start,
page_end, GFP_NOFS);
+
+ spin_lock(&root->fs_info->delalloc_lock);
+ root->fs_info->delalloc_bytes += PAGE_CACHE_SIZE -
+ existing_delalloc;
+ spin_unlock(&root->fs_info->delalloc_lock);
+
unlock_extent(em_tree, page_start, page_end, GFP_NOFS);
set_page_dirty(page);
unlock_page(page);
@@ -2418,6 +2432,89 @@
return 0;
}
+static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
+{
+ u64 new_size;
+ u64 old_size;
+ struct btrfs_ioctl_vol_args *vol_args;
+ struct btrfs_trans_handle *trans;
+ char *sizestr;
+ int ret = 0;
+ int namelen;
+ int mod = 0;
+
+ vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
+
+ if (!vol_args)
+ return -ENOMEM;
+
+ if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
+ ret = -EFAULT;
+ goto out;
+ }
+ namelen = strlen(vol_args->name);
+ if (namelen > BTRFS_VOL_NAME_MAX) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ sizestr = vol_args->name;
+ if (!strcmp(sizestr, "max"))
+ new_size = root->fs_info->sb->s_bdev->bd_inode->i_size;
+ else {
+ if (sizestr[0] == '-') {
+ mod = -1;
+ sizestr++;
+ } else if (sizestr[0] == '+') {
+ mod = 1;
+ sizestr++;
+ }
+ new_size = btrfs_parse_size(sizestr);
+ if (new_size == 0) {
+ ret = -EINVAL;
+ goto out;
+ }
+ }
+
+ mutex_lock(&root->fs_info->fs_mutex);
+ old_size = btrfs_super_total_bytes(&root->fs_info->super_copy);
+
+ if (mod < 0) {
+ if (new_size > old_size) {
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+ new_size = old_size - new_size;
+ } else if (mod > 0) {
+ new_size = old_size + new_size;
+ }
+
+ if (new_size < 256 * 1024 * 1024) {
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+ if (new_size > root->fs_info->sb->s_bdev->bd_inode->i_size) {
+ ret = -EFBIG;
+ goto out_unlock;
+ }
+ new_size = (new_size / root->sectorsize) * root->sectorsize;
+
+printk("new size is %Lu\n", new_size);
+ if (new_size > old_size) {
+ trans = btrfs_start_transaction(root, 1);
+ ret = btrfs_grow_extent_tree(trans, root, new_size);
+ btrfs_commit_transaction(trans, root);
+ } else {
+ ret = btrfs_shrink_extent_tree(root, new_size);
+ }
+
+out_unlock:
+ mutex_unlock(&root->fs_info->fs_mutex);
+out:
+ kfree(vol_args);
+ return ret;
+}
+
static int btrfs_ioctl_snap_create(struct btrfs_root *root, void __user *arg)
{
struct btrfs_ioctl_vol_args *vol_args;
@@ -2510,6 +2607,8 @@
return btrfs_ioctl_snap_create(root, (void __user *)arg);
case BTRFS_IOC_DEFRAG:
return btrfs_ioctl_defrag(file);
+ case BTRFS_IOC_RESIZE:
+ return btrfs_ioctl_resize(root, (void __user *)arg);
}
return -ENOTTY;
