Btrfs: Support for online FS resize (grow and shrink)

Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason
2007-12-21 16:27:24 -05:00
parent 5d4fb734b4
commit edbd8d4efe
8 changed files with 629 additions and 14 deletions

View File

@ -2346,7 +2346,7 @@ fail_unlock:
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 @@ int btrfs_defrag_file(struct file *file) {
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 @@ int btrfs_defrag_file(struct file *file) {
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 @@ int btrfs_defrag_file(struct file *file) {
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 @@ out_unlock:
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 @@ long btrfs_ioctl(struct file *file, unsigned int
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;