diff options
Diffstat (limited to 'fs/btrfs/ioctl.c')
| -rw-r--r-- | fs/btrfs/ioctl.c | 781 |
1 files changed, 781 insertions, 0 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c new file mode 100644 index 00000000000..da8de6cfdb5 --- /dev/null +++ b/fs/btrfs/ioctl.c @@ -0,0 +1,781 @@ +/* + * Copyright (C) 2007 Oracle. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ + +#include <linux/kernel.h> +#include <linux/bio.h> +#include <linux/buffer_head.h> +#include <linux/file.h> +#include <linux/fs.h> +#include <linux/pagemap.h> +#include <linux/highmem.h> +#include <linux/time.h> +#include <linux/init.h> +#include <linux/string.h> +#include <linux/smp_lock.h> +#include <linux/backing-dev.h> +#include <linux/mpage.h> +#include <linux/swap.h> +#include <linux/writeback.h> +#include <linux/statfs.h> +#include <linux/compat.h> +#include <linux/bit_spinlock.h> +#include <linux/version.h> +#include <linux/xattr.h> +#include "ctree.h" +#include "disk-io.h" +#include "transaction.h" +#include "btrfs_inode.h" +#include "ioctl.h" +#include "print-tree.h" +#include "volumes.h" + + + +static noinline int create_subvol(struct btrfs_root *root, char *name, + int namelen) +{ + struct btrfs_trans_handle *trans; + struct btrfs_key key; + struct btrfs_root_item root_item; + struct btrfs_inode_item *inode_item; + struct extent_buffer *leaf; + struct btrfs_root *new_root = root; + struct inode *dir; + int ret; + int err; + u64 objectid; + u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID; + unsigned long nr = 1; + + mutex_lock(&root->fs_info->fs_mutex); + ret = btrfs_check_free_space(root, 1, 0); + if (ret) + goto fail_commit; + + trans = btrfs_start_transaction(root, 1); + BUG_ON(!trans); + + ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root, + 0, &objectid); + if (ret) + goto fail; + + leaf = __btrfs_alloc_free_block(trans, root, root->leafsize, + objectid, trans->transid, 0, 0, + 0, 0); + if (IS_ERR(leaf)) + return PTR_ERR(leaf); + + btrfs_set_header_nritems(leaf, 0); + btrfs_set_header_level(leaf, 0); + btrfs_set_header_bytenr(leaf, leaf->start); + btrfs_set_header_generation(leaf, trans->transid); + btrfs_set_header_owner(leaf, objectid); + + write_extent_buffer(leaf, root->fs_info->fsid, + (unsigned long)btrfs_header_fsid(leaf), + BTRFS_FSID_SIZE); + btrfs_mark_buffer_dirty(leaf); + + inode_item = &root_item.inode; + memset(inode_item, 0, sizeof(*inode_item)); + inode_item->generation = cpu_to_le64(1); + inode_item->size = cpu_to_le64(3); + inode_item->nlink = cpu_to_le32(1); + inode_item->nblocks = cpu_to_le64(1); + inode_item->mode = cpu_to_le32(S_IFDIR | 0755); + + btrfs_set_root_bytenr(&root_item, leaf->start); + btrfs_set_root_level(&root_item, 0); + btrfs_set_root_refs(&root_item, 1); + btrfs_set_root_used(&root_item, 0); + + memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress)); + root_item.drop_level = 0; + + free_extent_buffer(leaf); + leaf = NULL; + + btrfs_set_root_dirid(&root_item, new_dirid); + + key.objectid = objectid; + key.offset = 1; + btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY); + ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key, + &root_item); + if (ret) + goto fail; + + /* + * insert the directory item + */ + key.offset = (u64)-1; + dir = root->fs_info->sb->s_root->d_inode; + ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root, + name, namelen, dir->i_ino, &key, + BTRFS_FT_DIR); + if (ret) + goto fail; + + ret = btrfs_insert_inode_ref(trans, root->fs_info->tree_root, + name, namelen, objectid, + root->fs_info->sb->s_root->d_inode->i_ino); + if (ret) + goto fail; + + ret = btrfs_commit_transaction(trans, root); + if (ret) + goto fail_commit; + + new_root = btrfs_read_fs_root(root->fs_info, &key, name, namelen); + BUG_ON(!new_root); + + trans = btrfs_start_transaction(new_root, 1); + BUG_ON(!trans); + + ret = btrfs_create_subvol_root(new_root, trans, new_dirid, + BTRFS_I(dir)->block_group); + if (ret) + goto fail; + + /* Invalidate existing dcache entry for new subvolume. */ + btrfs_invalidate_dcache_root(root, name, namelen); + +fail: + nr = trans->blocks_used; + err = btrfs_commit_transaction(trans, new_root); + if (err && !ret) + ret = err; +fail_commit: + mutex_unlock(&root->fs_info->fs_mutex); + btrfs_btree_balance_dirty(root, nr); + btrfs_throttle(root); + return ret; +} + +static int create_snapshot(struct btrfs_root *root, char *name, int namelen) +{ + struct btrfs_pending_snapshot *pending_snapshot; + struct btrfs_trans_handle *trans; + int ret; + int err; + unsigned long nr = 0; + + if (!root->ref_cows) + return -EINVAL; + + mutex_lock(&root->fs_info->fs_mutex); + ret = btrfs_check_free_space(root, 1, 0); + if (ret) + goto fail_unlock; + + pending_snapshot = kmalloc(sizeof(*pending_snapshot), GFP_NOFS); + if (!pending_snapshot) { + ret = -ENOMEM; + goto fail_unlock; + } + pending_snapshot->name = kmalloc(namelen + 1, GFP_NOFS); + if (!pending_snapshot->name) { + ret = -ENOMEM; + kfree(pending_snapshot); + goto fail_unlock; + } + memcpy(pending_snapshot->name, name, namelen); + pending_snapshot->name[namelen] = '\0'; + trans = btrfs_start_transaction(root, 1); + BUG_ON(!trans); + pending_snapshot->root = root; + list_add(&pending_snapshot->list, + &trans->transaction->pending_snapshots); + ret = btrfs_update_inode(trans, root, root->inode); + err = btrfs_commit_transaction(trans, root); + +fail_unlock: + mutex_unlock(&root->fs_info->fs_mutex); + btrfs_btree_balance_dirty(root, nr); + btrfs_throttle(root); + return ret; +} + +int btrfs_defrag_file(struct file *file) +{ + struct inode *inode = fdentry(file)->d_inode; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + struct page *page; + unsigned long last_index; + unsigned long ra_pages = root->fs_info->bdi.ra_pages; + unsigned long total_read = 0; + u64 page_start; + u64 page_end; + unsigned long i; + int ret; + + mutex_lock(&root->fs_info->fs_mutex); + ret = btrfs_check_free_space(root, inode->i_size, 0); + mutex_unlock(&root->fs_info->fs_mutex); + if (ret) + return -ENOSPC; + + mutex_lock(&inode->i_mutex); + last_index = inode->i_size >> PAGE_CACHE_SHIFT; + for (i = 0; i <= last_index; i++) { + if (total_read % ra_pages == 0) { + btrfs_force_ra(inode->i_mapping, &file->f_ra, file, i, + min(last_index, i + ra_pages - 1)); + } + total_read++; + page = grab_cache_page(inode->i_mapping, i); + if (!page) + goto out_unlock; + if (!PageUptodate(page)) { + btrfs_readpage(NULL, page); + lock_page(page); + if (!PageUptodate(page)) { + unlock_page(page); + page_cache_release(page); + goto out_unlock; + } + } + +#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18) + ClearPageDirty(page); +#else + cancel_dirty_page(page, PAGE_CACHE_SIZE); +#endif + wait_on_page_writeback(page); + set_page_extent_mapped(page); + + page_start = (u64)page->index << PAGE_CACHE_SHIFT; + page_end = page_start + PAGE_CACHE_SIZE - 1; + + lock_extent(io_tree, page_start, page_end, GFP_NOFS); + set_extent_delalloc(io_tree, page_start, + page_end, GFP_NOFS); + + unlock_extent(io_tree, page_start, page_end, GFP_NOFS); + set_page_dirty(page); + unlock_page(page); + page_cache_release(page); + balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1); + } + +out_unlock: + mutex_unlock(&inode->i_mutex); + return 0; +} + +/* + * Called inside transaction, so use GFP_NOFS + */ + +static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg) +{ + u64 new_size; + u64 old_size; + u64 devid = 1; + struct btrfs_ioctl_vol_args *vol_args; + struct btrfs_trans_handle *trans; + struct btrfs_device *device = NULL; + char *sizestr; + char *devstr = NULL; + 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; + } + + mutex_lock(&root->fs_info->fs_mutex); + sizestr = vol_args->name; + devstr = strchr(sizestr, ':'); + if (devstr) { + char *end; + sizestr = devstr + 1; + *devstr = '\0'; + devstr = vol_args->name; + devid = simple_strtoull(devstr, &end, 10); + printk(KERN_INFO "resizing devid %llu\n", devid); + } + device = btrfs_find_device(root, devid, NULL); + if (!device) { + printk(KERN_INFO "resizer unable to find device %llu\n", devid); + ret = -EINVAL; + goto out_unlock; + } + if (!strcmp(sizestr, "max")) + new_size = device->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_unlock; + } + } + + old_size = device->total_bytes; + + 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 > device->bdev->bd_inode->i_size) { + ret = -EFBIG; + goto out_unlock; + } + + do_div(new_size, root->sectorsize); + new_size *= root->sectorsize; + + printk(KERN_INFO "new size for %s is %llu\n", + device->name, (unsigned long long)new_size); + + if (new_size > old_size) { + trans = btrfs_start_transaction(root, 1); + ret = btrfs_grow_device(trans, device, new_size); + btrfs_commit_transaction(trans, root); + } else { + ret = btrfs_shrink_device(device, new_size); + } + +out_unlock: + mutex_unlock(&root->fs_info->fs_mutex); +out: + kfree(vol_args); + return ret; +} + +static noinline int btrfs_ioctl_snap_create(struct btrfs_root *root, + void __user *arg) +{ + struct btrfs_ioctl_vol_args *vol_args; + struct btrfs_dir_item *di; + struct btrfs_path *path; + u64 root_dirid; + int namelen; + int ret; + + 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; + } + if (strchr(vol_args->name, '/')) { + ret = -EINVAL; + goto out; + } + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto out; + } + + root_dirid = root->fs_info->sb->s_root->d_inode->i_ino, + mutex_lock(&root->fs_info->fs_mutex); + di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root, + path, root_dirid, + vol_args->name, namelen, 0); + mutex_unlock(&root->fs_info->fs_mutex); + btrfs_free_path(path); + + if (di && !IS_ERR(di)) { + ret = -EEXIST; + goto out; + } + + if (IS_ERR(di)) { + ret = PTR_ERR(di); + goto out; + } + + if (root == root->fs_info->tree_root) + ret = create_subvol(root, vol_args->name, namelen); + else + ret = create_snapshot(root, vol_args->name, namelen); +out: + kfree(vol_args); + return ret; +} + +static int btrfs_ioctl_defrag(struct file *file) +{ + struct inode *inode = fdentry(file)->d_inode; + struct btrfs_root *root = BTRFS_I(inode)->root; + + switch (inode->i_mode & S_IFMT) { + case S_IFDIR: + mutex_lock(&root->fs_info->fs_mutex); + btrfs_defrag_root(root, 0); + btrfs_defrag_root(root->fs_info->extent_root, 0); + mutex_unlock(&root->fs_info->fs_mutex); + break; + case S_IFREG: + btrfs_defrag_file(file); + break; + } + + return 0; +} + +long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg) +{ + struct btrfs_ioctl_vol_args *vol_args; + int ret; + + 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; + } + ret = btrfs_init_new_device(root, vol_args->name); + +out: + kfree(vol_args); + return ret; +} + +long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg) +{ + struct btrfs_ioctl_vol_args *vol_args; + int ret; + + 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; + } + ret = btrfs_rm_device(root, vol_args->name); + +out: + kfree(vol_args); + return ret; +} + +int dup_item_to_inode(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + struct extent_buffer *leaf, + int slot, + struct btrfs_key *key, + u64 destino) +{ + char *dup; + int len = btrfs_item_size_nr(leaf, slot); + struct btrfs_key ckey = *key; + int ret = 0; + + dup = kmalloc(len, GFP_NOFS); + if (!dup) + return -ENOMEM; + + read_extent_buffer(leaf, dup, btrfs_item_ptr_offset(leaf, slot), len); + btrfs_release_path(root, path); + + ckey.objectid = destino; + ret = btrfs_insert_item(trans, root, &ckey, dup, len); + kfree(dup); + return ret; +} + +long btrfs_ioctl_clone(struct file *file, unsigned long src_fd) +{ + struct inode *inode = fdentry(file)->d_inode; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct file *src_file; + struct inode *src; + struct btrfs_trans_handle *trans; + int ret; + u64 pos; + struct btrfs_path *path; + struct btrfs_key key; + struct extent_buffer *leaf; + u32 nritems; + int slot; + + src_file = fget(src_fd); + if (!src_file) + return -EBADF; + src = src_file->f_dentry->d_inode; + + ret = -EXDEV; + if (src->i_sb != inode->i_sb) + goto out_fput; + + if (inode < src) { + mutex_lock(&inode->i_mutex); + mutex_lock(&src->i_mutex); + } else { + mutex_lock(&src->i_mutex); + mutex_lock(&inode->i_mutex); + } + + ret = -ENOTEMPTY; + if (inode->i_size) + goto out_unlock; + + /* do any pending delalloc/csum calc on src, one way or + another, and lock file content */ + while (1) { + filemap_write_and_wait(src->i_mapping); + lock_extent(&BTRFS_I(src)->io_tree, 0, (u64)-1, GFP_NOFS); + if (BTRFS_I(src)->delalloc_bytes == 0) + break; + unlock_extent(&BTRFS_I(src)->io_tree, 0, (u64)-1, GFP_NOFS); + } + + mutex_lock(&root->fs_info->fs_mutex); + trans = btrfs_start_transaction(root, 0); + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto out; + } + key.offset = 0; + key.type = BTRFS_EXTENT_DATA_KEY; + key.objectid = src->i_ino; + pos = 0; + path->reada = 2; + + while (1) { + /* + * note the key will change type as we walk through the + * tree. + */ + ret = btrfs_search_slot(trans, root, &key, path, 0, 0); + if (ret < 0) + goto out; + + if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) { + ret = btrfs_next_leaf(root, path); + if (ret < 0) + goto out; + if (ret > 0) + break; + } + leaf = path->nodes[0]; + slot = path->slots[0]; + btrfs_item_key_to_cpu(leaf, &key, slot); + nritems = btrfs_header_nritems(leaf); + + if (btrfs_key_type(&key) > BTRFS_CSUM_ITEM_KEY || + key.objectid != src->i_ino) + break; + + if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) { + struct btrfs_file_extent_item *extent; + int found_type; + pos = key.offset; + extent = btrfs_item_ptr(leaf, slot, + struct btrfs_file_extent_item); + found_type = btrfs_file_extent_type(leaf, extent); + if (found_type == BTRFS_FILE_EXTENT_REG) { + u64 len = btrfs_file_extent_num_bytes(leaf, + extent); + u64 ds = btrfs_file_extent_disk_bytenr(leaf, + extent); + u64 dl = btrfs_file_extent_disk_num_bytes(leaf, + extent); + u64 off = btrfs_file_extent_offset(leaf, + extent); + btrfs_insert_file_extent(trans, root, + inode->i_ino, pos, + ds, dl, len, off); + /* ds == 0 means there's a hole */ + if (ds != 0) { + btrfs_inc_extent_ref(trans, root, + ds, dl, + root->root_key.objectid, + trans->transid, + inode->i_ino, pos); + } + pos = key.offset + len; + } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { + ret = dup_item_to_inode(trans, root, path, + leaf, slot, &key, + inode->i_ino); + if (ret) + goto out; + pos = key.offset + btrfs_item_size_nr(leaf, + slot); + } + } else if (btrfs_key_type(&key) == BTRFS_CSUM_ITEM_KEY) { + ret = dup_item_to_inode(trans, root, path, leaf, + slot, &key, inode->i_ino); + + if (ret) + goto out; + } + key.offset++; + btrfs_release_path(root, path); + } + + ret = 0; +out: + btrfs_free_path(path); + + inode->i_blocks = src->i_blocks; + i_size_write(inode, src->i_size); + btrfs_update_inode(trans, root, inode); + + unlock_extent(&BTRFS_I(src)->io_tree, 0, (u64)-1, GFP_NOFS); + + btrfs_end_transaction(trans, root); + mutex_unlock(&root->fs_info->fs_mutex); + +out_unlock: + mutex_unlock(&src->i_mutex); + mutex_unlock(&inode->i_mutex); +out_fput: + fput(src_file); + return ret; +} + +/* + * there are many ways the trans_start and trans_end ioctls can lead + * to deadlocks. They should only be used by applications that + * basically own the machine, and have a very in depth understanding + * of all the possible deadlocks and enospc problems. + */ +long btrfs_ioctl_trans_start(struct file *file) +{ + struct inode *inode = fdentry(file)->d_inode; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_trans_handle *trans; + int ret = 0; + + mutex_lock(&root->fs_info->fs_mutex); + if (file->private_data) { + ret = -EINPROGRESS; + goto out; + } + trans = btrfs_start_transaction(root, 0); + if (trans) + file->private_data = trans; + else + ret = -ENOMEM; + /*printk(KERN_INFO "btrfs_ioctl_trans_start on %p\n", file);*/ +out: + mutex_unlock(&root->fs_info->fs_mutex); + return ret; +} + +/* + * there are many ways the trans_start and trans_end ioctls can lead + * to deadlocks. They should only be used by applications that + * basically own the machine, and have a very in depth understanding + * of all the possible deadlocks and enospc problems. + */ +long btrfs_ioctl_trans_end(struct file *file) +{ + struct inode *inode = fdentry(file)->d_inode; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_trans_handle *trans; + int ret = 0; + + mutex_lock(&root->fs_info->fs_mutex); + trans = file->private_data; + if (!trans) { + ret = -EINVAL; + goto out; + } + btrfs_end_transaction(trans, root); + file->private_data = 0; +out: + mutex_unlock(&root->fs_info->fs_mutex); + return ret; +} + +long btrfs_ioctl(struct file *file, unsigned int + cmd, unsigned long arg) +{ + struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root; + + switch (cmd) { + case BTRFS_IOC_SNAP_CREATE: + 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); + case BTRFS_IOC_ADD_DEV: + return btrfs_ioctl_add_dev(root, (void __user *)arg); + case BTRFS_IOC_RM_DEV: + return btrfs_ioctl_rm_dev(root, (void __user *)arg); + case BTRFS_IOC_BALANCE: + return btrfs_balance(root->fs_info->dev_root); + case BTRFS_IOC_CLONE: + return btrfs_ioctl_clone(file, arg); + case BTRFS_IOC_TRANS_START: + return btrfs_ioctl_trans_start(file); + case BTRFS_IOC_TRANS_END: + return btrfs_ioctl_trans_end(file); + case BTRFS_IOC_SYNC: + btrfs_sync_fs(file->f_dentry->d_sb, 1); + return 0; + } + + return -ENOTTY; +} |