diff options
Diffstat (limited to 'fs/btrfs/ioctl.c')
| -rw-r--r-- | fs/btrfs/ioctl.c | 1132 |
1 files changed, 1132 insertions, 0 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c new file mode 100644 index 0000000..c2aa33e --- /dev/null +++ b/fs/btrfs/ioctl.c @@ -0,0 +1,1132 @@ +/* + * 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/fsnotify.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/mount.h> +#include <linux/mpage.h> +#include <linux/namei.h> +#include <linux/swap.h> +#include <linux/writeback.h> +#include <linux/statfs.h> +#include <linux/compat.h> +#include <linux/bit_spinlock.h> +#include <linux/security.h> +#include <linux/version.h> +#include <linux/xattr.h> +#include <linux/vmalloc.h> +#include "compat.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" +#include "locking.h" + + + +static noinline int create_subvol(struct btrfs_root *root, + struct dentry *dentry, + 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; + u64 index = 0; + unsigned long nr = 1; + + 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, 0, + objectid, trans->transid, 0, 0, 0); + if (IS_ERR(leaf)) { + ret = PTR_ERR(leaf); + goto fail; + } + + 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->nbytes = cpu_to_le64(root->leafsize); + inode_item->mode = cpu_to_le32(S_IFDIR | 0755); + + btrfs_set_root_bytenr(&root_item, leaf->start); + btrfs_set_root_generation(&root_item, trans->transid); + btrfs_set_root_level(&root_item, 0); + btrfs_set_root_refs(&root_item, 1); + btrfs_set_root_used(&root_item, 0); + btrfs_set_root_last_snapshot(&root_item, 0); + + memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress)); + root_item.drop_level = 0; + + btrfs_tree_unlock(leaf); + 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 = dentry->d_parent->d_inode; + ret = btrfs_set_inode_index(dir, &index); + BUG_ON(ret); + + ret = btrfs_insert_dir_item(trans, root, + name, namelen, dir->i_ino, &key, + BTRFS_FT_DIR, index); + if (ret) + goto fail; + + btrfs_i_size_write(dir, dir->i_size + namelen * 2); + ret = btrfs_update_inode(trans, root, dir); + BUG_ON(ret); + + /* add the backref first */ + ret = btrfs_add_root_ref(trans, root->fs_info->tree_root, + objectid, BTRFS_ROOT_BACKREF_KEY, + root->root_key.objectid, + dir->i_ino, index, name, namelen); + + BUG_ON(ret); + + /* now add the forward ref */ + ret = btrfs_add_root_ref(trans, root->fs_info->tree_root, + root->root_key.objectid, BTRFS_ROOT_REF_KEY, + objectid, + dir->i_ino, index, name, namelen); + + BUG_ON(ret); + + ret = btrfs_commit_transaction(trans, root); + if (ret) + goto fail_commit; + + new_root = btrfs_read_fs_root_no_name(root->fs_info, &key); + BUG_ON(!new_root); + + trans = btrfs_start_transaction(new_root, 1); + BUG_ON(!trans); + + ret = btrfs_create_subvol_root(trans, new_root, dentry, new_dirid, + BTRFS_I(dir)->block_group); + if (ret) + goto fail; + +fail: + nr = trans->blocks_used; + err = btrfs_commit_transaction(trans, new_root); + if (err && !ret) + ret = err; +fail_commit: + btrfs_btree_balance_dirty(root, nr); + return ret; +} + +static int create_snapshot(struct btrfs_root *root, struct dentry *dentry, + char *name, int namelen) +{ + struct btrfs_pending_snapshot *pending_snapshot; + struct btrfs_trans_handle *trans; + int ret = 0; + int err; + unsigned long nr = 0; + + if (!root->ref_cows) + return -EINVAL; + + ret = btrfs_check_free_space(root, 1, 0); + if (ret) + goto fail_unlock; + + pending_snapshot = kzalloc(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'; + pending_snapshot->dentry = dentry; + trans = btrfs_start_transaction(root, 1); + BUG_ON(!trans); + pending_snapshot->root = root; + list_add(&pending_snapshot->list, + &trans->transaction->pending_snapshots); + err = btrfs_commit_transaction(trans, root); + +fail_unlock: + btrfs_btree_balance_dirty(root, nr); + return ret; +} + +/* copy of may_create in fs/namei.c() */ +static inline int btrfs_may_create(struct inode *dir, struct dentry *child) +{ + if (child->d_inode) + return -EEXIST; + if (IS_DEADDIR(dir)) + return -ENOENT; + return inode_permission(dir, MAY_WRITE | MAY_EXEC); +} + +/* + * Create a new subvolume below @parent. This is largely modeled after + * sys_mkdirat and vfs_mkdir, but we only do a single component lookup + * inside this filesystem so it's quite a bit simpler. + */ +static noinline int btrfs_mksubvol(struct path *parent, char *name, + int mode, int namelen, + struct btrfs_root *snap_src) +{ + struct dentry *dentry; + int error; + + mutex_lock_nested(&parent->dentry->d_inode->i_mutex, I_MUTEX_PARENT); + + dentry = lookup_one_len(name, parent->dentry, namelen); + error = PTR_ERR(dentry); + if (IS_ERR(dentry)) + goto out_unlock; + + error = -EEXIST; + if (dentry->d_inode) + goto out_dput; + + if (!IS_POSIXACL(parent->dentry->d_inode)) + mode &= ~current->fs->umask; + + error = mnt_want_write(parent->mnt); + if (error) + goto out_dput; + + error = btrfs_may_create(parent->dentry->d_inode, dentry); + if (error) + goto out_drop_write; + + /* + * Actually perform the low-level subvolume creation after all + * this VFS fuzz. + * + * Eventually we want to pass in an inode under which we create this + * subvolume, but for now all are under the filesystem root. + * + * Also we should pass on the mode eventually to allow creating new + * subvolume with specific mode bits. + */ + if (snap_src) { + struct dentry *dir = dentry->d_parent; + struct dentry *test = dir->d_parent; + struct btrfs_path *path = btrfs_alloc_path(); + int ret; + u64 test_oid; + u64 parent_oid = BTRFS_I(dir->d_inode)->root->root_key.objectid; + + test_oid = snap_src->root_key.objectid; + + ret = btrfs_find_root_ref(snap_src->fs_info->tree_root, + path, parent_oid, test_oid); + if (ret == 0) + goto create; + btrfs_release_path(snap_src->fs_info->tree_root, path); + + /* we need to make sure we aren't creating a directory loop + * by taking a snapshot of something that has our current + * subvol in its directory tree. So, this loops through + * the dentries and checks the forward refs for each subvolume + * to see if is references the subvolume where we are + * placing this new snapshot. + */ + while (1) { + if (!test || + dir == snap_src->fs_info->sb->s_root || + test == snap_src->fs_info->sb->s_root || + test->d_inode->i_sb != snap_src->fs_info->sb) { + break; + } + if (S_ISLNK(test->d_inode->i_mode)) { + printk(KERN_INFO "Btrfs symlink in snapshot " + "path, failed\n"); + error = -EMLINK; + btrfs_free_path(path); + goto out_drop_write; + } + test_oid = + BTRFS_I(test->d_inode)->root->root_key.objectid; + ret = btrfs_find_root_ref(snap_src->fs_info->tree_root, + path, test_oid, parent_oid); + if (ret == 0) { + printk(KERN_INFO "Btrfs snapshot creation " + "failed, looping\n"); + error = -EMLINK; + btrfs_free_path(path); + goto out_drop_write; + } + btrfs_release_path(snap_src->fs_info->tree_root, path); + test = test->d_parent; + } +create: + btrfs_free_path(path); + error = create_snapshot(snap_src, dentry, name, namelen); + } else { + error = create_subvol(BTRFS_I(parent->dentry->d_inode)->root, + dentry, name, namelen); + } + if (error) + goto out_drop_write; + + fsnotify_mkdir(parent->dentry->d_inode, dentry); +out_drop_write: + mnt_drop_write(parent->mnt); +out_dput: + dput(dentry); +out_unlock: + mutex_unlock(&parent->dentry->d_inode->i_mutex); + return error; +} + + +static 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 btrfs_ordered_extent *ordered; + 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; + + ret = btrfs_check_free_space(root, inode->i_size, 0); + 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++; +again: + 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; + } + } + + wait_on_page_writeback(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); + + ordered = btrfs_lookup_ordered_extent(inode, page_start); + if (ordered) { + unlock_extent(io_tree, page_start, page_end, GFP_NOFS); + unlock_page(page); + page_cache_release(page); + btrfs_start_ordered_extent(inode, ordered, 1); + btrfs_put_ordered_extent(ordered); + goto again; + } + set_page_extent_mapped(page); + + /* + * this makes sure page_mkwrite is called on the + * page if it is dirtied again later + */ + clear_page_dirty_for_io(page); + + btrfs_set_extent_delalloc(inode, page_start, page_end); + + 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; + + if (root->fs_info->sb->s_flags & MS_RDONLY) + return -EROFS; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + 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; + } + + vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; + namelen = strlen(vol_args->name); + + mutex_lock(&root->fs_info->volume_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, 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->volume_mutex); +out: + kfree(vol_args); + return ret; +} + +static noinline int btrfs_ioctl_snap_create(struct file *file, + void __user *arg, int subvol) +{ + struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root; + struct btrfs_ioctl_vol_args *vol_args; + struct btrfs_dir_item *di; + struct btrfs_path *path; + struct file *src_file; + u64 root_dirid; + int namelen; + int ret = 0; + + if (root->fs_info->sb->s_flags & MS_RDONLY) + return -EROFS; + + 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; + } + + vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; + namelen = strlen(vol_args->name); + 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, + di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root, + path, root_dirid, + vol_args->name, namelen, 0); + btrfs_free_path(path); + + if (di && !IS_ERR(di)) { + ret = -EEXIST; + goto out; + } + + if (IS_ERR(di)) { + ret = PTR_ERR(di); + goto out; + } + + if (subvol) { + ret = btrfs_mksubvol(&file->f_path, vol_args->name, + file->f_path.dentry->d_inode->i_mode, + namelen, NULL); + } else { + struct inode *src_inode; + src_file = fget(vol_args->fd); + if (!src_file) { + ret = -EINVAL; + goto out; + } + + src_inode = src_file->f_path.dentry->d_inode; + if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) { + printk(KERN_INFO "btrfs: Snapshot src from " + "another FS\n"); + ret = -EINVAL; + fput(src_file); + goto out; + } + ret = btrfs_mksubvol(&file->f_path, vol_args->name, + file->f_path.dentry->d_inode->i_mode, + namelen, BTRFS_I(src_inode)->root); + fput(src_file); + } + +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; + int ret; + + ret = mnt_want_write(file->f_path.mnt); + if (ret) + return ret; + + switch (inode->i_mode & S_IFMT) { + case S_IFDIR: + if (!capable(CAP_SYS_ADMIN)) { + ret = -EPERM; + goto out; + } + btrfs_defrag_root(root, 0); + btrfs_defrag_root(root->fs_info->extent_root, 0); + break; + case S_IFREG: + if (!(file->f_mode & FMODE_WRITE)) { + ret = -EINVAL; + goto out; + } + btrfs_defrag_file(file); + break; + } +out: + mnt_drop_write(file->f_path.mnt); + return ret; +} + +static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg) +{ + struct btrfs_ioctl_vol_args *vol_args; + int ret; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + 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; + } + vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; + ret = btrfs_init_new_device(root, vol_args->name); + +out: + kfree(vol_args); + return ret; +} + +static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg) +{ + struct btrfs_ioctl_vol_args *vol_args; + int ret; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + if (root->fs_info->sb->s_flags & MS_RDONLY) + return -EROFS; + + 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; + } + vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; + ret = btrfs_rm_device(root, vol_args->name); + +out: + kfree(vol_args); + return ret; +} + +static long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, + u64 off, u64 olen, u64 destoff) +{ + 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; + struct btrfs_path *path; + struct extent_buffer *leaf; + char *buf; + struct btrfs_key key; + u32 nritems; + int slot; + int ret; + u64 len = olen; + u64 bs = root->fs_info->sb->s_blocksize; + u64 hint_byte; + + /* + * TODO: + * - split compressed inline extents. annoying: we need to + * decompress into destination's address_space (the file offset + * may change, so source mapping won't do), then recompress (or + * otherwise reinsert) a subrange. + * - allow ranges within the same file to be cloned (provided + * they don't overlap)? + */ + + /* the destination must be opened for writing */ + if (!(file->f_mode & FMODE_WRITE)) + return -EINVAL; + + ret = mnt_want_write(file->f_path.mnt); + if (ret) + return ret; + + src_file = fget(srcfd); + if (!src_file) { + ret = -EBADF; + goto out_drop_write; + } + src = src_file->f_dentry->d_inode; + + ret = -EINVAL; + if (src == inode) + goto out_fput; + + ret = -EISDIR; + if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode)) + goto out_fput; + + ret = -EXDEV; + if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root) + goto out_fput; + + ret = -ENOMEM; + buf = vmalloc(btrfs_level_size(root, 0)); + if (!buf) + goto out_fput; + + path = btrfs_alloc_path(); + if (!path) { + vfree(buf); + goto out_fput; + } + path->reada = 2; + + if (inode < src) { + mutex_lock(&inode->i_mutex); + mutex_lock(&src->i_mutex); + } else { + mutex_lock(&src->i_mutex); + mutex_lock(&inode->i_mutex); + } + + /* determine range to clone */ + ret = -EINVAL; + if (off >= src->i_size || off + len > src->i_size) + goto out_unlock; + if (len == 0) + olen = len = src->i_size - off; + /* if we extend to eof, continue to block boundary */ + if (off + len == src->i_size) + len = ((src->i_size + bs-1) & ~(bs-1)) + - off; + + /* verify the end result is block aligned */ + if ((off & (bs-1)) || + ((off + len) & (bs-1))) + goto out_unlock; + + /* do any pending delalloc/csum calc on src, one way or + another, and lock file content */ + while (1) { + struct btrfs_ordered_extent *ordered; + lock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS); + ordered = btrfs_lookup_first_ordered_extent(inode, off+len); + if (BTRFS_I(src)->delalloc_bytes == 0 && !ordered) + break; + unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS); + if (ordered) + btrfs_put_ordered_extent(ordered); + btrfs_wait_ordered_range(src, off, off+len); + } + + trans = btrfs_start_transaction(root, 1); + BUG_ON(!trans); + + /* punch hole in destination first */ + btrfs_drop_extents(trans, root, inode, off, off+len, 0, &hint_byte); + + /* clone data */ + key.objectid = src->i_ino; + key.type = BTRFS_EXTENT_DATA_KEY; + key.offset = 0; + + 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; + + nritems = btrfs_header_nritems(path->nodes[0]); + if (path->slots[0] >= nritems) { + ret = btrfs_next_leaf(root, path); + if (ret < 0) + goto out; + if (ret > 0) + break; + nritems = btrfs_header_nritems(path->nodes[0]); + } + leaf = path->nodes[0]; + slot = path->slots[0]; + + btrfs_item_key_to_cpu(leaf, &key, slot); + if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY || + key.objectid != src->i_ino) + break; + + if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) { + struct btrfs_file_extent_item *extent; + int type; + u32 size; + struct btrfs_key new_key; + u64 disko = 0, diskl = 0; + u64 datao = 0, datal = 0; + u8 comp; + + size = btrfs_item_size_nr(leaf, slot); + read_extent_buffer(leaf, buf, + btrfs_item_ptr_offset(leaf, slot), + size); + + extent = btrfs_item_ptr(leaf, slot, + struct btrfs_file_extent_item); + comp = btrfs_file_extent_compression(leaf, extent); + type = btrfs_file_extent_type(leaf, extent); + if (type == BTRFS_FILE_EXTENT_REG) { + disko = btrfs_file_extent_disk_bytenr(leaf, + extent); + diskl = btrfs_file_extent_disk_num_bytes(leaf, + extent); + datao = btrfs_file_extent_offset(leaf, extent); + datal = btrfs_file_extent_num_bytes(leaf, + extent); + } else if (type == BTRFS_FILE_EXTENT_INLINE) { + /* take upper bound, may be compressed */ + datal = btrfs_file_extent_ram_bytes(leaf, + extent); + } + btrfs_release_path(root, path); + + if (key.offset + datal < off || + key.offset >= off+len) + goto next; + + memcpy(&new_key, &key, sizeof(new_key)); + new_key.objectid = inode->i_ino; + new_key.offset = key.offset + destoff - off; + + if (type == BTRFS_FILE_EXTENT_REG) { + ret = btrfs_insert_empty_item(trans, root, path, + &new_key, size); + if (ret) + goto out; + + leaf = path->nodes[0]; + slot = path->slots[0]; + write_extent_buffer(leaf, buf, + btrfs_item_ptr_offset(leaf, slot), + size); + + extent = btrfs_item_ptr(leaf, slot, + struct btrfs_file_extent_item); + + if (off > key.offset) { + datao += off - key.offset; + datal -= off - key.offset; + } + if (key.offset + datao + datal + key.offset > + off + len) + datal = off + len - key.offset - datao; + /* disko == 0 means it's a hole */ + if (!disko) + datao = 0; + + btrfs_set_file_extent_offset(leaf, extent, + datao); + btrfs_set_file_extent_num_bytes(leaf, extent, + datal); + if (disko) { + inode_add_bytes(inode, datal); + ret = btrfs_inc_extent_ref(trans, root, + disko, diskl, leaf->start, + root->root_key.objectid, + trans->transid, + inode->i_ino); + BUG_ON(ret); + } + } else if (type == BTRFS_FILE_EXTENT_INLINE) { + u64 skip = 0; + u64 trim = 0; + if (off > key.offset) { + skip = off - key.offset; + new_key.offset += skip; + } + + if (key.offset + datal > off+len) + trim = key.offset + datal - (off+len); + + if (comp && (skip || trim)) { + ret = -EINVAL; + goto out; + } + size -= skip + trim; + datal -= skip + trim; + ret = btrfs_insert_empty_item(trans, root, path, + &new_key, size); + if (ret) + goto out; + + if (skip) { + u32 start = + btrfs_file_extent_calc_inline_size(0); + memmove(buf+start, buf+start+skip, + datal); + } + + leaf = path->nodes[0]; + slot = path->slots[0]; + write_extent_buffer(leaf, buf, + btrfs_item_ptr_offset(leaf, slot), + size); + inode_add_bytes(inode, datal); + } + + btrfs_mark_buffer_dirty(leaf); + } + +next: + btrfs_release_path(root, path); + key.offset++; + } + ret = 0; +out: + btrfs_release_path(root, path); + if (ret == 0) { + inode->i_mtime = inode->i_ctime = CURRENT_TIME; + if (destoff + olen > inode->i_size) + btrfs_i_size_write(inode, destoff + olen); + BTRFS_I(inode)->flags = BTRFS_I(src)->flags; + ret = btrfs_update_inode(trans, root, inode); + } + btrfs_end_transaction(trans, root); + unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS); + if (ret) + vmtruncate(inode, 0); +out_unlock: + mutex_unlock(&src->i_mutex); + mutex_unlock(&inode->i_mutex); + vfree(buf); + btrfs_free_path(path); +out_fput: + fput(src_file); +out_drop_write: + mnt_drop_write(file->f_path.mnt); + return ret; +} + +static long btrfs_ioctl_clone_range(struct file *file, void __user *argp) +{ + struct btrfs_ioctl_clone_range_args args; + + if (copy_from_user(&args, argp, sizeof(args))) + return -EFAULT; + return btrfs_ioctl_clone(file, args.src_fd, args.src_offset, + args.src_length, args.dest_offset); +} + +/* + * 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. + */ +static 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; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + if (file->private_data) { + ret = -EINPROGRESS; + goto out; + } + + ret = mnt_want_write(file->f_path.mnt); + if (ret) + goto out; + + mutex_lock(&root->fs_info->trans_mutex); + root->fs_info->open_ioctl_trans++; + mutex_unlock(&root->fs_info->trans_mutex); + + trans = btrfs_start_ioctl_transaction(root, 0); + if (trans) + file->private_data = trans; + else + ret = -ENOMEM; + /*printk(KERN_INFO "btrfs_ioctl_trans_start on %p\n", file);*/ +out: + 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; + + trans = file->private_data; + if (!trans) { + ret = -EINVAL; + goto out; + } + btrfs_end_transaction(trans, root); + file->private_data = NULL; + + mutex_lock(&root->fs_info->trans_mutex); + root->fs_info->open_ioctl_trans--; + mutex_unlock(&root->fs_info->trans_mutex); + + mnt_drop_write(file->f_path.mnt); + +out: + 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; + void __user *argp = (void __user *)arg; + + switch (cmd) { + case BTRFS_IOC_SNAP_CREATE: + return btrfs_ioctl_snap_create(file, argp, 0); + case BTRFS_IOC_SUBVOL_CREATE: + return btrfs_ioctl_snap_create(file, argp, 1); + case BTRFS_IOC_DEFRAG: + return btrfs_ioctl_defrag(file); + case BTRFS_IOC_RESIZE: + return btrfs_ioctl_resize(root, argp); + case BTRFS_IOC_ADD_DEV: + return btrfs_ioctl_add_dev(root, argp); + case BTRFS_IOC_RM_DEV: + return btrfs_ioctl_rm_dev(root, argp); + case BTRFS_IOC_BALANCE: + return btrfs_balance(root->fs_info->dev_root); + case BTRFS_IOC_CLONE: + return btrfs_ioctl_clone(file, arg, 0, 0, 0); + case BTRFS_IOC_CLONE_RANGE: + return btrfs_ioctl_clone_range(file, argp); + 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; +} |
