diff options
Diffstat (limited to 'fs/btrfs/ioctl.c')
| -rw-r--r-- | fs/btrfs/ioctl.c | 2914 |
1 files changed, 2914 insertions, 0 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c new file mode 100644 index 00000000..a3c4751e --- /dev/null +++ b/fs/btrfs/ioctl.c @@ -0,0 +1,2914 @@ +/* + * 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/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/xattr.h> +#include <linux/vmalloc.h> +#include <linux/slab.h> +#include <linux/blkdev.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" +#include "inode-map.h" + +/* Mask out flags that are inappropriate for the given type of inode. */ +static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags) +{ + if (S_ISDIR(mode)) + return flags; + else if (S_ISREG(mode)) + return flags & ~FS_DIRSYNC_FL; + else + return flags & (FS_NODUMP_FL | FS_NOATIME_FL); +} + +/* + * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl. + */ +static unsigned int btrfs_flags_to_ioctl(unsigned int flags) +{ + unsigned int iflags = 0; + + if (flags & BTRFS_INODE_SYNC) + iflags |= FS_SYNC_FL; + if (flags & BTRFS_INODE_IMMUTABLE) + iflags |= FS_IMMUTABLE_FL; + if (flags & BTRFS_INODE_APPEND) + iflags |= FS_APPEND_FL; + if (flags & BTRFS_INODE_NODUMP) + iflags |= FS_NODUMP_FL; + if (flags & BTRFS_INODE_NOATIME) + iflags |= FS_NOATIME_FL; + if (flags & BTRFS_INODE_DIRSYNC) + iflags |= FS_DIRSYNC_FL; + if (flags & BTRFS_INODE_NODATACOW) + iflags |= FS_NOCOW_FL; + + if ((flags & BTRFS_INODE_COMPRESS) && !(flags & BTRFS_INODE_NOCOMPRESS)) + iflags |= FS_COMPR_FL; + else if (flags & BTRFS_INODE_NOCOMPRESS) + iflags |= FS_NOCOMP_FL; + + return iflags; +} + +/* + * Update inode->i_flags based on the btrfs internal flags. + */ +void btrfs_update_iflags(struct inode *inode) +{ + struct btrfs_inode *ip = BTRFS_I(inode); + + inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC); + + if (ip->flags & BTRFS_INODE_SYNC) + inode->i_flags |= S_SYNC; + if (ip->flags & BTRFS_INODE_IMMUTABLE) + inode->i_flags |= S_IMMUTABLE; + if (ip->flags & BTRFS_INODE_APPEND) + inode->i_flags |= S_APPEND; + if (ip->flags & BTRFS_INODE_NOATIME) + inode->i_flags |= S_NOATIME; + if (ip->flags & BTRFS_INODE_DIRSYNC) + inode->i_flags |= S_DIRSYNC; +} + +/* + * Inherit flags from the parent inode. + * + * Unlike extN we don't have any flags we don't want to inherit currently. + */ +void btrfs_inherit_iflags(struct inode *inode, struct inode *dir) +{ + unsigned int flags; + + if (!dir) + return; + + flags = BTRFS_I(dir)->flags; + + if (S_ISREG(inode->i_mode)) + flags &= ~BTRFS_INODE_DIRSYNC; + else if (!S_ISDIR(inode->i_mode)) + flags &= (BTRFS_INODE_NODUMP | BTRFS_INODE_NOATIME); + + BTRFS_I(inode)->flags = flags; + btrfs_update_iflags(inode); +} + +static int btrfs_ioctl_getflags(struct file *file, void __user *arg) +{ + struct btrfs_inode *ip = BTRFS_I(file->f_path.dentry->d_inode); + unsigned int flags = btrfs_flags_to_ioctl(ip->flags); + + if (copy_to_user(arg, &flags, sizeof(flags))) + return -EFAULT; + return 0; +} + +static int check_flags(unsigned int flags) +{ + if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \ + FS_NOATIME_FL | FS_NODUMP_FL | \ + FS_SYNC_FL | FS_DIRSYNC_FL | \ + FS_NOCOMP_FL | FS_COMPR_FL | + FS_NOCOW_FL)) + return -EOPNOTSUPP; + + if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL)) + return -EINVAL; + + return 0; +} + +static int btrfs_ioctl_setflags(struct file *file, void __user *arg) +{ + struct inode *inode = file->f_path.dentry->d_inode; + struct btrfs_inode *ip = BTRFS_I(inode); + struct btrfs_root *root = ip->root; + struct btrfs_trans_handle *trans; + unsigned int flags, oldflags; + int ret; + + if (btrfs_root_readonly(root)) + return -EROFS; + + if (copy_from_user(&flags, arg, sizeof(flags))) + return -EFAULT; + + ret = check_flags(flags); + if (ret) + return ret; + + if (!inode_owner_or_capable(inode)) + return -EACCES; + + mutex_lock(&inode->i_mutex); + + flags = btrfs_mask_flags(inode->i_mode, flags); + oldflags = btrfs_flags_to_ioctl(ip->flags); + if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) { + if (!capable(CAP_LINUX_IMMUTABLE)) { + ret = -EPERM; + goto out_unlock; + } + } + + ret = mnt_want_write(file->f_path.mnt); + if (ret) + goto out_unlock; + + if (flags & FS_SYNC_FL) + ip->flags |= BTRFS_INODE_SYNC; + else + ip->flags &= ~BTRFS_INODE_SYNC; + if (flags & FS_IMMUTABLE_FL) + ip->flags |= BTRFS_INODE_IMMUTABLE; + else + ip->flags &= ~BTRFS_INODE_IMMUTABLE; + if (flags & FS_APPEND_FL) + ip->flags |= BTRFS_INODE_APPEND; + else + ip->flags &= ~BTRFS_INODE_APPEND; + if (flags & FS_NODUMP_FL) + ip->flags |= BTRFS_INODE_NODUMP; + else + ip->flags &= ~BTRFS_INODE_NODUMP; + if (flags & FS_NOATIME_FL) + ip->flags |= BTRFS_INODE_NOATIME; + else + ip->flags &= ~BTRFS_INODE_NOATIME; + if (flags & FS_DIRSYNC_FL) + ip->flags |= BTRFS_INODE_DIRSYNC; + else + ip->flags &= ~BTRFS_INODE_DIRSYNC; + if (flags & FS_NOCOW_FL) + ip->flags |= BTRFS_INODE_NODATACOW; + else + ip->flags &= ~BTRFS_INODE_NODATACOW; + + /* + * The COMPRESS flag can only be changed by users, while the NOCOMPRESS + * flag may be changed automatically if compression code won't make + * things smaller. + */ + if (flags & FS_NOCOMP_FL) { + ip->flags &= ~BTRFS_INODE_COMPRESS; + ip->flags |= BTRFS_INODE_NOCOMPRESS; + } else if (flags & FS_COMPR_FL) { + ip->flags |= BTRFS_INODE_COMPRESS; + ip->flags &= ~BTRFS_INODE_NOCOMPRESS; + } else { + ip->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS); + } + + trans = btrfs_join_transaction(root); + BUG_ON(IS_ERR(trans)); + + ret = btrfs_update_inode(trans, root, inode); + BUG_ON(ret); + + btrfs_update_iflags(inode); + inode->i_ctime = CURRENT_TIME; + btrfs_end_transaction(trans, root); + + mnt_drop_write(file->f_path.mnt); + + ret = 0; + out_unlock: + mutex_unlock(&inode->i_mutex); + return ret; +} + +static int btrfs_ioctl_getversion(struct file *file, int __user *arg) +{ + struct inode *inode = file->f_path.dentry->d_inode; + + return put_user(inode->i_generation, arg); +} + +static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg) +{ + struct btrfs_root *root = fdentry(file)->d_sb->s_fs_info; + struct btrfs_fs_info *fs_info = root->fs_info; + struct btrfs_device *device; + struct request_queue *q; + struct fstrim_range range; + u64 minlen = ULLONG_MAX; + u64 num_devices = 0; + int ret; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + rcu_read_lock(); + list_for_each_entry_rcu(device, &fs_info->fs_devices->devices, + dev_list) { + if (!device->bdev) + continue; + q = bdev_get_queue(device->bdev); + if (blk_queue_discard(q)) { + num_devices++; + minlen = min((u64)q->limits.discard_granularity, + minlen); + } + } + rcu_read_unlock(); + if (!num_devices) + return -EOPNOTSUPP; + + if (copy_from_user(&range, arg, sizeof(range))) + return -EFAULT; + + range.minlen = max(range.minlen, minlen); + ret = btrfs_trim_fs(root, &range); + if (ret < 0) + return ret; + + if (copy_to_user(arg, &range, sizeof(range))) + return -EFAULT; + + return 0; +} + +static noinline int create_subvol(struct btrfs_root *root, + struct dentry *dentry, + char *name, int namelen, + u64 *async_transid) +{ + 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; + struct dentry *parent = dget_parent(dentry); + struct inode *dir; + int ret; + int err; + u64 objectid; + u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID; + u64 index = 0; + + ret = btrfs_find_free_objectid(root->fs_info->tree_root, &objectid); + if (ret) { + dput(parent); + return ret; + } + + dir = parent->d_inode; + + /* + * 1 - inode item + * 2 - refs + * 1 - root item + * 2 - dir items + */ + trans = btrfs_start_transaction(root, 6); + if (IS_ERR(trans)) { + dput(parent); + return PTR_ERR(trans); + } + + leaf = btrfs_alloc_free_block(trans, root, root->leafsize, + 0, objectid, NULL, 0, 0, 0); + if (IS_ERR(leaf)) { + ret = PTR_ERR(leaf); + goto fail; + } + + memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header)); + btrfs_set_header_bytenr(leaf, leaf->start); + btrfs_set_header_generation(leaf, trans->transid); + btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV); + btrfs_set_header_owner(leaf, objectid); + + write_extent_buffer(leaf, root->fs_info->fsid, + (unsigned long)btrfs_header_fsid(leaf), + BTRFS_FSID_SIZE); + write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid, + (unsigned long)btrfs_header_chunk_tree_uuid(leaf), + BTRFS_UUID_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); + + root_item.flags = 0; + root_item.byte_limit = 0; + inode_item->flags = cpu_to_le64(BTRFS_INODE_ROOT_ITEM_INIT); + + 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, leaf->len); + 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 = 0; + 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; + + key.offset = (u64)-1; + new_root = btrfs_read_fs_root_no_name(root->fs_info, &key); + BUG_ON(IS_ERR(new_root)); + + btrfs_record_root_in_trans(trans, new_root); + + ret = btrfs_create_subvol_root(trans, new_root, new_dirid); + /* + * insert the directory item + */ + ret = btrfs_set_inode_index(dir, &index); + BUG_ON(ret); + + ret = btrfs_insert_dir_item(trans, root, + name, namelen, dir, &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); + + ret = btrfs_add_root_ref(trans, root->fs_info->tree_root, + objectid, root->root_key.objectid, + btrfs_ino(dir), index, name, namelen); + + BUG_ON(ret); + + d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry)); +fail: + dput(parent); + if (async_transid) { + *async_transid = trans->transid; + err = btrfs_commit_transaction_async(trans, root, 1); + } else { + err = btrfs_commit_transaction(trans, root); + } + if (err && !ret) + ret = err; + return ret; +} + +static int create_snapshot(struct btrfs_root *root, struct dentry *dentry, + char *name, int namelen, u64 *async_transid, + bool readonly) +{ + struct inode *inode; + struct dentry *parent; + struct btrfs_pending_snapshot *pending_snapshot; + struct btrfs_trans_handle *trans; + int ret; + + if (!root->ref_cows) + return -EINVAL; + + pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS); + if (!pending_snapshot) + return -ENOMEM; + + btrfs_init_block_rsv(&pending_snapshot->block_rsv); + pending_snapshot->dentry = dentry; + pending_snapshot->root = root; + pending_snapshot->readonly = readonly; + + trans = btrfs_start_transaction(root->fs_info->extent_root, 5); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto fail; + } + + ret = btrfs_snap_reserve_metadata(trans, pending_snapshot); + BUG_ON(ret); + + spin_lock(&root->fs_info->trans_lock); + list_add(&pending_snapshot->list, + &trans->transaction->pending_snapshots); + spin_unlock(&root->fs_info->trans_lock); + if (async_transid) { + *async_transid = trans->transid; + ret = btrfs_commit_transaction_async(trans, + root->fs_info->extent_root, 1); + } else { + ret = btrfs_commit_transaction(trans, + root->fs_info->extent_root); + } + BUG_ON(ret); + + ret = pending_snapshot->error; + if (ret) + goto fail; + + ret = btrfs_orphan_cleanup(pending_snapshot->snap); + if (ret) + goto fail; + + parent = dget_parent(dentry); + inode = btrfs_lookup_dentry(parent->d_inode, dentry); + dput(parent); + if (IS_ERR(inode)) { + ret = PTR_ERR(inode); + goto fail; + } + BUG_ON(!inode); + d_instantiate(dentry, inode); + ret = 0; +fail: + kfree(pending_snapshot); + return ret; +} + +/* copy of check_sticky in fs/namei.c() +* It's inline, so penalty for filesystems that don't use sticky bit is +* minimal. +*/ +static inline int btrfs_check_sticky(struct inode *dir, struct inode *inode) +{ + uid_t fsuid = current_fsuid(); + + if (!(dir->i_mode & S_ISVTX)) + return 0; + if (inode->i_uid == fsuid) + return 0; + if (dir->i_uid == fsuid) + return 0; + return !capable(CAP_FOWNER); +} + +/* copy of may_delete in fs/namei.c() + * Check whether we can remove a link victim from directory dir, check + * whether the type of victim is right. + * 1. We can't do it if dir is read-only (done in permission()) + * 2. We should have write and exec permissions on dir + * 3. We can't remove anything from append-only dir + * 4. We can't do anything with immutable dir (done in permission()) + * 5. If the sticky bit on dir is set we should either + * a. be owner of dir, or + * b. be owner of victim, or + * c. have CAP_FOWNER capability + * 6. If the victim is append-only or immutable we can't do antyhing with + * links pointing to it. + * 7. If we were asked to remove a directory and victim isn't one - ENOTDIR. + * 8. If we were asked to remove a non-directory and victim isn't one - EISDIR. + * 9. We can't remove a root or mountpoint. + * 10. We don't allow removal of NFS sillyrenamed files; it's handled by + * nfs_async_unlink(). + */ + +static int btrfs_may_delete(struct inode *dir,struct dentry *victim,int isdir) +{ + int error; + + if (!victim->d_inode) + return -ENOENT; + + BUG_ON(victim->d_parent->d_inode != dir); + audit_inode_child(victim, dir); + + error = inode_permission(dir, MAY_WRITE | MAY_EXEC); + if (error) + return error; + if (IS_APPEND(dir)) + return -EPERM; + if (btrfs_check_sticky(dir, victim->d_inode)|| + IS_APPEND(victim->d_inode)|| + IS_IMMUTABLE(victim->d_inode) || IS_SWAPFILE(victim->d_inode)) + return -EPERM; + if (isdir) { + if (!S_ISDIR(victim->d_inode->i_mode)) + return -ENOTDIR; + if (IS_ROOT(victim)) + return -EBUSY; + } else if (S_ISDIR(victim->d_inode->i_mode)) + return -EISDIR; + if (IS_DEADDIR(dir)) + return -ENOENT; + if (victim->d_flags & DCACHE_NFSFS_RENAMED) + return -EBUSY; + return 0; +} + +/* 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 namelen, + struct btrfs_root *snap_src, + u64 *async_transid, bool readonly) +{ + struct inode *dir = parent->dentry->d_inode; + struct dentry *dentry; + int error; + + mutex_lock_nested(&dir->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; + + error = mnt_want_write(parent->mnt); + if (error) + goto out_dput; + + error = btrfs_may_create(dir, dentry); + if (error) + goto out_drop_write; + + down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem); + + if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0) + goto out_up_read; + + if (snap_src) { + error = create_snapshot(snap_src, dentry, + name, namelen, async_transid, readonly); + } else { + error = create_subvol(BTRFS_I(dir)->root, dentry, + name, namelen, async_transid); + } + if (!error) + fsnotify_mkdir(dir, dentry); +out_up_read: + up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem); +out_drop_write: + mnt_drop_write(parent->mnt); +out_dput: + dput(dentry); +out_unlock: + mutex_unlock(&dir->i_mutex); + return error; +} + +/* + * When we're defragging a range, we don't want to kick it off again + * if it is really just waiting for delalloc to send it down. + * If we find a nice big extent or delalloc range for the bytes in the + * file you want to defrag, we return 0 to let you know to skip this + * part of the file + */ +static int check_defrag_in_cache(struct inode *inode, u64 offset, int thresh) +{ + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + struct extent_map *em = NULL; + struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; + u64 end; + + read_lock(&em_tree->lock); + em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE); + read_unlock(&em_tree->lock); + + if (em) { + end = extent_map_end(em); + free_extent_map(em); + if (end - offset > thresh) + return 0; + } + /* if we already have a nice delalloc here, just stop */ + thresh /= 2; + end = count_range_bits(io_tree, &offset, offset + thresh, + thresh, EXTENT_DELALLOC, 1); + if (end >= thresh) + return 0; + return 1; +} + +/* + * helper function to walk through a file and find extents + * newer than a specific transid, and smaller than thresh. + * + * This is used by the defragging code to find new and small + * extents + */ +static int find_new_extents(struct btrfs_root *root, + struct inode *inode, u64 newer_than, + u64 *off, int thresh) +{ + struct btrfs_path *path; + struct btrfs_key min_key; + struct btrfs_key max_key; + struct extent_buffer *leaf; + struct btrfs_file_extent_item *extent; + int type; + int ret; + u64 ino = btrfs_ino(inode); + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + min_key.objectid = ino; + min_key.type = BTRFS_EXTENT_DATA_KEY; + min_key.offset = *off; + + max_key.objectid = ino; + max_key.type = (u8)-1; + max_key.offset = (u64)-1; + + path->keep_locks = 1; + + while(1) { + ret = btrfs_search_forward(root, &min_key, &max_key, + path, 0, newer_than); + if (ret != 0) + goto none; + if (min_key.objectid != ino) + goto none; + if (min_key.type != BTRFS_EXTENT_DATA_KEY) + goto none; + + leaf = path->nodes[0]; + extent = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + + type = btrfs_file_extent_type(leaf, extent); + if (type == BTRFS_FILE_EXTENT_REG && + btrfs_file_extent_num_bytes(leaf, extent) < thresh && + check_defrag_in_cache(inode, min_key.offset, thresh)) { + *off = min_key.offset; + btrfs_free_path(path); + return 0; + } + + if (min_key.offset == (u64)-1) + goto none; + + min_key.offset++; + btrfs_release_path(path); + } +none: + btrfs_free_path(path); + return -ENOENT; +} + +static int should_defrag_range(struct inode *inode, u64 start, u64 len, + int thresh, u64 *last_len, u64 *skip, + u64 *defrag_end) +{ + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + struct extent_map *em = NULL; + struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; + int ret = 1; + + /* + * make sure that once we start defragging and extent, we keep on + * defragging it + */ + if (start < *defrag_end) + return 1; + + *skip = 0; + + /* + * hopefully we have this extent in the tree already, try without + * the full extent lock + */ + read_lock(&em_tree->lock); + em = lookup_extent_mapping(em_tree, start, len); + read_unlock(&em_tree->lock); + + if (!em) { + /* get the big lock and read metadata off disk */ + lock_extent(io_tree, start, start + len - 1, GFP_NOFS); + em = btrfs_get_extent(inode, NULL, 0, start, len, 0); + unlock_extent(io_tree, start, start + len - 1, GFP_NOFS); + + if (IS_ERR(em)) + return 0; + } + + /* this will cover holes, and inline extents */ + if (em->block_start >= EXTENT_MAP_LAST_BYTE) + ret = 0; + + /* + * we hit a real extent, if it is big don't bother defragging it again + */ + if ((*last_len == 0 || *last_len >= thresh) && em->len >= thresh) + ret = 0; + + /* + * last_len ends up being a counter of how many bytes we've defragged. + * every time we choose not to defrag an extent, we reset *last_len + * so that the next tiny extent will force a defrag. + * + * The end result of this is that tiny extents before a single big + * extent will force at least part of that big extent to be defragged. + */ + if (ret) { + *last_len += len; + *defrag_end = extent_map_end(em); + } else { + *last_len = 0; + *skip = extent_map_end(em); + *defrag_end = 0; + } + + free_extent_map(em); + return ret; +} + +/* + * it doesn't do much good to defrag one or two pages + * at a time. This pulls in a nice chunk of pages + * to COW and defrag. + * + * It also makes sure the delalloc code has enough + * dirty data to avoid making new small extents as part + * of the defrag + * + * It's a good idea to start RA on this range + * before calling this. + */ +static int cluster_pages_for_defrag(struct inode *inode, + struct page **pages, + unsigned long start_index, + int num_pages) +{ + unsigned long file_end; + u64 isize = i_size_read(inode); + u64 page_start; + u64 page_end; + int ret; + int i; + int i_done; + struct btrfs_ordered_extent *ordered; + struct extent_state *cached_state = NULL; + + if (isize == 0) + return 0; + file_end = (isize - 1) >> PAGE_CACHE_SHIFT; + + ret = btrfs_delalloc_reserve_space(inode, + num_pages << PAGE_CACHE_SHIFT); + if (ret) + return ret; +again: + ret = 0; + i_done = 0; + + /* step one, lock all the pages */ + for (i = 0; i < num_pages; i++) { + struct page *page; + page = grab_cache_page(inode->i_mapping, + start_index + i); + if (!page) + break; + + if (!PageUptodate(page)) { + btrfs_readpage(NULL, page); + lock_page(page); + if (!PageUptodate(page)) { + unlock_page(page); + page_cache_release(page); + ret = -EIO; + break; + } + } + isize = i_size_read(inode); + file_end = (isize - 1) >> PAGE_CACHE_SHIFT; + if (!isize || page->index > file_end || + page->mapping != inode->i_mapping) { + /* whoops, we blew past eof, skip this page */ + unlock_page(page); + page_cache_release(page); + break; + } + pages[i] = page; + i_done++; + } + if (!i_done || ret) + goto out; + + if (!(inode->i_sb->s_flags & MS_ACTIVE)) + goto out; + + /* + * so now we have a nice long stream of locked + * and up to date pages, lets wait on them + */ + for (i = 0; i < i_done; i++) + wait_on_page_writeback(pages[i]); + + page_start = page_offset(pages[0]); + page_end = page_offset(pages[i_done - 1]) + PAGE_CACHE_SIZE; + + lock_extent_bits(&BTRFS_I(inode)->io_tree, + page_start, page_end - 1, 0, &cached_state, + GFP_NOFS); + ordered = btrfs_lookup_first_ordered_extent(inode, page_end - 1); + if (ordered && + ordered->file_offset + ordered->len > page_start && + ordered->file_offset < page_end) { + btrfs_put_ordered_extent(ordered); + unlock_extent_cached(&BTRFS_I(inode)->io_tree, + page_start, page_end - 1, + &cached_state, GFP_NOFS); + for (i = 0; i < i_done; i++) { + unlock_page(pages[i]); + page_cache_release(pages[i]); + } + btrfs_wait_ordered_range(inode, page_start, + page_end - page_start); + goto again; + } + if (ordered) + btrfs_put_ordered_extent(ordered); + + clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, + page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC | + EXTENT_DO_ACCOUNTING, 0, 0, &cached_state, + GFP_NOFS); + + if (i_done != num_pages) { + atomic_inc(&BTRFS_I(inode)->outstanding_extents); + btrfs_delalloc_release_space(inode, + (num_pages - i_done) << PAGE_CACHE_SHIFT); + } + + + btrfs_set_extent_delalloc(inode, page_start, page_end - 1, + &cached_state); + + unlock_extent_cached(&BTRFS_I(inode)->io_tree, + page_start, page_end - 1, &cached_state, + GFP_NOFS); + + for (i = 0; i < i_done; i++) { + clear_page_dirty_for_io(pages[i]); + ClearPageChecked(pages[i]); + set_page_extent_mapped(pages[i]); + set_page_dirty(pages[i]); + unlock_page(pages[i]); + page_cache_release(pages[i]); + } + return i_done; +out: + for (i = 0; i < i_done; i++) { + unlock_page(pages[i]); + page_cache_release(pages[i]); + } + btrfs_delalloc_release_space(inode, num_pages << PAGE_CACHE_SHIFT); + return ret; + +} + +int btrfs_defrag_file(struct inode *inode, struct file *file, + struct btrfs_ioctl_defrag_range_args *range, + u64 newer_than, unsigned long max_to_defrag) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_super_block *disk_super; + struct file_ra_state *ra = NULL; + unsigned long last_index; + u64 features; + u64 last_len = 0; + u64 skip = 0; + u64 defrag_end = 0; + u64 newer_off = range->start; + int newer_left = 0; + unsigned long i; + int ret; + int defrag_count = 0; + int compress_type = BTRFS_COMPRESS_ZLIB; + int extent_thresh = range->extent_thresh; + int newer_cluster = (256 * 1024) >> PAGE_CACHE_SHIFT; + u64 new_align = ~((u64)128 * 1024 - 1); + struct page **pages = NULL; + + if (extent_thresh == 0) + extent_thresh = 256 * 1024; + + if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) { + if (range->compress_type > BTRFS_COMPRESS_TYPES) + return -EINVAL; + if (range->compress_type) + compress_type = range->compress_type; + } + + if (inode->i_size == 0) + return 0; + + /* + * if we were not given a file, allocate a readahead + * context + */ + if (!file) { + ra = kzalloc(sizeof(*ra), GFP_NOFS); + if (!ra) + return -ENOMEM; + file_ra_state_init(ra, inode->i_mapping); + } else { + ra = &file->f_ra; + } + + pages = kmalloc(sizeof(struct page *) * newer_cluster, + GFP_NOFS); + if (!pages) { + ret = -ENOMEM; + goto out_ra; + } + + /* find the last page to defrag */ + if (range->start + range->len > range->start) { + last_index = min_t(u64, inode->i_size - 1, + range->start + range->len - 1) >> PAGE_CACHE_SHIFT; + } else { + last_index = (inode->i_size - 1) >> PAGE_CACHE_SHIFT; + } + + if (newer_than) { + ret = find_new_extents(root, inode, newer_than, + &newer_off, 64 * 1024); + if (!ret) { + range->start = newer_off; + /* + * we always align our defrag to help keep + * the extents in the file evenly spaced + */ + i = (newer_off & new_align) >> PAGE_CACHE_SHIFT; + newer_left = newer_cluster; + } else + goto out_ra; + } else { + i = range->start >> PAGE_CACHE_SHIFT; + } + if (!max_to_defrag) + max_to_defrag = last_index - 1; + + while (i <= last_index && defrag_count < max_to_defrag) { + /* + * make sure we stop running if someone unmounts + * the FS + */ + if (!(inode->i_sb->s_flags & MS_ACTIVE)) + break; + + if (!newer_than && + !should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT, + PAGE_CACHE_SIZE, + extent_thresh, + &last_len, &skip, + &defrag_end)) { + unsigned long next; + /* + * the should_defrag function tells us how much to skip + * bump our counter by the suggested amount + */ + next = (skip + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; + i = max(i + 1, next); + continue; + } + if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) + BTRFS_I(inode)->force_compress = compress_type; + + btrfs_force_ra(inode->i_mapping, ra, file, i, newer_cluster); + + ret = cluster_pages_for_defrag(inode, pages, i, newer_cluster); + if (ret < 0) + goto out_ra; + + defrag_count += ret; + balance_dirty_pages_ratelimited_nr(inode->i_mapping, ret); + i += ret; + + if (newer_than) { + if (newer_off == (u64)-1) + break; + + newer_off = max(newer_off + 1, + (u64)i << PAGE_CACHE_SHIFT); + + ret = find_new_extents(root, inode, + newer_than, &newer_off, + 64 * 1024); + if (!ret) { + range->start = newer_off; + i = (newer_off & new_align) >> PAGE_CACHE_SHIFT; + newer_left = newer_cluster; + } else { + break; + } + } else { + i++; + } + } + + if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) + filemap_flush(inode->i_mapping); + + if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) { + /* the filemap_flush will queue IO into the worker threads, but + * we have to make sure the IO is actually started and that + * ordered extents get created before we return + */ + atomic_inc(&root->fs_info->async_submit_draining); + while (atomic_read(&root->fs_info->nr_async_submits) || + atomic_read(&root->fs_info->async_delalloc_pages)) { + wait_event(root->fs_info->async_submit_wait, + (atomic_read(&root->fs_info->nr_async_submits) == 0 && + atomic_read(&root->fs_info->async_delalloc_pages) == 0)); + } + atomic_dec(&root->fs_info->async_submit_draining); + + mutex_lock(&inode->i_mutex); + BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE; + mutex_unlock(&inode->i_mutex); + } + + disk_super = &root->fs_info->super_copy; + features = btrfs_super_incompat_flags(disk_super); + if (range->compress_type == BTRFS_COMPRESS_LZO) { + features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO; + btrfs_set_super_incompat_flags(disk_super, features); + } + + if (!file) + kfree(ra); + return defrag_count; + +out_ra: + if (!file) + kfree(ra); + kfree(pages); + return ret; +} + +static noinline 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 mod = 0; + + if (root->fs_info->sb->s_flags & MS_RDONLY) + return -EROFS; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + vol_args = memdup_user(arg, sizeof(*vol_args)); + if (IS_ERR(vol_args)) + return PTR_ERR(vol_args); + + vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; + + 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", + (unsigned long long)devid); + } + device = btrfs_find_device(root, devid, NULL, NULL); + if (!device) { + printk(KERN_INFO "resizer unable to find device %llu\n", + (unsigned long long)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 = memparse(sizestr, NULL); + 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, 0); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto out_unlock; + } + 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); + kfree(vol_args); + return ret; +} + +static noinline int btrfs_ioctl_snap_create_transid(struct file *file, + char *name, + unsigned long fd, + int subvol, + u64 *transid, + bool readonly) +{ + struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root; + struct file *src_file; + int namelen; + int ret = 0; + + if (root->fs_info->sb->s_flags & MS_RDONLY) + return -EROFS; + + namelen = strlen(name); + if (strchr(name, '/')) { + ret = -EINVAL; + goto out; + } + + if (subvol) { + ret = btrfs_mksubvol(&file->f_path, name, namelen, + NULL, transid, readonly); + } else { + struct inode *src_inode; + src_file = fget(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, name, namelen, + BTRFS_I(src_inode)->root, + transid, readonly); + fput(src_file); + } +out: + return ret; +} + +static noinline int btrfs_ioctl_snap_create(struct file *file, + void __user *arg, int subvol) +{ + struct btrfs_ioctl_vol_args *vol_args; + int ret; + + vol_args = memdup_user(arg, sizeof(*vol_args)); + if (IS_ERR(vol_args)) + return PTR_ERR(vol_args); + vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; + + ret = btrfs_ioctl_snap_create_transid(file, vol_args->name, + vol_args->fd, subvol, + NULL, false); + + kfree(vol_args); + return ret; +} + +static noinline int btrfs_ioctl_snap_create_v2(struct file *file, + void __user *arg, int subvol) +{ + struct btrfs_ioctl_vol_args_v2 *vol_args; + int ret; + u64 transid = 0; + u64 *ptr = NULL; + bool readonly = false; + + vol_args = memdup_user(arg, sizeof(*vol_args)); + if (IS_ERR(vol_args)) + return PTR_ERR(vol_args); + vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0'; + + if (vol_args->flags & + ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY)) { + ret = -EOPNOTSUPP; + goto out; + } + + if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC) + ptr = &transid; + if (vol_args->flags & BTRFS_SUBVOL_RDONLY) + readonly = true; + + ret = btrfs_ioctl_snap_create_transid(file, vol_args->name, + vol_args->fd, subvol, + ptr, readonly); + + if (ret == 0 && ptr && + copy_to_user(arg + + offsetof(struct btrfs_ioctl_vol_args_v2, + transid), ptr, sizeof(*ptr))) + ret = -EFAULT; +out: + kfree(vol_args); + return ret; +} + +static noinline int btrfs_ioctl_subvol_getflags(struct file *file, + void __user *arg) +{ + struct inode *inode = fdentry(file)->d_inode; + struct btrfs_root *root = BTRFS_I(inode)->root; + int ret = 0; + u64 flags = 0; + + if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) + return -EINVAL; + + down_read(&root->fs_info->subvol_sem); + if (btrfs_root_readonly(root)) + flags |= BTRFS_SUBVOL_RDONLY; + up_read(&root->fs_info->subvol_sem); + + if (copy_to_user(arg, &flags, sizeof(flags))) + ret = -EFAULT; + + return ret; +} + +static noinline int btrfs_ioctl_subvol_setflags(struct file *file, + void __user *arg) +{ + struct inode *inode = fdentry(file)->d_inode; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_trans_handle *trans; + u64 root_flags; + u64 flags; + int ret = 0; + + if (root->fs_info->sb->s_flags & MS_RDONLY) + return -EROFS; + + if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) + return -EINVAL; + + if (copy_from_user(&flags, arg, sizeof(flags))) + return -EFAULT; + + if (flags & BTRFS_SUBVOL_CREATE_ASYNC) + return -EINVAL; + + if (flags & ~BTRFS_SUBVOL_RDONLY) + return -EOPNOTSUPP; + + if (!inode_owner_or_capable(inode)) + return -EACCES; + + down_write(&root->fs_info->subvol_sem); + + /* nothing to do */ + if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root)) + goto out; + + root_flags = btrfs_root_flags(&root->root_item); + if (flags & BTRFS_SUBVOL_RDONLY) + btrfs_set_root_flags(&root->root_item, + root_flags | BTRFS_ROOT_SUBVOL_RDONLY); + else + btrfs_set_root_flags(&root->root_item, + root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY); + + trans = btrfs_start_transaction(root, 1); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto out_reset; + } + + ret = btrfs_update_root(trans, root->fs_info->tree_root, + &root->root_key, &root->root_item); + + btrfs_commit_transaction(trans, root); +out_reset: + if (ret) + btrfs_set_root_flags(&root->root_item, root_flags); +out: + up_write(&root->fs_info->subvol_sem); + return ret; +} + +/* + * helper to check if the subvolume references other subvolumes + */ +static noinline int may_destroy_subvol(struct btrfs_root *root) +{ + struct btrfs_path *path; + struct btrfs_key key; + int ret; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = root->root_key.objectid; + key.type = BTRFS_ROOT_REF_KEY; + key.offset = (u64)-1; + + ret = btrfs_search_slot(NULL, root->fs_info->tree_root, + &key, path, 0, 0); + if (ret < 0) + goto out; + BUG_ON(ret == 0); + + ret = 0; + if (path->slots[0] > 0) { + path->slots[0]--; + btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); + if (key.objectid == root->root_key.objectid && + key.type == BTRFS_ROOT_REF_KEY) + ret = -ENOTEMPTY; + } +out: + btrfs_free_path(path); + return ret; +} + +static noinline int key_in_sk(struct btrfs_key *key, + struct btrfs_ioctl_search_key *sk) +{ + struct btrfs_key test; + int ret; + + test.objectid = sk->min_objectid; + test.type = sk->min_type; + test.offset = sk->min_offset; + + ret = btrfs_comp_cpu_keys(key, &test); + if (ret < 0) + return 0; + + test.objectid = sk->max_objectid; + test.type = sk->max_type; + test.offset = sk->max_offset; + + ret = btrfs_comp_cpu_keys(key, &test); + if (ret > 0) + return 0; + return 1; +} + +static noinline int copy_to_sk(struct btrfs_root *root, + struct btrfs_path *path, + struct btrfs_key *key, + struct btrfs_ioctl_search_key *sk, + char *buf, + unsigned long *sk_offset, + int *num_found) +{ + u64 found_transid; + struct extent_buffer *leaf; + struct btrfs_ioctl_search_header sh; + unsigned long item_off; + unsigned long item_len; + int nritems; + int i; + int slot; + int ret = 0; + + leaf = path->nodes[0]; + slot = path->slots[0]; + nritems = btrfs_header_nritems(leaf); + + if (btrfs_header_generation(leaf) > sk->max_transid) { + i = nritems; + goto advance_key; + } + found_transid = btrfs_header_generation(leaf); + + for (i = slot; i < nritems; i++) { + item_off = btrfs_item_ptr_offset(leaf, i); + item_len = btrfs_item_size_nr(leaf, i); + + if (item_len > BTRFS_SEARCH_ARGS_BUFSIZE) + item_len = 0; + + if (sizeof(sh) + item_len + *sk_offset > + BTRFS_SEARCH_ARGS_BUFSIZE) { + ret = 1; + goto overflow; + } + + btrfs_item_key_to_cpu(leaf, key, i); + if (!key_in_sk(key, sk)) + continue; + + sh.objectid = key->objectid; + sh.offset = key->offset; + sh.type = key->type; + sh.len = item_len; + sh.transid = found_transid; + + /* copy search result header */ + memcpy(buf + *sk_offset, &sh, sizeof(sh)); + *sk_offset += sizeof(sh); + + if (item_len) { + char *p = buf + *sk_offset; + /* copy the item */ + read_extent_buffer(leaf, p, + item_off, item_len); + *sk_offset += item_len; + } + (*num_found)++; + + if (*num_found >= sk->nr_items) + break; + } +advance_key: + ret = 0; + if (key->offset < (u64)-1 && key->offset < sk->max_offset) + key->offset++; + else if (key->type < (u8)-1 && key->type < sk->max_type) { + key->offset = 0; + key->type++; + } else if (key->objectid < (u64)-1 && key->objectid < sk->max_objectid) { + key->offset = 0; + key->type = 0; + key->objectid++; + } else + ret = 1; +overflow: + return ret; +} + +static noinline int search_ioctl(struct inode *inode, + struct btrfs_ioctl_search_args *args) +{ + struct btrfs_root *root; + struct btrfs_key key; + struct btrfs_key max_key; + struct btrfs_path *path; + struct btrfs_ioctl_search_key *sk = &args->key; + struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info; + int ret; + int num_found = 0; + unsigned long sk_offset = 0; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + if (sk->tree_id == 0) { + /* search the root of the inode that was passed */ + root = BTRFS_I(inode)->root; + } else { + key.objectid = sk->tree_id; + key.type = BTRFS_ROOT_ITEM_KEY; + key.offset = (u64)-1; + root = btrfs_read_fs_root_no_name(info, &key); + if (IS_ERR(root)) { + printk(KERN_ERR "could not find root %llu\n", + sk->tree_id); + btrfs_free_path(path); + return -ENOENT; + } + } + + key.objectid = sk->min_objectid; + key.type = sk->min_type; + key.offset = sk->min_offset; + + max_key.objectid = sk->max_objectid; + max_key.type = sk->max_type; + max_key.offset = sk->max_offset; + + path->keep_locks = 1; + + while(1) { + ret = btrfs_search_forward(root, &key, &max_key, path, 0, + sk->min_transid); + if (ret != 0) { + if (ret > 0) + ret = 0; + goto err; + } + ret = copy_to_sk(root, path, &key, sk, args->buf, + &sk_offset, &num_found); + btrfs_release_path(path); + if (ret || num_found >= sk->nr_items) + break; + + } + ret = 0; +err: + sk->nr_items = num_found; + btrfs_free_path(path); + return ret; +} + +static noinline int btrfs_ioctl_tree_search(struct file *file, + void __user *argp) +{ + struct btrfs_ioctl_search_args *args; + struct inode *inode; + int ret; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + args = memdup_user(argp, sizeof(*args)); + if (IS_ERR(args)) + return PTR_ERR(args); + + inode = fdentry(file)->d_inode; + ret = search_ioctl(inode, args); + if (ret == 0 && copy_to_user(argp, args, sizeof(*args))) + ret = -EFAULT; + kfree(args); + return ret; +} + +/* + * Search INODE_REFs to identify path name of 'dirid' directory + * in a 'tree_id' tree. and sets path name to 'name'. + */ +static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info, + u64 tree_id, u64 dirid, char *name) +{ + struct btrfs_root *root; + struct btrfs_key key; + char *ptr; + int ret = -1; + int slot; + int len; + int total_len = 0; + struct btrfs_inode_ref *iref; + struct extent_buffer *l; + struct btrfs_path *path; + + if (dirid == BTRFS_FIRST_FREE_OBJECTID) { + name[0]='\0'; + return 0; + } + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX]; + + key.objectid = tree_id; + key.type = BTRFS_ROOT_ITEM_KEY; + key.offset = (u64)-1; + root = btrfs_read_fs_root_no_name(info, &key); + if (IS_ERR(root)) { + printk(KERN_ERR "could not find root %llu\n", tree_id); + ret = -ENOENT; + goto out; + } + + key.objectid = dirid; + key.type = BTRFS_INODE_REF_KEY; + key.offset = (u64)-1; + + while(1) { + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; + + l = path->nodes[0]; + slot = path->slots[0]; + if (ret > 0 && slot > 0) + slot--; + btrfs_item_key_to_cpu(l, &key, slot); + + if (ret > 0 && (key.objectid != dirid || + key.type != BTRFS_INODE_REF_KEY)) { + ret = -ENOENT; + goto out; + } + + iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref); + len = btrfs_inode_ref_name_len(l, iref); + ptr -= len + 1; + total_len += len + 1; + if (ptr < name) + goto out; + + *(ptr + len) = '/'; + read_extent_buffer(l, ptr,(unsigned long)(iref + 1), len); + + if (key.offset == BTRFS_FIRST_FREE_OBJECTID) + break; + + btrfs_release_path(path); + key.objectid = key.offset; + key.offset = (u64)-1; + dirid = key.objectid; + + } + if (ptr < name) + goto out; + memcpy(name, ptr, total_len); + name[total_len]='\0'; + ret = 0; +out: + btrfs_free_path(path); + return ret; +} + +static noinline int btrfs_ioctl_ino_lookup(struct file *file, + void __user *argp) +{ + struct btrfs_ioctl_ino_lookup_args *args; + struct inode *inode; + int ret; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + args = memdup_user(argp, sizeof(*args)); + if (IS_ERR(args)) + return PTR_ERR(args); + + inode = fdentry(file)->d_inode; + + if (args->treeid == 0) + args->treeid = BTRFS_I(inode)->root->root_key.objectid; + + ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info, + args->treeid, args->objectid, + args->name); + + if (ret == 0 && copy_to_user(argp, args, sizeof(*args))) + ret = -EFAULT; + + kfree(args); + return ret; +} + +static noinline int btrfs_ioctl_snap_destroy(struct file *file, + void __user *arg) +{ + struct dentry *parent = fdentry(file); + struct dentry *dentry; + struct inode *dir = parent->d_inode; + struct inode *inode; + struct btrfs_root *root = BTRFS_I(dir)->root; + struct btrfs_root *dest = NULL; + struct btrfs_ioctl_vol_args *vol_args; + struct btrfs_trans_handle *trans; + int namelen; + int ret; + int err = 0; + + vol_args = memdup_user(arg, sizeof(*vol_args)); + if (IS_ERR(vol_args)) + return PTR_ERR(vol_args); + + vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; + namelen = strlen(vol_args->name); + if (strchr(vol_args->name, '/') || + strncmp(vol_args->name, "..", namelen) == 0) { + err = -EINVAL; + goto out; + } + + err = mnt_want_write(file->f_path.mnt); + if (err) + goto out; + + mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); + dentry = lookup_one_len(vol_args->name, parent, namelen); + if (IS_ERR(dentry)) { + err = PTR_ERR(dentry); + goto out_unlock_dir; + } + + if (!dentry->d_inode) { + err = -ENOENT; + goto out_dput; + } + + inode = dentry->d_inode; + dest = BTRFS_I(inode)->root; + if (!capable(CAP_SYS_ADMIN)){ + /* + * Regular user. Only allow this with a special mount + * option, when the user has write+exec access to the + * subvol root, and when rmdir(2) would have been + * allowed. + * + * Note that this is _not_ check that the subvol is + * empty or doesn't contain data that we wouldn't + * otherwise be able to delete. + * + * Users who want to delete empty subvols should try + * rmdir(2). + */ + err = -EPERM; + if (!btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED)) + goto out_dput; + + /* + * Do not allow deletion if the parent dir is the same + * as the dir to be deleted. That means the ioctl + * must be called on the dentry referencing the root + * of the subvol, not a random directory contained + * within it. + */ + err = -EINVAL; + if (root == dest) + goto out_dput; + + err = inode_permission(inode, MAY_WRITE | MAY_EXEC); + if (err) + goto out_dput; + + /* check if subvolume may be deleted by a non-root user */ + err = btrfs_may_delete(dir, dentry, 1); + if (err) + goto out_dput; + } + + if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) { + err = -EINVAL; + goto out_dput; + } + + mutex_lock(&inode->i_mutex); + err = d_invalidate(dentry); + if (err) + goto out_unlock; + + down_write(&root->fs_info->subvol_sem); + + err = may_destroy_subvol(dest); + if (err) + goto out_up_write; + + trans = btrfs_start_transaction(root, 0); + if (IS_ERR(trans)) { + err = PTR_ERR(trans); + goto out_up_write; + } + trans->block_rsv = &root->fs_info->global_block_rsv; + + ret = btrfs_unlink_subvol(trans, root, dir, + dest->root_key.objectid, + dentry->d_name.name, + dentry->d_name.len); + BUG_ON(ret); + + btrfs_record_root_in_trans(trans, dest); + + memset(&dest->root_item.drop_progress, 0, + sizeof(dest->root_item.drop_progress)); + dest->root_item.drop_level = 0; + btrfs_set_root_refs(&dest->root_item, 0); + + if (!xchg(&dest->orphan_item_inserted, 1)) { + ret = btrfs_insert_orphan_item(trans, + root->fs_info->tree_root, + dest->root_key.objectid); + BUG_ON(ret); + } + + ret = btrfs_end_transaction(trans, root); + BUG_ON(ret); + inode->i_flags |= S_DEAD; +out_up_write: + up_write(&root->fs_info->subvol_sem); +out_unlock: + mutex_unlock(&inode->i_mutex); + if (!err) { + shrink_dcache_sb(root->fs_info->sb); + btrfs_invalidate_inodes(dest); + d_delete(dentry); + } +out_dput: + dput(dentry); +out_unlock_dir: + mutex_unlock(&dir->i_mutex); + mnt_drop_write(file->f_path.mnt); +out: + kfree(vol_args); + return err; +} + +static int btrfs_ioctl_defrag(struct file *file, void __user *argp) +{ + struct inode *inode = fdentry(file)->d_inode; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_ioctl_defrag_range_args *range; + int ret; + + if (btrfs_root_readonly(root)) + return -EROFS; + + 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; + } + ret = btrfs_defrag_root(root, 0); + if (ret) + goto out; + ret = btrfs_defrag_root(root->fs_info->extent_root, 0); + break; + case S_IFREG: + if (!(file->f_mode & FMODE_WRITE)) { + ret = -EINVAL; + goto out; + } + + range = kzalloc(sizeof(*range), GFP_KERNEL); + if (!range) { + ret = -ENOMEM; + goto out; + } + + if (argp) { + if (copy_from_user(range, argp, + sizeof(*range))) { + ret = -EFAULT; + kfree(range); + goto out; + } + /* compression requires us to start the IO */ + if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) { + range->flags |= BTRFS_DEFRAG_RANGE_START_IO; + range->extent_thresh = (u32)-1; + } + } else { + /* the rest are all set to zero by kzalloc */ + range->len = (u64)-1; + } + ret = btrfs_defrag_file(fdentry(file)->d_inode, file, + range, 0, 0); + if (ret > 0) + ret = 0; + kfree(range); + break; + default: + ret = -EINVAL; + } +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 = memdup_user(arg, sizeof(*vol_args)); + if (IS_ERR(vol_args)) + return PTR_ERR(vol_args); + + vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; + ret = btrfs_init_new_device(root, vol_args->name); + + 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 = memdup_user(arg, sizeof(*vol_args)); + if (IS_ERR(vol_args)) + return PTR_ERR(vol_args); + + vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; + ret = btrfs_rm_device(root, vol_args->name); + + kfree(vol_args); + return ret; +} + +static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg) +{ + struct btrfs_ioctl_fs_info_args *fi_args; + struct btrfs_device *device; + struct btrfs_device *next; + struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices; + int ret = 0; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL); + if (!fi_args) + return -ENOMEM; + + fi_args->num_devices = fs_devices->num_devices; + memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid)); + + mutex_lock(&fs_devices->device_list_mutex); + list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) { + if (device->devid > fi_args->max_id) + fi_args->max_id = device->devid; + } + mutex_unlock(&fs_devices->device_list_mutex); + + if (copy_to_user(arg, fi_args, sizeof(*fi_args))) + ret = -EFAULT; + + kfree(fi_args); + return ret; +} + +static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg) +{ + struct btrfs_ioctl_dev_info_args *di_args; + struct btrfs_device *dev; + struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices; + int ret = 0; + char *s_uuid = NULL; + char empty_uuid[BTRFS_UUID_SIZE] = {0}; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + di_args = memdup_user(arg, sizeof(*di_args)); + if (IS_ERR(di_args)) + return PTR_ERR(di_args); + + if (memcmp(empty_uuid, di_args->uuid, BTRFS_UUID_SIZE) != 0) + s_uuid = di_args->uuid; + + mutex_lock(&fs_devices->device_list_mutex); + dev = btrfs_find_device(root, di_args->devid, s_uuid, NULL); + mutex_unlock(&fs_devices->device_list_mutex); + + if (!dev) { + ret = -ENODEV; + goto out; + } + + di_args->devid = dev->devid; + di_args->bytes_used = dev->bytes_used; + di_args->total_bytes = dev->total_bytes; + memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid)); + strncpy(di_args->path, dev->name, sizeof(di_args->path)); + +out: + if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args))) + ret = -EFAULT; + + kfree(di_args); + return ret; +} + +static noinline 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) || (file->f_flags & O_APPEND)) + return -EINVAL; + + if (btrfs_root_readonly(root)) + return -EROFS; + + 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; + + /* the src must be open for reading */ + if (!(src_file->f_mode & FMODE_READ)) + 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_nested(&inode->i_mutex, I_MUTEX_PARENT); + mutex_lock_nested(&src->i_mutex, I_MUTEX_CHILD); + } else { + mutex_lock_nested(&src->i_mutex, I_MUTEX_PARENT); + mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD); + } + + /* determine range to clone */ + ret = -EINVAL; + if (off + len > src->i_size || off + len < off) + 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 = ALIGN(src->i_size, bs) - off; + + /* verify the end result is block aligned */ + if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) || + !IS_ALIGNED(destoff, bs)) + 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(src, off+len); + if (!ordered && + !test_range_bit(&BTRFS_I(src)->io_tree, off, off+len, + EXTENT_DELALLOC, 0, NULL)) + 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, len); + } + + /* clone data */ + key.objectid = btrfs_ino(src); + 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(NULL, 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 != btrfs_ino(src)) + 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; + u64 endoff; + + 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 || + type == BTRFS_FILE_EXTENT_PREALLOC) { + 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(path); + + if (key.offset + datal <= off || + key.offset >= off+len) + goto next; + + memcpy(&new_key, &key, sizeof(new_key)); + new_key.objectid = btrfs_ino(inode); + if (off <= key.offset) + new_key.offset = key.offset + destoff - off; + else + new_key.offset = destoff; + + trans = btrfs_start_transaction(root, 1); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto out; + } + + if (type == BTRFS_FILE_EXTENT_REG || + type == BTRFS_FILE_EXTENT_PREALLOC) { + if (off > key.offset) { + datao += off - key.offset; + datal -= off - key.offset; + } + + if (key.offset + datal > off + len) + datal = off + len - key.offset; + + ret = btrfs_drop_extents(trans, inode, + new_key.offset, + new_key.offset + datal, + &hint_byte, 1); + BUG_ON(ret); + + ret = btrfs_insert_empty_item(trans, root, path, + &new_key, size); + BUG_ON(ret); + + 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); + + /* 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, 0, + root->root_key.objectid, + btrfs_ino(inode), + new_key.offset - datao); + 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; + btrfs_end_transaction(trans, root); + goto out; + } + size -= skip + trim; + datal -= skip + trim; + + ret = btrfs_drop_extents(trans, inode, + new_key.offset, + new_key.offset + datal, + &hint_byte, 1); + BUG_ON(ret); + + ret = btrfs_insert_empty_item(trans, root, path, + &new_key, size); + BUG_ON(ret); + + 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); + btrfs_release_path(path); + + inode->i_mtime = inode->i_ctime = CURRENT_TIME; + + /* + * we round up to the block size at eof when + * determining which extents to clone above, + * but shouldn't round up the file size + */ + endoff = new_key.offset + datal; + if (endoff > destoff+olen) + endoff = destoff+olen; + if (endoff > inode->i_size) + btrfs_i_size_write(inode, endoff); + + BTRFS_I(inode)->flags = BTRFS_I(src)->flags; + ret = btrfs_update_inode(trans, root, inode); + BUG_ON(ret); + btrfs_end_transaction(trans, root); + } +next: + btrfs_release_path(path); + key.offset++; + } + ret = 0; +out: + btrfs_release_path(path); + unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS); +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; + + ret = -EPERM; + if (!capable(CAP_SYS_ADMIN)) + goto out; + + ret = -EINPROGRESS; + if (file->private_data) + goto out; + + ret = -EROFS; + if (btrfs_root_readonly(root)) + goto out; + + ret = mnt_want_write(file->f_path.mnt); + if (ret) + goto out; + + atomic_inc(&root->fs_info->open_ioctl_trans); + + ret = -ENOMEM; + trans = btrfs_start_ioctl_transaction(root); + if (IS_ERR(trans)) + goto out_drop; + + file->private_data = trans; + return 0; + +out_drop: + atomic_dec(&root->fs_info->open_ioctl_trans); + mnt_drop_write(file->f_path.mnt); +out: + return ret; +} + +static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp) +{ + struct inode *inode = fdentry(file)->d_inode; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_root *new_root; + struct btrfs_dir_item *di; + struct btrfs_trans_handle *trans; + struct btrfs_path *path; + struct btrfs_key location; + struct btrfs_disk_key disk_key; + struct btrfs_super_block *disk_super; + u64 features; + u64 objectid = 0; + u64 dir_id; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + if (copy_from_user(&objectid, argp, sizeof(objectid))) + return -EFAULT; + + if (!objectid) + objectid = root->root_key.objectid; + + location.objectid = objectid; + location.type = BTRFS_ROOT_ITEM_KEY; + location.offset = (u64)-1; + + new_root = btrfs_read_fs_root_no_name(root->fs_info, &location); + if (IS_ERR(new_root)) + return PTR_ERR(new_root); + + if (btrfs_root_refs(&new_root->root_item) == 0) + return -ENOENT; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + path->leave_spinning = 1; + + trans = btrfs_start_transaction(root, 1); + if (IS_ERR(trans)) { + btrfs_free_path(path); + return PTR_ERR(trans); + } + + dir_id = btrfs_super_root_dir(&root->fs_info->super_copy); + di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path, + dir_id, "default", 7, 1); + if (IS_ERR_OR_NULL(di)) { + btrfs_free_path(path); + btrfs_end_transaction(trans, root); + printk(KERN_ERR "Umm, you don't have the default dir item, " + "this isn't going to work\n"); + return -ENOENT; + } + + btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key); + btrfs_set_dir_item_key(path->nodes[0], di, &disk_key); + btrfs_mark_buffer_dirty(path->nodes[0]); + btrfs_free_path(path); + + disk_super = &root->fs_info->super_copy; + features = btrfs_super_incompat_flags(disk_super); + if (!(features & BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL)) { + features |= BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL; + btrfs_set_super_incompat_flags(disk_super, features); + } + btrfs_end_transaction(trans, root); + + return 0; +} + +static void get_block_group_info(struct list_head *groups_list, + struct btrfs_ioctl_space_info *space) +{ + struct btrfs_block_group_cache *block_group; + + space->total_bytes = 0; + space->used_bytes = 0; + space->flags = 0; + list_for_each_entry(block_group, groups_list, list) { + space->flags = block_group->flags; + space->total_bytes += block_group->key.offset; + space->used_bytes += + btrfs_block_group_used(&block_group->item); + } +} + +long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg) +{ + struct btrfs_ioctl_space_args space_args; + struct btrfs_ioctl_space_info space; + struct btrfs_ioctl_space_info *dest; + struct btrfs_ioctl_space_info *dest_orig; + struct btrfs_ioctl_space_info __user *user_dest; + struct btrfs_space_info *info; + u64 types[] = {BTRFS_BLOCK_GROUP_DATA, + BTRFS_BLOCK_GROUP_SYSTEM, + BTRFS_BLOCK_GROUP_METADATA, + BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA}; + int num_types = 4; + int alloc_size; + int ret = 0; + u64 slot_count = 0; + int i, c; + + if (copy_from_user(&space_args, + (struct btrfs_ioctl_space_args __user *)arg, + sizeof(space_args))) + return -EFAULT; + + for (i = 0; i < num_types; i++) { + struct btrfs_space_info *tmp; + + info = NULL; + rcu_read_lock(); + list_for_each_entry_rcu(tmp, &root->fs_info->space_info, + list) { + if (tmp->flags == types[i]) { + info = tmp; + break; + } + } + rcu_read_unlock(); + + if (!info) + continue; + + down_read(&info->groups_sem); + for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) { + if (!list_empty(&info->block_groups[c])) + slot_count++; + } + up_read(&info->groups_sem); + } + + /* space_slots == 0 means they are asking for a count */ + if (space_args.space_slots == 0) { + space_args.total_spaces = slot_count; + goto out; + } + + slot_count = min_t(u64, space_args.space_slots, slot_count); + + alloc_size = sizeof(*dest) * slot_count; + + /* we generally have at most 6 or so space infos, one for each raid + * level. So, a whole page should be more than enough for everyone + */ + if (alloc_size > PAGE_CACHE_SIZE) + return -ENOMEM; + + space_args.total_spaces = 0; + dest = kmalloc(alloc_size, GFP_NOFS); + if (!dest) + return -ENOMEM; + dest_orig = dest; + + /* now we have a buffer to copy into */ + for (i = 0; i < num_types; i++) { + struct btrfs_space_info *tmp; + + if (!slot_count) + break; + + info = NULL; + rcu_read_lock(); + list_for_each_entry_rcu(tmp, &root->fs_info->space_info, + list) { + if (tmp->flags == types[i]) { + info = tmp; + break; + } + } + rcu_read_unlock(); + + if (!info) + continue; + down_read(&info->groups_sem); + for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) { + if (!list_empty(&info->block_groups[c])) { + get_block_group_info(&info->block_groups[c], + &space); + memcpy(dest, &space, sizeof(space)); + dest++; + space_args.total_spaces++; + slot_count--; + } + if (!slot_count) + break; + } + up_read(&info->groups_sem); + } + + user_dest = (struct btrfs_ioctl_space_info *) + (arg + sizeof(struct btrfs_ioctl_space_args)); + + if (copy_to_user(user_dest, dest_orig, alloc_size)) + ret = -EFAULT; + + kfree(dest_orig); +out: + if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args))) + ret = -EFAULT; + + 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; + + trans = file->private_data; + if (!trans) + return -EINVAL; + file->private_data = NULL; + + btrfs_end_transaction(trans, root); + + atomic_dec(&root->fs_info->open_ioctl_trans); + + mnt_drop_write(file->f_path.mnt); + return 0; +} + +static noinline long btrfs_ioctl_start_sync(struct file *file, void __user *argp) +{ + struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root; + struct btrfs_trans_handle *trans; + u64 transid; + int ret; + + trans = btrfs_start_transaction(root, 0); + if (IS_ERR(trans)) + return PTR_ERR(trans); + transid = trans->transid; + ret = btrfs_commit_transaction_async(trans, root, 0); + if (ret) { + btrfs_end_transaction(trans, root); + return ret; + } + + if (argp) + if (copy_to_user(argp, &transid, sizeof(transid))) + return -EFAULT; + return 0; +} + +static noinline long btrfs_ioctl_wait_sync(struct file *file, void __user *argp) +{ + struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root; + u64 transid; + + if (argp) { + if (copy_from_user(&transid, argp, sizeof(transid))) + return -EFAULT; + } else { + transid = 0; /* current trans */ + } + return btrfs_wait_for_commit(root, transid); +} + +static long btrfs_ioctl_scrub(struct btrfs_root *root, void __user *arg) +{ + int ret; + struct btrfs_ioctl_scrub_args *sa; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + sa = memdup_user(arg, sizeof(*sa)); + if (IS_ERR(sa)) + return PTR_ERR(sa); + + ret = btrfs_scrub_dev(root, sa->devid, sa->start, sa->end, + &sa->progress, sa->flags & BTRFS_SCRUB_READONLY); + + if (copy_to_user(arg, sa, sizeof(*sa))) + ret = -EFAULT; + + kfree(sa); + return ret; +} + +static long btrfs_ioctl_scrub_cancel(struct btrfs_root *root, void __user *arg) +{ + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + return btrfs_scrub_cancel(root); +} + +static long btrfs_ioctl_scrub_progress(struct btrfs_root *root, + void __user *arg) +{ + struct btrfs_ioctl_scrub_args *sa; + int ret; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + sa = memdup_user(arg, sizeof(*sa)); + if (IS_ERR(sa)) + return PTR_ERR(sa); + + ret = btrfs_scrub_progress(root, sa->devid, &sa->progress); + + if (copy_to_user(arg, sa, sizeof(*sa))) + ret = -EFAULT; + + kfree(sa); + 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 FS_IOC_GETFLAGS: + return btrfs_ioctl_getflags(file, argp); + case FS_IOC_SETFLAGS: + return btrfs_ioctl_setflags(file, argp); + case FS_IOC_GETVERSION: + return btrfs_ioctl_getversion(file, argp); + case FITRIM: + return btrfs_ioctl_fitrim(file, argp); + case BTRFS_IOC_SNAP_CREATE: + return btrfs_ioctl_snap_create(file, argp, 0); + case BTRFS_IOC_SNAP_CREATE_V2: + return btrfs_ioctl_snap_create_v2(file, argp, 0); + case BTRFS_IOC_SUBVOL_CREATE: + return btrfs_ioctl_snap_create(file, argp, 1); + case BTRFS_IOC_SNAP_DESTROY: + return btrfs_ioctl_snap_destroy(file, argp); + case BTRFS_IOC_SUBVOL_GETFLAGS: + return btrfs_ioctl_subvol_getflags(file, argp); + case BTRFS_IOC_SUBVOL_SETFLAGS: + return btrfs_ioctl_subvol_setflags(file, argp); + case BTRFS_IOC_DEFAULT_SUBVOL: + return btrfs_ioctl_default_subvol(file, argp); + case BTRFS_IOC_DEFRAG: + return btrfs_ioctl_defrag(file, NULL); + case BTRFS_IOC_DEFRAG_RANGE: + return btrfs_ioctl_defrag(file, argp); + 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_FS_INFO: + return btrfs_ioctl_fs_info(root, argp); + case BTRFS_IOC_DEV_INFO: + return btrfs_ioctl_dev_info(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_TREE_SEARCH: + return btrfs_ioctl_tree_search(file, argp); + case BTRFS_IOC_INO_LOOKUP: + return btrfs_ioctl_ino_lookup(file, argp); + case BTRFS_IOC_SPACE_INFO: + return btrfs_ioctl_space_info(root, argp); + case BTRFS_IOC_SYNC: + btrfs_sync_fs(file->f_dentry->d_sb, 1); + return 0; + case BTRFS_IOC_START_SYNC: + return btrfs_ioctl_start_sync(file, argp); + case BTRFS_IOC_WAIT_SYNC: + return btrfs_ioctl_wait_sync(file, argp); + case BTRFS_IOC_SCRUB: + return btrfs_ioctl_scrub(root, argp); + case BTRFS_IOC_SCRUB_CANCEL: + return btrfs_ioctl_scrub_cancel(root, argp); + case BTRFS_IOC_SCRUB_PROGRESS: + return btrfs_ioctl_scrub_progress(root, argp); + } + + return -ENOTTY; +} |