linux/fs/btrfs/ioctl.c
Chris Mason 7d9eb12c87 Btrfs: Add locking around volume management (device add/remove/balance)
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:04 -04:00

770 lines
18 KiB
C

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