Commit 8a4b83cc authored by Chris Mason's avatar Chris Mason

Btrfs: Add support for device scanning and detection ioctls

Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 239b14b3
......@@ -37,7 +37,7 @@ extern struct kmem_cache *btrfs_transaction_cachep;
extern struct kmem_cache *btrfs_bit_radix_cachep;
extern struct kmem_cache *btrfs_path_cachep;
#define BTRFS_MAGIC "_B4RfS_M"
#define BTRFS_MAGIC "_B5RfS_M"
#define BTRFS_MAX_LEVEL 8
......@@ -238,6 +238,7 @@ struct btrfs_super_block {
__le64 total_bytes;
__le64 bytes_used;
__le64 root_dir_objectid;
__le64 num_devices;
__le32 sectorsize;
__le32 nodesize;
__le32 leafsize;
......@@ -440,6 +441,7 @@ struct btrfs_block_group_cache {
};
struct btrfs_device;
struct btrfs_fs_devices;
struct btrfs_fs_info {
u8 fsid[BTRFS_FSID_SIZE];
struct btrfs_root *extent_root;
......@@ -489,7 +491,7 @@ struct btrfs_fs_info {
u64 total_pinned;
struct list_head dirty_cowonly_roots;
struct list_head devices;
struct btrfs_fs_devices *fs_devices;
struct list_head space_info;
spinlock_t delalloc_lock;
spinlock_t new_trans_lock;
......@@ -677,6 +679,19 @@ BTRFS_SETGET_FUNCS(device_io_width, struct btrfs_dev_item, io_width, 32);
BTRFS_SETGET_FUNCS(device_sector_size, struct btrfs_dev_item, sector_size, 32);
BTRFS_SETGET_FUNCS(device_id, struct btrfs_dev_item, devid, 64);
BTRFS_SETGET_STACK_FUNCS(stack_device_type, struct btrfs_dev_item, type, 64);
BTRFS_SETGET_STACK_FUNCS(stack_device_total_bytes, struct btrfs_dev_item,
total_bytes, 64);
BTRFS_SETGET_STACK_FUNCS(stack_device_bytes_used, struct btrfs_dev_item,
bytes_used, 64);
BTRFS_SETGET_STACK_FUNCS(stack_device_io_align, struct btrfs_dev_item,
io_align, 32);
BTRFS_SETGET_STACK_FUNCS(stack_device_io_width, struct btrfs_dev_item,
io_width, 32);
BTRFS_SETGET_STACK_FUNCS(stack_device_sector_size, struct btrfs_dev_item,
sector_size, 32);
BTRFS_SETGET_STACK_FUNCS(stack_device_id, struct btrfs_dev_item, devid, 64);
static inline char *btrfs_device_uuid(struct btrfs_dev_item *d)
{
return (char *)d + offsetof(struct btrfs_dev_item, uuid);
......@@ -1106,6 +1121,8 @@ BTRFS_SETGET_STACK_FUNCS(super_stripesize, struct btrfs_super_block,
stripesize, 32);
BTRFS_SETGET_STACK_FUNCS(super_root_dir, struct btrfs_super_block,
root_dir_objectid, 64);
BTRFS_SETGET_STACK_FUNCS(super_num_devices, struct btrfs_super_block,
num_devices, 64);
static inline unsigned long btrfs_leaf_data(struct extent_buffer *l)
{
......
......@@ -365,12 +365,12 @@ static int close_all_devices(struct btrfs_fs_info *fs_info)
struct list_head *next;
struct btrfs_device *device;
list = &fs_info->devices;
while(!list_empty(list)) {
next = list->next;
list_del(next);
list = &fs_info->fs_devices->devices;
list_for_each(next, list) {
device = list_entry(next, struct btrfs_device, dev_list);
kfree(device);
if (device->bdev && device->bdev != fs_info->sb->s_bdev)
close_bdev_excl(device->bdev);
device->bdev = NULL;
}
return 0;
}
......@@ -655,7 +655,8 @@ static int add_hasher(struct btrfs_fs_info *info, char *type) {
return 0;
}
#endif
struct btrfs_root *open_ctree(struct super_block *sb)
struct btrfs_root *open_ctree(struct super_block *sb,
struct btrfs_fs_devices *fs_devices)
{
u32 sectorsize;
u32 nodesize;
......@@ -697,8 +698,8 @@ struct btrfs_root *open_ctree(struct super_block *sb)
fs_info->extent_root = extent_root;
fs_info->chunk_root = chunk_root;
fs_info->dev_root = dev_root;
fs_info->fs_devices = fs_devices;
INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
INIT_LIST_HEAD(&fs_info->devices);
INIT_LIST_HEAD(&fs_info->space_info);
btrfs_mapping_init(&fs_info->mapping_tree);
fs_info->sb = sb;
......@@ -779,6 +780,12 @@ struct btrfs_root *open_ctree(struct super_block *sb)
if (!btrfs_super_root(disk_super))
goto fail_sb_buffer;
if (btrfs_super_num_devices(disk_super) != fs_devices->num_devices) {
printk("Btrfs: wanted %llu devices, but found %llu\n",
(unsigned long long)btrfs_super_num_devices(disk_super),
(unsigned long long)fs_devices->num_devices);
goto fail_sb_buffer;
}
nodesize = btrfs_super_nodesize(disk_super);
leafsize = btrfs_super_leafsize(disk_super);
sectorsize = btrfs_super_sectorsize(disk_super);
......@@ -799,8 +806,6 @@ struct btrfs_root *open_ctree(struct super_block *sb)
}
mutex_lock(&fs_info->fs_mutex);
ret = btrfs_read_super_device(tree_root, fs_info->sb_buffer);
BUG_ON(ret);
ret = btrfs_read_sys_array(tree_root);
BUG_ON(ret);
......@@ -859,6 +864,7 @@ struct btrfs_root *open_ctree(struct super_block *sb)
fail_iput:
iput(fs_info->btree_inode);
fail:
close_all_devices(fs_info);
kfree(extent_root);
kfree(tree_root);
kfree(fs_info);
......
......@@ -21,6 +21,7 @@
#define BTRFS_SUPER_INFO_OFFSET (16 * 1024)
struct btrfs_device;
struct btrfs_fs_devices;
struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
u32 blocksize);
......@@ -29,7 +30,8 @@ struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
u64 bytenr, u32 blocksize);
int clean_tree_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct extent_buffer *buf);
struct btrfs_root *open_ctree(struct super_block *sb);
struct btrfs_root *open_ctree(struct super_block *sb,
struct btrfs_fs_devices *fs_devices);
int close_ctree(struct btrfs_root *root);
int write_ctree_super(struct btrfs_trans_handle *trans,
struct btrfs_root *root);
......
......@@ -22,8 +22,10 @@
#define BTRFS_IOCTL_MAGIC 0x94
#define BTRFS_VOL_NAME_MAX 255
#define BTRFS_PATH_NAME_MAX 4095
struct btrfs_ioctl_vol_args {
char name[BTRFS_VOL_NAME_MAX + 1];
char name[BTRFS_PATH_NAME_MAX + 1];
};
#define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \
......@@ -32,4 +34,6 @@ struct btrfs_ioctl_vol_args {
struct btrfs_ioctl_vol_args)
#define BTRFS_IOC_RESIZE _IOW(BTRFS_IOCTL_MAGIC, 3, \
struct btrfs_ioctl_vol_args)
#define BTRFS_IOC_SCAN_DEV _IOW(BTRFS_IOCTL_MAGIC, 4, \
struct btrfs_ioctl_vol_args)
#endif
......@@ -44,6 +44,7 @@
#include "ioctl.h"
#include "print-tree.h"
#include "xattr.h"
#include "volumes.h"
#define BTRFS_SUPER_MAGIC 0x9123683E
......@@ -216,7 +217,9 @@ static int parse_options (char * options,
return 1;
}
static int btrfs_fill_super(struct super_block * sb, void * data, int silent)
static int btrfs_fill_super(struct super_block * sb,
struct btrfs_fs_devices *fs_devices,
void * data, int silent)
{
struct inode * inode;
struct dentry * root_dentry;
......@@ -231,7 +234,7 @@ static int btrfs_fill_super(struct super_block * sb, void * data, int silent)
sb->s_xattr = btrfs_xattr_handlers;
sb->s_time_gran = 1;
tree_root = open_ctree(sb);
tree_root = open_ctree(sb, fs_devices);
if (!tree_root || IS_ERR(tree_root)) {
printk("btrfs: open_ctree failed\n");
......@@ -334,18 +337,23 @@ static int test_bdev_super(struct super_block *s, void *data)
int btrfs_get_sb_bdev(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data,
int (*fill_super)(struct super_block *, void *, int),
struct vfsmount *mnt, const char *subvol)
{
struct block_device *bdev = NULL;
struct super_block *s;
struct dentry *root;
struct btrfs_fs_devices *fs_devices = NULL;
int error = 0;
bdev = open_bdev_excl(dev_name, flags, fs_type);
if (IS_ERR(bdev))
return PTR_ERR(bdev);
error = btrfs_scan_one_device(dev_name, flags, fs_type, &fs_devices);
if (error)
return error;
error = btrfs_open_devices(fs_devices, flags, fs_type);
if (error)
return error;
bdev = fs_devices->lowest_bdev;
/*
* once the super is inserted into the list by sget, s_umount
* will protect the lockfs code from trying to start a snapshot
......@@ -372,7 +380,8 @@ int btrfs_get_sb_bdev(struct file_system_type *fs_type,
s->s_flags = flags;
strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
sb_set_blocksize(s, block_size(bdev));
error = fill_super(s, data, flags & MS_SILENT ? 1 : 0);
error = btrfs_fill_super(s, fs_devices, data,
flags & MS_SILENT ? 1 : 0);
if (error) {
up_write(&s->s_umount);
deactivate_super(s);
......@@ -408,7 +417,7 @@ int btrfs_get_sb_bdev(struct file_system_type *fs_type,
error_s:
error = PTR_ERR(s);
error_bdev:
close_bdev_excl(bdev);
btrfs_close_devices(fs_devices);
error:
return error;
}
......@@ -421,8 +430,7 @@ static int btrfs_get_sb(struct file_system_type *fs_type,
char *subvol_name = NULL;
parse_options((char *)data, NULL, &subvol_name);
ret = btrfs_get_sb_bdev(fs_type, flags, dev_name, data,
btrfs_fill_super, mnt,
ret = btrfs_get_sb_bdev(fs_type, flags, dev_name, data, mnt,
subvol_name ? subvol_name : "default");
if (subvol_name)
kfree(subvol_name);
......@@ -445,13 +453,6 @@ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
return 0;
}
static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
printk("btrfs control ioctl %d\n", cmd);
return 0;
}
static struct file_system_type btrfs_fs_type = {
.owner = THIS_MODULE,
.name = "btrfs",
......@@ -460,6 +461,31 @@ static struct file_system_type btrfs_fs_type = {
.fs_flags = FS_REQUIRES_DEV,
};
static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct btrfs_ioctl_vol_args *vol;
struct btrfs_fs_devices *fs_devices;
int ret;
int len;
vol = kmalloc(sizeof(*vol), GFP_KERNEL);
if (copy_from_user(vol, (void __user *)arg, sizeof(*vol))) {
ret = -EFAULT;
goto out;
}
len = strnlen(vol->name, BTRFS_PATH_NAME_MAX);
switch (cmd) {
case BTRFS_IOC_SCAN_DEV:
ret = btrfs_scan_one_device(vol->name, MS_RDONLY,
&btrfs_fs_type, &fs_devices);
break;
}
out:
kfree(vol);
return 0;
}
static void btrfs_write_super_lockfs(struct super_block *sb)
{
struct btrfs_root *root = btrfs_sb(sb);
......@@ -567,6 +593,7 @@ static void __exit exit_btrfs_fs(void)
btrfs_interface_exit();
unregister_filesystem(&btrfs_fs_type);
btrfs_exit_sysfs();
btrfs_cleanup_fs_uuids();
}
module_init(init_btrfs_fs)
......
......@@ -17,6 +17,7 @@
*/
#include <linux/sched.h>
#include <linux/bio.h>
#include <linux/buffer_head.h>
#include "ctree.h"
#include "extent_map.h"
#include "disk-io.h"
......@@ -28,6 +29,215 @@ struct map_lookup {
struct btrfs_device *dev;
u64 physical;
};
static DEFINE_MUTEX(uuid_mutex);
static LIST_HEAD(fs_uuids);
int btrfs_cleanup_fs_uuids(void)
{
struct btrfs_fs_devices *fs_devices;
struct list_head *uuid_cur;
struct list_head *devices_cur;
struct btrfs_device *dev;
list_for_each(uuid_cur, &fs_uuids) {
fs_devices = list_entry(uuid_cur, struct btrfs_fs_devices,
list);
while(!list_empty(&fs_devices->devices)) {
devices_cur = fs_devices->devices.next;
dev = list_entry(devices_cur, struct btrfs_device,
dev_list);
printk("uuid cleanup finds %s\n", dev->name);
if (dev->bdev) {
printk("closing\n");
close_bdev_excl(dev->bdev);
}
list_del(&dev->dev_list);
kfree(dev);
}
}
return 0;
}
static struct btrfs_device *__find_device(struct list_head *head, u64 devid)
{
struct btrfs_device *dev;
struct list_head *cur;
list_for_each(cur, head) {
dev = list_entry(cur, struct btrfs_device, dev_list);
if (dev->devid == devid)
return dev;
}
return NULL;
}
static struct btrfs_fs_devices *find_fsid(u8 *fsid)
{
struct list_head *cur;
struct btrfs_fs_devices *fs_devices;
list_for_each(cur, &fs_uuids) {
fs_devices = list_entry(cur, struct btrfs_fs_devices, list);
if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
return fs_devices;
}
return NULL;
}
static int device_list_add(const char *path,
struct btrfs_super_block *disk_super,
u64 devid, struct btrfs_fs_devices **fs_devices_ret)
{
struct btrfs_device *device;
struct btrfs_fs_devices *fs_devices;
u64 found_transid = btrfs_super_generation(disk_super);
fs_devices = find_fsid(disk_super->fsid);
if (!fs_devices) {
fs_devices = kmalloc(sizeof(*fs_devices), GFP_NOFS);
if (!fs_devices)
return -ENOMEM;
INIT_LIST_HEAD(&fs_devices->devices);
list_add(&fs_devices->list, &fs_uuids);
memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
fs_devices->latest_devid = devid;
fs_devices->latest_trans = found_transid;
fs_devices->lowest_devid = (u64)-1;
fs_devices->num_devices = 0;
device = NULL;
} else {
device = __find_device(&fs_devices->devices, devid);
}
if (!device) {
device = kzalloc(sizeof(*device), GFP_NOFS);
if (!device) {
/* we can safely leave the fs_devices entry around */
return -ENOMEM;
}
device->devid = devid;
device->name = kstrdup(path, GFP_NOFS);
if (!device->name) {
kfree(device);
return -ENOMEM;
}
list_add(&device->dev_list, &fs_devices->devices);
fs_devices->num_devices++;
}
if (found_transid > fs_devices->latest_trans) {
fs_devices->latest_devid = devid;
fs_devices->latest_trans = found_transid;
}
if (fs_devices->lowest_devid > devid) {
fs_devices->lowest_devid = devid;
printk("lowest devid now %Lu\n", devid);
}
*fs_devices_ret = fs_devices;
return 0;
}
int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
{
struct list_head *head = &fs_devices->devices;
struct list_head *cur;
struct btrfs_device *device;
mutex_lock(&uuid_mutex);
list_for_each(cur, head) {
device = list_entry(cur, struct btrfs_device, dev_list);
if (device->bdev) {
close_bdev_excl(device->bdev);
printk("close devices closes %s\n", device->name);
}
device->bdev = NULL;
}
mutex_unlock(&uuid_mutex);
return 0;
}
int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
int flags, void *holder)
{
struct block_device *bdev;
struct list_head *head = &fs_devices->devices;
struct list_head *cur;
struct btrfs_device *device;
int ret;
mutex_lock(&uuid_mutex);
list_for_each(cur, head) {
device = list_entry(cur, struct btrfs_device, dev_list);
bdev = open_bdev_excl(device->name, flags, holder);
printk("opening %s devid %Lu\n", device->name, device->devid);
if (IS_ERR(bdev)) {
printk("open %s failed\n", device->name);
ret = PTR_ERR(bdev);
goto fail;
}
if (device->devid == fs_devices->latest_devid)
fs_devices->latest_bdev = bdev;
if (device->devid == fs_devices->lowest_devid) {
fs_devices->lowest_bdev = bdev;
printk("lowest bdev %s\n", device->name);
}
device->bdev = bdev;
}
mutex_unlock(&uuid_mutex);
return 0;
fail:
mutex_unlock(&uuid_mutex);
btrfs_close_devices(fs_devices);
return ret;
}
int btrfs_scan_one_device(const char *path, int flags, void *holder,
struct btrfs_fs_devices **fs_devices_ret)
{
struct btrfs_super_block *disk_super;
struct block_device *bdev;
struct buffer_head *bh;
int ret;
u64 devid;
mutex_lock(&uuid_mutex);
printk("scan one opens %s\n", path);
bdev = open_bdev_excl(path, flags, holder);
if (IS_ERR(bdev)) {
printk("open failed\n");
ret = PTR_ERR(bdev);
goto error;
}
ret = set_blocksize(bdev, 4096);
if (ret)
goto error_close;
bh = __bread(bdev, BTRFS_SUPER_INFO_OFFSET / 4096, 4096);
if (!bh) {
ret = -EIO;
goto error_close;
}
disk_super = (struct btrfs_super_block *)bh->b_data;
if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
sizeof(disk_super->magic))) {
printk("no btrfs found on %s\n", path);
ret = -ENOENT;
goto error_brelse;
}
devid = le64_to_cpu(disk_super->dev_item.devid);
printk("found device %Lu on %s\n", devid, path);
ret = device_list_add(path, disk_super, devid, fs_devices_ret);
error_brelse:
brelse(bh);
error_close:
close_bdev_excl(bdev);
printk("scan one closes bdev %s\n", path);
error:
mutex_unlock(&uuid_mutex);
return ret;
}
/*
* this uses a pretty simple search, the expectation is that it is
......@@ -56,6 +266,10 @@ static int find_free_dev_extent(struct btrfs_trans_handle *trans,
/* FIXME use last free of some kind */
/* we don't want to overwrite the superblock on the drive,
* so we make sure to start at an offset of at least 1MB
*/
search_start = max((u64)1024 * 1024, search_start);
key.objectid = device->devid;
key.offset = search_start;
key.type = BTRFS_DEV_EXTENT_KEY;
......@@ -285,6 +499,7 @@ int btrfs_add_device(struct btrfs_trans_handle *trans,
leaf = path->nodes[0];
dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
device->devid = free_devid;
btrfs_set_device_id(leaf, dev_item, device->devid);
btrfs_set_device_type(leaf, dev_item, device->type);
btrfs_set_device_io_align(leaf, dev_item, device->io_align);
......@@ -382,7 +597,7 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
struct btrfs_device *device = NULL;
struct btrfs_chunk *chunk;
struct list_head private_devs;
struct list_head *dev_list = &extent_root->fs_info->devices;
struct list_head *dev_list = &extent_root->fs_info->fs_devices->devices;
struct list_head *cur;
struct extent_map_tree *em_tree;
struct map_lookup *map;
......@@ -449,7 +664,7 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
key.objectid,
calc_size, &dev_offset);
BUG_ON(ret);
printk("alloc chunk size %Lu from dev %Lu\n", calc_size, device->devid);
device->bytes_used += calc_size;
ret = btrfs_update_device(trans, device);
BUG_ON(ret);
......@@ -592,17 +807,9 @@ int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio)
struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid)
{
struct btrfs_device *dev;
struct list_head *cur = root->fs_info->devices.next;
struct list_head *head = &root->fs_info->devices;
struct list_head *head = &root->fs_info->fs_devices->devices;
while(cur != head) {
dev = list_entry(cur, struct btrfs_device, dev_list);
if (dev->devid == devid)
return dev;
cur = cur->next;
}
return NULL;
return __find_device(head, devid);
}
static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
......@@ -699,15 +906,16 @@ static int read_one_dev(struct btrfs_root *root,
devid = btrfs_device_id(leaf, dev_item);
device = btrfs_find_device(root, devid);
if (!device) {
printk("warning devid %Lu not found already\n", devid);
device = kmalloc(sizeof(*device), GFP_NOFS);
if (!device)
return -ENOMEM;
list_add(&device->dev_list, &root->fs_info->devices);
list_add(&device->dev_list,
&root->fs_info->fs_devices->devices);
}
fill_device_from_item(leaf, dev_item, device);
device->dev_root = root->fs_info->dev_root;
device->bdev = root->fs_info->sb->s_bdev;
ret = 0;
#if 0
ret = btrfs_open_device(device);
......
......@@ -24,6 +24,8 @@ struct btrfs_device {
struct block_device *bdev;
char *name;
/* the internal btrfs device id */
u64 devid;
......@@ -49,6 +51,20 @@ struct btrfs_device {
u8 uuid[BTRFS_DEV_UUID_SIZE];
};
struct btrfs_fs_devices {
u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
/* the device with this id has the most recent coyp of the super */
u64 latest_devid;
u64 latest_trans;
u64 lowest_devid;
u64 num_devices;
struct block_device *latest_bdev;
struct block_device *lowest_bdev;
struct list_head devices;
struct list_head list;
};
int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
struct btrfs_device *device,
u64 owner, u64 num_bytes, u64 *start);
......@@ -67,4 +83,13 @@ int btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf);
int btrfs_map_block(struct btrfs_mapping_tree *map_tree,
u64 logical, u64 *phys, u64 *length,
struct btrfs_device **dev);
int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
int flags, void *holder);
int btrfs_scan_one_device(const char *path, int flags, void *holder,
struct btrfs_fs_devices **fs_devices_ret);
int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
int btrfs_add_device(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_device *device);
int btrfs_cleanup_fs_uuids(void);
#endif
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