linux/fs/btrfs/volumes.h
Josef Bacik 6df9a95e63 Btrfs: make the chunk allocator completely tree lockless
When adjusting the enospc rules for relocation I ran into a deadlock because we
were relocating the only system chunk and that forced us to try and allocate a
new system chunk while holding locks in the chunk tree, which caused us to
deadlock.  To fix this I've moved all of the dev extent addition and chunk
addition out to the delayed chunk completion stuff.  We still keep the in-memory
stuff which makes sure everything is consistent.

One change I had to make was to search the commit root of the device tree to
find a free dev extent, and hold onto any chunk em's that we allocated in that
transaction so we do not allocate the same dev extent twice.  This has the side
effect of fixing a bug with balance that has been there ever since balance
existed.  Basically you can free a block group and it's dev extent and then
immediately allocate that dev extent for a new block group and write stuff to
that dev extent, all within the same transaction.  So if you happen to crash
during a balance you could come back to a completely broken file system.  This
patch should keep these sort of things from happening in the future since we
won't be able to allocate free'd dev extents until after the transaction
commits.  This has passed all of the xfstests and my super annoying stress test
followed by a balance.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-07-02 11:50:53 -04:00

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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.
*/
#ifndef __BTRFS_VOLUMES_
#define __BTRFS_VOLUMES_
#include <linux/bio.h>
#include <linux/sort.h>
#include <linux/btrfs.h>
#include "async-thread.h"
#define BTRFS_STRIPE_LEN (64 * 1024)
struct buffer_head;
struct btrfs_pending_bios {
struct bio *head;
struct bio *tail;
};
struct btrfs_device {
struct list_head dev_list;
struct list_head dev_alloc_list;
struct btrfs_fs_devices *fs_devices;
struct btrfs_root *dev_root;
/* regular prio bios */
struct btrfs_pending_bios pending_bios;
/* WRITE_SYNC bios */
struct btrfs_pending_bios pending_sync_bios;
int running_pending;
u64 generation;
int writeable;
int in_fs_metadata;
int missing;
int can_discard;
int is_tgtdev_for_dev_replace;
spinlock_t io_lock;
struct block_device *bdev;
/* the mode sent to blkdev_get */
fmode_t mode;
struct rcu_string *name;
/* the internal btrfs device id */
u64 devid;
/* size of the device */
u64 total_bytes;
/* size of the disk */
u64 disk_total_bytes;
/* bytes used */
u64 bytes_used;
/* optimal io alignment for this device */
u32 io_align;
/* optimal io width for this device */
u32 io_width;
/* minimal io size for this device */
u32 sector_size;
/* type and info about this device */
u64 type;
/* physical drive uuid (or lvm uuid) */
u8 uuid[BTRFS_UUID_SIZE];
/* per-device scrub information */
struct scrub_ctx *scrub_device;
struct btrfs_work work;
struct rcu_head rcu;
struct work_struct rcu_work;
/* readahead state */
spinlock_t reada_lock;
atomic_t reada_in_flight;
u64 reada_next;
struct reada_zone *reada_curr_zone;
struct radix_tree_root reada_zones;
struct radix_tree_root reada_extents;
/* for sending down flush barriers */
struct bio *flush_bio;
struct completion flush_wait;
int nobarriers;
/* disk I/O failure stats. For detailed description refer to
* enum btrfs_dev_stat_values in ioctl.h */
int dev_stats_valid;
int dev_stats_dirty; /* counters need to be written to disk */
atomic_t dev_stat_values[BTRFS_DEV_STAT_VALUES_MAX];
};
struct btrfs_fs_devices {
u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
/* the device with this id has the most recent copy of the super */
u64 latest_devid;
u64 latest_trans;
u64 num_devices;
u64 open_devices;
u64 rw_devices;
u64 missing_devices;
u64 total_rw_bytes;
u64 num_can_discard;
u64 total_devices;
struct block_device *latest_bdev;
/* all of the devices in the FS, protected by a mutex
* so we can safely walk it to write out the supers without
* worrying about add/remove by the multi-device code
*/
struct mutex device_list_mutex;
struct list_head devices;
/* devices not currently being allocated */
struct list_head alloc_list;
struct list_head list;
struct btrfs_fs_devices *seed;
int seeding;
int opened;
/* set when we find or add a device that doesn't have the
* nonrot flag set
*/
int rotating;
};
/*
* we need the mirror number and stripe index to be passed around
* the call chain while we are processing end_io (especially errors).
* Really, what we need is a btrfs_bio structure that has this info
* and is properly sized with its stripe array, but we're not there
* quite yet. We have our own btrfs bioset, and all of the bios
* we allocate are actually btrfs_io_bios. We'll cram as much of
* struct btrfs_bio as we can into this over time.
*/
struct btrfs_io_bio {
unsigned long mirror_num;
unsigned long stripe_index;
struct bio bio;
};
static inline struct btrfs_io_bio *btrfs_io_bio(struct bio *bio)
{
return container_of(bio, struct btrfs_io_bio, bio);
}
struct btrfs_bio_stripe {
struct btrfs_device *dev;
u64 physical;
u64 length; /* only used for discard mappings */
};
struct btrfs_bio;
typedef void (btrfs_bio_end_io_t) (struct btrfs_bio *bio, int err);
struct btrfs_bio {
atomic_t stripes_pending;
bio_end_io_t *end_io;
struct bio *orig_bio;
void *private;
atomic_t error;
int max_errors;
int num_stripes;
int mirror_num;
struct btrfs_bio_stripe stripes[];
};
struct btrfs_device_info {
struct btrfs_device *dev;
u64 dev_offset;
u64 max_avail;
u64 total_avail;
};
struct btrfs_raid_attr {
int sub_stripes; /* sub_stripes info for map */
int dev_stripes; /* stripes per dev */
int devs_max; /* max devs to use */
int devs_min; /* min devs needed */
int devs_increment; /* ndevs has to be a multiple of this */
int ncopies; /* how many copies to data has */
};
struct map_lookup {
u64 type;
int io_align;
int io_width;
int stripe_len;
int sector_size;
int num_stripes;
int sub_stripes;
struct btrfs_bio_stripe stripes[];
};
#define map_lookup_size(n) (sizeof(struct map_lookup) + \
(sizeof(struct btrfs_bio_stripe) * (n)))
/*
* Restriper's general type filter
*/
#define BTRFS_BALANCE_DATA (1ULL << 0)
#define BTRFS_BALANCE_SYSTEM (1ULL << 1)
#define BTRFS_BALANCE_METADATA (1ULL << 2)
#define BTRFS_BALANCE_TYPE_MASK (BTRFS_BALANCE_DATA | \
BTRFS_BALANCE_SYSTEM | \
BTRFS_BALANCE_METADATA)
#define BTRFS_BALANCE_FORCE (1ULL << 3)
#define BTRFS_BALANCE_RESUME (1ULL << 4)
/*
* Balance filters
*/
#define BTRFS_BALANCE_ARGS_PROFILES (1ULL << 0)
#define BTRFS_BALANCE_ARGS_USAGE (1ULL << 1)
#define BTRFS_BALANCE_ARGS_DEVID (1ULL << 2)
#define BTRFS_BALANCE_ARGS_DRANGE (1ULL << 3)
#define BTRFS_BALANCE_ARGS_VRANGE (1ULL << 4)
/*
* Profile changing flags. When SOFT is set we won't relocate chunk if
* it already has the target profile (even though it may be
* half-filled).
*/
#define BTRFS_BALANCE_ARGS_CONVERT (1ULL << 8)
#define BTRFS_BALANCE_ARGS_SOFT (1ULL << 9)
struct btrfs_balance_args;
struct btrfs_balance_progress;
struct btrfs_balance_control {
struct btrfs_fs_info *fs_info;
struct btrfs_balance_args data;
struct btrfs_balance_args meta;
struct btrfs_balance_args sys;
u64 flags;
struct btrfs_balance_progress stat;
};
int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
u64 end, u64 *length);
#define btrfs_bio_size(n) (sizeof(struct btrfs_bio) + \
(sizeof(struct btrfs_bio_stripe) * (n)))
int btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
u64 logical, u64 *length,
struct btrfs_bio **bbio_ret, int mirror_num);
int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
u64 chunk_start, u64 physical, u64 devid,
u64 **logical, int *naddrs, int *stripe_len);
int btrfs_read_sys_array(struct btrfs_root *root);
int btrfs_read_chunk_tree(struct btrfs_root *root);
int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
struct btrfs_root *extent_root, u64 type);
void btrfs_mapping_init(struct btrfs_mapping_tree *tree);
void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree);
int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
int mirror_num, int async_submit);
int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
fmode_t flags, void *holder);
int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
struct btrfs_fs_devices **fs_devices_ret);
int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
void btrfs_close_extra_devices(struct btrfs_fs_info *fs_info,
struct btrfs_fs_devices *fs_devices, int step);
int btrfs_find_device_missing_or_by_path(struct btrfs_root *root,
char *device_path,
struct btrfs_device **device);
int btrfs_rm_device(struct btrfs_root *root, char *device_path);
void btrfs_cleanup_fs_uuids(void);
int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len);
int btrfs_grow_device(struct btrfs_trans_handle *trans,
struct btrfs_device *device, u64 new_size);
struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid,
u8 *uuid, u8 *fsid);
int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
int btrfs_init_new_device(struct btrfs_root *root, char *path);
int btrfs_init_dev_replace_tgtdev(struct btrfs_root *root, char *device_path,
struct btrfs_device **device_out);
int btrfs_balance(struct btrfs_balance_control *bctl,
struct btrfs_ioctl_balance_args *bargs);
int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info);
int btrfs_recover_balance(struct btrfs_fs_info *fs_info);
int btrfs_pause_balance(struct btrfs_fs_info *fs_info);
int btrfs_cancel_balance(struct btrfs_fs_info *fs_info);
int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset);
int find_free_dev_extent(struct btrfs_trans_handle *trans,
struct btrfs_device *device, u64 num_bytes,
u64 *start, u64 *max_avail);
void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index);
int btrfs_get_dev_stats(struct btrfs_root *root,
struct btrfs_ioctl_get_dev_stats *stats);
void btrfs_init_devices_late(struct btrfs_fs_info *fs_info);
int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info);
int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info);
void btrfs_rm_dev_replace_srcdev(struct btrfs_fs_info *fs_info,
struct btrfs_device *srcdev);
void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
struct btrfs_device *tgtdev);
void btrfs_init_dev_replace_tgtdev_for_resume(struct btrfs_fs_info *fs_info,
struct btrfs_device *tgtdev);
int btrfs_scratch_superblock(struct btrfs_device *device);
int btrfs_is_parity_mirror(struct btrfs_mapping_tree *map_tree,
u64 logical, u64 len, int mirror_num);
unsigned long btrfs_full_stripe_len(struct btrfs_root *root,
struct btrfs_mapping_tree *map_tree,
u64 logical);
int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
struct btrfs_root *extent_root,
u64 chunk_offset, u64 chunk_size);
static inline void btrfs_dev_stat_inc(struct btrfs_device *dev,
int index)
{
atomic_inc(dev->dev_stat_values + index);
dev->dev_stats_dirty = 1;
}
static inline int btrfs_dev_stat_read(struct btrfs_device *dev,
int index)
{
return atomic_read(dev->dev_stat_values + index);
}
static inline int btrfs_dev_stat_read_and_reset(struct btrfs_device *dev,
int index)
{
int ret;
ret = atomic_xchg(dev->dev_stat_values + index, 0);
dev->dev_stats_dirty = 1;
return ret;
}
static inline void btrfs_dev_stat_set(struct btrfs_device *dev,
int index, unsigned long val)
{
atomic_set(dev->dev_stat_values + index, val);
dev->dev_stats_dirty = 1;
}
static inline void btrfs_dev_stat_reset(struct btrfs_device *dev,
int index)
{
btrfs_dev_stat_set(dev, index, 0);
}
#endif