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This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
Copyright (C) 2001-2008, LINBIT Information Technologies GmbH.
Copyright (C) 1999-2008, Philipp Reisner <>.
Copyright (C) 2002-2008, Lars Ellenberg <>.
drbd is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
drbd is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with drbd; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
#ifndef _DRBD_INT_H
#define _DRBD_INT_H
#include <linux/compiler.h>
#include <linux/types.h>
#include <linux/list.h>
#include <linux/sched.h>
#include <linux/bitops.h>
#include <linux/slab.h>
#include <linux/crypto.h>
#include <linux/ratelimit.h>
#include <linux/tcp.h>
#include <linux/mutex.h>
#include <linux/major.h>
#include <linux/blkdev.h>
#include <linux/genhd.h>
#include <linux/idr.h>
#include <net/tcp.h>
#include <linux/lru_cache.h>
#include <linux/prefetch.h>
#include <linux/drbd_genl_api.h>
#include <linux/drbd.h>
#include "drbd_state.h"
#ifdef __CHECKER__
# define __protected_by(x) __attribute__((require_context(x,1,999,"rdwr")))
# define __protected_read_by(x) __attribute__((require_context(x,1,999,"read")))
# define __protected_write_by(x) __attribute__((require_context(x,1,999,"write")))
# define __must_hold(x) __attribute__((context(x,1,1), require_context(x,1,999,"call")))
# define __protected_by(x)
# define __protected_read_by(x)
# define __protected_write_by(x)
# define __must_hold(x)
#define __no_warn(lock, stmt) do { __acquire(lock); stmt; __release(lock); } while (0)
/* module parameter, defined in drbd_main.c */
extern unsigned int minor_count;
extern bool disable_sendpage;
extern bool allow_oos;
extern int enable_faults;
extern int fault_rate;
extern int fault_devs;
extern char usermode_helper[];
/* I don't remember why XCPU ...
* This is used to wake the asender,
* and to interrupt sending the sending task
* on disconnect.
/* This is used to stop/restart our threads.
* Cannot use SIGTERM nor SIGKILL, since these
* are sent out by init on runlevel changes
* I choose SIGHUP for now.
#define ID_IN_SYNC (4711ULL)
#define ID_OUT_OF_SYNC (4712ULL)
#define ID_SYNCER (-1ULL)
#define UUID_NEW_BM_OFFSET ((u64)0x0001000000000000ULL)
struct drbd_conf;
struct drbd_tconn;
/* to shorten dev_warn(DEV, "msg"); and relatives statements */
#define DEV (disk_to_dev(mdev->vdisk))
#define conn_printk(LEVEL, TCONN, FMT, ARGS...) \
printk(LEVEL "d-con %s: " FMT, TCONN->name , ## ARGS)
#define conn_alert(TCONN, FMT, ARGS...) conn_printk(KERN_ALERT, TCONN, FMT, ## ARGS)
#define conn_crit(TCONN, FMT, ARGS...) conn_printk(KERN_CRIT, TCONN, FMT, ## ARGS)
#define conn_err(TCONN, FMT, ARGS...) conn_printk(KERN_ERR, TCONN, FMT, ## ARGS)
#define conn_warn(TCONN, FMT, ARGS...) conn_printk(KERN_WARNING, TCONN, FMT, ## ARGS)
#define conn_notice(TCONN, FMT, ARGS...) conn_printk(KERN_NOTICE, TCONN, FMT, ## ARGS)
#define conn_info(TCONN, FMT, ARGS...) conn_printk(KERN_INFO, TCONN, FMT, ## ARGS)
#define conn_dbg(TCONN, FMT, ARGS...) conn_printk(KERN_DEBUG, TCONN, FMT, ## ARGS)
#define D_ASSERT(exp) if (!(exp)) \
dev_err(DEV, "ASSERT( " #exp " ) in %s:%d\n", __FILE__, __LINE__)
* expect - Make an assertion
* Unlike the assert macro, this macro returns a boolean result.
#define expect(exp) ({ \
bool _bool = (exp); \
if (!_bool) \
dev_err(DEV, "ASSERTION %s FAILED in %s\n", \
#exp, __func__); \
_bool; \
/* Defines to control fault insertion */
enum {
DRBD_FAULT_MD_WR = 0, /* meta data write */
DRBD_FAULT_MD_RD = 1, /* read */
DRBD_FAULT_RS_WR = 2, /* resync */
DRBD_FAULT_DT_WR = 4, /* data */
DRBD_FAULT_DT_RA = 6, /* data read ahead */
DRBD_FAULT_BM_ALLOC = 7, /* bitmap allocation */
DRBD_FAULT_AL_EE = 8, /* alloc ee */
DRBD_FAULT_RECEIVE = 9, /* Changes some bytes upon receiving a [rs]data block */
extern unsigned int
_drbd_insert_fault(struct drbd_conf *mdev, unsigned int type);
static inline int
drbd_insert_fault(struct drbd_conf *mdev, unsigned int type) {
return fault_rate &&
(enable_faults & (1<<type)) &&
_drbd_insert_fault(mdev, type);
return 0;
/* integer division, round _UP_ to the next integer */
#define div_ceil(A, B) ((A)/(B) + ((A)%(B) ? 1 : 0))
/* usual integer division */
#define div_floor(A, B) ((A)/(B))
extern struct ratelimit_state drbd_ratelimit_state;
extern struct idr minors; /* RCU, updates: genl_lock() */
extern struct list_head drbd_tconns; /* RCU, updates: genl_lock() */
/* on the wire */
enum drbd_packet {
/* receiver (data socket) */
P_DATA = 0x00,
P_DATA_REPLY = 0x01, /* Response to P_DATA_REQUEST */
P_RS_DATA_REPLY = 0x02, /* Response to P_RS_DATA_REQUEST */
P_BARRIER = 0x03,
P_BITMAP = 0x04,
P_UNPLUG_REMOTE = 0x07, /* Used at various times to hint the peer */
P_DATA_REQUEST = 0x08, /* Used to ask for a data block */
P_RS_DATA_REQUEST = 0x09, /* Used to ask for a data block for resync */
P_SYNC_PARAM = 0x0a,
P_PROTOCOL = 0x0b,
P_UUIDS = 0x0c,
P_SIZES = 0x0d,
P_STATE = 0x0e,
P_SYNC_UUID = 0x0f,
/* asender (meta socket */
P_PING = 0x13,
P_PING_ACK = 0x14,
P_RECV_ACK = 0x15, /* Used in protocol B */
P_WRITE_ACK = 0x16, /* Used in protocol C */
P_RS_WRITE_ACK = 0x17, /* Is a P_WRITE_ACK, additionally call set_in_sync(). */
P_SUPERSEDED = 0x18, /* Used in proto C, two-primaries conflict detection */
P_NEG_ACK = 0x19, /* Sent if local disk is unusable */
P_NEG_DREPLY = 0x1a, /* Local disk is broken... */
P_NEG_RS_DREPLY = 0x1b, /* Local disk is broken... */
/* "new" commands, no longer fitting into the ordering scheme above */
P_OV_REQUEST = 0x1e, /* data socket */
P_OV_REPLY = 0x1f,
P_OV_RESULT = 0x20, /* meta socket */
P_CSUM_RS_REQUEST = 0x21, /* data socket */
P_RS_IS_IN_SYNC = 0x22, /* meta socket */
P_SYNC_PARAM89 = 0x23, /* data socket, protocol version 89 replacement for P_SYNC_PARAM */
P_COMPRESSED_BITMAP = 0x24, /* compressed or otherwise encoded bitmap transfer */
/* P_CKPT_FENCE_REQ = 0x25, * currently reserved for protocol D */
/* P_CKPT_DISABLE_REQ = 0x26, * currently reserved for protocol D */
P_DELAY_PROBE = 0x27, /* is used on BOTH sockets */
P_OUT_OF_SYNC = 0x28, /* Mark as out of sync (Outrunning), data socket */
P_RS_CANCEL = 0x29, /* meta: Used to cancel RS_DATA_REQUEST packet by SyncSource */
P_CONN_ST_CHG_REQ = 0x2a, /* data sock: Connection wide state request */
P_CONN_ST_CHG_REPLY = 0x2b, /* meta sock: Connection side state req reply */
P_RETRY_WRITE = 0x2c, /* Protocol C: retry conflicting write request */
P_PROTOCOL_UPDATE = 0x2d, /* data sock: is used in established connections */
P_MAY_IGNORE = 0x100, /* Flag to test if (cmd > P_MAY_IGNORE) ... */
P_MAX_OPT_CMD = 0x101,
/* special command ids for handshake */
P_INITIAL_META = 0xfff1, /* First Packet on the MetaSock */
P_INITIAL_DATA = 0xfff2, /* First Packet on the Socket */
P_CONNECTION_FEATURES = 0xfffe /* FIXED for the next century! */
extern const char *cmdname(enum drbd_packet cmd);
/* for sending/receiving the bitmap,
* possibly in some encoding scheme */
struct bm_xfer_ctx {
/* "const"
* stores total bits and long words
* of the bitmap, so we don't need to
* call the accessor functions over and again. */
unsigned long bm_bits;
unsigned long bm_words;
/* during xfer, current position within the bitmap */
unsigned long bit_offset;
unsigned long word_offset;
/* statistics; index: (h->command == P_BITMAP) */
unsigned packets[2];
unsigned bytes[2];
extern void INFO_bm_xfer_stats(struct drbd_conf *mdev,
const char *direction, struct bm_xfer_ctx *c);
static inline void bm_xfer_ctx_bit_to_word_offset(struct bm_xfer_ctx *c)
/* word_offset counts "native long words" (32 or 64 bit),
* aligned at 64 bit.
* Encoded packet may end at an unaligned bit offset.
* In case a fallback clear text packet is transmitted in
* between, we adjust this offset back to the last 64bit
* aligned "native long word", which makes coding and decoding
* the plain text bitmap much more convenient. */
#if BITS_PER_LONG == 64
c->word_offset = c->bit_offset >> 6;
#elif BITS_PER_LONG == 32
c->word_offset = c->bit_offset >> 5;
c->word_offset &= ~(1UL);
# error "unsupported BITS_PER_LONG"
#ifndef __packed
#define __packed __attribute__((packed))
/* This is the layout for a packet on the wire.
* The byteorder is the network byte order.
* (except block_id and barrier fields.
* these are pointers to local structs
* and have no relevance for the partner,
* which just echoes them as received.)
* NOTE that the payload starts at a long aligned offset,
* regardless of 32 or 64 bit arch!
struct p_header80 {
u32 magic;
u16 command;
u16 length; /* bytes of data after this header */
} __packed;
/* Header for big packets, Used for data packets exceeding 64kB */
struct p_header95 {
u16 magic; /* use DRBD_MAGIC_BIG here */
u16 command;
u32 length;
} __packed;
struct p_header100 {
u32 magic;
u16 volume;
u16 command;
u32 length;
u32 pad;
} __packed;
extern unsigned int drbd_header_size(struct drbd_tconn *tconn);
/* these defines must not be changed without changing the protocol version */
#define DP_HARDBARRIER 1 /* depricated */
#define DP_RW_SYNC 2 /* equals REQ_SYNC */
#define DP_MAY_SET_IN_SYNC 4
#define DP_UNPLUG 8 /* not used anymore */
#define DP_FUA 16 /* equals REQ_FUA */
#define DP_FLUSH 32 /* equals REQ_FLUSH */
#define DP_DISCARD 64 /* equals REQ_DISCARD */
#define DP_SEND_RECEIVE_ACK 128 /* This is a proto B write request */
#define DP_SEND_WRITE_ACK 256 /* This is a proto C write request */
struct p_data {
u64 sector; /* 64 bits sector number */
u64 block_id; /* to identify the request in protocol B&C */
u32 seq_num;
u32 dp_flags;
} __packed;
* commands which share a struct:
* p_block_ack:
* P_RECV_ACK (proto B), P_WRITE_ACK (proto C),
* P_SUPERSEDED (proto C, two-primaries conflict detection)
* p_block_req:
struct p_block_ack {
u64 sector;
u64 block_id;
u32 blksize;
u32 seq_num;
} __packed;
struct p_block_req {
u64 sector;
u64 block_id;
u32 blksize;
u32 pad; /* to multiple of 8 Byte */
} __packed;
* commands with their own struct for additional fields:
* ReportParams
struct p_connection_features {
u32 protocol_min;
u32 feature_flags;
u32 protocol_max;
/* should be more than enough for future enhancements
* for now, feature_flags and the reserved array shall be zero.
u32 _pad;
u64 reserved[7];
} __packed;
struct p_barrier {
u32 barrier; /* barrier number _handle_ only */
u32 pad; /* to multiple of 8 Byte */
} __packed;
struct p_barrier_ack {
u32 barrier;
u32 set_size;
} __packed;
struct p_rs_param {
u32 resync_rate;
/* Since protocol version 88 and higher. */
char verify_alg[0];
} __packed;
struct p_rs_param_89 {
u32 resync_rate;
/* protocol version 89: */
char verify_alg[SHARED_SECRET_MAX];
char csums_alg[SHARED_SECRET_MAX];
} __packed;
struct p_rs_param_95 {
u32 resync_rate;
char verify_alg[SHARED_SECRET_MAX];
char csums_alg[SHARED_SECRET_MAX];
u32 c_plan_ahead;
u32 c_delay_target;
u32 c_fill_target;
u32 c_max_rate;
} __packed;
enum drbd_conn_flags {
struct p_protocol {
u32 protocol;
u32 after_sb_0p;
u32 after_sb_1p;
u32 after_sb_2p;
u32 conn_flags;
u32 two_primaries;
/* Since protocol version 87 and higher. */
char integrity_alg[0];
} __packed;
struct p_uuids {
} __packed;
struct p_rs_uuid {
u64 uuid;
} __packed;
struct p_sizes {
u64 d_size; /* size of disk */
u64 u_size; /* user requested size */
u64 c_size; /* current exported size */
u32 max_bio_size; /* Maximal size of a BIO */
u16 queue_order_type; /* not yet implemented in DRBD*/
u16 dds_flags; /* use enum dds_flags here. */
} __packed;
struct p_state {
u32 state;
} __packed;
struct p_req_state {
u32 mask;
u32 val;
} __packed;
struct p_req_state_reply {
u32 retcode;
} __packed;
struct p_drbd06_param {
u64 size;
u32 state;
u32 blksize;
u32 protocol;
u32 version;
u32 gen_cnt[5];
u32 bit_map_gen[5];
} __packed;
struct p_block_desc {
u64 sector;
u32 blksize;
u32 pad; /* to multiple of 8 Byte */
} __packed;
/* Valid values for the encoding field.
* Bump proto version when changing this. */
enum drbd_bitmap_code {
/* RLE_VLI_Bytes = 0,
* and other bit variants had been defined during
* algorithm evaluation. */
RLE_VLI_Bits = 2,
struct p_compressed_bm {
/* (encoding & 0x0f): actual encoding, see enum drbd_bitmap_code
* (encoding & 0x80): polarity (set/unset) of first runlength
* ((encoding >> 4) & 0x07): pad_bits, number of trailing zero bits
* used to pad up to head.length bytes
u8 encoding;
u8 code[0];
} __packed;
struct p_delay_probe93 {
u32 seq_num; /* sequence number to match the two probe packets */
u32 offset; /* usecs the probe got sent after the reference time point */
} __packed;
* Bitmap packets need to fit within a single page on the sender and receiver,
* so we are limited to 4 KiB (and not to PAGE_SIZE, which can be bigger).
enum drbd_thread_state {
struct drbd_thread {
spinlock_t t_lock;
struct task_struct *task;
struct completion stop;
enum drbd_thread_state t_state;
int (*function) (struct drbd_thread *);
struct drbd_tconn *tconn;
int reset_cpu_mask;
char name[9];
static inline enum drbd_thread_state get_t_state(struct drbd_thread *thi)
/* THINK testing the t_state seems to be uncritical in all cases
* (but thread_{start,stop}), so we can read it *without* the lock.
* --lge */
return thi->t_state;
struct drbd_work {
struct list_head list;
int (*cb)(struct drbd_work *, int cancel);
union {
struct drbd_conf *mdev;
struct drbd_tconn *tconn;
#include "drbd_interval.h"
extern int drbd_wait_misc(struct drbd_conf *, struct drbd_interval *);
struct drbd_request {
struct drbd_work w;
/* if local IO is not allowed, will be NULL.
* if local IO _is_ allowed, holds the locally submitted bio clone,
* or, after local IO completion, the ERR_PTR(error).
* see drbd_request_endio(). */
struct bio *private_bio;
struct drbd_interval i;
/* epoch: used to check on "completion" whether this req was in
* the current epoch, and we therefore have to close it,
* causing a p_barrier packet to be send, starting a new epoch.
* This corresponds to "barrier" in struct p_barrier[_ack],
* and to "barrier_nr" in struct drbd_epoch (and various
* comments/function parameters/local variable names).
unsigned int epoch;
struct list_head tl_requests; /* ring list in the transfer log */
struct bio *master_bio; /* master bio pointer */
unsigned long start_time;
/* once it hits 0, we may complete the master_bio */
atomic_t completion_ref;
/* once it hits 0, we may destroy this drbd_request object */
struct kref kref;
unsigned rq_state; /* see comments above _req_mod() */
struct drbd_epoch {
struct drbd_tconn *tconn;
struct list_head list;
unsigned int barrier_nr;
atomic_t epoch_size; /* increased on every request added. */
atomic_t active; /* increased on every req. added, and dec on every finished. */
unsigned long flags;
/* drbd_epoch flag bits */
enum {
enum epoch_event {
EV_CLEANUP = 32, /* used as flag */
struct drbd_wq_barrier {
struct drbd_work w;
struct completion done;
struct digest_info {
int digest_size;
void *digest;
struct drbd_peer_request {
struct drbd_work w;
struct drbd_epoch *epoch; /* for writes */
struct page *pages;
atomic_t pending_bios;
struct drbd_interval i;
/* see comments on ee flag bits below */
unsigned long flags;
union {
u64 block_id;
struct digest_info *digest;
/* ee flag bits.
* While corresponding bios are in flight, the only modification will be
* set_bit WAS_ERROR, which has to be atomic.
* If no bios are in flight yet, or all have been completed,
* non-atomic modification to ee->flags is ok.
enum {
/* In case a barrier failed,
* we need to resubmit without the barrier flag. */
/* we may have several bios per peer request.
* if any of those fail, we set this flag atomically
* from the endio callback */
/* This ee has a pointer to a digest instead of a block id */
/* Conflicting local requests need to be restarted after this request */
/* The peer wants a write ACK for this (wire proto C) */
/* Is set when net_conf had two_primaries set while creating this peer_req */
#define EE_WAS_ERROR (1<<__EE_WAS_ERROR)
/* flag bits per mdev */
enum {
UNPLUG_REMOTE, /* sending a "UnplugRemote" could help */
MD_DIRTY, /* current uuids and flags not yet on disk */
USE_DEGR_WFC_T, /* degr-wfc-timeout instead of wfc-timeout. */
CRASHED_PRIMARY, /* This node was a crashed primary.
* Gets cleared when the state.conn
* goes into C_CONNECTED state. */
MD_NO_FUA, /* Users wants us to not use FUA/FLUSH on meta data dev */
SUSPEND_IO, /* suspend application io */
BITMAP_IO, /* suspend application io;
once no more io in flight, start bitmap io */
BITMAP_IO_QUEUED, /* Started bitmap IO */
GO_DISKLESS, /* Disk is being detached, on io-error or admin request. */
WAS_IO_ERROR, /* Local disk failed, returned IO error */
WAS_READ_ERROR, /* Local disk READ failed (set additionally to the above) */
FORCE_DETACH, /* Force-detach from local disk, aborting any pending local IO */
RESYNC_AFTER_NEG, /* Resync after online grow after the attach&negotiate finished. */
RESIZE_PENDING, /* Size change detected locally, waiting for the response from
* the peer, if it changed there as well. */
NEW_CUR_UUID, /* Create new current UUID when thawing IO */
AL_SUSPENDED, /* Activity logging is currently suspended. */
AHEAD_TO_SYNC_SOURCE, /* Ahead -> SyncSource queued */
B_RS_H_DONE, /* Before resync handler done (already executed) */
DISCARD_MY_DATA, /* discard_my_data flag per volume */
struct drbd_bitmap; /* opaque for drbd_conf */
/* definition of bits in bm_flags to be used in drbd_bm_lock
* and drbd_bitmap_io and friends. */
enum bm_flag {
/* do we need to kfree, or vfree bm_pages? */
BM_P_VMALLOCED = 0x10000, /* internal use only, will be masked out */
/* currently locked for bulk operation */
/* in detail, that is: */
BM_DONT_SET = 0x2,
/* so we can mark it locked for bulk operation,
* and still allow all non-bulk operations */
/* (test bit, count bit) allowed (common case) */
/* testing bits, as well as setting new bits allowed, but clearing bits
* would be unexpected. Used during bitmap receive. Setting new bits
* requires sending of "out-of-sync" information, though. */
/* for drbd_bm_write_copy_pages, everything is allowed,
* only concurrent bulk operations are locked out. */
struct drbd_work_queue {
struct list_head q;
spinlock_t q_lock; /* to protect the list. */
wait_queue_head_t q_wait;
struct drbd_socket {
struct mutex mutex;
struct socket *socket;
/* this way we get our
* send/receive buffers off the stack */
void *sbuf;
void *rbuf;
struct drbd_md {
u64 md_offset; /* sector offset to 'super' block */
u64 la_size_sect; /* last agreed size, unit sectors */
spinlock_t uuid_lock;
u64 uuid[UI_SIZE];
u64 device_uuid;
u32 flags;
u32 md_size_sect;
s32 al_offset; /* signed relative sector offset to activity log */
s32 bm_offset; /* signed relative sector offset to bitmap */
/* cached value of bdev->disk_conf->meta_dev_idx (see below) */
s32 meta_dev_idx;
/* see al_tr_number_to_on_disk_sector() */
u32 al_stripes;
u32 al_stripe_size_4k;
u32 al_size_4k; /* cached product of the above */
struct drbd_backing_dev {
struct block_device *backing_bdev;
struct block_device *md_bdev;
struct drbd_md md;
struct disk_conf *disk_conf; /* RCU, for updates: mdev->tconn->conf_update */
sector_t known_size; /* last known size of that backing device */
struct drbd_md_io {
unsigned int done;
int error;
struct bm_io_work {
struct drbd_work w;
char *why;
enum bm_flag flags;
int (*io_fn)(struct drbd_conf *mdev);
void (*done)(struct drbd_conf *mdev, int rv);
enum write_ordering_e {
struct fifo_buffer {
unsigned int head_index;
unsigned int size;
int total; /* sum of all values */
int values[0];
extern struct fifo_buffer *fifo_alloc(int fifo_size);
/* flag bits per tconn */
enum {
NET_CONGESTED, /* The data socket is congested */
RESOLVE_CONFLICTS, /* Set on one node, cleared on the peer! */
SEND_PING, /* whether asender should send a ping asap */
SIGNAL_ASENDER, /* whether asender wants to be interrupted */
GOT_PING_ACK, /* set when we receive a ping_ack packet, ping_wait gets woken */
CONN_WD_ST_CHG_REQ, /* A cluster wide state change on the connection is active */
CONN_DRY_RUN, /* Expect disconnect after resync handshake. */
CREATE_BARRIER, /* next P_DATA is preceded by a P_BARRIER */
STATE_SENT, /* Do not change state/UUIDs while this is set */
CALLBACK_PENDING, /* Whether we have a call_usermodehelper(, UMH_WAIT_PROC)
* pending, from drbd worker context.
* If set, bdi_write_congested() returns true,
* so shrink_page_list() would not recurse into,
* and potentially deadlock on, this drbd worker.
struct drbd_tconn { /* is a resource from the config file */
char *name; /* Resource name */
struct list_head all_tconn; /* linked on global drbd_tconns */
struct kref kref;
struct idr volumes; /* <tconn, vnr> to mdev mapping */
enum drbd_conns cstate; /* Only C_STANDALONE to C_WF_REPORT_PARAMS */
unsigned susp:1; /* IO suspended by user */
unsigned susp_nod:1; /* IO suspended because no data */
unsigned susp_fen:1; /* IO suspended because fence peer handler runs */
struct mutex cstate_mutex; /* Protects graceful disconnects */
unsigned long flags;
struct net_conf *net_conf; /* content protected by rcu */
struct mutex conf_update; /* mutex for ready-copy-update of net_conf and disk_conf */
wait_queue_head_t ping_wait; /* Woken upon reception of a ping, and a state change */
struct res_opts res_opts;
struct sockaddr_storage my_addr;
int my_addr_len;
struct sockaddr_storage peer_addr;
int peer_addr_len;
struct drbd_socket data; /* data/barrier/cstate/parameter packets */
struct drbd_socket meta; /* ping/ack (metadata) packets */
int agreed_pro_version; /* actually used protocol version */
unsigned long last_received; /* in jiffies, either socket */
unsigned int ko_count;
spinlock_t req_lock;
struct list_head transfer_log; /* all requests not yet fully processed */
struct crypto_hash *cram_hmac_tfm;
struct crypto_hash *integrity_tfm; /* checksums we compute, updates protected by tconn->data->mutex */
struct crypto_hash *peer_integrity_tfm; /* checksums we verify, only accessed from receiver thread */
struct crypto_hash *csums_tfm;
struct crypto_hash *verify_tfm;
void *int_dig_in;
void *int_dig_vv;
/* receiver side */
struct drbd_epoch *current_epoch;
spinlock_t epoch_lock;
unsigned int epochs;
enum write_ordering_e write_ordering;
atomic_t current_tle_nr; /* transfer log epoch number */
unsigned current_tle_writes; /* writes seen within this tl epoch */
unsigned long last_reconnect_jif;
struct drbd_thread receiver;
struct drbd_thread worker;
struct drbd_thread asender;
cpumask_var_t cpu_mask;
/* sender side */
struct drbd_work_queue sender_work;
struct {
/* whether this sender thread
* has processed a single write yet. */
bool seen_any_write_yet;
/* Which barrier number to send with the next P_BARRIER */
int current_epoch_nr;
/* how many write requests have been sent
* with req->epoch == current_epoch_nr.
* If none, no P_BARRIER will be sent. */
unsigned current_epoch_writes;
} send;
struct submit_worker {
struct workqueue_struct *wq;
struct work_struct worker;
spinlock_t lock;
struct list_head writes;
struct drbd_conf {
struct drbd_tconn *tconn;
int vnr; /* volume number within the connection */
struct kref kref;
/* things that are stored as / read from meta data on disk */
unsigned long flags;
/* configured by drbdsetup */
struct drbd_backing_dev *ldev __protected_by(local);
sector_t p_size; /* partner's disk size */
struct request_queue *rq_queue;
struct block_device *this_bdev;
struct gendisk *vdisk;
unsigned long last_reattach_jif;
struct drbd_work resync_work,
struct timer_list resync_timer;
struct timer_list md_sync_timer;
struct timer_list start_resync_timer;
struct timer_list request_timer;
struct {
unsigned int line;
const char* func;
} last_md_mark_dirty;
/* Used after attach while negotiating new disk state. */
union drbd_state new_state_tmp;
union drbd_dev_state state;
wait_queue_head_t misc_wait;
wait_queue_head_t state_wait; /* upon each state change. */
unsigned int send_cnt;
unsigned int recv_cnt;
unsigned int read_cnt;
unsigned int writ_cnt;
unsigned int al_writ_cnt;
unsigned int bm_writ_cnt;
atomic_t ap_bio_cnt; /* Requests we need to complete */
atomic_t ap_pending_cnt; /* AP data packets on the wire, ack expected */
atomic_t rs_pending_cnt; /* RS request/data packets on the wire */
atomic_t unacked_cnt; /* Need to send replies for */
atomic_t local_cnt; /* Waiting for local completion */
/* Interval tree of pending local requests */
struct rb_root read_requests;
struct rb_root write_requests;
/* blocks to resync in this run [unit BM_BLOCK_SIZE] */
unsigned long rs_total;
/* number of resync blocks that failed in this run */
unsigned long rs_failed;
/* Syncer's start time [unit jiffies] */
unsigned long rs_start;
/* cumulated time in PausedSyncX state [unit jiffies] */
unsigned long rs_paused;
/* skipped because csum was equal [unit BM_BLOCK_SIZE] */
unsigned long rs_same_csum;
/* block not up-to-date at mark [unit BM_BLOCK_SIZE] */
unsigned long rs_mark_left[DRBD_SYNC_MARKS];
/* marks's time [unit jiffies] */
unsigned long rs_mark_time[DRBD_SYNC_MARKS];
/* current index into rs_mark_{left,time} */
int rs_last_mark;
unsigned long rs_last_bcast; /* [unit jiffies] */
/* where does the admin want us to start? (sector) */
sector_t ov_start_sector;
sector_t ov_stop_sector;
/* where are we now? (sector) */
sector_t ov_position;
/* Start sector of out of sync range (to merge printk reporting). */
sector_t ov_last_oos_start;
/* size of out-of-sync range in sectors. */
sector_t ov_last_oos_size;
unsigned long ov_left; /* in bits */
struct drbd_bitmap *bitmap;
unsigned long bm_resync_fo; /* bit offset for drbd_bm_find_next */
/* Used to track operations of resync... */
struct lru_cache *resync;
/* Number of locked elements in resync LRU */
unsigned int resync_locked;
/* resync extent number waiting for application requests */
unsigned int resync_wenr;
int open_cnt;
u64 *p_uuid;
struct list_head active_ee; /* IO in progress (P_DATA gets written to disk) */
struct list_head sync_ee; /* IO in progress (P_RS_DATA_REPLY gets written to disk) */
struct list_head done_ee; /* need to send P_WRITE_ACK */
struct list_head read_ee; /* [RS]P_DATA_REQUEST being read */
struct list_head net_ee; /* zero-copy network send in progress */
int next_barrier_nr;
struct list_head resync_reads;
atomic_t pp_in_use; /* allocated from page pool */
atomic_t pp_in_use_by_net; /* sendpage()d, still referenced by tcp */
wait_queue_head_t ee_wait;
struct page *md_io_page; /* one page buffer for md_io */
struct drbd_md_io md_io;
atomic_t md_io_in_use; /* protects the md_io, md_io_page and md_io_tmpp */
spinlock_t al_lock;
wait_queue_head_t al_wait;
struct lru_cache *act_log; /* activity log */
unsigned int al_tr_number;
int al_tr_cycle;
wait_queue_head_t seq_wait;
atomic_t packet_seq;
unsigned int peer_seq;
spinlock_t peer_seq_lock;
unsigned int minor;
unsigned long comm_bm_set; /* communicated number of set bits. */
struct bm_io_work bm_io_work;
u64 ed_uuid; /* UUID of the exposed data */
struct mutex own_state_mutex;
struct mutex *state_mutex; /* either own_state_mutex or mdev->tconn->cstate_mutex */
char congestion_reason; /* Why we where congested... */
atomic_t rs_sect_in; /* for incoming resync data rate, SyncTarget */
atomic_t rs_sect_ev; /* for submitted resync data rate, both */
int rs_last_sect_ev; /* counter to compare with */
int rs_last_events; /* counter of read or write "events" (unit sectors)
* on the lower level device when we last looked. */
int c_sync_rate; /* current resync rate after syncer throttle magic */
struct fifo_buffer *rs_plan_s; /* correction values of resync planer (RCU, tconn->conn_update) */
int rs_in_flight; /* resync sectors in flight (to proxy, in proxy and from proxy) */
atomic_t ap_in_flight; /* App sectors in flight (waiting for ack) */
unsigned int peer_max_bio_size;
unsigned int local_max_bio_size;
/* any requests that would block in drbd_make_request()
* are deferred to this single-threaded work queue */
struct submit_worker submit;
static inline struct drbd_conf *minor_to_mdev(unsigned int minor)
return (struct drbd_conf *)idr_find(&minors, minor);
static inline unsigned int mdev_to_minor(struct drbd_conf *mdev)
return mdev->minor;
static inline struct drbd_conf *vnr_to_mdev(struct drbd_tconn *tconn, int vnr)
return (struct drbd_conf *)idr_find(&tconn->volumes, vnr);
* function declarations
/* drbd_main.c */
enum dds_flags {
DDSF_NO_RESYNC = 2, /* Do not run a resync for the new space */
extern void drbd_init_set_defaults(struct drbd_conf *mdev);
extern int drbd_thread_start(struct drbd_thread *thi);
extern void _drbd_thread_stop(struct drbd_thread *thi, int restart, int wait);
extern char *drbd_task_to_thread_name(struct drbd_tconn *tconn, struct task_struct *task);
extern void drbd_thread_current_set_cpu(struct drbd_thread *thi);
extern void drbd_calc_cpu_mask(struct drbd_tconn *tconn);
#define drbd_thread_current_set_cpu(A) ({})
#define drbd_calc_cpu_mask(A) ({})
extern void tl_release(struct drbd_tconn *, unsigned int barrier_nr,
unsigned int set_size);
extern void tl_clear(struct drbd_tconn *);
extern void drbd_free_sock(struct drbd_tconn *tconn);
extern int drbd_send(struct drbd_tconn *tconn, struct socket *sock,
void *buf, size_t size, unsigned msg_flags);
extern int drbd_send_all(struct drbd_tconn *, struct socket *, void *, size_t,
extern int __drbd_send_protocol(struct drbd_tconn *tconn, enum drbd_packet cmd);
extern int drbd_send_protocol(struct drbd_tconn *tconn);
extern int drbd_send_uuids(struct drbd_conf *mdev);
extern int drbd_send_uuids_skip_initial_sync(struct drbd_conf *mdev);
extern void drbd_gen_and_send_sync_uuid(struct drbd_conf *mdev);
extern int drbd_send_sizes(struct drbd_conf *mdev, int trigger_reply, enum dds_flags flags);
extern int drbd_send_state(struct drbd_conf *mdev, union drbd_state s);
extern int drbd_send_current_state(struct drbd_conf *mdev);
extern int drbd_send_sync_param(struct drbd_conf *mdev);
extern void drbd_send_b_ack(struct drbd_tconn *tconn, u32 barrier_nr,
u32 set_size);
extern int drbd_send_ack(struct drbd_conf *, enum drbd_packet,
struct drbd_peer_request *);
extern void drbd_send_ack_rp(struct drbd_conf *mdev, enum drbd_packet cmd,
struct p_block_req *rp);
extern void drbd_send_ack_dp(struct drbd_conf *mdev, enum drbd_packet cmd,
struct p_data *dp, int data_size);
extern int drbd_send_ack_ex(struct drbd_conf *mdev, enum drbd_packet cmd,
sector_t sector, int blksize, u64 block_id);
extern int drbd_send_out_of_sync(struct drbd_conf *, struct drbd_request *);
extern int drbd_send_block(struct drbd_conf *, enum drbd_packet,
struct drbd_peer_request *);
extern int drbd_send_dblock(struct drbd_conf *mdev, struct drbd_request *req);
extern int drbd_send_drequest(struct drbd_conf *mdev, int cmd,
sector_t sector, int size, u64 block_id);
extern int drbd_send_drequest_csum(struct drbd_conf *mdev, sector_t sector,
int size, void *digest, int digest_size,
enum drbd_packet cmd);
extern int drbd_send_ov_request(struct drbd_conf *mdev,sector_t sector,int size);
extern int drbd_send_bitmap(struct drbd_conf *mdev);
extern void drbd_send_sr_reply(struct drbd_conf *mdev, enum drbd_state_rv retcode);
extern void conn_send_sr_reply(struct drbd_tconn *tconn, enum drbd_state_rv retcode);
extern void drbd_free_bc(struct drbd_backing_dev *ldev);
extern void drbd_mdev_cleanup(struct drbd_conf *mdev);
void drbd_print_uuids(struct drbd_conf *mdev, const char *text);
extern void conn_md_sync(struct drbd_tconn *tconn);
extern void drbd_md_sync(struct drbd_conf *mdev);
extern int drbd_md_read(struct drbd_conf *mdev, struct drbd_backing_dev *bdev);
extern void drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local);
extern void _drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local);
extern void drbd_uuid_new_current(struct drbd_conf *mdev) __must_hold(local);
extern void drbd_uuid_set_bm(struct drbd_conf *mdev, u64 val) __must_hold(local);
extern void drbd_uuid_move_history(struct drbd_conf *mdev) __must_hold(local);
extern void __drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local);
extern void drbd_md_set_flag(struct drbd_conf *mdev, int flags) __must_hold(local);
extern void drbd_md_clear_flag(struct drbd_conf *mdev, int flags)__must_hold(local);
extern int drbd_md_test_flag(struct drbd_backing_dev *, int);
extern void drbd_md_mark_dirty(struct drbd_conf *mdev);
#define drbd_md_mark_dirty(m) drbd_md_mark_dirty_(m, __LINE__ , __func__ )
extern void drbd_md_mark_dirty_(struct drbd_conf *mdev,
unsigned int line, const char *func);
extern void drbd_queue_bitmap_io(struct drbd_conf *mdev,
int (*io_fn)(struct drbd_conf *),
void (*done)(struct drbd_conf *, int),
char *why, enum bm_flag flags);
extern int drbd_bitmap_io(struct drbd_conf *mdev,
int (*io_fn)(struct drbd_conf *),
char *why, enum bm_flag flags);
extern int drbd_bitmap_io_from_worker(struct drbd_conf *mdev,
int (*io_fn)(struct drbd_conf *),
char *why, enum bm_flag flags);
extern int drbd_bmio_set_n_write(struct drbd_conf *mdev);
extern int drbd_bmio_clear_n_write(struct drbd_conf *mdev);
extern void drbd_ldev_destroy(struct drbd_conf *mdev);
/* Meta data layout
* We currently have two possible layouts.
* Offsets in (512 byte) sectors.
* external:
* |----------- md_size_sect ------------------|
* [ 4k superblock ][ activity log ][ Bitmap ]
* | al_offset == 8 |
* | bm_offset = al_offset + X |
* ==> bitmap sectors = md_size_sect - bm_offset
* Variants:
* old, indexed fixed size meta data:
* internal:
* |----------- md_size_sect ------------------|
* [data.....][ Bitmap ][ activity log ][ 4k superblock ][padding*]
* | al_offset < 0 |
* | bm_offset = al_offset - Y |
* ==> bitmap sectors = Y = al_offset - bm_offset
* [padding*] are zero or up to 7 unused 512 Byte sectors to the
* end of the device, so that the [4k superblock] will be 4k aligned.
* The activity log consists of 4k transaction blocks,
* which are written in a ring-buffer, or striped ring-buffer like fashion,
* which are writtensize used to be fixed 32kB,
* but is about to become configurable.
/* Our old fixed size meta data layout
* allows up to about 3.8TB, so if you want more,
* you need to use the "flexible" meta data format. */
#define MD_128MB_SECT (128LLU << 11) /* 128 MB, unit sectors */
#define MD_4kB_SECT 8
#define MD_32kB_SECT 64
/* One activity log extent represents 4M of storage */
#define AL_EXTENT_SHIFT 22
/* We could make these currently hardcoded constants configurable
* variables at create-md time (or even re-configurable at runtime?).
* Which will require some more changes to the DRBD "super block"
* and attach code.
* updates per transaction:
* This many changes to the active set can be logged with one transaction.
* This number is arbitrary.
* context per transaction:
* This many context extent numbers are logged with each transaction.
* This number is resulting from the transaction block size (4k), the layout
* of the transaction header, and the number of updates per transaction.
* See drbd_actlog.c:struct al_transaction_on_disk
* */
#define AL_UPDATES_PER_TRANSACTION 64 // arbitrary
#define AL_CONTEXT_PER_TRANSACTION 919 // (4096 - 36 - 6*64)/4
#if BITS_PER_LONG == 32
#define LN2_BPL 5
#define cpu_to_lel(A) cpu_to_le32(A)
#define lel_to_cpu(A) le32_to_cpu(A)
#elif BITS_PER_LONG == 64
#define LN2_BPL 6
#define cpu_to_lel(A) cpu_to_le64(A)
#define lel_to_cpu(A) le64_to_cpu(A)
#error "LN2 of BITS_PER_LONG unknown!"
/* resync bitmap */
/* 16MB sized 'bitmap extent' to track syncer usage */
struct bm_extent {
int rs_left; /* number of bits set (out of sync) in this extent. */
int rs_failed; /* number of failed resync requests in this extent. */
unsigned long flags;
struct lc_element lce;
#define BME_NO_WRITES 0 /* bm_extent.flags: no more requests on this one! */
#define BME_LOCKED 1 /* bm_extent.flags: syncer active on this one. */
#define BME_PRIORITY 2 /* finish resync IO on this extent ASAP! App IO waiting! */
/* drbd_bitmap.c */
* We need to store one bit for a block.
* Example: 1GB disk @ 4096 byte blocks ==> we need 32 KB bitmap.
* Bit 0 ==> local node thinks this block is binary identical on both nodes
* Bit 1 ==> local node thinks this block needs to be synced.
#define SLEEP_TIME (HZ/10)
/* We do bitmap IO in units of 4k blocks.
* We also still have a hardcoded 4k per bit relation. */
#define BM_BLOCK_SHIFT 12 /* 4k per bit */
/* mostly arbitrarily set the represented size of one bitmap extent,
* aka resync extent, to 16 MiB (which is also 512 Byte worth of bitmap
* at 4k per bit resolution) */
#define BM_EXT_SHIFT 24 /* 16 MiB per resync extent */
#if (BM_EXT_SHIFT != 24) || (BM_BLOCK_SHIFT != 12)
#error "HAVE YOU FIXED drbdmeta AS WELL??"
/* thus many _storage_ sectors are described by one bit */
#define BM_SECT_TO_BIT(x) ((x)>>(BM_BLOCK_SHIFT-9))
#define BM_BIT_TO_SECT(x) ((sector_t)(x)<<(BM_BLOCK_SHIFT-9))
/* bit to represented kilo byte conversion */
#define Bit2KB(bits) ((bits)<<(BM_BLOCK_SHIFT-10))
/* in which _bitmap_ extent (resp. sector) the bit for a certain
* _storage_ sector is located in */
#define BM_SECT_TO_EXT(x) ((x)>>(BM_EXT_SHIFT-9))
/* how much _storage_ sectors we have per bitmap sector */
#define BM_EXT_TO_SECT(x) ((sector_t)(x) << (BM_EXT_SHIFT-9))
/* in one sector of the bitmap, we have this many activity_log extents. */
/* the extent in "PER_EXTENT" below is an activity log extent
* we need that many (long words/bytes) to store the bitmap
* of one AL_EXTENT_SIZE chunk of storage.
* we can store the bitmap for that many AL_EXTENTS within
* one sector of the _on_disk_ bitmap:
* bit 0 bit 37 bit 38 bit (512*8)-1
* ...|........|........|.. // ..|........|
* sect. 0 `296 `304 ^(512*8*8)-1
#define BM_BYTES_PER_EXT ( (AL_EXT_SIZE/BM_BLOCK_SIZE) / 8 ) // 128
#define BM_EXT_PER_SECT ( 512 / BM_BYTES_PER_EXTENT ) // 4
#define DRBD_MAX_SECTORS_32 (0xffffffffLU)
/* we have a certain meta data variant that has a fixed on-disk size of 128
* MiB, of which 4k are our "superblock", and 32k are the fixed size activity
* log, leaving this many sectors for the bitmap.
((MD_128MB_SECT - MD_32kB_SECT - MD_4kB_SECT) * (1LL<<(BM_EXT_SHIFT-9)))
#if !defined(CONFIG_LBDAF) && BITS_PER_LONG == 32
/* 16 TB in units of sectors */
#if BITS_PER_LONG == 32
/* adjust by one page worth of bitmap,
* so we won't wrap around in drbd_bm_find_next_bit.
* you should use 64bit OS for that much storage, anyways. */
/* we allow up to 1 PiB now on 64bit architecture with "flexible" meta data */
#define DRBD_MAX_SECTORS_FLEX (1UL << 51)
/* corresponds to (1UL << 38) bits right now. */
* so for typical PAGE_CACHE_SIZE of 4k, that is (1<<20) Byte.
* Since we may live in a mixed-platform cluster,
* we limit us to a platform agnostic constant here for now.
* A followup commit may allow even bigger BIO sizes,
* once we thought that through. */
#define DRBD_MAX_BIO_SIZE (1U << 20)
#error Architecture not supported: DRBD_MAX_BIO_SIZE > BIO_MAX_SIZE
#define DRBD_MAX_BIO_SIZE_SAFE (1U << 12) /* Works always = 4k */
#define DRBD_MAX_SIZE_H80_PACKET (1U << 15) /* Header 80 only allows packets up to 32KiB data */
#define DRBD_MAX_BIO_SIZE_P95 (1U << 17) /* Protocol 95 to 99 allows bios up to 128KiB */
extern int drbd_bm_init(struct drbd_conf *mdev);
extern int drbd_bm_resize(struct drbd_conf *mdev, sector_t sectors, int set_new_bits);
extern void drbd_bm_cleanup(struct drbd_conf *mdev);
extern void drbd_bm_set_all(struct drbd_conf *mdev);
extern void drbd_bm_clear_all(struct drbd_conf *mdev);
/* set/clear/test only a few bits at a time */
extern int drbd_bm_set_bits(
struct drbd_conf *mdev, unsigned long s, unsigned long e);
extern int drbd_bm_clear_bits(
struct drbd_conf *mdev, unsigned long s, unsigned long e);
extern int drbd_bm_count_bits(
struct drbd_conf *mdev, const unsigned long s, const unsigned long e);
/* bm_set_bits variant for use while holding drbd_bm_lock,
* may process the whole bitmap in one go */
extern void _drbd_bm_set_bits(struct drbd_conf *mdev,
const unsigned long s, const unsigned long e);
extern int drbd_bm_test_bit(struct drbd_conf *mdev, unsigned long bitnr);
extern int drbd_bm_e_weight(struct drbd_conf *mdev, unsigned long enr);
extern int drbd_bm_write_page(struct drbd_conf *mdev, unsigned int idx) __must_hold(local);
extern int drbd_bm_read(struct drbd_conf *mdev) __must_hold(local);
extern void drbd_bm_mark_for_writeout(struct drbd_conf *mdev, int page_nr);
extern int drbd_bm_write(struct drbd_conf *mdev) __must_hold(local);
extern int drbd_bm_write_hinted(struct drbd_conf *mdev) __must_hold(local);
extern int drbd_bm_write_all(struct drbd_conf *mdev) __must_hold(local);
extern int drbd_bm_write_copy_pages(struct drbd_conf *mdev) __must_hold(local);
extern size_t drbd_bm_words(struct drbd_conf *mdev);
extern unsigned long drbd_bm_bits(struct drbd_conf *mdev);
extern sector_t drbd_bm_capacity(struct drbd_conf *mdev);
#define DRBD_END_OF_BITMAP (~(unsigned long)0)
extern unsigned long drbd_bm_find_next(struct drbd_conf *mdev, unsigned long bm_fo);
/* bm_find_next variants for use while you hold drbd_bm_lock() */
extern unsigned long _drbd_bm_find_next(struct drbd_conf *mdev, unsigned long bm_fo);
extern unsigned long _drbd_bm_find_next_zero(struct drbd_conf *mdev, unsigned long bm_fo);
extern unsigned long _drbd_bm_total_weight(struct drbd_conf *mdev);
extern unsigned long drbd_bm_total_weight(struct drbd_conf *mdev);
extern int drbd_bm_rs_done(struct drbd_conf *mdev);
/* for receive_bitmap */
extern void drbd_bm_merge_lel(struct drbd_conf *mdev, size_t offset,
size_t number, unsigned long *buffer);
/* for _drbd_send_bitmap */
extern void drbd_bm_get_lel(struct drbd_conf *mdev, size_t offset,
size_t number, unsigned long *buffer);
extern void drbd_bm_lock(struct drbd_conf *mdev, char *why, enum bm_flag flags);
extern void drbd_bm_unlock(struct drbd_conf *mdev);
/* drbd_main.c */
extern struct kmem_cache *drbd_request_cache;
extern struct kmem_cache *drbd_ee_cache; /* peer requests */
extern struct kmem_cache *drbd_bm_ext_cache; /* bitmap extents */
extern struct kmem_cache *drbd_al_ext_cache; /* activity log extents */
extern mempool_t *drbd_request_mempool;
extern mempool_t *drbd_ee_mempool;
/* drbd's page pool, used to buffer data received from the peer,
* or data requested by the peer.
* This does not have an emergency reserve.
* When allocating from this pool, it first takes pages from the pool.
* Only if the pool is depleted will try to allocate from the system.
* The assumption is that pages taken from this pool will be processed,
* and given back, "quickly", and then can be recycled, so we can avoid
* frequent calls to alloc_page(), and still will be able to make progress even
* under memory pressure.
extern struct page *drbd_pp_pool;
extern spinlock_t drbd_pp_lock;
extern int drbd_pp_vacant;
extern wait_queue_head_t drbd_pp_wait;
/* We also need a standard (emergency-reserve backed) page pool
* for meta data IO (activity log, bitmap).
* We can keep it global, as long as it is used as "N pages at a time".
* 128 should be plenty, currently we probably can get away with as few as 1.
extern mempool_t *drbd_md_io_page_pool;
/* We also need to make sure we get a bio
* when we need it for housekeeping purposes */
extern struct bio_set *drbd_md_io_bio_set;
/* to allocate from that set */
extern struct bio *bio_alloc_drbd(gfp_t gfp_mask);
extern rwlock_t global_state_lock;
extern int conn_lowest_minor(struct drbd_tconn *tconn);
enum drbd_ret_code conn_new_minor(struct drbd_tconn *tconn, unsigned int minor, int vnr);
extern void drbd_minor_destroy(struct kref *kref);
extern int set_resource_options(struct drbd_tconn *tconn, struct res_opts *res_opts);
extern struct drbd_tconn *conn_create(const char *name, struct res_opts *res_opts);
extern void conn_destroy(struct kref *kref);
struct drbd_tconn *conn_get_by_name(const char *name);
extern struct drbd_tconn *conn_get_by_addrs(void *my_addr, int my_addr_len,
void *peer_addr, int peer_addr_len);
extern void conn_free_crypto(struct drbd_tconn *tconn);
extern int proc_details;
/* drbd_req */
extern void do_submit(struct work_struct *ws);
extern void __drbd_make_request(struct drbd_conf *, struct bio *, unsigned long);
extern void drbd_make_request(struct request_queue *q, struct bio *bio);
extern int drbd_read_remote(struct drbd_conf *mdev, struct drbd_request *req);
extern int drbd_merge_bvec(struct request_queue *q, struct bvec_merge_data *bvm, struct bio_vec *bvec);
extern int is_valid_ar_handle(struct drbd_request *, sector_t);
/* drbd_nl.c */
extern int drbd_msg_put_info(const char *info);
extern void drbd_suspend_io(struct drbd_conf *mdev);
extern void drbd_resume_io(struct drbd_conf *mdev);
extern char *ppsize(char *buf, unsigned long long size);
extern sector_t drbd_new_dev_size(struct drbd_conf *, struct drbd_backing_dev *, sector_t, int);
enum determine_dev_size { dev_size_error = -1, unchanged = 0, shrunk = 1, grew = 2 };
extern enum determine_dev_size drbd_determine_dev_size(struct drbd_conf *, enum dds_flags) __must_hold(local);
extern void resync_after_online_grow(struct drbd_conf *);
extern void drbd_reconsider_max_bio_size(struct drbd_conf *mdev);
extern enum drbd_state_rv drbd_set_role(struct drbd_conf *mdev,
enum drbd_role new_role,
int force);
extern bool conn_try_outdate_peer(struct drbd_tconn *tconn);
extern void conn_try_outdate_peer_async(struct drbd_tconn *tconn);
extern int drbd_khelper(struct drbd_conf *mdev, char *cmd);
/* drbd_worker.c */
extern int drbd_worker(struct drbd_thread *thi);
enum drbd_ret_code drbd_resync_after_valid(struct drbd_conf *mdev, int o_minor);
void drbd_resync_after_changed(struct drbd_conf *mdev);
extern void drbd_start_resync(struct drbd_conf *mdev, enum drbd_conns side);
extern void resume_next_sg(struct drbd_conf *mdev);
extern void suspend_other_sg(struct drbd_conf *mdev);
extern int drbd_resync_finished(struct drbd_conf *mdev);
/* maybe rather drbd_main.c ? */
extern void *drbd_md_get_buffer(struct drbd_conf *mdev);
extern void drbd_md_put_buffer(struct drbd_conf *mdev);
extern int drbd_md_sync_page_io(struct drbd_conf *mdev,
struct drbd_backing_dev *bdev, sector_t sector, int rw);
extern void drbd_ov_out_of_sync_found(struct drbd_conf *, sector_t, int);
extern void wait_until_done_or_force_detached(struct drbd_conf *mdev,
struct drbd_backing_dev *bdev, unsigned int *done);
extern void drbd_rs_controller_reset(struct drbd_conf *mdev);
static inline void ov_out_of_sync_print(struct drbd_conf *mdev)
if (mdev->ov_last_oos_size) {
dev_err(DEV, "Out of sync: start=%llu, size=%lu (sectors)\n",
(unsigned long long)mdev->ov_last_oos_start,
(unsigned long)mdev->ov_last_oos_size);
extern void drbd_csum_bio(struct drbd_conf *, struct crypto_hash *, struct bio *, void *);
extern void drbd_csum_ee(struct drbd_conf *, struct crypto_hash *,
struct drbd_peer_request *, void *);
/* worker callbacks */
extern int w_e_end_data_req(struct drbd_work *, int);
extern int w_e_end_rsdata_req(struct drbd_work *, int);
extern int w_e_end_csum_rs_req(struct drbd_work *, int);
extern int w_e_end_ov_reply(struct drbd_work *, int);
extern int w_e_end_ov_req(struct drbd_work *, int);
extern int w_ov_finished(struct drbd_work *, int);
extern int w_resync_timer(struct drbd_work *, int);
extern int w_send_write_hint(struct drbd_work *, int);
extern int w_make_resync_request(struct drbd_work *, int);
extern int w_send_dblock(struct drbd_work *, int);
extern int w_send_read_req(struct drbd_work *, int);
extern int w_prev_work_done(struct drbd_work *, int);
extern int w_e_reissue(struct drbd_work *, int);
extern int w_restart_disk_io(struct drbd_work *, int);
extern int w_send_out_of_sync(struct drbd_work *, int);
extern int w_start_resync(struct drbd_work *, int);
extern void resync_timer_fn(unsigned long data);
extern void start_resync_timer_fn(unsigned long data);
/* drbd_receiver.c */
extern int drbd_rs_should_slow_down(struct drbd_conf *mdev, sector_t sector);
extern int drbd_submit_peer_request(struct drbd_conf *,
struct drbd_peer_request *, const unsigned,
const int);
extern int drbd_free_peer_reqs(struct drbd_conf *, struct list_head *);
extern struct drbd_peer_request *drbd_alloc_peer_req(struct drbd_conf *, u64,
sector_t, unsigned int,
gfp_t) __must_hold(local);
extern void __drbd_free_peer_req(struct drbd_conf *, struct drbd_peer_request *,
#define drbd_free_peer_req(m,e) __drbd_free_peer_req(m, e, 0)
#define drbd_free_net_peer_req(m,e) __drbd_free_peer_req(m, e, 1)
extern struct page *drbd_alloc_pages(struct drbd_conf *, unsigned int, bool);
extern void drbd_set_recv_tcq(struct drbd_conf *mdev, int tcq_enabled);
extern void _drbd_clear_done_ee(struct drbd_conf *mdev, struct list_head *to_be_freed);
extern void conn_flush_workqueue(struct drbd_tconn *tconn);
extern int drbd_connected(struct drbd_conf *mdev);
static inline void drbd_flush_workqueue(struct drbd_conf *mdev)
/* Yes, there is kernel_setsockopt, but only since 2.6.18.
* So we have our own copy of it here. */
static inline int drbd_setsockopt(struct socket *sock, int level, int optname,
char *optval, int optlen)
mm_segment_t oldfs = get_fs();
char __user *uoptval;
int err;
uoptval = (char __user __force *)optval;
if (level == SOL_SOCKET)
err = sock_setsockopt(sock, level, optname, uoptval, optlen);
err = sock->ops->setsockopt(sock, level, optname, uoptval,
return err;
static inline void drbd_tcp_cork(struct socket *sock)
int val = 1;
(void) drbd_setsockopt(sock, SOL_TCP, TCP_CORK,
(char*)&val, sizeof(val));
static inline void drbd_tcp_uncork(struct socket *sock)
int val = 0;
(void) drbd_setsockopt(sock, SOL_TCP, TCP_CORK,
(char*)&val, sizeof(val));
static inline void drbd_tcp_nodelay(struct socket *sock)
int val = 1;
(void) drbd_setsockopt(sock, SOL_TCP, TCP_NODELAY,
(char*)&val, sizeof(val));
static inline void drbd_tcp_quickack(struct socket *sock)
int val = 2;
(void) drbd_setsockopt(sock, SOL_TCP, TCP_QUICKACK,
(char*)&val, sizeof(val));
void drbd_bump_write_ordering(struct drbd_tconn *tconn, enum write_ordering_e wo);
/* drbd_proc.c */
extern struct proc_dir_entry *drbd_proc;
extern const struct file_operations drbd_proc_fops;
extern const char *drbd_conn_str(enum drbd_conns s);
extern const char *drbd_role_str(enum drbd_role s);
/* drbd_actlog.c */
extern int drbd_al_begin_io_nonblock(struct drbd_conf *mdev, struct drbd_interval *i);
extern void drbd_al_begin_io_commit(struct drbd_conf *mdev, bool delegate);
extern bool drbd_al_begin_io_fastpath(struct drbd_conf *mdev, struct drbd_interval *i);
extern void drbd_al_begin_io(struct drbd_conf *mdev, struct drbd_interval *i, bool delegate);
extern void drbd_al_complete_io(struct drbd_conf *mdev, struct drbd_interval *i);
extern void drbd_rs_complete_io(struct drbd_conf *mdev, sector_t sector);
extern int drbd_rs_begin_io(struct drbd_conf *mdev, sector_t sector);
extern int drbd_try_rs_begin_io(struct drbd_conf *mdev, sector_t sector);
extern void drbd_rs_cancel_all(struct drbd_conf *mdev);
extern int drbd_rs_del_all(struct drbd_conf *mdev);
extern void drbd_rs_failed_io(struct drbd_conf *mdev,
sector_t sector, int size);
extern void drbd_advance_rs_marks(struct drbd_conf *mdev, unsigned long still_to_go);
extern void __drbd_set_in_sync(struct drbd_conf *mdev, sector_t sector,
int size, const char *file, const unsigned int line);
#define drbd_set_in_sync(mdev, sector, size) \
__drbd_set_in_sync(mdev, sector, size, __FILE__, __LINE__)
extern int __drbd_set_out_of_sync(struct drbd_conf *mdev, sector_t sector,
int size, const char *file, const unsigned int line);
#define drbd_set_out_of_sync(mdev, sector, size) \
__drbd_set_out_of_sync(mdev, sector, size, __FILE__, __LINE__)
extern void drbd_al_shrink(struct drbd_conf *mdev);
/* drbd_nl.c */
/* state info broadcast */
struct sib_info {
enum drbd_state_info_bcast_reason sib_reason;
union {
struct {
char *helper_name;
unsigned helper_exit_code;
struct {
union drbd_state os;
union drbd_state ns;
void drbd_bcast_event(struct drbd_conf *mdev, const struct sib_info *sib);
* inline helper functions
/* see also page_chain_add and friends in drbd_receiver.c */
static inline struct page *page_chain_next(struct page *page)
return (struct page *)page_private(page);
#define page_chain_for_each(page) \
for (; page && ({ prefetch(page_chain_next(page)); 1; }); \
page = page_chain_next(page))
#define page_chain_for_each_safe(page, n) \
for (; page && ({ n = page_chain_next(page); 1; }); page = n)
static inline int drbd_peer_req_has_active_page(struct drbd_peer_request *peer_req)
struct page *page = peer_req->pages;
page_chain_for_each(page) {
if (page_count(page) > 1)
return 1;
return 0;
static inline enum drbd_state_rv
_drbd_set_state(struct drbd_conf *mdev, union drbd_state ns,
enum chg_state_flags flags, struct completion *done)
enum drbd_state_rv rv;
rv = __drbd_set_state(mdev, ns, flags, done);
return rv;
static inline union drbd_state drbd_read_state(struct drbd_conf *mdev)
union drbd_state rv;
rv.i = mdev->state.i;
rv.susp = mdev->tconn->susp;
rv.susp_nod = mdev->tconn->susp_nod;
rv.susp_fen = mdev->tconn->susp_fen;
return rv;
enum drbd_force_detach_flags {
#define __drbd_chk_io_error(m,f) __drbd_chk_io_error_(m,f, __func__)
static inline void __drbd_chk_io_error_(struct drbd_conf *mdev,
enum drbd_force_detach_flags df,
const char *where)
enum drbd_io_error_p ep;
ep = rcu_dereference(mdev->ldev->disk_conf)->on_io_error;
switch (ep) {
case EP_PASS_ON: /* FIXME would this be better named "Ignore"? */
if (df == DRBD_READ_ERROR || df == DRBD_WRITE_ERROR) {
if (__ratelimit(&drbd_ratelimit_state))
dev_err(DEV, "Local IO failed in %s.\n", where);
if (mdev->state.disk > D_INCONSISTENT)
_drbd_set_state(_NS(mdev, disk, D_INCONSISTENT), CS_HARD, NULL);
/* Remember whether we saw a READ or WRITE error.
* Recovery of the affected area for WRITE failure is covered
* by the activity log.
* READ errors may fall outside that area though. Certain READ
* errors can be "healed" by writing good data to the affected
* blocks, which triggers block re-allocation in lower layers.
* If we can not write the bitmap after a READ error,
* we may need to trigger a full sync (see w_go_diskless()).
* Force-detach is not really an IO error, but rather a
* desperate measure to try to deal with a completely
* unresponsive lower level IO stack.
* Still it should be treated as a WRITE error.
* Meta IO error is always WRITE error:
* we read meta data only once during attach,
* which will fail in case of errors.
set_bit(WAS_IO_ERROR, &mdev->flags);
if (df == DRBD_READ_ERROR)
set_bit(WAS_READ_ERROR, &mdev->flags);
set_bit(FORCE_DETACH, &mdev->flags);
if (mdev->state.disk > D_FAILED) {
_drbd_set_state(_NS(mdev, disk, D_FAILED), CS_HARD, NULL);
"Local IO failed in %s. Detaching...\n", where);
* drbd_chk_io_error: Handle the on_io_error setting, should be called from all io completion handlers
* @mdev: DRBD device.
* @error: Error code passed to the IO completion callback
* @forcedetach: Force detach. I.e. the error happened while accessing the meta data
* See also drbd_main.c:after_state_ch() if (os.disk > D_FAILED && ns.disk == D_FAILED)
#define drbd_chk_io_error(m,e,f) drbd_chk_io_error_(m,e,f, __func__)
static inline void drbd_chk_io_error_(struct drbd_conf *mdev,
int error, enum drbd_force_detach_flags forcedetach, const char *where)
if (error) {
unsigned long flags;
spin_lock_irqsave(&mdev->tconn->req_lock, flags);
__drbd_chk_io_error_(mdev, forcedetach, where);
spin_unlock_irqrestore(&mdev->tconn->req_lock, flags);
* drbd_md_first_sector() - Returns the first sector number of the meta data area
* @bdev: Meta data block device.
* BTW, for internal meta data, this happens to be the maximum capacity
* we could agree upon with our peer node.
static inline sector_t drbd_md_first_sector(struct drbd_backing_dev *bdev)
switch (bdev->md.meta_dev_idx) {
return bdev->md.md_offset + bdev->md.bm_offset;
return bdev->md.md_offset;
* drbd_md_last_sector() - Return the last sector number of the meta data area
* @bdev: Meta data block device.
static inline sector_t drbd_md_last_sector(struct drbd_backing_dev *bdev)
switch (bdev->md.meta_dev_idx) {
return bdev->md.md_offset + MD_4kB_SECT -1;
return bdev->md.md_offset + bdev->md.md_size_sect -1;
/* Returns the number of 512 byte sectors of the device */
static inline sector_t drbd_get_capacity(struct block_device *bdev)
/* return bdev ? get_capacity(bdev->bd_disk) : 0; */
return bdev ? i_size_read(bdev->bd_inode) >> 9 : 0;
* drbd_get_max_capacity() - Returns the capacity we announce to out peer
* @bdev: Meta data block device.
* returns the capacity we announce to out peer. we clip ourselves at the
* various MAX_SECTORS, because if we don't, current implementation will
* oops sooner or later
static inline sector_t drbd_get_max_capacity(struct drbd_backing_dev *bdev)
sector_t s;
switch (bdev->md.meta_dev_idx) {
s = drbd_get_capacity(bdev->backing_bdev)
? min_t(sector_t, DRBD_MAX_SECTORS_FLEX,
: 0;
s = min_t(sector_t, DRBD_MAX_SECTORS_FLEX,
/* clip at maximum size the meta device can support */
s = min_t(sector_t, s,
- bdev->md.bm_offset));
s = min_t(sector_t, DRBD_MAX_SECTORS,
return s;
* drbd_md_ss() - Return the sector number of our meta data super block
* @bdev: Meta data block device.
static inline sector_t drbd_md_ss(struct drbd_backing_dev *bdev)
const int meta_dev_idx = bdev->md.meta_dev_idx;
if (meta_dev_idx == DRBD_MD_INDEX_FLEX_EXT)
return 0;
/* Since drbd08, internal meta data is always "flexible".
* position: last 4k aligned block of 4k size */
if (meta_dev_idx == DRBD_MD_INDEX_INTERNAL ||
meta_dev_idx == DRBD_MD_INDEX_FLEX_INT)
return (drbd_get_capacity(bdev->backing_bdev) & ~7ULL) - 8;
/* external, some index; this is the old fixed size layout */
return MD_128MB_SECT * bdev->md.meta_dev_idx;
static inline void
drbd_queue_work_front(struct drbd_work_queue *q, struct drbd_work *w)
unsigned long flags;
spin_lock_irqsave(&q->q_lock, flags);
list_add(&w->list, &q->q);
spin_unlock_irqrestore(&q->q_lock, flags);
static inline void
drbd_queue_work(struct drbd_work_queue *q, struct drbd_work *w)
unsigned long flags;
spin_lock_irqsave(&q->q_lock, flags);
list_add_tail(&w->list, &q->q);
spin_unlock_irqrestore(&q->q_lock, flags);
static inline void wake_asender(struct drbd_tconn *tconn)
if (test_bit(SIGNAL_ASENDER, &tconn->flags))
force_sig(DRBD_SIG, tconn->asender.task);
static inline void request_ping(struct drbd_tconn *tconn)
set_bit(SEND_PING, &tconn->flags);
extern void *conn_prepare_command(struct drbd_tconn *, struct drbd_socket *);
extern void *drbd_prepare_command(struct drbd_conf *, struct drbd_socket *);
extern int conn_send_command(struct drbd_tconn *, struct drbd_socket *,
enum drbd_packet, unsigned int, void *,
unsigned int);
extern int drbd_send_command(struct drbd_conf *, struct drbd_socket *,
enum drbd_packet, unsigned int, void *,
unsigned int);
extern int drbd_send_ping(struct drbd_tconn *tconn);
extern int drbd_send_ping_ack(struct drbd_tconn *tconn);
extern int drbd_send_state_req(struct drbd_conf *, union drbd_state, union drbd_state);
extern int conn_send_state_req(struct drbd_tconn *, union drbd_state, union drbd_state);
static inline void drbd_thread_stop(struct drbd_thread *thi)
_drbd_thread_stop(thi, false, true);
static inline void drbd_thread_stop_nowait(struct drbd_thread *thi)
_drbd_thread_stop(thi, false, false);
static inline void drbd_thread_restart_nowait(struct drbd_thread *thi)
_drbd_thread_stop(thi, true, false);
/* counts how many answer packets packets we expect from our peer,
* for either explicit application requests,
* or implicit barrier packets as necessary.
* increased:
* w_send_barrier
* it is much easier and equally valid to count what we queue for the
* worker, even before it actually was queued or send.
* (drbd_make_request_common; recovery path on read io-error)
* decreased:
* got_BarrierAck (respective tl_clear, tl_clear_barrier)
* _req_mod(req, DATA_RECEIVED)
* [from receive_DataReply]
* [from got_BlockAck (P_WRITE_ACK, P_RECV_ACK)]
* for some reason it is NOT decreased in got_NegAck,
* but in the resulting cleanup code from report_params.
* we should try to remember the reason for that...
* _req_mod(req, SEND_FAILED or SEND_CANCELED)
* [from tl_clear_barrier]
static inline void inc_ap_pending(struct drbd_conf *mdev)
#define ERR_IF_CNT_IS_NEGATIVE(which, func, line) \
if (atomic_read(&mdev->which) < 0) \
dev_err(DEV, "in %s:%d: " #which " = %d < 0 !\n", \
func, line, \
#define dec_ap_pending(mdev) _dec_ap_pending(mdev, __FUNCTION__, __LINE__)
static inline void _dec_ap_pending(struct drbd_conf *mdev, const char *func, int line)
if (atomic_dec_and_test(&mdev->ap_pending_cnt))
ERR_IF_CNT_IS_NEGATIVE(ap_pending_cnt, func, line);
/* counts how many resync-related answers we still expect from the peer
* increase decrease
* (or P_NEG_ACK with ID_SYNCER)
static inline void inc_rs_pending(struct drbd_conf *mdev)
#define dec_rs_pending(mdev) _dec_rs_pending(mdev, __FUNCTION__, __LINE__)
static inline void _dec_rs_pending(struct drbd_conf *mdev, const char *func, int line)
ERR_IF_CNT_IS_NEGATIVE(rs_pending_cnt, func, line);
/* counts how many answers we still need to send to the peer.
* increased on
* receive_Data unless protocol A;
* we need to send a P_RECV_ACK (proto B)
* or P_WRITE_ACK (proto C)
* receive_RSDataReply (recv_resync_read) we need to send a P_WRITE_ACK
* receive_DataRequest (receive_RSDataRequest) we need to send back P_DATA
* receive_Barrier_* we need to send a P_BARRIER_ACK
static inline void inc_unacked(struct drbd_conf *mdev)
#define dec_unacked(mdev) _dec_unacked(mdev, __FUNCTION__, __LINE__)
static inline void _dec_unacked(struct drbd_conf *mdev, const char *func, int line)
ERR_IF_CNT_IS_NEGATIVE(unacked_cnt, func, line);
#define sub_unacked(mdev, n) _sub_unacked(mdev, n, __FUNCTION__, __LINE__)
static inline void _sub_unacked(struct drbd_conf *mdev, int n, const char *func, int line)
atomic_sub(n, &mdev->unacked_cnt);
ERR_IF_CNT_IS_NEGATIVE(unacked_cnt, func, line);
* get_ldev() - Increase the ref count on mdev->ldev. Returns 0 if there is no ldev
* @M: DRBD device.
* You have to call put_ldev() when finished working with mdev->ldev.
#define get_ldev(M) __cond_lock(local, _get_ldev_if_state(M,D_INCONSISTENT))
#define get_ldev_if_state(M,MINS) __cond_lock(local, _get_ldev_if_state(M,MINS))
static inline void put_ldev(struct drbd_conf *mdev)
int i = atomic_dec_return(&mdev->local_cnt);
/* This may be called from some endio handler,
* so we must not sleep here. */
D_ASSERT(i >= 0);
if (i == 0) {
if (mdev->state.disk == D_DISKLESS)
/* even internal references gone, safe to destroy */
if (mdev->state.disk == D_FAILED) {
/* all application IO references gone. */
if (!test_and_set_bit(GO_DISKLESS, &mdev->flags))
drbd_queue_work(&mdev->tconn->sender_work, &mdev->go_diskless);
#ifndef __CHECKER__
static inline int _get_ldev_if_state(struct drbd_conf *mdev, enum drbd_disk_state mins)
int io_allowed;
/* never get a reference while D_DISKLESS */
if (mdev->state.disk == D_DISKLESS)
return 0;
io_allowed = (mdev->state.disk >= mins);
if (!io_allowed)
return io_allowed;
extern int _get_ldev_if_state(struct drbd_conf *mdev, enum drbd_disk_state mins);
/* you must have an "get_ldev" reference */
static inline void drbd_get_syncer_progress(struct drbd_conf *mdev,
unsigned long *bits_left, unsigned int *per_mil_done)
/* this is to break it at compile time when we change that, in case we
* want to support more than (1<<32) bits on a 32bit arch. */
typecheck(unsigned long, mdev->rs_total);
/* note: both rs_total and rs_left are in bits, i.e. in
* units of BM_BLOCK_SIZE.
* for the percentage, we don't care. */
if (mdev->state.conn == C_VERIFY_S || mdev->state.conn == C_VERIFY_T)
*bits_left = mdev->ov_left;
*bits_left = drbd_bm_total_weight(mdev) - mdev->rs_failed;
/* >> 10 to prevent overflow,
* +1 to prevent division by zero */
if (*bits_left > mdev->rs_total) {
/* doh. maybe a logic bug somewhere.
* may also be just a race condition
* between this and a disconnect during sync.
* for now, just prevent in-kernel buffer overflow.
dev_warn(DEV, "cs:%s rs_left=%lu > rs_total=%lu (rs_failed %lu)\n",
*bits_left, mdev->rs_total, mdev->rs_failed);
*per_mil_done = 0;
} else {
/* Make sure the division happens in long context.
* We allow up to one petabyte storage right now,
* at a granularity of 4k per bit that is 2**38 bits.
* After shift right and multiplication by 1000,
* this should still fit easily into a 32bit long,
* so we don't need a 64bit division on 32bit arch.
* Note: currently we don't support such large bitmaps on 32bit
* arch anyways, but no harm done to be prepared for it here.
unsigned int shift = mdev->rs_total > UINT_MAX ? 16 : 10;
unsigned long left = *bits_left >> shift;
unsigned long total = 1UL + (mdev->rs_total >> shift);
unsigned long tmp = 1000UL - left * 1000UL/total;
*per_mil_done = tmp;
/* this throttles on-the-fly application requests
* according to max_buffers settings;
* maybe re-implement using semaphores? */
static inline int drbd_get_max_buffers(struct drbd_conf *mdev)
struct net_conf *nc;
int mxb;
nc = rcu_dereference(mdev->tconn->net_conf);
mxb = nc ? nc->max_buffers : 1000000; /* arbitrary limit on open requests */
return mxb;
static inline int drbd_state_is_stable(struct drbd_conf *mdev)
union drbd_dev_state s = mdev->state;
/* DO NOT add a default clause, we want the compiler to warn us
* for any newly introduced state we may have forgotten to add here */
switch ((enum drbd_conns)s.conn) {
/* new io only accepted when there is no connection, ... */
/* ... or there is a well established connection. */
case C_VERIFY_S:
case C_VERIFY_T:
case C_AHEAD:
case C_BEHIND:
/* transitional states, IO allowed */
/* Allow IO in BM exchange states with new protocols */
if (mdev->tconn->agreed_pro_version < 96)
return 0;
/* no new io accepted in these states */
case C_MASK:
/* not "stable" */
return 0;
switch ((enum drbd_disk_state)s.disk) {
case D_UP_TO_DATE:
case D_FAILED:
/* disk state is stable as well. */
/* no new io accepted during transitional states */
case D_MASK:
/* not "stable" */
return 0;
return 1;
static inline int drbd_suspended(struct drbd_conf *mdev)
struct drbd_tconn *tconn = mdev->tconn;
return tconn->susp || tconn->susp_fen || tconn->susp_nod;
static inline bool may_inc_ap_bio(struct drbd_conf *mdev)
int mxb = drbd_get_max_buffers(mdev);
if (drbd_suspended(mdev))
return false;
if (test_bit(SUSPEND_IO, &mdev->flags))
return false;
/* to avoid potential deadlock or bitmap corruption,
* in various places, we only allow new application io
* to start during "stable" states. */
/* no new io accepted when attaching or detaching the disk */
if (!drbd_state_is_stable(mdev))
return false;
/* since some older kernels don't have atomic_add_unless,
* and we are within the spinlock anyways, we have this workaround. */
if (atomic_read(&mdev->ap_bio_cnt) > mxb)
return false;
if (test_bit(BITMAP_IO, &mdev->flags))
return false;
return true;
static inline bool inc_ap_bio_cond(struct drbd_conf *mdev)
bool rv = false;
rv = may_inc_ap_bio(mdev);
if (rv)
return rv;
static inline void inc_ap_bio(struct drbd_conf *mdev)
/* we wait here
* as long as the device is suspended
* until the bitmap is no longer on the fly during connection
* handshake as long as we would exceed the max_buffer limit.
* to avoid races with the reconnect code,
* we need to atomic_inc within the spinlock. */
wait_event(mdev->misc_wait, inc_ap_bio_cond(mdev));
static inline void dec_ap_bio(struct drbd_conf *mdev)
int mxb = drbd_get_max_buffers(mdev);
int ap_bio = atomic_dec_return(&mdev->ap_bio_cnt);
D_ASSERT(ap_bio >= 0);
if (ap_bio == 0 && test_bit(BITMAP_IO, &mdev->flags)) {
if (!test_and_set_bit(BITMAP_IO_QUEUED, &mdev->flags))
drbd_queue_work(&mdev->tconn->sender_work, &mdev->bm_io_work.w);
/* this currently does wake_up for every dec_ap_bio!
* maybe rather introduce some type of hysteresis?
* e.g. (ap_bio == mxb/2 || ap_bio == 0) ? */
if (ap_bio < mxb)
static inline bool verify_can_do_stop_sector(struct drbd_conf *mdev)
return mdev->tconn->agreed_pro_version >= 97 &&
mdev->tconn->agreed_pro_version != 100;
static inline int drbd_set_ed_uuid(struct drbd_conf *mdev, u64 val)
int changed = mdev->ed_uuid != val;
mdev->ed_uuid = val;
return changed;
static inline int drbd_queue_order_type(struct drbd_conf *mdev)
/* sorry, we currently have no working implementation
* of distributed TCQ stuff */
static inline void drbd_md_flush(struct drbd_conf *mdev)
int r;
if (mdev->ldev == NULL) {
dev_warn(DEV, "mdev->ldev == NULL in drbd_md_flush\n");
if (test_bit(MD_NO_FUA, &mdev->flags))
r = blkdev_issue_flush(mdev->ldev->md_bdev, GFP_NOIO, NULL);
if (r) {
set_bit(MD_NO_FUA, &mdev->flags);
dev_err(DEV, "meta data flush failed with status %d, disabling md-flushes\n", r);