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Diffstat (limited to 'drivers/block/drbd/drbd_int.h')
| -rw-r--r-- | drivers/block/drbd/drbd_int.h | 2252 |
1 files changed, 2252 insertions, 0 deletions
diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h new file mode 100644 index 0000000..2312d78 --- /dev/null +++ b/drivers/block/drbd/drbd_int.h @@ -0,0 +1,2252 @@ +/* + drbd_int.h + + 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 <philipp.reisner@linbit.com>. + Copyright (C) 2002-2008, Lars Ellenberg <lars.ellenberg@linbit.com>. + + 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 + 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 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/version.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 <net/tcp.h> +#include <linux/lru_cache.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"))) +#else +# define __protected_by(x) +# define __protected_read_by(x) +# define __protected_write_by(x) +# define __must_hold(x) +#endif + +#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 int disable_sendpage; +extern int allow_oos; +extern unsigned int cn_idx; + +#ifdef CONFIG_DRBD_FAULT_INJECTION +extern int enable_faults; +extern int fault_rate; +extern int fault_devs; +#endif + +extern char usermode_helper[]; + + +#ifndef TRUE +#define TRUE 1 +#endif +#ifndef FALSE +#define FALSE 0 +#endif + +/* I don't remember why XCPU ... + * This is used to wake the asender, + * and to interrupt sending the sending task + * on disconnect. + */ +#define DRBD_SIG SIGXCPU + +/* 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 DRBD_SIGKILL SIGHUP + +/* All EEs on the free list should have ID_VACANT (== 0) + * freshly allocated EEs get !ID_VACANT (== 1) + * so if it says "cannot dereference null pointer at adress 0x00000001", + * it is most likely one of these :( */ + +#define ID_IN_SYNC (4711ULL) +#define ID_OUT_OF_SYNC (4712ULL) + +#define ID_SYNCER (-1ULL) +#define ID_VACANT 0 +#define is_syncer_block_id(id) ((id) == ID_SYNCER) + +struct drbd_conf; + + +/* to shorten dev_warn(DEV, "msg"); and relatives statements */ +#define DEV (disk_to_dev(mdev->vdisk)) + +#define D_ASSERT(exp) if (!(exp)) \ + dev_err(DEV, "ASSERT( " #exp " ) in %s:%d\n", __FILE__, __LINE__) + +#define ERR_IF(exp) if (({ \ + int _b = (exp) != 0; \ + if (_b) dev_err(DEV, "%s: (%s) in %s:%d\n", \ + __func__, #exp, __FILE__, __LINE__); \ + _b; \ + })) + +/* 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_RS_RD = 3, + DRBD_FAULT_DT_WR = 4, /* data */ + DRBD_FAULT_DT_RD = 5, + DRBD_FAULT_DT_RA = 6, /* data read ahead */ + DRBD_FAULT_BM_ALLOC = 7, /* bitmap allocation */ + DRBD_FAULT_AL_EE = 8, /* alloc ee */ + + DRBD_FAULT_MAX, +}; + +#ifdef CONFIG_DRBD_FAULT_INJECTION +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); +} +#define FAULT_ACTIVE(_m, _t) (drbd_insert_fault((_m), (_t))) + +#else +#define FAULT_ACTIVE(_m, _t) (0) +#endif + +/* 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)) + +/* drbd_meta-data.c (still in drbd_main.c) */ +/* 4th incarnation of the disk layout. */ +#define DRBD_MD_MAGIC (DRBD_MAGIC+4) + +extern struct drbd_conf **minor_table; +extern struct ratelimit_state drbd_ratelimit_state; + +/* on the wire */ +enum drbd_packets { + /* 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_BECOME_SYNC_TARGET = 0x05, + P_BECOME_SYNC_SOURCE = 0x06, + 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, + P_AUTH_CHALLENGE = 0x10, + P_AUTH_RESPONSE = 0x11, + P_STATE_CHG_REQ = 0x12, + + /* 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_DISCARD_ACK = 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... */ + P_BARRIER_ACK = 0x1c, + P_STATE_CHG_REPLY = 0x1d, + + /* "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_MAX_CMD = 0x25, + P_MAY_IGNORE = 0x100, /* Flag to test if (cmd > P_MAY_IGNORE) ... */ + P_MAX_OPT_CMD = 0x101, + + /* special command ids for handshake */ + + P_HAND_SHAKE_M = 0xfff1, /* First Packet on the MetaSock */ + P_HAND_SHAKE_S = 0xfff2, /* First Packet on the Socket */ + + P_HAND_SHAKE = 0xfffe /* FIXED for the next century! */ +}; + +static inline const char *cmdname(enum drbd_packets cmd) +{ + /* THINK may need to become several global tables + * when we want to support more than + * one PRO_VERSION */ + static const char *cmdnames[] = { + [P_DATA] = "Data", + [P_DATA_REPLY] = "DataReply", + [P_RS_DATA_REPLY] = "RSDataReply", + [P_BARRIER] = "Barrier", + [P_BITMAP] = "ReportBitMap", + [P_BECOME_SYNC_TARGET] = "BecomeSyncTarget", + [P_BECOME_SYNC_SOURCE] = "BecomeSyncSource", + [P_UNPLUG_REMOTE] = "UnplugRemote", + [P_DATA_REQUEST] = "DataRequest", + [P_RS_DATA_REQUEST] = "RSDataRequest", + [P_SYNC_PARAM] = "SyncParam", + [P_SYNC_PARAM89] = "SyncParam89", + [P_PROTOCOL] = "ReportProtocol", + [P_UUIDS] = "ReportUUIDs", + [P_SIZES] = "ReportSizes", + [P_STATE] = "ReportState", + [P_SYNC_UUID] = "ReportSyncUUID", + [P_AUTH_CHALLENGE] = "AuthChallenge", + [P_AUTH_RESPONSE] = "AuthResponse", + [P_PING] = "Ping", + [P_PING_ACK] = "PingAck", + [P_RECV_ACK] = "RecvAck", + [P_WRITE_ACK] = "WriteAck", + [P_RS_WRITE_ACK] = "RSWriteAck", + [P_DISCARD_ACK] = "DiscardAck", + [P_NEG_ACK] = "NegAck", + [P_NEG_DREPLY] = "NegDReply", + [P_NEG_RS_DREPLY] = "NegRSDReply", + [P_BARRIER_ACK] = "BarrierAck", + [P_STATE_CHG_REQ] = "StateChgRequest", + [P_STATE_CHG_REPLY] = "StateChgReply", + [P_OV_REQUEST] = "OVRequest", + [P_OV_REPLY] = "OVReply", + [P_OV_RESULT] = "OVResult", + [P_MAX_CMD] = NULL, + }; + + if (cmd == P_HAND_SHAKE_M) + return "HandShakeM"; + if (cmd == P_HAND_SHAKE_S) + return "HandShakeS"; + if (cmd == P_HAND_SHAKE) + return "HandShake"; + if (cmd >= P_MAX_CMD) + return "Unknown"; + return cmdnames[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); +#else +# error "unsupported BITS_PER_LONG" +#endif +} + +#ifndef __packed +#define __packed __attribute__((packed)) +#endif + +/* 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_header { + u32 magic; + u16 command; + u16 length; /* bytes of data after this header */ + u8 payload[0]; +} __packed; +/* 8 bytes. packet FIXED for the next century! */ + +/* + * short commands, packets without payload, plain p_header: + * P_PING + * P_PING_ACK + * P_BECOME_SYNC_TARGET + * P_BECOME_SYNC_SOURCE + * P_UNPLUG_REMOTE + */ + +/* + * commands with out-of-struct payload: + * P_BITMAP (no additional fields) + * P_DATA, P_DATA_REPLY (see p_data) + * P_COMPRESSED_BITMAP (see receive_compressed_bitmap) + */ + +/* these defines must not be changed without changing the protocol version */ +#define DP_HARDBARRIER 1 +#define DP_RW_SYNC 2 +#define DP_MAY_SET_IN_SYNC 4 + +struct p_data { + struct p_header head; + 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_DISCARD_ACK (proto C, two-primaries conflict detection) + * p_block_req: + * P_DATA_REQUEST, P_RS_DATA_REQUEST + */ +struct p_block_ack { + struct p_header head; + u64 sector; + u64 block_id; + u32 blksize; + u32 seq_num; +} __packed; + + +struct p_block_req { + struct p_header head; + u64 sector; + u64 block_id; + u32 blksize; + u32 pad; /* to multiple of 8 Byte */ +} __packed; + +/* + * commands with their own struct for additional fields: + * P_HAND_SHAKE + * P_BARRIER + * P_BARRIER_ACK + * P_SYNC_PARAM + * ReportParams + */ + +struct p_handshake { + struct p_header head; /* 8 bytes */ + u32 protocol_min; + u32 feature_flags; + u32 protocol_max; + + /* should be more than enough for future enhancements + * for now, feature_flags and the reserverd array shall be zero. + */ + + u32 _pad; + u64 reserverd[7]; +} __packed; +/* 80 bytes, FIXED for the next century */ + +struct p_barrier { + struct p_header head; + u32 barrier; /* barrier number _handle_ only */ + u32 pad; /* to multiple of 8 Byte */ +} __packed; + +struct p_barrier_ack { + struct p_header head; + u32 barrier; + u32 set_size; +} __packed; + +struct p_rs_param { + struct p_header head; + u32 rate; + + /* Since protocol version 88 and higher. */ + char verify_alg[0]; +} __packed; + +struct p_rs_param_89 { + struct p_header head; + u32 rate; + /* protocol version 89: */ + char verify_alg[SHARED_SECRET_MAX]; + char csums_alg[SHARED_SECRET_MAX]; +} __packed; + +struct p_protocol { + struct p_header head; + u32 protocol; + u32 after_sb_0p; + u32 after_sb_1p; + u32 after_sb_2p; + u32 want_lose; + u32 two_primaries; + + /* Since protocol version 87 and higher. */ + char integrity_alg[0]; + +} __packed; + +struct p_uuids { + struct p_header head; + u64 uuid[UI_EXTENDED_SIZE]; +} __packed; + +struct p_rs_uuid { + struct p_header head; + u64 uuid; +} __packed; + +struct p_sizes { + struct p_header head; + u64 d_size; /* size of disk */ + u64 u_size; /* user requested size */ + u64 c_size; /* current exported size */ + u32 max_segment_size; /* Maximal size of a BIO */ + u32 queue_order_type; +} __packed; + +struct p_state { + struct p_header head; + u32 state; +} __packed; + +struct p_req_state { + struct p_header head; + u32 mask; + u32 val; +} __packed; + +struct p_req_state_reply { + struct p_header head; + 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_discard { + struct p_header head; + u64 block_id; + u32 seq_num; + u32 pad; +} __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 { + struct p_header head; + /* (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; + +/* DCBP: Drbd Compressed Bitmap Packet ... */ +static inline enum drbd_bitmap_code +DCBP_get_code(struct p_compressed_bm *p) +{ + return (enum drbd_bitmap_code)(p->encoding & 0x0f); +} + +static inline void +DCBP_set_code(struct p_compressed_bm *p, enum drbd_bitmap_code code) +{ + BUG_ON(code & ~0xf); + p->encoding = (p->encoding & ~0xf) | code; +} + +static inline int +DCBP_get_start(struct p_compressed_bm *p) +{ + return (p->encoding & 0x80) != 0; +} + +static inline void +DCBP_set_start(struct p_compressed_bm *p, int set) +{ + p->encoding = (p->encoding & ~0x80) | (set ? 0x80 : 0); +} + +static inline int +DCBP_get_pad_bits(struct p_compressed_bm *p) +{ + return (p->encoding >> 4) & 0x7; +} + +static inline void +DCBP_set_pad_bits(struct p_compressed_bm *p, int n) +{ + BUG_ON(n & ~0x7); + p->encoding = (p->encoding & (~0x7 << 4)) | (n << 4); +} + +/* one bitmap packet, including the p_header, + * should fit within one _architecture independend_ page. + * so we need to use the fixed size 4KiB page size + * most architechtures have used for a long time. + */ +#define BM_PACKET_PAYLOAD_BYTES (4096 - sizeof(struct p_header)) +#define BM_PACKET_WORDS (BM_PACKET_PAYLOAD_BYTES/sizeof(long)) +#define BM_PACKET_VLI_BYTES_MAX (4096 - sizeof(struct p_compressed_bm)) +#if (PAGE_SIZE < 4096) +/* drbd_send_bitmap / receive_bitmap would break horribly */ +#error "PAGE_SIZE too small" +#endif + +union p_polymorph { + struct p_header header; + struct p_handshake handshake; + struct p_data data; + struct p_block_ack block_ack; + struct p_barrier barrier; + struct p_barrier_ack barrier_ack; + struct p_rs_param_89 rs_param_89; + struct p_protocol protocol; + struct p_sizes sizes; + struct p_uuids uuids; + struct p_state state; + struct p_req_state req_state; + struct p_req_state_reply req_state_reply; + struct p_block_req block_req; +} __packed; + +/**********************************************************************/ +enum drbd_thread_state { + None, + Running, + Exiting, + Restarting +}; + +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_conf *mdev; + int reset_cpu_mask; +}; + +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 */ + + smp_rmb(); + return thi->t_state; +} + + +/* + * Having this as the first member of a struct provides sort of "inheritance". + * "derived" structs can be "drbd_queue_work()"ed. + * The callback should know and cast back to the descendant struct. + * drbd_request and drbd_epoch_entry are descendants of drbd_work. + */ +struct drbd_work; +typedef int (*drbd_work_cb)(struct drbd_conf *, struct drbd_work *, int cancel); +struct drbd_work { + struct list_head list; + drbd_work_cb cb; +}; + +struct drbd_tl_epoch; +struct drbd_request { + struct drbd_work w; + struct drbd_conf *mdev; + + /* 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_endio_pri(). */ + struct bio *private_bio; + + struct hlist_node colision; + sector_t sector; + unsigned int size; + unsigned int epoch; /* barrier_nr */ + + /* barrier_nr: used to check on "completion" whether this req was in + * the current epoch, and we therefore have to close it, + * starting a new epoch... + */ + + /* up to here, the struct layout is identical to drbd_epoch_entry; + * we might be able to use that to our advantage... */ + + struct list_head tl_requests; /* ring list in the transfer log */ + struct bio *master_bio; /* master bio pointer */ + unsigned long rq_state; /* see comments above _req_mod() */ + int seq_num; + unsigned long start_time; +}; + +struct drbd_tl_epoch { + struct drbd_work w; + struct list_head requests; /* requests before */ + struct drbd_tl_epoch *next; /* pointer to the next barrier */ + unsigned int br_number; /* the barriers identifier. */ + int n_req; /* number of requests attached before this barrier */ +}; + +struct drbd_request; + +/* These Tl_epoch_entries may be in one of 6 lists: + active_ee .. data packet being written + sync_ee .. syncer block being written + done_ee .. block written, need to send P_WRITE_ACK + read_ee .. [RS]P_DATA_REQUEST being read +*/ + +struct drbd_epoch { + 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 { + DE_BARRIER_IN_NEXT_EPOCH_ISSUED, + DE_BARRIER_IN_NEXT_EPOCH_DONE, + DE_CONTAINS_A_BARRIER, + DE_HAVE_BARRIER_NUMBER, + DE_IS_FINISHING, +}; + +enum epoch_event { + EV_PUT, + EV_GOT_BARRIER_NR, + EV_BARRIER_DONE, + EV_BECAME_LAST, + EV_CLEANUP = 32, /* used as flag */ +}; + +struct drbd_epoch_entry { + struct drbd_work w; + struct drbd_conf *mdev; + struct bio *private_bio; + struct hlist_node colision; + sector_t sector; + unsigned int size; + struct drbd_epoch *epoch; + + /* up to here, the struct layout is identical to drbd_request; + * we might be able to use that to our advantage... */ + + unsigned int flags; + u64 block_id; +}; + +struct drbd_wq_barrier { + struct drbd_work w; + struct completion done; +}; + +struct digest_info { + int digest_size; + void *digest; +}; + +/* ee flag bits */ +enum { + __EE_CALL_AL_COMPLETE_IO, + __EE_CONFLICT_PENDING, + __EE_MAY_SET_IN_SYNC, + __EE_IS_BARRIER, +}; +#define EE_CALL_AL_COMPLETE_IO (1<<__EE_CALL_AL_COMPLETE_IO) +#define EE_CONFLICT_PENDING (1<<__EE_CONFLICT_PENDING) +#define EE_MAY_SET_IN_SYNC (1<<__EE_MAY_SET_IN_SYNC) +#define EE_IS_BARRIER (1<<__EE_IS_BARRIER) + +/* global flag bits */ +enum { + CREATE_BARRIER, /* next P_DATA is preceeded by a P_BARRIER */ + SIGNAL_ASENDER, /* whether asender wants to be interrupted */ + SEND_PING, /* whether asender should send a ping asap */ + + STOP_SYNC_TIMER, /* tell timer to cancel itself */ + UNPLUG_QUEUED, /* only relevant with kernel 2.4 */ + UNPLUG_REMOTE, /* sending a "UnplugRemote" could help */ + MD_DIRTY, /* current uuids and flags not yet on disk */ + DISCARD_CONCURRENT, /* Set on one node, cleared on the peer! */ + USE_DEGR_WFC_T, /* degr-wfc-timeout instead of wfc-timeout. */ + CLUSTER_ST_CHANGE, /* Cluster wide state change going on... */ + CL_ST_CHG_SUCCESS, + CL_ST_CHG_FAIL, + CRASHED_PRIMARY, /* This node was a crashed primary. + * Gets cleared when the state.conn + * goes into C_CONNECTED state. */ + WRITE_BM_AFTER_RESYNC, /* A kmalloc() during resync failed */ + NO_BARRIER_SUPP, /* underlying block device doesn't implement barriers */ + CONSIDER_RESYNC, + + MD_NO_BARRIER, /* meta data device does not support barriers, + so don't even try */ + 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 */ + RESYNC_AFTER_NEG, /* Resync after online grow after the attach&negotiate finished. */ + NET_CONGESTED, /* The data socket is congested */ + + CONFIG_PENDING, /* serialization of (re)configuration requests. + * if set, also prevents the device from dying */ + DEVICE_DYING, /* device became unconfigured, + * but worker thread is still handling the cleanup. + * reconfiguring (nl_disk_conf, nl_net_conf) is dissalowed, + * while this is set. */ + RESIZE_PENDING, /* Size change detected locally, waiting for the response from + * the peer, if it changed there as well. */ +}; + +struct drbd_bitmap; /* opaque for drbd_conf */ + +/* TODO sort members for performance + * MAYBE group them further */ + +/* THINK maybe we actually want to use the default "event/%s" worker threads + * or similar in linux 2.6, which uses per cpu data and threads. + * + * To be general, this might need a spin_lock member. + * For now, please use the mdev->req_lock to protect list_head, + * see drbd_queue_work below. + */ +struct drbd_work_queue { + struct list_head q; + struct semaphore s; /* producers up it, worker down()s it */ + spinlock_t q_lock; /* to protect the list. */ +}; + +struct drbd_socket { + struct drbd_work_queue work; + struct mutex mutex; + struct socket *socket; + /* this way we get our + * send/receive buffers off the stack */ + union p_polymorph sbuf; + union p_polymorph rbuf; +}; + +struct drbd_md { + u64 md_offset; /* sector offset to 'super' block */ + + u64 la_size_sect; /* last agreed size, unit sectors */ + u64 uuid[UI_SIZE]; + u64 device_uuid; + u32 flags; + u32 md_size_sect; + + s32 al_offset; /* signed relative sector offset to al area */ + s32 bm_offset; /* signed relative sector offset to bitmap */ + + /* u32 al_nr_extents; important for restoring the AL + * is stored into sync_conf.al_extents, which in turn + * gets applied to act_log->nr_elements + */ +}; + +/* for sync_conf and other types... */ +#define NL_PACKET(name, number, fields) struct name { fields }; +#define NL_INTEGER(pn,pr,member) int member; +#define NL_INT64(pn,pr,member) __u64 member; +#define NL_BIT(pn,pr,member) unsigned member:1; +#define NL_STRING(pn,pr,member,len) unsigned char member[len]; int member ## _len; +#include "linux/drbd_nl.h" + +struct drbd_backing_dev { + struct block_device *backing_bdev; + struct block_device *md_bdev; + struct file *lo_file; + struct file *md_file; + struct drbd_md md; + struct disk_conf dc; /* The user provided config... */ + sector_t known_size; /* last known size of that backing device */ +}; + +struct drbd_md_io { + struct drbd_conf *mdev; + struct completion event; + int error; +}; + +struct bm_io_work { + struct drbd_work w; + char *why; + int (*io_fn)(struct drbd_conf *mdev); + void (*done)(struct drbd_conf *mdev, int rv); +}; + +enum write_ordering_e { + WO_none, + WO_drain_io, + WO_bdev_flush, + WO_bio_barrier +}; + +struct drbd_conf { + /* things that are stored as / read from meta data on disk */ + unsigned long flags; + + /* configured by drbdsetup */ + struct net_conf *net_conf; /* protected by get_net_conf() and put_net_conf() */ + struct syncer_conf sync_conf; + 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; + + 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; + struct drbd_work resync_work, + unplug_work, + md_sync_work; + struct timer_list resync_timer; + struct timer_list md_sync_timer; + + /* Used after attach while negotiating new disk state. */ + union drbd_state new_state_tmp; + + union drbd_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 replys for */ + atomic_t local_cnt; /* Waiting for local completion */ + atomic_t net_cnt; /* Users of net_conf */ + spinlock_t req_lock; + struct drbd_tl_epoch *unused_spare_tle; /* for pre-allocation */ + struct drbd_tl_epoch *newest_tle; + struct drbd_tl_epoch *oldest_tle; + struct list_head out_of_sequence_requests; + struct hlist_head *tl_hash; + unsigned int tl_hash_s; + + /* blocks to sync in this run [unit BM_BLOCK_SIZE] */ + unsigned long rs_total; + /* number of sync IOs 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; + /* block not up-to-date at mark [unit BM_BLOCK_SIZE] */ + unsigned long rs_mark_left; + /* marks's time [unit jiffies] */ + unsigned long rs_mark_time; + /* skipped because csum was equeal [unit BM_BLOCK_SIZE] */ + unsigned long rs_same_csum; + + /* where does the admin want us to start? (sector) */ + sector_t ov_start_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 crypto_hash *csums_tfm; + struct crypto_hash *verify_tfm; + + struct drbd_thread receiver; + struct drbd_thread worker; + struct drbd_thread asender; + 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 drbd_epoch *current_epoch; + spinlock_t epoch_lock; + unsigned int epochs; + enum write_ordering_e write_ordering; + struct list_head active_ee; /* IO in progress */ + struct list_head sync_ee; /* IO in progress */ + struct list_head done_ee; /* send ack */ + struct list_head read_ee; /* IO in progress */ + struct list_head net_ee; /* zero-copy network send in progress */ + struct hlist_head *ee_hash; /* is proteced by req_lock! */ + unsigned int ee_hash_s; + + /* this one is protected by ee_lock, single thread */ + struct drbd_epoch_entry *last_write_w_barrier; + + int next_barrier_nr; + struct hlist_head *app_reads_hash; /* is proteced by req_lock */ + struct list_head resync_reads; + atomic_t pp_in_use; + wait_queue_head_t ee_wait; + struct page *md_io_page; /* one page buffer for md_io */ + struct page *md_io_tmpp; /* for logical_block_size != 512 */ + struct mutex md_io_mutex; /* protects the md_io_buffer */ + 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; + int al_tr_pos; /* position of the next transaction in the journal */ + struct crypto_hash *cram_hmac_tfm; + struct crypto_hash *integrity_w_tfm; /* to be used by the worker thread */ + struct crypto_hash *integrity_r_tfm; /* to be used by the receiver thread */ + void *int_dig_out; + void *int_dig_in; + void *int_dig_vv; + 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. */ + cpumask_var_t cpu_mask; + struct bm_io_work bm_io_work; + u64 ed_uuid; /* UUID of the exposed data */ + struct mutex state_mutex; + char congestion_reason; /* Why we where congested... */ +}; + +static inline struct drbd_conf *minor_to_mdev(unsigned int minor) +{ + struct drbd_conf *mdev; + + mdev = minor < minor_count ? minor_table[minor] : NULL; + + return mdev; +} + +static inline unsigned int mdev_to_minor(struct drbd_conf *mdev) +{ + return mdev->minor; +} + +/* returns 1 if it was successfull, + * returns 0 if there was no data socket. + * so wherever you are going to use the data.socket, e.g. do + * if (!drbd_get_data_sock(mdev)) + * return 0; + * CODE(); + * drbd_put_data_sock(mdev); + */ +static inline int drbd_get_data_sock(struct drbd_conf *mdev) +{ + mutex_lock(&mdev->data.mutex); + /* drbd_disconnect() could have called drbd_free_sock() + * while we were waiting in down()... */ + if (unlikely(mdev->data.socket == NULL)) { + mutex_unlock(&mdev->data.mutex); + return 0; + } + return 1; +} + +static inline void drbd_put_data_sock(struct drbd_conf *mdev) +{ + mutex_unlock(&mdev->data.mutex); +} + +/* + * function declarations + *************************/ + +/* drbd_main.c */ + +enum chg_state_flags { + CS_HARD = 1, + CS_VERBOSE = 2, + CS_WAIT_COMPLETE = 4, + CS_SERIALIZE = 8, + CS_ORDERED = CS_WAIT_COMPLETE + CS_SERIALIZE, +}; + +extern void drbd_init_set_defaults(struct drbd_conf *mdev); +extern int drbd_change_state(struct drbd_conf *mdev, enum chg_state_flags f, + union drbd_state mask, union drbd_state val); +extern void drbd_force_state(struct drbd_conf *, union drbd_state, + union drbd_state); +extern int _drbd_request_state(struct drbd_conf *, union drbd_state, + union drbd_state, enum chg_state_flags); +extern int __drbd_set_state(struct drbd_conf *, union drbd_state, + enum chg_state_flags, struct completion *done); +extern void print_st_err(struct drbd_conf *, union drbd_state, + union drbd_state, int); +extern int drbd_thread_start(struct drbd_thread *thi); +extern void _drbd_thread_stop(struct drbd_thread *thi, int restart, int wait); +#ifdef CONFIG_SMP +extern void drbd_thread_current_set_cpu(struct drbd_conf *mdev); +extern void drbd_calc_cpu_mask(struct drbd_conf *mdev); +#else +#define drbd_thread_current_set_cpu(A) ({}) +#define drbd_calc_cpu_mask(A) ({}) +#endif +extern void drbd_free_resources(struct drbd_conf *mdev); +extern void tl_release(struct drbd_conf *mdev, unsigned int barrier_nr, + unsigned int set_size); +extern void tl_clear(struct drbd_conf *mdev); +extern void _tl_add_barrier(struct drbd_conf *, struct drbd_tl_epoch *); +extern void drbd_free_sock(struct drbd_conf *mdev); +extern int drbd_send(struct drbd_conf *mdev, struct socket *sock, + void *buf, size_t size, unsigned msg_flags); +extern int drbd_send_protocol(struct drbd_conf *mdev); +extern int drbd_send_uuids(struct drbd_conf *mdev); +extern int drbd_send_uuids_skip_initial_sync(struct drbd_conf *mdev); +extern int drbd_send_sync_uuid(struct drbd_conf *mdev, u64 val); +extern int drbd_send_sizes(struct drbd_conf *mdev, int trigger_reply); +extern int _drbd_send_state(struct drbd_conf *mdev); +extern int drbd_send_state(struct drbd_conf *mdev); +extern int _drbd_send_cmd(struct drbd_conf *mdev, struct socket *sock, + enum drbd_packets cmd, struct p_header *h, + size_t size, unsigned msg_flags); +#define USE_DATA_SOCKET 1 +#define USE_META_SOCKET 0 +extern int drbd_send_cmd(struct drbd_conf *mdev, int use_data_socket, + enum drbd_packets cmd, struct p_header *h, + size_t size); +extern int drbd_send_cmd2(struct drbd_conf *mdev, enum drbd_packets cmd, + char *data, size_t size); +extern int drbd_send_sync_param(struct drbd_conf *mdev, struct syncer_conf *sc); +extern int drbd_send_b_ack(struct drbd_conf *mdev, u32 barrier_nr, + u32 set_size); +extern int drbd_send_ack(struct drbd_conf *mdev, enum drbd_packets cmd, + struct drbd_epoch_entry *e); +extern int drbd_send_ack_rp(struct drbd_conf *mdev, enum drbd_packets cmd, + struct p_block_req *rp); +extern int drbd_send_ack_dp(struct drbd_conf *mdev, enum drbd_packets cmd, + struct p_data *dp); +extern int drbd_send_ack_ex(struct drbd_conf *mdev, enum drbd_packets cmd, + sector_t sector, int blksize, u64 block_id); +extern int drbd_send_block(struct drbd_conf *mdev, enum drbd_packets cmd, + struct drbd_epoch_entry *e); +extern int drbd_send_dblock(struct drbd_conf *mdev, struct drbd_request *req); +extern int _drbd_send_barrier(struct drbd_conf *mdev, + struct drbd_tl_epoch *barrier); +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_packets 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 int _drbd_send_bitmap(struct drbd_conf *mdev); +extern int drbd_send_sr_reply(struct drbd_conf *mdev, int retcode); +extern void drbd_free_bc(struct drbd_backing_dev *ldev); +extern void drbd_mdev_cleanup(struct drbd_conf *mdev); + +/* drbd_meta-data.c (still in drbd_main.c) */ +extern void drbd_md_sync(struct drbd_conf *mdev); +extern int drbd_md_read(struct drbd_conf *mdev, struct drbd_backing_dev *bdev); +/* maybe define them below as inline? */ +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_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_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); +extern void drbd_queue_bitmap_io(struct drbd_conf *mdev, + int (*io_fn)(struct drbd_conf *), + void (*done)(struct drbd_conf *, int), + char *why); +extern int drbd_bmio_set_n_write(struct drbd_conf *mdev); +extern int drbd_bmio_clear_n_write(struct drbd_conf *mdev); +extern int drbd_bitmap_io(struct drbd_conf *mdev, int (*io_fn)(struct drbd_conf *), char *why); + + +/* Meta data layout + We reserve a 128MB Block (4k aligned) + * either at the end of the backing device + * or on a seperate meta data device. */ + +#define MD_RESERVED_SECT (128LU << 11) /* 128 MB, unit sectors */ +/* The following numbers are sectors */ +#define MD_AL_OFFSET 8 /* 8 Sectors after start of meta area */ +#define MD_AL_MAX_SIZE 64 /* = 32 kb LOG ~ 3776 extents ~ 14 GB Storage */ +/* Allows up to about 3.8TB */ +#define MD_BM_OFFSET (MD_AL_OFFSET + MD_AL_MAX_SIZE) + +/* Since the smalles IO unit is usually 512 byte */ +#define MD_SECTOR_SHIFT 9 +#define MD_SECTOR_SIZE (1<<MD_SECTOR_SHIFT) + +/* activity log */ +#define AL_EXTENTS_PT ((MD_SECTOR_SIZE-12)/8-1) /* 61 ; Extents per 512B sector */ +#define AL_EXTENT_SHIFT 22 /* One extent represents 4M Storage */ +#define AL_EXTENT_SIZE (1<<AL_EXTENT_SHIFT) + +#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) +#else +#error "LN2 of BITS_PER_LONG unknown!" +#endif + +/* 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. */ + +/* 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 BM_BLOCK_SHIFT 12 /* 4k per bit */ +#define BM_BLOCK_SIZE (1<<BM_BLOCK_SHIFT) +/* (9+3) : 512 bytes @ 8 bits; representing 16M storage + * per sector of on disk bitmap */ +#define BM_EXT_SHIFT (BM_BLOCK_SHIFT + MD_SECTOR_SHIFT + 3) /* = 24 */ +#define BM_EXT_SIZE (1<<BM_EXT_SHIFT) + +#if (BM_EXT_SHIFT != 24) || (BM_BLOCK_SHIFT != 12) +#error "HAVE YOU FIXED drbdmeta AS WELL??" +#endif + +/* 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)) +#define BM_SECT_PER_BIT BM_BIT_TO_SECT(1) + +/* 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)) +#define BM_SECT_PER_EXT BM_EXT_TO_SECT(1) + +/* in one sector of the bitmap, we have this many activity_log extents. */ +#define AL_EXT_PER_BM_SECT (1 << (BM_EXT_SHIFT - AL_EXTENT_SHIFT)) +#define BM_WORDS_PER_AL_EXT (1 << (AL_EXTENT_SHIFT-BM_BLOCK_SHIFT-LN2_BPL)) + +#define BM_BLOCKS_PER_BM_EXT_B (BM_EXT_SHIFT - BM_BLOCK_SHIFT) +#define BM_BLOCKS_PER_BM_EXT_MASK ((1<<BM_BLOCKS_PER_BM_EXT_B) - 1) + +/* 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_WORDS_PER_EXT ( (AL_EXT_SIZE/BM_BLOCK_SIZE) / BITS_PER_LONG ) +#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) +#define DRBD_MAX_SECTORS_BM \ + ((MD_RESERVED_SECT - MD_BM_OFFSET) * (1LL<<(BM_EXT_SHIFT-9))) +#if DRBD_MAX_SECTORS_BM < DRBD_MAX_SECTORS_32 +#define DRBD_MAX_SECTORS DRBD_MAX_SECTORS_BM +#define DRBD_MAX_SECTORS_FLEX DRBD_MAX_SECTORS_BM +#elif !defined(CONFIG_LBD) && BITS_PER_LONG == 32 +#define DRBD_MAX_SECTORS DRBD_MAX_SECTORS_32 +#define DRBD_MAX_SECTORS_FLEX DRBD_MAX_SECTORS_32 +#else +#define DRBD_MAX_SECTORS DRBD_MAX_SECTORS_BM +/* 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. */ +#define DRBD_MAX_SECTORS_FLEX BM_BIT_TO_SECT(0xffff7fff) +#else +#define DRBD_MAX_SECTORS_FLEX BM_BIT_TO_SECT(0x1LU << 32) +#endif +#endif + +/* Sector shift value for the "hash" functions of tl_hash and ee_hash tables. + * With a value of 6 all IO in one 32K block make it to the same slot of the + * hash table. */ +#define HT_SHIFT 6 +#define DRBD_MAX_SEGMENT_SIZE (1U<<(9+HT_SHIFT)) + +/* Number of elements in the app_reads_hash */ +#define APP_R_HSIZE 15 + +extern int drbd_bm_init(struct drbd_conf *mdev); +extern int drbd_bm_resize(struct drbd_conf *mdev, sector_t sectors); +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); +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); +/* bm_set_bits variant for use while holding drbd_bm_lock */ +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_sect(struct drbd_conf *mdev, unsigned long enr) __must_hold(local); +extern int drbd_bm_read(struct drbd_conf *mdev) __must_hold(local); +extern int drbd_bm_write(struct drbd_conf *mdev) __must_hold(local); +extern unsigned long drbd_bm_ALe_set_all(struct drbd_conf *mdev, + unsigned long al_enr); +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); +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 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 and drbd_bm_write_sect */ +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); +extern void drbd_bm_unlock(struct drbd_conf *mdev); + +extern int drbd_bm_count_bits(struct drbd_conf *mdev, const unsigned long s, const unsigned long e); +/* drbd_main.c */ + +extern struct kmem_cache *drbd_request_cache; +extern struct kmem_cache *drbd_ee_cache; /* epoch entries */ +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; + +extern struct page *drbd_pp_pool; /* drbd's page pool */ +extern spinlock_t drbd_pp_lock; +extern int drbd_pp_vacant; +extern wait_queue_head_t drbd_pp_wait; + +extern rwlock_t global_state_lock; + +extern struct drbd_conf *drbd_new_device(unsigned int minor); +extern void drbd_free_mdev(struct drbd_conf *mdev); + +extern int proc_details; + +/* drbd_req */ +extern int drbd_make_request_26(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 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 *); +enum determine_dev_size { dev_size_error = -1, unchanged = 0, shrunk = 1, grew = 2 }; +extern enum determine_dev_size drbd_determin_dev_size(struct drbd_conf *) __must_hold(local); +extern void resync_after_online_grow(struct drbd_conf *); +extern void drbd_setup_queue_param(struct drbd_conf *mdev, unsigned int) __must_hold(local); +extern int drbd_set_role(struct drbd_conf *mdev, enum drbd_role new_role, + int force); +enum drbd_disk_state drbd_try_outdate_peer(struct drbd_conf *mdev); +extern int drbd_khelper(struct drbd_conf *mdev, char *cmd); + +/* drbd_worker.c */ +extern int drbd_worker(struct drbd_thread *thi); +extern int drbd_alter_sa(struct drbd_conf *mdev, int na); +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 int drbd_md_sync_page_io(struct drbd_conf *mdev, + struct drbd_backing_dev *bdev, sector_t sector, int rw); +extern void drbd_ov_oos_found(struct drbd_conf*, sector_t, int); + +static inline void ov_oos_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); + } + mdev->ov_last_oos_size=0; +} + + +extern void drbd_csum(struct drbd_conf *, struct crypto_hash *, struct bio *, void *); +/* worker callbacks */ +extern int w_req_cancel_conflict(struct drbd_conf *, struct drbd_work *, int); +extern int w_read_retry_remote(struct drbd_conf *, struct drbd_work *, int); +extern int w_e_end_data_req(struct drbd_conf *, struct drbd_work *, int); +extern int w_e_end_rsdata_req(struct drbd_conf *, struct drbd_work *, int); +extern int w_e_end_csum_rs_req(struct drbd_conf *, struct drbd_work *, int); +extern int w_e_end_ov_reply(struct drbd_conf *, struct drbd_work *, int); +extern int w_e_end_ov_req(struct drbd_conf *, struct drbd_work *, int); +extern int w_ov_finished(struct drbd_conf *, struct drbd_work *, int); +extern int w_resync_inactive(struct drbd_conf *, struct drbd_work *, int); +extern int w_resume_next_sg(struct drbd_conf *, struct drbd_work *, int); +extern int w_io_error(struct drbd_conf *, struct drbd_work *, int); +extern int w_send_write_hint(struct drbd_conf *, struct drbd_work *, int); +extern int w_make_resync_request(struct drbd_conf *, struct drbd_work *, int); +extern int w_send_dblock(struct drbd_conf *, struct drbd_work *, int); +extern int w_send_barrier(struct drbd_conf *, struct drbd_work *, int); +extern int w_send_read_req(struct drbd_conf *, struct drbd_work *, int); +extern int w_prev_work_done(struct drbd_conf *, struct drbd_work *, int); +extern int w_e_reissue(struct drbd_conf *, struct drbd_work *, int); + +extern void resync_timer_fn(unsigned long data); + +/* drbd_receiver.c */ +extern int drbd_release_ee(struct drbd_conf *mdev, struct list_head *list); +extern struct drbd_epoch_entry *drbd_alloc_ee(struct drbd_conf *mdev, + u64 id, + sector_t sector, + unsigned int data_size, + gfp_t gfp_mask) __must_hold(local); +extern void drbd_free_ee(struct drbd_conf *mdev, struct drbd_epoch_entry *e); +extern void drbd_wait_ee_list_empty(struct drbd_conf *mdev, + struct list_head *head); +extern void _drbd_wait_ee_list_empty(struct drbd_conf *mdev, + struct list_head *head); +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 drbd_flush_workqueue(struct drbd_conf *mdev); + +/* yes, there is kernel_setsockopt, but only since 2.6.18. we don't need to + * mess with get_fs/set_fs, we know we are KERNEL_DS always. */ +static inline int drbd_setsockopt(struct socket *sock, int level, int optname, + char __user *optval, int optlen) +{ + int err; + if (level == SOL_SOCKET) + err = sock_setsockopt(sock, level, optname, optval, optlen); + else + err = sock->ops->setsockopt(sock, level, optname, optval, + optlen); + return err; +} + +static inline void drbd_tcp_cork(struct socket *sock) +{ + int __user val = 1; + (void) drbd_setsockopt(sock, SOL_TCP, TCP_CORK, + (char __user *)&val, sizeof(val)); +} + +static inline void drbd_tcp_uncork(struct socket *sock) +{ + int __user val = 0; + (void) drbd_setsockopt(sock, SOL_TCP, TCP_CORK, + (char __user *)&val, sizeof(val)); +} + +static inline void drbd_tcp_nodelay(struct socket *sock) +{ + int __user val = 1; + (void) drbd_setsockopt(sock, SOL_TCP, TCP_NODELAY, + (char __user *)&val, sizeof(val)); +} + +static inline void drbd_tcp_quickack(struct socket *sock) +{ + int __user val = 1; + (void) drbd_setsockopt(sock, SOL_TCP, TCP_QUICKACK, + (char __user *)&val, sizeof(val)); +} + +void drbd_bump_write_ordering(struct drbd_conf *mdev, enum write_ordering_e wo); + +/* drbd_proc.c */ +extern struct proc_dir_entry *drbd_proc; +extern 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 void drbd_al_begin_io(struct drbd_conf *mdev, sector_t sector); +extern void drbd_al_complete_io(struct drbd_conf *mdev, sector_t sector); +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 int drbd_al_read_log(struct drbd_conf *mdev, struct drbd_backing_dev *); +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 void __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_apply_to_bm(struct drbd_conf *mdev); +extern void drbd_al_to_on_disk_bm(struct drbd_conf *mdev); +extern void drbd_al_shrink(struct drbd_conf *mdev); + + +/* drbd_nl.c */ + +void drbd_nl_cleanup(void); +int __init drbd_nl_init(void); +void drbd_bcast_state(struct drbd_conf *mdev, union drbd_state); +void drbd_bcast_sync_progress(struct drbd_conf *mdev); +void drbd_bcast_ee(struct drbd_conf *mdev, + const char *reason, const int dgs, + const char* seen_hash, const char* calc_hash, + const struct drbd_epoch_entry* e); + + +/** + * DOC: DRBD State macros + * + * These macros are used to express state changes in easily readable form. + * + * The NS macros expand to a mask and a value, that can be bit ored onto the + * current state as soon as the spinlock (req_lock) was taken. + * + * The _NS macros are used for state functions that get called with the + * spinlock. These macros expand directly to the new state value. + * + * Besides the basic forms NS() and _NS() additional _?NS[23] are defined + * to express state changes that affect more than one aspect of the state. + * + * E.g. NS2(conn, C_CONNECTED, peer, R_SECONDARY) + * Means that the network connection was established and that the peer + * is in secondary role. + */ +#define role_MASK R_MASK +#define peer_MASK R_MASK +#define disk_MASK D_MASK +#define pdsk_MASK D_MASK +#define conn_MASK C_MASK +#define susp_MASK 1 +#define user_isp_MASK 1 +#define aftr_isp_MASK 1 + +#define NS(T, S) \ + ({ union drbd_state mask; mask.i = 0; mask.T = T##_MASK; mask; }), \ + ({ union drbd_state val; val.i = 0; val.T = (S); val; }) +#define NS2(T1, S1, T2, S2) \ + ({ union drbd_state mask; mask.i = 0; mask.T1 = T1##_MASK; \ + mask.T2 = T2##_MASK; mask; }), \ + ({ union drbd_state val; val.i = 0; val.T1 = (S1); \ + val.T2 = (S2); val; }) +#define NS3(T1, S1, T2, S2, T3, S3) \ + ({ union drbd_state mask; mask.i = 0; mask.T1 = T1##_MASK; \ + mask.T2 = T2##_MASK; mask.T3 = T3##_MASK; mask; }), \ + ({ union drbd_state val; val.i = 0; val.T1 = (S1); \ + val.T2 = (S2); val.T3 = (S3); val; }) + +#define _NS(D, T, S) \ + D, ({ union drbd_state __ns; __ns.i = D->state.i; __ns.T = (S); __ns; }) +#define _NS2(D, T1, S1, T2, S2) \ + D, ({ union drbd_state __ns; __ns.i = D->state.i; __ns.T1 = (S1); \ + __ns.T2 = (S2); __ns; }) +#define _NS3(D, T1, S1, T2, S2, T3, S3) \ + D, ({ union drbd_state __ns; __ns.i = D->state.i; __ns.T1 = (S1); \ + __ns.T2 = (S2); __ns.T3 = (S3); __ns; }) + +/* + * inline helper functions + *************************/ + +static inline void drbd_state_lock(struct drbd_conf *mdev) +{ + wait_event(mdev->misc_wait, + !test_and_set_bit(CLUSTER_ST_CHANGE, &mdev->flags)); +} + +static inline void drbd_state_unlock(struct drbd_conf *mdev) +{ + clear_bit(CLUSTER_ST_CHANGE, &mdev->flags); + wake_up(&mdev->misc_wait); +} + +static inline int _drbd_set_state(struct drbd_conf *mdev, + union drbd_state ns, enum chg_state_flags flags, + struct completion *done) +{ + int rv; + + read_lock(&global_state_lock); + rv = __drbd_set_state(mdev, ns, flags, done); + read_unlock(&global_state_lock); + + return rv; +} + +/** + * drbd_request_state() - Reqest a state change + * @mdev: DRBD device. + * @mask: mask of state bits to change. + * @val: value of new state bits. + * + * This is the most graceful way of requesting a state change. It is verbose + * quite verbose in case the state change is not possible, and all those + * state changes are globally serialized. + */ +static inline int drbd_request_state(struct drbd_conf *mdev, + union drbd_state mask, + union drbd_state val) +{ + return _drbd_request_state(mdev, mask, val, CS_VERBOSE + CS_ORDERED); +} + +#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, int forcedetach, const char *where) +{ + switch (mdev->ldev->dc.on_io_error) { + case EP_PASS_ON: + if (!forcedetach) { + if (printk_ratelimit()) + dev_err(DEV, "Local IO failed in %s." + "Passing error on...\n", where); + break; + } + /* NOTE fall through to detach case if forcedetach set */ + case EP_DETACH: + case EP_CALL_HELPER: + if (mdev->state.disk > D_FAILED) { + _drbd_set_state(_NS(mdev, disk, D_FAILED), CS_HARD, NULL); + dev_err(DEV, "Local IO failed in %s." + "Detaching...\n", where); + } + break; + } +} + +/** + * 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, int forcedetach, const char *where) +{ + if (error) { + unsigned long flags; + spin_lock_irqsave(&mdev->req_lock, flags); + __drbd_chk_io_error_(mdev, forcedetach, where); + spin_unlock_irqrestore(&mdev->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->dc.meta_dev_idx) { + case DRBD_MD_INDEX_INTERNAL: + case DRBD_MD_INDEX_FLEX_INT: + return bdev->md.md_offset + bdev->md.bm_offset; + case DRBD_MD_INDEX_FLEX_EXT: + default: + 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->dc.meta_dev_idx) { + case DRBD_MD_INDEX_INTERNAL: + case DRBD_MD_INDEX_FLEX_INT: + return bdev->md.md_offset + MD_AL_OFFSET - 1; + case DRBD_MD_INDEX_FLEX_EXT: + default: + return bdev->md.md_offset + bdev->md.md_size_sect; + } +} + +/* 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 ? bdev->bd_inode->i_size >> 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->dc.meta_dev_idx) { + case DRBD_MD_INDEX_INTERNAL: + case DRBD_MD_INDEX_FLEX_INT: + s = drbd_get_capacity(bdev->backing_bdev) + ? min_t(sector_t, DRBD_MAX_SECTORS_FLEX, + drbd_md_first_sector(bdev)) + : 0; + break; + case DRBD_MD_INDEX_FLEX_EXT: + s = min_t(sector_t, DRBD_MAX_SECTORS_FLEX, + drbd_get_capacity(bdev->backing_bdev)); + /* clip at maximum size the meta device can support */ + s = min_t(sector_t, s, + BM_EXT_TO_SECT(bdev->md.md_size_sect + - bdev->md.bm_offset)); + break; + default: + s = min_t(sector_t, DRBD_MAX_SECTORS, + drbd_get_capacity(bdev->backing_bdev)); + } + return s; +} + +/** + * drbd_md_ss__() - Return the sector number of our meta data super block + * @mdev: DRBD device. + * @bdev: Meta data block device. + */ +static inline sector_t drbd_md_ss__(struct drbd_conf *mdev, + struct drbd_backing_dev *bdev) +{ + switch (bdev->dc.meta_dev_idx) { + default: /* external, some index */ + return MD_RESERVED_SECT * bdev->dc.meta_dev_idx; + case DRBD_MD_INDEX_INTERNAL: + /* with drbd08, internal meta data is always "flexible" */ + case DRBD_MD_INDEX_FLEX_INT: + /* sizeof(struct md_on_disk_07) == 4k + * position: last 4k aligned block of 4k size */ + if (!bdev->backing_bdev) { + if (__ratelimit(&drbd_ratelimit_state)) { + dev_err(DEV, "bdev->backing_bdev==NULL\n"); + dump_stack(); + } + return 0; + } + return (drbd_get_capacity(bdev->backing_bdev) & ~7ULL) + - MD_AL_OFFSET; + case DRBD_MD_INDEX_FLEX_EXT: + return 0; + } +} + +static inline void +_drbd_queue_work(struct drbd_work_queue *q, struct drbd_work *w) +{ + list_add_tail(&w->list, &q->q); + up(&q->s); +} + +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); + up(&q->s); /* within the spinlock, + see comment near end of drbd_worker() */ + 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); + up(&q->s); /* within the spinlock, + see comment near end of drbd_worker() */ + spin_unlock_irqrestore(&q->q_lock, flags); +} + +static inline void wake_asender(struct drbd_conf *mdev) +{ + if (test_bit(SIGNAL_ASENDER, &mdev->flags)) + force_sig(DRBD_SIG, mdev->asender.task); +} + +static inline void request_ping(struct drbd_conf *mdev) +{ + set_bit(SEND_PING, &mdev->flags); + wake_asender(mdev); +} + +static inline int drbd_send_short_cmd(struct drbd_conf *mdev, + enum drbd_packets cmd) +{ + struct p_header h; + return drbd_send_cmd(mdev, USE_DATA_SOCKET, cmd, &h, sizeof(h)); +} + +static inline int drbd_send_ping(struct drbd_conf *mdev) +{ + struct p_header h; + return drbd_send_cmd(mdev, USE_META_SOCKET, P_PING, &h, sizeof(h)); +} + +static inline int drbd_send_ping_ack(struct drbd_conf *mdev) +{ + struct p_header h; + return drbd_send_cmd(mdev, USE_META_SOCKET, P_PING_ACK, &h, sizeof(h)); +} + +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 + * _req_mod(req, queue_for_net_write or queue_for_net_read); + * 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] + * _req_mod(req, write_acked_by_peer or recv_acked_by_peer or neg_acked) + * [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) + * _req_mod(req, connection_lost_while_pending) + * [from tl_clear_barrier] + */ +static inline void inc_ap_pending(struct drbd_conf *mdev) +{ + atomic_inc(&mdev->ap_pending_cnt); +} + +#define ERR_IF_CNT_IS_NEGATIVE(which) \ + if (atomic_read(&mdev->which) < 0) \ + dev_err(DEV, "in %s:%d: " #which " = %d < 0 !\n", \ + __func__ , __LINE__ , \ + atomic_read(&mdev->which)) + +#define dec_ap_pending(mdev) do { \ + typecheck(struct drbd_conf *, mdev); \ + if (atomic_dec_and_test(&mdev->ap_pending_cnt)) \ + wake_up(&mdev->misc_wait); \ + ERR_IF_CNT_IS_NEGATIVE(ap_pending_cnt); } while (0) + +/* counts how many resync-related answers we still expect from the peer + * increase decrease + * C_SYNC_TARGET sends P_RS_DATA_REQUEST (and expects P_RS_DATA_REPLY) + * C_SYNC_SOURCE sends P_RS_DATA_REPLY (and expects P_WRITE_ACK whith ID_SYNCER) + * (or P_NEG_ACK with ID_SYNCER) + */ +static inline void inc_rs_pending(struct drbd_conf *mdev) +{ + atomic_inc(&mdev->rs_pending_cnt); +} + +#define dec_rs_pending(mdev) do { \ + typecheck(struct drbd_conf *, mdev); \ + atomic_dec(&mdev->rs_pending_cnt); \ + ERR_IF_CNT_IS_NEGATIVE(rs_pending_cnt); } while (0) + +/* 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) +{ + atomic_inc(&mdev->unacked_cnt); +} + +#define dec_unacked(mdev) do { \ + typecheck(struct drbd_conf *, mdev); \ + atomic_dec(&mdev->unacked_cnt); \ + ERR_IF_CNT_IS_NEGATIVE(unacked_cnt); } while (0) + +#define sub_unacked(mdev, n) do { \ + typecheck(struct drbd_conf *, mdev); \ + atomic_sub(n, &mdev->unacked_cnt); \ + ERR_IF_CNT_IS_NEGATIVE(unacked_cnt); } while (0) + + +static inline void put_net_conf(struct drbd_conf *mdev) +{ + if (atomic_dec_and_test(&mdev->net_cnt)) + wake_up(&mdev->misc_wait); +} + +/** + * get_net_conf() - Increase ref count on mdev->net_conf; Returns 0 if nothing there + * @mdev: DRBD device. + * + * You have to call put_net_conf() when finished working with mdev->net_conf. + */ +static inline int get_net_conf(struct drbd_conf *mdev) +{ + int have_net_conf; + + atomic_inc(&mdev->net_cnt); + have_net_conf = mdev->state.conn >= C_UNCONNECTED; + if (!have_net_conf) + put_net_conf(mdev); + return have_net_conf; +} + +/** + * 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) +{ + __release(local); + if (atomic_dec_and_test(&mdev->local_cnt)) + wake_up(&mdev->misc_wait); + D_ASSERT(atomic_read(&mdev->local_cnt) >= 0); +} + +#ifndef __CHECKER__ +static inline int _get_ldev_if_state(struct drbd_conf *mdev, enum drbd_disk_state mins) +{ + int io_allowed; + + atomic_inc(&mdev->local_cnt); + io_allowed = (mdev->state.disk >= mins); + if (!io_allowed) + put_ldev(mdev); + return io_allowed; +} +#else +extern int _get_ldev_if_state(struct drbd_conf *mdev, enum drbd_disk_state mins); +#endif + +/* 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 + * (we may feel 4TB maximum storage per drbd is not enough) + */ + 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. */ + + *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. + */ + smp_rmb(); + dev_warn(DEV, "cs:%s rs_left=%lu > rs_total=%lu (rs_failed %lu)\n", + drbd_conn_str(mdev->state.conn), + *bits_left, mdev->rs_total, mdev->rs_failed); + *per_mil_done = 0; + } else { + /* make sure the calculation happens in long context */ + unsigned long tmp = 1000UL - + (*bits_left >> 10)*1000UL + / ((mdev->rs_total >> 10) + 1UL); + *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) +{ + int mxb = 1000000; /* arbitrary limit on open requests */ + if (get_net_conf(mdev)) { + mxb = mdev->net_conf->max_buffers; + put_net_conf(mdev); + } + return mxb; +} + +static inline int drbd_state_is_stable(union drbd_state s) +{ + + /* 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, ... */ + case C_STANDALONE: + case C_WF_CONNECTION: + /* ... or there is a well established connection. */ + case C_CONNECTED: + case C_SYNC_SOURCE: + case C_SYNC_TARGET: + case C_VERIFY_S: + case C_VERIFY_T: + case C_PAUSED_SYNC_S: + case C_PAUSED_SYNC_T: + /* maybe stable, look at the disk state */ + break; + + /* no new io accepted during tansitional states + * like handshake or teardown */ + case C_DISCONNECTING: + case C_UNCONNECTED: + case C_TIMEOUT: + case C_BROKEN_PIPE: + case C_NETWORK_FAILURE: + case C_PROTOCOL_ERROR: + case C_TEAR_DOWN: + case C_WF_REPORT_PARAMS: + case C_STARTING_SYNC_S: + case C_STARTING_SYNC_T: + case C_WF_BITMAP_S: + case C_WF_BITMAP_T: + case C_WF_SYNC_UUID: + case C_MASK: + /* not "stable" */ + return 0; + } + + switch ((enum drbd_disk_state)s.disk) { + case D_DISKLESS: + case D_INCONSISTENT: + case D_OUTDATED: + case D_CONSISTENT: + case D_UP_TO_DATE: + /* disk state is stable as well. */ + break; + + /* no new io accepted during tansitional states */ + case D_ATTACHING: + case D_FAILED: + case D_NEGOTIATING: + case D_UNKNOWN: + case D_MASK: + /* not "stable" */ + return 0; + } + + return 1; +} + +static inline int __inc_ap_bio_cond(struct drbd_conf *mdev) +{ + int mxb = drbd_get_max_buffers(mdev); + + if (mdev->state.susp) + return 0; + if (test_bit(SUSPEND_IO, &mdev->flags)) + return 0; + + /* 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->state)) + return 0; + + /* 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 0; + if (test_bit(BITMAP_IO, &mdev->flags)) + return 0; + return 1; +} + +/* I'd like to use wait_event_lock_irq, + * but I'm not sure when it got introduced, + * and not sure when it has 3 or 4 arguments */ +static inline void inc_ap_bio(struct drbd_conf *mdev, int one_or_two) +{ + /* compare with after_state_ch, + * os.conn != C_WF_BITMAP_S && ns.conn == C_WF_BITMAP_S */ + DEFINE_WAIT(wait); + + /* 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 exeed the max_buffer limit. + * + * to avoid races with the reconnect code, + * we need to atomic_inc within the spinlock. */ + + spin_lock_irq(&mdev->req_lock); + while (!__inc_ap_bio_cond(mdev)) { + prepare_to_wait(&mdev->misc_wait, &wait, TASK_UNINTERRUPTIBLE); + spin_unlock_irq(&mdev->req_lock); + schedule(); + finish_wait(&mdev->misc_wait, &wait); + spin_lock_irq(&mdev->req_lock); + } + atomic_add(one_or_two, &mdev->ap_bio_cnt); + spin_unlock_irq(&mdev->req_lock); +} + +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); + /* 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) + wake_up(&mdev->misc_wait); + if (ap_bio == 0 && test_bit(BITMAP_IO, &mdev->flags)) { + if (!test_and_set_bit(BITMAP_IO_QUEUED, &mdev->flags)) + drbd_queue_work(&mdev->data.work, &mdev->bm_io_work.w); + } +} + +static inline void drbd_set_ed_uuid(struct drbd_conf *mdev, u64 val) +{ + mdev->ed_uuid = val; +} + +static inline int seq_cmp(u32 a, u32 b) +{ + /* we assume wrap around at 32bit. + * for wrap around at 24bit (old atomic_t), + * we'd have to + * a <<= 8; b <<= 8; + */ + return (s32)(a) - (s32)(b); +} +#define seq_lt(a, b) (seq_cmp((a), (b)) < 0) +#define seq_gt(a, b) (seq_cmp((a), (b)) > 0) +#define seq_ge(a, b) (seq_cmp((a), (b)) >= 0) +#define seq_le(a, b) (seq_cmp((a), (b)) <= 0) +/* CAUTION: please no side effects in arguments! */ +#define seq_max(a, b) ((u32)(seq_gt((a), (b)) ? (a) : (b))) + +static inline void update_peer_seq(struct drbd_conf *mdev, unsigned int new_seq) +{ + unsigned int m; + spin_lock(&mdev->peer_seq_lock); + m = seq_max(mdev->peer_seq, new_seq); + mdev->peer_seq = m; + spin_unlock(&mdev->peer_seq_lock); + if (m == new_seq) + wake_up(&mdev->seq_wait); +} + +static inline void drbd_update_congested(struct drbd_conf *mdev) +{ + struct sock *sk = mdev->data.socket->sk; + if (sk->sk_wmem_queued > sk->sk_sndbuf * 4 / 5) + set_bit(NET_CONGESTED, &mdev->flags); +} + +static inline int drbd_queue_order_type(struct drbd_conf *mdev) +{ + /* sorry, we currently have no working implementation + * of distributed TCQ stuff */ +#ifndef QUEUE_ORDERED_NONE +#define QUEUE_ORDERED_NONE 0 +#endif + return QUEUE_ORDERED_NONE; +} + +static inline void drbd_blk_run_queue(struct request_queue *q) +{ + if (q && q->unplug_fn) + q->unplug_fn(q); +} + +static inline void drbd_kick_lo(struct drbd_conf *mdev) +{ + if (get_ldev(mdev)) { + drbd_blk_run_queue(bdev_get_queue(mdev->ldev->backing_bdev)); + put_ldev(mdev); + } +} + +static inline void drbd_md_flush(struct drbd_conf *mdev) +{ + int r; + + if (test_bit(MD_NO_BARRIER, &mdev->flags)) + return; + + r = blkdev_issue_flush(mdev->ldev->md_bdev, NULL); + if (r) { + set_bit(MD_NO_BARRIER, &mdev->flags); + dev_err(DEV, "meta data flush failed with status %d, disabling md-flushes\n", r); + } +} + +#endif |
