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Message-Id: <1246017715-9821-7-git-send-email-philipp.reisner@linbit.com>
Date: Fri, 26 Jun 2009 14:01:46 +0200
From: Philipp Reisner <philipp.reisner@...bit.com>
To: linux-kernel@...r.kernel.org
Cc: Andrew Morton <akpm@...ux-foundation.org>,
Jens Axboe <jens.axboe@...cle.com>, Greg KH <gregkh@...e.de>,
Neil Brown <neilb@...e.de>,
James Bottomley <James.Bottomley@...senPartnership.com>,
Sam Ravnborg <sam@...nborg.org>, Dave Jones <davej@...hat.com>,
Nikanth Karthikesan <knikanth@...e.de>,
"Lars Marowsky-Bree" <lmb@...e.de>,
"Nicholas A. Bellinger" <nab@...ux-iscsi.org>,
Kyle Moffett <kyle@...fetthome.net>,
Bart Van Assche <bart.vanassche@...il.com>,
drbd-dev@...ts.linbit.com,
Lars Ellenberg <lars.ellenberg@...bit.com>,
Philipp Reisner <philipp.reisner@...bit.com>
Subject: [PATCH 06/15] drbd: internal data structures
The big "struct drbd_conf" describes one DRBD device.
Signed-off-by: Philipp Reisner <philipp.reisner@...bit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@...bit.com>
---
diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
new file mode 100644
index 0000000..a63595d
--- /dev/null
+++ b/drivers/block/drbd/drbd_int.h
@@ -0,0 +1,2246 @@
+/*
+ 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@...bit.com>.
+ Copyright (C) 2002-2008, Lars Ellenberg <lars.ellenberg@...bit.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/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 DRBD_ENABLE_FAULTS
+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,
+};
+
+extern void trace_drbd_resync(struct drbd_conf *mdev, int level, const char *fmt, ...);
+
+#ifdef DRBD_ENABLE_FAULTS
+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;
+ 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_TRACE_FLUSH, /* TRACE_ are not real events, only used for tracing */
+ EV_TRACE_ADD_BARRIER, /* Doing the first write as a barrier write */
+ EV_TRACE_SETTING_BI, /* Barrier is expressed with the first write of the next epoch */
+ EV_TRACE_ALLOC,
+ EV_TRACE_FREE,
+ 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 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 */
+ WORK_PENDING, /* completion flag for drbd_disconnect */
+ 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_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 cpumask_t drbd_calc_cpu_mask(struct drbd_conf *mdev);
+#else
+#define drbd_thread_current_set_cpu(A) ({})
+#define drbd_calc_cpu_mask(A) CPU_MASK_ALL
+#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 int drbd_io_error(struct drbd_conf *mdev, int forcedetach);
+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 int _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 void _drbd_bm_recount_bits(struct drbd_conf *mdev, char *file, int line);
+#define drbd_bm_recount_bits(mdev) \
+ _drbd_bm_recount_bits(mdev, __FILE__, __LINE__)
+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);
+
+/* 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 *conns_to_name(enum drbd_conns s);
+extern const char *roles_to_name(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);
+}
+
+static inline void __drbd_chk_io_error(struct drbd_conf *mdev, int forcedetach)
+{
+ switch (mdev->ldev->dc.on_io_error) {
+ case EP_PASS_ON:
+ if (!forcedetach) {
+ if (printk_ratelimit())
+ dev_err(DEV, "Local IO failed. Passing error on...\n");
+ 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. Detaching...\n");
+ }
+ 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_io_error().
+ */
+static inline void drbd_chk_io_error(struct drbd_conf *mdev,
+ int error, int forcedetach)
+{
+ if (error) {
+ unsigned long flags;
+ spin_lock_irqsave(&mdev->req_lock, flags);
+ __drbd_chk_io_error(mdev, forcedetach);
+ 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",
+ conns_to_name(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
diff --git a/drivers/block/drbd/drbd_wrappers.h b/drivers/block/drbd/drbd_wrappers.h
new file mode 100644
index 0000000..f93fa11
--- /dev/null
+++ b/drivers/block/drbd/drbd_wrappers.h
@@ -0,0 +1,91 @@
+#ifndef _DRBD_WRAPPERS_H
+#define _DRBD_WRAPPERS_H
+
+#include <linux/ctype.h>
+#include <linux/mm.h>
+
+/* see get_sb_bdev and bd_claim */
+extern char *drbd_sec_holder;
+
+/* sets the number of 512 byte sectors of our virtual device */
+static inline void drbd_set_my_capacity(struct drbd_conf *mdev,
+ sector_t size)
+{
+ /* set_capacity(mdev->this_bdev->bd_disk, size); */
+ set_capacity(mdev->vdisk, size);
+ mdev->this_bdev->bd_inode->i_size = (loff_t)size << 9;
+}
+
+#define drbd_bio_uptodate(bio) bio_flagged(bio, BIO_UPTODATE)
+
+static inline int drbd_bio_has_active_page(struct bio *bio)
+{
+ struct bio_vec *bvec;
+ int i;
+
+ __bio_for_each_segment(bvec, bio, i, 0) {
+ if (page_count(bvec->bv_page) > 1)
+ return 1;
+ }
+
+ return 0;
+}
+
+/* bi_end_io handlers */
+extern void drbd_md_io_complete(struct bio *bio, int error);
+extern void drbd_endio_read_sec(struct bio *bio, int error);
+extern void drbd_endio_write_sec(struct bio *bio, int error);
+extern void drbd_endio_pri(struct bio *bio, int error);
+
+/*
+ * used to submit our private bio
+ */
+static inline void drbd_generic_make_request(struct drbd_conf *mdev,
+ int fault_type, struct bio *bio)
+{
+ __release(local);
+ if (!bio->bi_bdev) {
+ printk(KERN_ERR "drbd%d: drbd_generic_make_request: "
+ "bio->bi_bdev == NULL\n",
+ mdev_to_minor(mdev));
+ dump_stack();
+ bio_endio(bio, -ENODEV);
+ return;
+ }
+
+ if (FAULT_ACTIVE(mdev, fault_type))
+ bio_endio(bio, -EIO);
+ else
+ generic_make_request(bio);
+}
+
+static inline void drbd_plug_device(struct drbd_conf *mdev)
+{
+ struct request_queue *q;
+ q = bdev_get_queue(mdev->this_bdev);
+
+ spin_lock_irq(q->queue_lock);
+
+/* XXX the check on !blk_queue_plugged is redundant,
+ * implicitly checked in blk_plug_device */
+
+ if (!blk_queue_plugged(q)) {
+ blk_plug_device(q);
+ del_timer(&q->unplug_timer);
+ /* unplugging should not happen automatically... */
+ }
+ spin_unlock_irq(q->queue_lock);
+}
+
+static inline int drbd_crypto_is_hash(struct crypto_tfm *tfm)
+{
+ return (crypto_tfm_alg_type(tfm) & CRYPTO_ALG_TYPE_HASH_MASK)
+ == CRYPTO_ALG_TYPE_HASH;
+}
+
+#ifndef __CHECKER__
+# undef __cond_lock
+# define __cond_lock(x,c) (c)
+#endif
+
+#endif
--
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