/* 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 . Copyright (C) 2002-2008, Lars Ellenberg . drbd is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. drbd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "drbd_state.h" #ifdef __CHECKER__ # define __protected_by(x) __attribute__((require_context(x,1,999,"rdwr"))) # define __protected_read_by(x) __attribute__((require_context(x,1,999,"read"))) # define __protected_write_by(x) __attribute__((require_context(x,1,999,"write"))) # define __must_hold(x) __attribute__((context(x,1,1), require_context(x,1,999,"call"))) #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; #ifdef CONFIG_DRBD_FAULT_INJECTION extern int enable_faults; extern int fault_rate; extern int fault_devs; #endif extern char usermode_helper[]; /* I don't remember why XCPU ... * This is used to wake the asender, * and to interrupt sending the sending task * on disconnect. */ #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 #define ID_IN_SYNC (4711ULL) #define ID_OUT_OF_SYNC (4712ULL) #define ID_SYNCER (-1ULL) #define UUID_NEW_BM_OFFSET ((u64)0x0001000000000000ULL) struct drbd_conf; struct drbd_tconn; /* to shorten dev_warn(DEV, "msg"); and relatives statements */ #define DEV (disk_to_dev(mdev->vdisk)) #define conn_printk(LEVEL, TCONN, FMT, ARGS...) \ printk(LEVEL "d-con %s: " FMT, TCONN->name , ## ARGS) #define conn_alert(TCONN, FMT, ARGS...) conn_printk(KERN_ALERT, TCONN, FMT, ## ARGS) #define conn_crit(TCONN, FMT, ARGS...) conn_printk(KERN_CRIT, TCONN, FMT, ## ARGS) #define conn_err(TCONN, FMT, ARGS...) conn_printk(KERN_ERR, TCONN, FMT, ## ARGS) #define conn_warn(TCONN, FMT, ARGS...) conn_printk(KERN_WARNING, TCONN, FMT, ## ARGS) #define conn_notice(TCONN, FMT, ARGS...) conn_printk(KERN_NOTICE, TCONN, FMT, ## ARGS) #define conn_info(TCONN, FMT, ARGS...) conn_printk(KERN_INFO, TCONN, FMT, ## ARGS) #define conn_dbg(TCONN, FMT, ARGS...) conn_printk(KERN_DEBUG, TCONN, FMT, ## ARGS) #define D_ASSERT(exp) if (!(exp)) \ dev_err(DEV, "ASSERT( " #exp " ) in %s:%d\n", __FILE__, __LINE__) /** * expect - Make an assertion * * Unlike the assert macro, this macro returns a boolean result. */ #define expect(exp) ({ \ bool _bool = (exp); \ if (!_bool) \ dev_err(DEV, "ASSERTION %s FAILED in %s\n", \ #exp, __func__); \ _bool; \ }) /* Defines to control fault insertion */ enum { DRBD_FAULT_MD_WR = 0, /* meta data write */ DRBD_FAULT_MD_RD = 1, /* read */ DRBD_FAULT_RS_WR = 2, /* resync */ DRBD_FAULT_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_RECEIVE = 9, /* Changes some bytes upon receiving a [rs]data block */ DRBD_FAULT_MAX, }; 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) { #ifdef CONFIG_DRBD_FAULT_INJECTION return fault_rate && (enable_faults & (1< P_MAY_IGNORE) ... */ P_MAX_OPT_CMD = 0x101, /* special command ids for handshake */ P_INITIAL_META = 0xfff1, /* First Packet on the MetaSock */ P_INITIAL_DATA = 0xfff2, /* First Packet on the Socket */ P_CONNECTION_FEATURES = 0xfffe /* FIXED for the next century! */ }; extern const char *cmdname(enum drbd_packet cmd); /* for sending/receiving the bitmap, * possibly in some encoding scheme */ struct bm_xfer_ctx { /* "const" * stores total bits and long words * of the bitmap, so we don't need to * call the accessor functions over and again. */ unsigned long bm_bits; unsigned long bm_words; /* during xfer, current position within the bitmap */ unsigned long bit_offset; unsigned long word_offset; /* statistics; index: (h->command == P_BITMAP) */ unsigned packets[2]; unsigned bytes[2]; }; extern void INFO_bm_xfer_stats(struct drbd_conf *mdev, const char *direction, struct bm_xfer_ctx *c); static inline void bm_xfer_ctx_bit_to_word_offset(struct bm_xfer_ctx *c) { /* word_offset counts "native long words" (32 or 64 bit), * aligned at 64 bit. * Encoded packet may end at an unaligned bit offset. * In case a fallback clear text packet is transmitted in * between, we adjust this offset back to the last 64bit * aligned "native long word", which makes coding and decoding * the plain text bitmap much more convenient. */ #if BITS_PER_LONG == 64 c->word_offset = c->bit_offset >> 6; #elif BITS_PER_LONG == 32 c->word_offset = c->bit_offset >> 5; c->word_offset &= ~(1UL); #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_header80 { u32 magic; u16 command; u16 length; /* bytes of data after this header */ } __packed; /* Header for big packets, Used for data packets exceeding 64kB */ struct p_header95 { u16 magic; /* use DRBD_MAGIC_BIG here */ u16 command; u32 length; } __packed; struct p_header100 { u32 magic; u16 volume; u16 command; u32 length; u32 pad; } __packed; extern unsigned int drbd_header_size(struct drbd_tconn *tconn); /* these defines must not be changed without changing the protocol version */ #define DP_HARDBARRIER 1 /* depricated */ #define DP_RW_SYNC 2 /* equals REQ_SYNC */ #define DP_MAY_SET_IN_SYNC 4 #define DP_UNPLUG 8 /* not used anymore */ #define DP_FUA 16 /* equals REQ_FUA */ #define DP_FLUSH 32 /* equals REQ_FLUSH */ #define DP_DISCARD 64 /* equals REQ_DISCARD */ #define DP_SEND_RECEIVE_ACK 128 /* This is a proto B write request */ #define DP_SEND_WRITE_ACK 256 /* This is a proto C write request */ struct p_data { u64 sector; /* 64 bits sector number */ u64 block_id; /* to identify the request in protocol B&C */ u32 seq_num; u32 dp_flags; } __packed; /* * commands which share a struct: * p_block_ack: * P_RECV_ACK (proto B), P_WRITE_ACK (proto C), * P_DISCARD_WRITE (proto C, two-primaries conflict detection) * p_block_req: * P_DATA_REQUEST, P_RS_DATA_REQUEST */ struct p_block_ack { u64 sector; u64 block_id; u32 blksize; u32 seq_num; } __packed; struct p_block_req { u64 sector; u64 block_id; u32 blksize; u32 pad; /* to multiple of 8 Byte */ } __packed; /* * commands with their own struct for additional fields: * P_CONNECTION_FEATURES * P_BARRIER * P_BARRIER_ACK * P_SYNC_PARAM * ReportParams */ struct p_connection_features { u32 protocol_min; u32 feature_flags; u32 protocol_max; /* should be more than enough for future enhancements * for now, feature_flags and the reserved array shall be zero. */ u32 _pad; u64 reserved[7]; } __packed; struct p_barrier { u32 barrier; /* barrier number _handle_ only */ u32 pad; /* to multiple of 8 Byte */ } __packed; struct p_barrier_ack { u32 barrier; u32 set_size; } __packed; struct p_rs_param { u32 resync_rate; /* Since protocol version 88 and higher. */ char verify_alg[0]; } __packed; struct p_rs_param_89 { u32 resync_rate; /* protocol version 89: */ char verify_alg[SHARED_SECRET_MAX]; char csums_alg[SHARED_SECRET_MAX]; } __packed; struct p_rs_param_95 { u32 resync_rate; char verify_alg[SHARED_SECRET_MAX]; char csums_alg[SHARED_SECRET_MAX]; u32 c_plan_ahead; u32 c_delay_target; u32 c_fill_target; u32 c_max_rate; } __packed; enum drbd_conn_flags { CF_DISCARD_MY_DATA = 1, CF_DRY_RUN = 2, }; struct p_protocol { u32 protocol; u32 after_sb_0p; u32 after_sb_1p; u32 after_sb_2p; u32 conn_flags; u32 two_primaries; /* Since protocol version 87 and higher. */ char integrity_alg[0]; } __packed; struct p_uuids { u64 uuid[UI_EXTENDED_SIZE]; } __packed; struct p_rs_uuid { u64 uuid; } __packed; struct p_sizes { u64 d_size; /* size of disk */ u64 u_size; /* user requested size */ u64 c_size; /* current exported size */ u32 max_bio_size; /* Maximal size of a BIO */ u16 queue_order_type; /* not yet implemented in DRBD*/ u16 dds_flags; /* use enum dds_flags here. */ } __packed; struct p_state { u32 state; } __packed; struct p_req_state { u32 mask; u32 val; } __packed; struct p_req_state_reply { u32 retcode; } __packed; struct p_drbd06_param { u64 size; u32 state; u32 blksize; u32 protocol; u32 version; u32 gen_cnt[5]; u32 bit_map_gen[5]; } __packed; struct p_discard { u64 block_id; u32 seq_num; u32 pad; } __packed; struct p_block_desc { u64 sector; u32 blksize; u32 pad; /* to multiple of 8 Byte */ } __packed; /* Valid values for the encoding field. * Bump proto version when changing this. */ enum drbd_bitmap_code { /* RLE_VLI_Bytes = 0, * and other bit variants had been defined during * algorithm evaluation. */ RLE_VLI_Bits = 2, }; struct p_compressed_bm { /* (encoding & 0x0f): actual encoding, see enum drbd_bitmap_code * (encoding & 0x80): polarity (set/unset) of first runlength * ((encoding >> 4) & 0x07): pad_bits, number of trailing zero bits * used to pad up to head.length bytes */ u8 encoding; u8 code[0]; } __packed; struct p_delay_probe93 { u32 seq_num; /* sequence number to match the two probe packets */ u32 offset; /* usecs the probe got sent after the reference time point */ } __packed; /* * Bitmap packets need to fit within a single page on the sender and receiver, * so we are limited to 4 KiB (and not to PAGE_SIZE, which can be bigger). */ #define DRBD_SOCKET_BUFFER_SIZE 4096 /**********************************************************************/ 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_tconn *tconn; int reset_cpu_mask; char name[9]; }; static inline enum drbd_thread_state get_t_state(struct drbd_thread *thi) { /* THINK testing the t_state seems to be uncritical in all cases * (but thread_{start,stop}), so we can read it *without* the lock. * --lge */ smp_rmb(); return thi->t_state; } struct drbd_work { struct list_head list; int (*cb)(struct drbd_work *, int cancel); union { struct drbd_conf *mdev; struct drbd_tconn *tconn; }; }; #include "drbd_interval.h" extern int drbd_wait_misc(struct drbd_conf *, struct drbd_interval *); struct drbd_request { struct drbd_work w; /* if local IO is not allowed, will be NULL. * if local IO _is_ allowed, holds the locally submitted bio clone, * or, after local IO completion, the ERR_PTR(error). * see drbd_request_endio(). */ struct bio *private_bio; struct drbd_interval i; 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... */ 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_writes; /* number of requests attached before this barrier */ }; 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_HAVE_BARRIER_NUMBER, }; enum epoch_event { EV_PUT, EV_GOT_BARRIER_NR, EV_BECAME_LAST, EV_CLEANUP = 32, /* used as flag */ }; struct drbd_wq_barrier { struct drbd_work w; struct completion done; }; struct digest_info { int digest_size; void *digest; }; struct drbd_peer_request { struct drbd_work w; struct drbd_epoch *epoch; /* for writes */ struct page *pages; atomic_t pending_bios; struct drbd_interval i; /* see comments on ee flag bits below */ unsigned long flags; union { u64 block_id; struct digest_info *digest; }; }; /* ee flag bits. * While corresponding bios are in flight, the only modification will be * set_bit WAS_ERROR, which has to be atomic. * If no bios are in flight yet, or all have been completed, * non-atomic modification to ee->flags is ok. */ enum { __EE_CALL_AL_COMPLETE_IO, __EE_MAY_SET_IN_SYNC, /* In case a barrier failed, * we need to resubmit without the barrier flag. */ __EE_RESUBMITTED, /* we may have several bios per peer request. * if any of those fail, we set this flag atomically * from the endio callback */ __EE_WAS_ERROR, /* This ee has a pointer to a digest instead of a block id */ __EE_HAS_DIGEST, /* Conflicting local requests need to be restarted after this request */ __EE_RESTART_REQUESTS, /* The peer wants a write ACK for this (wire proto C) */ __EE_SEND_WRITE_ACK, /* Is set when net_conf had two_primaries set while creating this peer_req */ __EE_IN_INTERVAL_TREE, }; #define EE_CALL_AL_COMPLETE_IO (1<<__EE_CALL_AL_COMPLETE_IO) #define EE_MAY_SET_IN_SYNC (1<<__EE_MAY_SET_IN_SYNC) #define EE_RESUBMITTED (1<<__EE_RESUBMITTED) #define EE_WAS_ERROR (1<<__EE_WAS_ERROR) #define EE_HAS_DIGEST (1<<__EE_HAS_DIGEST) #define EE_RESTART_REQUESTS (1<<__EE_RESTART_REQUESTS) #define EE_SEND_WRITE_ACK (1<<__EE_SEND_WRITE_ACK) #define EE_IN_INTERVAL_TREE (1<<__EE_IN_INTERVAL_TREE) /* flag bits per mdev */ enum { 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 */ USE_DEGR_WFC_T, /* degr-wfc-timeout instead of wfc-timeout. */ 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. */ NO_BARRIER_SUPP, /* underlying block device doesn't implement barriers */ CONSIDER_RESYNC, MD_NO_FUA, /* Users wants us to not use FUA/FLUSH on meta data dev */ SUSPEND_IO, /* suspend application io */ BITMAP_IO, /* suspend application io; once no more io in flight, start bitmap io */ BITMAP_IO_QUEUED, /* Started bitmap IO */ GO_DISKLESS, /* Disk is being detached, on io-error or admin request. */ WAS_IO_ERROR, /* Local disk failed returned IO error */ RESYNC_AFTER_NEG, /* Resync after online grow after the attach&negotiate finished. */ RESIZE_PENDING, /* Size change detected locally, waiting for the response from * the peer, if it changed there as well. */ NEW_CUR_UUID, /* Create new current UUID when thawing IO */ AL_SUSPENDED, /* Activity logging is currently suspended. */ AHEAD_TO_SYNC_SOURCE, /* Ahead -> SyncSource queued */ B_RS_H_DONE, /* Before resync handler done (already executed) */ DISCARD_MY_DATA, /* discard_my_data flag per volume */ }; struct drbd_bitmap; /* opaque for drbd_conf */ /* definition of bits in bm_flags to be used in drbd_bm_lock * and drbd_bitmap_io and friends. */ enum bm_flag { /* do we need to kfree, or vfree bm_pages? */ BM_P_VMALLOCED = 0x10000, /* internal use only, will be masked out */ /* currently locked for bulk operation */ BM_LOCKED_MASK = 0x7, /* in detail, that is: */ BM_DONT_CLEAR = 0x1, BM_DONT_SET = 0x2, BM_DONT_TEST = 0x4, /* (test bit, count bit) allowed (common case) */ BM_LOCKED_TEST_ALLOWED = 0x3, /* testing bits, as well as setting new bits allowed, but clearing bits * would be unexpected. Used during bitmap receive. Setting new bits * requires sending of "out-of-sync" information, though. */ BM_LOCKED_SET_ALLOWED = 0x1, /* clear is not expected while bitmap is locked for bulk operation */ }; /* 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. */ 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 */ void *sbuf; void *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 ldev->dc.al_extents, which in turn * gets applied to act_log->nr_elements */ }; struct drbd_backing_dev { struct block_device *backing_bdev; struct block_device *md_bdev; struct drbd_md md; struct disk_conf *disk_conf; /* RCU, for updates: mdev->tconn->conf_update */ sector_t known_size; /* last known size of that backing device */ }; struct drbd_md_io { unsigned int done; int error; }; struct bm_io_work { struct drbd_work w; char *why; enum bm_flag flags; int (*io_fn)(struct drbd_conf *mdev); void (*done)(struct drbd_conf *mdev, int rv); }; enum write_ordering_e { WO_none, WO_drain_io, WO_bdev_flush, }; struct fifo_buffer { unsigned int head_index; unsigned int size; int total; /* sum of all values */ int values[0]; }; extern struct fifo_buffer *fifo_alloc(int fifo_size); /* flag bits per tconn */ enum { NET_CONGESTED, /* The data socket is congested */ DISCARD_CONCURRENT, /* Set on one node, cleared on the peer! */ SEND_PING, /* whether asender should send a ping asap */ SIGNAL_ASENDER, /* whether asender wants to be interrupted */ GOT_PING_ACK, /* set when we receive a ping_ack packet, ping_wait gets woken */ CONN_WD_ST_CHG_OKAY, CONN_WD_ST_CHG_FAIL, CONN_DRY_RUN, /* Expect disconnect after resync handshake. */ CREATE_BARRIER, /* next P_DATA is preceded by a P_BARRIER */ }; struct drbd_tconn { /* is a resource from the config file */ char *name; /* Resource name */ struct list_head all_tconn; /* linked on global drbd_tconns */ struct kref kref; struct idr volumes; /* to mdev mapping */ enum drbd_conns cstate; /* Only C_STANDALONE to C_WF_REPORT_PARAMS */ unsigned susp:1; /* IO suspended by user */ unsigned susp_nod:1; /* IO suspended because no data */ unsigned susp_fen:1; /* IO suspended because fence peer handler runs */ struct mutex cstate_mutex; /* Protects graceful disconnects */ unsigned long flags; struct net_conf *net_conf; /* content protected by rcu */ struct mutex conf_update; /* mutex for ready-copy-update of net_conf and disk_conf */ wait_queue_head_t ping_wait; /* Woken upon reception of a ping, and a state change */ struct res_opts res_opts; struct sockaddr_storage my_addr; int my_addr_len; struct sockaddr_storage peer_addr; int peer_addr_len; struct drbd_socket data; /* data/barrier/cstate/parameter packets */ struct drbd_socket meta; /* ping/ack (metadata) packets */ int agreed_pro_version; /* actually used protocol version */ unsigned long last_received; /* in jiffies, either socket */ unsigned int ko_count; spinlock_t req_lock; struct 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 list_head barrier_acked_requests; struct crypto_hash *cram_hmac_tfm; struct crypto_hash *integrity_tfm; /* checksums we compute, updates protected by tconn->data->mutex */ struct crypto_hash *peer_integrity_tfm; /* checksums we verify, only accessed from receiver thread */ struct crypto_hash *csums_tfm; struct crypto_hash *verify_tfm; void *int_dig_in; void *int_dig_vv; enum write_ordering_e write_ordering; struct drbd_thread receiver; struct drbd_thread worker; struct drbd_thread asender; cpumask_var_t cpu_mask; }; struct drbd_conf { struct drbd_tconn *tconn; int vnr; /* volume number within the connection */ struct kref kref; /* things that are stored as / read from meta data on disk */ unsigned long flags; /* configured by drbdsetup */ struct drbd_backing_dev *ldev __protected_by(local); sector_t p_size; /* partner's disk size */ struct request_queue *rq_queue; struct block_device *this_bdev; struct gendisk *vdisk; struct drbd_work resync_work, unplug_work, go_diskless, md_sync_work, start_resync_work; struct timer_list resync_timer; struct timer_list md_sync_timer; struct timer_list start_resync_timer; struct timer_list request_timer; #ifdef DRBD_DEBUG_MD_SYNC struct { unsigned int line; const char* func; } last_md_mark_dirty; #endif /* Used after attach while negotiating new disk state. */ union drbd_state new_state_tmp; union drbd_dev_state state; wait_queue_head_t misc_wait; wait_queue_head_t state_wait; /* upon each state change. */ unsigned int send_cnt; unsigned int recv_cnt; unsigned int read_cnt; unsigned int writ_cnt; unsigned int al_writ_cnt; unsigned int bm_writ_cnt; atomic_t ap_bio_cnt; /* Requests we need to complete */ atomic_t ap_pending_cnt; /* AP data packets on the wire, ack expected */ atomic_t rs_pending_cnt; /* RS request/data packets on the wire */ atomic_t unacked_cnt; /* Need to send replies for */ atomic_t local_cnt; /* Waiting for local completion */ /* Interval tree of pending local requests */ struct rb_root read_requests; struct rb_root write_requests; /* blocks to resync in this run [unit BM_BLOCK_SIZE] */ unsigned long rs_total; /* number of resync blocks that failed in this run */ unsigned long rs_failed; /* Syncer's start time [unit jiffies] */ unsigned long rs_start; /* cumulated time in PausedSyncX state [unit jiffies] */ unsigned long rs_paused; /* skipped because csum was equal [unit BM_BLOCK_SIZE] */ unsigned long rs_same_csum; #define DRBD_SYNC_MARKS 8 #define DRBD_SYNC_MARK_STEP (3*HZ) /* block not up-to-date at mark [unit BM_BLOCK_SIZE] */ unsigned long rs_mark_left[DRBD_SYNC_MARKS]; /* marks's time [unit jiffies] */ unsigned long rs_mark_time[DRBD_SYNC_MARKS]; /* current index into rs_mark_{left,time} */ int rs_last_mark; /* 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 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; struct list_head active_ee; /* IO in progress (P_DATA gets written to disk) */ struct list_head sync_ee; /* IO in progress (P_RS_DATA_REPLY gets written to disk) */ struct list_head done_ee; /* need to send P_WRITE_ACK */ struct list_head read_ee; /* [RS]P_DATA_REQUEST being read */ struct list_head net_ee; /* zero-copy network send in progress */ int next_barrier_nr; struct list_head resync_reads; atomic_t pp_in_use; /* allocated from page pool */ atomic_t pp_in_use_by_net; /* sendpage()d, still referenced by tcp */ wait_queue_head_t ee_wait; struct page *md_io_page; /* one page buffer for md_io */ struct drbd_md_io md_io; atomic_t md_io_in_use; /* protects the md_io, md_io_page and md_io_tmpp */ spinlock_t al_lock; wait_queue_head_t al_wait; struct lru_cache *act_log; /* activity log */ unsigned int al_tr_number; int al_tr_cycle; int al_tr_pos; /* position of the next transaction in the journal */ wait_queue_head_t seq_wait; atomic_t packet_seq; unsigned int peer_seq; spinlock_t peer_seq_lock; unsigned int minor; unsigned long comm_bm_set; /* communicated number of set bits. */ struct bm_io_work bm_io_work; u64 ed_uuid; /* UUID of the exposed data */ struct mutex own_state_mutex; struct mutex *state_mutex; /* either own_state_mutex or mdev->tconn->cstate_mutex */ char congestion_reason; /* Why we where congested... */ atomic_t rs_sect_in; /* for incoming resync data rate, SyncTarget */ atomic_t rs_sect_ev; /* for submitted resync data rate, both */ int rs_last_sect_ev; /* counter to compare with */ int rs_last_events; /* counter of read or write "events" (unit sectors) * on the lower level device when we last looked. */ int c_sync_rate; /* current resync rate after syncer throttle magic */ struct fifo_buffer *rs_plan_s; /* correction values of resync planer (RCU, tconn->conn_update) */ int rs_in_flight; /* resync sectors in flight (to proxy, in proxy and from proxy) */ atomic_t ap_in_flight; /* App sectors in flight (waiting for ack) */ int peer_max_bio_size; int local_max_bio_size; }; static inline struct drbd_conf *minor_to_mdev(unsigned int minor) { return (struct drbd_conf *)idr_find(&minors, minor); } static inline unsigned int mdev_to_minor(struct drbd_conf *mdev) { return mdev->minor; } static inline struct drbd_conf *vnr_to_mdev(struct drbd_tconn *tconn, int vnr) { return (struct drbd_conf *)idr_find(&tconn->volumes, vnr); } /* * function declarations *************************/ /* drbd_main.c */ enum dds_flags { DDSF_FORCED = 1, DDSF_NO_RESYNC = 2, /* Do not run a resync for the new space */ }; extern void drbd_init_set_defaults(struct drbd_conf *mdev); extern int drbd_thread_start(struct drbd_thread *thi); extern void _drbd_thread_stop(struct drbd_thread *thi, int restart, int wait); extern char *drbd_task_to_thread_name(struct drbd_tconn *tconn, struct task_struct *task); #ifdef CONFIG_SMP extern void drbd_thread_current_set_cpu(struct drbd_thread *thi); extern void drbd_calc_cpu_mask(struct drbd_tconn *tconn); #else #define drbd_thread_current_set_cpu(A) ({}) #define drbd_calc_cpu_mask(A) ({}) #endif extern void tl_release(struct drbd_tconn *, unsigned int barrier_nr, unsigned int set_size); extern void tl_clear(struct drbd_tconn *); extern void _tl_add_barrier(struct drbd_tconn *, struct drbd_tl_epoch *); extern void drbd_free_sock(struct drbd_tconn *tconn); extern int drbd_send(struct drbd_tconn *tconn, struct socket *sock, void *buf, size_t size, unsigned msg_flags); extern int drbd_send_all(struct drbd_tconn *, struct socket *, void *, size_t, unsigned); extern int __drbd_send_protocol(struct drbd_tconn *tconn, enum drbd_packet cmd); extern int drbd_send_protocol(struct drbd_tconn *tconn); extern int drbd_send_uuids(struct drbd_conf *mdev); extern int drbd_send_uuids_skip_initial_sync(struct drbd_conf *mdev); extern void drbd_gen_and_send_sync_uuid(struct drbd_conf *mdev); extern int drbd_send_sizes(struct drbd_conf *mdev, int trigger_reply, enum dds_flags flags); extern int _conn_send_state_req(struct drbd_tconn *, int vnr, enum drbd_packet cmd, union drbd_state, union drbd_state); extern int drbd_send_state(struct drbd_conf *mdev, union drbd_state s); extern int drbd_send_current_state(struct drbd_conf *mdev); extern int drbd_send_sync_param(struct drbd_conf *mdev); extern void drbd_send_b_ack(struct drbd_conf *mdev, u32 barrier_nr, u32 set_size); extern int drbd_send_ack(struct drbd_conf *, enum drbd_packet, struct drbd_peer_request *); extern void drbd_send_ack_rp(struct drbd_conf *mdev, enum drbd_packet cmd, struct p_block_req *rp); extern void drbd_send_ack_dp(struct drbd_conf *mdev, enum drbd_packet cmd, struct p_data *dp, int data_size); extern int drbd_send_ack_ex(struct drbd_conf *mdev, enum drbd_packet cmd, sector_t sector, int blksize, u64 block_id); extern int drbd_send_out_of_sync(struct drbd_conf *, struct drbd_request *); extern int drbd_send_block(struct drbd_conf *, enum drbd_packet, struct drbd_peer_request *); extern int drbd_send_dblock(struct drbd_conf *mdev, struct drbd_request *req); extern int drbd_send_drequest(struct drbd_conf *mdev, int cmd, sector_t sector, int size, u64 block_id); extern int drbd_send_drequest_csum(struct drbd_conf *mdev, sector_t sector, int size, void *digest, int digest_size, enum drbd_packet cmd); extern int drbd_send_ov_request(struct drbd_conf *mdev,sector_t sector,int size); extern int drbd_send_bitmap(struct drbd_conf *mdev); extern void drbd_send_sr_reply(struct drbd_conf *mdev, enum drbd_state_rv retcode); extern void conn_send_sr_reply(struct drbd_tconn *tconn, enum drbd_state_rv retcode); extern void drbd_free_bc(struct drbd_backing_dev *ldev); extern void drbd_mdev_cleanup(struct drbd_conf *mdev); void drbd_print_uuids(struct drbd_conf *mdev, const char *text); extern void drbd_md_sync(struct drbd_conf *mdev); extern int drbd_md_read(struct drbd_conf *mdev, struct drbd_backing_dev *bdev); extern void drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local); extern void _drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local); extern void drbd_uuid_new_current(struct drbd_conf *mdev) __must_hold(local); extern void _drbd_uuid_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); #ifndef DRBD_DEBUG_MD_SYNC extern void drbd_md_mark_dirty(struct drbd_conf *mdev); #else #define drbd_md_mark_dirty(m) drbd_md_mark_dirty_(m, __LINE__ , __func__ ) extern void drbd_md_mark_dirty_(struct drbd_conf *mdev, unsigned int line, const char *func); #endif extern void drbd_queue_bitmap_io(struct drbd_conf *mdev, int (*io_fn)(struct drbd_conf *), void (*done)(struct drbd_conf *, int), char *why, enum bm_flag flags); extern int drbd_bitmap_io(struct drbd_conf *mdev, int (*io_fn)(struct drbd_conf *), char *why, enum bm_flag flags); extern int drbd_bmio_set_n_write(struct drbd_conf *mdev); extern int drbd_bmio_clear_n_write(struct drbd_conf *mdev); extern void drbd_go_diskless(struct drbd_conf *mdev); extern void drbd_ldev_destroy(struct drbd_conf *mdev); /* Meta data layout We reserve a 128MB Block (4k aligned) * either at the end of the backing device * or on a separate meta data device. */ /* The following numbers are sectors */ /* Allows up to about 3.8TB, so if you want more, * you need to use the "flexible" meta data format. */ #define MD_RESERVED_SECT (128LU << 11) /* 128 MB, unit sectors */ #define MD_AL_OFFSET 8 /* 8 Sectors after start of meta area */ #define MD_AL_SECTORS 64 /* = 32 kB on disk activity log ring buffer */ #define MD_BM_OFFSET (MD_AL_OFFSET + MD_AL_SECTORS) /* we do all meta data IO in 4k blocks */ #define MD_BLOCK_SHIFT 12 #define MD_BLOCK_SIZE (1< we need 32 KB bitmap. * Bit 0 ==> local node thinks this block is binary identical on both nodes * Bit 1 ==> local node thinks this block needs to be synced. */ #define SLEEP_TIME (HZ/10) /* We do bitmap IO in units of 4k blocks. * We also still have a hardcoded 4k per bit relation. */ #define BM_BLOCK_SHIFT 12 /* 4k per bit */ #define BM_BLOCK_SIZE (1<>(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< BIO_MAX_SIZE #error Architecture not supported: DRBD_MAX_BIO_SIZE > BIO_MAX_SIZE #endif #define DRBD_MAX_BIO_SIZE_SAFE (1 << 12) /* Works always = 4k */ #define DRBD_MAX_SIZE_H80_PACKET (1 << 15) /* Header 80 only allows packets up to 32KiB data */ #define DRBD_MAX_BIO_SIZE_P95 (1 << 17) /* Protocol 95 to 99 allows bios up to 128KiB */ extern int drbd_bm_init(struct drbd_conf *mdev); extern int drbd_bm_resize(struct drbd_conf *mdev, sector_t sectors, int set_new_bits); extern void drbd_bm_cleanup(struct drbd_conf *mdev); extern void drbd_bm_set_all(struct drbd_conf *mdev); extern void drbd_bm_clear_all(struct drbd_conf *mdev); /* set/clear/test only a few bits at a time */ extern int drbd_bm_set_bits( struct drbd_conf *mdev, unsigned long s, unsigned long e); extern int drbd_bm_clear_bits( struct drbd_conf *mdev, unsigned long s, unsigned long e); extern int drbd_bm_count_bits( struct drbd_conf *mdev, const unsigned long s, const unsigned long e); /* bm_set_bits variant for use while holding drbd_bm_lock, * may process the whole bitmap in one go */ extern void _drbd_bm_set_bits(struct drbd_conf *mdev, const unsigned long s, const unsigned long e); extern int drbd_bm_test_bit(struct drbd_conf *mdev, unsigned long bitnr); extern int drbd_bm_e_weight(struct drbd_conf *mdev, unsigned long enr); extern int drbd_bm_write_page(struct drbd_conf *mdev, unsigned int idx) __must_hold(local); extern int drbd_bm_read(struct drbd_conf *mdev) __must_hold(local); extern void drbd_bm_mark_for_writeout(struct drbd_conf *mdev, int page_nr); extern int drbd_bm_write(struct drbd_conf *mdev) __must_hold(local); extern int drbd_bm_write_hinted(struct drbd_conf *mdev) __must_hold(local); extern 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); #define DRBD_END_OF_BITMAP (~(unsigned long)0) extern unsigned long drbd_bm_find_next(struct drbd_conf *mdev, unsigned long bm_fo); /* bm_find_next variants for use while you hold drbd_bm_lock() */ extern unsigned long _drbd_bm_find_next(struct drbd_conf *mdev, unsigned long bm_fo); extern unsigned long _drbd_bm_find_next_zero(struct drbd_conf *mdev, unsigned long bm_fo); extern unsigned long _drbd_bm_total_weight(struct drbd_conf *mdev); extern unsigned long drbd_bm_total_weight(struct drbd_conf *mdev); extern int drbd_bm_rs_done(struct drbd_conf *mdev); /* for receive_bitmap */ extern void drbd_bm_merge_lel(struct drbd_conf *mdev, size_t offset, size_t number, unsigned long *buffer); /* for _drbd_send_bitmap */ extern void drbd_bm_get_lel(struct drbd_conf *mdev, size_t offset, size_t number, unsigned long *buffer); extern void drbd_bm_lock(struct drbd_conf *mdev, char *why, enum bm_flag flags); extern void drbd_bm_unlock(struct drbd_conf *mdev); /* drbd_main.c */ extern struct kmem_cache *drbd_request_cache; extern struct kmem_cache *drbd_ee_cache; /* peer requests */ extern struct kmem_cache *drbd_bm_ext_cache; /* bitmap extents */ extern struct kmem_cache *drbd_al_ext_cache; /* activity log extents */ extern mempool_t *drbd_request_mempool; extern mempool_t *drbd_ee_mempool; /* drbd's page pool, used to buffer data received from the peer, * or data requested by the peer. * * This does not have an emergency reserve. * * When allocating from this pool, it first takes pages from the pool. * Only if the pool is depleted will try to allocate from the system. * * The assumption is that pages taken from this pool will be processed, * and given back, "quickly", and then can be recycled, so we can avoid * frequent calls to alloc_page(), and still will be able to make progress even * under memory pressure. */ extern struct page *drbd_pp_pool; extern spinlock_t drbd_pp_lock; extern int drbd_pp_vacant; extern wait_queue_head_t drbd_pp_wait; /* We also need a standard (emergency-reserve backed) page pool * for meta data IO (activity log, bitmap). * We can keep it global, as long as it is used as "N pages at a time". * 128 should be plenty, currently we probably can get away with as few as 1. */ #define DRBD_MIN_POOL_PAGES 128 extern mempool_t *drbd_md_io_page_pool; /* We also need to make sure we get a bio * when we need it for housekeeping purposes */ extern struct bio_set *drbd_md_io_bio_set; /* to allocate from that set */ extern struct bio *bio_alloc_drbd(gfp_t gfp_mask); extern rwlock_t global_state_lock; extern int conn_lowest_minor(struct drbd_tconn *tconn); enum drbd_ret_code conn_new_minor(struct drbd_tconn *tconn, unsigned int minor, int vnr); extern void drbd_minor_destroy(struct kref *kref); extern int set_resource_options(struct drbd_tconn *tconn, struct res_opts *res_opts); extern struct drbd_tconn *conn_create(const char *name, struct res_opts *res_opts); extern void conn_destroy(struct kref *kref); struct drbd_tconn *conn_get_by_name(const char *name); extern struct drbd_tconn *conn_get_by_addrs(void *my_addr, int my_addr_len, void *peer_addr, int peer_addr_len); extern void conn_free_crypto(struct drbd_tconn *tconn); extern int proc_details; /* drbd_req */ extern int __drbd_make_request(struct drbd_conf *, struct bio *, unsigned long); extern int drbd_make_request(struct request_queue *q, struct bio *bio); extern int drbd_read_remote(struct drbd_conf *mdev, struct drbd_request *req); extern int drbd_merge_bvec(struct request_queue *q, struct bvec_merge_data *bvm, struct bio_vec *bvec); extern int is_valid_ar_handle(struct drbd_request *, sector_t); /* drbd_nl.c */ extern int drbd_msg_put_info(const char *info); extern void drbd_suspend_io(struct drbd_conf *mdev); extern void drbd_resume_io(struct drbd_conf *mdev); extern char *ppsize(char *buf, unsigned long long size); extern sector_t drbd_new_dev_size(struct drbd_conf *, struct drbd_backing_dev *, sector_t, int); enum determine_dev_size { dev_size_error = -1, unchanged = 0, shrunk = 1, grew = 2 }; extern enum determine_dev_size drbd_determine_dev_size(struct drbd_conf *, enum dds_flags) __must_hold(local); extern void resync_after_online_grow(struct drbd_conf *); extern void drbd_reconsider_max_bio_size(struct drbd_conf *mdev); extern enum drbd_state_rv drbd_set_role(struct drbd_conf *mdev, enum drbd_role new_role, int force); extern bool conn_try_outdate_peer(struct drbd_tconn *tconn); extern void conn_try_outdate_peer_async(struct drbd_tconn *tconn); extern int drbd_khelper(struct drbd_conf *mdev, char *cmd); /* drbd_worker.c */ extern int drbd_worker(struct drbd_thread *thi); enum drbd_ret_code drbd_resync_after_valid(struct drbd_conf *mdev, int o_minor); void drbd_resync_after_changed(struct drbd_conf *mdev); extern void drbd_start_resync(struct drbd_conf *mdev, enum drbd_conns side); extern void resume_next_sg(struct drbd_conf *mdev); extern void suspend_other_sg(struct drbd_conf *mdev); extern int drbd_resync_finished(struct drbd_conf *mdev); /* maybe rather drbd_main.c ? */ extern void *drbd_md_get_buffer(struct drbd_conf *mdev); extern void drbd_md_put_buffer(struct drbd_conf *mdev); extern int drbd_md_sync_page_io(struct drbd_conf *mdev, struct drbd_backing_dev *bdev, sector_t sector, int rw); extern void drbd_ov_out_of_sync_found(struct drbd_conf *, sector_t, int); extern void wait_until_done_or_disk_failure(struct drbd_conf *mdev, unsigned int *done); extern void drbd_rs_controller_reset(struct drbd_conf *mdev); static inline void ov_out_of_sync_print(struct drbd_conf *mdev) { if (mdev->ov_last_oos_size) { dev_err(DEV, "Out of sync: start=%llu, size=%lu (sectors)\n", (unsigned long long)mdev->ov_last_oos_start, (unsigned long)mdev->ov_last_oos_size); } mdev->ov_last_oos_size=0; } extern void drbd_csum_bio(struct drbd_conf *, struct crypto_hash *, struct bio *, void *); extern void drbd_csum_ee(struct drbd_conf *, struct crypto_hash *, struct drbd_peer_request *, void *); /* worker callbacks */ extern int w_read_retry_remote(struct drbd_work *, int); extern int w_e_end_data_req(struct drbd_work *, int); extern int w_e_end_rsdata_req(struct drbd_work *, int); extern int w_e_end_csum_rs_req(struct drbd_work *, int); extern int w_e_end_ov_reply(struct drbd_work *, int); extern int w_e_end_ov_req(struct drbd_work *, int); extern int w_ov_finished(struct drbd_work *, int); extern int w_resync_timer(struct drbd_work *, int); extern int w_send_write_hint(struct drbd_work *, int); extern int w_make_resync_request(struct drbd_work *, int); extern int w_send_dblock(struct drbd_work *, int); extern int w_send_barrier(struct drbd_work *, int); extern int w_send_read_req(struct drbd_work *, int); extern int w_prev_work_done(struct drbd_work *, int); extern int w_e_reissue(struct drbd_work *, int); extern int w_restart_disk_io(struct drbd_work *, int); extern int w_send_out_of_sync(struct drbd_work *, int); extern int w_start_resync(struct drbd_work *, int); extern void resync_timer_fn(unsigned long data); extern void start_resync_timer_fn(unsigned long data); /* drbd_receiver.c */ extern int drbd_rs_should_slow_down(struct drbd_conf *mdev, sector_t sector); extern int drbd_submit_peer_request(struct drbd_conf *, struct drbd_peer_request *, const unsigned, const int); extern int drbd_free_peer_reqs(struct drbd_conf *, struct list_head *); extern struct drbd_peer_request *drbd_alloc_peer_req(struct drbd_conf *, u64, sector_t, unsigned int, gfp_t) __must_hold(local); extern void __drbd_free_peer_req(struct drbd_conf *, struct drbd_peer_request *, int); #define drbd_free_peer_req(m,e) __drbd_free_peer_req(m, e, 0) #define drbd_free_net_peer_req(m,e) __drbd_free_peer_req(m, e, 1) extern struct page *drbd_alloc_pages(struct drbd_conf *, unsigned int, bool); extern void drbd_set_recv_tcq(struct drbd_conf *mdev, int tcq_enabled); extern void _drbd_clear_done_ee(struct drbd_conf *mdev, struct list_head *to_be_freed); extern void conn_flush_workqueue(struct drbd_tconn *tconn); extern int drbd_connected(struct drbd_conf *mdev); static inline void drbd_flush_workqueue(struct drbd_conf *mdev) { conn_flush_workqueue(mdev->tconn); } /* Yes, there is kernel_setsockopt, but only since 2.6.18. * So we have our own copy of it here. */ static inline int drbd_setsockopt(struct socket *sock, int level, int optname, char *optval, int optlen) { mm_segment_t oldfs = get_fs(); char __user *uoptval; int err; uoptval = (char __user __force *)optval; set_fs(KERNEL_DS); if (level == SOL_SOCKET) err = sock_setsockopt(sock, level, optname, uoptval, optlen); else err = sock->ops->setsockopt(sock, level, optname, uoptval, optlen); set_fs(oldfs); return err; } static inline void drbd_tcp_cork(struct socket *sock) { int val = 1; (void) drbd_setsockopt(sock, SOL_TCP, TCP_CORK, (char*)&val, sizeof(val)); } static inline void drbd_tcp_uncork(struct socket *sock) { int val = 0; (void) drbd_setsockopt(sock, SOL_TCP, TCP_CORK, (char*)&val, sizeof(val)); } static inline void drbd_tcp_nodelay(struct socket *sock) { int val = 1; (void) drbd_setsockopt(sock, SOL_TCP, TCP_NODELAY, (char*)&val, sizeof(val)); } static inline void drbd_tcp_quickack(struct socket *sock) { int val = 2; (void) drbd_setsockopt(sock, SOL_TCP, TCP_QUICKACK, (char*)&val, sizeof(val)); } void drbd_bump_write_ordering(struct drbd_tconn *tconn, enum write_ordering_e wo); /* drbd_proc.c */ extern struct proc_dir_entry *drbd_proc; extern const struct file_operations drbd_proc_fops; extern const char *drbd_conn_str(enum drbd_conns s); extern const char *drbd_role_str(enum drbd_role s); /* drbd_actlog.c */ extern void drbd_al_begin_io(struct drbd_conf *mdev, struct drbd_interval *i); extern void drbd_al_complete_io(struct drbd_conf *mdev, struct drbd_interval *i); extern void drbd_rs_complete_io(struct drbd_conf *mdev, sector_t sector); extern int drbd_rs_begin_io(struct drbd_conf *mdev, sector_t sector); extern int drbd_try_rs_begin_io(struct drbd_conf *mdev, sector_t sector); extern void drbd_rs_cancel_all(struct drbd_conf *mdev); extern int drbd_rs_del_all(struct drbd_conf *mdev); extern void drbd_rs_failed_io(struct drbd_conf *mdev, sector_t sector, int size); extern void drbd_advance_rs_marks(struct drbd_conf *mdev, unsigned long still_to_go); extern void __drbd_set_in_sync(struct drbd_conf *mdev, sector_t sector, int size, const char *file, const unsigned int line); #define drbd_set_in_sync(mdev, sector, size) \ __drbd_set_in_sync(mdev, sector, size, __FILE__, __LINE__) extern int __drbd_set_out_of_sync(struct drbd_conf *mdev, sector_t sector, int size, const char *file, const unsigned int line); #define drbd_set_out_of_sync(mdev, sector, size) \ __drbd_set_out_of_sync(mdev, sector, size, __FILE__, __LINE__) extern void drbd_al_shrink(struct drbd_conf *mdev); /* drbd_nl.c */ /* state info broadcast */ struct sib_info { enum drbd_state_info_bcast_reason sib_reason; union { struct { char *helper_name; unsigned helper_exit_code; }; struct { union drbd_state os; union drbd_state ns; }; }; }; void drbd_bcast_event(struct drbd_conf *mdev, const struct sib_info *sib); /* * inline helper functions *************************/ /* see also page_chain_add and friends in drbd_receiver.c */ static inline struct page *page_chain_next(struct page *page) { return (struct page *)page_private(page); } #define page_chain_for_each(page) \ for (; page && ({ prefetch(page_chain_next(page)); 1; }); \ page = page_chain_next(page)) #define page_chain_for_each_safe(page, n) \ for (; page && ({ n = page_chain_next(page); 1; }); page = n) static inline int drbd_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; } static inline int drbd_peer_req_has_active_page(struct drbd_peer_request *peer_req) { struct page *page = peer_req->pages; page_chain_for_each(page) { if (page_count(page) > 1) return 1; } return 0; } static inline enum drbd_state_rv _drbd_set_state(struct drbd_conf *mdev, union drbd_state ns, enum chg_state_flags flags, struct completion *done) { enum drbd_state_rv rv; read_lock(&global_state_lock); rv = __drbd_set_state(mdev, ns, flags, done); read_unlock(&global_state_lock); return rv; } static inline union drbd_state drbd_read_state(struct drbd_conf *mdev) { union drbd_state rv; rv.i = mdev->state.i; rv.susp = mdev->tconn->susp; rv.susp_nod = mdev->tconn->susp_nod; rv.susp_fen = mdev->tconn->susp_fen; return rv; } #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) { enum drbd_io_error_p ep; rcu_read_lock(); ep = rcu_dereference(mdev->ldev->disk_conf)->on_io_error; rcu_read_unlock(); switch (ep) { case EP_PASS_ON: /* FIXME would this be better named "Ignore"? */ if (!forcedetach) { if (__ratelimit(&drbd_ratelimit_state)) dev_err(DEV, "Local IO failed in %s.\n", where); if (mdev->state.disk > D_INCONSISTENT) _drbd_set_state(_NS(mdev, disk, D_INCONSISTENT), CS_HARD, NULL); break; } /* NOTE fall through to detach case if forcedetach set */ case EP_DETACH: case EP_CALL_HELPER: set_bit(WAS_IO_ERROR, &mdev->flags); 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->tconn->req_lock, flags); __drbd_chk_io_error_(mdev, forcedetach, where); spin_unlock_irqrestore(&mdev->tconn->req_lock, flags); } } /** * drbd_md_first_sector() - Returns the first sector number of the meta data area * @bdev: Meta data block device. * * BTW, for internal meta data, this happens to be the maximum capacity * we could agree upon with our peer node. */ static inline sector_t _drbd_md_first_sector(int meta_dev_idx, struct drbd_backing_dev *bdev) { switch (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; } } static inline sector_t drbd_md_first_sector(struct drbd_backing_dev *bdev) { int meta_dev_idx; rcu_read_lock(); meta_dev_idx = rcu_dereference(bdev->disk_conf)->meta_dev_idx; rcu_read_unlock(); return _drbd_md_first_sector(meta_dev_idx, bdev); } /** * 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) { int meta_dev_idx; rcu_read_lock(); meta_dev_idx = rcu_dereference(bdev->disk_conf)->meta_dev_idx; rcu_read_unlock(); switch (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 ? i_size_read(bdev->bd_inode) >> 9 : 0; } /** * drbd_get_max_capacity() - Returns the capacity we announce to out peer * @bdev: Meta data block device. * * returns the capacity we announce to out peer. we clip ourselves at the * various MAX_SECTORS, because if we don't, current implementation will * oops sooner or later */ static inline sector_t drbd_get_max_capacity(struct drbd_backing_dev *bdev) { sector_t s; int meta_dev_idx; rcu_read_lock(); meta_dev_idx = rcu_dereference(bdev->disk_conf)->meta_dev_idx; rcu_read_unlock(); switch (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(meta_dev_idx, 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) { int meta_dev_idx; rcu_read_lock(); meta_dev_idx = rcu_dereference(bdev->disk_conf)->meta_dev_idx; rcu_read_unlock(); switch (meta_dev_idx) { default: /* external, some index */ return MD_RESERVED_SECT * 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_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_tconn *tconn) { if (test_bit(SIGNAL_ASENDER, &tconn->flags)) force_sig(DRBD_SIG, tconn->asender.task); } static inline void request_ping(struct drbd_tconn *tconn) { set_bit(SEND_PING, &tconn->flags); wake_asender(tconn); } extern void *conn_prepare_command(struct drbd_tconn *, struct drbd_socket *); extern void *drbd_prepare_command(struct drbd_conf *, struct drbd_socket *); extern int conn_send_command(struct drbd_tconn *, struct drbd_socket *, enum drbd_packet, unsigned int, void *, unsigned int); extern int drbd_send_command(struct drbd_conf *, struct drbd_socket *, enum drbd_packet, unsigned int, void *, unsigned int); extern int drbd_send_ping(struct drbd_tconn *tconn); extern int drbd_send_ping_ack(struct drbd_tconn *tconn); extern int drbd_send_state_req(struct drbd_conf *, union drbd_state, union drbd_state); extern int conn_send_state_req(struct drbd_tconn *, union drbd_state, union drbd_state); static inline void drbd_thread_stop(struct drbd_thread *thi) { _drbd_thread_stop(thi, false, true); } static inline void drbd_thread_stop_nowait(struct drbd_thread *thi) { _drbd_thread_stop(thi, false, false); } static inline void drbd_thread_restart_nowait(struct drbd_thread *thi) { _drbd_thread_stop(thi, true, false); } /* counts how many answer packets packets we expect from our peer, * for either explicit application requests, * or implicit barrier packets as necessary. * increased: * w_send_barrier * _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, func, line) \ 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) _dec_ap_pending(mdev, __FUNCTION__, __LINE__) static inline void _dec_ap_pending(struct drbd_conf *mdev, const char *func, int line) { if (atomic_dec_and_test(&mdev->ap_pending_cnt)) wake_up(&mdev->misc_wait); ERR_IF_CNT_IS_NEGATIVE(ap_pending_cnt, func, line); } /* 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 with 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) _dec_rs_pending(mdev, __FUNCTION__, __LINE__) static inline void _dec_rs_pending(struct drbd_conf *mdev, const char *func, int line) { atomic_dec(&mdev->rs_pending_cnt); ERR_IF_CNT_IS_NEGATIVE(rs_pending_cnt, func, line); } /* counts how many answers we still need to send to the peer. * increased on * receive_Data unless protocol A; * we need to send a P_RECV_ACK (proto B) * or P_WRITE_ACK (proto C) * receive_RSDataReply (recv_resync_read) we need to send a P_WRITE_ACK * receive_DataRequest (receive_RSDataRequest) we need to send back P_DATA * receive_Barrier_* we need to send a P_BARRIER_ACK */ static inline void inc_unacked(struct drbd_conf *mdev) { atomic_inc(&mdev->unacked_cnt); } #define dec_unacked(mdev) _dec_unacked(mdev, __FUNCTION__, __LINE__) static inline void _dec_unacked(struct drbd_conf *mdev, const char *func, int line) { atomic_dec(&mdev->unacked_cnt); ERR_IF_CNT_IS_NEGATIVE(unacked_cnt, func, line); } #define sub_unacked(mdev, n) _sub_unacked(mdev, n, __FUNCTION__, __LINE__) static inline void _sub_unacked(struct drbd_conf *mdev, int n, const char *func, int line) { atomic_sub(n, &mdev->unacked_cnt); ERR_IF_CNT_IS_NEGATIVE(unacked_cnt, func, line); } /** * get_ldev() - Increase the ref count on mdev->ldev. Returns 0 if there is no ldev * @M: DRBD device. * * You have to call put_ldev() when finished working with mdev->ldev. */ #define get_ldev(M) __cond_lock(local, _get_ldev_if_state(M,D_INCONSISTENT)) #define get_ldev_if_state(M,MINS) __cond_lock(local, _get_ldev_if_state(M,MINS)) static inline void put_ldev(struct drbd_conf *mdev) { int i = atomic_dec_return(&mdev->local_cnt); /* This may be called from some endio handler, * so we must not sleep here. */ __release(local); D_ASSERT(i >= 0); if (i == 0) { if (mdev->state.disk == D_DISKLESS) /* even internal references gone, safe to destroy */ drbd_ldev_destroy(mdev); if (mdev->state.disk == D_FAILED) /* all application IO references gone. */ drbd_go_diskless(mdev); wake_up(&mdev->misc_wait); } } #ifndef __CHECKER__ static inline int _get_ldev_if_state(struct drbd_conf *mdev, enum drbd_disk_state mins) { int io_allowed; /* never get a reference while D_DISKLESS */ if (mdev->state.disk == D_DISKLESS) return 0; 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, in case we * want to support more than (1<<32) bits on a 32bit arch. */ typecheck(unsigned long, mdev->rs_total); /* note: both rs_total and rs_left are in bits, i.e. in * units of BM_BLOCK_SIZE. * for the percentage, we don't care. */ if (mdev->state.conn == C_VERIFY_S || mdev->state.conn == C_VERIFY_T) *bits_left = mdev->ov_left; else *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 division happens in long context. * We allow up to one petabyte storage right now, * at a granularity of 4k per bit that is 2**38 bits. * After shift right and multiplication by 1000, * this should still fit easily into a 32bit long, * so we don't need a 64bit division on 32bit arch. * Note: currently we don't support such large bitmaps on 32bit * arch anyways, but no harm done to be prepared for it here. */ unsigned int shift = mdev->rs_total > UINT_MAX ? 16 : 10; unsigned long left = *bits_left >> shift; unsigned long total = 1UL + (mdev->rs_total >> shift); unsigned long tmp = 1000UL - left * 1000UL/total; *per_mil_done = tmp; } } /* this throttles on-the-fly application requests * according to max_buffers settings; * maybe re-implement using semaphores? */ static inline int drbd_get_max_buffers(struct drbd_conf *mdev) { struct net_conf *nc; int mxb; rcu_read_lock(); nc = rcu_dereference(mdev->tconn->net_conf); mxb = nc ? nc->max_buffers : 1000000; /* arbitrary limit on open requests */ rcu_read_unlock(); return mxb; } static inline int drbd_state_is_stable(struct drbd_conf *mdev) { union drbd_dev_state s = mdev->state; /* DO NOT add a default clause, we want the compiler to warn us * for any newly introduced state we may have forgotten to add here */ switch ((enum drbd_conns)s.conn) { /* new io only accepted when there is no connection, ... */ 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: case C_AHEAD: case C_BEHIND: /* transitional states, IO allowed */ 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: break; /* Allow IO in BM exchange states with new protocols */ case C_WF_BITMAP_S: if (mdev->tconn->agreed_pro_version < 96) return 0; break; /* no new io accepted in these states */ 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: case D_FAILED: /* disk state is stable as well. */ break; /* no new io accepted during transitional states */ case D_ATTACHING: case D_NEGOTIATING: case D_UNKNOWN: case D_MASK: /* not "stable" */ return 0; } return 1; } static inline int drbd_suspended(struct drbd_conf *mdev) { struct drbd_tconn *tconn = mdev->tconn; return tconn->susp || tconn->susp_fen || tconn->susp_nod; } static inline bool may_inc_ap_bio(struct drbd_conf *mdev) { int mxb = drbd_get_max_buffers(mdev); if (drbd_suspended(mdev)) return false; if (test_bit(SUSPEND_IO, &mdev->flags)) return false; /* to avoid potential deadlock or bitmap corruption, * in various places, we only allow new application io * to start during "stable" states. */ /* no new io accepted when attaching or detaching the disk */ if (!drbd_state_is_stable(mdev)) return false; /* since some older kernels don't have atomic_add_unless, * and we are within the spinlock anyways, we have this workaround. */ if (atomic_read(&mdev->ap_bio_cnt) > mxb) return false; if (test_bit(BITMAP_IO, &mdev->flags)) return false; return true; } static inline bool inc_ap_bio_cond(struct drbd_conf *mdev) { bool rv = false; spin_lock_irq(&mdev->tconn->req_lock); rv = may_inc_ap_bio(mdev); if (rv) atomic_inc(&mdev->ap_bio_cnt); spin_unlock_irq(&mdev->tconn->req_lock); return rv; } static inline void inc_ap_bio(struct drbd_conf *mdev) { /* we wait here * as long as the device is suspended * until the bitmap is no longer on the fly during connection * handshake as long as we would exceed the max_buffer limit. * * to avoid races with the reconnect code, * we need to atomic_inc within the spinlock. */ wait_event(mdev->misc_wait, inc_ap_bio_cond(mdev)); } static inline void dec_ap_bio(struct drbd_conf *mdev) { int mxb = drbd_get_max_buffers(mdev); int ap_bio = atomic_dec_return(&mdev->ap_bio_cnt); D_ASSERT(ap_bio >= 0); /* 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->tconn->data.work, &mdev->bm_io_work.w); } } static inline int drbd_set_ed_uuid(struct drbd_conf *mdev, u64 val) { int changed = mdev->ed_uuid != val; mdev->ed_uuid = val; return changed; } static inline int drbd_queue_order_type(struct drbd_conf *mdev) { /* sorry, we currently have no working implementation * of distributed TCQ stuff */ #ifndef QUEUE_ORDERED_NONE #define QUEUE_ORDERED_NONE 0 #endif return QUEUE_ORDERED_NONE; } static inline void drbd_md_flush(struct drbd_conf *mdev) { int r; if (test_bit(MD_NO_FUA, &mdev->flags)) return; r = blkdev_issue_flush(mdev->ldev->md_bdev, GFP_KERNEL, NULL); if (r) { set_bit(MD_NO_FUA, &mdev->flags); dev_err(DEV, "meta data flush failed with status %d, disabling md-flushes\n", r); } } #endif