/* 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_strings.h" #include "drbd_state.h" #include "drbd_protocol.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 /* module parameter, defined in drbd_main.c */ extern unsigned int minor_count; extern bool disable_sendpage; extern bool allow_oos; void tl_abort_disk_io(struct drbd_device *device); #ifdef CONFIG_DRBD_FAULT_INJECTION extern int enable_faults; extern int fault_rate; extern int fault_devs; #endif extern char usermode_helper[]; /* 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_device; struct drbd_connection; #define __drbd_printk_device(level, device, fmt, args...) \ dev_printk(level, disk_to_dev((device)->vdisk), fmt, ## args) #define __drbd_printk_peer_device(level, peer_device, fmt, args...) \ dev_printk(level, disk_to_dev((peer_device)->device->vdisk), fmt, ## args) #define __drbd_printk_resource(level, resource, fmt, args...) \ printk(level "drbd %s: " fmt, (resource)->name, ## args) #define __drbd_printk_connection(level, connection, fmt, args...) \ printk(level "drbd %s: " fmt, (connection)->resource->name, ## args) void drbd_printk_with_wrong_object_type(void); #define __drbd_printk_if_same_type(obj, type, func, level, fmt, args...) \ (__builtin_types_compatible_p(typeof(obj), type) || \ __builtin_types_compatible_p(typeof(obj), const type)), \ func(level, (const type)(obj), fmt, ## args) #define drbd_printk(level, obj, fmt, args...) \ __builtin_choose_expr( \ __drbd_printk_if_same_type(obj, struct drbd_device *, \ __drbd_printk_device, level, fmt, ## args), \ __builtin_choose_expr( \ __drbd_printk_if_same_type(obj, struct drbd_resource *, \ __drbd_printk_resource, level, fmt, ## args), \ __builtin_choose_expr( \ __drbd_printk_if_same_type(obj, struct drbd_connection *, \ __drbd_printk_connection, level, fmt, ## args), \ __builtin_choose_expr( \ __drbd_printk_if_same_type(obj, struct drbd_peer_device *, \ __drbd_printk_peer_device, level, fmt, ## args), \ drbd_printk_with_wrong_object_type())))) #define drbd_dbg(obj, fmt, args...) \ drbd_printk(KERN_DEBUG, obj, fmt, ## args) #define drbd_alert(obj, fmt, args...) \ drbd_printk(KERN_ALERT, obj, fmt, ## args) #define drbd_err(obj, fmt, args...) \ drbd_printk(KERN_ERR, obj, fmt, ## args) #define drbd_warn(obj, fmt, args...) \ drbd_printk(KERN_WARNING, obj, fmt, ## args) #define drbd_info(obj, fmt, args...) \ drbd_printk(KERN_INFO, obj, fmt, ## args) #define drbd_emerg(obj, fmt, args...) \ drbd_printk(KERN_EMERG, obj, fmt, ## args) #define dynamic_drbd_dbg(device, fmt, args...) \ dynamic_dev_dbg(disk_to_dev(device->vdisk), fmt, ## args) #define D_ASSERT(device, exp) do { \ if (!(exp)) \ drbd_err(device, "ASSERT( " #exp " ) in %s:%d\n", __FILE__, __LINE__); \ } while (0) /** * expect - Make an assertion * * Unlike the assert macro, this macro returns a boolean result. */ #define expect(exp) ({ \ bool _bool = (exp); \ if (!_bool) \ drbd_err(device, "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_device *device, unsigned int type); static inline int drbd_insert_fault(struct drbd_device *device, unsigned int type) { #ifdef CONFIG_DRBD_FAULT_INJECTION return fault_rate && (enable_faults & (1<command == P_BITMAP) */ unsigned packets[2]; unsigned bytes[2]; }; extern void INFO_bm_xfer_stats(struct drbd_device *device, 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 } extern unsigned int drbd_header_size(struct drbd_connection *connection); /**********************************************************************/ 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_resource *resource; struct drbd_connection *connection; int reset_cpu_mask; const char *name; }; 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); }; struct drbd_device_work { struct drbd_work w; struct drbd_device *device; }; #include "drbd_interval.h" extern int drbd_wait_misc(struct drbd_device *, struct drbd_interval *); extern void lock_all_resources(void); extern void unlock_all_resources(void); struct drbd_request { struct drbd_work w; struct drbd_device *device; /* if local IO is not allowed, will be NULL. * if local IO _is_ allowed, holds the locally submitted bio clone, * or, after local IO completion, the ERR_PTR(error). * see drbd_request_endio(). */ struct bio *private_bio; struct drbd_interval i; /* epoch: used to check on "completion" whether this req was in * the current epoch, and we therefore have to close it, * causing a p_barrier packet to be send, starting a new epoch. * * This corresponds to "barrier" in struct p_barrier[_ack], * and to "barrier_nr" in struct drbd_epoch (and various * comments/function parameters/local variable names). */ unsigned int epoch; struct list_head tl_requests; /* ring list in the transfer log */ struct bio *master_bio; /* master bio pointer */ /* see struct drbd_device */ struct list_head req_pending_master_completion; struct list_head req_pending_local; /* for generic IO accounting */ unsigned long start_jif; /* for DRBD internal statistics */ /* Minimal set of time stamps to determine if we wait for activity log * transactions, local disk or peer. 32 bit "jiffies" are good enough, * we don't expect a DRBD request to be stalled for several month. */ /* before actual request processing */ unsigned long in_actlog_jif; /* local disk */ unsigned long pre_submit_jif; /* per connection */ unsigned long pre_send_jif; unsigned long acked_jif; unsigned long net_done_jif; /* Possibly even more detail to track each phase: * master_completion_jif * how long did it take to complete the master bio * (application visible latency) * allocated_jif * how long the master bio was blocked until we finally allocated * a tracking struct * in_actlog_jif * how long did we wait for activity log transactions * * net_queued_jif * when did we finally queue it for sending * pre_send_jif * when did we start sending it * post_send_jif * how long did we block in the network stack trying to send it * acked_jif * when did we receive (or fake, in protocol A) a remote ACK * net_done_jif * when did we receive final acknowledgement (P_BARRIER_ACK), * or decide, e.g. on connection loss, that we do no longer expect * anything from this peer for this request. * * pre_submit_jif * post_sub_jif * when did we start submiting to the lower level device, * and how long did we block in that submit function * local_completion_jif * how long did it take the lower level device to complete this request */ /* once it hits 0, we may complete the master_bio */ atomic_t completion_ref; /* once it hits 0, we may destroy this drbd_request object */ struct kref kref; unsigned rq_state; /* see comments above _req_mod() */ }; struct drbd_epoch { struct drbd_connection *connection; 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; }; /* Prototype declaration of function defined in drbd_receiver.c */ int drbdd_init(struct drbd_thread *); int drbd_asender(struct drbd_thread *); /* 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 digest_info { int digest_size; void *digest; }; struct drbd_peer_request { struct drbd_work w; struct drbd_peer_device *peer_device; 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; unsigned long submit_jif; 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, /* is this a TRIM aka REQ_DISCARD? */ __EE_IS_TRIM, /* our lower level cannot handle trim, * and we want to fall back to zeroout instead */ __EE_IS_TRIM_USE_ZEROOUT, /* 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, /* for debugfs: */ /* has this been submitted, or does it still wait for something else? */ __EE_SUBMITTED, /* this is/was a write request */ __EE_WRITE, /* this originates from application on peer * (not some resync or verify or other DRBD internal request) */ __EE_APPLICATION, }; #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_IS_TRIM (1<<__EE_IS_TRIM) #define EE_IS_TRIM_USE_ZEROOUT (1<<__EE_IS_TRIM_USE_ZEROOUT) #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) #define EE_SUBMITTED (1<<__EE_SUBMITTED) #define EE_WRITE (1<<__EE_WRITE) #define EE_APPLICATION (1<<__EE_APPLICATION) /* flag bits per device */ enum { UNPLUG_REMOTE, /* sending a "UnplugRemote" could help */ MD_DIRTY, /* current uuids and flags not yet on disk */ USE_DEGR_WFC_T, /* degr-wfc-timeout instead of wfc-timeout. */ 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. */ CONSIDER_RESYNC, MD_NO_FUA, /* Users wants us to not use FUA/FLUSH on meta data dev */ BITMAP_IO, /* suspend application io; once no more io in flight, start bitmap io */ BITMAP_IO_QUEUED, /* Started bitmap IO */ WAS_IO_ERROR, /* Local disk failed, returned IO error */ WAS_READ_ERROR, /* Local disk READ failed (set additionally to the above) */ FORCE_DETACH, /* Force-detach from local disk, aborting any pending local IO */ RESYNC_AFTER_NEG, /* Resync after online grow after the attach&negotiate finished. */ RESIZE_PENDING, /* Size change detected locally, waiting for the response from * the peer, if it changed there as well. */ NEW_CUR_UUID, /* Create new current UUID when thawing IO */ AL_SUSPENDED, /* Activity logging is currently suspended. */ AHEAD_TO_SYNC_SOURCE, /* Ahead -> SyncSource queued */ B_RS_H_DONE, /* Before resync handler done (already executed) */ DISCARD_MY_DATA, /* discard_my_data flag per volume */ READ_BALANCE_RR, FLUSH_PENDING, /* if set, device->flush_jif is when we submitted that flush * from drbd_flush_after_epoch() */ /* cleared only after backing device related structures have been destroyed. */ GOING_DISKLESS, /* Disk is being detached, because of io-error, or admin request. */ /* to be used in drbd_device_post_work() */ GO_DISKLESS, /* tell worker to schedule cleanup before detach */ DESTROY_DISK, /* tell worker to close backing devices and destroy related structures. */ MD_SYNC, /* tell worker to call drbd_md_sync() */ RS_START, /* tell worker to start resync/OV */ RS_PROGRESS, /* tell worker that resync made significant progress */ RS_DONE, /* tell worker that resync is done */ }; struct drbd_bitmap; /* opaque for drbd_device */ /* definition of bits in bm_flags to be used in drbd_bm_lock * and drbd_bitmap_io and friends. */ enum bm_flag { /* currently locked for bulk operation */ BM_LOCKED_MASK = 0xf, /* in detail, that is: */ BM_DONT_CLEAR = 0x1, BM_DONT_SET = 0x2, BM_DONT_TEST = 0x4, /* so we can mark it locked for bulk operation, * and still allow all non-bulk operations */ BM_IS_LOCKED = 0x8, /* (test bit, count bit) allowed (common case) */ BM_LOCKED_TEST_ALLOWED = BM_DONT_CLEAR | BM_DONT_SET | BM_IS_LOCKED, /* 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 = BM_DONT_CLEAR | BM_IS_LOCKED, /* for drbd_bm_write_copy_pages, everything is allowed, * only concurrent bulk operations are locked out. */ BM_LOCKED_CHANGE_ALLOWED = BM_IS_LOCKED, }; struct drbd_work_queue { struct list_head q; spinlock_t q_lock; /* to protect the list. */ wait_queue_head_t q_wait; }; struct drbd_socket { struct mutex mutex; struct socket *socket; /* this way we get our * send/receive buffers off the stack */ void *sbuf; void *rbuf; }; struct drbd_md { u64 md_offset; /* sector offset to 'super' block */ u64 la_size_sect; /* last agreed size, unit sectors */ spinlock_t uuid_lock; u64 uuid[UI_SIZE]; u64 device_uuid; u32 flags; u32 md_size_sect; s32 al_offset; /* signed relative sector offset to activity log */ s32 bm_offset; /* signed relative sector offset to bitmap */ /* cached value of bdev->disk_conf->meta_dev_idx (see below) */ s32 meta_dev_idx; /* see al_tr_number_to_on_disk_sector() */ u32 al_stripes; u32 al_stripe_size_4k; u32 al_size_4k; /* cached product of the above */ }; struct drbd_backing_dev { struct block_device *backing_bdev; struct block_device *md_bdev; struct drbd_md md; struct disk_conf *disk_conf; /* RCU, for updates: resource->conf_update */ sector_t known_size; /* last known size of that backing device */ }; struct drbd_md_io { struct page *page; unsigned long start_jif; /* last call to drbd_md_get_buffer */ unsigned long submit_jif; /* last _drbd_md_sync_page_io() submit */ const char *current_use; atomic_t in_use; unsigned int done; int error; }; struct bm_io_work { struct drbd_work w; char *why; enum bm_flag flags; int (*io_fn)(struct drbd_device *device); void (*done)(struct drbd_device *device, int rv); }; 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 connection */ enum { NET_CONGESTED, /* The data socket is congested */ RESOLVE_CONFLICTS, /* Set on one node, cleared on the peer! */ SEND_PING, GOT_PING_ACK, /* set when we receive a ping_ack packet, ping_wait gets woken */ CONN_WD_ST_CHG_REQ, /* A cluster wide state change on the connection is active */ CONN_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 */ STATE_SENT, /* Do not change state/UUIDs while this is set */ CALLBACK_PENDING, /* Whether we have a call_usermodehelper(, UMH_WAIT_PROC) * pending, from drbd worker context. * If set, bdi_write_congested() returns true, * so shrink_page_list() would not recurse into, * and potentially deadlock on, this drbd worker. */ DISCONNECT_SENT, DEVICE_WORK_PENDING, /* tell worker that some device has pending work */ }; enum which_state { NOW, OLD = NOW, NEW }; struct drbd_resource { char *name; #ifdef CONFIG_DEBUG_FS struct dentry *debugfs_res; struct dentry *debugfs_res_volumes; struct dentry *debugfs_res_connections; struct dentry *debugfs_res_in_flight_summary; #endif struct kref kref; struct idr devices; /* volume number to device mapping */ struct list_head connections; struct list_head resources; struct res_opts res_opts; struct mutex conf_update; /* mutex for ready-copy-update of net_conf and disk_conf */ struct mutex adm_mutex; /* mutex to serialize administrative requests */ spinlock_t req_lock; 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 */ enum write_ordering_e write_ordering; cpumask_var_t cpu_mask; }; struct drbd_thread_timing_details { unsigned long start_jif; void *cb_addr; const char *caller_fn; unsigned int line; unsigned int cb_nr; }; struct drbd_connection { struct list_head connections; struct drbd_resource *resource; #ifdef CONFIG_DEBUG_FS struct dentry *debugfs_conn; struct dentry *debugfs_conn_callback_history; struct dentry *debugfs_conn_oldest_requests; #endif struct kref kref; struct idr peer_devices; /* volume number to peer device mapping */ enum drbd_conns cstate; /* Only C_STANDALONE to C_WF_REPORT_PARAMS */ struct mutex cstate_mutex; /* Protects graceful disconnects */ unsigned int connect_cnt; /* Inc each time a connection is established */ unsigned long flags; struct net_conf *net_conf; /* content protected by rcu */ wait_queue_head_t ping_wait; /* Woken upon reception of a ping, and a state change */ 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 */ u32 agreed_features; unsigned long last_received; /* in jiffies, either socket */ unsigned int ko_count; struct list_head transfer_log; /* all requests not yet fully processed */ struct crypto_shash *cram_hmac_tfm; struct crypto_ahash *integrity_tfm; /* checksums we compute, updates protected by connection->data->mutex */ struct crypto_ahash *peer_integrity_tfm; /* checksums we verify, only accessed from receiver thread */ struct crypto_ahash *csums_tfm; struct crypto_ahash *verify_tfm; void *int_dig_in; void *int_dig_vv; /* receiver side */ struct drbd_epoch *current_epoch; spinlock_t epoch_lock; unsigned int epochs; atomic_t current_tle_nr; /* transfer log epoch number */ unsigned current_tle_writes; /* writes seen within this tl epoch */ unsigned long last_reconnect_jif; struct drbd_thread receiver; struct drbd_thread worker; struct drbd_thread ack_receiver; struct workqueue_struct *ack_sender; /* cached pointers, * so we can look up the oldest pending requests more quickly. * protected by resource->req_lock */ struct drbd_request *req_next; /* DRBD 9: todo.req_next */ struct drbd_request *req_ack_pending; struct drbd_request *req_not_net_done; /* sender side */ struct drbd_work_queue sender_work; #define DRBD_THREAD_DETAILS_HIST 16 unsigned int w_cb_nr; /* keeps counting up */ unsigned int r_cb_nr; /* keeps counting up */ struct drbd_thread_timing_details w_timing_details[DRBD_THREAD_DETAILS_HIST]; struct drbd_thread_timing_details r_timing_details[DRBD_THREAD_DETAILS_HIST]; struct { unsigned long last_sent_barrier_jif; /* whether this sender thread * has processed a single write yet. */ bool seen_any_write_yet; /* Which barrier number to send with the next P_BARRIER */ int current_epoch_nr; /* how many write requests have been sent * with req->epoch == current_epoch_nr. * If none, no P_BARRIER will be sent. */ unsigned current_epoch_writes; } send; }; static inline bool has_net_conf(struct drbd_connection *connection) { bool has_net_conf; rcu_read_lock(); has_net_conf = rcu_dereference(connection->net_conf); rcu_read_unlock(); return has_net_conf; } void __update_timing_details( struct drbd_thread_timing_details *tdp, unsigned int *cb_nr, void *cb, const char *fn, const unsigned int line); #define update_worker_timing_details(c, cb) \ __update_timing_details(c->w_timing_details, &c->w_cb_nr, cb, __func__ , __LINE__ ) #define update_receiver_timing_details(c, cb) \ __update_timing_details(c->r_timing_details, &c->r_cb_nr, cb, __func__ , __LINE__ ) struct submit_worker { struct workqueue_struct *wq; struct work_struct worker; /* protected by ..->resource->req_lock */ struct list_head writes; }; struct drbd_peer_device { struct list_head peer_devices; struct drbd_device *device; struct drbd_connection *connection; struct work_struct send_acks_work; #ifdef CONFIG_DEBUG_FS struct dentry *debugfs_peer_dev; #endif }; struct drbd_device { struct drbd_resource *resource; struct list_head peer_devices; struct list_head pending_bitmap_io; unsigned long flush_jif; #ifdef CONFIG_DEBUG_FS struct dentry *debugfs_minor; struct dentry *debugfs_vol; struct dentry *debugfs_vol_oldest_requests; struct dentry *debugfs_vol_act_log_extents; struct dentry *debugfs_vol_resync_extents; struct dentry *debugfs_vol_data_gen_id; struct dentry *debugfs_vol_ed_gen_id; #endif unsigned int vnr; /* volume number within the connection */ unsigned int minor; /* device minor number */ struct kref kref; /* things that are stored as / read from meta data on disk */ unsigned long flags; /* configured by drbdsetup */ struct drbd_backing_dev *ldev __protected_by(local); sector_t p_size; /* partner's disk size */ struct request_queue *rq_queue; struct block_device *this_bdev; struct gendisk *vdisk; unsigned long last_reattach_jif; struct drbd_work resync_work; struct drbd_work unplug_work; struct timer_list resync_timer; struct timer_list md_sync_timer; struct timer_list start_resync_timer; struct timer_list request_timer; /* 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_actlog_cnt; /* Requests waiting for activity log */ 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 */ atomic_t suspend_cnt; /* Interval tree of pending local requests */ struct rb_root read_requests; struct rb_root write_requests; /* for statistics and timeouts */ /* [0] read, [1] write */ struct list_head pending_master_completion[2]; struct list_head pending_completion[2]; /* use checksums for *this* resync */ bool use_csums; /* 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; unsigned long rs_last_bcast; /* [unit jiffies] */ /* where does the admin want us to start? (sector) */ sector_t ov_start_sector; sector_t ov_stop_sector; /* where are we now? (sector) */ sector_t ov_position; /* Start sector of out of sync range (to merge printk reporting). */ sector_t ov_last_oos_start; /* size of out-of-sync range in sectors. */ sector_t ov_last_oos_size; unsigned long ov_left; /* in bits */ struct drbd_bitmap *bitmap; unsigned long bm_resync_fo; /* bit offset for drbd_bm_find_next */ /* Used to track operations of resync... */ struct lru_cache *resync; /* Number of locked elements in resync LRU */ unsigned int resync_locked; /* resync extent number waiting for application requests */ unsigned int resync_wenr; int open_cnt; u64 *p_uuid; struct list_head active_ee; /* IO in progress (P_DATA gets written to disk) */ struct list_head sync_ee; /* IO in progress (P_RS_DATA_REPLY gets written to disk) */ struct list_head done_ee; /* need to send P_WRITE_ACK */ struct list_head read_ee; /* [RS]P_DATA_REQUEST being read */ struct list_head net_ee; /* zero-copy network send in progress */ int next_barrier_nr; struct list_head resync_reads; atomic_t pp_in_use; /* allocated from page pool */ atomic_t pp_in_use_by_net; /* sendpage()d, still referenced by tcp */ wait_queue_head_t ee_wait; struct drbd_md_io md_io; spinlock_t al_lock; wait_queue_head_t al_wait; struct lru_cache *act_log; /* activity log */ unsigned int al_tr_number; int al_tr_cycle; wait_queue_head_t seq_wait; atomic_t packet_seq; unsigned int peer_seq; spinlock_t peer_seq_lock; unsigned 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 first_peer_device(device)->connection->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, connection->conn_update) */ int rs_in_flight; /* resync sectors in flight (to proxy, in proxy and from proxy) */ atomic_t ap_in_flight; /* App sectors in flight (waiting for ack) */ unsigned int peer_max_bio_size; unsigned int local_max_bio_size; /* any requests that would block in drbd_make_request() * are deferred to this single-threaded work queue */ struct submit_worker submit; }; struct drbd_bm_aio_ctx { struct drbd_device *device; struct list_head list; /* on device->pending_bitmap_io */; unsigned long start_jif; atomic_t in_flight; unsigned int done; unsigned flags; #define BM_AIO_COPY_PAGES 1 #define BM_AIO_WRITE_HINTED 2 #define BM_AIO_WRITE_ALL_PAGES 4 #define BM_AIO_READ 8 int error; struct kref kref; }; struct drbd_config_context { /* assigned from drbd_genlmsghdr */ unsigned int minor; /* assigned from request attributes, if present */ unsigned int volume; #define VOLUME_UNSPECIFIED (-1U) /* pointer into the request skb, * limited lifetime! */ char *resource_name; struct nlattr *my_addr; struct nlattr *peer_addr; /* reply buffer */ struct sk_buff *reply_skb; /* pointer into reply buffer */ struct drbd_genlmsghdr *reply_dh; /* resolved from attributes, if possible */ struct drbd_device *device; struct drbd_resource *resource; struct drbd_connection *connection; }; static inline struct drbd_device *minor_to_device(unsigned int minor) { return (struct drbd_device *)idr_find(&drbd_devices, minor); } static inline struct drbd_peer_device *first_peer_device(struct drbd_device *device) { return list_first_entry_or_null(&device->peer_devices, struct drbd_peer_device, peer_devices); } static inline struct drbd_peer_device * conn_peer_device(struct drbd_connection *connection, int volume_number) { return idr_find(&connection->peer_devices, volume_number); } #define for_each_resource(resource, _resources) \ list_for_each_entry(resource, _resources, resources) #define for_each_resource_rcu(resource, _resources) \ list_for_each_entry_rcu(resource, _resources, resources) #define for_each_resource_safe(resource, tmp, _resources) \ list_for_each_entry_safe(resource, tmp, _resources, resources) #define for_each_connection(connection, resource) \ list_for_each_entry(connection, &resource->connections, connections) #define for_each_connection_rcu(connection, resource) \ list_for_each_entry_rcu(connection, &resource->connections, connections) #define for_each_connection_safe(connection, tmp, resource) \ list_for_each_entry_safe(connection, tmp, &resource->connections, connections) #define for_each_peer_device(peer_device, device) \ list_for_each_entry(peer_device, &device->peer_devices, peer_devices) #define for_each_peer_device_rcu(peer_device, device) \ list_for_each_entry_rcu(peer_device, &device->peer_devices, peer_devices) #define for_each_peer_device_safe(peer_device, tmp, device) \ list_for_each_entry_safe(peer_device, tmp, &device->peer_devices, peer_devices) static inline unsigned int device_to_minor(struct drbd_device *device) { return device->minor; } /* * 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_device *device); 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_thread *thi); #else #define drbd_thread_current_set_cpu(A) ({}) #endif extern void tl_release(struct drbd_connection *, unsigned int barrier_nr, unsigned int set_size); extern void tl_clear(struct drbd_connection *); extern void drbd_free_sock(struct drbd_connection *connection); extern int drbd_send(struct drbd_connection *connection, struct socket *sock, void *buf, size_t size, unsigned msg_flags); extern int drbd_send_all(struct drbd_connection *, struct socket *, void *, size_t, unsigned); extern int __drbd_send_protocol(struct drbd_connection *connection, enum drbd_packet cmd); extern int drbd_send_protocol(struct drbd_connection *connection); extern int drbd_send_uuids(struct drbd_peer_device *); extern int drbd_send_uuids_skip_initial_sync(struct drbd_peer_device *); extern void drbd_gen_and_send_sync_uuid(struct drbd_peer_device *); extern int drbd_send_sizes(struct drbd_peer_device *, int trigger_reply, enum dds_flags flags); extern int drbd_send_state(struct drbd_peer_device *, union drbd_state s); extern int drbd_send_current_state(struct drbd_peer_device *); extern int drbd_send_sync_param(struct drbd_peer_device *); extern void drbd_send_b_ack(struct drbd_connection *connection, u32 barrier_nr, u32 set_size); extern int drbd_send_ack(struct drbd_peer_device *, enum drbd_packet, struct drbd_peer_request *); extern void drbd_send_ack_rp(struct drbd_peer_device *, enum drbd_packet, struct p_block_req *rp); extern void drbd_send_ack_dp(struct drbd_peer_device *, enum drbd_packet, struct p_data *dp, int data_size); extern int drbd_send_ack_ex(struct drbd_peer_device *, enum drbd_packet, sector_t sector, int blksize, u64 block_id); extern int drbd_send_out_of_sync(struct drbd_peer_device *, struct drbd_request *); extern int drbd_send_block(struct drbd_peer_device *, enum drbd_packet, struct drbd_peer_request *); extern int drbd_send_dblock(struct drbd_peer_device *, struct drbd_request *req); extern int drbd_send_drequest(struct drbd_peer_device *, int cmd, sector_t sector, int size, u64 block_id); extern int drbd_send_drequest_csum(struct drbd_peer_device *, sector_t sector, int size, void *digest, int digest_size, enum drbd_packet cmd); extern int drbd_send_ov_request(struct drbd_peer_device *, sector_t sector, int size); extern int drbd_send_bitmap(struct drbd_device *device); extern void drbd_send_sr_reply(struct drbd_peer_device *, enum drbd_state_rv retcode); extern void conn_send_sr_reply(struct drbd_connection *connection, enum drbd_state_rv retcode); extern void drbd_backing_dev_free(struct drbd_device *device, struct drbd_backing_dev *ldev); extern void drbd_device_cleanup(struct drbd_device *device); void drbd_print_uuids(struct drbd_device *device, const char *text); extern void conn_md_sync(struct drbd_connection *connection); extern void drbd_md_write(struct drbd_device *device, void *buffer); extern void drbd_md_sync(struct drbd_device *device); extern int drbd_md_read(struct drbd_device *device, struct drbd_backing_dev *bdev); extern void drbd_uuid_set(struct drbd_device *device, int idx, u64 val) __must_hold(local); extern void _drbd_uuid_set(struct drbd_device *device, int idx, u64 val) __must_hold(local); extern void drbd_uuid_new_current(struct drbd_device *device) __must_hold(local); extern void drbd_uuid_set_bm(struct drbd_device *device, u64 val) __must_hold(local); extern void drbd_uuid_move_history(struct drbd_device *device) __must_hold(local); extern void __drbd_uuid_set(struct drbd_device *device, int idx, u64 val) __must_hold(local); extern void drbd_md_set_flag(struct drbd_device *device, int flags) __must_hold(local); extern void drbd_md_clear_flag(struct drbd_device *device, int flags)__must_hold(local); extern int drbd_md_test_flag(struct drbd_backing_dev *, int); extern void drbd_md_mark_dirty(struct drbd_device *device); extern void drbd_queue_bitmap_io(struct drbd_device *device, int (*io_fn)(struct drbd_device *), void (*done)(struct drbd_device *, int), char *why, enum bm_flag flags); extern int drbd_bitmap_io(struct drbd_device *device, int (*io_fn)(struct drbd_device *), char *why, enum bm_flag flags); extern int drbd_bitmap_io_from_worker(struct drbd_device *device, int (*io_fn)(struct drbd_device *), char *why, enum bm_flag flags); extern int drbd_bmio_set_n_write(struct drbd_device *device) __must_hold(local); extern int drbd_bmio_clear_n_write(struct drbd_device *device) __must_hold(local); /* Meta data layout * * We currently have two possible layouts. * Offsets in (512 byte) sectors. * external: * |----------- md_size_sect ------------------| * [ 4k superblock ][ activity log ][ Bitmap ] * | al_offset == 8 | * | bm_offset = al_offset + X | * ==> bitmap sectors = md_size_sect - bm_offset * * Variants: * old, indexed fixed size meta data: * * internal: * |----------- md_size_sect ------------------| * [data.....][ Bitmap ][ activity log ][ 4k superblock ][padding*] * | al_offset < 0 | * | bm_offset = al_offset - Y | * ==> bitmap sectors = Y = al_offset - bm_offset * * [padding*] are zero or up to 7 unused 512 Byte sectors to the * end of the device, so that the [4k superblock] will be 4k aligned. * * The activity log consists of 4k transaction blocks, * which are written in a ring-buffer, or striped ring-buffer like fashion, * which are writtensize used to be fixed 32kB, * but is about to become configurable. */ /* Our old fixed size meta data layout * allows up to about 3.8TB, so if you want more, * you need to use the "flexible" meta data format. */ #define MD_128MB_SECT (128LLU << 11) /* 128 MB, unit sectors */ #define MD_4kB_SECT 8 #define MD_32kB_SECT 64 /* One activity log extent represents 4M of storage */ #define AL_EXTENT_SHIFT 22 #define AL_EXTENT_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)) #define BM_BIT_TO_EXT(x) ((x) >> (BM_EXT_SHIFT - BM_BLOCK_SHIFT)) /* first storage sector a bitmap extent corresponds to */ #define BM_EXT_TO_SECT(x) ((sector_t)(x) << (BM_EXT_SHIFT-9)) /* how much _storage_ sectors we have per bitmap extent */ #define BM_SECT_PER_EXT BM_EXT_TO_SECT(1) /* how many bits are covered by one bitmap extent (resync extent) */ #define BM_BITS_PER_EXT (1UL << (BM_EXT_SHIFT - BM_BLOCK_SHIFT)) #define BM_BLOCKS_PER_BM_EXT_MASK (BM_BITS_PER_EXT - 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)) /* 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) /* we have a certain meta data variant that has a fixed on-disk size of 128 * MiB, of which 4k are our "superblock", and 32k are the fixed size activity * log, leaving this many sectors for the bitmap. */ #define DRBD_MAX_SECTORS_FIXED_BM \ ((MD_128MB_SECT - MD_32kB_SECT - MD_4kB_SECT) * (1LL<<(BM_EXT_SHIFT-9))) #if !defined(CONFIG_LBDAF) && 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_FIXED_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 /* we allow up to 1 PiB now on 64bit architecture with "flexible" meta data */ #define DRBD_MAX_SECTORS_FLEX (1UL << 51) /* corresponds to (1UL << 38) bits right now. */ #endif #endif /* BIO_MAX_SIZE is 256 * PAGE_SIZE, * so for typical PAGE_SIZE of 4k, that is (1<<20) Byte. * Since we may live in a mixed-platform cluster, * we limit us to a platform agnostic constant here for now. * A followup commit may allow even bigger BIO sizes, * once we thought that through. */ #define DRBD_MAX_BIO_SIZE (1U << 20) #if DRBD_MAX_BIO_SIZE > BIO_MAX_SIZE #error Architecture not supported: DRBD_MAX_BIO_SIZE > BIO_MAX_SIZE #endif #define DRBD_MAX_BIO_SIZE_SAFE (1U << 12) /* Works always = 4k */ #define DRBD_MAX_SIZE_H80_PACKET (1U << 15) /* Header 80 only allows packets up to 32KiB data */ #define DRBD_MAX_BIO_SIZE_P95 (1U << 17) /* Protocol 95 to 99 allows bios up to 128KiB */ /* For now, don't allow more than one activity log extent worth of data * to be discarded in one go. We may need to rework drbd_al_begin_io() * to allow for even larger discard ranges */ #define DRBD_MAX_DISCARD_SIZE AL_EXTENT_SIZE #define DRBD_MAX_DISCARD_SECTORS (DRBD_MAX_DISCARD_SIZE >> 9) extern int drbd_bm_init(struct drbd_device *device); extern int drbd_bm_resize(struct drbd_device *device, sector_t sectors, int set_new_bits); extern void drbd_bm_cleanup(struct drbd_device *device); extern void drbd_bm_set_all(struct drbd_device *device); extern void drbd_bm_clear_all(struct drbd_device *device); /* set/clear/test only a few bits at a time */ extern int drbd_bm_set_bits( struct drbd_device *device, unsigned long s, unsigned long e); extern int drbd_bm_clear_bits( struct drbd_device *device, unsigned long s, unsigned long e); extern int drbd_bm_count_bits( struct drbd_device *device, 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_device *device, const unsigned long s, const unsigned long e); extern int drbd_bm_test_bit(struct drbd_device *device, unsigned long bitnr); extern int drbd_bm_e_weight(struct drbd_device *device, unsigned long enr); extern int drbd_bm_read(struct drbd_device *device) __must_hold(local); extern void drbd_bm_mark_for_writeout(struct drbd_device *device, int page_nr); extern int drbd_bm_write(struct drbd_device *device) __must_hold(local); extern int drbd_bm_write_hinted(struct drbd_device *device) __must_hold(local); extern int drbd_bm_write_lazy(struct drbd_device *device, unsigned upper_idx) __must_hold(local); extern int drbd_bm_write_all(struct drbd_device *device) __must_hold(local); extern int drbd_bm_write_copy_pages(struct drbd_device *device) __must_hold(local); extern size_t drbd_bm_words(struct drbd_device *device); extern unsigned long drbd_bm_bits(struct drbd_device *device); extern sector_t drbd_bm_capacity(struct drbd_device *device); #define DRBD_END_OF_BITMAP (~(unsigned long)0) extern unsigned long drbd_bm_find_next(struct drbd_device *device, 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_device *device, unsigned long bm_fo); extern unsigned long _drbd_bm_find_next_zero(struct drbd_device *device, unsigned long bm_fo); extern unsigned long _drbd_bm_total_weight(struct drbd_device *device); extern unsigned long drbd_bm_total_weight(struct drbd_device *device); /* for receive_bitmap */ extern void drbd_bm_merge_lel(struct drbd_device *device, size_t offset, size_t number, unsigned long *buffer); /* for _drbd_send_bitmap */ extern void drbd_bm_get_lel(struct drbd_device *device, size_t offset, size_t number, unsigned long *buffer); extern void drbd_bm_lock(struct drbd_device *device, char *why, enum bm_flag flags); extern void drbd_bm_unlock(struct drbd_device *device); /* 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 struct mutex resources_mutex; extern int conn_lowest_minor(struct drbd_connection *connection); extern enum drbd_ret_code drbd_create_device(struct drbd_config_context *adm_ctx, unsigned int minor); extern void drbd_destroy_device(struct kref *kref); extern void drbd_delete_device(struct drbd_device *device); extern struct drbd_resource *drbd_create_resource(const char *name); extern void drbd_free_resource(struct drbd_resource *resource); extern int set_resource_options(struct drbd_resource *resource, struct res_opts *res_opts); extern struct drbd_connection *conn_create(const char *name, struct res_opts *res_opts); extern void drbd_destroy_connection(struct kref *kref); extern struct drbd_connection *conn_get_by_addrs(void *my_addr, int my_addr_len, void *peer_addr, int peer_addr_len); extern struct drbd_resource *drbd_find_resource(const char *name); extern void drbd_destroy_resource(struct kref *kref); extern void conn_free_crypto(struct drbd_connection *connection); extern int proc_details; /* drbd_req */ extern void do_submit(struct work_struct *ws); extern void __drbd_make_request(struct drbd_device *, struct bio *, unsigned long); extern blk_qc_t drbd_make_request(struct request_queue *q, struct bio *bio); extern int drbd_read_remote(struct drbd_device *device, struct drbd_request *req); extern int is_valid_ar_handle(struct drbd_request *, sector_t); /* drbd_nl.c */ extern struct mutex notification_mutex; extern void drbd_suspend_io(struct drbd_device *device); extern void drbd_resume_io(struct drbd_device *device); extern char *ppsize(char *buf, unsigned long long size); extern sector_t drbd_new_dev_size(struct drbd_device *, struct drbd_backing_dev *, sector_t, int); enum determine_dev_size { DS_ERROR_SHRINK = -3, DS_ERROR_SPACE_MD = -2, DS_ERROR = -1, DS_UNCHANGED = 0, DS_SHRUNK = 1, DS_GREW = 2, DS_GREW_FROM_ZERO = 3, }; extern enum determine_dev_size drbd_determine_dev_size(struct drbd_device *, enum dds_flags, struct resize_parms *) __must_hold(local); extern void resync_after_online_grow(struct drbd_device *); extern void drbd_reconsider_max_bio_size(struct drbd_device *device, struct drbd_backing_dev *bdev); extern enum drbd_state_rv drbd_set_role(struct drbd_device *device, enum drbd_role new_role, int force); extern bool conn_try_outdate_peer(struct drbd_connection *connection); extern void conn_try_outdate_peer_async(struct drbd_connection *connection); extern int drbd_khelper(struct drbd_device *device, char *cmd); /* drbd_worker.c */ /* bi_end_io handlers */ extern void drbd_md_endio(struct bio *bio); extern void drbd_peer_request_endio(struct bio *bio); extern void drbd_request_endio(struct bio *bio); extern int drbd_worker(struct drbd_thread *thi); enum drbd_ret_code drbd_resync_after_valid(struct drbd_device *device, int o_minor); void drbd_resync_after_changed(struct drbd_device *device); extern void drbd_start_resync(struct drbd_device *device, enum drbd_conns side); extern void resume_next_sg(struct drbd_device *device); extern void suspend_other_sg(struct drbd_device *device); extern int drbd_resync_finished(struct drbd_device *device); /* maybe rather drbd_main.c ? */ extern void *drbd_md_get_buffer(struct drbd_device *device, const char *intent); extern void drbd_md_put_buffer(struct drbd_device *device); extern int drbd_md_sync_page_io(struct drbd_device *device, struct drbd_backing_dev *bdev, sector_t sector, int op); extern void drbd_ov_out_of_sync_found(struct drbd_device *, sector_t, int); extern void wait_until_done_or_force_detached(struct drbd_device *device, struct drbd_backing_dev *bdev, unsigned int *done); extern void drbd_rs_controller_reset(struct drbd_device *device); static inline void ov_out_of_sync_print(struct drbd_device *device) { if (device->ov_last_oos_size) { drbd_err(device, "Out of sync: start=%llu, size=%lu (sectors)\n", (unsigned long long)device->ov_last_oos_start, (unsigned long)device->ov_last_oos_size); } device->ov_last_oos_size = 0; } extern void drbd_csum_bio(struct crypto_ahash *, struct bio *, void *); extern void drbd_csum_ee(struct crypto_ahash *, struct drbd_peer_request *, void *); /* worker callbacks */ extern int w_e_end_data_req(struct drbd_work *, int); extern int w_e_end_rsdata_req(struct drbd_work *, int); extern int w_e_end_csum_rs_req(struct drbd_work *, int); extern int w_e_end_ov_reply(struct drbd_work *, int); extern int w_e_end_ov_req(struct drbd_work *, int); extern int w_ov_finished(struct drbd_work *, int); extern int w_resync_timer(struct drbd_work *, int); extern int w_send_write_hint(struct drbd_work *, int); extern int w_send_dblock(struct drbd_work *, int); extern int w_send_read_req(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); extern void drbd_endio_write_sec_final(struct drbd_peer_request *peer_req); /* drbd_receiver.c */ extern int drbd_receiver(struct drbd_thread *thi); extern int drbd_ack_receiver(struct drbd_thread *thi); extern void drbd_send_ping_wf(struct work_struct *ws); extern void drbd_send_acks_wf(struct work_struct *ws); extern bool drbd_rs_c_min_rate_throttle(struct drbd_device *device); extern bool drbd_rs_should_slow_down(struct drbd_device *device, sector_t sector, bool throttle_if_app_is_waiting); extern int drbd_submit_peer_request(struct drbd_device *, struct drbd_peer_request *, const unsigned, const unsigned, const int); extern int drbd_free_peer_reqs(struct drbd_device *, struct list_head *); extern struct drbd_peer_request *drbd_alloc_peer_req(struct drbd_peer_device *, u64, sector_t, unsigned int, bool, gfp_t) __must_hold(local); extern void __drbd_free_peer_req(struct drbd_device *, 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_peer_device *, unsigned int, bool); extern void drbd_set_recv_tcq(struct drbd_device *device, int tcq_enabled); extern void _drbd_clear_done_ee(struct drbd_device *device, struct list_head *to_be_freed); extern int drbd_connected(struct drbd_peer_device *); static inline void drbd_tcp_cork(struct socket *sock) { int val = 1; (void) kernel_setsockopt(sock, SOL_TCP, TCP_CORK, (char*)&val, sizeof(val)); } static inline void drbd_tcp_uncork(struct socket *sock) { int val = 0; (void) kernel_setsockopt(sock, SOL_TCP, TCP_CORK, (char*)&val, sizeof(val)); } static inline void drbd_tcp_nodelay(struct socket *sock) { int val = 1; (void) kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY, (char*)&val, sizeof(val)); } static inline void drbd_tcp_quickack(struct socket *sock) { int val = 2; (void) kernel_setsockopt(sock, SOL_TCP, TCP_QUICKACK, (char*)&val, sizeof(val)); } /* sets the number of 512 byte sectors of our virtual device */ static inline void drbd_set_my_capacity(struct drbd_device *device, sector_t size) { /* set_capacity(device->this_bdev->bd_disk, size); */ set_capacity(device->vdisk, size); device->this_bdev->bd_inode->i_size = (loff_t)size << 9; } /* * used to submit our private bio */ static inline void drbd_generic_make_request(struct drbd_device *device, int fault_type, struct bio *bio) { __release(local); if (!bio->bi_bdev) { drbd_err(device, "drbd_generic_make_request: bio->bi_bdev == NULL\n"); bio->bi_error = -ENODEV; bio_endio(bio); return; } if (drbd_insert_fault(device, fault_type)) bio_io_error(bio); else generic_make_request(bio); } void drbd_bump_write_ordering(struct drbd_resource *resource, struct drbd_backing_dev *bdev, 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 bool drbd_al_begin_io_prepare(struct drbd_device *device, struct drbd_interval *i); extern int drbd_al_begin_io_nonblock(struct drbd_device *device, struct drbd_interval *i); extern void drbd_al_begin_io_commit(struct drbd_device *device); extern bool drbd_al_begin_io_fastpath(struct drbd_device *device, struct drbd_interval *i); extern void drbd_al_begin_io(struct drbd_device *device, struct drbd_interval *i); extern void drbd_al_complete_io(struct drbd_device *device, struct drbd_interval *i); extern void drbd_rs_complete_io(struct drbd_device *device, sector_t sector); extern int drbd_rs_begin_io(struct drbd_device *device, sector_t sector); extern int drbd_try_rs_begin_io(struct drbd_device *device, sector_t sector); extern void drbd_rs_cancel_all(struct drbd_device *device); extern int drbd_rs_del_all(struct drbd_device *device); extern void drbd_rs_failed_io(struct drbd_device *device, sector_t sector, int size); extern void drbd_advance_rs_marks(struct drbd_device *device, unsigned long still_to_go); enum update_sync_bits_mode { RECORD_RS_FAILED, SET_OUT_OF_SYNC, SET_IN_SYNC }; extern int __drbd_change_sync(struct drbd_device *device, sector_t sector, int size, enum update_sync_bits_mode mode); #define drbd_set_in_sync(device, sector, size) \ __drbd_change_sync(device, sector, size, SET_IN_SYNC) #define drbd_set_out_of_sync(device, sector, size) \ __drbd_change_sync(device, sector, size, SET_OUT_OF_SYNC) #define drbd_rs_failed_io(device, sector, size) \ __drbd_change_sync(device, sector, size, RECORD_RS_FAILED) extern void drbd_al_shrink(struct drbd_device *device); extern int drbd_al_initialize(struct drbd_device *, void *); /* 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_device *device, const struct sib_info *sib); extern void notify_resource_state(struct sk_buff *, unsigned int, struct drbd_resource *, struct resource_info *, enum drbd_notification_type); extern void notify_device_state(struct sk_buff *, unsigned int, struct drbd_device *, struct device_info *, enum drbd_notification_type); extern void notify_connection_state(struct sk_buff *, unsigned int, struct drbd_connection *, struct connection_info *, enum drbd_notification_type); extern void notify_peer_device_state(struct sk_buff *, unsigned int, struct drbd_peer_device *, struct peer_device_info *, enum drbd_notification_type); extern void notify_helper(enum drbd_notification_type, struct drbd_device *, struct drbd_connection *, const char *, int); /* * inline helper functions *************************/ /* see also page_chain_add and friends in drbd_receiver.c */ static inline struct page *page_chain_next(struct page *page) { return (struct page *)page_private(page); } #define page_chain_for_each(page) \ for (; page && ({ prefetch(page_chain_next(page)); 1; }); \ page = page_chain_next(page)) #define page_chain_for_each_safe(page, n) \ for (; page && ({ n = page_chain_next(page); 1; }); page = n) static inline int drbd_peer_req_has_active_page(struct drbd_peer_request *peer_req) { struct page *page = peer_req->pages; page_chain_for_each(page) { if (page_count(page) > 1) return 1; } return 0; } static inline union drbd_state drbd_read_state(struct drbd_device *device) { struct drbd_resource *resource = device->resource; union drbd_state rv; rv.i = device->state.i; rv.susp = resource->susp; rv.susp_nod = resource->susp_nod; rv.susp_fen = resource->susp_fen; return rv; } enum drbd_force_detach_flags { DRBD_READ_ERROR, DRBD_WRITE_ERROR, DRBD_META_IO_ERROR, DRBD_FORCE_DETACH, }; #define __drbd_chk_io_error(m,f) __drbd_chk_io_error_(m,f, __func__) static inline void __drbd_chk_io_error_(struct drbd_device *device, enum drbd_force_detach_flags df, const char *where) { enum drbd_io_error_p ep; rcu_read_lock(); ep = rcu_dereference(device->ldev->disk_conf)->on_io_error; rcu_read_unlock(); switch (ep) { case EP_PASS_ON: /* FIXME would this be better named "Ignore"? */ if (df == DRBD_READ_ERROR || df == DRBD_WRITE_ERROR) { if (__ratelimit(&drbd_ratelimit_state)) drbd_err(device, "Local IO failed in %s.\n", where); if (device->state.disk > D_INCONSISTENT) _drbd_set_state(_NS(device, disk, D_INCONSISTENT), CS_HARD, NULL); break; } /* NOTE fall through for DRBD_META_IO_ERROR or DRBD_FORCE_DETACH */ case EP_DETACH: case EP_CALL_HELPER: /* Remember whether we saw a READ or WRITE error. * * Recovery of the affected area for WRITE failure is covered * by the activity log. * READ errors may fall outside that area though. Certain READ * errors can be "healed" by writing good data to the affected * blocks, which triggers block re-allocation in lower layers. * * If we can not write the bitmap after a READ error, * we may need to trigger a full sync (see w_go_diskless()). * * Force-detach is not really an IO error, but rather a * desperate measure to try to deal with a completely * unresponsive lower level IO stack. * Still it should be treated as a WRITE error. * * Meta IO error is always WRITE error: * we read meta data only once during attach, * which will fail in case of errors. */ set_bit(WAS_IO_ERROR, &device->flags); if (df == DRBD_READ_ERROR) set_bit(WAS_READ_ERROR, &device->flags); if (df == DRBD_FORCE_DETACH) set_bit(FORCE_DETACH, &device->flags); if (device->state.disk > D_FAILED) { _drbd_set_state(_NS(device, disk, D_FAILED), CS_HARD, NULL); drbd_err(device, "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 * @device: 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_device *device, int error, enum drbd_force_detach_flags forcedetach, const char *where) { if (error) { unsigned long flags; spin_lock_irqsave(&device->resource->req_lock, flags); __drbd_chk_io_error_(device, forcedetach, where); spin_unlock_irqrestore(&device->resource->req_lock, flags); } } /** * drbd_md_first_sector() - Returns the first sector number of the meta data area * @bdev: Meta data block device. * * BTW, for internal meta data, this happens to be the maximum capacity * we could agree upon with our peer node. */ static inline sector_t drbd_md_first_sector(struct drbd_backing_dev *bdev) { switch (bdev->md.meta_dev_idx) { 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->md.meta_dev_idx) { case DRBD_MD_INDEX_INTERNAL: case DRBD_MD_INDEX_FLEX_INT: return bdev->md.md_offset + MD_4kB_SECT -1; case DRBD_MD_INDEX_FLEX_EXT: default: return bdev->md.md_offset + bdev->md.md_size_sect -1; } } /* Returns the number of 512 byte sectors of the device */ static inline sector_t drbd_get_capacity(struct block_device *bdev) { /* return bdev ? get_capacity(bdev->bd_disk) : 0; */ return bdev ? i_size_read(bdev->bd_inode) >> 9 : 0; } /** * drbd_get_max_capacity() - Returns the capacity we announce to out peer * @bdev: Meta data block device. * * returns the capacity we announce to out peer. we clip ourselves at the * various MAX_SECTORS, because if we don't, current implementation will * oops sooner or later */ static inline sector_t drbd_get_max_capacity(struct drbd_backing_dev *bdev) { sector_t s; switch (bdev->md.meta_dev_idx) { 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 * @bdev: Meta data block device. */ static inline sector_t drbd_md_ss(struct drbd_backing_dev *bdev) { const int meta_dev_idx = bdev->md.meta_dev_idx; if (meta_dev_idx == DRBD_MD_INDEX_FLEX_EXT) return 0; /* Since drbd08, internal meta data is always "flexible". * position: last 4k aligned block of 4k size */ if (meta_dev_idx == DRBD_MD_INDEX_INTERNAL || meta_dev_idx == DRBD_MD_INDEX_FLEX_INT) return (drbd_get_capacity(bdev->backing_bdev) & ~7ULL) - 8; /* external, some index; this is the old fixed size layout */ return MD_128MB_SECT * bdev->md.meta_dev_idx; } static inline void drbd_queue_work(struct drbd_work_queue *q, struct drbd_work *w) { unsigned long flags; spin_lock_irqsave(&q->q_lock, flags); list_add_tail(&w->list, &q->q); spin_unlock_irqrestore(&q->q_lock, flags); wake_up(&q->q_wait); } static inline void drbd_queue_work_if_unqueued(struct drbd_work_queue *q, struct drbd_work *w) { unsigned long flags; spin_lock_irqsave(&q->q_lock, flags); if (list_empty_careful(&w->list)) list_add_tail(&w->list, &q->q); spin_unlock_irqrestore(&q->q_lock, flags); wake_up(&q->q_wait); } static inline void drbd_device_post_work(struct drbd_device *device, int work_bit) { if (!test_and_set_bit(work_bit, &device->flags)) { struct drbd_connection *connection = first_peer_device(device)->connection; struct drbd_work_queue *q = &connection->sender_work; if (!test_and_set_bit(DEVICE_WORK_PENDING, &connection->flags)) wake_up(&q->q_wait); } } extern void drbd_flush_workqueue(struct drbd_work_queue *work_queue); /* To get the ack_receiver out of the blocking network stack, * so it can change its sk_rcvtimeo from idle- to ping-timeout, * and send a ping, we need to send a signal. * Which signal we send is irrelevant. */ static inline void wake_ack_receiver(struct drbd_connection *connection) { struct task_struct *task = connection->ack_receiver.task; if (task && get_t_state(&connection->ack_receiver) == RUNNING) force_sig(SIGXCPU, task); } static inline void request_ping(struct drbd_connection *connection) { set_bit(SEND_PING, &connection->flags); wake_ack_receiver(connection); } extern void *conn_prepare_command(struct drbd_connection *, struct drbd_socket *); extern void *drbd_prepare_command(struct drbd_peer_device *, struct drbd_socket *); extern int conn_send_command(struct drbd_connection *, struct drbd_socket *, enum drbd_packet, unsigned int, void *, unsigned int); extern int drbd_send_command(struct drbd_peer_device *, struct drbd_socket *, enum drbd_packet, unsigned int, void *, unsigned int); extern int drbd_send_ping(struct drbd_connection *connection); extern int drbd_send_ping_ack(struct drbd_connection *connection); extern int drbd_send_state_req(struct drbd_peer_device *, union drbd_state, union drbd_state); extern int conn_send_state_req(struct drbd_connection *, 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_device *device) { atomic_inc(&device->ap_pending_cnt); } #define ERR_IF_CNT_IS_NEGATIVE(which, func, line) \ if (atomic_read(&device->which) < 0) \ drbd_err(device, "in %s:%d: " #which " = %d < 0 !\n", \ func, line, \ atomic_read(&device->which)) #define dec_ap_pending(device) _dec_ap_pending(device, __func__, __LINE__) static inline void _dec_ap_pending(struct drbd_device *device, const char *func, int line) { if (atomic_dec_and_test(&device->ap_pending_cnt)) wake_up(&device->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_device *device) { atomic_inc(&device->rs_pending_cnt); } #define dec_rs_pending(device) _dec_rs_pending(device, __func__, __LINE__) static inline void _dec_rs_pending(struct drbd_device *device, const char *func, int line) { atomic_dec(&device->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_device *device) { atomic_inc(&device->unacked_cnt); } #define dec_unacked(device) _dec_unacked(device, __func__, __LINE__) static inline void _dec_unacked(struct drbd_device *device, const char *func, int line) { atomic_dec(&device->unacked_cnt); ERR_IF_CNT_IS_NEGATIVE(unacked_cnt, func, line); } #define sub_unacked(device, n) _sub_unacked(device, n, __func__, __LINE__) static inline void _sub_unacked(struct drbd_device *device, int n, const char *func, int line) { atomic_sub(n, &device->unacked_cnt); ERR_IF_CNT_IS_NEGATIVE(unacked_cnt, func, line); } static inline bool is_sync_state(enum drbd_conns connection_state) { return (connection_state == C_SYNC_SOURCE || connection_state == C_SYNC_TARGET || connection_state == C_PAUSED_SYNC_S || connection_state == C_PAUSED_SYNC_T); } /** * get_ldev() - Increase the ref count on device->ldev. Returns 0 if there is no ldev * @_device: DRBD device. * @_min_state: Minimum device state required for success. * * You have to call put_ldev() when finished working with device->ldev. */ #define get_ldev_if_state(_device, _min_state) \ (_get_ldev_if_state((_device), (_min_state)) ? \ ({ __acquire(x); true; }) : false) #define get_ldev(_device) get_ldev_if_state(_device, D_INCONSISTENT) static inline void put_ldev(struct drbd_device *device) { enum drbd_disk_state disk_state = device->state.disk; /* We must check the state *before* the atomic_dec becomes visible, * or we have a theoretical race where someone hitting zero, * while state still D_FAILED, will then see D_DISKLESS in the * condition below and calling into destroy, where he must not, yet. */ int i = atomic_dec_return(&device->local_cnt); /* This may be called from some endio handler, * so we must not sleep here. */ __release(local); D_ASSERT(device, i >= 0); if (i == 0) { if (disk_state == D_DISKLESS) /* even internal references gone, safe to destroy */ drbd_device_post_work(device, DESTROY_DISK); if (disk_state == D_FAILED) /* all application IO references gone. */ if (!test_and_set_bit(GOING_DISKLESS, &device->flags)) drbd_device_post_work(device, GO_DISKLESS); wake_up(&device->misc_wait); } } #ifndef __CHECKER__ static inline int _get_ldev_if_state(struct drbd_device *device, enum drbd_disk_state mins) { int io_allowed; /* never get a reference while D_DISKLESS */ if (device->state.disk == D_DISKLESS) return 0; atomic_inc(&device->local_cnt); io_allowed = (device->state.disk >= mins); if (!io_allowed) put_ldev(device); return io_allowed; } #else extern int _get_ldev_if_state(struct drbd_device *device, enum drbd_disk_state mins); #endif /* 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_device *device) { struct net_conf *nc; int mxb; rcu_read_lock(); nc = rcu_dereference(first_peer_device(device)->connection->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_device *device) { union drbd_dev_state s = device->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 (first_peer_device(device)->connection->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_device *device) { struct drbd_resource *resource = device->resource; return resource->susp || resource->susp_fen || resource->susp_nod; } static inline bool may_inc_ap_bio(struct drbd_device *device) { int mxb = drbd_get_max_buffers(device); if (drbd_suspended(device)) return false; if (atomic_read(&device->suspend_cnt)) 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(device)) 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(&device->ap_bio_cnt) > mxb) return false; if (test_bit(BITMAP_IO, &device->flags)) return false; return true; } static inline bool inc_ap_bio_cond(struct drbd_device *device) { bool rv = false; spin_lock_irq(&device->resource->req_lock); rv = may_inc_ap_bio(device); if (rv) atomic_inc(&device->ap_bio_cnt); spin_unlock_irq(&device->resource->req_lock); return rv; } static inline void inc_ap_bio(struct drbd_device *device) { /* 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(device->misc_wait, inc_ap_bio_cond(device)); } static inline void dec_ap_bio(struct drbd_device *device) { int mxb = drbd_get_max_buffers(device); int ap_bio = atomic_dec_return(&device->ap_bio_cnt); D_ASSERT(device, ap_bio >= 0); if (ap_bio == 0 && test_bit(BITMAP_IO, &device->flags)) { if (!test_and_set_bit(BITMAP_IO_QUEUED, &device->flags)) drbd_queue_work(&first_peer_device(device)-> connection->sender_work, &device->bm_io_work.w); } /* this currently does wake_up for every dec_ap_bio! * maybe rather introduce some type of hysteresis? * e.g. (ap_bio == mxb/2 || ap_bio == 0) ? */ if (ap_bio < mxb) wake_up(&device->misc_wait); } static inline bool verify_can_do_stop_sector(struct drbd_device *device) { return first_peer_device(device)->connection->agreed_pro_version >= 97 && first_peer_device(device)->connection->agreed_pro_version != 100; } static inline int drbd_set_ed_uuid(struct drbd_device *device, u64 val) { int changed = device->ed_uuid != val; device->ed_uuid = val; return changed; } static inline int drbd_queue_order_type(struct drbd_device *device) { /* 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 struct drbd_connection *first_connection(struct drbd_resource *resource) { return list_first_entry_or_null(&resource->connections, struct drbd_connection, connections); } #endif