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Diffstat (limited to 'drivers/block/drbd/drbd_int.h')
| -rw-r--r-- | drivers/block/drbd/drbd_int.h | 2328 |
1 files changed, 2328 insertions, 0 deletions
diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h new file mode 100644 index 000000000..b905e9888 --- /dev/null +++ b/drivers/block/drbd/drbd_int.h @@ -0,0 +1,2328 @@ +/* + drbd_int.h + + This file is part of DRBD by Philipp Reisner and Lars Ellenberg. + + Copyright (C) 2001-2008, LINBIT Information Technologies GmbH. + Copyright (C) 1999-2008, Philipp Reisner <philipp.reisner@linbit.com>. + Copyright (C) 2002-2008, Lars Ellenberg <lars.ellenberg@linbit.com>. + + drbd is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2, or (at your option) + any later version. + + drbd is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with drbd; see the file COPYING. If not, write to + the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. + +*/ + +#ifndef _DRBD_INT_H +#define _DRBD_INT_H + +#include <linux/compiler.h> +#include <linux/types.h> +#include <linux/list.h> +#include <linux/sched.h> +#include <linux/bitops.h> +#include <linux/slab.h> +#include <linux/crypto.h> +#include <linux/ratelimit.h> +#include <linux/tcp.h> +#include <linux/mutex.h> +#include <linux/major.h> +#include <linux/blkdev.h> +#include <linux/genhd.h> +#include <linux/idr.h> +#include <net/tcp.h> +#include <linux/lru_cache.h> +#include <linux/prefetch.h> +#include <linux/drbd_genl_api.h> +#include <linux/drbd.h> +#include "drbd_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[]; + + +/* 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_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<<type)) && + _drbd_insert_fault(device, type); +#else + return 0; +#endif +} + +/* integer division, round _UP_ to the next integer */ +#define div_ceil(A, B) ((A)/(B) + ((A)%(B) ? 1 : 0)) +/* usual integer division */ +#define div_floor(A, B) ((A)/(B)) + +extern struct ratelimit_state drbd_ratelimit_state; +extern struct idr drbd_devices; /* RCU, updates: genl_lock() */ +extern struct list_head drbd_resources; /* RCU, updates: genl_lock() */ + +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_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 *); + +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 */ + + 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 */ + 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 { + /* 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 = 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); +}; + +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 connection */ +enum { + NET_CONGESTED, /* The data socket is congested */ + RESOLVE_CONFLICTS, /* Set on one node, cleared on the peer! */ + SEND_PING, /* whether asender should send a ping asap */ + SIGNAL_ASENDER, /* whether asender wants to be interrupted */ + GOT_PING_ACK, /* set when we receive a ping_ack packet, ping_wait gets woken */ + CONN_WD_ST_CHG_REQ, /* A cluster wide state change on the connection is active */ + CONN_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 */ +}; + +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_hash *cram_hmac_tfm; + struct crypto_hash *integrity_tfm; /* checksums we compute, updates protected by connection->data->mutex */ + struct crypto_hash *peer_integrity_tfm; /* checksums we verify, only accessed from receiver thread */ + struct crypto_hash *csums_tfm; + struct crypto_hash *verify_tfm; + void *int_dig_in; + void *int_dig_vv; + + /* receiver side */ + struct drbd_epoch *current_epoch; + spinlock_t epoch_lock; + unsigned int epochs; + atomic_t current_tle_nr; /* transfer log epoch number */ + unsigned current_tle_writes; /* writes seen within this tl epoch */ + + unsigned long last_reconnect_jif; + struct drbd_thread receiver; + struct drbd_thread worker; + struct drbd_thread asender; + + /* 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 { + /* 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; +}; + +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; +#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; +#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 */ + + /* 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); +} + +#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_free_ldev(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<<AL_EXTENT_SHIFT) + +/* We could make these currently hardcoded constants configurable + * variables at create-md time (or even re-configurable at runtime?). + * Which will require some more changes to the DRBD "super block" + * and attach code. + * + * updates per transaction: + * This many changes to the active set can be logged with one transaction. + * This number is arbitrary. + * context per transaction: + * This many context extent numbers are logged with each transaction. + * This number is resulting from the transaction block size (4k), the layout + * of the transaction header, and the number of updates per transaction. + * See drbd_actlog.c:struct al_transaction_on_disk + * */ +#define AL_UPDATES_PER_TRANSACTION 64 // arbitrary +#define AL_CONTEXT_PER_TRANSACTION 919 // (4096 - 36 - 6*64)/4 + +#if BITS_PER_LONG == 32 +#define LN2_BPL 5 +#define cpu_to_lel(A) cpu_to_le32(A) +#define lel_to_cpu(A) le32_to_cpu(A) +#elif BITS_PER_LONG == 64 +#define LN2_BPL 6 +#define cpu_to_lel(A) cpu_to_le64(A) +#define lel_to_cpu(A) le64_to_cpu(A) +#else +#error "LN2 of BITS_PER_LONG unknown!" +#endif + +/* resync bitmap */ +/* 16MB sized 'bitmap extent' to track syncer usage */ +struct bm_extent { + int rs_left; /* number of bits set (out of sync) in this extent. */ + int rs_failed; /* number of failed resync requests in this extent. */ + unsigned long flags; + struct lc_element lce; +}; + +#define BME_NO_WRITES 0 /* bm_extent.flags: no more requests on this one! */ +#define BME_LOCKED 1 /* bm_extent.flags: syncer active on this one. */ +#define BME_PRIORITY 2 /* finish resync IO on this extent ASAP! App IO waiting! */ + +/* drbd_bitmap.c */ +/* + * We need to store one bit for a block. + * Example: 1GB disk @ 4096 byte blocks ==> we need 32 KB bitmap. + * Bit 0 ==> local node thinks this block is binary identical on both nodes + * Bit 1 ==> local node thinks this block needs to be synced. + */ + +#define SLEEP_TIME (HZ/10) + +/* We do bitmap IO in units of 4k blocks. + * We also still have a hardcoded 4k per bit relation. */ +#define BM_BLOCK_SHIFT 12 /* 4k per bit */ +#define BM_BLOCK_SIZE (1<<BM_BLOCK_SHIFT) +/* mostly arbitrarily set the represented size of one bitmap extent, + * aka resync extent, to 16 MiB (which is also 512 Byte worth of bitmap + * at 4k per bit resolution) */ +#define BM_EXT_SHIFT 24 /* 16 MiB per resync extent */ +#define BM_EXT_SIZE (1<<BM_EXT_SHIFT) + +#if (BM_EXT_SHIFT != 24) || (BM_BLOCK_SHIFT != 12) +#error "HAVE YOU FIXED drbdmeta AS WELL??" +#endif + +/* thus many _storage_ sectors are described by one bit */ +#define BM_SECT_TO_BIT(x) ((x)>>(BM_BLOCK_SHIFT-9)) +#define BM_BIT_TO_SECT(x) ((sector_t)(x)<<(BM_BLOCK_SHIFT-9)) +#define BM_SECT_PER_BIT BM_BIT_TO_SECT(1) + +/* bit to represented kilo byte conversion */ +#define Bit2KB(bits) ((bits)<<(BM_BLOCK_SHIFT-10)) + +/* in which _bitmap_ extent (resp. sector) the bit for a certain + * _storage_ sector is located in */ +#define BM_SECT_TO_EXT(x) ((x)>>(BM_EXT_SHIFT-9)) +#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_CACHE_SIZE, + * so for typical PAGE_CACHE_SIZE of 4k, that is (1<<20) Byte. + * Since we may live in a mixed-platform cluster, + * we limit us to a platform agnostic constant here for now. + * A followup commit may allow even bigger BIO sizes, + * once we thought that through. */ +#define DRBD_MAX_BIO_SIZE (1U << 20) +#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 rwlock_t global_state_lock; + +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 void 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 drbd_merge_bvec(struct request_queue *q, struct bvec_merge_data *bvm, struct bio_vec *bvec); +extern int is_valid_ar_handle(struct drbd_request *, sector_t); + + +/* drbd_nl.c */ +extern void drbd_suspend_io(struct drbd_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, int error); +extern void drbd_peer_request_endio(struct bio *bio, int error); +extern void drbd_request_endio(struct bio *bio, int error); +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 rw); +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_hash *, struct bio *, void *); +extern void drbd_csum_ee(struct crypto_hash *, struct drbd_peer_request *, void *); +/* worker callbacks */ +extern int w_e_end_data_req(struct drbd_work *, int); +extern int w_e_end_rsdata_req(struct drbd_work *, int); +extern int w_e_end_csum_rs_req(struct drbd_work *, int); +extern int w_e_end_ov_reply(struct drbd_work *, int); +extern int w_e_end_ov_req(struct drbd_work *, int); +extern int w_ov_finished(struct drbd_work *, int); +extern int w_resync_timer(struct drbd_work *, int); +extern int w_send_write_hint(struct drbd_work *, int); +extern int w_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_asender(struct drbd_thread *thi); +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 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_endio(bio, -ENODEV); + return; + } + + if (drbd_insert_fault(device, fault_type)) + bio_endio(bio, -EIO); + 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_initialize_al(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); + +/* + * inline helper functions + *************************/ + +/* see also page_chain_add and friends in drbd_receiver.c */ +static inline struct page *page_chain_next(struct page *page) +{ + return (struct page *)page_private(page); +} +#define page_chain_for_each(page) \ + for (; page && ({ prefetch(page_chain_next(page)); 1; }); \ + page = page_chain_next(page)) +#define page_chain_for_each_safe(page, n) \ + for (; page && ({ n = page_chain_next(page); 1; }); page = n) + + +static inline int drbd_peer_req_has_active_page(struct drbd_peer_request *peer_req) +{ + struct page *page = peer_req->pages; + page_chain_for_each(page) { + if (page_count(page) > 1) + return 1; + } + return 0; +} + +static inline enum drbd_state_rv +_drbd_set_state(struct drbd_device *device, 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(device, ns, flags, done); + read_unlock(&global_state_lock); + + return rv; +} + +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); + +static inline void wake_asender(struct drbd_connection *connection) +{ + if (test_bit(SIGNAL_ASENDER, &connection->flags)) + force_sig(DRBD_SIG, connection->asender.task); +} + +static inline void request_ping(struct drbd_connection *connection) +{ + set_bit(SEND_PING, &connection->flags); + wake_asender(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 (test_bit(SUSPEND_IO, &device->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(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 |