diff options
Diffstat (limited to 'drivers/block/drbd/drbd_main.c')
| -rw-r--r-- | drivers/block/drbd/drbd_main.c | 3735 |
1 files changed, 3735 insertions, 0 deletions
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c new file mode 100644 index 0000000..edf0b80 --- /dev/null +++ b/drivers/block/drbd/drbd_main.c @@ -0,0 +1,3735 @@ +/* + drbd.c + + 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>. + + Thanks to Carter Burden, Bart Grantham and Gennadiy Nerubayev + from Logicworks, Inc. for making SDP replication support possible. + + 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. + + */ + +#include <linux/autoconf.h> +#include <linux/module.h> +#include <linux/version.h> +#include <linux/drbd.h> +#include <asm/uaccess.h> +#include <asm/types.h> +#include <net/sock.h> +#include <linux/ctype.h> +#include <linux/smp_lock.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/proc_fs.h> +#include <linux/init.h> +#include <linux/mm.h> +#include <linux/memcontrol.h> +#include <linux/mm_inline.h> +#include <linux/slab.h> +#include <linux/random.h> +#include <linux/reboot.h> +#include <linux/notifier.h> +#include <linux/kthread.h> + +#define __KERNEL_SYSCALLS__ +#include <linux/unistd.h> +#include <linux/vmalloc.h> + +#include <linux/drbd_limits.h> +#include "drbd_int.h" +#include "drbd_tracing.h" +#include "drbd_req.h" /* only for _req_mod in tl_release and tl_clear */ + +#include "drbd_vli.h" + +struct after_state_chg_work { + struct drbd_work w; + union drbd_state os; + union drbd_state ns; + enum chg_state_flags flags; + struct completion *done; +}; + +int drbdd_init(struct drbd_thread *); +int drbd_worker(struct drbd_thread *); +int drbd_asender(struct drbd_thread *); + +int drbd_init(void); +static int drbd_open(struct block_device *bdev, fmode_t mode); +static int drbd_release(struct gendisk *gd, fmode_t mode); +static int w_after_state_ch(struct drbd_conf *mdev, struct drbd_work *w, int unused); +static void after_state_ch(struct drbd_conf *mdev, union drbd_state os, + union drbd_state ns, enum chg_state_flags flags); +static int w_md_sync(struct drbd_conf *mdev, struct drbd_work *w, int unused); +static void md_sync_timer_fn(unsigned long data); +static int w_bitmap_io(struct drbd_conf *mdev, struct drbd_work *w, int unused); + +DEFINE_TRACE(drbd_unplug); +DEFINE_TRACE(drbd_uuid); +DEFINE_TRACE(drbd_ee); +DEFINE_TRACE(drbd_packet); +DEFINE_TRACE(drbd_md_io); +DEFINE_TRACE(drbd_epoch); +DEFINE_TRACE(drbd_netlink); +DEFINE_TRACE(drbd_actlog); +DEFINE_TRACE(drbd_bio); +DEFINE_TRACE(_drbd_resync); +DEFINE_TRACE(drbd_req); + +MODULE_AUTHOR("Philipp Reisner <phil@linbit.com>, " + "Lars Ellenberg <lars@linbit.com>"); +MODULE_DESCRIPTION("drbd - Distributed Replicated Block Device v" REL_VERSION); +MODULE_VERSION(REL_VERSION); +MODULE_LICENSE("GPL"); +MODULE_PARM_DESC(minor_count, "Maximum number of drbd devices (1-255)"); +MODULE_ALIAS_BLOCKDEV_MAJOR(DRBD_MAJOR); + +#include <linux/moduleparam.h> +/* allow_open_on_secondary */ +MODULE_PARM_DESC(allow_oos, "DONT USE!"); +/* thanks to these macros, if compiled into the kernel (not-module), + * this becomes the boot parameter drbd.minor_count */ +module_param(minor_count, uint, 0444); +module_param(disable_sendpage, bool, 0644); +module_param(allow_oos, bool, 0); +module_param(cn_idx, uint, 0444); +module_param(proc_details, int, 0644); + +#ifdef CONFIG_DRBD_FAULT_INJECTION +int enable_faults; +int fault_rate; +static int fault_count; +int fault_devs; +/* bitmap of enabled faults */ +module_param(enable_faults, int, 0664); +/* fault rate % value - applies to all enabled faults */ +module_param(fault_rate, int, 0664); +/* count of faults inserted */ +module_param(fault_count, int, 0664); +/* bitmap of devices to insert faults on */ +module_param(fault_devs, int, 0644); +#endif + +/* module parameter, defined */ +unsigned int minor_count = 32; +int disable_sendpage; +int allow_oos; +unsigned int cn_idx = CN_IDX_DRBD; +int proc_details; /* Detail level in proc drbd*/ + +/* Module parameter for setting the user mode helper program + * to run. Default is /sbin/drbdadm */ +char usermode_helper[80] = "/sbin/drbdadm"; + +module_param_string(usermode_helper, usermode_helper, sizeof(usermode_helper), 0644); + +/* in 2.6.x, our device mapping and config info contains our virtual gendisks + * as member "struct gendisk *vdisk;" + */ +struct drbd_conf **minor_table; + +struct kmem_cache *drbd_request_cache; +struct kmem_cache *drbd_ee_cache; /* epoch entries */ +struct kmem_cache *drbd_bm_ext_cache; /* bitmap extents */ +struct kmem_cache *drbd_al_ext_cache; /* activity log extents */ +mempool_t *drbd_request_mempool; +mempool_t *drbd_ee_mempool; + +/* I do not use a standard mempool, because: + 1) I want to hand out the pre-allocated objects first. + 2) I want to be able to interrupt sleeping allocation with a signal. + Note: This is a single linked list, the next pointer is the private + member of struct page. + */ +struct page *drbd_pp_pool; +spinlock_t drbd_pp_lock; +int drbd_pp_vacant; +wait_queue_head_t drbd_pp_wait; + +DEFINE_RATELIMIT_STATE(drbd_ratelimit_state, 5 * HZ, 5); + +static struct block_device_operations drbd_ops = { + .owner = THIS_MODULE, + .open = drbd_open, + .release = drbd_release, +}; + +#define ARRY_SIZE(A) (sizeof(A)/sizeof(A[0])) + +#ifdef __CHECKER__ +/* When checking with sparse, and this is an inline function, sparse will + give tons of false positives. When this is a real functions sparse works. + */ +int _get_ldev_if_state(struct drbd_conf *mdev, enum drbd_disk_state mins) +{ + int io_allowed; + + atomic_inc(&mdev->local_cnt); + io_allowed = (mdev->state.disk >= mins); + if (!io_allowed) { + if (atomic_dec_and_test(&mdev->local_cnt)) + wake_up(&mdev->misc_wait); + } + return io_allowed; +} + +#endif + +/** + * DOC: The transfer log + * + * The transfer log is a single linked list of &struct drbd_tl_epoch objects. + * mdev->newest_tle points to the head, mdev->oldest_tle points to the tail + * of the list. There is always at least one &struct drbd_tl_epoch object. + * + * Each &struct drbd_tl_epoch has a circular double linked list of requests + * attached. + */ +static int tl_init(struct drbd_conf *mdev) +{ + struct drbd_tl_epoch *b; + + /* during device minor initialization, we may well use GFP_KERNEL */ + b = kmalloc(sizeof(struct drbd_tl_epoch), GFP_KERNEL); + if (!b) + return 0; + INIT_LIST_HEAD(&b->requests); + INIT_LIST_HEAD(&b->w.list); + b->next = NULL; + b->br_number = 4711; + b->n_req = 0; + b->w.cb = NULL; /* if this is != NULL, we need to dec_ap_pending in tl_clear */ + + mdev->oldest_tle = b; + mdev->newest_tle = b; + INIT_LIST_HEAD(&mdev->out_of_sequence_requests); + + mdev->tl_hash = NULL; + mdev->tl_hash_s = 0; + + return 1; +} + +static void tl_cleanup(struct drbd_conf *mdev) +{ + D_ASSERT(mdev->oldest_tle == mdev->newest_tle); + D_ASSERT(list_empty(&mdev->out_of_sequence_requests)); + kfree(mdev->oldest_tle); + mdev->oldest_tle = NULL; + kfree(mdev->unused_spare_tle); + mdev->unused_spare_tle = NULL; + kfree(mdev->tl_hash); + mdev->tl_hash = NULL; + mdev->tl_hash_s = 0; +} + +/** + * _tl_add_barrier() - Adds a barrier to the transfer log + * @mdev: DRBD device. + * @new: Barrier to be added before the current head of the TL. + * + * The caller must hold the req_lock. + */ +void _tl_add_barrier(struct drbd_conf *mdev, struct drbd_tl_epoch *new) +{ + struct drbd_tl_epoch *newest_before; + + INIT_LIST_HEAD(&new->requests); + INIT_LIST_HEAD(&new->w.list); + new->w.cb = NULL; /* if this is != NULL, we need to dec_ap_pending in tl_clear */ + new->next = NULL; + new->n_req = 0; + + newest_before = mdev->newest_tle; + /* never send a barrier number == 0, because that is special-cased + * when using TCQ for our write ordering code */ + new->br_number = (newest_before->br_number+1) ?: 1; + if (mdev->newest_tle != new) { + mdev->newest_tle->next = new; + mdev->newest_tle = new; + } +} + +/** + * tl_release() - Free or recycle the oldest &struct drbd_tl_epoch object of the TL + * @mdev: DRBD device. + * @barrier_nr: Expected identifier of the DRBD write barrier packet. + * @set_size: Expected number of requests before that barrier. + * + * In case the passed barrier_nr or set_size does not match the oldest + * &struct drbd_tl_epoch objects this function will cause a termination + * of the connection. + */ +void tl_release(struct drbd_conf *mdev, unsigned int barrier_nr, + unsigned int set_size) +{ + struct drbd_tl_epoch *b, *nob; /* next old barrier */ + struct list_head *le, *tle; + struct drbd_request *r; + + spin_lock_irq(&mdev->req_lock); + + b = mdev->oldest_tle; + + /* first some paranoia code */ + if (b == NULL) { + dev_err(DEV, "BAD! BarrierAck #%u received, but no epoch in tl!?\n", + barrier_nr); + goto bail; + } + if (b->br_number != barrier_nr) { + dev_err(DEV, "BAD! BarrierAck #%u received, expected #%u!\n", + barrier_nr, b->br_number); + goto bail; + } + if (b->n_req != set_size) { + dev_err(DEV, "BAD! BarrierAck #%u received with n_req=%u, expected n_req=%u!\n", + barrier_nr, set_size, b->n_req); + goto bail; + } + + /* Clean up list of requests processed during current epoch */ + list_for_each_safe(le, tle, &b->requests) { + r = list_entry(le, struct drbd_request, tl_requests); + _req_mod(r, barrier_acked); + } + /* There could be requests on the list waiting for completion + of the write to the local disk. To avoid corruptions of + slab's data structures we have to remove the lists head. + + Also there could have been a barrier ack out of sequence, overtaking + the write acks - which would be a bug and violating write ordering. + To not deadlock in case we lose connection while such requests are + still pending, we need some way to find them for the + _req_mode(connection_lost_while_pending). + + These have been list_move'd to the out_of_sequence_requests list in + _req_mod(, barrier_acked) above. + */ + list_del_init(&b->requests); + + nob = b->next; + if (test_and_clear_bit(CREATE_BARRIER, &mdev->flags)) { + _tl_add_barrier(mdev, b); + if (nob) + mdev->oldest_tle = nob; + /* if nob == NULL b was the only barrier, and becomes the new + barrier. Therefore mdev->oldest_tle points already to b */ + } else { + D_ASSERT(nob != NULL); + mdev->oldest_tle = nob; + kfree(b); + } + + spin_unlock_irq(&mdev->req_lock); + dec_ap_pending(mdev); + + return; + +bail: + spin_unlock_irq(&mdev->req_lock); + drbd_force_state(mdev, NS(conn, C_PROTOCOL_ERROR)); +} + + +/** + * tl_clear() - Clears all requests and &struct drbd_tl_epoch objects out of the TL + * @mdev: DRBD device. + * + * This is called after the connection to the peer was lost. The storage covered + * by the requests on the transfer gets marked as our of sync. Called from the + * receiver thread and the worker thread. + */ +void tl_clear(struct drbd_conf *mdev) +{ + struct drbd_tl_epoch *b, *tmp; + struct list_head *le, *tle; + struct drbd_request *r; + int new_initial_bnr = net_random(); + + spin_lock_irq(&mdev->req_lock); + + b = mdev->oldest_tle; + while (b) { + list_for_each_safe(le, tle, &b->requests) { + r = list_entry(le, struct drbd_request, tl_requests); + /* It would be nice to complete outside of spinlock. + * But this is easier for now. */ + _req_mod(r, connection_lost_while_pending); + } + tmp = b->next; + + /* there could still be requests on that ring list, + * in case local io is still pending */ + list_del(&b->requests); + + /* dec_ap_pending corresponding to queue_barrier. + * the newest barrier may not have been queued yet, + * in which case w.cb is still NULL. */ + if (b->w.cb != NULL) + dec_ap_pending(mdev); + + if (b == mdev->newest_tle) { + /* recycle, but reinit! */ + D_ASSERT(tmp == NULL); + INIT_LIST_HEAD(&b->requests); + INIT_LIST_HEAD(&b->w.list); + b->w.cb = NULL; + b->br_number = new_initial_bnr; + b->n_req = 0; + + mdev->oldest_tle = b; + break; + } + kfree(b); + b = tmp; + } + + /* we expect this list to be empty. */ + D_ASSERT(list_empty(&mdev->out_of_sequence_requests)); + + /* but just in case, clean it up anyways! */ + list_for_each_safe(le, tle, &mdev->out_of_sequence_requests) { + r = list_entry(le, struct drbd_request, tl_requests); + /* It would be nice to complete outside of spinlock. + * But this is easier for now. */ + _req_mod(r, connection_lost_while_pending); + } + + /* ensure bit indicating barrier is required is clear */ + clear_bit(CREATE_BARRIER, &mdev->flags); + + spin_unlock_irq(&mdev->req_lock); +} + +/** + * cl_wide_st_chg() - TRUE if the state change is a cluster wide one + * @mdev: DRBD device. + * @os: old (current) state. + * @ns: new (wanted) state. + */ +static int cl_wide_st_chg(struct drbd_conf *mdev, + union drbd_state os, union drbd_state ns) +{ + return (os.conn >= C_CONNECTED && ns.conn >= C_CONNECTED && + ((os.role != R_PRIMARY && ns.role == R_PRIMARY) || + (os.conn != C_STARTING_SYNC_T && ns.conn == C_STARTING_SYNC_T) || + (os.conn != C_STARTING_SYNC_S && ns.conn == C_STARTING_SYNC_S) || + (os.disk != D_DISKLESS && ns.disk == D_DISKLESS))) || + (os.conn >= C_CONNECTED && ns.conn == C_DISCONNECTING) || + (os.conn == C_CONNECTED && ns.conn == C_VERIFY_S); +} + +int drbd_change_state(struct drbd_conf *mdev, enum chg_state_flags f, + union drbd_state mask, union drbd_state val) +{ + unsigned long flags; + union drbd_state os, ns; + int rv; + + spin_lock_irqsave(&mdev->req_lock, flags); + os = mdev->state; + ns.i = (os.i & ~mask.i) | val.i; + rv = _drbd_set_state(mdev, ns, f, NULL); + ns = mdev->state; + spin_unlock_irqrestore(&mdev->req_lock, flags); + + return rv; +} + +/** + * drbd_force_state() - Impose a change which happens outside our control on our state + * @mdev: DRBD device. + * @mask: mask of state bits to change. + * @val: value of new state bits. + */ +void drbd_force_state(struct drbd_conf *mdev, + union drbd_state mask, union drbd_state val) +{ + drbd_change_state(mdev, CS_HARD, mask, val); +} + +static int is_valid_state(struct drbd_conf *mdev, union drbd_state ns); +static int is_valid_state_transition(struct drbd_conf *, + union drbd_state, union drbd_state); +static union drbd_state sanitize_state(struct drbd_conf *mdev, union drbd_state os, + union drbd_state ns, int *warn_sync_abort); +int drbd_send_state_req(struct drbd_conf *, + union drbd_state, union drbd_state); + +static enum drbd_state_ret_codes _req_st_cond(struct drbd_conf *mdev, + union drbd_state mask, union drbd_state val) +{ + union drbd_state os, ns; + unsigned long flags; + int rv; + + if (test_and_clear_bit(CL_ST_CHG_SUCCESS, &mdev->flags)) + return SS_CW_SUCCESS; + + if (test_and_clear_bit(CL_ST_CHG_FAIL, &mdev->flags)) + return SS_CW_FAILED_BY_PEER; + + rv = 0; + spin_lock_irqsave(&mdev->req_lock, flags); + os = mdev->state; + ns.i = (os.i & ~mask.i) | val.i; + ns = sanitize_state(mdev, os, ns, NULL); + + if (!cl_wide_st_chg(mdev, os, ns)) + rv = SS_CW_NO_NEED; + if (!rv) { + rv = is_valid_state(mdev, ns); + if (rv == SS_SUCCESS) { + rv = is_valid_state_transition(mdev, ns, os); + if (rv == SS_SUCCESS) + rv = 0; /* cont waiting, otherwise fail. */ + } + } + spin_unlock_irqrestore(&mdev->req_lock, flags); + + return rv; +} + +/** + * drbd_req_state() - Perform an eventually cluster wide state change + * @mdev: DRBD device. + * @mask: mask of state bits to change. + * @val: value of new state bits. + * @f: flags + * + * Should not be called directly, use drbd_request_state() or + * _drbd_request_state(). + */ +static int drbd_req_state(struct drbd_conf *mdev, + union drbd_state mask, union drbd_state val, + enum chg_state_flags f) +{ + struct completion done; + unsigned long flags; + union drbd_state os, ns; + int rv; + + init_completion(&done); + + if (f & CS_SERIALIZE) + mutex_lock(&mdev->state_mutex); + + spin_lock_irqsave(&mdev->req_lock, flags); + os = mdev->state; + ns.i = (os.i & ~mask.i) | val.i; + ns = sanitize_state(mdev, os, ns, NULL); + + if (cl_wide_st_chg(mdev, os, ns)) { + rv = is_valid_state(mdev, ns); + if (rv == SS_SUCCESS) + rv = is_valid_state_transition(mdev, ns, os); + spin_unlock_irqrestore(&mdev->req_lock, flags); + + if (rv < SS_SUCCESS) { + if (f & CS_VERBOSE) + print_st_err(mdev, os, ns, rv); + goto abort; + } + + drbd_state_lock(mdev); + if (!drbd_send_state_req(mdev, mask, val)) { + drbd_state_unlock(mdev); + rv = SS_CW_FAILED_BY_PEER; + if (f & CS_VERBOSE) + print_st_err(mdev, os, ns, rv); + goto abort; + } + + wait_event(mdev->state_wait, + (rv = _req_st_cond(mdev, mask, val))); + + if (rv < SS_SUCCESS) { + drbd_state_unlock(mdev); + if (f & CS_VERBOSE) + print_st_err(mdev, os, ns, rv); + goto abort; + } + spin_lock_irqsave(&mdev->req_lock, flags); + os = mdev->state; + ns.i = (os.i & ~mask.i) | val.i; + rv = _drbd_set_state(mdev, ns, f, &done); + drbd_state_unlock(mdev); + } else { + rv = _drbd_set_state(mdev, ns, f, &done); + } + + spin_unlock_irqrestore(&mdev->req_lock, flags); + + if (f & CS_WAIT_COMPLETE && rv == SS_SUCCESS) { + D_ASSERT(current != mdev->worker.task); + wait_for_completion(&done); + } + +abort: + if (f & CS_SERIALIZE) + mutex_unlock(&mdev->state_mutex); + + return rv; +} + +/** + * _drbd_request_state() - Request a state change (with flags) + * @mdev: DRBD device. + * @mask: mask of state bits to change. + * @val: value of new state bits. + * @f: flags + * + * Cousin of drbd_request_state(), useful with the CS_WAIT_COMPLETE + * flag, or when logging of failed state change requests is not desired. + */ +int _drbd_request_state(struct drbd_conf *mdev, union drbd_state mask, + union drbd_state val, enum chg_state_flags f) +{ + int rv; + + wait_event(mdev->state_wait, + (rv = drbd_req_state(mdev, mask, val, f)) != SS_IN_TRANSIENT_STATE); + + return rv; +} + +static void print_st(struct drbd_conf *mdev, char *name, union drbd_state ns) +{ + dev_err(DEV, " %s = { cs:%s ro:%s/%s ds:%s/%s %c%c%c%c }\n", + name, + drbd_conn_str(ns.conn), + drbd_role_str(ns.role), + drbd_role_str(ns.peer), + drbd_disk_str(ns.disk), + drbd_disk_str(ns.pdsk), + ns.susp ? 's' : 'r', + ns.aftr_isp ? 'a' : '-', + ns.peer_isp ? 'p' : '-', + ns.user_isp ? 'u' : '-' + ); +} + +void print_st_err(struct drbd_conf *mdev, + union drbd_state os, union drbd_state ns, int err) +{ + if (err == SS_IN_TRANSIENT_STATE) + return; + dev_err(DEV, "State change failed: %s\n", drbd_set_st_err_str(err)); + print_st(mdev, " state", os); + print_st(mdev, "wanted", ns); +} + + +#define drbd_peer_str drbd_role_str +#define drbd_pdsk_str drbd_disk_str + +#define drbd_susp_str(A) ((A) ? "1" : "0") +#define drbd_aftr_isp_str(A) ((A) ? "1" : "0") +#define drbd_peer_isp_str(A) ((A) ? "1" : "0") +#define drbd_user_isp_str(A) ((A) ? "1" : "0") + +#define PSC(A) \ + ({ if (ns.A != os.A) { \ + pbp += sprintf(pbp, #A "( %s -> %s ) ", \ + drbd_##A##_str(os.A), \ + drbd_##A##_str(ns.A)); \ + } }) + +/** + * is_valid_state() - Returns an SS_ error code if ns is not valid + * @mdev: DRBD device. + * @ns: State to consider. + */ +static int is_valid_state(struct drbd_conf *mdev, union drbd_state ns) +{ + /* See drbd_state_sw_errors in drbd_strings.c */ + + enum drbd_fencing_p fp; + int rv = SS_SUCCESS; + + fp = FP_DONT_CARE; + if (get_ldev(mdev)) { + fp = mdev->ldev->dc.fencing; + put_ldev(mdev); + } + + if (get_net_conf(mdev)) { + if (!mdev->net_conf->two_primaries && + ns.role == R_PRIMARY && ns.peer == R_PRIMARY) + rv = SS_TWO_PRIMARIES; + put_net_conf(mdev); + } + + if (rv <= 0) + /* already found a reason to abort */; + else if (ns.role == R_SECONDARY && mdev->open_cnt) + rv = SS_DEVICE_IN_USE; + + else if (ns.role == R_PRIMARY && ns.conn < C_CONNECTED && ns.disk < D_UP_TO_DATE) + rv = SS_NO_UP_TO_DATE_DISK; + + else if (fp >= FP_RESOURCE && + ns.role == R_PRIMARY && ns.conn < C_CONNECTED && ns.pdsk >= D_UNKNOWN) + rv = SS_PRIMARY_NOP; + + else if (ns.role == R_PRIMARY && ns.disk <= D_INCONSISTENT && ns.pdsk <= D_INCONSISTENT) + rv = SS_NO_UP_TO_DATE_DISK; + + else if (ns.conn > C_CONNECTED && ns.disk < D_INCONSISTENT) + rv = SS_NO_LOCAL_DISK; + + else if (ns.conn > C_CONNECTED && ns.pdsk < D_INCONSISTENT) + rv = SS_NO_REMOTE_DISK; + + else if ((ns.conn == C_CONNECTED || + ns.conn == C_WF_BITMAP_S || + ns.conn == C_SYNC_SOURCE || + ns.conn == C_PAUSED_SYNC_S) && + ns.disk == D_OUTDATED) + rv = SS_CONNECTED_OUTDATES; + + else if ((ns.conn == C_VERIFY_S || ns.conn == C_VERIFY_T) && + (mdev->sync_conf.verify_alg[0] == 0)) + rv = SS_NO_VERIFY_ALG; + + else if ((ns.conn == C_VERIFY_S || ns.conn == C_VERIFY_T) && + mdev->agreed_pro_version < 88) + rv = SS_NOT_SUPPORTED; + + return rv; +} + +/** + * is_valid_state_transition() - Returns an SS_ error code if the state transition is not possible + * @mdev: DRBD device. + * @ns: new state. + * @os: old state. + */ +static int is_valid_state_transition(struct drbd_conf *mdev, + union drbd_state ns, union drbd_state os) +{ + int rv = SS_SUCCESS; + + if ((ns.conn == C_STARTING_SYNC_T || ns.conn == C_STARTING_SYNC_S) && + os.conn > C_CONNECTED) + rv = SS_RESYNC_RUNNING; + + if (ns.conn == C_DISCONNECTING && os.conn == C_STANDALONE) + rv = SS_ALREADY_STANDALONE; + + if (ns.disk > D_ATTACHING && os.disk == D_DISKLESS) + rv = SS_IS_DISKLESS; + + if (ns.conn == C_WF_CONNECTION && os.conn < C_UNCONNECTED) + rv = SS_NO_NET_CONFIG; + + if (ns.disk == D_OUTDATED && os.disk < D_OUTDATED && os.disk != D_ATTACHING) + rv = SS_LOWER_THAN_OUTDATED; + + if (ns.conn == C_DISCONNECTING && os.conn == C_UNCONNECTED) + rv = SS_IN_TRANSIENT_STATE; + + if (ns.conn == os.conn && ns.conn == C_WF_REPORT_PARAMS) + rv = SS_IN_TRANSIENT_STATE; + + if ((ns.conn == C_VERIFY_S || ns.conn == C_VERIFY_T) && os.conn < C_CONNECTED) + rv = SS_NEED_CONNECTION; + + if ((ns.conn == C_VERIFY_S || ns.conn == C_VERIFY_T) && + ns.conn != os.conn && os.conn > C_CONNECTED) + rv = SS_RESYNC_RUNNING; + + if ((ns.conn == C_STARTING_SYNC_S || ns.conn == C_STARTING_SYNC_T) && + os.conn < C_CONNECTED) + rv = SS_NEED_CONNECTION; + + return rv; +} + +/** + * sanitize_state() - Resolves implicitly necessary additional changes to a state transition + * @mdev: DRBD device. + * @os: old state. + * @ns: new state. + * @warn_sync_abort: + * + * When we loose connection, we have to set the state of the peers disk (pdsk) + * to D_UNKNOWN. This rule and many more along those lines are in this function. + */ +static union drbd_state sanitize_state(struct drbd_conf *mdev, union drbd_state os, + union drbd_state ns, int *warn_sync_abort) +{ + enum drbd_fencing_p fp; + + fp = FP_DONT_CARE; + if (get_ldev(mdev)) { + fp = mdev->ldev->dc.fencing; + put_ldev(mdev); + } + + /* Disallow Network errors to configure a device's network part */ + if ((ns.conn >= C_TIMEOUT && ns.conn <= C_TEAR_DOWN) && + os.conn <= C_DISCONNECTING) + ns.conn = os.conn; + + /* After a network error (+C_TEAR_DOWN) only C_UNCONNECTED or C_DISCONNECTING can follow */ + if (os.conn >= C_TIMEOUT && os.conn <= C_TEAR_DOWN && + ns.conn != C_UNCONNECTED && ns.conn != C_DISCONNECTING) + ns.conn = os.conn; + + /* After C_DISCONNECTING only C_STANDALONE may follow */ + if (os.conn == C_DISCONNECTING && ns.conn != C_STANDALONE) + ns.conn = os.conn; + + if (ns.conn < C_CONNECTED) { + ns.peer_isp = 0; + ns.peer = R_UNKNOWN; + if (ns.pdsk > D_UNKNOWN || ns.pdsk < D_INCONSISTENT) + ns.pdsk = D_UNKNOWN; + } + + /* Clear the aftr_isp when becoming unconfigured */ + if (ns.conn == C_STANDALONE && ns.disk == D_DISKLESS && ns.role == R_SECONDARY) + ns.aftr_isp = 0; + + if (ns.conn <= C_DISCONNECTING && ns.disk == D_DISKLESS) + ns.pdsk = D_UNKNOWN; + + /* Abort resync if a disk fails/detaches */ + if (os.conn > C_CONNECTED && ns.conn > C_CONNECTED && + (ns.disk <= D_FAILED || ns.pdsk <= D_FAILED)) { + if (warn_sync_abort) + *warn_sync_abort = 1; + ns.conn = C_CONNECTED; + } + + if (ns.conn >= C_CONNECTED && + ((ns.disk == D_CONSISTENT || ns.disk == D_OUTDATED) || + (ns.disk == D_NEGOTIATING && ns.conn == C_WF_BITMAP_T))) { + switch (ns.conn) { + case C_WF_BITMAP_T: + case C_PAUSED_SYNC_T: + ns.disk = D_OUTDATED; + break; + case C_CONNECTED: + case C_WF_BITMAP_S: + case C_SYNC_SOURCE: + case C_PAUSED_SYNC_S: + ns.disk = D_UP_TO_DATE; + break; + case C_SYNC_TARGET: + ns.disk = D_INCONSISTENT; + dev_warn(DEV, "Implicitly set disk state Inconsistent!\n"); + break; + } + if (os.disk == D_OUTDATED && ns.disk == D_UP_TO_DATE) + dev_warn(DEV, "Implicitly set disk from Outdated to UpToDate\n"); + } + + if (ns.conn >= C_CONNECTED && + (ns.pdsk == D_CONSISTENT || ns.pdsk == D_OUTDATED)) { + switch (ns.conn) { + case C_CONNECTED: + case C_WF_BITMAP_T: + case C_PAUSED_SYNC_T: + case C_SYNC_TARGET: + ns.pdsk = D_UP_TO_DATE; + break; + case C_WF_BITMAP_S: + case C_PAUSED_SYNC_S: + ns.pdsk = D_OUTDATED; + break; + case C_SYNC_SOURCE: + ns.pdsk = D_INCONSISTENT; + dev_warn(DEV, "Implicitly set pdsk Inconsistent!\n"); + break; + } + if (os.pdsk == D_OUTDATED && ns.pdsk == D_UP_TO_DATE) + dev_warn(DEV, "Implicitly set pdsk from Outdated to UpToDate\n"); + } + + /* Connection breaks down before we finished "Negotiating" */ + if (ns.conn < C_CONNECTED && ns.disk == D_NEGOTIATING && + get_ldev_if_state(mdev, D_NEGOTIATING)) { + if (mdev->ed_uuid == mdev->ldev->md.uuid[UI_CURRENT]) { + ns.disk = mdev->new_state_tmp.disk; + ns.pdsk = mdev->new_state_tmp.pdsk; + } else { + dev_alert(DEV, "Connection lost while negotiating, no data!\n"); + ns.disk = D_DISKLESS; + ns.pdsk = D_UNKNOWN; + } + put_ldev(mdev); + } + + if (fp == FP_STONITH && + (ns.role == R_PRIMARY && + ns.conn < C_CONNECTED && + ns.pdsk > D_OUTDATED)) + ns.susp = 1; + + if (ns.aftr_isp || ns.peer_isp || ns.user_isp) { + if (ns.conn == C_SYNC_SOURCE) + ns.conn = C_PAUSED_SYNC_S; + if (ns.conn == C_SYNC_TARGET) + ns.conn = C_PAUSED_SYNC_T; + } else { + if (ns.conn == C_PAUSED_SYNC_S) + ns.conn = C_SYNC_SOURCE; + if (ns.conn == C_PAUSED_SYNC_T) + ns.conn = C_SYNC_TARGET; + } + + return ns; +} + +/* helper for __drbd_set_state */ +static void set_ov_position(struct drbd_conf *mdev, enum drbd_conns cs) +{ + if (cs == C_VERIFY_T) { + /* starting online verify from an arbitrary position + * does not fit well into the existing protocol. + * on C_VERIFY_T, we initialize ov_left and friends + * implicitly in receive_DataRequest once the + * first P_OV_REQUEST is received */ + mdev->ov_start_sector = ~(sector_t)0; + } else { + unsigned long bit = BM_SECT_TO_BIT(mdev->ov_start_sector); + if (bit >= mdev->rs_total) + mdev->ov_start_sector = + BM_BIT_TO_SECT(mdev->rs_total - 1); + mdev->ov_position = mdev->ov_start_sector; + } +} + +/** + * __drbd_set_state() - Set a new DRBD state + * @mdev: DRBD device. + * @ns: new state. + * @flags: Flags + * @done: Optional completion, that will get completed after the after_state_ch() finished + * + * Caller needs to hold req_lock, and global_state_lock. Do not call directly. + */ +int __drbd_set_state(struct drbd_conf *mdev, + union drbd_state ns, enum chg_state_flags flags, + struct completion *done) +{ + union drbd_state os; + int rv = SS_SUCCESS; + int warn_sync_abort = 0; + struct after_state_chg_work *ascw; + + os = mdev->state; + + ns = sanitize_state(mdev, os, ns, &warn_sync_abort); + + if (ns.i == os.i) + return SS_NOTHING_TO_DO; + + if (!(flags & CS_HARD)) { + /* pre-state-change checks ; only look at ns */ + /* See drbd_state_sw_errors in drbd_strings.c */ + + rv = is_valid_state(mdev, ns); + if (rv < SS_SUCCESS) { + /* If the old state was illegal as well, then let + this happen...*/ + + if (is_valid_state(mdev, os) == rv) { + dev_err(DEV, "Considering state change from bad state. " + "Error would be: '%s'\n", + drbd_set_st_err_str(rv)); + print_st(mdev, "old", os); + print_st(mdev, "new", ns); + rv = is_valid_state_transition(mdev, ns, os); + } + } else + rv = is_valid_state_transition(mdev, ns, os); + } + + if (rv < SS_SUCCESS) { + if (flags & CS_VERBOSE) + print_st_err(mdev, os, ns, rv); + return rv; + } + + if (warn_sync_abort) + dev_warn(DEV, "Resync aborted.\n"); + + { + char *pbp, pb[300]; + pbp = pb; + *pbp = 0; + PSC(role); + PSC(peer); + PSC(conn); + PSC(disk); + PSC(pdsk); + PSC(susp); + PSC(aftr_isp); + PSC(peer_isp); + PSC(user_isp); + dev_info(DEV, "%s\n", pb); + } + + /* solve the race between becoming unconfigured, + * worker doing the cleanup, and + * admin reconfiguring us: + * on (re)configure, first set CONFIG_PENDING, + * then wait for a potentially exiting worker, + * start the worker, and schedule one no_op. + * then proceed with configuration. + */ + if (ns.disk == D_DISKLESS && + ns.conn == C_STANDALONE && + ns.role == R_SECONDARY && + !test_and_set_bit(CONFIG_PENDING, &mdev->flags)) + set_bit(DEVICE_DYING, &mdev->flags); + + mdev->state.i = ns.i; + wake_up(&mdev->misc_wait); + wake_up(&mdev->state_wait); + + /* post-state-change actions */ + if (os.conn >= C_SYNC_SOURCE && ns.conn <= C_CONNECTED) { + set_bit(STOP_SYNC_TIMER, &mdev->flags); + mod_timer(&mdev->resync_timer, jiffies); + } + + /* aborted verify run. log the last position */ + if ((os.conn == C_VERIFY_S || os.conn == C_VERIFY_T) && + ns.conn < C_CONNECTED) { + mdev->ov_start_sector = + BM_BIT_TO_SECT(mdev->rs_total - mdev->ov_left); + dev_info(DEV, "Online Verify reached sector %llu\n", + (unsigned long long)mdev->ov_start_sector); + } + + if ((os.conn == C_PAUSED_SYNC_T || os.conn == C_PAUSED_SYNC_S) && + (ns.conn == C_SYNC_TARGET || ns.conn == C_SYNC_SOURCE)) { + dev_info(DEV, "Syncer continues.\n"); + mdev->rs_paused += (long)jiffies-(long)mdev->rs_mark_time; + if (ns.conn == C_SYNC_TARGET) { + if (!test_and_clear_bit(STOP_SYNC_TIMER, &mdev->flags)) + mod_timer(&mdev->resync_timer, jiffies); + /* This if (!test_bit) is only needed for the case + that a device that has ceased to used its timer, + i.e. it is already in drbd_resync_finished() gets + paused and resumed. */ + } + } + + if ((os.conn == C_SYNC_TARGET || os.conn == C_SYNC_SOURCE) && + (ns.conn == C_PAUSED_SYNC_T || ns.conn == C_PAUSED_SYNC_S)) { + dev_info(DEV, "Resync suspended\n"); + mdev->rs_mark_time = jiffies; + if (ns.conn == C_PAUSED_SYNC_T) + set_bit(STOP_SYNC_TIMER, &mdev->flags); + } + + if (os.conn == C_CONNECTED && + (ns.conn == C_VERIFY_S || ns.conn == C_VERIFY_T)) { + mdev->ov_position = 0; + mdev->rs_total = + mdev->rs_mark_left = drbd_bm_bits(mdev); + if (mdev->agreed_pro_version >= 90) + set_ov_position(mdev, ns.conn); + else + mdev->ov_start_sector = 0; + mdev->ov_left = mdev->rs_total + - BM_SECT_TO_BIT(mdev->ov_position); + mdev->rs_start = + mdev->rs_mark_time = jiffies; + mdev->ov_last_oos_size = 0; + mdev->ov_last_oos_start = 0; + + if (ns.conn == C_VERIFY_S) { + dev_info(DEV, "Starting Online Verify from sector %llu\n", + (unsigned long long)mdev->ov_position); + mod_timer(&mdev->resync_timer, jiffies); + } + } + + if (get_ldev(mdev)) { + u32 mdf = mdev->ldev->md.flags & ~(MDF_CONSISTENT|MDF_PRIMARY_IND| + MDF_CONNECTED_IND|MDF_WAS_UP_TO_DATE| + MDF_PEER_OUT_DATED|MDF_CRASHED_PRIMARY); + + if (test_bit(CRASHED_PRIMARY, &mdev->flags)) + mdf |= MDF_CRASHED_PRIMARY; + if (mdev->state.role == R_PRIMARY || + (mdev->state.pdsk < D_INCONSISTENT && mdev->state.peer == R_PRIMARY)) + mdf |= MDF_PRIMARY_IND; + if (mdev->state.conn > C_WF_REPORT_PARAMS) + mdf |= MDF_CONNECTED_IND; + if (mdev->state.disk > D_INCONSISTENT) + mdf |= MDF_CONSISTENT; + if (mdev->state.disk > D_OUTDATED) + mdf |= MDF_WAS_UP_TO_DATE; + if (mdev->state.pdsk <= D_OUTDATED && mdev->state.pdsk >= D_INCONSISTENT) + mdf |= MDF_PEER_OUT_DATED; + if (mdf != mdev->ldev->md.flags) { + mdev->ldev->md.flags = mdf; + drbd_md_mark_dirty(mdev); + } + if (os.disk < D_CONSISTENT && ns.disk >= D_CONSISTENT) + drbd_set_ed_uuid(mdev, mdev->ldev->md.uuid[UI_CURRENT]); + put_ldev(mdev); + } + + /* Peer was forced D_UP_TO_DATE & R_PRIMARY, consider to resync */ + if (os.disk == D_INCONSISTENT && os.pdsk == D_INCONSISTENT && + os.peer == R_SECONDARY && ns.peer == R_PRIMARY) + set_bit(CONSIDER_RESYNC, &mdev->flags); + + /* Receiver should clean up itself */ + if (os.conn != C_DISCONNECTING && ns.conn == C_DISCONNECTING) + drbd_thread_stop_nowait(&mdev->receiver); + + /* Now the receiver finished cleaning up itself, it should die */ + if (os.conn != C_STANDALONE && ns.conn == C_STANDALONE) + drbd_thread_stop_nowait(&mdev->receiver); + + /* Upon network failure, we need to restart the receiver. */ + if (os.conn > C_TEAR_DOWN && + ns.conn <= C_TEAR_DOWN && ns.conn >= C_TIMEOUT) + drbd_thread_restart_nowait(&mdev->receiver); + + ascw = kmalloc(sizeof(*ascw), GFP_ATOMIC); + if (ascw) { + ascw->os = os; + ascw->ns = ns; + ascw->flags = flags; + ascw->w.cb = w_after_state_ch; + ascw->done = done; + drbd_queue_work(&mdev->data.work, &ascw->w); + } else { + dev_warn(DEV, "Could not kmalloc an ascw\n"); + } + + return rv; +} + +static int w_after_state_ch(struct drbd_conf *mdev, struct drbd_work *w, int unused) +{ + struct after_state_chg_work *ascw = + container_of(w, struct after_state_chg_work, w); + after_state_ch(mdev, ascw->os, ascw->ns, ascw->flags); + if (ascw->flags & CS_WAIT_COMPLETE) { + D_ASSERT(ascw->done != NULL); + complete(ascw->done); + } + kfree(ascw); + + return 1; +} + +static void abw_start_sync(struct drbd_conf *mdev, int rv) +{ + if (rv) { + dev_err(DEV, "Writing the bitmap failed not starting resync.\n"); + _drbd_request_state(mdev, NS(conn, C_CONNECTED), CS_VERBOSE); + return; + } + + switch (mdev->state.conn) { + case C_STARTING_SYNC_T: + _drbd_request_state(mdev, NS(conn, C_WF_SYNC_UUID), CS_VERBOSE); + break; + case C_STARTING_SYNC_S: + drbd_start_resync(mdev, C_SYNC_SOURCE); + break; + } +} + +/** + * after_state_ch() - Perform after state change actions that may sleep + * @mdev: DRBD device. + * @os: old state. + * @ns: new state. + * @flags: Flags + */ +static void after_state_ch(struct drbd_conf *mdev, union drbd_state os, + union drbd_state ns, enum chg_state_flags flags) +{ + enum drbd_fencing_p fp; + + if (os.conn != C_CONNECTED && ns.conn == C_CONNECTED) { + clear_bit(CRASHED_PRIMARY, &mdev->flags); + if (mdev->p_uuid) + mdev->p_uuid[UI_FLAGS] &= ~((u64)2); + } + + fp = FP_DONT_CARE; + if (get_ldev(mdev)) { + fp = mdev->ldev->dc.fencing; + put_ldev(mdev); + } + + /* Inform userspace about the change... */ + drbd_bcast_state(mdev, ns); + + if (!(os.role == R_PRIMARY && os.disk < D_UP_TO_DATE && os.pdsk < D_UP_TO_DATE) && + (ns.role == R_PRIMARY && ns.disk < D_UP_TO_DATE && ns.pdsk < D_UP_TO_DATE)) + drbd_khelper(mdev, "pri-on-incon-degr"); + + /* Here we have the actions that are performed after a + state change. This function might sleep */ + + if (fp == FP_STONITH && ns.susp) { + /* case1: The outdate peer handler is successful: + * case2: The connection was established again: */ + if ((os.pdsk > D_OUTDATED && ns.pdsk <= D_OUTDATED) || + (os.conn < C_CONNECTED && ns.conn >= C_CONNECTED)) { + tl_clear(mdev); + spin_lock_irq(&mdev->req_lock); + _drbd_set_state(_NS(mdev, susp, 0), CS_VERBOSE, NULL); + spin_unlock_irq(&mdev->req_lock); + } + } + /* Do not change the order of the if above and the two below... */ + if (os.pdsk == D_DISKLESS && ns.pdsk > D_DISKLESS) { /* attach on the peer */ + drbd_send_uuids(mdev); + drbd_send_state(mdev); + } + if (os.conn != C_WF_BITMAP_S && ns.conn == C_WF_BITMAP_S) + drbd_queue_bitmap_io(mdev, &drbd_send_bitmap, NULL, "send_bitmap (WFBitMapS)"); + + /* Lost contact to peer's copy of the data */ + if ((os.pdsk >= D_INCONSISTENT && + os.pdsk != D_UNKNOWN && + os.pdsk != D_OUTDATED) + && (ns.pdsk < D_INCONSISTENT || + ns.pdsk == D_UNKNOWN || + ns.pdsk == D_OUTDATED)) { + kfree(mdev->p_uuid); + mdev->p_uuid = NULL; + if (get_ldev(mdev)) { + if ((ns.role == R_PRIMARY || ns.peer == R_PRIMARY) && + mdev->ldev->md.uuid[UI_BITMAP] == 0 && ns.disk >= D_UP_TO_DATE) { + drbd_uuid_new_current(mdev); + drbd_send_uuids(mdev); + } + put_ldev(mdev); + } + } + + if (ns.pdsk < D_INCONSISTENT && get_ldev(mdev)) { + if (ns.peer == R_PRIMARY && mdev->ldev->md.uuid[UI_BITMAP] == 0) + drbd_uuid_new_current(mdev); + + /* D_DISKLESS Peer becomes secondary */ + if (os.peer == R_PRIMARY && ns.peer == R_SECONDARY) + drbd_al_to_on_disk_bm(mdev); + put_ldev(mdev); + } + + /* Last part of the attaching process ... */ + if (ns.conn >= C_CONNECTED && + os.disk == D_ATTACHING && ns.disk == D_NEGOTIATING) { + kfree(mdev->p_uuid); /* We expect to receive up-to-date UUIDs soon. */ + mdev->p_uuid = NULL; /* ...to not use the old ones in the mean time */ + drbd_send_sizes(mdev, 0); /* to start sync... */ + drbd_send_uuids(mdev); + drbd_send_state(mdev); + } + + /* We want to pause/continue resync, tell peer. */ + if (ns.conn >= C_CONNECTED && + ((os.aftr_isp != ns.aftr_isp) || + (os.user_isp != ns.user_isp))) + drbd_send_state(mdev); + + /* In case one of the isp bits got set, suspend other devices. */ + if ((!os.aftr_isp && !os.peer_isp && !os.user_isp) && + (ns.aftr_isp || ns.peer_isp || ns.user_isp)) + suspend_other_sg(mdev); + + /* Make sure the peer gets informed about eventual state + changes (ISP bits) while we were in WFReportParams. */ + if (os.conn == C_WF_REPORT_PARAMS && ns.conn >= C_CONNECTED) + drbd_send_state(mdev); + + /* We are in the progress to start a full sync... */ + if ((os.conn != C_STARTING_SYNC_T && ns.conn == C_STARTING_SYNC_T) || + (os.conn != C_STARTING_SYNC_S && ns.conn == C_STARTING_SYNC_S)) + drbd_queue_bitmap_io(mdev, &drbd_bmio_set_n_write, &abw_start_sync, "set_n_write from StartingSync"); + + /* We are invalidating our self... */ + if (os.conn < C_CONNECTED && ns.conn < C_CONNECTED && + os.disk > D_INCONSISTENT && ns.disk == D_INCONSISTENT) + drbd_queue_bitmap_io(mdev, &drbd_bmio_set_n_write, NULL, "set_n_write from invalidate"); + + if (os.disk > D_FAILED && ns.disk == D_FAILED) { + enum drbd_io_error_p eh; + + eh = EP_PASS_ON; + if (get_ldev_if_state(mdev, D_FAILED)) { + eh = mdev->ldev->dc.on_io_error; + put_ldev(mdev); + } + + drbd_rs_cancel_all(mdev); + /* since get_ldev() only works as long as disk>=D_INCONSISTENT, + and it is D_DISKLESS here, local_cnt can only go down, it can + not increase... It will reach zero */ + wait_event(mdev->misc_wait, !atomic_read(&mdev->local_cnt)); + mdev->rs_total = 0; + mdev->rs_failed = 0; + atomic_set(&mdev->rs_pending_cnt, 0); + + spin_lock_irq(&mdev->req_lock); + _drbd_set_state(_NS(mdev, disk, D_DISKLESS), CS_HARD, NULL); + spin_unlock_irq(&mdev->req_lock); + + if (eh == EP_CALL_HELPER) + drbd_khelper(mdev, "local-io-error"); + } + + if (os.disk > D_DISKLESS && ns.disk == D_DISKLESS) { + + if (os.disk == D_FAILED) /* && ns.disk == D_DISKLESS*/ { + if (drbd_send_state(mdev)) + dev_warn(DEV, "Notified peer that my disk is broken.\n"); + else + dev_err(DEV, "Sending state in drbd_io_error() failed\n"); + } + + lc_destroy(mdev->resync); + mdev->resync = NULL; + lc_destroy(mdev->act_log); + mdev->act_log = NULL; + __no_warn(local, + drbd_free_bc(mdev->ldev); + mdev->ldev = NULL;); + + if (mdev->md_io_tmpp) + __free_page(mdev->md_io_tmpp); + } + + /* Disks got bigger while they were detached */ + if (ns.disk > D_NEGOTIATING && ns.pdsk > D_NEGOTIATING && + test_and_clear_bit(RESYNC_AFTER_NEG, &mdev->flags)) { + if (ns.conn == C_CONNECTED) + resync_after_online_grow(mdev); + } + + /* A resync finished or aborted, wake paused devices... */ + if ((os.conn > C_CONNECTED && ns.conn <= C_CONNECTED) || + (os.peer_isp && !ns.peer_isp) || + (os.user_isp && !ns.user_isp)) + resume_next_sg(mdev); + + /* Upon network connection, we need to start the receiver */ + if (os.conn == C_STANDALONE && ns.conn == C_UNCONNECTED) + drbd_thread_start(&mdev->receiver); + + /* Terminate worker thread if we are unconfigured - it will be + restarted as needed... */ + if (ns.disk == D_DISKLESS && + ns.conn == C_STANDALONE && + ns.role == R_SECONDARY) { + if (os.aftr_isp != ns.aftr_isp) + resume_next_sg(mdev); + /* set in __drbd_set_state, unless CONFIG_PENDING was set */ + if (test_bit(DEVICE_DYING, &mdev->flags)) + drbd_thread_stop_nowait(&mdev->worker); + } + + drbd_md_sync(mdev); +} + + +static int drbd_thread_setup(void *arg) +{ + struct drbd_thread *thi = (struct drbd_thread *) arg; + struct drbd_conf *mdev = thi->mdev; + unsigned long flags; + int retval; + +restart: + retval = thi->function(thi); + + spin_lock_irqsave(&thi->t_lock, flags); + + /* if the receiver has been "Exiting", the last thing it did + * was set the conn state to "StandAlone", + * if now a re-connect request comes in, conn state goes C_UNCONNECTED, + * and receiver thread will be "started". + * drbd_thread_start needs to set "Restarting" in that case. + * t_state check and assignment needs to be within the same spinlock, + * so either thread_start sees Exiting, and can remap to Restarting, + * or thread_start see None, and can proceed as normal. + */ + + if (thi->t_state == Restarting) { + dev_info(DEV, "Restarting %s\n", current->comm); + thi->t_state = Running; + spin_unlock_irqrestore(&thi->t_lock, flags); + goto restart; + } + + thi->task = NULL; + thi->t_state = None; + smp_mb(); + complete(&thi->stop); + spin_unlock_irqrestore(&thi->t_lock, flags); + + dev_info(DEV, "Terminating %s\n", current->comm); + + /* Release mod reference taken when thread was started */ + module_put(THIS_MODULE); + return retval; +} + +static void drbd_thread_init(struct drbd_conf *mdev, struct drbd_thread *thi, + int (*func) (struct drbd_thread *)) +{ + spin_lock_init(&thi->t_lock); + thi->task = NULL; + thi->t_state = None; + thi->function = func; + thi->mdev = mdev; +} + +int drbd_thread_start(struct drbd_thread *thi) +{ + struct drbd_conf *mdev = thi->mdev; + struct task_struct *nt; + unsigned long flags; + + const char *me = + thi == &mdev->receiver ? "receiver" : + thi == &mdev->asender ? "asender" : + thi == &mdev->worker ? "worker" : "NONSENSE"; + + /* is used from state engine doing drbd_thread_stop_nowait, + * while holding the req lock irqsave */ + spin_lock_irqsave(&thi->t_lock, flags); + + switch (thi->t_state) { + case None: + dev_info(DEV, "Starting %s thread (from %s [%d])\n", + me, current->comm, current->pid); + + /* Get ref on module for thread - this is released when thread exits */ + if (!try_module_get(THIS_MODULE)) { + dev_err(DEV, "Failed to get module reference in drbd_thread_start\n"); + spin_unlock_irqrestore(&thi->t_lock, flags); + return FALSE; + } + + init_completion(&thi->stop); + D_ASSERT(thi->task == NULL); + thi->reset_cpu_mask = 1; + thi->t_state = Running; + spin_unlock_irqrestore(&thi->t_lock, flags); + flush_signals(current); /* otherw. may get -ERESTARTNOINTR */ + + nt = kthread_create(drbd_thread_setup, (void *) thi, + "drbd%d_%s", mdev_to_minor(mdev), me); + + if (IS_ERR(nt)) { + dev_err(DEV, "Couldn't start thread\n"); + + module_put(THIS_MODULE); + return FALSE; + } + spin_lock_irqsave(&thi->t_lock, flags); + thi->task = nt; + thi->t_state = Running; + spin_unlock_irqrestore(&thi->t_lock, flags); + wake_up_process(nt); + break; + case Exiting: + thi->t_state = Restarting; + dev_info(DEV, "Restarting %s thread (from %s [%d])\n", + me, current->comm, current->pid); + /* fall through */ + case Running: + case Restarting: + default: + spin_unlock_irqrestore(&thi->t_lock, flags); + break; + } + + return TRUE; +} + + +void _drbd_thread_stop(struct drbd_thread *thi, int restart, int wait) +{ + unsigned long flags; + + enum drbd_thread_state ns = restart ? Restarting : Exiting; + + /* may be called from state engine, holding the req lock irqsave */ + spin_lock_irqsave(&thi->t_lock, flags); + + if (thi->t_state == None) { + spin_unlock_irqrestore(&thi->t_lock, flags); + if (restart) + drbd_thread_start(thi); + return; + } + + if (thi->t_state != ns) { + if (thi->task == NULL) { + spin_unlock_irqrestore(&thi->t_lock, flags); + return; + } + + thi->t_state = ns; + smp_mb(); + init_completion(&thi->stop); + if (thi->task != current) + force_sig(DRBD_SIGKILL, thi->task); + + } + + spin_unlock_irqrestore(&thi->t_lock, flags); + + if (wait) + wait_for_completion(&thi->stop); +} + +#ifdef CONFIG_SMP +/** + * drbd_calc_cpu_mask() - Generate CPU masks, spread over all CPUs + * @mdev: DRBD device. + * + * Forces all threads of a device onto the same CPU. This is beneficial for + * DRBD's performance. May be overwritten by user's configuration. + */ +void drbd_calc_cpu_mask(struct drbd_conf *mdev) +{ + int ord, cpu; + + /* user override. */ + if (cpumask_weight(mdev->cpu_mask)) + return; + + ord = mdev_to_minor(mdev) % cpumask_weight(cpu_online_mask); + for_each_online_cpu(cpu) { + if (ord-- == 0) { + cpumask_set_cpu(cpu, mdev->cpu_mask); + return; + } + } + /* should not be reached */ + cpumask_setall(mdev->cpu_mask); +} + +/** + * drbd_thread_current_set_cpu() - modifies the cpu mask of the _current_ thread + * @mdev: DRBD device. + * + * call in the "main loop" of _all_ threads, no need for any mutex, current won't die + * prematurely. + */ +void drbd_thread_current_set_cpu(struct drbd_conf *mdev) +{ + struct task_struct *p = current; + struct drbd_thread *thi = + p == mdev->asender.task ? &mdev->asender : + p == mdev->receiver.task ? &mdev->receiver : + p == mdev->worker.task ? &mdev->worker : + NULL; + ERR_IF(thi == NULL) + return; + if (!thi->reset_cpu_mask) + return; + thi->reset_cpu_mask = 0; + set_cpus_allowed_ptr(p, mdev->cpu_mask); +} +#endif + +/* the appropriate socket mutex must be held already */ +int _drbd_send_cmd(struct drbd_conf *mdev, struct socket *sock, + enum drbd_packets cmd, struct p_header *h, + size_t size, unsigned msg_flags) +{ + int sent, ok; + + ERR_IF(!h) return FALSE; + ERR_IF(!size) return FALSE; + + h->magic = BE_DRBD_MAGIC; + h->command = cpu_to_be16(cmd); + h->length = cpu_to_be16(size-sizeof(struct p_header)); + + trace_drbd_packet(mdev, sock, 0, (void *)h, __FILE__, __LINE__); + sent = drbd_send(mdev, sock, h, size, msg_flags); + + ok = (sent == size); + if (!ok) + dev_err(DEV, "short sent %s size=%d sent=%d\n", + cmdname(cmd), (int)size, sent); + return ok; +} + +/* don't pass the socket. we may only look at it + * when we hold the appropriate socket mutex. + */ +int drbd_send_cmd(struct drbd_conf *mdev, int use_data_socket, + enum drbd_packets cmd, struct p_header *h, size_t size) +{ + int ok = 0; + struct socket *sock; + + if (use_data_socket) { + mutex_lock(&mdev->data.mutex); + sock = mdev->data.socket; + } else { + mutex_lock(&mdev->meta.mutex); + sock = mdev->meta.socket; + } + + /* drbd_disconnect() could have called drbd_free_sock() + * while we were waiting in down()... */ + if (likely(sock != NULL)) + ok = _drbd_send_cmd(mdev, sock, cmd, h, size, 0); + + if (use_data_socket) + mutex_unlock(&mdev->data.mutex); + else + mutex_unlock(&mdev->meta.mutex); + return ok; +} + +int drbd_send_cmd2(struct drbd_conf *mdev, enum drbd_packets cmd, char *data, + size_t size) +{ + struct p_header h; + int ok; + + h.magic = BE_DRBD_MAGIC; + h.command = cpu_to_be16(cmd); + h.length = cpu_to_be16(size); + + if (!drbd_get_data_sock(mdev)) + return 0; + + trace_drbd_packet(mdev, mdev->data.socket, 0, (void *)&h, __FILE__, __LINE__); + + ok = (sizeof(h) == + drbd_send(mdev, mdev->data.socket, &h, sizeof(h), 0)); + ok = ok && (size == + drbd_send(mdev, mdev->data.socket, data, size, 0)); + + drbd_put_data_sock(mdev); + + return ok; +} + +int drbd_send_sync_param(struct drbd_conf *mdev, struct syncer_conf *sc) +{ + struct p_rs_param_89 *p; + struct socket *sock; + int size, rv; + const int apv = mdev->agreed_pro_version; + + size = apv <= 87 ? sizeof(struct p_rs_param) + : apv == 88 ? sizeof(struct p_rs_param) + + strlen(mdev->sync_conf.verify_alg) + 1 + : /* 89 */ sizeof(struct p_rs_param_89); + + /* used from admin command context and receiver/worker context. + * to avoid kmalloc, grab the socket right here, + * then use the pre-allocated sbuf there */ + mutex_lock(&mdev->data.mutex); + sock = mdev->data.socket; + + if (likely(sock != NULL)) { + enum drbd_packets cmd = apv >= 89 ? P_SYNC_PARAM89 : P_SYNC_PARAM; + + p = &mdev->data.sbuf.rs_param_89; + + /* initialize verify_alg and csums_alg */ + memset(p->verify_alg, 0, 2 * SHARED_SECRET_MAX); + + p->rate = cpu_to_be32(sc->rate); + + if (apv >= 88) + strcpy(p->verify_alg, mdev->sync_conf.verify_alg); + if (apv >= 89) + strcpy(p->csums_alg, mdev->sync_conf.csums_alg); + + rv = _drbd_send_cmd(mdev, sock, cmd, &p->head, size, 0); + } else + rv = 0; /* not ok */ + + mutex_unlock(&mdev->data.mutex); + + return rv; +} + +int drbd_send_protocol(struct drbd_conf *mdev) +{ + struct p_protocol *p; + int size, rv; + + size = sizeof(struct p_protocol); + + if (mdev->agreed_pro_version >= 87) + size += strlen(mdev->net_conf->integrity_alg) + 1; + + /* we must not recurse into our own queue, + * as that is blocked during handshake */ + p = kmalloc(size, GFP_NOIO); + if (p == NULL) + return 0; + + p->protocol = cpu_to_be32(mdev->net_conf->wire_protocol); + p->after_sb_0p = cpu_to_be32(mdev->net_conf->after_sb_0p); + p->after_sb_1p = cpu_to_be32(mdev->net_conf->after_sb_1p); + p->after_sb_2p = cpu_to_be32(mdev->net_conf->after_sb_2p); + p->want_lose = cpu_to_be32(mdev->net_conf->want_lose); + p->two_primaries = cpu_to_be32(mdev->net_conf->two_primaries); + + if (mdev->agreed_pro_version >= 87) + strcpy(p->integrity_alg, mdev->net_conf->integrity_alg); + + rv = drbd_send_cmd(mdev, USE_DATA_SOCKET, P_PROTOCOL, + (struct p_header *)p, size); + kfree(p); + return rv; +} + +int _drbd_send_uuids(struct drbd_conf *mdev, u64 uuid_flags) +{ + struct p_uuids p; + int i; + + if (!get_ldev_if_state(mdev, D_NEGOTIATING)) + return 1; + + for (i = UI_CURRENT; i < UI_SIZE; i++) + p.uuid[i] = mdev->ldev ? cpu_to_be64(mdev->ldev->md.uuid[i]) : 0; + + mdev->comm_bm_set = drbd_bm_total_weight(mdev); + p.uuid[UI_SIZE] = cpu_to_be64(mdev->comm_bm_set); + uuid_flags |= mdev->net_conf->want_lose ? 1 : 0; + uuid_flags |= test_bit(CRASHED_PRIMARY, &mdev->flags) ? 2 : 0; + uuid_flags |= mdev->new_state_tmp.disk == D_INCONSISTENT ? 4 : 0; + p.uuid[UI_FLAGS] = cpu_to_be64(uuid_flags); + + put_ldev(mdev); + + return drbd_send_cmd(mdev, USE_DATA_SOCKET, P_UUIDS, + (struct p_header *)&p, sizeof(p)); +} + +int drbd_send_uuids(struct drbd_conf *mdev) +{ + return _drbd_send_uuids(mdev, 0); +} + +int drbd_send_uuids_skip_initial_sync(struct drbd_conf *mdev) +{ + return _drbd_send_uuids(mdev, 8); +} + + +int drbd_send_sync_uuid(struct drbd_conf *mdev, u64 val) +{ + struct p_rs_uuid p; + + p.uuid = cpu_to_be64(val); + + return drbd_send_cmd(mdev, USE_DATA_SOCKET, P_SYNC_UUID, + (struct p_header *)&p, sizeof(p)); +} + +int drbd_send_sizes(struct drbd_conf *mdev, int trigger_reply) +{ + struct p_sizes p; + sector_t d_size, u_size; + int q_order_type; + int ok; + + if (get_ldev_if_state(mdev, D_NEGOTIATING)) { + D_ASSERT(mdev->ldev->backing_bdev); + d_size = drbd_get_max_capacity(mdev->ldev); + u_size = mdev->ldev->dc.disk_size; + q_order_type = drbd_queue_order_type(mdev); + p.queue_order_type = cpu_to_be32(drbd_queue_order_type(mdev)); + put_ldev(mdev); + } else { + d_size = 0; + u_size = 0; + q_order_type = QUEUE_ORDERED_NONE; + } + + p.d_size = cpu_to_be64(d_size); + p.u_size = cpu_to_be64(u_size); + p.c_size = cpu_to_be64(trigger_reply ? 0 : drbd_get_capacity(mdev->this_bdev)); + p.max_segment_size = cpu_to_be32(queue_max_segment_size(mdev->rq_queue)); + p.queue_order_type = cpu_to_be32(q_order_type); + + ok = drbd_send_cmd(mdev, USE_DATA_SOCKET, P_SIZES, + (struct p_header *)&p, sizeof(p)); + return ok; +} + +/** + * drbd_send_state() - Sends the drbd state to the peer + * @mdev: DRBD device. + */ +int drbd_send_state(struct drbd_conf *mdev) +{ + struct socket *sock; + struct p_state p; + int ok = 0; + + /* Grab state lock so we wont send state if we're in the middle + * of a cluster wide state change on another thread */ + drbd_state_lock(mdev); + + mutex_lock(&mdev->data.mutex); + + p.state = cpu_to_be32(mdev->state.i); /* Within the send mutex */ + sock = mdev->data.socket; + + if (likely(sock != NULL)) { + ok = _drbd_send_cmd(mdev, sock, P_STATE, + (struct p_header *)&p, sizeof(p), 0); + } + + mutex_unlock(&mdev->data.mutex); + + drbd_state_unlock(mdev); + return ok; +} + +int drbd_send_state_req(struct drbd_conf *mdev, + union drbd_state mask, union drbd_state val) +{ + struct p_req_state p; + + p.mask = cpu_to_be32(mask.i); + p.val = cpu_to_be32(val.i); + + return drbd_send_cmd(mdev, USE_DATA_SOCKET, P_STATE_CHG_REQ, + (struct p_header *)&p, sizeof(p)); +} + +int drbd_send_sr_reply(struct drbd_conf *mdev, int retcode) +{ + struct p_req_state_reply p; + + p.retcode = cpu_to_be32(retcode); + + return drbd_send_cmd(mdev, USE_META_SOCKET, P_STATE_CHG_REPLY, + (struct p_header *)&p, sizeof(p)); +} + +int fill_bitmap_rle_bits(struct drbd_conf *mdev, + struct p_compressed_bm *p, + struct bm_xfer_ctx *c) +{ + struct bitstream bs; + unsigned long plain_bits; + unsigned long tmp; + unsigned long rl; + unsigned len; + unsigned toggle; + int bits; + + /* may we use this feature? */ + if ((mdev->sync_conf.use_rle == 0) || + (mdev->agreed_pro_version < 90)) + return 0; + + if (c->bit_offset >= c->bm_bits) + return 0; /* nothing to do. */ + + /* use at most thus many bytes */ + bitstream_init(&bs, p->code, BM_PACKET_VLI_BYTES_MAX, 0); + memset(p->code, 0, BM_PACKET_VLI_BYTES_MAX); + /* plain bits covered in this code string */ + plain_bits = 0; + + /* p->encoding & 0x80 stores whether the first run length is set. + * bit offset is implicit. + * start with toggle == 2 to be able to tell the first iteration */ + toggle = 2; + + /* see how much plain bits we can stuff into one packet + * using RLE and VLI. */ + do { + tmp = (toggle == 0) ? _drbd_bm_find_next_zero(mdev, c->bit_offset) + : _drbd_bm_find_next(mdev, c->bit_offset); + if (tmp == -1UL) + tmp = c->bm_bits; + rl = tmp - c->bit_offset; + + if (toggle == 2) { /* first iteration */ + if (rl == 0) { + /* the first checked bit was set, + * store start value, */ + DCBP_set_start(p, 1); + /* but skip encoding of zero run length */ + toggle = !toggle; + continue; + } + DCBP_set_start(p, 0); + } + + /* paranoia: catch zero runlength. + * can only happen if bitmap is modified while we scan it. */ + if (rl == 0) { + dev_err(DEV, "unexpected zero runlength while encoding bitmap " + "t:%u bo:%lu\n", toggle, c->bit_offset); + return -1; + } + + bits = vli_encode_bits(&bs, rl); + if (bits == -ENOBUFS) /* buffer full */ + break; + if (bits <= 0) { + dev_err(DEV, "error while encoding bitmap: %d\n", bits); + return 0; + } + + toggle = !toggle; + plain_bits += rl; + c->bit_offset = tmp; + } while (c->bit_offset < c->bm_bits); + + len = bs.cur.b - p->code + !!bs.cur.bit; + + if (plain_bits < (len << 3)) { + /* incompressible with this method. + * we need to rewind both word and bit position. */ + c->bit_offset -= plain_bits; + bm_xfer_ctx_bit_to_word_offset(c); + c->bit_offset = c->word_offset * BITS_PER_LONG; + return 0; + } + + /* RLE + VLI was able to compress it just fine. + * update c->word_offset. */ + bm_xfer_ctx_bit_to_word_offset(c); + + /* store pad_bits */ + DCBP_set_pad_bits(p, (8 - bs.cur.bit) & 0x7); + + return len; +} + +enum { OK, FAILED, DONE } +send_bitmap_rle_or_plain(struct drbd_conf *mdev, + struct p_header *h, struct bm_xfer_ctx *c) +{ + struct p_compressed_bm *p = (void*)h; + unsigned long num_words; + int len; + int ok; + + len = fill_bitmap_rle_bits(mdev, p, c); + + if (len < 0) + return FAILED; + + if (len) { + DCBP_set_code(p, RLE_VLI_Bits); + ok = _drbd_send_cmd(mdev, mdev->data.socket, P_COMPRESSED_BITMAP, h, + sizeof(*p) + len, 0); + + c->packets[0]++; + c->bytes[0] += sizeof(*p) + len; + + if (c->bit_offset >= c->bm_bits) + len = 0; /* DONE */ + } else { + /* was not compressible. + * send a buffer full of plain text bits instead. */ + num_words = min_t(size_t, BM_PACKET_WORDS, c->bm_words - c->word_offset); + len = num_words * sizeof(long); + if (len) + drbd_bm_get_lel(mdev, c->word_offset, num_words, (unsigned long*)h->payload); + ok = _drbd_send_cmd(mdev, mdev->data.socket, P_BITMAP, + h, sizeof(struct p_header) + len, 0); + c->word_offset += num_words; + c->bit_offset = c->word_offset * BITS_PER_LONG; + + c->packets[1]++; + c->bytes[1] += sizeof(struct p_header) + len; + + if (c->bit_offset > c->bm_bits) + c->bit_offset = c->bm_bits; + } + ok = ok ? ((len == 0) ? DONE : OK) : FAILED; + + if (ok == DONE) + INFO_bm_xfer_stats(mdev, "send", c); + return ok; +} + +/* See the comment at receive_bitmap() */ +int _drbd_send_bitmap(struct drbd_conf *mdev) +{ + struct bm_xfer_ctx c; + struct p_header *p; + int ret; + + ERR_IF(!mdev->bitmap) return FALSE; + + /* maybe we should use some per thread scratch page, + * and allocate that during initial device creation? */ + p = (struct p_header *) __get_free_page(GFP_NOIO); + if (!p) { + dev_err(DEV, "failed to allocate one page buffer in %s\n", __func__); + return FALSE; + } + + if (get_ldev(mdev)) { + if (drbd_md_test_flag(mdev->ldev, MDF_FULL_SYNC)) { + dev_info(DEV, "Writing the whole bitmap, MDF_FullSync was set.\n"); + drbd_bm_set_all(mdev); + if (drbd_bm_write(mdev)) { + /* write_bm did fail! Leave full sync flag set in Meta P_DATA + * but otherwise process as per normal - need to tell other + * side that a full resync is required! */ + dev_err(DEV, "Failed to write bitmap to disk!\n"); + } else { + drbd_md_clear_flag(mdev, MDF_FULL_SYNC); + drbd_md_sync(mdev); + } + } + put_ldev(mdev); + } + + c = (struct bm_xfer_ctx) { + .bm_bits = drbd_bm_bits(mdev), + .bm_words = drbd_bm_words(mdev), + }; + + do { + ret = send_bitmap_rle_or_plain(mdev, p, &c); + } while (ret == OK); + + free_page((unsigned long) p); + return (ret == DONE); +} + +int drbd_send_bitmap(struct drbd_conf *mdev) +{ + int err; + + if (!drbd_get_data_sock(mdev)) + return -1; + err = !_drbd_send_bitmap(mdev); + drbd_put_data_sock(mdev); + return err; +} + +int drbd_send_b_ack(struct drbd_conf *mdev, u32 barrier_nr, u32 set_size) +{ + int ok; + struct p_barrier_ack p; + + p.barrier = barrier_nr; + p.set_size = cpu_to_be32(set_size); + + if (mdev->state.conn < C_CONNECTED) + return FALSE; + ok = drbd_send_cmd(mdev, USE_META_SOCKET, P_BARRIER_ACK, + (struct p_header *)&p, sizeof(p)); + return ok; +} + +/** + * _drbd_send_ack() - Sends an ack packet + * @mdev: DRBD device. + * @cmd: Packet command code. + * @sector: sector, needs to be in big endian byte order + * @blksize: size in byte, needs to be in big endian byte order + * @block_id: Id, big endian byte order + */ +static int _drbd_send_ack(struct drbd_conf *mdev, enum drbd_packets cmd, + u64 sector, + u32 blksize, + u64 block_id) +{ + int ok; + struct p_block_ack p; + + p.sector = sector; + p.block_id = block_id; + p.blksize = blksize; + p.seq_num = cpu_to_be32(atomic_add_return(1, &mdev->packet_seq)); + + if (!mdev->meta.socket || mdev->state.conn < C_CONNECTED) + return FALSE; + ok = drbd_send_cmd(mdev, USE_META_SOCKET, cmd, + (struct p_header *)&p, sizeof(p)); + return ok; +} + +int drbd_send_ack_dp(struct drbd_conf *mdev, enum drbd_packets cmd, + struct p_data *dp) +{ + const int header_size = sizeof(struct p_data) + - sizeof(struct p_header); + int data_size = ((struct p_header *)dp)->length - header_size; + + return _drbd_send_ack(mdev, cmd, dp->sector, cpu_to_be32(data_size), + dp->block_id); +} + +int drbd_send_ack_rp(struct drbd_conf *mdev, enum drbd_packets cmd, + struct p_block_req *rp) +{ + return _drbd_send_ack(mdev, cmd, rp->sector, rp->blksize, rp->block_id); +} + +/** + * drbd_send_ack() - Sends an ack packet + * @mdev: DRBD device. + * @cmd: Packet command code. + * @e: Epoch entry. + */ +int drbd_send_ack(struct drbd_conf *mdev, + enum drbd_packets cmd, struct drbd_epoch_entry *e) +{ + return _drbd_send_ack(mdev, cmd, + cpu_to_be64(e->sector), + cpu_to_be32(e->size), + e->block_id); +} + +/* This function misuses the block_id field to signal if the blocks + * are is sync or not. */ +int drbd_send_ack_ex(struct drbd_conf *mdev, enum drbd_packets cmd, + sector_t sector, int blksize, u64 block_id) +{ + return _drbd_send_ack(mdev, cmd, + cpu_to_be64(sector), + cpu_to_be32(blksize), + cpu_to_be64(block_id)); +} + +int drbd_send_drequest(struct drbd_conf *mdev, int cmd, + sector_t sector, int size, u64 block_id) +{ + int ok; + struct p_block_req p; + + p.sector = cpu_to_be64(sector); + p.block_id = block_id; + p.blksize = cpu_to_be32(size); + + ok = drbd_send_cmd(mdev, USE_DATA_SOCKET, cmd, + (struct p_header *)&p, sizeof(p)); + return ok; +} + +int drbd_send_drequest_csum(struct drbd_conf *mdev, + sector_t sector, int size, + void *digest, int digest_size, + enum drbd_packets cmd) +{ + int ok; + struct p_block_req p; + + p.sector = cpu_to_be64(sector); + p.block_id = BE_DRBD_MAGIC + 0xbeef; + p.blksize = cpu_to_be32(size); + + p.head.magic = BE_DRBD_MAGIC; + p.head.command = cpu_to_be16(cmd); + p.head.length = cpu_to_be16(sizeof(p) - sizeof(struct p_header) + digest_size); + + mutex_lock(&mdev->data.mutex); + + ok = (sizeof(p) == drbd_send(mdev, mdev->data.socket, &p, sizeof(p), 0)); + ok = ok && (digest_size == drbd_send(mdev, mdev->data.socket, digest, digest_size, 0)); + + mutex_unlock(&mdev->data.mutex); + + return ok; +} + +int drbd_send_ov_request(struct drbd_conf *mdev, sector_t sector, int size) +{ + int ok; + struct p_block_req p; + + p.sector = cpu_to_be64(sector); + p.block_id = BE_DRBD_MAGIC + 0xbabe; + p.blksize = cpu_to_be32(size); + + ok = drbd_send_cmd(mdev, USE_DATA_SOCKET, P_OV_REQUEST, + (struct p_header *)&p, sizeof(p)); + return ok; +} + +/* called on sndtimeo + * returns FALSE if we should retry, + * TRUE if we think connection is dead + */ +static int we_should_drop_the_connection(struct drbd_conf *mdev, struct socket *sock) +{ + int drop_it; + /* long elapsed = (long)(jiffies - mdev->last_received); */ + + drop_it = mdev->meta.socket == sock + || !mdev->asender.task + || get_t_state(&mdev->asender) != Running + || mdev->state.conn < C_CONNECTED; + + if (drop_it) + return TRUE; + + drop_it = !--mdev->ko_count; + if (!drop_it) { + dev_err(DEV, "[%s/%d] sock_sendmsg time expired, ko = %u\n", + current->comm, current->pid, mdev->ko_count); + request_ping(mdev); + } + + return drop_it; /* && (mdev->state == R_PRIMARY) */; +} + +/* The idea of sendpage seems to be to put some kind of reference + * to the page into the skb, and to hand it over to the NIC. In + * this process get_page() gets called. + * + * As soon as the page was really sent over the network put_page() + * gets called by some part of the network layer. [ NIC driver? ] + * + * [ get_page() / put_page() increment/decrement the count. If count + * reaches 0 the page will be freed. ] + * + * This works nicely with pages from FSs. + * But this means that in protocol A we might signal IO completion too early! + * + * In order not to corrupt data during a resync we must make sure + * that we do not reuse our own buffer pages (EEs) to early, therefore + * we have the net_ee list. + * + * XFS seems to have problems, still, it submits pages with page_count == 0! + * As a workaround, we disable sendpage on pages + * with page_count == 0 or PageSlab. + */ +static int _drbd_no_send_page(struct drbd_conf *mdev, struct page *page, + int offset, size_t size) +{ + int sent = drbd_send(mdev, mdev->data.socket, kmap(page) + offset, size, 0); + kunmap(page); + if (sent == size) + mdev->send_cnt += size>>9; + return sent == size; +} + +static int _drbd_send_page(struct drbd_conf *mdev, struct page *page, + int offset, size_t size) +{ + mm_segment_t oldfs = get_fs(); + int sent, ok; + int len = size; + + /* e.g. XFS meta- & log-data is in slab pages, which have a + * page_count of 0 and/or have PageSlab() set. + * we cannot use send_page for those, as that does get_page(); + * put_page(); and would cause either a VM_BUG directly, or + * __page_cache_release a page that would actually still be referenced + * by someone, leading to some obscure delayed Oops somewhere else. */ + if (disable_sendpage || (page_count(page) < 1) || PageSlab(page)) + return _drbd_no_send_page(mdev, page, offset, size); + + drbd_update_congested(mdev); + set_fs(KERNEL_DS); + do { + sent = mdev->data.socket->ops->sendpage(mdev->data.socket, page, + offset, len, + MSG_NOSIGNAL); + if (sent == -EAGAIN) { + if (we_should_drop_the_connection(mdev, + mdev->data.socket)) + break; + else + continue; + } + if (sent <= 0) { + dev_warn(DEV, "%s: size=%d len=%d sent=%d\n", + __func__, (int)size, len, sent); + break; + } + len -= sent; + offset += sent; + } while (len > 0 /* THINK && mdev->cstate >= C_CONNECTED*/); + set_fs(oldfs); + clear_bit(NET_CONGESTED, &mdev->flags); + + ok = (len == 0); + if (likely(ok)) + mdev->send_cnt += size>>9; + return ok; +} + +static int _drbd_send_bio(struct drbd_conf *mdev, struct bio *bio) +{ + struct bio_vec *bvec; + int i; + __bio_for_each_segment(bvec, bio, i, 0) { + if (!_drbd_no_send_page(mdev, bvec->bv_page, + bvec->bv_offset, bvec->bv_len)) + return 0; + } + return 1; +} + +static int _drbd_send_zc_bio(struct drbd_conf *mdev, struct bio *bio) +{ + struct bio_vec *bvec; + int i; + __bio_for_each_segment(bvec, bio, i, 0) { + if (!_drbd_send_page(mdev, bvec->bv_page, + bvec->bv_offset, bvec->bv_len)) + return 0; + } + + return 1; +} + +/* Used to send write requests + * R_PRIMARY -> Peer (P_DATA) + */ +int drbd_send_dblock(struct drbd_conf *mdev, struct drbd_request *req) +{ + int ok = 1; + struct p_data p; + unsigned int dp_flags = 0; + void *dgb; + int dgs; + + if (!drbd_get_data_sock(mdev)) + return 0; + + dgs = (mdev->agreed_pro_version >= 87 && mdev->integrity_w_tfm) ? + crypto_hash_digestsize(mdev->integrity_w_tfm) : 0; + + p.head.magic = BE_DRBD_MAGIC; + p.head.command = cpu_to_be16(P_DATA); + p.head.length = + cpu_to_be16(sizeof(p) - sizeof(struct p_header) + dgs + req->size); + + p.sector = cpu_to_be64(req->sector); + p.block_id = (unsigned long)req; + p.seq_num = cpu_to_be32(req->seq_num = + atomic_add_return(1, &mdev->packet_seq)); + dp_flags = 0; + + /* NOTE: no need to check if barriers supported here as we would + * not pass the test in make_request_common in that case + */ + if (bio_rw_flagged(req->master_bio, BIO_RW_BARRIER)) { + dev_err(DEV, "ASSERT FAILED would have set DP_HARDBARRIER\n"); + /* dp_flags |= DP_HARDBARRIER; */ + } + if (bio_rw_flagged(req->master_bio, BIO_RW_SYNCIO)) + dp_flags |= DP_RW_SYNC; + /* for now handle SYNCIO and UNPLUG + * as if they still were one and the same flag */ + if (bio_rw_flagged(req->master_bio, BIO_RW_UNPLUG)) + dp_flags |= DP_RW_SYNC; + if (mdev->state.conn >= C_SYNC_SOURCE && + mdev->state.conn <= C_PAUSED_SYNC_T) + dp_flags |= DP_MAY_SET_IN_SYNC; + + p.dp_flags = cpu_to_be32(dp_flags); + trace_drbd_packet(mdev, mdev->data.socket, 0, (void *)&p, __FILE__, __LINE__); + set_bit(UNPLUG_REMOTE, &mdev->flags); + ok = (sizeof(p) == + drbd_send(mdev, mdev->data.socket, &p, sizeof(p), MSG_MORE)); + if (ok && dgs) { + dgb = mdev->int_dig_out; + drbd_csum(mdev, mdev->integrity_w_tfm, req->master_bio, dgb); + ok = drbd_send(mdev, mdev->data.socket, dgb, dgs, MSG_MORE); + } + if (ok) { + if (mdev->net_conf->wire_protocol == DRBD_PROT_A) + ok = _drbd_send_bio(mdev, req->master_bio); + else + ok = _drbd_send_zc_bio(mdev, req->master_bio); + } + + drbd_put_data_sock(mdev); + return ok; +} + +/* answer packet, used to send data back for read requests: + * Peer -> (diskless) R_PRIMARY (P_DATA_REPLY) + * C_SYNC_SOURCE -> C_SYNC_TARGET (P_RS_DATA_REPLY) + */ +int drbd_send_block(struct drbd_conf *mdev, enum drbd_packets cmd, + struct drbd_epoch_entry *e) +{ + int ok; + struct p_data p; + void *dgb; + int dgs; + + dgs = (mdev->agreed_pro_version >= 87 && mdev->integrity_w_tfm) ? + crypto_hash_digestsize(mdev->integrity_w_tfm) : 0; + + p.head.magic = BE_DRBD_MAGIC; + p.head.command = cpu_to_be16(cmd); + p.head.length = + cpu_to_be16(sizeof(p) - sizeof(struct p_header) + dgs + e->size); + + p.sector = cpu_to_be64(e->sector); + p.block_id = e->block_id; + /* p.seq_num = 0; No sequence numbers here.. */ + + /* Only called by our kernel thread. + * This one may be interrupted by DRBD_SIG and/or DRBD_SIGKILL + * in response to admin command or module unload. + */ + if (!drbd_get_data_sock(mdev)) + return 0; + + trace_drbd_packet(mdev, mdev->data.socket, 0, (void *)&p, __FILE__, __LINE__); + ok = sizeof(p) == drbd_send(mdev, mdev->data.socket, &p, + sizeof(p), MSG_MORE); + if (ok && dgs) { + dgb = mdev->int_dig_out; + drbd_csum(mdev, mdev->integrity_w_tfm, e->private_bio, dgb); + ok = drbd_send(mdev, mdev->data.socket, dgb, dgs, MSG_MORE); + } + if (ok) + ok = _drbd_send_zc_bio(mdev, e->private_bio); + + drbd_put_data_sock(mdev); + return ok; +} + +/* + drbd_send distinguishes two cases: + + Packets sent via the data socket "sock" + and packets sent via the meta data socket "msock" + + sock msock + -----------------+-------------------------+------------------------------ + timeout conf.timeout / 2 conf.timeout / 2 + timeout action send a ping via msock Abort communication + and close all sockets +*/ + +/* + * you must have down()ed the appropriate [m]sock_mutex elsewhere! + */ +int drbd_send(struct drbd_conf *mdev, struct socket *sock, + void *buf, size_t size, unsigned msg_flags) +{ + struct kvec iov; + struct msghdr msg; + int rv, sent = 0; + + if (!sock) + return -1000; + + /* THINK if (signal_pending) return ... ? */ + + iov.iov_base = buf; + iov.iov_len = size; + + msg.msg_name = NULL; + msg.msg_namelen = 0; + msg.msg_control = NULL; + msg.msg_controllen = 0; + msg.msg_flags = msg_flags | MSG_NOSIGNAL; + + if (sock == mdev->data.socket) { + mdev->ko_count = mdev->net_conf->ko_count; + drbd_update_congested(mdev); + } + do { + /* STRANGE + * tcp_sendmsg does _not_ use its size parameter at all ? + * + * -EAGAIN on timeout, -EINTR on signal. + */ +/* THINK + * do we need to block DRBD_SIG if sock == &meta.socket ?? + * otherwise wake_asender() might interrupt some send_*Ack ! + */ + rv = kernel_sendmsg(sock, &msg, &iov, 1, size); + if (rv == -EAGAIN) { + if (we_should_drop_the_connection(mdev, sock)) + break; + else + continue; + } + D_ASSERT(rv != 0); + if (rv == -EINTR) { + flush_signals(current); + rv = 0; + } + if (rv < 0) + break; + sent += rv; + iov.iov_base += rv; + iov.iov_len -= rv; + } while (sent < size); + + if (sock == mdev->data.socket) + clear_bit(NET_CONGESTED, &mdev->flags); + + if (rv <= 0) { + if (rv != -EAGAIN) { + dev_err(DEV, "%s_sendmsg returned %d\n", + sock == mdev->meta.socket ? "msock" : "sock", + rv); + drbd_force_state(mdev, NS(conn, C_BROKEN_PIPE)); + } else + drbd_force_state(mdev, NS(conn, C_TIMEOUT)); + } + + return sent; +} + +static int drbd_open(struct block_device *bdev, fmode_t mode) +{ + struct drbd_conf *mdev = bdev->bd_disk->private_data; + unsigned long flags; + int rv = 0; + + spin_lock_irqsave(&mdev->req_lock, flags); + /* to have a stable mdev->state.role + * and no race with updating open_cnt */ + + if (mdev->state.role != R_PRIMARY) { + if (mode & FMODE_WRITE) + rv = -EROFS; + else if (!allow_oos) + rv = -EMEDIUMTYPE; + } + + if (!rv) + mdev->open_cnt++; + spin_unlock_irqrestore(&mdev->req_lock, flags); + + return rv; +} + +static int drbd_release(struct gendisk *gd, fmode_t mode) +{ + struct drbd_conf *mdev = gd->private_data; + mdev->open_cnt--; + return 0; +} + +static void drbd_unplug_fn(struct request_queue *q) +{ + struct drbd_conf *mdev = q->queuedata; + + trace_drbd_unplug(mdev, "got unplugged"); + + /* unplug FIRST */ + spin_lock_irq(q->queue_lock); + blk_remove_plug(q); + spin_unlock_irq(q->queue_lock); + + /* only if connected */ + spin_lock_irq(&mdev->req_lock); + if (mdev->state.pdsk >= D_INCONSISTENT && mdev->state.conn >= C_CONNECTED) { + D_ASSERT(mdev->state.role == R_PRIMARY); + if (test_and_clear_bit(UNPLUG_REMOTE, &mdev->flags)) { + /* add to the data.work queue, + * unless already queued. + * XXX this might be a good addition to drbd_queue_work + * anyways, to detect "double queuing" ... */ + if (list_empty(&mdev->unplug_work.list)) + drbd_queue_work(&mdev->data.work, + &mdev->unplug_work); + } + } + spin_unlock_irq(&mdev->req_lock); + + if (mdev->state.disk >= D_INCONSISTENT) + drbd_kick_lo(mdev); +} + +static void drbd_set_defaults(struct drbd_conf *mdev) +{ + mdev->sync_conf.after = DRBD_AFTER_DEF; + mdev->sync_conf.rate = DRBD_RATE_DEF; + mdev->sync_conf.al_extents = DRBD_AL_EXTENTS_DEF; + mdev->state = (union drbd_state) { + { .role = R_SECONDARY, + .peer = R_UNKNOWN, + .conn = C_STANDALONE, + .disk = D_DISKLESS, + .pdsk = D_UNKNOWN, + .susp = 0 + } }; +} + +void drbd_init_set_defaults(struct drbd_conf *mdev) +{ + /* the memset(,0,) did most of this. + * note: only assignments, no allocation in here */ + + drbd_set_defaults(mdev); + + /* for now, we do NOT yet support it, + * even though we start some framework + * to eventually support barriers */ + set_bit(NO_BARRIER_SUPP, &mdev->flags); + + atomic_set(&mdev->ap_bio_cnt, 0); + atomic_set(&mdev->ap_pending_cnt, 0); + atomic_set(&mdev->rs_pending_cnt, 0); + atomic_set(&mdev->unacked_cnt, 0); + atomic_set(&mdev->local_cnt, 0); + atomic_set(&mdev->net_cnt, 0); + atomic_set(&mdev->packet_seq, 0); + atomic_set(&mdev->pp_in_use, 0); + + mutex_init(&mdev->md_io_mutex); + mutex_init(&mdev->data.mutex); + mutex_init(&mdev->meta.mutex); + sema_init(&mdev->data.work.s, 0); + sema_init(&mdev->meta.work.s, 0); + mutex_init(&mdev->state_mutex); + + spin_lock_init(&mdev->data.work.q_lock); + spin_lock_init(&mdev->meta.work.q_lock); + + spin_lock_init(&mdev->al_lock); + spin_lock_init(&mdev->req_lock); + spin_lock_init(&mdev->peer_seq_lock); + spin_lock_init(&mdev->epoch_lock); + + INIT_LIST_HEAD(&mdev->active_ee); + INIT_LIST_HEAD(&mdev->sync_ee); + INIT_LIST_HEAD(&mdev->done_ee); + INIT_LIST_HEAD(&mdev->read_ee); + INIT_LIST_HEAD(&mdev->net_ee); + INIT_LIST_HEAD(&mdev->resync_reads); + INIT_LIST_HEAD(&mdev->data.work.q); + INIT_LIST_HEAD(&mdev->meta.work.q); + INIT_LIST_HEAD(&mdev->resync_work.list); + INIT_LIST_HEAD(&mdev->unplug_work.list); + INIT_LIST_HEAD(&mdev->md_sync_work.list); + INIT_LIST_HEAD(&mdev->bm_io_work.w.list); + mdev->resync_work.cb = w_resync_inactive; + mdev->unplug_work.cb = w_send_write_hint; + mdev->md_sync_work.cb = w_md_sync; + mdev->bm_io_work.w.cb = w_bitmap_io; + init_timer(&mdev->resync_timer); + init_timer(&mdev->md_sync_timer); + mdev->resync_timer.function = resync_timer_fn; + mdev->resync_timer.data = (unsigned long) mdev; + mdev->md_sync_timer.function = md_sync_timer_fn; + mdev->md_sync_timer.data = (unsigned long) mdev; + + init_waitqueue_head(&mdev->misc_wait); + init_waitqueue_head(&mdev->state_wait); + init_waitqueue_head(&mdev->ee_wait); + init_waitqueue_head(&mdev->al_wait); + init_waitqueue_head(&mdev->seq_wait); + + drbd_thread_init(mdev, &mdev->receiver, drbdd_init); + drbd_thread_init(mdev, &mdev->worker, drbd_worker); + drbd_thread_init(mdev, &mdev->asender, drbd_asender); + + mdev->agreed_pro_version = PRO_VERSION_MAX; + mdev->write_ordering = WO_bio_barrier; + mdev->resync_wenr = LC_FREE; +} + +void drbd_mdev_cleanup(struct drbd_conf *mdev) +{ + if (mdev->receiver.t_state != None) + dev_err(DEV, "ASSERT FAILED: receiver t_state == %d expected 0.\n", + mdev->receiver.t_state); + + /* no need to lock it, I'm the only thread alive */ + if (atomic_read(&mdev->current_epoch->epoch_size) != 0) + dev_err(DEV, "epoch_size:%d\n", atomic_read(&mdev->current_epoch->epoch_size)); + mdev->al_writ_cnt = + mdev->bm_writ_cnt = + mdev->read_cnt = + mdev->recv_cnt = + mdev->send_cnt = + mdev->writ_cnt = + mdev->p_size = + mdev->rs_start = + mdev->rs_total = + mdev->rs_failed = + mdev->rs_mark_left = + mdev->rs_mark_time = 0; + D_ASSERT(mdev->net_conf == NULL); + + drbd_set_my_capacity(mdev, 0); + if (mdev->bitmap) { + /* maybe never allocated. */ + drbd_bm_resize(mdev, 0); + drbd_bm_cleanup(mdev); + } + + drbd_free_resources(mdev); + + /* + * currently we drbd_init_ee only on module load, so + * we may do drbd_release_ee only on module unload! + */ + D_ASSERT(list_empty(&mdev->active_ee)); + D_ASSERT(list_empty(&mdev->sync_ee)); + D_ASSERT(list_empty(&mdev->done_ee)); + D_ASSERT(list_empty(&mdev->read_ee)); + D_ASSERT(list_empty(&mdev->net_ee)); + D_ASSERT(list_empty(&mdev->resync_reads)); + D_ASSERT(list_empty(&mdev->data.work.q)); + D_ASSERT(list_empty(&mdev->meta.work.q)); + D_ASSERT(list_empty(&mdev->resync_work.list)); + D_ASSERT(list_empty(&mdev->unplug_work.list)); + +} + + +static void drbd_destroy_mempools(void) +{ + struct page *page; + + while (drbd_pp_pool) { + page = drbd_pp_pool; + drbd_pp_pool = (struct page *)page_private(page); + __free_page(page); + drbd_pp_vacant--; + } + + /* D_ASSERT(atomic_read(&drbd_pp_vacant)==0); */ + + if (drbd_ee_mempool) + mempool_destroy(drbd_ee_mempool); + if (drbd_request_mempool) + mempool_destroy(drbd_request_mempool); + if (drbd_ee_cache) + kmem_cache_destroy(drbd_ee_cache); + if (drbd_request_cache) + kmem_cache_destroy(drbd_request_cache); + if (drbd_bm_ext_cache) + kmem_cache_destroy(drbd_bm_ext_cache); + if (drbd_al_ext_cache) + kmem_cache_destroy(drbd_al_ext_cache); + + drbd_ee_mempool = NULL; + drbd_request_mempool = NULL; + drbd_ee_cache = NULL; + drbd_request_cache = NULL; + drbd_bm_ext_cache = NULL; + drbd_al_ext_cache = NULL; + + return; +} + +static int drbd_create_mempools(void) +{ + struct page *page; + const int number = (DRBD_MAX_SEGMENT_SIZE/PAGE_SIZE) * minor_count; + int i; + + /* prepare our caches and mempools */ + drbd_request_mempool = NULL; + drbd_ee_cache = NULL; + drbd_request_cache = NULL; + drbd_bm_ext_cache = NULL; + drbd_al_ext_cache = NULL; + drbd_pp_pool = NULL; + + /* caches */ + drbd_request_cache = kmem_cache_create( + "drbd_req", sizeof(struct drbd_request), 0, 0, NULL); + if (drbd_request_cache == NULL) + goto Enomem; + + drbd_ee_cache = kmem_cache_create( + "drbd_ee", sizeof(struct drbd_epoch_entry), 0, 0, NULL); + if (drbd_ee_cache == NULL) + goto Enomem; + + drbd_bm_ext_cache = kmem_cache_create( + "drbd_bm", sizeof(struct bm_extent), 0, 0, NULL); + if (drbd_bm_ext_cache == NULL) + goto Enomem; + + drbd_al_ext_cache = kmem_cache_create( + "drbd_al", sizeof(struct lc_element), 0, 0, NULL); + if (drbd_al_ext_cache == NULL) + goto Enomem; + + /* mempools */ + drbd_request_mempool = mempool_create(number, + mempool_alloc_slab, mempool_free_slab, drbd_request_cache); + if (drbd_request_mempool == NULL) + goto Enomem; + + drbd_ee_mempool = mempool_create(number, + mempool_alloc_slab, mempool_free_slab, drbd_ee_cache); + if (drbd_request_mempool == NULL) + goto Enomem; + + /* drbd's page pool */ + spin_lock_init(&drbd_pp_lock); + + for (i = 0; i < number; i++) { + page = alloc_page(GFP_HIGHUSER); + if (!page) + goto Enomem; + set_page_private(page, (unsigned long)drbd_pp_pool); + drbd_pp_pool = page; + } + drbd_pp_vacant = number; + + return 0; + +Enomem: + drbd_destroy_mempools(); /* in case we allocated some */ + return -ENOMEM; +} + +static int drbd_notify_sys(struct notifier_block *this, unsigned long code, + void *unused) +{ + /* just so we have it. you never know what interesting things we + * might want to do here some day... + */ + + return NOTIFY_DONE; +} + +static struct notifier_block drbd_notifier = { + .notifier_call = drbd_notify_sys, +}; + +static void drbd_release_ee_lists(struct drbd_conf *mdev) +{ + int rr; + + rr = drbd_release_ee(mdev, &mdev->active_ee); + if (rr) + dev_err(DEV, "%d EEs in active list found!\n", rr); + + rr = drbd_release_ee(mdev, &mdev->sync_ee); + if (rr) + dev_err(DEV, "%d EEs in sync list found!\n", rr); + + rr = drbd_release_ee(mdev, &mdev->read_ee); + if (rr) + dev_err(DEV, "%d EEs in read list found!\n", rr); + + rr = drbd_release_ee(mdev, &mdev->done_ee); + if (rr) + dev_err(DEV, "%d EEs in done list found!\n", rr); + + rr = drbd_release_ee(mdev, &mdev->net_ee); + if (rr) + dev_err(DEV, "%d EEs in net list found!\n", rr); +} + +/* caution. no locking. + * currently only used from module cleanup code. */ +static void drbd_delete_device(unsigned int minor) +{ + struct drbd_conf *mdev = minor_to_mdev(minor); + + if (!mdev) + return; + + /* paranoia asserts */ + if (mdev->open_cnt != 0) + dev_err(DEV, "open_cnt = %d in %s:%u", mdev->open_cnt, + __FILE__ , __LINE__); + + ERR_IF (!list_empty(&mdev->data.work.q)) { + struct list_head *lp; + list_for_each(lp, &mdev->data.work.q) { + dev_err(DEV, "lp = %p\n", lp); + } + }; + /* end paranoia asserts */ + + del_gendisk(mdev->vdisk); + + /* cleanup stuff that may have been allocated during + * device (re-)configuration or state changes */ + + if (mdev->this_bdev) + bdput(mdev->this_bdev); + + drbd_free_resources(mdev); + + drbd_release_ee_lists(mdev); + + /* should be free'd on disconnect? */ + kfree(mdev->ee_hash); + /* + mdev->ee_hash_s = 0; + mdev->ee_hash = NULL; + */ + + lc_destroy(mdev->act_log); + lc_destroy(mdev->resync); + + kfree(mdev->p_uuid); + /* mdev->p_uuid = NULL; */ + + kfree(mdev->int_dig_out); + kfree(mdev->int_dig_in); + kfree(mdev->int_dig_vv); + + /* cleanup the rest that has been + * allocated from drbd_new_device + * and actually free the mdev itself */ + drbd_free_mdev(mdev); +} + +static void drbd_cleanup(void) +{ + unsigned int i; + + unregister_reboot_notifier(&drbd_notifier); + + drbd_nl_cleanup(); + + if (minor_table) { + if (drbd_proc) + remove_proc_entry("drbd", NULL); + i = minor_count; + while (i--) + drbd_delete_device(i); + drbd_destroy_mempools(); + } + + kfree(minor_table); + + unregister_blkdev(DRBD_MAJOR, "drbd"); + + printk(KERN_INFO "drbd: module cleanup done.\n"); +} + +/** + * drbd_congested() - Callback for pdflush + * @congested_data: User data + * @bdi_bits: Bits pdflush is currently interested in + * + * Returns 1<<BDI_async_congested and/or 1<<BDI_sync_congested if we are congested. + */ +static int drbd_congested(void *congested_data, int bdi_bits) +{ + struct drbd_conf *mdev = congested_data; + struct request_queue *q; + char reason = '-'; + int r = 0; + + if (!__inc_ap_bio_cond(mdev)) { + /* DRBD has frozen IO */ + r = bdi_bits; + reason = 'd'; + goto out; + } + + if (get_ldev(mdev)) { + q = bdev_get_queue(mdev->ldev->backing_bdev); + r = bdi_congested(&q->backing_dev_info, bdi_bits); + put_ldev(mdev); + if (r) + reason = 'b'; + } + + if (bdi_bits & (1 << BDI_async_congested) && test_bit(NET_CONGESTED, &mdev->flags)) { + r |= (1 << BDI_async_congested); + reason = reason == 'b' ? 'a' : 'n'; + } + +out: + mdev->congestion_reason = reason; + return r; +} + +struct drbd_conf *drbd_new_device(unsigned int minor) +{ + struct drbd_conf *mdev; + struct gendisk *disk; + struct request_queue *q; + + /* GFP_KERNEL, we are outside of all write-out paths */ + mdev = kzalloc(sizeof(struct drbd_conf), GFP_KERNEL); + if (!mdev) + return NULL; + if (!zalloc_cpumask_var(&mdev->cpu_mask, GFP_KERNEL)) + goto out_no_cpumask; + + mdev->minor = minor; + + drbd_init_set_defaults(mdev); + + q = blk_alloc_queue(GFP_KERNEL); + if (!q) + goto out_no_q; + mdev->rq_queue = q; + q->queuedata = mdev; + blk_queue_max_segment_size(q, DRBD_MAX_SEGMENT_SIZE); + + disk = alloc_disk(1); + if (!disk) + goto out_no_disk; + mdev->vdisk = disk; + + set_disk_ro(disk, TRUE); + + disk->queue = q; + disk->major = DRBD_MAJOR; + disk->first_minor = minor; + disk->fops = &drbd_ops; + sprintf(disk->disk_name, "drbd%d", minor); + disk->private_data = mdev; + + mdev->this_bdev = bdget(MKDEV(DRBD_MAJOR, minor)); + /* we have no partitions. we contain only ourselves. */ + mdev->this_bdev->bd_contains = mdev->this_bdev; + + q->backing_dev_info.congested_fn = drbd_congested; + q->backing_dev_info.congested_data = mdev; + + blk_queue_make_request(q, drbd_make_request_26); + blk_queue_bounce_limit(q, BLK_BOUNCE_ANY); + blk_queue_merge_bvec(q, drbd_merge_bvec); + q->queue_lock = &mdev->req_lock; /* needed since we use */ + /* plugging on a queue, that actually has no requests! */ + q->unplug_fn = drbd_unplug_fn; + + mdev->md_io_page = alloc_page(GFP_KERNEL); + if (!mdev->md_io_page) + goto out_no_io_page; + + if (drbd_bm_init(mdev)) + goto out_no_bitmap; + /* no need to lock access, we are still initializing this minor device. */ + if (!tl_init(mdev)) + goto out_no_tl; + + mdev->app_reads_hash = kzalloc(APP_R_HSIZE*sizeof(void *), GFP_KERNEL); + if (!mdev->app_reads_hash) + goto out_no_app_reads; + + mdev->current_epoch = kzalloc(sizeof(struct drbd_epoch), GFP_KERNEL); + if (!mdev->current_epoch) + goto out_no_epoch; + + INIT_LIST_HEAD(&mdev->current_epoch->list); + mdev->epochs = 1; + + return mdev; + +/* out_whatever_else: + kfree(mdev->current_epoch); */ +out_no_epoch: + kfree(mdev->app_reads_hash); +out_no_app_reads: + tl_cleanup(mdev); +out_no_tl: + drbd_bm_cleanup(mdev); +out_no_bitmap: + __free_page(mdev->md_io_page); +out_no_io_page: + put_disk(disk); +out_no_disk: + blk_cleanup_queue(q); +out_no_q: + free_cpumask_var(mdev->cpu_mask); +out_no_cpumask: + kfree(mdev); + return NULL; +} + +/* counterpart of drbd_new_device. + * last part of drbd_delete_device. */ +void drbd_free_mdev(struct drbd_conf *mdev) +{ + kfree(mdev->current_epoch); + kfree(mdev->app_reads_hash); + tl_cleanup(mdev); + if (mdev->bitmap) /* should no longer be there. */ + drbd_bm_cleanup(mdev); + __free_page(mdev->md_io_page); + put_disk(mdev->vdisk); + blk_cleanup_queue(mdev->rq_queue); + free_cpumask_var(mdev->cpu_mask); + kfree(mdev); +} + + +int __init drbd_init(void) +{ + int err; + + if (sizeof(struct p_handshake) != 80) { + printk(KERN_ERR + "drbd: never change the size or layout " + "of the HandShake packet.\n"); + return -EINVAL; + } + + if (1 > minor_count || minor_count > 255) { + printk(KERN_ERR + "drbd: invalid minor_count (%d)\n", minor_count); +#ifdef MODULE + return -EINVAL; +#else + minor_count = 8; +#endif + } + + err = drbd_nl_init(); + if (err) + return err; + + err = register_blkdev(DRBD_MAJOR, "drbd"); + if (err) { + printk(KERN_ERR + "drbd: unable to register block device major %d\n", + DRBD_MAJOR); + return err; + } + + register_reboot_notifier(&drbd_notifier); + + /* + * allocate all necessary structs + */ + err = -ENOMEM; + + init_waitqueue_head(&drbd_pp_wait); + + drbd_proc = NULL; /* play safe for drbd_cleanup */ + minor_table = kzalloc(sizeof(struct drbd_conf *)*minor_count, + GFP_KERNEL); + if (!minor_table) + goto Enomem; + + err = drbd_create_mempools(); + if (err) + goto Enomem; + + drbd_proc = proc_create("drbd", S_IFREG | S_IRUGO , NULL, &drbd_proc_fops); + if (!drbd_proc) { + printk(KERN_ERR "drbd: unable to register proc file\n"); + goto Enomem; + } + + rwlock_init(&global_state_lock); + + printk(KERN_INFO "drbd: initialized. " + "Version: " REL_VERSION " (api:%d/proto:%d-%d)\n", + API_VERSION, PRO_VERSION_MIN, PRO_VERSION_MAX); + printk(KERN_INFO "drbd: %s\n", drbd_buildtag()); + printk(KERN_INFO "drbd: registered as block device major %d\n", + DRBD_MAJOR); + printk(KERN_INFO "drbd: minor_table @ 0x%p\n", minor_table); + + return 0; /* Success! */ + +Enomem: + drbd_cleanup(); + if (err == -ENOMEM) + /* currently always the case */ + printk(KERN_ERR "drbd: ran out of memory\n"); + else + printk(KERN_ERR "drbd: initialization failure\n"); + return err; +} + +void drbd_free_bc(struct drbd_backing_dev *ldev) +{ + if (ldev == NULL) + return; + + bd_release(ldev->backing_bdev); + bd_release(ldev->md_bdev); + + fput(ldev->lo_file); + fput(ldev->md_file); + + kfree(ldev); +} + +void drbd_free_sock(struct drbd_conf *mdev) +{ + if (mdev->data.socket) { + kernel_sock_shutdown(mdev->data.socket, SHUT_RDWR); + sock_release(mdev->data.socket); + mdev->data.socket = NULL; + } + if (mdev->meta.socket) { + kernel_sock_shutdown(mdev->meta.socket, SHUT_RDWR); + sock_release(mdev->meta.socket); + mdev->meta.socket = NULL; + } +} + + +void drbd_free_resources(struct drbd_conf *mdev) +{ + crypto_free_hash(mdev->csums_tfm); + mdev->csums_tfm = NULL; + crypto_free_hash(mdev->verify_tfm); + mdev->verify_tfm = NULL; + crypto_free_hash(mdev->cram_hmac_tfm); + mdev->cram_hmac_tfm = NULL; + crypto_free_hash(mdev->integrity_w_tfm); + mdev->integrity_w_tfm = NULL; + crypto_free_hash(mdev->integrity_r_tfm); + mdev->integrity_r_tfm = NULL; + + drbd_free_sock(mdev); + + __no_warn(local, + drbd_free_bc(mdev->ldev); + mdev->ldev = NULL;); +} + +/* meta data management */ + +struct meta_data_on_disk { + u64 la_size; /* last agreed size. */ + u64 uuid[UI_SIZE]; /* UUIDs. */ + u64 device_uuid; + u64 reserved_u64_1; + u32 flags; /* MDF */ + u32 magic; + u32 md_size_sect; + u32 al_offset; /* offset to this block */ + u32 al_nr_extents; /* important for restoring the AL */ + /* `-- act_log->nr_elements <-- sync_conf.al_extents */ + u32 bm_offset; /* offset to the bitmap, from here */ + u32 bm_bytes_per_bit; /* BM_BLOCK_SIZE */ + u32 reserved_u32[4]; + +} __packed; + +/** + * drbd_md_sync() - Writes the meta data super block if the MD_DIRTY flag bit is set + * @mdev: DRBD device. + */ +void drbd_md_sync(struct drbd_conf *mdev) +{ + struct meta_data_on_disk *buffer; + sector_t sector; + int i; + + if (!test_and_clear_bit(MD_DIRTY, &mdev->flags)) + return; + del_timer(&mdev->md_sync_timer); + + /* We use here D_FAILED and not D_ATTACHING because we try to write + * metadata even if we detach due to a disk failure! */ + if (!get_ldev_if_state(mdev, D_FAILED)) + return; + + trace_drbd_md_io(mdev, WRITE, mdev->ldev); + + mutex_lock(&mdev->md_io_mutex); + buffer = (struct meta_data_on_disk *)page_address(mdev->md_io_page); + memset(buffer, 0, 512); + + buffer->la_size = cpu_to_be64(drbd_get_capacity(mdev->this_bdev)); + for (i = UI_CURRENT; i < UI_SIZE; i++) + buffer->uuid[i] = cpu_to_be64(mdev->ldev->md.uuid[i]); + buffer->flags = cpu_to_be32(mdev->ldev->md.flags); + buffer->magic = cpu_to_be32(DRBD_MD_MAGIC); + + buffer->md_size_sect = cpu_to_be32(mdev->ldev->md.md_size_sect); + buffer->al_offset = cpu_to_be32(mdev->ldev->md.al_offset); + buffer->al_nr_extents = cpu_to_be32(mdev->act_log->nr_elements); + buffer->bm_bytes_per_bit = cpu_to_be32(BM_BLOCK_SIZE); + buffer->device_uuid = cpu_to_be64(mdev->ldev->md.device_uuid); + + buffer->bm_offset = cpu_to_be32(mdev->ldev->md.bm_offset); + + D_ASSERT(drbd_md_ss__(mdev, mdev->ldev) == mdev->ldev->md.md_offset); + sector = mdev->ldev->md.md_offset; + + if (drbd_md_sync_page_io(mdev, mdev->ldev, sector, WRITE)) { + clear_bit(MD_DIRTY, &mdev->flags); + } else { + /* this was a try anyways ... */ + dev_err(DEV, "meta data update failed!\n"); + + drbd_chk_io_error(mdev, 1, TRUE); + } + + /* Update mdev->ldev->md.la_size_sect, + * since we updated it on metadata. */ + mdev->ldev->md.la_size_sect = drbd_get_capacity(mdev->this_bdev); + + mutex_unlock(&mdev->md_io_mutex); + put_ldev(mdev); +} + +/** + * drbd_md_read() - Reads in the meta data super block + * @mdev: DRBD device. + * @bdev: Device from which the meta data should be read in. + * + * Return 0 (NO_ERROR) on success, and an enum drbd_ret_codes in case + * something goes wrong. Currently only: ERR_IO_MD_DISK, ERR_MD_INVALID. + */ +int drbd_md_read(struct drbd_conf *mdev, struct drbd_backing_dev *bdev) +{ + struct meta_data_on_disk *buffer; + int i, rv = NO_ERROR; + + if (!get_ldev_if_state(mdev, D_ATTACHING)) + return ERR_IO_MD_DISK; + + trace_drbd_md_io(mdev, READ, bdev); + + mutex_lock(&mdev->md_io_mutex); + buffer = (struct meta_data_on_disk *)page_address(mdev->md_io_page); + + if (!drbd_md_sync_page_io(mdev, bdev, bdev->md.md_offset, READ)) { + /* NOTE: cant do normal error processing here as this is + called BEFORE disk is attached */ + dev_err(DEV, "Error while reading metadata.\n"); + rv = ERR_IO_MD_DISK; + goto err; + } + + if (be32_to_cpu(buffer->magic) != DRBD_MD_MAGIC) { + dev_err(DEV, "Error while reading metadata, magic not found.\n"); + rv = ERR_MD_INVALID; + goto err; + } + if (be32_to_cpu(buffer->al_offset) != bdev->md.al_offset) { + dev_err(DEV, "unexpected al_offset: %d (expected %d)\n", + be32_to_cpu(buffer->al_offset), bdev->md.al_offset); + rv = ERR_MD_INVALID; + goto err; + } + if (be32_to_cpu(buffer->bm_offset) != bdev->md.bm_offset) { + dev_err(DEV, "unexpected bm_offset: %d (expected %d)\n", + be32_to_cpu(buffer->bm_offset), bdev->md.bm_offset); + rv = ERR_MD_INVALID; + goto err; + } + if (be32_to_cpu(buffer->md_size_sect) != bdev->md.md_size_sect) { + dev_err(DEV, "unexpected md_size: %u (expected %u)\n", + be32_to_cpu(buffer->md_size_sect), bdev->md.md_size_sect); + rv = ERR_MD_INVALID; + goto err; + } + + if (be32_to_cpu(buffer->bm_bytes_per_bit) != BM_BLOCK_SIZE) { + dev_err(DEV, "unexpected bm_bytes_per_bit: %u (expected %u)\n", + be32_to_cpu(buffer->bm_bytes_per_bit), BM_BLOCK_SIZE); + rv = ERR_MD_INVALID; + goto err; + } + + bdev->md.la_size_sect = be64_to_cpu(buffer->la_size); + for (i = UI_CURRENT; i < UI_SIZE; i++) + bdev->md.uuid[i] = be64_to_cpu(buffer->uuid[i]); + bdev->md.flags = be32_to_cpu(buffer->flags); + mdev->sync_conf.al_extents = be32_to_cpu(buffer->al_nr_extents); + bdev->md.device_uuid = be64_to_cpu(buffer->device_uuid); + + if (mdev->sync_conf.al_extents < 7) + mdev->sync_conf.al_extents = 127; + + err: + mutex_unlock(&mdev->md_io_mutex); + put_ldev(mdev); + + return rv; +} + +/** + * drbd_md_mark_dirty() - Mark meta data super block as dirty + * @mdev: DRBD device. + * + * Call this function if you change anything that should be written to + * the meta-data super block. This function sets MD_DIRTY, and starts a + * timer that ensures that within five seconds you have to call drbd_md_sync(). + */ +void drbd_md_mark_dirty(struct drbd_conf *mdev) +{ + set_bit(MD_DIRTY, &mdev->flags); + mod_timer(&mdev->md_sync_timer, jiffies + 5*HZ); +} + + +static void drbd_uuid_move_history(struct drbd_conf *mdev) __must_hold(local) +{ + int i; + + for (i = UI_HISTORY_START; i < UI_HISTORY_END; i++) { + mdev->ldev->md.uuid[i+1] = mdev->ldev->md.uuid[i]; + + trace_drbd_uuid(mdev, i+1); + } +} + +void _drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local) +{ + if (idx == UI_CURRENT) { + if (mdev->state.role == R_PRIMARY) + val |= 1; + else + val &= ~((u64)1); + + drbd_set_ed_uuid(mdev, val); + } + + mdev->ldev->md.uuid[idx] = val; + trace_drbd_uuid(mdev, idx); + drbd_md_mark_dirty(mdev); +} + + +void drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local) +{ + if (mdev->ldev->md.uuid[idx]) { + drbd_uuid_move_history(mdev); + mdev->ldev->md.uuid[UI_HISTORY_START] = mdev->ldev->md.uuid[idx]; + trace_drbd_uuid(mdev, UI_HISTORY_START); + } + _drbd_uuid_set(mdev, idx, val); +} + +/** + * drbd_uuid_new_current() - Creates a new current UUID + * @mdev: DRBD device. + * + * Creates a new current UUID, and rotates the old current UUID into + * the bitmap slot. Causes an incremental resync upon next connect. + */ +void drbd_uuid_new_current(struct drbd_conf *mdev) __must_hold(local) +{ + u64 val; + + dev_info(DEV, "Creating new current UUID\n"); + D_ASSERT(mdev->ldev->md.uuid[UI_BITMAP] == 0); + mdev->ldev->md.uuid[UI_BITMAP] = mdev->ldev->md.uuid[UI_CURRENT]; + trace_drbd_uuid(mdev, UI_BITMAP); + + get_random_bytes(&val, sizeof(u64)); + _drbd_uuid_set(mdev, UI_CURRENT, val); +} + +void drbd_uuid_set_bm(struct drbd_conf *mdev, u64 val) __must_hold(local) +{ + if (mdev->ldev->md.uuid[UI_BITMAP] == 0 && val == 0) + return; + + if (val == 0) { + drbd_uuid_move_history(mdev); + mdev->ldev->md.uuid[UI_HISTORY_START] = mdev->ldev->md.uuid[UI_BITMAP]; + mdev->ldev->md.uuid[UI_BITMAP] = 0; + trace_drbd_uuid(mdev, UI_HISTORY_START); + trace_drbd_uuid(mdev, UI_BITMAP); + } else { + if (mdev->ldev->md.uuid[UI_BITMAP]) + dev_warn(DEV, "bm UUID already set"); + + mdev->ldev->md.uuid[UI_BITMAP] = val; + mdev->ldev->md.uuid[UI_BITMAP] &= ~((u64)1); + + trace_drbd_uuid(mdev, UI_BITMAP); + } + drbd_md_mark_dirty(mdev); +} + +/** + * drbd_bmio_set_n_write() - io_fn for drbd_queue_bitmap_io() or drbd_bitmap_io() + * @mdev: DRBD device. + * + * Sets all bits in the bitmap and writes the whole bitmap to stable storage. + */ +int drbd_bmio_set_n_write(struct drbd_conf *mdev) +{ + int rv = -EIO; + + if (get_ldev_if_state(mdev, D_ATTACHING)) { + drbd_md_set_flag(mdev, MDF_FULL_SYNC); + drbd_md_sync(mdev); + drbd_bm_set_all(mdev); + + rv = drbd_bm_write(mdev); + + if (!rv) { + drbd_md_clear_flag(mdev, MDF_FULL_SYNC); + drbd_md_sync(mdev); + } + + put_ldev(mdev); + } + + return rv; +} + +/** + * drbd_bmio_clear_n_write() - io_fn for drbd_queue_bitmap_io() or drbd_bitmap_io() + * @mdev: DRBD device. + * + * Clears all bits in the bitmap and writes the whole bitmap to stable storage. + */ +int drbd_bmio_clear_n_write(struct drbd_conf *mdev) +{ + int rv = -EIO; + + if (get_ldev_if_state(mdev, D_ATTACHING)) { + drbd_bm_clear_all(mdev); + rv = drbd_bm_write(mdev); + put_ldev(mdev); + } + + return rv; +} + +static int w_bitmap_io(struct drbd_conf *mdev, struct drbd_work *w, int unused) +{ + struct bm_io_work *work = container_of(w, struct bm_io_work, w); + int rv; + + D_ASSERT(atomic_read(&mdev->ap_bio_cnt) == 0); + + drbd_bm_lock(mdev, work->why); + rv = work->io_fn(mdev); + drbd_bm_unlock(mdev); + + clear_bit(BITMAP_IO, &mdev->flags); + wake_up(&mdev->misc_wait); + + if (work->done) + work->done(mdev, rv); + + clear_bit(BITMAP_IO_QUEUED, &mdev->flags); + work->why = NULL; + + return 1; +} + +/** + * drbd_queue_bitmap_io() - Queues an IO operation on the whole bitmap + * @mdev: DRBD device. + * @io_fn: IO callback to be called when bitmap IO is possible + * @done: callback to be called after the bitmap IO was performed + * @why: Descriptive text of the reason for doing the IO + * + * While IO on the bitmap happens we freeze application IO thus we ensure + * that drbd_set_out_of_sync() can not be called. This function MAY ONLY be + * called from worker context. It MUST NOT be used while a previous such + * work is still pending! + */ +void drbd_queue_bitmap_io(struct drbd_conf *mdev, + int (*io_fn)(struct drbd_conf *), + void (*done)(struct drbd_conf *, int), + char *why) +{ + D_ASSERT(current == mdev->worker.task); + + D_ASSERT(!test_bit(BITMAP_IO_QUEUED, &mdev->flags)); + D_ASSERT(!test_bit(BITMAP_IO, &mdev->flags)); + D_ASSERT(list_empty(&mdev->bm_io_work.w.list)); + if (mdev->bm_io_work.why) + dev_err(DEV, "FIXME going to queue '%s' but '%s' still pending?\n", + why, mdev->bm_io_work.why); + + mdev->bm_io_work.io_fn = io_fn; + mdev->bm_io_work.done = done; + mdev->bm_io_work.why = why; + + set_bit(BITMAP_IO, &mdev->flags); + if (atomic_read(&mdev->ap_bio_cnt) == 0) { + if (list_empty(&mdev->bm_io_work.w.list)) { + set_bit(BITMAP_IO_QUEUED, &mdev->flags); + drbd_queue_work(&mdev->data.work, &mdev->bm_io_work.w); + } else + dev_err(DEV, "FIXME avoided double queuing bm_io_work\n"); + } +} + +/** + * drbd_bitmap_io() - Does an IO operation on the whole bitmap + * @mdev: DRBD device. + * @io_fn: IO callback to be called when bitmap IO is possible + * @why: Descriptive text of the reason for doing the IO + * + * freezes application IO while that the actual IO operations runs. This + * functions MAY NOT be called from worker context. + */ +int drbd_bitmap_io(struct drbd_conf *mdev, int (*io_fn)(struct drbd_conf *), char *why) +{ + int rv; + + D_ASSERT(current != mdev->worker.task); + + drbd_suspend_io(mdev); + + drbd_bm_lock(mdev, why); + rv = io_fn(mdev); + drbd_bm_unlock(mdev); + + drbd_resume_io(mdev); + + return rv; +} + +void drbd_md_set_flag(struct drbd_conf *mdev, int flag) __must_hold(local) +{ + if ((mdev->ldev->md.flags & flag) != flag) { + drbd_md_mark_dirty(mdev); + mdev->ldev->md.flags |= flag; + } +} + +void drbd_md_clear_flag(struct drbd_conf *mdev, int flag) __must_hold(local) +{ + if ((mdev->ldev->md.flags & flag) != 0) { + drbd_md_mark_dirty(mdev); + mdev->ldev->md.flags &= ~flag; + } +} +int drbd_md_test_flag(struct drbd_backing_dev *bdev, int flag) +{ + return (bdev->md.flags & flag) != 0; +} + +static void md_sync_timer_fn(unsigned long data) +{ + struct drbd_conf *mdev = (struct drbd_conf *) data; + + drbd_queue_work_front(&mdev->data.work, &mdev->md_sync_work); +} + +static int w_md_sync(struct drbd_conf *mdev, struct drbd_work *w, int unused) +{ + dev_warn(DEV, "md_sync_timer expired! Worker calls drbd_md_sync().\n"); + drbd_md_sync(mdev); + + return 1; +} + +#ifdef CONFIG_DRBD_FAULT_INJECTION +/* Fault insertion support including random number generator shamelessly + * stolen from kernel/rcutorture.c */ +struct fault_random_state { + unsigned long state; + unsigned long count; +}; + +#define FAULT_RANDOM_MULT 39916801 /* prime */ +#define FAULT_RANDOM_ADD 479001701 /* prime */ +#define FAULT_RANDOM_REFRESH 10000 + +/* + * Crude but fast random-number generator. Uses a linear congruential + * generator, with occasional help from get_random_bytes(). + */ +static unsigned long +_drbd_fault_random(struct fault_random_state *rsp) +{ + long refresh; + + if (--rsp->count < 0) { + get_random_bytes(&refresh, sizeof(refresh)); + rsp->state += refresh; + rsp->count = FAULT_RANDOM_REFRESH; + } + rsp->state = rsp->state * FAULT_RANDOM_MULT + FAULT_RANDOM_ADD; + return swahw32(rsp->state); +} + +static char * +_drbd_fault_str(unsigned int type) { + static char *_faults[] = { + [DRBD_FAULT_MD_WR] = "Meta-data write", + [DRBD_FAULT_MD_RD] = "Meta-data read", + [DRBD_FAULT_RS_WR] = "Resync write", + [DRBD_FAULT_RS_RD] = "Resync read", + [DRBD_FAULT_DT_WR] = "Data write", + [DRBD_FAULT_DT_RD] = "Data read", + [DRBD_FAULT_DT_RA] = "Data read ahead", + [DRBD_FAULT_BM_ALLOC] = "BM allocation", + [DRBD_FAULT_AL_EE] = "EE allocation" + }; + + return (type < DRBD_FAULT_MAX) ? _faults[type] : "**Unknown**"; +} + +unsigned int +_drbd_insert_fault(struct drbd_conf *mdev, unsigned int type) +{ + static struct fault_random_state rrs = {0, 0}; + + unsigned int ret = ( + (fault_devs == 0 || + ((1 << mdev_to_minor(mdev)) & fault_devs) != 0) && + (((_drbd_fault_random(&rrs) % 100) + 1) <= fault_rate)); + + if (ret) { + fault_count++; + + if (printk_ratelimit()) + dev_warn(DEV, "***Simulating %s failure\n", + _drbd_fault_str(type)); + } + + return ret; +} +#endif + +const char *drbd_buildtag(void) +{ + /* DRBD built from external sources has here a reference to the + git hash of the source code. */ + + static char buildtag[38] = "\0uilt-in"; + + if (buildtag[0] == 0) { +#ifdef CONFIG_MODULES + if (THIS_MODULE != NULL) + sprintf(buildtag, "srcversion: %-24s", THIS_MODULE->srcversion); + else +#endif + buildtag[0] = 'b'; + } + + return buildtag; +} + +module_init(drbd_init) +module_exit(drbd_cleanup) + +/* For drbd_tracing: */ +EXPORT_SYMBOL(drbd_conn_str); +EXPORT_SYMBOL(drbd_role_str); +EXPORT_SYMBOL(drbd_disk_str); +EXPORT_SYMBOL(drbd_set_st_err_str); |
