| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Christoph Hellwig | 7004 | 55.02% | 86 | 24.57% |
| David Chinner | 3598 | 28.26% | 144 | 41.14% |
| Brian Foster | 764 | 6.00% | 23 | 6.57% |
| Darrick J. Wong | 351 | 2.76% | 23 | 6.57% |
| Mark Tinguely | 153 | 1.20% | 3 | 0.86% |
| Timothy Shimmin | 149 | 1.17% | 7 | 2.00% |
| Eric Sandeen | 133 | 1.04% | 5 | 1.43% |
| Jie Liu | 99 | 0.78% | 2 | 0.57% |
| Stephen Lord | 96 | 0.75% | 5 | 1.43% |
| Guo Xuenan | 71 | 0.56% | 1 | 0.29% |
| Nathan Scott | 64 | 0.50% | 15 | 4.29% |
| Leah Rumancik | 34 | 0.27% | 1 | 0.29% |
| Rik Van Riel | 30 | 0.24% | 1 | 0.29% |
| Joe Perches | 30 | 0.24% | 1 | 0.29% |
| Russell Cattelan | 25 | 0.20% | 2 | 0.57% |
| Bill O'Donnell | 23 | 0.18% | 2 | 0.57% |
| Michael Nishimoto | 17 | 0.13% | 1 | 0.29% |
| Lukas Herbolt | 16 | 0.13% | 1 | 0.29% |
| Carlos Maiolino | 12 | 0.09% | 3 | 0.86% |
| Glen Overby | 9 | 0.07% | 1 | 0.29% |
| Alex Elder | 9 | 0.07% | 1 | 0.29% |
| Geyslan G. Bem | 6 | 0.05% | 1 | 0.29% |
| Matthew Wilcox | 5 | 0.04% | 2 | 0.57% |
| Linus Torvalds (pre-git) | 4 | 0.03% | 2 | 0.57% |
| Hsiang Kao | 4 | 0.03% | 1 | 0.29% |
| Ian Kent | 3 | 0.02% | 1 | 0.29% |
| Linus Torvalds | 3 | 0.02% | 1 | 0.29% |
| Lachlan McIlroy | 3 | 0.02% | 2 | 0.57% |
| Malcolm Parsons | 2 | 0.02% | 1 | 0.29% |
| Ben Myers | 2 | 0.02% | 1 | 0.29% |
| Gustavo A. R. Silva | 2 | 0.02% | 1 | 0.29% |
| Geert Uytterhoeven | 1 | 0.01% | 1 | 0.29% |
| Zhi Yong Wu | 1 | 0.01% | 1 | 0.29% |
| Xie Shaowen | 1 | 0.01% | 1 | 0.29% |
| Harvey Harrison | 1 | 0.01% | 1 | 0.29% |
| Hariprasad Kelam | 1 | 0.01% | 1 | 0.29% |
| Jason A. Donenfeld | 1 | 0.01% | 1 | 0.29% |
| kbuild test robot | 1 | 0.01% | 1 | 0.29% |
| Marcin Ślusarz | 1 | 0.01% | 1 | 0.29% |
| Huang Chong | 1 | 0.01% | 1 | 0.29% |
| Total | 12730 | 350 |
// SPDX-License-Identifier: GPL-2.0 /* * Copyright (c) 2000-2005 Silicon Graphics, Inc. * All Rights Reserved. */ #include "xfs.h" #include "xfs_fs.h" #include "xfs_shared.h" #include "xfs_format.h" #include "xfs_log_format.h" #include "xfs_trans_resv.h" #include "xfs_mount.h" #include "xfs_errortag.h" #include "xfs_error.h" #include "xfs_trans.h" #include "xfs_trans_priv.h" #include "xfs_log.h" #include "xfs_log_priv.h" #include "xfs_trace.h" #include "xfs_sysfs.h" #include "xfs_sb.h" #include "xfs_health.h" struct kmem_cache *xfs_log_ticket_cache; /* Local miscellaneous function prototypes */ STATIC struct xlog * xlog_alloc_log( struct xfs_mount *mp, struct xfs_buftarg *log_target, xfs_daddr_t blk_offset, int num_bblks); STATIC int xlog_space_left( struct xlog *log, atomic64_t *head); STATIC void xlog_dealloc_log( struct xlog *log); /* local state machine functions */ STATIC void xlog_state_done_syncing( struct xlog_in_core *iclog); STATIC void xlog_state_do_callback( struct xlog *log); STATIC int xlog_state_get_iclog_space( struct xlog *log, int len, struct xlog_in_core **iclog, struct xlog_ticket *ticket, int *logoffsetp); STATIC void xlog_grant_push_ail( struct xlog *log, int need_bytes); STATIC void xlog_sync( struct xlog *log, struct xlog_in_core *iclog, struct xlog_ticket *ticket); #if defined(DEBUG) STATIC void xlog_verify_grant_tail( struct xlog *log); STATIC void xlog_verify_iclog( struct xlog *log, struct xlog_in_core *iclog, int count); STATIC void xlog_verify_tail_lsn( struct xlog *log, struct xlog_in_core *iclog); #else #define xlog_verify_grant_tail(a) #define xlog_verify_iclog(a,b,c) #define xlog_verify_tail_lsn(a,b) #endif STATIC int xlog_iclogs_empty( struct xlog *log); static int xfs_log_cover(struct xfs_mount *); /* * We need to make sure the buffer pointer returned is naturally aligned for the * biggest basic data type we put into it. We have already accounted for this * padding when sizing the buffer. * * However, this padding does not get written into the log, and hence we have to * track the space used by the log vectors separately to prevent log space hangs * due to inaccurate accounting (i.e. a leak) of the used log space through the * CIL context ticket. * * We also add space for the xlog_op_header that describes this region in the * log. This prepends the data region we return to the caller to copy their data * into, so do all the static initialisation of the ophdr now. Because the ophdr * is not 8 byte aligned, we have to be careful to ensure that we align the * start of the buffer such that the region we return to the call is 8 byte * aligned and packed against the tail of the ophdr. */ void * xlog_prepare_iovec( struct xfs_log_vec *lv, struct xfs_log_iovec **vecp, uint type) { struct xfs_log_iovec *vec = *vecp; struct xlog_op_header *oph; uint32_t len; void *buf; if (vec) { ASSERT(vec - lv->lv_iovecp < lv->lv_niovecs); vec++; } else { vec = &lv->lv_iovecp[0]; } len = lv->lv_buf_len + sizeof(struct xlog_op_header); if (!IS_ALIGNED(len, sizeof(uint64_t))) { lv->lv_buf_len = round_up(len, sizeof(uint64_t)) - sizeof(struct xlog_op_header); } vec->i_type = type; vec->i_addr = lv->lv_buf + lv->lv_buf_len; oph = vec->i_addr; oph->oh_clientid = XFS_TRANSACTION; oph->oh_res2 = 0; oph->oh_flags = 0; buf = vec->i_addr + sizeof(struct xlog_op_header); ASSERT(IS_ALIGNED((unsigned long)buf, sizeof(uint64_t))); *vecp = vec; return buf; } static void xlog_grant_sub_space( struct xlog *log, atomic64_t *head, int bytes) { int64_t head_val = atomic64_read(head); int64_t new, old; do { int cycle, space; xlog_crack_grant_head_val(head_val, &cycle, &space); space -= bytes; if (space < 0) { space += log->l_logsize; cycle--; } old = head_val; new = xlog_assign_grant_head_val(cycle, space); head_val = atomic64_cmpxchg(head, old, new); } while (head_val != old); } static void xlog_grant_add_space( struct xlog *log, atomic64_t *head, int bytes) { int64_t head_val = atomic64_read(head); int64_t new, old; do { int tmp; int cycle, space; xlog_crack_grant_head_val(head_val, &cycle, &space); tmp = log->l_logsize - space; if (tmp > bytes) space += bytes; else { space = bytes - tmp; cycle++; } old = head_val; new = xlog_assign_grant_head_val(cycle, space); head_val = atomic64_cmpxchg(head, old, new); } while (head_val != old); } STATIC void xlog_grant_head_init( struct xlog_grant_head *head) { xlog_assign_grant_head(&head->grant, 1, 0); INIT_LIST_HEAD(&head->waiters); spin_lock_init(&head->lock); } STATIC void xlog_grant_head_wake_all( struct xlog_grant_head *head) { struct xlog_ticket *tic; spin_lock(&head->lock); list_for_each_entry(tic, &head->waiters, t_queue) wake_up_process(tic->t_task); spin_unlock(&head->lock); } static inline int xlog_ticket_reservation( struct xlog *log, struct xlog_grant_head *head, struct xlog_ticket *tic) { if (head == &log->l_write_head) { ASSERT(tic->t_flags & XLOG_TIC_PERM_RESERV); return tic->t_unit_res; } if (tic->t_flags & XLOG_TIC_PERM_RESERV) return tic->t_unit_res * tic->t_cnt; return tic->t_unit_res; } STATIC bool xlog_grant_head_wake( struct xlog *log, struct xlog_grant_head *head, int *free_bytes) { struct xlog_ticket *tic; int need_bytes; bool woken_task = false; list_for_each_entry(tic, &head->waiters, t_queue) { /* * There is a chance that the size of the CIL checkpoints in * progress at the last AIL push target calculation resulted in * limiting the target to the log head (l_last_sync_lsn) at the * time. This may not reflect where the log head is now as the * CIL checkpoints may have completed. * * Hence when we are woken here, it may be that the head of the * log that has moved rather than the tail. As the tail didn't * move, there still won't be space available for the * reservation we require. However, if the AIL has already * pushed to the target defined by the old log head location, we * will hang here waiting for something else to update the AIL * push target. * * Therefore, if there isn't space to wake the first waiter on * the grant head, we need to push the AIL again to ensure the * target reflects both the current log tail and log head * position before we wait for the tail to move again. */ need_bytes = xlog_ticket_reservation(log, head, tic); if (*free_bytes < need_bytes) { if (!woken_task) xlog_grant_push_ail(log, need_bytes); return false; } *free_bytes -= need_bytes; trace_xfs_log_grant_wake_up(log, tic); wake_up_process(tic->t_task); woken_task = true; } return true; } STATIC int xlog_grant_head_wait( struct xlog *log, struct xlog_grant_head *head, struct xlog_ticket *tic, int need_bytes) __releases(&head->lock) __acquires(&head->lock) { list_add_tail(&tic->t_queue, &head->waiters); do { if (xlog_is_shutdown(log)) goto shutdown; xlog_grant_push_ail(log, need_bytes); __set_current_state(TASK_UNINTERRUPTIBLE); spin_unlock(&head->lock); XFS_STATS_INC(log->l_mp, xs_sleep_logspace); trace_xfs_log_grant_sleep(log, tic); schedule(); trace_xfs_log_grant_wake(log, tic); spin_lock(&head->lock); if (xlog_is_shutdown(log)) goto shutdown; } while (xlog_space_left(log, &head->grant) < need_bytes); list_del_init(&tic->t_queue); return 0; shutdown: list_del_init(&tic->t_queue); return -EIO; } /* * Atomically get the log space required for a log ticket. * * Once a ticket gets put onto head->waiters, it will only return after the * needed reservation is satisfied. * * This function is structured so that it has a lock free fast path. This is * necessary because every new transaction reservation will come through this * path. Hence any lock will be globally hot if we take it unconditionally on * every pass. * * As tickets are only ever moved on and off head->waiters under head->lock, we * only need to take that lock if we are going to add the ticket to the queue * and sleep. We can avoid taking the lock if the ticket was never added to * head->waiters because the t_queue list head will be empty and we hold the * only reference to it so it can safely be checked unlocked. */ STATIC int xlog_grant_head_check( struct xlog *log, struct xlog_grant_head *head, struct xlog_ticket *tic, int *need_bytes) { int free_bytes; int error = 0; ASSERT(!xlog_in_recovery(log)); /* * If there are other waiters on the queue then give them a chance at * logspace before us. Wake up the first waiters, if we do not wake * up all the waiters then go to sleep waiting for more free space, * otherwise try to get some space for this transaction. */ *need_bytes = xlog_ticket_reservation(log, head, tic); free_bytes = xlog_space_left(log, &head->grant); if (!list_empty_careful(&head->waiters)) { spin_lock(&head->lock); if (!xlog_grant_head_wake(log, head, &free_bytes) || free_bytes < *need_bytes) { error = xlog_grant_head_wait(log, head, tic, *need_bytes); } spin_unlock(&head->lock); } else if (free_bytes < *need_bytes) { spin_lock(&head->lock); error = xlog_grant_head_wait(log, head, tic, *need_bytes); spin_unlock(&head->lock); } return error; } bool xfs_log_writable( struct xfs_mount *mp) { /* * Do not write to the log on norecovery mounts, if the data or log * devices are read-only, or if the filesystem is shutdown. Read-only * mounts allow internal writes for log recovery and unmount purposes, * so don't restrict that case. */ if (xfs_has_norecovery(mp)) return false; if (xfs_readonly_buftarg(mp->m_ddev_targp)) return false; if (xfs_readonly_buftarg(mp->m_log->l_targ)) return false; if (xlog_is_shutdown(mp->m_log)) return false; return true; } /* * Replenish the byte reservation required by moving the grant write head. */ int xfs_log_regrant( struct xfs_mount *mp, struct xlog_ticket *tic) { struct xlog *log = mp->m_log; int need_bytes; int error = 0; if (xlog_is_shutdown(log)) return -EIO; XFS_STATS_INC(mp, xs_try_logspace); /* * This is a new transaction on the ticket, so we need to change the * transaction ID so that the next transaction has a different TID in * the log. Just add one to the existing tid so that we can see chains * of rolling transactions in the log easily. */ tic->t_tid++; xlog_grant_push_ail(log, tic->t_unit_res); tic->t_curr_res = tic->t_unit_res; if (tic->t_cnt > 0) return 0; trace_xfs_log_regrant(log, tic); error = xlog_grant_head_check(log, &log->l_write_head, tic, &need_bytes); if (error) goto out_error; xlog_grant_add_space(log, &log->l_write_head.grant, need_bytes); trace_xfs_log_regrant_exit(log, tic); xlog_verify_grant_tail(log); return 0; out_error: /* * If we are failing, make sure the ticket doesn't have any current * reservations. We don't want to add this back when the ticket/ * transaction gets cancelled. */ tic->t_curr_res = 0; tic->t_cnt = 0; /* ungrant will give back unit_res * t_cnt. */ return error; } /* * Reserve log space and return a ticket corresponding to the reservation. * * Each reservation is going to reserve extra space for a log record header. * When writes happen to the on-disk log, we don't subtract the length of the * log record header from any reservation. By wasting space in each * reservation, we prevent over allocation problems. */ int xfs_log_reserve( struct xfs_mount *mp, int unit_bytes, int cnt, struct xlog_ticket **ticp, bool permanent) { struct xlog *log = mp->m_log; struct xlog_ticket *tic; int need_bytes; int error = 0; if (xlog_is_shutdown(log)) return -EIO; XFS_STATS_INC(mp, xs_try_logspace); ASSERT(*ticp == NULL); tic = xlog_ticket_alloc(log, unit_bytes, cnt, permanent); *ticp = tic; xlog_grant_push_ail(log, tic->t_cnt ? tic->t_unit_res * tic->t_cnt : tic->t_unit_res); trace_xfs_log_reserve(log, tic); error = xlog_grant_head_check(log, &log->l_reserve_head, tic, &need_bytes); if (error) goto out_error; xlog_grant_add_space(log, &log->l_reserve_head.grant, need_bytes); xlog_grant_add_space(log, &log->l_write_head.grant, need_bytes); trace_xfs_log_reserve_exit(log, tic); xlog_verify_grant_tail(log); return 0; out_error: /* * If we are failing, make sure the ticket doesn't have any current * reservations. We don't want to add this back when the ticket/ * transaction gets cancelled. */ tic->t_curr_res = 0; tic->t_cnt = 0; /* ungrant will give back unit_res * t_cnt. */ return error; } /* * Run all the pending iclog callbacks and wake log force waiters and iclog * space waiters so they can process the newly set shutdown state. We really * don't care what order we process callbacks here because the log is shut down * and so state cannot change on disk anymore. However, we cannot wake waiters * until the callbacks have been processed because we may be in unmount and * we must ensure that all AIL operations the callbacks perform have completed * before we tear down the AIL. * * We avoid processing actively referenced iclogs so that we don't run callbacks * while the iclog owner might still be preparing the iclog for IO submssion. * These will be caught by xlog_state_iclog_release() and call this function * again to process any callbacks that may have been added to that iclog. */ static void xlog_state_shutdown_callbacks( struct xlog *log) { struct xlog_in_core *iclog; LIST_HEAD(cb_list); iclog = log->l_iclog; do { if (atomic_read(&iclog->ic_refcnt)) { /* Reference holder will re-run iclog callbacks. */ continue; } list_splice_init(&iclog->ic_callbacks, &cb_list); spin_unlock(&log->l_icloglock); xlog_cil_process_committed(&cb_list); spin_lock(&log->l_icloglock); wake_up_all(&iclog->ic_write_wait); wake_up_all(&iclog->ic_force_wait); } while ((iclog = iclog->ic_next) != log->l_iclog); wake_up_all(&log->l_flush_wait); } /* * Flush iclog to disk if this is the last reference to the given iclog and the * it is in the WANT_SYNC state. * * If XLOG_ICL_NEED_FUA is already set on the iclog, we need to ensure that the * log tail is updated correctly. NEED_FUA indicates that the iclog will be * written to stable storage, and implies that a commit record is contained * within the iclog. We need to ensure that the log tail does not move beyond * the tail that the first commit record in the iclog ordered against, otherwise * correct recovery of that checkpoint becomes dependent on future operations * performed on this iclog. * * Hence if NEED_FUA is set and the current iclog tail lsn is empty, write the * current tail into iclog. Once the iclog tail is set, future operations must * not modify it, otherwise they potentially violate ordering constraints for * the checkpoint commit that wrote the initial tail lsn value. The tail lsn in * the iclog will get zeroed on activation of the iclog after sync, so we * always capture the tail lsn on the iclog on the first NEED_FUA release * regardless of the number of active reference counts on this iclog. */ int xlog_state_release_iclog( struct xlog *log, struct xlog_in_core *iclog, struct xlog_ticket *ticket) { xfs_lsn_t tail_lsn; bool last_ref; lockdep_assert_held(&log->l_icloglock); trace_xlog_iclog_release(iclog, _RET_IP_); /* * Grabbing the current log tail needs to be atomic w.r.t. the writing * of the tail LSN into the iclog so we guarantee that the log tail does * not move between the first time we know that the iclog needs to be * made stable and when we eventually submit it. */ if ((iclog->ic_state == XLOG_STATE_WANT_SYNC || (iclog->ic_flags & XLOG_ICL_NEED_FUA)) && !iclog->ic_header.h_tail_lsn) { tail_lsn = xlog_assign_tail_lsn(log->l_mp); iclog->ic_header.h_tail_lsn = cpu_to_be64(tail_lsn); } last_ref = atomic_dec_and_test(&iclog->ic_refcnt); if (xlog_is_shutdown(log)) { /* * If there are no more references to this iclog, process the * pending iclog callbacks that were waiting on the release of * this iclog. */ if (last_ref) xlog_state_shutdown_callbacks(log); return -EIO; } if (!last_ref) return 0; if (iclog->ic_state != XLOG_STATE_WANT_SYNC) { ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE); return 0; } iclog->ic_state = XLOG_STATE_SYNCING; xlog_verify_tail_lsn(log, iclog); trace_xlog_iclog_syncing(iclog, _RET_IP_); spin_unlock(&log->l_icloglock); xlog_sync(log, iclog, ticket); spin_lock(&log->l_icloglock); return 0; } /* * Mount a log filesystem * * mp - ubiquitous xfs mount point structure * log_target - buftarg of on-disk log device * blk_offset - Start block # where block size is 512 bytes (BBSIZE) * num_bblocks - Number of BBSIZE blocks in on-disk log * * Return error or zero. */ int xfs_log_mount( xfs_mount_t *mp, struct xfs_buftarg *log_target, xfs_daddr_t blk_offset, int num_bblks) { struct xlog *log; int error = 0; int min_logfsbs; if (!xfs_has_norecovery(mp)) { xfs_notice(mp, "Mounting V%d Filesystem %pU", XFS_SB_VERSION_NUM(&mp->m_sb), &mp->m_sb.sb_uuid); } else { xfs_notice(mp, "Mounting V%d filesystem %pU in no-recovery mode. Filesystem will be inconsistent.", XFS_SB_VERSION_NUM(&mp->m_sb), &mp->m_sb.sb_uuid); ASSERT(xfs_is_readonly(mp)); } log = xlog_alloc_log(mp, log_target, blk_offset, num_bblks); if (IS_ERR(log)) { error = PTR_ERR(log); goto out; } mp->m_log = log; /* * Now that we have set up the log and it's internal geometry * parameters, we can validate the given log space and drop a critical * message via syslog if the log size is too small. A log that is too * small can lead to unexpected situations in transaction log space * reservation stage. The superblock verifier has already validated all * the other log geometry constraints, so we don't have to check those * here. * * Note: For v4 filesystems, we can't just reject the mount if the * validation fails. This would mean that people would have to * downgrade their kernel just to remedy the situation as there is no * way to grow the log (short of black magic surgery with xfs_db). * * We can, however, reject mounts for V5 format filesystems, as the * mkfs binary being used to make the filesystem should never create a * filesystem with a log that is too small. */ min_logfsbs = xfs_log_calc_minimum_size(mp); if (mp->m_sb.sb_logblocks < min_logfsbs) { xfs_warn(mp, "Log size %d blocks too small, minimum size is %d blocks", mp->m_sb.sb_logblocks, min_logfsbs); /* * Log check errors are always fatal on v5; or whenever bad * metadata leads to a crash. */ if (xfs_has_crc(mp)) { xfs_crit(mp, "AAIEEE! Log failed size checks. Abort!"); ASSERT(0); error = -EINVAL; goto out_free_log; } xfs_crit(mp, "Log size out of supported range."); xfs_crit(mp, "Continuing onwards, but if log hangs are experienced then please report this message in the bug report."); } /* * Initialize the AIL now we have a log. */ error = xfs_trans_ail_init(mp); if (error) { xfs_warn(mp, "AIL initialisation failed: error %d", error); goto out_free_log; } log->l_ailp = mp->m_ail; /* * skip log recovery on a norecovery mount. pretend it all * just worked. */ if (!xfs_has_norecovery(mp)) { error = xlog_recover(log); if (error) { xfs_warn(mp, "log mount/recovery failed: error %d", error); xlog_recover_cancel(log); goto out_destroy_ail; } } error = xfs_sysfs_init(&log->l_kobj, &xfs_log_ktype, &mp->m_kobj, "log"); if (error) goto out_destroy_ail; /* Normal transactions can now occur */ clear_bit(XLOG_ACTIVE_RECOVERY, &log->l_opstate); /* * Now the log has been fully initialised and we know were our * space grant counters are, we can initialise the permanent ticket * needed for delayed logging to work. */ xlog_cil_init_post_recovery(log); return 0; out_destroy_ail: xfs_trans_ail_destroy(mp); out_free_log: xlog_dealloc_log(log); out: return error; } /* * Finish the recovery of the file system. This is separate from the * xfs_log_mount() call, because it depends on the code in xfs_mountfs() to read * in the root and real-time bitmap inodes between calling xfs_log_mount() and * here. * * If we finish recovery successfully, start the background log work. If we are * not doing recovery, then we have a RO filesystem and we don't need to start * it. */ int xfs_log_mount_finish( struct xfs_mount *mp) { struct xlog *log = mp->m_log; int error = 0; if (xfs_has_norecovery(mp)) { ASSERT(xfs_is_readonly(mp)); return 0; } /* * During the second phase of log recovery, we need iget and * iput to behave like they do for an active filesystem. * xfs_fs_drop_inode needs to be able to prevent the deletion * of inodes before we're done replaying log items on those * inodes. Turn it off immediately after recovery finishes * so that we don't leak the quota inodes if subsequent mount * activities fail. * * We let all inodes involved in redo item processing end up on * the LRU instead of being evicted immediately so that if we do * something to an unlinked inode, the irele won't cause * premature truncation and freeing of the inode, which results * in log recovery failure. We have to evict the unreferenced * lru inodes after clearing SB_ACTIVE because we don't * otherwise clean up the lru if there's a subsequent failure in * xfs_mountfs, which leads to us leaking the inodes if nothing * else (e.g. quotacheck) references the inodes before the * mount failure occurs. */ mp->m_super->s_flags |= SB_ACTIVE; xfs_log_work_queue(mp); if (xlog_recovery_needed(log)) error = xlog_recover_finish(log); mp->m_super->s_flags &= ~SB_ACTIVE; evict_inodes(mp->m_super); /* * Drain the buffer LRU after log recovery. This is required for v4 * filesystems to avoid leaving around buffers with NULL verifier ops, * but we do it unconditionally to make sure we're always in a clean * cache state after mount. * * Don't push in the error case because the AIL may have pending intents * that aren't removed until recovery is cancelled. */ if (xlog_recovery_needed(log)) { if (!error) { xfs_log_force(mp, XFS_LOG_SYNC); xfs_ail_push_all_sync(mp->m_ail); } xfs_notice(mp, "Ending recovery (logdev: %s)", mp->m_logname ? mp->m_logname : "internal"); } else { xfs_info(mp, "Ending clean mount"); } xfs_buftarg_drain(mp->m_ddev_targp); clear_bit(XLOG_RECOVERY_NEEDED, &log->l_opstate); /* Make sure the log is dead if we're returning failure. */ ASSERT(!error || xlog_is_shutdown(log)); return error; } /* * The mount has failed. Cancel the recovery if it hasn't completed and destroy * the log. */ void xfs_log_mount_cancel( struct xfs_mount *mp) { xlog_recover_cancel(mp->m_log); xfs_log_unmount(mp); } /* * Flush out the iclog to disk ensuring that device caches are flushed and * the iclog hits stable storage before any completion waiters are woken. */ static inline int xlog_force_iclog( struct xlog_in_core *iclog) { atomic_inc(&iclog->ic_refcnt); iclog->ic_flags |= XLOG_ICL_NEED_FLUSH | XLOG_ICL_NEED_FUA; if (iclog->ic_state == XLOG_STATE_ACTIVE) xlog_state_switch_iclogs(iclog->ic_log, iclog, 0); return xlog_state_release_iclog(iclog->ic_log, iclog, NULL); } /* * Cycle all the iclogbuf locks to make sure all log IO completion * is done before we tear down these buffers. */ static void xlog_wait_iclog_completion(struct xlog *log) { int i; struct xlog_in_core *iclog = log->l_iclog; for (i = 0; i < log->l_iclog_bufs; i++) { down(&iclog->ic_sema); up(&iclog->ic_sema); iclog = iclog->ic_next; } } /* * Wait for the iclog and all prior iclogs to be written disk as required by the * log force state machine. Waiting on ic_force_wait ensures iclog completions * have been ordered and callbacks run before we are woken here, hence * guaranteeing that all the iclogs up to this one are on stable storage. */ int xlog_wait_on_iclog( struct xlog_in_core *iclog) __releases(iclog->ic_log->l_icloglock) { struct xlog *log = iclog->ic_log; trace_xlog_iclog_wait_on(iclog, _RET_IP_); if (!xlog_is_shutdown(log) && iclog->ic_state != XLOG_STATE_ACTIVE && iclog->ic_state != XLOG_STATE_DIRTY) { XFS_STATS_INC(log->l_mp, xs_log_force_sleep); xlog_wait(&iclog->ic_force_wait, &log->l_icloglock); } else { spin_unlock(&log->l_icloglock); } if (xlog_is_shutdown(log)) return -EIO; return 0; } /* * Write out an unmount record using the ticket provided. We have to account for * the data space used in the unmount ticket as this write is not done from a * transaction context that has already done the accounting for us. */ static int xlog_write_unmount_record( struct xlog *log, struct xlog_ticket *ticket) { struct { struct xlog_op_header ophdr; struct xfs_unmount_log_format ulf; } unmount_rec = { .ophdr = { .oh_clientid = XFS_LOG, .oh_tid = cpu_to_be32(ticket->t_tid), .oh_flags = XLOG_UNMOUNT_TRANS, }, .ulf = { .magic = XLOG_UNMOUNT_TYPE, }, }; struct xfs_log_iovec reg = { .i_addr = &unmount_rec, .i_len = sizeof(unmount_rec), .i_type = XLOG_REG_TYPE_UNMOUNT, }; struct xfs_log_vec vec = { .lv_niovecs = 1, .lv_iovecp = ®, }; LIST_HEAD(lv_chain); list_add(&vec.lv_list, &lv_chain); BUILD_BUG_ON((sizeof(struct xlog_op_header) + sizeof(struct xfs_unmount_log_format)) != sizeof(unmount_rec)); /* account for space used by record data */ ticket->t_curr_res -= sizeof(unmount_rec); return xlog_write(log, NULL, &lv_chain, ticket, reg.i_len); } /* * Mark the filesystem clean by writing an unmount record to the head of the * log. */ static void xlog_unmount_write( struct xlog *log) { struct xfs_mount *mp = log->l_mp; struct xlog_in_core *iclog; struct xlog_ticket *tic = NULL; int error; error = xfs_log_reserve(mp, 600, 1, &tic, 0); if (error) goto out_err; error = xlog_write_unmount_record(log, tic); /* * At this point, we're umounting anyway, so there's no point in * transitioning log state to shutdown. Just continue... */ out_err: if (error) xfs_alert(mp, "%s: unmount record failed", __func__); spin_lock(&log->l_icloglock); iclog = log->l_iclog; error = xlog_force_iclog(iclog); xlog_wait_on_iclog(iclog); if (tic) { trace_xfs_log_umount_write(log, tic); xfs_log_ticket_ungrant(log, tic); } } static void xfs_log_unmount_verify_iclog( struct xlog *log) { struct xlog_in_core *iclog = log->l_iclog; do { ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE); ASSERT(iclog->ic_offset == 0); } while ((iclog = iclog->ic_next) != log->l_iclog); } /* * Unmount record used to have a string "Unmount filesystem--" in the * data section where the "Un" was really a magic number (XLOG_UNMOUNT_TYPE). * We just write the magic number now since that particular field isn't * currently architecture converted and "Unmount" is a bit foo. * As far as I know, there weren't any dependencies on the old behaviour. */ static void xfs_log_unmount_write( struct xfs_mount *mp) { struct xlog *log = mp->m_log; if (!xfs_log_writable(mp)) return; xfs_log_force(mp, XFS_LOG_SYNC); if (xlog_is_shutdown(log)) return; /* * If we think the summary counters are bad, avoid writing the unmount * record to force log recovery at next mount, after which the summary * counters will be recalculated. Refer to xlog_check_unmount_rec for * more details. */ if (XFS_TEST_ERROR(xfs_fs_has_sickness(mp, XFS_SICK_FS_COUNTERS), mp, XFS_ERRTAG_FORCE_SUMMARY_RECALC)) { xfs_alert(mp, "%s: will fix summary counters at next mount", __func__); return; } xfs_log_unmount_verify_iclog(log); xlog_unmount_write(log); } /* * Empty the log for unmount/freeze. * * To do this, we first need to shut down the background log work so it is not * trying to cover the log as we clean up. We then need to unpin all objects in * the log so we can then flush them out. Once they have completed their IO and * run the callbacks removing themselves from the AIL, we can cover the log. */ int xfs_log_quiesce( struct xfs_mount *mp) { /* * Clear log incompat features since we're quiescing the log. Report * failures, though it's not fatal to have a higher log feature * protection level than the log contents actually require. */ if (xfs_clear_incompat_log_features(mp)) { int error; error = xfs_sync_sb(mp, false); if (error) xfs_warn(mp, "Failed to clear log incompat features on quiesce"); } cancel_delayed_work_sync(&mp->m_log->l_work); xfs_log_force(mp, XFS_LOG_SYNC); /* * The superblock buffer is uncached and while xfs_ail_push_all_sync() * will push it, xfs_buftarg_wait() will not wait for it. Further, * xfs_buf_iowait() cannot be used because it was pushed with the * XBF_ASYNC flag set, so we need to use a lock/unlock pair to wait for * the IO to complete. */ xfs_ail_push_all_sync(mp->m_ail); xfs_buftarg_wait(mp->m_ddev_targp); xfs_buf_lock(mp->m_sb_bp); xfs_buf_unlock(mp->m_sb_bp); return xfs_log_cover(mp); } void xfs_log_clean( struct xfs_mount *mp) { xfs_log_quiesce(mp); xfs_log_unmount_write(mp); } /* * Shut down and release the AIL and Log. * * During unmount, we need to ensure we flush all the dirty metadata objects * from the AIL so that the log is empty before we write the unmount record to * the log. Once this is done, we can tear down the AIL and the log. */ void xfs_log_unmount( struct xfs_mount *mp) { xfs_log_clean(mp); /* * If shutdown has come from iclog IO context, the log * cleaning will have been skipped and so we need to wait * for the iclog to complete shutdown processing before we * tear anything down. */ xlog_wait_iclog_completion(mp->m_log); xfs_buftarg_drain(mp->m_ddev_targp); xfs_trans_ail_destroy(mp); xfs_sysfs_del(&mp->m_log->l_kobj); xlog_dealloc_log(mp->m_log); } void xfs_log_item_init( struct xfs_mount *mp, struct xfs_log_item *item, int type, const struct xfs_item_ops *ops) { item->li_log = mp->m_log; item->li_ailp = mp->m_ail; item->li_type = type; item->li_ops = ops; item->li_lv = NULL; INIT_LIST_HEAD(&item->li_ail); INIT_LIST_HEAD(&item->li_cil); INIT_LIST_HEAD(&item->li_bio_list); INIT_LIST_HEAD(&item->li_trans); } /* * Wake up processes waiting for log space after we have moved the log tail. */ void xfs_log_space_wake( struct xfs_mount *mp) { struct xlog *log = mp->m_log; int free_bytes; if (xlog_is_shutdown(log)) return; if (!list_empty_careful(&log->l_write_head.waiters)) { ASSERT(!xlog_in_recovery(log)); spin_lock(&log->l_write_head.lock); free_bytes = xlog_space_left(log, &log->l_write_head.grant); xlog_grant_head_wake(log, &log->l_write_head, &free_bytes); spin_unlock(&log->l_write_head.lock); } if (!list_empty_careful(&log->l_reserve_head.waiters)) { ASSERT(!xlog_in_recovery(log)); spin_lock(&log->l_reserve_head.lock); free_bytes = xlog_space_left(log, &log->l_reserve_head.grant); xlog_grant_head_wake(log, &log->l_reserve_head, &free_bytes); spin_unlock(&log->l_reserve_head.lock); } } /* * Determine if we have a transaction that has gone to disk that needs to be * covered. To begin the transition to the idle state firstly the log needs to * be idle. That means the CIL, the AIL and the iclogs needs to be empty before * we start attempting to cover the log. * * Only if we are then in a state where covering is needed, the caller is * informed that dummy transactions are required to move the log into the idle * state. * * If there are any items in the AIl or CIL, then we do not want to attempt to * cover the log as we may be in a situation where there isn't log space * available to run a dummy transaction and this can lead to deadlocks when the * tail of the log is pinned by an item that is modified in the CIL. Hence * there's no point in running a dummy transaction at this point because we * can't start trying to idle the log until both the CIL and AIL are empty. */ static bool xfs_log_need_covered( struct xfs_mount *mp) { struct xlog *log = mp->m_log; bool needed = false; if (!xlog_cil_empty(log)) return false; spin_lock(&log->l_icloglock); switch (log->l_covered_state) { case XLOG_STATE_COVER_DONE: case XLOG_STATE_COVER_DONE2: case XLOG_STATE_COVER_IDLE: break; case XLOG_STATE_COVER_NEED: case XLOG_STATE_COVER_NEED2: if (xfs_ail_min_lsn(log->l_ailp)) break; if (!xlog_iclogs_empty(log)) break; needed = true; if (log->l_covered_state == XLOG_STATE_COVER_NEED) log->l_covered_state = XLOG_STATE_COVER_DONE; else log->l_covered_state = XLOG_STATE_COVER_DONE2; break; default: needed = true; break; } spin_unlock(&log->l_icloglock); return needed; } /* * Explicitly cover the log. This is similar to background log covering but * intended for usage in quiesce codepaths. The caller is responsible to ensure * the log is idle and suitable for covering. The CIL, iclog buffers and AIL * must all be empty. */ static int xfs_log_cover( struct xfs_mount *mp) { int error = 0; bool need_covered; ASSERT((xlog_cil_empty(mp->m_log) && xlog_iclogs_empty(mp->m_log) && !xfs_ail_min_lsn(mp->m_log->l_ailp)) || xlog_is_shutdown(mp->m_log)); if (!xfs_log_writable(mp)) return 0; /* * xfs_log_need_covered() is not idempotent because it progresses the * state machine if the log requires covering. Therefore, we must call * this function once and use the result until we've issued an sb sync. * Do so first to make that abundantly clear. * * Fall into the covering sequence if the log needs covering or the * mount has lazy superblock accounting to sync to disk. The sb sync * used for covering accumulates the in-core counters, so covering * handles this for us. */ need_covered = xfs_log_need_covered(mp); if (!need_covered && !xfs_has_lazysbcount(mp)) return 0; /* * To cover the log, commit the superblock twice (at most) in * independent checkpoints. The first serves as a reference for the * tail pointer. The sync transaction and AIL push empties the AIL and * updates the in-core tail to the LSN of the first checkpoint. The * second commit updates the on-disk tail with the in-core LSN, * covering the log. Push the AIL one more time to leave it empty, as * we found it. */ do { error = xfs_sync_sb(mp, true); if (error) break; xfs_ail_push_all_sync(mp->m_ail); } while (xfs_log_need_covered(mp)); return error; } /* * We may be holding the log iclog lock upon entering this routine. */ xfs_lsn_t xlog_assign_tail_lsn_locked( struct xfs_mount *mp) { struct xlog *log = mp->m_log; struct xfs_log_item *lip; xfs_lsn_t tail_lsn; assert_spin_locked(&mp->m_ail->ail_lock); /* * To make sure we always have a valid LSN for the log tail we keep * track of the last LSN which was committed in log->l_last_sync_lsn, * and use that when the AIL was empty. */ lip = xfs_ail_min(mp->m_ail); if (lip) tail_lsn = lip->li_lsn; else tail_lsn = atomic64_read(&log->l_last_sync_lsn); trace_xfs_log_assign_tail_lsn(log, tail_lsn); atomic64_set(&log->l_tail_lsn, tail_lsn); return tail_lsn; } xfs_lsn_t xlog_assign_tail_lsn( struct xfs_mount *mp) { xfs_lsn_t tail_lsn; spin_lock(&mp->m_ail->ail_lock); tail_lsn = xlog_assign_tail_lsn_locked(mp); spin_unlock(&mp->m_ail->ail_lock); return tail_lsn; } /* * Return the space in the log between the tail and the head. The head * is passed in the cycle/bytes formal parms. In the special case where * the reserve head has wrapped passed the tail, this calculation is no * longer valid. In this case, just return 0 which means there is no space * in the log. This works for all places where this function is called * with the reserve head. Of course, if the write head were to ever * wrap the tail, we should blow up. Rather than catch this case here, * we depend on other ASSERTions in other parts of the code. XXXmiken * * If reservation head is behind the tail, we have a problem. Warn about it, * but then treat it as if the log is empty. * * If the log is shut down, the head and tail may be invalid or out of whack, so * shortcut invalidity asserts in this case so that we don't trigger them * falsely. */ STATIC int xlog_space_left( struct xlog *log, atomic64_t *head) { int tail_bytes; int tail_cycle; int head_cycle; int head_bytes; xlog_crack_grant_head(head, &head_cycle, &head_bytes); xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_bytes); tail_bytes = BBTOB(tail_bytes); if (tail_cycle == head_cycle && head_bytes >= tail_bytes) return log->l_logsize - (head_bytes - tail_bytes); if (tail_cycle + 1 < head_cycle) return 0; /* Ignore potential inconsistency when shutdown. */ if (xlog_is_shutdown(log)) return log->l_logsize; if (tail_cycle < head_cycle) { ASSERT(tail_cycle == (head_cycle - 1)); return tail_bytes - head_bytes; } /* * The reservation head is behind the tail. In this case we just want to * return the size of the log as the amount of space left. */ xfs_alert(log->l_mp, "xlog_space_left: head behind tail"); xfs_alert(log->l_mp, " tail_cycle = %d, tail_bytes = %d", tail_cycle, tail_bytes); xfs_alert(log->l_mp, " GH cycle = %d, GH bytes = %d", head_cycle, head_bytes); ASSERT(0); return log->l_logsize; } static void xlog_ioend_work( struct work_struct *work) { struct xlog_in_core *iclog = container_of(work, struct xlog_in_core, ic_end_io_work); struct xlog *log = iclog->ic_log; int error; error = blk_status_to_errno(iclog->ic_bio.bi_status); #ifdef DEBUG /* treat writes with injected CRC errors as failed */ if (iclog->ic_fail_crc) error = -EIO; #endif /* * Race to shutdown the filesystem if we see an error. */ if (XFS_TEST_ERROR(error, log->l_mp, XFS_ERRTAG_IODONE_IOERR)) { xfs_alert(log->l_mp, "log I/O error %d", error); xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR); } xlog_state_done_syncing(iclog); bio_uninit(&iclog->ic_bio); /* * Drop the lock to signal that we are done. Nothing references the * iclog after this, so an unmount waiting on this lock can now tear it * down safely. As such, it is unsafe to reference the iclog after the * unlock as we could race with it being freed. */ up(&iclog->ic_sema); } /* * Return size of each in-core log record buffer. * * All machines get 8 x 32kB buffers by default, unless tuned otherwise. * * If the filesystem blocksize is too large, we may need to choose a * larger size since the directory code currently logs entire blocks. */ STATIC void xlog_get_iclog_buffer_size( struct xfs_mount *mp, struct xlog *log) { if (mp->m_logbufs <= 0) mp->m_logbufs = XLOG_MAX_ICLOGS; if (mp->m_logbsize <= 0) mp->m_logbsize = XLOG_BIG_RECORD_BSIZE; log->l_iclog_bufs = mp->m_logbufs; log->l_iclog_size = mp->m_logbsize; /* * # headers = size / 32k - one header holds cycles from 32k of data. */ log->l_iclog_heads = DIV_ROUND_UP(mp->m_logbsize, XLOG_HEADER_CYCLE_SIZE); log->l_iclog_hsize = log->l_iclog_heads << BBSHIFT; } void xfs_log_work_queue( struct xfs_mount *mp) { queue_delayed_work(mp->m_sync_workqueue, &mp->m_log->l_work, msecs_to_jiffies(xfs_syncd_centisecs * 10)); } /* * Clear the log incompat flags if we have the opportunity. * * This only happens if we're about to log the second dummy transaction as part * of covering the log and we can get the log incompat feature usage lock. */ static inline void xlog_clear_incompat( struct xlog *log) { struct xfs_mount *mp = log->l_mp; if (!xfs_sb_has_incompat_log_feature(&mp->m_sb, XFS_SB_FEAT_INCOMPAT_LOG_ALL)) return; if (log->l_covered_state != XLOG_STATE_COVER_DONE2) return; if (!down_write_trylock(&log->l_incompat_users)) return; xfs_clear_incompat_log_features(mp); up_write(&log->l_incompat_users); } /* * Every sync period we need to unpin all items in the AIL and push them to * disk. If there is nothing dirty, then we might need to cover the log to * indicate that the filesystem is idle. */ static void xfs_log_worker( struct work_struct *work) { struct xlog *log = container_of(to_delayed_work(work), struct xlog, l_work); struct xfs_mount *mp = log->l_mp; /* dgc: errors ignored - not fatal and nowhere to report them */ if (xfs_fs_writable(mp, SB_FREEZE_WRITE) && xfs_log_need_covered(mp)) { /* * Dump a transaction into the log that contains no real change. * This is needed to stamp the current tail LSN into the log * during the covering operation. * * We cannot use an inode here for this - that will push dirty * state back up into the VFS and then periodic inode flushing * will prevent log covering from making progress. Hence we * synchronously log the superblock instead to ensure the * superblock is immediately unpinned and can be written back. */ xlog_clear_incompat(log); xfs_sync_sb(mp, true); } else xfs_log_force(mp, 0); /* start pushing all the metadata that is currently dirty */ xfs_ail_push_all(mp->m_ail); /* queue us up again */ xfs_log_work_queue(mp); } /* * This routine initializes some of the log structure for a given mount point. * Its primary purpose is to fill in enough, so recovery can occur. However, * some other stuff may be filled in too. */ STATIC struct xlog * xlog_alloc_log( struct xfs_mount *mp, struct xfs_buftarg *log_target, xfs_daddr_t blk_offset, int num_bblks) { struct xlog *log; xlog_rec_header_t *head; xlog_in_core_t **iclogp; xlog_in_core_t *iclog, *prev_iclog=NULL; int i; int error = -ENOMEM; uint log2_size = 0; log = kzalloc(sizeof(struct xlog), GFP_KERNEL | __GFP_RETRY_MAYFAIL); if (!log) { xfs_warn(mp, "Log allocation failed: No memory!"); goto out; } log->l_mp = mp; log->l_targ = log_target; log->l_logsize = BBTOB(num_bblks); log->l_logBBstart = blk_offset; log->l_logBBsize = num_bblks; log->l_covered_state = XLOG_STATE_COVER_IDLE; set_bit(XLOG_ACTIVE_RECOVERY, &log->l_opstate); INIT_DELAYED_WORK(&log->l_work, xfs_log_worker); INIT_LIST_HEAD(&log->r_dfops); log->l_prev_block = -1; /* log->l_tail_lsn = 0x100000000LL; cycle = 1; current block = 0 */ xlog_assign_atomic_lsn(&log->l_tail_lsn, 1, 0); xlog_assign_atomic_lsn(&log->l_last_sync_lsn, 1, 0); log->l_curr_cycle = 1; /* 0 is bad since this is initial value */ if (xfs_has_logv2(mp) && mp->m_sb.sb_logsunit > 1) log->l_iclog_roundoff = mp->m_sb.sb_logsunit; else log->l_iclog_roundoff = BBSIZE; xlog_grant_head_init(&log->l_reserve_head); xlog_grant_head_init(&log->l_write_head); error = -EFSCORRUPTED; if (xfs_has_sector(mp)) { log2_size = mp->m_sb.sb_logsectlog; if (log2_size < BBSHIFT) { xfs_warn(mp, "Log sector size too small (0x%x < 0x%x)", log2_size, BBSHIFT); goto out_free_log; } log2_size -= BBSHIFT; if (log2_size > mp->m_sectbb_log) { xfs_warn(mp, "Log sector size too large (0x%x > 0x%x)", log2_size, mp->m_sectbb_log); goto out_free_log; } /* for larger sector sizes, must have v2 or external log */ if (log2_size && log->l_logBBstart > 0 && !xfs_has_logv2(mp)) { xfs_warn(mp, "log sector size (0x%x) invalid for configuration.", log2_size); goto out_free_log; } } log->l_sectBBsize = 1 << log2_size; init_rwsem(&log->l_incompat_users); xlog_get_iclog_buffer_size(mp, log); spin_lock_init(&log->l_icloglock); init_waitqueue_head(&log->l_flush_wait); iclogp = &log->l_iclog; /* * The amount of memory to allocate for the iclog structure is * rather funky due to the way the structure is defined. It is * done this way so that we can use different sizes for machines * with different amounts of memory. See the definition of * xlog_in_core_t in xfs_log_priv.h for details. */ ASSERT(log->l_iclog_size >= 4096); for (i = 0; i < log->l_iclog_bufs; i++) { size_t bvec_size = howmany(log->l_iclog_size, PAGE_SIZE) * sizeof(struct bio_vec); iclog = kzalloc(sizeof(*iclog) + bvec_size, GFP_KERNEL | __GFP_RETRY_MAYFAIL); if (!iclog) goto out_free_iclog; *iclogp = iclog; iclog->ic_prev = prev_iclog; prev_iclog = iclog; iclog->ic_data = kvzalloc(log->l_iclog_size, GFP_KERNEL | __GFP_RETRY_MAYFAIL); if (!iclog->ic_data) goto out_free_iclog; head = &iclog->ic_header; memset(head, 0, sizeof(xlog_rec_header_t)); head->h_magicno = cpu_to_be32(XLOG_HEADER_MAGIC_NUM); head->h_version = cpu_to_be32( xfs_has_logv2(log->l_mp) ? 2 : 1); head->h_size = cpu_to_be32(log->l_iclog_size); /* new fields */ head->h_fmt = cpu_to_be32(XLOG_FMT); memcpy(&head->h_fs_uuid, &mp->m_sb.sb_uuid, sizeof(uuid_t)); iclog->ic_size = log->l_iclog_size - log->l_iclog_hsize; iclog->ic_state = XLOG_STATE_ACTIVE; iclog->ic_log = log; atomic_set(&iclog->ic_refcnt, 0); INIT_LIST_HEAD(&iclog->ic_callbacks); iclog->ic_datap = (void *)iclog->ic_data + log->l_iclog_hsize; init_waitqueue_head(&iclog->ic_force_wait); init_waitqueue_head(&iclog->ic_write_wait); INIT_WORK(&iclog->ic_end_io_work, xlog_ioend_work); sema_init(&iclog->ic_sema, 1); iclogp = &iclog->ic_next; } *iclogp = log->l_iclog; /* complete ring */ log->l_iclog->ic_prev = prev_iclog; /* re-write 1st prev ptr */ log->l_ioend_workqueue = alloc_workqueue("xfs-log/%s", XFS_WQFLAGS(WQ_FREEZABLE | WQ_MEM_RECLAIM | WQ_HIGHPRI), 0, mp->m_super->s_id); if (!log->l_ioend_workqueue) goto out_free_iclog; error = xlog_cil_init(log); if (error) goto out_destroy_workqueue; return log; out_destroy_workqueue: destroy_workqueue(log->l_ioend_workqueue); out_free_iclog: for (iclog = log->l_iclog; iclog; iclog = prev_iclog) { prev_iclog = iclog->ic_next; kvfree(iclog->ic_data); kfree(iclog); if (prev_iclog == log->l_iclog) break; } out_free_log: kfree(log); out: return ERR_PTR(error); } /* xlog_alloc_log */ /* * Compute the LSN that we'd need to push the log tail towards in order to have * (a) enough on-disk log space to log the number of bytes specified, (b) at * least 25% of the log space free, and (c) at least 256 blocks free. If the * log free space already meets all three thresholds, this function returns * NULLCOMMITLSN. */ xfs_lsn_t xlog_grant_push_threshold( struct xlog *log, int need_bytes) { xfs_lsn_t threshold_lsn = 0; xfs_lsn_t last_sync_lsn; int free_blocks; int free_bytes; int threshold_block; int threshold_cycle; int free_threshold; ASSERT(BTOBB(need_bytes) < log->l_logBBsize); free_bytes = xlog_space_left(log, &log->l_reserve_head.grant); free_blocks = BTOBBT(free_bytes); /* * Set the threshold for the minimum number of free blocks in the * log to the maximum of what the caller needs, one quarter of the * log, and 256 blocks. */ free_threshold = BTOBB(need_bytes); free_threshold = max(free_threshold, (log->l_logBBsize >> 2)); free_threshold = max(free_threshold, 256); if (free_blocks >= free_threshold) return NULLCOMMITLSN; xlog_crack_atomic_lsn(&log->l_tail_lsn, &threshold_cycle, &threshold_block); threshold_block += free_threshold; if (threshold_block >= log->l_logBBsize) { threshold_block -= log->l_logBBsize; threshold_cycle += 1; } threshold_lsn = xlog_assign_lsn(threshold_cycle, threshold_block); /* * Don't pass in an lsn greater than the lsn of the last * log record known to be on disk. Use a snapshot of the last sync lsn * so that it doesn't change between the compare and the set. */ last_sync_lsn = atomic64_read(&log->l_last_sync_lsn); if (XFS_LSN_CMP(threshold_lsn, last_sync_lsn) > 0) threshold_lsn = last_sync_lsn; return threshold_lsn; } /* * Push the tail of the log if we need to do so to maintain the free log space * thresholds set out by xlog_grant_push_threshold. We may need to adopt a * policy which pushes on an lsn which is further along in the log once we * reach the high water mark. In this manner, we would be creating a low water * mark. */ STATIC void xlog_grant_push_ail( struct xlog *log, int need_bytes) { xfs_lsn_t threshold_lsn; threshold_lsn = xlog_grant_push_threshold(log, need_bytes); if (threshold_lsn == NULLCOMMITLSN || xlog_is_shutdown(log)) return; /* * Get the transaction layer to kick the dirty buffers out to * disk asynchronously. No point in trying to do this if * the filesystem is shutting down. */ xfs_ail_push(log->l_ailp, threshold_lsn); } /* * Stamp cycle number in every block */ STATIC void xlog_pack_data( struct xlog *log, struct xlog_in_core *iclog, int roundoff) { int i, j, k; int size = iclog->ic_offset + roundoff; __be32 cycle_lsn; char *dp; cycle_lsn = CYCLE_LSN_DISK(iclog->ic_header.h_lsn); dp = iclog->ic_datap; for (i = 0; i < BTOBB(size); i++) { if (i >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) break; iclog->ic_header.h_cycle_data[i] = *(__be32 *)dp; *(__be32 *)dp = cycle_lsn; dp += BBSIZE; } if (xfs_has_logv2(log->l_mp)) { xlog_in_core_2_t *xhdr = iclog->ic_data; for ( ; i < BTOBB(size); i++) { j = i / (XLOG_HEADER_CYCLE_SIZE / BBSIZE); k = i % (XLOG_HEADER_CYCLE_SIZE / BBSIZE); xhdr[j].hic_xheader.xh_cycle_data[k] = *(__be32 *)dp; *(__be32 *)dp = cycle_lsn; dp += BBSIZE; } for (i = 1; i < log->l_iclog_heads; i++) xhdr[i].hic_xheader.xh_cycle = cycle_lsn; } } /* * Calculate the checksum for a log buffer. * * This is a little more complicated than it should be because the various * headers and the actual data are non-contiguous. */ __le32 xlog_cksum( struct xlog *log, struct xlog_rec_header *rhead, char *dp, int size) { uint32_t crc; /* first generate the crc for the record header ... */ crc = xfs_start_cksum_update((char *)rhead, sizeof(struct xlog_rec_header), offsetof(struct xlog_rec_header, h_crc)); /* ... then for additional cycle data for v2 logs ... */ if (xfs_has_logv2(log->l_mp)) { union xlog_in_core2 *xhdr = (union xlog_in_core2 *)rhead; int i; int xheads; xheads = DIV_ROUND_UP(size, XLOG_HEADER_CYCLE_SIZE); for (i = 1; i < xheads; i++) { crc = crc32c(crc, &xhdr[i].hic_xheader, sizeof(struct xlog_rec_ext_header)); } } /* ... and finally for the payload */ crc = crc32c(crc, dp, size); return xfs_end_cksum(crc); } static void xlog_bio_end_io( struct bio *bio) { struct xlog_in_core *iclog = bio->bi_private; queue_work(iclog->ic_log->l_ioend_workqueue, &iclog->ic_end_io_work); } static int xlog_map_iclog_data( struct bio *bio, void *data, size_t count) { do { struct page *page = kmem_to_page(data); unsigned int off = offset_in_page(data); size_t len = min_t(size_t, count, PAGE_SIZE - off); if (bio_add_page(bio, page, len, off) != len) return -EIO; data += len; count -= len; } while (count); return 0; } STATIC void xlog_write_iclog( struct xlog *log, struct xlog_in_core *iclog, uint64_t bno, unsigned int count) { ASSERT(bno < log->l_logBBsize); trace_xlog_iclog_write(iclog, _RET_IP_); /* * We lock the iclogbufs here so that we can serialise against I/O * completion during unmount. We might be processing a shutdown * triggered during unmount, and that can occur asynchronously to the * unmount thread, and hence we need to ensure that completes before * tearing down the iclogbufs. Hence we need to hold the buffer lock * across the log IO to archieve that. */ down(&iclog->ic_sema); if (xlog_is_shutdown(log)) { /* * It would seem logical to return EIO here, but we rely on * the log state machine to propagate I/O errors instead of * doing it here. We kick of the state machine and unlock * the buffer manually, the code needs to be kept in sync * with the I/O completion path. */ goto sync; } /* * We use REQ_SYNC | REQ_IDLE here to tell the block layer the are more * IOs coming immediately after this one. This prevents the block layer * writeback throttle from throttling log writes behind background * metadata writeback and causing priority inversions. */ bio_init(&iclog->ic_bio, log->l_targ->bt_bdev, iclog->ic_bvec, howmany(count, PAGE_SIZE), REQ_OP_WRITE | REQ_META | REQ_SYNC | REQ_IDLE); iclog->ic_bio.bi_iter.bi_sector = log->l_logBBstart + bno; iclog->ic_bio.bi_end_io = xlog_bio_end_io; iclog->ic_bio.bi_private = iclog; if (iclog->ic_flags & XLOG_ICL_NEED_FLUSH) { iclog->ic_bio.bi_opf |= REQ_PREFLUSH; /* * For external log devices, we also need to flush the data * device cache first to ensure all metadata writeback covered * by the LSN in this iclog is on stable storage. This is slow, * but it *must* complete before we issue the external log IO. * * If the flush fails, we cannot conclude that past metadata * writeback from the log succeeded. Repeating the flush is * not possible, hence we must shut down with log IO error to * avoid shutdown re-entering this path and erroring out again. */ if (log->l_targ != log->l_mp->m_ddev_targp && blkdev_issue_flush(log->l_mp->m_ddev_targp->bt_bdev)) goto shutdown; } if (iclog->ic_flags & XLOG_ICL_NEED_FUA) iclog->ic_bio.bi_opf |= REQ_FUA; iclog->ic_flags &= ~(XLOG_ICL_NEED_FLUSH | XLOG_ICL_NEED_FUA); if (xlog_map_iclog_data(&iclog->ic_bio, iclog->ic_data, count)) goto shutdown; if (is_vmalloc_addr(iclog->ic_data)) flush_kernel_vmap_range(iclog->ic_data, count); /* * If this log buffer would straddle the end of the log we will have * to split it up into two bios, so that we can continue at the start. */ if (bno + BTOBB(count) > log->l_logBBsize) { struct bio *split; split = bio_split(&iclog->ic_bio, log->l_logBBsize - bno, GFP_NOIO, &fs_bio_set); bio_chain(split, &iclog->ic_bio); submit_bio(split); /* restart at logical offset zero for the remainder */ iclog->ic_bio.bi_iter.bi_sector = log->l_logBBstart; } submit_bio(&iclog->ic_bio); return; shutdown: xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR); sync: xlog_state_done_syncing(iclog); up(&iclog->ic_sema); } /* * We need to bump cycle number for the part of the iclog that is * written to the start of the log. Watch out for the header magic * number case, though. */ static void xlog_split_iclog( struct xlog *log, void *data, uint64_t bno, unsigned int count) { unsigned int split_offset = BBTOB(log->l_logBBsize - bno); unsigned int i; for (i = split_offset; i < count; i += BBSIZE) { uint32_t cycle = get_unaligned_be32(data + i); if (++cycle == XLOG_HEADER_MAGIC_NUM) cycle++; put_unaligned_be32(cycle, data + i); } } static int xlog_calc_iclog_size( struct xlog *log, struct xlog_in_core *iclog, uint32_t *roundoff) { uint32_t count_init, count; /* Add for LR header */ count_init = log->l_iclog_hsize + iclog->ic_offset; count = roundup(count_init, log->l_iclog_roundoff); *roundoff = count - count_init; ASSERT(count >= count_init); ASSERT(*roundoff < log->l_iclog_roundoff); return count; } /* * Flush out the in-core log (iclog) to the on-disk log in an asynchronous * fashion. Previously, we should have moved the current iclog * ptr in the log to point to the next available iclog. This allows further * write to continue while this code syncs out an iclog ready to go. * Before an in-core log can be written out, the data section must be scanned * to save away the 1st word of each BBSIZE block into the header. We replace * it with the current cycle count. Each BBSIZE block is tagged with the * cycle count because there in an implicit assumption that drives will * guarantee that entire 512 byte blocks get written at once. In other words, * we can't have part of a 512 byte block written and part not written. By * tagging each block, we will know which blocks are valid when recovering * after an unclean shutdown. * * This routine is single threaded on the iclog. No other thread can be in * this routine with the same iclog. Changing contents of iclog can there- * fore be done without grabbing the state machine lock. Updating the global * log will require grabbing the lock though. * * The entire log manager uses a logical block numbering scheme. Only * xlog_write_iclog knows about the fact that the log may not start with * block zero on a given device. */ STATIC void xlog_sync( struct xlog *log, struct xlog_in_core *iclog, struct xlog_ticket *ticket) { unsigned int count; /* byte count of bwrite */ unsigned int roundoff; /* roundoff to BB or stripe */ uint64_t bno; unsigned int size; ASSERT(atomic_read(&iclog->ic_refcnt) == 0); trace_xlog_iclog_sync(iclog, _RET_IP_); count = xlog_calc_iclog_size(log, iclog, &roundoff); /* * If we have a ticket, account for the roundoff via the ticket * reservation to avoid touching the hot grant heads needlessly. * Otherwise, we have to move grant heads directly. */ if (ticket) { ticket->t_curr_res -= roundoff; } else { xlog_grant_add_space(log, &log->l_reserve_head.grant, roundoff); xlog_grant_add_space(log, &log->l_write_head.grant, roundoff); } /* put cycle number in every block */ xlog_pack_data(log, iclog, roundoff); /* real byte length */ size = iclog->ic_offset; if (xfs_has_logv2(log->l_mp)) size += roundoff; iclog->ic_header.h_len = cpu_to_be32(size); XFS_STATS_INC(log->l_mp, xs_log_writes); XFS_STATS_ADD(log->l_mp, xs_log_blocks, BTOBB(count)); bno = BLOCK_LSN(be64_to_cpu(iclog->ic_header.h_lsn)); /* Do we need to split this write into 2 parts? */ if (bno + BTOBB(count) > log->l_logBBsize) xlog_split_iclog(log, &iclog->ic_header, bno, count); /* calculcate the checksum */ iclog->ic_header.h_crc = xlog_cksum(log, &iclog->ic_header, iclog->ic_datap, size); /* * Intentionally corrupt the log record CRC based on the error injection * frequency, if defined. This facilitates testing log recovery in the * event of torn writes. Hence, set the IOABORT state to abort the log * write on I/O completion and shutdown the fs. The subsequent mount * detects the bad CRC and attempts to recover. */ #ifdef DEBUG if (XFS_TEST_ERROR(false, log->l_mp, XFS_ERRTAG_LOG_BAD_CRC)) { iclog->ic_header.h_crc &= cpu_to_le32(0xAAAAAAAA); iclog->ic_fail_crc = true; xfs_warn(log->l_mp, "Intentionally corrupted log record at LSN 0x%llx. Shutdown imminent.", be64_to_cpu(iclog->ic_header.h_lsn)); } #endif xlog_verify_iclog(log, iclog, count); xlog_write_iclog(log, iclog, bno, count); } /* * Deallocate a log structure */ STATIC void xlog_dealloc_log( struct xlog *log) { xlog_in_core_t *iclog, *next_iclog; int i; /* * Destroy the CIL after waiting for iclog IO completion because an * iclog EIO error will try to shut down the log, which accesses the * CIL to wake up the waiters. */ xlog_cil_destroy(log); iclog = log->l_iclog; for (i = 0; i < log->l_iclog_bufs; i++) { next_iclog = iclog->ic_next; kvfree(iclog->ic_data); kfree(iclog); iclog = next_iclog; } log->l_mp->m_log = NULL; destroy_workqueue(log->l_ioend_workqueue); kfree(log); } /* * Update counters atomically now that memcpy is done. */ static inline void xlog_state_finish_copy( struct xlog *log, struct xlog_in_core *iclog, int record_cnt, int copy_bytes) { lockdep_assert_held(&log->l_icloglock); be32_add_cpu(&iclog->ic_header.h_num_logops, record_cnt); iclog->ic_offset += copy_bytes; } /* * print out info relating to regions written which consume * the reservation */ void xlog_print_tic_res( struct xfs_mount *mp, struct xlog_ticket *ticket) { xfs_warn(mp, "ticket reservation summary:"); xfs_warn(mp, " unit res = %d bytes", ticket->t_unit_res); xfs_warn(mp, " current res = %d bytes", ticket->t_curr_res); xfs_warn(mp, " original count = %d", ticket->t_ocnt); xfs_warn(mp, " remaining count = %d", ticket->t_cnt); } /* * Print a summary of the transaction. */ void xlog_print_trans( struct xfs_trans *tp) { struct xfs_mount *mp = tp->t_mountp; struct xfs_log_item *lip; /* dump core transaction and ticket info */ xfs_warn(mp, "transaction summary:"); xfs_warn(mp, " log res = %d", tp->t_log_res); xfs_warn(mp, " log count = %d", tp->t_log_count); xfs_warn(mp, " flags = 0x%x", tp->t_flags); xlog_print_tic_res(mp, tp->t_ticket); /* dump each log item */ list_for_each_entry(lip, &tp->t_items, li_trans) { struct xfs_log_vec *lv = lip->li_lv; struct xfs_log_iovec *vec; int i; xfs_warn(mp, "log item: "); xfs_warn(mp, " type = 0x%x", lip->li_type); xfs_warn(mp, " flags = 0x%lx", lip->li_flags); if (!lv) continue; xfs_warn(mp, " niovecs = %d", lv->lv_niovecs); xfs_warn(mp, " size = %d", lv->lv_size); xfs_warn(mp, " bytes = %d", lv->lv_bytes); xfs_warn(mp, " buf len = %d", lv->lv_buf_len); /* dump each iovec for the log item */ vec = lv->lv_iovecp; for (i = 0; i < lv->lv_niovecs; i++) { int dumplen = min(vec->i_len, 32); xfs_warn(mp, " iovec[%d]", i); xfs_warn(mp, " type = 0x%x", vec->i_type); xfs_warn(mp, " len = %d", vec->i_len); xfs_warn(mp, " first %d bytes of iovec[%d]:", dumplen, i); xfs_hex_dump(vec->i_addr, dumplen); vec++; } } } static inline void xlog_write_iovec( struct xlog_in_core *iclog, uint32_t *log_offset, void *data, uint32_t write_len, int *bytes_left, uint32_t *record_cnt, uint32_t *data_cnt) { ASSERT(*log_offset < iclog->ic_log->l_iclog_size); ASSERT(*log_offset % sizeof(int32_t) == 0); ASSERT(write_len % sizeof(int32_t) == 0); memcpy(iclog->ic_datap + *log_offset, data, write_len); *log_offset += write_len; *bytes_left -= write_len; (*record_cnt)++; *data_cnt += write_len; } /* * Write log vectors into a single iclog which is guaranteed by the caller * to have enough space to write the entire log vector into. */ static void xlog_write_full( struct xfs_log_vec *lv, struct xlog_ticket *ticket, struct xlog_in_core *iclog, uint32_t *log_offset, uint32_t *len, uint32_t *record_cnt, uint32_t *data_cnt) { int index; ASSERT(*log_offset + *len <= iclog->ic_size || iclog->ic_state == XLOG_STATE_WANT_SYNC); /* * Ordered log vectors have no regions to write so this * loop will naturally skip them. */ for (index = 0; index < lv->lv_niovecs; index++) { struct xfs_log_iovec *reg = &lv->lv_iovecp[index]; struct xlog_op_header *ophdr = reg->i_addr; ophdr->oh_tid = cpu_to_be32(ticket->t_tid); xlog_write_iovec(iclog, log_offset, reg->i_addr, reg->i_len, len, record_cnt, data_cnt); } } static int xlog_write_get_more_iclog_space( struct xlog_ticket *ticket, struct xlog_in_core **iclogp, uint32_t *log_offset, uint32_t len, uint32_t *record_cnt, uint32_t *data_cnt) { struct xlog_in_core *iclog = *iclogp; struct xlog *log = iclog->ic_log; int error; spin_lock(&log->l_icloglock); ASSERT(iclog->ic_state == XLOG_STATE_WANT_SYNC); xlog_state_finish_copy(log, iclog, *record_cnt, *data_cnt); error = xlog_state_release_iclog(log, iclog, ticket); spin_unlock(&log->l_icloglock); if (error) return error; error = xlog_state_get_iclog_space(log, len, &iclog, ticket, log_offset); if (error) return error; *record_cnt = 0; *data_cnt = 0; *iclogp = iclog; return 0; } /* * Write log vectors into a single iclog which is smaller than the current chain * length. We write until we cannot fit a full record into the remaining space * and then stop. We return the log vector that is to be written that cannot * wholly fit in the iclog. */ static int xlog_write_partial( struct xfs_log_vec *lv, struct xlog_ticket *ticket, struct xlog_in_core **iclogp, uint32_t *log_offset, uint32_t *len, uint32_t *record_cnt, uint32_t *data_cnt) { struct xlog_in_core *iclog = *iclogp; struct xlog_op_header *ophdr; int index = 0; uint32_t rlen; int error; /* walk the logvec, copying until we run out of space in the iclog */ for (index = 0; index < lv->lv_niovecs; index++) { struct xfs_log_iovec *reg = &lv->lv_iovecp[index]; uint32_t reg_offset = 0; /* * The first region of a continuation must have a non-zero * length otherwise log recovery will just skip over it and * start recovering from the next opheader it finds. Because we * mark the next opheader as a continuation, recovery will then * incorrectly add the continuation to the previous region and * that breaks stuff. * * Hence if there isn't space for region data after the * opheader, then we need to start afresh with a new iclog. */ if (iclog->ic_size - *log_offset <= sizeof(struct xlog_op_header)) { error = xlog_write_get_more_iclog_space(ticket, &iclog, log_offset, *len, record_cnt, data_cnt); if (error) return error; } ophdr = reg->i_addr; rlen = min_t(uint32_t, reg->i_len, iclog->ic_size - *log_offset); ophdr->oh_tid = cpu_to_be32(ticket->t_tid); ophdr->oh_len = cpu_to_be32(rlen - sizeof(struct xlog_op_header)); if (rlen != reg->i_len) ophdr->oh_flags |= XLOG_CONTINUE_TRANS; xlog_write_iovec(iclog, log_offset, reg->i_addr, rlen, len, record_cnt, data_cnt); /* If we wrote the whole region, move to the next. */ if (rlen == reg->i_len) continue; /* * We now have a partially written iovec, but it can span * multiple iclogs so we loop here. First we release the iclog * we currently have, then we get a new iclog and add a new * opheader. Then we continue copying from where we were until * we either complete the iovec or fill the iclog. If we * complete the iovec, then we increment the index and go right * back to the top of the outer loop. if we fill the iclog, we * run the inner loop again. * * This is complicated by the tail of a region using all the * space in an iclog and hence requiring us to release the iclog * and get a new one before returning to the outer loop. We must * always guarantee that we exit this inner loop with at least * space for log transaction opheaders left in the current * iclog, hence we cannot just terminate the loop at the end * of the of the continuation. So we loop while there is no * space left in the current iclog, and check for the end of the * continuation after getting a new iclog. */ do { /* * Ensure we include the continuation opheader in the * space we need in the new iclog by adding that size * to the length we require. This continuation opheader * needs to be accounted to the ticket as the space it * consumes hasn't been accounted to the lv we are * writing. */ error = xlog_write_get_more_iclog_space(ticket, &iclog, log_offset, *len + sizeof(struct xlog_op_header), record_cnt, data_cnt); if (error) return error; ophdr = iclog->ic_datap + *log_offset; ophdr->oh_tid = cpu_to_be32(ticket->t_tid); ophdr->oh_clientid = XFS_TRANSACTION; ophdr->oh_res2 = 0; ophdr->oh_flags = XLOG_WAS_CONT_TRANS; ticket->t_curr_res -= sizeof(struct xlog_op_header); *log_offset += sizeof(struct xlog_op_header); *data_cnt += sizeof(struct xlog_op_header); /* * If rlen fits in the iclog, then end the region * continuation. Otherwise we're going around again. */ reg_offset += rlen; rlen = reg->i_len - reg_offset; if (rlen <= iclog->ic_size - *log_offset) ophdr->oh_flags |= XLOG_END_TRANS; else ophdr->oh_flags |= XLOG_CONTINUE_TRANS; rlen = min_t(uint32_t, rlen, iclog->ic_size - *log_offset); ophdr->oh_len = cpu_to_be32(rlen); xlog_write_iovec(iclog, log_offset, reg->i_addr + reg_offset, rlen, len, record_cnt, data_cnt); } while (ophdr->oh_flags & XLOG_CONTINUE_TRANS); } /* * No more iovecs remain in this logvec so return the next log vec to * the caller so it can go back to fast path copying. */ *iclogp = iclog; return 0; } /* * Write some region out to in-core log * * This will be called when writing externally provided regions or when * writing out a commit record for a given transaction. * * General algorithm: * 1. Find total length of this write. This may include adding to the * lengths passed in. * 2. Check whether we violate the tickets reservation. * 3. While writing to this iclog * A. Reserve as much space in this iclog as can get * B. If this is first write, save away start lsn * C. While writing this region: * 1. If first write of transaction, write start record * 2. Write log operation header (header per region) * 3. Find out if we can fit entire region into this iclog * 4. Potentially, verify destination memcpy ptr * 5. Memcpy (partial) region * 6. If partial copy, release iclog; otherwise, continue * copying more regions into current iclog * 4. Mark want sync bit (in simulation mode) * 5. Release iclog for potential flush to on-disk log. * * ERRORS: * 1. Panic if reservation is overrun. This should never happen since * reservation amounts are generated internal to the filesystem. * NOTES: * 1. Tickets are single threaded data structures. * 2. The XLOG_END_TRANS & XLOG_CONTINUE_TRANS flags are passed down to the * syncing routine. When a single log_write region needs to span * multiple in-core logs, the XLOG_CONTINUE_TRANS bit should be set * on all log operation writes which don't contain the end of the * region. The XLOG_END_TRANS bit is used for the in-core log * operation which contains the end of the continued log_write region. * 3. When xlog_state_get_iclog_space() grabs the rest of the current iclog, * we don't really know exactly how much space will be used. As a result, * we don't update ic_offset until the end when we know exactly how many * bytes have been written out. */ int xlog_write( struct xlog *log, struct xfs_cil_ctx *ctx, struct list_head *lv_chain, struct xlog_ticket *ticket, uint32_t len) { struct xlog_in_core *iclog = NULL; struct xfs_log_vec *lv; uint32_t record_cnt = 0; uint32_t data_cnt = 0; int error = 0; int log_offset; if (ticket->t_curr_res < 0) { xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES, "ctx ticket reservation ran out. Need to up reservation"); xlog_print_tic_res(log->l_mp, ticket); xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR); } error = xlog_state_get_iclog_space(log, len, &iclog, ticket, &log_offset); if (error) return error; ASSERT(log_offset <= iclog->ic_size - 1); /* * If we have a context pointer, pass it the first iclog we are * writing to so it can record state needed for iclog write * ordering. */ if (ctx) xlog_cil_set_ctx_write_state(ctx, iclog); list_for_each_entry(lv, lv_chain, lv_list) { /* * If the entire log vec does not fit in the iclog, punt it to * the partial copy loop which can handle this case. */ if (lv->lv_niovecs && lv->lv_bytes > iclog->ic_size - log_offset) { error = xlog_write_partial(lv, ticket, &iclog, &log_offset, &len, &record_cnt, &data_cnt); if (error) { /* * We have no iclog to release, so just return * the error immediately. */ return error; } } else { xlog_write_full(lv, ticket, iclog, &log_offset, &len, &record_cnt, &data_cnt); } } ASSERT(len == 0); /* * We've already been guaranteed that the last writes will fit inside * the current iclog, and hence it will already have the space used by * those writes accounted to it. Hence we do not need to update the * iclog with the number of bytes written here. */ spin_lock(&log->l_icloglock); xlog_state_finish_copy(log, iclog, record_cnt, 0); error = xlog_state_release_iclog(log, iclog, ticket); spin_unlock(&log->l_icloglock); return error; } static void xlog_state_activate_iclog( struct xlog_in_core *iclog, int *iclogs_changed) { ASSERT(list_empty_careful(&iclog->ic_callbacks)); trace_xlog_iclog_activate(iclog, _RET_IP_); /* * If the number of ops in this iclog indicate it just contains the * dummy transaction, we can change state into IDLE (the second time * around). Otherwise we should change the state into NEED a dummy. * We don't need to cover the dummy. */ if (*iclogs_changed == 0 && iclog->ic_header.h_num_logops == cpu_to_be32(XLOG_COVER_OPS)) { *iclogs_changed = 1; } else { /* * We have two dirty iclogs so start over. This could also be * num of ops indicating this is not the dummy going out. */ *iclogs_changed = 2; } iclog->ic_state = XLOG_STATE_ACTIVE; iclog->ic_offset = 0; iclog->ic_header.h_num_logops = 0; memset(iclog->ic_header.h_cycle_data, 0, sizeof(iclog->ic_header.h_cycle_data)); iclog->ic_header.h_lsn = 0; iclog->ic_header.h_tail_lsn = 0; } /* * Loop through all iclogs and mark all iclogs currently marked DIRTY as * ACTIVE after iclog I/O has completed. */ static void xlog_state_activate_iclogs( struct xlog *log, int *iclogs_changed) { struct xlog_in_core *iclog = log->l_iclog; do { if (iclog->ic_state == XLOG_STATE_DIRTY) xlog_state_activate_iclog(iclog, iclogs_changed); /* * The ordering of marking iclogs ACTIVE must be maintained, so * an iclog doesn't become ACTIVE beyond one that is SYNCING. */ else if (iclog->ic_state != XLOG_STATE_ACTIVE) break; } while ((iclog = iclog->ic_next) != log->l_iclog); } static int xlog_covered_state( int prev_state, int iclogs_changed) { /* * We go to NEED for any non-covering writes. We go to NEED2 if we just * wrote the first covering record (DONE). We go to IDLE if we just * wrote the second covering record (DONE2) and remain in IDLE until a * non-covering write occurs. */ switch (prev_state) { case XLOG_STATE_COVER_IDLE: if (iclogs_changed == 1) return XLOG_STATE_COVER_IDLE; fallthrough; case XLOG_STATE_COVER_NEED: case XLOG_STATE_COVER_NEED2: break; case XLOG_STATE_COVER_DONE: if (iclogs_changed == 1) return XLOG_STATE_COVER_NEED2; break; case XLOG_STATE_COVER_DONE2: if (iclogs_changed == 1) return XLOG_STATE_COVER_IDLE; break; default: ASSERT(0); } return XLOG_STATE_COVER_NEED; } STATIC void xlog_state_clean_iclog( struct xlog *log, struct xlog_in_core *dirty_iclog) { int iclogs_changed = 0; trace_xlog_iclog_clean(dirty_iclog, _RET_IP_); dirty_iclog->ic_state = XLOG_STATE_DIRTY; xlog_state_activate_iclogs(log, &iclogs_changed); wake_up_all(&dirty_iclog->ic_force_wait); if (iclogs_changed) { log->l_covered_state = xlog_covered_state(log->l_covered_state, iclogs_changed); } } STATIC xfs_lsn_t xlog_get_lowest_lsn( struct xlog *log) { struct xlog_in_core *iclog = log->l_iclog; xfs_lsn_t lowest_lsn = 0, lsn; do { if (iclog->ic_state == XLOG_STATE_ACTIVE || iclog->ic_state == XLOG_STATE_DIRTY) continue; lsn = be64_to_cpu(iclog->ic_header.h_lsn); if ((lsn && !lowest_lsn) || XFS_LSN_CMP(lsn, lowest_lsn) < 0) lowest_lsn = lsn; } while ((iclog = iclog->ic_next) != log->l_iclog); return lowest_lsn; } /* * Completion of a iclog IO does not imply that a transaction has completed, as * transactions can be large enough to span many iclogs. We cannot change the * tail of the log half way through a transaction as this may be the only * transaction in the log and moving the tail to point to the middle of it * will prevent recovery from finding the start of the transaction. Hence we * should only update the last_sync_lsn if this iclog contains transaction * completion callbacks on it. * * We have to do this before we drop the icloglock to ensure we are the only one * that can update it. * * If we are moving the last_sync_lsn forwards, we also need to ensure we kick * the reservation grant head pushing. This is due to the fact that the push * target is bound by the current last_sync_lsn value. Hence if we have a large * amount of log space bound up in this committing transaction then the * last_sync_lsn value may be the limiting factor preventing tail pushing from * freeing space in the log. Hence once we've updated the last_sync_lsn we * should push the AIL to ensure the push target (and hence the grant head) is * no longer bound by the old log head location and can move forwards and make * progress again. */ static void xlog_state_set_callback( struct xlog *log, struct xlog_in_core *iclog, xfs_lsn_t header_lsn) { trace_xlog_iclog_callback(iclog, _RET_IP_); iclog->ic_state = XLOG_STATE_CALLBACK; ASSERT(XFS_LSN_CMP(atomic64_read(&log->l_last_sync_lsn), header_lsn) <= 0); if (list_empty_careful(&iclog->ic_callbacks)) return; atomic64_set(&log->l_last_sync_lsn, header_lsn); xlog_grant_push_ail(log, 0); } /* * Return true if we need to stop processing, false to continue to the next * iclog. The caller will need to run callbacks if the iclog is returned in the * XLOG_STATE_CALLBACK state. */ static bool xlog_state_iodone_process_iclog( struct xlog *log, struct xlog_in_core *iclog) { xfs_lsn_t lowest_lsn; xfs_lsn_t header_lsn; switch (iclog->ic_state) { case XLOG_STATE_ACTIVE: case XLOG_STATE_DIRTY: /* * Skip all iclogs in the ACTIVE & DIRTY states: */ return false; case XLOG_STATE_DONE_SYNC: /* * Now that we have an iclog that is in the DONE_SYNC state, do * one more check here to see if we have chased our tail around. * If this is not the lowest lsn iclog, then we will leave it * for another completion to process. */ header_lsn = be64_to_cpu(iclog->ic_header.h_lsn); lowest_lsn = xlog_get_lowest_lsn(log); if (lowest_lsn && XFS_LSN_CMP(lowest_lsn, header_lsn) < 0) return false; xlog_state_set_callback(log, iclog, header_lsn); return false; default: /* * Can only perform callbacks in order. Since this iclog is not * in the DONE_SYNC state, we skip the rest and just try to * clean up. */ return true; } } /* * Loop over all the iclogs, running attached callbacks on them. Return true if * we ran any callbacks, indicating that we dropped the icloglock. We don't need * to handle transient shutdown state here at all because * xlog_state_shutdown_callbacks() will be run to do the necessary shutdown * cleanup of the callbacks. */ static bool xlog_state_do_iclog_callbacks( struct xlog *log) __releases(&log->l_icloglock) __acquires(&log->l_icloglock) { struct xlog_in_core *first_iclog = log->l_iclog; struct xlog_in_core *iclog = first_iclog; bool ran_callback = false; do { LIST_HEAD(cb_list); if (xlog_state_iodone_process_iclog(log, iclog)) break; if (iclog->ic_state != XLOG_STATE_CALLBACK) { iclog = iclog->ic_next; continue; } list_splice_init(&iclog->ic_callbacks, &cb_list); spin_unlock(&log->l_icloglock); trace_xlog_iclog_callbacks_start(iclog, _RET_IP_); xlog_cil_process_committed(&cb_list); trace_xlog_iclog_callbacks_done(iclog, _RET_IP_); ran_callback = true; spin_lock(&log->l_icloglock); xlog_state_clean_iclog(log, iclog); iclog = iclog->ic_next; } while (iclog != first_iclog); return ran_callback; } /* * Loop running iclog completion callbacks until there are no more iclogs in a * state that can run callbacks. */ STATIC void xlog_state_do_callback( struct xlog *log) { int flushcnt = 0; int repeats = 0; spin_lock(&log->l_icloglock); while (xlog_state_do_iclog_callbacks(log)) { if (xlog_is_shutdown(log)) break; if (++repeats > 5000) { flushcnt += repeats; repeats = 0; xfs_warn(log->l_mp, "%s: possible infinite loop (%d iterations)", __func__, flushcnt); } } if (log->l_iclog->ic_state == XLOG_STATE_ACTIVE) wake_up_all(&log->l_flush_wait); spin_unlock(&log->l_icloglock); } /* * Finish transitioning this iclog to the dirty state. * * Callbacks could take time, so they are done outside the scope of the * global state machine log lock. */ STATIC void xlog_state_done_syncing( struct xlog_in_core *iclog) { struct xlog *log = iclog->ic_log; spin_lock(&log->l_icloglock); ASSERT(atomic_read(&iclog->ic_refcnt) == 0); trace_xlog_iclog_sync_done(iclog, _RET_IP_); /* * If we got an error, either on the first buffer, or in the case of * split log writes, on the second, we shut down the file system and * no iclogs should ever be attempted to be written to disk again. */ if (!xlog_is_shutdown(log)) { ASSERT(iclog->ic_state == XLOG_STATE_SYNCING); iclog->ic_state = XLOG_STATE_DONE_SYNC; } /* * Someone could be sleeping prior to writing out the next * iclog buffer, we wake them all, one will get to do the * I/O, the others get to wait for the result. */ wake_up_all(&iclog->ic_write_wait); spin_unlock(&log->l_icloglock); xlog_state_do_callback(log); } /* * If the head of the in-core log ring is not (ACTIVE or DIRTY), then we must * sleep. We wait on the flush queue on the head iclog as that should be * the first iclog to complete flushing. Hence if all iclogs are syncing, * we will wait here and all new writes will sleep until a sync completes. * * The in-core logs are used in a circular fashion. They are not used * out-of-order even when an iclog past the head is free. * * return: * * log_offset where xlog_write() can start writing into the in-core * log's data space. * * in-core log pointer to which xlog_write() should write. * * boolean indicating this is a continued write to an in-core log. * If this is the last write, then the in-core log's offset field * needs to be incremented, depending on the amount of data which * is copied. */ STATIC int xlog_state_get_iclog_space( struct xlog *log, int len, struct xlog_in_core **iclogp, struct xlog_ticket *ticket, int *logoffsetp) { int log_offset; xlog_rec_header_t *head; xlog_in_core_t *iclog; restart: spin_lock(&log->l_icloglock); if (xlog_is_shutdown(log)) { spin_unlock(&log->l_icloglock); return -EIO; } iclog = log->l_iclog; if (iclog->ic_state != XLOG_STATE_ACTIVE) { XFS_STATS_INC(log->l_mp, xs_log_noiclogs); /* Wait for log writes to have flushed */ xlog_wait(&log->l_flush_wait, &log->l_icloglock); goto restart; } head = &iclog->ic_header; atomic_inc(&iclog->ic_refcnt); /* prevents sync */ log_offset = iclog->ic_offset; trace_xlog_iclog_get_space(iclog, _RET_IP_); /* On the 1st write to an iclog, figure out lsn. This works * if iclogs marked XLOG_STATE_WANT_SYNC always write out what they are * committing to. If the offset is set, that's how many blocks * must be written. */ if (log_offset == 0) { ticket->t_curr_res -= log->l_iclog_hsize; head->h_cycle = cpu_to_be32(log->l_curr_cycle); head->h_lsn = cpu_to_be64( xlog_assign_lsn(log->l_curr_cycle, log->l_curr_block)); ASSERT(log->l_curr_block >= 0); } /* If there is enough room to write everything, then do it. Otherwise, * claim the rest of the region and make sure the XLOG_STATE_WANT_SYNC * bit is on, so this will get flushed out. Don't update ic_offset * until you know exactly how many bytes get copied. Therefore, wait * until later to update ic_offset. * * xlog_write() algorithm assumes that at least 2 xlog_op_header_t's * can fit into remaining data section. */ if (iclog->ic_size - iclog->ic_offset < 2*sizeof(xlog_op_header_t)) { int error = 0; xlog_state_switch_iclogs(log, iclog, iclog->ic_size); /* * If we are the only one writing to this iclog, sync it to * disk. We need to do an atomic compare and decrement here to * avoid racing with concurrent atomic_dec_and_lock() calls in * xlog_state_release_iclog() when there is more than one * reference to the iclog. */ if (!atomic_add_unless(&iclog->ic_refcnt, -1, 1)) error = xlog_state_release_iclog(log, iclog, ticket); spin_unlock(&log->l_icloglock); if (error) return error; goto restart; } /* Do we have enough room to write the full amount in the remainder * of this iclog? Or must we continue a write on the next iclog and * mark this iclog as completely taken? In the case where we switch * iclogs (to mark it taken), this particular iclog will release/sync * to disk in xlog_write(). */ if (len <= iclog->ic_size - iclog->ic_offset) iclog->ic_offset += len; else xlog_state_switch_iclogs(log, iclog, iclog->ic_size); *iclogp = iclog; ASSERT(iclog->ic_offset <= iclog->ic_size); spin_unlock(&log->l_icloglock); *logoffsetp = log_offset; return 0; } /* * The first cnt-1 times a ticket goes through here we don't need to move the * grant write head because the permanent reservation has reserved cnt times the * unit amount. Release part of current permanent unit reservation and reset * current reservation to be one units worth. Also move grant reservation head * forward. */ void xfs_log_ticket_regrant( struct xlog *log, struct xlog_ticket *ticket) { trace_xfs_log_ticket_regrant(log, ticket); if (ticket->t_cnt > 0) ticket->t_cnt--; xlog_grant_sub_space(log, &log->l_reserve_head.grant, ticket->t_curr_res); xlog_grant_sub_space(log, &log->l_write_head.grant, ticket->t_curr_res); ticket->t_curr_res = ticket->t_unit_res; trace_xfs_log_ticket_regrant_sub(log, ticket); /* just return if we still have some of the pre-reserved space */ if (!ticket->t_cnt) { xlog_grant_add_space(log, &log->l_reserve_head.grant, ticket->t_unit_res); trace_xfs_log_ticket_regrant_exit(log, ticket); ticket->t_curr_res = ticket->t_unit_res; } xfs_log_ticket_put(ticket); } /* * Give back the space left from a reservation. * * All the information we need to make a correct determination of space left * is present. For non-permanent reservations, things are quite easy. The * count should have been decremented to zero. We only need to deal with the * space remaining in the current reservation part of the ticket. If the * ticket contains a permanent reservation, there may be left over space which * needs to be released. A count of N means that N-1 refills of the current * reservation can be done before we need to ask for more space. The first * one goes to fill up the first current reservation. Once we run out of * space, the count will stay at zero and the only space remaining will be * in the current reservation field. */ void xfs_log_ticket_ungrant( struct xlog *log, struct xlog_ticket *ticket) { int bytes; trace_xfs_log_ticket_ungrant(log, ticket); if (ticket->t_cnt > 0) ticket->t_cnt--; trace_xfs_log_ticket_ungrant_sub(log, ticket); /* * If this is a permanent reservation ticket, we may be able to free * up more space based on the remaining count. */ bytes = ticket->t_curr_res; if (ticket->t_cnt > 0) { ASSERT(ticket->t_flags & XLOG_TIC_PERM_RESERV); bytes += ticket->t_unit_res*ticket->t_cnt; } xlog_grant_sub_space(log, &log->l_reserve_head.grant, bytes); xlog_grant_sub_space(log, &log->l_write_head.grant, bytes); trace_xfs_log_ticket_ungrant_exit(log, ticket); xfs_log_space_wake(log->l_mp); xfs_log_ticket_put(ticket); } /* * This routine will mark the current iclog in the ring as WANT_SYNC and move * the current iclog pointer to the next iclog in the ring. */ void xlog_state_switch_iclogs( struct xlog *log, struct xlog_in_core *iclog, int eventual_size) { ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE); assert_spin_locked(&log->l_icloglock); trace_xlog_iclog_switch(iclog, _RET_IP_); if (!eventual_size) eventual_size = iclog->ic_offset; iclog->ic_state = XLOG_STATE_WANT_SYNC; iclog->ic_header.h_prev_block = cpu_to_be32(log->l_prev_block); log->l_prev_block = log->l_curr_block; log->l_prev_cycle = log->l_curr_cycle; /* roll log?: ic_offset changed later */ log->l_curr_block += BTOBB(eventual_size)+BTOBB(log->l_iclog_hsize); /* Round up to next log-sunit */ if (log->l_iclog_roundoff > BBSIZE) { uint32_t sunit_bb = BTOBB(log->l_iclog_roundoff); log->l_curr_block = roundup(log->l_curr_block, sunit_bb); } if (log->l_curr_block >= log->l_logBBsize) { /* * Rewind the current block before the cycle is bumped to make * sure that the combined LSN never transiently moves forward * when the log wraps to the next cycle. This is to support the * unlocked sample of these fields from xlog_valid_lsn(). Most * other cases should acquire l_icloglock. */ log->l_curr_block -= log->l_logBBsize; ASSERT(log->l_curr_block >= 0); smp_wmb(); log->l_curr_cycle++; if (log->l_curr_cycle == XLOG_HEADER_MAGIC_NUM) log->l_curr_cycle++; } ASSERT(iclog == log->l_iclog); log->l_iclog = iclog->ic_next; } /* * Force the iclog to disk and check if the iclog has been completed before * xlog_force_iclog() returns. This can happen on synchronous (e.g. * pmem) or fast async storage because we drop the icloglock to issue the IO. * If completion has already occurred, tell the caller so that it can avoid an * unnecessary wait on the iclog. */ static int xlog_force_and_check_iclog( struct xlog_in_core *iclog, bool *completed) { xfs_lsn_t lsn = be64_to_cpu(iclog->ic_header.h_lsn); int error; *completed = false; error = xlog_force_iclog(iclog); if (error) return error; /* * If the iclog has already been completed and reused the header LSN * will have been rewritten by completion */ if (be64_to_cpu(iclog->ic_header.h_lsn) != lsn) *completed = true; return 0; } /* * Write out all data in the in-core log as of this exact moment in time. * * Data may be written to the in-core log during this call. However, * we don't guarantee this data will be written out. A change from past * implementation means this routine will *not* write out zero length LRs. * * Basically, we try and perform an intelligent scan of the in-core logs. * If we determine there is no flushable data, we just return. There is no * flushable data if: * * 1. the current iclog is active and has no data; the previous iclog * is in the active or dirty state. * 2. the current iclog is drity, and the previous iclog is in the * active or dirty state. * * We may sleep if: * * 1. the current iclog is not in the active nor dirty state. * 2. the current iclog dirty, and the previous iclog is not in the * active nor dirty state. * 3. the current iclog is active, and there is another thread writing * to this particular iclog. * 4. a) the current iclog is active and has no other writers * b) when we return from flushing out this iclog, it is still * not in the active nor dirty state. */ int xfs_log_force( struct xfs_mount *mp, uint flags) { struct xlog *log = mp->m_log; struct xlog_in_core *iclog; XFS_STATS_INC(mp, xs_log_force); trace_xfs_log_force(mp, 0, _RET_IP_); xlog_cil_force(log); spin_lock(&log->l_icloglock); if (xlog_is_shutdown(log)) goto out_error; iclog = log->l_iclog; trace_xlog_iclog_force(iclog, _RET_IP_); if (iclog->ic_state == XLOG_STATE_DIRTY || (iclog->ic_state == XLOG_STATE_ACTIVE && atomic_read(&iclog->ic_refcnt) == 0 && iclog->ic_offset == 0)) { /* * If the head is dirty or (active and empty), then we need to * look at the previous iclog. * * If the previous iclog is active or dirty we are done. There * is nothing to sync out. Otherwise, we attach ourselves to the * previous iclog and go to sleep. */ iclog = iclog->ic_prev; } else if (iclog->ic_state == XLOG_STATE_ACTIVE) { if (atomic_read(&iclog->ic_refcnt) == 0) { /* We have exclusive access to this iclog. */ bool completed; if (xlog_force_and_check_iclog(iclog, &completed)) goto out_error; if (completed) goto out_unlock; } else { /* * Someone else is still writing to this iclog, so we * need to ensure that when they release the iclog it * gets synced immediately as we may be waiting on it. */ xlog_state_switch_iclogs(log, iclog, 0); } } /* * The iclog we are about to wait on may contain the checkpoint pushed * by the above xlog_cil_force() call, but it may not have been pushed * to disk yet. Like the ACTIVE case above, we need to make sure caches * are flushed when this iclog is written. */ if (iclog->ic_state == XLOG_STATE_WANT_SYNC) iclog->ic_flags |= XLOG_ICL_NEED_FLUSH | XLOG_ICL_NEED_FUA; if (flags & XFS_LOG_SYNC) return xlog_wait_on_iclog(iclog); out_unlock: spin_unlock(&log->l_icloglock); return 0; out_error: spin_unlock(&log->l_icloglock); return -EIO; } /* * Force the log to a specific LSN. * * If an iclog with that lsn can be found: * If it is in the DIRTY state, just return. * If it is in the ACTIVE state, move the in-core log into the WANT_SYNC * state and go to sleep or return. * If it is in any other state, go to sleep or return. * * Synchronous forces are implemented with a wait queue. All callers trying * to force a given lsn to disk must wait on the queue attached to the * specific in-core log. When given in-core log finally completes its write * to disk, that thread will wake up all threads waiting on the queue. */ static int xlog_force_lsn( struct xlog *log, xfs_lsn_t lsn, uint flags, int *log_flushed, bool already_slept) { struct xlog_in_core *iclog; bool completed; spin_lock(&log->l_icloglock); if (xlog_is_shutdown(log)) goto out_error; iclog = log->l_iclog; while (be64_to_cpu(iclog->ic_header.h_lsn) != lsn) { trace_xlog_iclog_force_lsn(iclog, _RET_IP_); iclog = iclog->ic_next; if (iclog == log->l_iclog) goto out_unlock; } switch (iclog->ic_state) { case XLOG_STATE_ACTIVE: /* * We sleep here if we haven't already slept (e.g. this is the * first time we've looked at the correct iclog buf) and the * buffer before us is going to be sync'ed. The reason for this * is that if we are doing sync transactions here, by waiting * for the previous I/O to complete, we can allow a few more * transactions into this iclog before we close it down. * * Otherwise, we mark the buffer WANT_SYNC, and bump up the * refcnt so we can release the log (which drops the ref count). * The state switch keeps new transaction commits from using * this buffer. When the current commits finish writing into * the buffer, the refcount will drop to zero and the buffer * will go out then. */ if (!already_slept && (iclog->ic_prev->ic_state == XLOG_STATE_WANT_SYNC || iclog->ic_prev->ic_state == XLOG_STATE_SYNCING)) { xlog_wait(&iclog->ic_prev->ic_write_wait, &log->l_icloglock); return -EAGAIN; } if (xlog_force_and_check_iclog(iclog, &completed)) goto out_error; if (log_flushed) *log_flushed = 1; if (completed) goto out_unlock; break; case XLOG_STATE_WANT_SYNC: /* * This iclog may contain the checkpoint pushed by the * xlog_cil_force_seq() call, but there are other writers still * accessing it so it hasn't been pushed to disk yet. Like the * ACTIVE case above, we need to make sure caches are flushed * when this iclog is written. */ iclog->ic_flags |= XLOG_ICL_NEED_FLUSH | XLOG_ICL_NEED_FUA; break; default: /* * The entire checkpoint was written by the CIL force and is on * its way to disk already. It will be stable when it * completes, so we don't need to manipulate caches here at all. * We just need to wait for completion if necessary. */ break; } if (flags & XFS_LOG_SYNC) return xlog_wait_on_iclog(iclog); out_unlock: spin_unlock(&log->l_icloglock); return 0; out_error: spin_unlock(&log->l_icloglock); return -EIO; } /* * Force the log to a specific checkpoint sequence. * * First force the CIL so that all the required changes have been flushed to the * iclogs. If the CIL force completed it will return a commit LSN that indicates * the iclog that needs to be flushed to stable storage. If the caller needs * a synchronous log force, we will wait on the iclog with the LSN returned by * xlog_cil_force_seq() to be completed. */ int xfs_log_force_seq( struct xfs_mount *mp, xfs_csn_t seq, uint flags, int *log_flushed) { struct xlog *log = mp->m_log; xfs_lsn_t lsn; int ret; ASSERT(seq != 0); XFS_STATS_INC(mp, xs_log_force); trace_xfs_log_force(mp, seq, _RET_IP_); lsn = xlog_cil_force_seq(log, seq); if (lsn == NULLCOMMITLSN) return 0; ret = xlog_force_lsn(log, lsn, flags, log_flushed, false); if (ret == -EAGAIN) { XFS_STATS_INC(mp, xs_log_force_sleep); ret = xlog_force_lsn(log, lsn, flags, log_flushed, true); } return ret; } /* * Free a used ticket when its refcount falls to zero. */ void xfs_log_ticket_put( xlog_ticket_t *ticket) { ASSERT(atomic_read(&ticket->t_ref) > 0); if (atomic_dec_and_test(&ticket->t_ref)) kmem_cache_free(xfs_log_ticket_cache, ticket); } xlog_ticket_t * xfs_log_ticket_get( xlog_ticket_t *ticket) { ASSERT(atomic_read(&ticket->t_ref) > 0); atomic_inc(&ticket->t_ref); return ticket; } /* * Figure out the total log space unit (in bytes) that would be * required for a log ticket. */ static int xlog_calc_unit_res( struct xlog *log, int unit_bytes, int *niclogs) { int iclog_space; uint num_headers; /* * Permanent reservations have up to 'cnt'-1 active log operations * in the log. A unit in this case is the amount of space for one * of these log operations. Normal reservations have a cnt of 1 * and their unit amount is the total amount of space required. * * The following lines of code account for non-transaction data * which occupy space in the on-disk log. * * Normal form of a transaction is: * <oph><trans-hdr><start-oph><reg1-oph><reg1><reg2-oph>...<commit-oph> * and then there are LR hdrs, split-recs and roundoff at end of syncs. * * We need to account for all the leadup data and trailer data * around the transaction data. * And then we need to account for the worst case in terms of using * more space. * The worst case will happen if: * - the placement of the transaction happens to be such that the * roundoff is at its maximum * - the transaction data is synced before the commit record is synced * i.e. <transaction-data><roundoff> | <commit-rec><roundoff> * Therefore the commit record is in its own Log Record. * This can happen as the commit record is called with its * own region to xlog_write(). * This then means that in the worst case, roundoff can happen for * the commit-rec as well. * The commit-rec is smaller than padding in this scenario and so it is * not added separately. */ /* for trans header */ unit_bytes += sizeof(xlog_op_header_t); unit_bytes += sizeof(xfs_trans_header_t); /* for start-rec */ unit_bytes += sizeof(xlog_op_header_t); /* * for LR headers - the space for data in an iclog is the size minus * the space used for the headers. If we use the iclog size, then we * undercalculate the number of headers required. * * Furthermore - the addition of op headers for split-recs might * increase the space required enough to require more log and op * headers, so take that into account too. * * IMPORTANT: This reservation makes the assumption that if this * transaction is the first in an iclog and hence has the LR headers * accounted to it, then the remaining space in the iclog is * exclusively for this transaction. i.e. if the transaction is larger * than the iclog, it will be the only thing in that iclog. * Fundamentally, this means we must pass the entire log vector to * xlog_write to guarantee this. */ iclog_space = log->l_iclog_size - log->l_iclog_hsize; num_headers = howmany(unit_bytes, iclog_space); /* for split-recs - ophdrs added when data split over LRs */ unit_bytes += sizeof(xlog_op_header_t) * num_headers; /* add extra header reservations if we overrun */ while (!num_headers || howmany(unit_bytes, iclog_space) > num_headers) { unit_bytes += sizeof(xlog_op_header_t); num_headers++; } unit_bytes += log->l_iclog_hsize * num_headers; /* for commit-rec LR header - note: padding will subsume the ophdr */ unit_bytes += log->l_iclog_hsize; /* roundoff padding for transaction data and one for commit record */ unit_bytes += 2 * log->l_iclog_roundoff; if (niclogs) *niclogs = num_headers; return unit_bytes; } int xfs_log_calc_unit_res( struct xfs_mount *mp, int unit_bytes) { return xlog_calc_unit_res(mp->m_log, unit_bytes, NULL); } /* * Allocate and initialise a new log ticket. */ struct xlog_ticket * xlog_ticket_alloc( struct xlog *log, int unit_bytes, int cnt, bool permanent) { struct xlog_ticket *tic; int unit_res; tic = kmem_cache_zalloc(xfs_log_ticket_cache, GFP_KERNEL | __GFP_NOFAIL); unit_res = xlog_calc_unit_res(log, unit_bytes, &tic->t_iclog_hdrs); atomic_set(&tic->t_ref, 1); tic->t_task = current; INIT_LIST_HEAD(&tic->t_queue); tic->t_unit_res = unit_res; tic->t_curr_res = unit_res; tic->t_cnt = cnt; tic->t_ocnt = cnt; tic->t_tid = get_random_u32(); if (permanent) tic->t_flags |= XLOG_TIC_PERM_RESERV; return tic; } #if defined(DEBUG) /* * Check to make sure the grant write head didn't just over lap the tail. If * the cycles are the same, we can't be overlapping. Otherwise, make sure that * the cycles differ by exactly one and check the byte count. * * This check is run unlocked, so can give false positives. Rather than assert * on failures, use a warn-once flag and a panic tag to allow the admin to * determine if they want to panic the machine when such an error occurs. For * debug kernels this will have the same effect as using an assert but, unlinke * an assert, it can be turned off at runtime. */ STATIC void xlog_verify_grant_tail( struct xlog *log) { int tail_cycle, tail_blocks; int cycle, space; xlog_crack_grant_head(&log->l_write_head.grant, &cycle, &space); xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_blocks); if (tail_cycle != cycle) { if (cycle - 1 != tail_cycle && !test_and_set_bit(XLOG_TAIL_WARN, &log->l_opstate)) { xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES, "%s: cycle - 1 != tail_cycle", __func__); } if (space > BBTOB(tail_blocks) && !test_and_set_bit(XLOG_TAIL_WARN, &log->l_opstate)) { xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES, "%s: space > BBTOB(tail_blocks)", __func__); } } } /* check if it will fit */ STATIC void xlog_verify_tail_lsn( struct xlog *log, struct xlog_in_core *iclog) { xfs_lsn_t tail_lsn = be64_to_cpu(iclog->ic_header.h_tail_lsn); int blocks; if (CYCLE_LSN(tail_lsn) == log->l_prev_cycle) { blocks = log->l_logBBsize - (log->l_prev_block - BLOCK_LSN(tail_lsn)); if (blocks < BTOBB(iclog->ic_offset)+BTOBB(log->l_iclog_hsize)) xfs_emerg(log->l_mp, "%s: ran out of log space", __func__); } else { ASSERT(CYCLE_LSN(tail_lsn)+1 == log->l_prev_cycle); if (BLOCK_LSN(tail_lsn) == log->l_prev_block) xfs_emerg(log->l_mp, "%s: tail wrapped", __func__); blocks = BLOCK_LSN(tail_lsn) - log->l_prev_block; if (blocks < BTOBB(iclog->ic_offset) + 1) xfs_emerg(log->l_mp, "%s: ran out of log space", __func__); } } /* * Perform a number of checks on the iclog before writing to disk. * * 1. Make sure the iclogs are still circular * 2. Make sure we have a good magic number * 3. Make sure we don't have magic numbers in the data * 4. Check fields of each log operation header for: * A. Valid client identifier * B. tid ptr value falls in valid ptr space (user space code) * C. Length in log record header is correct according to the * individual operation headers within record. * 5. When a bwrite will occur within 5 blocks of the front of the physical * log, check the preceding blocks of the physical log to make sure all * the cycle numbers agree with the current cycle number. */ STATIC void xlog_verify_iclog( struct xlog *log, struct xlog_in_core *iclog, int count) { xlog_op_header_t *ophead; xlog_in_core_t *icptr; xlog_in_core_2_t *xhdr; void *base_ptr, *ptr, *p; ptrdiff_t field_offset; uint8_t clientid; int len, i, j, k, op_len; int idx; /* check validity of iclog pointers */ spin_lock(&log->l_icloglock); icptr = log->l_iclog; for (i = 0; i < log->l_iclog_bufs; i++, icptr = icptr->ic_next) ASSERT(icptr); if (icptr != log->l_iclog) xfs_emerg(log->l_mp, "%s: corrupt iclog ring", __func__); spin_unlock(&log->l_icloglock); /* check log magic numbers */ if (iclog->ic_header.h_magicno != cpu_to_be32(XLOG_HEADER_MAGIC_NUM)) xfs_emerg(log->l_mp, "%s: invalid magic num", __func__); base_ptr = ptr = &iclog->ic_header; p = &iclog->ic_header; for (ptr += BBSIZE; ptr < base_ptr + count; ptr += BBSIZE) { if (*(__be32 *)ptr == cpu_to_be32(XLOG_HEADER_MAGIC_NUM)) xfs_emerg(log->l_mp, "%s: unexpected magic num", __func__); } /* check fields */ len = be32_to_cpu(iclog->ic_header.h_num_logops); base_ptr = ptr = iclog->ic_datap; ophead = ptr; xhdr = iclog->ic_data; for (i = 0; i < len; i++) { ophead = ptr; /* clientid is only 1 byte */ p = &ophead->oh_clientid; field_offset = p - base_ptr; if (field_offset & 0x1ff) { clientid = ophead->oh_clientid; } else { idx = BTOBBT((void *)&ophead->oh_clientid - iclog->ic_datap); if (idx >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) { j = idx / (XLOG_HEADER_CYCLE_SIZE / BBSIZE); k = idx % (XLOG_HEADER_CYCLE_SIZE / BBSIZE); clientid = xlog_get_client_id( xhdr[j].hic_xheader.xh_cycle_data[k]); } else { clientid = xlog_get_client_id( iclog->ic_header.h_cycle_data[idx]); } } if (clientid != XFS_TRANSACTION && clientid != XFS_LOG) { xfs_warn(log->l_mp, "%s: op %d invalid clientid %d op "PTR_FMT" offset 0x%lx", __func__, i, clientid, ophead, (unsigned long)field_offset); } /* check length */ p = &ophead->oh_len; field_offset = p - base_ptr; if (field_offset & 0x1ff) { op_len = be32_to_cpu(ophead->oh_len); } else { idx = BTOBBT((void *)&ophead->oh_len - iclog->ic_datap); if (idx >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) { j = idx / (XLOG_HEADER_CYCLE_SIZE / BBSIZE); k = idx % (XLOG_HEADER_CYCLE_SIZE / BBSIZE); op_len = be32_to_cpu(xhdr[j].hic_xheader.xh_cycle_data[k]); } else { op_len = be32_to_cpu(iclog->ic_header.h_cycle_data[idx]); } } ptr += sizeof(xlog_op_header_t) + op_len; } } #endif /* * Perform a forced shutdown on the log. * * This can be called from low level log code to trigger a shutdown, or from the * high level mount shutdown code when the mount shuts down. * * Our main objectives here are to make sure that: * a. if the shutdown was not due to a log IO error, flush the logs to * disk. Anything modified after this is ignored. * b. the log gets atomically marked 'XLOG_IO_ERROR' for all interested * parties to find out. Nothing new gets queued after this is done. * c. Tasks sleeping on log reservations, pinned objects and * other resources get woken up. * d. The mount is also marked as shut down so that log triggered shutdowns * still behave the same as if they called xfs_forced_shutdown(). * * Return true if the shutdown cause was a log IO error and we actually shut the * log down. */ bool xlog_force_shutdown( struct xlog *log, uint32_t shutdown_flags) { bool log_error = (shutdown_flags & SHUTDOWN_LOG_IO_ERROR); if (!log) return false; /* * Flush all the completed transactions to disk before marking the log * being shut down. We need to do this first as shutting down the log * before the force will prevent the log force from flushing the iclogs * to disk. * * When we are in recovery, there are no transactions to flush, and * we don't want to touch the log because we don't want to perturb the * current head/tail for future recovery attempts. Hence we need to * avoid a log force in this case. * * If we are shutting down due to a log IO error, then we must avoid * trying to write the log as that may just result in more IO errors and * an endless shutdown/force loop. */ if (!log_error && !xlog_in_recovery(log)) xfs_log_force(log->l_mp, XFS_LOG_SYNC); /* * Atomically set the shutdown state. If the shutdown state is already * set, there someone else is performing the shutdown and so we are done * here. This should never happen because we should only ever get called * once by the first shutdown caller. * * Much of the log state machine transitions assume that shutdown state * cannot change once they hold the log->l_icloglock. Hence we need to * hold that lock here, even though we use the atomic test_and_set_bit() * operation to set the shutdown state. */ spin_lock(&log->l_icloglock); if (test_and_set_bit(XLOG_IO_ERROR, &log->l_opstate)) { spin_unlock(&log->l_icloglock); return false; } spin_unlock(&log->l_icloglock); /* * If this log shutdown also sets the mount shutdown state, issue a * shutdown warning message. */ if (!test_and_set_bit(XFS_OPSTATE_SHUTDOWN, &log->l_mp->m_opstate)) { xfs_alert_tag(log->l_mp, XFS_PTAG_SHUTDOWN_LOGERROR, "Filesystem has been shut down due to log error (0x%x).", shutdown_flags); xfs_alert(log->l_mp, "Please unmount the filesystem and rectify the problem(s)."); if (xfs_error_level >= XFS_ERRLEVEL_HIGH) xfs_stack_trace(); } /* * We don't want anybody waiting for log reservations after this. That * means we have to wake up everybody queued up on reserveq as well as * writeq. In addition, we make sure in xlog_{re}grant_log_space that * we don't enqueue anything once the SHUTDOWN flag is set, and this * action is protected by the grant locks. */ xlog_grant_head_wake_all(&log->l_reserve_head); xlog_grant_head_wake_all(&log->l_write_head); /* * Wake up everybody waiting on xfs_log_force. Wake the CIL push first * as if the log writes were completed. The abort handling in the log * item committed callback functions will do this again under lock to * avoid races. */ spin_lock(&log->l_cilp->xc_push_lock); wake_up_all(&log->l_cilp->xc_start_wait); wake_up_all(&log->l_cilp->xc_commit_wait); spin_unlock(&log->l_cilp->xc_push_lock); spin_lock(&log->l_icloglock); xlog_state_shutdown_callbacks(log); spin_unlock(&log->l_icloglock); wake_up_var(&log->l_opstate); return log_error; } STATIC int xlog_iclogs_empty( struct xlog *log) { xlog_in_core_t *iclog; iclog = log->l_iclog; do { /* endianness does not matter here, zero is zero in * any language. */ if (iclog->ic_header.h_num_logops) return 0; iclog = iclog->ic_next; } while (iclog != log->l_iclog); return 1; } /* * Verify that an LSN stamped into a piece of metadata is valid. This is * intended for use in read verifiers on v5 superblocks. */ bool xfs_log_check_lsn( struct xfs_mount *mp, xfs_lsn_t lsn) { struct xlog *log = mp->m_log; bool valid; /* * norecovery mode skips mount-time log processing and unconditionally * resets the in-core LSN. We can't validate in this mode, but * modifications are not allowed anyways so just return true. */ if (xfs_has_norecovery(mp)) return true; /* * Some metadata LSNs are initialized to NULL (e.g., the agfl). This is * handled by recovery and thus safe to ignore here. */ if (lsn == NULLCOMMITLSN) return true; valid = xlog_valid_lsn(mp->m_log, lsn); /* warn the user about what's gone wrong before verifier failure */ if (!valid) { spin_lock(&log->l_icloglock); xfs_warn(mp, "Corruption warning: Metadata has LSN (%d:%d) ahead of current LSN (%d:%d). " "Please unmount and run xfs_repair (>= v4.3) to resolve.", CYCLE_LSN(lsn), BLOCK_LSN(lsn), log->l_curr_cycle, log->l_curr_block); spin_unlock(&log->l_icloglock); } return valid; } /* * Notify the log that we're about to start using a feature that is protected * by a log incompat feature flag. This will prevent log covering from * clearing those flags. */ void xlog_use_incompat_feat( struct xlog *log) { down_read(&log->l_incompat_users); } /* Notify the log that we've finished using log incompat features. */ void xlog_drop_incompat_feat( struct xlog *log) { up_read(&log->l_incompat_users); }
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