/* * Copyright (c) 2000-2005 Silicon Graphics, Inc. * All Rights Reserved. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation. * * This program is distributed in the hope that it would be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #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_error.h" #include "xfs_trans.h" #include "xfs_trans_priv.h" #include "xfs_log.h" #include "xfs_log_priv.h" #include "xfs_log_recover.h" #include "xfs_inode.h" #include "xfs_trace.h" #include "xfs_fsops.h" #include "xfs_cksum.h" #include "xfs_sysfs.h" #include "xfs_sb.h" kmem_zone_t *xfs_log_ticket_zone; /* Local miscellaneous function prototypes */ STATIC int xlog_commit_record( struct xlog *log, struct xlog_ticket *ticket, struct xlog_in_core **iclog, xfs_lsn_t *commitlsnp); 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 int xlog_sync( struct xlog *log, struct xlog_in_core *iclog); STATIC void xlog_dealloc_log( struct xlog *log); /* local state machine functions */ STATIC void xlog_state_done_syncing(xlog_in_core_t *iclog, int); STATIC void xlog_state_do_callback( struct xlog *log, int aborted, struct xlog_in_core *iclog); STATIC int xlog_state_get_iclog_space( struct xlog *log, int len, struct xlog_in_core **iclog, struct xlog_ticket *ticket, int *continued_write, int *logoffsetp); STATIC int xlog_state_release_iclog( struct xlog *log, struct xlog_in_core *iclog); STATIC void xlog_state_switch_iclogs( struct xlog *log, struct xlog_in_core *iclog, int eventual_size); STATIC void xlog_state_want_sync( struct xlog *log, struct xlog_in_core *iclog); STATIC void xlog_grant_push_ail( struct xlog *log, int need_bytes); STATIC void xlog_regrant_reserve_log_space( struct xlog *log, struct xlog_ticket *ticket); STATIC void xlog_ungrant_log_space( struct xlog *log, struct xlog_ticket *ticket); #if defined(DEBUG) STATIC void xlog_verify_dest_ptr( struct xlog *log, void *ptr); STATIC void xlog_verify_grant_tail( struct xlog *log); STATIC void xlog_verify_iclog( struct xlog *log, struct xlog_in_core *iclog, int count, bool syncing); STATIC void xlog_verify_tail_lsn( struct xlog *log, struct xlog_in_core *iclog, xfs_lsn_t tail_lsn); #else #define xlog_verify_dest_ptr(a,b) #define xlog_verify_grant_tail(a) #define xlog_verify_iclog(a,b,c,d) #define xlog_verify_tail_lsn(a,b,c) #endif STATIC int xlog_iclogs_empty( struct xlog *log); 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; } else { if (tic->t_flags & XLOG_TIC_PERM_RESERV) return tic->t_unit_res * tic->t_cnt; else 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; list_for_each_entry(tic, &head->waiters, t_queue) { need_bytes = xlog_ticket_reservation(log, head, tic); if (*free_bytes < need_bytes) return false; *free_bytes -= need_bytes; trace_xfs_log_grant_wake_up(log, tic); wake_up_process(tic->t_task); } 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_FORCED_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_FORCED_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(!(log->l_flags & XLOG_ACTIVE_RECOVERY)); /* * 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; } static void xlog_tic_reset_res(xlog_ticket_t *tic) { tic->t_res_num = 0; tic->t_res_arr_sum = 0; tic->t_res_num_ophdrs = 0; } static void xlog_tic_add_region(xlog_ticket_t *tic, uint len, uint type) { if (tic->t_res_num == XLOG_TIC_LEN_MAX) { /* add to overflow and start again */ tic->t_res_o_flow += tic->t_res_arr_sum; tic->t_res_num = 0; tic->t_res_arr_sum = 0; } tic->t_res_arr[tic->t_res_num].r_len = len; tic->t_res_arr[tic->t_res_num].r_type = type; tic->t_res_arr_sum += len; tic->t_res_num++; } /* * 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_FORCED_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; xlog_tic_reset_res(tic); 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 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, __uint8_t client, bool permanent, uint t_type) { struct xlog *log = mp->m_log; struct xlog_ticket *tic; int need_bytes; int error = 0; ASSERT(client == XFS_TRANSACTION || client == XFS_LOG); if (XLOG_FORCED_SHUTDOWN(log)) return -EIO; XFS_STATS_INC(mp, xs_try_logspace); ASSERT(*ticp == NULL); tic = xlog_ticket_alloc(log, unit_bytes, cnt, client, permanent, KM_SLEEP | KM_MAYFAIL); if (!tic) return -ENOMEM; tic->t_trans_type = t_type; *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; } /* * NOTES: * * 1. currblock field gets updated at startup and after in-core logs * marked as with WANT_SYNC. */ /* * This routine is called when a user of a log manager ticket is done with * the reservation. If the ticket was ever used, then a commit record for * the associated transaction is written out as a log operation header with * no data. The flag XLOG_TIC_INITED is set when the first write occurs with * a given ticket. If the ticket was one with a permanent reservation, then * a few operations are done differently. Permanent reservation tickets by * default don't release the reservation. They just commit the current * transaction with the belief that the reservation is still needed. A flag * must be passed in before permanent reservations are actually released. * When these type of tickets are not released, they need to be set into * the inited state again. By doing this, a start record will be written * out when the next write occurs. */ xfs_lsn_t xfs_log_done( struct xfs_mount *mp, struct xlog_ticket *ticket, struct xlog_in_core **iclog, bool regrant) { struct xlog *log = mp->m_log; xfs_lsn_t lsn = 0; if (XLOG_FORCED_SHUTDOWN(log) || /* * If nothing was ever written, don't write out commit record. * If we get an error, just continue and give back the log ticket. */ (((ticket->t_flags & XLOG_TIC_INITED) == 0) && (xlog_commit_record(log, ticket, iclog, &lsn)))) { lsn = (xfs_lsn_t) -1; regrant = false; } if (!regrant) { trace_xfs_log_done_nonperm(log, ticket); /* * Release ticket if not permanent reservation or a specific * request has been made to release a permanent reservation. */ xlog_ungrant_log_space(log, ticket); } else { trace_xfs_log_done_perm(log, ticket); xlog_regrant_reserve_log_space(log, ticket); /* If this ticket was a permanent reservation and we aren't * trying to release it, reset the inited flags; so next time * we write, a start record will be written out. */ ticket->t_flags |= XLOG_TIC_INITED; } xfs_log_ticket_put(ticket); return lsn; } /* * Attaches a new iclog I/O completion callback routine during * transaction commit. If the log is in error state, a non-zero * return code is handed back and the caller is responsible for * executing the callback at an appropriate time. */ int xfs_log_notify( struct xfs_mount *mp, struct xlog_in_core *iclog, xfs_log_callback_t *cb) { int abortflg; spin_lock(&iclog->ic_callback_lock); abortflg = (iclog->ic_state & XLOG_STATE_IOERROR); if (!abortflg) { ASSERT_ALWAYS((iclog->ic_state == XLOG_STATE_ACTIVE) || (iclog->ic_state == XLOG_STATE_WANT_SYNC)); cb->cb_next = NULL; *(iclog->ic_callback_tail) = cb; iclog->ic_callback_tail = &(cb->cb_next); } spin_unlock(&iclog->ic_callback_lock); return abortflg; } int xfs_log_release_iclog( struct xfs_mount *mp, struct xlog_in_core *iclog) { if (xlog_state_release_iclog(mp->m_log, iclog)) { xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR); return -EIO; } 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, xfs_buftarg_t *log_target, xfs_daddr_t blk_offset, int num_bblks) { int error = 0; int min_logfsbs; if (!(mp->m_flags & XFS_MOUNT_NORECOVERY)) { xfs_notice(mp, "Mounting V%d Filesystem", XFS_SB_VERSION_NUM(&mp->m_sb)); } else { xfs_notice(mp, "Mounting V%d filesystem in no-recovery mode. Filesystem will be inconsistent.", XFS_SB_VERSION_NUM(&mp->m_sb)); ASSERT(mp->m_flags & XFS_MOUNT_RDONLY); } mp->m_log = xlog_alloc_log(mp, log_target, blk_offset, num_bblks); if (IS_ERR(mp->m_log)) { error = PTR_ERR(mp->m_log); goto out; } /* * Validate the given log space and drop a critical message via syslog * if the log size is too small that would lead to some unexpected * situations in transaction log space reservation stage. * * Note: 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 CRC 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); error = -EINVAL; } else if (mp->m_sb.sb_logblocks > XFS_MAX_LOG_BLOCKS) { xfs_warn(mp, "Log size %d blocks too large, maximum size is %lld blocks", mp->m_sb.sb_logblocks, XFS_MAX_LOG_BLOCKS); error = -EINVAL; } else if (XFS_FSB_TO_B(mp, mp->m_sb.sb_logblocks) > XFS_MAX_LOG_BYTES) { xfs_warn(mp, "log size %lld bytes too large, maximum size is %lld bytes", XFS_FSB_TO_B(mp, mp->m_sb.sb_logblocks), XFS_MAX_LOG_BYTES); error = -EINVAL; } if (error) { if (xfs_sb_version_hascrc(&mp->m_sb)) { xfs_crit(mp, "AAIEEE! Log failed size checks. Abort!"); ASSERT(0); 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; } mp->m_log->l_ailp = mp->m_ail; /* * skip log recovery on a norecovery mount. pretend it all * just worked. */ if (!(mp->m_flags & XFS_MOUNT_NORECOVERY)) { int readonly = (mp->m_flags & XFS_MOUNT_RDONLY); if (readonly) mp->m_flags &= ~XFS_MOUNT_RDONLY; error = xlog_recover(mp->m_log); if (readonly) mp->m_flags |= XFS_MOUNT_RDONLY; if (error) { xfs_warn(mp, "log mount/recovery failed: error %d", error); xlog_recover_cancel(mp->m_log); goto out_destroy_ail; } } error = xfs_sysfs_init(&mp->m_log->l_kobj, &xfs_log_ktype, &mp->m_kobj, "log"); if (error) goto out_destroy_ail; /* Normal transactions can now occur */ mp->m_log->l_flags &= ~XLOG_ACTIVE_RECOVERY; /* * 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(mp->m_log); return 0; out_destroy_ail: xfs_trans_ail_destroy(mp); out_free_log: xlog_dealloc_log(mp->m_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) { int error = 0; if (mp->m_flags & XFS_MOUNT_NORECOVERY) { ASSERT(mp->m_flags & XFS_MOUNT_RDONLY); return 0; } error = xlog_recover_finish(mp->m_log); if (!error) xfs_log_work_queue(mp); return error; } /* * The mount has failed. Cancel the recovery if it hasn't completed and destroy * the log. */ int xfs_log_mount_cancel( struct xfs_mount *mp) { int error; error = xlog_recover_cancel(mp->m_log); xfs_log_unmount(mp); return error; } /* * Final log writes as part of unmount. * * Mark the filesystem clean as unmount happens. Note that during relocation * this routine needs to be executed as part of source-bag while the * deallocation must not be done until source-end. */ /* * 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. */ int xfs_log_unmount_write(xfs_mount_t *mp) { struct xlog *log = mp->m_log; xlog_in_core_t *iclog; #ifdef DEBUG xlog_in_core_t *first_iclog; #endif xlog_ticket_t *tic = NULL; xfs_lsn_t lsn; int error; /* * Don't write out unmount record on read-only mounts. * Or, if we are doing a forced umount (typically because of IO errors). */ if (mp->m_flags & XFS_MOUNT_RDONLY) return 0; error = _xfs_log_force(mp, XFS_LOG_SYNC, NULL); ASSERT(error || !(XLOG_FORCED_SHUTDOWN(log))); #ifdef DEBUG first_iclog = iclog = log->l_iclog; do { if (!(iclog->ic_state & XLOG_STATE_IOERROR)) { ASSERT(iclog->ic_state & XLOG_STATE_ACTIVE); ASSERT(iclog->ic_offset == 0); } iclog = iclog->ic_next; } while (iclog != first_iclog); #endif if (! (XLOG_FORCED_SHUTDOWN(log))) { error = xfs_log_reserve(mp, 600, 1, &tic, XFS_LOG, 0, XLOG_UNMOUNT_REC_TYPE); if (!error) { /* the data section must be 32 bit size aligned */ struct { __uint16_t magic; __uint16_t pad1; __uint32_t pad2; /* may as well make it 64 bits */ } magic = { .magic = XLOG_UNMOUNT_TYPE, }; struct xfs_log_iovec reg = { .i_addr = &magic, .i_len = sizeof(magic), .i_type = XLOG_REG_TYPE_UNMOUNT, }; struct xfs_log_vec vec = { .lv_niovecs = 1, .lv_iovecp = ®, }; /* remove inited flag, and account for space used */ tic->t_flags = 0; tic->t_curr_res -= sizeof(magic); error = xlog_write(log, &vec, tic, &lsn, NULL, XLOG_UNMOUNT_TRANS); /* * At this point, we're umounting anyway, * so there's no point in transitioning log state * to IOERROR. Just continue... */ } if (error) xfs_alert(mp, "%s: unmount record failed", __func__); spin_lock(&log->l_icloglock); iclog = log->l_iclog; atomic_inc(&iclog->ic_refcnt); xlog_state_want_sync(log, iclog); spin_unlock(&log->l_icloglock); error = xlog_state_release_iclog(log, iclog); spin_lock(&log->l_icloglock); if (!(iclog->ic_state == XLOG_STATE_ACTIVE || iclog->ic_state == XLOG_STATE_DIRTY)) { if (!XLOG_FORCED_SHUTDOWN(log)) { xlog_wait(&iclog->ic_force_wait, &log->l_icloglock); } else { spin_unlock(&log->l_icloglock); } } else { spin_unlock(&log->l_icloglock); } if (tic) { trace_xfs_log_umount_write(log, tic); xlog_ungrant_log_space(log, tic); xfs_log_ticket_put(tic); } } else { /* * We're already in forced_shutdown mode, couldn't * even attempt to write out the unmount transaction. * * Go through the motions of sync'ing and releasing * the iclog, even though no I/O will actually happen, * we need to wait for other log I/Os that may already * be in progress. Do this as a separate section of * code so we'll know if we ever get stuck here that * we're in this odd situation of trying to unmount * a file system that went into forced_shutdown as * the result of an unmount.. */ spin_lock(&log->l_icloglock); iclog = log->l_iclog; atomic_inc(&iclog->ic_refcnt); xlog_state_want_sync(log, iclog); spin_unlock(&log->l_icloglock); error = xlog_state_release_iclog(log, iclog); spin_lock(&log->l_icloglock); if ( ! ( iclog->ic_state == XLOG_STATE_ACTIVE || iclog->ic_state == XLOG_STATE_DIRTY || iclog->ic_state == XLOG_STATE_IOERROR) ) { xlog_wait(&iclog->ic_force_wait, &log->l_icloglock); } else { spin_unlock(&log->l_icloglock); } } return error; } /* xfs_log_unmount_write */ /* * 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 write the unmount * record. */ void xfs_log_quiesce( struct xfs_mount *mp) { 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_wait_buftarg() 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_wait_buftarg(mp->m_ddev_targp); xfs_buf_lock(mp->m_sb_bp); xfs_buf_unlock(mp->m_sb_bp); 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_quiesce(mp); 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_mountp = mp; 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); } /* * 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_FORCED_SHUTDOWN(log)) return; if (!list_empty_careful(&log->l_write_head.waiters)) { ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY)); 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(!(log->l_flags & XLOG_ACTIVE_RECOVERY)); 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. */ int xfs_log_need_covered(xfs_mount_t *mp) { struct xlog *log = mp->m_log; int needed = 0; if (!xfs_fs_writable(mp, SB_FREEZE_WRITE)) return 0; if (!xlog_cil_empty(log)) return 0; 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 = 1; 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 = 1; break; } spin_unlock(&log->l_icloglock); return needed; } /* * 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->xa_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->xa_lock); tail_lsn = xlog_assign_tail_lsn_locked(mp); spin_unlock(&mp->m_ail->xa_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 * * This code also handles the case where the reservation head is behind * the tail. The details of this case are described below, but the end * result is that we return the size of the log as the amount of space left. */ STATIC int xlog_space_left( struct xlog *log, atomic64_t *head) { int free_bytes; 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) free_bytes = log->l_logsize - (head_bytes - tail_bytes); else if (tail_cycle + 1 < head_cycle) return 0; else if (tail_cycle < head_cycle) { ASSERT(tail_cycle == (head_cycle - 1)); free_bytes = tail_bytes - head_bytes; } else { /* * 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); free_bytes = log->l_logsize; } return free_bytes; } /* * Log function which is called when an io completes. * * The log manager needs its own routine, in order to control what * happens with the buffer after the write completes. */ void xlog_iodone(xfs_buf_t *bp) { struct xlog_in_core *iclog = bp->b_fspriv; struct xlog *l = iclog->ic_log; int aborted = 0; /* * Race to shutdown the filesystem if we see an error or the iclog is in * IOABORT state. The IOABORT state is only set in DEBUG mode to inject * CRC errors into log recovery. */ if (XFS_TEST_ERROR(bp->b_error, l->l_mp, XFS_ERRTAG_IODONE_IOERR, XFS_RANDOM_IODONE_IOERR) || iclog->ic_state & XLOG_STATE_IOABORT) { if (iclog->ic_state & XLOG_STATE_IOABORT) iclog->ic_state &= ~XLOG_STATE_IOABORT; xfs_buf_ioerror_alert(bp, __func__); xfs_buf_stale(bp); xfs_force_shutdown(l->l_mp, SHUTDOWN_LOG_IO_ERROR); /* * This flag will be propagated to the trans-committed * callback routines to let them know that the log-commit * didn't succeed. */ aborted = XFS_LI_ABORTED; } else if (iclog->ic_state & XLOG_STATE_IOERROR) { aborted = XFS_LI_ABORTED; } /* log I/O is always issued ASYNC */ ASSERT(bp->b_flags & XBF_ASYNC); xlog_state_done_syncing(iclog, aborted); /* * drop the buffer lock now that we are done. Nothing references * the buffer after this, so an unmount waiting on this lock can now * tear it down safely. As such, it is unsafe to reference the buffer * (bp) after the unlock as we could race with it being freed. */ xfs_buf_unlock(bp); } /* * 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) { int size; int xhdrs; if (mp->m_logbufs <= 0) log->l_iclog_bufs = XLOG_MAX_ICLOGS; else log->l_iclog_bufs = mp->m_logbufs; /* * Buffer size passed in from mount system call. */ if (mp->m_logbsize > 0) { size = log->l_iclog_size = mp->m_logbsize; log->l_iclog_size_log = 0; while (size != 1) { log->l_iclog_size_log++; size >>= 1; } if (xfs_sb_version_haslogv2(&mp->m_sb)) { /* # headers = size / 32k * one header holds cycles from 32k of data */ xhdrs = mp->m_logbsize / XLOG_HEADER_CYCLE_SIZE; if (mp->m_logbsize % XLOG_HEADER_CYCLE_SIZE) xhdrs++; log->l_iclog_hsize = xhdrs << BBSHIFT; log->l_iclog_heads = xhdrs; } else { ASSERT(mp->m_logbsize <= XLOG_BIG_RECORD_BSIZE); log->l_iclog_hsize = BBSIZE; log->l_iclog_heads = 1; } goto done; } /* All machines use 32kB buffers by default. */ log->l_iclog_size = XLOG_BIG_RECORD_BSIZE; log->l_iclog_size_log = XLOG_BIG_RECORD_BSHIFT; /* the default log size is 16k or 32k which is one header sector */ log->l_iclog_hsize = BBSIZE; log->l_iclog_heads = 1; done: /* are we being asked to make the sizes selected above visible? */ if (mp->m_logbufs == 0) mp->m_logbufs = log->l_iclog_bufs; if (mp->m_logbsize == 0) mp->m_logbsize = log->l_iclog_size; } /* xlog_get_iclog_buffer_size */ void xfs_log_work_queue( struct xfs_mount *mp) { queue_delayed_work(mp->m_log_workqueue, &mp->m_log->l_work, msecs_to_jiffies(xfs_syncd_centisecs * 10)); } /* * 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. */ 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_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. */ 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; xfs_buf_t *bp; int i; int error = -ENOMEM; uint log2_size = 0; log = kmem_zalloc(sizeof(struct xlog), KM_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; log->l_flags |= XLOG_ACTIVE_RECOVERY; INIT_DELAYED_WORK(&log->l_work, xfs_log_worker); 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 */ xlog_grant_head_init(&log->l_reserve_head); xlog_grant_head_init(&log->l_write_head); error = -EFSCORRUPTED; if (xfs_sb_version_hassector(&mp->m_sb)) { 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_sb_version_haslogv2(&mp->m_sb)) { xfs_warn(mp, "log sector size (0x%x) invalid for configuration.", log2_size); goto out_free_log; } } log->l_sectBBsize = 1 << log2_size; xlog_get_iclog_buffer_size(mp, log); /* * Use a NULL block for the extra log buffer used during splits so that * it will trigger errors if we ever try to do IO on it without first * having set it up properly. */ error = -ENOMEM; bp = xfs_buf_alloc(mp->m_logdev_targp, XFS_BUF_DADDR_NULL, BTOBB(log->l_iclog_size), 0); if (!bp) goto out_free_log; /* * The iclogbuf buffer locks are held over IO but we are not going to do * IO yet. Hence unlock the buffer so that the log IO path can grab it * when appropriately. */ ASSERT(xfs_buf_islocked(bp)); xfs_buf_unlock(bp); /* use high priority wq for log I/O completion */ bp->b_ioend_wq = mp->m_log_workqueue; bp->b_iodone = xlog_iodone; log->l_xbuf = bp; 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++) { *iclogp = kmem_zalloc(sizeof(xlog_in_core_t), KM_MAYFAIL); if (!*iclogp) goto out_free_iclog; iclog = *iclogp; iclog->ic_prev = prev_iclog; prev_iclog = iclog; bp = xfs_buf_get_uncached(mp->m_logdev_targp, BTOBB(log->l_iclog_size), 0); if (!bp) goto out_free_iclog; ASSERT(xfs_buf_islocked(bp)); xfs_buf_unlock(bp); /* use high priority wq for log I/O completion */ bp->b_ioend_wq = mp->m_log_workqueue; bp->b_iodone = xlog_iodone; iclog->ic_bp = bp; iclog->ic_data = bp->b_addr; #ifdef DEBUG log->l_iclog_bak[i] = &iclog->ic_header; #endif 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_sb_version_haslogv2(&log->l_mp->m_sb) ? 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 = BBTOB(bp->b_length) - log->l_iclog_hsize; iclog->ic_state = XLOG_STATE_ACTIVE; iclog->ic_log = log; atomic_set(&iclog->ic_refcnt, 0); spin_lock_init(&iclog->ic_callback_lock); iclog->ic_callback_tail = &(iclog->ic_callback); iclog->ic_datap = (char *)iclog->ic_data + log->l_iclog_hsize; init_waitqueue_head(&iclog->ic_force_wait); init_waitqueue_head(&iclog->ic_write_wait); iclogp = &iclog->ic_next; } *iclogp = log->l_iclog; /* complete ring */ log->l_iclog->ic_prev = prev_iclog; /* re-write 1st prev ptr */ error = xlog_cil_init(log); if (error) goto out_free_iclog; return log; out_free_iclog: for (iclog = log->l_iclog; iclog; iclog = prev_iclog) { prev_iclog = iclog->ic_next; if (iclog->ic_bp) xfs_buf_free(iclog->ic_bp); kmem_free(iclog); } spinlock_destroy(&log->l_icloglock); xfs_buf_free(log->l_xbuf); out_free_log: kmem_free(log); out: return ERR_PTR(error); } /* xlog_alloc_log */ /* * Write out the commit record of a transaction associated with the given * ticket. Return the lsn of the commit record. */ STATIC int xlog_commit_record( struct xlog *log, struct xlog_ticket *ticket, struct xlog_in_core **iclog, xfs_lsn_t *commitlsnp) { struct xfs_mount *mp = log->l_mp; int error; struct xfs_log_iovec reg = { .i_addr = NULL, .i_len = 0, .i_type = XLOG_REG_TYPE_COMMIT, }; struct xfs_log_vec vec = { .lv_niovecs = 1, .lv_iovecp = ®, }; ASSERT_ALWAYS(iclog); error = xlog_write(log, &vec, ticket, commitlsnp, iclog, XLOG_COMMIT_TRANS); if (error) xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR); return error; } /* * Push on the buffer cache code if we ever use more than 75% of the on-disk * log space. This code pushes on the lsn which would supposedly free up * the 25% which we want to leave free. 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 = 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; 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; /* * 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. */ if (!XLOG_FORCED_SHUTDOWN(log)) 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_sb_version_haslogv2(&log->l_mp->m_sb)) { 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((char *)rhead, sizeof(struct xlog_rec_header), offsetof(struct xlog_rec_header, h_crc)); /* ... then for additional cycle data for v2 logs ... */ if (xfs_sb_version_haslogv2(&log->l_mp->m_sb)) { union xlog_in_core2 *xhdr = (union xlog_in_core2 *)rhead; int i; int xheads; xheads = size / XLOG_HEADER_CYCLE_SIZE; if (size % XLOG_HEADER_CYCLE_SIZE) xheads++; 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); } /* * The bdstrat callback function for log bufs. This gives us a central * place to trap bufs in case we get hit by a log I/O error and need to * shutdown. Actually, in practice, even when we didn't get a log error, * we transition the iclogs to IOERROR state *after* flushing all existing * iclogs to disk. This is because we don't want anymore new transactions to be * started or completed afterwards. * * We lock the iclogbufs here so that we can serialise against IO 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 acheive that. */ STATIC int xlog_bdstrat( struct xfs_buf *bp) { struct xlog_in_core *iclog = bp->b_fspriv; xfs_buf_lock(bp); if (iclog->ic_state & XLOG_STATE_IOERROR) { xfs_buf_ioerror(bp, -EIO); xfs_buf_stale(bp); xfs_buf_ioend(bp); /* * 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. Similarly, IO completion will unlock the * buffer, so we don't do it here. */ return 0; } xfs_buf_submit(bp); return 0; } /* * 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 * log_sync (and then only bwrite()) know about the fact that the log may * not start with block zero on a given device. The log block start offset * is added immediately before calling bwrite(). */ STATIC int xlog_sync( struct xlog *log, struct xlog_in_core *iclog) { xfs_buf_t *bp; int i; uint count; /* byte count of bwrite */ uint count_init; /* initial count before roundup */ int roundoff; /* roundoff to BB or stripe */ int split = 0; /* split write into two regions */ int error; int v2 = xfs_sb_version_haslogv2(&log->l_mp->m_sb); int size; XFS_STATS_INC(log->l_mp, xs_log_writes); ASSERT(atomic_read(&iclog->ic_refcnt) == 0); /* Add for LR header */ count_init = log->l_iclog_hsize + iclog->ic_offset; /* Round out the log write size */ if (v2 && log->l_mp->m_sb.sb_logsunit > 1) { /* we have a v2 stripe unit to use */ count = XLOG_LSUNITTOB(log, XLOG_BTOLSUNIT(log, count_init)); } else { count = BBTOB(BTOBB(count_init)); } roundoff = count - count_init; ASSERT(roundoff >= 0); ASSERT((v2 && log->l_mp->m_sb.sb_logsunit > 1 && roundoff < log->l_mp->m_sb.sb_logsunit) || (log->l_mp->m_sb.sb_logsunit <= 1 && roundoff < BBTOB(1))); /* move grant heads by roundoff in sync */ 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 (v2) size += roundoff; iclog->ic_header.h_len = cpu_to_be32(size); bp = iclog->ic_bp; XFS_BUF_SET_ADDR(bp, BLOCK_LSN(be64_to_cpu(iclog->ic_header.h_lsn))); XFS_STATS_ADD(log->l_mp, xs_log_blocks, BTOBB(count)); /* Do we need to split this write into 2 parts? */ if (XFS_BUF_ADDR(bp) + BTOBB(count) > log->l_logBBsize) { char *dptr; split = count - (BBTOB(log->l_logBBsize - XFS_BUF_ADDR(bp))); count = BBTOB(log->l_logBBsize - XFS_BUF_ADDR(bp)); iclog->ic_bwritecnt = 2; /* * Bump the cycle numbers at the start of each block in the * part of the iclog that ends up in the buffer that gets * written to the start of the log. * * Watch out for the header magic number case, though. */ dptr = (char *)&iclog->ic_header + count; for (i = 0; i < split; i += BBSIZE) { __uint32_t cycle = be32_to_cpu(*(__be32 *)dptr); if (++cycle == XLOG_HEADER_MAGIC_NUM) cycle++; *(__be32 *)dptr = cpu_to_be32(cycle); dptr += BBSIZE; } } else { iclog->ic_bwritecnt = 1; } /* calculcate the checksum */ iclog->ic_header.h_crc = xlog_cksum(log, &iclog->ic_header, iclog->ic_datap, size); #ifdef DEBUG /* * 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. */ if (log->l_badcrc_factor && (prandom_u32() % log->l_badcrc_factor == 0)) { iclog->ic_header.h_crc &= 0xAAAAAAAA; iclog->ic_state |= XLOG_STATE_IOABORT; xfs_warn(log->l_mp, "Intentionally corrupted log record at LSN 0x%llx. Shutdown imminent.", be64_to_cpu(iclog->ic_header.h_lsn)); } #endif bp->b_io_length = BTOBB(count); bp->b_fspriv = iclog; bp->b_flags &= ~(XBF_FUA | XBF_FLUSH); bp->b_flags |= (XBF_ASYNC | XBF_SYNCIO | XBF_WRITE); if (log->l_mp->m_flags & XFS_MOUNT_BARRIER) { bp->b_flags |= XBF_FUA; /* * Flush the data device before flushing the log to make * sure all meta data written back from the AIL actually made * it to disk before stamping the new log tail LSN into the * log buffer. For an external log we need to issue the * flush explicitly, and unfortunately synchronously here; * for an internal log we can simply use the block layer * state machine for preflushes. */ if (log->l_mp->m_logdev_targp != log->l_mp->m_ddev_targp) xfs_blkdev_issue_flush(log->l_mp->m_ddev_targp); else bp->b_flags |= XBF_FLUSH; } ASSERT(XFS_BUF_ADDR(bp) <= log->l_logBBsize-1); ASSERT(XFS_BUF_ADDR(bp) + BTOBB(count) <= log->l_logBBsize); xlog_verify_iclog(log, iclog, count, true); /* account for log which doesn't start at block #0 */ XFS_BUF_SET_ADDR(bp, XFS_BUF_ADDR(bp) + log->l_logBBstart); /* * Don't call xfs_bwrite here. We do log-syncs even when the filesystem * is shutting down. */ error = xlog_bdstrat(bp); if (error) { xfs_buf_ioerror_alert(bp, "xlog_sync"); return error; } if (split) { bp = iclog->ic_log->l_xbuf; XFS_BUF_SET_ADDR(bp, 0); /* logical 0 */ xfs_buf_associate_memory(bp, (char *)&iclog->ic_header + count, split); bp->b_fspriv = iclog; bp->b_flags &= ~(XBF_FUA | XBF_FLUSH); bp->b_flags |= (XBF_ASYNC | XBF_SYNCIO | XBF_WRITE); if (log->l_mp->m_flags & XFS_MOUNT_BARRIER) bp->b_flags |= XBF_FUA; ASSERT(XFS_BUF_ADDR(bp) <= log->l_logBBsize-1); ASSERT(XFS_BUF_ADDR(bp) + BTOBB(count) <= log->l_logBBsize); /* account for internal log which doesn't start at block #0 */ XFS_BUF_SET_ADDR(bp, XFS_BUF_ADDR(bp) + log->l_logBBstart); error = xlog_bdstrat(bp); if (error) { xfs_buf_ioerror_alert(bp, "xlog_sync (split)"); return error; } } return 0; } /* xlog_sync */ /* * Deallocate a log structure */ STATIC void xlog_dealloc_log( struct xlog *log) { xlog_in_core_t *iclog, *next_iclog; int i; xlog_cil_destroy(log); /* * Cycle all the iclogbuf locks to make sure all log IO completion * is done before we tear down these buffers. */ iclog = log->l_iclog; for (i = 0; i < log->l_iclog_bufs; i++) { xfs_buf_lock(iclog->ic_bp); xfs_buf_unlock(iclog->ic_bp); iclog = iclog->ic_next; } /* * Always need to ensure that the extra buffer does not point to memory * owned by another log buffer before we free it. Also, cycle the lock * first to ensure we've completed IO on it. */ xfs_buf_lock(log->l_xbuf); xfs_buf_unlock(log->l_xbuf); xfs_buf_set_empty(log->l_xbuf, BTOBB(log->l_iclog_size)); xfs_buf_free(log->l_xbuf); iclog = log->l_iclog; for (i = 0; i < log->l_iclog_bufs; i++) { xfs_buf_free(iclog->ic_bp); next_iclog = iclog->ic_next; kmem_free(iclog); iclog = next_iclog; } spinlock_destroy(&log->l_icloglock); log->l_mp->m_log = NULL; kmem_free(log); } /* xlog_dealloc_log */ /* * Update counters atomically now that memcpy is done. */ /* ARGSUSED */ static inline void xlog_state_finish_copy( struct xlog *log, struct xlog_in_core *iclog, int record_cnt, int copy_bytes) { spin_lock(&log->l_icloglock); be32_add_cpu(&iclog->ic_header.h_num_logops, record_cnt); iclog->ic_offset += copy_bytes; spin_unlock(&log->l_icloglock); } /* xlog_state_finish_copy */ /* * print out info relating to regions written which consume * the reservation */ void xlog_print_tic_res( struct xfs_mount *mp, struct xlog_ticket *ticket) { uint i; uint ophdr_spc = ticket->t_res_num_ophdrs * (uint)sizeof(xlog_op_header_t); /* match with XLOG_REG_TYPE_* in xfs_log.h */ static char *res_type_str[XLOG_REG_TYPE_MAX] = { "bformat", "bchunk", "efi_format", "efd_format", "iformat", "icore", "iext", "ibroot", "ilocal", "iattr_ext", "iattr_broot", "iattr_local", "qformat", "dquot", "quotaoff", "LR header", "unmount", "commit", "trans header" }; static char *trans_type_str[XFS_TRANS_TYPE_MAX] = { "SETATTR_NOT_SIZE", "SETATTR_SIZE", "INACTIVE", "CREATE", "CREATE_TRUNC", "TRUNCATE_FILE", "REMOVE", "LINK", "RENAME", "MKDIR", "RMDIR", "SYMLINK", "SET_DMATTRS", "GROWFS", "STRAT_WRITE", "DIOSTRAT", "WRITE_SYNC", "WRITEID", "ADDAFORK", "ATTRINVAL", "ATRUNCATE", "ATTR_SET", "ATTR_RM", "ATTR_FLAG", "CLEAR_AGI_BUCKET", "QM_SBCHANGE", "DUMMY1", "DUMMY2", "QM_QUOTAOFF", "QM_DQALLOC", "QM_SETQLIM", "QM_DQCLUSTER", "QM_QINOCREATE", "QM_QUOTAOFF_END", "FSYNC_TS", "GROWFSRT_ALLOC", "GROWFSRT_ZERO", "GROWFSRT_FREE", "SWAPEXT", "CHECKPOINT", "ICREATE", "CREATE_TMPFILE" }; xfs_warn(mp, "xlog_write: reservation summary:"); xfs_warn(mp, " trans type = %s (%u)", ((ticket->t_trans_type <= 0 || ticket->t_trans_type > XFS_TRANS_TYPE_MAX) ? "bad-trans-type" : trans_type_str[ticket->t_trans_type-1]), ticket->t_trans_type); 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, " total reg = %u bytes (o/flow = %u bytes)", ticket->t_res_arr_sum, ticket->t_res_o_flow); xfs_warn(mp, " ophdrs = %u (ophdr space = %u bytes)", ticket->t_res_num_ophdrs, ophdr_spc); xfs_warn(mp, " ophdr + reg = %u bytes", ticket->t_res_arr_sum + ticket->t_res_o_flow + ophdr_spc); xfs_warn(mp, " num regions = %u", ticket->t_res_num); for (i = 0; i < ticket->t_res_num; i++) { uint r_type = ticket->t_res_arr[i].r_type; xfs_warn(mp, "region[%u]: %s - %u bytes", i, ((r_type <= 0 || r_type > XLOG_REG_TYPE_MAX) ? "bad-rtype" : res_type_str[r_type-1]), ticket->t_res_arr[i].r_len); } xfs_alert_tag(mp, XFS_PTAG_LOGRES, "xlog_write: reservation ran out. Need to up reservation"); xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR); } /* * Calculate the potential space needed by the log vector. Each region gets * its own xlog_op_header_t and may need to be double word aligned. */ static int xlog_write_calc_vec_length( struct xlog_ticket *ticket, struct xfs_log_vec *log_vector) { struct xfs_log_vec *lv; int headers = 0; int len = 0; int i; /* acct for start rec of xact */ if (ticket->t_flags & XLOG_TIC_INITED) headers++; for (lv = log_vector; lv; lv = lv->lv_next) { /* we don't write ordered log vectors */ if (lv->lv_buf_len == XFS_LOG_VEC_ORDERED) continue; headers += lv->lv_niovecs; for (i = 0; i < lv->lv_niovecs; i++) { struct xfs_log_iovec *vecp = &lv->lv_iovecp[i]; len += vecp->i_len; xlog_tic_add_region(ticket, vecp->i_len, vecp->i_type); } } ticket->t_res_num_ophdrs += headers; len += headers * sizeof(struct xlog_op_header); return len; } /* * If first write for transaction, insert start record We can't be trying to * commit if we are inited. We can't have any "partial_copy" if we are inited. */ static int xlog_write_start_rec( struct xlog_op_header *ophdr, struct xlog_ticket *ticket) { if (!(ticket->t_flags & XLOG_TIC_INITED)) return 0; ophdr->oh_tid = cpu_to_be32(ticket->t_tid); ophdr->oh_clientid = ticket->t_clientid; ophdr->oh_len = 0; ophdr->oh_flags = XLOG_START_TRANS; ophdr->oh_res2 = 0; ticket->t_flags &= ~XLOG_TIC_INITED; return sizeof(struct xlog_op_header); } static xlog_op_header_t * xlog_write_setup_ophdr( struct xlog *log, struct xlog_op_header *ophdr, struct xlog_ticket *ticket, uint flags) { ophdr->oh_tid = cpu_to_be32(ticket->t_tid); ophdr->oh_clientid = ticket->t_clientid; ophdr->oh_res2 = 0; /* are we copying a commit or unmount record? */ ophdr->oh_flags = flags; /* * We've seen logs corrupted with bad transaction client ids. This * makes sure that XFS doesn't generate them on. Turn this into an EIO * and shut down the filesystem. */ switch (ophdr->oh_clientid) { case XFS_TRANSACTION: case XFS_VOLUME: case XFS_LOG: break; default: xfs_warn(log->l_mp, "Bad XFS transaction clientid 0x%x in ticket 0x%p", ophdr->oh_clientid, ticket); return NULL; } return ophdr; } /* * Set up the parameters of the region copy into the log. This has * to handle region write split across multiple log buffers - this * state is kept external to this function so that this code can * be written in an obvious, self documenting manner. */ static int xlog_write_setup_copy( struct xlog_ticket *ticket, struct xlog_op_header *ophdr, int space_available, int space_required, int *copy_off, int *copy_len, int *last_was_partial_copy, int *bytes_consumed) { int still_to_copy; still_to_copy = space_required - *bytes_consumed; *copy_off = *bytes_consumed; if (still_to_copy <= space_available) { /* write of region completes here */ *copy_len = still_to_copy; ophdr->oh_len = cpu_to_be32(*copy_len); if (*last_was_partial_copy) ophdr->oh_flags |= (XLOG_END_TRANS|XLOG_WAS_CONT_TRANS); *last_was_partial_copy = 0; *bytes_consumed = 0; return 0; } /* partial write of region, needs extra log op header reservation */ *copy_len = space_available; ophdr->oh_len = cpu_to_be32(*copy_len); ophdr->oh_flags |= XLOG_CONTINUE_TRANS; if (*last_was_partial_copy) ophdr->oh_flags |= XLOG_WAS_CONT_TRANS; *bytes_consumed += *copy_len; (*last_was_partial_copy)++; /* account for new log op header */ ticket->t_curr_res -= sizeof(struct xlog_op_header); ticket->t_res_num_ophdrs++; return sizeof(struct xlog_op_header); } static int xlog_write_copy_finish( struct xlog *log, struct xlog_in_core *iclog, uint flags, int *record_cnt, int *data_cnt, int *partial_copy, int *partial_copy_len, int log_offset, struct xlog_in_core **commit_iclog) { if (*partial_copy) { /* * This iclog has already been marked WANT_SYNC by * xlog_state_get_iclog_space. */ xlog_state_finish_copy(log, iclog, *record_cnt, *data_cnt); *record_cnt = 0; *data_cnt = 0; return xlog_state_release_iclog(log, iclog); } *partial_copy = 0; *partial_copy_len = 0; if (iclog->ic_size - log_offset <= sizeof(xlog_op_header_t)) { /* no more space in this iclog - push it. */ xlog_state_finish_copy(log, iclog, *record_cnt, *data_cnt); *record_cnt = 0; *data_cnt = 0; spin_lock(&log->l_icloglock); xlog_state_want_sync(log, iclog); spin_unlock(&log->l_icloglock); if (!commit_iclog) return xlog_state_release_iclog(log, iclog); ASSERT(flags & XLOG_COMMIT_TRANS); *commit_iclog = 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_log_vec *log_vector, struct xlog_ticket *ticket, xfs_lsn_t *start_lsn, struct xlog_in_core **commit_iclog, uint flags) { struct xlog_in_core *iclog = NULL; struct xfs_log_iovec *vecp; struct xfs_log_vec *lv; int len; int index; int partial_copy = 0; int partial_copy_len = 0; int contwr = 0; int record_cnt = 0; int data_cnt = 0; int error; *start_lsn = 0; len = xlog_write_calc_vec_length(ticket, log_vector); /* * Region headers and bytes are already accounted for. * We only need to take into account start records and * split regions in this function. */ if (ticket->t_flags & XLOG_TIC_INITED) ticket->t_curr_res -= sizeof(xlog_op_header_t); /* * Commit record headers need to be accounted for. These * come in as separate writes so are easy to detect. */ if (flags & (XLOG_COMMIT_TRANS | XLOG_UNMOUNT_TRANS)) ticket->t_curr_res -= sizeof(xlog_op_header_t); if (ticket->t_curr_res < 0) xlog_print_tic_res(log->l_mp, ticket); index = 0; lv = log_vector; vecp = lv->lv_iovecp; while (lv && (!lv->lv_niovecs || index < lv->lv_niovecs)) { void *ptr; int log_offset; error = xlog_state_get_iclog_space(log, len, &iclog, ticket, &contwr, &log_offset); if (error) return error; ASSERT(log_offset <= iclog->ic_size - 1); ptr = iclog->ic_datap + log_offset; /* start_lsn is the first lsn written to. That's all we need. */ if (!*start_lsn) *start_lsn = be64_to_cpu(iclog->ic_header.h_lsn); /* * This loop writes out as many regions as can fit in the amount * of space which was allocated by xlog_state_get_iclog_space(). */ while (lv && (!lv->lv_niovecs || index < lv->lv_niovecs)) { struct xfs_log_iovec *reg; struct xlog_op_header *ophdr; int start_rec_copy; int copy_len; int copy_off; bool ordered = false; /* ordered log vectors have no regions to write */ if (lv->lv_buf_len == XFS_LOG_VEC_ORDERED) { ASSERT(lv->lv_niovecs == 0); ordered = true; goto next_lv; } reg = &vecp[index]; ASSERT(reg->i_len % sizeof(__int32_t) == 0); ASSERT((unsigned long)ptr % sizeof(__int32_t) == 0); start_rec_copy = xlog_write_start_rec(ptr, ticket); if (start_rec_copy) { record_cnt++; xlog_write_adv_cnt(&ptr, &len, &log_offset, start_rec_copy); } ophdr = xlog_write_setup_ophdr(log, ptr, ticket, flags); if (!ophdr) return -EIO; xlog_write_adv_cnt(&ptr, &len, &log_offset, sizeof(struct xlog_op_header)); len += xlog_write_setup_copy(ticket, ophdr, iclog->ic_size-log_offset, reg->i_len, ©_off, ©_len, &partial_copy, &partial_copy_len); xlog_verify_dest_ptr(log, ptr); /* * Copy region. * * Unmount records just log an opheader, so can have * empty payloads with no data region to copy. Hence we * only copy the payload if the vector says it has data * to copy. */ ASSERT(copy_len >= 0); if (copy_len > 0) { memcpy(ptr, reg->i_addr + copy_off, copy_len); xlog_write_adv_cnt(&ptr, &len, &log_offset, copy_len); } copy_len += start_rec_copy + sizeof(xlog_op_header_t); record_cnt++; data_cnt += contwr ? copy_len : 0; error = xlog_write_copy_finish(log, iclog, flags, &record_cnt, &data_cnt, &partial_copy, &partial_copy_len, log_offset, commit_iclog); if (error) return error; /* * if we had a partial copy, we need to get more iclog * space but we don't want to increment the region * index because there is still more is this region to * write. * * If we completed writing this region, and we flushed * the iclog (indicated by resetting of the record * count), then we also need to get more log space. If * this was the last record, though, we are done and * can just return. */ if (partial_copy) break; if (++index == lv->lv_niovecs) { next_lv: lv = lv->lv_next; index = 0; if (lv) vecp = lv->lv_iovecp; } if (record_cnt == 0 && ordered == false) { if (!lv) return 0; break; } } } ASSERT(len == 0); xlog_state_finish_copy(log, iclog, record_cnt, data_cnt); if (!commit_iclog) return xlog_state_release_iclog(log, iclog); ASSERT(flags & XLOG_COMMIT_TRANS); *commit_iclog = iclog; return 0; } /***************************************************************************** * * State Machine functions * ***************************************************************************** */ /* Clean iclogs starting from the head. This ordering must be * maintained, so an iclog doesn't become ACTIVE beyond one that * is SYNCING. This is also required to maintain the notion that we use * a ordered wait queue to hold off would be writers to the log when every * iclog is trying to sync to disk. * * State Change: DIRTY -> ACTIVE */ STATIC void xlog_state_clean_log( struct xlog *log) { xlog_in_core_t *iclog; int changed = 0; iclog = log->l_iclog; do { if (iclog->ic_state == XLOG_STATE_DIRTY) { iclog->ic_state = XLOG_STATE_ACTIVE; iclog->ic_offset = 0; ASSERT(iclog->ic_callback == NULL); /* * 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 (!changed && (be32_to_cpu(iclog->ic_header.h_num_logops) == XLOG_COVER_OPS)) { changed = 1; } else { /* * We have two dirty iclogs so start over * This could also be num of ops indicates * this is not the dummy going out. */ changed = 2; } 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; } else if (iclog->ic_state == XLOG_STATE_ACTIVE) /* do nothing */; else break; /* stop cleaning */ iclog = iclog->ic_next; } while (iclog != log->l_iclog); /* log is locked when we are called */ /* * Change state for the dummy log recording. * We usually go to NEED. But we go to NEED2 if the changed indicates * we are done writing the dummy record. * If we are done with the second dummy recored (DONE2), then * we go to IDLE. */ if (changed) { switch (log->l_covered_state) { case XLOG_STATE_COVER_IDLE: case XLOG_STATE_COVER_NEED: case XLOG_STATE_COVER_NEED2: log->l_covered_state = XLOG_STATE_COVER_NEED; break; case XLOG_STATE_COVER_DONE: if (changed == 1) log->l_covered_state = XLOG_STATE_COVER_NEED2; else log->l_covered_state = XLOG_STATE_COVER_NEED; break; case XLOG_STATE_COVER_DONE2: if (changed == 1) log->l_covered_state = XLOG_STATE_COVER_IDLE; else log->l_covered_state = XLOG_STATE_COVER_NEED; break; default: ASSERT(0); } } } /* xlog_state_clean_log */ STATIC xfs_lsn_t xlog_get_lowest_lsn( struct xlog *log) { xlog_in_core_t *lsn_log; xfs_lsn_t lowest_lsn, lsn; lsn_log = log->l_iclog; lowest_lsn = 0; do { if (!(lsn_log->ic_state & (XLOG_STATE_ACTIVE|XLOG_STATE_DIRTY))) { lsn = be64_to_cpu(lsn_log->ic_header.h_lsn); if ((lsn && !lowest_lsn) || (XFS_LSN_CMP(lsn, lowest_lsn) < 0)) { lowest_lsn = lsn; } } lsn_log = lsn_log->ic_next; } while (lsn_log != log->l_iclog); return lowest_lsn; } STATIC void xlog_state_do_callback( struct xlog *log, int aborted, struct xlog_in_core *ciclog) { xlog_in_core_t *iclog; xlog_in_core_t *first_iclog; /* used to know when we've * processed all iclogs once */ xfs_log_callback_t *cb, *cb_next; int flushcnt = 0; xfs_lsn_t lowest_lsn; int ioerrors; /* counter: iclogs with errors */ int loopdidcallbacks; /* flag: inner loop did callbacks*/ int funcdidcallbacks; /* flag: function did callbacks */ int repeats; /* for issuing console warnings if * looping too many times */ int wake = 0; spin_lock(&log->l_icloglock); first_iclog = iclog = log->l_iclog; ioerrors = 0; funcdidcallbacks = 0; repeats = 0; do { /* * Scan all iclogs starting with the one pointed to by the * log. Reset this starting point each time the log is * unlocked (during callbacks). * * Keep looping through iclogs until one full pass is made * without running any callbacks. */ first_iclog = log->l_iclog; iclog = log->l_iclog; loopdidcallbacks = 0; repeats++; do { /* skip all iclogs in the ACTIVE & DIRTY states */ if (iclog->ic_state & (XLOG_STATE_ACTIVE|XLOG_STATE_DIRTY)) { iclog = iclog->ic_next; continue; } /* * Between marking a filesystem SHUTDOWN and stopping * the log, we do flush all iclogs to disk (if there * wasn't a log I/O error). So, we do want things to * go smoothly in case of just a SHUTDOWN w/o a * LOG_IO_ERROR. */ if (!(iclog->ic_state & XLOG_STATE_IOERROR)) { /* * Can only perform callbacks in order. Since * this iclog is not in the DONE_SYNC/ * DO_CALLBACK state, we skip the rest and * just try to clean up. If we set our iclog * to DO_CALLBACK, we will not process it when * we retry since a previous iclog is in the * CALLBACK and the state cannot change since * we are holding the l_icloglock. */ if (!(iclog->ic_state & (XLOG_STATE_DONE_SYNC | XLOG_STATE_DO_CALLBACK))) { if (ciclog && (ciclog->ic_state == XLOG_STATE_DONE_SYNC)) { ciclog->ic_state = XLOG_STATE_DO_CALLBACK; } break; } /* * We now have an iclog that is in either the * DO_CALLBACK or DONE_SYNC states. The other * states (WANT_SYNC, SYNCING, or CALLBACK were * caught by the above if and are going to * clean (i.e. we aren't doing their callbacks) * see the above if. */ /* * We will do one more check here to see if we * have chased our tail around. */ lowest_lsn = xlog_get_lowest_lsn(log); if (lowest_lsn && XFS_LSN_CMP(lowest_lsn, be64_to_cpu(iclog->ic_header.h_lsn)) < 0) { iclog = iclog->ic_next; continue; /* Leave this iclog for * another thread */ } iclog->ic_state = XLOG_STATE_CALLBACK; /* * 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 th etail 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. */ ASSERT(XFS_LSN_CMP(atomic64_read(&log->l_last_sync_lsn), be64_to_cpu(iclog->ic_header.h_lsn)) <= 0); if (iclog->ic_callback) atomic64_set(&log->l_last_sync_lsn, be64_to_cpu(iclog->ic_header.h_lsn)); } else ioerrors++; spin_unlock(&log->l_icloglock); /* * Keep processing entries in the callback list until * we come around and it is empty. We need to * atomically see that the list is empty and change the * state to DIRTY so that we don't miss any more * callbacks being added. */ spin_lock(&iclog->ic_callback_lock); cb = iclog->ic_callback; while (cb) { iclog->ic_callback_tail = &(iclog->ic_callback); iclog->ic_callback = NULL; spin_unlock(&iclog->ic_callback_lock); /* perform callbacks in the order given */ for (; cb; cb = cb_next) { cb_next = cb->cb_next; cb->cb_func(cb->cb_arg, aborted); } spin_lock(&iclog->ic_callback_lock); cb = iclog->ic_callback; } loopdidcallbacks++; funcdidcallbacks++; spin_lock(&log->l_icloglock); ASSERT(iclog->ic_callback == NULL); spin_unlock(&iclog->ic_callback_lock); if (!(iclog->ic_state & XLOG_STATE_IOERROR)) iclog->ic_state = XLOG_STATE_DIRTY; /* * Transition from DIRTY to ACTIVE if applicable. * NOP if STATE_IOERROR. */ xlog_state_clean_log(log); /* wake up threads waiting in xfs_log_force() */ wake_up_all(&iclog->ic_force_wait); iclog = iclog->ic_next; } while (first_iclog != iclog); if (repeats > 5000) { flushcnt += repeats; repeats = 0; xfs_warn(log->l_mp, "%s: possible infinite loop (%d iterations)", __func__, flushcnt); } } while (!ioerrors && loopdidcallbacks); #ifdef DEBUG /* * Make one last gasp attempt to see if iclogs are being left in limbo. * If the above loop finds an iclog earlier than the current iclog and * in one of the syncing states, the current iclog is put into * DO_CALLBACK and the callbacks are deferred to the completion of the * earlier iclog. Walk the iclogs in order and make sure that no iclog * is in DO_CALLBACK unless an earlier iclog is in one of the syncing * states. * * Note that SYNCING|IOABORT is a valid state so we cannot just check * for ic_state == SYNCING. */ if (funcdidcallbacks) { first_iclog = iclog = log->l_iclog; do { ASSERT(iclog->ic_state != XLOG_STATE_DO_CALLBACK); /* * Terminate the loop if iclogs are found in states * which will cause other threads to clean up iclogs. * * SYNCING - i/o completion will go through logs * DONE_SYNC - interrupt thread should be waiting for * l_icloglock * IOERROR - give up hope all ye who enter here */ if (iclog->ic_state == XLOG_STATE_WANT_SYNC || iclog->ic_state & XLOG_STATE_SYNCING || iclog->ic_state == XLOG_STATE_DONE_SYNC || iclog->ic_state == XLOG_STATE_IOERROR ) break; iclog = iclog->ic_next; } while (first_iclog != iclog); } #endif if (log->l_iclog->ic_state & (XLOG_STATE_ACTIVE|XLOG_STATE_IOERROR)) wake = 1; spin_unlock(&log->l_icloglock); if (wake) wake_up_all(&log->l_flush_wait); } /* * Finish transitioning this iclog to the dirty state. * * Make sure that we completely execute this routine only when this is * the last call to the iclog. There is a good chance that iclog flushes, * when we reach the end of the physical log, get turned into 2 separate * calls to bwrite. Hence, one iclog flush could generate two calls to this * routine. By using the reference count bwritecnt, we guarantee that only * the second completion goes through. * * Callbacks could take time, so they are done outside the scope of the * global state machine log lock. */ STATIC void xlog_state_done_syncing( xlog_in_core_t *iclog, int aborted) { struct xlog *log = iclog->ic_log; spin_lock(&log->l_icloglock); ASSERT(iclog->ic_state == XLOG_STATE_SYNCING || iclog->ic_state == XLOG_STATE_IOERROR); ASSERT(atomic_read(&iclog->ic_refcnt) == 0); ASSERT(iclog->ic_bwritecnt == 1 || iclog->ic_bwritecnt == 2); /* * If we got an error, either on the first buffer, or in the case of * split log writes, on the second, we mark ALL iclogs STATE_IOERROR, * and none should ever be attempted to be written to disk * again. */ if (iclog->ic_state != XLOG_STATE_IOERROR) { if (--iclog->ic_bwritecnt == 1) { spin_unlock(&log->l_icloglock); return; } 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, aborted, iclog); /* also cleans log */ } /* xlog_state_done_syncing */ /* * 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 *continued_write, int *logoffsetp) { int log_offset; xlog_rec_header_t *head; xlog_in_core_t *iclog; int error; restart: spin_lock(&log->l_icloglock); if (XLOG_FORCED_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; /* 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; xlog_tic_add_region(ticket, log->l_iclog_hsize, XLOG_REG_TYPE_LRHEADER); 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)) { xlog_state_switch_iclogs(log, iclog, iclog->ic_size); /* * If I'm 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)) { /* we are the only one */ spin_unlock(&log->l_icloglock); error = xlog_state_release_iclog(log, iclog); if (error) return error; } else { spin_unlock(&log->l_icloglock); } 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) { *continued_write = 0; iclog->ic_offset += len; } else { *continued_write = 1; 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; } /* xlog_state_get_iclog_space */ /* The first cnt-1 times 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. */ STATIC void xlog_regrant_reserve_log_space( struct xlog *log, struct xlog_ticket *ticket) { trace_xfs_log_regrant_reserve_enter(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; xlog_tic_reset_res(ticket); trace_xfs_log_regrant_reserve_sub(log, ticket); /* just return if we still have some of the pre-reserved space */ if (ticket->t_cnt > 0) return; xlog_grant_add_space(log, &log->l_reserve_head.grant, ticket->t_unit_res); trace_xfs_log_regrant_reserve_exit(log, ticket); ticket->t_curr_res = ticket->t_unit_res; xlog_tic_reset_res(ticket); } /* xlog_regrant_reserve_log_space */ /* * 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. */ STATIC void xlog_ungrant_log_space( struct xlog *log, struct xlog_ticket *ticket) { int bytes; if (ticket->t_cnt > 0) ticket->t_cnt--; trace_xfs_log_ungrant_enter(log, ticket); trace_xfs_log_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_ungrant_exit(log, ticket); xfs_log_space_wake(log->l_mp); } /* * Flush iclog to disk if this is the last reference to the given iclog and * the WANT_SYNC bit is set. * * When this function is entered, the iclog is not necessarily in the * WANT_SYNC state. It may be sitting around waiting to get filled. * * */ STATIC int xlog_state_release_iclog( struct xlog *log, struct xlog_in_core *iclog) { int sync = 0; /* do we sync? */ if (iclog->ic_state & XLOG_STATE_IOERROR) return -EIO; ASSERT(atomic_read(&iclog->ic_refcnt) > 0); if (!atomic_dec_and_lock(&iclog->ic_refcnt, &log->l_icloglock)) return 0; if (iclog->ic_state & XLOG_STATE_IOERROR) { spin_unlock(&log->l_icloglock); return -EIO; } ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE || iclog->ic_state == XLOG_STATE_WANT_SYNC); if (iclog->ic_state == XLOG_STATE_WANT_SYNC) { /* update tail before writing to iclog */ xfs_lsn_t tail_lsn = xlog_assign_tail_lsn(log->l_mp); sync++; iclog->ic_state = XLOG_STATE_SYNCING; iclog->ic_header.h_tail_lsn = cpu_to_be64(tail_lsn); xlog_verify_tail_lsn(log, iclog, tail_lsn); /* cycle incremented when incrementing curr_block */ } spin_unlock(&log->l_icloglock); /* * We let the log lock go, so it's possible that we hit a log I/O * error or some other SHUTDOWN condition that marks the iclog * as XLOG_STATE_IOERROR before the bwrite. However, we know that * this iclog has consistent data, so we ignore IOERROR * flags after this point. */ if (sync) return xlog_sync(log, iclog); return 0; } /* xlog_state_release_iclog */ /* * 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. * When this routine is called from xlog_state_get_iclog_space(), the * exact size of the iclog has not yet been determined. All we know is * that every data block. We have run out of space in this log record. */ STATIC void xlog_state_switch_iclogs( struct xlog *log, struct xlog_in_core *iclog, int eventual_size) { ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE); 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 (xfs_sb_version_haslogv2(&log->l_mp->m_sb) && log->l_mp->m_sb.sb_logsunit > 1) { __uint32_t sunit_bb = BTOBB(log->l_mp->m_sb.sb_logsunit); 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; } /* xlog_state_switch_iclogs */ /* * 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, int *log_flushed) { struct xlog *log = mp->m_log; struct xlog_in_core *iclog; xfs_lsn_t lsn; XFS_STATS_INC(mp, xs_log_force); xlog_cil_force(log); spin_lock(&log->l_icloglock); iclog = log->l_iclog; if (iclog->ic_state & XLOG_STATE_IOERROR) { spin_unlock(&log->l_icloglock); return -EIO; } /* If the head iclog is not active nor dirty, we just attach * ourselves to the head and go to sleep. */ if (iclog->ic_state == XLOG_STATE_ACTIVE || iclog->ic_state == XLOG_STATE_DIRTY) { /* * 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. */ if (iclog->ic_state == XLOG_STATE_DIRTY || (atomic_read(&iclog->ic_refcnt) == 0 && iclog->ic_offset == 0)) { iclog = iclog->ic_prev; if (iclog->ic_state == XLOG_STATE_ACTIVE || iclog->ic_state == XLOG_STATE_DIRTY) goto no_sleep; else goto maybe_sleep; } else { if (atomic_read(&iclog->ic_refcnt) == 0) { /* We are the only one with access to this * iclog. Flush it out now. There should * be a roundoff of zero to show that someone * has already taken care of the roundoff from * the previous sync. */ atomic_inc(&iclog->ic_refcnt); lsn = be64_to_cpu(iclog->ic_header.h_lsn); xlog_state_switch_iclogs(log, iclog, 0); spin_unlock(&log->l_icloglock); if (xlog_state_release_iclog(log, iclog)) return -EIO; if (log_flushed) *log_flushed = 1; spin_lock(&log->l_icloglock); if (be64_to_cpu(iclog->ic_header.h_lsn) == lsn && iclog->ic_state != XLOG_STATE_DIRTY) goto maybe_sleep; else goto no_sleep; } else { /* Someone else is writing to this iclog. * Use its call to flush out the data. However, * the other thread may not force out this LR, * so we mark it WANT_SYNC. */ xlog_state_switch_iclogs(log, iclog, 0); goto maybe_sleep; } } } /* By the time we come around again, the iclog could've been filled * which would give it another lsn. If we have a new lsn, just * return because the relevant data has been flushed. */ maybe_sleep: if (flags & XFS_LOG_SYNC) { /* * We must check if we're shutting down here, before * we wait, while we're holding the l_icloglock. * Then we check again after waking up, in case our * sleep was disturbed by a bad news. */ if (iclog->ic_state & XLOG_STATE_IOERROR) { spin_unlock(&log->l_icloglock); return -EIO; } XFS_STATS_INC(mp, xs_log_force_sleep); xlog_wait(&iclog->ic_force_wait, &log->l_icloglock); /* * No need to grab the log lock here since we're * only deciding whether or not to return EIO * and the memory read should be atomic. */ if (iclog->ic_state & XLOG_STATE_IOERROR) return -EIO; if (log_flushed) *log_flushed = 1; } else { no_sleep: spin_unlock(&log->l_icloglock); } return 0; } /* * Wrapper for _xfs_log_force(), to be used when caller doesn't care * about errors or whether the log was flushed or not. This is the normal * interface to use when trying to unpin items or move the log forward. */ void xfs_log_force( xfs_mount_t *mp, uint flags) { int error; trace_xfs_log_force(mp, 0); error = _xfs_log_force(mp, flags, NULL); if (error) xfs_warn(mp, "%s: error %d returned.", __func__, error); } /* * Force the in-core log to disk for a specific LSN. * * Find in-core log with lsn. * 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 signal variable. All callers * to force a given lsn to disk will wait on a the sv 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 * sv. */ int _xfs_log_force_lsn( struct xfs_mount *mp, xfs_lsn_t lsn, uint flags, int *log_flushed) { struct xlog *log = mp->m_log; struct xlog_in_core *iclog; int already_slept = 0; ASSERT(lsn != 0); XFS_STATS_INC(mp, xs_log_force); lsn = xlog_cil_force_lsn(log, lsn); if (lsn == NULLCOMMITLSN) return 0; try_again: spin_lock(&log->l_icloglock); iclog = log->l_iclog; if (iclog->ic_state & XLOG_STATE_IOERROR) { spin_unlock(&log->l_icloglock); return -EIO; } do { if (be64_to_cpu(iclog->ic_header.h_lsn) != lsn) { iclog = iclog->ic_next; continue; } if (iclog->ic_state == XLOG_STATE_DIRTY) { spin_unlock(&log->l_icloglock); return 0; } if (iclog->ic_state == 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 | XLOG_STATE_SYNCING))) { ASSERT(!(iclog->ic_state & XLOG_STATE_IOERROR)); XFS_STATS_INC(mp, xs_log_force_sleep); xlog_wait(&iclog->ic_prev->ic_write_wait, &log->l_icloglock); if (log_flushed) *log_flushed = 1; already_slept = 1; goto try_again; } atomic_inc(&iclog->ic_refcnt); xlog_state_switch_iclogs(log, iclog, 0); spin_unlock(&log->l_icloglock); if (xlog_state_release_iclog(log, iclog)) return -EIO; if (log_flushed) *log_flushed = 1; spin_lock(&log->l_icloglock); } if ((flags & XFS_LOG_SYNC) && /* sleep */ !(iclog->ic_state & (XLOG_STATE_ACTIVE | XLOG_STATE_DIRTY))) { /* * Don't wait on completion if we know that we've * gotten a log write error. */ if (iclog->ic_state & XLOG_STATE_IOERROR) { spin_unlock(&log->l_icloglock); return -EIO; } XFS_STATS_INC(mp, xs_log_force_sleep); xlog_wait(&iclog->ic_force_wait, &log->l_icloglock); /* * No need to grab the log lock here since we're * only deciding whether or not to return EIO * and the memory read should be atomic. */ if (iclog->ic_state & XLOG_STATE_IOERROR) return -EIO; if (log_flushed) *log_flushed = 1; } else { /* just return */ spin_unlock(&log->l_icloglock); } return 0; } while (iclog != log->l_iclog); spin_unlock(&log->l_icloglock); return 0; } /* * Wrapper for _xfs_log_force_lsn(), to be used when caller doesn't care * about errors or whether the log was flushed or not. This is the normal * interface to use when trying to unpin items or move the log forward. */ void xfs_log_force_lsn( xfs_mount_t *mp, xfs_lsn_t lsn, uint flags) { int error; trace_xfs_log_force(mp, lsn); error = _xfs_log_force_lsn(mp, lsn, flags, NULL); if (error) xfs_warn(mp, "%s: error %d returned.", __func__, error); } /* * Called when we want to mark the current iclog as being ready to sync to * disk. */ STATIC void xlog_state_want_sync( struct xlog *log, struct xlog_in_core *iclog) { assert_spin_locked(&log->l_icloglock); if (iclog->ic_state == XLOG_STATE_ACTIVE) { xlog_state_switch_iclogs(log, iclog, 0); } else { ASSERT(iclog->ic_state & (XLOG_STATE_WANT_SYNC|XLOG_STATE_IOERROR)); } } /***************************************************************************** * * TICKET functions * ***************************************************************************** */ /* * 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_zone_free(xfs_log_ticket_zone, 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. */ int xfs_log_calc_unit_res( struct xfs_mount *mp, int unit_bytes) { struct xlog *log = mp->m_log; 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: * ... * 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. | * 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; /* for roundoff padding for transaction data and one for commit record */ if (xfs_sb_version_haslogv2(&mp->m_sb) && mp->m_sb.sb_logsunit > 1) { /* log su roundoff */ unit_bytes += 2 * mp->m_sb.sb_logsunit; } else { /* BB roundoff */ unit_bytes += 2 * BBSIZE; } return unit_bytes; } /* * Allocate and initialise a new log ticket. */ struct xlog_ticket * xlog_ticket_alloc( struct xlog *log, int unit_bytes, int cnt, char client, bool permanent, xfs_km_flags_t alloc_flags) { struct xlog_ticket *tic; int unit_res; tic = kmem_zone_zalloc(xfs_log_ticket_zone, alloc_flags); if (!tic) return NULL; unit_res = xfs_log_calc_unit_res(log->l_mp, unit_bytes); 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 = prandom_u32(); tic->t_clientid = client; tic->t_flags = XLOG_TIC_INITED; tic->t_trans_type = 0; if (permanent) tic->t_flags |= XLOG_TIC_PERM_RESERV; xlog_tic_reset_res(tic); return tic; } /****************************************************************************** * * Log debug routines * ****************************************************************************** */ #if defined(DEBUG) /* * Make sure that the destination ptr is within the valid data region of * one of the iclogs. This uses backup pointers stored in a different * part of the log in case we trash the log structure. */ void xlog_verify_dest_ptr( struct xlog *log, void *ptr) { int i; int good_ptr = 0; for (i = 0; i < log->l_iclog_bufs; i++) { if (ptr >= log->l_iclog_bak[i] && ptr <= log->l_iclog_bak[i] + log->l_iclog_size) good_ptr++; } if (!good_ptr) xfs_emerg(log->l_mp, "%s: invalid ptr", __func__); } /* * 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 && !(log->l_flags & XLOG_TAIL_WARN)) { xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES, "%s: cycle - 1 != tail_cycle", __func__); log->l_flags |= XLOG_TAIL_WARN; } if (space > BBTOB(tail_blocks) && !(log->l_flags & XLOG_TAIL_WARN)) { xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES, "%s: space > BBTOB(tail_blocks)", __func__); log->l_flags |= XLOG_TAIL_WARN; } } } /* check if it will fit */ STATIC void xlog_verify_tail_lsn( struct xlog *log, struct xlog_in_core *iclog, xfs_lsn_t 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__); } } /* xlog_verify_tail_lsn */ /* * 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, bool syncing) { 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 (!syncing || (field_offset & 0x1ff)) { clientid = ophead->oh_clientid; } else { idx = BTOBBT((char *)&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: invalid clientid %d op 0x%p offset 0x%lx", __func__, clientid, ophead, (unsigned long)field_offset); /* check length */ p = &ophead->oh_len; field_offset = p - base_ptr; if (!syncing || (field_offset & 0x1ff)) { op_len = be32_to_cpu(ophead->oh_len); } else { idx = BTOBBT((uintptr_t)&ophead->oh_len - (uintptr_t)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; } } /* xlog_verify_iclog */ #endif /* * Mark all iclogs IOERROR. l_icloglock is held by the caller. */ STATIC int xlog_state_ioerror( struct xlog *log) { xlog_in_core_t *iclog, *ic; iclog = log->l_iclog; if (! (iclog->ic_state & XLOG_STATE_IOERROR)) { /* * Mark all the incore logs IOERROR. * From now on, no log flushes will result. */ ic = iclog; do { ic->ic_state = XLOG_STATE_IOERROR; ic = ic->ic_next; } while (ic != iclog); return 0; } /* * Return non-zero, if state transition has already happened. */ return 1; } /* * This is called from xfs_force_shutdown, when we're forcibly * shutting down the filesystem, typically because of an IO error. * Our main objectives here are to make sure that: * a. if !logerror, flush the logs to disk. Anything modified * after this is ignored. * b. the filesystem gets marked 'SHUTDOWN' for all interested * parties to find out, 'atomically'. * c. those who're sleeping on log reservations, pinned objects and * other resources get woken up, and be told the bad news. * d. nothing new gets queued up after (b) and (c) are done. * * Note: for the !logerror case we need to flush the regions held in memory out * to disk first. This needs to be done before the log is marked as shutdown, * otherwise the iclog writes will fail. */ int xfs_log_force_umount( struct xfs_mount *mp, int logerror) { struct xlog *log; int retval; log = mp->m_log; /* * If this happens during log recovery, don't worry about * locking; the log isn't open for business yet. */ if (!log || log->l_flags & XLOG_ACTIVE_RECOVERY) { mp->m_flags |= XFS_MOUNT_FS_SHUTDOWN; if (mp->m_sb_bp) mp->m_sb_bp->b_flags |= XBF_DONE; return 0; } /* * Somebody could've already done the hard work for us. * No need to get locks for this. */ if (logerror && log->l_iclog->ic_state & XLOG_STATE_IOERROR) { ASSERT(XLOG_FORCED_SHUTDOWN(log)); return 1; } /* * Flush all the completed transactions to disk before marking the log * being shut down. We need to do it in this order to ensure that * completed operations are safely on disk before we shut down, and that * we don't have to issue any buffer IO after the shutdown flags are set * to guarantee this. */ if (!logerror) _xfs_log_force(mp, XFS_LOG_SYNC, NULL); /* * mark the filesystem and the as in a shutdown state and wake * everybody up to tell them the bad news. */ spin_lock(&log->l_icloglock); mp->m_flags |= XFS_MOUNT_FS_SHUTDOWN; if (mp->m_sb_bp) mp->m_sb_bp->b_flags |= XBF_DONE; /* * Mark the log and the iclogs with IO error flags to prevent any * further log IO from being issued or completed. */ log->l_flags |= XLOG_IO_ERROR; retval = xlog_state_ioerror(log); spin_unlock(&log->l_icloglock); /* * 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. */ wake_up_all(&log->l_cilp->xc_commit_wait); xlog_state_do_callback(log, XFS_LI_ABORTED, NULL); #ifdef XFSERRORDEBUG { xlog_in_core_t *iclog; spin_lock(&log->l_icloglock); iclog = log->l_iclog; do { ASSERT(iclog->ic_callback == 0); iclog = iclog->ic_next; } while (iclog != log->l_iclog); spin_unlock(&log->l_icloglock); } #endif /* return non-zero if log IOERROR transition had already happened */ return retval; } 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 (mp->m_flags & XFS_MOUNT_NORECOVERY) 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; }