--- /dev/null
+/*
+ * 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,
+ char *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(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(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(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,
+ uint flags)
+{
+ 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;
+ if (ticket->t_flags & XLOG_TIC_PERM_RESERV) {
+ flags |= XFS_LOG_REL_PERM_RESERV;
+ }
+ }
+
+
+ if ((ticket->t_flags & XLOG_TIC_PERM_RESERV) == 0 ||
+ (flags & XFS_LOG_REL_PERM_RESERV)) {
+ 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);
+ xfs_log_ticket_put(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;
+ }
+
+ 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. Continuing onwards, but if log hangs are\n"
+"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);
+ 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(xfs_mount_t *mp)
+{
+ int error = 0;
+
+ if (!(mp->m_flags & XFS_MOUNT_NORECOVERY)) {
+ error = xlog_recover_finish(mp->m_log);
+ if (!error)
+ xfs_log_work_queue(mp);
+ } else {
+ ASSERT(mp->m_flags & XFS_MOUNT_RDONLY);
+ }
+
+
+ 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\n"
+ " tail_cycle = %d, tail_bytes = %d\n"
+ " GH cycle = %d, GH bytes = %d",
+ tail_cycle, tail_bytes, 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.
+ */
+ if (XFS_TEST_ERROR(bp->b_error, l->l_mp,
+ XFS_ERRTAG_IODONE_IOERR, XFS_RANDOM_IODONE_IOERR)) {
+ 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(XFS_BUF_ISASYNC(bp));
+ 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] = (xfs_caddr_t)&(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;
+ xfs_caddr_t 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;
+
+ for (i = 1; i < log->l_iclog_heads; 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(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(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);
+
+ bp->b_io_length = BTOBB(count);
+ bp->b_fspriv = iclog;
+ XFS_BUF_ZEROFLAGS(bp);
+ XFS_BUF_ASYNC(bp);
+ bp->b_flags |= XBF_SYNCIO;
+
+ 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.
+ */
+ XFS_BUF_WRITE(bp);
+
+ 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;
+ XFS_BUF_ZEROFLAGS(bp);
+ XFS_BUF_ASYNC(bp);
+ bp->b_flags |= XBF_SYNCIO;
+ 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);
+ XFS_BUF_WRITE(bp);
+ 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",
+ "SB_UNIT",
+ "FSYNC_TS",
+ "GROWFSRT_ALLOC",
+ "GROWFSRT_ZERO",
+ "GROWFSRT_FREE",
+ "SWAPEXT"
+ };
+
+ xfs_warn(mp,
+ "xlog_write: reservation summary:\n"
+ " trans type = %s (%u)\n"
+ " unit res = %d bytes\n"
+ " current res = %d bytes\n"
+ " total reg = %u bytes (o/flow = %u bytes)\n"
+ " ophdrs = %u (ophdr space = %u bytes)\n"
+ " ophdr + reg = %u bytes\n"
+ " num regions = %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,
+ ticket->t_unit_res,
+ ticket->t_curr_res,
+ ticket->t_res_arr_sum, ticket->t_res_o_flow,
+ ticket->t_res_num_ophdrs, ophdr_spc,
+ ticket->t_res_arr_sum +
+ ticket->t_res_o_flow + ophdr_spc,
+ 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 */
+ ASSERT(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);
+
+ /*
+ * make one last gasp attempt to see if iclogs are being left in
+ * limbo..
+ */
+#ifdef DEBUG
+ 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(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) {
+ log->l_curr_cycle++;
+ if (log->l_curr_cycle == XLOG_HEADER_MAGIC_NUM)
+ log->l_curr_cycle++;
+ log->l_curr_block -= log->l_logBBsize;
+ ASSERT(log->l_curr_block >= 0);
+ }
+ 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(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(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(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(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(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:
+ * <oph><trans-hdr><start-oph><reg1-oph><reg1><reg2-oph>...<commit-oph>
+ * and then there are LR hdrs, split-recs and roundoff at end of syncs.
+ *
+ * We need to account for all the leadup data and trailer data
+ * around the transaction data.
+ * And then we need to account for the worst case in terms of using
+ * more space.
+ * The worst case will happen if:
+ * - the placement of the transaction happens to be such that the
+ * roundoff is at its maximum
+ * - the transaction data is synced before the commit record is synced
+ * i.e. <transaction-data><roundoff> | <commit-rec><roundoff>
+ * Therefore the commit record is in its own Log Record.
+ * This can happen as the commit record is called with its
+ * own region to xlog_write().
+ * This then means that in the worst case, roundoff can happen for
+ * the commit-rec as well.
+ * The commit-rec is smaller than padding in this scenario and so it is
+ * not added separately.
+ */
+
+ /* for trans header */
+ unit_bytes += sizeof(xlog_op_header_t);
+ unit_bytes += sizeof(xfs_trans_header_t);
+
+ /* for start-rec */
+ unit_bytes += sizeof(xlog_op_header_t);
+
+ /*
+ * for LR headers - the space for data in an iclog is the size minus
+ * the space used for the headers. If we use the iclog size, then we
+ * undercalculate the number of headers required.
+ *
+ * Furthermore - the addition of op headers for split-recs might
+ * increase the space required enough to require more log and op
+ * headers, so take that into account too.
+ *
+ * IMPORTANT: This reservation makes the assumption that if this
+ * transaction is the first in an iclog and hence has the LR headers
+ * accounted to it, then the remaining space in the iclog is
+ * exclusively for this transaction. i.e. if the transaction is larger
+ * than the iclog, it will be the only thing in that iclog.
+ * Fundamentally, this means we must pass the entire log vector to
+ * xlog_write to guarantee this.
+ */
+ iclog_space = log->l_iclog_size - log->l_iclog_hsize;
+ num_headers = howmany(unit_bytes, iclog_space);
+
+ /* for split-recs - ophdrs added when data split over LRs */
+ unit_bytes += sizeof(xlog_op_header_t) * num_headers;
+
+ /* add extra header reservations if we overrun */
+ while (!num_headers ||
+ howmany(unit_bytes, iclog_space) > num_headers) {
+ unit_bytes += sizeof(xlog_op_header_t);
+ num_headers++;
+ }
+ unit_bytes += log->l_iclog_hsize * num_headers;
+
+ /* for commit-rec LR header - note: padding will subsume the ophdr */
+ unit_bytes += log->l_iclog_hsize;
+
+ /* 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,
+ char *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;
+ xfs_caddr_t ptr;
+ xfs_caddr_t base_ptr;
+ __psint_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__);
+
+ ptr = (xfs_caddr_t) &iclog->ic_header;
+ for (ptr += BBSIZE; ptr < ((xfs_caddr_t)&iclog->ic_header) + 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);
+ ptr = iclog->ic_datap;
+ base_ptr = ptr;
+ ophead = (xlog_op_header_t *)ptr;
+ xhdr = iclog->ic_data;
+ for (i = 0; i < len; i++) {
+ ophead = (xlog_op_header_t *)ptr;
+
+ /* clientid is only 1 byte */
+ field_offset = (__psint_t)
+ ((xfs_caddr_t)&(ophead->oh_clientid) - base_ptr);
+ if (!syncing || (field_offset & 0x1ff)) {
+ clientid = ophead->oh_clientid;
+ } else {
+ idx = BTOBBT((xfs_caddr_t)&(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 */
+ field_offset = (__psint_t)
+ ((xfs_caddr_t)&(ophead->oh_len) - base_ptr);
+ if (!syncing || (field_offset & 0x1ff)) {
+ op_len = be32_to_cpu(ophead->oh_len);
+ } else {
+ idx = BTOBBT((__psint_t)&ophead->oh_len -
+ (__psint_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)
+ XFS_BUF_DONE(mp->m_sb_bp);
+ 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)
+ XFS_BUF_DONE(mp->m_sb_bp);
+
+ /*
+ * 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;
+}
+
Code Review / kvmfornfv.git / blobdiff