// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2000-2005 Silicon Graphics, Inc.
* All Rights Reserved.
*/
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_errortag.h"
#include "xfs_error.h"
#include "xfs_trans.h"
#include "xfs_trans_priv.h"
#include "xfs_log.h"
#include "xfs_log_priv.h"
#include "xfs_trace.h"
#include "xfs_sysfs.h"
#include "xfs_sb.h"
#include "xfs_health.h"
struct kmem_cache *xfs_log_ticket_cache;
/* Local miscellaneous function prototypes */
STATIC struct xlog *
xlog_alloc_log(
struct xfs_mount *mp,
struct xfs_buftarg *log_target,
xfs_daddr_t blk_offset,
int num_bblks);
STATIC void
xlog_dealloc_log(
struct xlog *log);
/* local state machine functions */
STATIC void xlog_state_done_syncing(
struct xlog_in_core *iclog);
STATIC void xlog_state_do_callback(
struct xlog *log);
STATIC int
xlog_state_get_iclog_space(
struct xlog *log,
int len,
struct xlog_in_core **iclog,
struct xlog_ticket *ticket,
int *logoffsetp);
STATIC void
xlog_sync(
struct xlog *log,
struct xlog_in_core *iclog,
struct xlog_ticket *ticket);
#if defined(DEBUG)
STATIC void
xlog_verify_iclog(
struct xlog *log,
struct xlog_in_core *iclog,
int count);
STATIC void
xlog_verify_tail_lsn(
struct xlog *log,
struct xlog_in_core *iclog);
#else
#define xlog_verify_iclog(a,b,c)
#define xlog_verify_tail_lsn(a,b)
#endif
STATIC int
xlog_iclogs_empty(
struct xlog *log);
static int
xfs_log_cover(struct xfs_mount *);
/*
* We need to make sure the buffer pointer returned is naturally aligned for the
* biggest basic data type we put into it. We have already accounted for this
* padding when sizing the buffer.
*
* However, this padding does not get written into the log, and hence we have to
* track the space used by the log vectors separately to prevent log space hangs
* due to inaccurate accounting (i.e. a leak) of the used log space through the
* CIL context ticket.
*
* We also add space for the xlog_op_header that describes this region in the
* log. This prepends the data region we return to the caller to copy their data
* into, so do all the static initialisation of the ophdr now. Because the ophdr
* is not 8 byte aligned, we have to be careful to ensure that we align the
* start of the buffer such that the region we return to the call is 8 byte
* aligned and packed against the tail of the ophdr.
*/
void *
xlog_prepare_iovec(
struct xfs_log_vec *lv,
struct xfs_log_iovec **vecp,
uint type)
{
struct xfs_log_iovec *vec = *vecp;
struct xlog_op_header *oph;
uint32_t len;
void *buf;
if (vec) {
ASSERT(vec - lv->lv_iovecp < lv->lv_niovecs);
vec++;
} else {
vec = &lv->lv_iovecp[0];
}
len = lv->lv_buf_len + sizeof(struct xlog_op_header);
if (!IS_ALIGNED(len, sizeof(uint64_t))) {
lv->lv_buf_len = round_up(len, sizeof(uint64_t)) -
sizeof(struct xlog_op_header);
}
vec->i_type = type;
vec->i_addr = lv->lv_buf + lv->lv_buf_len;
oph = vec->i_addr;
oph->oh_clientid = XFS_TRANSACTION;
oph->oh_res2 = 0;
oph->oh_flags = 0;
buf = vec->i_addr + sizeof(struct xlog_op_header);
ASSERT(IS_ALIGNED((unsigned long)buf, sizeof(uint64_t)));
*vecp = vec;
return buf;
}
static inline void
xlog_grant_sub_space(
struct xlog_grant_head *head,
int64_t bytes)
{
atomic64_sub(bytes, &head->grant);
}
static inline void
xlog_grant_add_space(
struct xlog_grant_head *head,
int64_t bytes)
{
atomic64_add(bytes, &head->grant);
}
static void
xlog_grant_head_init(
struct xlog_grant_head *head)
{
atomic64_set(&head->grant, 0);
INIT_LIST_HEAD(&head->waiters);
spin_lock_init(&head->lock);
}
void
xlog_grant_return_space(
struct xlog *log,
xfs_lsn_t old_head,
xfs_lsn_t new_head)
{
int64_t diff = xlog_lsn_sub(log, new_head, old_head);
xlog_grant_sub_space(&log->l_reserve_head, diff);
xlog_grant_sub_space(&log->l_write_head, diff);
}
/*
* Return the space in the log between the tail and the head. In the case where
* we have overrun available reservation space, return 0. The memory barrier
* pairs with the smp_wmb() in xlog_cil_ail_insert() to ensure that grant head
* vs tail space updates are seen in the correct order and hence avoid
* transients as space is transferred from the grant heads to the AIL on commit
* completion.
*/
static uint64_t
xlog_grant_space_left(
struct xlog *log,
struct xlog_grant_head *head)
{
int64_t free_bytes;
smp_rmb(); /* paired with smp_wmb in xlog_cil_ail_insert() */
free_bytes = log->l_logsize - READ_ONCE(log->l_tail_space) -
atomic64_read(&head->grant);
if (free_bytes > 0)
return free_bytes;
return 0;
}
STATIC void
xlog_grant_head_wake_all(
struct xlog_grant_head *head)
{
struct xlog_ticket *tic;
spin_lock(&head->lock);
list_for_each_entry(tic, &head->waiters, t_queue)
wake_up_process(tic->t_task);
spin_unlock(&head->lock);
}
static inline int
xlog_ticket_reservation(
struct xlog *log,
struct xlog_grant_head *head,
struct xlog_ticket *tic)
{
if (head == &log->l_write_head) {
ASSERT(tic->t_flags & XLOG_TIC_PERM_RESERV);
return tic->t_unit_res;
}
if (tic->t_flags & XLOG_TIC_PERM_RESERV)
return tic->t_unit_res * tic->t_cnt;
return tic->t_unit_res;
}
STATIC bool
xlog_grant_head_wake(
struct xlog *log,
struct xlog_grant_head *head,
int *free_bytes)
{
struct xlog_ticket *tic;
int need_bytes;
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_is_shutdown(log))
goto shutdown;
__set_current_state(TASK_UNINTERRUPTIBLE);
spin_unlock(&head->lock);
XFS_STATS_INC(log->l_mp, xs_sleep_logspace);
/* Push on the AIL to free up all the log space. */
xfs_ail_push_all(log->l_ailp);
trace_xfs_log_grant_sleep(log, tic);
schedule();
trace_xfs_log_grant_wake(log, tic);
spin_lock(&head->lock);
if (xlog_is_shutdown(log))
goto shutdown;
} while (xlog_grant_space_left(log, head) < need_bytes);
list_del_init(&tic->t_queue);
return 0;
shutdown:
list_del_init(&tic->t_queue);
return -EIO;
}
/*
* Atomically get the log space required for a log ticket.
*
* Once a ticket gets put onto head->waiters, it will only return after the
* needed reservation is satisfied.
*
* This function is structured so that it has a lock free fast path. This is
* necessary because every new transaction reservation will come through this
* path. Hence any lock will be globally hot if we take it unconditionally on
* every pass.
*
* As tickets are only ever moved on and off head->waiters under head->lock, we
* only need to take that lock if we are going to add the ticket to the queue
* and sleep. We can avoid taking the lock if the ticket was never added to
* head->waiters because the t_queue list head will be empty and we hold the
* only reference to it so it can safely be checked unlocked.
*/
STATIC int
xlog_grant_head_check(
struct xlog *log,
struct xlog_grant_head *head,
struct xlog_ticket *tic,
int *need_bytes)
{
int free_bytes;
int error = 0;
ASSERT(!xlog_in_recovery(log));
/*
* If there are other waiters on the queue then give them a chance at
* logspace before us. Wake up the first waiters, if we do not wake
* up all the waiters then go to sleep waiting for more free space,
* otherwise try to get some space for this transaction.
*/
*need_bytes = xlog_ticket_reservation(log, head, tic);
free_bytes = xlog_grant_space_left(log, head);
if (!list_empty_careful(&head->waiters)) {
spin_lock(&head->lock);
if (!xlog_grant_head_wake(log, head, &free_bytes) ||
free_bytes < *need_bytes) {
error = xlog_grant_head_wait(log, head, tic,
*need_bytes);
}
spin_unlock(&head->lock);
} else if (free_bytes < *need_bytes) {
spin_lock(&head->lock);
error = xlog_grant_head_wait(log, head, tic, *need_bytes);
spin_unlock(&head->lock);
}
return error;
}
bool
xfs_log_writable(
struct xfs_mount *mp)
{
/*
* Do not write to the log on norecovery mounts, if the data or log
* devices are read-only, or if the filesystem is shutdown. Read-only
* mounts allow internal writes for log recovery and unmount purposes,
* so don't restrict that case.
*/
if (xfs_has_norecovery(mp))
return false;
if (xfs_readonly_buftarg(mp->m_ddev_targp))
return false;
if (xfs_readonly_buftarg(mp->m_log->l_targ))
return false;
if (xlog_is_shutdown(mp->m_log))
return false;
return true;
}
/*
* Replenish the byte reservation required by moving the grant write head.
*/
int
xfs_log_regrant(
struct xfs_mount *mp,
struct xlog_ticket *tic)
{
struct xlog *log = mp->m_log;
int need_bytes;
int error = 0;
if (xlog_is_shutdown(log))
return -EIO;
XFS_STATS_INC(mp, xs_try_logspace);
/*
* This is a new transaction on the ticket, so we need to change the
* transaction ID so that the next transaction has a different TID in
* the log. Just add one to the existing tid so that we can see chains
* of rolling transactions in the log easily.
*/
tic->t_tid++;
tic->t_curr_res = tic->t_unit_res;
if (tic->t_cnt > 0)
return 0;
trace_xfs_log_regrant(log, tic);
error = xlog_grant_head_check(log, &log->l_write_head, tic,
&need_bytes);
if (error)
goto out_error;
xlog_grant_add_space(&log->l_write_head, need_bytes);
trace_xfs_log_regrant_exit(log, tic);
return 0;
out_error:
/*
* If we are failing, make sure the ticket doesn't have any current
* reservations. We don't want to add this back when the ticket/
* transaction gets cancelled.
*/
tic->t_curr_res = 0;
tic->t_cnt = 0; /* ungrant will give back unit_res * t_cnt. */
return error;
}
/*
* Reserve log space and return a ticket corresponding to the reservation.
*
* Each reservation is going to reserve extra space for a log record header.
* When writes happen to the on-disk log, we don't subtract the length of the
* log record header from any reservation. By wasting space in each
* reservation, we prevent over allocation problems.
*/
int
xfs_log_reserve(
struct xfs_mount *mp,
int unit_bytes,
int cnt,
struct xlog_ticket **ticp,
bool permanent)
{
struct xlog *log = mp->m_log;
struct xlog_ticket *tic;
int need_bytes;
int error = 0;
if (xlog_is_shutdown(log))
return -EIO;
XFS_STATS_INC(mp, xs_try_logspace);
ASSERT(*ticp == NULL);
tic = xlog_ticket_alloc(log, unit_bytes, cnt, permanent);
*ticp = tic;
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->l_reserve_head, need_bytes);
xlog_grant_add_space(&log->l_write_head, need_bytes);
trace_xfs_log_reserve_exit(log, tic);
return 0;
out_error:
/*
* If we are failing, make sure the ticket doesn't have any current
* reservations. We don't want to add this back when the ticket/
* transaction gets cancelled.
*/
tic->t_curr_res = 0;
tic->t_cnt = 0; /* ungrant will give back unit_res * t_cnt. */
return error;
}
/*
* Run all the pending iclog callbacks and wake log force waiters and iclog
* space waiters so they can process the newly set shutdown state. We really
* don't care what order we process callbacks here because the log is shut down
* and so state cannot change on disk anymore. However, we cannot wake waiters
* until the callbacks have been processed because we may be in unmount and
* we must ensure that all AIL operations the callbacks perform have completed
* before we tear down the AIL.
*
* We avoid processing actively referenced iclogs so that we don't run callbacks
* while the iclog owner might still be preparing the iclog for IO submssion.
* These will be caught by xlog_state_iclog_release() and call this function
* again to process any callbacks that may have been added to that iclog.
*/
static void
xlog_state_shutdown_callbacks(
struct xlog *log)
{
struct xlog_in_core *iclog;
LIST_HEAD(cb_list);
iclog = log->l_iclog;
do {
if (atomic_read(&iclog->ic_refcnt)) {
/* Reference holder will re-run iclog callbacks. */
continue;
}
list_splice_init(&iclog->ic_callbacks, &cb_list);
spin_unlock(&log->l_icloglock);
xlog_cil_process_committed(&cb_list);
spin_lock(&log->l_icloglock);
wake_up_all(&iclog->ic_write_wait);
wake_up_all(&iclog->ic_force_wait);
} while ((iclog = iclog->ic_next) != log->l_iclog);
wake_up_all(&log->l_flush_wait);
}
/*
* Flush iclog to disk if this is the last reference to the given iclog and the
* it is in the WANT_SYNC state.
*
* If XLOG_ICL_NEED_FUA is already set on the iclog, we need to ensure that the
* log tail is updated correctly. NEED_FUA indicates that the iclog will be
* written to stable storage, and implies that a commit record is contained
* within the iclog. We need to ensure that the log tail does not move beyond
* the tail that the first commit record in the iclog ordered against, otherwise
* correct recovery of that checkpoint becomes dependent on future operations
* performed on this iclog.
*
* Hence if NEED_FUA is set and the current iclog tail lsn is empty, write the
* current tail into iclog. Once the iclog tail is set, future operations must
* not modify it, otherwise they potentially violate ordering constraints for
* the checkpoint commit that wrote the initial tail lsn value. The tail lsn in
* the iclog will get zeroed on activation of the iclog after sync, so we
* always capture the tail lsn on the iclog on the first NEED_FUA release
* regardless of the number of active reference counts on this iclog.
*/
int
xlog_state_release_iclog(
struct xlog *log,
struct xlog_in_core *iclog,
struct xlog_ticket *ticket)
{
bool last_ref;
lockdep_assert_held(&log->l_icloglock);
trace_xlog_iclog_release(iclog, _RET_IP_);
/*
* Grabbing the current log tail needs to be atomic w.r.t. the writing
* of the tail LSN into the iclog so we guarantee that the log tail does
* not move between the first time we know that the iclog needs to be
* made stable and when we eventually submit it.
*/
if ((iclog->ic_state == XLOG_STATE_WANT_SYNC ||
(iclog->ic_flags & XLOG_ICL_NEED_FUA)) &&
!iclog->ic_header.h_tail_lsn) {
iclog->ic_header.h_tail_lsn =
cpu_to_be64(atomic64_read(&log->l_tail_lsn));
}
last_ref = atomic_dec_and_test(&iclog->ic_refcnt);
if (xlog_is_shutdown(log)) {
/*
* If there are no more references to this iclog, process the
* pending iclog callbacks that were waiting on the release of
* this iclog.
*/
if (last_ref)
xlog_state_shutdown_callbacks(log);
return -EIO;
}
if (!last_ref)
return 0;
if (iclog->ic_state != XLOG_STATE_WANT_SYNC) {
ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE);
return 0;
}
iclog->ic_state = XLOG_STATE_SYNCING;
xlog_verify_tail_lsn(log, iclog);
trace_xlog_iclog_syncing(iclog, _RET_IP_);
spin_unlock(&log->l_icloglock);
xlog_sync(log, iclog, ticket);
spin_lock(&log->l_icloglock);
return 0;
}
/*
* Mount a log filesystem
*
* mp - ubiquitous xfs mount point structure
* log_target - buftarg of on-disk log device
* blk_offset - Start block # where block size is 512 bytes (BBSIZE)
* num_bblocks - Number of BBSIZE blocks in on-disk log
*
* Return error or zero.
*/
int
xfs_log_mount(
xfs_mount_t *mp,
struct xfs_buftarg *log_target,
xfs_daddr_t blk_offset,
int num_bblks)
{
struct xlog *log;
int error = 0;
int min_logfsbs;
if (!xfs_has_norecovery(mp)) {
xfs_notice(mp, "Mounting V%d Filesystem %pU",
XFS_SB_VERSION_NUM(&mp->m_sb),
&mp->m_sb.sb_uuid);
} else {
xfs_notice(mp,
"Mounting V%d filesystem %pU in no-recovery mode. Filesystem will be inconsistent.",
XFS_SB_VERSION_NUM(&mp->m_sb),
&mp->m_sb.sb_uuid);
ASSERT(xfs_is_readonly(mp));
}
log = xlog_alloc_log(mp, log_target, blk_offset, num_bblks);
if (IS_ERR(log)) {
error = PTR_ERR(log);
goto out;
}
mp->m_log = log;
/*
* Now that we have set up the log and it's internal geometry
* parameters, we can validate the given log space and drop a critical
* message via syslog if the log size is too small. A log that is too
* small can lead to unexpected situations in transaction log space
* reservation stage. The superblock verifier has already validated all
* the other log geometry constraints, so we don't have to check those
* here.
*
* Note: For v4 filesystems, we can't just reject the mount if the
* validation fails. This would mean that people would have to
* downgrade their kernel just to remedy the situation as there is no
* way to grow the log (short of black magic surgery with xfs_db).
*
* We can, however, reject mounts for V5 format filesystems, as the
* mkfs binary being used to make the filesystem should never create a
* filesystem with a log that is too small.
*/
min_logfsbs = xfs_log_calc_minimum_size(mp);
if (mp->m_sb.sb_logblocks < min_logfsbs) {
xfs_warn(mp,
"Log size %d blocks too small, minimum size is %d blocks",
mp->m_sb.sb_logblocks, min_logfsbs);
/*
* Log check errors are always fatal on v5; or whenever bad
* metadata leads to a crash.
*/
if (xfs_has_crc(mp)) {
xfs_crit(mp, "AAIEEE! Log failed size checks. Abort!");
ASSERT(0);
error = -EINVAL;
goto out_free_log;
}
xfs_crit(mp, "Log size out of supported range.");
xfs_crit(mp,
"Continuing onwards, but if log hangs are experienced then please report this message in the bug report.");
}
/*
* Initialize the AIL now we have a log.
*/
error = xfs_trans_ail_init(mp);
if (error) {
xfs_warn(mp, "AIL initialisation failed: error %d", error);
goto out_free_log;
}
log->l_ailp = mp->m_ail;
/*
* skip log recovery on a norecovery mount. pretend it all
* just worked.
*/
if (!xfs_has_norecovery(mp)) {
error = xlog_recover(log);
if (error) {
xfs_warn(mp, "log mount/recovery failed: error %d",
error);
xlog_recover_cancel(log);
goto out_destroy_ail;
}
}
error = xfs_sysfs_init(&log->l_kobj, &xfs_log_ktype, &mp->m_kobj,
"log");
if (error)
goto out_destroy_ail;
/* Normal transactions can now occur */
clear_bit(XLOG_ACTIVE_RECOVERY, &log->l_opstate);
/*
* Now the log has been fully initialised and we know were our
* space grant counters are, we can initialise the permanent ticket
* needed for delayed logging to work.
*/
xlog_cil_init_post_recovery(log);
return 0;
out_destroy_ail:
xfs_trans_ail_destroy(mp);
out_free_log:
xlog_dealloc_log(log);
out:
return error;
}
/*
* Finish the recovery of the file system. This is separate from the
* xfs_log_mount() call, because it depends on the code in xfs_mountfs() to read
* in the root and real-time bitmap inodes between calling xfs_log_mount() and
* here.
*
* If we finish recovery successfully, start the background log work. If we are
* not doing recovery, then we have a RO filesystem and we don't need to start
* it.
*/
int
xfs_log_mount_finish(
struct xfs_mount *mp)
{
struct xlog *log = mp->m_log;
int error = 0;
if (xfs_has_norecovery(mp)) {
ASSERT(xfs_is_readonly(mp));
return 0;
}
/*
* During the second phase of log recovery, we need iget and
* iput to behave like they do for an active filesystem.
* xfs_fs_drop_inode needs to be able to prevent the deletion
* of inodes before we're done replaying log items on those
* inodes. Turn it off immediately after recovery finishes
* so that we don't leak the quota inodes if subsequent mount
* activities fail.
*
* We let all inodes involved in redo item processing end up on
* the LRU instead of being evicted immediately so that if we do
* something to an unlinked inode, the irele won't cause
* premature truncation and freeing of the inode, which results
* in log recovery failure. We have to evict the unreferenced
* lru inodes after clearing SB_ACTIVE because we don't
* otherwise clean up the lru if there's a subsequent failure in
* xfs_mountfs, which leads to us leaking the inodes if nothing
* else (e.g. quotacheck) references the inodes before the
* mount failure occurs.
*/
mp->m_super->s_flags |= SB_ACTIVE;
xfs_log_work_queue(mp);
if (xlog_recovery_needed(log))
error = xlog_recover_finish(log);
mp->m_super->s_flags &= ~SB_ACTIVE;
evict_inodes(mp->m_super);
/*
* Drain the buffer LRU after log recovery. This is required for v4
* filesystems to avoid leaving around buffers with NULL verifier ops,
* but we do it unconditionally to make sure we're always in a clean
* cache state after mount.
*
* Don't push in the error case because the AIL may have pending intents
* that aren't removed until recovery is cancelled.
*/
if (xlog_recovery_needed(log)) {
if (!error) {
xfs_log_force(mp, XFS_LOG_SYNC);
xfs_ail_push_all_sync(mp->m_ail);
}
xfs_notice(mp, "Ending recovery (logdev: %s)",
mp->m_logname ? mp->m_logname : "internal");
} else {
xfs_info(mp, "Ending clean mount");
}
xfs_buftarg_drain(mp->m_ddev_targp);
clear_bit(XLOG_RECOVERY_NEEDED, &log->l_opstate);
/* Make sure the log is dead if we're returning failure. */
ASSERT(!error || xlog_is_shutdown(log));
return error;
}
/*
* The mount has failed. Cancel the recovery if it hasn't completed and destroy
* the log.
*/
void
xfs_log_mount_cancel(
struct xfs_mount *mp)
{
xlog_recover_cancel(mp->m_log);
xfs_log_unmount(mp);
}
/*
* Flush out the iclog to disk ensuring that device caches are flushed and
* the iclog hits stable storage before any completion waiters are woken.
*/
static inline int
xlog_force_iclog(
struct xlog_in_core *iclog)
{
atomic_inc(&iclog->ic_refcnt);
iclog->ic_flags |= XLOG_ICL_NEED_FLUSH | XLOG_ICL_NEED_FUA;
if (iclog->ic_state == XLOG_STATE_ACTIVE)
xlog_state_switch_iclogs(iclog->ic_log, iclog, 0);
return xlog_state_release_iclog(iclog->ic_log, iclog, NULL);
}
/*
* Cycle all the iclogbuf locks to make sure all log IO completion
* is done before we tear down these buffers.
*/
static void
xlog_wait_iclog_completion(struct xlog *log)
{
int i;
struct xlog_in_core *iclog = log->l_iclog;
for (i = 0; i < log->l_iclog_bufs; i++) {
down(&iclog->ic_sema);
up(&iclog->ic_sema);
iclog = iclog->ic_next;
}
}
/*
* Wait for the iclog and all prior iclogs to be written disk as required by the
* log force state machine. Waiting on ic_force_wait ensures iclog completions
* have been ordered and callbacks run before we are woken here, hence
* guaranteeing that all the iclogs up to this one are on stable storage.
*/
int
xlog_wait_on_iclog(
struct xlog_in_core *iclog)
__releases(iclog->ic_log->l_icloglock)
{
struct xlog *log = iclog->ic_log;
trace_xlog_iclog_wait_on(iclog, _RET_IP_);
if (!xlog_is_shutdown(log) &&
iclog->ic_state != XLOG_STATE_ACTIVE &&
iclog->ic_state != XLOG_STATE_DIRTY) {
XFS_STATS_INC(log->l_mp, xs_log_force_sleep);
xlog_wait(&iclog->ic_force_wait, &log->l_icloglock);
} else {
spin_unlock(&log->l_icloglock);
}
if (xlog_is_shutdown(log))
return -EIO;
return 0;
}
/*
* Write out an unmount record using the ticket provided. We have to account for
* the data space used in the unmount ticket as this write is not done from a
* transaction context that has already done the accounting for us.
*/
static int
xlog_write_unmount_record(
struct xlog *log,
struct xlog_ticket *ticket)
{
struct {
struct xlog_op_header ophdr;
struct xfs_unmount_log_format ulf;
} unmount_rec = {
.ophdr = {
.oh_clientid = XFS_LOG,
.oh_tid = cpu_to_be32(ticket->t_tid),
.oh_flags = XLOG_UNMOUNT_TRANS,
},
.ulf = {
.magic = XLOG_UNMOUNT_TYPE,
},
};
struct xfs_log_iovec reg = {
.i_addr = &unmount_rec,
.i_len = sizeof(unmount_rec),
.i_type = XLOG_REG_TYPE_UNMOUNT,
};
struct xfs_log_vec vec = {
.lv_niovecs = 1,
.lv_iovecp = ®,
};
LIST_HEAD(lv_chain);
list_add(&vec.lv_list, &lv_chain);
BUILD_BUG_ON((sizeof(struct xlog_op_header) +
sizeof(struct xfs_unmount_log_format)) !=
sizeof(unmount_rec));
/* account for space used by record data */
ticket->t_curr_res -= sizeof(unmount_rec);
return xlog_write(log, NULL, &lv_chain, ticket, reg.i_len);
}
/*
* Mark the filesystem clean by writing an unmount record to the head of the
* log.
*/
static void
xlog_unmount_write(
struct xlog *log)
{
struct xfs_mount *mp = log->l_mp;
struct xlog_in_core *iclog;
struct xlog_ticket *tic = NULL;
int error;
error = xfs_log_reserve(mp, 600, 1, &tic, 0);
if (error)
goto out_err;
error = xlog_write_unmount_record(log, tic);
/*
* At this point, we're umounting anyway, so there's no point in
* transitioning log state to shutdown. Just continue...
*/
out_err:
if (error)
xfs_alert(mp, "%s: unmount record failed", __func__);
spin_lock(&log->l_icloglock);
iclog = log->l_iclog;
error = xlog_force_iclog(iclog);
xlog_wait_on_iclog(iclog);
if (tic) {
trace_xfs_log_umount_write(log, tic);
xfs_log_ticket_ungrant(log, tic);
}
}
static void
xfs_log_unmount_verify_iclog(
struct xlog *log)
{
struct xlog_in_core *iclog = log->l_iclog;
do {
ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE);
ASSERT(iclog->ic_offset == 0);
} while ((iclog = iclog->ic_next) != log->l_iclog);
}
/*
* Unmount record used to have a string "Unmount filesystem--" in the
* data section where the "Un" was really a magic number (XLOG_UNMOUNT_TYPE).
* We just write the magic number now since that particular field isn't
* currently architecture converted and "Unmount" is a bit foo.
* As far as I know, there weren't any dependencies on the old behaviour.
*/
static void
xfs_log_unmount_write(
struct xfs_mount *mp)
{
struct xlog *log = mp->m_log;
if (!xfs_log_writable(mp))
return;
xfs_log_force(mp, XFS_LOG_SYNC);
if (xlog_is_shutdown(log))
return;
/*
* If we think the summary counters are bad, avoid writing the unmount
* record to force log recovery at next mount, after which the summary
* counters will be recalculated. Refer to xlog_check_unmount_rec for
* more details.
*/
if (XFS_TEST_ERROR(xfs_fs_has_sickness(mp, XFS_SICK_FS_COUNTERS), mp,
XFS_ERRTAG_FORCE_SUMMARY_RECALC)) {
xfs_alert(mp, "%s: will fix summary counters at next mount",
__func__);
return;
}
xfs_log_unmount_verify_iclog(log);
xlog_unmount_write(log);
}
/*
* Empty the log for unmount/freeze.
*
* To do this, we first need to shut down the background log work so it is not
* trying to cover the log as we clean up. We then need to unpin all objects in
* the log so we can then flush them out. Once they have completed their IO and
* run the callbacks removing themselves from the AIL, we can cover the log.
*/
int
xfs_log_quiesce(
struct xfs_mount *mp)
{
/*
* Clear log incompat features since we're quiescing the log. Report
* failures, though it's not fatal to have a higher log feature
* protection level than the log contents actually require.
*/
if (xfs_clear_incompat_log_features(mp)) {
int error;
error = xfs_sync_sb(mp, false);
if (error)
xfs_warn(mp,
"Failed to clear log incompat features on quiesce");
}
cancel_delayed_work_sync(&mp->m_log->l_work);
xfs_log_force(mp, XFS_LOG_SYNC);
/*
* The superblock buffer is uncached and while xfs_ail_push_all_sync()
* will push it, xfs_buftarg_wait() will not wait for it. Further,
* xfs_buf_iowait() cannot be used because it was pushed with the
* XBF_ASYNC flag set, so we need to use a lock/unlock pair to wait for
* the IO to complete.
*/
xfs_ail_push_all_sync(mp->m_ail);
xfs_buftarg_wait(mp->m_ddev_targp);
xfs_buf_lock(mp->m_sb_bp);
xfs_buf_unlock(mp->m_sb_bp);
return xfs_log_cover(mp);
}
void
xfs_log_clean(
struct xfs_mount *mp)
{
xfs_log_quiesce(mp);
xfs_log_unmount_write(mp);
}
/*
* Shut down and release the AIL and Log.
*
* During unmount, we need to ensure we flush all the dirty metadata objects
* from the AIL so that the log is empty before we write the unmount record to
* the log. Once this is done, we can tear down the AIL and the log.
*/
void
xfs_log_unmount(
struct xfs_mount *mp)
{
xfs_log_clean(mp);
/*
* If shutdown has come from iclog IO context, the log
* cleaning will have been skipped and so we need to wait
* for the iclog to complete shutdown processing before we
* tear anything down.
*/
xlog_wait_iclog_completion(mp->m_log);
xfs_buftarg_drain(mp->m_ddev_targp);
xfs_trans_ail_destroy(mp);
xfs_sysfs_del(&mp->m_log->l_kobj);
xlog_dealloc_log(mp->m_log);
}
void
xfs_log_item_init(
struct xfs_mount *mp,
struct xfs_log_item *item,
int type,
const struct xfs_item_ops *ops)
{
item->li_log = mp->m_log;
item->li_ailp = mp->m_ail;
item->li_type = type;
item->li_ops = ops;
item->li_lv = NULL;
INIT_LIST_HEAD(&item->li_ail);
INIT_LIST_HEAD(&item->li_cil);
INIT_LIST_HEAD(&item->li_bio_list);
INIT_LIST_HEAD(&item->li_trans);
}
/*
* Wake up processes waiting for log space after we have moved the log tail.
*/
void
xfs_log_space_wake(
struct xfs_mount *mp)
{
struct xlog *log = mp->m_log;
int free_bytes;
if (xlog_is_shutdown(log))
return;
if (!list_empty_careful(&log->l_write_head.waiters)) {
ASSERT(!xlog_in_recovery(log));
spin_lock(&log->l_write_head.lock);
free_bytes = xlog_grant_space_left(log, &log->l_write_head);
xlog_grant_head_wake(log, &log->l_write_head, &free_bytes);
spin_unlock(&log->l_write_head.lock);
}
if (!list_empty_careful(&log->l_reserve_head.waiters)) {
ASSERT(!xlog_in_recovery(log));
spin_lock(&log->l_reserve_head.lock);
free_bytes = xlog_grant_space_left(log, &log->l_reserve_head);
xlog_grant_head_wake(log, &log->l_reserve_head, &free_bytes);
spin_unlock(&log->l_reserve_head.lock);
}
}
/*
* Determine if we have a transaction that has gone to disk that needs to be
* covered. To begin the transition to the idle state firstly the log needs to
* be idle. That means the CIL, the AIL and the iclogs needs to be empty before
* we start attempting to cover the log.
*
* Only if we are then in a state where covering is needed, the caller is
* informed that dummy transactions are required to move the log into the idle
* state.
*
* If there are any items in the AIl or CIL, then we do not want to attempt to
* cover the log as we may be in a situation where there isn't log space
* available to run a dummy transaction and this can lead to deadlocks when the
* tail of the log is pinned by an item that is modified in the CIL. Hence
* there's no point in running a dummy transaction at this point because we
* can't start trying to idle the log until both the CIL and AIL are empty.
*/
static bool
xfs_log_need_covered(
struct xfs_mount *mp)
{
struct xlog *log = mp->m_log;
bool needed = false;
if (!xlog_cil_empty(log))
return false;
spin_lock(&log->l_icloglock);
switch (log->l_covered_state) {
case XLOG_STATE_COVER_DONE:
case XLOG_STATE_COVER_DONE2:
case XLOG_STATE_COVER_IDLE:
break;
case XLOG_STATE_COVER_NEED:
case XLOG_STATE_COVER_NEED2:
if (xfs_ail_min_lsn(log->l_ailp))
break;
if (!xlog_iclogs_empty(log))
break;
needed = true;
if (log->l_covered_state == XLOG_STATE_COVER_NEED)
log->l_covered_state = XLOG_STATE_COVER_DONE;
else
log->l_covered_state = XLOG_STATE_COVER_DONE2;
break;
default:
needed = true;
break;
}
spin_unlock(&log->l_icloglock);
return needed;
}
/*
* Explicitly cover the log. This is similar to background log covering but
* intended for usage in quiesce codepaths. The caller is responsible to ensure
* the log is idle and suitable for covering. The CIL, iclog buffers and AIL
* must all be empty.
*/
static int
xfs_log_cover(
struct xfs_mount *mp)
{
int error = 0;
bool need_covered;
ASSERT((xlog_cil_empty(mp->m_log) && xlog_iclogs_empty(mp->m_log) &&
!xfs_ail_min_lsn(mp->m_log->l_ailp)) ||
xlog_is_shutdown(mp->m_log));
if (!xfs_log_writable(mp))
return 0;
/*
* xfs_log_need_covered() is not idempotent because it progresses the
* state machine if the log requires covering. Therefore, we must call
* this function once and use the result until we've issued an sb sync.
* Do so first to make that abundantly clear.
*
* Fall into the covering sequence if the log needs covering or the
* mount has lazy superblock accounting to sync to disk. The sb sync
* used for covering accumulates the in-core counters, so covering
* handles this for us.
*/
need_covered = xfs_log_need_covered(mp);
if (!need_covered && !xfs_has_lazysbcount(mp))
return 0;
/*
* To cover the log, commit the superblock twice (at most) in
* independent checkpoints. The first serves as a reference for the
* tail pointer. The sync transaction and AIL push empties the AIL and
* updates the in-core tail to the LSN of the first checkpoint. The
* second commit updates the on-disk tail with the in-core LSN,
* covering the log. Push the AIL one more time to leave it empty, as
* we found it.
*/
do {
error = xfs_sync_sb(mp, true);
if (error)
break;
xfs_ail_push_all_sync(mp->m_ail);
} while (xfs_log_need_covered(mp));
return error;
}
static void
xlog_ioend_work(
struct work_struct *work)
{
struct xlog_in_core *iclog =
container_of(work, struct xlog_in_core, ic_end_io_work);
struct xlog *log = iclog->ic_log;
int error;
error = blk_status_to_errno(iclog->ic_bio.bi_status);
#ifdef DEBUG
/* treat writes with injected CRC errors as failed */
if (iclog->ic_fail_crc)
error = -EIO;
#endif
/*
* Race to shutdown the filesystem if we see an error.
*/
if (XFS_TEST_ERROR(error, log->l_mp, XFS_ERRTAG_IODONE_IOERR)) {
xfs_alert(log->l_mp, "log I/O error %d", error);
xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR);
}
xlog_state_done_syncing(iclog);
bio_uninit(&iclog->ic_bio);
/*
* Drop the lock to signal that we are done. Nothing references the
* iclog after this, so an unmount waiting on this lock can now tear it
* down safely. As such, it is unsafe to reference the iclog after the
* unlock as we could race with it being freed.
*/
up(&iclog->ic_sema);
}
/*
* Return size of each in-core log record buffer.
*
* All machines get 8 x 32kB buffers by default, unless tuned otherwise.
*
* If the filesystem blocksize is too large, we may need to choose a
* larger size since the directory code currently logs entire blocks.
*/
STATIC void
xlog_get_iclog_buffer_size(
struct xfs_mount *mp,
struct xlog *log)
{
if (mp->m_logbufs <= 0)
mp->m_logbufs = XLOG_MAX_ICLOGS;
if (mp->m_logbsize <= 0)
mp->m_logbsize = XLOG_BIG_RECORD_BSIZE;
log->l_iclog_bufs = mp->m_logbufs;
log->l_iclog_size = mp->m_logbsize;
/*
* # headers = size / 32k - one header holds cycles from 32k of data.
*/
log->l_iclog_heads =
DIV_ROUND_UP(mp->m_logbsize, XLOG_HEADER_CYCLE_SIZE);
log->l_iclog_hsize = log->l_iclog_heads << BBSHIFT;
}
void
xfs_log_work_queue(
struct xfs_mount *mp)
{
queue_delayed_work(mp->m_sync_workqueue, &mp->m_log->l_work,
msecs_to_jiffies(xfs_syncd_centisecs * 10));
}
/*
* Clear the log incompat flags if we have the opportunity.
*
* This only happens if we're about to log the second dummy transaction as part
* of covering the log.
*/
static inline void
xlog_clear_incompat(
struct xlog *log)
{
struct xfs_mount *mp = log->l_mp;
if (!xfs_sb_has_incompat_log_feature(&mp->m_sb,
XFS_SB_FEAT_INCOMPAT_LOG_ALL))
return;
if (log->l_covered_state != XLOG_STATE_COVER_DONE2)
return;
xfs_clear_incompat_log_features(mp);
}
/*
* Every sync period we need to unpin all items in the AIL and push them to
* disk. If there is nothing dirty, then we might need to cover the log to
* indicate that the filesystem is idle.
*/
static void
xfs_log_worker(
struct work_struct *work)
{
struct xlog *log = container_of(to_delayed_work(work),
struct xlog, l_work);
struct xfs_mount *mp = log->l_mp;
/* dgc: errors ignored - not fatal and nowhere to report them */
if (xfs_fs_writable(mp, SB_FREEZE_WRITE) && xfs_log_need_covered(mp)) {
/*
* Dump a transaction into the log that contains no real change.
* This is needed to stamp the current tail LSN into the log
* during the covering operation.
*
* We cannot use an inode here for this - that will push dirty
* state back up into the VFS and then periodic inode flushing
* will prevent log covering from making progress. Hence we
* synchronously log the superblock instead to ensure the
* superblock is immediately unpinned and can be written back.
*/
xlog_clear_incompat(log);
xfs_sync_sb(mp, true);
} else
xfs_log_force(mp, 0);
/* start pushing all the metadata that is currently dirty */
xfs_ail_push_all(mp->m_ail);
/* queue us up again */
xfs_log_work_queue(mp);
}
/*
* This routine initializes some of the log structure for a given mount point.
* Its primary purpose is to fill in enough, so recovery can occur. However,
* some other stuff may be filled in too.
*/
STATIC struct xlog *
xlog_alloc_log(
struct xfs_mount *mp,
struct xfs_buftarg *log_target,
xfs_daddr_t blk_offset,
int num_bblks)
{
struct xlog *log;
xlog_rec_header_t *head;
xlog_in_core_t **iclogp;
xlog_in_core_t *iclog, *prev_iclog=NULL;
int i;
int error = -ENOMEM;
uint log2_size = 0;
log = kzalloc(sizeof(struct xlog), GFP_KERNEL | __GFP_RETRY_MAYFAIL);
if (!log) {
xfs_warn(mp, "Log allocation failed: No memory!");
goto out;
}
log->l_mp = mp;
log->l_targ = log_target;
log->l_logsize = BBTOB(num_bblks);
log->l_logBBstart = blk_offset;
log->l_logBBsize = num_bblks;
log->l_covered_state = XLOG_STATE_COVER_IDLE;
set_bit(XLOG_ACTIVE_RECOVERY, &log->l_opstate);
INIT_DELAYED_WORK(&log->l_work, xfs_log_worker);
INIT_LIST_HEAD(&log->r_dfops);
log->l_prev_block = -1;
/* log->l_tail_lsn = 0x100000000LL; cycle = 1; current block = 0 */
xlog_assign_atomic_lsn(&log->l_tail_lsn, 1, 0);
log->l_curr_cycle = 1; /* 0 is bad since this is initial value */
if (xfs_has_logv2(mp) && mp->m_sb.sb_logsunit > 1)
log->l_iclog_roundoff = mp->m_sb.sb_logsunit;
else
log->l_iclog_roundoff = BBSIZE;
xlog_grant_head_init(&log->l_reserve_head);
xlog_grant_head_init(&log->l_write_head);
error = -EFSCORRUPTED;
if (xfs_has_sector(mp)) {
log2_size = mp->m_sb.sb_logsectlog;
if (log2_size < BBSHIFT) {
xfs_warn(mp, "Log sector size too small (0x%x < 0x%x)",
log2_size, BBSHIFT);
goto out_free_log;
}
log2_size -= BBSHIFT;
if (log2_size > mp->m_sectbb_log) {
xfs_warn(mp, "Log sector size too large (0x%x > 0x%x)",
log2_size, mp->m_sectbb_log);
goto out_free_log;
}
/* for larger sector sizes, must have v2 or external log */
if (log2_size && log->l_logBBstart > 0 &&
!xfs_has_logv2(mp)) {
xfs_warn(mp,
"log sector size (0x%x) invalid for configuration.",
log2_size);
goto out_free_log;
}
}
log->l_sectBBsize = 1 << log2_size;
xlog_get_iclog_buffer_size(mp, log);
spin_lock_init(&log->l_icloglock);
init_waitqueue_head(&log->l_flush_wait);
iclogp = &log->l_iclog;
/*
* The amount of memory to allocate for the iclog structure is
* rather funky due to the way the structure is defined. It is
* done this way so that we can use different sizes for machines
* with different amounts of memory. See the definition of
* xlog_in_core_t in xfs_log_priv.h for details.
*/
ASSERT(log->l_iclog_size >= 4096);
for (i = 0; i < log->l_iclog_bufs; i++) {
size_t bvec_size = howmany(log->l_iclog_size, PAGE_SIZE) *
sizeof(struct bio_vec);
iclog = kzalloc(sizeof(*iclog) + bvec_size,
GFP_KERNEL | __GFP_RETRY_MAYFAIL);
if (!iclog)
goto out_free_iclog;
*iclogp = iclog;
iclog->ic_prev = prev_iclog;
prev_iclog = iclog;
iclog->ic_data = kvzalloc(log->l_iclog_size,
GFP_KERNEL | __GFP_RETRY_MAYFAIL);
if (!iclog->ic_data)
goto out_free_iclog;
head = &iclog->ic_header;
memset(head, 0, sizeof(xlog_rec_header_t));
head->h_magicno = cpu_to_be32(XLOG_HEADER_MAGIC_NUM);
head->h_version = cpu_to_be32(
xfs_has_logv2(log->l_mp) ? 2 : 1);
head->h_size = cpu_to_be32(log->l_iclog_size);
/* new fields */
head->h_fmt = cpu_to_be32(XLOG_FMT);
memcpy(&head->h_fs_uuid, &mp->m_sb.sb_uuid, sizeof(uuid_t));
iclog->ic_size = log->l_iclog_size - log->l_iclog_hsize;
iclog->ic_state = XLOG_STATE_ACTIVE;
iclog->ic_log = log;
atomic_set(&iclog->ic_refcnt, 0);
INIT_LIST_HEAD(&iclog->ic_callbacks);
iclog->ic_datap = (void *)iclog->ic_data + log->l_iclog_hsize;
init_waitqueue_head(&iclog->ic_force_wait);
init_waitqueue_head(&iclog->ic_write_wait);
INIT_WORK(&iclog->ic_end_io_work, xlog_ioend_work);
sema_init(&iclog->ic_sema, 1);
iclogp = &iclog->ic_next;
}
*iclogp = log->l_iclog; /* complete ring */
log->l_iclog->ic_prev = prev_iclog; /* re-write 1st prev ptr */
log->l_ioend_workqueue = alloc_workqueue("xfs-log/%s",
XFS_WQFLAGS(WQ_FREEZABLE | WQ_MEM_RECLAIM |
WQ_HIGHPRI),
0, mp->m_super->s_id);
if (!log->l_ioend_workqueue)
goto out_free_iclog;
error = xlog_cil_init(log);
if (error)
goto out_destroy_workqueue;
return log;
out_destroy_workqueue:
destroy_workqueue(log->l_ioend_workqueue);
out_free_iclog:
for (iclog = log->l_iclog; iclog; iclog = prev_iclog) {
prev_iclog = iclog->ic_next;
kvfree(iclog->ic_data);
kfree(iclog);
if (prev_iclog == log->l_iclog)
break;
}
out_free_log:
kfree(log);
out:
return ERR_PTR(error);
} /* xlog_alloc_log */
/*
* Stamp cycle number in every block
*/
STATIC void
xlog_pack_data(
struct xlog *log,
struct xlog_in_core *iclog,
int roundoff)
{
int i, j, k;
int size = iclog->ic_offset + roundoff;
__be32 cycle_lsn;
char *dp;
cycle_lsn = CYCLE_LSN_DISK(iclog->ic_header.h_lsn);
dp = iclog->ic_datap;
for (i = 0; i < BTOBB(size); i++) {
if (i >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE))
break;
iclog->ic_header.h_cycle_data[i] = *(__be32 *)dp;
*(__be32 *)dp = cycle_lsn;
dp += BBSIZE;
}
if (xfs_has_logv2(log->l_mp)) {
xlog_in_core_2_t *xhdr = iclog->ic_data;
for ( ; i < BTOBB(size); i++) {
j = i / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
k = i % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
xhdr[j].hic_xheader.xh_cycle_data[k] = *(__be32 *)dp;
*(__be32 *)dp = cycle_lsn;
dp += BBSIZE;
}
for (i = 1; i < log->l_iclog_heads; i++)
xhdr[i].hic_xheader.xh_cycle = cycle_lsn;
}
}
/*
* Calculate the checksum for a log buffer.
*
* This is a little more complicated than it should be because the various
* headers and the actual data are non-contiguous.
*/
__le32
xlog_cksum(
struct xlog *log,
struct xlog_rec_header *rhead,
char *dp,
int size)
{
uint32_t crc;
/* first generate the crc for the record header ... */
crc = xfs_start_cksum_update((char *)rhead,
sizeof(struct xlog_rec_header),
offsetof(struct xlog_rec_header, h_crc));
/* ... then for additional cycle data for v2 logs ... */
if (xfs_has_logv2(log->l_mp)) {
union xlog_in_core2 *xhdr = (union xlog_in_core2 *)rhead;
int i;
int xheads;
xheads = DIV_ROUND_UP(size, XLOG_HEADER_CYCLE_SIZE);
for (i = 1; i < xheads; i++) {
crc = crc32c(crc, &xhdr[i].hic_xheader,
sizeof(struct xlog_rec_ext_header));
}
}
/* ... and finally for the payload */
crc = crc32c(crc, dp, size);
return xfs_end_cksum(crc);
}
static void
xlog_bio_end_io(
struct bio *bio)
{
struct xlog_in_core *iclog = bio->bi_private;
queue_work(iclog->ic_log->l_ioend_workqueue,
&iclog->ic_end_io_work);
}
static int
xlog_map_iclog_data(
struct bio *bio,
void *data,
size_t count)
{
do {
struct page *page = kmem_to_page(data);
unsigned int off = offset_in_page(data);
size_t len = min_t(size_t, count, PAGE_SIZE - off);
if (bio_add_page(bio, page, len, off) != len)
return -EIO;
data += len;
count -= len;
} while (count);
return 0;
}
STATIC void
xlog_write_iclog(
struct xlog *log,
struct xlog_in_core *iclog,
uint64_t bno,
unsigned int count)
{
ASSERT(bno < log->l_logBBsize);
trace_xlog_iclog_write(iclog, _RET_IP_);
/*
* We lock the iclogbufs here so that we can serialise against I/O
* completion during unmount. We might be processing a shutdown
* triggered during unmount, and that can occur asynchronously to the
* unmount thread, and hence we need to ensure that completes before
* tearing down the iclogbufs. Hence we need to hold the buffer lock
* across the log IO to archieve that.
*/
down(&iclog->ic_sema);
if (xlog_is_shutdown(log)) {
/*
* It would seem logical to return EIO here, but we rely on
* the log state machine to propagate I/O errors instead of
* doing it here. We kick of the state machine and unlock
* the buffer manually, the code needs to be kept in sync
* with the I/O completion path.
*/
goto sync;
}
/*
* We use REQ_SYNC | REQ_IDLE here to tell the block layer the are more
* IOs coming immediately after this one. This prevents the block layer
* writeback throttle from throttling log writes behind background
* metadata writeback and causing priority inversions.
*/
bio_init(&iclog->ic_bio, log->l_targ->bt_bdev, iclog->ic_bvec,
howmany(count, PAGE_SIZE),
REQ_OP_WRITE | REQ_META | REQ_SYNC | REQ_IDLE);
iclog->ic_bio.bi_iter.bi_sector = log->l_logBBstart + bno;
iclog->ic_bio.bi_end_io = xlog_bio_end_io;
iclog->ic_bio.bi_private = iclog;
if (iclog->ic_flags & XLOG_ICL_NEED_FLUSH) {
iclog->ic_bio.bi_opf |= REQ_PREFLUSH;
/*
* For external log devices, we also need to flush the data
* device cache first to ensure all metadata writeback covered
* by the LSN in this iclog is on stable storage. This is slow,
* but it *must* complete before we issue the external log IO.
*
* If the flush fails, we cannot conclude that past metadata
* writeback from the log succeeded. Repeating the flush is
* not possible, hence we must shut down with log IO error to
* avoid shutdown re-entering this path and erroring out again.
*/
if (log->l_targ != log->l_mp->m_ddev_targp &&
blkdev_issue_flush(log->l_mp->m_ddev_targp->bt_bdev))
goto shutdown;
}
if (iclog->ic_flags & XLOG_ICL_NEED_FUA)
iclog->ic_bio.bi_opf |= REQ_FUA;
iclog->ic_flags &= ~(XLOG_ICL_NEED_FLUSH | XLOG_ICL_NEED_FUA);
if (xlog_map_iclog_data(&iclog->ic_bio, iclog->ic_data, count))
goto shutdown;
if (is_vmalloc_addr(iclog->ic_data))
flush_kernel_vmap_range(iclog->ic_data, count);
/*
* If this log buffer would straddle the end of the log we will have
* to split it up into two bios, so that we can continue at the start.
*/
if (bno + BTOBB(count) > log->l_logBBsize) {
struct bio *split;
split = bio_split(&iclog->ic_bio, log->l_logBBsize - bno,
GFP_NOIO, &fs_bio_set);
bio_chain(split, &iclog->ic_bio);
submit_bio(split);
/* restart at logical offset zero for the remainder */
iclog->ic_bio.bi_iter.bi_sector = log->l_logBBstart;
}
submit_bio(&iclog->ic_bio);
return;
shutdown:
xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR);
sync:
xlog_state_done_syncing(iclog);
up(&iclog->ic_sema);
}
/*
* We need to bump cycle number for the part of the iclog that is
* written to the start of the log. Watch out for the header magic
* number case, though.
*/
static void
xlog_split_iclog(
struct xlog *log,
void *data,
uint64_t bno,
unsigned int count)
{
unsigned int split_offset = BBTOB(log->l_logBBsize - bno);
unsigned int i;
for (i = split_offset; i < count; i += BBSIZE) {
uint32_t cycle = get_unaligned_be32(data + i);
if (++cycle == XLOG_HEADER_MAGIC_NUM)
cycle++;
put_unaligned_be32(cycle, data + i);
}
}
static int
xlog_calc_iclog_size(
struct xlog *log,
struct xlog_in_core *iclog,
uint32_t *roundoff)
{
uint32_t count_init, count;
/* Add for LR header */
count_init = log->l_iclog_hsize + iclog->ic_offset;
count = roundup(count_init, log->l_iclog_roundoff);
*roundoff = count - count_init;
ASSERT(count >= count_init);
ASSERT(*roundoff < log->l_iclog_roundoff);
return count;
}
/*
* Flush out the in-core log (iclog) to the on-disk log in an asynchronous
* fashion. Previously, we should have moved the current iclog
* ptr in the log to point to the next available iclog. This allows further
* write to continue while this code syncs out an iclog ready to go.
* Before an in-core log can be written out, the data section must be scanned
* to save away the 1st word of each BBSIZE block into the header. We replace
* it with the current cycle count. Each BBSIZE block is tagged with the
* cycle count because there in an implicit assumption that drives will
* guarantee that entire 512 byte blocks get written at once. In other words,
* we can't have part of a 512 byte block written and part not written. By
* tagging each block, we will know which blocks are valid when recovering
* after an unclean shutdown.
*
* This routine is single threaded on the iclog. No other thread can be in
* this routine with the same iclog. Changing contents of iclog can there-
* fore be done without grabbing the state machine lock. Updating the global
* log will require grabbing the lock though.
*
* The entire log manager uses a logical block numbering scheme. Only
* xlog_write_iclog knows about the fact that the log may not start with
* block zero on a given device.
*/
STATIC void
xlog_sync(
struct xlog *log,
struct xlog_in_core *iclog,
struct xlog_ticket *ticket)
{
unsigned int count; /* byte count of bwrite */
unsigned int roundoff; /* roundoff to BB or stripe */
uint64_t bno;
unsigned int size;
ASSERT(atomic_read(&iclog->ic_refcnt) == 0);
trace_xlog_iclog_sync(iclog, _RET_IP_);
count = xlog_calc_iclog_size(log, iclog, &roundoff);
/*
* If we have a ticket, account for the roundoff via the ticket
* reservation to avoid touching the hot grant heads needlessly.
* Otherwise, we have to move grant heads directly.
*/
if (ticket) {
ticket->t_curr_res -= roundoff;
} else {
xlog_grant_add_space(&log->l_reserve_head, roundoff);
xlog_grant_add_space(&log->l_write_head, roundoff);
}
/* put cycle number in every block */
xlog_pack_data(log, iclog, roundoff);
/* real byte length */
size = iclog->ic_offset;
if (xfs_has_logv2(log->l_mp))
size += roundoff;
iclog->ic_header.h_len = cpu_to_be32(size);
XFS_STATS_INC(log->l_mp, xs_log_writes);
XFS_STATS_ADD(log->l_mp, xs_log_blocks, BTOBB(count));
bno = BLOCK_LSN(be64_to_cpu(iclog->ic_header.h_lsn));
/* Do we need to split this write into 2 parts? */
if (bno + BTOBB(count) > log->l_logBBsize)
xlog_split_iclog(log, &iclog->ic_header, bno, count);
/* calculcate the checksum */
iclog->ic_header.h_crc = xlog_cksum(log, &iclog->ic_header,
iclog->ic_datap, size);
/*
* Intentionally corrupt the log record CRC based on the error injection
* frequency, if defined. This facilitates testing log recovery in the
* event of torn writes. Hence, set the IOABORT state to abort the log
* write on I/O completion and shutdown the fs. The subsequent mount
* detects the bad CRC and attempts to recover.
*/
#ifdef DEBUG
if (XFS_TEST_ERROR(false, log->l_mp, XFS_ERRTAG_LOG_BAD_CRC)) {
iclog->ic_header.h_crc &= cpu_to_le32(0xAAAAAAAA);
iclog->ic_fail_crc = true;
xfs_warn(log->l_mp,
"Intentionally corrupted log record at LSN 0x%llx. Shutdown imminent.",
be64_to_cpu(iclog->ic_header.h_lsn));
}
#endif
xlog_verify_iclog(log, iclog, count);
xlog_write_iclog(log, iclog, bno, count);
}
/*
* Deallocate a log structure
*/
STATIC void
xlog_dealloc_log(
struct xlog *log)
{
xlog_in_core_t *iclog, *next_iclog;
int i;
/*
* Destroy the CIL after waiting for iclog IO completion because an
* iclog EIO error will try to shut down the log, which accesses the
* CIL to wake up the waiters.
*/
xlog_cil_destroy(log);
iclog = log->l_iclog;
for (i = 0; i < log->l_iclog_bufs; i++) {
next_iclog = iclog->ic_next;
kvfree(iclog->ic_data);
kfree(iclog);
iclog = next_iclog;
}
log->l_mp->m_log = NULL;
destroy_workqueue(log->l_ioend_workqueue);
kfree(log);
}
/*
* Update counters atomically now that memcpy is done.
*/
static inline void
xlog_state_finish_copy(
struct xlog *log,
struct xlog_in_core *iclog,
int record_cnt,
int copy_bytes)
{
lockdep_assert_held(&log->l_icloglock);
be32_add_cpu(&iclog->ic_header.h_num_logops, record_cnt);
iclog->ic_offset += copy_bytes;
}
/*
* print out info relating to regions written which consume
* the reservation
*/
void
xlog_print_tic_res(
struct xfs_mount *mp,
struct xlog_ticket *ticket)
{
xfs_warn(mp, "ticket reservation summary:");
xfs_warn(mp, " unit res = %d bytes", ticket->t_unit_res);
xfs_warn(mp, " current res = %d bytes", ticket->t_curr_res);
xfs_warn(mp, " original count = %d", ticket->t_ocnt);
xfs_warn(mp, " remaining count = %d", ticket->t_cnt);
}
/*
* Print a summary of the transaction.
*/
void
xlog_print_trans(
struct xfs_trans *tp)
{
struct xfs_mount *mp = tp->t_mountp;
struct xfs_log_item *lip;
/* dump core transaction and ticket info */
xfs_warn(mp, "transaction summary:");
xfs_warn(mp, " log res = %d", tp->t_log_res);
xfs_warn(mp, " log count = %d", tp->t_log_count);
xfs_warn(mp, " flags = 0x%x", tp->t_flags);
xlog_print_tic_res(mp, tp->t_ticket);
/* dump each log item */
list_for_each_entry(lip, &tp->t_items, li_trans) {
struct xfs_log_vec *lv = lip->li_lv;
struct xfs_log_iovec *vec;
int i;
xfs_warn(mp, "log item: ");
xfs_warn(mp, " type = 0x%x", lip->li_type);
xfs_warn(mp, " flags = 0x%lx", lip->li_flags);
if (!lv)
continue;
xfs_warn(mp, " niovecs = %d", lv->lv_niovecs);
xfs_warn(mp, " size = %d", lv->lv_size);
xfs_warn(mp, " bytes = %d", lv->lv_bytes);
xfs_warn(mp, " buf len = %d", lv->lv_buf_len);
/* dump each iovec for the log item */
vec = lv->lv_iovecp;
for (i = 0; i < lv->lv_niovecs; i++) {
int dumplen = min(vec->i_len, 32);
xfs_warn(mp, " iovec[%d]", i);
xfs_warn(mp, " type = 0x%x", vec->i_type);
xfs_warn(mp, " len = %d", vec->i_len);
xfs_warn(mp, " first %d bytes of iovec[%d]:", dumplen, i);
xfs_hex_dump(vec->i_addr, dumplen);
vec++;
}
}
}
static inline void
xlog_write_iovec(
struct xlog_in_core *iclog,
uint32_t *log_offset,
void *data,
uint32_t write_len,
int *bytes_left,
uint32_t *record_cnt,
uint32_t *data_cnt)
{
ASSERT(*log_offset < iclog->ic_log->l_iclog_size);
ASSERT(*log_offset % sizeof(int32_t) == 0);
ASSERT(write_len % sizeof(int32_t) == 0);
memcpy(iclog->ic_datap + *log_offset, data, write_len);
*log_offset += write_len;
*bytes_left -= write_len;
(*record_cnt)++;
*data_cnt += write_len;
}
/*
* Write log vectors into a single iclog which is guaranteed by the caller
* to have enough space to write the entire log vector into.
*/
static void
xlog_write_full(
struct xfs_log_vec *lv,
struct xlog_ticket *ticket,
struct xlog_in_core *iclog,
uint32_t *log_offset,
uint32_t *len,
uint32_t *record_cnt,
uint32_t *data_cnt)
{
int index;
ASSERT(*log_offset + *len <= iclog->ic_size ||
iclog->ic_state == XLOG_STATE_WANT_SYNC);
/*
* Ordered log vectors have no regions to write so this
* loop will naturally skip them.
*/
for (index = 0; index < lv->lv_niovecs; index++) {
struct xfs_log_iovec *reg = &lv->lv_iovecp[index];
struct xlog_op_header *ophdr = reg->i_addr;
ophdr->oh_tid = cpu_to_be32(ticket->t_tid);
xlog_write_iovec(iclog, log_offset, reg->i_addr,
reg->i_len, len, record_cnt, data_cnt);
}
}
static int
xlog_write_get_more_iclog_space(
struct xlog_ticket *ticket,
struct xlog_in_core **iclogp,
uint32_t *log_offset,
uint32_t len,
uint32_t *record_cnt,
uint32_t *data_cnt)
{
struct xlog_in_core *iclog = *iclogp;
struct xlog *log = iclog->ic_log;
int error;
spin_lock(&log->l_icloglock);
ASSERT(iclog->ic_state == XLOG_STATE_WANT_SYNC);
xlog_state_finish_copy(log, iclog, *record_cnt, *data_cnt);
error = xlog_state_release_iclog(log, iclog, ticket);
spin_unlock(&log->l_icloglock);
if (error)
return error;
error = xlog_state_get_iclog_space(log, len, &iclog, ticket,
log_offset);
if (error)
return error;
*record_cnt = 0;
*data_cnt = 0;
*iclogp = iclog;
return 0;
}
/*
* Write log vectors into a single iclog which is smaller than the current chain
* length. We write until we cannot fit a full record into the remaining space
* and then stop. We return the log vector that is to be written that cannot
* wholly fit in the iclog.
*/
static int
xlog_write_partial(
struct xfs_log_vec *lv,
struct xlog_ticket *ticket,
struct xlog_in_core **iclogp,
uint32_t *log_offset,
uint32_t *len,
uint32_t *record_cnt,
uint32_t *data_cnt)
{
struct xlog_in_core *iclog = *iclogp;
struct xlog_op_header *ophdr;
int index = 0;
uint32_t rlen;
int error;
/* walk the logvec, copying until we run out of space in the iclog */
for (index = 0; index < lv->lv_niovecs; index++) {
struct xfs_log_iovec *reg = &lv->lv_iovecp[index];
uint32_t reg_offset = 0;
/*
* The first region of a continuation must have a non-zero
* length otherwise log recovery will just skip over it and
* start recovering from the next opheader it finds. Because we
* mark the next opheader as a continuation, recovery will then
* incorrectly add the continuation to the previous region and
* that breaks stuff.
*
* Hence if there isn't space for region data after the
* opheader, then we need to start afresh with a new iclog.
*/
if (iclog->ic_size - *log_offset <=
sizeof(struct xlog_op_header)) {
error = xlog_write_get_more_iclog_space(ticket,
&iclog, log_offset, *len, record_cnt,
data_cnt);
if (error)
return error;
}
ophdr = reg->i_addr;
rlen = min_t(uint32_t, reg->i_len, iclog->ic_size - *log_offset);
ophdr->oh_tid = cpu_to_be32(ticket->t_tid);
ophdr->oh_len = cpu_to_be32(rlen - sizeof(struct xlog_op_header));
if (rlen != reg->i_len)
ophdr->oh_flags |= XLOG_CONTINUE_TRANS;
xlog_write_iovec(iclog, log_offset, reg->i_addr,
rlen, len, record_cnt, data_cnt);
/* If we wrote the whole region, move to the next. */
if (rlen == reg->i_len)
continue;
/*
* We now have a partially written iovec, but it can span
* multiple iclogs so we loop here. First we release the iclog
* we currently have, then we get a new iclog and add a new
* opheader. Then we continue copying from where we were until
* we either complete the iovec or fill the iclog. If we
* complete the iovec, then we increment the index and go right
* back to the top of the outer loop. if we fill the iclog, we
* run the inner loop again.
*
* This is complicated by the tail of a region using all the
* space in an iclog and hence requiring us to release the iclog
* and get a new one before returning to the outer loop. We must
* always guarantee that we exit this inner loop with at least
* space for log transaction opheaders left in the current
* iclog, hence we cannot just terminate the loop at the end
* of the of the continuation. So we loop while there is no
* space left in the current iclog, and check for the end of the
* continuation after getting a new iclog.
*/
do {
/*
* Ensure we include the continuation opheader in the
* space we need in the new iclog by adding that size
* to the length we require. This continuation opheader
* needs to be accounted to the ticket as the space it
* consumes hasn't been accounted to the lv we are
* writing.
*/
error = xlog_write_get_more_iclog_space(ticket,
&iclog, log_offset,
*len + sizeof(struct xlog_op_header),
record_cnt, data_cnt);
if (error)
return error;
ophdr = iclog->ic_datap + *log_offset;
ophdr->oh_tid = cpu_to_be32(ticket->t_tid);
ophdr->oh_clientid = XFS_TRANSACTION;
ophdr->oh_res2 = 0;
ophdr->oh_flags = XLOG_WAS_CONT_TRANS;
ticket->t_curr_res -= sizeof(struct xlog_op_header);
*log_offset += sizeof(struct xlog_op_header);
*data_cnt += sizeof(struct xlog_op_header);
/*
* If rlen fits in the iclog, then end the region
* continuation. Otherwise we're going around again.
*/
reg_offset += rlen;
rlen = reg->i_len - reg_offset;
if (rlen <= iclog->ic_size - *log_offset)
ophdr->oh_flags |= XLOG_END_TRANS;
else
ophdr->oh_flags |= XLOG_CONTINUE_TRANS;
rlen = min_t(uint32_t, rlen, iclog->ic_size - *log_offset);
ophdr->oh_len = cpu_to_be32(rlen);
xlog_write_iovec(iclog, log_offset,
reg->i_addr + reg_offset,
rlen, len, record_cnt, data_cnt);
} while (ophdr->oh_flags & XLOG_CONTINUE_TRANS);
}
/*
* No more iovecs remain in this logvec so return the next log vec to
* the caller so it can go back to fast path copying.
*/
*iclogp = iclog;
return 0;
}
/*
* Write some region out to in-core log
*
* This will be called when writing externally provided regions or when
* writing out a commit record for a given transaction.
*
* General algorithm:
* 1. Find total length of this write. This may include adding to the
* lengths passed in.
* 2. Check whether we violate the tickets reservation.
* 3. While writing to this iclog
* A. Reserve as much space in this iclog as can get
* B. If this is first write, save away start lsn
* C. While writing this region:
* 1. If first write of transaction, write start record
* 2. Write log operation header (header per region)
* 3. Find out if we can fit entire region into this iclog
* 4. Potentially, verify destination memcpy ptr
* 5. Memcpy (partial) region
* 6. If partial copy, release iclog; otherwise, continue
* copying more regions into current iclog
* 4. Mark want sync bit (in simulation mode)
* 5. Release iclog for potential flush to on-disk log.
*
* ERRORS:
* 1. Panic if reservation is overrun. This should never happen since
* reservation amounts are generated internal to the filesystem.
* NOTES:
* 1. Tickets are single threaded data structures.
* 2. The XLOG_END_TRANS & XLOG_CONTINUE_TRANS flags are passed down to the
* syncing routine. When a single log_write region needs to span
* multiple in-core logs, the XLOG_CONTINUE_TRANS bit should be set
* on all log operation writes which don't contain the end of the
* region. The XLOG_END_TRANS bit is used for the in-core log
* operation which contains the end of the continued log_write region.
* 3. When xlog_state_get_iclog_space() grabs the rest of the current iclog,
* we don't really know exactly how much space will be used. As a result,
* we don't update ic_offset until the end when we know exactly how many
* bytes have been written out.
*/
int
xlog_write(
struct xlog *log,
struct xfs_cil_ctx *ctx,
struct list_head *lv_chain,
struct xlog_ticket *ticket,
uint32_t len)
{
struct xlog_in_core *iclog = NULL;
struct xfs_log_vec *lv;
uint32_t record_cnt = 0;
uint32_t data_cnt = 0;
int error = 0;
int log_offset;
if (ticket->t_curr_res < 0) {
xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
"ctx ticket reservation ran out. Need to up reservation");
xlog_print_tic_res(log->l_mp, ticket);
xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR);
}
error = xlog_state_get_iclog_space(log, len, &iclog, ticket,
&log_offset);
if (error)
return error;
ASSERT(log_offset <= iclog->ic_size - 1);
/*
* If we have a context pointer, pass it the first iclog we are
* writing to so it can record state needed for iclog write
* ordering.
*/
if (ctx)
xlog_cil_set_ctx_write_state(ctx, iclog);
list_for_each_entry(lv, lv_chain, lv_list) {
/*
* If the entire log vec does not fit in the iclog, punt it to
* the partial copy loop which can handle this case.
*/
if (lv->lv_niovecs &&
lv->lv_bytes > iclog->ic_size - log_offset) {
error = xlog_write_partial(lv, ticket, &iclog,
&log_offset, &len, &record_cnt,
&data_cnt);
if (error) {
/*
* We have no iclog to release, so just return
* the error immediately.
*/
return error;
}
} else {
xlog_write_full(lv, ticket, iclog, &log_offset,
&len, &record_cnt, &data_cnt);
}
}
ASSERT(len == 0);
/*
* We've already been guaranteed that the last writes will fit inside
* the current iclog, and hence it will already have the space used by
* those writes accounted to it. Hence we do not need to update the
* iclog with the number of bytes written here.
*/
spin_lock(&log->l_icloglock);
xlog_state_finish_copy(log, iclog, record_cnt, 0);
error = xlog_state_release_iclog(log, iclog, ticket);
spin_unlock(&log->l_icloglock);
return error;
}
static void
xlog_state_activate_iclog(
struct xlog_in_core *iclog,
int *iclogs_changed)
{
ASSERT(list_empty_careful(&iclog->ic_callbacks));
trace_xlog_iclog_activate(iclog, _RET_IP_);
/*
* If the number of ops in this iclog indicate it just contains the
* dummy transaction, we can change state into IDLE (the second time
* around). Otherwise we should change the state into NEED a dummy.
* We don't need to cover the dummy.
*/
if (*iclogs_changed == 0 &&
iclog->ic_header.h_num_logops == cpu_to_be32(XLOG_COVER_OPS)) {
*iclogs_changed = 1;
} else {
/*
* We have two dirty iclogs so start over. This could also be
* num of ops indicating this is not the dummy going out.
*/
*iclogs_changed = 2;
}
iclog->ic_state = XLOG_STATE_ACTIVE;
iclog->ic_offset = 0;
iclog->ic_header.h_num_logops = 0;
memset(iclog->ic_header.h_cycle_data, 0,
sizeof(iclog->ic_header.h_cycle_data));
iclog->ic_header.h_lsn = 0;
iclog->ic_header.h_tail_lsn = 0;
}
/*
* Loop through all iclogs and mark all iclogs currently marked DIRTY as
* ACTIVE after iclog I/O has completed.
*/
static void
xlog_state_activate_iclogs(
struct xlog *log,
int *iclogs_changed)
{
struct xlog_in_core *iclog = log->l_iclog;
do {
if (iclog->ic_state == XLOG_STATE_DIRTY)
xlog_state_activate_iclog(iclog, iclogs_changed);
/*
* The ordering of marking iclogs ACTIVE must be maintained, so
* an iclog doesn't become ACTIVE beyond one that is SYNCING.
*/
else if (iclog->ic_state != XLOG_STATE_ACTIVE)
break;
} while ((iclog = iclog->ic_next) != log->l_iclog);
}
static int
xlog_covered_state(
int prev_state,
int iclogs_changed)
{
/*
* We go to NEED for any non-covering writes. We go to NEED2 if we just
* wrote the first covering record (DONE). We go to IDLE if we just
* wrote the second covering record (DONE2) and remain in IDLE until a
* non-covering write occurs.
*/
switch (prev_state) {
case XLOG_STATE_COVER_IDLE:
if (iclogs_changed == 1)
return XLOG_STATE_COVER_IDLE;
fallthrough;
case XLOG_STATE_COVER_NEED:
case XLOG_STATE_COVER_NEED2:
break;
case XLOG_STATE_COVER_DONE:
if (iclogs_changed == 1)
return XLOG_STATE_COVER_NEED2;
break;
case XLOG_STATE_COVER_DONE2:
if (iclogs_changed == 1)
return XLOG_STATE_COVER_IDLE;
break;
default:
ASSERT(0);
}
return XLOG_STATE_COVER_NEED;
}
STATIC void
xlog_state_clean_iclog(
struct xlog *log,
struct xlog_in_core *dirty_iclog)
{
int iclogs_changed = 0;
trace_xlog_iclog_clean(dirty_iclog, _RET_IP_);
dirty_iclog->ic_state = XLOG_STATE_DIRTY;
xlog_state_activate_iclogs(log, &iclogs_changed);
wake_up_all(&dirty_iclog->ic_force_wait);
if (iclogs_changed) {
log->l_covered_state = xlog_covered_state(log->l_covered_state,
iclogs_changed);
}
}
STATIC xfs_lsn_t
xlog_get_lowest_lsn(
struct xlog *log)
{
struct xlog_in_core *iclog = log->l_iclog;
xfs_lsn_t lowest_lsn = 0, lsn;
do {
if (iclog->ic_state == XLOG_STATE_ACTIVE ||
iclog->ic_state == XLOG_STATE_DIRTY)
continue;
lsn = be64_to_cpu(iclog->ic_header.h_lsn);
if ((lsn && !lowest_lsn) || XFS_LSN_CMP(lsn, lowest_lsn) < 0)
lowest_lsn = lsn;
} while ((iclog = iclog->ic_next) != log->l_iclog);
return lowest_lsn;
}
/*
* Return true if we need to stop processing, false to continue to the next
* iclog. The caller will need to run callbacks if the iclog is returned in the
* XLOG_STATE_CALLBACK state.
*/
static bool
xlog_state_iodone_process_iclog(
struct xlog *log,
struct xlog_in_core *iclog)
{
xfs_lsn_t lowest_lsn;
xfs_lsn_t header_lsn;
switch (iclog->ic_state) {
case XLOG_STATE_ACTIVE:
case XLOG_STATE_DIRTY:
/*
* Skip all iclogs in the ACTIVE & DIRTY states:
*/
return false;
case XLOG_STATE_DONE_SYNC:
/*
* Now that we have an iclog that is in the DONE_SYNC state, do
* one more check here to see if we have chased our tail around.
* If this is not the lowest lsn iclog, then we will leave it
* for another completion to process.
*/
header_lsn = be64_to_cpu(iclog->ic_header.h_lsn);
lowest_lsn = xlog_get_lowest_lsn(log);
if (lowest_lsn && XFS_LSN_CMP(lowest_lsn, header_lsn) < 0)
return false;
/*
* If there are no callbacks on this iclog, we can mark it clean
* immediately and return. Otherwise we need to run the
* callbacks.
*/
if (list_empty(&iclog->ic_callbacks)) {
xlog_state_clean_iclog(log, iclog);
return false;
}
trace_xlog_iclog_callback(iclog, _RET_IP_);
iclog->ic_state = XLOG_STATE_CALLBACK;
return false;
default:
/*
* Can only perform callbacks in order. Since this iclog is not
* in the DONE_SYNC state, we skip the rest and just try to
* clean up.
*/
return true;
}
}
/*
* Loop over all the iclogs, running attached callbacks on them. Return true if
* we ran any callbacks, indicating that we dropped the icloglock. We don't need
* to handle transient shutdown state here at all because
* xlog_state_shutdown_callbacks() will be run to do the necessary shutdown
* cleanup of the callbacks.
*/
static bool
xlog_state_do_iclog_callbacks(
struct xlog *log)
__releases(&log->l_icloglock)
__acquires(&log->l_icloglock)
{
struct xlog_in_core *first_iclog = log->l_iclog;
struct xlog_in_core *iclog = first_iclog;
bool ran_callback = false;
do {
LIST_HEAD(cb_list);
if (xlog_state_iodone_process_iclog(log, iclog))
break;
if (iclog->ic_state != XLOG_STATE_CALLBACK) {
iclog = iclog->ic_next;
continue;
}
list_splice_init(&iclog->ic_callbacks, &cb_list);
spin_unlock(&log->l_icloglock);
trace_xlog_iclog_callbacks_start(iclog, _RET_IP_);
xlog_cil_process_committed(&cb_list);
trace_xlog_iclog_callbacks_done(iclog, _RET_IP_);
ran_callback = true;
spin_lock(&log->l_icloglock);
xlog_state_clean_iclog(log, iclog);
iclog = iclog->ic_next;
} while (iclog != first_iclog);
return ran_callback;
}
/*
* Loop running iclog completion callbacks until there are no more iclogs in a
* state that can run callbacks.
*/
STATIC void
xlog_state_do_callback(
struct xlog *log)
{
int flushcnt = 0;
int repeats = 0;
spin_lock(&log->l_icloglock);
while (xlog_state_do_iclog_callbacks(log)) {
if (xlog_is_shutdown(log))
break;
if (++repeats > 5000) {
flushcnt += repeats;
repeats = 0;
xfs_warn(log->l_mp,
"%s: possible infinite loop (%d iterations)",
__func__, flushcnt);
}
}
if (log->l_iclog->ic_state == XLOG_STATE_ACTIVE)
wake_up_all(&log->l_flush_wait);
spin_unlock(&log->l_icloglock);
}
/*
* Finish transitioning this iclog to the dirty state.
*
* Callbacks could take time, so they are done outside the scope of the
* global state machine log lock.
*/
STATIC void
xlog_state_done_syncing(
struct xlog_in_core *iclog)
{
struct xlog *log = iclog->ic_log;
spin_lock(&log->l_icloglock);
ASSERT(atomic_read(&iclog->ic_refcnt) == 0);
trace_xlog_iclog_sync_done(iclog, _RET_IP_);
/*
* If we got an error, either on the first buffer, or in the case of
* split log writes, on the second, we shut down the file system and
* no iclogs should ever be attempted to be written to disk again.
*/
if (!xlog_is_shutdown(log)) {
ASSERT(iclog->ic_state == XLOG_STATE_SYNCING);
iclog->ic_state = XLOG_STATE_DONE_SYNC;
}
/*
* Someone could be sleeping prior to writing out the next
* iclog buffer, we wake them all, one will get to do the
* I/O, the others get to wait for the result.
*/
wake_up_all(&iclog->ic_write_wait);
spin_unlock(&log->l_icloglock);
xlog_state_do_callback(log);
}
/*
* If the head of the in-core log ring is not (ACTIVE or DIRTY), then we must
* sleep. We wait on the flush queue on the head iclog as that should be
* the first iclog to complete flushing. Hence if all iclogs are syncing,
* we will wait here and all new writes will sleep until a sync completes.
*
* The in-core logs are used in a circular fashion. They are not used
* out-of-order even when an iclog past the head is free.
*
* return:
* * log_offset where xlog_write() can start writing into the in-core
* log's data space.
* * in-core log pointer to which xlog_write() should write.
* * boolean indicating this is a continued write to an in-core log.
* If this is the last write, then the in-core log's offset field
* needs to be incremented, depending on the amount of data which
* is copied.
*/
STATIC int
xlog_state_get_iclog_space(
struct xlog *log,
int len,
struct xlog_in_core **iclogp,
struct xlog_ticket *ticket,
int *logoffsetp)
{
int log_offset;
xlog_rec_header_t *head;
xlog_in_core_t *iclog;
restart:
spin_lock(&log->l_icloglock);
if (xlog_is_shutdown(log)) {
spin_unlock(&log->l_icloglock);
return -EIO;
}
iclog = log->l_iclog;
if (iclog->ic_state != XLOG_STATE_ACTIVE) {
XFS_STATS_INC(log->l_mp, xs_log_noiclogs);
/* Wait for log writes to have flushed */
xlog_wait(&log->l_flush_wait, &log->l_icloglock);
goto restart;
}
head = &iclog->ic_header;
atomic_inc(&iclog->ic_refcnt); /* prevents sync */
log_offset = iclog->ic_offset;
trace_xlog_iclog_get_space(iclog, _RET_IP_);
/* On the 1st write to an iclog, figure out lsn. This works
* if iclogs marked XLOG_STATE_WANT_SYNC always write out what they are
* committing to. If the offset is set, that's how many blocks
* must be written.
*/
if (log_offset == 0) {
ticket->t_curr_res -= log->l_iclog_hsize;
head->h_cycle = cpu_to_be32(log->l_curr_cycle);
head->h_lsn = cpu_to_be64(
xlog_assign_lsn(log->l_curr_cycle, log->l_curr_block));
ASSERT(log->l_curr_block >= 0);
}
/* If there is enough room to write everything, then do it. Otherwise,
* claim the rest of the region and make sure the XLOG_STATE_WANT_SYNC
* bit is on, so this will get flushed out. Don't update ic_offset
* until you know exactly how many bytes get copied. Therefore, wait
* until later to update ic_offset.
*
* xlog_write() algorithm assumes that at least 2 xlog_op_header_t's
* can fit into remaining data section.
*/
if (iclog->ic_size - iclog->ic_offset < 2*sizeof(xlog_op_header_t)) {
int error = 0;
xlog_state_switch_iclogs(log, iclog, iclog->ic_size);
/*
* If we are the only one writing to this iclog, sync it to
* disk. We need to do an atomic compare and decrement here to
* avoid racing with concurrent atomic_dec_and_lock() calls in
* xlog_state_release_iclog() when there is more than one
* reference to the iclog.
*/
if (!atomic_add_unless(&iclog->ic_refcnt, -1, 1))
error = xlog_state_release_iclog(log, iclog, ticket);
spin_unlock(&log->l_icloglock);
if (error)
return error;
goto restart;
}
/* Do we have enough room to write the full amount in the remainder
* of this iclog? Or must we continue a write on the next iclog and
* mark this iclog as completely taken? In the case where we switch
* iclogs (to mark it taken), this particular iclog will release/sync
* to disk in xlog_write().
*/
if (len <= iclog->ic_size - iclog->ic_offset)
iclog->ic_offset += len;
else
xlog_state_switch_iclogs(log, iclog, iclog->ic_size);
*iclogp = iclog;
ASSERT(iclog->ic_offset <= iclog->ic_size);
spin_unlock(&log->l_icloglock);
*logoffsetp = log_offset;
return 0;
}
/*
* The first cnt-1 times a ticket goes through here we don't need to move the
* grant write head because the permanent reservation has reserved cnt times the
* unit amount. Release part of current permanent unit reservation and reset
* current reservation to be one units worth. Also move grant reservation head
* forward.
*/
void
xfs_log_ticket_regrant(
struct xlog *log,
struct xlog_ticket *ticket)
{
trace_xfs_log_ticket_regrant(log, ticket);
if (ticket->t_cnt > 0)
ticket->t_cnt--;
xlog_grant_sub_space(&log->l_reserve_head, ticket->t_curr_res);
xlog_grant_sub_space(&log->l_write_head, ticket->t_curr_res);
ticket->t_curr_res = ticket->t_unit_res;
trace_xfs_log_ticket_regrant_sub(log, ticket);
/* just return if we still have some of the pre-reserved space */
if (!ticket->t_cnt) {
xlog_grant_add_space(&log->l_reserve_head, ticket->t_unit_res);
trace_xfs_log_ticket_regrant_exit(log, ticket);
ticket->t_curr_res = ticket->t_unit_res;
}
xfs_log_ticket_put(ticket);
}
/*
* Give back the space left from a reservation.
*
* All the information we need to make a correct determination of space left
* is present. For non-permanent reservations, things are quite easy. The
* count should have been decremented to zero. We only need to deal with the
* space remaining in the current reservation part of the ticket. If the
* ticket contains a permanent reservation, there may be left over space which
* needs to be released. A count of N means that N-1 refills of the current
* reservation can be done before we need to ask for more space. The first
* one goes to fill up the first current reservation. Once we run out of
* space, the count will stay at zero and the only space remaining will be
* in the current reservation field.
*/
void
xfs_log_ticket_ungrant(
struct xlog *log,
struct xlog_ticket *ticket)
{
int bytes;
trace_xfs_log_ticket_ungrant(log, ticket);
if (ticket->t_cnt > 0)
ticket->t_cnt--;
trace_xfs_log_ticket_ungrant_sub(log, ticket);
/*
* If this is a permanent reservation ticket, we may be able to free
* up more space based on the remaining count.
*/
bytes = ticket->t_curr_res;
if (ticket->t_cnt > 0) {
ASSERT(ticket->t_flags & XLOG_TIC_PERM_RESERV);
bytes += ticket->t_unit_res*ticket->t_cnt;
}
xlog_grant_sub_space(&log->l_reserve_head, bytes);
xlog_grant_sub_space(&log->l_write_head, bytes);
trace_xfs_log_ticket_ungrant_exit(log, ticket);
xfs_log_space_wake(log->l_mp);
xfs_log_ticket_put(ticket);
}
/*
* This routine will mark the current iclog in the ring as WANT_SYNC and move
* the current iclog pointer to the next iclog in the ring.
*/
void
xlog_state_switch_iclogs(
struct xlog *log,
struct xlog_in_core *iclog,
int eventual_size)
{
ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE);
assert_spin_locked(&log->l_icloglock);
trace_xlog_iclog_switch(iclog, _RET_IP_);
if (!eventual_size)
eventual_size = iclog->ic_offset;
iclog->ic_state = XLOG_STATE_WANT_SYNC;
iclog->ic_header.h_prev_block = cpu_to_be32(log->l_prev_block);
log->l_prev_block = log->l_curr_block;
log->l_prev_cycle = log->l_curr_cycle;
/* roll log?: ic_offset changed later */
log->l_curr_block += BTOBB(eventual_size)+BTOBB(log->l_iclog_hsize);
/* Round up to next log-sunit */
if (log->l_iclog_roundoff > BBSIZE) {
uint32_t sunit_bb = BTOBB(log->l_iclog_roundoff);
log->l_curr_block = roundup(log->l_curr_block, sunit_bb);
}
if (log->l_curr_block >= log->l_logBBsize) {
/*
* Rewind the current block before the cycle is bumped to make
* sure that the combined LSN never transiently moves forward
* when the log wraps to the next cycle. This is to support the
* unlocked sample of these fields from xlog_valid_lsn(). Most
* other cases should acquire l_icloglock.
*/
log->l_curr_block -= log->l_logBBsize;
ASSERT(log->l_curr_block >= 0);
smp_wmb();
log->l_curr_cycle++;
if (log->l_curr_cycle == XLOG_HEADER_MAGIC_NUM)
log->l_curr_cycle++;
}
ASSERT(iclog == log->l_iclog);
log->l_iclog = iclog->ic_next;
}
/*
* Force the iclog to disk and check if the iclog has been completed before
* xlog_force_iclog() returns. This can happen on synchronous (e.g.
* pmem) or fast async storage because we drop the icloglock to issue the IO.
* If completion has already occurred, tell the caller so that it can avoid an
* unnecessary wait on the iclog.
*/
static int
xlog_force_and_check_iclog(
struct xlog_in_core *iclog,
bool *completed)
{
xfs_lsn_t lsn = be64_to_cpu(iclog->ic_header.h_lsn);
int error;
*completed = false;
error = xlog_force_iclog(iclog);
if (error)
return error;
/*
* If the iclog has already been completed and reused the header LSN
* will have been rewritten by completion
*/
if (be64_to_cpu(iclog->ic_header.h_lsn) != lsn)
*completed = true;
return 0;
}
/*
* Write out all data in the in-core log as of this exact moment in time.
*
* Data may be written to the in-core log during this call. However,
* we don't guarantee this data will be written out. A change from past
* implementation means this routine will *not* write out zero length LRs.
*
* Basically, we try and perform an intelligent scan of the in-core logs.
* If we determine there is no flushable data, we just return. There is no
* flushable data if:
*
* 1. the current iclog is active and has no data; the previous iclog
* is in the active or dirty state.
* 2. the current iclog is drity, and the previous iclog is in the
* active or dirty state.
*
* We may sleep if:
*
* 1. the current iclog is not in the active nor dirty state.
* 2. the current iclog dirty, and the previous iclog is not in the
* active nor dirty state.
* 3. the current iclog is active, and there is another thread writing
* to this particular iclog.
* 4. a) the current iclog is active and has no other writers
* b) when we return from flushing out this iclog, it is still
* not in the active nor dirty state.
*/
int
xfs_log_force(
struct xfs_mount *mp,
uint flags)
{
struct xlog *log = mp->m_log;
struct xlog_in_core *iclog;
XFS_STATS_INC(mp, xs_log_force);
trace_xfs_log_force(mp, 0, _RET_IP_);
xlog_cil_force(log);
spin_lock(&log->l_icloglock);
if (xlog_is_shutdown(log))
goto out_error;
iclog = log->l_iclog;
trace_xlog_iclog_force(iclog, _RET_IP_);
if (iclog->ic_state == XLOG_STATE_DIRTY ||
(iclog->ic_state == XLOG_STATE_ACTIVE &&
atomic_read(&iclog->ic_refcnt) == 0 && iclog->ic_offset == 0)) {
/*
* If the head is dirty or (active and empty), then we need to
* look at the previous iclog.
*
* If the previous iclog is active or dirty we are done. There
* is nothing to sync out. Otherwise, we attach ourselves to the
* previous iclog and go to sleep.
*/
iclog = iclog->ic_prev;
} else if (iclog->ic_state == XLOG_STATE_ACTIVE) {
if (atomic_read(&iclog->ic_refcnt) == 0) {
/* We have exclusive access to this iclog. */
bool completed;
if (xlog_force_and_check_iclog(iclog, &completed))
goto out_error;
if (completed)
goto out_unlock;
} else {
/*
* Someone else is still writing to this iclog, so we
* need to ensure that when they release the iclog it
* gets synced immediately as we may be waiting on it.
*/
xlog_state_switch_iclogs(log, iclog, 0);
}
}
/*
* The iclog we are about to wait on may contain the checkpoint pushed
* by the above xlog_cil_force() call, but it may not have been pushed
* to disk yet. Like the ACTIVE case above, we need to make sure caches
* are flushed when this iclog is written.
*/
if (iclog->ic_state == XLOG_STATE_WANT_SYNC)
iclog->ic_flags |= XLOG_ICL_NEED_FLUSH | XLOG_ICL_NEED_FUA;
if (flags & XFS_LOG_SYNC)
return xlog_wait_on_iclog(iclog);
out_unlock:
spin_unlock(&log->l_icloglock);
return 0;
out_error:
spin_unlock(&log->l_icloglock);
return -EIO;
}
/*
* Force the log to a specific LSN.
*
* If an iclog with that lsn can be found:
* If it is in the DIRTY state, just return.
* If it is in the ACTIVE state, move the in-core log into the WANT_SYNC
* state and go to sleep or return.
* If it is in any other state, go to sleep or return.
*
* Synchronous forces are implemented with a wait queue. All callers trying
* to force a given lsn to disk must wait on the queue attached to the
* specific in-core log. When given in-core log finally completes its write
* to disk, that thread will wake up all threads waiting on the queue.
*/
static int
xlog_force_lsn(
struct xlog *log,
xfs_lsn_t lsn,
uint flags,
int *log_flushed,
bool already_slept)
{
struct xlog_in_core *iclog;
bool completed;
spin_lock(&log->l_icloglock);
if (xlog_is_shutdown(log))
goto out_error;
iclog = log->l_iclog;
while (be64_to_cpu(iclog->ic_header.h_lsn) != lsn) {
trace_xlog_iclog_force_lsn(iclog, _RET_IP_);
iclog = iclog->ic_next;
if (iclog == log->l_iclog)
goto out_unlock;
}
switch (iclog->ic_state) {
case XLOG_STATE_ACTIVE:
/*
* We sleep here if we haven't already slept (e.g. this is the
* first time we've looked at the correct iclog buf) and the
* buffer before us is going to be sync'ed. The reason for this
* is that if we are doing sync transactions here, by waiting
* for the previous I/O to complete, we can allow a few more
* transactions into this iclog before we close it down.
*
* Otherwise, we mark the buffer WANT_SYNC, and bump up the
* refcnt so we can release the log (which drops the ref count).
* The state switch keeps new transaction commits from using
* this buffer. When the current commits finish writing into
* the buffer, the refcount will drop to zero and the buffer
* will go out then.
*/
if (!already_slept &&
(iclog->ic_prev->ic_state == XLOG_STATE_WANT_SYNC ||
iclog->ic_prev->ic_state == XLOG_STATE_SYNCING)) {
xlog_wait(&iclog->ic_prev->ic_write_wait,
&log->l_icloglock);
return -EAGAIN;
}
if (xlog_force_and_check_iclog(iclog, &completed))
goto out_error;
if (log_flushed)
*log_flushed = 1;
if (completed)
goto out_unlock;
break;
case XLOG_STATE_WANT_SYNC:
/*
* This iclog may contain the checkpoint pushed by the
* xlog_cil_force_seq() call, but there are other writers still
* accessing it so it hasn't been pushed to disk yet. Like the
* ACTIVE case above, we need to make sure caches are flushed
* when this iclog is written.
*/
iclog->ic_flags |= XLOG_ICL_NEED_FLUSH | XLOG_ICL_NEED_FUA;
break;
default:
/*
* The entire checkpoint was written by the CIL force and is on
* its way to disk already. It will be stable when it
* completes, so we don't need to manipulate caches here at all.
* We just need to wait for completion if necessary.
*/
break;
}
if (flags & XFS_LOG_SYNC)
return xlog_wait_on_iclog(iclog);
out_unlock:
spin_unlock(&log->l_icloglock);
return 0;
out_error:
spin_unlock(&log->l_icloglock);
return -EIO;
}
/*
* Force the log to a specific checkpoint sequence.
*
* First force the CIL so that all the required changes have been flushed to the
* iclogs. If the CIL force completed it will return a commit LSN that indicates
* the iclog that needs to be flushed to stable storage. If the caller needs
* a synchronous log force, we will wait on the iclog with the LSN returned by
* xlog_cil_force_seq() to be completed.
*/
int
xfs_log_force_seq(
struct xfs_mount *mp,
xfs_csn_t seq,
uint flags,
int *log_flushed)
{
struct xlog *log = mp->m_log;
xfs_lsn_t lsn;
int ret;
ASSERT(seq != 0);
XFS_STATS_INC(mp, xs_log_force);
trace_xfs_log_force(mp, seq, _RET_IP_);
lsn = xlog_cil_force_seq(log, seq);
if (lsn == NULLCOMMITLSN)
return 0;
ret = xlog_force_lsn(log, lsn, flags, log_flushed, false);
if (ret == -EAGAIN) {
XFS_STATS_INC(mp, xs_log_force_sleep);
ret = xlog_force_lsn(log, lsn, flags, log_flushed, true);
}
return ret;
}
/*
* Free a used ticket when its refcount falls to zero.
*/
void
xfs_log_ticket_put(
xlog_ticket_t *ticket)
{
ASSERT(atomic_read(&ticket->t_ref) > 0);
if (atomic_dec_and_test(&ticket->t_ref))
kmem_cache_free(xfs_log_ticket_cache, ticket);
}
xlog_ticket_t *
xfs_log_ticket_get(
xlog_ticket_t *ticket)
{
ASSERT(atomic_read(&ticket->t_ref) > 0);
atomic_inc(&ticket->t_ref);
return ticket;
}
/*
* Figure out the total log space unit (in bytes) that would be
* required for a log ticket.
*/
static int
xlog_calc_unit_res(
struct xlog *log,
int unit_bytes,
int *niclogs)
{
int iclog_space;
uint num_headers;
/*
* Permanent reservations have up to 'cnt'-1 active log operations
* in the log. A unit in this case is the amount of space for one
* of these log operations. Normal reservations have a cnt of 1
* and their unit amount is the total amount of space required.
*
* The following lines of code account for non-transaction data
* which occupy space in the on-disk log.
*
* Normal form of a transaction is:
* <oph><trans-hdr><start-oph><reg1-oph><reg1><reg2-oph>...<commit-oph>
* and then there are LR hdrs, split-recs and roundoff at end of syncs.
*
* We need to account for all the leadup data and trailer data
* around the transaction data.
* And then we need to account for the worst case in terms of using
* more space.
* The worst case will happen if:
* - the placement of the transaction happens to be such that the
* roundoff is at its maximum
* - the transaction data is synced before the commit record is synced
* i.e. <transaction-data><roundoff> | <commit-rec><roundoff>
* Therefore the commit record is in its own Log Record.
* This can happen as the commit record is called with its
* own region to xlog_write().
* This then means that in the worst case, roundoff can happen for
* the commit-rec as well.
* The commit-rec is smaller than padding in this scenario and so it is
* not added separately.
*/
/* for trans header */
unit_bytes += sizeof(xlog_op_header_t);
unit_bytes += sizeof(xfs_trans_header_t);
/* for start-rec */
unit_bytes += sizeof(xlog_op_header_t);
/*
* for LR headers - the space for data in an iclog is the size minus
* the space used for the headers. If we use the iclog size, then we
* undercalculate the number of headers required.
*
* Furthermore - the addition of op headers for split-recs might
* increase the space required enough to require more log and op
* headers, so take that into account too.
*
* IMPORTANT: This reservation makes the assumption that if this
* transaction is the first in an iclog and hence has the LR headers
* accounted to it, then the remaining space in the iclog is
* exclusively for this transaction. i.e. if the transaction is larger
* than the iclog, it will be the only thing in that iclog.
* Fundamentally, this means we must pass the entire log vector to
* xlog_write to guarantee this.
*/
iclog_space = log->l_iclog_size - log->l_iclog_hsize;
num_headers = howmany(unit_bytes, iclog_space);
/* for split-recs - ophdrs added when data split over LRs */
unit_bytes += sizeof(xlog_op_header_t) * num_headers;
/* add extra header reservations if we overrun */
while (!num_headers ||
howmany(unit_bytes, iclog_space) > num_headers) {
unit_bytes += sizeof(xlog_op_header_t);
num_headers++;
}
unit_bytes += log->l_iclog_hsize * num_headers;
/* for commit-rec LR header - note: padding will subsume the ophdr */
unit_bytes += log->l_iclog_hsize;
/* roundoff padding for transaction data and one for commit record */
unit_bytes += 2 * log->l_iclog_roundoff;
if (niclogs)
*niclogs = num_headers;
return unit_bytes;
}
int
xfs_log_calc_unit_res(
struct xfs_mount *mp,
int unit_bytes)
{
return xlog_calc_unit_res(mp->m_log, unit_bytes, NULL);
}
/*
* Allocate and initialise a new log ticket.
*/
struct xlog_ticket *
xlog_ticket_alloc(
struct xlog *log,
int unit_bytes,
int cnt,
bool permanent)
{
struct xlog_ticket *tic;
int unit_res;
tic = kmem_cache_zalloc(xfs_log_ticket_cache,
GFP_KERNEL | __GFP_NOFAIL);
unit_res = xlog_calc_unit_res(log, unit_bytes, &tic->t_iclog_hdrs);
atomic_set(&tic->t_ref, 1);
tic->t_task = current;
INIT_LIST_HEAD(&tic->t_queue);
tic->t_unit_res = unit_res;
tic->t_curr_res = unit_res;
tic->t_cnt = cnt;
tic->t_ocnt = cnt;
tic->t_tid = get_random_u32();
if (permanent)
tic->t_flags |= XLOG_TIC_PERM_RESERV;
return tic;
}
#if defined(DEBUG)
static void
xlog_verify_dump_tail(
struct xlog *log,
struct xlog_in_core *iclog)
{
xfs_alert(log->l_mp,
"ran out of log space tail 0x%llx/0x%llx, head lsn 0x%llx, head 0x%x/0x%x, prev head 0x%x/0x%x",
iclog ? be64_to_cpu(iclog->ic_header.h_tail_lsn) : -1,
atomic64_read(&log->l_tail_lsn),
log->l_ailp->ail_head_lsn,
log->l_curr_cycle, log->l_curr_block,
log->l_prev_cycle, log->l_prev_block);
xfs_alert(log->l_mp,
"write grant 0x%llx, reserve grant 0x%llx, tail_space 0x%llx, size 0x%x, iclog flags 0x%x",
atomic64_read(&log->l_write_head.grant),
atomic64_read(&log->l_reserve_head.grant),
log->l_tail_space, log->l_logsize,
iclog ? iclog->ic_flags : -1);
}
/* Check if the new iclog will fit in the log. */
STATIC void
xlog_verify_tail_lsn(
struct xlog *log,
struct xlog_in_core *iclog)
{
xfs_lsn_t tail_lsn = be64_to_cpu(iclog->ic_header.h_tail_lsn);
int blocks;
if (CYCLE_LSN(tail_lsn) == log->l_prev_cycle) {
blocks = log->l_logBBsize -
(log->l_prev_block - BLOCK_LSN(tail_lsn));
if (blocks < BTOBB(iclog->ic_offset) +
BTOBB(log->l_iclog_hsize)) {
xfs_emerg(log->l_mp,
"%s: ran out of log space", __func__);
xlog_verify_dump_tail(log, iclog);
}
return;
}
if (CYCLE_LSN(tail_lsn) + 1 != log->l_prev_cycle) {
xfs_emerg(log->l_mp, "%s: head has wrapped tail.", __func__);
xlog_verify_dump_tail(log, iclog);
return;
}
if (BLOCK_LSN(tail_lsn) == log->l_prev_block) {
xfs_emerg(log->l_mp, "%s: tail wrapped", __func__);
xlog_verify_dump_tail(log, iclog);
return;
}
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 iclog space", __func__);
xlog_verify_dump_tail(log, iclog);
}
}
/*
* Perform a number of checks on the iclog before writing to disk.
*
* 1. Make sure the iclogs are still circular
* 2. Make sure we have a good magic number
* 3. Make sure we don't have magic numbers in the data
* 4. Check fields of each log operation header for:
* A. Valid client identifier
* B. tid ptr value falls in valid ptr space (user space code)
* C. Length in log record header is correct according to the
* individual operation headers within record.
* 5. When a bwrite will occur within 5 blocks of the front of the physical
* log, check the preceding blocks of the physical log to make sure all
* the cycle numbers agree with the current cycle number.
*/
STATIC void
xlog_verify_iclog(
struct xlog *log,
struct xlog_in_core *iclog,
int count)
{
xlog_op_header_t *ophead;
xlog_in_core_t *icptr;
xlog_in_core_2_t *xhdr;
void *base_ptr, *ptr, *p;
ptrdiff_t field_offset;
uint8_t clientid;
int len, i, j, k, op_len;
int idx;
/* check validity of iclog pointers */
spin_lock(&log->l_icloglock);
icptr = log->l_iclog;
for (i = 0; i < log->l_iclog_bufs; i++, icptr = icptr->ic_next)
ASSERT(icptr);
if (icptr != log->l_iclog)
xfs_emerg(log->l_mp, "%s: corrupt iclog ring", __func__);
spin_unlock(&log->l_icloglock);
/* check log magic numbers */
if (iclog->ic_header.h_magicno != cpu_to_be32(XLOG_HEADER_MAGIC_NUM))
xfs_emerg(log->l_mp, "%s: invalid magic num", __func__);
base_ptr = ptr = &iclog->ic_header;
p = &iclog->ic_header;
for (ptr += BBSIZE; ptr < base_ptr + count; ptr += BBSIZE) {
if (*(__be32 *)ptr == cpu_to_be32(XLOG_HEADER_MAGIC_NUM))
xfs_emerg(log->l_mp, "%s: unexpected magic num",
__func__);
}
/* check fields */
len = be32_to_cpu(iclog->ic_header.h_num_logops);
base_ptr = ptr = iclog->ic_datap;
ophead = ptr;
xhdr = iclog->ic_data;
for (i = 0; i < len; i++) {
ophead = ptr;
/* clientid is only 1 byte */
p = &ophead->oh_clientid;
field_offset = p - base_ptr;
if (field_offset & 0x1ff) {
clientid = ophead->oh_clientid;
} else {
idx = BTOBBT((void *)&ophead->oh_clientid - iclog->ic_datap);
if (idx >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) {
j = idx / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
k = idx % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
clientid = xlog_get_client_id(
xhdr[j].hic_xheader.xh_cycle_data[k]);
} else {
clientid = xlog_get_client_id(
iclog->ic_header.h_cycle_data[idx]);
}
}
if (clientid != XFS_TRANSACTION && clientid != XFS_LOG) {
xfs_warn(log->l_mp,
"%s: op %d invalid clientid %d op "PTR_FMT" offset 0x%lx",
__func__, i, clientid, ophead,
(unsigned long)field_offset);
}
/* check length */
p = &ophead->oh_len;
field_offset = p - base_ptr;
if (field_offset & 0x1ff) {
op_len = be32_to_cpu(ophead->oh_len);
} else {
idx = BTOBBT((void *)&ophead->oh_len - iclog->ic_datap);
if (idx >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) {
j = idx / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
k = idx % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
op_len = be32_to_cpu(xhdr[j].hic_xheader.xh_cycle_data[k]);
} else {
op_len = be32_to_cpu(iclog->ic_header.h_cycle_data[idx]);
}
}
ptr += sizeof(xlog_op_header_t) + op_len;
}
}
#endif
/*
* Perform a forced shutdown on the log.
*
* This can be called from low level log code to trigger a shutdown, or from the
* high level mount shutdown code when the mount shuts down.
*
* Our main objectives here are to make sure that:
* a. if the shutdown was not due to a log IO error, flush the logs to
* disk. Anything modified after this is ignored.
* b. the log gets atomically marked 'XLOG_IO_ERROR' for all interested
* parties to find out. Nothing new gets queued after this is done.
* c. Tasks sleeping on log reservations, pinned objects and
* other resources get woken up.
* d. The mount is also marked as shut down so that log triggered shutdowns
* still behave the same as if they called xfs_forced_shutdown().
*
* Return true if the shutdown cause was a log IO error and we actually shut the
* log down.
*/
bool
xlog_force_shutdown(
struct xlog *log,
uint32_t shutdown_flags)
{
bool log_error = (shutdown_flags & SHUTDOWN_LOG_IO_ERROR);
if (!log)
return false;
/*
* Flush all the completed transactions to disk before marking the log
* being shut down. We need to do this first as shutting down the log
* before the force will prevent the log force from flushing the iclogs
* to disk.
*
* When we are in recovery, there are no transactions to flush, and
* we don't want to touch the log because we don't want to perturb the
* current head/tail for future recovery attempts. Hence we need to
* avoid a log force in this case.
*
* If we are shutting down due to a log IO error, then we must avoid
* trying to write the log as that may just result in more IO errors and
* an endless shutdown/force loop.
*/
if (!log_error && !xlog_in_recovery(log))
xfs_log_force(log->l_mp, XFS_LOG_SYNC);
/*
* Atomically set the shutdown state. If the shutdown state is already
* set, there someone else is performing the shutdown and so we are done
* here. This should never happen because we should only ever get called
* once by the first shutdown caller.
*
* Much of the log state machine transitions assume that shutdown state
* cannot change once they hold the log->l_icloglock. Hence we need to
* hold that lock here, even though we use the atomic test_and_set_bit()
* operation to set the shutdown state.
*/
spin_lock(&log->l_icloglock);
if (test_and_set_bit(XLOG_IO_ERROR, &log->l_opstate)) {
spin_unlock(&log->l_icloglock);
return false;
}
spin_unlock(&log->l_icloglock);
/*
* If this log shutdown also sets the mount shutdown state, issue a
* shutdown warning message.
*/
if (!xfs_set_shutdown(log->l_mp)) {
xfs_alert_tag(log->l_mp, XFS_PTAG_SHUTDOWN_LOGERROR,
"Filesystem has been shut down due to log error (0x%x).",
shutdown_flags);
xfs_alert(log->l_mp,
"Please unmount the filesystem and rectify the problem(s).");
if (xfs_error_level >= XFS_ERRLEVEL_HIGH)
xfs_stack_trace();
}
/*
* We don't want anybody waiting for log reservations after this. That
* means we have to wake up everybody queued up on reserveq as well as
* writeq. In addition, we make sure in xlog_{re}grant_log_space that
* we don't enqueue anything once the SHUTDOWN flag is set, and this
* action is protected by the grant locks.
*/
xlog_grant_head_wake_all(&log->l_reserve_head);
xlog_grant_head_wake_all(&log->l_write_head);
/*
* Wake up everybody waiting on xfs_log_force. Wake the CIL push first
* as if the log writes were completed. The abort handling in the log
* item committed callback functions will do this again under lock to
* avoid races.
*/
spin_lock(&log->l_cilp->xc_push_lock);
wake_up_all(&log->l_cilp->xc_start_wait);
wake_up_all(&log->l_cilp->xc_commit_wait);
spin_unlock(&log->l_cilp->xc_push_lock);
spin_lock(&log->l_icloglock);
xlog_state_shutdown_callbacks(log);
spin_unlock(&log->l_icloglock);
wake_up_var(&log->l_opstate);
return log_error;
}
STATIC int
xlog_iclogs_empty(
struct xlog *log)
{
xlog_in_core_t *iclog;
iclog = log->l_iclog;
do {
/* endianness does not matter here, zero is zero in
* any language.
*/
if (iclog->ic_header.h_num_logops)
return 0;
iclog = iclog->ic_next;
} while (iclog != log->l_iclog);
return 1;
}
/*
* Verify that an LSN stamped into a piece of metadata is valid. This is
* intended for use in read verifiers on v5 superblocks.
*/
bool
xfs_log_check_lsn(
struct xfs_mount *mp,
xfs_lsn_t lsn)
{
struct xlog *log = mp->m_log;
bool valid;
/*
* norecovery mode skips mount-time log processing and unconditionally
* resets the in-core LSN. We can't validate in this mode, but
* modifications are not allowed anyways so just return true.
*/
if (xfs_has_norecovery(mp))
return true;
/*
* Some metadata LSNs are initialized to NULL (e.g., the agfl). This is
* handled by recovery and thus safe to ignore here.
*/
if (lsn == NULLCOMMITLSN)
return true;
valid = xlog_valid_lsn(mp->m_log, lsn);
/* warn the user about what's gone wrong before verifier failure */
if (!valid) {
spin_lock(&log->l_icloglock);
xfs_warn(mp,
"Corruption warning: Metadata has LSN (%d:%d) ahead of current LSN (%d:%d). "
"Please unmount and run xfs_repair (>= v4.3) to resolve.",
CYCLE_LSN(lsn), BLOCK_LSN(lsn),
log->l_curr_cycle, log->l_curr_block);
spin_unlock(&log->l_icloglock);
}
return valid;
}
Codebase Browser
linux