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linux/fs/xfs/xfs_log.c
Darrick J. Wong 8e9800f9f2 xfs: don't allow log writes if the data device is readonly 
While running generic/050 with an external log, I observed this warning
in dmesg:

Trying to write to read-only block-device sda4 (partno 4)
WARNING: CPU: 2 PID: 215677 at block/blk-core.c:704 submit_bio_checks+0x256/0x510
Call Trace:
 submit_bio_noacct+0x2c/0x430
 _xfs_buf_ioapply+0x283/0x3c0 [xfs]
 __xfs_buf_submit+0x6a/0x210 [xfs]
 xfs_buf_delwri_submit_buffers+0xf8/0x270 [xfs]
 xfsaild+0x2db/0xc50 [xfs]
 kthread+0x14b/0x170

I think this happened because we tried to cover the log after a readonly
mount, and the AIL tried to write the primary superblock to the data
device.  The test marks the data device readonly, but it doesn't do the
same to the external log device.  Therefore, XFS thinks that the log is
writable, even though AIL writes whine to dmesg because the data device
is read only.

Fix this by amending xfs_log_writable to prevent writes when the AIL
can't possible write anything into the filesystem.

Note: As for the external log or the rt devices being readonly--
xfs_blkdev_get will complain about that if we aren't doing a norecovery
mount.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2021-05-04 08:43:27 -07:00

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// 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"
kmem_zone_t *xfs_log_ticket_zone;
/* Local miscellaneous function prototypes */
STATIC struct xlog *
xlog_alloc_log(
struct xfs_mount *mp,
struct xfs_buftarg *log_target,
xfs_daddr_t blk_offset,
int num_bblks);
STATIC int
xlog_space_left(
struct xlog *log,
atomic64_t *head);
STATIC void
xlog_dealloc_log(
struct xlog *log);
/* local state machine functions */
STATIC void xlog_state_done_syncing(
struct xlog_in_core *iclog);
STATIC int
xlog_state_get_iclog_space(
struct xlog *log,
int len,
struct xlog_in_core **iclog,
struct xlog_ticket *ticket,
int *continued_write,
int *logoffsetp);
STATIC void
xlog_state_switch_iclogs(
struct xlog *log,
struct xlog_in_core *iclog,
int eventual_size);
STATIC void
xlog_grant_push_ail(
struct xlog *log,
int need_bytes);
STATIC void
xlog_sync(
struct xlog *log,
struct xlog_in_core *iclog);
#if defined(DEBUG)
STATIC void
xlog_verify_dest_ptr(
struct xlog *log,
void *ptr);
STATIC void
xlog_verify_grant_tail(
struct xlog *log);
STATIC void
xlog_verify_iclog(
struct xlog *log,
struct xlog_in_core *iclog,
int count);
STATIC void
xlog_verify_tail_lsn(
struct xlog *log,
struct xlog_in_core *iclog,
xfs_lsn_t tail_lsn);
#else
#define xlog_verify_dest_ptr(a,b)
#define xlog_verify_grant_tail(a)
#define xlog_verify_iclog(a,b,c)
#define xlog_verify_tail_lsn(a,b,c)
#endif
STATIC int
xlog_iclogs_empty(
struct xlog *log);
static int
xfs_log_cover(struct xfs_mount *);
static void
xlog_grant_sub_space(
struct xlog *log,
atomic64_t *head,
int bytes)
{
int64_t head_val = atomic64_read(head);
int64_t new, old;
do {
int cycle, space;
xlog_crack_grant_head_val(head_val, &cycle, &space);
space -= bytes;
if (space < 0) {
space += log->l_logsize;
cycle--;
}
old = head_val;
new = xlog_assign_grant_head_val(cycle, space);
head_val = atomic64_cmpxchg(head, old, new);
} while (head_val != old);
}
static void
xlog_grant_add_space(
struct xlog *log,
atomic64_t *head,
int bytes)
{
int64_t head_val = atomic64_read(head);
int64_t new, old;
do {
int tmp;
int cycle, space;
xlog_crack_grant_head_val(head_val, &cycle, &space);
tmp = log->l_logsize - space;
if (tmp > bytes)
space += bytes;
else {
space = bytes - tmp;
cycle++;
}
old = head_val;
new = xlog_assign_grant_head_val(cycle, space);
head_val = atomic64_cmpxchg(head, old, new);
} while (head_val != old);
}
STATIC void
xlog_grant_head_init(
struct xlog_grant_head *head)
{
xlog_assign_grant_head(&head->grant, 1, 0);
INIT_LIST_HEAD(&head->waiters);
spin_lock_init(&head->lock);
}
STATIC void
xlog_grant_head_wake_all(
struct xlog_grant_head *head)
{
struct xlog_ticket *tic;
spin_lock(&head->lock);
list_for_each_entry(tic, &head->waiters, t_queue)
wake_up_process(tic->t_task);
spin_unlock(&head->lock);
}
static inline int
xlog_ticket_reservation(
struct xlog *log,
struct xlog_grant_head *head,
struct xlog_ticket *tic)
{
if (head == &log->l_write_head) {
ASSERT(tic->t_flags & XLOG_TIC_PERM_RESERV);
return tic->t_unit_res;
} else {
if (tic->t_flags & XLOG_TIC_PERM_RESERV)
return tic->t_unit_res * tic->t_cnt;
else
return tic->t_unit_res;
}
}
STATIC bool
xlog_grant_head_wake(
struct xlog *log,
struct xlog_grant_head *head,
int *free_bytes)
{
struct xlog_ticket *tic;
int need_bytes;
bool woken_task = false;
list_for_each_entry(tic, &head->waiters, t_queue) {
/*
* There is a chance that the size of the CIL checkpoints in
* progress at the last AIL push target calculation resulted in
* limiting the target to the log head (l_last_sync_lsn) at the
* time. This may not reflect where the log head is now as the
* CIL checkpoints may have completed.
*
* Hence when we are woken here, it may be that the head of the
* log that has moved rather than the tail. As the tail didn't
* move, there still won't be space available for the
* reservation we require. However, if the AIL has already
* pushed to the target defined by the old log head location, we
* will hang here waiting for something else to update the AIL
* push target.
*
* Therefore, if there isn't space to wake the first waiter on
* the grant head, we need to push the AIL again to ensure the
* target reflects both the current log tail and log head
* position before we wait for the tail to move again.
*/
need_bytes = xlog_ticket_reservation(log, head, tic);
if (*free_bytes < need_bytes) {
if (!woken_task)
xlog_grant_push_ail(log, need_bytes);
return false;
}
*free_bytes -= need_bytes;
trace_xfs_log_grant_wake_up(log, tic);
wake_up_process(tic->t_task);
woken_task = true;
}
return true;
}
STATIC int
xlog_grant_head_wait(
struct xlog *log,
struct xlog_grant_head *head,
struct xlog_ticket *tic,
int need_bytes) __releases(&head->lock)
__acquires(&head->lock)
{
list_add_tail(&tic->t_queue, &head->waiters);
do {
if (XLOG_FORCED_SHUTDOWN(log))
goto shutdown;
xlog_grant_push_ail(log, need_bytes);
__set_current_state(TASK_UNINTERRUPTIBLE);
spin_unlock(&head->lock);
XFS_STATS_INC(log->l_mp, xs_sleep_logspace);
trace_xfs_log_grant_sleep(log, tic);
schedule();
trace_xfs_log_grant_wake(log, tic);
spin_lock(&head->lock);
if (XLOG_FORCED_SHUTDOWN(log))
goto shutdown;
} while (xlog_space_left(log, &head->grant) < need_bytes);
list_del_init(&tic->t_queue);
return 0;
shutdown:
list_del_init(&tic->t_queue);
return -EIO;
}
/*
* Atomically get the log space required for a log ticket.
*
* Once a ticket gets put onto head->waiters, it will only return after the
* needed reservation is satisfied.
*
* This function is structured so that it has a lock free fast path. This is
* necessary because every new transaction reservation will come through this
* path. Hence any lock will be globally hot if we take it unconditionally on
* every pass.
*
* As tickets are only ever moved on and off head->waiters under head->lock, we
* only need to take that lock if we are going to add the ticket to the queue
* and sleep. We can avoid taking the lock if the ticket was never added to
* head->waiters because the t_queue list head will be empty and we hold the
* only reference to it so it can safely be checked unlocked.
*/
STATIC int
xlog_grant_head_check(
struct xlog *log,
struct xlog_grant_head *head,
struct xlog_ticket *tic,
int *need_bytes)
{
int free_bytes;
int error = 0;
ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
/*
* If there are other waiters on the queue then give them a chance at
* logspace before us. Wake up the first waiters, if we do not wake
* up all the waiters then go to sleep waiting for more free space,
* otherwise try to get some space for this transaction.
*/
*need_bytes = xlog_ticket_reservation(log, head, tic);
free_bytes = xlog_space_left(log, &head->grant);
if (!list_empty_careful(&head->waiters)) {
spin_lock(&head->lock);
if (!xlog_grant_head_wake(log, head, &free_bytes) ||
free_bytes < *need_bytes) {
error = xlog_grant_head_wait(log, head, tic,
*need_bytes);
}
spin_unlock(&head->lock);
} else if (free_bytes < *need_bytes) {
spin_lock(&head->lock);
error = xlog_grant_head_wait(log, head, tic, *need_bytes);
spin_unlock(&head->lock);
}
return error;
}
static void
xlog_tic_reset_res(xlog_ticket_t *tic)
{
tic->t_res_num = 0;
tic->t_res_arr_sum = 0;
tic->t_res_num_ophdrs = 0;
}
static void
xlog_tic_add_region(xlog_ticket_t *tic, uint len, uint type)
{
if (tic->t_res_num == XLOG_TIC_LEN_MAX) {
/* add to overflow and start again */
tic->t_res_o_flow += tic->t_res_arr_sum;
tic->t_res_num = 0;
tic->t_res_arr_sum = 0;
}
tic->t_res_arr[tic->t_res_num].r_len = len;
tic->t_res_arr[tic->t_res_num].r_type = type;
tic->t_res_arr_sum += len;
tic->t_res_num++;
}
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 (mp->m_flags & XFS_MOUNT_NORECOVERY)
return false;
if (xfs_readonly_buftarg(mp->m_ddev_targp))
return false;
if (xfs_readonly_buftarg(mp->m_log->l_targ))
return false;
if (XFS_FORCED_SHUTDOWN(mp))
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_FORCED_SHUTDOWN(log))
return -EIO;
XFS_STATS_INC(mp, xs_try_logspace);
/*
* This is a new transaction on the ticket, so we need to change the
* transaction ID so that the next transaction has a different TID in
* the log. Just add one to the existing tid so that we can see chains
* of rolling transactions in the log easily.
*/
tic->t_tid++;
xlog_grant_push_ail(log, tic->t_unit_res);
tic->t_curr_res = tic->t_unit_res;
xlog_tic_reset_res(tic);
if (tic->t_cnt > 0)
return 0;
trace_xfs_log_regrant(log, tic);
error = xlog_grant_head_check(log, &log->l_write_head, tic,
&need_bytes);
if (error)
goto out_error;
xlog_grant_add_space(log, &log->l_write_head.grant, need_bytes);
trace_xfs_log_regrant_exit(log, tic);
xlog_verify_grant_tail(log);
return 0;
out_error:
/*
* If we are failing, make sure the ticket doesn't have any current
* reservations. We don't want to add this back when the ticket/
* transaction gets cancelled.
*/
tic->t_curr_res = 0;
tic->t_cnt = 0; /* ungrant will give back unit_res * t_cnt. */
return error;
}
/*
* Reserve log space and return a ticket corresponding 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,
uint8_t client,
bool permanent)
{
struct xlog *log = mp->m_log;
struct xlog_ticket *tic;
int need_bytes;
int error = 0;
ASSERT(client == XFS_TRANSACTION || client == XFS_LOG);
if (XLOG_FORCED_SHUTDOWN(log))
return -EIO;
XFS_STATS_INC(mp, xs_try_logspace);
ASSERT(*ticp == NULL);
tic = xlog_ticket_alloc(log, unit_bytes, cnt, client, permanent);
*ticp = tic;
xlog_grant_push_ail(log, tic->t_cnt ? tic->t_unit_res * tic->t_cnt
: tic->t_unit_res);
trace_xfs_log_reserve(log, tic);
error = xlog_grant_head_check(log, &log->l_reserve_head, tic,
&need_bytes);
if (error)
goto out_error;
xlog_grant_add_space(log, &log->l_reserve_head.grant, need_bytes);
xlog_grant_add_space(log, &log->l_write_head.grant, need_bytes);
trace_xfs_log_reserve_exit(log, tic);
xlog_verify_grant_tail(log);
return 0;
out_error:
/*
* If we are failing, make sure the ticket doesn't have any current
* reservations. We don't want to add this back when the ticket/
* transaction gets cancelled.
*/
tic->t_curr_res = 0;
tic->t_cnt = 0; /* ungrant will give back unit_res * t_cnt. */
return error;
}
static bool
__xlog_state_release_iclog(
struct xlog *log,
struct xlog_in_core *iclog)
{
lockdep_assert_held(&log->l_icloglock);
if (iclog->ic_state == XLOG_STATE_WANT_SYNC) {
/* update tail before writing to iclog */
xfs_lsn_t tail_lsn = xlog_assign_tail_lsn(log->l_mp);
iclog->ic_state = XLOG_STATE_SYNCING;
iclog->ic_header.h_tail_lsn = cpu_to_be64(tail_lsn);
xlog_verify_tail_lsn(log, iclog, tail_lsn);
/* cycle incremented when incrementing curr_block */
return true;
}
ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE);
return false;
}
/*
* Flush iclog to disk if this is the last reference to the given iclog and the
* it is in the WANT_SYNC state.
*/
static int
xlog_state_release_iclog(
struct xlog *log,
struct xlog_in_core *iclog)
{
lockdep_assert_held(&log->l_icloglock);
if (iclog->ic_state == XLOG_STATE_IOERROR)
return -EIO;
if (atomic_dec_and_test(&iclog->ic_refcnt) &&
__xlog_state_release_iclog(log, iclog)) {
spin_unlock(&log->l_icloglock);
xlog_sync(log, iclog);
spin_lock(&log->l_icloglock);
}
return 0;
}
void
xfs_log_release_iclog(
struct xlog_in_core *iclog)
{
struct xlog *log = iclog->ic_log;
bool sync = false;
if (atomic_dec_and_lock(&iclog->ic_refcnt, &log->l_icloglock)) {
if (iclog->ic_state != XLOG_STATE_IOERROR)
sync = __xlog_state_release_iclog(log, iclog);
spin_unlock(&log->l_icloglock);
}
if (sync)
xlog_sync(log, iclog);
}
/*
* Mount a log filesystem
*
* mp - ubiquitous xfs mount point structure
* log_target - buftarg of on-disk log device
* blk_offset - Start block # where block size is 512 bytes (BBSIZE)
* num_bblocks - Number of BBSIZE blocks in on-disk log
*
* Return error or zero.
*/
int
xfs_log_mount(
xfs_mount_t *mp,
xfs_buftarg_t *log_target,
xfs_daddr_t blk_offset,
int num_bblks)
{
bool fatal = xfs_sb_version_hascrc(&mp->m_sb);
int error = 0;
int min_logfsbs;
if (!(mp->m_flags & XFS_MOUNT_NORECOVERY)) {
xfs_notice(mp, "Mounting V%d Filesystem",
XFS_SB_VERSION_NUM(&mp->m_sb));
} else {
xfs_notice(mp,
"Mounting V%d filesystem in no-recovery mode. Filesystem will be inconsistent.",
XFS_SB_VERSION_NUM(&mp->m_sb));
ASSERT(mp->m_flags & XFS_MOUNT_RDONLY);
}
mp->m_log = xlog_alloc_log(mp, log_target, blk_offset, num_bblks);
if (IS_ERR(mp->m_log)) {
error = PTR_ERR(mp->m_log);
goto out;
}
/*
* Validate the given log space and drop a critical message via syslog
* if the log size is too small that would lead to some unexpected
* situations in transaction log space reservation stage.
*
* Note: we can't just reject the mount if the validation fails. This
* would mean that people would have to downgrade their kernel just to
* remedy the situation as there is no way to grow the log (short of
* black magic surgery with xfs_db).
*
* We can, however, reject mounts for CRC format filesystems, as the
* mkfs binary being used to make the filesystem should never create a
* filesystem with a log that is too small.
*/
min_logfsbs = xfs_log_calc_minimum_size(mp);
if (mp->m_sb.sb_logblocks < min_logfsbs) {
xfs_warn(mp,
"Log size %d blocks too small, minimum size is %d blocks",
mp->m_sb.sb_logblocks, min_logfsbs);
error = -EINVAL;
} else if (mp->m_sb.sb_logblocks > XFS_MAX_LOG_BLOCKS) {
xfs_warn(mp,
"Log size %d blocks too large, maximum size is %lld blocks",
mp->m_sb.sb_logblocks, XFS_MAX_LOG_BLOCKS);
error = -EINVAL;
} else if (XFS_FSB_TO_B(mp, mp->m_sb.sb_logblocks) > XFS_MAX_LOG_BYTES) {
xfs_warn(mp,
"log size %lld bytes too large, maximum size is %lld bytes",
XFS_FSB_TO_B(mp, mp->m_sb.sb_logblocks),
XFS_MAX_LOG_BYTES);
error = -EINVAL;
} else if (mp->m_sb.sb_logsunit > 1 &&
mp->m_sb.sb_logsunit % mp->m_sb.sb_blocksize) {
xfs_warn(mp,
"log stripe unit %u bytes must be a multiple of block size",
mp->m_sb.sb_logsunit);
error = -EINVAL;
fatal = true;
}
if (error) {
/*
* Log check errors are always fatal on v5; or whenever bad
* metadata leads to a crash.
*/
if (fatal) {
xfs_crit(mp, "AAIEEE! Log failed size checks. Abort!");
ASSERT(0);
goto out_free_log;
}
xfs_crit(mp, "Log size out of supported range.");
xfs_crit(mp,
"Continuing onwards, but if log hangs are experienced then please report this message in the bug report.");
}
/*
* Initialize the AIL now we have a log.
*/
error = xfs_trans_ail_init(mp);
if (error) {
xfs_warn(mp, "AIL initialisation failed: error %d", error);
goto out_free_log;
}
mp->m_log->l_ailp = mp->m_ail;
/*
* skip log recovery on a norecovery mount. pretend it all
* just worked.
*/
if (!(mp->m_flags & XFS_MOUNT_NORECOVERY)) {
int readonly = (mp->m_flags & XFS_MOUNT_RDONLY);
if (readonly)
mp->m_flags &= ~XFS_MOUNT_RDONLY;
error = xlog_recover(mp->m_log);
if (readonly)
mp->m_flags |= XFS_MOUNT_RDONLY;
if (error) {
xfs_warn(mp, "log mount/recovery failed: error %d",
error);
xlog_recover_cancel(mp->m_log);
goto out_destroy_ail;
}
}
error = xfs_sysfs_init(&mp->m_log->l_kobj, &xfs_log_ktype, &mp->m_kobj,
"log");
if (error)
goto out_destroy_ail;
/* Normal transactions can now occur */
mp->m_log->l_flags &= ~XLOG_ACTIVE_RECOVERY;
/*
* Now the log has been fully initialised and we know were our
* space grant counters are, we can initialise the permanent ticket
* needed for delayed logging to work.
*/
xlog_cil_init_post_recovery(mp->m_log);
return 0;
out_destroy_ail:
xfs_trans_ail_destroy(mp);
out_free_log:
xlog_dealloc_log(mp->m_log);
out:
return error;
}
/*
* Finish the recovery of the file system. This is separate from the
* xfs_log_mount() call, because it depends on the code in xfs_mountfs() to read
* in the root and real-time bitmap inodes between calling xfs_log_mount() and
* here.
*
* If we finish recovery successfully, start the background log work. If we are
* not doing recovery, then we have a RO filesystem and we don't need to start
* it.
*/
int
xfs_log_mount_finish(
struct xfs_mount *mp)
{
int error = 0;
bool readonly = (mp->m_flags & XFS_MOUNT_RDONLY);
bool recovered = mp->m_log->l_flags & XLOG_RECOVERY_NEEDED;
if (mp->m_flags & XFS_MOUNT_NORECOVERY) {
ASSERT(mp->m_flags & XFS_MOUNT_RDONLY);
return 0;
} else if (readonly) {
/* Allow unlinked processing to proceed */
mp->m_flags &= ~XFS_MOUNT_RDONLY;
}
/*
* 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;
error = xlog_recover_finish(mp->m_log);
if (!error)
xfs_log_work_queue(mp);
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 (!error && recovered) {
xfs_log_force(mp, XFS_LOG_SYNC);
xfs_ail_push_all_sync(mp->m_ail);
}
xfs_buftarg_drain(mp->m_ddev_targp);
if (readonly)
mp->m_flags |= XFS_MOUNT_RDONLY;
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);
}
/*
* Wait for the iclog to be written disk, or return an error if the log has been
* shut down.
*/
static int
xlog_wait_on_iclog(
struct xlog_in_core *iclog)
__releases(iclog->ic_log->l_icloglock)
{
struct xlog *log = iclog->ic_log;
if (!XLOG_FORCED_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_FORCED_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,
xfs_lsn_t *lsn,
uint flags)
{
struct xfs_unmount_log_format ulf = {
.magic = XLOG_UNMOUNT_TYPE,
};
struct xfs_log_iovec reg = {
.i_addr = &ulf,
.i_len = sizeof(ulf),
.i_type = XLOG_REG_TYPE_UNMOUNT,
};
struct xfs_log_vec vec = {
.lv_niovecs = 1,
.lv_iovecp = &reg,
};
/* account for space used by record data */
ticket->t_curr_res -= sizeof(ulf);
return xlog_write(log, &vec, ticket, lsn, NULL, flags, false);
}
/*
* 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;
xfs_lsn_t lsn;
uint flags = XLOG_UNMOUNT_TRANS;
int error;
error = xfs_log_reserve(mp, 600, 1, &tic, XFS_LOG, 0);
if (error)
goto out_err;
error = xlog_write_unmount_record(log, tic, &lsn, flags);
/*
* At this point, we're umounting anyway, so there's no point in
* transitioning log state to IOERROR. Just continue...
*/
out_err:
if (error)
xfs_alert(mp, "%s: unmount record failed", __func__);
spin_lock(&log->l_icloglock);
iclog = log->l_iclog;
atomic_inc(&iclog->ic_refcnt);
if (iclog->ic_state == XLOG_STATE_ACTIVE)
xlog_state_switch_iclogs(log, iclog, 0);
else
ASSERT(iclog->ic_state == XLOG_STATE_WANT_SYNC ||
iclog->ic_state == XLOG_STATE_IOERROR);
error = xlog_state_release_iclog(log, 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_FORCED_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)
{
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);
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_mountp = mp;
item->li_ailp = mp->m_ail;
item->li_type = type;
item->li_ops = ops;
item->li_lv = NULL;
INIT_LIST_HEAD(&item->li_ail);
INIT_LIST_HEAD(&item->li_cil);
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_FORCED_SHUTDOWN(log))
return;
if (!list_empty_careful(&log->l_write_head.waiters)) {
ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
spin_lock(&log->l_write_head.lock);
free_bytes = xlog_space_left(log, &log->l_write_head.grant);
xlog_grant_head_wake(log, &log->l_write_head, &free_bytes);
spin_unlock(&log->l_write_head.lock);
}
if (!list_empty_careful(&log->l_reserve_head.waiters)) {
ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
spin_lock(&log->l_reserve_head.lock);
free_bytes = xlog_space_left(log, &log->l_reserve_head.grant);
xlog_grant_head_wake(log, &log->l_reserve_head, &free_bytes);
spin_unlock(&log->l_reserve_head.lock);
}
}
/*
* Determine if we have a transaction that has gone to disk that needs to be
* covered. To begin the transition to the idle state firstly the log needs to
* be idle. That means the CIL, the AIL and the iclogs needs to be empty before
* we start attempting to cover the log.
*
* Only if we are then in a state where covering is needed, the caller is
* informed that dummy transactions are required to move the log into the idle
* state.
*
* If there are any items in the AIl or CIL, then we do not want to attempt to
* cover the log as we may be in a situation where there isn't log space
* available to run a dummy transaction and this can lead to deadlocks when the
* tail of the log is pinned by an item that is modified in the CIL. Hence
* there's no point in running a dummy transaction at this point because we
* can't start trying to idle the log until both the CIL and AIL are empty.
*/
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)) ||
XFS_FORCED_SHUTDOWN(mp));
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_sb_version_haslazysbcount(&mp->m_sb))
return 0;
/*
* To cover the log, commit the superblock twice (at most) in
* independent checkpoints. The first serves as a reference for the
* tail pointer. The sync transaction and AIL push empties the AIL and
* updates the in-core tail to the LSN of the first checkpoint. The
* second commit updates the on-disk tail with the in-core LSN,
* covering the log. Push the AIL one more time to leave it empty, as
* we found it.
*/
do {
error = xfs_sync_sb(mp, true);
if (error)
break;
xfs_ail_push_all_sync(mp->m_ail);
} while (xfs_log_need_covered(mp));
return error;
}
/*
* We may be holding the log iclog lock upon entering this routine.
*/
xfs_lsn_t
xlog_assign_tail_lsn_locked(
struct xfs_mount *mp)
{
struct xlog *log = mp->m_log;
struct xfs_log_item *lip;
xfs_lsn_t tail_lsn;
assert_spin_locked(&mp->m_ail->ail_lock);
/*
* To make sure we always have a valid LSN for the log tail we keep
* track of the last LSN which was committed in log->l_last_sync_lsn,
* and use that when the AIL was empty.
*/
lip = xfs_ail_min(mp->m_ail);
if (lip)
tail_lsn = lip->li_lsn;
else
tail_lsn = atomic64_read(&log->l_last_sync_lsn);
trace_xfs_log_assign_tail_lsn(log, tail_lsn);
atomic64_set(&log->l_tail_lsn, tail_lsn);
return tail_lsn;
}
xfs_lsn_t
xlog_assign_tail_lsn(
struct xfs_mount *mp)
{
xfs_lsn_t tail_lsn;
spin_lock(&mp->m_ail->ail_lock);
tail_lsn = xlog_assign_tail_lsn_locked(mp);
spin_unlock(&mp->m_ail->ail_lock);
return tail_lsn;
}
/*
* Return the space in the log between the tail and the head. The head
* is passed in the cycle/bytes formal parms. In the special case where
* the reserve head has wrapped passed the tail, this calculation is no
* longer valid. In this case, just return 0 which means there is no space
* in the log. This works for all places where this function is called
* with the reserve head. Of course, if the write head were to ever
* wrap the tail, we should blow up. Rather than catch this case here,
* we depend on other ASSERTions in other parts of the code. XXXmiken
*
* This code also handles the case where the reservation head is behind
* the tail. The details of this case are described below, but the end
* result is that we return the size of the log as the amount of space left.
*/
STATIC int
xlog_space_left(
struct xlog *log,
atomic64_t *head)
{
int free_bytes;
int tail_bytes;
int tail_cycle;
int head_cycle;
int head_bytes;
xlog_crack_grant_head(head, &head_cycle, &head_bytes);
xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_bytes);
tail_bytes = BBTOB(tail_bytes);
if (tail_cycle == head_cycle && head_bytes >= tail_bytes)
free_bytes = log->l_logsize - (head_bytes - tail_bytes);
else if (tail_cycle + 1 < head_cycle)
return 0;
else if (tail_cycle < head_cycle) {
ASSERT(tail_cycle == (head_cycle - 1));
free_bytes = tail_bytes - head_bytes;
} else {
/*
* The reservation head is behind the tail.
* In this case we just want to return the size of the
* log as the amount of space left.
*/
xfs_alert(log->l_mp, "xlog_space_left: head behind tail");
xfs_alert(log->l_mp,
" tail_cycle = %d, tail_bytes = %d",
tail_cycle, tail_bytes);
xfs_alert(log->l_mp,
" GH cycle = %d, GH bytes = %d",
head_cycle, head_bytes);
ASSERT(0);
free_bytes = log->l_logsize;
}
return free_bytes;
}
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);
xfs_force_shutdown(log->l_mp, 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));
}
/*
* 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.
*/
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 = kmem_zalloc(sizeof(struct xlog), KM_MAYFAIL);
if (!log) {
xfs_warn(mp, "Log allocation failed: No memory!");
goto out;
}
log->l_mp = mp;
log->l_targ = log_target;
log->l_logsize = BBTOB(num_bblks);
log->l_logBBstart = blk_offset;
log->l_logBBsize = num_bblks;
log->l_covered_state = XLOG_STATE_COVER_IDLE;
log->l_flags |= XLOG_ACTIVE_RECOVERY;
INIT_DELAYED_WORK(&log->l_work, xfs_log_worker);
log->l_prev_block = -1;
/* log->l_tail_lsn = 0x100000000LL; cycle = 1; current block = 0 */
xlog_assign_atomic_lsn(&log->l_tail_lsn, 1, 0);
xlog_assign_atomic_lsn(&log->l_last_sync_lsn, 1, 0);
log->l_curr_cycle = 1; /* 0 is bad since this is initial value */
xlog_grant_head_init(&log->l_reserve_head);
xlog_grant_head_init(&log->l_write_head);
error = -EFSCORRUPTED;
if (xfs_sb_version_hassector(&mp->m_sb)) {
log2_size = mp->m_sb.sb_logsectlog;
if (log2_size < BBSHIFT) {
xfs_warn(mp, "Log sector size too small (0x%x < 0x%x)",
log2_size, BBSHIFT);
goto out_free_log;
}
log2_size -= BBSHIFT;
if (log2_size > mp->m_sectbb_log) {
xfs_warn(mp, "Log sector size too large (0x%x > 0x%x)",
log2_size, mp->m_sectbb_log);
goto out_free_log;
}
/* for larger sector sizes, must have v2 or external log */
if (log2_size && log->l_logBBstart > 0 &&
!xfs_sb_version_haslogv2(&mp->m_sb)) {
xfs_warn(mp,
"log sector size (0x%x) invalid for configuration.",
log2_size);
goto out_free_log;
}
}
log->l_sectBBsize = 1 << log2_size;
xlog_get_iclog_buffer_size(mp, log);
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++) {
int align_mask = xfs_buftarg_dma_alignment(mp->m_logdev_targp);
size_t bvec_size = howmany(log->l_iclog_size, PAGE_SIZE) *
sizeof(struct bio_vec);
iclog = kmem_zalloc(sizeof(*iclog) + bvec_size, KM_MAYFAIL);
if (!iclog)
goto out_free_iclog;
*iclogp = iclog;
iclog->ic_prev = prev_iclog;
prev_iclog = iclog;
iclog->ic_data = kmem_alloc_io(log->l_iclog_size, align_mask,
KM_MAYFAIL | KM_ZERO);
if (!iclog->ic_data)
goto out_free_iclog;
#ifdef DEBUG
log->l_iclog_bak[i] = &iclog->ic_header;
#endif
head = &iclog->ic_header;
memset(head, 0, sizeof(xlog_rec_header_t));
head->h_magicno = cpu_to_be32(XLOG_HEADER_MAGIC_NUM);
head->h_version = cpu_to_be32(
xfs_sb_version_haslogv2(&log->l_mp->m_sb) ? 2 : 1);
head->h_size = cpu_to_be32(log->l_iclog_size);
/* new fields */
head->h_fmt = cpu_to_be32(XLOG_FMT);
memcpy(&head->h_fs_uuid, &mp->m_sb.sb_uuid, sizeof(uuid_t));
iclog->ic_size = log->l_iclog_size - log->l_iclog_hsize;
iclog->ic_state = XLOG_STATE_ACTIVE;
iclog->ic_log = log;
atomic_set(&iclog->ic_refcnt, 0);
spin_lock_init(&iclog->ic_callback_lock);
INIT_LIST_HEAD(&iclog->ic_callbacks);
iclog->ic_datap = (char *)iclog->ic_data + log->l_iclog_hsize;
init_waitqueue_head(&iclog->ic_force_wait);
init_waitqueue_head(&iclog->ic_write_wait);
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;
kmem_free(iclog->ic_data);
kmem_free(iclog);
if (prev_iclog == log->l_iclog)
break;
}
out_free_log:
kmem_free(log);
out:
return ERR_PTR(error);
} /* xlog_alloc_log */
/*
* Write out the commit record of a transaction associated with the given
* ticket to close off a running log write. Return the lsn of the commit record.
*/
int
xlog_commit_record(
struct xlog *log,
struct xlog_ticket *ticket,
struct xlog_in_core **iclog,
xfs_lsn_t *lsn)
{
struct xfs_log_iovec reg = {
.i_addr = NULL,
.i_len = 0,
.i_type = XLOG_REG_TYPE_COMMIT,
};
struct xfs_log_vec vec = {
.lv_niovecs = 1,
.lv_iovecp = &reg,
};
int error;
if (XLOG_FORCED_SHUTDOWN(log))
return -EIO;
error = xlog_write(log, &vec, ticket, lsn, iclog, XLOG_COMMIT_TRANS,
false);
if (error)
xfs_force_shutdown(log->l_mp, SHUTDOWN_LOG_IO_ERROR);
return error;
}
/*
* Compute the LSN that we'd need to push the log tail towards in order to have
* (a) enough on-disk log space to log the number of bytes specified, (b) at
* least 25% of the log space free, and (c) at least 256 blocks free. If the
* log free space already meets all three thresholds, this function returns
* NULLCOMMITLSN.
*/
xfs_lsn_t
xlog_grant_push_threshold(
struct xlog *log,
int need_bytes)
{
xfs_lsn_t threshold_lsn = 0;
xfs_lsn_t last_sync_lsn;
int free_blocks;
int free_bytes;
int threshold_block;
int threshold_cycle;
int free_threshold;
ASSERT(BTOBB(need_bytes) < log->l_logBBsize);
free_bytes = xlog_space_left(log, &log->l_reserve_head.grant);
free_blocks = BTOBBT(free_bytes);
/*
* Set the threshold for the minimum number of free blocks in the
* log to the maximum of what the caller needs, one quarter of the
* log, and 256 blocks.
*/
free_threshold = BTOBB(need_bytes);
free_threshold = max(free_threshold, (log->l_logBBsize >> 2));
free_threshold = max(free_threshold, 256);
if (free_blocks >= free_threshold)
return NULLCOMMITLSN;
xlog_crack_atomic_lsn(&log->l_tail_lsn, &threshold_cycle,
&threshold_block);
threshold_block += free_threshold;
if (threshold_block >= log->l_logBBsize) {
threshold_block -= log->l_logBBsize;
threshold_cycle += 1;
}
threshold_lsn = xlog_assign_lsn(threshold_cycle,
threshold_block);
/*
* Don't pass in an lsn greater than the lsn of the last
* log record known to be on disk. Use a snapshot of the last sync lsn
* so that it doesn't change between the compare and the set.
*/
last_sync_lsn = atomic64_read(&log->l_last_sync_lsn);
if (XFS_LSN_CMP(threshold_lsn, last_sync_lsn) > 0)
threshold_lsn = last_sync_lsn;
return threshold_lsn;
}
/*
* Push the tail of the log if we need to do so to maintain the free log space
* thresholds set out by xlog_grant_push_threshold. We may need to adopt a
* policy which pushes on an lsn which is further along in the log once we
* reach the high water mark. In this manner, we would be creating a low water
* mark.
*/
STATIC void
xlog_grant_push_ail(
struct xlog *log,
int need_bytes)
{
xfs_lsn_t threshold_lsn;
threshold_lsn = xlog_grant_push_threshold(log, need_bytes);
if (threshold_lsn == NULLCOMMITLSN || XLOG_FORCED_SHUTDOWN(log))
return;
/*
* Get the transaction layer to kick the dirty buffers out to
* disk asynchronously. No point in trying to do this if
* the filesystem is shutting down.
*/
xfs_ail_push(log->l_ailp, threshold_lsn);
}
/*
* Stamp cycle number in every block
*/
STATIC void
xlog_pack_data(
struct xlog *log,
struct xlog_in_core *iclog,
int roundoff)
{
int i, j, k;
int size = iclog->ic_offset + roundoff;
__be32 cycle_lsn;
char *dp;
cycle_lsn = CYCLE_LSN_DISK(iclog->ic_header.h_lsn);
dp = iclog->ic_datap;
for (i = 0; i < BTOBB(size); i++) {
if (i >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE))
break;
iclog->ic_header.h_cycle_data[i] = *(__be32 *)dp;
*(__be32 *)dp = cycle_lsn;
dp += BBSIZE;
}
if (xfs_sb_version_haslogv2(&log->l_mp->m_sb)) {
xlog_in_core_2_t *xhdr = iclog->ic_data;
for ( ; i < BTOBB(size); i++) {
j = i / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
k = i % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
xhdr[j].hic_xheader.xh_cycle_data[k] = *(__be32 *)dp;
*(__be32 *)dp = cycle_lsn;
dp += BBSIZE;
}
for (i = 1; i < log->l_iclog_heads; i++)
xhdr[i].hic_xheader.xh_cycle = cycle_lsn;
}
}
/*
* Calculate the checksum for a log buffer.
*
* This is a little more complicated than it should be because the various
* headers and the actual data are non-contiguous.
*/
__le32
xlog_cksum(
struct xlog *log,
struct xlog_rec_header *rhead,
char *dp,
int size)
{
uint32_t crc;
/* first generate the crc for the record header ... */
crc = xfs_start_cksum_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_sb_version_haslogv2(&log->l_mp->m_sb)) {
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,
bool need_flush)
{
ASSERT(bno < log->l_logBBsize);
/*
* 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 (unlikely(iclog->ic_state == XLOG_STATE_IOERROR)) {
/*
* 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.
*/
xlog_state_done_syncing(iclog);
up(&iclog->ic_sema);
return;
}
bio_init(&iclog->ic_bio, iclog->ic_bvec, howmany(count, PAGE_SIZE));
bio_set_dev(&iclog->ic_bio, log->l_targ->bt_bdev);
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;
/*
* 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.
*/
iclog->ic_bio.bi_opf = REQ_OP_WRITE | REQ_META | REQ_SYNC |
REQ_IDLE | REQ_FUA;
if (need_flush)
iclog->ic_bio.bi_opf |= REQ_PREFLUSH;
if (xlog_map_iclog_data(&iclog->ic_bio, iclog->ic_data, count)) {
xfs_force_shutdown(log->l_mp, SHUTDOWN_LOG_IO_ERROR);
return;
}
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);
}
/*
* 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;
bool use_lsunit;
use_lsunit = xfs_sb_version_haslogv2(&log->l_mp->m_sb) &&
log->l_mp->m_sb.sb_logsunit > 1;
/* Add for LR header */
count_init = log->l_iclog_hsize + iclog->ic_offset;
/* Round out the log write size */
if (use_lsunit) {
/* we have a v2 stripe unit to use */
count = XLOG_LSUNITTOB(log, XLOG_BTOLSUNIT(log, count_init));
} else {
count = BBTOB(BTOBB(count_init));
}
ASSERT(count >= count_init);
*roundoff = count - count_init;
if (use_lsunit)
ASSERT(*roundoff < log->l_mp->m_sb.sb_logsunit);
else
ASSERT(*roundoff < BBTOB(1));
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)
{
unsigned int count; /* byte count of bwrite */
unsigned int roundoff; /* roundoff to BB or stripe */
uint64_t bno;
unsigned int size;
bool need_flush = true, split = false;
ASSERT(atomic_read(&iclog->ic_refcnt) == 0);
count = xlog_calc_iclog_size(log, iclog, &roundoff);
/* move grant heads by roundoff in sync */
xlog_grant_add_space(log, &log->l_reserve_head.grant, roundoff);
xlog_grant_add_space(log, &log->l_write_head.grant, roundoff);
/* put cycle number in every block */
xlog_pack_data(log, iclog, roundoff);
/* real byte length */
size = iclog->ic_offset;
if (xfs_sb_version_haslogv2(&log->l_mp->m_sb))
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);
split = true;
}
/* 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
/*
* Flush the data device before flushing the log to make sure all meta
* data written back from the AIL actually made it to disk before
* stamping the new log tail LSN into the log buffer. For an external
* log we need to issue the flush explicitly, and unfortunately
* synchronously here; for an internal log we can simply use the block
* layer state machine for preflushes.
*/
if (log->l_targ != log->l_mp->m_ddev_targp || split) {
xfs_blkdev_issue_flush(log->l_mp->m_ddev_targp);
need_flush = false;
}
xlog_verify_iclog(log, iclog, count);
xlog_write_iclog(log, iclog, bno, count, need_flush);
}
/*
* Deallocate a log structure
*/
STATIC void
xlog_dealloc_log(
struct xlog *log)
{
xlog_in_core_t *iclog, *next_iclog;
int i;
xlog_cil_destroy(log);
/*
* Cycle all the iclogbuf locks to make sure all log IO completion
* is done before we tear down these buffers.
*/
iclog = log->l_iclog;
for (i = 0; i < log->l_iclog_bufs; i++) {
down(&iclog->ic_sema);
up(&iclog->ic_sema);
iclog = iclog->ic_next;
}
iclog = log->l_iclog;
for (i = 0; i < log->l_iclog_bufs; i++) {
next_iclog = iclog->ic_next;
kmem_free(iclog->ic_data);
kmem_free(iclog);
iclog = next_iclog;
}
log->l_mp->m_log = NULL;
destroy_workqueue(log->l_ioend_workqueue);
kmem_free(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)
{
uint i;
uint ophdr_spc = ticket->t_res_num_ophdrs * (uint)sizeof(xlog_op_header_t);
/* match with XLOG_REG_TYPE_* in xfs_log.h */
#define REG_TYPE_STR(type, str) [XLOG_REG_TYPE_##type] = str
static char *res_type_str[] = {
REG_TYPE_STR(BFORMAT, "bformat"),
REG_TYPE_STR(BCHUNK, "bchunk"),
REG_TYPE_STR(EFI_FORMAT, "efi_format"),
REG_TYPE_STR(EFD_FORMAT, "efd_format"),
REG_TYPE_STR(IFORMAT, "iformat"),
REG_TYPE_STR(ICORE, "icore"),
REG_TYPE_STR(IEXT, "iext"),
REG_TYPE_STR(IBROOT, "ibroot"),
REG_TYPE_STR(ILOCAL, "ilocal"),
REG_TYPE_STR(IATTR_EXT, "iattr_ext"),
REG_TYPE_STR(IATTR_BROOT, "iattr_broot"),
REG_TYPE_STR(IATTR_LOCAL, "iattr_local"),
REG_TYPE_STR(QFORMAT, "qformat"),
REG_TYPE_STR(DQUOT, "dquot"),
REG_TYPE_STR(QUOTAOFF, "quotaoff"),
REG_TYPE_STR(LRHEADER, "LR header"),
REG_TYPE_STR(UNMOUNT, "unmount"),
REG_TYPE_STR(COMMIT, "commit"),
REG_TYPE_STR(TRANSHDR, "trans header"),
REG_TYPE_STR(ICREATE, "inode create"),
REG_TYPE_STR(RUI_FORMAT, "rui_format"),
REG_TYPE_STR(RUD_FORMAT, "rud_format"),
REG_TYPE_STR(CUI_FORMAT, "cui_format"),
REG_TYPE_STR(CUD_FORMAT, "cud_format"),
REG_TYPE_STR(BUI_FORMAT, "bui_format"),
REG_TYPE_STR(BUD_FORMAT, "bud_format"),
};
BUILD_BUG_ON(ARRAY_SIZE(res_type_str) != XLOG_REG_TYPE_MAX + 1);
#undef REG_TYPE_STR
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, " total reg = %u bytes (o/flow = %u bytes)",
ticket->t_res_arr_sum, ticket->t_res_o_flow);
xfs_warn(mp, " ophdrs = %u (ophdr space = %u bytes)",
ticket->t_res_num_ophdrs, ophdr_spc);
xfs_warn(mp, " ophdr + reg = %u bytes",
ticket->t_res_arr_sum + ticket->t_res_o_flow + ophdr_spc);
xfs_warn(mp, " num regions = %u",
ticket->t_res_num);
for (i = 0; i < ticket->t_res_num; i++) {
uint r_type = ticket->t_res_arr[i].r_type;
xfs_warn(mp, "region[%u]: %s - %u bytes", i,
((r_type <= 0 || r_type > XLOG_REG_TYPE_MAX) ?
"bad-rtype" : res_type_str[r_type]),
ticket->t_res_arr[i].r_len);
}
}
/*
* 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++;
}
}
}
/*
* Calculate the potential space needed by the log vector. We may need a start
* record, and each region gets its own struct xlog_op_header and may need to be
* double word aligned.
*/
static int
xlog_write_calc_vec_length(
struct xlog_ticket *ticket,
struct xfs_log_vec *log_vector,
bool need_start_rec)
{
struct xfs_log_vec *lv;
int headers = need_start_rec ? 1 : 0;
int len = 0;
int i;
for (lv = log_vector; lv; lv = lv->lv_next) {
/* we don't write ordered log vectors */
if (lv->lv_buf_len == XFS_LOG_VEC_ORDERED)
continue;
headers += lv->lv_niovecs;
for (i = 0; i < lv->lv_niovecs; i++) {
struct xfs_log_iovec *vecp = &lv->lv_iovecp[i];
len += vecp->i_len;
xlog_tic_add_region(ticket, vecp->i_len, vecp->i_type);
}
}
ticket->t_res_num_ophdrs += headers;
len += headers * sizeof(struct xlog_op_header);
return len;
}
static void
xlog_write_start_rec(
struct xlog_op_header *ophdr,
struct xlog_ticket *ticket)
{
ophdr->oh_tid = cpu_to_be32(ticket->t_tid);
ophdr->oh_clientid = ticket->t_clientid;
ophdr->oh_len = 0;
ophdr->oh_flags = XLOG_START_TRANS;
ophdr->oh_res2 = 0;
}
static xlog_op_header_t *
xlog_write_setup_ophdr(
struct xlog *log,
struct xlog_op_header *ophdr,
struct xlog_ticket *ticket,
uint flags)
{
ophdr->oh_tid = cpu_to_be32(ticket->t_tid);
ophdr->oh_clientid = ticket->t_clientid;
ophdr->oh_res2 = 0;
/* are we copying a commit or unmount record? */
ophdr->oh_flags = flags;
/*
* We've seen logs corrupted with bad transaction client ids. This
* makes sure that XFS doesn't generate them on. Turn this into an EIO
* and shut down the filesystem.
*/
switch (ophdr->oh_clientid) {
case XFS_TRANSACTION:
case XFS_VOLUME:
case XFS_LOG:
break;
default:
xfs_warn(log->l_mp,
"Bad XFS transaction clientid 0x%x in ticket "PTR_FMT,
ophdr->oh_clientid, ticket);
return NULL;
}
return ophdr;
}
/*
* Set up the parameters of the region copy into the log. This has
* to handle region write split across multiple log buffers - this
* state is kept external to this function so that this code can
* be written in an obvious, self documenting manner.
*/
static int
xlog_write_setup_copy(
struct xlog_ticket *ticket,
struct xlog_op_header *ophdr,
int space_available,
int space_required,
int *copy_off,
int *copy_len,
int *last_was_partial_copy,
int *bytes_consumed)
{
int still_to_copy;
still_to_copy = space_required - *bytes_consumed;
*copy_off = *bytes_consumed;
if (still_to_copy <= space_available) {
/* write of region completes here */
*copy_len = still_to_copy;
ophdr->oh_len = cpu_to_be32(*copy_len);
if (*last_was_partial_copy)
ophdr->oh_flags |= (XLOG_END_TRANS|XLOG_WAS_CONT_TRANS);
*last_was_partial_copy = 0;
*bytes_consumed = 0;
return 0;
}
/* partial write of region, needs extra log op header reservation */
*copy_len = space_available;
ophdr->oh_len = cpu_to_be32(*copy_len);
ophdr->oh_flags |= XLOG_CONTINUE_TRANS;
if (*last_was_partial_copy)
ophdr->oh_flags |= XLOG_WAS_CONT_TRANS;
*bytes_consumed += *copy_len;
(*last_was_partial_copy)++;
/* account for new log op header */
ticket->t_curr_res -= sizeof(struct xlog_op_header);
ticket->t_res_num_ophdrs++;
return sizeof(struct xlog_op_header);
}
static int
xlog_write_copy_finish(
struct xlog *log,
struct xlog_in_core *iclog,
uint flags,
int *record_cnt,
int *data_cnt,
int *partial_copy,
int *partial_copy_len,
int log_offset,
struct xlog_in_core **commit_iclog)
{
int error;
if (*partial_copy) {
/*
* This iclog has already been marked WANT_SYNC by
* xlog_state_get_iclog_space.
*/
spin_lock(&log->l_icloglock);
xlog_state_finish_copy(log, iclog, *record_cnt, *data_cnt);
*record_cnt = 0;
*data_cnt = 0;
goto release_iclog;
}
*partial_copy = 0;
*partial_copy_len = 0;
if (iclog->ic_size - log_offset <= sizeof(xlog_op_header_t)) {
/* no more space in this iclog - push it. */
spin_lock(&log->l_icloglock);
xlog_state_finish_copy(log, iclog, *record_cnt, *data_cnt);
*record_cnt = 0;
*data_cnt = 0;
if (iclog->ic_state == XLOG_STATE_ACTIVE)
xlog_state_switch_iclogs(log, iclog, 0);
else
ASSERT(iclog->ic_state == XLOG_STATE_WANT_SYNC ||
iclog->ic_state == XLOG_STATE_IOERROR);
if (!commit_iclog)
goto release_iclog;
spin_unlock(&log->l_icloglock);
ASSERT(flags & XLOG_COMMIT_TRANS);
*commit_iclog = iclog;
}
return 0;
release_iclog:
error = xlog_state_release_iclog(log, iclog);
spin_unlock(&log->l_icloglock);
return error;
}
/*
* Write some region out to in-core log
*
* This will be called when writing externally provided regions or when
* writing out a commit record for a given transaction.
*
* General algorithm:
* 1. Find total length of this write. This may include adding to the
* lengths passed in.
* 2. Check whether we violate the tickets reservation.
* 3. While writing to this iclog
* A. Reserve as much space in this iclog as can get
* B. If this is first write, save away start lsn
* C. While writing this region:
* 1. If first write of transaction, write start record
* 2. Write log operation header (header per region)
* 3. Find out if we can fit entire region into this iclog
* 4. Potentially, verify destination memcpy ptr
* 5. Memcpy (partial) region
* 6. If partial copy, release iclog; otherwise, continue
* copying more regions into current iclog
* 4. Mark want sync bit (in simulation mode)
* 5. Release iclog for potential flush to on-disk log.
*
* ERRORS:
* 1. Panic if reservation is overrun. This should never happen since
* reservation amounts are generated internal to the filesystem.
* NOTES:
* 1. Tickets are single threaded data structures.
* 2. The XLOG_END_TRANS & XLOG_CONTINUE_TRANS flags are passed down to the
* syncing routine. When a single log_write region needs to span
* multiple in-core logs, the XLOG_CONTINUE_TRANS bit should be set
* on all log operation writes which don't contain the end of the
* region. The XLOG_END_TRANS bit is used for the in-core log
* operation which contains the end of the continued log_write region.
* 3. When xlog_state_get_iclog_space() grabs the rest of the current iclog,
* we don't really know exactly how much space will be used. As a result,
* we don't update ic_offset until the end when we know exactly how many
* bytes have been written out.
*/
int
xlog_write(
struct xlog *log,
struct xfs_log_vec *log_vector,
struct xlog_ticket *ticket,
xfs_lsn_t *start_lsn,
struct xlog_in_core **commit_iclog,
uint flags,
bool need_start_rec)
{
struct xlog_in_core *iclog = NULL;
struct xfs_log_vec *lv = log_vector;
struct xfs_log_iovec *vecp = lv->lv_iovecp;
int index = 0;
int len;
int partial_copy = 0;
int partial_copy_len = 0;
int contwr = 0;
int record_cnt = 0;
int data_cnt = 0;
int error = 0;
/*
* If this is a commit or unmount transaction, we don't need a start
* record to be written. We do, however, have to account for the
* commit or unmount header that gets written. Hence we always have
* to account for an extra xlog_op_header here.
*/
ticket->t_curr_res -= sizeof(struct xlog_op_header);
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);
xfs_force_shutdown(log->l_mp, SHUTDOWN_LOG_IO_ERROR);
}
len = xlog_write_calc_vec_length(ticket, log_vector, need_start_rec);
*start_lsn = 0;
while (lv && (!lv->lv_niovecs || index < lv->lv_niovecs)) {
void *ptr;
int log_offset;
error = xlog_state_get_iclog_space(log, len, &iclog, ticket,
&contwr, &log_offset);
if (error)
return error;
ASSERT(log_offset <= iclog->ic_size - 1);
ptr = iclog->ic_datap + log_offset;
/* start_lsn is the first lsn written to. That's all we need. */
if (!*start_lsn)
*start_lsn = be64_to_cpu(iclog->ic_header.h_lsn);
/*
* This loop writes out as many regions as can fit in the amount
* of space which was allocated by xlog_state_get_iclog_space().
*/
while (lv && (!lv->lv_niovecs || index < lv->lv_niovecs)) {
struct xfs_log_iovec *reg;
struct xlog_op_header *ophdr;
int copy_len;
int copy_off;
bool ordered = false;
/* ordered log vectors have no regions to write */
if (lv->lv_buf_len == XFS_LOG_VEC_ORDERED) {
ASSERT(lv->lv_niovecs == 0);
ordered = true;
goto next_lv;
}
reg = &vecp[index];
ASSERT(reg->i_len % sizeof(int32_t) == 0);
ASSERT((unsigned long)ptr % sizeof(int32_t) == 0);
/*
* Before we start formatting log vectors, we need to
* write a start record. Only do this for the first
* iclog we write to.
*/
if (need_start_rec) {
xlog_write_start_rec(ptr, ticket);
xlog_write_adv_cnt(&ptr, &len, &log_offset,
sizeof(struct xlog_op_header));
}
ophdr = xlog_write_setup_ophdr(log, ptr, ticket, flags);
if (!ophdr)
return -EIO;
xlog_write_adv_cnt(&ptr, &len, &log_offset,
sizeof(struct xlog_op_header));
len += xlog_write_setup_copy(ticket, ophdr,
iclog->ic_size-log_offset,
reg->i_len,
&copy_off, &copy_len,
&partial_copy,
&partial_copy_len);
xlog_verify_dest_ptr(log, ptr);
/*
* Copy region.
*
* Unmount records just log an opheader, so can have
* empty payloads with no data region to copy. Hence we
* only copy the payload if the vector says it has data
* to copy.
*/
ASSERT(copy_len >= 0);
if (copy_len > 0) {
memcpy(ptr, reg->i_addr + copy_off, copy_len);
xlog_write_adv_cnt(&ptr, &len, &log_offset,
copy_len);
}
copy_len += sizeof(struct xlog_op_header);
record_cnt++;
if (need_start_rec) {
copy_len += sizeof(struct xlog_op_header);
record_cnt++;
need_start_rec = false;
}
data_cnt += contwr ? copy_len : 0;
error = xlog_write_copy_finish(log, iclog, flags,
&record_cnt, &data_cnt,
&partial_copy,
&partial_copy_len,
log_offset,
commit_iclog);
if (error)
return error;
/*
* if we had a partial copy, we need to get more iclog
* space but we don't want to increment the region
* index because there is still more is this region to
* write.
*
* If we completed writing this region, and we flushed
* the iclog (indicated by resetting of the record
* count), then we also need to get more log space. If
* this was the last record, though, we are done and
* can just return.
*/
if (partial_copy)
break;
if (++index == lv->lv_niovecs) {
next_lv:
lv = lv->lv_next;
index = 0;
if (lv)
vecp = lv->lv_iovecp;
}
if (record_cnt == 0 && !ordered) {
if (!lv)
return 0;
break;
}
}
}
ASSERT(len == 0);
spin_lock(&log->l_icloglock);
xlog_state_finish_copy(log, iclog, record_cnt, data_cnt);
if (commit_iclog) {
ASSERT(flags & XLOG_COMMIT_TRANS);
*commit_iclog = iclog;
} else {
error = xlog_state_release_iclog(log, iclog);
}
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));
/*
* 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;
}
/*
* 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;
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;
dirty_iclog->ic_state = XLOG_STATE_DIRTY;
xlog_state_activate_iclogs(log, &iclogs_changed);
wake_up_all(&dirty_iclog->ic_force_wait);
if (iclogs_changed) {
log->l_covered_state = xlog_covered_state(log->l_covered_state,
iclogs_changed);
}
}
STATIC xfs_lsn_t
xlog_get_lowest_lsn(
struct xlog *log)
{
struct xlog_in_core *iclog = log->l_iclog;
xfs_lsn_t lowest_lsn = 0, lsn;
do {
if (iclog->ic_state == XLOG_STATE_ACTIVE ||
iclog->ic_state == XLOG_STATE_DIRTY)
continue;
lsn = be64_to_cpu(iclog->ic_header.h_lsn);
if ((lsn && !lowest_lsn) || XFS_LSN_CMP(lsn, lowest_lsn) < 0)
lowest_lsn = lsn;
} while ((iclog = iclog->ic_next) != log->l_iclog);
return lowest_lsn;
}
/*
* Completion of a iclog IO does not imply that a transaction has completed, as
* transactions can be large enough to span many iclogs. We cannot change the
* tail of the log half way through a transaction as this may be the only
* transaction in the log and moving the tail to point to the middle of it
* will prevent recovery from finding the start of the transaction. Hence we
* should only update the last_sync_lsn if this iclog contains transaction
* completion callbacks on it.
*
* We have to do this before we drop the icloglock to ensure we are the only one
* that can update it.
*
* If we are moving the last_sync_lsn forwards, we also need to ensure we kick
* the reservation grant head pushing. This is due to the fact that the push
* target is bound by the current last_sync_lsn value. Hence if we have a large
* amount of log space bound up in this committing transaction then the
* last_sync_lsn value may be the limiting factor preventing tail pushing from
* freeing space in the log. Hence once we've updated the last_sync_lsn we
* should push the AIL to ensure the push target (and hence the grant head) is
* no longer bound by the old log head location and can move forwards and make
* progress again.
*/
static void
xlog_state_set_callback(
struct xlog *log,
struct xlog_in_core *iclog,
xfs_lsn_t header_lsn)
{
iclog->ic_state = XLOG_STATE_CALLBACK;
ASSERT(XFS_LSN_CMP(atomic64_read(&log->l_last_sync_lsn),
header_lsn) <= 0);
if (list_empty_careful(&iclog->ic_callbacks))
return;
atomic64_set(&log->l_last_sync_lsn, header_lsn);
xlog_grant_push_ail(log, 0);
}
/*
* Return true if we need to stop processing, false to continue to the next
* iclog. The caller will need to run callbacks if the iclog is returned in the
* XLOG_STATE_CALLBACK state.
*/
static bool
xlog_state_iodone_process_iclog(
struct xlog *log,
struct xlog_in_core *iclog,
bool *ioerror)
{
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_IOERROR:
/*
* Between marking a filesystem SHUTDOWN and stopping the log,
* we do flush all iclogs to disk (if there wasn't a log I/O
* error). So, we do want things to go smoothly in case of just
* a SHUTDOWN w/o a LOG_IO_ERROR.
*/
*ioerror = true;
return false;
case XLOG_STATE_DONE_SYNC:
/*
* Now that we have an iclog that is in the DONE_SYNC state, do
* one more check here to see if we have chased our tail around.
* If this is not the lowest lsn iclog, then we will leave it
* for another completion to process.
*/
header_lsn = be64_to_cpu(iclog->ic_header.h_lsn);
lowest_lsn = xlog_get_lowest_lsn(log);
if (lowest_lsn && XFS_LSN_CMP(lowest_lsn, header_lsn) < 0)
return false;
xlog_state_set_callback(log, iclog, header_lsn);
return false;
default:
/*
* Can only perform callbacks in order. Since this iclog is not
* in the DONE_SYNC state, we skip the rest and just try to
* clean up.
*/
return true;
}
}
/*
* Keep processing entries in the iclog callback list until we come around and
* it is empty. We need to atomically see that the list is empty and change the
* state to DIRTY so that we don't miss any more callbacks being added.
*
* This function is called with the icloglock held and returns with it held. We
* drop it while running callbacks, however, as holding it over thousands of
* callbacks is unnecessary and causes excessive contention if we do.
*/
static void
xlog_state_do_iclog_callbacks(
struct xlog *log,
struct xlog_in_core *iclog)
__releases(&log->l_icloglock)
__acquires(&log->l_icloglock)
{
spin_unlock(&log->l_icloglock);
spin_lock(&iclog->ic_callback_lock);
while (!list_empty(&iclog->ic_callbacks)) {
LIST_HEAD(tmp);
list_splice_init(&iclog->ic_callbacks, &tmp);
spin_unlock(&iclog->ic_callback_lock);
xlog_cil_process_committed(&tmp);
spin_lock(&iclog->ic_callback_lock);
}
/*
* Pick up the icloglock while still holding the callback lock so we
* serialise against anyone trying to add more callbacks to this iclog
* now we've finished processing.
*/
spin_lock(&log->l_icloglock);
spin_unlock(&iclog->ic_callback_lock);
}
STATIC void
xlog_state_do_callback(
struct xlog *log)
{
struct xlog_in_core *iclog;
struct xlog_in_core *first_iclog;
bool cycled_icloglock;
bool ioerror;
int flushcnt = 0;
int repeats = 0;
spin_lock(&log->l_icloglock);
do {
/*
* Scan all iclogs starting with the one pointed to by the
* log. Reset this starting point each time the log is
* unlocked (during callbacks).
*
* Keep looping through iclogs until one full pass is made
* without running any callbacks.
*/
first_iclog = log->l_iclog;
iclog = log->l_iclog;
cycled_icloglock = false;
ioerror = false;
repeats++;
do {
if (xlog_state_iodone_process_iclog(log, iclog,
&ioerror))
break;
if (iclog->ic_state != XLOG_STATE_CALLBACK &&
iclog->ic_state != XLOG_STATE_IOERROR) {
iclog = iclog->ic_next;
continue;
}
/*
* Running callbacks will drop the icloglock which means
* we'll have to run at least one more complete loop.
*/
cycled_icloglock = true;
xlog_state_do_iclog_callbacks(log, iclog);
if (XLOG_FORCED_SHUTDOWN(log))
wake_up_all(&iclog->ic_force_wait);
else
xlog_state_clean_iclog(log, iclog);
iclog = iclog->ic_next;
} while (first_iclog != iclog);
if (repeats > 5000) {
flushcnt += repeats;
repeats = 0;
xfs_warn(log->l_mp,
"%s: possible infinite loop (%d iterations)",
__func__, flushcnt);
}
} while (!ioerror && cycled_icloglock);
if (log->l_iclog->ic_state == XLOG_STATE_ACTIVE ||
log->l_iclog->ic_state == XLOG_STATE_IOERROR)
wake_up_all(&log->l_flush_wait);
spin_unlock(&log->l_icloglock);
}
/*
* Finish transitioning this iclog to the dirty state.
*
* Make sure that we completely execute this routine only when this is
* the last call to the iclog. There is a good chance that iclog flushes,
* when we reach the end of the physical log, get turned into 2 separate
* calls to bwrite. Hence, one iclog flush could generate two calls to this
* routine. By using the reference count bwritecnt, we guarantee that only
* the second completion goes through.
*
* Callbacks could take time, so they are done outside the scope of the
* global state machine log lock.
*/
STATIC void
xlog_state_done_syncing(
struct xlog_in_core *iclog)
{
struct xlog *log = iclog->ic_log;
spin_lock(&log->l_icloglock);
ASSERT(atomic_read(&iclog->ic_refcnt) == 0);
/*
* 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_FORCED_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 *continued_write,
int *logoffsetp)
{
int log_offset;
xlog_rec_header_t *head;
xlog_in_core_t *iclog;
restart:
spin_lock(&log->l_icloglock);
if (XLOG_FORCED_SHUTDOWN(log)) {
spin_unlock(&log->l_icloglock);
return -EIO;
}
iclog = log->l_iclog;
if (iclog->ic_state != XLOG_STATE_ACTIVE) {
XFS_STATS_INC(log->l_mp, xs_log_noiclogs);
/* Wait for log writes to have flushed */
xlog_wait(&log->l_flush_wait, &log->l_icloglock);
goto restart;
}
head = &iclog->ic_header;
atomic_inc(&iclog->ic_refcnt); /* prevents sync */
log_offset = iclog->ic_offset;
/* On the 1st write to an iclog, figure out lsn. This works
* if iclogs marked XLOG_STATE_WANT_SYNC always write out what they are
* committing to. If the offset is set, that's how many blocks
* must be written.
*/
if (log_offset == 0) {
ticket->t_curr_res -= log->l_iclog_hsize;
xlog_tic_add_region(ticket,
log->l_iclog_hsize,
XLOG_REG_TYPE_LRHEADER);
head->h_cycle = cpu_to_be32(log->l_curr_cycle);
head->h_lsn = cpu_to_be64(
xlog_assign_lsn(log->l_curr_cycle, log->l_curr_block));
ASSERT(log->l_curr_block >= 0);
}
/* If there is enough room to write everything, then do it. Otherwise,
* claim the rest of the region and make sure the XLOG_STATE_WANT_SYNC
* bit is on, so this will get flushed out. Don't update ic_offset
* until you know exactly how many bytes get copied. Therefore, wait
* until later to update ic_offset.
*
* xlog_write() algorithm assumes that at least 2 xlog_op_header_t's
* can fit into remaining data section.
*/
if (iclog->ic_size - iclog->ic_offset < 2*sizeof(xlog_op_header_t)) {
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);
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) {
*continued_write = 0;
iclog->ic_offset += len;
} else {
*continued_write = 1;
xlog_state_switch_iclogs(log, iclog, iclog->ic_size);
}
*iclogp = iclog;
ASSERT(iclog->ic_offset <= iclog->ic_size);
spin_unlock(&log->l_icloglock);
*logoffsetp = log_offset;
return 0;
}
/*
* The first cnt-1 times a ticket goes through here we don't need to move the
* grant write head because the permanent reservation has reserved cnt times the
* unit amount. Release part of current permanent unit reservation and reset
* current reservation to be one units worth. Also move grant reservation head
* forward.
*/
void
xfs_log_ticket_regrant(
struct xlog *log,
struct xlog_ticket *ticket)
{
trace_xfs_log_ticket_regrant(log, ticket);
if (ticket->t_cnt > 0)
ticket->t_cnt--;
xlog_grant_sub_space(log, &log->l_reserve_head.grant,
ticket->t_curr_res);
xlog_grant_sub_space(log, &log->l_write_head.grant,
ticket->t_curr_res);
ticket->t_curr_res = ticket->t_unit_res;
xlog_tic_reset_res(ticket);
trace_xfs_log_ticket_regrant_sub(log, ticket);
/* just return if we still have some of the pre-reserved space */
if (!ticket->t_cnt) {
xlog_grant_add_space(log, &log->l_reserve_head.grant,
ticket->t_unit_res);
trace_xfs_log_ticket_regrant_exit(log, ticket);
ticket->t_curr_res = ticket->t_unit_res;
xlog_tic_reset_res(ticket);
}
xfs_log_ticket_put(ticket);
}
/*
* Give back the space left from a reservation.
*
* All the information we need to make a correct determination of space left
* is present. For non-permanent reservations, things are quite easy. The
* count should have been decremented to zero. We only need to deal with the
* space remaining in the current reservation part of the ticket. If the
* ticket contains a permanent reservation, there may be left over space which
* needs to be released. A count of N means that N-1 refills of the current
* reservation can be done before we need to ask for more space. The first
* one goes to fill up the first current reservation. Once we run out of
* space, the count will stay at zero and the only space remaining will be
* in the current reservation field.
*/
void
xfs_log_ticket_ungrant(
struct xlog *log,
struct xlog_ticket *ticket)
{
int bytes;
trace_xfs_log_ticket_ungrant(log, ticket);
if (ticket->t_cnt > 0)
ticket->t_cnt--;
trace_xfs_log_ticket_ungrant_sub(log, ticket);
/*
* If this is a permanent reservation ticket, we may be able to free
* up more space based on the remaining count.
*/
bytes = ticket->t_curr_res;
if (ticket->t_cnt > 0) {
ASSERT(ticket->t_flags & XLOG_TIC_PERM_RESERV);
bytes += ticket->t_unit_res*ticket->t_cnt;
}
xlog_grant_sub_space(log, &log->l_reserve_head.grant, bytes);
xlog_grant_sub_space(log, &log->l_write_head.grant, bytes);
trace_xfs_log_ticket_ungrant_exit(log, ticket);
xfs_log_space_wake(log->l_mp);
xfs_log_ticket_put(ticket);
}
/*
* This routine will mark the current iclog in the ring as WANT_SYNC and move
* the current iclog pointer to the next iclog in the ring.
*/
STATIC 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);
if (!eventual_size)
eventual_size = iclog->ic_offset;
iclog->ic_state = XLOG_STATE_WANT_SYNC;
iclog->ic_header.h_prev_block = cpu_to_be32(log->l_prev_block);
log->l_prev_block = log->l_curr_block;
log->l_prev_cycle = log->l_curr_cycle;
/* roll log?: ic_offset changed later */
log->l_curr_block += BTOBB(eventual_size)+BTOBB(log->l_iclog_hsize);
/* Round up to next log-sunit */
if (xfs_sb_version_haslogv2(&log->l_mp->m_sb) &&
log->l_mp->m_sb.sb_logsunit > 1) {
uint32_t sunit_bb = BTOBB(log->l_mp->m_sb.sb_logsunit);
log->l_curr_block = roundup(log->l_curr_block, sunit_bb);
}
if (log->l_curr_block >= log->l_logBBsize) {
/*
* Rewind the current block before the cycle is bumped to make
* sure that the combined LSN never transiently moves forward
* when the log wraps to the next cycle. This is to support the
* unlocked sample of these fields from xlog_valid_lsn(). Most
* other cases should acquire l_icloglock.
*/
log->l_curr_block -= log->l_logBBsize;
ASSERT(log->l_curr_block >= 0);
smp_wmb();
log->l_curr_cycle++;
if (log->l_curr_cycle == XLOG_HEADER_MAGIC_NUM)
log->l_curr_cycle++;
}
ASSERT(iclog == log->l_iclog);
log->l_iclog = iclog->ic_next;
}
/*
* 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_lsn_t lsn;
XFS_STATS_INC(mp, xs_log_force);
trace_xfs_log_force(mp, 0, _RET_IP_);
xlog_cil_force(log);
spin_lock(&log->l_icloglock);
iclog = log->l_iclog;
if (iclog->ic_state == XLOG_STATE_IOERROR)
goto out_error;
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 are the only one with access to this iclog.
*
* Flush it out now. There should be a roundoff of zero
* to show that someone has already taken care of the
* roundoff from the previous sync.
*/
atomic_inc(&iclog->ic_refcnt);
lsn = be64_to_cpu(iclog->ic_header.h_lsn);
xlog_state_switch_iclogs(log, iclog, 0);
if (xlog_state_release_iclog(log, iclog))
goto out_error;
if (be64_to_cpu(iclog->ic_header.h_lsn) != lsn)
goto out_unlock;
} else {
/*
* Someone else is writing to this iclog.
*
* Use its call to flush out the data. However, the
* other thread may not force out this LR, so we mark
* it WANT_SYNC.
*/
xlog_state_switch_iclogs(log, iclog, 0);
}
} else {
/*
* If the head iclog is not active nor dirty, we just attach
* ourselves to the head and go to sleep if necessary.
*/
;
}
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;
}
static int
__xfs_log_force_lsn(
struct xfs_mount *mp,
xfs_lsn_t lsn,
uint flags,
int *log_flushed,
bool already_slept)
{
struct xlog *log = mp->m_log;
struct xlog_in_core *iclog;
spin_lock(&log->l_icloglock);
iclog = log->l_iclog;
if (iclog->ic_state == XLOG_STATE_IOERROR)
goto out_error;
while (be64_to_cpu(iclog->ic_header.h_lsn) != lsn) {
iclog = iclog->ic_next;
if (iclog == log->l_iclog)
goto out_unlock;
}
if (iclog->ic_state == XLOG_STATE_ACTIVE) {
/*
* We sleep here if we haven't already slept (e.g. this is the
* first time we've looked at the correct iclog buf) and the
* buffer before us is going to be sync'ed. The reason for this
* is that if we are doing sync transactions here, by waiting
* for the previous I/O to complete, we can allow a few more
* transactions into this iclog before we close it down.
*
* Otherwise, we mark the buffer WANT_SYNC, and bump up the
* refcnt so we can release the log (which drops the ref count).
* The state switch keeps new transaction commits from using
* this buffer. When the current commits finish writing into
* the buffer, the refcount will drop to zero and the buffer
* will go out then.
*/
if (!already_slept &&
(iclog->ic_prev->ic_state == XLOG_STATE_WANT_SYNC ||
iclog->ic_prev->ic_state == XLOG_STATE_SYNCING)) {
XFS_STATS_INC(mp, xs_log_force_sleep);
xlog_wait(&iclog->ic_prev->ic_write_wait,
&log->l_icloglock);
return -EAGAIN;
}
atomic_inc(&iclog->ic_refcnt);
xlog_state_switch_iclogs(log, iclog, 0);
if (xlog_state_release_iclog(log, iclog))
goto out_error;
if (log_flushed)
*log_flushed = 1;
}
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 in-core log to disk for a specific LSN.
*
* Find in-core log with lsn.
* If it is in the DIRTY state, just return.
* If it is in the ACTIVE state, move the in-core log into the WANT_SYNC
* state and go to sleep or return.
* If it is in any other state, go to sleep or return.
*
* Synchronous forces are implemented with a 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.
*/
int
xfs_log_force_lsn(
struct xfs_mount *mp,
xfs_lsn_t lsn,
uint flags,
int *log_flushed)
{
int ret;
ASSERT(lsn != 0);
XFS_STATS_INC(mp, xs_log_force);
trace_xfs_log_force(mp, lsn, _RET_IP_);
lsn = xlog_cil_force_lsn(mp->m_log, lsn);
if (lsn == NULLCOMMITLSN)
return 0;
ret = __xfs_log_force_lsn(mp, lsn, flags, log_flushed, false);
if (ret == -EAGAIN)
ret = __xfs_log_force_lsn(mp, 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_zone, ticket);
}
xlog_ticket_t *
xfs_log_ticket_get(
xlog_ticket_t *ticket)
{
ASSERT(atomic_read(&ticket->t_ref) > 0);
atomic_inc(&ticket->t_ref);
return ticket;
}
/*
* Figure out the total log space unit (in bytes) that would be
* required for a log ticket.
*/
int
xfs_log_calc_unit_res(
struct xfs_mount *mp,
int unit_bytes)
{
struct xlog *log = mp->m_log;
int iclog_space;
uint num_headers;
/*
* Permanent reservations have up to 'cnt'-1 active log operations
* in the log. A unit in this case is the amount of space for one
* of these log operations. Normal reservations have a cnt of 1
* and their unit amount is the total amount of space required.
*
* The following lines of code account for non-transaction data
* which occupy space in the on-disk log.
*
* Normal form of a transaction is:
* <oph><trans-hdr><start-oph><reg1-oph><reg1><reg2-oph>...<commit-oph>
* and then there are LR hdrs, split-recs and roundoff at end of syncs.
*
* We need to account for all the leadup data and trailer data
* around the transaction data.
* And then we need to account for the worst case in terms of using
* more space.
* The worst case will happen if:
* - the placement of the transaction happens to be such that the
* roundoff is at its maximum
* - the transaction data is synced before the commit record is synced
* i.e. <transaction-data><roundoff> | <commit-rec><roundoff>
* Therefore the commit record is in its own Log Record.
* This can happen as the commit record is called with its
* own region to xlog_write().
* This then means that in the worst case, roundoff can happen for
* the commit-rec as well.
* The commit-rec is smaller than padding in this scenario and so it is
* not added separately.
*/
/* for trans header */
unit_bytes += sizeof(xlog_op_header_t);
unit_bytes += sizeof(xfs_trans_header_t);
/* for start-rec */
unit_bytes += sizeof(xlog_op_header_t);
/*
* for LR headers - the space for data in an iclog is the size minus
* the space used for the headers. If we use the iclog size, then we
* undercalculate the number of headers required.
*
* Furthermore - the addition of op headers for split-recs might
* increase the space required enough to require more log and op
* headers, so take that into account too.
*
* IMPORTANT: This reservation makes the assumption that if this
* transaction is the first in an iclog and hence has the LR headers
* accounted to it, then the remaining space in the iclog is
* exclusively for this transaction. i.e. if the transaction is larger
* than the iclog, it will be the only thing in that iclog.
* Fundamentally, this means we must pass the entire log vector to
* xlog_write to guarantee this.
*/
iclog_space = log->l_iclog_size - log->l_iclog_hsize;
num_headers = howmany(unit_bytes, iclog_space);
/* for split-recs - ophdrs added when data split over LRs */
unit_bytes += sizeof(xlog_op_header_t) * num_headers;
/* add extra header reservations if we overrun */
while (!num_headers ||
howmany(unit_bytes, iclog_space) > num_headers) {
unit_bytes += sizeof(xlog_op_header_t);
num_headers++;
}
unit_bytes += log->l_iclog_hsize * num_headers;
/* for commit-rec LR header - note: padding will subsume the ophdr */
unit_bytes += log->l_iclog_hsize;
/* for roundoff padding for transaction data and one for commit record */
if (xfs_sb_version_haslogv2(&mp->m_sb) && mp->m_sb.sb_logsunit > 1) {
/* log su roundoff */
unit_bytes += 2 * mp->m_sb.sb_logsunit;
} else {
/* BB roundoff */
unit_bytes += 2 * BBSIZE;
}
return unit_bytes;
}
/*
* Allocate and initialise a new log ticket.
*/
struct xlog_ticket *
xlog_ticket_alloc(
struct xlog *log,
int unit_bytes,
int cnt,
char client,
bool permanent)
{
struct xlog_ticket *tic;
int unit_res;
tic = kmem_cache_zalloc(xfs_log_ticket_zone, GFP_NOFS | __GFP_NOFAIL);
unit_res = xfs_log_calc_unit_res(log->l_mp, unit_bytes);
atomic_set(&tic->t_ref, 1);
tic->t_task = current;
INIT_LIST_HEAD(&tic->t_queue);
tic->t_unit_res = unit_res;
tic->t_curr_res = unit_res;
tic->t_cnt = cnt;
tic->t_ocnt = cnt;
tic->t_tid = prandom_u32();
tic->t_clientid = client;
if (permanent)
tic->t_flags |= XLOG_TIC_PERM_RESERV;
xlog_tic_reset_res(tic);
return tic;
}
#if defined(DEBUG)
/*
* Make sure that the destination ptr is within the valid data region of
* one of the iclogs. This uses backup pointers stored in a different
* part of the log in case we trash the log structure.
*/
STATIC void
xlog_verify_dest_ptr(
struct xlog *log,
void *ptr)
{
int i;
int good_ptr = 0;
for (i = 0; i < log->l_iclog_bufs; i++) {
if (ptr >= log->l_iclog_bak[i] &&
ptr <= log->l_iclog_bak[i] + log->l_iclog_size)
good_ptr++;
}
if (!good_ptr)
xfs_emerg(log->l_mp, "%s: invalid ptr", __func__);
}
/*
* Check to make sure the grant write head didn't just over lap the tail. If
* the cycles are the same, we can't be overlapping. Otherwise, make sure that
* the cycles differ by exactly one and check the byte count.
*
* This check is run unlocked, so can give false positives. Rather than assert
* on failures, use a warn-once flag and a panic tag to allow the admin to
* determine if they want to panic the machine when such an error occurs. For
* debug kernels this will have the same effect as using an assert but, unlinke
* an assert, it can be turned off at runtime.
*/
STATIC void
xlog_verify_grant_tail(
struct xlog *log)
{
int tail_cycle, tail_blocks;
int cycle, space;
xlog_crack_grant_head(&log->l_write_head.grant, &cycle, &space);
xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_blocks);
if (tail_cycle != cycle) {
if (cycle - 1 != tail_cycle &&
!(log->l_flags & XLOG_TAIL_WARN)) {
xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
"%s: cycle - 1 != tail_cycle", __func__);
log->l_flags |= XLOG_TAIL_WARN;
}
if (space > BBTOB(tail_blocks) &&
!(log->l_flags & XLOG_TAIL_WARN)) {
xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
"%s: space > BBTOB(tail_blocks)", __func__);
log->l_flags |= XLOG_TAIL_WARN;
}
}
}
/* check if it will fit */
STATIC void
xlog_verify_tail_lsn(
struct xlog *log,
struct xlog_in_core *iclog,
xfs_lsn_t tail_lsn)
{
int blocks;
if (CYCLE_LSN(tail_lsn) == log->l_prev_cycle) {
blocks =
log->l_logBBsize - (log->l_prev_block - BLOCK_LSN(tail_lsn));
if (blocks < BTOBB(iclog->ic_offset)+BTOBB(log->l_iclog_hsize))
xfs_emerg(log->l_mp, "%s: ran out of log space", __func__);
} else {
ASSERT(CYCLE_LSN(tail_lsn)+1 == log->l_prev_cycle);
if (BLOCK_LSN(tail_lsn) == log->l_prev_block)
xfs_emerg(log->l_mp, "%s: tail wrapped", __func__);
blocks = BLOCK_LSN(tail_lsn) - log->l_prev_block;
if (blocks < BTOBB(iclog->ic_offset) + 1)
xfs_emerg(log->l_mp, "%s: ran out of log space", __func__);
}
}
/*
* 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((char *)&ophead->oh_clientid - iclog->ic_datap);
if (idx >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) {
j = idx / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
k = idx % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
clientid = xlog_get_client_id(
xhdr[j].hic_xheader.xh_cycle_data[k]);
} else {
clientid = xlog_get_client_id(
iclog->ic_header.h_cycle_data[idx]);
}
}
if (clientid != XFS_TRANSACTION && clientid != XFS_LOG)
xfs_warn(log->l_mp,
"%s: invalid clientid %d op "PTR_FMT" offset 0x%lx",
__func__, 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((uintptr_t)&ophead->oh_len -
(uintptr_t)iclog->ic_datap);
if (idx >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) {
j = idx / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
k = idx % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
op_len = be32_to_cpu(xhdr[j].hic_xheader.xh_cycle_data[k]);
} else {
op_len = be32_to_cpu(iclog->ic_header.h_cycle_data[idx]);
}
}
ptr += sizeof(xlog_op_header_t) + op_len;
}
}
#endif
/*
* Mark all iclogs IOERROR. l_icloglock is held by the caller.
*/
STATIC int
xlog_state_ioerror(
struct xlog *log)
{
xlog_in_core_t *iclog, *ic;
iclog = log->l_iclog;
if (iclog->ic_state != XLOG_STATE_IOERROR) {
/*
* Mark all the incore logs IOERROR.
* From now on, no log flushes will result.
*/
ic = iclog;
do {
ic->ic_state = XLOG_STATE_IOERROR;
ic = ic->ic_next;
} while (ic != iclog);
return 0;
}
/*
* Return non-zero, if state transition has already happened.
*/
return 1;
}
/*
* This is called from xfs_force_shutdown, when we're forcibly
* shutting down the filesystem, typically because of an IO error.
* Our main objectives here are to make sure that:
* a. if !logerror, flush the logs to disk. Anything modified
* after this is ignored.
* b. the filesystem gets marked 'SHUTDOWN' for all interested
* parties to find out, 'atomically'.
* c. those who're sleeping on log reservations, pinned objects and
* other resources get woken up, and be told the bad news.
* d. nothing new gets queued up after (b) and (c) are done.
*
* Note: for the !logerror case we need to flush the regions held in memory out
* to disk first. This needs to be done before the log is marked as shutdown,
* otherwise the iclog writes will fail.
*/
int
xfs_log_force_umount(
struct xfs_mount *mp,
int logerror)
{
struct xlog *log;
int retval;
log = mp->m_log;
/*
* If this happens during log recovery, don't worry about
* locking; the log isn't open for business yet.
*/
if (!log ||
log->l_flags & XLOG_ACTIVE_RECOVERY) {
mp->m_flags |= XFS_MOUNT_FS_SHUTDOWN;
if (mp->m_sb_bp)
mp->m_sb_bp->b_flags |= XBF_DONE;
return 0;
}
/*
* Somebody could've already done the hard work for us.
* No need to get locks for this.
*/
if (logerror && log->l_iclog->ic_state == XLOG_STATE_IOERROR) {
ASSERT(XLOG_FORCED_SHUTDOWN(log));
return 1;
}
/*
* Flush all the completed transactions to disk before marking the log
* being shut down. We need to do it in this order to ensure that
* completed operations are safely on disk before we shut down, and that
* we don't have to issue any buffer IO after the shutdown flags are set
* to guarantee this.
*/
if (!logerror)
xfs_log_force(mp, XFS_LOG_SYNC);
/*
* mark the filesystem and the as in a shutdown state and wake
* everybody up to tell them the bad news.
*/
spin_lock(&log->l_icloglock);
mp->m_flags |= XFS_MOUNT_FS_SHUTDOWN;
if (mp->m_sb_bp)
mp->m_sb_bp->b_flags |= XBF_DONE;
/*
* Mark the log and the iclogs with IO error flags to prevent any
* further log IO from being issued or completed.
*/
log->l_flags |= XLOG_IO_ERROR;
retval = xlog_state_ioerror(log);
spin_unlock(&log->l_icloglock);
/*
* We don't want anybody waiting for log reservations after this. That
* means we have to wake up everybody queued up on reserveq as well as
* writeq. In addition, we make sure in xlog_{re}grant_log_space that
* we don't enqueue anything once the SHUTDOWN flag is set, and this
* action is protected by the grant locks.
*/
xlog_grant_head_wake_all(&log->l_reserve_head);
xlog_grant_head_wake_all(&log->l_write_head);
/*
* Wake up everybody waiting on xfs_log_force. Wake the CIL push first
* as if the log writes were completed. The abort handling in the log
* item committed callback functions will do this again under lock to
* avoid races.
*/
spin_lock(&log->l_cilp->xc_push_lock);
wake_up_all(&log->l_cilp->xc_commit_wait);
spin_unlock(&log->l_cilp->xc_push_lock);
xlog_state_do_callback(log);
/* return non-zero if log IOERROR transition had already happened */
return retval;
}
STATIC int
xlog_iclogs_empty(
struct xlog *log)
{
xlog_in_core_t *iclog;
iclog = log->l_iclog;
do {
/* endianness does not matter here, zero is zero in
* any language.
*/
if (iclog->ic_header.h_num_logops)
return 0;
iclog = iclog->ic_next;
} while (iclog != log->l_iclog);
return 1;
}
/*
* Verify that an LSN stamped into a piece of metadata is valid. This is
* intended for use in read verifiers on v5 superblocks.
*/
bool
xfs_log_check_lsn(
struct xfs_mount *mp,
xfs_lsn_t lsn)
{
struct xlog *log = mp->m_log;
bool valid;
/*
* norecovery mode skips mount-time log processing and unconditionally
* resets the in-core LSN. We can't validate in this mode, but
* modifications are not allowed anyways so just return true.
*/
if (mp->m_flags & XFS_MOUNT_NORECOVERY)
return true;
/*
* Some metadata LSNs are initialized to NULL (e.g., the agfl). This is
* handled by recovery and thus safe to ignore here.
*/
if (lsn == NULLCOMMITLSN)
return true;
valid = xlog_valid_lsn(mp->m_log, lsn);
/* warn the user about what's gone wrong before verifier failure */
if (!valid) {
spin_lock(&log->l_icloglock);
xfs_warn(mp,
"Corruption warning: Metadata has LSN (%d:%d) ahead of current LSN (%d:%d). "
"Please unmount and run xfs_repair (>= v4.3) to resolve.",
CYCLE_LSN(lsn), BLOCK_LSN(lsn),
log->l_curr_cycle, log->l_curr_block);
spin_unlock(&log->l_icloglock);
}
return valid;
}
bool
xfs_log_in_recovery(
struct xfs_mount *mp)
{
struct xlog *log = mp->m_log;
return log->l_flags & XLOG_ACTIVE_RECOVERY;
}
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