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xfs: call xlog_state_release_iclog with l_icloglock held 

All but one caller of xlog_state_release_iclog hold l_icloglock and need
to drop and reacquire it to call xlog_state_release_iclog.  Switch the
xlog_state_release_iclog calling conventions to expect the lock to be
held, and open code the logic (using a shared helper) in the only
remaining caller that does not have the lock (and where not holding it
is a nice performance optimization).  Also move the refactored code to
require the least amount of forward declarations.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
[darrick: minor whitespace cleanup]
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
This commit is contained in:
Christoph Hellwig 2019-10-14 10:36:41 -07:00 committed by Darrick J. Wong
parent 390aab0a16
commit df732b29c8
1 changed files with 92 additions and 100 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

192
fs/xfs/xfs_log.c
View File

@ -57,10 +57,6 @@ xlog_state_get_iclog_space(
struct xlog_ticket *ticket,
int *continued_write,
int *logoffsetp);
STATIC int
xlog_state_release_iclog(
struct xlog *log,
struct xlog_in_core *iclog);
STATIC void
xlog_state_switch_iclogs(
struct xlog *log,
@ -83,7 +79,10 @@ STATIC void
xlog_ungrant_log_space(
struct xlog *log,
struct xlog_ticket *ticket);
STATIC void
xlog_sync(
struct xlog *log,
struct xlog_in_core *iclog);
#if defined(DEBUG)
STATIC void
xlog_verify_dest_ptr(
@ -552,16 +551,71 @@ xfs_log_done(
return lsn;
}
int
xfs_log_release_iclog(
struct xfs_mount *mp,
static bool
__xlog_state_release_iclog(
struct xlog *log,
struct xlog_in_core *iclog)
{
if (xlog_state_release_iclog(mp->m_log, 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;
}
int
xfs_log_release_iclog(
struct xfs_mount *mp,
struct xlog_in_core *iclog)
{
struct xlog *log = mp->m_log;
bool sync;
if (iclog->ic_state & XLOG_STATE_IOERROR) {
xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR);
return -EIO;
}
if (atomic_dec_and_lock(&iclog->ic_refcnt, &log->l_icloglock)) {
sync = __xlog_state_release_iclog(log, iclog);
spin_unlock(&log->l_icloglock);
if (sync)
xlog_sync(log, iclog);
}
return 0;
}
@ -866,10 +920,7 @@ out_err:
iclog = log->l_iclog;
atomic_inc(&iclog->ic_refcnt);
xlog_state_want_sync(log, iclog);
spin_unlock(&log->l_icloglock);
error = xlog_state_release_iclog(log, iclog);
spin_lock(&log->l_icloglock);
switch (iclog->ic_state) {
default:
if (!XLOG_FORCED_SHUTDOWN(log)) {
@ -950,13 +1001,9 @@ xfs_log_unmount_write(xfs_mount_t *mp)
spin_lock(&log->l_icloglock);
iclog = log->l_iclog;
atomic_inc(&iclog->ic_refcnt);
xlog_state_want_sync(log, iclog);
spin_unlock(&log->l_icloglock);
error = xlog_state_release_iclog(log, iclog);
spin_lock(&log->l_icloglock);
if ( ! ( iclog->ic_state == XLOG_STATE_ACTIVE
|| iclog->ic_state == XLOG_STATE_DIRTY
|| iclog->ic_state == XLOG_STATE_IOERROR) ) {
@ -2255,6 +2302,8 @@ xlog_write_copy_finish(
int log_offset,
struct xlog_in_core **commit_iclog)
{
int error;
if (*partial_copy) {
/*
* This iclog has already been marked WANT_SYNC by
@ -2262,10 +2311,9 @@ xlog_write_copy_finish(
*/
spin_lock(&log->l_icloglock);
xlog_state_finish_copy(log, iclog, *record_cnt, *data_cnt);
spin_unlock(&log->l_icloglock);
*record_cnt = 0;
*data_cnt = 0;
return xlog_state_release_iclog(log, iclog);
goto release_iclog;
}
*partial_copy = 0;
@ -2279,15 +2327,19 @@ xlog_write_copy_finish(
*data_cnt = 0;
xlog_state_want_sync(log, iclog);
spin_unlock(&log->l_icloglock);
if (!commit_iclog)
return xlog_state_release_iclog(log, 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;
}
/*
@ -2349,7 +2401,7 @@ xlog_write(
int contwr = 0;
int record_cnt = 0;
int data_cnt = 0;
int error;
int error = 0;
*start_lsn = 0;
@ -2502,13 +2554,15 @@ next_lv:
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);
if (!commit_iclog)
return xlog_state_release_iclog(log, iclog);
ASSERT(flags & XLOG_COMMIT_TRANS);
*commit_iclog = iclog;
return 0;
return error;
}
@ -2979,7 +3033,6 @@ xlog_state_get_iclog_space(
int log_offset;
xlog_rec_header_t *head;
xlog_in_core_t *iclog;
int error;
restart:
spin_lock(&log->l_icloglock);
@ -3028,24 +3081,22 @@ restart:
* 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 I'm the only one writing to this iclog, sync it to disk.
* We need to do an atomic compare and decrement here to avoid
* racing with concurrent atomic_dec_and_lock() calls in
* 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)) {
/* we are the only one */
spin_unlock(&log->l_icloglock);
if (!atomic_add_unless(&iclog->ic_refcnt, -1, 1))
error = xlog_state_release_iclog(log, iclog);
if (error)
return error;
} else {
spin_unlock(&log->l_icloglock);
}
spin_unlock(&log->l_icloglock);
if (error)
return error;
goto restart;
}
@ -3156,60 +3207,6 @@ xlog_ungrant_log_space(
xfs_log_space_wake(log->l_mp);
}
/*
* Flush iclog to disk if this is the last reference to the given iclog and
* the WANT_SYNC bit is set.
*
* When this function is entered, the iclog is not necessarily in the
* WANT_SYNC state. It may be sitting around waiting to get filled.
*
*
*/
STATIC int
xlog_state_release_iclog(
struct xlog *log,
struct xlog_in_core *iclog)
{
int sync = 0; /* do we sync? */
if (iclog->ic_state & XLOG_STATE_IOERROR)
return -EIO;
ASSERT(atomic_read(&iclog->ic_refcnt) > 0);
if (!atomic_dec_and_lock(&iclog->ic_refcnt, &log->l_icloglock))
return 0;
if (iclog->ic_state & XLOG_STATE_IOERROR) {
spin_unlock(&log->l_icloglock);
return -EIO;
}
ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE ||
iclog->ic_state == XLOG_STATE_WANT_SYNC);
if (iclog->ic_state == XLOG_STATE_WANT_SYNC) {
/* update tail before writing to iclog */
xfs_lsn_t tail_lsn = xlog_assign_tail_lsn(log->l_mp);
sync++;
iclog->ic_state = XLOG_STATE_SYNCING;
iclog->ic_header.h_tail_lsn = cpu_to_be64(tail_lsn);
xlog_verify_tail_lsn(log, iclog, tail_lsn);
/* cycle incremented when incrementing curr_block */
}
spin_unlock(&log->l_icloglock);
/*
* We let the log lock go, so it's possible that we hit a log I/O
* error or some other SHUTDOWN condition that marks the iclog
* as XLOG_STATE_IOERROR before the bwrite. However, we know that
* this iclog has consistent data, so we ignore IOERROR
* flags after this point.
*/
if (sync)
xlog_sync(log, iclog);
return 0;
} /* xlog_state_release_iclog */
/*
* This routine will mark the current iclog in the ring as WANT_SYNC
* and move the current iclog pointer to the next iclog in the ring.
@ -3333,12 +3330,9 @@ xfs_log_force(
atomic_inc(&iclog->ic_refcnt);
lsn = be64_to_cpu(iclog->ic_header.h_lsn);
xlog_state_switch_iclogs(log, iclog, 0);
spin_unlock(&log->l_icloglock);
if (xlog_state_release_iclog(log, iclog))
return -EIO;
goto out_error;
spin_lock(&log->l_icloglock);
if (be64_to_cpu(iclog->ic_header.h_lsn) != lsn ||
iclog->ic_state == XLOG_STATE_DIRTY)
goto out_unlock;
@ -3433,12 +3427,10 @@ __xfs_log_force_lsn(
}
atomic_inc(&iclog->ic_refcnt);
xlog_state_switch_iclogs(log, iclog, 0);
spin_unlock(&log->l_icloglock);
if (xlog_state_release_iclog(log, iclog))
return -EIO;
goto out_error;
if (log_flushed)
*log_flushed = 1;
spin_lock(&log->l_icloglock);
}
if (!(flags & XFS_LOG_SYNC) ||