fs/xfs/xfs_log_priv.h

1 // SPDX-License-Identifier: GPL-2.0
3  * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
74  * By covering, we mean changing the h_tail_lsn in the last on-disk
75  * log write such that no allocation transactions will be re-done during
76  * recovery after a system crash. Recovery starts at the last on-disk
80  * space allocation transactions which can undo non-transactional changes
93  * non-dummy transaction. The first dummy changes the h_tail_lsn to
102  *  IDLE -- no logging has been done on the file system or
104  *  NEED -- logging has occurred and we need a dummy transaction
106  *  DONE -- we were in the NEED state and have committed a dummy
108  *  NEED2 -- we detected that a dummy transaction has gone to the
110  *  DONE2 -- we committed a dummy transaction when in the NEED2 state.
118  * 2.) When we finish writing the on-disk log (xlog_state_clean_log).
161  * - A log record header is 512 bytes.  There is plenty of room to grow the
163  * - ic_data follows, so a write to disk can start at the beginning of
165  * - ic_forcewait is used to implement synchronous forcing of the iclog to disk.
166  * - ic_next is the pointer to the next iclog in the ring.
167  * - ic_log is a pointer back to the global log structure.
168  * - ic_size is the full size of the log buffer, minus the cycle headers.
169  * - ic_offset is the current number of bytes written to in this iclog.
170  * - ic_refcnt is bumped when someone is writing to the log.
171  * - ic_state is the state of the iclog.
178  *	- ic_callbacks
179  *	- ic_refcnt
180  *	- fields protected by the global l_icloglock
183  * We'll put all the read-only and l_icloglock fields in the first cacheline,
202 #define ic_header	ic_data->hic_header
213  * The CIL context is used to aggregate per-transaction details as well be
214  * passed to the iclog for checkpoint post-commit processing.  After being
244  * Per-cpu CIL tracking items
336  * CIL is large enough to maintain sufficient in-memory relogging to avoid
340  * issues when we are running low on memory - pinned memory cannot be reclaimed,
346  * As such, the CIL push threshold ends up being the smaller of two thresholds:
347  * - a threshold large enough that it allows CIL to be pushed and progress to be
349  *   defined to be 12.5% of the log space - half the 25% push threshold of the
351  * - small enough that it doesn't pin excessive amounts of memory but maintains
358  * new threshold at which we block committing transactions until the background
364  * twice the background push space threshold so we keep in line with the AIL
367  * Note: this is not a -hard- limit as blocking is applied after the transaction
374  * occurred. Hence the simple throttle, and an ASSERT check to tell us that
378 	min_t(int, (log)->l_logsize >> 3, BBTOB(XLOG_TOTAL_REC_SHIFT(log)) << 4)
434 	 * l_tail_lsn is atomic so it can be set and read without needing to
465 	return test_bit(XLOG_RECOVERY_NEEDED, &log->l_opstate);  in xlog_recovery_needed()
471 	return test_bit(XLOG_ACTIVE_RECOVERY, &log->l_opstate);  in xlog_in_recovery()
477 	return test_bit(XLOG_IO_ERROR, &log->l_opstate);  in xlog_is_shutdown()
488 	wait_var_event(&log->l_opstate, xlog_is_shutdown(log));  in xlog_shutdown_wait()
522  * When we crack an atomic LSN, we sample it first so that the value will not
525  * be used to sample and crack LSNs that are stored and updated in atomic
538  * Calculate and assign a value to an atomic LSN variable from component pieces.
568 	xlog_cil_force_seq(log, log->l_cilp->xc_current_sequence);  in xlog_cil_force()
592 		__releases(iclog->ic_log->l_icloglock);
607 		return BBTOB(hi_block - lo_block);  in xlog_lsn_sub()
609 	return (uint64_t)log->l_logsize - BBTOB(lo_block - hi_block);  in xlog_lsn_sub()
642 	cur_cycle = READ_ONCE(log->l_curr_cycle);  in xlog_valid_lsn()
644 	cur_block = READ_ONCE(log->l_curr_block);  in xlog_valid_lsn()
653 		spin_lock(&log->l_icloglock);  in xlog_valid_lsn()
654 		cur_cycle = log->l_curr_cycle;  in xlog_valid_lsn()
655 		cur_block = log->l_curr_block;  in xlog_valid_lsn()
656 		spin_unlock(&log->l_icloglock);  in xlog_valid_lsn()