636 lines
24 KiB
C
636 lines
24 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
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* All Rights Reserved.
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*/
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#ifndef __XFS_LOG_PRIV_H__
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#define __XFS_LOG_PRIV_H__
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struct xfs_buf;
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struct xlog;
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struct xlog_ticket;
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struct xfs_mount;
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/*
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* Flags for log structure
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*/
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#define XLOG_ACTIVE_RECOVERY 0x2 /* in the middle of recovery */
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#define XLOG_RECOVERY_NEEDED 0x4 /* log was recovered */
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#define XLOG_IO_ERROR 0x8 /* log hit an I/O error, and being
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shutdown */
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#define XLOG_TAIL_WARN 0x10 /* log tail verify warning issued */
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/*
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* get client id from packed copy.
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*
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* this hack is here because the xlog_pack code copies four bytes
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* of xlog_op_header containing the fields oh_clientid, oh_flags
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* and oh_res2 into the packed copy.
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*
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* later on this four byte chunk is treated as an int and the
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* client id is pulled out.
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*
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* this has endian issues, of course.
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*/
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static inline uint xlog_get_client_id(__be32 i)
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{
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return be32_to_cpu(i) >> 24;
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}
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/*
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* In core log state
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*/
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enum xlog_iclog_state {
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XLOG_STATE_ACTIVE, /* Current IC log being written to */
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XLOG_STATE_WANT_SYNC, /* Want to sync this iclog; no more writes */
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XLOG_STATE_SYNCING, /* This IC log is syncing */
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XLOG_STATE_DONE_SYNC, /* Done syncing to disk */
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XLOG_STATE_CALLBACK, /* Callback functions now */
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XLOG_STATE_DIRTY, /* Dirty IC log, not ready for ACTIVE status */
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XLOG_STATE_IOERROR, /* IO error happened in sync'ing log */
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};
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/*
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* Log ticket flags
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*/
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#define XLOG_TIC_PERM_RESERV 0x1 /* permanent reservation */
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#define XLOG_TIC_FLAGS \
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{ XLOG_TIC_PERM_RESERV, "XLOG_TIC_PERM_RESERV" }
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/*
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* Below are states for covering allocation transactions.
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* By covering, we mean changing the h_tail_lsn in the last on-disk
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* log write such that no allocation transactions will be re-done during
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* recovery after a system crash. Recovery starts at the last on-disk
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* log write.
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*
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* These states are used to insert dummy log entries to cover
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* space allocation transactions which can undo non-transactional changes
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* after a crash. Writes to a file with space
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* already allocated do not result in any transactions. Allocations
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* might include space beyond the EOF. So if we just push the EOF a
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* little, the last transaction for the file could contain the wrong
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* size. If there is no file system activity, after an allocation
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* transaction, and the system crashes, the allocation transaction
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* will get replayed and the file will be truncated. This could
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* be hours/days/... after the allocation occurred.
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*
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* The fix for this is to do two dummy transactions when the
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* system is idle. We need two dummy transaction because the h_tail_lsn
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* in the log record header needs to point beyond the last possible
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* non-dummy transaction. The first dummy changes the h_tail_lsn to
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* the first transaction before the dummy. The second dummy causes
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* h_tail_lsn to point to the first dummy. Recovery starts at h_tail_lsn.
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*
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* These dummy transactions get committed when everything
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* is idle (after there has been some activity).
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*
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* There are 5 states used to control this.
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*
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* IDLE -- no logging has been done on the file system or
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* we are done covering previous transactions.
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* NEED -- logging has occurred and we need a dummy transaction
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* when the log becomes idle.
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* DONE -- we were in the NEED state and have committed a dummy
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* transaction.
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* NEED2 -- we detected that a dummy transaction has gone to the
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* on disk log with no other transactions.
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* DONE2 -- we committed a dummy transaction when in the NEED2 state.
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*
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* There are two places where we switch states:
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*
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* 1.) In xfs_sync, when we detect an idle log and are in NEED or NEED2.
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* We commit the dummy transaction and switch to DONE or DONE2,
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* respectively. In all other states, we don't do anything.
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*
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* 2.) When we finish writing the on-disk log (xlog_state_clean_log).
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*
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* No matter what state we are in, if this isn't the dummy
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* transaction going out, the next state is NEED.
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* So, if we aren't in the DONE or DONE2 states, the next state
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* is NEED. We can't be finishing a write of the dummy record
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* unless it was committed and the state switched to DONE or DONE2.
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*
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* If we are in the DONE state and this was a write of the
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* dummy transaction, we move to NEED2.
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*
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* If we are in the DONE2 state and this was a write of the
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* dummy transaction, we move to IDLE.
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*
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*
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* Writing only one dummy transaction can get appended to
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* one file space allocation. When this happens, the log recovery
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* code replays the space allocation and a file could be truncated.
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* This is why we have the NEED2 and DONE2 states before going idle.
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*/
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#define XLOG_STATE_COVER_IDLE 0
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#define XLOG_STATE_COVER_NEED 1
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#define XLOG_STATE_COVER_DONE 2
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#define XLOG_STATE_COVER_NEED2 3
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#define XLOG_STATE_COVER_DONE2 4
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#define XLOG_COVER_OPS 5
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/* Ticket reservation region accounting */
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#define XLOG_TIC_LEN_MAX 15
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/*
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* Reservation region
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* As would be stored in xfs_log_iovec but without the i_addr which
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* we don't care about.
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*/
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typedef struct xlog_res {
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uint r_len; /* region length :4 */
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uint r_type; /* region's transaction type :4 */
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} xlog_res_t;
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typedef struct xlog_ticket {
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struct list_head t_queue; /* reserve/write queue */
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struct task_struct *t_task; /* task that owns this ticket */
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xlog_tid_t t_tid; /* transaction identifier : 4 */
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atomic_t t_ref; /* ticket reference count : 4 */
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int t_curr_res; /* current reservation in bytes : 4 */
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int t_unit_res; /* unit reservation in bytes : 4 */
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char t_ocnt; /* original count : 1 */
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char t_cnt; /* current count : 1 */
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char t_clientid; /* who does this belong to; : 1 */
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char t_flags; /* properties of reservation : 1 */
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/* reservation array fields */
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uint t_res_num; /* num in array : 4 */
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uint t_res_num_ophdrs; /* num op hdrs : 4 */
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uint t_res_arr_sum; /* array sum : 4 */
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uint t_res_o_flow; /* sum overflow : 4 */
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xlog_res_t t_res_arr[XLOG_TIC_LEN_MAX]; /* array of res : 8 * 15 */
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} xlog_ticket_t;
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/*
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* - A log record header is 512 bytes. There is plenty of room to grow the
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* xlog_rec_header_t into the reserved space.
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* - ic_data follows, so a write to disk can start at the beginning of
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* the iclog.
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* - ic_forcewait is used to implement synchronous forcing of the iclog to disk.
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* - ic_next is the pointer to the next iclog in the ring.
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* - ic_log is a pointer back to the global log structure.
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* - ic_size is the full size of the log buffer, minus the cycle headers.
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* - ic_offset is the current number of bytes written to in this iclog.
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* - ic_refcnt is bumped when someone is writing to the log.
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* - ic_state is the state of the iclog.
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*
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* Because of cacheline contention on large machines, we need to separate
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* various resources onto different cachelines. To start with, make the
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* structure cacheline aligned. The following fields can be contended on
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* by independent processes:
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*
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* - ic_callbacks
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* - ic_refcnt
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* - fields protected by the global l_icloglock
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*
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* so we need to ensure that these fields are located in separate cachelines.
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* We'll put all the read-only and l_icloglock fields in the first cacheline,
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* and move everything else out to subsequent cachelines.
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*/
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typedef struct xlog_in_core {
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wait_queue_head_t ic_force_wait;
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wait_queue_head_t ic_write_wait;
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struct xlog_in_core *ic_next;
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struct xlog_in_core *ic_prev;
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struct xlog *ic_log;
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u32 ic_size;
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u32 ic_offset;
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enum xlog_iclog_state ic_state;
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char *ic_datap; /* pointer to iclog data */
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/* Callback structures need their own cacheline */
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spinlock_t ic_callback_lock ____cacheline_aligned_in_smp;
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struct list_head ic_callbacks;
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/* reference counts need their own cacheline */
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atomic_t ic_refcnt ____cacheline_aligned_in_smp;
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xlog_in_core_2_t *ic_data;
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#define ic_header ic_data->hic_header
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#ifdef DEBUG
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bool ic_fail_crc : 1;
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#endif
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struct semaphore ic_sema;
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struct work_struct ic_end_io_work;
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struct bio ic_bio;
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struct bio_vec ic_bvec[];
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} xlog_in_core_t;
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/*
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* The CIL context is used to aggregate per-transaction details as well be
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* passed to the iclog for checkpoint post-commit processing. After being
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* passed to the iclog, another context needs to be allocated for tracking the
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* next set of transactions to be aggregated into a checkpoint.
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*/
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struct xfs_cil;
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struct xfs_cil_ctx {
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struct xfs_cil *cil;
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xfs_csn_t sequence; /* chkpt sequence # */
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xfs_lsn_t start_lsn; /* first LSN of chkpt commit */
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xfs_lsn_t commit_lsn; /* chkpt commit record lsn */
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struct xlog_ticket *ticket; /* chkpt ticket */
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int nvecs; /* number of regions */
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int space_used; /* aggregate size of regions */
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struct list_head busy_extents; /* busy extents in chkpt */
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struct xfs_log_vec *lv_chain; /* logvecs being pushed */
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struct list_head iclog_entry;
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struct list_head committing; /* ctx committing list */
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struct work_struct discard_endio_work;
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};
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/*
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* Committed Item List structure
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*
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* This structure is used to track log items that have been committed but not
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* yet written into the log. It is used only when the delayed logging mount
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* option is enabled.
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*
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* This structure tracks the list of committing checkpoint contexts so
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* we can avoid the problem of having to hold out new transactions during a
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* flush until we have a the commit record LSN of the checkpoint. We can
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* traverse the list of committing contexts in xlog_cil_push_lsn() to find a
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* sequence match and extract the commit LSN directly from there. If the
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* checkpoint is still in the process of committing, we can block waiting for
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* the commit LSN to be determined as well. This should make synchronous
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* operations almost as efficient as the old logging methods.
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*/
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struct xfs_cil {
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struct xlog *xc_log;
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struct list_head xc_cil;
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spinlock_t xc_cil_lock;
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struct rw_semaphore xc_ctx_lock ____cacheline_aligned_in_smp;
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struct xfs_cil_ctx *xc_ctx;
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spinlock_t xc_push_lock ____cacheline_aligned_in_smp;
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xfs_csn_t xc_push_seq;
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struct list_head xc_committing;
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wait_queue_head_t xc_commit_wait;
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xfs_csn_t xc_current_sequence;
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struct work_struct xc_push_work;
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wait_queue_head_t xc_push_wait; /* background push throttle */
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} ____cacheline_aligned_in_smp;
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/*
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* The amount of log space we allow the CIL to aggregate is difficult to size.
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* Whatever we choose, we have to make sure we can get a reservation for the
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* log space effectively, that it is large enough to capture sufficient
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* relogging to reduce log buffer IO significantly, but it is not too large for
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* the log or induces too much latency when writing out through the iclogs. We
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* track both space consumed and the number of vectors in the checkpoint
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* context, so we need to decide which to use for limiting.
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*
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* Every log buffer we write out during a push needs a header reserved, which
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* is at least one sector and more for v2 logs. Hence we need a reservation of
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* at least 512 bytes per 32k of log space just for the LR headers. That means
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* 16KB of reservation per megabyte of delayed logging space we will consume,
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* plus various headers. The number of headers will vary based on the num of
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* io vectors, so limiting on a specific number of vectors is going to result
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* in transactions of varying size. IOWs, it is more consistent to track and
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* limit space consumed in the log rather than by the number of objects being
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* logged in order to prevent checkpoint ticket overruns.
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*
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* Further, use of static reservations through the log grant mechanism is
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* problematic. It introduces a lot of complexity (e.g. reserve grant vs write
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* grant) and a significant deadlock potential because regranting write space
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* can block on log pushes. Hence if we have to regrant log space during a log
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* push, we can deadlock.
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*
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* However, we can avoid this by use of a dynamic "reservation stealing"
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* technique during transaction commit whereby unused reservation space in the
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* transaction ticket is transferred to the CIL ctx commit ticket to cover the
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* space needed by the checkpoint transaction. This means that we never need to
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* specifically reserve space for the CIL checkpoint transaction, nor do we
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* need to regrant space once the checkpoint completes. This also means the
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* checkpoint transaction ticket is specific to the checkpoint context, rather
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* than the CIL itself.
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*
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* With dynamic reservations, we can effectively make up arbitrary limits for
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* the checkpoint size so long as they don't violate any other size rules.
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* Recovery imposes a rule that no transaction exceed half the log, so we are
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* limited by that. Furthermore, the log transaction reservation subsystem
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* tries to keep 25% of the log free, so we need to keep below that limit or we
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* risk running out of free log space to start any new transactions.
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*
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* In order to keep background CIL push efficient, we only need to ensure the
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* CIL is large enough to maintain sufficient in-memory relogging to avoid
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* repeated physical writes of frequently modified metadata. If we allow the CIL
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* to grow to a substantial fraction of the log, then we may be pinning hundreds
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* of megabytes of metadata in memory until the CIL flushes. This can cause
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* issues when we are running low on memory - pinned memory cannot be reclaimed,
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* and the CIL consumes a lot of memory. Hence we need to set an upper physical
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* size limit for the CIL that limits the maximum amount of memory pinned by the
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* CIL but does not limit performance by reducing relogging efficiency
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* significantly.
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*
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* As such, the CIL push threshold ends up being the smaller of two thresholds:
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* - a threshold large enough that it allows CIL to be pushed and progress to be
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* made without excessive blocking of incoming transaction commits. This is
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|
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* defined to be 12.5% of the log space - half the 25% push threshold of the
|
||
|
|
* AIL.
|
||
|
|
* - small enough that it doesn't pin excessive amounts of memory but maintains
|
||
|
|
* close to peak relogging efficiency. This is defined to be 16x the iclog
|
||
|
|
* buffer window (32MB) as measurements have shown this to be roughly the
|
||
|
|
* point of diminishing performance increases under highly concurrent
|
||
|
|
* modification workloads.
|
||
|
|
*
|
||
|
|
* To prevent the CIL from overflowing upper commit size bounds, we introduce a
|
||
|
|
* new threshold at which we block committing transactions until the background
|
||
|
|
* CIL commit commences and switches to a new context. While this is not a hard
|
||
|
|
* limit, it forces the process committing a transaction to the CIL to block and
|
||
|
|
* yeild the CPU, giving the CIL push work a chance to be scheduled and start
|
||
|
|
* work. This prevents a process running lots of transactions from overfilling
|
||
|
|
* the CIL because it is not yielding the CPU. We set the blocking limit at
|
||
|
|
* twice the background push space threshold so we keep in line with the AIL
|
||
|
|
* push thresholds.
|
||
|
|
*
|
||
|
|
* Note: this is not a -hard- limit as blocking is applied after the transaction
|
||
|
|
* is inserted into the CIL and the push has been triggered. It is largely a
|
||
|
|
* throttling mechanism that allows the CIL push to be scheduled and run. A hard
|
||
|
|
* limit will be difficult to implement without introducing global serialisation
|
||
|
|
* in the CIL commit fast path, and it's not at all clear that we actually need
|
||
|
|
* such hard limits given the ~7 years we've run without a hard limit before
|
||
|
|
* finding the first situation where a checkpoint size overflow actually
|
||
|
|
* occurred. Hence the simple throttle, and an ASSERT check to tell us that
|
||
|
|
* we've overrun the max size.
|
||
|
|
*/
|
||
|
|
#define XLOG_CIL_SPACE_LIMIT(log) \
|
||
|
|
min_t(int, (log)->l_logsize >> 3, BBTOB(XLOG_TOTAL_REC_SHIFT(log)) << 4)
|
||
|
|
|
||
|
|
#define XLOG_CIL_BLOCKING_SPACE_LIMIT(log) \
|
||
|
|
(XLOG_CIL_SPACE_LIMIT(log) * 2)
|
||
|
|
|
||
|
|
/*
|
||
|
|
* ticket grant locks, queues and accounting have their own cachlines
|
||
|
|
* as these are quite hot and can be operated on concurrently.
|
||
|
|
*/
|
||
|
|
struct xlog_grant_head {
|
||
|
|
spinlock_t lock ____cacheline_aligned_in_smp;
|
||
|
|
struct list_head waiters;
|
||
|
|
atomic64_t grant;
|
||
|
|
};
|
||
|
|
|
||
|
|
/*
|
||
|
|
* The reservation head lsn is not made up of a cycle number and block number.
|
||
|
|
* Instead, it uses a cycle number and byte number. Logs don't expect to
|
||
|
|
* overflow 31 bits worth of byte offset, so using a byte number will mean
|
||
|
|
* that round off problems won't occur when releasing partial reservations.
|
||
|
|
*/
|
||
|
|
struct xlog {
|
||
|
|
/* The following fields don't need locking */
|
||
|
|
struct xfs_mount *l_mp; /* mount point */
|
||
|
|
struct xfs_ail *l_ailp; /* AIL log is working with */
|
||
|
|
struct xfs_cil *l_cilp; /* CIL log is working with */
|
||
|
|
struct xfs_buftarg *l_targ; /* buftarg of log */
|
||
|
|
struct workqueue_struct *l_ioend_workqueue; /* for I/O completions */
|
||
|
|
struct delayed_work l_work; /* background flush work */
|
||
|
|
uint l_flags;
|
||
|
|
uint l_quotaoffs_flag; /* XFS_DQ_*, for QUOTAOFFs */
|
||
|
|
struct list_head *l_buf_cancel_table;
|
||
|
|
int l_iclog_hsize; /* size of iclog header */
|
||
|
|
int l_iclog_heads; /* # of iclog header sectors */
|
||
|
|
uint l_sectBBsize; /* sector size in BBs (2^n) */
|
||
|
|
int l_iclog_size; /* size of log in bytes */
|
||
|
|
int l_iclog_bufs; /* number of iclog buffers */
|
||
|
|
xfs_daddr_t l_logBBstart; /* start block of log */
|
||
|
|
int l_logsize; /* size of log in bytes */
|
||
|
|
int l_logBBsize; /* size of log in BB chunks */
|
||
|
|
|
||
|
|
/* The following block of fields are changed while holding icloglock */
|
||
|
|
wait_queue_head_t l_flush_wait ____cacheline_aligned_in_smp;
|
||
|
|
/* waiting for iclog flush */
|
||
|
|
int l_covered_state;/* state of "covering disk
|
||
|
|
* log entries" */
|
||
|
|
xlog_in_core_t *l_iclog; /* head log queue */
|
||
|
|
spinlock_t l_icloglock; /* grab to change iclog state */
|
||
|
|
int l_curr_cycle; /* Cycle number of log writes */
|
||
|
|
int l_prev_cycle; /* Cycle number before last
|
||
|
|
* block increment */
|
||
|
|
int l_curr_block; /* current logical log block */
|
||
|
|
int l_prev_block; /* previous logical log block */
|
||
|
|
|
||
|
|
/*
|
||
|
|
* l_last_sync_lsn and l_tail_lsn are atomics so they can be set and
|
||
|
|
* read without needing to hold specific locks. To avoid operations
|
||
|
|
* contending with other hot objects, place each of them on a separate
|
||
|
|
* cacheline.
|
||
|
|
*/
|
||
|
|
/* lsn of last LR on disk */
|
||
|
|
atomic64_t l_last_sync_lsn ____cacheline_aligned_in_smp;
|
||
|
|
/* lsn of 1st LR with unflushed * buffers */
|
||
|
|
atomic64_t l_tail_lsn ____cacheline_aligned_in_smp;
|
||
|
|
|
||
|
|
struct xlog_grant_head l_reserve_head;
|
||
|
|
struct xlog_grant_head l_write_head;
|
||
|
|
|
||
|
|
struct xfs_kobj l_kobj;
|
||
|
|
|
||
|
|
/* The following field are used for debugging; need to hold icloglock */
|
||
|
|
#ifdef DEBUG
|
||
|
|
void *l_iclog_bak[XLOG_MAX_ICLOGS];
|
||
|
|
#endif
|
||
|
|
/* log recovery lsn tracking (for buffer submission */
|
||
|
|
xfs_lsn_t l_recovery_lsn;
|
||
|
|
};
|
||
|
|
|
||
|
|
#define XLOG_BUF_CANCEL_BUCKET(log, blkno) \
|
||
|
|
((log)->l_buf_cancel_table + ((uint64_t)blkno % XLOG_BC_TABLE_SIZE))
|
||
|
|
|
||
|
|
#define XLOG_FORCED_SHUTDOWN(log) \
|
||
|
|
(unlikely((log)->l_flags & XLOG_IO_ERROR))
|
||
|
|
|
||
|
|
/* common routines */
|
||
|
|
extern int
|
||
|
|
xlog_recover(
|
||
|
|
struct xlog *log);
|
||
|
|
extern int
|
||
|
|
xlog_recover_finish(
|
||
|
|
struct xlog *log);
|
||
|
|
extern void
|
||
|
|
xlog_recover_cancel(struct xlog *);
|
||
|
|
|
||
|
|
extern __le32 xlog_cksum(struct xlog *log, struct xlog_rec_header *rhead,
|
||
|
|
char *dp, int size);
|
||
|
|
|
||
|
|
extern kmem_zone_t *xfs_log_ticket_zone;
|
||
|
|
struct xlog_ticket *
|
||
|
|
xlog_ticket_alloc(
|
||
|
|
struct xlog *log,
|
||
|
|
int unit_bytes,
|
||
|
|
int count,
|
||
|
|
char client,
|
||
|
|
bool permanent);
|
||
|
|
|
||
|
|
static inline void
|
||
|
|
xlog_write_adv_cnt(void **ptr, int *len, int *off, size_t bytes)
|
||
|
|
{
|
||
|
|
*ptr += bytes;
|
||
|
|
*len -= bytes;
|
||
|
|
*off += bytes;
|
||
|
|
}
|
||
|
|
|
||
|
|
void xlog_print_tic_res(struct xfs_mount *mp, struct xlog_ticket *ticket);
|
||
|
|
void xlog_print_trans(struct xfs_trans *);
|
||
|
|
int xlog_write(struct xlog *log, struct xfs_log_vec *log_vector,
|
||
|
|
struct xlog_ticket *tic, xfs_lsn_t *start_lsn,
|
||
|
|
struct xlog_in_core **commit_iclog, uint flags,
|
||
|
|
bool need_start_rec);
|
||
|
|
int xlog_commit_record(struct xlog *log, struct xlog_ticket *ticket,
|
||
|
|
struct xlog_in_core **iclog, xfs_lsn_t *lsn);
|
||
|
|
void xfs_log_ticket_ungrant(struct xlog *log, struct xlog_ticket *ticket);
|
||
|
|
void xfs_log_ticket_regrant(struct xlog *log, struct xlog_ticket *ticket);
|
||
|
|
|
||
|
|
/*
|
||
|
|
* When we crack an atomic LSN, we sample it first so that the value will not
|
||
|
|
* change while we are cracking it into the component values. This means we
|
||
|
|
* will always get consistent component values to work from. This should always
|
||
|
|
* be used to sample and crack LSNs that are stored and updated in atomic
|
||
|
|
* variables.
|
||
|
|
*/
|
||
|
|
static inline void
|
||
|
|
xlog_crack_atomic_lsn(atomic64_t *lsn, uint *cycle, uint *block)
|
||
|
|
{
|
||
|
|
xfs_lsn_t val = atomic64_read(lsn);
|
||
|
|
|
||
|
|
*cycle = CYCLE_LSN(val);
|
||
|
|
*block = BLOCK_LSN(val);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Calculate and assign a value to an atomic LSN variable from component pieces.
|
||
|
|
*/
|
||
|
|
static inline void
|
||
|
|
xlog_assign_atomic_lsn(atomic64_t *lsn, uint cycle, uint block)
|
||
|
|
{
|
||
|
|
atomic64_set(lsn, xlog_assign_lsn(cycle, block));
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* When we crack the grant head, we sample it first so that the value will not
|
||
|
|
* change while we are cracking it into the component values. This means we
|
||
|
|
* will always get consistent component values to work from.
|
||
|
|
*/
|
||
|
|
static inline void
|
||
|
|
xlog_crack_grant_head_val(int64_t val, int *cycle, int *space)
|
||
|
|
{
|
||
|
|
*cycle = val >> 32;
|
||
|
|
*space = val & 0xffffffff;
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline void
|
||
|
|
xlog_crack_grant_head(atomic64_t *head, int *cycle, int *space)
|
||
|
|
{
|
||
|
|
xlog_crack_grant_head_val(atomic64_read(head), cycle, space);
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline int64_t
|
||
|
|
xlog_assign_grant_head_val(int cycle, int space)
|
||
|
|
{
|
||
|
|
return ((int64_t)cycle << 32) | space;
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline void
|
||
|
|
xlog_assign_grant_head(atomic64_t *head, int cycle, int space)
|
||
|
|
{
|
||
|
|
atomic64_set(head, xlog_assign_grant_head_val(cycle, space));
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Committed Item List interfaces
|
||
|
|
*/
|
||
|
|
int xlog_cil_init(struct xlog *log);
|
||
|
|
void xlog_cil_init_post_recovery(struct xlog *log);
|
||
|
|
void xlog_cil_destroy(struct xlog *log);
|
||
|
|
bool xlog_cil_empty(struct xlog *log);
|
||
|
|
void xlog_cil_commit(struct xlog *log, struct xfs_trans *tp,
|
||
|
|
xfs_csn_t *commit_seq, bool regrant);
|
||
|
|
|
||
|
|
/*
|
||
|
|
* CIL force routines
|
||
|
|
*/
|
||
|
|
xfs_lsn_t xlog_cil_force_seq(struct xlog *log, xfs_csn_t sequence);
|
||
|
|
|
||
|
|
static inline void
|
||
|
|
xlog_cil_force(struct xlog *log)
|
||
|
|
{
|
||
|
|
xlog_cil_force_seq(log, log->l_cilp->xc_current_sequence);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Wrapper function for waiting on a wait queue serialised against wakeups
|
||
|
|
* by a spinlock. This matches the semantics of all the wait queues used in the
|
||
|
|
* log code.
|
||
|
|
*/
|
||
|
|
static inline void
|
||
|
|
xlog_wait(
|
||
|
|
struct wait_queue_head *wq,
|
||
|
|
struct spinlock *lock)
|
||
|
|
__releases(lock)
|
||
|
|
{
|
||
|
|
DECLARE_WAITQUEUE(wait, current);
|
||
|
|
|
||
|
|
add_wait_queue_exclusive(wq, &wait);
|
||
|
|
__set_current_state(TASK_UNINTERRUPTIBLE);
|
||
|
|
spin_unlock(lock);
|
||
|
|
schedule();
|
||
|
|
remove_wait_queue(wq, &wait);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* The LSN is valid so long as it is behind the current LSN. If it isn't, this
|
||
|
|
* means that the next log record that includes this metadata could have a
|
||
|
|
* smaller LSN. In turn, this means that the modification in the log would not
|
||
|
|
* replay.
|
||
|
|
*/
|
||
|
|
static inline bool
|
||
|
|
xlog_valid_lsn(
|
||
|
|
struct xlog *log,
|
||
|
|
xfs_lsn_t lsn)
|
||
|
|
{
|
||
|
|
int cur_cycle;
|
||
|
|
int cur_block;
|
||
|
|
bool valid = true;
|
||
|
|
|
||
|
|
/*
|
||
|
|
* First, sample the current lsn without locking to avoid added
|
||
|
|
* contention from metadata I/O. The current cycle and block are updated
|
||
|
|
* (in xlog_state_switch_iclogs()) and read here in a particular order
|
||
|
|
* to avoid false negatives (e.g., thinking the metadata LSN is valid
|
||
|
|
* when it is not).
|
||
|
|
*
|
||
|
|
* The current block is always rewound before the cycle is bumped in
|
||
|
|
* xlog_state_switch_iclogs() to ensure the current LSN is never seen in
|
||
|
|
* a transiently forward state. Instead, we can see the LSN in a
|
||
|
|
* transiently behind state if we happen to race with a cycle wrap.
|
||
|
|
*/
|
||
|
|
cur_cycle = READ_ONCE(log->l_curr_cycle);
|
||
|
|
smp_rmb();
|
||
|
|
cur_block = READ_ONCE(log->l_curr_block);
|
||
|
|
|
||
|
|
if ((CYCLE_LSN(lsn) > cur_cycle) ||
|
||
|
|
(CYCLE_LSN(lsn) == cur_cycle && BLOCK_LSN(lsn) > cur_block)) {
|
||
|
|
/*
|
||
|
|
* If the metadata LSN appears invalid, it's possible the check
|
||
|
|
* above raced with a wrap to the next log cycle. Grab the lock
|
||
|
|
* to check for sure.
|
||
|
|
*/
|
||
|
|
spin_lock(&log->l_icloglock);
|
||
|
|
cur_cycle = log->l_curr_cycle;
|
||
|
|
cur_block = log->l_curr_block;
|
||
|
|
spin_unlock(&log->l_icloglock);
|
||
|
|
|
||
|
|
if ((CYCLE_LSN(lsn) > cur_cycle) ||
|
||
|
|
(CYCLE_LSN(lsn) == cur_cycle && BLOCK_LSN(lsn) > cur_block))
|
||
|
|
valid = false;
|
||
|
|
}
|
||
|
|
|
||
|
|
return valid;
|
||
|
|
}
|
||
|
|
|
||
|
|
#endif /* __XFS_LOG_PRIV_H__ */
|