Message ID | 20210305051143.182133-14-david@fromorbit.com (mailing list archive) |
---|---|
State | Superseded |
Headers | show |
Series | xfs: consolidated log and optimisation changes | expand |
On Fri, Mar 05, 2021 at 04:11:11PM +1100, Dave Chinner wrote: > From: Dave Chinner <dchinner@redhat.com> > > In doing an investigation into AIL push stalls, I was looking at the > log force code to see if an async CIL push could be done instead. > This lead me to xfs_log_force_lsn() and looking at how it works. > > xfs_log_force_lsn() is only called from inode synchronisation > contexts such as fsync(), and it takes the ip->i_itemp->ili_last_lsn > value as the LSN to sync the log to. This gets passed to > xlog_cil_force_lsn() via xfs_log_force_lsn() to flush the CIL to the > journal, and then used by xfs_log_force_lsn() to flush the iclogs to > the journal. > > The problem with is that ip->i_itemp->ili_last_lsn does not store a > log sequence number. What it stores is passed to it from the > ->iop_committing method, which is called by xfs_log_commit_cil(). > The value this passes to the iop_committing method is the CIL > context sequence number that the item was committed to. > > As it turns out, xlog_cil_force_lsn() converts the sequence to an > actual commit LSN for the related context and returns that to > xfs_log_force_lsn(). xfs_log_force_lsn() overwrites it's "lsn" > variable that contained a sequence with an actual LSN and then uses > that to sync the iclogs. > > This caused me some confusion for a while, even though I originally > wrote all this code a decade ago. ->iop_committing is only used by > a couple of log item types, and only inode items use the sequence > number it is passed. > > Let's clean up the API, CIL structures and inode log item to call it > a sequence number, and make it clear that the high level code is > using CIL sequence numbers and not on-disk LSNs for integrity > synchronisation purposes. > > Signed-off-by: Dave Chinner <dchinner@redhat.com> > --- > fs/xfs/libxfs/xfs_types.h | 1 + > fs/xfs/xfs_buf_item.c | 2 +- > fs/xfs/xfs_dquot_item.c | 2 +- > fs/xfs/xfs_file.c | 14 +++++++------- > fs/xfs/xfs_inode.c | 10 +++++----- > fs/xfs/xfs_inode_item.c | 4 ++-- > fs/xfs/xfs_inode_item.h | 2 +- > fs/xfs/xfs_log.c | 27 ++++++++++++++------------- > fs/xfs/xfs_log.h | 4 +--- > fs/xfs/xfs_log_cil.c | 22 +++++++++------------- > fs/xfs/xfs_log_priv.h | 15 +++++++-------- > fs/xfs/xfs_trans.c | 6 +++--- > fs/xfs/xfs_trans.h | 4 ++-- > 13 files changed, 54 insertions(+), 59 deletions(-) > > diff --git a/fs/xfs/libxfs/xfs_types.h b/fs/xfs/libxfs/xfs_types.h > index 064bd6e8c922..0870ef6f933d 100644 > --- a/fs/xfs/libxfs/xfs_types.h > +++ b/fs/xfs/libxfs/xfs_types.h > @@ -21,6 +21,7 @@ typedef int32_t xfs_suminfo_t; /* type of bitmap summary info */ > typedef uint32_t xfs_rtword_t; /* word type for bitmap manipulations */ > > typedef int64_t xfs_lsn_t; /* log sequence number */ > +typedef int64_t xfs_csn_t; /* CIL sequence number */ I'm unfamiliar with the internal format of CIL sequence numbers. Do they have the same cycle:offset segmented structure as LSNs do? Or are they a simple linear integer that increases as we checkpoint committed items? Looking through the current code, I see a couple of places where we initialize them to 1, and I also see that when we create a new cil context we set its sequence to one more than the context that it will replace. I also see a bunch of comparisons of cil context sequence numbers that use standard integer operators, but then I also see one instance of: if (XFS_LSN_CMP(lip->li_seq, ctx->sequence) != 0) return false; return true in xfs_log_item_in_current_chkpt. AFAICT this could be replaced with a simple: return lip->li_seq == ctx->sequence; But the fact that we're using LSN_CMP in /one/ place sticks out like a sore thumb to me, and now I'm confused. Is my understanding incorrect, or is this operator use incorrect? > typedef uint32_t xfs_dablk_t; /* dir/attr block number (in file) */ > typedef uint32_t xfs_dahash_t; /* dir/attr hash value */ > diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c > index 14d1fefcbf4c..1cb087b320b1 100644 > --- a/fs/xfs/xfs_buf_item.c > +++ b/fs/xfs/xfs_buf_item.c > @@ -713,7 +713,7 @@ xfs_buf_item_release( > STATIC void > xfs_buf_item_committing( > struct xfs_log_item *lip, > - xfs_lsn_t commit_lsn) > + xfs_csn_t seq) > { > return xfs_buf_item_release(lip); > } > diff --git a/fs/xfs/xfs_dquot_item.c b/fs/xfs/xfs_dquot_item.c > index 8c1fdf37ee8f..8ed47b739b6c 100644 > --- a/fs/xfs/xfs_dquot_item.c > +++ b/fs/xfs/xfs_dquot_item.c > @@ -188,7 +188,7 @@ xfs_qm_dquot_logitem_release( > STATIC void > xfs_qm_dquot_logitem_committing( > struct xfs_log_item *lip, > - xfs_lsn_t commit_lsn) > + xfs_csn_t seq) > { > return xfs_qm_dquot_logitem_release(lip); Weird, I didn't know that you could use return like this -- both _release and _committing return void. --D > } > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c > index 24c7f45fc4eb..ac3120dfe477 100644 > --- a/fs/xfs/xfs_file.c > +++ b/fs/xfs/xfs_file.c > @@ -119,8 +119,8 @@ xfs_dir_fsync( > return xfs_log_force_inode(ip); > } > > -static xfs_lsn_t > -xfs_fsync_lsn( > +static xfs_csn_t > +xfs_fsync_seq( > struct xfs_inode *ip, > bool datasync) > { > @@ -128,7 +128,7 @@ xfs_fsync_lsn( > return 0; > if (datasync && !(ip->i_itemp->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP)) > return 0; > - return ip->i_itemp->ili_last_lsn; > + return ip->i_itemp->ili_commit_seq; > } > > /* > @@ -151,12 +151,12 @@ xfs_fsync_flush_log( > int *log_flushed) > { > int error = 0; > - xfs_lsn_t lsn; > + xfs_csn_t seq; > > xfs_ilock(ip, XFS_ILOCK_SHARED); > - lsn = xfs_fsync_lsn(ip, datasync); > - if (lsn) { > - error = xfs_log_force_lsn(ip->i_mount, lsn, XFS_LOG_SYNC, > + seq = xfs_fsync_seq(ip, datasync); > + if (seq) { > + error = xfs_log_force_seq(ip->i_mount, seq, XFS_LOG_SYNC, > log_flushed); > > spin_lock(&ip->i_itemp->ili_lock); > diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c > index bed2beb169e4..1c2ef1f1859a 100644 > --- a/fs/xfs/xfs_inode.c > +++ b/fs/xfs/xfs_inode.c > @@ -2644,7 +2644,7 @@ xfs_iunpin( > trace_xfs_inode_unpin_nowait(ip, _RET_IP_); > > /* Give the log a push to start the unpinning I/O */ > - xfs_log_force_lsn(ip->i_mount, ip->i_itemp->ili_last_lsn, 0, NULL); > + xfs_log_force_seq(ip->i_mount, ip->i_itemp->ili_commit_seq, 0, NULL); > > } > > @@ -3652,16 +3652,16 @@ int > xfs_log_force_inode( > struct xfs_inode *ip) > { > - xfs_lsn_t lsn = 0; > + xfs_csn_t seq = 0; > > xfs_ilock(ip, XFS_ILOCK_SHARED); > if (xfs_ipincount(ip)) > - lsn = ip->i_itemp->ili_last_lsn; > + seq = ip->i_itemp->ili_commit_seq; > xfs_iunlock(ip, XFS_ILOCK_SHARED); > > - if (!lsn) > + if (!seq) > return 0; > - return xfs_log_force_lsn(ip->i_mount, lsn, XFS_LOG_SYNC, NULL); > + return xfs_log_force_seq(ip->i_mount, seq, XFS_LOG_SYNC, NULL); > } > > /* > diff --git a/fs/xfs/xfs_inode_item.c b/fs/xfs/xfs_inode_item.c > index 6ff91e5bf3cd..3aba4559469f 100644 > --- a/fs/xfs/xfs_inode_item.c > +++ b/fs/xfs/xfs_inode_item.c > @@ -617,9 +617,9 @@ xfs_inode_item_committed( > STATIC void > xfs_inode_item_committing( > struct xfs_log_item *lip, > - xfs_lsn_t commit_lsn) > + xfs_csn_t seq) > { > - INODE_ITEM(lip)->ili_last_lsn = commit_lsn; > + INODE_ITEM(lip)->ili_commit_seq = seq; > return xfs_inode_item_release(lip); > } > > diff --git a/fs/xfs/xfs_inode_item.h b/fs/xfs/xfs_inode_item.h > index 4b926e32831c..403b45ab9aa2 100644 > --- a/fs/xfs/xfs_inode_item.h > +++ b/fs/xfs/xfs_inode_item.h > @@ -33,7 +33,7 @@ struct xfs_inode_log_item { > unsigned int ili_fields; /* fields to be logged */ > unsigned int ili_fsync_fields; /* logged since last fsync */ > xfs_lsn_t ili_flush_lsn; /* lsn at last flush */ > - xfs_lsn_t ili_last_lsn; /* lsn at last transaction */ > + xfs_csn_t ili_commit_seq; /* last transaction commit */ > }; > > static inline int xfs_inode_clean(struct xfs_inode *ip) > diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c > index ed44d67d7099..145db0f88060 100644 > --- a/fs/xfs/xfs_log.c > +++ b/fs/xfs/xfs_log.c > @@ -3273,14 +3273,13 @@ xfs_log_force( > } > > static int > -__xfs_log_force_lsn( > - struct xfs_mount *mp, > +xlog_force_lsn( > + struct xlog *log, > 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); > @@ -3313,8 +3312,6 @@ __xfs_log_force_lsn( > 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; > @@ -3352,25 +3349,29 @@ __xfs_log_force_lsn( > * to disk, that thread will wake up all threads waiting on the queue. > */ > int > -xfs_log_force_lsn( > +xfs_log_force_seq( > struct xfs_mount *mp, > - xfs_lsn_t lsn, > + xfs_csn_t seq, > uint flags, > int *log_flushed) > { > + struct xlog *log = mp->m_log; > + xfs_lsn_t lsn; > int ret; > - ASSERT(lsn != 0); > + ASSERT(seq != 0); > > XFS_STATS_INC(mp, xs_log_force); > - trace_xfs_log_force(mp, lsn, _RET_IP_); > + trace_xfs_log_force(mp, seq, _RET_IP_); > > - lsn = xlog_cil_force_lsn(mp->m_log, lsn); > + lsn = xlog_cil_force_seq(log, seq); > 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); > + ret = xlog_force_lsn(log, lsn, flags, log_flushed, false); > + if (ret == -EAGAIN) { > + XFS_STATS_INC(mp, xs_log_force_sleep); > + ret = xlog_force_lsn(log, lsn, flags, log_flushed, true); > + } > return ret; > } > > diff --git a/fs/xfs/xfs_log.h b/fs/xfs/xfs_log.h > index 044e02cb8921..ba96f4ad9576 100644 > --- a/fs/xfs/xfs_log.h > +++ b/fs/xfs/xfs_log.h > @@ -107,7 +106,7 @@ struct xfs_item_ops; > struct xfs_trans; > > int xfs_log_force(struct xfs_mount *mp, uint flags); > -int xfs_log_force_lsn(struct xfs_mount *mp, xfs_lsn_t lsn, uint flags, > +int xfs_log_force_seq(struct xfs_mount *mp, xfs_csn_t seq, uint flags, > int *log_forced); > int xfs_log_mount(struct xfs_mount *mp, > struct xfs_buftarg *log_target, > @@ -132,8 +132,6 @@ bool xfs_log_writable(struct xfs_mount *mp); > struct xlog_ticket *xfs_log_ticket_get(struct xlog_ticket *ticket); > void xfs_log_ticket_put(struct xlog_ticket *ticket); > > -void xfs_log_commit_cil(struct xfs_mount *mp, struct xfs_trans *tp, > - xfs_lsn_t *commit_lsn, bool regrant); > void xlog_cil_process_committed(struct list_head *list); > bool xfs_log_item_in_current_chkpt(struct xfs_log_item *lip); > > diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c > index 2f0adc35d8ec..44bb7cc17541 100644 > --- a/fs/xfs/xfs_log_cil.c > +++ b/fs/xfs/xfs_log_cil.c > @@ -794,7 +794,7 @@ xlog_cil_push_work( > * that higher sequences will wait for us to write out a commit record > * before they do. > * > - * xfs_log_force_lsn requires us to mirror the new sequence into the cil > + * xfs_log_force_seq requires us to mirror the new sequence into the cil > * structure atomically with the addition of this sequence to the > * committing list. This also ensures that we can do unlocked checks > * against the current sequence in log forces without risking > @@ -1058,16 +1058,14 @@ xlog_cil_empty( > * allowed again. > */ > void > -xfs_log_commit_cil( > - struct xfs_mount *mp, > +xlog_cil_commit( > + struct xlog *log, > struct xfs_trans *tp, > - xfs_lsn_t *commit_lsn, > + xfs_csn_t *commit_seq, > bool regrant) > { > - struct xlog *log = mp->m_log; > struct xfs_cil *cil = log->l_cilp; > struct xfs_log_item *lip, *next; > - xfs_lsn_t xc_commit_lsn; > > /* > * Do all necessary memory allocation before we lock the CIL. > @@ -1081,10 +1079,6 @@ xfs_log_commit_cil( > > xlog_cil_insert_items(log, tp); > > - xc_commit_lsn = cil->xc_ctx->sequence; > - if (commit_lsn) > - *commit_lsn = xc_commit_lsn; > - > if (regrant && !XLOG_FORCED_SHUTDOWN(log)) > xfs_log_ticket_regrant(log, tp->t_ticket); > else > @@ -1107,8 +1101,10 @@ xfs_log_commit_cil( > list_for_each_entry_safe(lip, next, &tp->t_items, li_trans) { > xfs_trans_del_item(lip); > if (lip->li_ops->iop_committing) > - lip->li_ops->iop_committing(lip, xc_commit_lsn); > + lip->li_ops->iop_committing(lip, cil->xc_ctx->sequence); > } > + if (commit_seq) > + *commit_seq = cil->xc_ctx->sequence; > > /* xlog_cil_push_background() releases cil->xc_ctx_lock */ > xlog_cil_push_background(log); > @@ -1125,9 +1121,9 @@ xfs_log_commit_cil( > * iclog flush is necessary following this call. > */ > xfs_lsn_t > -xlog_cil_force_lsn( > +xlog_cil_force_seq( > struct xlog *log, > - xfs_lsn_t sequence) > + xfs_csn_t sequence) > { > struct xfs_cil *cil = log->l_cilp; > struct xfs_cil_ctx *ctx; > diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h > index 0552e96d2b64..31ce2ce21e27 100644 > --- a/fs/xfs/xfs_log_priv.h > +++ b/fs/xfs/xfs_log_priv.h > @@ -234,7 +234,7 @@ struct xfs_cil; > > struct xfs_cil_ctx { > struct xfs_cil *cil; > - xfs_lsn_t sequence; /* chkpt sequence # */ > + xfs_csn_t sequence; /* chkpt sequence # */ > xfs_lsn_t start_lsn; /* first LSN of chkpt commit */ > xfs_lsn_t commit_lsn; /* chkpt commit record lsn */ > struct xlog_ticket *ticket; /* chkpt ticket */ > @@ -272,10 +272,10 @@ struct xfs_cil { > struct xfs_cil_ctx *xc_ctx; > > spinlock_t xc_push_lock ____cacheline_aligned_in_smp; > - xfs_lsn_t xc_push_seq; > + xfs_csn_t xc_push_seq; > struct list_head xc_committing; > wait_queue_head_t xc_commit_wait; > - xfs_lsn_t xc_current_sequence; > + xfs_csn_t xc_current_sequence; > struct work_struct xc_push_work; > wait_queue_head_t xc_push_wait; /* background push throttle */ > } ____cacheline_aligned_in_smp; > @@ -552,19 +552,18 @@ 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_lsn( > - struct xlog *log, > - xfs_lsn_t sequence); > +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_lsn(log, log->l_cilp->xc_current_sequence); > + xlog_cil_force_seq(log, log->l_cilp->xc_current_sequence); > } > > /* > diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c > index b22a09e9daee..21ac7c048380 100644 > --- a/fs/xfs/xfs_trans.c > +++ b/fs/xfs/xfs_trans.c > @@ -851,7 +851,7 @@ __xfs_trans_commit( > bool regrant) > { > struct xfs_mount *mp = tp->t_mountp; > - xfs_lsn_t commit_lsn = -1; > + xfs_csn_t commit_seq = 0; > int error = 0; > int sync = tp->t_flags & XFS_TRANS_SYNC; > > @@ -893,7 +893,7 @@ __xfs_trans_commit( > xfs_trans_apply_sb_deltas(tp); > xfs_trans_apply_dquot_deltas(tp); > > - xfs_log_commit_cil(mp, tp, &commit_lsn, regrant); > + xlog_cil_commit(mp->m_log, tp, &commit_seq, regrant); > > xfs_trans_free(tp); > > @@ -902,7 +902,7 @@ __xfs_trans_commit( > * log out now and wait for it. > */ > if (sync) { > - error = xfs_log_force_lsn(mp, commit_lsn, XFS_LOG_SYNC, NULL); > + error = xfs_log_force_seq(mp, commit_seq, XFS_LOG_SYNC, NULL); > XFS_STATS_INC(mp, xs_trans_sync); > } else { > XFS_STATS_INC(mp, xs_trans_async); > diff --git a/fs/xfs/xfs_trans.h b/fs/xfs/xfs_trans.h > index 9dd745cf77c9..6276c7d251e6 100644 > --- a/fs/xfs/xfs_trans.h > +++ b/fs/xfs/xfs_trans.h > @@ -43,7 +43,7 @@ struct xfs_log_item { > struct list_head li_cil; /* CIL pointers */ > struct xfs_log_vec *li_lv; /* active log vector */ > struct xfs_log_vec *li_lv_shadow; /* standby vector */ > - xfs_lsn_t li_seq; /* CIL commit seq */ > + xfs_csn_t li_seq; /* CIL commit seq */ > }; > > /* > @@ -69,7 +69,7 @@ struct xfs_item_ops { > void (*iop_pin)(struct xfs_log_item *); > void (*iop_unpin)(struct xfs_log_item *, int remove); > uint (*iop_push)(struct xfs_log_item *, struct list_head *); > - void (*iop_committing)(struct xfs_log_item *, xfs_lsn_t commit_lsn); > + void (*iop_committing)(struct xfs_log_item *lip, xfs_csn_t seq); > void (*iop_release)(struct xfs_log_item *); > xfs_lsn_t (*iop_committed)(struct xfs_log_item *, xfs_lsn_t); > int (*iop_recover)(struct xfs_log_item *lip, > -- > 2.28.0 >
On Mon, Mar 08, 2021 at 02:53:23PM -0800, Darrick J. Wong wrote: > On Fri, Mar 05, 2021 at 04:11:11PM +1100, Dave Chinner wrote: > > From: Dave Chinner <dchinner@redhat.com> > > > > In doing an investigation into AIL push stalls, I was looking at the > > log force code to see if an async CIL push could be done instead. > > This lead me to xfs_log_force_lsn() and looking at how it works. > > > > xfs_log_force_lsn() is only called from inode synchronisation > > contexts such as fsync(), and it takes the ip->i_itemp->ili_last_lsn > > value as the LSN to sync the log to. This gets passed to > > xlog_cil_force_lsn() via xfs_log_force_lsn() to flush the CIL to the > > journal, and then used by xfs_log_force_lsn() to flush the iclogs to > > the journal. > > > > The problem with is that ip->i_itemp->ili_last_lsn does not store a > > log sequence number. What it stores is passed to it from the > > ->iop_committing method, which is called by xfs_log_commit_cil(). > > The value this passes to the iop_committing method is the CIL > > context sequence number that the item was committed to. > > > > As it turns out, xlog_cil_force_lsn() converts the sequence to an > > actual commit LSN for the related context and returns that to > > xfs_log_force_lsn(). xfs_log_force_lsn() overwrites it's "lsn" > > variable that contained a sequence with an actual LSN and then uses > > that to sync the iclogs. > > > > This caused me some confusion for a while, even though I originally > > wrote all this code a decade ago. ->iop_committing is only used by > > a couple of log item types, and only inode items use the sequence > > number it is passed. > > > > Let's clean up the API, CIL structures and inode log item to call it > > a sequence number, and make it clear that the high level code is > > using CIL sequence numbers and not on-disk LSNs for integrity > > synchronisation purposes. > > > > Signed-off-by: Dave Chinner <dchinner@redhat.com> > > --- > > fs/xfs/libxfs/xfs_types.h | 1 + > > fs/xfs/xfs_buf_item.c | 2 +- > > fs/xfs/xfs_dquot_item.c | 2 +- > > fs/xfs/xfs_file.c | 14 +++++++------- > > fs/xfs/xfs_inode.c | 10 +++++----- > > fs/xfs/xfs_inode_item.c | 4 ++-- > > fs/xfs/xfs_inode_item.h | 2 +- > > fs/xfs/xfs_log.c | 27 ++++++++++++++------------- > > fs/xfs/xfs_log.h | 4 +--- > > fs/xfs/xfs_log_cil.c | 22 +++++++++------------- > > fs/xfs/xfs_log_priv.h | 15 +++++++-------- > > fs/xfs/xfs_trans.c | 6 +++--- > > fs/xfs/xfs_trans.h | 4 ++-- > > 13 files changed, 54 insertions(+), 59 deletions(-) > > > > diff --git a/fs/xfs/libxfs/xfs_types.h b/fs/xfs/libxfs/xfs_types.h > > index 064bd6e8c922..0870ef6f933d 100644 > > --- a/fs/xfs/libxfs/xfs_types.h > > +++ b/fs/xfs/libxfs/xfs_types.h > > @@ -21,6 +21,7 @@ typedef int32_t xfs_suminfo_t; /* type of bitmap summary info */ > > typedef uint32_t xfs_rtword_t; /* word type for bitmap manipulations */ > > > > typedef int64_t xfs_lsn_t; /* log sequence number */ > > +typedef int64_t xfs_csn_t; /* CIL sequence number */ > > I'm unfamiliar with the internal format of CIL sequence numbers. Do > they have the same cycle:offset segmented structure as LSNs do? Or are > they a simple linear integer that increases as we checkpoint committed > items? Monotonic increasing integer, only ever used in memory and never written to disk. > > Looking through the current code, I see a couple of places where we > initialize them to 1, and I also see that when we create a new cil > context we set its sequence to one more than the context that it will > replace. > > I also see a bunch of comparisons of cil context sequence numbers that > use standard integer operators, but then I also see one instance of: > > if (XFS_LSN_CMP(lip->li_seq, ctx->sequence) != 0) > return false; > return true > > in xfs_log_item_in_current_chkpt. AFAICT this could be replaced with a > simple: > > return lip->li_seq == ctx->sequence; Yup, missed that, will fix. -Dave.
diff --git a/fs/xfs/libxfs/xfs_types.h b/fs/xfs/libxfs/xfs_types.h index 064bd6e8c922..0870ef6f933d 100644 --- a/fs/xfs/libxfs/xfs_types.h +++ b/fs/xfs/libxfs/xfs_types.h @@ -21,6 +21,7 @@ typedef int32_t xfs_suminfo_t; /* type of bitmap summary info */ typedef uint32_t xfs_rtword_t; /* word type for bitmap manipulations */ typedef int64_t xfs_lsn_t; /* log sequence number */ +typedef int64_t xfs_csn_t; /* CIL sequence number */ typedef uint32_t xfs_dablk_t; /* dir/attr block number (in file) */ typedef uint32_t xfs_dahash_t; /* dir/attr hash value */ diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c index 14d1fefcbf4c..1cb087b320b1 100644 --- a/fs/xfs/xfs_buf_item.c +++ b/fs/xfs/xfs_buf_item.c @@ -713,7 +713,7 @@ xfs_buf_item_release( STATIC void xfs_buf_item_committing( struct xfs_log_item *lip, - xfs_lsn_t commit_lsn) + xfs_csn_t seq) { return xfs_buf_item_release(lip); } diff --git a/fs/xfs/xfs_dquot_item.c b/fs/xfs/xfs_dquot_item.c index 8c1fdf37ee8f..8ed47b739b6c 100644 --- a/fs/xfs/xfs_dquot_item.c +++ b/fs/xfs/xfs_dquot_item.c @@ -188,7 +188,7 @@ xfs_qm_dquot_logitem_release( STATIC void xfs_qm_dquot_logitem_committing( struct xfs_log_item *lip, - xfs_lsn_t commit_lsn) + xfs_csn_t seq) { return xfs_qm_dquot_logitem_release(lip); } diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 24c7f45fc4eb..ac3120dfe477 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -119,8 +119,8 @@ xfs_dir_fsync( return xfs_log_force_inode(ip); } -static xfs_lsn_t -xfs_fsync_lsn( +static xfs_csn_t +xfs_fsync_seq( struct xfs_inode *ip, bool datasync) { @@ -128,7 +128,7 @@ xfs_fsync_lsn( return 0; if (datasync && !(ip->i_itemp->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP)) return 0; - return ip->i_itemp->ili_last_lsn; + return ip->i_itemp->ili_commit_seq; } /* @@ -151,12 +151,12 @@ xfs_fsync_flush_log( int *log_flushed) { int error = 0; - xfs_lsn_t lsn; + xfs_csn_t seq; xfs_ilock(ip, XFS_ILOCK_SHARED); - lsn = xfs_fsync_lsn(ip, datasync); - if (lsn) { - error = xfs_log_force_lsn(ip->i_mount, lsn, XFS_LOG_SYNC, + seq = xfs_fsync_seq(ip, datasync); + if (seq) { + error = xfs_log_force_seq(ip->i_mount, seq, XFS_LOG_SYNC, log_flushed); spin_lock(&ip->i_itemp->ili_lock); diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c index bed2beb169e4..1c2ef1f1859a 100644 --- a/fs/xfs/xfs_inode.c +++ b/fs/xfs/xfs_inode.c @@ -2644,7 +2644,7 @@ xfs_iunpin( trace_xfs_inode_unpin_nowait(ip, _RET_IP_); /* Give the log a push to start the unpinning I/O */ - xfs_log_force_lsn(ip->i_mount, ip->i_itemp->ili_last_lsn, 0, NULL); + xfs_log_force_seq(ip->i_mount, ip->i_itemp->ili_commit_seq, 0, NULL); } @@ -3652,16 +3652,16 @@ int xfs_log_force_inode( struct xfs_inode *ip) { - xfs_lsn_t lsn = 0; + xfs_csn_t seq = 0; xfs_ilock(ip, XFS_ILOCK_SHARED); if (xfs_ipincount(ip)) - lsn = ip->i_itemp->ili_last_lsn; + seq = ip->i_itemp->ili_commit_seq; xfs_iunlock(ip, XFS_ILOCK_SHARED); - if (!lsn) + if (!seq) return 0; - return xfs_log_force_lsn(ip->i_mount, lsn, XFS_LOG_SYNC, NULL); + return xfs_log_force_seq(ip->i_mount, seq, XFS_LOG_SYNC, NULL); } /* diff --git a/fs/xfs/xfs_inode_item.c b/fs/xfs/xfs_inode_item.c index 6ff91e5bf3cd..3aba4559469f 100644 --- a/fs/xfs/xfs_inode_item.c +++ b/fs/xfs/xfs_inode_item.c @@ -617,9 +617,9 @@ xfs_inode_item_committed( STATIC void xfs_inode_item_committing( struct xfs_log_item *lip, - xfs_lsn_t commit_lsn) + xfs_csn_t seq) { - INODE_ITEM(lip)->ili_last_lsn = commit_lsn; + INODE_ITEM(lip)->ili_commit_seq = seq; return xfs_inode_item_release(lip); } diff --git a/fs/xfs/xfs_inode_item.h b/fs/xfs/xfs_inode_item.h index 4b926e32831c..403b45ab9aa2 100644 --- a/fs/xfs/xfs_inode_item.h +++ b/fs/xfs/xfs_inode_item.h @@ -33,7 +33,7 @@ struct xfs_inode_log_item { unsigned int ili_fields; /* fields to be logged */ unsigned int ili_fsync_fields; /* logged since last fsync */ xfs_lsn_t ili_flush_lsn; /* lsn at last flush */ - xfs_lsn_t ili_last_lsn; /* lsn at last transaction */ + xfs_csn_t ili_commit_seq; /* last transaction commit */ }; static inline int xfs_inode_clean(struct xfs_inode *ip) diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index ed44d67d7099..145db0f88060 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -3273,14 +3273,13 @@ xfs_log_force( } static int -__xfs_log_force_lsn( - struct xfs_mount *mp, +xlog_force_lsn( + struct xlog *log, 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); @@ -3313,8 +3312,6 @@ __xfs_log_force_lsn( 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; @@ -3352,25 +3349,29 @@ __xfs_log_force_lsn( * to disk, that thread will wake up all threads waiting on the queue. */ int -xfs_log_force_lsn( +xfs_log_force_seq( struct xfs_mount *mp, - xfs_lsn_t lsn, + xfs_csn_t seq, uint flags, int *log_flushed) { + struct xlog *log = mp->m_log; + xfs_lsn_t lsn; int ret; - ASSERT(lsn != 0); + ASSERT(seq != 0); XFS_STATS_INC(mp, xs_log_force); - trace_xfs_log_force(mp, lsn, _RET_IP_); + trace_xfs_log_force(mp, seq, _RET_IP_); - lsn = xlog_cil_force_lsn(mp->m_log, lsn); + lsn = xlog_cil_force_seq(log, seq); 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); + ret = xlog_force_lsn(log, lsn, flags, log_flushed, false); + if (ret == -EAGAIN) { + XFS_STATS_INC(mp, xs_log_force_sleep); + ret = xlog_force_lsn(log, lsn, flags, log_flushed, true); + } return ret; } diff --git a/fs/xfs/xfs_log.h b/fs/xfs/xfs_log.h index 044e02cb8921..ba96f4ad9576 100644 --- a/fs/xfs/xfs_log.h +++ b/fs/xfs/xfs_log.h @@ -106,7 +106,7 @@ struct xfs_item_ops; struct xfs_trans; int xfs_log_force(struct xfs_mount *mp, uint flags); -int xfs_log_force_lsn(struct xfs_mount *mp, xfs_lsn_t lsn, uint flags, +int xfs_log_force_seq(struct xfs_mount *mp, xfs_csn_t seq, uint flags, int *log_forced); int xfs_log_mount(struct xfs_mount *mp, struct xfs_buftarg *log_target, @@ -132,8 +132,6 @@ bool xfs_log_writable(struct xfs_mount *mp); struct xlog_ticket *xfs_log_ticket_get(struct xlog_ticket *ticket); void xfs_log_ticket_put(struct xlog_ticket *ticket); -void xfs_log_commit_cil(struct xfs_mount *mp, struct xfs_trans *tp, - xfs_lsn_t *commit_lsn, bool regrant); void xlog_cil_process_committed(struct list_head *list); bool xfs_log_item_in_current_chkpt(struct xfs_log_item *lip); diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c index 2f0adc35d8ec..44bb7cc17541 100644 --- a/fs/xfs/xfs_log_cil.c +++ b/fs/xfs/xfs_log_cil.c @@ -794,7 +794,7 @@ xlog_cil_push_work( * that higher sequences will wait for us to write out a commit record * before they do. * - * xfs_log_force_lsn requires us to mirror the new sequence into the cil + * xfs_log_force_seq requires us to mirror the new sequence into the cil * structure atomically with the addition of this sequence to the * committing list. This also ensures that we can do unlocked checks * against the current sequence in log forces without risking @@ -1058,16 +1058,14 @@ xlog_cil_empty( * allowed again. */ void -xfs_log_commit_cil( - struct xfs_mount *mp, +xlog_cil_commit( + struct xlog *log, struct xfs_trans *tp, - xfs_lsn_t *commit_lsn, + xfs_csn_t *commit_seq, bool regrant) { - struct xlog *log = mp->m_log; struct xfs_cil *cil = log->l_cilp; struct xfs_log_item *lip, *next; - xfs_lsn_t xc_commit_lsn; /* * Do all necessary memory allocation before we lock the CIL. @@ -1081,10 +1079,6 @@ xfs_log_commit_cil( xlog_cil_insert_items(log, tp); - xc_commit_lsn = cil->xc_ctx->sequence; - if (commit_lsn) - *commit_lsn = xc_commit_lsn; - if (regrant && !XLOG_FORCED_SHUTDOWN(log)) xfs_log_ticket_regrant(log, tp->t_ticket); else @@ -1107,8 +1101,10 @@ xfs_log_commit_cil( list_for_each_entry_safe(lip, next, &tp->t_items, li_trans) { xfs_trans_del_item(lip); if (lip->li_ops->iop_committing) - lip->li_ops->iop_committing(lip, xc_commit_lsn); + lip->li_ops->iop_committing(lip, cil->xc_ctx->sequence); } + if (commit_seq) + *commit_seq = cil->xc_ctx->sequence; /* xlog_cil_push_background() releases cil->xc_ctx_lock */ xlog_cil_push_background(log); @@ -1125,9 +1121,9 @@ xfs_log_commit_cil( * iclog flush is necessary following this call. */ xfs_lsn_t -xlog_cil_force_lsn( +xlog_cil_force_seq( struct xlog *log, - xfs_lsn_t sequence) + xfs_csn_t sequence) { struct xfs_cil *cil = log->l_cilp; struct xfs_cil_ctx *ctx; diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h index 0552e96d2b64..31ce2ce21e27 100644 --- a/fs/xfs/xfs_log_priv.h +++ b/fs/xfs/xfs_log_priv.h @@ -234,7 +234,7 @@ struct xfs_cil; struct xfs_cil_ctx { struct xfs_cil *cil; - xfs_lsn_t sequence; /* chkpt sequence # */ + xfs_csn_t sequence; /* chkpt sequence # */ xfs_lsn_t start_lsn; /* first LSN of chkpt commit */ xfs_lsn_t commit_lsn; /* chkpt commit record lsn */ struct xlog_ticket *ticket; /* chkpt ticket */ @@ -272,10 +272,10 @@ struct xfs_cil { struct xfs_cil_ctx *xc_ctx; spinlock_t xc_push_lock ____cacheline_aligned_in_smp; - xfs_lsn_t xc_push_seq; + xfs_csn_t xc_push_seq; struct list_head xc_committing; wait_queue_head_t xc_commit_wait; - xfs_lsn_t xc_current_sequence; + xfs_csn_t xc_current_sequence; struct work_struct xc_push_work; wait_queue_head_t xc_push_wait; /* background push throttle */ } ____cacheline_aligned_in_smp; @@ -552,19 +552,18 @@ 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_lsn( - struct xlog *log, - xfs_lsn_t sequence); +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_lsn(log, log->l_cilp->xc_current_sequence); + xlog_cil_force_seq(log, log->l_cilp->xc_current_sequence); } /* diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c index b22a09e9daee..21ac7c048380 100644 --- a/fs/xfs/xfs_trans.c +++ b/fs/xfs/xfs_trans.c @@ -851,7 +851,7 @@ __xfs_trans_commit( bool regrant) { struct xfs_mount *mp = tp->t_mountp; - xfs_lsn_t commit_lsn = -1; + xfs_csn_t commit_seq = 0; int error = 0; int sync = tp->t_flags & XFS_TRANS_SYNC; @@ -893,7 +893,7 @@ __xfs_trans_commit( xfs_trans_apply_sb_deltas(tp); xfs_trans_apply_dquot_deltas(tp); - xfs_log_commit_cil(mp, tp, &commit_lsn, regrant); + xlog_cil_commit(mp->m_log, tp, &commit_seq, regrant); xfs_trans_free(tp); @@ -902,7 +902,7 @@ __xfs_trans_commit( * log out now and wait for it. */ if (sync) { - error = xfs_log_force_lsn(mp, commit_lsn, XFS_LOG_SYNC, NULL); + error = xfs_log_force_seq(mp, commit_seq, XFS_LOG_SYNC, NULL); XFS_STATS_INC(mp, xs_trans_sync); } else { XFS_STATS_INC(mp, xs_trans_async); diff --git a/fs/xfs/xfs_trans.h b/fs/xfs/xfs_trans.h index 9dd745cf77c9..6276c7d251e6 100644 --- a/fs/xfs/xfs_trans.h +++ b/fs/xfs/xfs_trans.h @@ -43,7 +43,7 @@ struct xfs_log_item { struct list_head li_cil; /* CIL pointers */ struct xfs_log_vec *li_lv; /* active log vector */ struct xfs_log_vec *li_lv_shadow; /* standby vector */ - xfs_lsn_t li_seq; /* CIL commit seq */ + xfs_csn_t li_seq; /* CIL commit seq */ }; /* @@ -69,7 +69,7 @@ struct xfs_item_ops { void (*iop_pin)(struct xfs_log_item *); void (*iop_unpin)(struct xfs_log_item *, int remove); uint (*iop_push)(struct xfs_log_item *, struct list_head *); - void (*iop_committing)(struct xfs_log_item *, xfs_lsn_t commit_lsn); + void (*iop_committing)(struct xfs_log_item *lip, xfs_csn_t seq); void (*iop_release)(struct xfs_log_item *); xfs_lsn_t (*iop_committed)(struct xfs_log_item *, xfs_lsn_t); int (*iop_recover)(struct xfs_log_item *lip,