From: Dave Chinner dchinner@redhat.com
commit 5f9b4b0de8dc2fb8eb655463b438001c111570fe upstream.
[backported from CIL scalability series for dependency]
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 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 Reviewed-by: Brian Foster bfoster@redhat.com Reviewed-by: Darrick J. Wong djwong@kernel.org Reviewed-by: Allison Henderson allison.henderson@oracle.com Signed-off-by: Darrick J. Wong djwong@kernel.org Signed-off-by: Amir Goldstein amir73il@gmail.com Acked-by: Darrick J. Wong djwong@kernel.org --- 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 | 30 +++++++++++------------------- fs/xfs/xfs_log_priv.h | 15 +++++++-------- fs/xfs/xfs_trans.c | 6 +++--- fs/xfs/xfs_trans.h | 4 ++-- 13 files changed, 56 insertions(+), 65 deletions(-)
diff --git a/fs/xfs/libxfs/xfs_types.h b/fs/xfs/libxfs/xfs_types.h index 397d94775440..1ce06173c2f5 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 8c6e26d62ef2..5d6535370f87 100644 --- a/fs/xfs/xfs_buf_item.c +++ b/fs/xfs/xfs_buf_item.c @@ -632,7 +632,7 @@ 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 414d856e2e75..4d6bf8d4974f 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -118,8 +118,8 @@ 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) { @@ -127,7 +127,7 @@ 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; }
/* @@ -150,12 +150,12 @@ 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 03497741aef7..1f61e085676b 100644 --- a/fs/xfs/xfs_inode.c +++ b/fs/xfs/xfs_inode.c @@ -2754,7 +2754,7 @@ 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);
}
@@ -3716,16 +3716,16 @@ 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 b445e63cbc3c..05791456adbb 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -3210,14 +3210,13 @@ 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); @@ -3250,8 +3249,6 @@ __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; @@ -3289,25 +3286,29 @@ __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 98c913da7587..a1089f8b7169 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 cd5c04dabe2e..88730883bb70 100644 --- a/fs/xfs/xfs_log_cil.c +++ b/fs/xfs/xfs_log_cil.c @@ -777,7 +777,7 @@ 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 @@ -1020,16 +1020,14 @@ 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. @@ -1043,10 +1041,6 @@ 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 @@ -1069,8 +1063,10 @@ 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); @@ -1087,9 +1083,9 @@ 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; @@ -1185,21 +1181,17 @@ bool xfs_log_item_in_current_chkpt( struct xfs_log_item *lip) { - struct xfs_cil_ctx *ctx; + struct xfs_cil_ctx *ctx = lip->li_mountp->m_log->l_cilp->xc_ctx;
if (list_empty(&lip->li_cil)) return false;
- ctx = lip->li_mountp->m_log->l_cilp->xc_ctx; - /* * li_seq is written on the first commit of a log item to record the * first checkpoint it is written to. Hence if it is different to the * current sequence, we're in a new checkpoint. */ - if (XFS_LSN_CMP(lip->li_seq, ctx->sequence) != 0) - return false; - return true; + return lip->li_seq == ctx->sequence; }
/* diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h index 1c6fdbf3d506..42cd1602ac25 100644 --- a/fs/xfs/xfs_log_priv.h +++ b/fs/xfs/xfs_log_priv.h @@ -230,7 +230,7 @@ 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 */ @@ -268,10 +268,10 @@ 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; @@ -547,19 +547,18 @@ 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 36166bae24a6..73a1de7ceefc 100644 --- a/fs/xfs/xfs_trans.c +++ b/fs/xfs/xfs_trans.c @@ -832,7 +832,7 @@ __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;
@@ -874,7 +874,7 @@ __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);
@@ -883,7 +883,7 @@ __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 075eeade4f7d..97485559008b 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,