1 files changed, 154 insertions, 99 deletions

diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c
index d4fadbe8ac9..7d6197c5849 100644
--- a/fs/xfs/xfs_log_cil.c
+++ b/fs/xfs/xfs_log_cil.c
@@ -18,9 +18,7 @@
 #include "xfs.h"
 #include "xfs_fs.h"
 #include "xfs_types.h"
-#include "xfs_bit.h"
 #include "xfs_log.h"
-#include "xfs_inum.h"
 #include "xfs_trans.h"
 #include "xfs_trans_priv.h"
 #include "xfs_log_priv.h"
@@ -29,61 +27,10 @@
 #include "xfs_mount.h"
 #include "xfs_error.h"
 #include "xfs_alloc.h"
+#include "xfs_extent_busy.h"
 #include "xfs_discard.h"
 
 /*
- * Perform initial CIL structure initialisation.
- */
-int
-xlog_cil_init(
-        struct log      *log)
-{
-        struct xfs_cil  *cil;
-        struct xfs_cil_ctx *ctx;
-
-        cil = kmem_zalloc(sizeof(*cil), KM_SLEEP|KM_MAYFAIL);
-        if (!cil)
-                return ENOMEM;
-
-        ctx = kmem_zalloc(sizeof(*ctx), KM_SLEEP|KM_MAYFAIL);
-        if (!ctx) {
-                kmem_free(cil);
-                return ENOMEM;
-        }
-
-        INIT_LIST_HEAD(&cil->xc_cil);
-        INIT_LIST_HEAD(&cil->xc_committing);
-        spin_lock_init(&cil->xc_cil_lock);
-        init_rwsem(&cil->xc_ctx_lock);
-        init_waitqueue_head(&cil->xc_commit_wait);
-
-        INIT_LIST_HEAD(&ctx->committing);
-        INIT_LIST_HEAD(&ctx->busy_extents);
-        ctx->sequence = 1;
-        ctx->cil = cil;
-        cil->xc_ctx = ctx;
-        cil->xc_current_sequence = ctx->sequence;
-
-        cil->xc_log = log;
-        log->l_cilp = cil;
-        return 0;
-}
-
-void
-xlog_cil_destroy(
-        struct log      *log)
-{
-        if (log->l_cilp->xc_ctx) {
-                if (log->l_cilp->xc_ctx->ticket)
-                        xfs_log_ticket_put(log->l_cilp->xc_ctx->ticket);
-                kmem_free(log->l_cilp->xc_ctx);
-        }
-
-        ASSERT(list_empty(&log->l_cilp->xc_cil));
-        kmem_free(log->l_cilp);
-}
-
-/*
  * Allocate a new ticket. Failing to get a new ticket makes it really hard to
  * recover, so we don't allow failure here. Also, we allocate in a context that
  * we don't want to be issuing transactions from, so we need to tell the
@@ -390,8 +337,8 @@ xlog_cil_committed(
         xfs_trans_committed_bulk(ctx->cil->xc_log->l_ailp, ctx->lv_chain,
                                         ctx->start_lsn, abort);
 
-        xfs_alloc_busy_sort(&ctx->busy_extents);
-        xfs_alloc_busy_clear(mp, &ctx->busy_extents,
+        xfs_extent_busy_sort(&ctx->busy_extents);
+        xfs_extent_busy_clear(mp, &ctx->busy_extents,
                              (mp->m_flags & XFS_MOUNT_DISCARD) && !abort);
 
         spin_lock(&ctx->cil->xc_cil_lock);
@@ -404,7 +351,7 @@ xlog_cil_committed(
                 ASSERT(mp->m_flags & XFS_MOUNT_DISCARD);
 
                 xfs_discard_extents(mp, &ctx->busy_extents);
-                xfs_alloc_busy_clear(mp, &ctx->busy_extents, false);
+                xfs_extent_busy_clear(mp, &ctx->busy_extents, false);
         }
 
         kmem_free(ctx);
@@ -426,8 +373,7 @@ xlog_cil_committed(
  */
 STATIC int
 xlog_cil_push(
-        struct log              *log,
-        xfs_lsn_t               push_seq)
+        struct log              *log)
 {
         struct xfs_cil          *cil = log->l_cilp;
         struct xfs_log_vec      *lv;
@@ -443,39 +389,36 @@ xlog_cil_push(
         struct xfs_log_iovec    lhdr;
         struct xfs_log_vec      lvhdr = { NULL };
         xfs_lsn_t               commit_lsn;
+        xfs_lsn_t               push_seq;
 
         if (!cil)
                 return 0;
 
-        ASSERT(!push_seq || push_seq <= cil->xc_ctx->sequence);
-
         new_ctx = kmem_zalloc(sizeof(*new_ctx), KM_SLEEP|KM_NOFS);
         new_ctx->ticket = xlog_cil_ticket_alloc(log);
 
-        /*
-         * Lock out transaction commit, but don't block for background pushes
-         * unless we are well over the CIL space limit. See the definition of
-         * XLOG_CIL_HARD_SPACE_LIMIT() for the full explanation of the logic
-         * used here.
-         */
-        if (!down_write_trylock(&cil->xc_ctx_lock)) {
-                if (!push_seq &&
-                    cil->xc_ctx->space_used < XLOG_CIL_HARD_SPACE_LIMIT(log))
-                        goto out_free_ticket;
-                down_write(&cil->xc_ctx_lock);
-        }
+        down_write(&cil->xc_ctx_lock);
         ctx = cil->xc_ctx;
 
-        /* check if we've anything to push */
-        if (list_empty(&cil->xc_cil))
-                goto out_skip;
+        spin_lock(&cil->xc_cil_lock);
+        push_seq = cil->xc_push_seq;
+        ASSERT(push_seq <= ctx->sequence);
 
-        /* check for spurious background flush */
-        if (!push_seq && cil->xc_ctx->space_used < XLOG_CIL_SPACE_LIMIT(log))
+        /*
+         * Check if we've anything to push. If there is nothing, then we don't
+         * move on to a new sequence number and so we have to be able to push
+         * this sequence again later.
+         */
+        if (list_empty(&cil->xc_cil)) {
+                cil->xc_push_seq = 0;
+                spin_unlock(&cil->xc_cil_lock);
                 goto out_skip;
+        }
+        spin_unlock(&cil->xc_cil_lock);
+
 
         /* check for a previously pushed seqeunce */
-        if (push_seq && push_seq < cil->xc_ctx->sequence)
+        if (push_seq < cil->xc_ctx->sequence)
                 goto out_skip;
 
         /*
@@ -629,7 +572,6 @@ restart:
 
 out_skip:
         up_write(&cil->xc_ctx_lock);
-out_free_ticket:
         xfs_log_ticket_put(new_ctx->ticket);
         kmem_free(new_ctx);
         return 0;
@@ -641,6 +583,82 @@ out_abort:
         return XFS_ERROR(EIO);
 }
 
+static void
+xlog_cil_push_work(
+        struct work_struct      *work)
+{
+        struct xfs_cil          *cil = container_of(work, struct xfs_cil,
+                                                        xc_push_work);
+        xlog_cil_push(cil->xc_log);
+}
+
+/*
+ * We need to push CIL every so often so we don't cache more than we can fit in
+ * the log. The limit really is that a checkpoint can't be more than half the
+ * log (the current checkpoint is not allowed to overwrite the previous
+ * checkpoint), but commit latency and memory usage limit this to a smaller
+ * size.
+ */
+static void
+xlog_cil_push_background(
+        struct log      *log)
+{
+        struct xfs_cil  *cil = log->l_cilp;
+
+        /*
+         * The cil won't be empty because we are called while holding the
+         * context lock so whatever we added to the CIL will still be there
+         */
+        ASSERT(!list_empty(&cil->xc_cil));
+
+        /*
+         * don't do a background push if we haven't used up all the
+         * space available yet.
+         */
+        if (cil->xc_ctx->space_used < XLOG_CIL_SPACE_LIMIT(log))
+                return;
+
+        spin_lock(&cil->xc_cil_lock);
+        if (cil->xc_push_seq < cil->xc_current_sequence) {
+                cil->xc_push_seq = cil->xc_current_sequence;
+                queue_work(log->l_mp->m_cil_workqueue, &cil->xc_push_work);
+        }
+        spin_unlock(&cil->xc_cil_lock);
+
+}
+
+static void
+xlog_cil_push_foreground(
+        struct log      *log,
+        xfs_lsn_t       push_seq)
+{
+        struct xfs_cil  *cil = log->l_cilp;
+
+        if (!cil)
+                return;
+
+        ASSERT(push_seq && push_seq <= cil->xc_current_sequence);
+
+        /* start on any pending background push to minimise wait time on it */
+        flush_work(&cil->xc_push_work);
+
+        /*
+         * If the CIL is empty or we've already pushed the sequence then
+         * there's no work we need to do.
+         */
+        spin_lock(&cil->xc_cil_lock);
+        if (list_empty(&cil->xc_cil) || push_seq <= cil->xc_push_seq) {
+                spin_unlock(&cil->xc_cil_lock);
+                return;
+        }
+
+        cil->xc_push_seq = push_seq;
+        spin_unlock(&cil->xc_cil_lock);
+
+        /* do the push now */
+        xlog_cil_push(log);
+}
+
 /*
  * Commit a transaction with the given vector to the Committed Item List.
  *
@@ -667,7 +685,6 @@ xfs_log_commit_cil(
 {
         struct log              *log = mp->m_log;
         int                     log_flags = 0;
-        int                     push = 0;
         struct xfs_log_vec      *log_vector;
 
         if (flags & XFS_TRANS_RELEASE_LOG_RES)
@@ -719,21 +736,9 @@ xfs_log_commit_cil(
          */
         xfs_trans_free_items(tp, *commit_lsn, 0);
 
-        /* check for background commit before unlock */
-        if (log->l_cilp->xc_ctx->space_used > XLOG_CIL_SPACE_LIMIT(log))
-                push = 1;
+        xlog_cil_push_background(log);
 
         up_read(&log->l_cilp->xc_ctx_lock);
-
-        /*
-         * We need to push CIL every so often so we don't cache more than we
-         * can fit in the log. The limit really is that a checkpoint can't be
-         * more than half the log (the current checkpoint is not allowed to
-         * overwrite the previous checkpoint), but commit latency and memory
-         * usage limit this to a smaller size in most cases.
-         */
-        if (push)
-                xlog_cil_push(log, 0);
         return 0;
 }
 
@@ -746,9 +751,6 @@ xfs_log_commit_cil(
  *
  * We return the current commit lsn to allow the callers to determine if a
  * iclog flush is necessary following this call.
- *
- * XXX: Initially, just push the CIL unconditionally and return whatever
- * commit lsn is there. It'll be empty, so this is broken for now.
  */
 xfs_lsn_t
 xlog_cil_force_lsn(
@@ -766,8 +768,7 @@ xlog_cil_force_lsn(
          * xlog_cil_push() handles racing pushes for the same sequence,
          * so no need to deal with it here.
          */
-        if (sequence == cil->xc_current_sequence)
-                xlog_cil_push(log, sequence);
+        xlog_cil_push_foreground(log, sequence);
 
         /*
          * See if we can find a previous sequence still committing.
@@ -826,3 +827,57 @@ xfs_log_item_in_current_chkpt(
                 return false;
         return true;
 }
+
+/*
+ * Perform initial CIL structure initialisation.
+ */
+int
+xlog_cil_init(
+        struct log      *log)
+{
+        struct xfs_cil  *cil;
+        struct xfs_cil_ctx *ctx;
+
+        cil = kmem_zalloc(sizeof(*cil), KM_SLEEP|KM_MAYFAIL);
+        if (!cil)
+                return ENOMEM;
+
+        ctx = kmem_zalloc(sizeof(*ctx), KM_SLEEP|KM_MAYFAIL);
+        if (!ctx) {
+                kmem_free(cil);
+                return ENOMEM;
+        }
+
+        INIT_WORK(&cil->xc_push_work, xlog_cil_push_work);
+        INIT_LIST_HEAD(&cil->xc_cil);
+        INIT_LIST_HEAD(&cil->xc_committing);
+        spin_lock_init(&cil->xc_cil_lock);
+        init_rwsem(&cil->xc_ctx_lock);
+        init_waitqueue_head(&cil->xc_commit_wait);
+
+        INIT_LIST_HEAD(&ctx->committing);
+        INIT_LIST_HEAD(&ctx->busy_extents);
+        ctx->sequence = 1;
+        ctx->cil = cil;
+        cil->xc_ctx = ctx;
+        cil->xc_current_sequence = ctx->sequence;
+
+        cil->xc_log = log;
+        log->l_cilp = cil;
+        return 0;
+}
+
+void
+xlog_cil_destroy(
+        struct log      *log)
+{
+        if (log->l_cilp->xc_ctx) {
+                if (log->l_cilp->xc_ctx->ticket)
+                        xfs_log_ticket_put(log->l_cilp->xc_ctx->ticket);
+                kmem_free(log->l_cilp->xc_ctx);
+        }
+
+        ASSERT(list_empty(&log->l_cilp->xc_cil));
+        kmem_free(log->l_cilp);
+}
+