static int ocfs2_local_alloc_slide_window(struct ocfs2_super *osb,
struct inode *local_alloc_inode);
+static inline int ocfs2_la_state_enabled(struct ocfs2_super *osb)
+{
+ return (osb->local_alloc_state == OCFS2_LA_THROTTLED ||
+ osb->local_alloc_state == OCFS2_LA_ENABLED);
+}
+
+void ocfs2_local_alloc_seen_free_bits(struct ocfs2_super *osb,
+ unsigned int num_clusters)
+{
+ spin_lock(&osb->osb_lock);
+ if (osb->local_alloc_state == OCFS2_LA_DISABLED ||
+ osb->local_alloc_state == OCFS2_LA_THROTTLED)
+ if (num_clusters >= osb->local_alloc_default_bits) {
+ cancel_delayed_work(&osb->la_enable_wq);
+ osb->local_alloc_state = OCFS2_LA_ENABLED;
+ }
+ spin_unlock(&osb->osb_lock);
+}
+
+void ocfs2_la_enable_worker(struct work_struct *work)
+{
+ struct ocfs2_super *osb =
+ container_of(work, struct ocfs2_super,
+ la_enable_wq.work);
+ spin_lock(&osb->osb_lock);
+ osb->local_alloc_state = OCFS2_LA_ENABLED;
+ spin_unlock(&osb->osb_lock);
+}
+
/*
* Tell us whether a given allocation should use the local alloc
* file. Otherwise, it has to go to the main bitmap.
+ *
+ * This function does semi-dirty reads of local alloc size and state!
+ * This is ok however, as the values are re-checked once under mutex.
*/
int ocfs2_alloc_should_use_local(struct ocfs2_super *osb, u64 bits)
{
- int la_bits = osb->local_alloc_bits;
int ret = 0;
+ int la_bits;
+
+ spin_lock(&osb->osb_lock);
+ la_bits = osb->local_alloc_bits;
- if (osb->local_alloc_state != OCFS2_LA_ENABLED)
+ if (!ocfs2_la_state_enabled(osb))
goto bail;
/* la_bits should be at least twice the size (in clusters) of
bail:
mlog(0, "state=%d, bits=%llu, la_bits=%d, ret=%d\n",
osb->local_alloc_state, (unsigned long long)bits, la_bits, ret);
+ spin_unlock(&osb->osb_lock);
return ret;
}
mlog_entry_void();
+ cancel_delayed_work(&osb->la_enable_wq);
+ flush_workqueue(ocfs2_wq);
+
if (osb->local_alloc_state == OCFS2_LA_UNUSED)
goto out;
}
/*
- * make sure we've got at least bitswanted contiguous bits in the
+ * make sure we've got at least bits_wanted contiguous bits in the
* local alloc. You lose them when you drop i_mutex.
*
* We will add ourselves to the transaction passed in, but may start
mutex_lock(&local_alloc_inode->i_mutex);
- if (osb->local_alloc_state != OCFS2_LA_ENABLED) {
- status = -ENOSPC;
- goto bail;
- }
-
- if (bits_wanted > osb->local_alloc_bits) {
- mlog(0, "Asking for more than my max window size!\n");
+ /*
+ * We must double check state and allocator bits because
+ * another process may have changed them while holding i_mutex.
+ */
+ spin_lock(&osb->osb_lock);
+ if (!ocfs2_la_state_enabled(osb) ||
+ (bits_wanted > osb->local_alloc_bits)) {
+ spin_unlock(&osb->osb_lock);
status = -ENOSPC;
goto bail;
}
+ spin_unlock(&osb->osb_lock);
alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;
mlog_errno(status);
goto bail;
}
+
+ /*
+ * Under certain conditions, the window slide code
+ * might have reduced the number of bits available or
+ * disabled the the local alloc entirely. Re-check
+ * here and return -ENOSPC if necessary.
+ */
+ status = -ENOSPC;
+ if (!ocfs2_la_state_enabled(osb))
+ goto bail;
+
+ free_bits = le32_to_cpu(alloc->id1.bitmap1.i_total) -
+ le32_to_cpu(alloc->id1.bitmap1.i_used);
+ if (bits_wanted > free_bits)
+ goto bail;
}
ac->ac_inode = local_alloc_inode;
return status;
}
+enum ocfs2_la_event {
+ OCFS2_LA_EVENT_SLIDE, /* Normal window slide. */
+ OCFS2_LA_EVENT_FRAGMENTED, /* The global bitmap has
+ * enough bits theoretically
+ * free, but a contiguous
+ * allocation could not be
+ * found. */
+ OCFS2_LA_EVENT_ENOSPC, /* Global bitmap doesn't have
+ * enough bits free to satisfy
+ * our request. */
+};
+#define OCFS2_LA_ENABLE_INTERVAL (30 * HZ)
+/*
+ * Given an event, calculate the size of our next local alloc window.
+ *
+ * This should always be called under i_mutex of the local alloc inode
+ * so that local alloc disabling doesn't race with processes trying to
+ * use the allocator.
+ *
+ * Returns the state which the local alloc was left in. This value can
+ * be ignored by some paths.
+ */
+static int ocfs2_recalc_la_window(struct ocfs2_super *osb,
+ enum ocfs2_la_event event)
+{
+ unsigned int bits;
+ int state;
+
+ spin_lock(&osb->osb_lock);
+ if (osb->local_alloc_state == OCFS2_LA_DISABLED) {
+ WARN_ON_ONCE(osb->local_alloc_state == OCFS2_LA_DISABLED);
+ goto out_unlock;
+ }
+
+ /*
+ * ENOSPC and fragmentation are treated similarly for now.
+ */
+ if (event == OCFS2_LA_EVENT_ENOSPC ||
+ event == OCFS2_LA_EVENT_FRAGMENTED) {
+ /*
+ * We ran out of contiguous space in the primary
+ * bitmap. Drastically reduce the number of bits used
+ * by local alloc until we have to disable it.
+ */
+ bits = osb->local_alloc_bits >> 1;
+ if (bits > ocfs2_megabytes_to_clusters(osb->sb, 1)) {
+ /*
+ * By setting state to THROTTLED, we'll keep
+ * the number of local alloc bits used down
+ * until an event occurs which would give us
+ * reason to assume the bitmap situation might
+ * have changed.
+ */
+ osb->local_alloc_state = OCFS2_LA_THROTTLED;
+ osb->local_alloc_bits = bits;
+ } else {
+ osb->local_alloc_state = OCFS2_LA_DISABLED;
+ }
+ queue_delayed_work(ocfs2_wq, &osb->la_enable_wq,
+ OCFS2_LA_ENABLE_INTERVAL);
+ goto out_unlock;
+ }
+
+ /*
+ * Don't increase the size of the local alloc window until we
+ * know we might be able to fulfill the request. Otherwise, we
+ * risk bouncing around the global bitmap during periods of
+ * low space.
+ */
+ if (osb->local_alloc_state != OCFS2_LA_THROTTLED)
+ osb->local_alloc_bits = osb->local_alloc_default_bits;
+
+out_unlock:
+ state = osb->local_alloc_state;
+ spin_unlock(&osb->osb_lock);
+
+ return state;
+}
+
static int ocfs2_local_alloc_reserve_for_window(struct ocfs2_super *osb,
struct ocfs2_alloc_context **ac,
struct inode **bitmap_inode,
goto bail;
}
+retry_enospc:
(*ac)->ac_bits_wanted = osb->local_alloc_bits;
status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
+ if (status == -ENOSPC) {
+ if (ocfs2_recalc_la_window(osb, OCFS2_LA_EVENT_ENOSPC) ==
+ OCFS2_LA_DISABLED)
+ goto bail;
+
+ ocfs2_free_ac_resource(*ac);
+ memset(*ac, 0, sizeof(struct ocfs2_alloc_context));
+ goto retry_enospc;
+ }
if (status < 0) {
- if (status != -ENOSPC)
- mlog_errno(status);
+ mlog_errno(status);
goto bail;
}
* the more specific cluster api to claim bits. */
status = ocfs2_claim_clusters(osb, handle, ac, osb->local_alloc_bits,
&cluster_off, &cluster_count);
+ if (status == -ENOSPC) {
+retry_enospc:
+ /*
+ * Note: We could also try syncing the journal here to
+ * allow use of any free bits which the current
+ * transaction can't give us access to. --Mark
+ */
+ if (ocfs2_recalc_la_window(osb, OCFS2_LA_EVENT_FRAGMENTED) ==
+ OCFS2_LA_DISABLED)
+ goto bail;
+
+ status = ocfs2_claim_clusters(osb, handle, ac,
+ osb->local_alloc_bits,
+ &cluster_off,
+ &cluster_count);
+ if (status == -ENOSPC)
+ goto retry_enospc;
+ /*
+ * We only shrunk the *minimum* number of in our
+ * request - it's entirely possible that the allocator
+ * might give us more than we asked for.
+ */
+ if (status == 0) {
+ spin_lock(&osb->osb_lock);
+ osb->local_alloc_bits = cluster_count;
+ spin_unlock(&osb->osb_lock);
+ }
+ }
if (status < 0) {
if (status != -ENOSPC)
mlog_errno(status);
mlog_entry_void();
+ ocfs2_recalc_la_window(osb, OCFS2_LA_EVENT_SLIDE);
+
/* This will lock the main bitmap for us. */
status = ocfs2_local_alloc_reserve_for_window(osb,
&ac,
projects / linux-2.6-omap-h63xx.git / blobdiff