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authorAlexander Aring <aahringo@redhat.com>2021-03-01 17:05:16 -0500
committerDavid Teigland <teigland@redhat.com>2021-03-09 08:56:42 -0600
commitf0747ebf48f362ebfc93bc383d6be2b8c8f05b5a (patch)
tree5b5db4b5a597c2e3dd5d6d0ee5ef1de2b210f1e4 /fs/dlm
parente1a7cbce53f6524e28421b980464a36f0fa9631c (diff)
downloadlinux-f0747ebf48f362ebfc93bc383d6be2b8c8f05b5a.tar.bz2
fs: dlm: simplify writequeue handling
This patch cleans up the current dlm sending allocator handling by using some named macros, list functionality and removes some goto statements. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
Diffstat (limited to 'fs/dlm')
-rw-r--r--fs/dlm/lowcomms.c83
1 files changed, 43 insertions, 40 deletions
diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c
index 97d0c93dd644..a97c69ddbff0 100644
--- a/fs/dlm/lowcomms.c
+++ b/fs/dlm/lowcomms.c
@@ -102,6 +102,9 @@ struct listen_connection {
struct work_struct rwork;
};
+#define DLM_WQ_REMAIN_BYTES(e) (PAGE_SIZE - e->end)
+#define DLM_WQ_LENGTH_BYTES(e) (e->end - e->offset)
+
/* An entry waiting to be sent */
struct writequeue_entry {
struct list_head list;
@@ -1351,7 +1354,7 @@ static struct writequeue_entry *new_writequeue_entry(struct connection *con,
{
struct writequeue_entry *entry;
- entry = kmalloc(sizeof(struct writequeue_entry), allocation);
+ entry = kzalloc(sizeof(*entry), allocation);
if (!entry)
return NULL;
@@ -1361,20 +1364,48 @@ static struct writequeue_entry *new_writequeue_entry(struct connection *con,
return NULL;
}
- entry->offset = 0;
- entry->len = 0;
- entry->end = 0;
- entry->users = 0;
entry->con = con;
+ entry->users = 1;
return entry;
}
+static struct writequeue_entry *new_wq_entry(struct connection *con, int len,
+ gfp_t allocation, char **ppc)
+{
+ struct writequeue_entry *e;
+
+ spin_lock(&con->writequeue_lock);
+ if (!list_empty(&con->writequeue)) {
+ e = list_last_entry(&con->writequeue, struct writequeue_entry, list);
+ if (DLM_WQ_REMAIN_BYTES(e) >= len) {
+ *ppc = page_address(e->page) + e->end;
+ e->end += len;
+ e->users++;
+ spin_unlock(&con->writequeue_lock);
+
+ return e;
+ }
+ }
+ spin_unlock(&con->writequeue_lock);
+
+ e = new_writequeue_entry(con, allocation);
+ if (!e)
+ return NULL;
+
+ *ppc = page_address(e->page);
+ e->end += len;
+
+ spin_lock(&con->writequeue_lock);
+ list_add_tail(&e->list, &con->writequeue);
+ spin_unlock(&con->writequeue_lock);
+
+ return e;
+};
+
void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc)
{
struct connection *con;
- struct writequeue_entry *e;
- int offset = 0;
if (len > DEFAULT_BUFFER_SIZE ||
len < sizeof(struct dlm_header)) {
@@ -1388,35 +1419,7 @@ void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc)
if (!con)
return NULL;
- spin_lock(&con->writequeue_lock);
- e = list_entry(con->writequeue.prev, struct writequeue_entry, list);
- if ((&e->list == &con->writequeue) ||
- (PAGE_SIZE - e->end < len)) {
- e = NULL;
- } else {
- offset = e->end;
- e->end += len;
- e->users++;
- }
- spin_unlock(&con->writequeue_lock);
-
- if (e) {
- got_one:
- *ppc = page_address(e->page) + offset;
- return e;
- }
-
- e = new_writequeue_entry(con, allocation);
- if (e) {
- spin_lock(&con->writequeue_lock);
- offset = e->end;
- e->end += len;
- e->users++;
- list_add_tail(&e->list, &con->writequeue);
- spin_unlock(&con->writequeue_lock);
- goto got_one;
- }
- return NULL;
+ return new_wq_entry(con, len, allocation, ppc);
}
void dlm_lowcomms_commit_buffer(void *mh)
@@ -1429,7 +1432,8 @@ void dlm_lowcomms_commit_buffer(void *mh)
users = --e->users;
if (users)
goto out;
- e->len = e->end - e->offset;
+
+ e->len = DLM_WQ_LENGTH_BYTES(e);
spin_unlock(&con->writequeue_lock);
queue_work(send_workqueue, &con->swork);
@@ -1455,11 +1459,10 @@ static void send_to_sock(struct connection *con)
spin_lock(&con->writequeue_lock);
for (;;) {
- e = list_entry(con->writequeue.next, struct writequeue_entry,
- list);
- if ((struct list_head *) e == &con->writequeue)
+ if (list_empty(&con->writequeue))
break;
+ e = list_first_entry(&con->writequeue, struct writequeue_entry, list);
len = e->len;
offset = e->offset;
BUG_ON(len == 0 && e->users == 0);