xfs: convert log grant ticket queues to list heads

The grant write and reserve queues use a roll-your-own double linked
list, so convert it to a standard list_head structure and convert
all the list traversals to use list_for_each_entry(). We can also
get rid of the XLOG_TIC_IN_Q flag as we can use the list_empty()
check to tell if the ticket is in a list or not.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

1 files changed, 4 insertions, 7 deletions

diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h
index c1ce505313e9..a5b3c021a406 100644
--- a/fs/xfs/xfs_log_priv.h
+++ b/fs/xfs/xfs_log_priv.h
@@ -132,12 +132,10 @@ static inline uint xlog_get_client_id(__be32 i)
  */
 #define XLOG_TIC_INITED         0x1     /* has been initialized */
 #define XLOG_TIC_PERM_RESERV    0x2     /* permanent reservation */
-#define XLOG_TIC_IN_Q           0x4
 
 #define XLOG_TIC_FLAGS \
         { XLOG_TIC_INITED,      "XLOG_TIC_INITED" }, \
-        { XLOG_TIC_PERM_RESERV, "XLOG_TIC_PERM_RESERV" }, \
-        { XLOG_TIC_IN_Q,        "XLOG_TIC_IN_Q" }
+        { XLOG_TIC_PERM_RESERV, "XLOG_TIC_PERM_RESERV" }
 
 #endif  /* __KERNEL__ */
 
@@ -244,8 +242,7 @@ typedef struct xlog_res {
 
 typedef struct xlog_ticket {
         sv_t               t_wait;       /* ticket wait queue            : 20 */
-        struct xlog_ticket *t_next;      /*                              :4|8 */
-        struct xlog_ticket *t_prev;      /*                              :4|8 */
+        struct list_head   t_queue;      /* reserve/write queue */
         xlog_tid_t         t_tid;        /* transaction identifier       : 4  */
         atomic_t           t_ref;        /* ticket reference count       : 4  */
         int                t_curr_res;   /* current reservation in bytes : 4  */
@@ -519,8 +516,8 @@ typedef struct log {
 
         /* The following block of fields are changed while holding grant_lock */
         spinlock_t              l_grant_lock ____cacheline_aligned_in_smp;
-        xlog_ticket_t           *l_reserve_headq;
-        xlog_ticket_t           *l_write_headq;
+        struct list_head        l_reserveq;
+        struct list_head        l_writeq;
         int                     l_grant_reserve_cycle;
         int                     l_grant_reserve_bytes;
         int                     l_grant_write_cycle;