OpenZFS 8491 - uberblock on-disk padding to reserve space for smoothly merging zpool...

[zfs] / include / sys / zfs_rlock.h

diff --git a/include/sys/zfs_rlock.h b/include/sys/zfs_rlock.h
index 722c341e23eda66f65b53412f2d43291938030cf..8483b4e8bf03c9052604a7fb7d83c4379b930052 100644 (file)
--- a/include/sys/zfs_rlock.h
+++ b/include/sys/zfs_rlock.h
@@ -26,15 +26,18 @@
 #ifndef        _SYS_FS_ZFS_RLOCK_H
 #define        _SYS_FS_ZFS_RLOCK_H
 
-
-
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-#ifdef _KERNEL
+#include <sys/list.h>
+#include <sys/avl.h>
 
-#include <sys/zfs_znode.h>
+#ifdef _KERNEL
+#include <sys/condvar.h>
+#else
+#include <sys/zfs_context.h>
+#endif
 
 typedef enum {
        RL_READER,
@@ -42,8 +45,16 @@ typedef enum {
        RL_APPEND
 } rl_type_t;
 
+typedef struct zfs_rlock {
+       kmutex_t zr_mutex;      /* protects changes to zr_avl */
+       avl_tree_t zr_avl;      /* avl tree of range locks */
+       uint64_t *zr_size;      /* points to znode->z_size */
+       uint_t *zr_blksz;       /* points to znode->z_blksz */
+       uint64_t *zr_max_blksz; /* points to zfsvfs->z_max_blksz */
+} zfs_rlock_t;
+
 typedef struct rl {
-       znode_t *r_zp;          /* znode this lock applies to */
+       zfs_rlock_t *r_zrl;
        avl_node_t r_node;      /* avl node link */
        uint64_t r_off;         /* file range offset */
        uint64_t r_len;         /* file range length */
@@ -54,19 +65,19 @@ typedef struct rl {
        uint8_t r_proxy;        /* acting for original range */
        uint8_t r_write_wanted; /* writer wants to lock this range */
        uint8_t r_read_wanted;  /* reader wants to lock this range */
+       list_node_t rl_node;    /* used for deferred release */
 } rl_t;
 
 /*
- * Lock a range (offset, length) as either shared (READER)
- * or exclusive (WRITER or APPEND). APPEND is a special type that
- * is converted to WRITER that specified to lock from the start of the
- * end of file.  zfs_range_lock() returns the range lock structure.
+ * Lock a range (offset, length) as either shared (RL_READER)
+ * or exclusive (RL_WRITER or RL_APPEND).  RL_APPEND is a special type that
+ * is converted to RL_WRITER that specified to lock from the start of the
+ * end of file.  Returns the range lock structure.
  */
-rl_t *zfs_range_lock(znode_t *zp, uint64_t off, uint64_t len, rl_type_t type);
+rl_t *zfs_range_lock(zfs_rlock_t *zrl, uint64_t off, uint64_t len,
+    rl_type_t type);
 
-/*
- * Unlock range and destroy range lock structure.
- */
+/* Unlock range and destroy range lock structure. */
 void zfs_range_unlock(rl_t *rl);
 
 /*
@@ -76,11 +87,28 @@ void zfs_range_unlock(rl_t *rl);
 void zfs_range_reduce(rl_t *rl, uint64_t off, uint64_t len);
 
 /*
- * AVL comparison function used to compare range locks
+ * AVL comparison function used to order range locks
+ * Locks are ordered on the start offset of the range.
  */
 int zfs_range_compare(const void *arg1, const void *arg2);
 
-#endif /* _KERNEL */
+static inline void
+zfs_rlock_init(zfs_rlock_t *zrl)
+{
+       mutex_init(&zrl->zr_mutex, NULL, MUTEX_DEFAULT, NULL);
+       avl_create(&zrl->zr_avl, zfs_range_compare,
+           sizeof (rl_t), offsetof(rl_t, r_node));
+       zrl->zr_size = NULL;
+       zrl->zr_blksz = NULL;
+       zrl->zr_max_blksz = NULL;
+}
+
+static inline void
+zfs_rlock_destroy(zfs_rlock_t *zrl)
+{
+       avl_destroy(&zrl->zr_avl);
+       mutex_destroy(&zrl->zr_mutex);
+}
 
 #ifdef __cplusplus
 }