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NEX-9200 Improve the scalability of attribute locking in zfs_zget
Reviewed by: Joyce McIntosh <joyce.mcintosh@nexenta.com>
Reviewed by: Sanjay Nadkarni <sanjay.nadkarni@nexenta.com>


 230                 rrm_enter_read(&(zfsvfs)->z_teardown_lock, FTAG); \
 231                 if ((zfsvfs)->z_unmounted) { \
 232                         ZFS_EXIT(zfsvfs); \
 233                         return (EIO); \
 234                 } \
 235         }
 236 
 237 /* Must be called before exiting the vop */
 238 #define ZFS_EXIT(zfsvfs) rrm_exit(&(zfsvfs)->z_teardown_lock, FTAG)
 239 
 240 /* Verifies the znode is valid */
 241 #define ZFS_VERIFY_ZP(zp) \
 242         if ((zp)->z_sa_hdl == NULL) { \
 243                 ZFS_EXIT((zp)->z_zfsvfs); \
 244                 return (EIO); \
 245         } \
 246 
 247 /*
 248  * Macros for dealing with dmu_buf_hold
 249  */
 250 #define ZFS_OBJ_HASH(obj_num)   ((obj_num) & (ZFS_OBJ_MTX_SZ - 1))
 251 #define ZFS_OBJ_MUTEX(zfsvfs, obj_num)  \
 252         (&(zfsvfs)->z_hold_mtx[ZFS_OBJ_HASH(obj_num)])
 253 #define ZFS_OBJ_HOLD_ENTER(zfsvfs, obj_num) \
 254         mutex_enter(ZFS_OBJ_MUTEX((zfsvfs), (obj_num)))
 255 #define ZFS_OBJ_HOLD_TRYENTER(zfsvfs, obj_num) \
 256         mutex_tryenter(ZFS_OBJ_MUTEX((zfsvfs), (obj_num)))
 257 #define ZFS_OBJ_HOLD_EXIT(zfsvfs, obj_num) \
 258         mutex_exit(ZFS_OBJ_MUTEX((zfsvfs), (obj_num)))
 259 
 260 /* Encode ZFS stored time values from a struct timespec */
 261 #define ZFS_TIME_ENCODE(tp, stmp)               \
 262 {                                               \
 263         (stmp)[0] = (uint64_t)(tp)->tv_sec;  \
 264         (stmp)[1] = (uint64_t)(tp)->tv_nsec; \
 265 }
 266 
 267 /* Decode ZFS stored time values to a struct timespec */
 268 #define ZFS_TIME_DECODE(tp, stmp)               \
 269 {                                               \
 270         (tp)->tv_sec = (time_t)(stmp)[0];            \
 271         (tp)->tv_nsec = (long)(stmp)[1];             \
 272 }




 230                 rrm_enter_read(&(zfsvfs)->z_teardown_lock, FTAG); \
 231                 if ((zfsvfs)->z_unmounted) { \
 232                         ZFS_EXIT(zfsvfs); \
 233                         return (EIO); \
 234                 } \
 235         }
 236 
 237 /* Must be called before exiting the vop */
 238 #define ZFS_EXIT(zfsvfs) rrm_exit(&(zfsvfs)->z_teardown_lock, FTAG)
 239 
 240 /* Verifies the znode is valid */
 241 #define ZFS_VERIFY_ZP(zp) \
 242         if ((zp)->z_sa_hdl == NULL) { \
 243                 ZFS_EXIT((zp)->z_zfsvfs); \
 244                 return (EIO); \
 245         } \
 246 
 247 /*
 248  * Macros for dealing with dmu_buf_hold
 249  */
 250 #define ZFS_OBJ_HASH(obj_num, table_sz) ((obj_num) & (table_sz - 1))
 251 #define ZFS_OBJ_MUTEX(zfsvfs, obj_num)  \
 252         (&(zfsvfs)->z_hold_mtx[ZFS_OBJ_HASH(obj_num, (zfsvfs)->z_hold_mtx_sz)])
 253 #define ZFS_OBJ_HOLD_ENTER(zfsvfs, obj_num) \
 254         mutex_enter(ZFS_OBJ_MUTEX((zfsvfs), (obj_num)))
 255 #define ZFS_OBJ_HOLD_TRYENTER(zfsvfs, obj_num) \
 256         mutex_tryenter(ZFS_OBJ_MUTEX((zfsvfs), (obj_num)))
 257 #define ZFS_OBJ_HOLD_EXIT(zfsvfs, obj_num) \
 258         mutex_exit(ZFS_OBJ_MUTEX((zfsvfs), (obj_num)))
 259 
 260 /* Encode ZFS stored time values from a struct timespec */
 261 #define ZFS_TIME_ENCODE(tp, stmp)               \
 262 {                                               \
 263         (stmp)[0] = (uint64_t)(tp)->tv_sec;  \
 264         (stmp)[1] = (uint64_t)(tp)->tv_nsec; \
 265 }
 266 
 267 /* Decode ZFS stored time values to a struct timespec */
 268 #define ZFS_TIME_DECODE(tp, stmp)               \
 269 {                                               \
 270         (tp)->tv_sec = (time_t)(stmp)[0];            \
 271         (tp)->tv_nsec = (long)(stmp)[1];             \
 272 }