fs/xfs/linux-2.6/xfs_vnode.c

   1 /*
   2  * Copyright (c) 2000-2003 Silicon Graphics, Inc.  All Rights Reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of version 2 of the GNU General Public License as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it would be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  11  *
  12  * Further, this software is distributed without any warranty that it is
  13  * free of the rightful claim of any third person regarding infringement
  14  * or the like.  Any license provided herein, whether implied or
  15  * otherwise, applies only to this software file.  Patent licenses, if
  16  * any, provided herein do not apply to combinations of this program with
  17  * other software, or any other product whatsoever.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write the Free Software Foundation, Inc., 59
  21  * Temple Place - Suite 330, Boston MA 02111-1307, USA.
  22  *
  23  * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
  24  * Mountain View, CA  94043, or:
  25  *
  26  * http://www.sgi.com
  27  *
  28  * For further information regarding this notice, see:
  29  *
  30  * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
  31  */
  32
  33 #include "xfs.h"
  34
  35
  36 uint64_t vn_generation;         /* vnode generation number */
  37 DEFINE_SPINLOCK(vnumber_lock);
  38
  39 /*
  40  * Dedicated vnode inactive/reclaim sync semaphores.
  41  * Prime number of hash buckets since address is used as the key.
  42  */
  43 #define NVSYNC                  37
  44 #define vptosync(v)             (&vsync[((unsigned long)v) % NVSYNC])
  45 sv_t vsync[NVSYNC];
  46
  47
  48 void
  49 vn_init(void)
  50 {
  51         register sv_t *svp;
  52         register int i;
  53
  54         for (svp = vsync, i = 0; i < NVSYNC; i++, svp++)
  55                 init_sv(svp, SV_DEFAULT, "vsy", i);
  56 }
  57
  58 /*
  59  * Clean a vnode of filesystem-specific data and prepare it for reuse.
  60  */
  61 STATIC int
  62 vn_reclaim(
  63         struct vnode    *vp)
  64 {
  65         int             error;
  66
  67         XFS_STATS_INC(vn_reclaim);
  68         vn_trace_entry(vp, "vn_reclaim", (inst_t *)__return_address);
  69
  70         /*
  71          * Only make the VOP_RECLAIM call if there are behaviors
  72          * to call.
  73          */
  74         if (vp->v_fbhv) {
  75                 VOP_RECLAIM(vp, error);
  76                 if (error)
  77                         return -error;
  78         }
  79         ASSERT(vp->v_fbhv == NULL);
  80
  81         vp->v_fbhv = NULL;
  82
  83 #ifdef XFS_VNODE_TRACE
  84         ktrace_free(vp->v_trace);
  85         vp->v_trace = NULL;
  86 #endif
  87
  88         return 0;
  89 }
  90
  91 struct vnode *
  92 vn_initialize(
  93         struct inode    *inode)
  94 {
  95         struct vnode    *vp = LINVFS_GET_VP(inode);
  96
  97         XFS_STATS_INC(vn_active);
  98         XFS_STATS_INC(vn_alloc);
  99
 100         vp->v_flag = VMODIFIED;
 101         spinlock_init(&vp->v_lock, "v_lock");
 102
 103         spin_lock(&vnumber_lock);
 104         if (!++vn_generation)   /* v_number shouldn't be zero */
 105                 vn_generation++;
 106         vp->v_number = vn_generation;
 107         spin_unlock(&vnumber_lock);
 108
 109         ASSERT(VN_CACHED(vp) == 0);
 110
 111         /* Initialize the first behavior and the behavior chain head. */
 112         vn_bhv_head_init(VN_BHV_HEAD(vp), "vnode");
 113
 114 #ifdef  XFS_VNODE_TRACE
 115         vp->v_trace = ktrace_alloc(VNODE_TRACE_SIZE, KM_SLEEP);
 116 #endif  /* XFS_VNODE_TRACE */
 117
 118         vn_trace_exit(vp, "vn_initialize", (inst_t *)__return_address);
 119         return vp;
 120 }
 121
 122 /*
 123  * Revalidate the Linux inode from the vattr.
 124  * Note: i_size _not_ updated; we must hold the inode
 125  * semaphore when doing that - callers responsibility.
 126  */
 127 void
 128 vn_revalidate_core(
 129         struct vnode    *vp,
 130         vattr_t         *vap)
 131 {
 132         struct inode    *inode = LINVFS_GET_IP(vp);
 133
 134         inode->i_mode       = vap->va_mode;
 135         inode->i_nlink      = vap->va_nlink;
 136         inode->i_uid        = vap->va_uid;
 137         inode->i_gid        = vap->va_gid;
 138         inode->i_blocks     = vap->va_nblocks;
 139         inode->i_mtime      = vap->va_mtime;
 140         inode->i_ctime      = vap->va_ctime;
 141         inode->i_atime      = vap->va_atime;
 142         if (vap->va_xflags & XFS_XFLAG_IMMUTABLE)
 143                 inode->i_flags |= S_IMMUTABLE;
 144         else
 145                 inode->i_flags &= ~S_IMMUTABLE;
 146         if (vap->va_xflags & XFS_XFLAG_APPEND)
 147                 inode->i_flags |= S_APPEND;
 148         else
 149                 inode->i_flags &= ~S_APPEND;
 150         if (vap->va_xflags & XFS_XFLAG_SYNC)
 151                 inode->i_flags |= S_SYNC;
 152         else
 153                 inode->i_flags &= ~S_SYNC;
 154         if (vap->va_xflags & XFS_XFLAG_NOATIME)
 155                 inode->i_flags |= S_NOATIME;
 156         else
 157                 inode->i_flags &= ~S_NOATIME;
 158 }
 159
 160 /*
 161  * Revalidate the Linux inode from the vnode.
 162  */
 163 int
 164 vn_revalidate(
 165         struct vnode    *vp)
 166 {
 167         vattr_t         va;
 168         int             error;
 169
 170         vn_trace_entry(vp, "vn_revalidate", (inst_t *)__return_address);
 171         ASSERT(vp->v_fbhv != NULL);
 172
 173         va.va_mask = XFS_AT_STAT|XFS_AT_XFLAGS;
 174         VOP_GETATTR(vp, &va, 0, NULL, error);
 175         if (!error) {
 176                 vn_revalidate_core(vp, &va);
 177                 VUNMODIFY(vp);
 178         }
 179         return -error;
 180 }
 181
 182 /*
 183  * purge a vnode from the cache
 184  * At this point the vnode is guaranteed to have no references (vn_count == 0)
 185  * The caller has to make sure that there are no ways someone could
 186  * get a handle (via vn_get) on the vnode (usually done via a mount/vfs lock).
 187  */
 188 void
 189 vn_purge(
 190         struct vnode    *vp,
 191         vmap_t          *vmap)
 192 {
 193         vn_trace_entry(vp, "vn_purge", (inst_t *)__return_address);
 194
 195         /*
 196          * Check whether vp has already been reclaimed since our caller
 197          * sampled its version while holding a filesystem cache lock that
 198          * its VOP_RECLAIM function acquires.
 199          */
 200         VN_LOCK(vp);
 201         if (vp->v_number != vmap->v_number) {
 202                 VN_UNLOCK(vp, 0);
 203                 return;
 204         }
 205
 206         /*
 207          * Another process could have raced in and gotten this vnode...
 208          */
 209         if (vn_count(vp) > 0) {
 210                 VN_UNLOCK(vp, 0);
 211                 return;
 212         }
 213
 214         XFS_STATS_DEC(vn_active);
 215         VN_UNLOCK(vp, 0);
 216
 217         /*
 218          * Call VOP_RECLAIM and clean vp. The FSYNC_INVAL flag tells
 219          * vp's filesystem to flush and invalidate all cached resources.
 220          * When vn_reclaim returns, vp should have no private data,
 221          * either in a system cache or attached to v_data.
 222          */
 223         if (vn_reclaim(vp) != 0)
 224                 panic("vn_purge: cannot reclaim");
 225 }
 226
 227 /*
 228  * Add a reference to a referenced vnode.
 229  */
 230 struct vnode *
 231 vn_hold(
 232         struct vnode    *vp)
 233 {
 234         struct inode    *inode;
 235
 236         XFS_STATS_INC(vn_hold);
 237
 238         VN_LOCK(vp);
 239         inode = igrab(LINVFS_GET_IP(vp));
 240         ASSERT(inode);
 241         VN_UNLOCK(vp, 0);
 242
 243         return vp;
 244 }
 245
 246 /*
 247  *  Call VOP_INACTIVE on last reference.
 248  */
 249 void
 250 vn_rele(
 251         struct vnode    *vp)
 252 {
 253         int             vcnt;
 254         int             cache;
 255
 256         XFS_STATS_INC(vn_rele);
 257
 258         VN_LOCK(vp);
 259
 260         vn_trace_entry(vp, "vn_rele", (inst_t *)__return_address);
 261         vcnt = vn_count(vp);
 262
 263         /*
 264          * Since we always get called from put_inode we know
 265          * that i_count won't be decremented after we
 266          * return.
 267          */
 268         if (!vcnt) {
 269                 VN_UNLOCK(vp, 0);
 270
 271                 /*
 272                  * Do not make the VOP_INACTIVE call if there
 273                  * are no behaviors attached to the vnode to call.
 274                  */
 275                 if (vp->v_fbhv)
 276                         VOP_INACTIVE(vp, NULL, cache);
 277
 278                 VN_LOCK(vp);
 279                 vp->v_flag &= ~VMODIFIED;
 280         }
 281
 282         VN_UNLOCK(vp, 0);
 283
 284         vn_trace_exit(vp, "vn_rele", (inst_t *)__return_address);
 285 }
 286
 287 /*
 288  * Finish the removal of a vnode.
 289  */
 290 void
 291 vn_remove(
 292         struct vnode    *vp)
 293 {
 294         vmap_t          vmap;
 295
 296         /* Make sure we don't do this to the same vnode twice */
 297         if (!(vp->v_fbhv))
 298                 return;
 299
 300         XFS_STATS_INC(vn_remove);
 301         vn_trace_exit(vp, "vn_remove", (inst_t *)__return_address);
 302
 303         /*
 304          * After the following purge the vnode
 305          * will no longer exist.
 306          */
 307         VMAP(vp, vmap);
 308         vn_purge(vp, &vmap);
 309 }
 310
 311
 312 #ifdef  XFS_VNODE_TRACE
 313
 314 #define KTRACE_ENTER(vp, vk, s, line, ra)                       \
 315         ktrace_enter(   (vp)->v_trace,                          \
 316 /*  0 */                (void *)(__psint_t)(vk),                \
 317 /*  1 */                (void *)(s),                            \
 318 /*  2 */                (void *)(__psint_t) line,               \
 319 /*  3 */                (void *)(__psint_t)(vn_count(vp)),      \
 320 /*  4 */                (void *)(ra),                           \
 321 /*  5 */                (void *)(__psunsigned_t)(vp)->v_flag,   \
 322 /*  6 */                (void *)(__psint_t)current_cpu(),       \
 323 /*  7 */                (void *)(__psint_t)current_pid(),       \
 324 /*  8 */                (void *)__return_address,               \
 325 /*  9 */                NULL, NULL, NULL, NULL, NULL, NULL, NULL)
 326
 327 /*
 328  * Vnode tracing code.
 329  */
 330 void
 331 vn_trace_entry(vnode_t *vp, const char *func, inst_t *ra)
 332 {
 333         KTRACE_ENTER(vp, VNODE_KTRACE_ENTRY, func, 0, ra);
 334 }
 335
 336 void
 337 vn_trace_exit(vnode_t *vp, const char *func, inst_t *ra)
 338 {
 339         KTRACE_ENTER(vp, VNODE_KTRACE_EXIT, func, 0, ra);
 340 }
 341
 342 void
 343 vn_trace_hold(vnode_t *vp, char *file, int line, inst_t *ra)
 344 {
 345         KTRACE_ENTER(vp, VNODE_KTRACE_HOLD, file, line, ra);
 346 }
 347
 348 void
 349 vn_trace_ref(vnode_t *vp, char *file, int line, inst_t *ra)
 350 {
 351         KTRACE_ENTER(vp, VNODE_KTRACE_REF, file, line, ra);
 352 }
 353
 354 void
 355 vn_trace_rele(vnode_t *vp, char *file, int line, inst_t *ra)
 356 {
 357         KTRACE_ENTER(vp, VNODE_KTRACE_RELE, file, line, ra);
 358 }
 359 #endif  /* XFS_VNODE_TRACE */