linux/fs/xfs/xfs_extfree_item.c
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   1/*
   2 * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
   3 * All Rights Reserved.
   4 *
   5 * This program is free software; you can redistribute it and/or
   6 * modify it under the terms of the GNU General Public License as
   7 * published by the Free Software Foundation.
   8 *
   9 * This program is distributed in the hope that it would be useful,
  10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 * GNU General Public License for more details.
  13 *
  14 * You should have received a copy of the GNU General Public License
  15 * along with this program; if not, write the Free Software Foundation,
  16 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17 */
  18#include "xfs.h"
  19#include "xfs_fs.h"
  20#include "xfs_types.h"
  21#include "xfs_log.h"
  22#include "xfs_trans.h"
  23#include "xfs_buf_item.h"
  24#include "xfs_sb.h"
  25#include "xfs_ag.h"
  26#include "xfs_mount.h"
  27#include "xfs_trans_priv.h"
  28#include "xfs_extfree_item.h"
  29
  30
  31kmem_zone_t     *xfs_efi_zone;
  32kmem_zone_t     *xfs_efd_zone;
  33
  34static inline struct xfs_efi_log_item *EFI_ITEM(struct xfs_log_item *lip)
  35{
  36        return container_of(lip, struct xfs_efi_log_item, efi_item);
  37}
  38
  39void
  40xfs_efi_item_free(
  41        struct xfs_efi_log_item *efip)
  42{
  43        if (efip->efi_format.efi_nextents > XFS_EFI_MAX_FAST_EXTENTS)
  44                kmem_free(efip);
  45        else
  46                kmem_zone_free(xfs_efi_zone, efip);
  47}
  48
  49/*
  50 * Freeing the efi requires that we remove it from the AIL if it has already
  51 * been placed there. However, the EFI may not yet have been placed in the AIL
  52 * when called by xfs_efi_release() from EFD processing due to the ordering of
  53 * committed vs unpin operations in bulk insert operations. Hence the
  54 * test_and_clear_bit(XFS_EFI_COMMITTED) to ensure only the last caller frees
  55 * the EFI.
  56 */
  57STATIC void
  58__xfs_efi_release(
  59        struct xfs_efi_log_item *efip)
  60{
  61        struct xfs_ail          *ailp = efip->efi_item.li_ailp;
  62
  63        if (!test_and_clear_bit(XFS_EFI_COMMITTED, &efip->efi_flags)) {
  64                spin_lock(&ailp->xa_lock);
  65                /* xfs_trans_ail_delete() drops the AIL lock. */
  66                xfs_trans_ail_delete(ailp, &efip->efi_item,
  67                                     SHUTDOWN_LOG_IO_ERROR);
  68                xfs_efi_item_free(efip);
  69        }
  70}
  71
  72/*
  73 * This returns the number of iovecs needed to log the given efi item.
  74 * We only need 1 iovec for an efi item.  It just logs the efi_log_format
  75 * structure.
  76 */
  77STATIC uint
  78xfs_efi_item_size(
  79        struct xfs_log_item     *lip)
  80{
  81        return 1;
  82}
  83
  84/*
  85 * This is called to fill in the vector of log iovecs for the
  86 * given efi log item. We use only 1 iovec, and we point that
  87 * at the efi_log_format structure embedded in the efi item.
  88 * It is at this point that we assert that all of the extent
  89 * slots in the efi item have been filled.
  90 */
  91STATIC void
  92xfs_efi_item_format(
  93        struct xfs_log_item     *lip,
  94        struct xfs_log_iovec    *log_vector)
  95{
  96        struct xfs_efi_log_item *efip = EFI_ITEM(lip);
  97        uint                    size;
  98
  99        ASSERT(atomic_read(&efip->efi_next_extent) ==
 100                                efip->efi_format.efi_nextents);
 101
 102        efip->efi_format.efi_type = XFS_LI_EFI;
 103
 104        size = sizeof(xfs_efi_log_format_t);
 105        size += (efip->efi_format.efi_nextents - 1) * sizeof(xfs_extent_t);
 106        efip->efi_format.efi_size = 1;
 107
 108        log_vector->i_addr = &efip->efi_format;
 109        log_vector->i_len = size;
 110        log_vector->i_type = XLOG_REG_TYPE_EFI_FORMAT;
 111        ASSERT(size >= sizeof(xfs_efi_log_format_t));
 112}
 113
 114
 115/*
 116 * Pinning has no meaning for an efi item, so just return.
 117 */
 118STATIC void
 119xfs_efi_item_pin(
 120        struct xfs_log_item     *lip)
 121{
 122}
 123
 124/*
 125 * While EFIs cannot really be pinned, the unpin operation is the last place at
 126 * which the EFI is manipulated during a transaction.  If we are being asked to
 127 * remove the EFI it's because the transaction has been cancelled and by
 128 * definition that means the EFI cannot be in the AIL so remove it from the
 129 * transaction and free it.  Otherwise coordinate with xfs_efi_release() (via
 130 * XFS_EFI_COMMITTED) to determine who gets to free the EFI.
 131 */
 132STATIC void
 133xfs_efi_item_unpin(
 134        struct xfs_log_item     *lip,
 135        int                     remove)
 136{
 137        struct xfs_efi_log_item *efip = EFI_ITEM(lip);
 138
 139        if (remove) {
 140                ASSERT(!(lip->li_flags & XFS_LI_IN_AIL));
 141                if (lip->li_desc)
 142                        xfs_trans_del_item(lip);
 143                xfs_efi_item_free(efip);
 144                return;
 145        }
 146        __xfs_efi_release(efip);
 147}
 148
 149/*
 150 * Efi items have no locking or pushing.  However, since EFIs are pulled from
 151 * the AIL when their corresponding EFDs are committed to disk, their situation
 152 * is very similar to being pinned.  Return XFS_ITEM_PINNED so that the caller
 153 * will eventually flush the log.  This should help in getting the EFI out of
 154 * the AIL.
 155 */
 156STATIC uint
 157xfs_efi_item_push(
 158        struct xfs_log_item     *lip,
 159        struct list_head        *buffer_list)
 160{
 161        return XFS_ITEM_PINNED;
 162}
 163
 164STATIC void
 165xfs_efi_item_unlock(
 166        struct xfs_log_item     *lip)
 167{
 168        if (lip->li_flags & XFS_LI_ABORTED)
 169                xfs_efi_item_free(EFI_ITEM(lip));
 170}
 171
 172/*
 173 * The EFI is logged only once and cannot be moved in the log, so simply return
 174 * the lsn at which it's been logged.  For bulk transaction committed
 175 * processing, the EFI may be processed but not yet unpinned prior to the EFD
 176 * being processed. Set the XFS_EFI_COMMITTED flag so this case can be detected
 177 * when processing the EFD.
 178 */
 179STATIC xfs_lsn_t
 180xfs_efi_item_committed(
 181        struct xfs_log_item     *lip,
 182        xfs_lsn_t               lsn)
 183{
 184        struct xfs_efi_log_item *efip = EFI_ITEM(lip);
 185
 186        set_bit(XFS_EFI_COMMITTED, &efip->efi_flags);
 187        return lsn;
 188}
 189
 190/*
 191 * The EFI dependency tracking op doesn't do squat.  It can't because
 192 * it doesn't know where the free extent is coming from.  The dependency
 193 * tracking has to be handled by the "enclosing" metadata object.  For
 194 * example, for inodes, the inode is locked throughout the extent freeing
 195 * so the dependency should be recorded there.
 196 */
 197STATIC void
 198xfs_efi_item_committing(
 199        struct xfs_log_item     *lip,
 200        xfs_lsn_t               lsn)
 201{
 202}
 203
 204/*
 205 * This is the ops vector shared by all efi log items.
 206 */
 207static const struct xfs_item_ops xfs_efi_item_ops = {
 208        .iop_size       = xfs_efi_item_size,
 209        .iop_format     = xfs_efi_item_format,
 210        .iop_pin        = xfs_efi_item_pin,
 211        .iop_unpin      = xfs_efi_item_unpin,
 212        .iop_unlock     = xfs_efi_item_unlock,
 213        .iop_committed  = xfs_efi_item_committed,
 214        .iop_push       = xfs_efi_item_push,
 215        .iop_committing = xfs_efi_item_committing
 216};
 217
 218
 219/*
 220 * Allocate and initialize an efi item with the given number of extents.
 221 */
 222struct xfs_efi_log_item *
 223xfs_efi_init(
 224        struct xfs_mount        *mp,
 225        uint                    nextents)
 226
 227{
 228        struct xfs_efi_log_item *efip;
 229        uint                    size;
 230
 231        ASSERT(nextents > 0);
 232        if (nextents > XFS_EFI_MAX_FAST_EXTENTS) {
 233                size = (uint)(sizeof(xfs_efi_log_item_t) +
 234                        ((nextents - 1) * sizeof(xfs_extent_t)));
 235                efip = kmem_zalloc(size, KM_SLEEP);
 236        } else {
 237                efip = kmem_zone_zalloc(xfs_efi_zone, KM_SLEEP);
 238        }
 239
 240        xfs_log_item_init(mp, &efip->efi_item, XFS_LI_EFI, &xfs_efi_item_ops);
 241        efip->efi_format.efi_nextents = nextents;
 242        efip->efi_format.efi_id = (__psint_t)(void*)efip;
 243        atomic_set(&efip->efi_next_extent, 0);
 244
 245        return efip;
 246}
 247
 248/*
 249 * Copy an EFI format buffer from the given buf, and into the destination
 250 * EFI format structure.
 251 * The given buffer can be in 32 bit or 64 bit form (which has different padding),
 252 * one of which will be the native format for this kernel.
 253 * It will handle the conversion of formats if necessary.
 254 */
 255int
 256xfs_efi_copy_format(xfs_log_iovec_t *buf, xfs_efi_log_format_t *dst_efi_fmt)
 257{
 258        xfs_efi_log_format_t *src_efi_fmt = buf->i_addr;
 259        uint i;
 260        uint len = sizeof(xfs_efi_log_format_t) + 
 261                (src_efi_fmt->efi_nextents - 1) * sizeof(xfs_extent_t);  
 262        uint len32 = sizeof(xfs_efi_log_format_32_t) + 
 263                (src_efi_fmt->efi_nextents - 1) * sizeof(xfs_extent_32_t);  
 264        uint len64 = sizeof(xfs_efi_log_format_64_t) + 
 265                (src_efi_fmt->efi_nextents - 1) * sizeof(xfs_extent_64_t);  
 266
 267        if (buf->i_len == len) {
 268                memcpy((char *)dst_efi_fmt, (char*)src_efi_fmt, len);
 269                return 0;
 270        } else if (buf->i_len == len32) {
 271                xfs_efi_log_format_32_t *src_efi_fmt_32 = buf->i_addr;
 272
 273                dst_efi_fmt->efi_type     = src_efi_fmt_32->efi_type;
 274                dst_efi_fmt->efi_size     = src_efi_fmt_32->efi_size;
 275                dst_efi_fmt->efi_nextents = src_efi_fmt_32->efi_nextents;
 276                dst_efi_fmt->efi_id       = src_efi_fmt_32->efi_id;
 277                for (i = 0; i < dst_efi_fmt->efi_nextents; i++) {
 278                        dst_efi_fmt->efi_extents[i].ext_start =
 279                                src_efi_fmt_32->efi_extents[i].ext_start;
 280                        dst_efi_fmt->efi_extents[i].ext_len =
 281                                src_efi_fmt_32->efi_extents[i].ext_len;
 282                }
 283                return 0;
 284        } else if (buf->i_len == len64) {
 285                xfs_efi_log_format_64_t *src_efi_fmt_64 = buf->i_addr;
 286
 287                dst_efi_fmt->efi_type     = src_efi_fmt_64->efi_type;
 288                dst_efi_fmt->efi_size     = src_efi_fmt_64->efi_size;
 289                dst_efi_fmt->efi_nextents = src_efi_fmt_64->efi_nextents;
 290                dst_efi_fmt->efi_id       = src_efi_fmt_64->efi_id;
 291                for (i = 0; i < dst_efi_fmt->efi_nextents; i++) {
 292                        dst_efi_fmt->efi_extents[i].ext_start =
 293                                src_efi_fmt_64->efi_extents[i].ext_start;
 294                        dst_efi_fmt->efi_extents[i].ext_len =
 295                                src_efi_fmt_64->efi_extents[i].ext_len;
 296                }
 297                return 0;
 298        }
 299        return EFSCORRUPTED;
 300}
 301
 302/*
 303 * This is called by the efd item code below to release references to the given
 304 * efi item.  Each efd calls this with the number of extents that it has
 305 * logged, and when the sum of these reaches the total number of extents logged
 306 * by this efi item we can free the efi item.
 307 */
 308void
 309xfs_efi_release(xfs_efi_log_item_t      *efip,
 310                uint                    nextents)
 311{
 312        ASSERT(atomic_read(&efip->efi_next_extent) >= nextents);
 313        if (atomic_sub_and_test(nextents, &efip->efi_next_extent))
 314                __xfs_efi_release(efip);
 315}
 316
 317static inline struct xfs_efd_log_item *EFD_ITEM(struct xfs_log_item *lip)
 318{
 319        return container_of(lip, struct xfs_efd_log_item, efd_item);
 320}
 321
 322STATIC void
 323xfs_efd_item_free(struct xfs_efd_log_item *efdp)
 324{
 325        if (efdp->efd_format.efd_nextents > XFS_EFD_MAX_FAST_EXTENTS)
 326                kmem_free(efdp);
 327        else
 328                kmem_zone_free(xfs_efd_zone, efdp);
 329}
 330
 331/*
 332 * This returns the number of iovecs needed to log the given efd item.
 333 * We only need 1 iovec for an efd item.  It just logs the efd_log_format
 334 * structure.
 335 */
 336STATIC uint
 337xfs_efd_item_size(
 338        struct xfs_log_item     *lip)
 339{
 340        return 1;
 341}
 342
 343/*
 344 * This is called to fill in the vector of log iovecs for the
 345 * given efd log item. We use only 1 iovec, and we point that
 346 * at the efd_log_format structure embedded in the efd item.
 347 * It is at this point that we assert that all of the extent
 348 * slots in the efd item have been filled.
 349 */
 350STATIC void
 351xfs_efd_item_format(
 352        struct xfs_log_item     *lip,
 353        struct xfs_log_iovec    *log_vector)
 354{
 355        struct xfs_efd_log_item *efdp = EFD_ITEM(lip);
 356        uint                    size;
 357
 358        ASSERT(efdp->efd_next_extent == efdp->efd_format.efd_nextents);
 359
 360        efdp->efd_format.efd_type = XFS_LI_EFD;
 361
 362        size = sizeof(xfs_efd_log_format_t);
 363        size += (efdp->efd_format.efd_nextents - 1) * sizeof(xfs_extent_t);
 364        efdp->efd_format.efd_size = 1;
 365
 366        log_vector->i_addr = &efdp->efd_format;
 367        log_vector->i_len = size;
 368        log_vector->i_type = XLOG_REG_TYPE_EFD_FORMAT;
 369        ASSERT(size >= sizeof(xfs_efd_log_format_t));
 370}
 371
 372/*
 373 * Pinning has no meaning for an efd item, so just return.
 374 */
 375STATIC void
 376xfs_efd_item_pin(
 377        struct xfs_log_item     *lip)
 378{
 379}
 380
 381/*
 382 * Since pinning has no meaning for an efd item, unpinning does
 383 * not either.
 384 */
 385STATIC void
 386xfs_efd_item_unpin(
 387        struct xfs_log_item     *lip,
 388        int                     remove)
 389{
 390}
 391
 392/*
 393 * There isn't much you can do to push on an efd item.  It is simply stuck
 394 * waiting for the log to be flushed to disk.
 395 */
 396STATIC uint
 397xfs_efd_item_push(
 398        struct xfs_log_item     *lip,
 399        struct list_head        *buffer_list)
 400{
 401        return XFS_ITEM_PINNED;
 402}
 403
 404STATIC void
 405xfs_efd_item_unlock(
 406        struct xfs_log_item     *lip)
 407{
 408        if (lip->li_flags & XFS_LI_ABORTED)
 409                xfs_efd_item_free(EFD_ITEM(lip));
 410}
 411
 412/*
 413 * When the efd item is committed to disk, all we need to do
 414 * is delete our reference to our partner efi item and then
 415 * free ourselves.  Since we're freeing ourselves we must
 416 * return -1 to keep the transaction code from further referencing
 417 * this item.
 418 */
 419STATIC xfs_lsn_t
 420xfs_efd_item_committed(
 421        struct xfs_log_item     *lip,
 422        xfs_lsn_t               lsn)
 423{
 424        struct xfs_efd_log_item *efdp = EFD_ITEM(lip);
 425
 426        /*
 427         * If we got a log I/O error, it's always the case that the LR with the
 428         * EFI got unpinned and freed before the EFD got aborted.
 429         */
 430        if (!(lip->li_flags & XFS_LI_ABORTED))
 431                xfs_efi_release(efdp->efd_efip, efdp->efd_format.efd_nextents);
 432
 433        xfs_efd_item_free(efdp);
 434        return (xfs_lsn_t)-1;
 435}
 436
 437/*
 438 * The EFD dependency tracking op doesn't do squat.  It can't because
 439 * it doesn't know where the free extent is coming from.  The dependency
 440 * tracking has to be handled by the "enclosing" metadata object.  For
 441 * example, for inodes, the inode is locked throughout the extent freeing
 442 * so the dependency should be recorded there.
 443 */
 444STATIC void
 445xfs_efd_item_committing(
 446        struct xfs_log_item     *lip,
 447        xfs_lsn_t               lsn)
 448{
 449}
 450
 451/*
 452 * This is the ops vector shared by all efd log items.
 453 */
 454static const struct xfs_item_ops xfs_efd_item_ops = {
 455        .iop_size       = xfs_efd_item_size,
 456        .iop_format     = xfs_efd_item_format,
 457        .iop_pin        = xfs_efd_item_pin,
 458        .iop_unpin      = xfs_efd_item_unpin,
 459        .iop_unlock     = xfs_efd_item_unlock,
 460        .iop_committed  = xfs_efd_item_committed,
 461        .iop_push       = xfs_efd_item_push,
 462        .iop_committing = xfs_efd_item_committing
 463};
 464
 465/*
 466 * Allocate and initialize an efd item with the given number of extents.
 467 */
 468struct xfs_efd_log_item *
 469xfs_efd_init(
 470        struct xfs_mount        *mp,
 471        struct xfs_efi_log_item *efip,
 472        uint                    nextents)
 473
 474{
 475        struct xfs_efd_log_item *efdp;
 476        uint                    size;
 477
 478        ASSERT(nextents > 0);
 479        if (nextents > XFS_EFD_MAX_FAST_EXTENTS) {
 480                size = (uint)(sizeof(xfs_efd_log_item_t) +
 481                        ((nextents - 1) * sizeof(xfs_extent_t)));
 482                efdp = kmem_zalloc(size, KM_SLEEP);
 483        } else {
 484                efdp = kmem_zone_zalloc(xfs_efd_zone, KM_SLEEP);
 485        }
 486
 487        xfs_log_item_init(mp, &efdp->efd_item, XFS_LI_EFD, &xfs_efd_item_ops);
 488        efdp->efd_efip = efip;
 489        efdp->efd_format.efd_nextents = nextents;
 490        efdp->efd_format.efd_efi_id = efip->efi_format.efi_id;
 491
 492        return efdp;
 493}
 494
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