fs/xfs/xfs_trans_extfree.c

   1 /*
   2  * Copyright (c) 2000,2005 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_shared.h"
  21 #include "xfs_format.h"
  22 #include "xfs_log_format.h"
  23 #include "xfs_trans_resv.h"
  24 #include "xfs_mount.h"
  25 #include "xfs_trans.h"
  26 #include "xfs_trans_priv.h"
  27 #include "xfs_extfree_item.h"
  28 #include "xfs_alloc.h"
  29
  30 /*
  31  * This routine is called to allocate an "extent free intention"
  32  * log item that will hold nextents worth of extents.  The
  33  * caller must use all nextents extents, because we are not
  34  * flexible about this at all.
  35  */
  36 xfs_efi_log_item_t *
  37 xfs_trans_get_efi(xfs_trans_t   *tp,
  38                   uint          nextents)
  39 {
  40         xfs_efi_log_item_t      *efip;
  41
  42         ASSERT(tp != NULL);
  43         ASSERT(nextents > 0);
  44
  45         efip = xfs_efi_init(tp->t_mountp, nextents);
  46         ASSERT(efip != NULL);
  47
  48         /*
  49          * Get a log_item_desc to point at the new item.
  50          */
  51         xfs_trans_add_item(tp, &efip->efi_item);
  52         return efip;
  53 }
  54
  55 /*
  56  * This routine is called to indicate that the described
  57  * extent is to be logged as needing to be freed.  It should
  58  * be called once for each extent to be freed.
  59  */
  60 void
  61 xfs_trans_log_efi_extent(xfs_trans_t            *tp,
  62                          xfs_efi_log_item_t     *efip,
  63                          xfs_fsblock_t          start_block,
  64                          xfs_extlen_t           ext_len)
  65 {
  66         uint                    next_extent;
  67         xfs_extent_t            *extp;
  68
  69         tp->t_flags |= XFS_TRANS_DIRTY;
  70         efip->efi_item.li_desc->lid_flags |= XFS_LID_DIRTY;
  71
  72         /*
  73          * atomic_inc_return gives us the value after the increment;
  74          * we want to use it as an array index so we need to subtract 1 from
  75          * it.
  76          */
  77         next_extent = atomic_inc_return(&efip->efi_next_extent) - 1;
  78         ASSERT(next_extent < efip->efi_format.efi_nextents);
  79         extp = &(efip->efi_format.efi_extents[next_extent]);
  80         extp->ext_start = start_block;
  81         extp->ext_len = ext_len;
  82 }
  83
  84
  85 /*
  86  * This routine is called to allocate an "extent free done"
  87  * log item that will hold nextents worth of extents.  The
  88  * caller must use all nextents extents, because we are not
  89  * flexible about this at all.
  90  */
  91 xfs_efd_log_item_t *
  92 xfs_trans_get_efd(xfs_trans_t           *tp,
  93                   xfs_efi_log_item_t    *efip,
  94                   uint                  nextents)
  95 {
  96         xfs_efd_log_item_t      *efdp;
  97
  98         ASSERT(tp != NULL);
  99         ASSERT(nextents > 0);
 100
 101         efdp = xfs_efd_init(tp->t_mountp, efip, nextents);
 102         ASSERT(efdp != NULL);
 103
 104         /*
 105          * Get a log_item_desc to point at the new item.
 106          */
 107         xfs_trans_add_item(tp, &efdp->efd_item);
 108         return efdp;
 109 }
 110
 111 /*
 112  * Free an extent and log it to the EFD. Note that the transaction is marked
 113  * dirty regardless of whether the extent free succeeds or fails to support the
 114  * EFI/EFD lifecycle rules.
 115  */
 116 int
 117 xfs_trans_free_extent(
 118         struct xfs_trans        *tp,
 119         struct xfs_efd_log_item *efdp,
 120         xfs_fsblock_t           start_block,
 121         xfs_extlen_t            ext_len)
 122 {
 123         uint                    next_extent;
 124         struct xfs_extent       *extp;
 125         int                     error;
 126
 127         error = xfs_free_extent(tp, start_block, ext_len);
 128
 129         /*
 130          * Mark the transaction dirty, even on error. This ensures the
 131          * transaction is aborted, which:
 132          *
 133          * 1.) releases the EFI and frees the EFD
 134          * 2.) shuts down the filesystem
 135          */
 136         tp->t_flags |= XFS_TRANS_DIRTY;
 137         efdp->efd_item.li_desc->lid_flags |= XFS_LID_DIRTY;
 138
 139         next_extent = efdp->efd_next_extent;
 140         ASSERT(next_extent < efdp->efd_format.efd_nextents);
 141         extp = &(efdp->efd_format.efd_extents[next_extent]);
 142         extp->ext_start = start_block;
 143         extp->ext_len = ext_len;
 144         efdp->efd_next_extent++;
 145
 146         return error;
 147 }