Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / fs / xfs / xfs_bmap_util.c
diff --git a/kernel/fs/xfs/xfs_bmap_util.c b/kernel/fs/xfs/xfs_bmap_util.c
new file mode 100644 (file)
index 0000000..a52bbd3
--- /dev/null
@@ -0,0 +1,1920 @@
+/*
+ * Copyright (c) 2000-2006 Silicon Graphics, Inc.
+ * Copyright (c) 2012 Red Hat, Inc.
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_log_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_bit.h"
+#include "xfs_mount.h"
+#include "xfs_da_format.h"
+#include "xfs_inode.h"
+#include "xfs_btree.h"
+#include "xfs_trans.h"
+#include "xfs_extfree_item.h"
+#include "xfs_alloc.h"
+#include "xfs_bmap.h"
+#include "xfs_bmap_util.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_rtalloc.h"
+#include "xfs_error.h"
+#include "xfs_quota.h"
+#include "xfs_trans_space.h"
+#include "xfs_trace.h"
+#include "xfs_icache.h"
+#include "xfs_log.h"
+
+/* Kernel only BMAP related definitions and functions */
+
+/*
+ * Convert the given file system block to a disk block.  We have to treat it
+ * differently based on whether the file is a real time file or not, because the
+ * bmap code does.
+ */
+xfs_daddr_t
+xfs_fsb_to_db(struct xfs_inode *ip, xfs_fsblock_t fsb)
+{
+       return (XFS_IS_REALTIME_INODE(ip) ? \
+                (xfs_daddr_t)XFS_FSB_TO_BB((ip)->i_mount, (fsb)) : \
+                XFS_FSB_TO_DADDR((ip)->i_mount, (fsb)));
+}
+
+/*
+ * Routine to be called at transaction's end by xfs_bmapi, xfs_bunmapi
+ * caller.  Frees all the extents that need freeing, which must be done
+ * last due to locking considerations.  We never free any extents in
+ * the first transaction.
+ *
+ * Return 1 if the given transaction was committed and a new one
+ * started, and 0 otherwise in the committed parameter.
+ */
+int                                            /* error */
+xfs_bmap_finish(
+       xfs_trans_t             **tp,           /* transaction pointer addr */
+       xfs_bmap_free_t         *flist,         /* i/o: list extents to free */
+       int                     *committed)     /* xact committed or not */
+{
+       xfs_efd_log_item_t      *efd;           /* extent free data */
+       xfs_efi_log_item_t      *efi;           /* extent free intention */
+       int                     error;          /* error return value */
+       xfs_bmap_free_item_t    *free;          /* free extent item */
+       struct xfs_trans_res    tres;           /* new log reservation */
+       xfs_mount_t             *mp;            /* filesystem mount structure */
+       xfs_bmap_free_item_t    *next;          /* next item on free list */
+       xfs_trans_t             *ntp;           /* new transaction pointer */
+
+       ASSERT((*tp)->t_flags & XFS_TRANS_PERM_LOG_RES);
+       if (flist->xbf_count == 0) {
+               *committed = 0;
+               return 0;
+       }
+       ntp = *tp;
+       efi = xfs_trans_get_efi(ntp, flist->xbf_count);
+       for (free = flist->xbf_first; free; free = free->xbfi_next)
+               xfs_trans_log_efi_extent(ntp, efi, free->xbfi_startblock,
+                       free->xbfi_blockcount);
+
+       tres.tr_logres = ntp->t_log_res;
+       tres.tr_logcount = ntp->t_log_count;
+       tres.tr_logflags = XFS_TRANS_PERM_LOG_RES;
+       ntp = xfs_trans_dup(*tp);
+       error = xfs_trans_commit(*tp, 0);
+       *tp = ntp;
+       *committed = 1;
+       /*
+        * We have a new transaction, so we should return committed=1,
+        * even though we're returning an error.
+        */
+       if (error)
+               return error;
+
+       /*
+        * transaction commit worked ok so we can drop the extra ticket
+        * reference that we gained in xfs_trans_dup()
+        */
+       xfs_log_ticket_put(ntp->t_ticket);
+
+       error = xfs_trans_reserve(ntp, &tres, 0, 0);
+       if (error)
+               return error;
+       efd = xfs_trans_get_efd(ntp, efi, flist->xbf_count);
+       for (free = flist->xbf_first; free != NULL; free = next) {
+               next = free->xbfi_next;
+               if ((error = xfs_free_extent(ntp, free->xbfi_startblock,
+                               free->xbfi_blockcount))) {
+                       /*
+                        * The bmap free list will be cleaned up at a
+                        * higher level.  The EFI will be canceled when
+                        * this transaction is aborted.
+                        * Need to force shutdown here to make sure it
+                        * happens, since this transaction may not be
+                        * dirty yet.
+                        */
+                       mp = ntp->t_mountp;
+                       if (!XFS_FORCED_SHUTDOWN(mp))
+                               xfs_force_shutdown(mp,
+                                                  (error == -EFSCORRUPTED) ?
+                                                  SHUTDOWN_CORRUPT_INCORE :
+                                                  SHUTDOWN_META_IO_ERROR);
+                       return error;
+               }
+               xfs_trans_log_efd_extent(ntp, efd, free->xbfi_startblock,
+                       free->xbfi_blockcount);
+               xfs_bmap_del_free(flist, NULL, free);
+       }
+       return 0;
+}
+
+int
+xfs_bmap_rtalloc(
+       struct xfs_bmalloca     *ap)    /* bmap alloc argument struct */
+{
+       xfs_alloctype_t atype = 0;      /* type for allocation routines */
+       int             error;          /* error return value */
+       xfs_mount_t     *mp;            /* mount point structure */
+       xfs_extlen_t    prod = 0;       /* product factor for allocators */
+       xfs_extlen_t    ralen = 0;      /* realtime allocation length */
+       xfs_extlen_t    align;          /* minimum allocation alignment */
+       xfs_rtblock_t   rtb;
+
+       mp = ap->ip->i_mount;
+       align = xfs_get_extsz_hint(ap->ip);
+       prod = align / mp->m_sb.sb_rextsize;
+       error = xfs_bmap_extsize_align(mp, &ap->got, &ap->prev,
+                                       align, 1, ap->eof, 0,
+                                       ap->conv, &ap->offset, &ap->length);
+       if (error)
+               return error;
+       ASSERT(ap->length);
+       ASSERT(ap->length % mp->m_sb.sb_rextsize == 0);
+
+       /*
+        * If the offset & length are not perfectly aligned
+        * then kill prod, it will just get us in trouble.
+        */
+       if (do_mod(ap->offset, align) || ap->length % align)
+               prod = 1;
+       /*
+        * Set ralen to be the actual requested length in rtextents.
+        */
+       ralen = ap->length / mp->m_sb.sb_rextsize;
+       /*
+        * If the old value was close enough to MAXEXTLEN that
+        * we rounded up to it, cut it back so it's valid again.
+        * Note that if it's a really large request (bigger than
+        * MAXEXTLEN), we don't hear about that number, and can't
+        * adjust the starting point to match it.
+        */
+       if (ralen * mp->m_sb.sb_rextsize >= MAXEXTLEN)
+               ralen = MAXEXTLEN / mp->m_sb.sb_rextsize;
+
+       /*
+        * Lock out other modifications to the RT bitmap inode.
+        */
+       xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL);
+       xfs_trans_ijoin(ap->tp, mp->m_rbmip, XFS_ILOCK_EXCL);
+
+       /*
+        * If it's an allocation to an empty file at offset 0,
+        * pick an extent that will space things out in the rt area.
+        */
+       if (ap->eof && ap->offset == 0) {
+               xfs_rtblock_t uninitialized_var(rtx); /* realtime extent no */
+
+               error = xfs_rtpick_extent(mp, ap->tp, ralen, &rtx);
+               if (error)
+                       return error;
+               ap->blkno = rtx * mp->m_sb.sb_rextsize;
+       } else {
+               ap->blkno = 0;
+       }
+
+       xfs_bmap_adjacent(ap);
+
+       /*
+        * Realtime allocation, done through xfs_rtallocate_extent.
+        */
+       atype = ap->blkno == 0 ?  XFS_ALLOCTYPE_ANY_AG : XFS_ALLOCTYPE_NEAR_BNO;
+       do_div(ap->blkno, mp->m_sb.sb_rextsize);
+       rtb = ap->blkno;
+       ap->length = ralen;
+       if ((error = xfs_rtallocate_extent(ap->tp, ap->blkno, 1, ap->length,
+                               &ralen, atype, ap->wasdel, prod, &rtb)))
+               return error;
+       if (rtb == NULLFSBLOCK && prod > 1 &&
+           (error = xfs_rtallocate_extent(ap->tp, ap->blkno, 1,
+                                          ap->length, &ralen, atype,
+                                          ap->wasdel, 1, &rtb)))
+               return error;
+       ap->blkno = rtb;
+       if (ap->blkno != NULLFSBLOCK) {
+               ap->blkno *= mp->m_sb.sb_rextsize;
+               ralen *= mp->m_sb.sb_rextsize;
+               ap->length = ralen;
+               ap->ip->i_d.di_nblocks += ralen;
+               xfs_trans_log_inode(ap->tp, ap->ip, XFS_ILOG_CORE);
+               if (ap->wasdel)
+                       ap->ip->i_delayed_blks -= ralen;
+               /*
+                * Adjust the disk quota also. This was reserved
+                * earlier.
+                */
+               xfs_trans_mod_dquot_byino(ap->tp, ap->ip,
+                       ap->wasdel ? XFS_TRANS_DQ_DELRTBCOUNT :
+                                       XFS_TRANS_DQ_RTBCOUNT, (long) ralen);
+       } else {
+               ap->length = 0;
+       }
+       return 0;
+}
+
+/*
+ * Check if the endoff is outside the last extent. If so the caller will grow
+ * the allocation to a stripe unit boundary.  All offsets are considered outside
+ * the end of file for an empty fork, so 1 is returned in *eof in that case.
+ */
+int
+xfs_bmap_eof(
+       struct xfs_inode        *ip,
+       xfs_fileoff_t           endoff,
+       int                     whichfork,
+       int                     *eof)
+{
+       struct xfs_bmbt_irec    rec;
+       int                     error;
+
+       error = xfs_bmap_last_extent(NULL, ip, whichfork, &rec, eof);
+       if (error || *eof)
+               return error;
+
+       *eof = endoff >= rec.br_startoff + rec.br_blockcount;
+       return 0;
+}
+
+/*
+ * Extent tree block counting routines.
+ */
+
+/*
+ * Count leaf blocks given a range of extent records.
+ */
+STATIC void
+xfs_bmap_count_leaves(
+       xfs_ifork_t             *ifp,
+       xfs_extnum_t            idx,
+       int                     numrecs,
+       int                     *count)
+{
+       int             b;
+
+       for (b = 0; b < numrecs; b++) {
+               xfs_bmbt_rec_host_t *frp = xfs_iext_get_ext(ifp, idx + b);
+               *count += xfs_bmbt_get_blockcount(frp);
+       }
+}
+
+/*
+ * Count leaf blocks given a range of extent records originally
+ * in btree format.
+ */
+STATIC void
+xfs_bmap_disk_count_leaves(
+       struct xfs_mount        *mp,
+       struct xfs_btree_block  *block,
+       int                     numrecs,
+       int                     *count)
+{
+       int             b;
+       xfs_bmbt_rec_t  *frp;
+
+       for (b = 1; b <= numrecs; b++) {
+               frp = XFS_BMBT_REC_ADDR(mp, block, b);
+               *count += xfs_bmbt_disk_get_blockcount(frp);
+       }
+}
+
+/*
+ * Recursively walks each level of a btree
+ * to count total fsblocks in use.
+ */
+STATIC int                                     /* error */
+xfs_bmap_count_tree(
+       xfs_mount_t     *mp,            /* file system mount point */
+       xfs_trans_t     *tp,            /* transaction pointer */
+       xfs_ifork_t     *ifp,           /* inode fork pointer */
+       xfs_fsblock_t   blockno,        /* file system block number */
+       int             levelin,        /* level in btree */
+       int             *count)         /* Count of blocks */
+{
+       int                     error;
+       xfs_buf_t               *bp, *nbp;
+       int                     level = levelin;
+       __be64                  *pp;
+       xfs_fsblock_t           bno = blockno;
+       xfs_fsblock_t           nextbno;
+       struct xfs_btree_block  *block, *nextblock;
+       int                     numrecs;
+
+       error = xfs_btree_read_bufl(mp, tp, bno, 0, &bp, XFS_BMAP_BTREE_REF,
+                                               &xfs_bmbt_buf_ops);
+       if (error)
+               return error;
+       *count += 1;
+       block = XFS_BUF_TO_BLOCK(bp);
+
+       if (--level) {
+               /* Not at node above leaves, count this level of nodes */
+               nextbno = be64_to_cpu(block->bb_u.l.bb_rightsib);
+               while (nextbno != NULLFSBLOCK) {
+                       error = xfs_btree_read_bufl(mp, tp, nextbno, 0, &nbp,
+                                               XFS_BMAP_BTREE_REF,
+                                               &xfs_bmbt_buf_ops);
+                       if (error)
+                               return error;
+                       *count += 1;
+                       nextblock = XFS_BUF_TO_BLOCK(nbp);
+                       nextbno = be64_to_cpu(nextblock->bb_u.l.bb_rightsib);
+                       xfs_trans_brelse(tp, nbp);
+               }
+
+               /* Dive to the next level */
+               pp = XFS_BMBT_PTR_ADDR(mp, block, 1, mp->m_bmap_dmxr[1]);
+               bno = be64_to_cpu(*pp);
+               if (unlikely((error =
+                    xfs_bmap_count_tree(mp, tp, ifp, bno, level, count)) < 0)) {
+                       xfs_trans_brelse(tp, bp);
+                       XFS_ERROR_REPORT("xfs_bmap_count_tree(1)",
+                                        XFS_ERRLEVEL_LOW, mp);
+                       return -EFSCORRUPTED;
+               }
+               xfs_trans_brelse(tp, bp);
+       } else {
+               /* count all level 1 nodes and their leaves */
+               for (;;) {
+                       nextbno = be64_to_cpu(block->bb_u.l.bb_rightsib);
+                       numrecs = be16_to_cpu(block->bb_numrecs);
+                       xfs_bmap_disk_count_leaves(mp, block, numrecs, count);
+                       xfs_trans_brelse(tp, bp);
+                       if (nextbno == NULLFSBLOCK)
+                               break;
+                       bno = nextbno;
+                       error = xfs_btree_read_bufl(mp, tp, bno, 0, &bp,
+                                               XFS_BMAP_BTREE_REF,
+                                               &xfs_bmbt_buf_ops);
+                       if (error)
+                               return error;
+                       *count += 1;
+                       block = XFS_BUF_TO_BLOCK(bp);
+               }
+       }
+       return 0;
+}
+
+/*
+ * Count fsblocks of the given fork.
+ */
+int                                            /* error */
+xfs_bmap_count_blocks(
+       xfs_trans_t             *tp,            /* transaction pointer */
+       xfs_inode_t             *ip,            /* incore inode */
+       int                     whichfork,      /* data or attr fork */
+       int                     *count)         /* out: count of blocks */
+{
+       struct xfs_btree_block  *block; /* current btree block */
+       xfs_fsblock_t           bno;    /* block # of "block" */
+       xfs_ifork_t             *ifp;   /* fork structure */
+       int                     level;  /* btree level, for checking */
+       xfs_mount_t             *mp;    /* file system mount structure */
+       __be64                  *pp;    /* pointer to block address */
+
+       bno = NULLFSBLOCK;
+       mp = ip->i_mount;
+       ifp = XFS_IFORK_PTR(ip, whichfork);
+       if ( XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_EXTENTS ) {
+               xfs_bmap_count_leaves(ifp, 0,
+                       ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t),
+                       count);
+               return 0;
+       }
+
+       /*
+        * Root level must use BMAP_BROOT_PTR_ADDR macro to get ptr out.
+        */
+       block = ifp->if_broot;
+       level = be16_to_cpu(block->bb_level);
+       ASSERT(level > 0);
+       pp = XFS_BMAP_BROOT_PTR_ADDR(mp, block, 1, ifp->if_broot_bytes);
+       bno = be64_to_cpu(*pp);
+       ASSERT(bno != NULLFSBLOCK);
+       ASSERT(XFS_FSB_TO_AGNO(mp, bno) < mp->m_sb.sb_agcount);
+       ASSERT(XFS_FSB_TO_AGBNO(mp, bno) < mp->m_sb.sb_agblocks);
+
+       if (unlikely(xfs_bmap_count_tree(mp, tp, ifp, bno, level, count) < 0)) {
+               XFS_ERROR_REPORT("xfs_bmap_count_blocks(2)", XFS_ERRLEVEL_LOW,
+                                mp);
+               return -EFSCORRUPTED;
+       }
+
+       return 0;
+}
+
+/*
+ * returns 1 for success, 0 if we failed to map the extent.
+ */
+STATIC int
+xfs_getbmapx_fix_eof_hole(
+       xfs_inode_t             *ip,            /* xfs incore inode pointer */
+       struct getbmapx         *out,           /* output structure */
+       int                     prealloced,     /* this is a file with
+                                                * preallocated data space */
+       __int64_t               end,            /* last block requested */
+       xfs_fsblock_t           startblock)
+{
+       __int64_t               fixlen;
+       xfs_mount_t             *mp;            /* file system mount point */
+       xfs_ifork_t             *ifp;           /* inode fork pointer */
+       xfs_extnum_t            lastx;          /* last extent pointer */
+       xfs_fileoff_t           fileblock;
+
+       if (startblock == HOLESTARTBLOCK) {
+               mp = ip->i_mount;
+               out->bmv_block = -1;
+               fixlen = XFS_FSB_TO_BB(mp, XFS_B_TO_FSB(mp, XFS_ISIZE(ip)));
+               fixlen -= out->bmv_offset;
+               if (prealloced && out->bmv_offset + out->bmv_length == end) {
+                       /* Came to hole at EOF. Trim it. */
+                       if (fixlen <= 0)
+                               return 0;
+                       out->bmv_length = fixlen;
+               }
+       } else {
+               if (startblock == DELAYSTARTBLOCK)
+                       out->bmv_block = -2;
+               else
+                       out->bmv_block = xfs_fsb_to_db(ip, startblock);
+               fileblock = XFS_BB_TO_FSB(ip->i_mount, out->bmv_offset);
+               ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
+               if (xfs_iext_bno_to_ext(ifp, fileblock, &lastx) &&
+                  (lastx == (ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t))-1))
+                       out->bmv_oflags |= BMV_OF_LAST;
+       }
+
+       return 1;
+}
+
+/*
+ * Get inode's extents as described in bmv, and format for output.
+ * Calls formatter to fill the user's buffer until all extents
+ * are mapped, until the passed-in bmv->bmv_count slots have
+ * been filled, or until the formatter short-circuits the loop,
+ * if it is tracking filled-in extents on its own.
+ */
+int                                            /* error code */
+xfs_getbmap(
+       xfs_inode_t             *ip,
+       struct getbmapx         *bmv,           /* user bmap structure */
+       xfs_bmap_format_t       formatter,      /* format to user */
+       void                    *arg)           /* formatter arg */
+{
+       __int64_t               bmvend;         /* last block requested */
+       int                     error = 0;      /* return value */
+       __int64_t               fixlen;         /* length for -1 case */
+       int                     i;              /* extent number */
+       int                     lock;           /* lock state */
+       xfs_bmbt_irec_t         *map;           /* buffer for user's data */
+       xfs_mount_t             *mp;            /* file system mount point */
+       int                     nex;            /* # of user extents can do */
+       int                     nexleft;        /* # of user extents left */
+       int                     subnex;         /* # of bmapi's can do */
+       int                     nmap;           /* number of map entries */
+       struct getbmapx         *out;           /* output structure */
+       int                     whichfork;      /* data or attr fork */
+       int                     prealloced;     /* this is a file with
+                                                * preallocated data space */
+       int                     iflags;         /* interface flags */
+       int                     bmapi_flags;    /* flags for xfs_bmapi */
+       int                     cur_ext = 0;
+
+       mp = ip->i_mount;
+       iflags = bmv->bmv_iflags;
+       whichfork = iflags & BMV_IF_ATTRFORK ? XFS_ATTR_FORK : XFS_DATA_FORK;
+
+       if (whichfork == XFS_ATTR_FORK) {
+               if (XFS_IFORK_Q(ip)) {
+                       if (ip->i_d.di_aformat != XFS_DINODE_FMT_EXTENTS &&
+                           ip->i_d.di_aformat != XFS_DINODE_FMT_BTREE &&
+                           ip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL)
+                               return -EINVAL;
+               } else if (unlikely(
+                          ip->i_d.di_aformat != 0 &&
+                          ip->i_d.di_aformat != XFS_DINODE_FMT_EXTENTS)) {
+                       XFS_ERROR_REPORT("xfs_getbmap", XFS_ERRLEVEL_LOW,
+                                        ip->i_mount);
+                       return -EFSCORRUPTED;
+               }
+
+               prealloced = 0;
+               fixlen = 1LL << 32;
+       } else {
+               if (ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS &&
+                   ip->i_d.di_format != XFS_DINODE_FMT_BTREE &&
+                   ip->i_d.di_format != XFS_DINODE_FMT_LOCAL)
+                       return -EINVAL;
+
+               if (xfs_get_extsz_hint(ip) ||
+                   ip->i_d.di_flags & (XFS_DIFLAG_PREALLOC|XFS_DIFLAG_APPEND)){
+                       prealloced = 1;
+                       fixlen = mp->m_super->s_maxbytes;
+               } else {
+                       prealloced = 0;
+                       fixlen = XFS_ISIZE(ip);
+               }
+       }
+
+       if (bmv->bmv_length == -1) {
+               fixlen = XFS_FSB_TO_BB(mp, XFS_B_TO_FSB(mp, fixlen));
+               bmv->bmv_length =
+                       max_t(__int64_t, fixlen - bmv->bmv_offset, 0);
+       } else if (bmv->bmv_length == 0) {
+               bmv->bmv_entries = 0;
+               return 0;
+       } else if (bmv->bmv_length < 0) {
+               return -EINVAL;
+       }
+
+       nex = bmv->bmv_count - 1;
+       if (nex <= 0)
+               return -EINVAL;
+       bmvend = bmv->bmv_offset + bmv->bmv_length;
+
+
+       if (bmv->bmv_count > ULONG_MAX / sizeof(struct getbmapx))
+               return -ENOMEM;
+       out = kmem_zalloc_large(bmv->bmv_count * sizeof(struct getbmapx), 0);
+       if (!out)
+               return -ENOMEM;
+
+       xfs_ilock(ip, XFS_IOLOCK_SHARED);
+       if (whichfork == XFS_DATA_FORK) {
+               if (!(iflags & BMV_IF_DELALLOC) &&
+                   (ip->i_delayed_blks || XFS_ISIZE(ip) > ip->i_d.di_size)) {
+                       error = filemap_write_and_wait(VFS_I(ip)->i_mapping);
+                       if (error)
+                               goto out_unlock_iolock;
+
+                       /*
+                        * Even after flushing the inode, there can still be
+                        * delalloc blocks on the inode beyond EOF due to
+                        * speculative preallocation.  These are not removed
+                        * until the release function is called or the inode
+                        * is inactivated.  Hence we cannot assert here that
+                        * ip->i_delayed_blks == 0.
+                        */
+               }
+
+               lock = xfs_ilock_data_map_shared(ip);
+       } else {
+               lock = xfs_ilock_attr_map_shared(ip);
+       }
+
+       /*
+        * Don't let nex be bigger than the number of extents
+        * we can have assuming alternating holes and real extents.
+        */
+       if (nex > XFS_IFORK_NEXTENTS(ip, whichfork) * 2 + 1)
+               nex = XFS_IFORK_NEXTENTS(ip, whichfork) * 2 + 1;
+
+       bmapi_flags = xfs_bmapi_aflag(whichfork);
+       if (!(iflags & BMV_IF_PREALLOC))
+               bmapi_flags |= XFS_BMAPI_IGSTATE;
+
+       /*
+        * Allocate enough space to handle "subnex" maps at a time.
+        */
+       error = -ENOMEM;
+       subnex = 16;
+       map = kmem_alloc(subnex * sizeof(*map), KM_MAYFAIL | KM_NOFS);
+       if (!map)
+               goto out_unlock_ilock;
+
+       bmv->bmv_entries = 0;
+
+       if (XFS_IFORK_NEXTENTS(ip, whichfork) == 0 &&
+           (whichfork == XFS_ATTR_FORK || !(iflags & BMV_IF_DELALLOC))) {
+               error = 0;
+               goto out_free_map;
+       }
+
+       nexleft = nex;
+
+       do {
+               nmap = (nexleft > subnex) ? subnex : nexleft;
+               error = xfs_bmapi_read(ip, XFS_BB_TO_FSBT(mp, bmv->bmv_offset),
+                                      XFS_BB_TO_FSB(mp, bmv->bmv_length),
+                                      map, &nmap, bmapi_flags);
+               if (error)
+                       goto out_free_map;
+               ASSERT(nmap <= subnex);
+
+               for (i = 0; i < nmap && nexleft && bmv->bmv_length; i++) {
+                       out[cur_ext].bmv_oflags = 0;
+                       if (map[i].br_state == XFS_EXT_UNWRITTEN)
+                               out[cur_ext].bmv_oflags |= BMV_OF_PREALLOC;
+                       else if (map[i].br_startblock == DELAYSTARTBLOCK)
+                               out[cur_ext].bmv_oflags |= BMV_OF_DELALLOC;
+                       out[cur_ext].bmv_offset =
+                               XFS_FSB_TO_BB(mp, map[i].br_startoff);
+                       out[cur_ext].bmv_length =
+                               XFS_FSB_TO_BB(mp, map[i].br_blockcount);
+                       out[cur_ext].bmv_unused1 = 0;
+                       out[cur_ext].bmv_unused2 = 0;
+
+                       /*
+                        * delayed allocation extents that start beyond EOF can
+                        * occur due to speculative EOF allocation when the
+                        * delalloc extent is larger than the largest freespace
+                        * extent at conversion time. These extents cannot be
+                        * converted by data writeback, so can exist here even
+                        * if we are not supposed to be finding delalloc
+                        * extents.
+                        */
+                       if (map[i].br_startblock == DELAYSTARTBLOCK &&
+                           map[i].br_startoff <= XFS_B_TO_FSB(mp, XFS_ISIZE(ip)))
+                               ASSERT((iflags & BMV_IF_DELALLOC) != 0);
+
+                        if (map[i].br_startblock == HOLESTARTBLOCK &&
+                           whichfork == XFS_ATTR_FORK) {
+                               /* came to the end of attribute fork */
+                               out[cur_ext].bmv_oflags |= BMV_OF_LAST;
+                               goto out_free_map;
+                       }
+
+                       if (!xfs_getbmapx_fix_eof_hole(ip, &out[cur_ext],
+                                       prealloced, bmvend,
+                                       map[i].br_startblock))
+                               goto out_free_map;
+
+                       bmv->bmv_offset =
+                               out[cur_ext].bmv_offset +
+                               out[cur_ext].bmv_length;
+                       bmv->bmv_length =
+                               max_t(__int64_t, 0, bmvend - bmv->bmv_offset);
+
+                       /*
+                        * In case we don't want to return the hole,
+                        * don't increase cur_ext so that we can reuse
+                        * it in the next loop.
+                        */
+                       if ((iflags & BMV_IF_NO_HOLES) &&
+                           map[i].br_startblock == HOLESTARTBLOCK) {
+                               memset(&out[cur_ext], 0, sizeof(out[cur_ext]));
+                               continue;
+                       }
+
+                       nexleft--;
+                       bmv->bmv_entries++;
+                       cur_ext++;
+               }
+       } while (nmap && nexleft && bmv->bmv_length);
+
+ out_free_map:
+       kmem_free(map);
+ out_unlock_ilock:
+       xfs_iunlock(ip, lock);
+ out_unlock_iolock:
+       xfs_iunlock(ip, XFS_IOLOCK_SHARED);
+
+       for (i = 0; i < cur_ext; i++) {
+               int full = 0;   /* user array is full */
+
+               /* format results & advance arg */
+               error = formatter(&arg, &out[i], &full);
+               if (error || full)
+                       break;
+       }
+
+       kmem_free(out);
+       return error;
+}
+
+/*
+ * dead simple method of punching delalyed allocation blocks from a range in
+ * the inode. Walks a block at a time so will be slow, but is only executed in
+ * rare error cases so the overhead is not critical. This will always punch out
+ * both the start and end blocks, even if the ranges only partially overlap
+ * them, so it is up to the caller to ensure that partial blocks are not
+ * passed in.
+ */
+int
+xfs_bmap_punch_delalloc_range(
+       struct xfs_inode        *ip,
+       xfs_fileoff_t           start_fsb,
+       xfs_fileoff_t           length)
+{
+       xfs_fileoff_t           remaining = length;
+       int                     error = 0;
+
+       ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
+
+       do {
+               int             done;
+               xfs_bmbt_irec_t imap;
+               int             nimaps = 1;
+               xfs_fsblock_t   firstblock;
+               xfs_bmap_free_t flist;
+
+               /*
+                * Map the range first and check that it is a delalloc extent
+                * before trying to unmap the range. Otherwise we will be
+                * trying to remove a real extent (which requires a
+                * transaction) or a hole, which is probably a bad idea...
+                */
+               error = xfs_bmapi_read(ip, start_fsb, 1, &imap, &nimaps,
+                                      XFS_BMAPI_ENTIRE);
+
+               if (error) {
+                       /* something screwed, just bail */
+                       if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) {
+                               xfs_alert(ip->i_mount,
+                       "Failed delalloc mapping lookup ino %lld fsb %lld.",
+                                               ip->i_ino, start_fsb);
+                       }
+                       break;
+               }
+               if (!nimaps) {
+                       /* nothing there */
+                       goto next_block;
+               }
+               if (imap.br_startblock != DELAYSTARTBLOCK) {
+                       /* been converted, ignore */
+                       goto next_block;
+               }
+               WARN_ON(imap.br_blockcount == 0);
+
+               /*
+                * Note: while we initialise the firstblock/flist pair, they
+                * should never be used because blocks should never be
+                * allocated or freed for a delalloc extent and hence we need
+                * don't cancel or finish them after the xfs_bunmapi() call.
+                */
+               xfs_bmap_init(&flist, &firstblock);
+               error = xfs_bunmapi(NULL, ip, start_fsb, 1, 0, 1, &firstblock,
+                                       &flist, &done);
+               if (error)
+                       break;
+
+               ASSERT(!flist.xbf_count && !flist.xbf_first);
+next_block:
+               start_fsb++;
+               remaining--;
+       } while(remaining > 0);
+
+       return error;
+}
+
+/*
+ * Test whether it is appropriate to check an inode for and free post EOF
+ * blocks. The 'force' parameter determines whether we should also consider
+ * regular files that are marked preallocated or append-only.
+ */
+bool
+xfs_can_free_eofblocks(struct xfs_inode *ip, bool force)
+{
+       /* prealloc/delalloc exists only on regular files */
+       if (!S_ISREG(ip->i_d.di_mode))
+               return false;
+
+       /*
+        * Zero sized files with no cached pages and delalloc blocks will not
+        * have speculative prealloc/delalloc blocks to remove.
+        */
+       if (VFS_I(ip)->i_size == 0 &&
+           VFS_I(ip)->i_mapping->nrpages == 0 &&
+           ip->i_delayed_blks == 0)
+               return false;
+
+       /* If we haven't read in the extent list, then don't do it now. */
+       if (!(ip->i_df.if_flags & XFS_IFEXTENTS))
+               return false;
+
+       /*
+        * Do not free real preallocated or append-only files unless the file
+        * has delalloc blocks and we are forced to remove them.
+        */
+       if (ip->i_d.di_flags & (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND))
+               if (!force || ip->i_delayed_blks == 0)
+                       return false;
+
+       return true;
+}
+
+/*
+ * This is called by xfs_inactive to free any blocks beyond eof
+ * when the link count isn't zero and by xfs_dm_punch_hole() when
+ * punching a hole to EOF.
+ */
+int
+xfs_free_eofblocks(
+       xfs_mount_t     *mp,
+       xfs_inode_t     *ip,
+       bool            need_iolock)
+{
+       xfs_trans_t     *tp;
+       int             error;
+       xfs_fileoff_t   end_fsb;
+       xfs_fileoff_t   last_fsb;
+       xfs_filblks_t   map_len;
+       int             nimaps;
+       xfs_bmbt_irec_t imap;
+
+       /*
+        * Figure out if there are any blocks beyond the end
+        * of the file.  If not, then there is nothing to do.
+        */
+       end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_ISIZE(ip));
+       last_fsb = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes);
+       if (last_fsb <= end_fsb)
+               return 0;
+       map_len = last_fsb - end_fsb;
+
+       nimaps = 1;
+       xfs_ilock(ip, XFS_ILOCK_SHARED);
+       error = xfs_bmapi_read(ip, end_fsb, map_len, &imap, &nimaps, 0);
+       xfs_iunlock(ip, XFS_ILOCK_SHARED);
+
+       if (!error && (nimaps != 0) &&
+           (imap.br_startblock != HOLESTARTBLOCK ||
+            ip->i_delayed_blks)) {
+               /*
+                * Attach the dquots to the inode up front.
+                */
+               error = xfs_qm_dqattach(ip, 0);
+               if (error)
+                       return error;
+
+               /*
+                * There are blocks after the end of file.
+                * Free them up now by truncating the file to
+                * its current size.
+                */
+               tp = xfs_trans_alloc(mp, XFS_TRANS_INACTIVE);
+
+               if (need_iolock) {
+                       if (!xfs_ilock_nowait(ip, XFS_IOLOCK_EXCL)) {
+                               xfs_trans_cancel(tp, 0);
+                               return -EAGAIN;
+                       }
+               }
+
+               error = xfs_trans_reserve(tp, &M_RES(mp)->tr_itruncate, 0, 0);
+               if (error) {
+                       ASSERT(XFS_FORCED_SHUTDOWN(mp));
+                       xfs_trans_cancel(tp, 0);
+                       if (need_iolock)
+                               xfs_iunlock(ip, XFS_IOLOCK_EXCL);
+                       return error;
+               }
+
+               xfs_ilock(ip, XFS_ILOCK_EXCL);
+               xfs_trans_ijoin(tp, ip, 0);
+
+               /*
+                * Do not update the on-disk file size.  If we update the
+                * on-disk file size and then the system crashes before the
+                * contents of the file are flushed to disk then the files
+                * may be full of holes (ie NULL files bug).
+                */
+               error = xfs_itruncate_extents(&tp, ip, XFS_DATA_FORK,
+                                             XFS_ISIZE(ip));
+               if (error) {
+                       /*
+                        * If we get an error at this point we simply don't
+                        * bother truncating the file.
+                        */
+                       xfs_trans_cancel(tp,
+                                        (XFS_TRANS_RELEASE_LOG_RES |
+                                         XFS_TRANS_ABORT));
+               } else {
+                       error = xfs_trans_commit(tp,
+                                               XFS_TRANS_RELEASE_LOG_RES);
+                       if (!error)
+                               xfs_inode_clear_eofblocks_tag(ip);
+               }
+
+               xfs_iunlock(ip, XFS_ILOCK_EXCL);
+               if (need_iolock)
+                       xfs_iunlock(ip, XFS_IOLOCK_EXCL);
+       }
+       return error;
+}
+
+int
+xfs_alloc_file_space(
+       struct xfs_inode        *ip,
+       xfs_off_t               offset,
+       xfs_off_t               len,
+       int                     alloc_type)
+{
+       xfs_mount_t             *mp = ip->i_mount;
+       xfs_off_t               count;
+       xfs_filblks_t           allocated_fsb;
+       xfs_filblks_t           allocatesize_fsb;
+       xfs_extlen_t            extsz, temp;
+       xfs_fileoff_t           startoffset_fsb;
+       xfs_fsblock_t           firstfsb;
+       int                     nimaps;
+       int                     quota_flag;
+       int                     rt;
+       xfs_trans_t             *tp;
+       xfs_bmbt_irec_t         imaps[1], *imapp;
+       xfs_bmap_free_t         free_list;
+       uint                    qblocks, resblks, resrtextents;
+       int                     committed;
+       int                     error;
+
+       trace_xfs_alloc_file_space(ip);
+
+       if (XFS_FORCED_SHUTDOWN(mp))
+               return -EIO;
+
+       error = xfs_qm_dqattach(ip, 0);
+       if (error)
+               return error;
+
+       if (len <= 0)
+               return -EINVAL;
+
+       rt = XFS_IS_REALTIME_INODE(ip);
+       extsz = xfs_get_extsz_hint(ip);
+
+       count = len;
+       imapp = &imaps[0];
+       nimaps = 1;
+       startoffset_fsb = XFS_B_TO_FSBT(mp, offset);
+       allocatesize_fsb = XFS_B_TO_FSB(mp, count);
+
+       /*
+        * Allocate file space until done or until there is an error
+        */
+       while (allocatesize_fsb && !error) {
+               xfs_fileoff_t   s, e;
+
+               /*
+                * Determine space reservations for data/realtime.
+                */
+               if (unlikely(extsz)) {
+                       s = startoffset_fsb;
+                       do_div(s, extsz);
+                       s *= extsz;
+                       e = startoffset_fsb + allocatesize_fsb;
+                       if ((temp = do_mod(startoffset_fsb, extsz)))
+                               e += temp;
+                       if ((temp = do_mod(e, extsz)))
+                               e += extsz - temp;
+               } else {
+                       s = 0;
+                       e = allocatesize_fsb;
+               }
+
+               /*
+                * The transaction reservation is limited to a 32-bit block
+                * count, hence we need to limit the number of blocks we are
+                * trying to reserve to avoid an overflow. We can't allocate
+                * more than @nimaps extents, and an extent is limited on disk
+                * to MAXEXTLEN (21 bits), so use that to enforce the limit.
+                */
+               resblks = min_t(xfs_fileoff_t, (e - s), (MAXEXTLEN * nimaps));
+               if (unlikely(rt)) {
+                       resrtextents = qblocks = resblks;
+                       resrtextents /= mp->m_sb.sb_rextsize;
+                       resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
+                       quota_flag = XFS_QMOPT_RES_RTBLKS;
+               } else {
+                       resrtextents = 0;
+                       resblks = qblocks = XFS_DIOSTRAT_SPACE_RES(mp, resblks);
+                       quota_flag = XFS_QMOPT_RES_REGBLKS;
+               }
+
+               /*
+                * Allocate and setup the transaction.
+                */
+               tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT);
+               error = xfs_trans_reserve(tp, &M_RES(mp)->tr_write,
+                                         resblks, resrtextents);
+               /*
+                * Check for running out of space
+                */
+               if (error) {
+                       /*
+                        * Free the transaction structure.
+                        */
+                       ASSERT(error == -ENOSPC || XFS_FORCED_SHUTDOWN(mp));
+                       xfs_trans_cancel(tp, 0);
+                       break;
+               }
+               xfs_ilock(ip, XFS_ILOCK_EXCL);
+               error = xfs_trans_reserve_quota_nblks(tp, ip, qblocks,
+                                                     0, quota_flag);
+               if (error)
+                       goto error1;
+
+               xfs_trans_ijoin(tp, ip, 0);
+
+               xfs_bmap_init(&free_list, &firstfsb);
+               error = xfs_bmapi_write(tp, ip, startoffset_fsb,
+                                       allocatesize_fsb, alloc_type, &firstfsb,
+                                       0, imapp, &nimaps, &free_list);
+               if (error) {
+                       goto error0;
+               }
+
+               /*
+                * Complete the transaction
+                */
+               error = xfs_bmap_finish(&tp, &free_list, &committed);
+               if (error) {
+                       goto error0;
+               }
+
+               error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
+               xfs_iunlock(ip, XFS_ILOCK_EXCL);
+               if (error) {
+                       break;
+               }
+
+               allocated_fsb = imapp->br_blockcount;
+
+               if (nimaps == 0) {
+                       error = -ENOSPC;
+                       break;
+               }
+
+               startoffset_fsb += allocated_fsb;
+               allocatesize_fsb -= allocated_fsb;
+       }
+
+       return error;
+
+error0:        /* Cancel bmap, unlock inode, unreserve quota blocks, cancel trans */
+       xfs_bmap_cancel(&free_list);
+       xfs_trans_unreserve_quota_nblks(tp, ip, (long)qblocks, 0, quota_flag);
+
+error1:        /* Just cancel transaction */
+       xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
+       xfs_iunlock(ip, XFS_ILOCK_EXCL);
+       return error;
+}
+
+/*
+ * Zero file bytes between startoff and endoff inclusive.
+ * The iolock is held exclusive and no blocks are buffered.
+ *
+ * This function is used by xfs_free_file_space() to zero
+ * partial blocks when the range to free is not block aligned.
+ * When unreserving space with boundaries that are not block
+ * aligned we round up the start and round down the end
+ * boundaries and then use this function to zero the parts of
+ * the blocks that got dropped during the rounding.
+ */
+STATIC int
+xfs_zero_remaining_bytes(
+       xfs_inode_t             *ip,
+       xfs_off_t               startoff,
+       xfs_off_t               endoff)
+{
+       xfs_bmbt_irec_t         imap;
+       xfs_fileoff_t           offset_fsb;
+       xfs_off_t               lastoffset;
+       xfs_off_t               offset;
+       xfs_buf_t               *bp;
+       xfs_mount_t             *mp = ip->i_mount;
+       int                     nimap;
+       int                     error = 0;
+
+       /*
+        * Avoid doing I/O beyond eof - it's not necessary
+        * since nothing can read beyond eof.  The space will
+        * be zeroed when the file is extended anyway.
+        */
+       if (startoff >= XFS_ISIZE(ip))
+               return 0;
+
+       if (endoff > XFS_ISIZE(ip))
+               endoff = XFS_ISIZE(ip);
+
+       for (offset = startoff; offset <= endoff; offset = lastoffset + 1) {
+               uint lock_mode;
+
+               offset_fsb = XFS_B_TO_FSBT(mp, offset);
+               nimap = 1;
+
+               lock_mode = xfs_ilock_data_map_shared(ip);
+               error = xfs_bmapi_read(ip, offset_fsb, 1, &imap, &nimap, 0);
+               xfs_iunlock(ip, lock_mode);
+
+               if (error || nimap < 1)
+                       break;
+               ASSERT(imap.br_blockcount >= 1);
+               ASSERT(imap.br_startoff == offset_fsb);
+               lastoffset = XFS_FSB_TO_B(mp, imap.br_startoff + 1) - 1;
+               if (lastoffset > endoff)
+                       lastoffset = endoff;
+               if (imap.br_startblock == HOLESTARTBLOCK)
+                       continue;
+               ASSERT(imap.br_startblock != DELAYSTARTBLOCK);
+               if (imap.br_state == XFS_EXT_UNWRITTEN)
+                       continue;
+
+               error = xfs_buf_read_uncached(XFS_IS_REALTIME_INODE(ip) ?
+                               mp->m_rtdev_targp : mp->m_ddev_targp,
+                               xfs_fsb_to_db(ip, imap.br_startblock),
+                               BTOBB(mp->m_sb.sb_blocksize),
+                               0, &bp, NULL);
+               if (error)
+                       return error;
+
+               memset(bp->b_addr +
+                               (offset - XFS_FSB_TO_B(mp, imap.br_startoff)),
+                      0, lastoffset - offset + 1);
+
+               error = xfs_bwrite(bp);
+               xfs_buf_relse(bp);
+               if (error)
+                       return error;
+       }
+       return error;
+}
+
+int
+xfs_free_file_space(
+       struct xfs_inode        *ip,
+       xfs_off_t               offset,
+       xfs_off_t               len)
+{
+       int                     committed;
+       int                     done;
+       xfs_fileoff_t           endoffset_fsb;
+       int                     error;
+       xfs_fsblock_t           firstfsb;
+       xfs_bmap_free_t         free_list;
+       xfs_bmbt_irec_t         imap;
+       xfs_off_t               ioffset;
+       xfs_off_t               iendoffset;
+       xfs_extlen_t            mod=0;
+       xfs_mount_t             *mp;
+       int                     nimap;
+       uint                    resblks;
+       xfs_off_t               rounding;
+       int                     rt;
+       xfs_fileoff_t           startoffset_fsb;
+       xfs_trans_t             *tp;
+
+       mp = ip->i_mount;
+
+       trace_xfs_free_file_space(ip);
+
+       error = xfs_qm_dqattach(ip, 0);
+       if (error)
+               return error;
+
+       error = 0;
+       if (len <= 0)   /* if nothing being freed */
+               return error;
+       rt = XFS_IS_REALTIME_INODE(ip);
+       startoffset_fsb = XFS_B_TO_FSB(mp, offset);
+       endoffset_fsb = XFS_B_TO_FSBT(mp, offset + len);
+
+       /* wait for the completion of any pending DIOs */
+       inode_dio_wait(VFS_I(ip));
+
+       rounding = max_t(xfs_off_t, 1 << mp->m_sb.sb_blocklog, PAGE_CACHE_SIZE);
+       ioffset = round_down(offset, rounding);
+       iendoffset = round_up(offset + len, rounding) - 1;
+       error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping, ioffset,
+                                            iendoffset);
+       if (error)
+               goto out;
+       truncate_pagecache_range(VFS_I(ip), ioffset, iendoffset);
+
+       /*
+        * Need to zero the stuff we're not freeing, on disk.
+        * If it's a realtime file & can't use unwritten extents then we
+        * actually need to zero the extent edges.  Otherwise xfs_bunmapi
+        * will take care of it for us.
+        */
+       if (rt && !xfs_sb_version_hasextflgbit(&mp->m_sb)) {
+               nimap = 1;
+               error = xfs_bmapi_read(ip, startoffset_fsb, 1,
+                                       &imap, &nimap, 0);
+               if (error)
+                       goto out;
+               ASSERT(nimap == 0 || nimap == 1);
+               if (nimap && imap.br_startblock != HOLESTARTBLOCK) {
+                       xfs_daddr_t     block;
+
+                       ASSERT(imap.br_startblock != DELAYSTARTBLOCK);
+                       block = imap.br_startblock;
+                       mod = do_div(block, mp->m_sb.sb_rextsize);
+                       if (mod)
+                               startoffset_fsb += mp->m_sb.sb_rextsize - mod;
+               }
+               nimap = 1;
+               error = xfs_bmapi_read(ip, endoffset_fsb - 1, 1,
+                                       &imap, &nimap, 0);
+               if (error)
+                       goto out;
+               ASSERT(nimap == 0 || nimap == 1);
+               if (nimap && imap.br_startblock != HOLESTARTBLOCK) {
+                       ASSERT(imap.br_startblock != DELAYSTARTBLOCK);
+                       mod++;
+                       if (mod && (mod != mp->m_sb.sb_rextsize))
+                               endoffset_fsb -= mod;
+               }
+       }
+       if ((done = (endoffset_fsb <= startoffset_fsb)))
+               /*
+                * One contiguous piece to clear
+                */
+               error = xfs_zero_remaining_bytes(ip, offset, offset + len - 1);
+       else {
+               /*
+                * Some full blocks, possibly two pieces to clear
+                */
+               if (offset < XFS_FSB_TO_B(mp, startoffset_fsb))
+                       error = xfs_zero_remaining_bytes(ip, offset,
+                               XFS_FSB_TO_B(mp, startoffset_fsb) - 1);
+               if (!error &&
+                   XFS_FSB_TO_B(mp, endoffset_fsb) < offset + len)
+                       error = xfs_zero_remaining_bytes(ip,
+                               XFS_FSB_TO_B(mp, endoffset_fsb),
+                               offset + len - 1);
+       }
+
+       /*
+        * free file space until done or until there is an error
+        */
+       resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
+       while (!error && !done) {
+
+               /*
+                * allocate and setup the transaction. Allow this
+                * transaction to dip into the reserve blocks to ensure
+                * the freeing of the space succeeds at ENOSPC.
+                */
+               tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT);
+               error = xfs_trans_reserve(tp, &M_RES(mp)->tr_write, resblks, 0);
+
+               /*
+                * check for running out of space
+                */
+               if (error) {
+                       /*
+                        * Free the transaction structure.
+                        */
+                       ASSERT(error == -ENOSPC || XFS_FORCED_SHUTDOWN(mp));
+                       xfs_trans_cancel(tp, 0);
+                       break;
+               }
+               xfs_ilock(ip, XFS_ILOCK_EXCL);
+               error = xfs_trans_reserve_quota(tp, mp,
+                               ip->i_udquot, ip->i_gdquot, ip->i_pdquot,
+                               resblks, 0, XFS_QMOPT_RES_REGBLKS);
+               if (error)
+                       goto error1;
+
+               xfs_trans_ijoin(tp, ip, 0);
+
+               /*
+                * issue the bunmapi() call to free the blocks
+                */
+               xfs_bmap_init(&free_list, &firstfsb);
+               error = xfs_bunmapi(tp, ip, startoffset_fsb,
+                                 endoffset_fsb - startoffset_fsb,
+                                 0, 2, &firstfsb, &free_list, &done);
+               if (error) {
+                       goto error0;
+               }
+
+               /*
+                * complete the transaction
+                */
+               error = xfs_bmap_finish(&tp, &free_list, &committed);
+               if (error) {
+                       goto error0;
+               }
+
+               error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
+               xfs_iunlock(ip, XFS_ILOCK_EXCL);
+       }
+
+ out:
+       return error;
+
+ error0:
+       xfs_bmap_cancel(&free_list);
+ error1:
+       xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
+       xfs_iunlock(ip, XFS_ILOCK_EXCL);
+       goto out;
+}
+
+/*
+ * Preallocate and zero a range of a file. This mechanism has the allocation
+ * semantics of fallocate and in addition converts data in the range to zeroes.
+ */
+int
+xfs_zero_file_space(
+       struct xfs_inode        *ip,
+       xfs_off_t               offset,
+       xfs_off_t               len)
+{
+       struct xfs_mount        *mp = ip->i_mount;
+       uint                    blksize;
+       int                     error;
+
+       trace_xfs_zero_file_space(ip);
+
+       blksize = 1 << mp->m_sb.sb_blocklog;
+
+       /*
+        * Punch a hole and prealloc the range. We use hole punch rather than
+        * unwritten extent conversion for two reasons:
+        *
+        * 1.) Hole punch handles partial block zeroing for us.
+        *
+        * 2.) If prealloc returns ENOSPC, the file range is still zero-valued
+        * by virtue of the hole punch.
+        */
+       error = xfs_free_file_space(ip, offset, len);
+       if (error)
+               goto out;
+
+       error = xfs_alloc_file_space(ip, round_down(offset, blksize),
+                                    round_up(offset + len, blksize) -
+                                    round_down(offset, blksize),
+                                    XFS_BMAPI_PREALLOC);
+out:
+       return error;
+
+}
+
+/*
+ * @next_fsb will keep track of the extent currently undergoing shift.
+ * @stop_fsb will keep track of the extent at which we have to stop.
+ * If we are shifting left, we will start with block (offset + len) and
+ * shift each extent till last extent.
+ * If we are shifting right, we will start with last extent inside file space
+ * and continue until we reach the block corresponding to offset.
+ */
+static int
+xfs_shift_file_space(
+       struct xfs_inode        *ip,
+       xfs_off_t               offset,
+       xfs_off_t               len,
+       enum shift_direction    direction)
+{
+       int                     done = 0;
+       struct xfs_mount        *mp = ip->i_mount;
+       struct xfs_trans        *tp;
+       int                     error;
+       struct xfs_bmap_free    free_list;
+       xfs_fsblock_t           first_block;
+       int                     committed;
+       xfs_fileoff_t           stop_fsb;
+       xfs_fileoff_t           next_fsb;
+       xfs_fileoff_t           shift_fsb;
+
+       ASSERT(direction == SHIFT_LEFT || direction == SHIFT_RIGHT);
+
+       if (direction == SHIFT_LEFT) {
+               next_fsb = XFS_B_TO_FSB(mp, offset + len);
+               stop_fsb = XFS_B_TO_FSB(mp, VFS_I(ip)->i_size);
+       } else {
+               /*
+                * If right shift, delegate the work of initialization of
+                * next_fsb to xfs_bmap_shift_extent as it has ilock held.
+                */
+               next_fsb = NULLFSBLOCK;
+               stop_fsb = XFS_B_TO_FSB(mp, offset);
+       }
+
+       shift_fsb = XFS_B_TO_FSB(mp, len);
+
+       /*
+        * Trim eofblocks to avoid shifting uninitialized post-eof preallocation
+        * into the accessible region of the file.
+        */
+       if (xfs_can_free_eofblocks(ip, true)) {
+               error = xfs_free_eofblocks(mp, ip, false);
+               if (error)
+                       return error;
+       }
+
+       /*
+        * Writeback and invalidate cache for the remainder of the file as we're
+        * about to shift down every extent from offset to EOF.
+        */
+       error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
+                                            offset, -1);
+       if (error)
+               return error;
+       error = invalidate_inode_pages2_range(VFS_I(ip)->i_mapping,
+                                       offset >> PAGE_CACHE_SHIFT, -1);
+       if (error)
+               return error;
+
+       /*
+        * The extent shiting code works on extent granularity. So, if
+        * stop_fsb is not the starting block of extent, we need to split
+        * the extent at stop_fsb.
+        */
+       if (direction == SHIFT_RIGHT) {
+               error = xfs_bmap_split_extent(ip, stop_fsb);
+               if (error)
+                       return error;
+       }
+
+       while (!error && !done) {
+               tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT);
+               /*
+                * We would need to reserve permanent block for transaction.
+                * This will come into picture when after shifting extent into
+                * hole we found that adjacent extents can be merged which
+                * may lead to freeing of a block during record update.
+                */
+               error = xfs_trans_reserve(tp, &M_RES(mp)->tr_write,
+                               XFS_DIOSTRAT_SPACE_RES(mp, 0), 0);
+               if (error) {
+                       xfs_trans_cancel(tp, 0);
+                       break;
+               }
+
+               xfs_ilock(ip, XFS_ILOCK_EXCL);
+               error = xfs_trans_reserve_quota(tp, mp, ip->i_udquot,
+                               ip->i_gdquot, ip->i_pdquot,
+                               XFS_DIOSTRAT_SPACE_RES(mp, 0), 0,
+                               XFS_QMOPT_RES_REGBLKS);
+               if (error)
+                       goto out;
+
+               xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
+
+               xfs_bmap_init(&free_list, &first_block);
+
+               /*
+                * We are using the write transaction in which max 2 bmbt
+                * updates are allowed
+                */
+               error = xfs_bmap_shift_extents(tp, ip, &next_fsb, shift_fsb,
+                               &done, stop_fsb, &first_block, &free_list,
+                               direction, XFS_BMAP_MAX_SHIFT_EXTENTS);
+               if (error)
+                       goto out;
+
+               error = xfs_bmap_finish(&tp, &free_list, &committed);
+               if (error)
+                       goto out;
+
+               error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
+       }
+
+       return error;
+
+out:
+       xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
+       return error;
+}
+
+/*
+ * xfs_collapse_file_space()
+ *     This routine frees disk space and shift extent for the given file.
+ *     The first thing we do is to free data blocks in the specified range
+ *     by calling xfs_free_file_space(). It would also sync dirty data
+ *     and invalidate page cache over the region on which collapse range
+ *     is working. And Shift extent records to the left to cover a hole.
+ * RETURNS:
+ *     0 on success
+ *     errno on error
+ *
+ */
+int
+xfs_collapse_file_space(
+       struct xfs_inode        *ip,
+       xfs_off_t               offset,
+       xfs_off_t               len)
+{
+       int error;
+
+       ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
+       trace_xfs_collapse_file_space(ip);
+
+       error = xfs_free_file_space(ip, offset, len);
+       if (error)
+               return error;
+
+       return xfs_shift_file_space(ip, offset, len, SHIFT_LEFT);
+}
+
+/*
+ * xfs_insert_file_space()
+ *     This routine create hole space by shifting extents for the given file.
+ *     The first thing we do is to sync dirty data and invalidate page cache
+ *     over the region on which insert range is working. And split an extent
+ *     to two extents at given offset by calling xfs_bmap_split_extent.
+ *     And shift all extent records which are laying between [offset,
+ *     last allocated extent] to the right to reserve hole range.
+ * RETURNS:
+ *     0 on success
+ *     errno on error
+ */
+int
+xfs_insert_file_space(
+       struct xfs_inode        *ip,
+       loff_t                  offset,
+       loff_t                  len)
+{
+       ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
+       trace_xfs_insert_file_space(ip);
+
+       return xfs_shift_file_space(ip, offset, len, SHIFT_RIGHT);
+}
+
+/*
+ * We need to check that the format of the data fork in the temporary inode is
+ * valid for the target inode before doing the swap. This is not a problem with
+ * attr1 because of the fixed fork offset, but attr2 has a dynamically sized
+ * data fork depending on the space the attribute fork is taking so we can get
+ * invalid formats on the target inode.
+ *
+ * E.g. target has space for 7 extents in extent format, temp inode only has
+ * space for 6.  If we defragment down to 7 extents, then the tmp format is a
+ * btree, but when swapped it needs to be in extent format. Hence we can't just
+ * blindly swap data forks on attr2 filesystems.
+ *
+ * Note that we check the swap in both directions so that we don't end up with
+ * a corrupt temporary inode, either.
+ *
+ * Note that fixing the way xfs_fsr sets up the attribute fork in the source
+ * inode will prevent this situation from occurring, so all we do here is
+ * reject and log the attempt. basically we are putting the responsibility on
+ * userspace to get this right.
+ */
+static int
+xfs_swap_extents_check_format(
+       xfs_inode_t     *ip,    /* target inode */
+       xfs_inode_t     *tip)   /* tmp inode */
+{
+
+       /* Should never get a local format */
+       if (ip->i_d.di_format == XFS_DINODE_FMT_LOCAL ||
+           tip->i_d.di_format == XFS_DINODE_FMT_LOCAL)
+               return -EINVAL;
+
+       /*
+        * if the target inode has less extents that then temporary inode then
+        * why did userspace call us?
+        */
+       if (ip->i_d.di_nextents < tip->i_d.di_nextents)
+               return -EINVAL;
+
+       /*
+        * if the target inode is in extent form and the temp inode is in btree
+        * form then we will end up with the target inode in the wrong format
+        * as we already know there are less extents in the temp inode.
+        */
+       if (ip->i_d.di_format == XFS_DINODE_FMT_EXTENTS &&
+           tip->i_d.di_format == XFS_DINODE_FMT_BTREE)
+               return -EINVAL;
+
+       /* Check temp in extent form to max in target */
+       if (tip->i_d.di_format == XFS_DINODE_FMT_EXTENTS &&
+           XFS_IFORK_NEXTENTS(tip, XFS_DATA_FORK) >
+                       XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK))
+               return -EINVAL;
+
+       /* Check target in extent form to max in temp */
+       if (ip->i_d.di_format == XFS_DINODE_FMT_EXTENTS &&
+           XFS_IFORK_NEXTENTS(ip, XFS_DATA_FORK) >
+                       XFS_IFORK_MAXEXT(tip, XFS_DATA_FORK))
+               return -EINVAL;
+
+       /*
+        * If we are in a btree format, check that the temp root block will fit
+        * in the target and that it has enough extents to be in btree format
+        * in the target.
+        *
+        * Note that we have to be careful to allow btree->extent conversions
+        * (a common defrag case) which will occur when the temp inode is in
+        * extent format...
+        */
+       if (tip->i_d.di_format == XFS_DINODE_FMT_BTREE) {
+               if (XFS_IFORK_BOFF(ip) &&
+                   XFS_BMAP_BMDR_SPACE(tip->i_df.if_broot) > XFS_IFORK_BOFF(ip))
+                       return -EINVAL;
+               if (XFS_IFORK_NEXTENTS(tip, XFS_DATA_FORK) <=
+                   XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK))
+                       return -EINVAL;
+       }
+
+       /* Reciprocal target->temp btree format checks */
+       if (ip->i_d.di_format == XFS_DINODE_FMT_BTREE) {
+               if (XFS_IFORK_BOFF(tip) &&
+                   XFS_BMAP_BMDR_SPACE(ip->i_df.if_broot) > XFS_IFORK_BOFF(tip))
+                       return -EINVAL;
+               if (XFS_IFORK_NEXTENTS(ip, XFS_DATA_FORK) <=
+                   XFS_IFORK_MAXEXT(tip, XFS_DATA_FORK))
+                       return -EINVAL;
+       }
+
+       return 0;
+}
+
+static int
+xfs_swap_extent_flush(
+       struct xfs_inode        *ip)
+{
+       int     error;
+
+       error = filemap_write_and_wait(VFS_I(ip)->i_mapping);
+       if (error)
+               return error;
+       truncate_pagecache_range(VFS_I(ip), 0, -1);
+
+       /* Verify O_DIRECT for ftmp */
+       if (VFS_I(ip)->i_mapping->nrpages)
+               return -EINVAL;
+       return 0;
+}
+
+int
+xfs_swap_extents(
+       xfs_inode_t     *ip,    /* target inode */
+       xfs_inode_t     *tip,   /* tmp inode */
+       xfs_swapext_t   *sxp)
+{
+       xfs_mount_t     *mp = ip->i_mount;
+       xfs_trans_t     *tp;
+       xfs_bstat_t     *sbp = &sxp->sx_stat;
+       xfs_ifork_t     *tempifp, *ifp, *tifp;
+       int             src_log_flags, target_log_flags;
+       int             error = 0;
+       int             aforkblks = 0;
+       int             taforkblks = 0;
+       __uint64_t      tmp;
+       int             lock_flags;
+
+       tempifp = kmem_alloc(sizeof(xfs_ifork_t), KM_MAYFAIL);
+       if (!tempifp) {
+               error = -ENOMEM;
+               goto out;
+       }
+
+       /*
+        * Lock the inodes against other IO, page faults and truncate to
+        * begin with.  Then we can ensure the inodes are flushed and have no
+        * page cache safely. Once we have done this we can take the ilocks and
+        * do the rest of the checks.
+        */
+       lock_flags = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
+       xfs_lock_two_inodes(ip, tip, XFS_IOLOCK_EXCL);
+       xfs_lock_two_inodes(ip, tip, XFS_MMAPLOCK_EXCL);
+
+       /* Verify that both files have the same format */
+       if ((ip->i_d.di_mode & S_IFMT) != (tip->i_d.di_mode & S_IFMT)) {
+               error = -EINVAL;
+               goto out_unlock;
+       }
+
+       /* Verify both files are either real-time or non-realtime */
+       if (XFS_IS_REALTIME_INODE(ip) != XFS_IS_REALTIME_INODE(tip)) {
+               error = -EINVAL;
+               goto out_unlock;
+       }
+
+       error = xfs_swap_extent_flush(ip);
+       if (error)
+               goto out_unlock;
+       error = xfs_swap_extent_flush(tip);
+       if (error)
+               goto out_unlock;
+
+       tp = xfs_trans_alloc(mp, XFS_TRANS_SWAPEXT);
+       error = xfs_trans_reserve(tp, &M_RES(mp)->tr_ichange, 0, 0);
+       if (error) {
+               xfs_trans_cancel(tp, 0);
+               goto out_unlock;
+       }
+
+       /*
+        * Lock and join the inodes to the tansaction so that transaction commit
+        * or cancel will unlock the inodes from this point onwards.
+        */
+       xfs_lock_two_inodes(ip, tip, XFS_ILOCK_EXCL);
+       lock_flags |= XFS_ILOCK_EXCL;
+       xfs_trans_ijoin(tp, ip, lock_flags);
+       xfs_trans_ijoin(tp, tip, lock_flags);
+
+
+       /* Verify all data are being swapped */
+       if (sxp->sx_offset != 0 ||
+           sxp->sx_length != ip->i_d.di_size ||
+           sxp->sx_length != tip->i_d.di_size) {
+               error = -EFAULT;
+               goto out_trans_cancel;
+       }
+
+       trace_xfs_swap_extent_before(ip, 0);
+       trace_xfs_swap_extent_before(tip, 1);
+
+       /* check inode formats now that data is flushed */
+       error = xfs_swap_extents_check_format(ip, tip);
+       if (error) {
+               xfs_notice(mp,
+                   "%s: inode 0x%llx format is incompatible for exchanging.",
+                               __func__, ip->i_ino);
+               goto out_trans_cancel;
+       }
+
+       /*
+        * Compare the current change & modify times with that
+        * passed in.  If they differ, we abort this swap.
+        * This is the mechanism used to ensure the calling
+        * process that the file was not changed out from
+        * under it.
+        */
+       if ((sbp->bs_ctime.tv_sec != VFS_I(ip)->i_ctime.tv_sec) ||
+           (sbp->bs_ctime.tv_nsec != VFS_I(ip)->i_ctime.tv_nsec) ||
+           (sbp->bs_mtime.tv_sec != VFS_I(ip)->i_mtime.tv_sec) ||
+           (sbp->bs_mtime.tv_nsec != VFS_I(ip)->i_mtime.tv_nsec)) {
+               error = -EBUSY;
+               goto out_trans_cancel;
+       }
+       /*
+        * Count the number of extended attribute blocks
+        */
+       if ( ((XFS_IFORK_Q(ip) != 0) && (ip->i_d.di_anextents > 0)) &&
+            (ip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL)) {
+               error = xfs_bmap_count_blocks(tp, ip, XFS_ATTR_FORK, &aforkblks);
+               if (error)
+                       goto out_trans_cancel;
+       }
+       if ( ((XFS_IFORK_Q(tip) != 0) && (tip->i_d.di_anextents > 0)) &&
+            (tip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL)) {
+               error = xfs_bmap_count_blocks(tp, tip, XFS_ATTR_FORK,
+                       &taforkblks);
+               if (error)
+                       goto out_trans_cancel;
+       }
+
+       /*
+        * Before we've swapped the forks, lets set the owners of the forks
+        * appropriately. We have to do this as we are demand paging the btree
+        * buffers, and so the validation done on read will expect the owner
+        * field to be correctly set. Once we change the owners, we can swap the
+        * inode forks.
+        *
+        * Note the trickiness in setting the log flags - we set the owner log
+        * flag on the opposite inode (i.e. the inode we are setting the new
+        * owner to be) because once we swap the forks and log that, log
+        * recovery is going to see the fork as owned by the swapped inode,
+        * not the pre-swapped inodes.
+        */
+       src_log_flags = XFS_ILOG_CORE;
+       target_log_flags = XFS_ILOG_CORE;
+       if (ip->i_d.di_version == 3 &&
+           ip->i_d.di_format == XFS_DINODE_FMT_BTREE) {
+               target_log_flags |= XFS_ILOG_DOWNER;
+               error = xfs_bmbt_change_owner(tp, ip, XFS_DATA_FORK,
+                                             tip->i_ino, NULL);
+               if (error)
+                       goto out_trans_cancel;
+       }
+
+       if (tip->i_d.di_version == 3 &&
+           tip->i_d.di_format == XFS_DINODE_FMT_BTREE) {
+               src_log_flags |= XFS_ILOG_DOWNER;
+               error = xfs_bmbt_change_owner(tp, tip, XFS_DATA_FORK,
+                                             ip->i_ino, NULL);
+               if (error)
+                       goto out_trans_cancel;
+       }
+
+       /*
+        * Swap the data forks of the inodes
+        */
+       ifp = &ip->i_df;
+       tifp = &tip->i_df;
+       *tempifp = *ifp;        /* struct copy */
+       *ifp = *tifp;           /* struct copy */
+       *tifp = *tempifp;       /* struct copy */
+
+       /*
+        * Fix the on-disk inode values
+        */
+       tmp = (__uint64_t)ip->i_d.di_nblocks;
+       ip->i_d.di_nblocks = tip->i_d.di_nblocks - taforkblks + aforkblks;
+       tip->i_d.di_nblocks = tmp + taforkblks - aforkblks;
+
+       tmp = (__uint64_t) ip->i_d.di_nextents;
+       ip->i_d.di_nextents = tip->i_d.di_nextents;
+       tip->i_d.di_nextents = tmp;
+
+       tmp = (__uint64_t) ip->i_d.di_format;
+       ip->i_d.di_format = tip->i_d.di_format;
+       tip->i_d.di_format = tmp;
+
+       /*
+        * The extents in the source inode could still contain speculative
+        * preallocation beyond EOF (e.g. the file is open but not modified
+        * while defrag is in progress). In that case, we need to copy over the
+        * number of delalloc blocks the data fork in the source inode is
+        * tracking beyond EOF so that when the fork is truncated away when the
+        * temporary inode is unlinked we don't underrun the i_delayed_blks
+        * counter on that inode.
+        */
+       ASSERT(tip->i_delayed_blks == 0);
+       tip->i_delayed_blks = ip->i_delayed_blks;
+       ip->i_delayed_blks = 0;
+
+       switch (ip->i_d.di_format) {
+       case XFS_DINODE_FMT_EXTENTS:
+               /* If the extents fit in the inode, fix the
+                * pointer.  Otherwise it's already NULL or
+                * pointing to the extent.
+                */
+               if (ip->i_d.di_nextents <= XFS_INLINE_EXTS) {
+                       ifp->if_u1.if_extents =
+                               ifp->if_u2.if_inline_ext;
+               }
+               src_log_flags |= XFS_ILOG_DEXT;
+               break;
+       case XFS_DINODE_FMT_BTREE:
+               ASSERT(ip->i_d.di_version < 3 ||
+                      (src_log_flags & XFS_ILOG_DOWNER));
+               src_log_flags |= XFS_ILOG_DBROOT;
+               break;
+       }
+
+       switch (tip->i_d.di_format) {
+       case XFS_DINODE_FMT_EXTENTS:
+               /* If the extents fit in the inode, fix the
+                * pointer.  Otherwise it's already NULL or
+                * pointing to the extent.
+                */
+               if (tip->i_d.di_nextents <= XFS_INLINE_EXTS) {
+                       tifp->if_u1.if_extents =
+                               tifp->if_u2.if_inline_ext;
+               }
+               target_log_flags |= XFS_ILOG_DEXT;
+               break;
+       case XFS_DINODE_FMT_BTREE:
+               target_log_flags |= XFS_ILOG_DBROOT;
+               ASSERT(tip->i_d.di_version < 3 ||
+                      (target_log_flags & XFS_ILOG_DOWNER));
+               break;
+       }
+
+       xfs_trans_log_inode(tp, ip,  src_log_flags);
+       xfs_trans_log_inode(tp, tip, target_log_flags);
+
+       /*
+        * If this is a synchronous mount, make sure that the
+        * transaction goes to disk before returning to the user.
+        */
+       if (mp->m_flags & XFS_MOUNT_WSYNC)
+               xfs_trans_set_sync(tp);
+
+       error = xfs_trans_commit(tp, 0);
+
+       trace_xfs_swap_extent_after(ip, 0);
+       trace_xfs_swap_extent_after(tip, 1);
+out:
+       kmem_free(tempifp);
+       return error;
+
+out_unlock:
+       xfs_iunlock(ip, lock_flags);
+       xfs_iunlock(tip, lock_flags);
+       goto out;
+
+out_trans_cancel:
+       xfs_trans_cancel(tp, 0);
+       goto out;
+}