mirror of https://gitee.com/openkylin/linux.git
xfs: factor extent allocation out of xfs_bmapi
To further improve the readability of xfs_bmapi(), factor the extent allocation out into a separate function. This removes a large block of logic from the xfs_bmapi() code loop and makes it easier to see the operational logic flow for xfs_bmapi(). Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
This commit is contained in:
Dave Chinner
Alex Elder
parent
1fd044d9c6
commit
7e47a4efde
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@ -4605,6 +4605,147 @@ xfs_bmapi_delay(
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}
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STATIC int
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xfs_bmapi_allocate(
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struct xfs_bmalloca *bma,
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xfs_extnum_t *lastx,
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struct xfs_btree_cur **cur,
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xfs_fsblock_t *firstblock,
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struct xfs_bmap_free *flist,
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int flags,
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int *nallocs,
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int *logflags)
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{
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struct xfs_mount *mp = bma->ip->i_mount;
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int whichfork = (flags & XFS_BMAPI_ATTRFORK) ?
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XFS_ATTR_FORK : XFS_DATA_FORK;
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struct xfs_ifork *ifp = XFS_IFORK_PTR(bma->ip, whichfork);
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xfs_fsblock_t abno;
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xfs_extlen_t alen;
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xfs_fileoff_t aoff;
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int error;
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int rt;
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rt = (whichfork == XFS_DATA_FORK) && XFS_IS_REALTIME_INODE(bma->ip);
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/*
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* For the wasdelay case, we could also just allocate the stuff asked
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* for in this bmap call but that wouldn't be as good.
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*/
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if (bma->wasdel) {
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alen = (xfs_extlen_t)bma->gotp->br_blockcount;
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aoff = bma->gotp->br_startoff;
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if (*lastx != NULLEXTNUM && *lastx) {
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xfs_bmbt_get_all(xfs_iext_get_ext(ifp, *lastx - 1),
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bma->prevp);
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}
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} else {
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alen = (xfs_extlen_t)XFS_FILBLKS_MIN(bma->alen, MAXEXTLEN);
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if (!bma->eof)
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alen = (xfs_extlen_t)XFS_FILBLKS_MIN(alen,
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bma->gotp->br_startoff - bma->off);
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aoff = bma->off;
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}
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/*
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* Indicate if this is the first user data in the file, or just any
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* user data.
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*/
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if (!(flags & XFS_BMAPI_METADATA)) {
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bma->userdata = (aoff == 0) ?
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XFS_ALLOC_INITIAL_USER_DATA : XFS_ALLOC_USERDATA;
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}
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/*
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* Fill in changeable bma fields.
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*/
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bma->alen = alen;
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bma->off = aoff;
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bma->firstblock = *firstblock;
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bma->minlen = (flags & XFS_BMAPI_CONTIG) ? alen : 1;
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bma->low = flist->xbf_low;
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bma->aeof = 0;
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/*
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* Only want to do the alignment at the eof if it is userdata and
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* allocation length is larger than a stripe unit.
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*/
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if (mp->m_dalign && alen >= mp->m_dalign &&
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!(flags & XFS_BMAPI_METADATA) && whichfork == XFS_DATA_FORK) {
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error = xfs_bmap_isaeof(bma->ip, aoff, whichfork, &bma->aeof);
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if (error)
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return error;
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}
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error = xfs_bmap_alloc(bma);
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if (error)
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return error;
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/*
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* Copy out result fields.
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*/
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abno = bma->rval;
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flist->xbf_low = bma->low;
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alen = bma->alen;
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aoff = bma->off;
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ASSERT(*firstblock == NULLFSBLOCK ||
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XFS_FSB_TO_AGNO(mp, *firstblock) ==
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XFS_FSB_TO_AGNO(mp, bma->firstblock) ||
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(flist->xbf_low &&
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XFS_FSB_TO_AGNO(mp, *firstblock) <
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XFS_FSB_TO_AGNO(mp, bma->firstblock)));
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*firstblock = bma->firstblock;
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if (*cur)
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(*cur)->bc_private.b.firstblock = *firstblock;
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if (abno == NULLFSBLOCK)
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return 0;
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if ((ifp->if_flags & XFS_IFBROOT) && !*cur) {
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(*cur) = xfs_bmbt_init_cursor(mp, bma->tp, bma->ip, whichfork);
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(*cur)->bc_private.b.firstblock = *firstblock;
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(*cur)->bc_private.b.flist = flist;
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}
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/*
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* Bump the number of extents we've allocated
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* in this call.
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*/
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(*nallocs)++;
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if (*cur)
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(*cur)->bc_private.b.flags =
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bma->wasdel ? XFS_BTCUR_BPRV_WASDEL : 0;
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bma->gotp->br_startoff = aoff;
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bma->gotp->br_startblock = abno;
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bma->gotp->br_blockcount = alen;
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bma->gotp->br_state = XFS_EXT_NORM;
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/*
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* A wasdelay extent has been initialized, so shouldn't be flagged
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* as unwritten.
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*/
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if (!bma->wasdel && (flags & XFS_BMAPI_PREALLOC) &&
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xfs_sb_version_hasextflgbit(&mp->m_sb))
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bma->gotp->br_state = XFS_EXT_UNWRITTEN;
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error = xfs_bmap_add_extent(bma->tp, bma->ip, lastx, cur, bma->gotp,
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firstblock, flist, logflags, whichfork);
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if (error)
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return error;
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/*
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* Update our extent pointer, given that xfs_bmap_add_extent might
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* have merged it into one of the neighbouring ones.
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*/
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xfs_bmbt_get_all(xfs_iext_get_ext(ifp, *lastx), bma->gotp);
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ASSERT(bma->gotp->br_startoff <= aoff);
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ASSERT(bma->gotp->br_startoff + bma->gotp->br_blockcount >=
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aoff + alen);
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ASSERT(bma->gotp->br_state == XFS_EXT_NORM ||
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bma->gotp->br_state == XFS_EXT_UNWRITTEN);
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return 0;
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}
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/*
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* Map file blocks to filesystem blocks.
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* File range is given by the bno/len pair.
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@ -4632,9 +4773,6 @@ xfs_bmapi(
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int *nmap, /* i/o: mval size/count */
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xfs_bmap_free_t *flist) /* i/o: list extents to free */
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{
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xfs_fsblock_t abno; /* allocated block number */
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xfs_extlen_t alen; /* allocated extent length */
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xfs_fileoff_t aoff; /* allocated file offset */
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xfs_bmalloca_t bma = { 0 }; /* args for xfs_bmap_alloc */
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xfs_btree_cur_t *cur; /* bmap btree cursor */
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xfs_fileoff_t end; /* end of mapped file region */
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@ -4646,7 +4784,6 @@ xfs_bmapi(
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xfs_extnum_t lastx; /* last useful extent number */
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int logflags; /* flags for transaction logging */
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xfs_extlen_t minleft; /* min blocks left after allocation */
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xfs_extlen_t minlen; /* min allocation size */
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xfs_mount_t *mp; /* xfs mount structure */
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int n; /* current extent index */
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int nallocs; /* number of extents alloc'd */
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@ -4737,7 +4874,13 @@ xfs_bmapi(
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n = 0;
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end = bno + len;
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obno = bno;
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bma.ip = NULL;
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bma.tp = tp;
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bma.ip = ip;
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bma.prevp = &prev;
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bma.gotp = &got;
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bma.total = total;
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bma.userdata = 0;
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while (bno < end && n < *nmap) {
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/*
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@ -4753,144 +4896,23 @@ xfs_bmapi(
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* that we found, if any.
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*/
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if (wr && (inhole || wasdelay)) {
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/*
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* For the wasdelay case, we could also just
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* allocate the stuff asked for in this bmap call
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* but that wouldn't be as good.
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*/
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if (wasdelay) {
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alen = (xfs_extlen_t)got.br_blockcount;
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aoff = got.br_startoff;
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if (lastx != NULLEXTNUM && lastx) {
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ep = xfs_iext_get_ext(ifp, lastx - 1);
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xfs_bmbt_get_all(ep, &prev);
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}
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} else {
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alen = (xfs_extlen_t)
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XFS_FILBLKS_MIN(len, MAXEXTLEN);
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if (!eof)
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alen = (xfs_extlen_t)
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XFS_FILBLKS_MIN(alen,
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got.br_startoff - bno);
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aoff = bno;
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}
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minlen = (flags & XFS_BMAPI_CONTIG) ? alen : 1;
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{
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/*
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* If first time, allocate and fill in
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* once-only bma fields.
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*/
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if (bma.ip == NULL) {
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bma.tp = tp;
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bma.ip = ip;
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bma.prevp = &prev;
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bma.gotp = &got;
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bma.total = total;
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bma.userdata = 0;
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}
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/* Indicate if this is the first user data
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* in the file, or just any user data.
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*/
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if (!(flags & XFS_BMAPI_METADATA)) {
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bma.userdata = (aoff == 0) ?
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XFS_ALLOC_INITIAL_USER_DATA :
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XFS_ALLOC_USERDATA;
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}
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/*
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* Fill in changeable bma fields.
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*/
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bma.eof = eof;
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bma.firstblock = *firstblock;
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bma.alen = alen;
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bma.off = aoff;
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bma.conv = !!(flags & XFS_BMAPI_CONVERT);
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bma.wasdel = wasdelay;
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bma.minlen = minlen;
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bma.low = flist->xbf_low;
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bma.minleft = minleft;
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/*
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* Only want to do the alignment at the
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* eof if it is userdata and allocation length
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* is larger than a stripe unit.
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*/
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if (mp->m_dalign && alen >= mp->m_dalign &&
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(!(flags & XFS_BMAPI_METADATA)) &&
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(whichfork == XFS_DATA_FORK)) {
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if ((error = xfs_bmap_isaeof(ip, aoff,
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whichfork, &bma.aeof)))
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goto error0;
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} else
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bma.aeof = 0;
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/*
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* Call allocator.
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*/
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if ((error = xfs_bmap_alloc(&bma)))
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goto error0;
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/*
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* Copy out result fields.
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*/
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abno = bma.rval;
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if ((flist->xbf_low = bma.low))
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minleft = 0;
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alen = bma.alen;
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aoff = bma.off;
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ASSERT(*firstblock == NULLFSBLOCK ||
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XFS_FSB_TO_AGNO(mp, *firstblock) ==
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XFS_FSB_TO_AGNO(mp, bma.firstblock) ||
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(flist->xbf_low &&
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XFS_FSB_TO_AGNO(mp, *firstblock) <
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XFS_FSB_TO_AGNO(mp, bma.firstblock)));
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*firstblock = bma.firstblock;
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if (cur)
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cur->bc_private.b.firstblock =
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*firstblock;
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if (abno == NULLFSBLOCK)
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break;
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if ((ifp->if_flags & XFS_IFBROOT) && !cur) {
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cur = xfs_bmbt_init_cursor(mp, tp,
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ip, whichfork);
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cur->bc_private.b.firstblock =
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*firstblock;
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cur->bc_private.b.flist = flist;
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}
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/*
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* Bump the number of extents we've allocated
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* in this call.
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*/
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nallocs++;
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}
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if (cur)
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cur->bc_private.b.flags =
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wasdelay ? XFS_BTCUR_BPRV_WASDEL : 0;
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got.br_startoff = aoff;
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got.br_startblock = abno;
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got.br_blockcount = alen;
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got.br_state = XFS_EXT_NORM; /* assume normal */
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/*
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* Determine state of extent, and the filesystem.
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* A wasdelay extent has been initialized, so
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* shouldn't be flagged as unwritten.
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*/
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if (wr && xfs_sb_version_hasextflgbit(&mp->m_sb)) {
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if (!wasdelay && (flags & XFS_BMAPI_PREALLOC))
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got.br_state = XFS_EXT_UNWRITTEN;
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}
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error = xfs_bmap_add_extent(tp, ip, &lastx, &cur, &got,
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firstblock, flist, &tmp_logflags,
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whichfork);
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bma.eof = eof;
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bma.conv = !!(flags & XFS_BMAPI_CONVERT);
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bma.wasdel = wasdelay;
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bma.alen = len;
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bma.off = bno;
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bma.minleft = minleft;
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error = xfs_bmapi_allocate(&bma, &lastx, &cur,
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firstblock, flist, flags, &nallocs,
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&tmp_logflags);
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logflags |= tmp_logflags;
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if (error)
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goto error0;
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ep = xfs_iext_get_ext(ifp, lastx);
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xfs_bmbt_get_all(ep, &got);
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ASSERT(got.br_startoff <= aoff);
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ASSERT(got.br_startoff + got.br_blockcount >=
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aoff + alen);
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ASSERT(got.br_state == XFS_EXT_NORM ||
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got.br_state == XFS_EXT_UNWRITTEN);
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/*
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* Fall down into the found allocated space case.
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*/
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if (flist && flist->xbf_low)
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minleft = 0;
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if (bma.rval == NULLFSBLOCK)
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break;
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} else if (inhole) {
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/*
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* Reading in a hole.
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