xfs: create xfs_bmap_util.[ch]
There is a bunch of code in xfs_bmap.c that is kernel specific and
not shared with userspace. To minimise the difference between the
kernel and userspace code, shift this unshared code to
xfs_bmap_util.c, and the declarations to xfs_bmap_util.h.
The biggest issue here is xfs_bmap_finish() - userspace has it's own
definition of this function, and so we need to move it out of
xfs_bmap.[ch]. This means several other files need to include
xfs_bmap_util.h as well.
It also introduces and interesting dance for the stack switching
code in xfs_bmapi_allocate(). The stack switching/workqueue code is
actually moved to xfs_bmap_util.c, so that userspace can simply use
a #define in a header file to connect the dots without needing to
know about the stack switch code at all.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
new file mode 100644
index 0000000..8e48ddf
--- /dev/null
+++ b/fs/xfs/xfs_bmap_util.c
@@ -0,0 +1,834 @@
+/*
+ * Copyright (c) 2000-2006 Silicon Graphics, 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_format.h"
+#include "xfs_bit.h"
+#include "xfs_log.h"
+#include "xfs_inum.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_ag.h"
+#include "xfs_mount.h"
+#include "xfs_da_btree.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_alloc_btree.h"
+#include "xfs_ialloc_btree.h"
+#include "xfs_dinode.h"
+#include "xfs_inode.h"
+#include "xfs_btree.h"
+#include "xfs_extfree_item.h"
+#include "xfs_alloc.h"
+#include "xfs_bmap.h"
+#include "xfs_bmap_util.h"
+#include "xfs_rtalloc.h"
+#include "xfs_error.h"
+#include "xfs_quota.h"
+#include "xfs_trans_space.h"
+#include "xfs_trace.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 */
+ unsigned int logres; /* new log reservation */
+ unsigned int logcount; /* new log count */
+ 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);
+ logres = ntp->t_log_res;
+ logcount = ntp->t_log_count;
+ 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);
+
+ if ((error = xfs_trans_reserve(ntp, 0, logres, 0, XFS_TRANS_PERM_LOG_RES,
+ logcount)))
+ 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;
+}
+
+/*
+ * Stack switching interfaces for allocation
+ */
+static void
+xfs_bmapi_allocate_worker(
+ struct work_struct *work)
+{
+ struct xfs_bmalloca *args = container_of(work,
+ struct xfs_bmalloca, work);
+ unsigned long pflags;
+
+ /* we are in a transaction context here */
+ current_set_flags_nested(&pflags, PF_FSTRANS);
+
+ args->result = __xfs_bmapi_allocate(args);
+ complete(args->done);
+
+ current_restore_flags_nested(&pflags, PF_FSTRANS);
+}
+
+/*
+ * Some allocation requests often come in with little stack to work on. Push
+ * them off to a worker thread so there is lots of stack to use. Otherwise just
+ * call directly to avoid the context switch overhead here.
+ */
+int
+xfs_bmapi_allocate(
+ struct xfs_bmalloca *args)
+{
+ DECLARE_COMPLETION_ONSTACK(done);
+
+ if (!args->stack_switch)
+ return __xfs_bmapi_allocate(args);
+
+
+ args->done = &done;
+ INIT_WORK_ONSTACK(&args->work, xfs_bmapi_allocate_worker);
+ queue_work(xfs_alloc_wq, &args->work);
+ wait_for_completion(&done);
+ return args->result;
+}
+
+/*
+ * 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 is 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 XFS_ERROR(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 != NULLDFSBNO);
+ 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 XFS_ERROR(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 XFS_ERROR(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 XFS_ERROR(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 XFS_ERROR(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 XFS_ERROR(EINVAL);
+ }
+
+ nex = bmv->bmv_count - 1;
+ if (nex <= 0)
+ return XFS_ERROR(EINVAL);
+ bmvend = bmv->bmv_offset + bmv->bmv_length;
+
+
+ if (bmv->bmv_count > ULONG_MAX / sizeof(struct getbmapx))
+ return XFS_ERROR(ENOMEM);
+ out = kmem_zalloc(bmv->bmv_count * sizeof(struct getbmapx), KM_MAYFAIL);
+ if (!out) {
+ out = kmem_zalloc_large(bmv->bmv_count *
+ sizeof(struct getbmapx));
+ if (!out)
+ return XFS_ERROR(ENOMEM);
+ }
+
+ xfs_ilock(ip, XFS_IOLOCK_SHARED);
+ if (whichfork == XFS_DATA_FORK && !(iflags & BMV_IF_DELALLOC)) {
+ if (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_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_map_shared(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;
+ }
+
+ if (is_vmalloc_addr(out))
+ kmem_free_large(out);
+ else
+ 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 alays 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;
+}