v4.19.13 snapshot.
diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
new file mode 100644
index 0000000..6de8d90
--- /dev/null
+++ b/fs/xfs/xfs_bmap_util.c
@@ -0,0 +1,1992 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2000-2006 Silicon Graphics, Inc.
+ * Copyright (c) 2012 Red Hat, Inc.
+ * All Rights Reserved.
+ */
+#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_defer.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"
+#include "xfs_rmap_btree.h"
+#include "xfs_iomap.h"
+#include "xfs_reflink.h"
+#include "xfs_refcount.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 zero an extent on disk allocated to the specific inode.
+ *
+ * The VFS functions take a linearised filesystem block offset, so we have to
+ * convert the sparse xfs fsb to the right format first.
+ * VFS types are real funky, too.
+ */
+int
+xfs_zero_extent(
+ struct xfs_inode *ip,
+ xfs_fsblock_t start_fsb,
+ xfs_off_t count_fsb)
+{
+ struct xfs_mount *mp = ip->i_mount;
+ xfs_daddr_t sector = xfs_fsb_to_db(ip, start_fsb);
+ sector_t block = XFS_BB_TO_FSBT(mp, sector);
+
+ return blkdev_issue_zeroout(xfs_find_bdev_for_inode(VFS_I(ip)),
+ block << (mp->m_super->s_blocksize_bits - 9),
+ count_fsb << (mp->m_super->s_blocksize_bits - 9),
+ GFP_NOFS, 0);
+}
+
+#ifdef CONFIG_XFS_RT
+int
+xfs_bmap_rtalloc(
+ struct xfs_bmalloca *ap) /* bmap alloc argument struct */
+{
+ int error; /* error return value */
+ xfs_mount_t *mp; /* mount point structure */
+ xfs_extlen_t prod = 0; /* product factor for allocators */
+ xfs_extlen_t mod = 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.
+ */
+ div_u64_rem(ap->offset, align, &mod);
+ if (mod || 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 modifications to both the RT bitmap and summary inodes
+ */
+ xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL|XFS_ILOCK_RTBITMAP);
+ xfs_trans_ijoin(ap->tp, mp->m_rbmip, XFS_ILOCK_EXCL);
+ xfs_ilock(mp->m_rsumip, XFS_ILOCK_EXCL|XFS_ILOCK_RTSUM);
+ xfs_trans_ijoin(ap->tp, mp->m_rsumip, 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.
+ */
+ do_div(ap->blkno, mp->m_sb.sb_rextsize);
+ rtb = ap->blkno;
+ ap->length = ralen;
+ error = xfs_rtallocate_extent(ap->tp, ap->blkno, 1, ap->length,
+ &ralen, ap->wasdel, prod, &rtb);
+ if (error)
+ 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);
+
+ /* Zero the extent if we were asked to do so */
+ if (ap->datatype & XFS_ALLOC_USERDATA_ZERO) {
+ error = xfs_zero_extent(ap->ip, ap->blkno, ap->length);
+ if (error)
+ return error;
+ }
+ } else {
+ ap->length = 0;
+ }
+ return 0;
+}
+#endif /* CONFIG_XFS_RT */
+
+/*
+ * 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. Delayed allocation
+ * extents are not counted towards the totals.
+ */
+xfs_extnum_t
+xfs_bmap_count_leaves(
+ struct xfs_ifork *ifp,
+ xfs_filblks_t *count)
+{
+ struct xfs_iext_cursor icur;
+ struct xfs_bmbt_irec got;
+ xfs_extnum_t numrecs = 0;
+
+ for_each_xfs_iext(ifp, &icur, &got) {
+ if (!isnullstartblock(got.br_startblock)) {
+ *count += got.br_blockcount;
+ numrecs++;
+ }
+ }
+
+ return numrecs;
+}
+
+/*
+ * 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,
+ xfs_filblks_t *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
+xfs_bmap_count_tree(
+ struct xfs_mount *mp,
+ struct xfs_trans *tp,
+ struct xfs_ifork *ifp,
+ xfs_fsblock_t blockno,
+ int levelin,
+ xfs_extnum_t *nextents,
+ xfs_filblks_t *count)
+{
+ int error;
+ struct xfs_buf *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);
+ error = xfs_bmap_count_tree(mp, tp, ifp, bno, level, nextents,
+ count);
+ if (error) {
+ 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);
+ (*nextents) += 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. Delayed allocation extents are
+ * not counted towards the totals.
+ */
+int
+xfs_bmap_count_blocks(
+ struct xfs_trans *tp,
+ struct xfs_inode *ip,
+ int whichfork,
+ xfs_extnum_t *nextents,
+ xfs_filblks_t *count)
+{
+ struct xfs_mount *mp; /* file system mount structure */
+ __be64 *pp; /* pointer to block address */
+ struct xfs_btree_block *block; /* current btree block */
+ struct xfs_ifork *ifp; /* fork structure */
+ xfs_fsblock_t bno; /* block # of "block" */
+ int level; /* btree level, for checking */
+ int error;
+
+ bno = NULLFSBLOCK;
+ mp = ip->i_mount;
+ *nextents = 0;
+ *count = 0;
+ ifp = XFS_IFORK_PTR(ip, whichfork);
+ if (!ifp)
+ return 0;
+
+ switch (XFS_IFORK_FORMAT(ip, whichfork)) {
+ case XFS_DINODE_FMT_EXTENTS:
+ *nextents = xfs_bmap_count_leaves(ifp, count);
+ return 0;
+ case XFS_DINODE_FMT_BTREE:
+ if (!(ifp->if_flags & XFS_IFEXTENTS)) {
+ error = xfs_iread_extents(tp, ip, whichfork);
+ if (error)
+ return error;
+ }
+
+ /*
+ * 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);
+
+ error = xfs_bmap_count_tree(mp, tp, ifp, bno, level,
+ nextents, count);
+ if (error) {
+ XFS_ERROR_REPORT("xfs_bmap_count_blocks(2)",
+ XFS_ERRLEVEL_LOW, mp);
+ return -EFSCORRUPTED;
+ }
+ return 0;
+ }
+
+ return 0;
+}
+
+static int
+xfs_getbmap_report_one(
+ struct xfs_inode *ip,
+ struct getbmapx *bmv,
+ struct kgetbmap *out,
+ int64_t bmv_end,
+ struct xfs_bmbt_irec *got)
+{
+ struct kgetbmap *p = out + bmv->bmv_entries;
+ bool shared = false, trimmed = false;
+ int error;
+
+ error = xfs_reflink_trim_around_shared(ip, got, &shared, &trimmed);
+ if (error)
+ return error;
+
+ if (isnullstartblock(got->br_startblock) ||
+ got->br_startblock == DELAYSTARTBLOCK) {
+ /*
+ * Delalloc 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 (got->br_startoff < XFS_B_TO_FSB(ip->i_mount, XFS_ISIZE(ip)))
+ ASSERT((bmv->bmv_iflags & BMV_IF_DELALLOC) != 0);
+
+ p->bmv_oflags |= BMV_OF_DELALLOC;
+ p->bmv_block = -2;
+ } else {
+ p->bmv_block = xfs_fsb_to_db(ip, got->br_startblock);
+ }
+
+ if (got->br_state == XFS_EXT_UNWRITTEN &&
+ (bmv->bmv_iflags & BMV_IF_PREALLOC))
+ p->bmv_oflags |= BMV_OF_PREALLOC;
+
+ if (shared)
+ p->bmv_oflags |= BMV_OF_SHARED;
+
+ p->bmv_offset = XFS_FSB_TO_BB(ip->i_mount, got->br_startoff);
+ p->bmv_length = XFS_FSB_TO_BB(ip->i_mount, got->br_blockcount);
+
+ bmv->bmv_offset = p->bmv_offset + p->bmv_length;
+ bmv->bmv_length = max(0LL, bmv_end - bmv->bmv_offset);
+ bmv->bmv_entries++;
+ return 0;
+}
+
+static void
+xfs_getbmap_report_hole(
+ struct xfs_inode *ip,
+ struct getbmapx *bmv,
+ struct kgetbmap *out,
+ int64_t bmv_end,
+ xfs_fileoff_t bno,
+ xfs_fileoff_t end)
+{
+ struct kgetbmap *p = out + bmv->bmv_entries;
+
+ if (bmv->bmv_iflags & BMV_IF_NO_HOLES)
+ return;
+
+ p->bmv_block = -1;
+ p->bmv_offset = XFS_FSB_TO_BB(ip->i_mount, bno);
+ p->bmv_length = XFS_FSB_TO_BB(ip->i_mount, end - bno);
+
+ bmv->bmv_offset = p->bmv_offset + p->bmv_length;
+ bmv->bmv_length = max(0LL, bmv_end - bmv->bmv_offset);
+ bmv->bmv_entries++;
+}
+
+static inline bool
+xfs_getbmap_full(
+ struct getbmapx *bmv)
+{
+ return bmv->bmv_length == 0 || bmv->bmv_entries >= bmv->bmv_count - 1;
+}
+
+static bool
+xfs_getbmap_next_rec(
+ struct xfs_bmbt_irec *rec,
+ xfs_fileoff_t total_end)
+{
+ xfs_fileoff_t end = rec->br_startoff + rec->br_blockcount;
+
+ if (end == total_end)
+ return false;
+
+ rec->br_startoff += rec->br_blockcount;
+ if (!isnullstartblock(rec->br_startblock) &&
+ rec->br_startblock != DELAYSTARTBLOCK)
+ rec->br_startblock += rec->br_blockcount;
+ rec->br_blockcount = total_end - end;
+ return true;
+}
+
+/*
+ * 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(
+ struct xfs_inode *ip,
+ struct getbmapx *bmv, /* user bmap structure */
+ struct kgetbmap *out)
+{
+ struct xfs_mount *mp = ip->i_mount;
+ int iflags = bmv->bmv_iflags;
+ int whichfork, lock, error = 0;
+ int64_t bmv_end, max_len;
+ xfs_fileoff_t bno, first_bno;
+ struct xfs_ifork *ifp;
+ struct xfs_bmbt_irec got, rec;
+ xfs_filblks_t len;
+ struct xfs_iext_cursor icur;
+
+ if (bmv->bmv_iflags & ~BMV_IF_VALID)
+ return -EINVAL;
+#ifndef DEBUG
+ /* Only allow CoW fork queries if we're debugging. */
+ if (iflags & BMV_IF_COWFORK)
+ return -EINVAL;
+#endif
+ if ((iflags & BMV_IF_ATTRFORK) && (iflags & BMV_IF_COWFORK))
+ return -EINVAL;
+
+ if (bmv->bmv_length < -1)
+ return -EINVAL;
+ bmv->bmv_entries = 0;
+ if (bmv->bmv_length == 0)
+ return 0;
+
+ if (iflags & BMV_IF_ATTRFORK)
+ whichfork = XFS_ATTR_FORK;
+ else if (iflags & BMV_IF_COWFORK)
+ whichfork = XFS_COW_FORK;
+ else
+ whichfork = XFS_DATA_FORK;
+ ifp = XFS_IFORK_PTR(ip, whichfork);
+
+ xfs_ilock(ip, XFS_IOLOCK_SHARED);
+ switch (whichfork) {
+ case XFS_ATTR_FORK:
+ if (!XFS_IFORK_Q(ip))
+ goto out_unlock_iolock;
+
+ max_len = 1LL << 32;
+ lock = xfs_ilock_attr_map_shared(ip);
+ break;
+ case XFS_COW_FORK:
+ /* No CoW fork? Just return */
+ if (!ifp)
+ goto out_unlock_iolock;
+
+ if (xfs_get_cowextsz_hint(ip))
+ max_len = mp->m_super->s_maxbytes;
+ else
+ max_len = XFS_ISIZE(ip);
+
+ lock = XFS_ILOCK_SHARED;
+ xfs_ilock(ip, lock);
+ break;
+ case 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.
+ */
+ }
+
+ if (xfs_get_extsz_hint(ip) ||
+ (ip->i_d.di_flags &
+ (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND)))
+ max_len = mp->m_super->s_maxbytes;
+ else
+ max_len = XFS_ISIZE(ip);
+
+ lock = xfs_ilock_data_map_shared(ip);
+ break;
+ }
+
+ switch (XFS_IFORK_FORMAT(ip, whichfork)) {
+ case XFS_DINODE_FMT_EXTENTS:
+ case XFS_DINODE_FMT_BTREE:
+ break;
+ case XFS_DINODE_FMT_LOCAL:
+ /* Local format inode forks report no extents. */
+ goto out_unlock_ilock;
+ default:
+ error = -EINVAL;
+ goto out_unlock_ilock;
+ }
+
+ if (bmv->bmv_length == -1) {
+ max_len = XFS_FSB_TO_BB(mp, XFS_B_TO_FSB(mp, max_len));
+ bmv->bmv_length = max(0LL, max_len - bmv->bmv_offset);
+ }
+
+ bmv_end = bmv->bmv_offset + bmv->bmv_length;
+
+ first_bno = bno = XFS_BB_TO_FSBT(mp, bmv->bmv_offset);
+ len = XFS_BB_TO_FSB(mp, bmv->bmv_length);
+
+ if (!(ifp->if_flags & XFS_IFEXTENTS)) {
+ error = xfs_iread_extents(NULL, ip, whichfork);
+ if (error)
+ goto out_unlock_ilock;
+ }
+
+ if (!xfs_iext_lookup_extent(ip, ifp, bno, &icur, &got)) {
+ /*
+ * Report a whole-file hole if the delalloc flag is set to
+ * stay compatible with the old implementation.
+ */
+ if (iflags & BMV_IF_DELALLOC)
+ xfs_getbmap_report_hole(ip, bmv, out, bmv_end, bno,
+ XFS_B_TO_FSB(mp, XFS_ISIZE(ip)));
+ goto out_unlock_ilock;
+ }
+
+ while (!xfs_getbmap_full(bmv)) {
+ xfs_trim_extent(&got, first_bno, len);
+
+ /*
+ * Report an entry for a hole if this extent doesn't directly
+ * follow the previous one.
+ */
+ if (got.br_startoff > bno) {
+ xfs_getbmap_report_hole(ip, bmv, out, bmv_end, bno,
+ got.br_startoff);
+ if (xfs_getbmap_full(bmv))
+ break;
+ }
+
+ /*
+ * In order to report shared extents accurately, we report each
+ * distinct shared / unshared part of a single bmbt record with
+ * an individual getbmapx record.
+ */
+ bno = got.br_startoff + got.br_blockcount;
+ rec = got;
+ do {
+ error = xfs_getbmap_report_one(ip, bmv, out, bmv_end,
+ &rec);
+ if (error || xfs_getbmap_full(bmv))
+ goto out_unlock_ilock;
+ } while (xfs_getbmap_next_rec(&rec, bno));
+
+ if (!xfs_iext_next_extent(ifp, &icur, &got)) {
+ xfs_fileoff_t end = XFS_B_TO_FSB(mp, XFS_ISIZE(ip));
+
+ out[bmv->bmv_entries - 1].bmv_oflags |= BMV_OF_LAST;
+
+ if (whichfork != XFS_ATTR_FORK && bno < end &&
+ !xfs_getbmap_full(bmv)) {
+ xfs_getbmap_report_hole(ip, bmv, out, bmv_end,
+ bno, end);
+ }
+ break;
+ }
+
+ if (bno >= first_bno + len)
+ break;
+ }
+
+out_unlock_ilock:
+ xfs_iunlock(ip, lock);
+out_unlock_iolock:
+ xfs_iunlock(ip, XFS_IOLOCK_SHARED);
+ return error;
+}
+
+/*
+ * Dead simple method of punching delalyed allocation blocks from a range in
+ * the inode. 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)
+{
+ struct xfs_ifork *ifp = &ip->i_df;
+ xfs_fileoff_t end_fsb = start_fsb + length;
+ struct xfs_bmbt_irec got, del;
+ struct xfs_iext_cursor icur;
+ int error = 0;
+
+ ASSERT(ifp->if_flags & XFS_IFEXTENTS);
+
+ xfs_ilock(ip, XFS_ILOCK_EXCL);
+ if (!xfs_iext_lookup_extent_before(ip, ifp, &end_fsb, &icur, &got))
+ goto out_unlock;
+
+ while (got.br_startoff + got.br_blockcount > start_fsb) {
+ del = got;
+ xfs_trim_extent(&del, start_fsb, length);
+
+ /*
+ * A delete can push the cursor forward. Step back to the
+ * previous extent on non-delalloc or extents outside the
+ * target range.
+ */
+ if (!del.br_blockcount ||
+ !isnullstartblock(del.br_startblock)) {
+ if (!xfs_iext_prev_extent(ifp, &icur, &got))
+ break;
+ continue;
+ }
+
+ error = xfs_bmap_del_extent_delay(ip, XFS_DATA_FORK, &icur,
+ &got, &del);
+ if (error || !xfs_iext_get_extent(ifp, &icur, &got))
+ break;
+ }
+
+out_unlock:
+ xfs_iunlock(ip, XFS_ILOCK_EXCL);
+ 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(VFS_I(ip)->i_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 to free any blocks beyond eof. The caller must hold
+ * IOLOCK_EXCL unless we are in the inode reclaim path and have the only
+ * reference to the inode.
+ */
+int
+xfs_free_eofblocks(
+ struct xfs_inode *ip)
+{
+ struct xfs_trans *tp;
+ int error;
+ xfs_fileoff_t end_fsb;
+ xfs_fileoff_t last_fsb;
+ xfs_filblks_t map_len;
+ int nimaps;
+ struct xfs_bmbt_irec imap;
+ struct xfs_mount *mp = ip->i_mount;
+
+ /*
+ * 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 there are blocks after the end of file, truncate the file to its
+ * current size to free them up.
+ */
+ 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);
+ if (error)
+ return error;
+
+ /* wait on dio to ensure i_size has settled */
+ inode_dio_wait(VFS_I(ip));
+
+ error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0,
+ &tp);
+ if (error) {
+ ASSERT(XFS_FORCED_SHUTDOWN(mp));
+ 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_flags(&tp, ip, XFS_DATA_FORK,
+ XFS_ISIZE(ip), XFS_BMAPI_NODISCARD);
+ if (error) {
+ /*
+ * If we get an error at this point we simply don't
+ * bother truncating the file.
+ */
+ xfs_trans_cancel(tp);
+ } else {
+ error = xfs_trans_commit(tp);
+ if (!error)
+ xfs_inode_clear_eofblocks_tag(ip);
+ }
+
+ xfs_iunlock(ip, XFS_ILOCK_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;
+ int nimaps;
+ int quota_flag;
+ int rt;
+ xfs_trans_t *tp;
+ xfs_bmbt_irec_t imaps[1], *imapp;
+ uint qblocks, resblks, resrtextents;
+ int error;
+
+ trace_xfs_alloc_file_space(ip);
+
+ if (XFS_FORCED_SHUTDOWN(mp))
+ return -EIO;
+
+ error = xfs_qm_dqattach(ip);
+ 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;
+ div_u64_rem(startoffset_fsb, extsz, &temp);
+ if (temp)
+ e += temp;
+ div_u64_rem(e, extsz, &temp);
+ if (temp)
+ 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.
+ */
+ error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks,
+ resrtextents, 0, &tp);
+
+ /*
+ * Check for running out of space
+ */
+ if (error) {
+ /*
+ * Free the transaction structure.
+ */
+ ASSERT(error == -ENOSPC || XFS_FORCED_SHUTDOWN(mp));
+ 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);
+
+ error = xfs_bmapi_write(tp, ip, startoffset_fsb,
+ allocatesize_fsb, alloc_type, resblks,
+ imapp, &nimaps);
+ if (error)
+ goto error0;
+
+ /*
+ * Complete the transaction
+ */
+ error = xfs_trans_commit(tp);
+ 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: /* unlock inode, unreserve quota blocks, cancel trans */
+ xfs_trans_unreserve_quota_nblks(tp, ip, (long)qblocks, 0, quota_flag);
+
+error1: /* Just cancel transaction */
+ xfs_trans_cancel(tp);
+ xfs_iunlock(ip, XFS_ILOCK_EXCL);
+ return error;
+}
+
+static int
+xfs_unmap_extent(
+ struct xfs_inode *ip,
+ xfs_fileoff_t startoffset_fsb,
+ xfs_filblks_t len_fsb,
+ int *done)
+{
+ struct xfs_mount *mp = ip->i_mount;
+ struct xfs_trans *tp;
+ uint resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
+ int error;
+
+ error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, 0, &tp);
+ if (error) {
+ ASSERT(error == -ENOSPC || XFS_FORCED_SHUTDOWN(mp));
+ return error;
+ }
+
+ 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 out_trans_cancel;
+
+ xfs_trans_ijoin(tp, ip, 0);
+
+ error = xfs_bunmapi(tp, ip, startoffset_fsb, len_fsb, 0, 2, done);
+ if (error)
+ goto out_trans_cancel;
+
+ error = xfs_trans_commit(tp);
+out_unlock:
+ xfs_iunlock(ip, XFS_ILOCK_EXCL);
+ return error;
+
+out_trans_cancel:
+ xfs_trans_cancel(tp);
+ goto out_unlock;
+}
+
+static int
+xfs_adjust_extent_unmap_boundaries(
+ struct xfs_inode *ip,
+ xfs_fileoff_t *startoffset_fsb,
+ xfs_fileoff_t *endoffset_fsb)
+{
+ struct xfs_mount *mp = ip->i_mount;
+ struct xfs_bmbt_irec imap;
+ int nimap, error;
+ xfs_extlen_t mod = 0;
+
+ nimap = 1;
+ error = xfs_bmapi_read(ip, *startoffset_fsb, 1, &imap, &nimap, 0);
+ if (error)
+ return error;
+
+ if (nimap && imap.br_startblock != HOLESTARTBLOCK) {
+ ASSERT(imap.br_startblock != DELAYSTARTBLOCK);
+ div_u64_rem(imap.br_startblock, mp->m_sb.sb_rextsize, &mod);
+ 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)
+ return error;
+
+ if (nimap && imap.br_startblock != HOLESTARTBLOCK) {
+ ASSERT(imap.br_startblock != DELAYSTARTBLOCK);
+ mod++;
+ if (mod && mod != mp->m_sb.sb_rextsize)
+ *endoffset_fsb -= mod;
+ }
+
+ return 0;
+}
+
+static int
+xfs_flush_unmap_range(
+ struct xfs_inode *ip,
+ xfs_off_t offset,
+ xfs_off_t len)
+{
+ struct xfs_mount *mp = ip->i_mount;
+ struct inode *inode = VFS_I(ip);
+ xfs_off_t rounding, start, end;
+ int error;
+
+ /* wait for the completion of any pending DIOs */
+ inode_dio_wait(inode);
+
+ rounding = max_t(xfs_off_t, 1 << mp->m_sb.sb_blocklog, PAGE_SIZE);
+ start = round_down(offset, rounding);
+ end = round_up(offset + len, rounding) - 1;
+
+ error = filemap_write_and_wait_range(inode->i_mapping, start, end);
+ if (error)
+ return error;
+ truncate_pagecache_range(inode, start, end);
+ return 0;
+}
+
+int
+xfs_free_file_space(
+ struct xfs_inode *ip,
+ xfs_off_t offset,
+ xfs_off_t len)
+{
+ struct xfs_mount *mp = ip->i_mount;
+ xfs_fileoff_t startoffset_fsb;
+ xfs_fileoff_t endoffset_fsb;
+ int done = 0, error;
+
+ trace_xfs_free_file_space(ip);
+
+ error = xfs_qm_dqattach(ip);
+ if (error)
+ return error;
+
+ if (len <= 0) /* if nothing being freed */
+ return 0;
+
+ error = xfs_flush_unmap_range(ip, offset, len);
+ if (error)
+ return error;
+
+ startoffset_fsb = XFS_B_TO_FSB(mp, offset);
+ endoffset_fsb = XFS_B_TO_FSBT(mp, offset + len);
+
+ /*
+ * Need to zero the stuff we're not freeing, on disk. If it's a RT file
+ * and we can't use unwritten extents then we actually need to ensure
+ * to zero the whole extent, otherwise we just need to take of block
+ * boundaries, and xfs_bunmapi will handle the rest.
+ */
+ if (XFS_IS_REALTIME_INODE(ip) &&
+ !xfs_sb_version_hasextflgbit(&mp->m_sb)) {
+ error = xfs_adjust_extent_unmap_boundaries(ip, &startoffset_fsb,
+ &endoffset_fsb);
+ if (error)
+ return error;
+ }
+
+ if (endoffset_fsb > startoffset_fsb) {
+ while (!done) {
+ error = xfs_unmap_extent(ip, startoffset_fsb,
+ endoffset_fsb - startoffset_fsb, &done);
+ if (error)
+ return error;
+ }
+ }
+
+ /*
+ * Now that we've unmap all full blocks we'll have to zero out any
+ * partial block at the beginning and/or end. iomap_zero_range is smart
+ * enough to skip any holes, including those we just created, but we
+ * must take care not to zero beyond EOF and enlarge i_size.
+ */
+ if (offset >= XFS_ISIZE(ip))
+ return 0;
+ if (offset + len > XFS_ISIZE(ip))
+ len = XFS_ISIZE(ip) - offset;
+ error = iomap_zero_range(VFS_I(ip), offset, len, NULL, &xfs_iomap_ops);
+ if (error)
+ return error;
+
+ /*
+ * If we zeroed right up to EOF and EOF straddles a page boundary we
+ * must make sure that the post-EOF area is also zeroed because the
+ * page could be mmap'd and iomap_zero_range doesn't do that for us.
+ * Writeback of the eof page will do this, albeit clumsily.
+ */
+ if (offset + len >= XFS_ISIZE(ip) && ((offset + len) & PAGE_MASK)) {
+ error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
+ (offset + len) & ~PAGE_MASK, LLONG_MAX);
+ }
+
+ return error;
+}
+
+/*
+ * 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;
+
+}
+
+static int
+xfs_prepare_shift(
+ struct xfs_inode *ip,
+ loff_t offset)
+{
+ int error;
+
+ /*
+ * 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(ip);
+ 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_SHIFT, -1);
+ if (error)
+ return error;
+
+ /*
+ * Clean out anything hanging around in the cow fork now that
+ * we've flushed all the dirty data out to disk to avoid having
+ * CoW extents at the wrong offsets.
+ */
+ if (xfs_inode_has_cow_data(ip)) {
+ error = xfs_reflink_cancel_cow_range(ip, offset, NULLFILEOFF,
+ true);
+ if (error)
+ return error;
+ }
+
+ return 0;
+}
+
+/*
+ * 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)
+{
+ struct xfs_mount *mp = ip->i_mount;
+ struct xfs_trans *tp;
+ int error;
+ xfs_fileoff_t next_fsb = XFS_B_TO_FSB(mp, offset + len);
+ xfs_fileoff_t shift_fsb = XFS_B_TO_FSB(mp, len);
+ uint resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
+ bool done = false;
+
+ ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
+ ASSERT(xfs_isilocked(ip, XFS_MMAPLOCK_EXCL));
+
+ trace_xfs_collapse_file_space(ip);
+
+ error = xfs_free_file_space(ip, offset, len);
+ if (error)
+ return error;
+
+ error = xfs_prepare_shift(ip, offset);
+ if (error)
+ return error;
+
+ while (!error && !done) {
+ error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, 0,
+ &tp);
+ if (error)
+ 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 out_trans_cancel;
+ xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
+
+ error = xfs_bmap_collapse_extents(tp, ip, &next_fsb, shift_fsb,
+ &done);
+ if (error)
+ goto out_trans_cancel;
+
+ error = xfs_trans_commit(tp);
+ }
+
+ return error;
+
+out_trans_cancel:
+ xfs_trans_cancel(tp);
+ return error;
+}
+
+/*
+ * 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)
+{
+ struct xfs_mount *mp = ip->i_mount;
+ struct xfs_trans *tp;
+ int error;
+ xfs_fileoff_t stop_fsb = XFS_B_TO_FSB(mp, offset);
+ xfs_fileoff_t next_fsb = NULLFSBLOCK;
+ xfs_fileoff_t shift_fsb = XFS_B_TO_FSB(mp, len);
+ bool done = false;
+
+ ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
+ ASSERT(xfs_isilocked(ip, XFS_MMAPLOCK_EXCL));
+
+ trace_xfs_insert_file_space(ip);
+
+ error = xfs_bmap_can_insert_extents(ip, stop_fsb, shift_fsb);
+ if (error)
+ return error;
+
+ error = xfs_prepare_shift(ip, offset);
+ if (error)
+ return error;
+
+ /*
+ * The extent shifting 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.
+ */
+ error = xfs_bmap_split_extent(ip, stop_fsb);
+ if (error)
+ return error;
+
+ while (!error && !done) {
+ error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0, 0,
+ &tp);
+ if (error)
+ break;
+
+ xfs_ilock(ip, XFS_ILOCK_EXCL);
+ xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
+ error = xfs_bmap_insert_extents(tp, ip, &next_fsb, shift_fsb,
+ &done, stop_fsb);
+ if (error)
+ goto out_trans_cancel;
+
+ error = xfs_trans_commit(tp);
+ }
+
+ return error;
+
+out_trans_cancel:
+ xfs_trans_cancel(tp);
+ return error;
+}
+
+/*
+ * 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(
+ struct xfs_inode *ip, /* target inode */
+ struct xfs_inode *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 we have to use the (expensive) rmap swap method, we can
+ * handle any number of extents and any format.
+ */
+ if (xfs_sb_version_hasrmapbt(&ip->i_mount->m_sb))
+ return 0;
+
+ /*
+ * 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_Q(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_Q(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;
+}
+
+/*
+ * Move extents from one file to another, when rmap is enabled.
+ */
+STATIC int
+xfs_swap_extent_rmap(
+ struct xfs_trans **tpp,
+ struct xfs_inode *ip,
+ struct xfs_inode *tip)
+{
+ struct xfs_trans *tp = *tpp;
+ struct xfs_bmbt_irec irec;
+ struct xfs_bmbt_irec uirec;
+ struct xfs_bmbt_irec tirec;
+ xfs_fileoff_t offset_fsb;
+ xfs_fileoff_t end_fsb;
+ xfs_filblks_t count_fsb;
+ int error;
+ xfs_filblks_t ilen;
+ xfs_filblks_t rlen;
+ int nimaps;
+ uint64_t tip_flags2;
+
+ /*
+ * If the source file has shared blocks, we must flag the donor
+ * file as having shared blocks so that we get the shared-block
+ * rmap functions when we go to fix up the rmaps. The flags
+ * will be switch for reals later.
+ */
+ tip_flags2 = tip->i_d.di_flags2;
+ if (ip->i_d.di_flags2 & XFS_DIFLAG2_REFLINK)
+ tip->i_d.di_flags2 |= XFS_DIFLAG2_REFLINK;
+
+ offset_fsb = 0;
+ end_fsb = XFS_B_TO_FSB(ip->i_mount, i_size_read(VFS_I(ip)));
+ count_fsb = (xfs_filblks_t)(end_fsb - offset_fsb);
+
+ while (count_fsb) {
+ /* Read extent from the donor file */
+ nimaps = 1;
+ error = xfs_bmapi_read(tip, offset_fsb, count_fsb, &tirec,
+ &nimaps, 0);
+ if (error)
+ goto out;
+ ASSERT(nimaps == 1);
+ ASSERT(tirec.br_startblock != DELAYSTARTBLOCK);
+
+ trace_xfs_swap_extent_rmap_remap(tip, &tirec);
+ ilen = tirec.br_blockcount;
+
+ /* Unmap the old blocks in the source file. */
+ while (tirec.br_blockcount) {
+ ASSERT(tp->t_firstblock == NULLFSBLOCK);
+ trace_xfs_swap_extent_rmap_remap_piece(tip, &tirec);
+
+ /* Read extent from the source file */
+ nimaps = 1;
+ error = xfs_bmapi_read(ip, tirec.br_startoff,
+ tirec.br_blockcount, &irec,
+ &nimaps, 0);
+ if (error)
+ goto out;
+ ASSERT(nimaps == 1);
+ ASSERT(tirec.br_startoff == irec.br_startoff);
+ trace_xfs_swap_extent_rmap_remap_piece(ip, &irec);
+
+ /* Trim the extent. */
+ uirec = tirec;
+ uirec.br_blockcount = rlen = min_t(xfs_filblks_t,
+ tirec.br_blockcount,
+ irec.br_blockcount);
+ trace_xfs_swap_extent_rmap_remap_piece(tip, &uirec);
+
+ /* Remove the mapping from the donor file. */
+ error = xfs_bmap_unmap_extent(tp, tip, &uirec);
+ if (error)
+ goto out;
+
+ /* Remove the mapping from the source file. */
+ error = xfs_bmap_unmap_extent(tp, ip, &irec);
+ if (error)
+ goto out;
+
+ /* Map the donor file's blocks into the source file. */
+ error = xfs_bmap_map_extent(tp, ip, &uirec);
+ if (error)
+ goto out;
+
+ /* Map the source file's blocks into the donor file. */
+ error = xfs_bmap_map_extent(tp, tip, &irec);
+ if (error)
+ goto out;
+
+ error = xfs_defer_finish(tpp);
+ tp = *tpp;
+ if (error)
+ goto out;
+
+ tirec.br_startoff += rlen;
+ if (tirec.br_startblock != HOLESTARTBLOCK &&
+ tirec.br_startblock != DELAYSTARTBLOCK)
+ tirec.br_startblock += rlen;
+ tirec.br_blockcount -= rlen;
+ }
+
+ /* Roll on... */
+ count_fsb -= ilen;
+ offset_fsb += ilen;
+ }
+
+ tip->i_d.di_flags2 = tip_flags2;
+ return 0;
+
+out:
+ trace_xfs_swap_extent_rmap_error(ip, error, _RET_IP_);
+ tip->i_d.di_flags2 = tip_flags2;
+ return error;
+}
+
+/* Swap the extents of two files by swapping data forks. */
+STATIC int
+xfs_swap_extent_forks(
+ struct xfs_trans *tp,
+ struct xfs_inode *ip,
+ struct xfs_inode *tip,
+ int *src_log_flags,
+ int *target_log_flags)
+{
+ xfs_filblks_t aforkblks = 0;
+ xfs_filblks_t taforkblks = 0;
+ xfs_extnum_t junk;
+ uint64_t tmp;
+ int error;
+
+ /*
+ * 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, &junk,
+ &aforkblks);
+ if (error)
+ return error;
+ }
+ 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, &junk,
+ &taforkblks);
+ if (error)
+ return error;
+ }
+
+ /*
+ * Btree format (v3) inodes have the inode number stamped in the bmbt
+ * block headers. We can't start changing the bmbt blocks until the
+ * inode owner change is logged so recovery does the right thing in the
+ * event of a crash. Set the owner change log flags now and leave the
+ * bmbt scan as the last step.
+ */
+ if (ip->i_d.di_version == 3 &&
+ ip->i_d.di_format == XFS_DINODE_FMT_BTREE)
+ (*target_log_flags) |= XFS_ILOG_DOWNER;
+ if (tip->i_d.di_version == 3 &&
+ tip->i_d.di_format == XFS_DINODE_FMT_BTREE)
+ (*src_log_flags) |= XFS_ILOG_DOWNER;
+
+ /*
+ * Swap the data forks of the inodes
+ */
+ swap(ip->i_df, tip->i_df);
+
+ /*
+ * 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;
+
+ swap(ip->i_d.di_nextents, tip->i_d.di_nextents);
+ swap(ip->i_d.di_format, tip->i_d.di_format);
+
+ /*
+ * 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:
+ (*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:
+ (*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;
+ }
+
+ return 0;
+}
+
+/*
+ * Fix up the owners of the bmbt blocks to refer to the current inode. The
+ * change owner scan attempts to order all modified buffers in the current
+ * transaction. In the event of ordered buffer failure, the offending buffer is
+ * physically logged as a fallback and the scan returns -EAGAIN. We must roll
+ * the transaction in this case to replenish the fallback log reservation and
+ * restart the scan. This process repeats until the scan completes.
+ */
+static int
+xfs_swap_change_owner(
+ struct xfs_trans **tpp,
+ struct xfs_inode *ip,
+ struct xfs_inode *tmpip)
+{
+ int error;
+ struct xfs_trans *tp = *tpp;
+
+ do {
+ error = xfs_bmbt_change_owner(tp, ip, XFS_DATA_FORK, ip->i_ino,
+ NULL);
+ /* success or fatal error */
+ if (error != -EAGAIN)
+ break;
+
+ error = xfs_trans_roll(tpp);
+ if (error)
+ break;
+ tp = *tpp;
+
+ /*
+ * Redirty both inodes so they can relog and keep the log tail
+ * moving forward.
+ */
+ xfs_trans_ijoin(tp, ip, 0);
+ xfs_trans_ijoin(tp, tmpip, 0);
+ xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+ xfs_trans_log_inode(tp, tmpip, XFS_ILOG_CORE);
+ } while (true);
+
+ return error;
+}
+
+int
+xfs_swap_extents(
+ struct xfs_inode *ip, /* target inode */
+ struct xfs_inode *tip, /* tmp inode */
+ struct xfs_swapext *sxp)
+{
+ struct xfs_mount *mp = ip->i_mount;
+ struct xfs_trans *tp;
+ struct xfs_bstat *sbp = &sxp->sx_stat;
+ int src_log_flags, target_log_flags;
+ int error = 0;
+ int lock_flags;
+ uint64_t f;
+ int resblks = 0;
+
+ /*
+ * 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_two_nondirectories(VFS_I(ip), VFS_I(tip));
+ lock_flags = XFS_MMAPLOCK_EXCL;
+ xfs_lock_two_inodes(ip, XFS_MMAPLOCK_EXCL, tip, XFS_MMAPLOCK_EXCL);
+
+ /* Verify that both files have the same format */
+ if ((VFS_I(ip)->i_mode & S_IFMT) != (VFS_I(tip)->i_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;
+
+ /*
+ * Extent "swapping" with rmap requires a permanent reservation and
+ * a block reservation because it's really just a remap operation
+ * performed with log redo items!
+ */
+ if (xfs_sb_version_hasrmapbt(&mp->m_sb)) {
+ int w = XFS_DATA_FORK;
+ uint32_t ipnext = XFS_IFORK_NEXTENTS(ip, w);
+ uint32_t tipnext = XFS_IFORK_NEXTENTS(tip, w);
+
+ /*
+ * Conceptually this shouldn't affect the shape of either bmbt,
+ * but since we atomically move extents one by one, we reserve
+ * enough space to rebuild both trees.
+ */
+ resblks = XFS_SWAP_RMAP_SPACE_RES(mp, ipnext, w);
+ resblks += XFS_SWAP_RMAP_SPACE_RES(mp, tipnext, w);
+
+ /*
+ * Handle the corner case where either inode might straddle the
+ * btree format boundary. If so, the inode could bounce between
+ * btree <-> extent format on unmap -> remap cycles, freeing and
+ * allocating a bmapbt block each time.
+ */
+ if (ipnext == (XFS_IFORK_MAXEXT(ip, w) + 1))
+ resblks += XFS_IFORK_MAXEXT(ip, w);
+ if (tipnext == (XFS_IFORK_MAXEXT(tip, w) + 1))
+ resblks += XFS_IFORK_MAXEXT(tip, w);
+ }
+ error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, 0, &tp);
+ if (error)
+ 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, XFS_ILOCK_EXCL, tip, XFS_ILOCK_EXCL);
+ lock_flags |= XFS_ILOCK_EXCL;
+ xfs_trans_ijoin(tp, ip, 0);
+ xfs_trans_ijoin(tp, tip, 0);
+
+
+ /* 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;
+ }
+
+ /*
+ * 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 (xfs_sb_version_hasrmapbt(&mp->m_sb))
+ error = xfs_swap_extent_rmap(&tp, ip, tip);
+ else
+ error = xfs_swap_extent_forks(tp, ip, tip, &src_log_flags,
+ &target_log_flags);
+ if (error)
+ goto out_trans_cancel;
+
+ /* Do we have to swap reflink flags? */
+ if ((ip->i_d.di_flags2 & XFS_DIFLAG2_REFLINK) ^
+ (tip->i_d.di_flags2 & XFS_DIFLAG2_REFLINK)) {
+ f = ip->i_d.di_flags2 & XFS_DIFLAG2_REFLINK;
+ ip->i_d.di_flags2 &= ~XFS_DIFLAG2_REFLINK;
+ ip->i_d.di_flags2 |= tip->i_d.di_flags2 & XFS_DIFLAG2_REFLINK;
+ tip->i_d.di_flags2 &= ~XFS_DIFLAG2_REFLINK;
+ tip->i_d.di_flags2 |= f & XFS_DIFLAG2_REFLINK;
+ }
+
+ /* Swap the cow forks. */
+ if (xfs_sb_version_hasreflink(&mp->m_sb)) {
+ ASSERT(ip->i_cformat == XFS_DINODE_FMT_EXTENTS);
+ ASSERT(tip->i_cformat == XFS_DINODE_FMT_EXTENTS);
+
+ swap(ip->i_cnextents, tip->i_cnextents);
+ swap(ip->i_cowfp, tip->i_cowfp);
+
+ if (ip->i_cowfp && ip->i_cowfp->if_bytes)
+ xfs_inode_set_cowblocks_tag(ip);
+ else
+ xfs_inode_clear_cowblocks_tag(ip);
+ if (tip->i_cowfp && tip->i_cowfp->if_bytes)
+ xfs_inode_set_cowblocks_tag(tip);
+ else
+ xfs_inode_clear_cowblocks_tag(tip);
+ }
+
+ xfs_trans_log_inode(tp, ip, src_log_flags);
+ xfs_trans_log_inode(tp, tip, target_log_flags);
+
+ /*
+ * The extent forks have been swapped, but crc=1,rmapbt=0 filesystems
+ * have inode number owner values in the bmbt blocks that still refer to
+ * the old inode. Scan each bmbt to fix up the owner values with the
+ * inode number of the current inode.
+ */
+ if (src_log_flags & XFS_ILOG_DOWNER) {
+ error = xfs_swap_change_owner(&tp, ip, tip);
+ if (error)
+ goto out_trans_cancel;
+ }
+ if (target_log_flags & XFS_ILOG_DOWNER) {
+ error = xfs_swap_change_owner(&tp, tip, ip);
+ if (error)
+ goto out_trans_cancel;
+ }
+
+ /*
+ * 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);
+
+ trace_xfs_swap_extent_after(ip, 0);
+ trace_xfs_swap_extent_after(tip, 1);
+
+out_unlock:
+ xfs_iunlock(ip, lock_flags);
+ xfs_iunlock(tip, lock_flags);
+ unlock_two_nondirectories(VFS_I(ip), VFS_I(tip));
+ return error;
+
+out_trans_cancel:
+ xfs_trans_cancel(tp);
+ goto out_unlock;
+}