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-rw-r--r--fs/xfs/xfs_bmap_util.c1856
1 files changed, 1856 insertions, 0 deletions
diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
new file mode 100644
index 000000000..04d0c2bff
--- /dev/null
+++ b/fs/xfs/xfs_bmap_util.c
@@ -0,0 +1,1856 @@
+// 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_defer.h"
+#include "xfs_inode.h"
+#include "xfs_btree.h"
+#include "xfs_trans.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_iomap.h"
+#include "xfs_reflink.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)
+{
+ if (XFS_IS_REALTIME_INODE(ip))
+ return XFS_FSB_TO_BB(ip->i_mount, fsb);
+ return 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;
+ struct xfs_buftarg *target = xfs_inode_buftarg(ip);
+ xfs_daddr_t sector = xfs_fsb_to_db(ip, start_fsb);
+ sector_t block = XFS_BB_TO_FSBT(mp, sector);
+
+ return blkdev_issue_zeroout(target->bt_bdev,
+ 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)
+{
+ struct xfs_mount *mp = ap->ip->i_mount;
+ xfs_fileoff_t orig_offset = ap->offset;
+ xfs_rtblock_t rtb;
+ 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_extlen_t orig_length = ap->length;
+ xfs_extlen_t minlen = mp->m_sb.sb_rextsize;
+ xfs_extlen_t raminlen;
+ bool rtlocked = false;
+ bool ignore_locality = false;
+ int error;
+
+ align = xfs_get_extsz_hint(ap->ip);
+retry:
+ 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 we shifted the file offset downward to satisfy an extent size
+ * hint, increase minlen by that amount so that the allocator won't
+ * give us an allocation that's too short to cover at least one of the
+ * blocks that the caller asked for.
+ */
+ if (ap->offset != orig_offset)
+ minlen += orig_offset - ap->offset;
+
+ /*
+ * 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 XFS_BMBT_MAX_EXTLEN 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
+ * XFS_BMBT_MAX_EXTLEN), we don't hear about that number, and can't
+ * adjust the starting point to match it.
+ */
+ if (ralen * mp->m_sb.sb_rextsize >= XFS_MAX_BMBT_EXTLEN)
+ ralen = XFS_MAX_BMBT_EXTLEN / mp->m_sb.sb_rextsize;
+
+ /*
+ * Lock out modifications to both the RT bitmap and summary inodes
+ */
+ if (!rtlocked) {
+ 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);
+ rtlocked = true;
+ }
+
+ /*
+ * 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 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.
+ */
+ if (ignore_locality)
+ ap->blkno = 0;
+ else
+ do_div(ap->blkno, mp->m_sb.sb_rextsize);
+ rtb = ap->blkno;
+ ap->length = ralen;
+ raminlen = max_t(xfs_extlen_t, 1, minlen / mp->m_sb.sb_rextsize);
+ error = xfs_rtallocate_extent(ap->tp, ap->blkno, raminlen, ap->length,
+ &ralen, ap->wasdel, prod, &rtb);
+ if (error)
+ return error;
+
+ if (rtb != NULLRTBLOCK) {
+ ap->blkno = rtb * mp->m_sb.sb_rextsize;
+ ap->length = ralen * mp->m_sb.sb_rextsize;
+ ap->ip->i_nblocks += ap->length;
+ xfs_trans_log_inode(ap->tp, ap->ip, XFS_ILOG_CORE);
+ if (ap->wasdel)
+ ap->ip->i_delayed_blks -= ap->length;
+ /*
+ * 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, ap->length);
+ return 0;
+ }
+
+ if (align > mp->m_sb.sb_rextsize) {
+ /*
+ * We previously enlarged the request length to try to satisfy
+ * an extent size hint. The allocator didn't return anything,
+ * so reset the parameters to the original values and try again
+ * without alignment criteria.
+ */
+ ap->offset = orig_offset;
+ ap->length = orig_length;
+ minlen = align = mp->m_sb.sb_rextsize;
+ goto retry;
+ }
+
+ if (!ignore_locality && ap->blkno != 0) {
+ /*
+ * If we can't allocate near a specific rt extent, try again
+ * without locality criteria.
+ */
+ ignore_locality = true;
+ goto retry;
+ }
+
+ ap->blkno = NULLFSBLOCK;
+ ap->length = 0;
+ return 0;
+}
+#endif /* CONFIG_XFS_RT */
+
+/*
+ * 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 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 = ip->i_mount;
+ struct xfs_ifork *ifp = xfs_ifork_ptr(ip, whichfork);
+ struct xfs_btree_cur *cur;
+ xfs_extlen_t btblocks = 0;
+ int error;
+
+ *nextents = 0;
+ *count = 0;
+
+ if (!ifp)
+ return 0;
+
+ switch (ifp->if_format) {
+ case XFS_DINODE_FMT_BTREE:
+ error = xfs_iread_extents(tp, ip, whichfork);
+ if (error)
+ return error;
+
+ cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
+ error = xfs_btree_count_blocks(cur, &btblocks);
+ xfs_btree_del_cursor(cur, error);
+ if (error)
+ return error;
+
+ /*
+ * xfs_btree_count_blocks includes the root block contained in
+ * the inode fork in @btblocks, so subtract one because we're
+ * only interested in allocated disk blocks.
+ */
+ *count += btblocks - 1;
+
+ fallthrough;
+ case XFS_DINODE_FMT_EXTENTS:
+ *nextents = xfs_bmap_count_leaves(ifp, count);
+ break;
+ }
+
+ 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;
+ int error;
+
+ error = xfs_reflink_trim_around_shared(ip, got, &shared);
+ 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;
+
+ xfs_ilock(ip, XFS_IOLOCK_SHARED);
+ switch (whichfork) {
+ case XFS_ATTR_FORK:
+ lock = xfs_ilock_attr_map_shared(ip);
+ if (!xfs_inode_has_attr_fork(ip))
+ goto out_unlock_ilock;
+
+ max_len = 1LL << 32;
+ break;
+ case XFS_COW_FORK:
+ lock = XFS_ILOCK_SHARED;
+ xfs_ilock(ip, lock);
+
+ /* No CoW fork? Just return */
+ if (!xfs_ifork_ptr(ip, whichfork))
+ goto out_unlock_ilock;
+
+ if (xfs_get_cowextsz_hint(ip))
+ max_len = mp->m_super->s_maxbytes;
+ else
+ max_len = XFS_ISIZE(ip);
+ break;
+ case XFS_DATA_FORK:
+ if (!(iflags & BMV_IF_DELALLOC) &&
+ (ip->i_delayed_blks || XFS_ISIZE(ip) > ip->i_disk_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_diflags &
+ (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;
+ }
+
+ ifp = xfs_ifork_ptr(ip, whichfork);
+
+ switch (ifp->if_format) {
+ 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);
+
+ 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(!xfs_need_iread_extents(ifp));
+
+ 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)
+{
+ struct xfs_bmbt_irec imap;
+ struct xfs_mount *mp = ip->i_mount;
+ xfs_fileoff_t end_fsb;
+ xfs_fileoff_t last_fsb;
+ int nimaps = 1;
+ int error;
+
+ /*
+ * Caller must either hold the exclusive io lock; or be inactivating
+ * the inode, which guarantees there are no other users of the inode.
+ */
+ ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL) ||
+ (VFS_I(ip)->i_state & I_FREEING));
+
+ /* 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 (xfs_need_iread_extents(&ip->i_df))
+ 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_diflags & (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND))
+ if (!force || ip->i_delayed_blks == 0)
+ return false;
+
+ /*
+ * Do not try to free post-EOF blocks if EOF is beyond the end of the
+ * range supported by the page cache, because the truncation will loop
+ * forever.
+ */
+ end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_ISIZE(ip));
+ if (XFS_IS_REALTIME_INODE(ip) && mp->m_sb.sb_rextsize > 1)
+ end_fsb = roundup_64(end_fsb, mp->m_sb.sb_rextsize);
+ last_fsb = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes);
+ if (last_fsb <= end_fsb)
+ return false;
+
+ /*
+ * Look up the mapping for the first block past EOF. If we can't find
+ * it, there's nothing to free.
+ */
+ xfs_ilock(ip, XFS_ILOCK_SHARED);
+ error = xfs_bmapi_read(ip, end_fsb, last_fsb - end_fsb, &imap, &nimaps,
+ 0);
+ xfs_iunlock(ip, XFS_ILOCK_SHARED);
+ if (error || nimaps == 0)
+ return false;
+
+ /*
+ * If there's a real mapping there or there are delayed allocation
+ * reservations, then we have post-EOF blocks to try to free.
+ */
+ return imap.br_startblock != HOLESTARTBLOCK || ip->i_delayed_blks;
+}
+
+/*
+ * 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;
+ struct xfs_mount *mp = ip->i_mount;
+ int error;
+
+ /* 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_is_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)
+ goto err_cancel;
+
+ error = xfs_trans_commit(tp);
+ if (error)
+ goto out_unlock;
+
+ xfs_inode_clear_eofblocks_tag(ip);
+ goto out_unlock;
+
+err_cancel:
+ /*
+ * If we get an error at this point we simply don't
+ * bother truncating the file.
+ */
+ xfs_trans_cancel(tp);
+out_unlock:
+ 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)
+{
+ xfs_mount_t *mp = ip->i_mount;
+ xfs_off_t count;
+ xfs_filblks_t allocated_fsb;
+ xfs_filblks_t allocatesize_fsb;
+ xfs_extlen_t extsz, temp;
+ xfs_fileoff_t startoffset_fsb;
+ xfs_fileoff_t endoffset_fsb;
+ int nimaps;
+ int rt;
+ xfs_trans_t *tp;
+ xfs_bmbt_irec_t imaps[1], *imapp;
+ int error;
+
+ trace_xfs_alloc_file_space(ip);
+
+ if (xfs_is_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);
+ endoffset_fsb = XFS_B_TO_FSB(mp, offset + count);
+ allocatesize_fsb = endoffset_fsb - startoffset_fsb;
+
+ /*
+ * Allocate file space until done or until there is an error
+ */
+ while (allocatesize_fsb && !error) {
+ xfs_fileoff_t s, e;
+ unsigned int dblocks, rblocks, resblks;
+
+ /*
+ * 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 XFS_BMBT_MAX_EXTLEN (21 bits), so use that to enforce the
+ * limit.
+ */
+ resblks = min_t(xfs_fileoff_t, (e - s),
+ (XFS_MAX_BMBT_EXTLEN * nimaps));
+ if (unlikely(rt)) {
+ dblocks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
+ rblocks = resblks;
+ } else {
+ dblocks = XFS_DIOSTRAT_SPACE_RES(mp, resblks);
+ rblocks = 0;
+ }
+
+ error = xfs_trans_alloc_inode(ip, &M_RES(mp)->tr_write,
+ dblocks, rblocks, false, &tp);
+ if (error)
+ break;
+
+ error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK,
+ XFS_IEXT_ADD_NOSPLIT_CNT);
+ if (error == -EFBIG)
+ error = xfs_iext_count_upgrade(tp, ip,
+ XFS_IEXT_ADD_NOSPLIT_CNT);
+ if (error)
+ goto error;
+
+ error = xfs_bmapi_write(tp, ip, startoffset_fsb,
+ allocatesize_fsb, XFS_BMAPI_PREALLOC, 0, imapp,
+ &nimaps);
+ if (error)
+ goto error;
+
+ ip->i_diflags |= XFS_DIFLAG_PREALLOC;
+ xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+
+ 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;
+
+error:
+ 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_inode(ip, &M_RES(mp)->tr_write, resblks, 0,
+ false, &tp);
+ if (error)
+ return error;
+
+ error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK,
+ XFS_IEXT_PUNCH_HOLE_CNT);
+ if (error == -EFBIG)
+ error = xfs_iext_count_upgrade(tp, ip, XFS_IEXT_PUNCH_HOLE_CNT);
+ if (error)
+ goto out_trans_cancel;
+
+ 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;
+}
+
+/* Caller must first wait for the completion of any pending DIOs if required. */
+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;
+
+ rounding = max_t(xfs_off_t, mp->m_sb.sb_blocksize, 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;
+
+ startoffset_fsb = XFS_B_TO_FSB(mp, offset);
+ endoffset_fsb = XFS_B_TO_FSBT(mp, offset + len);
+
+ /* We can only free complete realtime extents. */
+ if (XFS_IS_REALTIME_INODE(ip) && mp->m_sb.sb_rextsize > 1) {
+ startoffset_fsb = roundup_64(startoffset_fsb,
+ mp->m_sb.sb_rextsize);
+ endoffset_fsb = rounddown_64(endoffset_fsb,
+ mp->m_sb.sb_rextsize);
+ }
+
+ /*
+ * Need to zero the stuff we're not freeing, on disk.
+ */
+ 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. xfs_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 = xfs_zero_range(ip, offset, len, NULL);
+ 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 xfs_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_in_page(offset + len) > 0) {
+ error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
+ round_down(offset + len, PAGE_SIZE), LLONG_MAX);
+ }
+
+ return error;
+}
+
+static int
+xfs_prepare_shift(
+ struct xfs_inode *ip,
+ loff_t offset)
+{
+ struct xfs_mount *mp = ip->i_mount;
+ 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;
+ }
+
+ /*
+ * Shift operations must stabilize the start block offset boundary along
+ * with the full range of the operation. If we don't, a COW writeback
+ * completion could race with an insert, front merge with the start
+ * extent (after split) during the shift and corrupt the file. Start
+ * with the block just prior to the start to stabilize the boundary.
+ */
+ offset = round_down(offset, mp->m_sb.sb_blocksize);
+ if (offset)
+ offset -= mp->m_sb.sb_blocksize;
+
+ /*
+ * Writeback and invalidate cache for the remainder of the file as we're
+ * about to shift down every extent from offset to EOF.
+ */
+ error = xfs_flush_unmap_range(ip, offset, XFS_ISIZE(ip));
+ 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);
+ 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;
+
+ error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0, 0, &tp);
+ if (error)
+ return error;
+
+ xfs_ilock(ip, XFS_ILOCK_EXCL);
+ xfs_trans_ijoin(tp, ip, 0);
+
+ while (!done) {
+ error = xfs_bmap_collapse_extents(tp, ip, &next_fsb, shift_fsb,
+ &done);
+ if (error)
+ goto out_trans_cancel;
+ if (done)
+ break;
+
+ /* finish any deferred frees and roll the transaction */
+ error = xfs_defer_finish(&tp);
+ if (error)
+ goto out_trans_cancel;
+ }
+
+ error = xfs_trans_commit(tp);
+ xfs_iunlock(ip, XFS_ILOCK_EXCL);
+ return error;
+
+out_trans_cancel:
+ xfs_trans_cancel(tp);
+ xfs_iunlock(ip, XFS_ILOCK_EXCL);
+ 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;
+
+ error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write,
+ XFS_DIOSTRAT_SPACE_RES(mp, 0), 0, 0, &tp);
+ if (error)
+ return error;
+
+ xfs_ilock(ip, XFS_ILOCK_EXCL);
+ xfs_trans_ijoin(tp, ip, 0);
+
+ error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK,
+ XFS_IEXT_PUNCH_HOLE_CNT);
+ if (error == -EFBIG)
+ error = xfs_iext_count_upgrade(tp, ip, XFS_IEXT_PUNCH_HOLE_CNT);
+ if (error)
+ goto out_trans_cancel;
+
+ /*
+ * 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(tp, ip, stop_fsb);
+ if (error)
+ goto out_trans_cancel;
+
+ do {
+ error = xfs_defer_finish(&tp);
+ if (error)
+ goto out_trans_cancel;
+
+ error = xfs_bmap_insert_extents(tp, ip, &next_fsb, shift_fsb,
+ &done, stop_fsb);
+ if (error)
+ goto out_trans_cancel;
+ } while (!done);
+
+ error = xfs_trans_commit(tp);
+ xfs_iunlock(ip, XFS_ILOCK_EXCL);
+ return error;
+
+out_trans_cancel:
+ xfs_trans_cancel(tp);
+ xfs_iunlock(ip, XFS_ILOCK_EXCL);
+ 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 */
+{
+ struct xfs_ifork *ifp = &ip->i_df;
+ struct xfs_ifork *tifp = &tip->i_df;
+
+ /* User/group/project quota ids must match if quotas are enforced. */
+ if (XFS_IS_QUOTA_ON(ip->i_mount) &&
+ (!uid_eq(VFS_I(ip)->i_uid, VFS_I(tip)->i_uid) ||
+ !gid_eq(VFS_I(ip)->i_gid, VFS_I(tip)->i_gid) ||
+ ip->i_projid != tip->i_projid))
+ return -EINVAL;
+
+ /* Should never get a local format */
+ if (ifp->if_format == XFS_DINODE_FMT_LOCAL ||
+ tifp->if_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 (ifp->if_nextents < tifp->if_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_has_rmapbt(ip->i_mount))
+ 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 (ifp->if_format == XFS_DINODE_FMT_EXTENTS &&
+ tifp->if_format == XFS_DINODE_FMT_BTREE)
+ return -EINVAL;
+
+ /* Check temp in extent form to max in target */
+ if (tifp->if_format == XFS_DINODE_FMT_EXTENTS &&
+ tifp->if_nextents > XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK))
+ return -EINVAL;
+
+ /* Check target in extent form to max in temp */
+ if (ifp->if_format == XFS_DINODE_FMT_EXTENTS &&
+ ifp->if_nextents > 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 (tifp->if_format == XFS_DINODE_FMT_BTREE) {
+ if (xfs_inode_has_attr_fork(ip) &&
+ XFS_BMAP_BMDR_SPACE(tifp->if_broot) > xfs_inode_fork_boff(ip))
+ return -EINVAL;
+ if (tifp->if_nextents <= XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK))
+ return -EINVAL;
+ }
+
+ /* Reciprocal target->temp btree format checks */
+ if (ifp->if_format == XFS_DINODE_FMT_BTREE) {
+ if (xfs_inode_has_attr_fork(tip) &&
+ XFS_BMAP_BMDR_SPACE(ip->i_df.if_broot) > xfs_inode_fork_boff(tip))
+ return -EINVAL;
+ if (ifp->if_nextents <= 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_diflags2;
+ if (ip->i_diflags2 & XFS_DIFLAG2_REFLINK)
+ tip->i_diflags2 |= 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);
+
+ if (xfs_bmap_is_real_extent(&uirec)) {
+ error = xfs_iext_count_may_overflow(ip,
+ XFS_DATA_FORK,
+ XFS_IEXT_SWAP_RMAP_CNT);
+ if (error == -EFBIG)
+ error = xfs_iext_count_upgrade(tp, ip,
+ XFS_IEXT_SWAP_RMAP_CNT);
+ if (error)
+ goto out;
+ }
+
+ if (xfs_bmap_is_real_extent(&irec)) {
+ error = xfs_iext_count_may_overflow(tip,
+ XFS_DATA_FORK,
+ XFS_IEXT_SWAP_RMAP_CNT);
+ if (error == -EFBIG)
+ error = xfs_iext_count_upgrade(tp, ip,
+ XFS_IEXT_SWAP_RMAP_CNT);
+ if (error)
+ goto out;
+ }
+
+ /* Remove the mapping from the donor file. */
+ xfs_bmap_unmap_extent(tp, tip, &uirec);
+
+ /* Remove the mapping from the source file. */
+ xfs_bmap_unmap_extent(tp, ip, &irec);
+
+ /* Map the donor file's blocks into the source file. */
+ xfs_bmap_map_extent(tp, ip, &uirec);
+
+ /* Map the source file's blocks into the donor file. */
+ xfs_bmap_map_extent(tp, tip, &irec);
+
+ 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_diflags2 = tip_flags2;
+ return 0;
+
+out:
+ trace_xfs_swap_extent_rmap_error(ip, error, _RET_IP_);
+ tip->i_diflags2 = 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_inode_has_attr_fork(ip) && ip->i_af.if_nextents > 0 &&
+ ip->i_af.if_format != XFS_DINODE_FMT_LOCAL) {
+ error = xfs_bmap_count_blocks(tp, ip, XFS_ATTR_FORK, &junk,
+ &aforkblks);
+ if (error)
+ return error;
+ }
+ if (xfs_inode_has_attr_fork(tip) && tip->i_af.if_nextents > 0 &&
+ tip->i_af.if_format != 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 (xfs_has_v3inodes(ip->i_mount)) {
+ if (ip->i_df.if_format == XFS_DINODE_FMT_BTREE)
+ (*target_log_flags) |= XFS_ILOG_DOWNER;
+ if (tip->i_df.if_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_nblocks;
+ ip->i_nblocks = tip->i_nblocks - taforkblks + aforkblks;
+ tip->i_nblocks = tmp + taforkblks - aforkblks;
+
+ /*
+ * 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_df.if_format) {
+ case XFS_DINODE_FMT_EXTENTS:
+ (*src_log_flags) |= XFS_ILOG_DEXT;
+ break;
+ case XFS_DINODE_FMT_BTREE:
+ ASSERT(!xfs_has_v3inodes(ip->i_mount) ||
+ (*src_log_flags & XFS_ILOG_DOWNER));
+ (*src_log_flags) |= XFS_ILOG_DBROOT;
+ break;
+ }
+
+ switch (tip->i_df.if_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(!xfs_has_v3inodes(ip->i_mount) ||
+ (*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;
+ uint64_t f;
+ int resblks = 0;
+ unsigned int flags = 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));
+ filemap_invalidate_lock_two(VFS_I(ip)->i_mapping,
+ VFS_I(tip)->i_mapping);
+
+ /* 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_qm_dqattach(ip);
+ if (error)
+ goto out_unlock;
+
+ error = xfs_qm_dqattach(tip);
+ if (error)
+ 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;
+
+ if (xfs_inode_has_cow_data(tip)) {
+ error = xfs_reflink_cancel_cow_range(tip, 0, NULLFILEOFF, true);
+ 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_has_rmapbt(mp)) {
+ int w = XFS_DATA_FORK;
+ uint32_t ipnext = ip->i_df.if_nextents;
+ uint32_t tipnext = tip->i_df.if_nextents;
+
+ /*
+ * 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);
+
+ /*
+ * If either inode straddles a bmapbt block allocation boundary,
+ * the rmapbt algorithm triggers repeated allocs and frees as
+ * extents are remapped. This can exhaust the block reservation
+ * prematurely and cause shutdown. Return freed blocks to the
+ * transaction reservation to counter this behavior.
+ */
+ flags |= XFS_TRANS_RES_FDBLKS;
+ }
+ error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, flags,
+ &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);
+ 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_disk_size ||
+ sxp->sx_length != tip->i_disk_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_has_rmapbt(mp))
+ 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_diflags2 & XFS_DIFLAG2_REFLINK) ^
+ (tip->i_diflags2 & XFS_DIFLAG2_REFLINK)) {
+ f = ip->i_diflags2 & XFS_DIFLAG2_REFLINK;
+ ip->i_diflags2 &= ~XFS_DIFLAG2_REFLINK;
+ ip->i_diflags2 |= tip->i_diflags2 & XFS_DIFLAG2_REFLINK;
+ tip->i_diflags2 &= ~XFS_DIFLAG2_REFLINK;
+ tip->i_diflags2 |= f & XFS_DIFLAG2_REFLINK;
+ }
+
+ /* Swap the cow forks. */
+ if (xfs_has_reflink(mp)) {
+ ASSERT(!ip->i_cowfp ||
+ ip->i_cowfp->if_format == XFS_DINODE_FMT_EXTENTS);
+ ASSERT(!tip->i_cowfp ||
+ tip->i_cowfp->if_format == XFS_DINODE_FMT_EXTENTS);
+
+ 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 (xfs_has_wsync(mp))
+ 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_ilock:
+ xfs_iunlock(ip, XFS_ILOCK_EXCL);
+ xfs_iunlock(tip, XFS_ILOCK_EXCL);
+out_unlock:
+ filemap_invalidate_unlock_two(VFS_I(ip)->i_mapping,
+ VFS_I(tip)->i_mapping);
+ unlock_two_nondirectories(VFS_I(ip), VFS_I(tip));
+ return error;
+
+out_trans_cancel:
+ xfs_trans_cancel(tp);
+ goto out_unlock_ilock;
+}