@@ -158,6 +158,13 @@ static inline int xfs_bmapi_whichfork(int bmapi_flags)
{ BMAP_ATTRFORK, "ATTR" }, \
{ BMAP_COWFORK, "COW" }
+/* Return true if the extent is an allocated extent, written or not. */
+static inline bool xfs_bmap_is_real_extent(struct xfs_bmbt_irec *irec)
+{
+ return irec->br_startblock != HOLESTARTBLOCK &&
+ irec->br_startblock != DELAYSTARTBLOCK &&
+ !isnullstartblock(irec->br_startblock);
+}
/*
* Return true if the extent is a real, allocated extent, or false if it is a
@@ -165,10 +172,8 @@ static inline int xfs_bmapi_whichfork(int bmapi_flags)
*/
static inline bool xfs_bmap_is_written_extent(struct xfs_bmbt_irec *irec)
{
- return irec->br_state != XFS_EXT_UNWRITTEN &&
- irec->br_startblock != HOLESTARTBLOCK &&
- irec->br_startblock != DELAYSTARTBLOCK &&
- !isnullstartblock(irec->br_startblock);
+ return xfs_bmap_is_real_extent(irec) &&
+ irec->br_state != XFS_EXT_UNWRITTEN;
}
/*
@@ -986,41 +986,28 @@ xfs_reflink_ag_has_free_space(
}
/*
- * Unmap a range of blocks from a file, then map other blocks into the hole.
- * The range to unmap is (destoff : destoff + srcioff + irec->br_blockcount).
- * The extent irec is mapped into dest at irec->br_startoff.
+ * Remap the given extent into the file. The dmap blockcount will be set to
+ * the number of blocks that were actually remapped.
*/
STATIC int
xfs_reflink_remap_extent(
struct xfs_inode *ip,
- struct xfs_bmbt_irec *irec,
- xfs_fileoff_t destoff,
+ struct xfs_bmbt_irec *dmap,
xfs_off_t new_isize)
{
+ struct xfs_bmbt_irec smap;
struct xfs_mount *mp = ip->i_mount;
- bool real_extent = xfs_bmap_is_written_extent(irec);
struct xfs_trans *tp;
- unsigned int resblks;
- struct xfs_bmbt_irec uirec;
- xfs_filblks_t rlen;
- xfs_filblks_t unmap_len;
xfs_off_t newlen;
- int64_t qres;
+ int64_t qres, qdelta;
+ unsigned int resblks;
+ bool smap_real;
+ bool dmap_written = xfs_bmap_is_written_extent(dmap);
+ int nimaps;
int error;
- unmap_len = irec->br_startoff + irec->br_blockcount - destoff;
- trace_xfs_reflink_punch_range(ip, destoff, unmap_len);
-
- /* No reflinking if we're low on space */
- if (real_extent) {
- error = xfs_reflink_ag_has_free_space(mp,
- XFS_FSB_TO_AGNO(mp, irec->br_startblock));
- if (error)
- goto out;
- }
-
/* Start a rolling transaction to switch the mappings */
- resblks = XFS_EXTENTADD_SPACE_RES(ip->i_mount, XFS_DATA_FORK);
+ resblks = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK);
error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, 0, &tp);
if (error)
goto out;
@@ -1029,92 +1016,121 @@ xfs_reflink_remap_extent(
xfs_trans_ijoin(tp, ip, 0);
/*
- * Reserve quota for this operation. We don't know if the first unmap
- * in the dest file will cause a bmap btree split, so we always reserve
- * at least enough blocks for that split. If the extent being mapped
- * in is written, we need to reserve quota for that too.
+ * Read what's currently mapped in the destination file into smap.
+ * If smap isn't a hole, we will have to remove it before we can add
+ * dmap to the destination file.
*/
- qres = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK);
- if (real_extent)
- qres += irec->br_blockcount;
- error = xfs_trans_reserve_quota_nblks(tp, ip, qres, 0,
- XFS_QMOPT_RES_REGBLKS);
+ nimaps = 1;
+ error = xfs_bmapi_read(ip, dmap->br_startoff, dmap->br_blockcount,
+ &smap, &nimaps, 0);
if (error)
goto out_cancel;
+ ASSERT(nimaps == 1 && smap.br_startoff == dmap->br_startoff);
+ smap_real = xfs_bmap_is_real_extent(&smap);
- trace_xfs_reflink_remap(ip, irec->br_startoff,
- irec->br_blockcount, irec->br_startblock);
+ /*
+ * We can only remap as many blocks as the smaller of the two extent
+ * maps, because we can only remap one extent at a time.
+ */
+ dmap->br_blockcount = min(dmap->br_blockcount, smap.br_blockcount);
+ ASSERT(dmap->br_blockcount == smap.br_blockcount);
- /* Unmap the old blocks in the data fork. */
- rlen = unmap_len;
- while (rlen) {
- ASSERT(tp->t_firstblock == NULLFSBLOCK);
- error = __xfs_bunmapi(tp, ip, destoff, &rlen, 0, 1);
+ trace_xfs_reflink_remap_extent_dest(ip, &smap);
+
+ /* No reflinking if the AG of the dest mapping is low on space. */
+ if (dmap_written) {
+ error = xfs_reflink_ag_has_free_space(mp,
+ XFS_FSB_TO_AGNO(mp, dmap->br_startblock));
if (error)
goto out_cancel;
+ }
+ /*
+ * Compute quota reservation if we think the quota block counter for
+ * this file could increase.
+ *
+ * We start by reserving enough blocks to handle a bmbt split.
+ *
+ * If we are mapping a written extent into the file, we need to have
+ * enough quota block count reservation to handle the blocks in that
+ * extent.
+ *
+ * Note that if we're replacing a delalloc reservation with a written
+ * extent, we have to take the full quota reservation because removing
+ * the delalloc reservation gives the block count back to the quota
+ * count. This is suboptimal, but the VFS flushed the dest range
+ * before we started. That should have removed all the delalloc
+ * reservations, but we code defensively.
+ */
+ qdelta = 0;
+ qres = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK);
+ if (dmap_written)
+ qres += dmap->br_blockcount;
+ error = xfs_trans_reserve_quota_nblks(tp, ip, qres, 0,
+ XFS_QMOPT_RES_REGBLKS);
+ if (error)
+ goto out_cancel;
+
+ if (smap_real) {
/*
- * Trim the extent to whatever got unmapped.
- * Remember, bunmapi works backwards.
+ * If the extent we're unmapping is backed by storage (written
+ * or not), unmap the extent and drop its refcount.
*/
- uirec.br_startblock = irec->br_startblock + rlen;
- uirec.br_startoff = irec->br_startoff + rlen;
- uirec.br_blockcount = unmap_len - rlen;
- uirec.br_state = irec->br_state;
- unmap_len = rlen;
-
- /* If this isn't a real mapping, we're done. */
- if (!real_extent || uirec.br_blockcount == 0)
- goto next_extent;
-
- trace_xfs_reflink_remap(ip, uirec.br_startoff,
- uirec.br_blockcount, uirec.br_startblock);
+ xfs_bmap_unmap_extent(tp, ip, &smap);
+ xfs_refcount_decrease_extent(tp, &smap);
+ qdelta -= smap.br_blockcount;
+ } else if (smap.br_startblock == DELAYSTARTBLOCK) {
+ xfs_filblks_t len = smap.br_blockcount;
- /* Update the refcount tree */
- xfs_refcount_increase_extent(tp, &uirec);
-
- /* Map the new blocks into the data fork. */
- xfs_bmap_map_extent(tp, ip, &uirec);
+ /*
+ * If the extent we're unmapping is a delalloc reservation,
+ * we can use the regular bunmapi function to release the
+ * incore state. Dropping the delalloc reservation takes care
+ * of the quota reservation for us.
+ */
+ error = __xfs_bunmapi(NULL, ip, smap.br_startoff, &len, 0, 1);
+ if (error)
+ goto out_cancel;
+ ASSERT(len == 0);
+ }
- /* Update quota accounting. */
- xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_BCOUNT,
- uirec.br_blockcount);
+ /*
+ * If the extent we're sharing is backed by written storage, increase
+ * its refcount and map it into the file.
+ */
+ if (dmap_written) {
+ xfs_refcount_increase_extent(tp, dmap);
+ xfs_bmap_map_extent(tp, ip, dmap);
+ qdelta += dmap->br_blockcount;
+ }
- /* Update dest isize if needed. */
- newlen = XFS_FSB_TO_B(mp,
- uirec.br_startoff + uirec.br_blockcount);
- newlen = min_t(xfs_off_t, newlen, new_isize);
- if (newlen > i_size_read(VFS_I(ip))) {
- trace_xfs_reflink_update_inode_size(ip, newlen);
- i_size_write(VFS_I(ip), newlen);
- ip->i_d.di_size = newlen;
- xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
- }
+ xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_BCOUNT, qdelta);
-next_extent:
- /* Process all the deferred stuff. */
- error = xfs_defer_finish(&tp);
- if (error)
- goto out_cancel;
+ /* Update dest isize if needed. */
+ newlen = XFS_FSB_TO_B(mp, dmap->br_startoff + dmap->br_blockcount);
+ newlen = min_t(xfs_off_t, newlen, new_isize);
+ if (newlen > i_size_read(VFS_I(ip))) {
+ trace_xfs_reflink_update_inode_size(ip, newlen);
+ i_size_write(VFS_I(ip), newlen);
+ ip->i_d.di_size = newlen;
+ xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
}
+ /* Commit everything and unlock. */
error = xfs_trans_commit(tp);
- xfs_iunlock(ip, XFS_ILOCK_EXCL);
- if (error)
- goto out;
- return 0;
+ goto out_unlock;
out_cancel:
xfs_trans_cancel(tp);
+out_unlock:
xfs_iunlock(ip, XFS_ILOCK_EXCL);
out:
- trace_xfs_reflink_remap_extent_error(ip, error, _RET_IP_);
+ if (error)
+ trace_xfs_reflink_remap_extent_error(ip, error, _RET_IP_);
return error;
}
-/*
- * Iteratively remap one file's extents (and holes) to another's.
- */
+/* Remap a range of one file to the other. */
int
xfs_reflink_remap_blocks(
struct xfs_inode *src,
@@ -1125,25 +1141,22 @@ xfs_reflink_remap_blocks(
loff_t *remapped)
{
struct xfs_bmbt_irec imap;
- xfs_fileoff_t srcoff;
- xfs_fileoff_t destoff;
+ struct xfs_mount *mp = src->i_mount;
+ xfs_fileoff_t srcoff = XFS_B_TO_FSBT(mp, pos_in);
+ xfs_fileoff_t destoff = XFS_B_TO_FSBT(mp, pos_out);
xfs_filblks_t len;
- xfs_filblks_t range_len;
xfs_filblks_t remapped_len = 0;
xfs_off_t new_isize = pos_out + remap_len;
int nimaps;
int error = 0;
- destoff = XFS_B_TO_FSBT(src->i_mount, pos_out);
- srcoff = XFS_B_TO_FSBT(src->i_mount, pos_in);
- len = XFS_B_TO_FSB(src->i_mount, remap_len);
+ len = min_t(xfs_filblks_t, XFS_B_TO_FSB(mp, remap_len),
+ XFS_MAX_FILEOFF);
- /* drange = (destoff, destoff + len); srange = (srcoff, srcoff + len) */
- while (len) {
- uint lock_mode;
+ trace_xfs_reflink_remap_blocks(src, srcoff, len, dest, destoff);
- trace_xfs_reflink_remap_blocks_loop(src, srcoff, len,
- dest, destoff);
+ while (len > 0) {
+ unsigned int lock_mode;
/* Read extent from the source file */
nimaps = 1;
@@ -1152,18 +1165,25 @@ xfs_reflink_remap_blocks(
xfs_iunlock(src, lock_mode);
if (error)
break;
- ASSERT(nimaps == 1);
-
- trace_xfs_reflink_remap_imap(src, srcoff, len, XFS_DATA_FORK,
- &imap);
+ /*
+ * The caller supposedly flushed all dirty pages in the source
+ * file range, which means that writeback should have allocated
+ * or deleted all delalloc reservations in that range. If we
+ * find one, that's a good sign that something is seriously
+ * wrong here.
+ */
+ ASSERT(nimaps == 1 && imap.br_startoff == srcoff);
+ if (imap.br_startblock == DELAYSTARTBLOCK) {
+ ASSERT(imap.br_startblock != DELAYSTARTBLOCK);
+ error = -EFSCORRUPTED;
+ break;
+ }
- /* Translate imap into the destination file. */
- range_len = imap.br_startoff + imap.br_blockcount - srcoff;
- imap.br_startoff += destoff - srcoff;
+ trace_xfs_reflink_remap_extent_src(src, &imap);
- /* Clear dest from destoff to the end of imap and map it in. */
- error = xfs_reflink_remap_extent(dest, &imap, destoff,
- new_isize);
+ /* Remap into the destination file at the given offset. */
+ imap.br_startoff = destoff;
+ error = xfs_reflink_remap_extent(dest, &imap, new_isize);
if (error)
break;
@@ -1173,10 +1193,10 @@ xfs_reflink_remap_blocks(
}
/* Advance drange/srange */
- srcoff += range_len;
- destoff += range_len;
- len -= range_len;
- remapped_len += range_len;
+ srcoff += imap.br_blockcount;
+ destoff += imap.br_blockcount;
+ len -= imap.br_blockcount;
+ remapped_len += imap.br_blockcount;
}
if (error)
@@ -3078,8 +3078,7 @@ DEFINE_EVENT(xfs_inode_irec_class, name, \
DEFINE_INODE_EVENT(xfs_reflink_set_inode_flag);
DEFINE_INODE_EVENT(xfs_reflink_unset_inode_flag);
DEFINE_ITRUNC_EVENT(xfs_reflink_update_inode_size);
-DEFINE_IMAP_EVENT(xfs_reflink_remap_imap);
-TRACE_EVENT(xfs_reflink_remap_blocks_loop,
+TRACE_EVENT(xfs_reflink_remap_blocks,
TP_PROTO(struct xfs_inode *src, xfs_fileoff_t soffset,
xfs_filblks_t len, struct xfs_inode *dest,
xfs_fileoff_t doffset),
@@ -3110,59 +3109,14 @@ TRACE_EVENT(xfs_reflink_remap_blocks_loop,
__entry->dest_ino,
__entry->dest_lblk)
);
-TRACE_EVENT(xfs_reflink_punch_range,
- TP_PROTO(struct xfs_inode *ip, xfs_fileoff_t lblk,
- xfs_extlen_t len),
- TP_ARGS(ip, lblk, len),
- TP_STRUCT__entry(
- __field(dev_t, dev)
- __field(xfs_ino_t, ino)
- __field(xfs_fileoff_t, lblk)
- __field(xfs_extlen_t, len)
- ),
- TP_fast_assign(
- __entry->dev = VFS_I(ip)->i_sb->s_dev;
- __entry->ino = ip->i_ino;
- __entry->lblk = lblk;
- __entry->len = len;
- ),
- TP_printk("dev %d:%d ino 0x%llx lblk 0x%llx len 0x%x",
- MAJOR(__entry->dev), MINOR(__entry->dev),
- __entry->ino,
- __entry->lblk,
- __entry->len)
-);
-TRACE_EVENT(xfs_reflink_remap,
- TP_PROTO(struct xfs_inode *ip, xfs_fileoff_t lblk,
- xfs_extlen_t len, xfs_fsblock_t new_pblk),
- TP_ARGS(ip, lblk, len, new_pblk),
- TP_STRUCT__entry(
- __field(dev_t, dev)
- __field(xfs_ino_t, ino)
- __field(xfs_fileoff_t, lblk)
- __field(xfs_extlen_t, len)
- __field(xfs_fsblock_t, new_pblk)
- ),
- TP_fast_assign(
- __entry->dev = VFS_I(ip)->i_sb->s_dev;
- __entry->ino = ip->i_ino;
- __entry->lblk = lblk;
- __entry->len = len;
- __entry->new_pblk = new_pblk;
- ),
- TP_printk("dev %d:%d ino 0x%llx lblk 0x%llx len 0x%x new_pblk %llu",
- MAJOR(__entry->dev), MINOR(__entry->dev),
- __entry->ino,
- __entry->lblk,
- __entry->len,
- __entry->new_pblk)
-);
DEFINE_DOUBLE_IO_EVENT(xfs_reflink_remap_range);
DEFINE_INODE_ERROR_EVENT(xfs_reflink_remap_range_error);
DEFINE_INODE_ERROR_EVENT(xfs_reflink_set_inode_flag_error);
DEFINE_INODE_ERROR_EVENT(xfs_reflink_update_inode_size_error);
DEFINE_INODE_ERROR_EVENT(xfs_reflink_remap_blocks_error);
DEFINE_INODE_ERROR_EVENT(xfs_reflink_remap_extent_error);
+DEFINE_INODE_IREC_EVENT(xfs_reflink_remap_extent_src);
+DEFINE_INODE_IREC_EVENT(xfs_reflink_remap_extent_dest);
/* dedupe tracepoints */
DEFINE_DOUBLE_IO_EVENT(xfs_reflink_compare_extents);