xfs: fill out the srcmap in iomap_begin

Replace our local hacks to report the source block in the main iomap
with the proper scrmap reporting.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
This commit is contained in:
Christoph Hellwig 2019-10-19 09:09:44 -07:00 committed by Darrick J. Wong
parent ae36b53c6c
commit 36adcbace2

View file

@ -527,7 +527,8 @@ xfs_file_iomap_begin_delay(
loff_t offset,
loff_t count,
unsigned flags,
struct iomap *iomap)
struct iomap *iomap,
struct iomap *srcmap)
{
struct xfs_inode *ip = XFS_I(inode);
struct xfs_mount *mp = ip->i_mount;
@ -721,11 +722,13 @@ xfs_file_iomap_begin_delay(
found_cow:
xfs_iunlock(ip, XFS_ILOCK_EXCL);
if (imap.br_startoff <= offset_fsb) {
/* ensure we only report blocks we have a reservation for */
xfs_trim_extent(&imap, cmap.br_startoff, cmap.br_blockcount);
return xfs_bmbt_to_iomap(ip, iomap, &imap, IOMAP_F_SHARED);
error = xfs_bmbt_to_iomap(ip, srcmap, &imap, 0);
if (error)
return error;
} else {
xfs_trim_extent(&cmap, offset_fsb,
imap.br_startoff - offset_fsb);
}
xfs_trim_extent(&cmap, offset_fsb, imap.br_startoff - offset_fsb);
return xfs_bmbt_to_iomap(ip, iomap, &cmap, IOMAP_F_SHARED);
out_unlock:
@ -933,7 +936,7 @@ xfs_file_iomap_begin(
{
struct xfs_inode *ip = XFS_I(inode);
struct xfs_mount *mp = ip->i_mount;
struct xfs_bmbt_irec imap;
struct xfs_bmbt_irec imap, cmap;
xfs_fileoff_t offset_fsb, end_fsb;
int nimaps = 1, error = 0;
bool shared = false;
@ -947,7 +950,7 @@ xfs_file_iomap_begin(
!IS_DAX(inode) && !xfs_get_extsz_hint(ip)) {
/* Reserve delalloc blocks for regular writeback. */
return xfs_file_iomap_begin_delay(inode, offset, length, flags,
iomap);
iomap, srcmap);
}
/*
@ -987,9 +990,6 @@ xfs_file_iomap_begin(
* been done up front, so we don't need to do them here.
*/
if (xfs_is_cow_inode(ip)) {
struct xfs_bmbt_irec cmap;
bool directio = (flags & IOMAP_DIRECT);
/* if zeroing doesn't need COW allocation, then we are done. */
if ((flags & IOMAP_ZERO) &&
!needs_cow_for_zeroing(&imap, nimaps))
@ -997,23 +997,11 @@ xfs_file_iomap_begin(
/* may drop and re-acquire the ilock */
error = xfs_reflink_allocate_cow(ip, &imap, &cmap, &shared,
&lockmode, directio);
&lockmode, flags & IOMAP_DIRECT);
if (error)
goto out_unlock;
/*
* For buffered writes we need to report the address of the
* previous block (if there was any) so that the higher level
* write code can perform read-modify-write operations; we
* won't need the CoW fork mapping until writeback. For direct
* I/O, which must be block aligned, we need to report the
* newly allocated address. If the data fork has a hole, copy
* the COW fork mapping to avoid allocating to the data fork.
*/
if (shared &&
(directio || imap.br_startblock == HOLESTARTBLOCK))
imap = cmap;
if (shared)
goto out_found_cow;
end_fsb = imap.br_startoff + imap.br_blockcount;
length = XFS_FSB_TO_B(mp, end_fsb) - offset;
}
@ -1074,6 +1062,17 @@ xfs_file_iomap_begin(
trace_xfs_iomap_found(ip, offset, length, XFS_DATA_FORK, &imap);
goto out_finish;
out_found_cow:
xfs_iunlock(ip, lockmode);
length = XFS_FSB_TO_B(mp, cmap.br_startoff + cmap.br_blockcount);
trace_xfs_iomap_found(ip, offset, length - offset, XFS_COW_FORK, &cmap);
if (imap.br_startblock != HOLESTARTBLOCK) {
error = xfs_bmbt_to_iomap(ip, srcmap, &imap, 0);
if (error)
return error;
}
return xfs_bmbt_to_iomap(ip, iomap, &cmap, IOMAP_F_SHARED);
out_unlock:
xfs_iunlock(ip, lockmode);
return error;