From 87ad54d754e845ca5c7e96300088ebb382c958dc Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Fri, 3 Nov 2017 10:34:44 -0700
Subject: [PATCH 61/77] xfs: simplify xfs_reflink_convert_cow
Git-commit: b121459c7a56d2fb5a8ca6727bf9f87982738b01
Patch-mainline: v4.15-rc1
References: bsc#1095344
Instead of looking up extents to convert and calling xfs_bmapi_write on
each of them just let xfs_bmapi_write handle the full range. To make
this robust add a new XFS_BMAPI_CONVERT_ONLY that only converts ranges
and never allocates blocks.
[darrick: shorten the stringified CONVERT_ONLY trace flag]
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>
Acked-by: Nikolay Borisov <nborisov@suse.com>
---
fs/xfs/libxfs/xfs_bmap.c | 3 ++-
fs/xfs/libxfs/xfs_bmap.h | 6 +++++-
fs/xfs/xfs_reflink.c | 29 +++++++++++------------------
3 files changed, 18 insertions(+), 20 deletions(-)
diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index c0e20c6b8815..760f3cbb1dee 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -4347,7 +4347,8 @@ xfs_bmapi_write(
* First, deal with the hole before the allocated space
* that we found, if any.
*/
- if (need_alloc || wasdelay) {
+ if ((need_alloc || wasdelay) &&
+ !(flags & XFS_BMAPI_CONVERT_ONLY)) {
bma.eof = eof;
bma.conv = !!(flags & XFS_BMAPI_CONVERT);
bma.wasdel = wasdelay;
diff --git a/fs/xfs/libxfs/xfs_bmap.h b/fs/xfs/libxfs/xfs_bmap.h
index af64e90a9f03..5f4f97003157 100644
--- a/fs/xfs/libxfs/xfs_bmap.h
+++ b/fs/xfs/libxfs/xfs_bmap.h
@@ -113,6 +113,9 @@ struct xfs_extent_free_item
/* Only convert delalloc space, don't allocate entirely new extents */
#define XFS_BMAPI_DELALLOC 0x400
+/* Only convert unwritten extents, don't allocate new blocks */
+#define XFS_BMAPI_CONVERT_ONLY 0x800
+
#define XFS_BMAPI_FLAGS \
{ XFS_BMAPI_ENTIRE, "ENTIRE" }, \
{ XFS_BMAPI_METADATA, "METADATA" }, \
@@ -124,7 +127,8 @@ struct xfs_extent_free_item
{ XFS_BMAPI_ZERO, "ZERO" }, \
{ XFS_BMAPI_REMAP, "REMAP" }, \
{ XFS_BMAPI_COWFORK, "COWFORK" }, \
- { XFS_BMAPI_DELALLOC, "DELALLOC" }
+ { XFS_BMAPI_DELALLOC, "DELALLOC" }, \
+ { XFS_BMAPI_CONVERT_ONLY, "CONVERT_ONLY" }
static inline int xfs_bmapi_aflag(int w)
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index a89cdf1f89b0..51ea77e3c579 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -350,29 +350,22 @@ xfs_reflink_convert_cow(
xfs_off_t offset,
xfs_off_t count)
{
- struct xfs_bmbt_irec got;
- struct xfs_defer_ops dfops;
struct xfs_mount *mp = ip->i_mount;
- struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset);
xfs_fileoff_t end_fsb = XFS_B_TO_FSB(mp, offset + count);
- struct xfs_iext_cursor icur;
- bool found;
- int error = 0;
-
- xfs_ilock(ip, XFS_ILOCK_EXCL);
+ xfs_filblks_t count_fsb = end_fsb - offset_fsb;
+ struct xfs_bmbt_irec imap;
+ struct xfs_defer_ops dfops;
+ xfs_fsblock_t first_block = NULLFSBLOCK;
+ int nimaps = 1, error = 0;
- /* Convert all the extents to real from unwritten. */
- for (found = xfs_iext_lookup_extent(ip, ifp, offset_fsb, &icur, &got);
- found && got.br_startoff < end_fsb;
- found = xfs_iext_next_extent(ifp, &icur, &got)) {
- error = xfs_reflink_convert_cow_extent(ip, &got, offset_fsb,
- end_fsb - offset_fsb, &dfops);
- if (error)
- break;
- }
+ ASSERT(count != 0);
- /* Finish up. */
+ xfs_ilock(ip, XFS_ILOCK_EXCL);
+ error = xfs_bmapi_write(NULL, ip, offset_fsb, count_fsb,
+ XFS_BMAPI_COWFORK | XFS_BMAPI_CONVERT |
+ XFS_BMAPI_CONVERT_ONLY, &first_block, 0, &imap, &nimaps,
+ &dfops);
xfs_iunlock(ip, XFS_ILOCK_EXCL);
return error;
}
--
2.7.4