From: John Garry <john.g.garry@oracle.com> mainline inclusion from mainline-v6.15-rc2 commit 514df14fae97c91521ef53faf3a386e26afb8bee category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/ID2HML CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- Refactor xfs_reflink_end_cow_extent() into separate parts which process the CoW range and commit the transaction. This refactoring will be used in future for when it is required to commit a range of extents as a single transaction, similar to how it was done pre-commit d6f215f359637. Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: John Garry <john.g.garry@oracle.com> Signed-off-by: Long Li <leo.lilong@huawei.com> --- fs/xfs/xfs_reflink.c | 72 ++++++++++++++++++++++++++------------------ 1 file changed, 42 insertions(+), 30 deletions(-) diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index 3431d0d8b6f3..a8a48587d1ed 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -702,41 +702,25 @@ xfs_reflink_cancel_cow_range( * requirements as low as possible. */ STATIC int -xfs_reflink_end_cow_extent( +xfs_reflink_end_cow_extent_locked( + struct xfs_trans *tp, struct xfs_inode *ip, xfs_fileoff_t *offset_fsb, xfs_fileoff_t end_fsb) { struct xfs_iext_cursor icur; struct xfs_bmbt_irec got, del, data; - struct xfs_mount *mp = ip->i_mount; - struct xfs_trans *tp; struct xfs_ifork *ifp = xfs_ifork_ptr(ip, XFS_COW_FORK); - unsigned int resblks; int nmaps; int error; - resblks = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK); - error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, - XFS_TRANS_RESERVE, &tp); - if (error) - return error; - - /* - * Lock the inode. We have to ijoin without automatic unlock because - * the lead transaction is the refcountbt record deletion; the data - * fork update follows as a deferred log item. - */ - xfs_ilock(ip, XFS_ILOCK_EXCL); - xfs_trans_ijoin(tp, ip, 0); - error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK, XFS_IEXT_REFLINK_END_COW_CNT); if (error == -EFBIG) error = xfs_iext_count_upgrade(tp, ip, XFS_IEXT_REFLINK_END_COW_CNT); if (error) - goto out_cancel; + return error; /* * In case of racing, overlapping AIO writes no COW extents might be @@ -746,7 +730,7 @@ xfs_reflink_end_cow_extent( if (!xfs_iext_lookup_extent(ip, ifp, *offset_fsb, &icur, &got) || got.br_startoff >= end_fsb) { *offset_fsb = end_fsb; - goto out_cancel; + return 0; } /* @@ -760,7 +744,7 @@ xfs_reflink_end_cow_extent( if (!xfs_iext_next_extent(ifp, &icur, &got) || got.br_startoff >= end_fsb) { *offset_fsb = end_fsb; - goto out_cancel; + return 0; } } del = got; @@ -771,7 +755,7 @@ xfs_reflink_end_cow_extent( error = xfs_bmapi_read(ip, del.br_startoff, del.br_blockcount, &data, &nmaps, 0); if (error) - goto out_cancel; + return error; /* We can only remap the smaller of the two extent sizes. */ data.br_blockcount = min(data.br_blockcount, del.br_blockcount); @@ -801,7 +785,7 @@ xfs_reflink_end_cow_extent( error = xfs_bunmapi(NULL, ip, data.br_startoff, data.br_blockcount, 0, 1, &done); if (error) - goto out_cancel; + return error; ASSERT(done); } @@ -818,17 +802,45 @@ xfs_reflink_end_cow_extent( /* Remove the mapping from the CoW fork. */ xfs_bmap_del_extent_cow(ip, &icur, &got, &del); - error = xfs_trans_commit(tp); - xfs_iunlock(ip, XFS_ILOCK_EXCL); - if (error) - return error; - /* Update the caller about how much progress we made. */ *offset_fsb = del.br_startoff + del.br_blockcount; return 0; +} -out_cancel: - xfs_trans_cancel(tp); +/* + * Remap part of the CoW fork into the data fork. + * + * We aim to remap the range starting at @offset_fsb and ending at @end_fsb + * into the data fork; this function will remap what it can (at the end of the + * range) and update @end_fsb appropriately. Each remap gets its own + * transaction because we can end up merging and splitting bmbt blocks for + * every remap operation and we'd like to keep the block reservation + * requirements as low as possible. + */ +STATIC int +xfs_reflink_end_cow_extent( + struct xfs_inode *ip, + xfs_fileoff_t *offset_fsb, + xfs_fileoff_t end_fsb) +{ + struct xfs_mount *mp = ip->i_mount; + struct xfs_trans *tp; + unsigned int resblks; + int error; + + resblks = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK); + error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, + XFS_TRANS_RESERVE, &tp); + if (error) + return error; + xfs_ilock(ip, XFS_ILOCK_EXCL); + xfs_trans_ijoin(tp, ip, 0); + + error = xfs_reflink_end_cow_extent_locked(tp, ip, offset_fsb, end_fsb); + if (error) + xfs_trans_cancel(tp); + else + error = xfs_trans_commit(tp); xfs_iunlock(ip, XFS_ILOCK_EXCL); return error; } -- 2.39.2