From: "Darrick J. Wong" <djwong@kernel.org> mainline-inclusion from mainline-v5.11-rc4 commit f41a0716f4b08678a73173d71ff3f409b996df2d category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I4KIAO CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... ------------------------------------------------- Don't stall the cowblocks scan on a locked inode if we possibly can. We'd much rather the background scanner keep moving. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Lihong Kou <koulihong@huawei.com> Reviewed-by: Zhang Yi <yi.zhang@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- fs/xfs/xfs_icache.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c index 2b87317120e1..7427cf62d96b 100644 --- a/fs/xfs/xfs_icache.c +++ b/fs/xfs/xfs_icache.c @@ -1605,17 +1605,31 @@ xfs_inode_free_cowblocks( void *args) { struct xfs_eofblocks *eofb = args; + bool wait; int ret = 0; + wait = eofb && (eofb->eof_flags & XFS_EOF_FLAGS_SYNC); + if (!xfs_prep_free_cowblocks(ip)) return 0; if (!xfs_inode_matches_eofb(ip, eofb)) return 0; - /* Free the CoW blocks */ - xfs_ilock(ip, XFS_IOLOCK_EXCL); - xfs_ilock(ip, XFS_MMAPLOCK_EXCL); + /* + * If the caller is waiting, return -EAGAIN to keep the background + * scanner moving and revisit the inode in a subsequent pass. + */ + if (!xfs_ilock_nowait(ip, XFS_IOLOCK_EXCL)) { + if (wait) + return -EAGAIN; + return 0; + } + if (!xfs_ilock_nowait(ip, XFS_MMAPLOCK_EXCL)) { + if (wait) + ret = -EAGAIN; + goto out_iolock; + } /* * Check again, nobody else should be able to dirty blocks or change @@ -1625,6 +1639,7 @@ xfs_inode_free_cowblocks( ret = xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF, false); xfs_iunlock(ip, XFS_MMAPLOCK_EXCL); +out_iolock: xfs_iunlock(ip, XFS_IOLOCK_EXCL); return ret; -- 2.20.1