From: John Garry <john.g.garry@oracle.com> mainline inclusion from mainline-v6.15-rc2 commit 9dffc58f23849783ab2f6c2c9f5af9b94a42666f 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... -------------------------------- Update the limits returned from xfs_get_atomic_write_{min, max, max_opt)(). No reflink support always means no CoW-based atomic writes. For updating xfs_get_atomic_write_min(), we support blocksize only and that depends on HW or reflink support. For updating xfs_get_atomic_write_max(), for no reflink, we are limited to blocksize but only if HW support. Otherwise we are limited to combined limit in mp->m_atomic_write_unit_max. For updating xfs_get_atomic_write_max_opt(), ultimately we are limited by the bdev atomic write limit. If xfs_get_atomic_write_max() does not report
1x blocksize, then just continue to report 0 as before.
Reviewed-by: Darrick J. Wong <djwong@kernel.org> [djwong: update comments in the helper functions] Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: John Garry <john.g.garry@oracle.com> Conflicts: fs/xfs/xfs_file.c fs/xfs/xfs_iops.c Signed-off-by: Long Li <leo.lilong@huawei.com> --- fs/xfs/xfs_file.c | 2 +- fs/xfs/xfs_iops.c | 50 +++++++++++++++++++++++++++++++++++++++++------ 2 files changed, 45 insertions(+), 7 deletions(-) diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 885a6e984414..ff7326d84444 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -1318,7 +1318,7 @@ xfs_file_open( return -EIO; file->f_mode |= FMODE_NOWAIT | FMODE_BUF_RASYNC | FMODE_BUF_WASYNC | FMODE_DIO_PARALLEL_WRITE | FMODE_CAN_ODIRECT; - if (xfs_inode_can_hw_atomic_write(XFS_I(inode))) + if (xfs_get_atomic_write_min(XFS_I(inode)) > 0) file->f_mode |= FMODE_CAN_ATOMIC_WRITE; return generic_file_open(inode, file); } diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c index 3fc464c84ad7..57223706f028 100644 --- a/fs/xfs/xfs_iops.c +++ b/fs/xfs/xfs_iops.c @@ -566,27 +566,65 @@ unsigned int xfs_get_atomic_write_min( struct xfs_inode *ip) { - if (!xfs_inode_can_hw_atomic_write(ip)) - return 0; + struct xfs_mount *mp = ip->i_mount; + + /* + * If we can complete an atomic write via atomic out of place writes, + * then advertise a minimum size of one fsblock. Without this + * mechanism, we can only guarantee atomic writes up to a single LBA. + * + * If out of place writes are not available, we can guarantee an atomic + * write of exactly one single fsblock if the bdev will make that + * guarantee for us. + */ + if (xfs_inode_can_hw_atomic_write(ip) || xfs_can_sw_atomic_write(mp)) + return mp->m_sb.sb_blocksize; - return ip->i_mount->m_sb.sb_blocksize; + return 0; } unsigned int xfs_get_atomic_write_max( struct xfs_inode *ip) { - if (!xfs_inode_can_hw_atomic_write(ip)) + struct xfs_mount *mp = ip->i_mount; + + /* + * If out of place writes are not available, we can guarantee an atomic + * write of exactly one single fsblock if the bdev will make that + * guarantee for us. + */ + if (!xfs_can_sw_atomic_write(mp)) { + if (xfs_inode_can_hw_atomic_write(ip)) + return mp->m_sb.sb_blocksize; return 0; + } - return ip->i_mount->m_sb.sb_blocksize; + /* + * If we can complete an atomic write via atomic out of place writes, + * then advertise a maximum size of whatever we can complete through + * that means. Hardware support is reported via max_opt, not here. + */ + return XFS_FSB_TO_B(mp, mp->m_awu_max); } unsigned int xfs_get_atomic_write_max_opt( struct xfs_inode *ip) { - return 0; + unsigned int awu_max = xfs_get_atomic_write_max(ip); + + /* if the max is 1x block, then just keep behaviour that opt is 0 */ + if (awu_max <= ip->i_mount->m_sb.sb_blocksize) + return 0; + + /* + * Advertise the maximum size of an atomic write that we can tell the + * block device to perform for us. In general the bdev limit will be + * less than our out of place write limit, but we don't want to exceed + * the awu_max. + */ + return min(awu_max, xfs_inode_buftarg(ip)->bt_bdev_awu_max); } static void -- 2.39.2