| Message ID | 20250415121425.4146847-14-john.g.garry@oracle.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | large atomic writes for xfs | expand |
On Tue, Apr 15, 2025 at 12:14:24PM +0000, John Garry wrote: > 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] Same here, there should be a Signed-off-by: "Darrick J. Wong" <djwong@kernel.org> after this comment. --D > Signed-off-by: John Garry <john.g.garry@oracle.com> > --- > fs/xfs/xfs_file.c | 2 +- > fs/xfs/xfs_iops.c | 53 +++++++++++++++++++++++++++++++++++++++++------ > 2 files changed, 48 insertions(+), 7 deletions(-) > > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c > index 81a377f65aa3..d1ddbc4a98c3 100644 > --- a/fs/xfs/xfs_file.c > +++ b/fs/xfs/xfs_file.c > @@ -1557,7 +1557,7 @@ xfs_file_open( > if (xfs_is_shutdown(XFS_M(inode->i_sb))) > return -EIO; > file->f_mode |= FMODE_NOWAIT | FMODE_CAN_ODIRECT; > - if (xfs_inode_can_hw_atomicwrite(XFS_I(inode))) > + if (xfs_get_atomic_write_min(XFS_I(inode))) > 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 3b5aa39dbfe9..183524d06bc3 100644 > --- a/fs/xfs/xfs_iops.c > +++ b/fs/xfs/xfs_iops.c > @@ -605,27 +605,68 @@ unsigned int > xfs_get_atomic_write_min( > struct xfs_inode *ip) > { > - if (!xfs_inode_can_hw_atomicwrite(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_atomicwrite(ip) || xfs_has_reflink(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_atomicwrite(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_has_reflink(mp)) { > + if (xfs_inode_can_hw_atomicwrite(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. > + */ > + if (XFS_IS_REALTIME_INODE(ip)) > + return XFS_FSB_TO_B(mp, mp->m_groups[XG_TYPE_RTG].awu_max); > + return XFS_FSB_TO_B(mp, mp->m_groups[XG_TYPE_AG].awu_max); > } > > unsigned int > xfs_get_atomic_write_max_opt( > struct xfs_inode *ip) > { > - return 0; > + struct xfs_buftarg *target = xfs_inode_buftarg(ip); > + 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, target->bt_bdev_awu_max); > } > > static void > -- > 2.31.1 > >
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 81a377f65aa3..d1ddbc4a98c3 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -1557,7 +1557,7 @@ xfs_file_open( if (xfs_is_shutdown(XFS_M(inode->i_sb))) return -EIO; file->f_mode |= FMODE_NOWAIT | FMODE_CAN_ODIRECT; - if (xfs_inode_can_hw_atomicwrite(XFS_I(inode))) + if (xfs_get_atomic_write_min(XFS_I(inode))) 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 3b5aa39dbfe9..183524d06bc3 100644 --- a/fs/xfs/xfs_iops.c +++ b/fs/xfs/xfs_iops.c @@ -605,27 +605,68 @@ unsigned int xfs_get_atomic_write_min( struct xfs_inode *ip) { - if (!xfs_inode_can_hw_atomicwrite(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_atomicwrite(ip) || xfs_has_reflink(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_atomicwrite(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_has_reflink(mp)) { + if (xfs_inode_can_hw_atomicwrite(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. + */ + if (XFS_IS_REALTIME_INODE(ip)) + return XFS_FSB_TO_B(mp, mp->m_groups[XG_TYPE_RTG].awu_max); + return XFS_FSB_TO_B(mp, mp->m_groups[XG_TYPE_AG].awu_max); } unsigned int xfs_get_atomic_write_max_opt( struct xfs_inode *ip) { - return 0; + struct xfs_buftarg *target = xfs_inode_buftarg(ip); + 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, target->bt_bdev_awu_max); } static void
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: John Garry <john.g.garry@oracle.com> --- fs/xfs/xfs_file.c | 2 +- fs/xfs/xfs_iops.c | 53 +++++++++++++++++++++++++++++++++++++++++------ 2 files changed, 48 insertions(+), 7 deletions(-)