mirrors
/
linux-stable
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
1
0
Fork 0
Code Issues Releases Wiki Activity

xfs: support shrinking unused space in the last AG 

As the first step of shrinking, this attempts to enable shrinking
unused space in the last allocation group by fixing up freespace
btree, agi, agf and adjusting super block and use a helper
xfs_ag_shrink_space() to fixup the last AG.

This can be all done in one transaction for now, so I think no
additional protection is needed.

Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
This commit is contained in:
Gao Xiang 2021-03-23 19:05:39 -07:00 committed by Darrick J. Wong
parent 46141dc891
commit fb2fc17201
2 changed files with 59 additions and 35 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

93
fs/xfs/xfs_fsops.c
View File

@ -91,23 +91,25 @@ xfs_growfs_data_private(
xfs_agnumber_t nagcount;
xfs_agnumber_t nagimax = 0;
xfs_rfsblock_t nb, nb_div, nb_mod;
xfs_rfsblock_t delta;
int64_t delta;
bool lastag_extended;
xfs_agnumber_t oagcount;
struct xfs_trans *tp;
struct aghdr_init_data id = {};
nb = in->newblocks;
if (nb < mp->m_sb.sb_dblocks)
return -EINVAL;
if ((error = xfs_sb_validate_fsb_count(&mp->m_sb, nb)))
return error;
error = xfs_buf_read_uncached(mp->m_ddev_targp,
XFS_FSB_TO_BB(mp, nb) - XFS_FSS_TO_BB(mp, 1),
XFS_FSS_TO_BB(mp, 1), 0, &bp, NULL);
error = xfs_sb_validate_fsb_count(&mp->m_sb, nb);
if (error)
return error;
xfs_buf_relse(bp);
if (nb > mp->m_sb.sb_dblocks) {
error = xfs_buf_read_uncached(mp->m_ddev_targp,
XFS_FSB_TO_BB(mp, nb) - XFS_FSS_TO_BB(mp, 1),
XFS_FSS_TO_BB(mp, 1), 0, &bp, NULL);
if (error)
return error;
xfs_buf_relse(bp);
}
nb_div = nb;
nb_mod = do_div(nb_div, mp->m_sb.sb_agblocks);
@ -115,10 +117,16 @@ xfs_growfs_data_private(
if (nb_mod && nb_mod < XFS_MIN_AG_BLOCKS) {
nagcount--;
nb = (xfs_rfsblock_t)nagcount * mp->m_sb.sb_agblocks;
if (nb < mp->m_sb.sb_dblocks)
return -EINVAL;
}
delta = nb - mp->m_sb.sb_dblocks;
/*
* Reject filesystems with a single AG because they are not
* supported, and reject a shrink operation that would cause a
* filesystem to become unsupported.
*/
if (delta < 0 && nagcount < 2)
return -EINVAL;
oagcount = mp->m_sb.sb_agcount;
/* allocate the new per-ag structures */
@ -126,15 +134,31 @@ xfs_growfs_data_private(
error = xfs_initialize_perag(mp, nagcount, &nagimax);
if (error)
return error;
} else if (nagcount < oagcount) {
/* TODO: shrinking the entire AGs hasn't yet completed */
return -EINVAL;
}
error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growdata,
XFS_GROWFS_SPACE_RES(mp), 0, XFS_TRANS_RESERVE, &tp);
(delta > 0 ? XFS_GROWFS_SPACE_RES(mp) : -delta), 0,
XFS_TRANS_RESERVE, &tp);
if (error)
return error;
error = xfs_resizefs_init_new_ags(tp, &id, oagcount, nagcount,
delta, &lastag_extended);
if (delta > 0) {
error = xfs_resizefs_init_new_ags(tp, &id, oagcount, nagcount,
delta, &lastag_extended);
} else {
static struct ratelimit_state shrink_warning = \
RATELIMIT_STATE_INIT("shrink_warning", 86400 * HZ, 1);
ratelimit_set_flags(&shrink_warning, RATELIMIT_MSG_ON_RELEASE);
if (__ratelimit(&shrink_warning))
xfs_alert(mp,
"EXPERIMENTAL online shrink feature in use. Use at your own risk!");
error = xfs_ag_shrink_space(mp, &tp, nagcount - 1, -delta);
}
if (error)
goto out_trans_cancel;
@ -169,28 +193,29 @@ xfs_growfs_data_private(
xfs_set_low_space_thresholds(mp);
mp->m_alloc_set_aside = xfs_alloc_set_aside(mp);
/*
* If we expanded the last AG, free the per-AG reservation
* so we can reinitialize it with the new size.
*/
if (lastag_extended) {
struct xfs_perag *pag;
if (delta > 0) {
/*
* If we expanded the last AG, free the per-AG reservation
* so we can reinitialize it with the new size.
*/
if (lastag_extended) {
struct xfs_perag *pag;
pag = xfs_perag_get(mp, id.agno);
error = xfs_ag_resv_free(pag);
xfs_perag_put(pag);
if (error)
return error;
pag = xfs_perag_get(mp, id.agno);
error = xfs_ag_resv_free(pag);
xfs_perag_put(pag);
if (error)
return error;
}
/*
* Reserve AG metadata blocks. ENOSPC here does not mean there
* was a growfs failure, just that there still isn't space for
* new user data after the grow has been run.
*/
error = xfs_fs_reserve_ag_blocks(mp);
if (error == -ENOSPC)
error = 0;
}
/*
* Reserve AG metadata blocks. ENOSPC here does not mean there was a
* growfs failure, just that there still isn't space for new user data
* after the grow has been run.
*/
error = xfs_fs_reserve_ag_blocks(mp);
if (error == -ENOSPC)
error = 0;
return error;
out_trans_cancel:

1
fs/xfs/xfs_trans.c
View File

@ -436,7 +436,6 @@ xfs_trans_mod_sb(
tp->t_res_frextents_delta += delta;
break;
case XFS_TRANS_SB_DBLOCKS:
ASSERT(delta > 0);
tp->t_dblocks_delta += delta;
break;
case XFS_TRANS_SB_AGCOUNT: