[PATCH 18/37] xfs: check that the rtrmapbt maxlevels doesn't increase when growing fs

Darrick J. Wong
2024-12-13T01:05:17Z

From: Darrick J. Wong <djwong@kernel.org>

The size of filesystem transaction reservations depends on the maximum
height (maxlevels) of the realtime btrees. Since we don't want a grow
operation to increase the reservation size enough that we'll fail the
minimum log size checks on the next mount, constrain growfs operations
if they would cause an increase in those maxlevels.

Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
---
fs/xfs/xfs_fsops.c | 11 +++++++++++
fs/xfs/xfs_rtalloc.c | 25 ++++++++++++++++++-------
fs/xfs/xfs_rtalloc.h | 10 ++++++++++
fs/xfs/xfs_trace.h | 21 +++++++++++++++++++++
4 files changed, 60 insertions(+), 7 deletions(-)

diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
index e1145107d8cbd1..9df5a09c0acd3b 100644
--- a/fs/xfs/xfs_fsops.c
+++ b/fs/xfs/xfs_fsops.c
@@ -22,6 +22,7 @@
#include "xfs_ag_resv.h"
#include "xfs_trace.h"
#include "xfs_rtalloc.h"
+#include "xfs_rtrmap_btree.h"

/*
* Write new AG headers to disk. Non-transactional, but need to be
@@ -114,6 +115,12 @@ xfs_growfs_data_private(
xfs_buf_relse(bp);
}

+ /* Make sure the new fs size won't cause problems with the log. */
+ error = xfs_growfs_check_rtgeom(mp, nb, mp->m_sb.sb_rblocks,
+ mp->m_sb.sb_rextsize);
+ if (error)
+ return error;
+
nb_div = nb;
nb_mod = do_div(nb_div, mp->m_sb.sb_agblocks);
if (nb_mod && nb_mod >= XFS_MIN_AG_BLOCKS)
@@ -221,7 +228,11 @@ xfs_growfs_data_private(
error = xfs_fs_reserve_ag_blocks(mp);
if (error == -ENOSPC)
error = 0;
+
+ /* Compute new maxlevels for rt btrees. */
+ xfs_rtrmapbt_compute_maxlevels(mp);
}
+
return error;

out_trans_cancel:
diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
index c7efd926413981..3c1bce5a4855f2 100644
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -989,9 +989,11 @@ xfs_growfs_rt_bmblock(
goto out_free;

/*
- * Ensure the mount RT feature flag is now set.
+ * Ensure the mount RT feature flag is now set, and compute new
+ * maxlevels for rt btrees.
*/
mp->m_features |= XFS_FEAT_REALTIME;
+ xfs_rtrmapbt_compute_maxlevels(mp);

kfree(nmp);
return 0;
@@ -1159,29 +1161,37 @@ xfs_growfs_rtg(
return error;
}

-static int
+int
xfs_growfs_check_rtgeom(
const struct xfs_mount *mp,
+ xfs_rfsblock_t dblocks,
xfs_rfsblock_t rblocks,
xfs_extlen_t rextsize)
{
+ xfs_extlen_t min_logfsbs;
struct xfs_mount *nmp;
- int error = 0;

nmp = xfs_growfs_rt_alloc_fake_mount(mp, rblocks, rextsize);
if (!nmp)
return -ENOMEM;
+ nmp->m_sb.sb_dblocks = dblocks;
+
+ xfs_rtrmapbt_compute_maxlevels(nmp);
+ xfs_trans_resv_calc(nmp, M_RES(nmp));

/*
* New summary size can't be more than half the size of the log. This
* prevents us from getting a log overflow, since we'll log basically
* the whole summary file at once.
*/
- if (nmp->m_rsumblocks > (mp->m_sb.sb_logblocks >> 1))
- error = -EINVAL;
+ min_logfsbs = min_t(xfs_extlen_t, xfs_log_calc_minimum_size(nmp),
+ nmp->m_rsumblocks * 2);

kfree(nmp);
- return error;
+
+ if (min_logfsbs > mp->m_sb.sb_logblocks)
+ return -EINVAL;
+ return 0;
}

/*
@@ -1300,7 +1310,8 @@ xfs_growfs_rt(
goto out_unlock;

/* Make sure the new fs size won't cause problems with the log. */
- error = xfs_growfs_check_rtgeom(mp, in->newblocks, in->extsize);
+ error = xfs_growfs_check_rtgeom(mp, mp->m_sb.sb_dblocks, in->newblocks,
+ in->extsize);
if (error)
goto out_unlock;

diff --git a/fs/xfs/xfs_rtalloc.h b/fs/xfs/xfs_rtalloc.h
index d87523e6a55006..9044f7226ab6fc 100644
--- a/fs/xfs/xfs_rtalloc.h
+++ b/fs/xfs/xfs_rtalloc.h
@@ -46,6 +46,8 @@ xfs_growfs_rt(
xfs_growfs_rt_t *in); /* user supplied growfs struct */

int xfs_rtalloc_reinit_frextents(struct xfs_mount *mp);
+int xfs_growfs_check_rtgeom(const struct xfs_mount *mp, xfs_rfsblock_t dblocks,
+ xfs_rfsblock_t rblocks, xfs_agblock_t rextsize);
#else
# define xfs_growfs_rt(mp,in) (-ENOSYS)
# define xfs_rtalloc_reinit_frextents(m) (0)
@@ -65,6 +67,14 @@ xfs_rtmount_init(
# define xfs_rtunmount_inodes(m)
# define xfs_rt_resv_free(mp) ((void)0)
# define xfs_rt_resv_init(mp) (0)
+
+static inline int
+xfs_growfs_check_rtgeom(const struct xfs_mount *mp,
+ xfs_rfsblock_t dblocks, xfs_rfsblock_t rblocks,
+ xfs_extlen_t rextsize)
+{
+ return 0;
+}
#endif /* CONFIG_XFS_RT */

#endif /* __XFS_RTALLOC_H__ */
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index a098935163b7c2..84cdc145e2d96a 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -5622,6 +5622,27 @@ DEFINE_METAFILE_RESV_EVENT(xfs_metafile_resv_free_space);
DEFINE_METAFILE_RESV_EVENT(xfs_metafile_resv_critical);
DEFINE_INODE_ERROR_EVENT(xfs_metafile_resv_init_error);

+#ifdef CONFIG_XFS_RT
+TRACE_EVENT(xfs_growfs_check_rtgeom,
+ TP_PROTO(const struct xfs_mount *mp, unsigned int min_logfsbs),
+ TP_ARGS(mp, min_logfsbs),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(unsigned int, logblocks)
+ __field(unsigned int, min_logfsbs)
+ ),
+ TP_fast_assign(
+ __entry->dev = mp->m_super->s_dev;
+ __entry->logblocks = mp->m_sb.sb_logblocks;
+ __entry->min_logfsbs = min_logfsbs;
+ ),
+ TP_printk("dev %d:%d logblocks %u min_logfsbs %u",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->logblocks,
+ __entry->min_logfsbs)
+);
+#endif /* CONFIG_XFS_RT */
+
#endif /* _TRACE_XFS_H */

#undef TRACE_INCLUDE_PATH