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xfs: reduce the absurdly large log operation count

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Back in the early days of reflink and rmap development I set the
transaction reservation sizes to be overly generous for rmap+reflink
filesystems, and a little under-generous for rmap-only filesystems.

Since we don't need *eight* transaction rolls to handle three new log
intent items, decrease the logcounts to what we actually need, and amend
the shadow reservation computation function to reflect what we used to
do so that the minimum log size doesn't change.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Darrick J. Wong 2022-04-25 18:38:14 -07:00
parent 918247ce54
commit 4ecf9e7c69
3 changed files with 76 additions and 31 deletions
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51
fs/xfs/libxfs/xfs_log_rlimit.c
View File

@ -37,6 +37,53 @@ xfs_log_calc_max_attrsetm_res(
M_RES(mp)->tr_attrsetrt.tr_logres * nblks;
}
/*
* Compute an alternate set of log reservation sizes for use exclusively with
* minimum log size calculations.
*/
static void
xfs_log_calc_trans_resv_for_minlogblocks(
struct xfs_mount *mp,
struct xfs_trans_resv *resv)
{
unsigned int rmap_maxlevels = mp->m_rmap_maxlevels;
/*
* In the early days of rmap+reflink, we always set the rmap maxlevels
* to 9 even if the AG was small enough that it would never grow to
* that height. Transaction reservation sizes influence the minimum
* log size calculation, which influences the size of the log that mkfs
* creates. Use the old value here to ensure that newly formatted
* small filesystems will mount on older kernels.
*/
if (xfs_has_rmapbt(mp) && xfs_has_reflink(mp))
mp->m_rmap_maxlevels = XFS_OLD_REFLINK_RMAP_MAXLEVELS;
xfs_trans_resv_calc(mp, resv);
if (xfs_has_reflink(mp)) {
/*
* In the early days of reflink, typical log operation counts
* were greatly overestimated.
*/
resv->tr_write.tr_logcount = XFS_WRITE_LOG_COUNT_REFLINK;
resv->tr_itruncate.tr_logcount =
XFS_ITRUNCATE_LOG_COUNT_REFLINK;
resv->tr_qm_dqalloc.tr_logcount = XFS_WRITE_LOG_COUNT_REFLINK;
} else if (xfs_has_rmapbt(mp)) {
/*
* In the early days of non-reflink rmap, the impact of rmapbt
* updates on log counts were not taken into account at all.
*/
resv->tr_write.tr_logcount = XFS_WRITE_LOG_COUNT;
resv->tr_itruncate.tr_logcount = XFS_ITRUNCATE_LOG_COUNT;
resv->tr_qm_dqalloc.tr_logcount = XFS_WRITE_LOG_COUNT;
}
/* Put everything back the way it was. This goes at the end. */
mp->m_rmap_maxlevels = rmap_maxlevels;
}
/*
* Iterate over the log space reservation table to figure out and return
* the maximum one in terms of the pre-calculated values which were done
@ -47,7 +94,7 @@ xfs_log_get_max_trans_res(
struct xfs_mount *mp,
struct xfs_trans_res *max_resp)
{
struct xfs_trans_resv resv;
struct xfs_trans_resv resv = {};
struct xfs_trans_res *resp;
struct xfs_trans_res *end_resp;
unsigned int i;
@ -56,7 +103,7 @@ xfs_log_get_max_trans_res(
attr_space = xfs_log_calc_max_attrsetm_res(mp);
memcpy(&resv, M_RES(mp), sizeof(struct xfs_trans_resv));
xfs_log_calc_trans_resv_for_minlogblocks(mp, &resv);
resp = (struct xfs_trans_res *)&resv;
end_resp = (struct xfs_trans_res *)(&resv + 1);

46
fs/xfs/libxfs/xfs_trans_resv.c
View File

@ -815,36 +815,18 @@ xfs_trans_resv_calc(
struct xfs_mount *mp,
struct xfs_trans_resv *resp)
{
unsigned int rmap_maxlevels = mp->m_rmap_maxlevels;
/*
* In the early days of rmap+reflink, we always set the rmap maxlevels
* to 9 even if the AG was small enough that it would never grow to
* that height. Transaction reservation sizes influence the minimum
* log size calculation, which influences the size of the log that mkfs
* creates. Use the old value here to ensure that newly formatted
* small filesystems will mount on older kernels.
*/
if (xfs_has_rmapbt(mp) && xfs_has_reflink(mp))
mp->m_rmap_maxlevels = XFS_OLD_REFLINK_RMAP_MAXLEVELS;
int logcount_adj = 0;
/*
* The following transactions are logged in physical format and
* require a permanent reservation on space.
*/
resp->tr_write.tr_logres = xfs_calc_write_reservation(mp);
if (xfs_has_reflink(mp))
resp->tr_write.tr_logcount = XFS_WRITE_LOG_COUNT_REFLINK;
else
resp->tr_write.tr_logcount = XFS_WRITE_LOG_COUNT;
resp->tr_write.tr_logcount = XFS_WRITE_LOG_COUNT;
resp->tr_write.tr_logflags |= XFS_TRANS_PERM_LOG_RES;
resp->tr_itruncate.tr_logres = xfs_calc_itruncate_reservation(mp);
if (xfs_has_reflink(mp))
resp->tr_itruncate.tr_logcount =
XFS_ITRUNCATE_LOG_COUNT_REFLINK;
else
resp->tr_itruncate.tr_logcount = XFS_ITRUNCATE_LOG_COUNT;
resp->tr_itruncate.tr_logcount = XFS_ITRUNCATE_LOG_COUNT;
resp->tr_itruncate.tr_logflags |= XFS_TRANS_PERM_LOG_RES;
resp->tr_rename.tr_logres = xfs_calc_rename_reservation(mp);
@ -901,10 +883,7 @@ xfs_trans_resv_calc(
resp->tr_growrtalloc.tr_logflags |= XFS_TRANS_PERM_LOG_RES;
resp->tr_qm_dqalloc.tr_logres = xfs_calc_qm_dqalloc_reservation(mp);
if (xfs_has_reflink(mp))
resp->tr_qm_dqalloc.tr_logcount = XFS_WRITE_LOG_COUNT_REFLINK;
else
resp->tr_qm_dqalloc.tr_logcount = XFS_WRITE_LOG_COUNT;
resp->tr_qm_dqalloc.tr_logcount = XFS_WRITE_LOG_COUNT;
resp->tr_qm_dqalloc.tr_logflags |= XFS_TRANS_PERM_LOG_RES;
/*
@ -931,6 +910,19 @@ xfs_trans_resv_calc(
resp->tr_growrtzero.tr_logres = xfs_calc_growrtzero_reservation(mp);
resp->tr_growrtfree.tr_logres = xfs_calc_growrtfree_reservation(mp);
/* Put everything back the way it was. This goes at the end. */
mp->m_rmap_maxlevels = rmap_maxlevels;
/*
* Add one logcount for BUI items that appear with rmap or reflink,
* one logcount for refcount intent items, and one logcount for rmap
* intent items.
*/
if (xfs_has_reflink(mp) || xfs_has_rmapbt(mp))
logcount_adj++;
if (xfs_has_reflink(mp))
logcount_adj++;
if (xfs_has_rmapbt(mp))
logcount_adj++;
resp->tr_itruncate.tr_logcount += logcount_adj;
resp->tr_write.tr_logcount += logcount_adj;
resp->tr_qm_dqalloc.tr_logcount += logcount_adj;
}

10
fs/xfs/libxfs/xfs_trans_resv.h
View File

@ -73,7 +73,6 @@ struct xfs_trans_resv {
#define XFS_DEFAULT_LOG_COUNT 1
#define XFS_DEFAULT_PERM_LOG_COUNT 2
#define XFS_ITRUNCATE_LOG_COUNT 2
#define XFS_ITRUNCATE_LOG_COUNT_REFLINK 8
#define XFS_INACTIVE_LOG_COUNT 2
#define XFS_CREATE_LOG_COUNT 2
#define XFS_CREATE_TMPFILE_LOG_COUNT 2
@ -83,12 +82,19 @@ struct xfs_trans_resv {
#define XFS_LINK_LOG_COUNT 2
#define XFS_RENAME_LOG_COUNT 2
#define XFS_WRITE_LOG_COUNT 2
#define XFS_WRITE_LOG_COUNT_REFLINK 8
#define XFS_ADDAFORK_LOG_COUNT 2
#define XFS_ATTRINVAL_LOG_COUNT 1
#define XFS_ATTRSET_LOG_COUNT 3
#define XFS_ATTRRM_LOG_COUNT 3
/*
* Original log operation counts were overestimated in the early days of
* reflink. These are retained here purely for minimum log size calculations
* and must not be used for runtime reservations.
*/
#define XFS_ITRUNCATE_LOG_COUNT_REFLINK 8
#define XFS_WRITE_LOG_COUNT_REFLINK 8
void xfs_trans_resv_calc(struct xfs_mount *mp, struct xfs_trans_resv *resp);
uint xfs_allocfree_log_count(struct xfs_mount *mp, uint num_ops);