Re: [PATCH 59/60] xfs: Add xfs_log_rlimit.c

Michael L. Semon
2013-06-21T06:11:00Z

I'm still looking for Jeff's input on this particular patch. However, I
did want to report success on xfs/297. The Pentium 4 test PC was left to
rest for a few hours, then it was started again. The latest xfsprogs
patchset was applied to xfsprogs.

512b blocks, internal logdev, no CRC, projid32bit=1, tracers on: PASS
512b blocks, internal logdev, no CRC, projid32bit=0, tracers on: PASS
512b blocks, internal logdev, no CRC, projid32bit=0, tracers off: PASS
1k blocks, internal logdev, no CRC, tracers off: PASS
...rebooted to avoid RT throttling slowing things down...
1k blocks, internal logdev, CRC, tracers off: PASS
2k blocks, internal logdev, CRC, tracers off: PASS
2k blocks, external logdev, CRC, rtdev, tracers off: PASS
4k blocks, default mkfs.xfs: PASS

Something was fixed between the new xfsprogs and the PC's chance to reset
100%. What? I really don't know! But there is success.

Great job, Dave and Jeff!

Michael

On 06/19/2013 12:51 AM, Dave Chinner wrote:
> From: Jie Liu <jeff.liu@oracle.com>
>
> Add source files for xfs_log_rlimit.c The new file is used for log
> size calculations and validation shared with userspace.
>
> [dchinner: xfs_log_calc_max_attrsetm_res() does not modify the
> tr_attrsetm reservation, just calculates the maximum. ]
>
> [dchinner: rework loop in xfs_log_get_max_trans_res() ]
>
> Signed-off-by: Jie Liu <jeff.liu@oracle.com>
> Signed-off-by: Dave Chinner <dchinner@redhat.com>
> ---
> fs/xfs/Makefile | 1 +
> fs/xfs/xfs_log_format.h | 8 ++-
> fs/xfs/xfs_log_rlimit.c | 145 +++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 153 insertions(+), 1 deletion(-)
> create mode 100644 fs/xfs/xfs_log_rlimit.c
>
> diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile
> index c5c38a9..22691eb 100644
> --- a/fs/xfs/Makefile
> +++ b/fs/xfs/Makefile
> @@ -81,6 +81,7 @@ xfs-y += xfs_alloc.o \
> xfs_inode_fork.o \
> xfs_inode_buf.o \
> xfs_log_recover.o \
> + xfs_log_rlimit.o \
> xfs_sb.o \
> xfs_symlink_remote.o \
> xfs_trans_resv.o
> diff --git a/fs/xfs/xfs_log_format.h b/fs/xfs/xfs_log_format.h
> index 37a7ff9..8f46b6a 100644
> --- a/fs/xfs/xfs_log_format.h
> +++ b/fs/xfs/xfs_log_format.h
> @@ -1,5 +1,6 @@
> /*
> * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
> + * Copyright (c) 2013 Jie Liu.
> * All Rights Reserved.
> *
> * This program is free software; you can redistribute it and/or
> @@ -19,6 +20,7 @@
> #define __XFS_LOG_FORMAT_H__
>
> struct xfs_mount;
> +struct xfs_trans_res;
>
> typedef __uint32_t xlog_tid_t;
>
> @@ -41,6 +43,9 @@ typedef __uint32_t xlog_tid_t;
>
> #define XLOG_HEADER_SIZE 512
>
> +/* Minimum number of transactions that must fit in the log (defined by mkfs) */
> +#define XFS_MIN_LOG_FACTOR 3
> +
> #define XLOG_REC_SHIFT(log) \
> BTOBB(1 << (xfs_sb_version_haslogv2(&log->l_mp->m_sb) ? \
> XLOG_MAX_RECORD_BSHIFT : XLOG_BIG_RECORD_BSHIFT))
> @@ -125,7 +130,6 @@ typedef struct xlog_op_header {
> __u16 oh_res2; /* 32 bit align : 2 b */
> } xlog_op_header_t;
>
> -
> /* valid values for h_fmt */
> #define XLOG_FMT_UNKNOWN 0
> #define XLOG_FMT_LINUX_LE 1
> @@ -178,5 +182,7 @@ typedef struct xfs_log_iovec {
> } xfs_log_iovec_t;
>
> int xfs_log_calc_unit_res(struct xfs_mount *mp, int unit_bytes);
> +int xfs_log_calc_minimum_size(struct xfs_mount *);
> +
>
> #endif /* __XFS_LOG_FORMAT_H__ */
> diff --git a/fs/xfs/xfs_log_rlimit.c b/fs/xfs/xfs_log_rlimit.c
> new file mode 100644
> index 0000000..e3f4b4e
> --- /dev/null
> +++ b/fs/xfs/xfs_log_rlimit.c
> @@ -0,0 +1,145 @@
> +/*
> + * Copyright (c) 2013 Jie Liu.
> + * All Rights Reserved.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it would be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write the Free Software Foundation,
> + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
> + */
> +#include "xfs.h"
> +#include "xfs_fs.h"
> +#include "xfs_log.h"
> +#include "xfs_trans.h"
> +#include "xfs_ag.h"
> +#include "xfs_sb.h"
> +#include "xfs_mount.h"
> +#include "xfs_trans_space.h"
> +#include "xfs_bmap_btree.h"
> +#include "xfs_inode.h"
> +#include "xfs_da_btree.h"
> +#include "xfs_attr_leaf.h"
> +
> +/*
> + * Calculate the maximum length in bytes that would be required for a local
> + * attribute value as large attributes out of line are not logged.
> + */
> +STATIC int
> +xfs_log_calc_max_attrsetm_res(
> + struct xfs_mount *mp)
> +{
> + int size;
> + int nblks;
> +
> + size = xfs_attr_leaf_entsize_local_max(mp->m_sb.sb_blocksize) -
> + MAXNAMELEN - 1;
> + nblks = XFS_DAENTER_SPACE_RES(mp, XFS_ATTR_FORK);
> + nblks += XFS_B_TO_FSB(mp, size);
> + nblks += XFS_NEXTENTADD_SPACE_RES(mp, size, XFS_ATTR_FORK);
> +
> + return M_RES(mp)->tr_attrsetm.tr_logres +
> + M_RES(mp)->tr_attrsetrt.tr_logres * nblks;
> +}
> +
> +/*
> + * 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
> + * at mount time.
> + */
> +STATIC void
> +xfs_log_get_max_trans_res(
> + struct xfs_mount *mp,
> + struct xfs_trans_res *max_resp)
> +{
> + struct xfs_trans_res *resp;
> + struct xfs_trans_res *end_resp;
> + int log_space = 0;
> + int attr_space;
> +
> + attr_space = xfs_log_calc_max_attrsetm_res(mp);
> +
> + resp = (struct xfs_trans_res *)M_RES(mp);
> + end_resp = (struct xfs_trans_res *)(M_RES(mp) + 1);
> + for (; resp < end_resp; resp++) {
> + int tmp = resp->tr_logcount > 1 ?
> + resp->tr_logres * resp->tr_logcount :
> + resp->tr_logres;
> + if (log_space < tmp) {
> + log_space = tmp;
> + *max_resp = *resp; /* struct copy */
> + }
> + }
> +
> + if (attr_space > log_space) {
> + *max_resp = M_RES(mp)->tr_attrsetm; /* struct copy */
> + max_resp->tr_logres = attr_space;
> + }
> +}
> +
> +/*
> + * Calculate the minimum valid log size for the given superblock configuration.
> + * Used to calculate the minimum log size at mkfs time, and to determine if
> + * the log is large enough or not at mount time. Returns the minimum size in
> + * filesystem block size units.
> + */
> +int
> +xfs_log_calc_minimum_size(
> + struct xfs_mount *mp)
> +{
> + struct xfs_trans_res tres = {0};
> + int max_logres;
> + int min_logblks = 0;
> + int lsunit = 0;
> +
> + xfs_log_get_max_trans_res(mp, &tres);
> +
> + max_logres = xfs_log_calc_unit_res(mp, tres.tr_logres);
> + if (tres.tr_logcount > 1)
> + max_logres *= tres.tr_logcount;
> +
> + if (xfs_sb_version_haslogv2(&mp->m_sb) && mp->m_sb.sb_logsunit > 1)
> + lsunit = BTOBB(mp->m_sb.sb_logsunit);
> +
> + /*
> + * Two factors should be taken into account for calculating the minimum
> + * log space.
> + * 1) The fundamental limitation is that no single transaction can be
> + * larger than half size of the log.
> + *
> + * From mkfs.xfs, this is considered by the XFS_MIN_LOG_FACTOR
> + * define, which is set to 3. That means we can definitely fit
> + * maximally sized 2 transactions in the log. We'll use this same
> + * value here.
> + *
> + * 2) If the lsunit option is specified, a transaction requires 2 LSU
> + * for the reservation because there are two log writes that can
> + * require padding - the transaction data and the commit record which
> + * are written separately and both can require padding to the LSU.
> + * Consider that we can have an active CIL reservation holding 2*LSU,
> + * but the CIL is not over a push threshold, in this case, if we
> + * don't have enough log space for at one new transaction, which
> + * includes another 2*LSU in the reservation, we will run into dead
> + * loop situation in log space grant procedure. i.e.
> + * xlog_grant_head_wait().
> + *
> + * Hence the log size needs to be able to contain two maximally sized
> + * and padded transactions, which is (2 * (2 * LSU + maxlres)).
> + *
> + * Also, the log size should be a multiple of the log stripe unit, round
> + * it up to lsunit boundary if lsunit is specified.
> + */
> + if (lsunit)
> + min_logblks = roundup(BTOBB(max_logres), lsunit) + 2 * lsunit;
> + else
> + min_logblks = BTOBB(max_logres);
> + min_logblks *= XFS_MIN_LOG_FACTOR;
> + return XFS_BB_TO_FSB(mp, min_logblks);
> +}
>