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[XFS] Lazy Superblock Counters

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When we have a couple of hundred transactions on the fly at once, they all
typically modify the on disk superblock in some way.
create/unclink/mkdir/rmdir modify inode counts, allocation/freeing modify
free block counts.

When these counts are modified in a transaction, they must eventually lock
the superblock buffer and apply the mods. The buffer then remains locked
until the transaction is committed into the incore log buffer. The result
of this is that with enough transactions on the fly the incore superblock
buffer becomes a bottleneck.

The result of contention on the incore superblock buffer is that
transaction rates fall - the more pressure that is put on the superblock
buffer, the slower things go.

The key to removing the contention is to not require the superblock fields
in question to be locked. We do that by not marking the superblock dirty
in the transaction. IOWs, we modify the incore superblock but do not
modify the cached superblock buffer. In short, we do not log superblock
modifications to critical fields in the superblock on every transaction.
In fact we only do it just before we write the superblock to disk every
sync period or just before unmount.

This creates an interesting problem - if we don't log or write out the
fields in every transaction, then how do the values get recovered after a
crash? the answer is simple - we keep enough duplicate, logged information
in other structures that we can reconstruct the correct count after log
recovery has been performed.

It is the AGF and AGI structures that contain the duplicate information;
after recovery, we walk every AGI and AGF and sum their individual
counters to get the correct value, and we do a transaction into the log to
correct them. An optimisation of this is that if we have a clean unmount
record, we know the value in the superblock is correct, so we can avoid
the summation walk under normal conditions and so mount/recovery times do
not change under normal operation.

One wrinkle that was discovered during development was that the blocks
used in the freespace btrees are never accounted for in the AGF counters.
This was once a valid optimisation to make; when the filesystem is full,
the free space btrees are empty and consume no space. Hence when it
matters, the "accounting" is correct. But that means the when we do the
AGF summations, we would not have a correct count and xfs_check would
complain. Hence a new counter was added to track the number of blocks used
by the free space btrees. This is an *on-disk format change*.

As a result of this, lazy superblock counters are a mkfs option and at the
moment on linux there is no way to convert an old filesystem. This is
possible - xfs_db can be used to twiddle the right bits and then
xfs_repair will do the format conversion for you. Similarly, you can
convert backwards as well. At some point we'll add functionality to
xfs_admin to do the bit twiddling easily....

SGI-PV: 964999
SGI-Modid: xfs-linux-melb:xfs-kern:28652a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tim Shimmin <tes@sgi.com>
This commit is contained in:
David Chinner 2007-05-24 15:26:31 +10:00 committed by Tim Shimmin
parent 3260f78ad6
commit 92821e2ba4
18 changed files with 337 additions and 54 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

3
fs/xfs/linux-2.6/xfs_super.c
View file

@ -547,7 +547,8 @@ vfs_sync_worker(
if (!(vfsp->vfs_flag & VFS_RDONLY))
error = bhv_vfs_sync(vfsp, SYNC_FSDATA | SYNC_BDFLUSH | \
SYNC_ATTR | SYNC_REFCACHE, NULL);
SYNC_ATTR | SYNC_REFCACHE | SYNC_SUPER,
NULL);
vfsp->vfs_sync_seq++;
wake_up(&vfsp->vfs_wait_single_sync_task);
}

1
fs/xfs/linux-2.6/xfs_vfs.h
View file

@ -92,6 +92,7 @@ typedef enum {
#define SYNC_REFCACHE 0x0040 /* prune some of the nfs ref cache */
#define SYNC_REMOUNT 0x0080 /* remount readonly, no dummy LRs */
#define SYNC_IOWAIT 0x0100 /* wait for all I/O to complete */
#define SYNC_SUPER 0x0200 /* flush superblock to disk */
#define SHUTDOWN_META_IO_ERROR 0x0001 /* write attempt to metadata failed */
#define SHUTDOWN_LOG_IO_ERROR 0x0002 /* write attempt to the log failed */

8
fs/xfs/xfs_ag.h
View file

@ -68,6 +68,7 @@ typedef struct xfs_agf {
__be32 agf_flcount; /* count of blocks in freelist */
__be32 agf_freeblks; /* total free blocks */
__be32 agf_longest; /* longest free space */
__be32 agf_btreeblks; /* # of blocks held in AGF btrees */
} xfs_agf_t;
#define XFS_AGF_MAGICNUM 0x00000001
@ -81,7 +82,8 @@ typedef struct xfs_agf {
#define XFS_AGF_FLCOUNT 0x00000100
#define XFS_AGF_FREEBLKS 0x00000200
#define XFS_AGF_LONGEST 0x00000400
#define XFS_AGF_NUM_BITS 11
#define XFS_AGF_BTREEBLKS 0x00000800
#define XFS_AGF_NUM_BITS 12
#define XFS_AGF_ALL_BITS ((1 << XFS_AGF_NUM_BITS) - 1)
/* disk block (xfs_daddr_t) in the AG */
@ -186,11 +188,13 @@ typedef struct xfs_perag
__uint32_t pagf_flcount; /* count of blocks in freelist */
xfs_extlen_t pagf_freeblks; /* total free blocks */
xfs_extlen_t pagf_longest; /* longest free space */
__uint32_t pagf_btreeblks; /* # of blocks held in AGF btrees */
xfs_agino_t pagi_freecount; /* number of free inodes */
xfs_agino_t pagi_count; /* number of allocated inodes */
int pagb_count; /* pagb slots in use */
#ifdef __KERNEL__
lock_t pagb_lock; /* lock for pagb_list */
#endif
int pagb_count; /* pagb slots in use */
xfs_perag_busy_t *pagb_list; /* unstable blocks */
} xfs_perag_t;

48
fs/xfs/xfs_alloc.c
View file

@ -1447,7 +1447,8 @@ xfs_alloc_ag_vextent_small(
else if (args->minlen == 1 && args->alignment == 1 && !args->isfl &&
(be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_flcount)
> args->minleft)) {
if ((error = xfs_alloc_get_freelist(args->tp, args->agbp, &fbno)))
error = xfs_alloc_get_freelist(args->tp, args->agbp, &fbno, 0);
if (error)
goto error0;
if (fbno != NULLAGBLOCK) {
if (args->userdata) {
@ -1923,7 +1924,8 @@ xfs_alloc_fix_freelist(
while (be32_to_cpu(agf->agf_flcount) > need) {
xfs_buf_t *bp;
if ((error = xfs_alloc_get_freelist(tp, agbp, &bno)))
error = xfs_alloc_get_freelist(tp, agbp, &bno, 0);
if (error)
return error;
if ((error = xfs_free_ag_extent(tp, agbp, args->agno, bno, 1, 1)))
return error;
@ -1973,8 +1975,9 @@ xfs_alloc_fix_freelist(
* Put each allocated block on the list.
*/
for (bno = targs.agbno; bno < targs.agbno + targs.len; bno++) {
if ((error = xfs_alloc_put_freelist(tp, agbp, agflbp,
bno)))
error = xfs_alloc_put_freelist(tp, agbp,
agflbp, bno, 0);
if (error)
return error;
}
}
@ -1991,13 +1994,15 @@ int /* error */
xfs_alloc_get_freelist(
xfs_trans_t *tp, /* transaction pointer */
xfs_buf_t *agbp, /* buffer containing the agf structure */
xfs_agblock_t *bnop) /* block address retrieved from freelist */
xfs_agblock_t *bnop, /* block address retrieved from freelist */
int btreeblk) /* destination is a AGF btree */
{
xfs_agf_t *agf; /* a.g. freespace structure */
xfs_agfl_t *agfl; /* a.g. freelist structure */
xfs_buf_t *agflbp;/* buffer for a.g. freelist structure */
xfs_agblock_t bno; /* block number returned */
int error;
int logflags;
#ifdef XFS_ALLOC_TRACE
static char fname[] = "xfs_alloc_get_freelist";
#endif
@ -2032,8 +2037,16 @@ xfs_alloc_get_freelist(
be32_add(&agf->agf_flcount, -1);
xfs_trans_agflist_delta(tp, -1);
pag->pagf_flcount--;
TRACE_MODAGF(NULL, agf, XFS_AGF_FLFIRST | XFS_AGF_FLCOUNT);
xfs_alloc_log_agf(tp, agbp, XFS_AGF_FLFIRST | XFS_AGF_FLCOUNT);
logflags = XFS_AGF_FLFIRST | XFS_AGF_FLCOUNT;
if (btreeblk) {
be32_add(&agf->agf_btreeblks, 1);
pag->pagf_btreeblks++;
logflags |= XFS_AGF_BTREEBLKS;
}
TRACE_MODAGF(NULL, agf, logflags);
xfs_alloc_log_agf(tp, agbp, logflags);
*bnop = bno;
/*
@ -2071,6 +2084,7 @@ xfs_alloc_log_agf(
offsetof(xfs_agf_t, agf_flcount),
offsetof(xfs_agf_t, agf_freeblks),
offsetof(xfs_agf_t, agf_longest),
offsetof(xfs_agf_t, agf_btreeblks),
sizeof(xfs_agf_t)
};
@ -2106,12 +2120,14 @@ xfs_alloc_put_freelist(
xfs_trans_t *tp, /* transaction pointer */
xfs_buf_t *agbp, /* buffer for a.g. freelist header */
xfs_buf_t *agflbp,/* buffer for a.g. free block array */
xfs_agblock_t bno) /* block being freed */
xfs_agblock_t bno, /* block being freed */
int btreeblk) /* block came from a AGF btree */
{
xfs_agf_t *agf; /* a.g. freespace structure */
xfs_agfl_t *agfl; /* a.g. free block array */
__be32 *blockp;/* pointer to array entry */
int error;
int logflags;
#ifdef XFS_ALLOC_TRACE
static char fname[] = "xfs_alloc_put_freelist";
#endif
@ -2132,11 +2148,22 @@ xfs_alloc_put_freelist(
be32_add(&agf->agf_flcount, 1);
xfs_trans_agflist_delta(tp, 1);
pag->pagf_flcount++;
logflags = XFS_AGF_FLLAST | XFS_AGF_FLCOUNT;
if (btreeblk) {
be32_add(&agf->agf_btreeblks, -1);
pag->pagf_btreeblks--;
logflags |= XFS_AGF_BTREEBLKS;
}
TRACE_MODAGF(NULL, agf, logflags);
xfs_alloc_log_agf(tp, agbp, logflags);
ASSERT(be32_to_cpu(agf->agf_flcount) <= XFS_AGFL_SIZE(mp));
blockp = &agfl->agfl_bno[be32_to_cpu(agf->agf_fllast)];
*blockp = cpu_to_be32(bno);
TRACE_MODAGF(NULL, agf, XFS_AGF_FLLAST | XFS_AGF_FLCOUNT);
xfs_alloc_log_agf(tp, agbp, XFS_AGF_FLLAST | XFS_AGF_FLCOUNT);
TRACE_MODAGF(NULL, agf, logflags);
xfs_alloc_log_agf(tp, agbp, logflags);
xfs_trans_log_buf(tp, agflbp,
(int)((xfs_caddr_t)blockp - (xfs_caddr_t)agfl),
(int)((xfs_caddr_t)blockp - (xfs_caddr_t)agfl +
@ -2196,6 +2223,7 @@ xfs_alloc_read_agf(
pag = &mp->m_perag[agno];
if (!pag->pagf_init) {
pag->pagf_freeblks = be32_to_cpu(agf->agf_freeblks);
pag->pagf_btreeblks = be32_to_cpu(agf->agf_btreeblks);
pag->pagf_flcount = be32_to_cpu(agf->agf_flcount);
pag->pagf_longest = be32_to_cpu(agf->agf_longest);
pag->pagf_levels[XFS_BTNUM_BNOi] =

6
fs/xfs/xfs_alloc.h
View file

@ -136,7 +136,8 @@ int /* error */
xfs_alloc_get_freelist(
struct xfs_trans *tp, /* transaction pointer */
struct xfs_buf *agbp, /* buffer containing the agf structure */
xfs_agblock_t *bnop); /* block address retrieved from freelist */
xfs_agblock_t *bnop, /* block address retrieved from freelist */
int btreeblk); /* destination is a AGF btree */
/*
* Log the given fields from the agf structure.
@ -165,7 +166,8 @@ xfs_alloc_put_freelist(
struct xfs_trans *tp, /* transaction pointer */
struct xfs_buf *agbp, /* buffer for a.g. freelist header */
struct xfs_buf *agflbp,/* buffer for a.g. free block array */
xfs_agblock_t bno); /* block being freed */
xfs_agblock_t bno, /* block being freed */
int btreeblk); /* owner was a AGF btree */
/*
* Read in the allocation group header (free/alloc section).

20
fs/xfs/xfs_alloc_btree.c
View file

@ -226,8 +226,9 @@ xfs_alloc_delrec(
/*
* Put this buffer/block on the ag's freelist.
*/
if ((error = xfs_alloc_put_freelist(cur->bc_tp,
cur->bc_private.a.agbp, NULL, bno)))
error = xfs_alloc_put_freelist(cur->bc_tp,
cur->bc_private.a.agbp, NULL, bno, 1);
if (error)
return error;
/*
* Since blocks move to the free list without the
@ -549,8 +550,9 @@ xfs_alloc_delrec(
/*
* Free the deleting block by putting it on the freelist.
*/
if ((error = xfs_alloc_put_freelist(cur->bc_tp, cur->bc_private.a.agbp,
NULL, rbno)))
error = xfs_alloc_put_freelist(cur->bc_tp,
cur->bc_private.a.agbp, NULL, rbno, 1);
if (error)
return error;
/*
* Since blocks move to the free list without the coordination
@ -1320,8 +1322,9 @@ xfs_alloc_newroot(
/*
* Get a buffer from the freelist blocks, for the new root.
*/
if ((error = xfs_alloc_get_freelist(cur->bc_tp, cur->bc_private.a.agbp,
&nbno)))
error = xfs_alloc_get_freelist(cur->bc_tp,
cur->bc_private.a.agbp, &nbno, 1);
if (error)
return error;
/*
* None available, we fail.
@ -1604,8 +1607,9 @@ xfs_alloc_split(
* Allocate the new block from the freelist.
* If we can't do it, we're toast. Give up.
*/
if ((error = xfs_alloc_get_freelist(cur->bc_tp, cur->bc_private.a.agbp,
&rbno)))
error = xfs_alloc_get_freelist(cur->bc_tp,
cur->bc_private.a.agbp, &rbno, 1);
if (error)
return error;
if (rbno == NULLAGBLOCK) {
*stat = 0;

1
fs/xfs/xfs_fs.h
View file

@ -238,6 +238,7 @@ typedef struct xfs_fsop_resblks {
#define XFS_FSOP_GEOM_FLAGS_LOGV2 0x0100 /* log format version 2 */
#define XFS_FSOP_GEOM_FLAGS_SECTOR 0x0200 /* sector sizes >1BB */
#define XFS_FSOP_GEOM_FLAGS_ATTR2 0x0400 /* inline attributes rework */
#define XFS_FSOP_GEOM_FLAGS_LAZYSB 0x4000 /* lazy superblock counters */
/*

2
fs/xfs/xfs_fsops.c
View file

@ -94,6 +94,8 @@ xfs_fs_geometry(
XFS_FSOP_GEOM_FLAGS_DIRV2 : 0) |
(XFS_SB_VERSION_HASSECTOR(&mp->m_sb) ?
XFS_FSOP_GEOM_FLAGS_SECTOR : 0) |
(xfs_sb_version_haslazysbcount(&mp->m_sb) ?
XFS_FSOP_GEOM_FLAGS_LAZYSB : 0) |
(XFS_SB_VERSION_HASATTR2(&mp->m_sb) ?
XFS_FSOP_GEOM_FLAGS_ATTR2 : 0);
geo->logsectsize = XFS_SB_VERSION_HASSECTOR(&mp->m_sb) ?

28
fs/xfs/xfs_ialloc.c
View file

@ -123,6 +123,7 @@ xfs_ialloc_ag_alloc(
int blks_per_cluster; /* fs blocks per inode cluster */
xfs_btree_cur_t *cur; /* inode btree cursor */
xfs_daddr_t d; /* disk addr of buffer */
xfs_agnumber_t agno;
int error;
xfs_buf_t *fbuf; /* new free inodes' buffer */
xfs_dinode_t *free; /* new free inode structure */
@ -302,15 +303,15 @@ xfs_ialloc_ag_alloc(
}
be32_add(&agi->agi_count, newlen);
be32_add(&agi->agi_freecount, newlen);
agno = be32_to_cpu(agi->agi_seqno);
down_read(&args.mp->m_peraglock);
args.mp->m_perag[be32_to_cpu(agi->agi_seqno)].pagi_freecount += newlen;
args.mp->m_perag[agno].pagi_freecount += newlen;
up_read(&args.mp->m_peraglock);
agi->agi_newino = cpu_to_be32(newino);
/*
* Insert records describing the new inode chunk into the btree.
*/
cur = xfs_btree_init_cursor(args.mp, tp, agbp,
be32_to_cpu(agi->agi_seqno),
cur = xfs_btree_init_cursor(args.mp, tp, agbp, agno,
XFS_BTNUM_INO, (xfs_inode_t *)0, 0);
for (thisino = newino;
thisino < newino + newlen;
@ -1387,6 +1388,7 @@ xfs_ialloc_read_agi(
pag = &mp->m_perag[agno];
if (!pag->pagi_init) {
pag->pagi_freecount = be32_to_cpu(agi->agi_freecount);
pag->pagi_count = be32_to_cpu(agi->agi_count);
pag->pagi_init = 1;
} else {
/*
@ -1410,3 +1412,23 @@ xfs_ialloc_read_agi(
*bpp = bp;
return 0;
}
/*
* Read in the agi to initialise the per-ag data in the mount structure
*/
int
xfs_ialloc_pagi_init(
xfs_mount_t *mp, /* file system mount structure */
xfs_trans_t *tp, /* transaction pointer */
xfs_agnumber_t agno) /* allocation group number */
{
xfs_buf_t *bp = NULL;
int error;
error = xfs_ialloc_read_agi(mp, tp, agno, &bp);
if (error)
return error;
if (bp)
xfs_trans_brelse(tp, bp);
return 0;
}

10
fs/xfs/xfs_ialloc.h
View file

@ -149,6 +149,16 @@ xfs_ialloc_read_agi(
xfs_agnumber_t agno, /* allocation group number */
struct xfs_buf **bpp); /* allocation group hdr buf */
/*
* Read in the allocation group header to initialise the per-ag data
* in the mount structure
*/
int
xfs_ialloc_pagi_init(
struct xfs_mount *mp, /* file system mount structure */
struct xfs_trans *tp, /* transaction pointer */
xfs_agnumber_t agno); /* allocation group number */
#endif /* __KERNEL__ */
#endif /* __XFS_IALLOC_H__ */

4
fs/xfs/xfs_log.c
View file

@ -817,10 +817,8 @@ xfs_log_need_covered(xfs_mount_t *mp)
SPLDECL(s);
int needed = 0, gen;
xlog_t *log = mp->m_log;
bhv_vfs_t *vfsp = XFS_MTOVFS(mp);
if (vfs_test_for_freeze(vfsp) || XFS_FORCED_SHUTDOWN(mp) ||
(vfsp->vfs_flag & VFS_RDONLY))
if (!xfs_fs_writable(mp))
return 0;
s = LOG_LOCK(log);

8
fs/xfs/xfs_log_recover.c
View file

@ -927,6 +927,14 @@ xlog_find_tail(
ASSIGN_ANY_LSN_HOST(log->l_last_sync_lsn, log->l_curr_cycle,
after_umount_blk);
*tail_blk = after_umount_blk;
/*
* Note that the unmount was clean. If the unmount
* was not clean, we need to know this to rebuild the
* superblock counters from the perag headers if we
* have a filesystem using non-persistent counters.
*/
log->l_mp->m_flags |= XFS_MOUNT_WAS_CLEAN;
}
}

154
fs/xfs/xfs_mount.c
View file

@ -643,6 +643,64 @@ xfs_mount_common(xfs_mount_t *mp, xfs_sb_t *sbp)
sbp->sb_inopblock);
mp->m_ialloc_blks = mp->m_ialloc_inos >> sbp->sb_inopblog;
}
/*
* xfs_initialize_perag_data
*
* Read in each per-ag structure so we can count up the number of
* allocated inodes, free inodes and used filesystem blocks as this
* information is no longer persistent in the superblock. Once we have
* this information, write it into the in-core superblock structure.
*/
STATIC int
xfs_initialize_perag_data(xfs_mount_t *mp, xfs_agnumber_t agcount)
{
xfs_agnumber_t index;
xfs_perag_t *pag;
xfs_sb_t *sbp = &mp->m_sb;
uint64_t ifree = 0;
uint64_t ialloc = 0;
uint64_t bfree = 0;
uint64_t bfreelst = 0;
uint64_t btree = 0;
int error;
int s;
for (index = 0; index < agcount; index++) {
/*
* read the agf, then the agi. This gets us
* all the inforamtion we need and populates the
* per-ag structures for us.
*/
error = xfs_alloc_pagf_init(mp, NULL, index, 0);
if (error)
return error;
error = xfs_ialloc_pagi_init(mp, NULL, index);
if (error)
return error;
pag = &mp->m_perag[index];
ifree += pag->pagi_freecount;
ialloc += pag->pagi_count;
bfree += pag->pagf_freeblks;
bfreelst += pag->pagf_flcount;
btree += pag->pagf_btreeblks;
}
/*
* Overwrite incore superblock counters with just-read data
*/
s = XFS_SB_LOCK(mp);
sbp->sb_ifree = ifree;
sbp->sb_icount = ialloc;
sbp->sb_fdblocks = bfree + bfreelst + btree;
XFS_SB_UNLOCK(mp, s);
/* Fixup the per-cpu counters as well. */
xfs_icsb_reinit_counters(mp);
return 0;
}
/*
* xfs_mountfs
*
@ -986,6 +1044,34 @@ xfs_mountfs(
goto error2;
}
/*
* Now the log is mounted, we know if it was an unclean shutdown or
* not. If it was, with the first phase of recovery has completed, we
* have consistent AG blocks on disk. We have not recovered EFIs yet,
* but they are recovered transactionally in the second recovery phase
* later.
*
* Hence we can safely re-initialise incore superblock counters from
* the per-ag data. These may not be correct if the filesystem was not
* cleanly unmounted, so we need to wait for recovery to finish before
* doing this.
*
* If the filesystem was cleanly unmounted, then we can trust the
* values in the superblock to be correct and we don't need to do
* anything here.
*
* If we are currently making the filesystem, the initialisation will
* fail as the perag data is in an undefined state.
*/
if (xfs_sb_version_haslazysbcount(&mp->m_sb) &&
!XFS_LAST_UNMOUNT_WAS_CLEAN(mp) &&
!mp->m_sb.sb_inprogress) {
error = xfs_initialize_perag_data(mp, sbp->sb_agcount);
if (error) {
goto error2;
}
}
/*
* Get and sanity-check the root inode.
* Save the pointer to it in the mount structure.
@ -1049,6 +1135,7 @@ xfs_mountfs(
goto error4;
}
/*
* Complete the quota initialisation, post-log-replay component.
*/
@ -1111,10 +1198,9 @@ xfs_unmountfs(xfs_mount_t *mp, struct cred *cr)
xfs_binval(mp->m_rtdev_targp);
}
xfs_log_sbcount(mp, 1);
xfs_unmountfs_writesb(mp);
xfs_unmountfs_wait(mp); /* wait for async bufs */
xfs_log_unmount(mp); /* Done! No more fs ops. */
xfs_freesb(mp);
@ -1160,6 +1246,62 @@ xfs_unmountfs_wait(xfs_mount_t *mp)
xfs_wait_buftarg(mp->m_ddev_targp);
}
int
xfs_fs_writable(xfs_mount_t *mp)
{
bhv_vfs_t *vfsp = XFS_MTOVFS(mp);
return !(vfs_test_for_freeze(vfsp) || XFS_FORCED_SHUTDOWN(mp) ||
(vfsp->vfs_flag & VFS_RDONLY));
}
/*
* xfs_log_sbcount
*
* Called either periodically to keep the on disk superblock values
* roughly up to date or from unmount to make sure the values are
* correct on a clean unmount.
*
* Note this code can be called during the process of freezing, so
* we may need to use the transaction allocator which does not not
* block when the transaction subsystem is in its frozen state.
*/
int
xfs_log_sbcount(
xfs_mount_t *mp,
uint sync)
{
xfs_trans_t *tp;
int error;
if (!xfs_fs_writable(mp))
return 0;
xfs_icsb_sync_counters(mp);
/*
* we don't need to do this if we are updating the superblock
* counters on every modification.
*/
if (!xfs_sb_version_haslazysbcount(&mp->m_sb))
return 0;
tp = _xfs_trans_alloc(mp, XFS_TRANS_SB_COUNT);
error = xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0,
XFS_DEFAULT_LOG_COUNT);
if (error) {
xfs_trans_cancel(tp, 0);
return error;
}
xfs_mod_sb(tp, XFS_SB_IFREE | XFS_SB_ICOUNT | XFS_SB_FDBLOCKS);
if (sync)
xfs_trans_set_sync(tp);
xfs_trans_commit(tp, 0);
return 0;
}
int
xfs_unmountfs_writesb(xfs_mount_t *mp)
{
@ -1171,16 +1313,15 @@ xfs_unmountfs_writesb(xfs_mount_t *mp)
* skip superblock write if fs is read-only, or
* if we are doing a forced umount.
*/
sbp = xfs_getsb(mp, 0);
if (!(XFS_MTOVFS(mp)->vfs_flag & VFS_RDONLY ||
XFS_FORCED_SHUTDOWN(mp))) {
xfs_icsb_sync_counters(mp);
sbp = xfs_getsb(mp, 0);
sb = XFS_BUF_TO_SBP(sbp);
/*
* mark shared-readonly if desired
*/
sb = XFS_BUF_TO_SBP(sbp);
if (mp->m_mk_sharedro) {
if (!(sb->sb_flags & XFS_SBF_READONLY))
sb->sb_flags |= XFS_SBF_READONLY;
@ -1189,6 +1330,7 @@ xfs_unmountfs_writesb(xfs_mount_t *mp)
xfs_fs_cmn_err(CE_NOTE, mp,
"Unmounting, marking shared read-only");
}
XFS_BUF_UNDONE(sbp);
XFS_BUF_UNREAD(sbp);
XFS_BUF_UNDELAYWRITE(sbp);
@ -1203,8 +1345,8 @@ xfs_unmountfs_writesb(xfs_mount_t *mp)
mp, sbp, XFS_BUF_ADDR(sbp));
if (error && mp->m_mk_sharedro)
xfs_fs_cmn_err(CE_ALERT, mp, "Superblock write error detected while unmounting. Filesystem may not be marked shared readonly");
xfs_buf_relse(sbp);
}
xfs_buf_relse(sbp);
return error;
}

10
fs/xfs/xfs_mount.h
View file

@ -429,12 +429,12 @@ typedef struct xfs_mount {
/*
* Flags for m_flags.
*/
#define XFS_MOUNT_WSYNC (1ULL << 0) /* for nfs - all metadata ops
#define XFS_MOUNT_WSYNC (1ULL << 0) /* for nfs - all metadata ops
must be synchronous except
for space allocations */
#define XFS_MOUNT_INO64 (1ULL << 1)
#define XFS_MOUNT_INO64 (1ULL << 1)
/* (1ULL << 2) -- currently unused */
/* (1ULL << 3) -- currently unused */
#define XFS_MOUNT_WAS_CLEAN (1ULL << 3)
#define XFS_MOUNT_FS_SHUTDOWN (1ULL << 4) /* atomic stop of all filesystem
operations, typically for
disk errors in metadata */
@ -511,6 +511,8 @@ xfs_preferred_iosize(xfs_mount_t *mp)
#define XFS_MAXIOFFSET(mp) ((mp)->m_maxioffset)
#define XFS_LAST_UNMOUNT_WAS_CLEAN(mp) \
((mp)->m_flags & XFS_MOUNT_WAS_CLEAN)
#define XFS_FORCED_SHUTDOWN(mp) ((mp)->m_flags & XFS_MOUNT_FS_SHUTDOWN)
#define xfs_force_shutdown(m,f) \
bhv_vfs_force_shutdown((XFS_MTOVFS(m)), f, __FILE__, __LINE__)
@ -602,6 +604,7 @@ typedef struct xfs_mod_sb {
extern xfs_mount_t *xfs_mount_init(void);
extern void xfs_mod_sb(xfs_trans_t *, __int64_t);
extern int xfs_log_sbcount(xfs_mount_t *, uint);
extern void xfs_mount_free(xfs_mount_t *mp, int remove_bhv);
extern int xfs_mountfs(struct bhv_vfs *, xfs_mount_t *mp, int);
extern void xfs_mountfs_check_barriers(xfs_mount_t *mp);
@ -618,6 +621,7 @@ extern int xfs_mod_incore_sb_batch(xfs_mount_t *, xfs_mod_sb_t *,
extern struct xfs_buf *xfs_getsb(xfs_mount_t *, int);
extern int xfs_readsb(xfs_mount_t *, int);
extern void xfs_freesb(xfs_mount_t *);
extern int xfs_fs_writable(xfs_mount_t *);
extern void xfs_do_force_shutdown(bhv_desc_t *, int, char *, int);
extern int xfs_syncsub(xfs_mount_t *, int, int *);
extern int xfs_sync_inodes(xfs_mount_t *, int, int *);

16
fs/xfs/xfs_sb.h
View file

@ -74,12 +74,13 @@ struct xfs_mount;
*/
#define XFS_SB_VERSION2_REALFBITS 0x00ffffff /* Mask: features */
#define XFS_SB_VERSION2_RESERVED1BIT 0x00000001
#define XFS_SB_VERSION2_RESERVED2BIT 0x00000002
#define XFS_SB_VERSION2_LAZYSBCOUNTBIT 0x00000002 /* Superblk counters */
#define XFS_SB_VERSION2_RESERVED4BIT 0x00000004
#define XFS_SB_VERSION2_ATTR2BIT 0x00000008 /* Inline attr rework */
#define XFS_SB_VERSION2_OKREALFBITS \
(XFS_SB_VERSION2_ATTR2BIT)
(XFS_SB_VERSION2_LAZYSBCOUNTBIT | \
XFS_SB_VERSION2_ATTR2BIT)
#define XFS_SB_VERSION2_OKSASHFBITS \
(0)
#define XFS_SB_VERSION2_OKREALBITS \
@ -181,6 +182,9 @@ typedef enum {
#define XFS_SB_SHARED_VN XFS_SB_MVAL(SHARED_VN)
#define XFS_SB_UNIT XFS_SB_MVAL(UNIT)
#define XFS_SB_WIDTH XFS_SB_MVAL(WIDTH)
#define XFS_SB_ICOUNT XFS_SB_MVAL(ICOUNT)
#define XFS_SB_IFREE XFS_SB_MVAL(IFREE)
#define XFS_SB_FDBLOCKS XFS_SB_MVAL(FDBLOCKS)
#define XFS_SB_FEATURES2 XFS_SB_MVAL(FEATURES2)
#define XFS_SB_NUM_BITS ((int)XFS_SBS_FIELDCOUNT)
#define XFS_SB_ALL_BITS ((1LL << XFS_SB_NUM_BITS) - 1)
@ -188,7 +192,7 @@ typedef enum {
(XFS_SB_UUID | XFS_SB_ROOTINO | XFS_SB_RBMINO | XFS_SB_RSUMINO | \
XFS_SB_VERSIONNUM | XFS_SB_UQUOTINO | XFS_SB_GQUOTINO | \
XFS_SB_QFLAGS | XFS_SB_SHARED_VN | XFS_SB_UNIT | XFS_SB_WIDTH | \
XFS_SB_FEATURES2)
XFS_SB_ICOUNT | XFS_SB_IFREE | XFS_SB_FDBLOCKS | XFS_SB_FEATURES2)
/*
@ -414,6 +418,12 @@ static inline int xfs_sb_version_hasmorebits(xfs_sb_t *sbp)
* ((sbp)->sb_features2 & XFS_SB_VERSION2_FUNBIT)
*/
static inline int xfs_sb_version_haslazysbcount(xfs_sb_t *sbp)
{
return (XFS_SB_VERSION_HASMOREBITS(sbp) && \
((sbp)->sb_features2 & XFS_SB_VERSION2_LAZYSBCOUNTBIT));
}
#define XFS_SB_VERSION_HASATTR2(sbp) xfs_sb_version_hasattr2(sbp)
static inline int xfs_sb_version_hasattr2(xfs_sb_t *sbp)
{

58
fs/xfs/xfs_trans.c
View file

@ -427,6 +427,14 @@ undo_blocks:
*
* Mark the transaction structure to indicate that the superblock
* needs to be updated before committing.
*
* Because we may not be keeping track of allocated/free inodes and
* used filesystem blocks in the superblock, we do not mark the
* superblock dirty in this transaction if we modify these fields.
* We still need to update the transaction deltas so that they get
* applied to the incore superblock, but we don't want them to
* cause the superblock to get locked and logged if these are the
* only fields in the superblock that the transaction modifies.
*/
void
xfs_trans_mod_sb(
@ -434,13 +442,19 @@ xfs_trans_mod_sb(
uint field,
int64_t delta)
{
uint32_t flags = (XFS_TRANS_DIRTY|XFS_TRANS_SB_DIRTY);
xfs_mount_t *mp = tp->t_mountp;
switch (field) {
case XFS_TRANS_SB_ICOUNT:
tp->t_icount_delta += delta;
if (xfs_sb_version_haslazysbcount(&mp->m_sb))
flags &= ~XFS_TRANS_SB_DIRTY;
break;
case XFS_TRANS_SB_IFREE:
tp->t_ifree_delta += delta;
if (xfs_sb_version_haslazysbcount(&mp->m_sb))
flags &= ~XFS_TRANS_SB_DIRTY;
break;
case XFS_TRANS_SB_FDBLOCKS:
/*
@ -453,6 +467,8 @@ xfs_trans_mod_sb(
ASSERT(tp->t_blk_res_used <= tp->t_blk_res);
}
tp->t_fdblocks_delta += delta;
if (xfs_sb_version_haslazysbcount(&mp->m_sb))
flags &= ~XFS_TRANS_SB_DIRTY;
break;
case XFS_TRANS_SB_RES_FDBLOCKS:
/*
@ -462,6 +478,8 @@ xfs_trans_mod_sb(
*/
ASSERT(delta < 0);
tp->t_res_fdblocks_delta += delta;
if (xfs_sb_version_haslazysbcount(&mp->m_sb))
flags &= ~XFS_TRANS_SB_DIRTY;
break;
case XFS_TRANS_SB_FREXTENTS:
/*
@ -544,18 +562,23 @@ xfs_trans_apply_sb_deltas(
(tp->t_ag_freeblks_delta + tp->t_ag_flist_delta +
tp->t_ag_btree_delta));
if (tp->t_icount_delta != 0) {
INT_MOD(sbp->sb_icount, ARCH_CONVERT, tp->t_icount_delta);
}
if (tp->t_ifree_delta != 0) {
INT_MOD(sbp->sb_ifree, ARCH_CONVERT, tp->t_ifree_delta);
}
/*
* Only update the superblock counters if we are logging them
*/
if (!xfs_sb_version_haslazysbcount(&(tp->t_mountp->m_sb))) {
if (tp->t_icount_delta != 0) {
INT_MOD(sbp->sb_icount, ARCH_CONVERT, tp->t_icount_delta);
}
if (tp->t_ifree_delta != 0) {
INT_MOD(sbp->sb_ifree, ARCH_CONVERT, tp->t_ifree_delta);
}
if (tp->t_fdblocks_delta != 0) {
INT_MOD(sbp->sb_fdblocks, ARCH_CONVERT, tp->t_fdblocks_delta);
}
if (tp->t_res_fdblocks_delta != 0) {
INT_MOD(sbp->sb_fdblocks, ARCH_CONVERT, tp->t_res_fdblocks_delta);
if (tp->t_fdblocks_delta != 0) {
INT_MOD(sbp->sb_fdblocks, ARCH_CONVERT, tp->t_fdblocks_delta);
}
if (tp->t_res_fdblocks_delta != 0) {
INT_MOD(sbp->sb_fdblocks, ARCH_CONVERT, tp->t_res_fdblocks_delta);
}
}
if (tp->t_frextents_delta != 0) {
@ -627,6 +650,7 @@ xfs_trans_unreserve_and_mod_sb(
{
xfs_mod_sb_t msb[14]; /* If you add cases, add entries */
xfs_mod_sb_t *msbp;
xfs_mount_t *mp = tp->t_mountp;
/* REFERENCED */
int error;
int rsvd;
@ -659,8 +683,15 @@ xfs_trans_unreserve_and_mod_sb(
* The t_res_fdblocks_delta and t_res_frextents_delta fields are
* explicitly NOT applied to the in-core superblock.
* The idea is that that has already been done.
*
* If we are not logging superblock counters, then the inode
* allocated/free and used block counts are not updated in the
* on disk superblock. In this case, XFS_TRANS_SB_DIRTY will
* not be set when the transaction is updated but we still need
* to update the incore superblock with the changes.
*/
if (tp->t_flags & XFS_TRANS_SB_DIRTY) {
if (xfs_sb_version_haslazysbcount(&mp->m_sb) ||
(tp->t_flags & XFS_TRANS_SB_DIRTY)) {
if (tp->t_icount_delta != 0) {
msbp->msb_field = XFS_SBS_ICOUNT;
msbp->msb_delta = tp->t_icount_delta;
@ -676,6 +707,9 @@ xfs_trans_unreserve_and_mod_sb(
msbp->msb_delta = tp->t_fdblocks_delta;
msbp++;
}
}
if (tp->t_flags & XFS_TRANS_SB_DIRTY) {
if (tp->t_frextents_delta != 0) {
msbp->msb_field = XFS_SBS_FREXTENTS;
msbp->msb_delta = tp->t_frextents_delta;

3
fs/xfs/xfs_trans.h
View file

@ -94,7 +94,8 @@ typedef struct xfs_trans_header {
#define XFS_TRANS_GROWFSRT_ZERO 38
#define XFS_TRANS_GROWFSRT_FREE 39
#define XFS_TRANS_SWAPEXT 40
#define XFS_TRANS_TYPE_MAX 40
#define XFS_TRANS_SB_COUNT 41
#define XFS_TRANS_TYPE_MAX 41
/* new transaction types need to be reflected in xfs_logprint(8) */

11
fs/xfs/xfs_vfsops.c
View file

@ -672,6 +672,7 @@ xfs_mntupdate(
} else if (!(vfsp->vfs_flag & VFS_RDONLY)) { /* rw -> ro */
bhv_vfs_sync(vfsp, SYNC_FSDATA|SYNC_BDFLUSH|SYNC_ATTR, NULL);
xfs_quiesce_fs(mp);
xfs_log_sbcount(mp, 1);
xfs_log_unmount_write(mp);
xfs_unmountfs_writesb(mp);
vfsp->vfs_flag |= VFS_RDONLY;
@ -1496,6 +1497,15 @@ xfs_syncsub(
xfs_refcache_purge_some(mp);
}
/*
* If asked, update the disk superblock with incore counter values if we
* are using non-persistent counters so that they don't get too far out
* of sync if we crash or get a forced shutdown. We don't want to force
* this to disk, just get a transaction into the iclogs....
*/
if (flags & SYNC_SUPER)
xfs_log_sbcount(mp, 0);
/*
* Now check to see if the log needs a "dummy" transaction.
*/
@ -1962,6 +1972,7 @@ xfs_freeze(
ASSERT_ALWAYS(atomic_read(&mp->m_active_trans) == 0);
/* Push the superblock and write an unmount record */
xfs_log_sbcount(mp, 1);
xfs_log_unmount_write(mp);
xfs_unmountfs_writesb(mp);
xfs_fs_log_dummy(mp);