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linux/fs/xfs/xfs_mount.c
Dave Chinner c854363e80 xfs: Use delayed write for inodes rather than async V2 
We currently do background inode flush asynchronously, resulting in
inodes being written in whatever order the background writeback
issues them. Not only that, there are also blocking and non-blocking
asynchronous inode flushes, depending on where the flush comes from.

This patch completely removes asynchronous inode writeback. It
removes all the strange writeback modes and replaces them with
either a synchronous flush or a non-blocking delayed write flush.
That is, inode flushes will only issue IO directly if they are
synchronous, and background flushing may do nothing if the operation
would block (e.g. on a pinned inode or buffer lock).

Delayed write flushes will now result in the inode buffer sitting in
the delwri queue of the buffer cache to be flushed by either an AIL
push or by the xfsbufd timing out the buffer. This will allow
accumulation of dirty inode buffers in memory and allow optimisation
of inode cluster writeback at the xfsbufd level where we have much
greater queue depths than the block layer elevators. We will also
get adjacent inode cluster buffer IO merging for free when a later
patch in the series allows sorting of the delayed write buffers
before dispatch.

This effectively means that any inode that is written back by
background writeback will be seen as flush locked during AIL
pushing, and will result in the buffers being pushed from there.
This writeback path is currently non-optimal, but the next patch
in the series will fix that problem.

A side effect of this delayed write mechanism is that background
inode reclaim will no longer directly flush inodes, nor can it wait
on the flush lock. The result is that inode reclaim must leave the
inode in the reclaimable state until it is clean. Hence attempts to
reclaim a dirty inode in the background will simply skip the inode
until it is clean and this allows other mechanisms (i.e. xfsbufd) to
do more optimal writeback of the dirty buffers. As a result, the
inode reclaim code has been rewritten so that it no longer relies on
the ambiguous return values of xfs_iflush() to determine whether it
is safe to reclaim an inode.

Portions of this patch are derived from patches by Christoph
Hellwig.

Version 2:
- cleanup reclaim code as suggested by Christoph
- log background reclaim inode flush errors
- just pass sync flags to xfs_iflush

Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-02-06 12:39:36 +11:00

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/*
* Copyright (c) 2000-2005 Silicon Graphics, Inc.
* 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_types.h"
#include "xfs_bit.h"
#include "xfs_log.h"
#include "xfs_inum.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir2.h"
#include "xfs_dmapi.h"
#include "xfs_mount.h"
#include "xfs_bmap_btree.h"
#include "xfs_alloc_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_dir2_sf.h"
#include "xfs_attr_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_btree.h"
#include "xfs_ialloc.h"
#include "xfs_alloc.h"
#include "xfs_rtalloc.h"
#include "xfs_bmap.h"
#include "xfs_error.h"
#include "xfs_rw.h"
#include "xfs_quota.h"
#include "xfs_fsops.h"
#include "xfs_utils.h"
#include "xfs_trace.h"
STATIC void xfs_unmountfs_wait(xfs_mount_t *);
#ifdef HAVE_PERCPU_SB
STATIC void xfs_icsb_balance_counter(xfs_mount_t *, xfs_sb_field_t,
int);
STATIC void xfs_icsb_balance_counter_locked(xfs_mount_t *, xfs_sb_field_t,
int);
STATIC int xfs_icsb_modify_counters(xfs_mount_t *, xfs_sb_field_t,
int64_t, int);
STATIC void xfs_icsb_disable_counter(xfs_mount_t *, xfs_sb_field_t);
#else
#define xfs_icsb_balance_counter(mp, a, b) do { } while (0)
#define xfs_icsb_balance_counter_locked(mp, a, b) do { } while (0)
#define xfs_icsb_modify_counters(mp, a, b, c) do { } while (0)
#endif
static const struct {
short offset;
short type; /* 0 = integer
* 1 = binary / string (no translation)
*/
} xfs_sb_info[] = {
{ offsetof(xfs_sb_t, sb_magicnum), 0 },
{ offsetof(xfs_sb_t, sb_blocksize), 0 },
{ offsetof(xfs_sb_t, sb_dblocks), 0 },
{ offsetof(xfs_sb_t, sb_rblocks), 0 },
{ offsetof(xfs_sb_t, sb_rextents), 0 },
{ offsetof(xfs_sb_t, sb_uuid), 1 },
{ offsetof(xfs_sb_t, sb_logstart), 0 },
{ offsetof(xfs_sb_t, sb_rootino), 0 },
{ offsetof(xfs_sb_t, sb_rbmino), 0 },
{ offsetof(xfs_sb_t, sb_rsumino), 0 },
{ offsetof(xfs_sb_t, sb_rextsize), 0 },
{ offsetof(xfs_sb_t, sb_agblocks), 0 },
{ offsetof(xfs_sb_t, sb_agcount), 0 },
{ offsetof(xfs_sb_t, sb_rbmblocks), 0 },
{ offsetof(xfs_sb_t, sb_logblocks), 0 },
{ offsetof(xfs_sb_t, sb_versionnum), 0 },
{ offsetof(xfs_sb_t, sb_sectsize), 0 },
{ offsetof(xfs_sb_t, sb_inodesize), 0 },
{ offsetof(xfs_sb_t, sb_inopblock), 0 },
{ offsetof(xfs_sb_t, sb_fname[0]), 1 },
{ offsetof(xfs_sb_t, sb_blocklog), 0 },
{ offsetof(xfs_sb_t, sb_sectlog), 0 },
{ offsetof(xfs_sb_t, sb_inodelog), 0 },
{ offsetof(xfs_sb_t, sb_inopblog), 0 },
{ offsetof(xfs_sb_t, sb_agblklog), 0 },
{ offsetof(xfs_sb_t, sb_rextslog), 0 },
{ offsetof(xfs_sb_t, sb_inprogress), 0 },
{ offsetof(xfs_sb_t, sb_imax_pct), 0 },
{ offsetof(xfs_sb_t, sb_icount), 0 },
{ offsetof(xfs_sb_t, sb_ifree), 0 },
{ offsetof(xfs_sb_t, sb_fdblocks), 0 },
{ offsetof(xfs_sb_t, sb_frextents), 0 },
{ offsetof(xfs_sb_t, sb_uquotino), 0 },
{ offsetof(xfs_sb_t, sb_gquotino), 0 },
{ offsetof(xfs_sb_t, sb_qflags), 0 },
{ offsetof(xfs_sb_t, sb_flags), 0 },
{ offsetof(xfs_sb_t, sb_shared_vn), 0 },
{ offsetof(xfs_sb_t, sb_inoalignmt), 0 },
{ offsetof(xfs_sb_t, sb_unit), 0 },
{ offsetof(xfs_sb_t, sb_width), 0 },
{ offsetof(xfs_sb_t, sb_dirblklog), 0 },
{ offsetof(xfs_sb_t, sb_logsectlog), 0 },
{ offsetof(xfs_sb_t, sb_logsectsize),0 },
{ offsetof(xfs_sb_t, sb_logsunit), 0 },
{ offsetof(xfs_sb_t, sb_features2), 0 },
{ offsetof(xfs_sb_t, sb_bad_features2), 0 },
{ sizeof(xfs_sb_t), 0 }
};
static DEFINE_MUTEX(xfs_uuid_table_mutex);
static int xfs_uuid_table_size;
static uuid_t *xfs_uuid_table;
/*
* See if the UUID is unique among mounted XFS filesystems.
* Mount fails if UUID is nil or a FS with the same UUID is already mounted.
*/
STATIC int
xfs_uuid_mount(
struct xfs_mount *mp)
{
uuid_t *uuid = &mp->m_sb.sb_uuid;
int hole, i;
if (mp->m_flags & XFS_MOUNT_NOUUID)
return 0;
if (uuid_is_nil(uuid)) {
cmn_err(CE_WARN,
"XFS: Filesystem %s has nil UUID - can't mount",
mp->m_fsname);
return XFS_ERROR(EINVAL);
}
mutex_lock(&xfs_uuid_table_mutex);
for (i = 0, hole = -1; i < xfs_uuid_table_size; i++) {
if (uuid_is_nil(&xfs_uuid_table[i])) {
hole = i;
continue;
}
if (uuid_equal(uuid, &xfs_uuid_table[i]))
goto out_duplicate;
}
if (hole < 0) {
xfs_uuid_table = kmem_realloc(xfs_uuid_table,
(xfs_uuid_table_size + 1) * sizeof(*xfs_uuid_table),
xfs_uuid_table_size * sizeof(*xfs_uuid_table),
KM_SLEEP);
hole = xfs_uuid_table_size++;
}
xfs_uuid_table[hole] = *uuid;
mutex_unlock(&xfs_uuid_table_mutex);
return 0;
out_duplicate:
mutex_unlock(&xfs_uuid_table_mutex);
cmn_err(CE_WARN, "XFS: Filesystem %s has duplicate UUID - can't mount",
mp->m_fsname);
return XFS_ERROR(EINVAL);
}
STATIC void
xfs_uuid_unmount(
struct xfs_mount *mp)
{
uuid_t *uuid = &mp->m_sb.sb_uuid;
int i;
if (mp->m_flags & XFS_MOUNT_NOUUID)
return;
mutex_lock(&xfs_uuid_table_mutex);
for (i = 0; i < xfs_uuid_table_size; i++) {
if (uuid_is_nil(&xfs_uuid_table[i]))
continue;
if (!uuid_equal(uuid, &xfs_uuid_table[i]))
continue;
memset(&xfs_uuid_table[i], 0, sizeof(uuid_t));
break;
}
ASSERT(i < xfs_uuid_table_size);
mutex_unlock(&xfs_uuid_table_mutex);
}
/*
* Reference counting access wrappers to the perag structures.
*/
struct xfs_perag *
xfs_perag_get(struct xfs_mount *mp, xfs_agnumber_t agno)
{
struct xfs_perag *pag;
int ref = 0;
spin_lock(&mp->m_perag_lock);
pag = radix_tree_lookup(&mp->m_perag_tree, agno);
if (pag) {
ASSERT(atomic_read(&pag->pag_ref) >= 0);
/* catch leaks in the positive direction during testing */
ASSERT(atomic_read(&pag->pag_ref) < 1000);
ref = atomic_inc_return(&pag->pag_ref);
}
spin_unlock(&mp->m_perag_lock);
trace_xfs_perag_get(mp, agno, ref, _RET_IP_);
return pag;
}
void
xfs_perag_put(struct xfs_perag *pag)
{
int ref;
ASSERT(atomic_read(&pag->pag_ref) > 0);
ref = atomic_dec_return(&pag->pag_ref);
trace_xfs_perag_put(pag->pag_mount, pag->pag_agno, ref, _RET_IP_);
}
/*
* Free up the resources associated with a mount structure. Assume that
* the structure was initially zeroed, so we can tell which fields got
* initialized.
*/
STATIC void
xfs_free_perag(
xfs_mount_t *mp)
{
xfs_agnumber_t agno;
struct xfs_perag *pag;
for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
spin_lock(&mp->m_perag_lock);
pag = radix_tree_delete(&mp->m_perag_tree, agno);
ASSERT(pag);
ASSERT(atomic_read(&pag->pag_ref) == 0);
spin_unlock(&mp->m_perag_lock);
kmem_free(pag);
}
}
/*
* Check size of device based on the (data/realtime) block count.
* Note: this check is used by the growfs code as well as mount.
*/
int
xfs_sb_validate_fsb_count(
xfs_sb_t *sbp,
__uint64_t nblocks)
{
ASSERT(PAGE_SHIFT >= sbp->sb_blocklog);
ASSERT(sbp->sb_blocklog >= BBSHIFT);
#if XFS_BIG_BLKNOS /* Limited by ULONG_MAX of page cache index */
if (nblocks >> (PAGE_CACHE_SHIFT - sbp->sb_blocklog) > ULONG_MAX)
return E2BIG;
#else /* Limited by UINT_MAX of sectors */
if (nblocks << (sbp->sb_blocklog - BBSHIFT) > UINT_MAX)
return E2BIG;
#endif
return 0;
}
/*
* Check the validity of the SB found.
*/
STATIC int
xfs_mount_validate_sb(
xfs_mount_t *mp,
xfs_sb_t *sbp,
int flags)
{
/*
* If the log device and data device have the
* same device number, the log is internal.
* Consequently, the sb_logstart should be non-zero. If
* we have a zero sb_logstart in this case, we may be trying to mount
* a volume filesystem in a non-volume manner.
*/
if (sbp->sb_magicnum != XFS_SB_MAGIC) {
xfs_fs_mount_cmn_err(flags, "bad magic number");
return XFS_ERROR(EWRONGFS);
}
if (!xfs_sb_good_version(sbp)) {
xfs_fs_mount_cmn_err(flags, "bad version");
return XFS_ERROR(EWRONGFS);
}
if (unlikely(
sbp->sb_logstart == 0 && mp->m_logdev_targp == mp->m_ddev_targp)) {
xfs_fs_mount_cmn_err(flags,
"filesystem is marked as having an external log; "
"specify logdev on the\nmount command line.");
return XFS_ERROR(EINVAL);
}
if (unlikely(
sbp->sb_logstart != 0 && mp->m_logdev_targp != mp->m_ddev_targp)) {
xfs_fs_mount_cmn_err(flags,
"filesystem is marked as having an internal log; "
"do not specify logdev on\nthe mount command line.");
return XFS_ERROR(EINVAL);
}
/*
* More sanity checking. These were stolen directly from
* xfs_repair.
*/
if (unlikely(
sbp->sb_agcount <= 0 ||
sbp->sb_sectsize < XFS_MIN_SECTORSIZE ||
sbp->sb_sectsize > XFS_MAX_SECTORSIZE ||
sbp->sb_sectlog < XFS_MIN_SECTORSIZE_LOG ||
sbp->sb_sectlog > XFS_MAX_SECTORSIZE_LOG ||
sbp->sb_sectsize != (1 << sbp->sb_sectlog) ||
sbp->sb_blocksize < XFS_MIN_BLOCKSIZE ||
sbp->sb_blocksize > XFS_MAX_BLOCKSIZE ||
sbp->sb_blocklog < XFS_MIN_BLOCKSIZE_LOG ||
sbp->sb_blocklog > XFS_MAX_BLOCKSIZE_LOG ||
sbp->sb_blocksize != (1 << sbp->sb_blocklog) ||
sbp->sb_inodesize < XFS_DINODE_MIN_SIZE ||
sbp->sb_inodesize > XFS_DINODE_MAX_SIZE ||
sbp->sb_inodelog < XFS_DINODE_MIN_LOG ||
sbp->sb_inodelog > XFS_DINODE_MAX_LOG ||
sbp->sb_inodesize != (1 << sbp->sb_inodelog) ||
(sbp->sb_blocklog - sbp->sb_inodelog != sbp->sb_inopblog) ||
(sbp->sb_rextsize * sbp->sb_blocksize > XFS_MAX_RTEXTSIZE) ||
(sbp->sb_rextsize * sbp->sb_blocksize < XFS_MIN_RTEXTSIZE) ||
(sbp->sb_imax_pct > 100 /* zero sb_imax_pct is valid */))) {
xfs_fs_mount_cmn_err(flags, "SB sanity check 1 failed");
return XFS_ERROR(EFSCORRUPTED);
}
/*
* Sanity check AG count, size fields against data size field
*/
if (unlikely(
sbp->sb_dblocks == 0 ||
sbp->sb_dblocks >
(xfs_drfsbno_t)sbp->sb_agcount * sbp->sb_agblocks ||
sbp->sb_dblocks < (xfs_drfsbno_t)(sbp->sb_agcount - 1) *
sbp->sb_agblocks + XFS_MIN_AG_BLOCKS)) {
xfs_fs_mount_cmn_err(flags, "SB sanity check 2 failed");
return XFS_ERROR(EFSCORRUPTED);
}
/*
* Until this is fixed only page-sized or smaller data blocks work.
*/
if (unlikely(sbp->sb_blocksize > PAGE_SIZE)) {
xfs_fs_mount_cmn_err(flags,
"file system with blocksize %d bytes",
sbp->sb_blocksize);
xfs_fs_mount_cmn_err(flags,
"only pagesize (%ld) or less will currently work.",
PAGE_SIZE);
return XFS_ERROR(ENOSYS);
}
/*
* Currently only very few inode sizes are supported.
*/
switch (sbp->sb_inodesize) {
case 256:
case 512:
case 1024:
case 2048:
break;
default:
xfs_fs_mount_cmn_err(flags,
"inode size of %d bytes not supported",
sbp->sb_inodesize);
return XFS_ERROR(ENOSYS);
}
if (xfs_sb_validate_fsb_count(sbp, sbp->sb_dblocks) ||
xfs_sb_validate_fsb_count(sbp, sbp->sb_rblocks)) {
xfs_fs_mount_cmn_err(flags,
"file system too large to be mounted on this system.");
return XFS_ERROR(E2BIG);
}
if (unlikely(sbp->sb_inprogress)) {
xfs_fs_mount_cmn_err(flags, "file system busy");
return XFS_ERROR(EFSCORRUPTED);
}
/*
* Version 1 directory format has never worked on Linux.
*/
if (unlikely(!xfs_sb_version_hasdirv2(sbp))) {
xfs_fs_mount_cmn_err(flags,
"file system using version 1 directory format");
return XFS_ERROR(ENOSYS);
}
return 0;
}
STATIC void
xfs_initialize_perag_icache(
xfs_perag_t *pag)
{
if (!pag->pag_ici_init) {
rwlock_init(&pag->pag_ici_lock);
INIT_RADIX_TREE(&pag->pag_ici_root, GFP_ATOMIC);
pag->pag_ici_init = 1;
}
}
int
xfs_initialize_perag(
xfs_mount_t *mp,
xfs_agnumber_t agcount,
xfs_agnumber_t *maxagi)
{
xfs_agnumber_t index, max_metadata;
xfs_agnumber_t first_initialised = 0;
xfs_perag_t *pag;
xfs_agino_t agino;
xfs_ino_t ino;
xfs_sb_t *sbp = &mp->m_sb;
xfs_ino_t max_inum = XFS_MAXINUMBER_32;
int error = -ENOMEM;
/* Check to see if the filesystem can overflow 32 bit inodes */
agino = XFS_OFFBNO_TO_AGINO(mp, sbp->sb_agblocks - 1, 0);
ino = XFS_AGINO_TO_INO(mp, agcount - 1, agino);
/*
* Walk the current per-ag tree so we don't try to initialise AGs
* that already exist (growfs case). Allocate and insert all the
* AGs we don't find ready for initialisation.
*/
for (index = 0; index < agcount; index++) {
pag = xfs_perag_get(mp, index);
if (pag) {
xfs_perag_put(pag);
continue;
}
if (!first_initialised)
first_initialised = index;
pag = kmem_zalloc(sizeof(*pag), KM_MAYFAIL);
if (!pag)
goto out_unwind;
if (radix_tree_preload(GFP_NOFS))
goto out_unwind;
spin_lock(&mp->m_perag_lock);
if (radix_tree_insert(&mp->m_perag_tree, index, pag)) {
BUG();
spin_unlock(&mp->m_perag_lock);
radix_tree_preload_end();
error = -EEXIST;
goto out_unwind;
}
pag->pag_agno = index;
pag->pag_mount = mp;
spin_unlock(&mp->m_perag_lock);
radix_tree_preload_end();
}
/* Clear the mount flag if no inode can overflow 32 bits
* on this filesystem, or if specifically requested..
*/
if ((mp->m_flags & XFS_MOUNT_SMALL_INUMS) && ino > max_inum) {
mp->m_flags |= XFS_MOUNT_32BITINODES;
} else {
mp->m_flags &= ~XFS_MOUNT_32BITINODES;
}
/* If we can overflow then setup the ag headers accordingly */
if (mp->m_flags & XFS_MOUNT_32BITINODES) {
/* Calculate how much should be reserved for inodes to
* meet the max inode percentage.
*/
if (mp->m_maxicount) {
__uint64_t icount;
icount = sbp->sb_dblocks * sbp->sb_imax_pct;
do_div(icount, 100);
icount += sbp->sb_agblocks - 1;
do_div(icount, sbp->sb_agblocks);
max_metadata = icount;
} else {
max_metadata = agcount;
}
for (index = 0; index < agcount; index++) {
ino = XFS_AGINO_TO_INO(mp, index, agino);
if (ino > max_inum) {
index++;
break;
}
/* This ag is preferred for inodes */
pag = xfs_perag_get(mp, index);
pag->pagi_inodeok = 1;
if (index < max_metadata)
pag->pagf_metadata = 1;
xfs_initialize_perag_icache(pag);
xfs_perag_put(pag);
}
} else {
/* Setup default behavior for smaller filesystems */
for (index = 0; index < agcount; index++) {
pag = xfs_perag_get(mp, index);
pag->pagi_inodeok = 1;
xfs_initialize_perag_icache(pag);
xfs_perag_put(pag);
}
}
if (maxagi)
*maxagi = index;
return 0;
out_unwind:
kmem_free(pag);
for (; index > first_initialised; index--) {
pag = radix_tree_delete(&mp->m_perag_tree, index);
kmem_free(pag);
}
return error;
}
void
xfs_sb_from_disk(
xfs_sb_t *to,
xfs_dsb_t *from)
{
to->sb_magicnum = be32_to_cpu(from->sb_magicnum);
to->sb_blocksize = be32_to_cpu(from->sb_blocksize);
to->sb_dblocks = be64_to_cpu(from->sb_dblocks);
to->sb_rblocks = be64_to_cpu(from->sb_rblocks);
to->sb_rextents = be64_to_cpu(from->sb_rextents);
memcpy(&to->sb_uuid, &from->sb_uuid, sizeof(to->sb_uuid));
to->sb_logstart = be64_to_cpu(from->sb_logstart);
to->sb_rootino = be64_to_cpu(from->sb_rootino);
to->sb_rbmino = be64_to_cpu(from->sb_rbmino);
to->sb_rsumino = be64_to_cpu(from->sb_rsumino);
to->sb_rextsize = be32_to_cpu(from->sb_rextsize);
to->sb_agblocks = be32_to_cpu(from->sb_agblocks);
to->sb_agcount = be32_to_cpu(from->sb_agcount);
to->sb_rbmblocks = be32_to_cpu(from->sb_rbmblocks);
to->sb_logblocks = be32_to_cpu(from->sb_logblocks);
to->sb_versionnum = be16_to_cpu(from->sb_versionnum);
to->sb_sectsize = be16_to_cpu(from->sb_sectsize);
to->sb_inodesize = be16_to_cpu(from->sb_inodesize);
to->sb_inopblock = be16_to_cpu(from->sb_inopblock);
memcpy(&to->sb_fname, &from->sb_fname, sizeof(to->sb_fname));
to->sb_blocklog = from->sb_blocklog;
to->sb_sectlog = from->sb_sectlog;
to->sb_inodelog = from->sb_inodelog;
to->sb_inopblog = from->sb_inopblog;
to->sb_agblklog = from->sb_agblklog;
to->sb_rextslog = from->sb_rextslog;
to->sb_inprogress = from->sb_inprogress;
to->sb_imax_pct = from->sb_imax_pct;
to->sb_icount = be64_to_cpu(from->sb_icount);
to->sb_ifree = be64_to_cpu(from->sb_ifree);
to->sb_fdblocks = be64_to_cpu(from->sb_fdblocks);
to->sb_frextents = be64_to_cpu(from->sb_frextents);
to->sb_uquotino = be64_to_cpu(from->sb_uquotino);
to->sb_gquotino = be64_to_cpu(from->sb_gquotino);
to->sb_qflags = be16_to_cpu(from->sb_qflags);
to->sb_flags = from->sb_flags;
to->sb_shared_vn = from->sb_shared_vn;
to->sb_inoalignmt = be32_to_cpu(from->sb_inoalignmt);
to->sb_unit = be32_to_cpu(from->sb_unit);
to->sb_width = be32_to_cpu(from->sb_width);
to->sb_dirblklog = from->sb_dirblklog;
to->sb_logsectlog = from->sb_logsectlog;
to->sb_logsectsize = be16_to_cpu(from->sb_logsectsize);
to->sb_logsunit = be32_to_cpu(from->sb_logsunit);
to->sb_features2 = be32_to_cpu(from->sb_features2);
to->sb_bad_features2 = be32_to_cpu(from->sb_bad_features2);
}
/*
* Copy in core superblock to ondisk one.
*
* The fields argument is mask of superblock fields to copy.
*/
void
xfs_sb_to_disk(
xfs_dsb_t *to,
xfs_sb_t *from,
__int64_t fields)
{
xfs_caddr_t to_ptr = (xfs_caddr_t)to;
xfs_caddr_t from_ptr = (xfs_caddr_t)from;
xfs_sb_field_t f;
int first;
int size;
ASSERT(fields);
if (!fields)
return;
while (fields) {
f = (xfs_sb_field_t)xfs_lowbit64((__uint64_t)fields);
first = xfs_sb_info[f].offset;
size = xfs_sb_info[f + 1].offset - first;
ASSERT(xfs_sb_info[f].type == 0 || xfs_sb_info[f].type == 1);
if (size == 1 || xfs_sb_info[f].type == 1) {
memcpy(to_ptr + first, from_ptr + first, size);
} else {
switch (size) {
case 2:
*(__be16 *)(to_ptr + first) =
cpu_to_be16(*(__u16 *)(from_ptr + first));
break;
case 4:
*(__be32 *)(to_ptr + first) =
cpu_to_be32(*(__u32 *)(from_ptr + first));
break;
case 8:
*(__be64 *)(to_ptr + first) =
cpu_to_be64(*(__u64 *)(from_ptr + first));
break;
default:
ASSERT(0);
}
}
fields &= ~(1LL << f);
}
}
/*
* xfs_readsb
*
* Does the initial read of the superblock.
*/
int
xfs_readsb(xfs_mount_t *mp, int flags)
{
unsigned int sector_size;
unsigned int extra_flags;
xfs_buf_t *bp;
int error;
ASSERT(mp->m_sb_bp == NULL);
ASSERT(mp->m_ddev_targp != NULL);
/*
* Allocate a (locked) buffer to hold the superblock.
* This will be kept around at all times to optimize
* access to the superblock.
*/
sector_size = xfs_getsize_buftarg(mp->m_ddev_targp);
extra_flags = XBF_LOCK | XBF_FS_MANAGED | XBF_MAPPED;
bp = xfs_buf_read(mp->m_ddev_targp, XFS_SB_DADDR, BTOBB(sector_size),
extra_flags);
if (!bp || XFS_BUF_ISERROR(bp)) {
xfs_fs_mount_cmn_err(flags, "SB read failed");
error = bp ? XFS_BUF_GETERROR(bp) : ENOMEM;
goto fail;
}
ASSERT(XFS_BUF_ISBUSY(bp));
ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
/*
* Initialize the mount structure from the superblock.
* But first do some basic consistency checking.
*/
xfs_sb_from_disk(&mp->m_sb, XFS_BUF_TO_SBP(bp));
error = xfs_mount_validate_sb(mp, &(mp->m_sb), flags);
if (error) {
xfs_fs_mount_cmn_err(flags, "SB validate failed");
goto fail;
}
/*
* We must be able to do sector-sized and sector-aligned IO.
*/
if (sector_size > mp->m_sb.sb_sectsize) {
xfs_fs_mount_cmn_err(flags,
"device supports only %u byte sectors (not %u)",
sector_size, mp->m_sb.sb_sectsize);
error = ENOSYS;
goto fail;
}
/*
* If device sector size is smaller than the superblock size,
* re-read the superblock so the buffer is correctly sized.
*/
if (sector_size < mp->m_sb.sb_sectsize) {
XFS_BUF_UNMANAGE(bp);
xfs_buf_relse(bp);
sector_size = mp->m_sb.sb_sectsize;
bp = xfs_buf_read(mp->m_ddev_targp, XFS_SB_DADDR,
BTOBB(sector_size), extra_flags);
if (!bp || XFS_BUF_ISERROR(bp)) {
xfs_fs_mount_cmn_err(flags, "SB re-read failed");
error = bp ? XFS_BUF_GETERROR(bp) : ENOMEM;
goto fail;
}
ASSERT(XFS_BUF_ISBUSY(bp));
ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
}
/* Initialize per-cpu counters */
xfs_icsb_reinit_counters(mp);
mp->m_sb_bp = bp;
xfs_buf_relse(bp);
ASSERT(XFS_BUF_VALUSEMA(bp) > 0);
return 0;
fail:
if (bp) {
XFS_BUF_UNMANAGE(bp);
xfs_buf_relse(bp);
}
return error;
}
/*
* xfs_mount_common
*
* Mount initialization code establishing various mount
* fields from the superblock associated with the given
* mount structure
*/
STATIC void
xfs_mount_common(xfs_mount_t *mp, xfs_sb_t *sbp)
{
mp->m_agfrotor = mp->m_agirotor = 0;
spin_lock_init(&mp->m_agirotor_lock);
mp->m_maxagi = mp->m_sb.sb_agcount;
mp->m_blkbit_log = sbp->sb_blocklog + XFS_NBBYLOG;
mp->m_blkbb_log = sbp->sb_blocklog - BBSHIFT;
mp->m_sectbb_log = sbp->sb_sectlog - BBSHIFT;
mp->m_agno_log = xfs_highbit32(sbp->sb_agcount - 1) + 1;
mp->m_agino_log = sbp->sb_inopblog + sbp->sb_agblklog;
mp->m_blockmask = sbp->sb_blocksize - 1;
mp->m_blockwsize = sbp->sb_blocksize >> XFS_WORDLOG;
mp->m_blockwmask = mp->m_blockwsize - 1;
mp->m_alloc_mxr[0] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, 1);
mp->m_alloc_mxr[1] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, 0);
mp->m_alloc_mnr[0] = mp->m_alloc_mxr[0] / 2;
mp->m_alloc_mnr[1] = mp->m_alloc_mxr[1] / 2;
mp->m_inobt_mxr[0] = xfs_inobt_maxrecs(mp, sbp->sb_blocksize, 1);
mp->m_inobt_mxr[1] = xfs_inobt_maxrecs(mp, sbp->sb_blocksize, 0);
mp->m_inobt_mnr[0] = mp->m_inobt_mxr[0] / 2;
mp->m_inobt_mnr[1] = mp->m_inobt_mxr[1] / 2;
mp->m_bmap_dmxr[0] = xfs_bmbt_maxrecs(mp, sbp->sb_blocksize, 1);
mp->m_bmap_dmxr[1] = xfs_bmbt_maxrecs(mp, sbp->sb_blocksize, 0);
mp->m_bmap_dmnr[0] = mp->m_bmap_dmxr[0] / 2;
mp->m_bmap_dmnr[1] = mp->m_bmap_dmxr[1] / 2;
mp->m_bsize = XFS_FSB_TO_BB(mp, 1);
mp->m_ialloc_inos = (int)MAX((__uint16_t)XFS_INODES_PER_CHUNK,
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;
for (index = 0; index < agcount; index++) {
/*
* read the agf, then the agi. This gets us
* all the information 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 = xfs_perag_get(mp, index);
ifree += pag->pagi_freecount;
ialloc += pag->pagi_count;
bfree += pag->pagf_freeblks;
bfreelst += pag->pagf_flcount;
btree += pag->pagf_btreeblks;
xfs_perag_put(pag);
}
/*
* Overwrite incore superblock counters with just-read data
*/
spin_lock(&mp->m_sb_lock);
sbp->sb_ifree = ifree;
sbp->sb_icount = ialloc;
sbp->sb_fdblocks = bfree + bfreelst + btree;
spin_unlock(&mp->m_sb_lock);
/* Fixup the per-cpu counters as well. */
xfs_icsb_reinit_counters(mp);
return 0;
}
/*
* Update alignment values based on mount options and sb values
*/
STATIC int
xfs_update_alignment(xfs_mount_t *mp)
{
xfs_sb_t *sbp = &(mp->m_sb);
if (mp->m_dalign) {
/*
* If stripe unit and stripe width are not multiples
* of the fs blocksize turn off alignment.
*/
if ((BBTOB(mp->m_dalign) & mp->m_blockmask) ||
(BBTOB(mp->m_swidth) & mp->m_blockmask)) {
if (mp->m_flags & XFS_MOUNT_RETERR) {
cmn_err(CE_WARN,
"XFS: alignment check 1 failed");
return XFS_ERROR(EINVAL);
}
mp->m_dalign = mp->m_swidth = 0;
} else {
/*
* Convert the stripe unit and width to FSBs.
*/
mp->m_dalign = XFS_BB_TO_FSBT(mp, mp->m_dalign);
if (mp->m_dalign && (sbp->sb_agblocks % mp->m_dalign)) {
if (mp->m_flags & XFS_MOUNT_RETERR) {
return XFS_ERROR(EINVAL);
}
xfs_fs_cmn_err(CE_WARN, mp,
"stripe alignment turned off: sunit(%d)/swidth(%d) incompatible with agsize(%d)",
mp->m_dalign, mp->m_swidth,
sbp->sb_agblocks);
mp->m_dalign = 0;
mp->m_swidth = 0;
} else if (mp->m_dalign) {
mp->m_swidth = XFS_BB_TO_FSBT(mp, mp->m_swidth);
} else {
if (mp->m_flags & XFS_MOUNT_RETERR) {
xfs_fs_cmn_err(CE_WARN, mp,
"stripe alignment turned off: sunit(%d) less than bsize(%d)",
mp->m_dalign,
mp->m_blockmask +1);
return XFS_ERROR(EINVAL);
}
mp->m_swidth = 0;
}
}
/*
* Update superblock with new values
* and log changes
*/
if (xfs_sb_version_hasdalign(sbp)) {
if (sbp->sb_unit != mp->m_dalign) {
sbp->sb_unit = mp->m_dalign;
mp->m_update_flags |= XFS_SB_UNIT;
}
if (sbp->sb_width != mp->m_swidth) {
sbp->sb_width = mp->m_swidth;
mp->m_update_flags |= XFS_SB_WIDTH;
}
}
} else if ((mp->m_flags & XFS_MOUNT_NOALIGN) != XFS_MOUNT_NOALIGN &&
xfs_sb_version_hasdalign(&mp->m_sb)) {
mp->m_dalign = sbp->sb_unit;
mp->m_swidth = sbp->sb_width;
}
return 0;
}
/*
* Set the maximum inode count for this filesystem
*/
STATIC void
xfs_set_maxicount(xfs_mount_t *mp)
{
xfs_sb_t *sbp = &(mp->m_sb);
__uint64_t icount;
if (sbp->sb_imax_pct) {
/*
* Make sure the maximum inode count is a multiple
* of the units we allocate inodes in.
*/
icount = sbp->sb_dblocks * sbp->sb_imax_pct;
do_div(icount, 100);
do_div(icount, mp->m_ialloc_blks);
mp->m_maxicount = (icount * mp->m_ialloc_blks) <<
sbp->sb_inopblog;
} else {
mp->m_maxicount = 0;
}
}
/*
* Set the default minimum read and write sizes unless
* already specified in a mount option.
* We use smaller I/O sizes when the file system
* is being used for NFS service (wsync mount option).
*/
STATIC void
xfs_set_rw_sizes(xfs_mount_t *mp)
{
xfs_sb_t *sbp = &(mp->m_sb);
int readio_log, writeio_log;
if (!(mp->m_flags & XFS_MOUNT_DFLT_IOSIZE)) {
if (mp->m_flags & XFS_MOUNT_WSYNC) {
readio_log = XFS_WSYNC_READIO_LOG;
writeio_log = XFS_WSYNC_WRITEIO_LOG;
} else {
readio_log = XFS_READIO_LOG_LARGE;
writeio_log = XFS_WRITEIO_LOG_LARGE;
}
} else {
readio_log = mp->m_readio_log;
writeio_log = mp->m_writeio_log;
}
if (sbp->sb_blocklog > readio_log) {
mp->m_readio_log = sbp->sb_blocklog;
} else {
mp->m_readio_log = readio_log;
}
mp->m_readio_blocks = 1 << (mp->m_readio_log - sbp->sb_blocklog);
if (sbp->sb_blocklog > writeio_log) {
mp->m_writeio_log = sbp->sb_blocklog;
} else {
mp->m_writeio_log = writeio_log;
}
mp->m_writeio_blocks = 1 << (mp->m_writeio_log - sbp->sb_blocklog);
}
/*
* Set whether we're using inode alignment.
*/
STATIC void
xfs_set_inoalignment(xfs_mount_t *mp)
{
if (xfs_sb_version_hasalign(&mp->m_sb) &&
mp->m_sb.sb_inoalignmt >=
XFS_B_TO_FSBT(mp, mp->m_inode_cluster_size))
mp->m_inoalign_mask = mp->m_sb.sb_inoalignmt - 1;
else
mp->m_inoalign_mask = 0;
/*
* If we are using stripe alignment, check whether
* the stripe unit is a multiple of the inode alignment
*/
if (mp->m_dalign && mp->m_inoalign_mask &&
!(mp->m_dalign & mp->m_inoalign_mask))
mp->m_sinoalign = mp->m_dalign;
else
mp->m_sinoalign = 0;
}
/*
* Check that the data (and log if separate) are an ok size.
*/
STATIC int
xfs_check_sizes(xfs_mount_t *mp)
{
xfs_buf_t *bp;
xfs_daddr_t d;
int error;
d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks);
if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_dblocks) {
cmn_err(CE_WARN, "XFS: size check 1 failed");
return XFS_ERROR(E2BIG);
}
error = xfs_read_buf(mp, mp->m_ddev_targp,
d - XFS_FSS_TO_BB(mp, 1),
XFS_FSS_TO_BB(mp, 1), 0, &bp);
if (!error) {
xfs_buf_relse(bp);
} else {
cmn_err(CE_WARN, "XFS: size check 2 failed");
if (error == ENOSPC)
error = XFS_ERROR(E2BIG);
return error;
}
if (mp->m_logdev_targp != mp->m_ddev_targp) {
d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_logblocks);
if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_logblocks) {
cmn_err(CE_WARN, "XFS: size check 3 failed");
return XFS_ERROR(E2BIG);
}
error = xfs_read_buf(mp, mp->m_logdev_targp,
d - XFS_FSB_TO_BB(mp, 1),
XFS_FSB_TO_BB(mp, 1), 0, &bp);
if (!error) {
xfs_buf_relse(bp);
} else {
cmn_err(CE_WARN, "XFS: size check 3 failed");
if (error == ENOSPC)
error = XFS_ERROR(E2BIG);
return error;
}
}
return 0;
}
/*
* Clear the quotaflags in memory and in the superblock.
*/
int
xfs_mount_reset_sbqflags(
struct xfs_mount *mp)
{
int error;
struct xfs_trans *tp;
mp->m_qflags = 0;
/*
* It is OK to look at sb_qflags here in mount path,
* without m_sb_lock.
*/
if (mp->m_sb.sb_qflags == 0)
return 0;
spin_lock(&mp->m_sb_lock);
mp->m_sb.sb_qflags = 0;
spin_unlock(&mp->m_sb_lock);
/*
* If the fs is readonly, let the incore superblock run
* with quotas off but don't flush the update out to disk
*/
if (mp->m_flags & XFS_MOUNT_RDONLY)
return 0;
#ifdef QUOTADEBUG
xfs_fs_cmn_err(CE_NOTE, mp, "Writing superblock quota changes");
#endif
tp = xfs_trans_alloc(mp, XFS_TRANS_QM_SBCHANGE);
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);
xfs_fs_cmn_err(CE_ALERT, mp,
"xfs_mount_reset_sbqflags: Superblock update failed!");
return error;
}
xfs_mod_sb(tp, XFS_SB_QFLAGS);
return xfs_trans_commit(tp, 0);
}
__uint64_t
xfs_default_resblks(xfs_mount_t *mp)
{
__uint64_t resblks;
/*
* We default to 5% or 1024 fsbs of space reserved, whichever is smaller.
* This may drive us straight to ENOSPC on mount, but that implies
* we were already there on the last unmount. Warn if this occurs.
*/
resblks = mp->m_sb.sb_dblocks;
do_div(resblks, 20);
resblks = min_t(__uint64_t, resblks, 1024);
return resblks;
}
/*
* This function does the following on an initial mount of a file system:
* - reads the superblock from disk and init the mount struct
* - if we're a 32-bit kernel, do a size check on the superblock
* so we don't mount terabyte filesystems
* - init mount struct realtime fields
* - allocate inode hash table for fs
* - init directory manager
* - perform recovery and init the log manager
*/
int
xfs_mountfs(
xfs_mount_t *mp)
{
xfs_sb_t *sbp = &(mp->m_sb);
xfs_inode_t *rip;
__uint64_t resblks;
uint quotamount = 0;
uint quotaflags = 0;
int error = 0;
xfs_mount_common(mp, sbp);
/*
* Check for a mismatched features2 values. Older kernels
* read & wrote into the wrong sb offset for sb_features2
* on some platforms due to xfs_sb_t not being 64bit size aligned
* when sb_features2 was added, which made older superblock
* reading/writing routines swap it as a 64-bit value.
*
* For backwards compatibility, we make both slots equal.
*
* If we detect a mismatched field, we OR the set bits into the
* existing features2 field in case it has already been modified; we
* don't want to lose any features. We then update the bad location
* with the ORed value so that older kernels will see any features2
* flags, and mark the two fields as needing updates once the
* transaction subsystem is online.
*/
if (xfs_sb_has_mismatched_features2(sbp)) {
cmn_err(CE_WARN,
"XFS: correcting sb_features alignment problem");
sbp->sb_features2 |= sbp->sb_bad_features2;
sbp->sb_bad_features2 = sbp->sb_features2;
mp->m_update_flags |= XFS_SB_FEATURES2 | XFS_SB_BAD_FEATURES2;
/*
* Re-check for ATTR2 in case it was found in bad_features2
* slot.
*/
if (xfs_sb_version_hasattr2(&mp->m_sb) &&
!(mp->m_flags & XFS_MOUNT_NOATTR2))
mp->m_flags |= XFS_MOUNT_ATTR2;
}
if (xfs_sb_version_hasattr2(&mp->m_sb) &&
(mp->m_flags & XFS_MOUNT_NOATTR2)) {
xfs_sb_version_removeattr2(&mp->m_sb);
mp->m_update_flags |= XFS_SB_FEATURES2;
/* update sb_versionnum for the clearing of the morebits */
if (!sbp->sb_features2)
mp->m_update_flags |= XFS_SB_VERSIONNUM;
}
/*
* Check if sb_agblocks is aligned at stripe boundary
* If sb_agblocks is NOT aligned turn off m_dalign since
* allocator alignment is within an ag, therefore ag has
* to be aligned at stripe boundary.
*/
error = xfs_update_alignment(mp);
if (error)
goto out;
xfs_alloc_compute_maxlevels(mp);
xfs_bmap_compute_maxlevels(mp, XFS_DATA_FORK);
xfs_bmap_compute_maxlevels(mp, XFS_ATTR_FORK);
xfs_ialloc_compute_maxlevels(mp);
xfs_set_maxicount(mp);
mp->m_maxioffset = xfs_max_file_offset(sbp->sb_blocklog);
error = xfs_uuid_mount(mp);
if (error)
goto out;
/*
* Set the minimum read and write sizes
*/
xfs_set_rw_sizes(mp);
/*
* Set the inode cluster size.
* This may still be overridden by the file system
* block size if it is larger than the chosen cluster size.
*/
mp->m_inode_cluster_size = XFS_INODE_BIG_CLUSTER_SIZE;
/*
* Set inode alignment fields
*/
xfs_set_inoalignment(mp);
/*
* Check that the data (and log if separate) are an ok size.
*/
error = xfs_check_sizes(mp);
if (error)
goto out_remove_uuid;
/*
* Initialize realtime fields in the mount structure
*/
error = xfs_rtmount_init(mp);
if (error) {
cmn_err(CE_WARN, "XFS: RT mount failed");
goto out_remove_uuid;
}
/*
* Copies the low order bits of the timestamp and the randomly
* set "sequence" number out of a UUID.
*/
uuid_getnodeuniq(&sbp->sb_uuid, mp->m_fixedfsid);
mp->m_dmevmask = 0; /* not persistent; set after each mount */
xfs_dir_mount(mp);
/*
* Initialize the attribute manager's entries.
*/
mp->m_attr_magicpct = (mp->m_sb.sb_blocksize * 37) / 100;
/*
* Initialize the precomputed transaction reservations values.
*/
xfs_trans_init(mp);
/*
* Allocate and initialize the per-ag data.
*/
spin_lock_init(&mp->m_perag_lock);
INIT_RADIX_TREE(&mp->m_perag_tree, GFP_NOFS);
error = xfs_initialize_perag(mp, sbp->sb_agcount, &mp->m_maxagi);
if (error) {
cmn_err(CE_WARN, "XFS: Failed per-ag init: %d", error);
goto out_remove_uuid;
}
if (!sbp->sb_logblocks) {
cmn_err(CE_WARN, "XFS: no log defined");
XFS_ERROR_REPORT("xfs_mountfs", XFS_ERRLEVEL_LOW, mp);
error = XFS_ERROR(EFSCORRUPTED);
goto out_free_perag;
}
/*
* log's mount-time initialization. Perform 1st part recovery if needed
*/
error = xfs_log_mount(mp, mp->m_logdev_targp,
XFS_FSB_TO_DADDR(mp, sbp->sb_logstart),
XFS_FSB_TO_BB(mp, sbp->sb_logblocks));
if (error) {
cmn_err(CE_WARN, "XFS: log mount failed");
goto out_free_perag;
}
/*
* 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 out_free_perag;
}
/*
* Get and sanity-check the root inode.
* Save the pointer to it in the mount structure.
*/
error = xfs_iget(mp, NULL, sbp->sb_rootino, 0, XFS_ILOCK_EXCL, &rip, 0);
if (error) {
cmn_err(CE_WARN, "XFS: failed to read root inode");
goto out_log_dealloc;
}
ASSERT(rip != NULL);
if (unlikely((rip->i_d.di_mode & S_IFMT) != S_IFDIR)) {
cmn_err(CE_WARN, "XFS: corrupted root inode");
cmn_err(CE_WARN, "Device %s - root %llu is not a directory",
XFS_BUFTARG_NAME(mp->m_ddev_targp),
(unsigned long long)rip->i_ino);
xfs_iunlock(rip, XFS_ILOCK_EXCL);
XFS_ERROR_REPORT("xfs_mountfs_int(2)", XFS_ERRLEVEL_LOW,
mp);
error = XFS_ERROR(EFSCORRUPTED);
goto out_rele_rip;
}
mp->m_rootip = rip; /* save it */
xfs_iunlock(rip, XFS_ILOCK_EXCL);
/*
* Initialize realtime inode pointers in the mount structure
*/
error = xfs_rtmount_inodes(mp);
if (error) {
/*
* Free up the root inode.
*/
cmn_err(CE_WARN, "XFS: failed to read RT inodes");
goto out_rele_rip;
}
/*
* If this is a read-only mount defer the superblock updates until
* the next remount into writeable mode. Otherwise we would never
* perform the update e.g. for the root filesystem.
*/
if (mp->m_update_flags && !(mp->m_flags & XFS_MOUNT_RDONLY)) {
error = xfs_mount_log_sb(mp, mp->m_update_flags);
if (error) {
cmn_err(CE_WARN, "XFS: failed to write sb changes");
goto out_rtunmount;
}
}
/*
* Initialise the XFS quota management subsystem for this mount
*/
if (XFS_IS_QUOTA_RUNNING(mp)) {
error = xfs_qm_newmount(mp, &quotamount, &quotaflags);
if (error)
goto out_rtunmount;
} else {
ASSERT(!XFS_IS_QUOTA_ON(mp));
/*
* If a file system had quotas running earlier, but decided to
* mount without -o uquota/pquota/gquota options, revoke the
* quotachecked license.
*/
if (mp->m_sb.sb_qflags & XFS_ALL_QUOTA_ACCT) {
cmn_err(CE_NOTE,
"XFS: resetting qflags for filesystem %s",
mp->m_fsname);
error = xfs_mount_reset_sbqflags(mp);
if (error)
return error;
}
}
/*
* Finish recovering the file system. This part needed to be
* delayed until after the root and real-time bitmap inodes
* were consistently read in.
*/
error = xfs_log_mount_finish(mp);
if (error) {
cmn_err(CE_WARN, "XFS: log mount finish failed");
goto out_rtunmount;
}
/*
* Complete the quota initialisation, post-log-replay component.
*/
if (quotamount) {
ASSERT(mp->m_qflags == 0);
mp->m_qflags = quotaflags;
xfs_qm_mount_quotas(mp);
}
#if defined(DEBUG) && defined(XFS_LOUD_RECOVERY)
if (XFS_IS_QUOTA_ON(mp))
xfs_fs_cmn_err(CE_NOTE, mp, "Disk quotas turned on");
else
xfs_fs_cmn_err(CE_NOTE, mp, "Disk quotas not turned on");
#endif
/*
* Now we are mounted, reserve a small amount of unused space for
* privileged transactions. This is needed so that transaction
* space required for critical operations can dip into this pool
* when at ENOSPC. This is needed for operations like create with
* attr, unwritten extent conversion at ENOSPC, etc. Data allocations
* are not allowed to use this reserved space.
*/
if (!(mp->m_flags & XFS_MOUNT_RDONLY)) {
resblks = xfs_default_resblks(mp);
error = xfs_reserve_blocks(mp, &resblks, NULL);
if (error)
cmn_err(CE_WARN, "XFS: Unable to allocate reserve "
"blocks. Continuing without a reserve pool.");
}
return 0;
out_rtunmount:
xfs_rtunmount_inodes(mp);
out_rele_rip:
IRELE(rip);
out_log_dealloc:
xfs_log_unmount(mp);
out_free_perag:
xfs_free_perag(mp);
out_remove_uuid:
xfs_uuid_unmount(mp);
out:
return error;
}
/*
* This flushes out the inodes,dquots and the superblock, unmounts the
* log and makes sure that incore structures are freed.
*/
void
xfs_unmountfs(
struct xfs_mount *mp)
{
__uint64_t resblks;
int error;
xfs_qm_unmount_quotas(mp);
xfs_rtunmount_inodes(mp);
IRELE(mp->m_rootip);
/*
* We can potentially deadlock here if we have an inode cluster
* that has been freed has its buffer still pinned in memory because
* the transaction is still sitting in a iclog. The stale inodes
* on that buffer will have their flush locks held until the
* transaction hits the disk and the callbacks run. the inode
* flush takes the flush lock unconditionally and with nothing to
* push out the iclog we will never get that unlocked. hence we
* need to force the log first.
*/
xfs_log_force(mp, XFS_LOG_SYNC);
/*
* Do a delwri reclaim pass first so that as many dirty inodes are
* queued up for IO as possible. Then flush the buffers before making
* a synchronous path to catch all the remaining inodes are reclaimed.
* This makes the reclaim process as quick as possible by avoiding
* synchronous writeout and blocking on inodes already in the delwri
* state as much as possible.
*/
xfs_reclaim_inodes(mp, 0);
XFS_bflush(mp->m_ddev_targp);
xfs_reclaim_inodes(mp, SYNC_WAIT);
xfs_qm_unmount(mp);
/*
* Flush out the log synchronously so that we know for sure
* that nothing is pinned. This is important because bflush()
* will skip pinned buffers.
*/
xfs_log_force(mp, XFS_LOG_SYNC);
xfs_binval(mp->m_ddev_targp);
if (mp->m_rtdev_targp) {
xfs_binval(mp->m_rtdev_targp);
}
/*
* Unreserve any blocks we have so that when we unmount we don't account
* the reserved free space as used. This is really only necessary for
* lazy superblock counting because it trusts the incore superblock
* counters to be absolutely correct on clean unmount.
*
* We don't bother correcting this elsewhere for lazy superblock
* counting because on mount of an unclean filesystem we reconstruct the
* correct counter value and this is irrelevant.
*
* For non-lazy counter filesystems, this doesn't matter at all because
* we only every apply deltas to the superblock and hence the incore
* value does not matter....
*/
resblks = 0;
error = xfs_reserve_blocks(mp, &resblks, NULL);
if (error)
cmn_err(CE_WARN, "XFS: Unable to free reserved block pool. "
"Freespace may not be correct on next mount.");
error = xfs_log_sbcount(mp, 1);
if (error)
cmn_err(CE_WARN, "XFS: Unable to update superblock counters. "
"Freespace may not be correct on next mount.");
xfs_unmountfs_writesb(mp);
xfs_unmountfs_wait(mp); /* wait for async bufs */
xfs_log_unmount_write(mp);
xfs_log_unmount(mp);
xfs_uuid_unmount(mp);
#if defined(DEBUG)
xfs_errortag_clearall(mp, 0);
#endif
xfs_free_perag(mp);
}
STATIC void
xfs_unmountfs_wait(xfs_mount_t *mp)
{
if (mp->m_logdev_targp != mp->m_ddev_targp)
xfs_wait_buftarg(mp->m_logdev_targp);
if (mp->m_rtdev_targp)
xfs_wait_buftarg(mp->m_rtdev_targp);
xfs_wait_buftarg(mp->m_ddev_targp);
}
int
xfs_fs_writable(xfs_mount_t *mp)
{
return !(xfs_test_for_freeze(mp) || XFS_FORCED_SHUTDOWN(mp) ||
(mp->m_flags & XFS_MOUNT_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, 0);
/*
* 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, KM_SLEEP);
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);
error = xfs_trans_commit(tp, 0);
return error;
}
int
xfs_unmountfs_writesb(xfs_mount_t *mp)
{
xfs_buf_t *sbp;
int error = 0;
/*
* skip superblock write if fs is read-only, or
* if we are doing a forced umount.
*/
if (!((mp->m_flags & XFS_MOUNT_RDONLY) ||
XFS_FORCED_SHUTDOWN(mp))) {
sbp = xfs_getsb(mp, 0);
XFS_BUF_UNDONE(sbp);
XFS_BUF_UNREAD(sbp);
XFS_BUF_UNDELAYWRITE(sbp);
XFS_BUF_WRITE(sbp);
XFS_BUF_UNASYNC(sbp);
ASSERT(XFS_BUF_TARGET(sbp) == mp->m_ddev_targp);
xfsbdstrat(mp, sbp);
error = xfs_iowait(sbp);
if (error)
xfs_ioerror_alert("xfs_unmountfs_writesb",
mp, sbp, XFS_BUF_ADDR(sbp));
xfs_buf_relse(sbp);
}
return error;
}
/*
* xfs_mod_sb() can be used to copy arbitrary changes to the
* in-core superblock into the superblock buffer to be logged.
* It does not provide the higher level of locking that is
* needed to protect the in-core superblock from concurrent
* access.
*/
void
xfs_mod_sb(xfs_trans_t *tp, __int64_t fields)
{
xfs_buf_t *bp;
int first;
int last;
xfs_mount_t *mp;
xfs_sb_field_t f;
ASSERT(fields);
if (!fields)
return;
mp = tp->t_mountp;
bp = xfs_trans_getsb(tp, mp, 0);
first = sizeof(xfs_sb_t);
last = 0;
/* translate/copy */
xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb, fields);
/* find modified range */
f = (xfs_sb_field_t)xfs_highbit64((__uint64_t)fields);
ASSERT((1LL << f) & XFS_SB_MOD_BITS);
last = xfs_sb_info[f + 1].offset - 1;
f = (xfs_sb_field_t)xfs_lowbit64((__uint64_t)fields);
ASSERT((1LL << f) & XFS_SB_MOD_BITS);
first = xfs_sb_info[f].offset;
xfs_trans_log_buf(tp, bp, first, last);
}
/*
* xfs_mod_incore_sb_unlocked() is a utility routine common used to apply
* a delta to a specified field in the in-core superblock. Simply
* switch on the field indicated and apply the delta to that field.
* Fields are not allowed to dip below zero, so if the delta would
* do this do not apply it and return EINVAL.
*
* The m_sb_lock must be held when this routine is called.
*/
STATIC int
xfs_mod_incore_sb_unlocked(
xfs_mount_t *mp,
xfs_sb_field_t field,
int64_t delta,
int rsvd)
{
int scounter; /* short counter for 32 bit fields */
long long lcounter; /* long counter for 64 bit fields */
long long res_used, rem;
/*
* With the in-core superblock spin lock held, switch
* on the indicated field. Apply the delta to the
* proper field. If the fields value would dip below
* 0, then do not apply the delta and return EINVAL.
*/
switch (field) {
case XFS_SBS_ICOUNT:
lcounter = (long long)mp->m_sb.sb_icount;
lcounter += delta;
if (lcounter < 0) {
ASSERT(0);
return XFS_ERROR(EINVAL);
}
mp->m_sb.sb_icount = lcounter;
return 0;
case XFS_SBS_IFREE:
lcounter = (long long)mp->m_sb.sb_ifree;
lcounter += delta;
if (lcounter < 0) {
ASSERT(0);
return XFS_ERROR(EINVAL);
}
mp->m_sb.sb_ifree = lcounter;
return 0;
case XFS_SBS_FDBLOCKS:
lcounter = (long long)
mp->m_sb.sb_fdblocks - XFS_ALLOC_SET_ASIDE(mp);
res_used = (long long)(mp->m_resblks - mp->m_resblks_avail);
if (delta > 0) { /* Putting blocks back */
if (res_used > delta) {
mp->m_resblks_avail += delta;
} else {
rem = delta - res_used;
mp->m_resblks_avail = mp->m_resblks;
lcounter += rem;
}
} else { /* Taking blocks away */
lcounter += delta;
/*
* If were out of blocks, use any available reserved blocks if
* were allowed to.
*/
if (lcounter < 0) {
if (rsvd) {
lcounter = (long long)mp->m_resblks_avail + delta;
if (lcounter < 0) {
return XFS_ERROR(ENOSPC);
}
mp->m_resblks_avail = lcounter;
return 0;
} else { /* not reserved */
return XFS_ERROR(ENOSPC);
}
}
}
mp->m_sb.sb_fdblocks = lcounter + XFS_ALLOC_SET_ASIDE(mp);
return 0;
case XFS_SBS_FREXTENTS:
lcounter = (long long)mp->m_sb.sb_frextents;
lcounter += delta;
if (lcounter < 0) {
return XFS_ERROR(ENOSPC);
}
mp->m_sb.sb_frextents = lcounter;
return 0;
case XFS_SBS_DBLOCKS:
lcounter = (long long)mp->m_sb.sb_dblocks;
lcounter += delta;
if (lcounter < 0) {
ASSERT(0);
return XFS_ERROR(EINVAL);
}
mp->m_sb.sb_dblocks = lcounter;
return 0;
case XFS_SBS_AGCOUNT:
scounter = mp->m_sb.sb_agcount;
scounter += delta;
if (scounter < 0) {
ASSERT(0);
return XFS_ERROR(EINVAL);
}
mp->m_sb.sb_agcount = scounter;
return 0;
case XFS_SBS_IMAX_PCT:
scounter = mp->m_sb.sb_imax_pct;
scounter += delta;
if (scounter < 0) {
ASSERT(0);
return XFS_ERROR(EINVAL);
}
mp->m_sb.sb_imax_pct = scounter;
return 0;
case XFS_SBS_REXTSIZE:
scounter = mp->m_sb.sb_rextsize;
scounter += delta;
if (scounter < 0) {
ASSERT(0);
return XFS_ERROR(EINVAL);
}
mp->m_sb.sb_rextsize = scounter;
return 0;
case XFS_SBS_RBMBLOCKS:
scounter = mp->m_sb.sb_rbmblocks;
scounter += delta;
if (scounter < 0) {
ASSERT(0);
return XFS_ERROR(EINVAL);
}
mp->m_sb.sb_rbmblocks = scounter;
return 0;
case XFS_SBS_RBLOCKS:
lcounter = (long long)mp->m_sb.sb_rblocks;
lcounter += delta;
if (lcounter < 0) {
ASSERT(0);
return XFS_ERROR(EINVAL);
}
mp->m_sb.sb_rblocks = lcounter;
return 0;
case XFS_SBS_REXTENTS:
lcounter = (long long)mp->m_sb.sb_rextents;
lcounter += delta;
if (lcounter < 0) {
ASSERT(0);
return XFS_ERROR(EINVAL);
}
mp->m_sb.sb_rextents = lcounter;
return 0;
case XFS_SBS_REXTSLOG:
scounter = mp->m_sb.sb_rextslog;
scounter += delta;
if (scounter < 0) {
ASSERT(0);
return XFS_ERROR(EINVAL);
}
mp->m_sb.sb_rextslog = scounter;
return 0;
default:
ASSERT(0);
return XFS_ERROR(EINVAL);
}
}
/*
* xfs_mod_incore_sb() is used to change a field in the in-core
* superblock structure by the specified delta. This modification
* is protected by the m_sb_lock. Just use the xfs_mod_incore_sb_unlocked()
* routine to do the work.
*/
int
xfs_mod_incore_sb(
xfs_mount_t *mp,
xfs_sb_field_t field,
int64_t delta,
int rsvd)
{
int status;
/* check for per-cpu counters */
switch (field) {
#ifdef HAVE_PERCPU_SB
case XFS_SBS_ICOUNT:
case XFS_SBS_IFREE:
case XFS_SBS_FDBLOCKS:
if (!(mp->m_flags & XFS_MOUNT_NO_PERCPU_SB)) {
status = xfs_icsb_modify_counters(mp, field,
delta, rsvd);
break;
}
/* FALLTHROUGH */
#endif
default:
spin_lock(&mp->m_sb_lock);
status = xfs_mod_incore_sb_unlocked(mp, field, delta, rsvd);
spin_unlock(&mp->m_sb_lock);
break;
}
return status;
}
/*
* xfs_mod_incore_sb_batch() is used to change more than one field
* in the in-core superblock structure at a time. This modification
* is protected by a lock internal to this module. The fields and
* changes to those fields are specified in the array of xfs_mod_sb
* structures passed in.
*
* Either all of the specified deltas will be applied or none of
* them will. If any modified field dips below 0, then all modifications
* will be backed out and EINVAL will be returned.
*/
int
xfs_mod_incore_sb_batch(xfs_mount_t *mp, xfs_mod_sb_t *msb, uint nmsb, int rsvd)
{
int status=0;
xfs_mod_sb_t *msbp;
/*
* Loop through the array of mod structures and apply each
* individually. If any fail, then back out all those
* which have already been applied. Do all of this within
* the scope of the m_sb_lock so that all of the changes will
* be atomic.
*/
spin_lock(&mp->m_sb_lock);
msbp = &msb[0];
for (msbp = &msbp[0]; msbp < (msb + nmsb); msbp++) {
/*
* Apply the delta at index n. If it fails, break
* from the loop so we'll fall into the undo loop
* below.
*/
switch (msbp->msb_field) {
#ifdef HAVE_PERCPU_SB
case XFS_SBS_ICOUNT:
case XFS_SBS_IFREE:
case XFS_SBS_FDBLOCKS:
if (!(mp->m_flags & XFS_MOUNT_NO_PERCPU_SB)) {
spin_unlock(&mp->m_sb_lock);
status = xfs_icsb_modify_counters(mp,
msbp->msb_field,
msbp->msb_delta, rsvd);
spin_lock(&mp->m_sb_lock);
break;
}
/* FALLTHROUGH */
#endif
default:
status = xfs_mod_incore_sb_unlocked(mp,
msbp->msb_field,
msbp->msb_delta, rsvd);
break;
}
if (status != 0) {
break;
}
}
/*
* If we didn't complete the loop above, then back out
* any changes made to the superblock. If you add code
* between the loop above and here, make sure that you
* preserve the value of status. Loop back until
* we step below the beginning of the array. Make sure
* we don't touch anything back there.
*/
if (status != 0) {
msbp--;
while (msbp >= msb) {
switch (msbp->msb_field) {
#ifdef HAVE_PERCPU_SB
case XFS_SBS_ICOUNT:
case XFS_SBS_IFREE:
case XFS_SBS_FDBLOCKS:
if (!(mp->m_flags & XFS_MOUNT_NO_PERCPU_SB)) {
spin_unlock(&mp->m_sb_lock);
status = xfs_icsb_modify_counters(mp,
msbp->msb_field,
-(msbp->msb_delta),
rsvd);
spin_lock(&mp->m_sb_lock);
break;
}
/* FALLTHROUGH */
#endif
default:
status = xfs_mod_incore_sb_unlocked(mp,
msbp->msb_field,
-(msbp->msb_delta),
rsvd);
break;
}
ASSERT(status == 0);
msbp--;
}
}
spin_unlock(&mp->m_sb_lock);
return status;
}
/*
* xfs_getsb() is called to obtain the buffer for the superblock.
* The buffer is returned locked and read in from disk.
* The buffer should be released with a call to xfs_brelse().
*
* If the flags parameter is BUF_TRYLOCK, then we'll only return
* the superblock buffer if it can be locked without sleeping.
* If it can't then we'll return NULL.
*/
xfs_buf_t *
xfs_getsb(
xfs_mount_t *mp,
int flags)
{
xfs_buf_t *bp;
ASSERT(mp->m_sb_bp != NULL);
bp = mp->m_sb_bp;
if (flags & XBF_TRYLOCK) {
if (!XFS_BUF_CPSEMA(bp)) {
return NULL;
}
} else {
XFS_BUF_PSEMA(bp, PRIBIO);
}
XFS_BUF_HOLD(bp);
ASSERT(XFS_BUF_ISDONE(bp));
return bp;
}
/*
* Used to free the superblock along various error paths.
*/
void
xfs_freesb(
xfs_mount_t *mp)
{
xfs_buf_t *bp;
/*
* Use xfs_getsb() so that the buffer will be locked
* when we call xfs_buf_relse().
*/
bp = xfs_getsb(mp, 0);
XFS_BUF_UNMANAGE(bp);
xfs_buf_relse(bp);
mp->m_sb_bp = NULL;
}
/*
* Used to log changes to the superblock unit and width fields which could
* be altered by the mount options, as well as any potential sb_features2
* fixup. Only the first superblock is updated.
*/
int
xfs_mount_log_sb(
xfs_mount_t *mp,
__int64_t fields)
{
xfs_trans_t *tp;
int error;
ASSERT(fields & (XFS_SB_UNIT | XFS_SB_WIDTH | XFS_SB_UUID |
XFS_SB_FEATURES2 | XFS_SB_BAD_FEATURES2 |
XFS_SB_VERSIONNUM));
tp = xfs_trans_alloc(mp, XFS_TRANS_SB_UNIT);
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, fields);
error = xfs_trans_commit(tp, 0);
return error;
}
#ifdef HAVE_PERCPU_SB
/*
* Per-cpu incore superblock counters
*
* Simple concept, difficult implementation
*
* Basically, replace the incore superblock counters with a distributed per cpu
* counter for contended fields (e.g. free block count).
*
* Difficulties arise in that the incore sb is used for ENOSPC checking, and
* hence needs to be accurately read when we are running low on space. Hence
* there is a method to enable and disable the per-cpu counters based on how
* much "stuff" is available in them.
*
* Basically, a counter is enabled if there is enough free resource to justify
* running a per-cpu fast-path. If the per-cpu counter runs out (i.e. a local
* ENOSPC), then we disable the counters to synchronise all callers and
* re-distribute the available resources.
*
* If, once we redistributed the available resources, we still get a failure,
* we disable the per-cpu counter and go through the slow path.
*
* The slow path is the current xfs_mod_incore_sb() function. This means that
* when we disable a per-cpu counter, we need to drain its resources back to
* the global superblock. We do this after disabling the counter to prevent
* more threads from queueing up on the counter.
*
* Essentially, this means that we still need a lock in the fast path to enable
* synchronisation between the global counters and the per-cpu counters. This
* is not a problem because the lock will be local to a CPU almost all the time
* and have little contention except when we get to ENOSPC conditions.
*
* Basically, this lock becomes a barrier that enables us to lock out the fast
* path while we do things like enabling and disabling counters and
* synchronising the counters.
*
* Locking rules:
*
* 1. m_sb_lock before picking up per-cpu locks
* 2. per-cpu locks always picked up via for_each_online_cpu() order
* 3. accurate counter sync requires m_sb_lock + per cpu locks
* 4. modifying per-cpu counters requires holding per-cpu lock
* 5. modifying global counters requires holding m_sb_lock
* 6. enabling or disabling a counter requires holding the m_sb_lock
* and _none_ of the per-cpu locks.
*
* Disabled counters are only ever re-enabled by a balance operation
* that results in more free resources per CPU than a given threshold.
* To ensure counters don't remain disabled, they are rebalanced when
* the global resource goes above a higher threshold (i.e. some hysteresis
* is present to prevent thrashing).
*/
#ifdef CONFIG_HOTPLUG_CPU
/*
* hot-plug CPU notifier support.
*
* We need a notifier per filesystem as we need to be able to identify
* the filesystem to balance the counters out. This is achieved by
* having a notifier block embedded in the xfs_mount_t and doing pointer
* magic to get the mount pointer from the notifier block address.
*/
STATIC int
xfs_icsb_cpu_notify(
struct notifier_block *nfb,
unsigned long action,
void *hcpu)
{
xfs_icsb_cnts_t *cntp;
xfs_mount_t *mp;
mp = (xfs_mount_t *)container_of(nfb, xfs_mount_t, m_icsb_notifier);
cntp = (xfs_icsb_cnts_t *)
per_cpu_ptr(mp->m_sb_cnts, (unsigned long)hcpu);
switch (action) {
case CPU_UP_PREPARE:
case CPU_UP_PREPARE_FROZEN:
/* Easy Case - initialize the area and locks, and
* then rebalance when online does everything else for us. */
memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
break;
case CPU_ONLINE:
case CPU_ONLINE_FROZEN:
xfs_icsb_lock(mp);
xfs_icsb_balance_counter(mp, XFS_SBS_ICOUNT, 0);
xfs_icsb_balance_counter(mp, XFS_SBS_IFREE, 0);
xfs_icsb_balance_counter(mp, XFS_SBS_FDBLOCKS, 0);
xfs_icsb_unlock(mp);
break;
case CPU_DEAD:
case CPU_DEAD_FROZEN:
/* Disable all the counters, then fold the dead cpu's
* count into the total on the global superblock and
* re-enable the counters. */
xfs_icsb_lock(mp);
spin_lock(&mp->m_sb_lock);
xfs_icsb_disable_counter(mp, XFS_SBS_ICOUNT);
xfs_icsb_disable_counter(mp, XFS_SBS_IFREE);
xfs_icsb_disable_counter(mp, XFS_SBS_FDBLOCKS);
mp->m_sb.sb_icount += cntp->icsb_icount;
mp->m_sb.sb_ifree += cntp->icsb_ifree;
mp->m_sb.sb_fdblocks += cntp->icsb_fdblocks;
memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
xfs_icsb_balance_counter_locked(mp, XFS_SBS_ICOUNT, 0);
xfs_icsb_balance_counter_locked(mp, XFS_SBS_IFREE, 0);
xfs_icsb_balance_counter_locked(mp, XFS_SBS_FDBLOCKS, 0);
spin_unlock(&mp->m_sb_lock);
xfs_icsb_unlock(mp);
break;
}
return NOTIFY_OK;
}
#endif /* CONFIG_HOTPLUG_CPU */
int
xfs_icsb_init_counters(
xfs_mount_t *mp)
{
xfs_icsb_cnts_t *cntp;
int i;
mp->m_sb_cnts = alloc_percpu(xfs_icsb_cnts_t);
if (mp->m_sb_cnts == NULL)
return -ENOMEM;
#ifdef CONFIG_HOTPLUG_CPU
mp->m_icsb_notifier.notifier_call = xfs_icsb_cpu_notify;
mp->m_icsb_notifier.priority = 0;
register_hotcpu_notifier(&mp->m_icsb_notifier);
#endif /* CONFIG_HOTPLUG_CPU */
for_each_online_cpu(i) {
cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
}
mutex_init(&mp->m_icsb_mutex);
/*
* start with all counters disabled so that the
* initial balance kicks us off correctly
*/
mp->m_icsb_counters = -1;
return 0;
}
void
xfs_icsb_reinit_counters(
xfs_mount_t *mp)
{
xfs_icsb_lock(mp);
/*
* start with all counters disabled so that the
* initial balance kicks us off correctly
*/
mp->m_icsb_counters = -1;
xfs_icsb_balance_counter(mp, XFS_SBS_ICOUNT, 0);
xfs_icsb_balance_counter(mp, XFS_SBS_IFREE, 0);
xfs_icsb_balance_counter(mp, XFS_SBS_FDBLOCKS, 0);
xfs_icsb_unlock(mp);
}
void
xfs_icsb_destroy_counters(
xfs_mount_t *mp)
{
if (mp->m_sb_cnts) {
unregister_hotcpu_notifier(&mp->m_icsb_notifier);
free_percpu(mp->m_sb_cnts);
}
mutex_destroy(&mp->m_icsb_mutex);
}
STATIC void
xfs_icsb_lock_cntr(
xfs_icsb_cnts_t *icsbp)
{
while (test_and_set_bit(XFS_ICSB_FLAG_LOCK, &icsbp->icsb_flags)) {
ndelay(1000);
}
}
STATIC void
xfs_icsb_unlock_cntr(
xfs_icsb_cnts_t *icsbp)
{
clear_bit(XFS_ICSB_FLAG_LOCK, &icsbp->icsb_flags);
}
STATIC void
xfs_icsb_lock_all_counters(
xfs_mount_t *mp)
{
xfs_icsb_cnts_t *cntp;
int i;
for_each_online_cpu(i) {
cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
xfs_icsb_lock_cntr(cntp);
}
}
STATIC void
xfs_icsb_unlock_all_counters(
xfs_mount_t *mp)
{
xfs_icsb_cnts_t *cntp;
int i;
for_each_online_cpu(i) {
cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
xfs_icsb_unlock_cntr(cntp);
}
}
STATIC void
xfs_icsb_count(
xfs_mount_t *mp,
xfs_icsb_cnts_t *cnt,
int flags)
{
xfs_icsb_cnts_t *cntp;
int i;
memset(cnt, 0, sizeof(xfs_icsb_cnts_t));
if (!(flags & XFS_ICSB_LAZY_COUNT))
xfs_icsb_lock_all_counters(mp);
for_each_online_cpu(i) {
cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
cnt->icsb_icount += cntp->icsb_icount;
cnt->icsb_ifree += cntp->icsb_ifree;
cnt->icsb_fdblocks += cntp->icsb_fdblocks;
}
if (!(flags & XFS_ICSB_LAZY_COUNT))
xfs_icsb_unlock_all_counters(mp);
}
STATIC int
xfs_icsb_counter_disabled(
xfs_mount_t *mp,
xfs_sb_field_t field)
{
ASSERT((field >= XFS_SBS_ICOUNT) && (field <= XFS_SBS_FDBLOCKS));
return test_bit(field, &mp->m_icsb_counters);
}
STATIC void
xfs_icsb_disable_counter(
xfs_mount_t *mp,
xfs_sb_field_t field)
{
xfs_icsb_cnts_t cnt;
ASSERT((field >= XFS_SBS_ICOUNT) && (field <= XFS_SBS_FDBLOCKS));
/*
* If we are already disabled, then there is nothing to do
* here. We check before locking all the counters to avoid
* the expensive lock operation when being called in the
* slow path and the counter is already disabled. This is
* safe because the only time we set or clear this state is under
* the m_icsb_mutex.
*/
if (xfs_icsb_counter_disabled(mp, field))
return;
xfs_icsb_lock_all_counters(mp);
if (!test_and_set_bit(field, &mp->m_icsb_counters)) {
/* drain back to superblock */
xfs_icsb_count(mp, &cnt, XFS_ICSB_LAZY_COUNT);
switch(field) {
case XFS_SBS_ICOUNT:
mp->m_sb.sb_icount = cnt.icsb_icount;
break;
case XFS_SBS_IFREE:
mp->m_sb.sb_ifree = cnt.icsb_ifree;
break;
case XFS_SBS_FDBLOCKS:
mp->m_sb.sb_fdblocks = cnt.icsb_fdblocks;
break;
default:
BUG();
}
}
xfs_icsb_unlock_all_counters(mp);
}
STATIC void
xfs_icsb_enable_counter(
xfs_mount_t *mp,
xfs_sb_field_t field,
uint64_t count,
uint64_t resid)
{
xfs_icsb_cnts_t *cntp;
int i;
ASSERT((field >= XFS_SBS_ICOUNT) && (field <= XFS_SBS_FDBLOCKS));
xfs_icsb_lock_all_counters(mp);
for_each_online_cpu(i) {
cntp = per_cpu_ptr(mp->m_sb_cnts, i);
switch (field) {
case XFS_SBS_ICOUNT:
cntp->icsb_icount = count + resid;
break;
case XFS_SBS_IFREE:
cntp->icsb_ifree = count + resid;
break;
case XFS_SBS_FDBLOCKS:
cntp->icsb_fdblocks = count + resid;
break;
default:
BUG();
break;
}
resid = 0;
}
clear_bit(field, &mp->m_icsb_counters);
xfs_icsb_unlock_all_counters(mp);
}
void
xfs_icsb_sync_counters_locked(
xfs_mount_t *mp,
int flags)
{
xfs_icsb_cnts_t cnt;
xfs_icsb_count(mp, &cnt, flags);
if (!xfs_icsb_counter_disabled(mp, XFS_SBS_ICOUNT))
mp->m_sb.sb_icount = cnt.icsb_icount;
if (!xfs_icsb_counter_disabled(mp, XFS_SBS_IFREE))
mp->m_sb.sb_ifree = cnt.icsb_ifree;
if (!xfs_icsb_counter_disabled(mp, XFS_SBS_FDBLOCKS))
mp->m_sb.sb_fdblocks = cnt.icsb_fdblocks;
}
/*
* Accurate update of per-cpu counters to incore superblock
*/
void
xfs_icsb_sync_counters(
xfs_mount_t *mp,
int flags)
{
spin_lock(&mp->m_sb_lock);
xfs_icsb_sync_counters_locked(mp, flags);
spin_unlock(&mp->m_sb_lock);
}
/*
* Balance and enable/disable counters as necessary.
*
* Thresholds for re-enabling counters are somewhat magic. inode counts are
* chosen to be the same number as single on disk allocation chunk per CPU, and
* free blocks is something far enough zero that we aren't going thrash when we
* get near ENOSPC. We also need to supply a minimum we require per cpu to
* prevent looping endlessly when xfs_alloc_space asks for more than will
* be distributed to a single CPU but each CPU has enough blocks to be
* reenabled.
*
* Note that we can be called when counters are already disabled.
* xfs_icsb_disable_counter() optimises the counter locking in this case to
* prevent locking every per-cpu counter needlessly.
*/
#define XFS_ICSB_INO_CNTR_REENABLE (uint64_t)64
#define XFS_ICSB_FDBLK_CNTR_REENABLE(mp) \
(uint64_t)(512 + XFS_ALLOC_SET_ASIDE(mp))
STATIC void
xfs_icsb_balance_counter_locked(
xfs_mount_t *mp,
xfs_sb_field_t field,
int min_per_cpu)
{
uint64_t count, resid;
int weight = num_online_cpus();
uint64_t min = (uint64_t)min_per_cpu;
/* disable counter and sync counter */
xfs_icsb_disable_counter(mp, field);
/* update counters - first CPU gets residual*/
switch (field) {
case XFS_SBS_ICOUNT:
count = mp->m_sb.sb_icount;
resid = do_div(count, weight);
if (count < max(min, XFS_ICSB_INO_CNTR_REENABLE))
return;
break;
case XFS_SBS_IFREE:
count = mp->m_sb.sb_ifree;
resid = do_div(count, weight);
if (count < max(min, XFS_ICSB_INO_CNTR_REENABLE))
return;
break;
case XFS_SBS_FDBLOCKS:
count = mp->m_sb.sb_fdblocks;
resid = do_div(count, weight);
if (count < max(min, XFS_ICSB_FDBLK_CNTR_REENABLE(mp)))
return;
break;
default:
BUG();
count = resid = 0; /* quiet, gcc */
break;
}
xfs_icsb_enable_counter(mp, field, count, resid);
}
STATIC void
xfs_icsb_balance_counter(
xfs_mount_t *mp,
xfs_sb_field_t fields,
int min_per_cpu)
{
spin_lock(&mp->m_sb_lock);
xfs_icsb_balance_counter_locked(mp, fields, min_per_cpu);
spin_unlock(&mp->m_sb_lock);
}
STATIC int
xfs_icsb_modify_counters(
xfs_mount_t *mp,
xfs_sb_field_t field,
int64_t delta,
int rsvd)
{
xfs_icsb_cnts_t *icsbp;
long long lcounter; /* long counter for 64 bit fields */
int ret = 0;
might_sleep();
again:
preempt_disable();
icsbp = this_cpu_ptr(mp->m_sb_cnts);
/*
* if the counter is disabled, go to slow path
*/
if (unlikely(xfs_icsb_counter_disabled(mp, field)))
goto slow_path;
xfs_icsb_lock_cntr(icsbp);
if (unlikely(xfs_icsb_counter_disabled(mp, field))) {
xfs_icsb_unlock_cntr(icsbp);
goto slow_path;
}
switch (field) {
case XFS_SBS_ICOUNT:
lcounter = icsbp->icsb_icount;
lcounter += delta;
if (unlikely(lcounter < 0))
goto balance_counter;
icsbp->icsb_icount = lcounter;
break;
case XFS_SBS_IFREE:
lcounter = icsbp->icsb_ifree;
lcounter += delta;
if (unlikely(lcounter < 0))
goto balance_counter;
icsbp->icsb_ifree = lcounter;
break;
case XFS_SBS_FDBLOCKS:
BUG_ON((mp->m_resblks - mp->m_resblks_avail) != 0);
lcounter = icsbp->icsb_fdblocks - XFS_ALLOC_SET_ASIDE(mp);
lcounter += delta;
if (unlikely(lcounter < 0))
goto balance_counter;
icsbp->icsb_fdblocks = lcounter + XFS_ALLOC_SET_ASIDE(mp);
break;
default:
BUG();
break;
}
xfs_icsb_unlock_cntr(icsbp);
preempt_enable();
return 0;
slow_path:
preempt_enable();
/*
* serialise with a mutex so we don't burn lots of cpu on
* the superblock lock. We still need to hold the superblock
* lock, however, when we modify the global structures.
*/
xfs_icsb_lock(mp);
/*
* Now running atomically.
*
* If the counter is enabled, someone has beaten us to rebalancing.
* Drop the lock and try again in the fast path....
*/
if (!(xfs_icsb_counter_disabled(mp, field))) {
xfs_icsb_unlock(mp);
goto again;
}
/*
* The counter is currently disabled. Because we are
* running atomically here, we know a rebalance cannot
* be in progress. Hence we can go straight to operating
* on the global superblock. We do not call xfs_mod_incore_sb()
* here even though we need to get the m_sb_lock. Doing so
* will cause us to re-enter this function and deadlock.
* Hence we get the m_sb_lock ourselves and then call
* xfs_mod_incore_sb_unlocked() as the unlocked path operates
* directly on the global counters.
*/
spin_lock(&mp->m_sb_lock);
ret = xfs_mod_incore_sb_unlocked(mp, field, delta, rsvd);
spin_unlock(&mp->m_sb_lock);
/*
* Now that we've modified the global superblock, we
* may be able to re-enable the distributed counters
* (e.g. lots of space just got freed). After that
* we are done.
*/
if (ret != ENOSPC)
xfs_icsb_balance_counter(mp, field, 0);
xfs_icsb_unlock(mp);
return ret;
balance_counter:
xfs_icsb_unlock_cntr(icsbp);
preempt_enable();
/*
* We may have multiple threads here if multiple per-cpu
* counters run dry at the same time. This will mean we can
* do more balances than strictly necessary but it is not
* the common slowpath case.
*/
xfs_icsb_lock(mp);
/*
* running atomically.
*
* This will leave the counter in the correct state for future
* accesses. After the rebalance, we simply try again and our retry
* will either succeed through the fast path or slow path without
* another balance operation being required.
*/
xfs_icsb_balance_counter(mp, field, delta);
xfs_icsb_unlock(mp);
goto again;
}
#endif
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