/*
* 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_btree.h"
#include "xfs_dir2_sf.h"
#include "xfs_attr_sf.h"
#include "xfs_inode.h"
#include "xfs_dinode.h"
#include "xfs_error.h"
#include "xfs_mru_cache.h"
#include "xfs_filestream.h"
#include "xfs_vnodeops.h"
#include "xfs_utils.h"
#include "xfs_buf_item.h"
#include "xfs_inode_item.h"
#include "xfs_rw.h"
#include <linux/kthread.h>
#include <linux/freezer.h>
/*
* xfs_sync flushes any pending I/O to file system vfsp.
*
* This routine is called by vfs_sync() to make sure that things make it
* out to disk eventually, on sync() system calls to flush out everything,
* and when the file system is unmounted. For the vfs_sync() case, all
* we really need to do is sync out the log to make all of our meta-data
* updates permanent (except for timestamps). For calls from pflushd(),
* dirty pages are kept moving by calling pdflush() on the inodes
* containing them. We also flush the inodes that we can lock without
* sleeping and the superblock if we can lock it without sleeping from
* vfs_sync() so that items at the tail of the log are always moving out.
*
* Flags:
* SYNC_BDFLUSH - We're being called from vfs_sync() so we don't want
* to sleep if we can help it. All we really need
* to do is ensure that the log is synced at least
* periodically. We also push the inodes and
* superblock if we can lock them without sleeping
* and they are not pinned.
* SYNC_ATTR - We need to flush the inodes. If SYNC_BDFLUSH is not
* set, then we really want to lock each inode and flush
* it.
* SYNC_WAIT - All the flushes that take place in this call should
* be synchronous.
* SYNC_DELWRI - This tells us to push dirty pages associated with
* inodes. SYNC_WAIT and SYNC_BDFLUSH are used to
* determine if they should be flushed sync, async, or
* delwri.
* SYNC_CLOSE - This flag is passed when the system is being
* unmounted. We should sync and invalidate everything.
* SYNC_FSDATA - This indicates that the caller would like to make
* sure the superblock is safe on disk. We can ensure
* this by simply making sure the log gets flushed
* if SYNC_BDFLUSH is set, and by actually writing it
* out otherwise.
* SYNC_IOWAIT - The caller wants us to wait for all data I/O to complete
* before we return (including direct I/O). Forms the drain
* side of the write barrier needed to safely quiesce the
* filesystem.
*
*/
int
xfs_sync(
xfs_mount_t *mp,
int flags)
{
int error;
/*
* Get the Quota Manager to flush the dquots.
*
* If XFS quota support is not enabled or this filesystem
* instance does not use quotas XFS_QM_DQSYNC will always
* return zero.
*/
error = XFS_QM_DQSYNC(mp, flags);
if (error) {
/*
* If we got an IO error, we will be shutting down.
* So, there's nothing more for us to do here.
*/
ASSERT(error != EIO || XFS_FORCED_SHUTDOWN(mp));
if (XFS_FORCED_SHUTDOWN(mp))
return XFS_ERROR(error);
}
if (flags & SYNC_IOWAIT)
xfs_filestream_flush(mp);
return xfs_syncsub(mp, flags, NULL);
}
/*
* Sync all the inodes in the given AG according to the
* direction given by the flags.
*/
STATIC int
xfs_sync_inodes_ag(
xfs_mount_t *mp,
int ag,
int flags,
int *bypassed)
{
xfs_inode_t *ip = NULL;
struct inode *vp = NULL;
xfs_perag_t *pag = &mp->m_perag[ag];
boolean_t vnode_refed = B_FALSE;
int nr_found;
int first_index = 0;
int error = 0;
int last_error = 0;
int fflag = XFS_B_ASYNC;
int lock_flags = XFS_ILOCK_SHARED;
if (flags & SYNC_DELWRI)
fflag = XFS_B_DELWRI;
if (flags & SYNC_WAIT)
fflag = 0; /* synchronous overrides all */
if (flags & (SYNC_DELWRI | SYNC_CLOSE)) {
/*
* We need the I/O lock if we're going to call any of
* the flush/inval routines.
*/
lock_flags |= XFS_IOLOCK_SHARED;
}
do {
/*
* use a gang lookup to find the next inode in the tree
* as the tree is sparse and a gang lookup walks to find
* the number of objects requested.
*/
read_lock(&pag->pag_ici_lock);
nr_found = radix_tree_gang_lookup(&pag->pag_ici_root,
(void**)&ip, first_index, 1);
if (!nr_found) {
read_unlock(&pag->pag_ici_lock);
break;
}
/* update the index for the next lookup */
first_index = XFS_INO_TO_AGINO(mp, ip->i_ino + 1);
/*
* skip inodes in reclaim. Let xfs_syncsub do that for
* us so we don't need to worry.
*/
vp = VFS_I(ip);
if (!vp) {
read_unlock(&pag->pag_ici_lock);
continue;
}
/* bad inodes are dealt with elsewhere */
if (VN_BAD(vp)) {
read_unlock(&pag->pag_ici_lock);
continue;
}
/* nothing to sync during shutdown */
if (XFS_FORCED_SHUTDOWN(mp) && !(flags & SYNC_CLOSE)) {
read_unlock(&pag->pag_ici_lock);
return 0;
}
/*
* The inode lock here actually coordinates with the almost
* spurious inode lock in xfs_ireclaim() to prevent the vnode
* we handle here without a reference from being freed while we
* reference it. If we lock the inode while it's on the mount
* list here, then the spurious inode lock in xfs_ireclaim()
* after the inode is pulled from the mount list will sleep
* until we release it here. This keeps the vnode from being
* freed while we reference it.
*/
if (xfs_ilock_nowait(ip, lock_flags) == 0) {
vp = vn_grab(vp);
read_unlock(&pag->pag_ici_lock);
if (!vp)
continue;
xfs_ilock(ip, lock_flags);
ASSERT(vp == VFS_I(ip));
ASSERT(ip->i_mount == mp);
vnode_refed = B_TRUE;
} else {
/* safe to unlock here as we have a reference */
read_unlock(&pag->pag_ici_lock);
}
/*
* If we have to flush data or wait for I/O completion
* we need to drop the ilock that we currently hold.
* If we need to drop the lock, insert a marker if we
* have not already done so.
*/
if (flags & SYNC_CLOSE) {
xfs_iunlock(ip, XFS_ILOCK_SHARED);
if (XFS_FORCED_SHUTDOWN(mp))
xfs_tosspages(ip, 0, -1, FI_REMAPF);
else
error = xfs_flushinval_pages(ip, 0, -1,
FI_REMAPF);
/* wait for I/O on freeze */
if (flags & SYNC_IOWAIT)
vn_iowait(ip);
xfs_ilock(ip, XFS_ILOCK_SHARED);
}
if ((flags & SYNC_DELWRI) && VN_DIRTY(vp)) {
xfs_iunlock(ip, XFS_ILOCK_SHARED);
error = xfs_flush_pages(ip, 0, -1, fflag, FI_NONE);
if (flags & SYNC_IOWAIT)
vn_iowait(ip);
xfs_ilock(ip, XFS_ILOCK_SHARED);
}
if ((flags & SYNC_ATTR) && !xfs_inode_clean(ip)) {
if (flags & SYNC_WAIT) {
xfs_iflock(ip);
if (!xfs_inode_clean(ip))
error = xfs_iflush(ip, XFS_IFLUSH_SYNC);
else
xfs_ifunlock(ip);
} else if (xfs_iflock_nowait(ip)) {
if (!xfs_inode_clean(ip))
error = xfs_iflush(ip, XFS_IFLUSH_DELWRI);
else
xfs_ifunlock(ip);
} else if (bypassed) {
(*bypassed)++;
}
}
if (lock_flags)
xfs_iunlock(ip, lock_flags);
if (vnode_refed) {
IRELE(ip);
vnode_refed = B_FALSE;
}
if (error)
last_error = error;
/*
* bail out if the filesystem is corrupted.
*/
if (error == EFSCORRUPTED)
return XFS_ERROR(error);
} while (nr_found);
return last_error;
}
int
xfs_sync_inodes(
xfs_mount_t *mp,
int flags,
int *bypassed)
{
int error;
int last_error;
int i;
if (bypassed)
*bypassed = 0;
if (mp->m_flags & XFS_MOUNT_RDONLY)
return 0;
error = 0;
last_error = 0;
for (i = 0; i < mp->m_sb.sb_agcount; i++) {
if (!mp->m_perag[i].pag_ici_init)
continue;
error = xfs_sync_inodes_ag(mp, i, flags, bypassed);
if (error)
last_error = error;
if (error == EFSCORRUPTED)
break;
}
return XFS_ERROR(last_error);
}
/*
* xfs sync routine for internal use
*
* This routine supports all of the flags defined for the generic vfs_sync
* interface as explained above under xfs_sync.
*
*/
int
xfs_syncsub(
xfs_mount_t *mp,
int flags,
int *bypassed)
{
int error = 0;
int last_error = 0;
uint log_flags = XFS_LOG_FORCE;
xfs_buf_t *bp;
xfs_buf_log_item_t *bip;
/*
* Sync out the log. This ensures that the log is periodically
* flushed even if there is not enough activity to fill it up.
*/
if (flags & SYNC_WAIT)
log_flags |= XFS_LOG_SYNC;
xfs_log_force(mp, (xfs_lsn_t)0, log_flags);
if (flags & (SYNC_ATTR|SYNC_DELWRI)) {
if (flags & SYNC_BDFLUSH)
xfs_finish_reclaim_all(mp, 1, XFS_IFLUSH_DELWRI_ELSE_ASYNC);
else
error = xfs_sync_inodes(mp, flags, bypassed);
}
/*
* Flushing out dirty data above probably generated more
* log activity, so if this isn't vfs_sync() then flush
* the log again.
*/
if (flags & SYNC_DELWRI) {
xfs_log_force(mp, (xfs_lsn_t)0, log_flags);
}
if (flags & SYNC_FSDATA) {
/*
* If this is vfs_sync() then only sync the superblock
* if we can lock it without sleeping and it is not pinned.
*/
if (flags & SYNC_BDFLUSH) {
bp = xfs_getsb(mp, XFS_BUF_TRYLOCK);
if (bp != NULL) {
bip = XFS_BUF_FSPRIVATE(bp,xfs_buf_log_item_t*);
if ((bip != NULL) &&
xfs_buf_item_dirty(bip)) {
if (!(XFS_BUF_ISPINNED(bp))) {
XFS_BUF_ASYNC(bp);
error = xfs_bwrite(mp, bp);
} else {
xfs_buf_relse(bp);
}
} else {
xfs_buf_relse(bp);
}
}
} else {
bp = xfs_getsb(mp, 0);
/*
* If the buffer is pinned then push on the log so
* we won't get stuck waiting in the write for
* someone, maybe ourselves, to flush the log.
* Even though we just pushed the log above, we
* did not have the superblock buffer locked at
* that point so it can become pinned in between
* there and here.
*/
if (XFS_BUF_ISPINNED(bp))
xfs_log_force(mp, (xfs_lsn_t)0, XFS_LOG_FORCE);
if (flags & SYNC_WAIT)
XFS_BUF_UNASYNC(bp);
else
XFS_BUF_ASYNC(bp);
error = xfs_bwrite(mp, bp);
}
if (error) {
last_error = error;
}
}
/*
* Now check to see if the log needs a "dummy" transaction.
*/
if (!(flags & SYNC_REMOUNT) && xfs_log_need_covered(mp)) {
xfs_trans_t *tp;
xfs_inode_t *ip;
/*
* Put a dummy transaction in the log to tell
* recovery that all others are OK.
*/
tp = xfs_trans_alloc(mp, XFS_TRANS_DUMMY1);
if ((error = xfs_trans_reserve(tp, 0,
XFS_ICHANGE_LOG_RES(mp),
0, 0, 0))) {
xfs_trans_cancel(tp, 0);
return error;
}
ip = mp->m_rootip;
xfs_ilock(ip, XFS_ILOCK_EXCL);
xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
xfs_trans_ihold(tp, ip);
xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
error = xfs_trans_commit(tp, 0);
xfs_iunlock(ip, XFS_ILOCK_EXCL);
xfs_log_force(mp, (xfs_lsn_t)0, log_flags);
}
/*
* When shutting down, we need to insure that the AIL is pushed
* to disk or the filesystem can appear corrupt from the PROM.
*/
if ((flags & (SYNC_CLOSE|SYNC_WAIT)) == (SYNC_CLOSE|SYNC_WAIT)) {
XFS_bflush(mp->m_ddev_targp);
if (mp->m_rtdev_targp) {
XFS_bflush(mp->m_rtdev_targp);
}
}
return XFS_ERROR(last_error);
}
/*
* Enqueue a work item to be picked up by the vfs xfssyncd thread.
* Doing this has two advantages:
* - It saves on stack space, which is tight in certain situations
* - It can be used (with care) as a mechanism to avoid deadlocks.
* Flushing while allocating in a full filesystem requires both.
*/
STATIC void
xfs_syncd_queue_work(
struct xfs_mount *mp,
void *data,
void (*syncer)(struct xfs_mount *, void *))
{
struct bhv_vfs_sync_work *work;
work = kmem_alloc(sizeof(struct bhv_vfs_sync_work), KM_SLEEP);
INIT_LIST_HEAD(&work->w_list);
work->w_syncer = syncer;
work->w_data = data;
work->w_mount = mp;
spin_lock(&mp->m_sync_lock);
list_add_tail(&work->w_list, &mp->m_sync_list);
spin_unlock(&mp->m_sync_lock);
wake_up_process(mp->m_sync_task);
}
/*
* Flush delayed allocate data, attempting to free up reserved space
* from existing allocations. At this point a new allocation attempt
* has failed with ENOSPC and we are in the process of scratching our
* heads, looking about for more room...
*/
STATIC void
xfs_flush_inode_work(
struct xfs_mount *mp,
void *arg)
{
struct inode *inode = arg;
filemap_flush(inode->i_mapping);
iput(inode);
}
void
xfs_flush_inode(
xfs_inode_t *ip)
{
struct inode *inode = VFS_I(ip);
igrab(inode);
xfs_syncd_queue_work(ip->i_mount, inode, xfs_flush_inode_work);
delay(msecs_to_jiffies(500));
}
/*
* This is the "bigger hammer" version of xfs_flush_inode_work...
* (IOW, "If at first you don't succeed, use a Bigger Hammer").
*/
STATIC void
xfs_flush_device_work(
struct xfs_mount *mp,
void *arg)
{
struct inode *inode = arg;
sync_blockdev(mp->m_super->s_bdev);
iput(inode);
}
void
xfs_flush_device(
xfs_inode_t *ip)
{
struct inode *inode = VFS_I(ip);
igrab(inode);
xfs_syncd_queue_work(ip->i_mount, inode, xfs_flush_device_work);
delay(msecs_to_jiffies(500));
xfs_log_force(ip->i_mount, (xfs_lsn_t)0, XFS_LOG_FORCE|XFS_LOG_SYNC);
}
STATIC void
xfs_sync_worker(
struct xfs_mount *mp,
void *unused)
{
int error;
if (!(mp->m_flags & XFS_MOUNT_RDONLY))
error = xfs_sync(mp, SYNC_FSDATA | SYNC_BDFLUSH | SYNC_ATTR);
mp->m_sync_seq++;
wake_up(&mp->m_wait_single_sync_task);
}
STATIC int
xfssyncd(
void *arg)
{
struct xfs_mount *mp = arg;
long timeleft;
bhv_vfs_sync_work_t *work, *n;
LIST_HEAD (tmp);
set_freezable();
timeleft = xfs_syncd_centisecs * msecs_to_jiffies(10);
for (;;) {
timeleft = schedule_timeout_interruptible(timeleft);
/* swsusp */
try_to_freeze();
if (kthread_should_stop() && list_empty(&mp->m_sync_list))
break;
spin_lock(&mp->m_sync_lock);
/*
* We can get woken by laptop mode, to do a sync -
* that's the (only!) case where the list would be
* empty with time remaining.
*/
if (!timeleft || list_empty(&mp->m_sync_list)) {
if (!timeleft)
timeleft = xfs_syncd_centisecs *
msecs_to_jiffies(10);
INIT_LIST_HEAD(&mp->m_sync_work.w_list);
list_add_tail(&mp->m_sync_work.w_list,
&mp->m_sync_list);
}
list_for_each_entry_safe(work, n, &mp->m_sync_list, w_list)
list_move(&work->w_list, &tmp);
spin_unlock(&mp->m_sync_lock);
list_for_each_entry_safe(work, n, &tmp, w_list) {
(*work->w_syncer)(mp, work->w_data);
list_del(&work->w_list);
if (work == &mp->m_sync_work)
continue;
kmem_free(work);
}
}
return 0;
}
int
xfs_syncd_init(
struct xfs_mount *mp)
{
mp->m_sync_work.w_syncer = xfs_sync_worker;
mp->m_sync_work.w_mount = mp;
mp->m_sync_task = kthread_run(xfssyncd, mp, "xfssyncd");
if (IS_ERR(mp->m_sync_task))
return -PTR_ERR(mp->m_sync_task);
return 0;
}
void
xfs_syncd_stop(
struct xfs_mount *mp)
{
kthread_stop(mp->m_sync_task);
}
