/*
* 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>
/*
* 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)
{
xfs_perag_t *pag = &mp->m_perag[ag];
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) {
/*
* We need the I/O lock if we're going to call any of
* the flush/inval routines.
*/
lock_flags |= XFS_IOLOCK_SHARED;
}
do {
struct inode *inode;
boolean_t inode_refed;
xfs_inode_t *ip = NULL;
/*
* 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.
*/
if (xfs_iflags_test(ip, (XFS_IRECLAIM|XFS_IRECLAIMABLE))) {
read_unlock(&pag->pag_ici_lock);
continue;
}
/* bad inodes are dealt with elsewhere */
inode = VFS_I(ip);
if (is_bad_inode(inode)) {
read_unlock(&pag->pag_ici_lock);
continue;
}
/* nothing to sync during shutdown */
if (XFS_FORCED_SHUTDOWN(mp)) {
read_unlock(&pag->pag_ici_lock);
return 0;
}
/*
* If we can't get a reference on the VFS_I, the inode must be
* in reclaim. If we can get the inode lock without blocking,
* it is safe to flush the inode because we hold the tree lock
* and xfs_iextract will block right now. Hence if we lock the
* inode while holding the tree lock, xfs_ireclaim() is
* guaranteed to block on the inode lock we now hold and hence
* it is safe to reference the inode until we drop the inode
* locks completely.
*/
inode_refed = B_FALSE;
if (igrab(inode)) {
read_unlock(&pag->pag_ici_lock);
xfs_ilock(ip, lock_flags);
inode_refed = B_TRUE;
} else {
if (!xfs_ilock_nowait(ip, lock_flags)) {
/* leave it to reclaim */
read_unlock(&pag->pag_ici_lock);
continue;
}
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_DELWRI) && VN_DIRTY(inode)) {
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);
}
}
if (lock_flags)
xfs_iunlock(ip, lock_flags);
if (inode_refed) {
IRELE(ip);
}
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 error;
int last_error;
int i;
int lflags = XFS_LOG_FORCE;
if (mp->m_flags & XFS_MOUNT_RDONLY)
return 0;
error = 0;
last_error = 0;
if (flags & SYNC_WAIT)
lflags |= XFS_LOG_SYNC;
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);
if (error)
last_error = error;
if (error == EFSCORRUPTED)
break;
}
if (flags & SYNC_DELWRI)
xfs_log_force(mp, 0, lflags);
return XFS_ERROR(last_error);
}
STATIC int
xfs_commit_dummy_trans(
struct xfs_mount *mp,
uint log_flags)
{
struct xfs_inode *ip = mp->m_rootip;
struct xfs_trans *tp;
int error;
/*
* Put a dummy transaction in the log to tell recovery
* that all others are OK.
*/
tp = xfs_trans_alloc(mp, XFS_TRANS_DUMMY1);
error = xfs_trans_reserve(tp, 0, XFS_ICHANGE_LOG_RES(mp), 0, 0, 0);
if (error) {
xfs_trans_cancel(tp, 0);
return error;
}
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);
/* XXX(hch): ignoring the error here.. */
error = xfs_trans_commit(tp, 0);
xfs_iunlock(ip, XFS_ILOCK_EXCL);
xfs_log_force(mp, 0, log_flags);
return 0;
}
int
xfs_sync_fsdata(
struct xfs_mount *mp,
int flags)
{
struct xfs_buf *bp;
struct xfs_buf_log_item *bip;
int error = 0;
/*
* If this is xfssyncd() then only sync the superblock if we can
* lock it without sleeping and it is not pinned.
*/
if (flags & SYNC_BDFLUSH) {
ASSERT(!(flags & SYNC_WAIT));
bp = xfs_getsb(mp, XFS_BUF_TRYLOCK);
if (!bp)
goto out;
bip = XFS_BUF_FSPRIVATE(bp, struct xfs_buf_log_item *);
if (!bip || !xfs_buf_item_dirty(bip) || XFS_BUF_ISPINNED(bp))
goto out_brelse;
} 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, 0, XFS_LOG_FORCE);
}
if (flags & SYNC_WAIT)
XFS_BUF_UNASYNC(bp);
else
XFS_BUF_ASYNC(bp);
return xfs_bwrite(mp, bp);
out_brelse:
xfs_buf_relse(bp);
out:
return error;
}
/*
* When remounting a filesystem read-only or freezing the filesystem, we have
* two phases to execute. This first phase is syncing the data before we
* quiesce the filesystem, and the second is flushing all the inodes out after
* we've waited for all the transactions created by the first phase to
* complete. The second phase ensures that the inodes are written to their
* location on disk rather than just existing in transactions in the log. This
* means after a quiesce there is no log replay required to write the inodes to
* disk (this is the main difference between a sync and a quiesce).
*/
/*
* First stage of freeze - no writers will make progress now we are here,
* so we flush delwri and delalloc buffers here, then wait for all I/O to
* complete. Data is frozen at that point. Metadata is not frozen,
* transactions can still occur here so don't bother flushing the buftarg
* because it'll just get dirty again.
*/
int
xfs_quiesce_data(
struct xfs_mount *mp)
{
int error;
/* push non-blocking */
xfs_sync_inodes(mp, SYNC_DELWRI|SYNC_BDFLUSH);
XFS_QM_DQSYNC(mp, SYNC_BDFLUSH);
xfs_filestream_flush(mp);
/* push and block */
xfs_sync_inodes(mp, SYNC_DELWRI|SYNC_WAIT|SYNC_IOWAIT);
XFS_QM_DQSYNC(mp, SYNC_WAIT);
/* write superblock and hoover up shutdown errors */
error = xfs_sync_fsdata(mp, 0);
/* flush data-only devices */
if (mp->m_rtdev_targp)
XFS_bflush(mp->m_rtdev_targp);
return error;
}
STATIC void
xfs_quiesce_fs(
struct xfs_mount *mp)
{
int count = 0, pincount;
xfs_flush_buftarg(mp->m_ddev_targp, 0);
xfs_finish_reclaim_all(mp, 0, XFS_IFLUSH_DELWRI_ELSE_ASYNC);
/*
* This loop must run at least twice. The first instance of the loop
* will flush most meta data but that will generate more meta data
* (typically directory updates). Which then must be flushed and
* logged before we can write the unmount record.
*/
do {
xfs_sync_inodes(mp, SYNC_ATTR|SYNC_WAIT);
pincount = xfs_flush_buftarg(mp->m_ddev_targp, 1);
if (!pincount) {
delay(50);
count++;
}
} while (count < 2);
}
/*
* Second stage of a quiesce. The data is already synced, now we have to take
* care of the metadata. New transactions are already blocked, so we need to
* wait for any remaining transactions to drain out before proceding.
*/
void
xfs_quiesce_attr(
struct xfs_mount *mp)
{
int error = 0;
/* wait for all modifications to complete */
while (atomic_read(&mp->m_active_trans) > 0)
delay(100);
/* flush inodes and push all remaining buffers out to disk */
xfs_quiesce_fs(mp);
ASSERT_ALWAYS(atomic_read(&mp->m_active_trans) == 0);
/* Push the superblock and write an unmount record */
error = xfs_log_sbcount(mp, 1);
if (error)
xfs_fs_cmn_err(CE_WARN, mp,
"xfs_attr_quiesce: failed to log sb changes. "
"Frozen image may not be consistent.");
xfs_log_unmount_write(mp);
xfs_unmountfs_writesb(mp);
}
/*
* 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);
}
/*
* Every sync period we need to unpin all items, reclaim inodes, sync
* quota and write out the superblock. We might need to cover the log
* to indicate it is idle.
*/
STATIC void
xfs_sync_worker(
struct xfs_mount *mp,
void *unused)
{
int error;
if (!(mp->m_flags & XFS_MOUNT_RDONLY)) {
xfs_log_force(mp, (xfs_lsn_t)0, XFS_LOG_FORCE);
xfs_finish_reclaim_all(mp, 1, XFS_IFLUSH_DELWRI_ELSE_ASYNC);
/* dgc: errors ignored here */
error = XFS_QM_DQSYNC(mp, SYNC_BDFLUSH);
error = xfs_sync_fsdata(mp, SYNC_BDFLUSH);
if (xfs_log_need_covered(mp))
error = xfs_commit_dummy_trans(mp, XFS_LOG_FORCE);
}
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);
}
