/*
* 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 "xfs_quota.h"
#include <linux/kthread.h>
#include <linux/freezer.h>
STATIC xfs_inode_t *
xfs_inode_ag_lookup(
struct xfs_mount *mp,
struct xfs_perag *pag,
uint32_t *first_index,
int tag)
{
int nr_found;
struct xfs_inode *ip;
/*
* 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);
if (tag == XFS_ICI_NO_TAG) {
nr_found = radix_tree_gang_lookup(&pag->pag_ici_root,
(void **)&ip, *first_index, 1);
} else {
nr_found = radix_tree_gang_lookup_tag(&pag->pag_ici_root,
(void **)&ip, *first_index, 1, tag);
}
if (!nr_found)
goto unlock;
/*
* Update the index for the next lookup. Catch overflows
* into the next AG range which can occur if we have inodes
* in the last block of the AG and we are currently
* pointing to the last inode.
*/
*first_index = XFS_INO_TO_AGINO(mp, ip->i_ino + 1);
if (*first_index < XFS_INO_TO_AGINO(mp, ip->i_ino))
goto unlock;
return ip;
unlock:
read_unlock(&pag->pag_ici_lock);
return NULL;
}
STATIC int
xfs_inode_ag_walk(
struct xfs_mount *mp,
xfs_agnumber_t ag,
int (*execute)(struct xfs_inode *ip,
struct xfs_perag *pag, int flags),
int flags,
int tag)
{
struct xfs_perag *pag = &mp->m_perag[ag];
uint32_t first_index;
int last_error = 0;
int skipped;
restart:
skipped = 0;
first_index = 0;
do {
int error = 0;
xfs_inode_t *ip;
ip = xfs_inode_ag_lookup(mp, pag, &first_index, tag);
if (!ip)
break;
error = execute(ip, pag, flags);
if (error == EAGAIN) {
skipped++;
continue;
}
if (error)
last_error = error;
/*
* bail out if the filesystem is corrupted.
*/
if (error == EFSCORRUPTED)
break;
} while (1);
if (skipped) {
delay(1);
goto restart;
}
xfs_put_perag(mp, pag);
return last_error;
}
int
xfs_inode_ag_iterator(
struct xfs_mount *mp,
int (*execute)(struct xfs_inode *ip,
struct xfs_perag *pag, int flags),
int flags,
int tag)
{
int error = 0;
int last_error = 0;
xfs_agnumber_t ag;
for (ag = 0; ag < mp->m_sb.sb_agcount; ag++) {
if (!mp->m_perag[ag].pag_ici_init)
continue;
error = xfs_inode_ag_walk(mp, ag, execute, flags, tag);
if (error) {
last_error = error;
if (error == EFSCORRUPTED)
break;
}
}
return XFS_ERROR(last_error);
}
/* must be called with pag_ici_lock held and releases it */
int
xfs_sync_inode_valid(
struct xfs_inode *ip,
struct xfs_perag *pag)
{
struct inode *inode = VFS_I(ip);
/* nothing to sync during shutdown */
if (XFS_FORCED_SHUTDOWN(ip->i_mount)) {
read_unlock(&pag->pag_ici_lock);
return EFSCORRUPTED;
}
/*
* If we can't get a reference on the inode, it must be in reclaim.
* Leave it for the reclaim code to flush. Also avoid inodes that
* haven't been fully initialised.
*/
if (!igrab(inode)) {
read_unlock(&pag->pag_ici_lock);
return ENOENT;
}
read_unlock(&pag->pag_ici_lock);
if (is_bad_inode(inode) || xfs_iflags_test(ip, XFS_INEW)) {
IRELE(ip);
return ENOENT;
}
return 0;
}
STATIC int
xfs_sync_inode_data(
struct xfs_inode *ip,
struct xfs_perag *pag,
int flags)
{
struct inode *inode = VFS_I(ip);
struct address_space *mapping = inode->i_mapping;
int error = 0;
error = xfs_sync_inode_valid(ip, pag);
if (error)
return error;
if (!mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
goto out_wait;
if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED)) {
if (flags & SYNC_TRYLOCK)
goto out_wait;
xfs_ilock(ip, XFS_IOLOCK_SHARED);
}
error = xfs_flush_pages(ip, 0, -1, (flags & SYNC_WAIT) ?
0 : XFS_B_ASYNC, FI_NONE);
xfs_iunlock(ip, XFS_IOLOCK_SHARED);
out_wait:
if (flags & SYNC_WAIT)
xfs_ioend_wait(ip);
IRELE(ip);
return error;
}
STATIC int
xfs_sync_inode_attr(
struct xfs_inode *ip,
struct xfs_perag *pag,
int flags)
{
int error = 0;
error = xfs_sync_inode_valid(ip, pag);
if (error)
return error;
xfs_ilock(ip, XFS_ILOCK_SHARED);
if (xfs_inode_clean(ip))
goto out_unlock;
if (!xfs_iflock_nowait(ip)) {
if (!(flags & SYNC_WAIT))
goto out_unlock;
xfs_iflock(ip);
}
if (xfs_inode_clean(ip)) {
xfs_ifunlock(ip);
goto out_unlock;
}
error = xfs_iflush(ip, (flags & SYNC_WAIT) ?
XFS_IFLUSH_SYNC : XFS_IFLUSH_DELWRI);
out_unlock:
xfs_iunlock(ip, XFS_ILOCK_SHARED);
IRELE(ip);
return error;
}
/*
* Write out pagecache data for the whole filesystem.
*/
int
xfs_sync_data(
struct xfs_mount *mp,
int flags)
{
int error;
ASSERT((flags & ~(SYNC_TRYLOCK|SYNC_WAIT)) == 0);
error = xfs_inode_ag_iterator(mp, xfs_sync_inode_data, flags,
XFS_ICI_NO_TAG);
if (error)
return XFS_ERROR(error);
xfs_log_force(mp, 0,
(flags & SYNC_WAIT) ?
XFS_LOG_FORCE | XFS_LOG_SYNC :
XFS_LOG_FORCE);
return 0;
}
/*
* Write out inode metadata (attributes) for the whole filesystem.
*/
int
xfs_sync_attr(
struct xfs_mount *mp,
int flags)
{
ASSERT((flags & ~SYNC_WAIT) == 0);
return xfs_inode_ag_iterator(mp, xfs_sync_inode_attr, flags,
XFS_ICI_NO_TAG);
}
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_TRYLOCK) {
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_data(mp, 0);
xfs_qm_sync(mp, SYNC_TRYLOCK);
xfs_filestream_flush(mp);
/* push and block */
xfs_sync_data(mp, SYNC_WAIT);
xfs_qm_sync(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_reclaim_inodes(mp, 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_attr(mp, 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);
/*
* Just warn here till VFS can correctly support
* read-only remount without racing.
*/
WARN_ON(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 completion *completion)
{
struct xfs_sync_work *work;
work = kmem_alloc(sizeof(struct xfs_sync_work), KM_SLEEP);
INIT_LIST_HEAD(&work->w_list);
work->w_syncer = syncer;
work->w_data = data;
work->w_mount = mp;
work->w_completion = completion;
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_inodes_work(
struct xfs_mount *mp,
void *arg)
{
struct inode *inode = arg;
xfs_sync_data(mp, SYNC_TRYLOCK);
xfs_sync_data(mp, SYNC_TRYLOCK | SYNC_WAIT);
iput(inode);
}
void
xfs_flush_inodes(
xfs_inode_t *ip)
{
struct inode *inode = VFS_I(ip);
DECLARE_COMPLETION_ONSTACK(completion);
igrab(inode);
xfs_syncd_queue_work(ip->i_mount, inode, xfs_flush_inodes_work, &completion);
wait_for_completion(&completion);
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_reclaim_inodes(mp, XFS_IFLUSH_DELWRI_ELSE_ASYNC);
/* dgc: errors ignored here */
error = xfs_qm_sync(mp, SYNC_TRYLOCK);
error = xfs_sync_fsdata(mp, SYNC_TRYLOCK);
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;
xfs_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;
if (work->w_completion)
complete(work->w_completion);
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_work.w_completion = NULL;
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);
}
int
xfs_reclaim_inode(
xfs_inode_t *ip,
int locked,
int sync_mode)
{
xfs_perag_t *pag = xfs_get_perag(ip->i_mount, ip->i_ino);
/* The hash lock here protects a thread in xfs_iget_core from
* racing with us on linking the inode back with a vnode.
* Once we have the XFS_IRECLAIM flag set it will not touch
* us.
*/
write_lock(&pag->pag_ici_lock);
spin_lock(&ip->i_flags_lock);
if (__xfs_iflags_test(ip, XFS_IRECLAIM) ||
!__xfs_iflags_test(ip, XFS_IRECLAIMABLE)) {
spin_unlock(&ip->i_flags_lock);
write_unlock(&pag->pag_ici_lock);
if (locked) {
xfs_ifunlock(ip);
xfs_iunlock(ip, XFS_ILOCK_EXCL);
}
return -EAGAIN;
}
__xfs_iflags_set(ip, XFS_IRECLAIM);
spin_unlock(&ip->i_flags_lock);
write_unlock(&pag->pag_ici_lock);
xfs_put_perag(ip->i_mount, pag);
/*
* If the inode is still dirty, then flush it out. If the inode
* is not in the AIL, then it will be OK to flush it delwri as
* long as xfs_iflush() does not keep any references to the inode.
* We leave that decision up to xfs_iflush() since it has the
* knowledge of whether it's OK to simply do a delwri flush of
* the inode or whether we need to wait until the inode is
* pulled from the AIL.
* We get the flush lock regardless, though, just to make sure
* we don't free it while it is being flushed.
*/
if (!locked) {
xfs_ilock(ip, XFS_ILOCK_EXCL);
xfs_iflock(ip);
}
/*
* In the case of a forced shutdown we rely on xfs_iflush() to
* wait for the inode to be unpinned before returning an error.
*/
if (!is_bad_inode(VFS_I(ip)) && xfs_iflush(ip, sync_mode) == 0) {
/* synchronize with xfs_iflush_done */
xfs_iflock(ip);
xfs_ifunlock(ip);
}
xfs_iunlock(ip, XFS_ILOCK_EXCL);
xfs_ireclaim(ip);
return 0;
}
void
__xfs_inode_set_reclaim_tag(
struct xfs_perag *pag,
struct xfs_inode *ip)
{
radix_tree_tag_set(&pag->pag_ici_root,
XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino),
XFS_ICI_RECLAIM_TAG);
}
/*
* We set the inode flag atomically with the radix tree tag.
* Once we get tag lookups on the radix tree, this inode flag
* can go away.
*/
void
xfs_inode_set_reclaim_tag(
xfs_inode_t *ip)
{
xfs_mount_t *mp = ip->i_mount;
xfs_perag_t *pag = xfs_get_perag(mp, ip->i_ino);
read_lock(&pag->pag_ici_lock);
spin_lock(&ip->i_flags_lock);
__xfs_inode_set_reclaim_tag(pag, ip);
__xfs_iflags_set(ip, XFS_IRECLAIMABLE);
spin_unlock(&ip->i_flags_lock);
read_unlock(&pag->pag_ici_lock);
xfs_put_perag(mp, pag);
}
void
__xfs_inode_clear_reclaim_tag(
xfs_mount_t *mp,
xfs_perag_t *pag,
xfs_inode_t *ip)
{
radix_tree_tag_clear(&pag->pag_ici_root,
XFS_INO_TO_AGINO(mp, ip->i_ino), XFS_ICI_RECLAIM_TAG);
}
STATIC int
xfs_reclaim_inode_now(
struct xfs_inode *ip,
struct xfs_perag *pag,
int flags)
{
/* ignore if already under reclaim */
if (xfs_iflags_test(ip, XFS_IRECLAIM)) {
read_unlock(&pag->pag_ici_lock);
return 0;
}
read_unlock(&pag->pag_ici_lock);
return xfs_reclaim_inode(ip, 0, flags);
}
int
xfs_reclaim_inodes(
xfs_mount_t *mp,
int mode)
{
return xfs_inode_ag_iterator(mp, xfs_reclaim_inode_now, mode,
XFS_ICI_RECLAIM_TAG);
}
