forked from Minki/linux
1a387d3be2
When we need to cover the log, we issue dummy transactions to ensure the current log tail is on disk. Unfortunately we currently use the root inode in the dummy transaction, and the act of committing the transaction dirties the inode at the VFS level. As a result, the VFS writeback of the dirty inode will prevent the filesystem from idling long enough for the log covering state machine to complete. The state machine gets stuck in a loop issuing new dummy transactions to cover the log and never makes progress. To avoid this problem, the dummy transactions should not cause externally visible state changes. To ensure this occurs, make sure that dummy transactions log an unchanging field in the superblock as it's state is never propagated outside the filesystem. This allows the log covering state machine to complete successfully and the filesystem now correctly enters a fully idle state about 90s after the last modification was made. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
922 lines
23 KiB
C
922 lines
23 KiB
C
/*
|
|
* 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_mount.h"
|
|
#include "xfs_bmap_btree.h"
|
|
#include "xfs_inode.h"
|
|
#include "xfs_dinode.h"
|
|
#include "xfs_error.h"
|
|
#include "xfs_filestream.h"
|
|
#include "xfs_vnodeops.h"
|
|
#include "xfs_inode_item.h"
|
|
#include "xfs_quota.h"
|
|
#include "xfs_trace.h"
|
|
#include "xfs_fsops.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.
|
|
*/
|
|
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)
|
|
return NULL;
|
|
|
|
/*
|
|
* 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))
|
|
return NULL;
|
|
return ip;
|
|
}
|
|
|
|
STATIC int
|
|
xfs_inode_ag_walk(
|
|
struct xfs_mount *mp,
|
|
struct xfs_perag *pag,
|
|
int (*execute)(struct xfs_inode *ip,
|
|
struct xfs_perag *pag, int flags),
|
|
int flags,
|
|
int tag,
|
|
int exclusive,
|
|
int *nr_to_scan)
|
|
{
|
|
uint32_t first_index;
|
|
int last_error = 0;
|
|
int skipped;
|
|
|
|
restart:
|
|
skipped = 0;
|
|
first_index = 0;
|
|
do {
|
|
int error = 0;
|
|
xfs_inode_t *ip;
|
|
|
|
if (exclusive)
|
|
write_lock(&pag->pag_ici_lock);
|
|
else
|
|
read_lock(&pag->pag_ici_lock);
|
|
ip = xfs_inode_ag_lookup(mp, pag, &first_index, tag);
|
|
if (!ip) {
|
|
if (exclusive)
|
|
write_unlock(&pag->pag_ici_lock);
|
|
else
|
|
read_unlock(&pag->pag_ici_lock);
|
|
break;
|
|
}
|
|
|
|
/* execute releases pag->pag_ici_lock */
|
|
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 ((*nr_to_scan)--);
|
|
|
|
if (skipped) {
|
|
delay(1);
|
|
goto restart;
|
|
}
|
|
return last_error;
|
|
}
|
|
|
|
/*
|
|
* Select the next per-ag structure to iterate during the walk. The reclaim
|
|
* walk is optimised only to walk AGs with reclaimable inodes in them.
|
|
*/
|
|
static struct xfs_perag *
|
|
xfs_inode_ag_iter_next_pag(
|
|
struct xfs_mount *mp,
|
|
xfs_agnumber_t *first,
|
|
int tag)
|
|
{
|
|
struct xfs_perag *pag = NULL;
|
|
|
|
if (tag == XFS_ICI_RECLAIM_TAG) {
|
|
int found;
|
|
int ref;
|
|
|
|
spin_lock(&mp->m_perag_lock);
|
|
found = radix_tree_gang_lookup_tag(&mp->m_perag_tree,
|
|
(void **)&pag, *first, 1, tag);
|
|
if (found <= 0) {
|
|
spin_unlock(&mp->m_perag_lock);
|
|
return NULL;
|
|
}
|
|
*first = pag->pag_agno + 1;
|
|
/* open coded pag reference increment */
|
|
ref = atomic_inc_return(&pag->pag_ref);
|
|
spin_unlock(&mp->m_perag_lock);
|
|
trace_xfs_perag_get_reclaim(mp, pag->pag_agno, ref, _RET_IP_);
|
|
} else {
|
|
pag = xfs_perag_get(mp, *first);
|
|
(*first)++;
|
|
}
|
|
return pag;
|
|
}
|
|
|
|
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 exclusive,
|
|
int *nr_to_scan)
|
|
{
|
|
struct xfs_perag *pag;
|
|
int error = 0;
|
|
int last_error = 0;
|
|
xfs_agnumber_t ag;
|
|
int nr;
|
|
|
|
nr = nr_to_scan ? *nr_to_scan : INT_MAX;
|
|
ag = 0;
|
|
while ((pag = xfs_inode_ag_iter_next_pag(mp, &ag, tag))) {
|
|
error = xfs_inode_ag_walk(mp, pag, execute, flags, tag,
|
|
exclusive, &nr);
|
|
xfs_perag_put(pag);
|
|
if (error) {
|
|
last_error = error;
|
|
if (error == EFSCORRUPTED)
|
|
break;
|
|
}
|
|
if (nr <= 0)
|
|
break;
|
|
}
|
|
if (nr_to_scan)
|
|
*nr_to_scan = nr;
|
|
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);
|
|
int error = EFSCORRUPTED;
|
|
|
|
/* nothing to sync during shutdown */
|
|
if (XFS_FORCED_SHUTDOWN(ip->i_mount))
|
|
goto out_unlock;
|
|
|
|
/* avoid new or reclaimable inodes. Leave for reclaim code to flush */
|
|
error = ENOENT;
|
|
if (xfs_iflags_test(ip, XFS_INEW | XFS_IRECLAIMABLE | XFS_IRECLAIM))
|
|
goto out_unlock;
|
|
|
|
/* If we can't grab the inode, it must on it's way to reclaim. */
|
|
if (!igrab(inode))
|
|
goto out_unlock;
|
|
|
|
if (is_bad_inode(inode)) {
|
|
IRELE(ip);
|
|
goto out_unlock;
|
|
}
|
|
|
|
/* inode is valid */
|
|
error = 0;
|
|
out_unlock:
|
|
read_unlock(&pag->pag_ici_lock);
|
|
return error;
|
|
}
|
|
|
|
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 : XBF_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);
|
|
|
|
out_unlock:
|
|
xfs_iunlock(ip, XFS_ILOCK_SHARED);
|
|
IRELE(ip);
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* Write out pagecache data for the whole filesystem.
|
|
*/
|
|
STATIC 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, 0, NULL);
|
|
if (error)
|
|
return XFS_ERROR(error);
|
|
|
|
xfs_log_force(mp, (flags & SYNC_WAIT) ? XFS_LOG_SYNC : 0);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Write out inode metadata (attributes) for the whole filesystem.
|
|
*/
|
|
STATIC 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, 0, NULL);
|
|
}
|
|
|
|
STATIC int
|
|
xfs_sync_fsdata(
|
|
struct xfs_mount *mp)
|
|
{
|
|
struct xfs_buf *bp;
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
bp = xfs_getsb(mp, 0);
|
|
if (XFS_BUF_ISPINNED(bp))
|
|
xfs_log_force(mp, 0);
|
|
|
|
return xfs_bwrite(mp, bp);
|
|
}
|
|
|
|
/*
|
|
* 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, error2 = 0;
|
|
|
|
/* push non-blocking */
|
|
xfs_sync_data(mp, 0);
|
|
xfs_qm_sync(mp, SYNC_TRYLOCK);
|
|
|
|
/* push and block till complete */
|
|
xfs_sync_data(mp, SYNC_WAIT);
|
|
xfs_qm_sync(mp, SYNC_WAIT);
|
|
|
|
/* write superblock and hoover up shutdown errors */
|
|
error = xfs_sync_fsdata(mp);
|
|
|
|
/* make sure all delwri buffers are written out */
|
|
xfs_flush_buftarg(mp->m_ddev_targp, 1);
|
|
|
|
/* mark the log as covered if needed */
|
|
if (xfs_log_need_covered(mp))
|
|
error2 = xfs_fs_log_dummy(mp, SYNC_WAIT);
|
|
|
|
/* flush data-only devices */
|
|
if (mp->m_rtdev_targp)
|
|
XFS_bflush(mp->m_rtdev_targp);
|
|
|
|
return error ? error : error2;
|
|
}
|
|
|
|
STATIC void
|
|
xfs_quiesce_fs(
|
|
struct xfs_mount *mp)
|
|
{
|
|
int count = 0, pincount;
|
|
|
|
xfs_reclaim_inodes(mp, 0);
|
|
xfs_flush_buftarg(mp->m_ddev_targp, 0);
|
|
|
|
/*
|
|
* 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. We also so sync
|
|
* reclaim of inodes to catch any that the above delwri flush skipped.
|
|
*/
|
|
do {
|
|
xfs_reclaim_inodes(mp, SYNC_WAIT);
|
|
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_LOG_SYNC);
|
|
}
|
|
|
|
/*
|
|
* Every sync period we need to unpin all items, reclaim inodes and sync
|
|
* disk quotas. We might need to cover the log to indicate that the
|
|
* filesystem is idle and not frozen.
|
|
*/
|
|
STATIC void
|
|
xfs_sync_worker(
|
|
struct xfs_mount *mp,
|
|
void *unused)
|
|
{
|
|
int error;
|
|
|
|
if (!(mp->m_flags & XFS_MOUNT_RDONLY)) {
|
|
xfs_log_force(mp, 0);
|
|
xfs_reclaim_inodes(mp, 0);
|
|
/* dgc: errors ignored here */
|
|
error = xfs_qm_sync(mp, SYNC_TRYLOCK);
|
|
if (mp->m_super->s_frozen == SB_UNFROZEN &&
|
|
xfs_log_need_covered(mp))
|
|
error = xfs_fs_log_dummy(mp, 0);
|
|
}
|
|
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 (;;) {
|
|
if (list_empty(&mp->m_sync_list))
|
|
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_splice_init(&mp->m_sync_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/%s", mp->m_fsname);
|
|
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);
|
|
}
|
|
|
|
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);
|
|
|
|
if (!pag->pag_ici_reclaimable) {
|
|
/* propagate the reclaim tag up into the perag radix tree */
|
|
spin_lock(&ip->i_mount->m_perag_lock);
|
|
radix_tree_tag_set(&ip->i_mount->m_perag_tree,
|
|
XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino),
|
|
XFS_ICI_RECLAIM_TAG);
|
|
spin_unlock(&ip->i_mount->m_perag_lock);
|
|
trace_xfs_perag_set_reclaim(ip->i_mount, pag->pag_agno,
|
|
-1, _RET_IP_);
|
|
}
|
|
pag->pag_ici_reclaimable++;
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
struct xfs_mount *mp = ip->i_mount;
|
|
struct xfs_perag *pag;
|
|
|
|
pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
|
|
write_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);
|
|
write_unlock(&pag->pag_ici_lock);
|
|
xfs_perag_put(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);
|
|
pag->pag_ici_reclaimable--;
|
|
if (!pag->pag_ici_reclaimable) {
|
|
/* clear the reclaim tag from the perag radix tree */
|
|
spin_lock(&ip->i_mount->m_perag_lock);
|
|
radix_tree_tag_clear(&ip->i_mount->m_perag_tree,
|
|
XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino),
|
|
XFS_ICI_RECLAIM_TAG);
|
|
spin_unlock(&ip->i_mount->m_perag_lock);
|
|
trace_xfs_perag_clear_reclaim(ip->i_mount, pag->pag_agno,
|
|
-1, _RET_IP_);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Inodes in different states need to be treated differently, and the return
|
|
* value of xfs_iflush is not sufficient to get this right. The following table
|
|
* lists the inode states and the reclaim actions necessary for non-blocking
|
|
* reclaim:
|
|
*
|
|
*
|
|
* inode state iflush ret required action
|
|
* --------------- ---------- ---------------
|
|
* bad - reclaim
|
|
* shutdown EIO unpin and reclaim
|
|
* clean, unpinned 0 reclaim
|
|
* stale, unpinned 0 reclaim
|
|
* clean, pinned(*) 0 requeue
|
|
* stale, pinned EAGAIN requeue
|
|
* dirty, delwri ok 0 requeue
|
|
* dirty, delwri blocked EAGAIN requeue
|
|
* dirty, sync flush 0 reclaim
|
|
*
|
|
* (*) dgc: I don't think the clean, pinned state is possible but it gets
|
|
* handled anyway given the order of checks implemented.
|
|
*
|
|
* As can be seen from the table, the return value of xfs_iflush() is not
|
|
* sufficient to correctly decide the reclaim action here. The checks in
|
|
* xfs_iflush() might look like duplicates, but they are not.
|
|
*
|
|
* Also, because we get the flush lock first, we know that any inode that has
|
|
* been flushed delwri has had the flush completed by the time we check that
|
|
* the inode is clean. The clean inode check needs to be done before flushing
|
|
* the inode delwri otherwise we would loop forever requeuing clean inodes as
|
|
* we cannot tell apart a successful delwri flush and a clean inode from the
|
|
* return value of xfs_iflush().
|
|
*
|
|
* Note that because the inode is flushed delayed write by background
|
|
* writeback, the flush lock may already be held here and waiting on it can
|
|
* result in very long latencies. Hence for sync reclaims, where we wait on the
|
|
* flush lock, the caller should push out delayed write inodes first before
|
|
* trying to reclaim them to minimise the amount of time spent waiting. For
|
|
* background relaim, we just requeue the inode for the next pass.
|
|
*
|
|
* Hence the order of actions after gaining the locks should be:
|
|
* bad => reclaim
|
|
* shutdown => unpin and reclaim
|
|
* pinned, delwri => requeue
|
|
* pinned, sync => unpin
|
|
* stale => reclaim
|
|
* clean => reclaim
|
|
* dirty, delwri => flush and requeue
|
|
* dirty, sync => flush, wait and reclaim
|
|
*/
|
|
STATIC int
|
|
xfs_reclaim_inode(
|
|
struct xfs_inode *ip,
|
|
struct xfs_perag *pag,
|
|
int sync_mode)
|
|
{
|
|
int error = 0;
|
|
|
|
/*
|
|
* The radix tree lock here protects a thread in xfs_iget from racing
|
|
* with us starting reclaim on the inode. Once we have the
|
|
* XFS_IRECLAIM flag set it will not touch us.
|
|
*/
|
|
spin_lock(&ip->i_flags_lock);
|
|
ASSERT_ALWAYS(__xfs_iflags_test(ip, XFS_IRECLAIMABLE));
|
|
if (__xfs_iflags_test(ip, XFS_IRECLAIM)) {
|
|
/* ignore as it is already under reclaim */
|
|
spin_unlock(&ip->i_flags_lock);
|
|
write_unlock(&pag->pag_ici_lock);
|
|
return 0;
|
|
}
|
|
__xfs_iflags_set(ip, XFS_IRECLAIM);
|
|
spin_unlock(&ip->i_flags_lock);
|
|
write_unlock(&pag->pag_ici_lock);
|
|
|
|
xfs_ilock(ip, XFS_ILOCK_EXCL);
|
|
if (!xfs_iflock_nowait(ip)) {
|
|
if (!(sync_mode & SYNC_WAIT))
|
|
goto out;
|
|
xfs_iflock(ip);
|
|
}
|
|
|
|
if (is_bad_inode(VFS_I(ip)))
|
|
goto reclaim;
|
|
if (XFS_FORCED_SHUTDOWN(ip->i_mount)) {
|
|
xfs_iunpin_wait(ip);
|
|
goto reclaim;
|
|
}
|
|
if (xfs_ipincount(ip)) {
|
|
if (!(sync_mode & SYNC_WAIT)) {
|
|
xfs_ifunlock(ip);
|
|
goto out;
|
|
}
|
|
xfs_iunpin_wait(ip);
|
|
}
|
|
if (xfs_iflags_test(ip, XFS_ISTALE))
|
|
goto reclaim;
|
|
if (xfs_inode_clean(ip))
|
|
goto reclaim;
|
|
|
|
/* Now we have an inode that needs flushing */
|
|
error = xfs_iflush(ip, sync_mode);
|
|
if (sync_mode & SYNC_WAIT) {
|
|
xfs_iflock(ip);
|
|
goto reclaim;
|
|
}
|
|
|
|
/*
|
|
* When we have to flush an inode but don't have SYNC_WAIT set, we
|
|
* flush the inode out using a delwri buffer and wait for the next
|
|
* call into reclaim to find it in a clean state instead of waiting for
|
|
* it now. We also don't return errors here - if the error is transient
|
|
* then the next reclaim pass will flush the inode, and if the error
|
|
* is permanent then the next sync reclaim will reclaim the inode and
|
|
* pass on the error.
|
|
*/
|
|
if (error && error != EAGAIN && !XFS_FORCED_SHUTDOWN(ip->i_mount)) {
|
|
xfs_fs_cmn_err(CE_WARN, ip->i_mount,
|
|
"inode 0x%llx background reclaim flush failed with %d",
|
|
(long long)ip->i_ino, error);
|
|
}
|
|
out:
|
|
xfs_iflags_clear(ip, XFS_IRECLAIM);
|
|
xfs_iunlock(ip, XFS_ILOCK_EXCL);
|
|
/*
|
|
* We could return EAGAIN here to make reclaim rescan the inode tree in
|
|
* a short while. However, this just burns CPU time scanning the tree
|
|
* waiting for IO to complete and xfssyncd never goes back to the idle
|
|
* state. Instead, return 0 to let the next scheduled background reclaim
|
|
* attempt to reclaim the inode again.
|
|
*/
|
|
return 0;
|
|
|
|
reclaim:
|
|
xfs_ifunlock(ip);
|
|
xfs_iunlock(ip, XFS_ILOCK_EXCL);
|
|
|
|
XFS_STATS_INC(xs_ig_reclaims);
|
|
/*
|
|
* Remove the inode from the per-AG radix tree.
|
|
*
|
|
* Because radix_tree_delete won't complain even if the item was never
|
|
* added to the tree assert that it's been there before to catch
|
|
* problems with the inode life time early on.
|
|
*/
|
|
write_lock(&pag->pag_ici_lock);
|
|
if (!radix_tree_delete(&pag->pag_ici_root,
|
|
XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino)))
|
|
ASSERT(0);
|
|
write_unlock(&pag->pag_ici_lock);
|
|
|
|
/*
|
|
* Here we do an (almost) spurious inode lock in order to coordinate
|
|
* with inode cache radix tree lookups. This is because the lookup
|
|
* can reference the inodes in the cache without taking references.
|
|
*
|
|
* We make that OK here by ensuring that we wait until the inode is
|
|
* unlocked after the lookup before we go ahead and free it. We get
|
|
* both the ilock and the iolock because the code may need to drop the
|
|
* ilock one but will still hold the iolock.
|
|
*/
|
|
xfs_ilock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
|
|
xfs_qm_dqdetach(ip);
|
|
xfs_iunlock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
|
|
|
|
xfs_inode_free(ip);
|
|
return error;
|
|
|
|
}
|
|
|
|
int
|
|
xfs_reclaim_inodes(
|
|
xfs_mount_t *mp,
|
|
int mode)
|
|
{
|
|
return xfs_inode_ag_iterator(mp, xfs_reclaim_inode, mode,
|
|
XFS_ICI_RECLAIM_TAG, 1, NULL);
|
|
}
|
|
|
|
/*
|
|
* Shrinker infrastructure.
|
|
*/
|
|
static int
|
|
xfs_reclaim_inode_shrink(
|
|
struct shrinker *shrink,
|
|
int nr_to_scan,
|
|
gfp_t gfp_mask)
|
|
{
|
|
struct xfs_mount *mp;
|
|
struct xfs_perag *pag;
|
|
xfs_agnumber_t ag;
|
|
int reclaimable;
|
|
|
|
mp = container_of(shrink, struct xfs_mount, m_inode_shrink);
|
|
if (nr_to_scan) {
|
|
if (!(gfp_mask & __GFP_FS))
|
|
return -1;
|
|
|
|
xfs_inode_ag_iterator(mp, xfs_reclaim_inode, 0,
|
|
XFS_ICI_RECLAIM_TAG, 1, &nr_to_scan);
|
|
/* if we don't exhaust the scan, don't bother coming back */
|
|
if (nr_to_scan > 0)
|
|
return -1;
|
|
}
|
|
|
|
reclaimable = 0;
|
|
ag = 0;
|
|
while ((pag = xfs_inode_ag_iter_next_pag(mp, &ag,
|
|
XFS_ICI_RECLAIM_TAG))) {
|
|
reclaimable += pag->pag_ici_reclaimable;
|
|
xfs_perag_put(pag);
|
|
}
|
|
return reclaimable;
|
|
}
|
|
|
|
void
|
|
xfs_inode_shrinker_register(
|
|
struct xfs_mount *mp)
|
|
{
|
|
mp->m_inode_shrink.shrink = xfs_reclaim_inode_shrink;
|
|
mp->m_inode_shrink.seeks = DEFAULT_SEEKS;
|
|
register_shrinker(&mp->m_inode_shrink);
|
|
}
|
|
|
|
void
|
|
xfs_inode_shrinker_unregister(
|
|
struct xfs_mount *mp)
|
|
{
|
|
unregister_shrinker(&mp->m_inode_shrink);
|
|
}
|