#include "xfs_log.h"
#include "xfs_inum.h"
#include "xfs_trans.h"
+#include "xfs_trans_priv.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 "xfs_trace.h"
+#include "xfs_fsops.h"
#include <linux/kthread.h>
#include <linux/freezer.h>
+struct workqueue_struct *xfs_syncd_wq; /* sync workqueue */
-STATIC xfs_inode_t *
-xfs_inode_ag_lookup(
- struct xfs_mount *mp,
- struct xfs_perag *pag,
- uint32_t *first_index,
- int tag)
+/*
+ * The inode lookup is done in batches to keep the amount of lock traffic and
+ * radix tree lookups to a minimum. The batch size is a trade off between
+ * lookup reduction and stack usage. This is in the reclaim path, so we can't
+ * be too greedy.
+ */
+#define XFS_LOOKUP_BATCH 32
+
+STATIC int
+xfs_inode_ag_walk_grab(
+ struct xfs_inode *ip)
{
- int nr_found;
- struct xfs_inode *ip;
+ struct inode *inode = VFS_I(ip);
+
+ ASSERT(rcu_read_lock_held());
/*
- * 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.
+ * check for stale RCU freed inode
+ *
+ * If the inode has been reallocated, it doesn't matter if it's not in
+ * the AG we are walking - we are walking for writeback, so if it
+ * passes all the "valid inode" checks and is dirty, then we'll write
+ * it back anyway. If it has been reallocated and still being
+ * initialised, the XFS_INEW check below will catch it.
*/
- 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);
+ spin_lock(&ip->i_flags_lock);
+ if (!ip->i_ino)
+ goto out_unlock_noent;
+
+ /* avoid new or reclaimable inodes. Leave for reclaim code to flush */
+ if (__xfs_iflags_test(ip, XFS_INEW | XFS_IRECLAIMABLE | XFS_IRECLAIM))
+ goto out_unlock_noent;
+ spin_unlock(&ip->i_flags_lock);
+
+ /* nothing to sync during shutdown */
+ if (XFS_FORCED_SHUTDOWN(ip->i_mount))
+ return EFSCORRUPTED;
+
+ /* If we can't grab the inode, it must on it's way to reclaim. */
+ if (!igrab(inode))
+ return ENOENT;
+
+ if (is_bad_inode(inode)) {
+ IRELE(ip);
+ return ENOENT;
}
- 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;
+ /* inode is valid */
+ return 0;
+
+out_unlock_noent:
+ spin_unlock(&ip->i_flags_lock);
+ return ENOENT;
}
STATIC int
xfs_inode_ag_walk(
struct xfs_mount *mp,
- xfs_agnumber_t ag,
+ struct xfs_perag *pag,
int (*execute)(struct xfs_inode *ip,
struct xfs_perag *pag, int flags),
- int flags,
- int tag,
- int exclusive)
+ int flags)
{
- struct xfs_perag *pag = &mp->m_perag[ag];
uint32_t first_index;
int last_error = 0;
int skipped;
+ int done;
+ int nr_found;
restart:
+ done = 0;
skipped = 0;
first_index = 0;
+ nr_found = 0;
do {
+ struct xfs_inode *batch[XFS_LOOKUP_BATCH];
int error = 0;
- xfs_inode_t *ip;
+ int i;
- 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);
+ rcu_read_lock();
+ nr_found = radix_tree_gang_lookup(&pag->pag_ici_root,
+ (void **)batch, first_index,
+ XFS_LOOKUP_BATCH);
+ if (!nr_found) {
+ rcu_read_unlock();
break;
}
- /* execute releases pag->pag_ici_lock */
- error = execute(ip, pag, flags);
- if (error == EAGAIN) {
- skipped++;
- continue;
+ /*
+ * Grab the inodes before we drop the lock. if we found
+ * nothing, nr == 0 and the loop will be skipped.
+ */
+ for (i = 0; i < nr_found; i++) {
+ struct xfs_inode *ip = batch[i];
+
+ if (done || xfs_inode_ag_walk_grab(ip))
+ batch[i] = 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.
+ *
+ * Because we may see inodes that are from the wrong AG
+ * due to RCU freeing and reallocation, only update the
+ * index if it lies in this AG. It was a race that lead
+ * us to see this inode, so another lookup from the
+ * same index will not find it again.
+ */
+ if (XFS_INO_TO_AGNO(mp, ip->i_ino) != pag->pag_agno)
+ continue;
+ first_index = XFS_INO_TO_AGINO(mp, ip->i_ino + 1);
+ if (first_index < XFS_INO_TO_AGINO(mp, ip->i_ino))
+ done = 1;
+ }
+
+ /* unlock now we've grabbed the inodes. */
+ rcu_read_unlock();
+
+ for (i = 0; i < nr_found; i++) {
+ if (!batch[i])
+ continue;
+ error = execute(batch[i], pag, flags);
+ IRELE(batch[i]);
+ if (error == EAGAIN) {
+ skipped++;
+ continue;
+ }
+ if (error && last_error != EFSCORRUPTED)
+ last_error = error;
}
- if (error)
- last_error = error;
/* bail out if the filesystem is corrupted. */
if (error == EFSCORRUPTED)
break;
- } while (1);
+ } while (nr_found && !done);
if (skipped) {
delay(1);
goto restart;
}
-
- xfs_put_perag(mp, pag);
return last_error;
}
struct xfs_mount *mp,
int (*execute)(struct xfs_inode *ip,
struct xfs_perag *pag, int flags),
- int flags,
- int tag,
- int exclusive)
+ int flags)
{
+ struct xfs_perag *pag;
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,
- exclusive);
+ ag = 0;
+ while ((pag = xfs_perag_get(mp, ag))) {
+ ag = pag->pag_agno + 1;
+ error = xfs_inode_ag_walk(mp, pag, execute, flags);
+ xfs_perag_put(pag);
if (error) {
last_error = error;
if (error == EFSCORRUPTED)
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 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;
}
error = xfs_flush_pages(ip, 0, -1, (flags & SYNC_WAIT) ?
- 0 : XFS_B_ASYNC, FI_NONE);
+ 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;
}
{
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;
goto out_unlock;
}
- error = xfs_iflush(ip, (flags & SYNC_WAIT) ?
- XFS_IFLUSH_SYNC : XFS_IFLUSH_DELWRI);
+ 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.
*/
-int
+STATIC int
xfs_sync_data(
struct xfs_mount *mp,
int flags)
ASSERT((flags & ~(SYNC_TRYLOCK|SYNC_WAIT)) == 0);
- error = xfs_inode_ag_iterator(mp, xfs_sync_inode_data, flags,
- XFS_ICI_NO_TAG, 0);
+ error = xfs_inode_ag_iterator(mp, xfs_sync_inode_data, flags);
if (error)
return XFS_ERROR(error);
- xfs_log_force(mp, 0,
- (flags & SYNC_WAIT) ?
- XFS_LOG_FORCE | XFS_LOG_SYNC :
- XFS_LOG_FORCE);
+ xfs_log_force(mp, (flags & SYNC_WAIT) ? XFS_LOG_SYNC : 0);
return 0;
}
/*
* Write out inode metadata (attributes) for the whole filesystem.
*/
-int
+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);
+ return xfs_inode_ag_iterator(mp, xfs_sync_inode_attr, flags);
}
STATIC int
-xfs_commit_dummy_trans(
- struct xfs_mount *mp,
- uint flags)
-{
- struct xfs_inode *ip = mp->m_rootip;
- struct xfs_trans *tp;
- int error;
- int log_flags = XFS_LOG_FORCE;
-
- if (flags & SYNC_WAIT)
- log_flags |= XFS_LOG_SYNC;
-
- /*
- * 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);
- error = xfs_trans_commit(tp, 0);
- xfs_iunlock(ip, XFS_ILOCK_EXCL);
-
- /* the log force ensures this transaction is pushed to disk */
- xfs_log_force(mp, 0, log_flags);
- return error;
-}
-
-int
xfs_sync_fsdata(
- struct xfs_mount *mp,
- int flags)
+ struct xfs_mount *mp)
{
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 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 (flags & SYNC_TRYLOCK) {
- ASSERT(!(flags & SYNC_WAIT));
-
- bp = xfs_getsb(mp, XFS_BUF_TRYLOCK);
- if (!bp)
- goto out;
+ bp = xfs_getsb(mp, 0);
+ if (XFS_BUF_ISPINNED(bp))
+ xfs_log_force(mp, 0);
- 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);
-
- error = xfs_bwrite(mp, bp);
- if (error)
- return error;
-
- /*
- * If this is a data integrity sync make sure all pending buffers
- * are flushed out for the log coverage check below.
- */
- if (flags & SYNC_WAIT)
- xfs_flush_buftarg(mp->m_ddev_targp, 1);
-
- if (xfs_log_need_covered(mp))
- error = xfs_commit_dummy_trans(mp, flags);
- return error;
-
- out_brelse:
- xfs_buf_relse(bp);
- out:
- return error;
+ return xfs_bwrite(mp, bp);
}
/*
xfs_quiesce_data(
struct xfs_mount *mp)
{
- int error;
+ int error, error2 = 0;
/* push non-blocking */
xfs_sync_data(mp, 0);
xfs_sync_data(mp, SYNC_WAIT);
xfs_qm_sync(mp, SYNC_WAIT);
- /* drop inode references pinned by filestreams */
- xfs_filestream_flush(mp);
-
/* write superblock and hoover up shutdown errors */
- error = xfs_sync_fsdata(mp, SYNC_WAIT);
+ 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);
/* flush data-only devices */
if (mp->m_rtdev_targp)
XFS_bflush(mp->m_rtdev_targp);
- return error;
+ return error ? error : error2;
}
STATIC void
{
int count = 0, pincount;
+ xfs_reclaim_inodes(mp, 0);
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.
+ * 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) {
/*
* 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.
+ * wait for any remaining transactions to drain out before proceeding.
*/
void
xfs_quiesce_attr(
/* 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. "
+ xfs_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)
+static void
+xfs_syncd_queue_sync(
+ struct xfs_mount *mp)
{
- 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);
+ queue_delayed_work(xfs_syncd_wq, &mp->m_sync_work,
+ msecs_to_jiffies(xfs_syncd_centisecs * 10));
}
/*
- * 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...
+ * 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_flush_inodes_work(
- struct xfs_mount *mp,
- void *arg)
+xfs_sync_worker(
+ struct work_struct *work)
{
- struct inode *inode = arg;
- xfs_sync_data(mp, SYNC_TRYLOCK);
- xfs_sync_data(mp, SYNC_TRYLOCK | SYNC_WAIT);
- iput(inode);
+ struct xfs_mount *mp = container_of(to_delayed_work(work),
+ struct xfs_mount, m_sync_work);
+ int error;
+
+ if (!(mp->m_flags & XFS_MOUNT_RDONLY)) {
+ /* dgc: errors ignored here */
+ if (mp->m_super->s_frozen == SB_UNFROZEN &&
+ xfs_log_need_covered(mp))
+ error = xfs_fs_log_dummy(mp);
+ else
+ xfs_log_force(mp, 0);
+ error = xfs_qm_sync(mp, SYNC_TRYLOCK);
+
+ /* start pushing all the metadata that is currently dirty */
+ xfs_ail_push_all(mp->m_ail);
+ }
+
+ /* queue us up again */
+ xfs_syncd_queue_sync(mp);
}
-void
-xfs_flush_inodes(
- xfs_inode_t *ip)
+/*
+ * Queue a new inode reclaim pass if there are reclaimable inodes and there
+ * isn't a reclaim pass already in progress. By default it runs every 5s based
+ * on the xfs syncd work default of 30s. Perhaps this should have it's own
+ * tunable, but that can be done if this method proves to be ineffective or too
+ * aggressive.
+ */
+static void
+xfs_syncd_queue_reclaim(
+ struct xfs_mount *mp)
{
- 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);
+ /*
+ * We can have inodes enter reclaim after we've shut down the syncd
+ * workqueue during unmount, so don't allow reclaim work to be queued
+ * during unmount.
+ */
+ if (!(mp->m_super->s_flags & MS_ACTIVE))
+ return;
+
+ rcu_read_lock();
+ if (radix_tree_tagged(&mp->m_perag_tree, XFS_ICI_RECLAIM_TAG)) {
+ queue_delayed_work(xfs_syncd_wq, &mp->m_reclaim_work,
+ msecs_to_jiffies(xfs_syncd_centisecs / 6 * 10));
+ }
+ rcu_read_unlock();
}
/*
- * 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.
+ * This is a fast pass over the inode cache to try to get reclaim moving on as
+ * many inodes as possible in a short period of time. It kicks itself every few
+ * seconds, as well as being kicked by the inode cache shrinker when memory
+ * goes low. It scans as quickly as possible avoiding locked inodes or those
+ * already being flushed, and once done schedules a future pass.
*/
STATIC void
-xfs_sync_worker(
- struct xfs_mount *mp,
- void *unused)
+xfs_reclaim_worker(
+ struct work_struct *work)
{
- int error;
+ struct xfs_mount *mp = container_of(to_delayed_work(work),
+ struct xfs_mount, m_reclaim_work);
- 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);
- }
- mp->m_sync_seq++;
- wake_up(&mp->m_wait_single_sync_task);
+ xfs_reclaim_inodes(mp, SYNC_TRYLOCK);
+ xfs_syncd_queue_reclaim(mp);
}
-STATIC int
-xfssyncd(
- void *arg)
+/*
+ * 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.
+ *
+ * Queue a new data flush if there isn't one already in progress and
+ * wait for completion of the flush. This means that we only ever have one
+ * inode flush in progress no matter how many ENOSPC events are occurring and
+ * so will prevent the system from bogging down due to every concurrent
+ * ENOSPC event scanning all the active inodes in the system for writeback.
+ */
+void
+xfs_flush_inodes(
+ struct xfs_inode *ip)
{
- 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;
+ struct xfs_mount *mp = ip->i_mount;
- 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);
- }
- }
+ queue_work(xfs_syncd_wq, &mp->m_flush_work);
+ flush_work_sync(&mp->m_flush_work);
+}
- return 0;
+STATIC void
+xfs_flush_worker(
+ struct work_struct *work)
+{
+ struct xfs_mount *mp = container_of(work,
+ struct xfs_mount, m_flush_work);
+
+ xfs_sync_data(mp, SYNC_TRYLOCK);
+ xfs_sync_data(mp, SYNC_TRYLOCK | SYNC_WAIT);
}
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);
+ INIT_WORK(&mp->m_flush_work, xfs_flush_worker);
+ INIT_DELAYED_WORK(&mp->m_sync_work, xfs_sync_worker);
+ INIT_DELAYED_WORK(&mp->m_reclaim_work, xfs_reclaim_worker);
+
+ xfs_syncd_queue_sync(mp);
+ xfs_syncd_queue_reclaim(mp);
+
return 0;
}
xfs_syncd_stop(
struct xfs_mount *mp)
{
- kthread_stop(mp->m_sync_task);
+ cancel_delayed_work_sync(&mp->m_sync_work);
+ cancel_delayed_work_sync(&mp->m_reclaim_work);
+ cancel_work_sync(&mp->m_flush_work);
}
void
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);
+
+ /* schedule periodic background inode reclaim */
+ xfs_syncd_queue_reclaim(ip->i_mount);
+
+ trace_xfs_perag_set_reclaim(ip->i_mount, pag->pag_agno,
+ -1, _RET_IP_);
+ }
+ pag->pag_ici_reclaimable++;
}
/*
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);
+ struct xfs_mount *mp = ip->i_mount;
+ struct xfs_perag *pag;
- read_lock(&pag->pag_ici_lock);
+ pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
+ spin_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);
+ spin_unlock(&pag->pag_ici_lock);
+ xfs_perag_put(pag);
+}
+
+STATIC void
+__xfs_inode_clear_reclaim(
+ xfs_perag_t *pag,
+ xfs_inode_t *ip)
+{
+ 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_);
+ }
}
void
{
radix_tree_tag_clear(&pag->pag_ici_root,
XFS_INO_TO_AGINO(mp, ip->i_ino), XFS_ICI_RECLAIM_TAG);
+ __xfs_inode_clear_reclaim(pag, ip);
}
+/*
+ * Grab the inode for reclaim exclusively.
+ * Return 0 if we grabbed it, non-zero otherwise.
+ */
STATIC int
-xfs_reclaim_inode(
+xfs_reclaim_inode_grab(
struct xfs_inode *ip,
- struct xfs_perag *pag,
- int sync_mode)
+ int flags)
{
+ ASSERT(rcu_read_lock_held());
+
+ /* quick check for stale RCU freed inode */
+ if (!ip->i_ino)
+ return 1;
+
+ /*
+ * do some unlocked checks first to avoid unnecessary lock traffic.
+ * The first is a flush lock check, the second is a already in reclaim
+ * check. Only do these checks if we are not going to block on locks.
+ */
+ if ((flags & SYNC_TRYLOCK) &&
+ (!ip->i_flush.done || __xfs_iflags_test(ip, XFS_IRECLAIM))) {
+ return 1;
+ }
+
/*
* 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.
+ *
+ * Due to RCU lookup, we may find inodes that have been freed and only
+ * have XFS_IRECLAIM set. Indeed, we may see reallocated inodes that
+ * aren't candidates for reclaim at all, so we must check the
+ * XFS_IRECLAIMABLE is set first before proceeding to reclaim.
*/
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 */
+ if (!__xfs_iflags_test(ip, XFS_IRECLAIMABLE) ||
+ __xfs_iflags_test(ip, XFS_IRECLAIM)) {
+ /* not a reclaim candidate. */
spin_unlock(&ip->i_flags_lock);
- write_unlock(&pag->pag_ici_lock);
- return 0;
+ return 1;
}
__xfs_iflags_set(ip, XFS_IRECLAIM);
spin_unlock(&ip->i_flags_lock);
- write_unlock(&pag->pag_ici_lock);
+ return 0;
+}
- /*
- * 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.
- */
+/*
+ * 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;
+
+restart:
+ error = 0;
xfs_ilock(ip, XFS_ILOCK_EXCL);
- xfs_iflock(ip);
+ 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;
/*
- * In the case of a forced shutdown we rely on xfs_iflush() to
- * wait for the inode to be unpinned before returning an error.
+ * Now we have an inode that needs flushing.
+ *
+ * We do a nonblocking flush here even if we are doing a SYNC_WAIT
+ * reclaim as we can deadlock with inode cluster removal.
+ * xfs_ifree_cluster() can lock the inode buffer before it locks the
+ * ip->i_lock, and we are doing the exact opposite here. As a result,
+ * doing a blocking xfs_itobp() to get the cluster buffer will result
+ * in an ABBA deadlock with xfs_ifree_cluster().
+ *
+ * As xfs_ifree_cluser() must gather all inodes that are active in the
+ * cache to mark them stale, if we hit this case we don't actually want
+ * to do IO here - we want the inode marked stale so we can simply
+ * reclaim it. Hence if we get an EAGAIN error on a SYNC_WAIT flush,
+ * just unlock the inode, back off and try again. Hopefully the next
+ * pass through will see the stale flag set on the inode.
*/
- if (!is_bad_inode(VFS_I(ip)) && xfs_iflush(ip, sync_mode) == 0) {
- /* synchronize with xfs_iflush_done */
+ error = xfs_iflush(ip, SYNC_TRYLOCK | sync_mode);
+ if (sync_mode & SYNC_WAIT) {
+ if (error == EAGAIN) {
+ xfs_iunlock(ip, XFS_ILOCK_EXCL);
+ /* backoff longer than in xfs_ifree_cluster */
+ delay(2);
+ goto restart;
+ }
xfs_iflock(ip);
- xfs_ifunlock(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_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);
- xfs_ireclaim(ip);
+ /*
+ * 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.
+ */
+ spin_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);
+ __xfs_inode_clear_reclaim(pag, ip);
+ spin_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;
+
+}
+
+/*
+ * Walk the AGs and reclaim the inodes in them. Even if the filesystem is
+ * corrupted, we still want to try to reclaim all the inodes. If we don't,
+ * then a shut down during filesystem unmount reclaim walk leak all the
+ * unreclaimed inodes.
+ */
+int
+xfs_reclaim_inodes_ag(
+ struct xfs_mount *mp,
+ int flags,
+ int *nr_to_scan)
+{
+ struct xfs_perag *pag;
+ int error = 0;
+ int last_error = 0;
+ xfs_agnumber_t ag;
+ int trylock = flags & SYNC_TRYLOCK;
+ int skipped;
+
+restart:
+ ag = 0;
+ skipped = 0;
+ while ((pag = xfs_perag_get_tag(mp, ag, XFS_ICI_RECLAIM_TAG))) {
+ unsigned long first_index = 0;
+ int done = 0;
+ int nr_found = 0;
+
+ ag = pag->pag_agno + 1;
+
+ if (trylock) {
+ if (!mutex_trylock(&pag->pag_ici_reclaim_lock)) {
+ skipped++;
+ xfs_perag_put(pag);
+ continue;
+ }
+ first_index = pag->pag_ici_reclaim_cursor;
+ } else
+ mutex_lock(&pag->pag_ici_reclaim_lock);
+
+ do {
+ struct xfs_inode *batch[XFS_LOOKUP_BATCH];
+ int i;
+
+ rcu_read_lock();
+ nr_found = radix_tree_gang_lookup_tag(
+ &pag->pag_ici_root,
+ (void **)batch, first_index,
+ XFS_LOOKUP_BATCH,
+ XFS_ICI_RECLAIM_TAG);
+ if (!nr_found) {
+ rcu_read_unlock();
+ break;
+ }
+
+ /*
+ * Grab the inodes before we drop the lock. if we found
+ * nothing, nr == 0 and the loop will be skipped.
+ */
+ for (i = 0; i < nr_found; i++) {
+ struct xfs_inode *ip = batch[i];
+
+ if (done || xfs_reclaim_inode_grab(ip, flags))
+ batch[i] = 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.
+ *
+ * Because we may see inodes that are from the
+ * wrong AG due to RCU freeing and
+ * reallocation, only update the index if it
+ * lies in this AG. It was a race that lead us
+ * to see this inode, so another lookup from
+ * the same index will not find it again.
+ */
+ if (XFS_INO_TO_AGNO(mp, ip->i_ino) !=
+ pag->pag_agno)
+ continue;
+ first_index = XFS_INO_TO_AGINO(mp, ip->i_ino + 1);
+ if (first_index < XFS_INO_TO_AGINO(mp, ip->i_ino))
+ done = 1;
+ }
+
+ /* unlock now we've grabbed the inodes. */
+ rcu_read_unlock();
+
+ for (i = 0; i < nr_found; i++) {
+ if (!batch[i])
+ continue;
+ error = xfs_reclaim_inode(batch[i], pag, flags);
+ if (error && last_error != EFSCORRUPTED)
+ last_error = error;
+ }
+
+ *nr_to_scan -= XFS_LOOKUP_BATCH;
+
+ } while (nr_found && !done && *nr_to_scan > 0);
+
+ if (trylock && !done)
+ pag->pag_ici_reclaim_cursor = first_index;
+ else
+ pag->pag_ici_reclaim_cursor = 0;
+ mutex_unlock(&pag->pag_ici_reclaim_lock);
+ xfs_perag_put(pag);
+ }
+
+ /*
+ * if we skipped any AG, and we still have scan count remaining, do
+ * another pass this time using blocking reclaim semantics (i.e
+ * waiting on the reclaim locks and ignoring the reclaim cursors). This
+ * ensure that when we get more reclaimers than AGs we block rather
+ * than spin trying to execute reclaim.
+ */
+ if (trylock && skipped && *nr_to_scan > 0) {
+ trylock = 0;
+ goto restart;
+ }
+ return XFS_ERROR(last_error);
}
int
xfs_mount_t *mp,
int mode)
{
- return xfs_inode_ag_iterator(mp, xfs_reclaim_inode, mode,
- XFS_ICI_RECLAIM_TAG, 1);
+ int nr_to_scan = INT_MAX;
+
+ return xfs_reclaim_inodes_ag(mp, mode, &nr_to_scan);
+}
+
+/*
+ * Inode cache shrinker.
+ *
+ * When called we make sure that there is a background (fast) inode reclaim in
+ * progress, while we will throttle the speed of reclaim via doiing synchronous
+ * reclaim of inodes. That means if we come across dirty inodes, we wait for
+ * them to be cleaned, which we hope will not be very long due to the
+ * background walker having already kicked the IO off on those dirty inodes.
+ */
+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) {
+ /* kick background reclaimer and push the AIL */
+ xfs_syncd_queue_reclaim(mp);
+ xfs_ail_push_all(mp->m_ail);
+
+ if (!(gfp_mask & __GFP_FS))
+ return -1;
+
+ xfs_reclaim_inodes_ag(mp, SYNC_TRYLOCK | SYNC_WAIT,
+ &nr_to_scan);
+ /* terminate if we don't exhaust the scan */
+ if (nr_to_scan > 0)
+ return -1;
+ }
+
+ reclaimable = 0;
+ ag = 0;
+ while ((pag = xfs_perag_get_tag(mp, ag, XFS_ICI_RECLAIM_TAG))) {
+ ag = pag->pag_agno + 1;
+ 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);
}
Code Review / linux-2.6.git / blobdiff