xfs_icache.c 42.7 KB
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// SPDX-License-Identifier: GPL-2.0
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/*
 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 */
#include "xfs.h"
#include "xfs_fs.h"
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#include "xfs_shared.h"
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#include "xfs_format.h"
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#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
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#include "xfs_sb.h"
#include "xfs_mount.h"
#include "xfs_inode.h"
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#include "xfs_trans.h"
#include "xfs_trans_priv.h"
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#include "xfs_inode_item.h"
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#include "xfs_quota.h"
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#include "xfs_trace.h"
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#include "xfs_icache.h"
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#include "xfs_bmap_util.h"
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#include "xfs_dquot_item.h"
#include "xfs_dquot.h"
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#include "xfs_reflink.h"
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#include "xfs_ialloc.h"
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#include <linux/iversion.h>
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/*
 * Allocate and initialise an xfs_inode.
 */
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struct xfs_inode *
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xfs_inode_alloc(
	struct xfs_mount	*mp,
	xfs_ino_t		ino)
{
	struct xfs_inode	*ip;

	/*
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	 * XXX: If this didn't occur in transactions, we could drop GFP_NOFAIL
	 * and return NULL here on ENOMEM.
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	 */
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	ip = kmem_cache_alloc(xfs_inode_zone, GFP_KERNEL | __GFP_NOFAIL);

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	if (inode_init_always(mp->m_super, VFS_I(ip))) {
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		kmem_cache_free(xfs_inode_zone, ip);
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		return NULL;
	}

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	/* VFS doesn't initialise i_mode! */
	VFS_I(ip)->i_mode = 0;

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	XFS_STATS_INC(mp, vn_active);
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	ASSERT(atomic_read(&ip->i_pincount) == 0);
	ASSERT(ip->i_ino == 0);

	/* initialise the xfs inode */
	ip->i_ino = ino;
	ip->i_mount = mp;
	memset(&ip->i_imap, 0, sizeof(struct xfs_imap));
	ip->i_afp = NULL;
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	ip->i_cowfp = NULL;
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	memset(&ip->i_df, 0, sizeof(ip->i_df));
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	ip->i_flags = 0;
	ip->i_delayed_blks = 0;
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	memset(&ip->i_d, 0, sizeof(ip->i_d));
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	ip->i_sick = 0;
	ip->i_checked = 0;
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	INIT_WORK(&ip->i_ioend_work, xfs_end_io);
	INIT_LIST_HEAD(&ip->i_ioend_list);
	spin_lock_init(&ip->i_ioend_lock);
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	return ip;
}

STATIC void
xfs_inode_free_callback(
	struct rcu_head		*head)
{
	struct inode		*inode = container_of(head, struct inode, i_rcu);
	struct xfs_inode	*ip = XFS_I(inode);

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	switch (VFS_I(ip)->i_mode & S_IFMT) {
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	case S_IFREG:
	case S_IFDIR:
	case S_IFLNK:
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		xfs_idestroy_fork(&ip->i_df);
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		break;
	}

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	if (ip->i_afp) {
		xfs_idestroy_fork(ip->i_afp);
		kmem_cache_free(xfs_ifork_zone, ip->i_afp);
	}
	if (ip->i_cowfp) {
		xfs_idestroy_fork(ip->i_cowfp);
		kmem_cache_free(xfs_ifork_zone, ip->i_cowfp);
	}
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	if (ip->i_itemp) {
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		ASSERT(!test_bit(XFS_LI_IN_AIL,
				 &ip->i_itemp->ili_item.li_flags));
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		xfs_inode_item_destroy(ip);
		ip->i_itemp = NULL;
	}

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	kmem_cache_free(xfs_inode_zone, ip);
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}

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static void
__xfs_inode_free(
	struct xfs_inode	*ip)
{
	/* asserts to verify all state is correct here */
	ASSERT(atomic_read(&ip->i_pincount) == 0);
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	ASSERT(!ip->i_itemp || list_empty(&ip->i_itemp->ili_item.li_bio_list));
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	XFS_STATS_DEC(ip->i_mount, vn_active);

	call_rcu(&VFS_I(ip)->i_rcu, xfs_inode_free_callback);
}

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void
xfs_inode_free(
	struct xfs_inode	*ip)
{
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	ASSERT(!xfs_iflags_test(ip, XFS_IFLUSHING));
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	/*
	 * Because we use RCU freeing we need to ensure the inode always
	 * appears to be reclaimed with an invalid inode number when in the
	 * free state. The ip->i_flags_lock provides the barrier against lookup
	 * races.
	 */
	spin_lock(&ip->i_flags_lock);
	ip->i_flags = XFS_IRECLAIM;
	ip->i_ino = 0;
	spin_unlock(&ip->i_flags_lock);

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	__xfs_inode_free(ip);
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}

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/*
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 * Queue background inode reclaim work if there are reclaimable inodes and there
 * isn't reclaim work already scheduled or in progress.
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 */
static void
xfs_reclaim_work_queue(
	struct xfs_mount        *mp)
{

	rcu_read_lock();
	if (radix_tree_tagged(&mp->m_perag_tree, XFS_ICI_RECLAIM_TAG)) {
		queue_delayed_work(mp->m_reclaim_workqueue, &mp->m_reclaim_work,
			msecs_to_jiffies(xfs_syncd_centisecs / 6 * 10));
	}
	rcu_read_unlock();
}

static void
xfs_perag_set_reclaim_tag(
	struct xfs_perag	*pag)
{
	struct xfs_mount	*mp = pag->pag_mount;

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	lockdep_assert_held(&pag->pag_ici_lock);
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	if (pag->pag_ici_reclaimable++)
		return;

	/* propagate the reclaim tag up into the perag radix tree */
	spin_lock(&mp->m_perag_lock);
	radix_tree_tag_set(&mp->m_perag_tree, pag->pag_agno,
			   XFS_ICI_RECLAIM_TAG);
	spin_unlock(&mp->m_perag_lock);

	/* schedule periodic background inode reclaim */
	xfs_reclaim_work_queue(mp);

	trace_xfs_perag_set_reclaim(mp, pag->pag_agno, -1, _RET_IP_);
}

static void
xfs_perag_clear_reclaim_tag(
	struct xfs_perag	*pag)
{
	struct xfs_mount	*mp = pag->pag_mount;

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	lockdep_assert_held(&pag->pag_ici_lock);
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	if (--pag->pag_ici_reclaimable)
		return;

	/* clear the reclaim tag from the perag radix tree */
	spin_lock(&mp->m_perag_lock);
	radix_tree_tag_clear(&mp->m_perag_tree, pag->pag_agno,
			     XFS_ICI_RECLAIM_TAG);
	spin_unlock(&mp->m_perag_lock);
	trace_xfs_perag_clear_reclaim(mp, pag->pag_agno, -1, _RET_IP_);
}


/*
 * 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(
	struct xfs_inode	*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));
	spin_lock(&pag->pag_ici_lock);
	spin_lock(&ip->i_flags_lock);

	radix_tree_tag_set(&pag->pag_ici_root, XFS_INO_TO_AGINO(mp, ip->i_ino),
			   XFS_ICI_RECLAIM_TAG);
	xfs_perag_set_reclaim_tag(pag);
	__xfs_iflags_set(ip, XFS_IRECLAIMABLE);

	spin_unlock(&ip->i_flags_lock);
	spin_unlock(&pag->pag_ici_lock);
	xfs_perag_put(pag);
}

STATIC void
xfs_inode_clear_reclaim_tag(
	struct xfs_perag	*pag,
	xfs_ino_t		ino)
{
	radix_tree_tag_clear(&pag->pag_ici_root,
			     XFS_INO_TO_AGINO(pag->pag_mount, ino),
			     XFS_ICI_RECLAIM_TAG);
	xfs_perag_clear_reclaim_tag(pag);
}

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static void
xfs_inew_wait(
	struct xfs_inode	*ip)
{
	wait_queue_head_t *wq = bit_waitqueue(&ip->i_flags, __XFS_INEW_BIT);
	DEFINE_WAIT_BIT(wait, &ip->i_flags, __XFS_INEW_BIT);

	do {
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		prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE);
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		if (!xfs_iflags_test(ip, XFS_INEW))
			break;
		schedule();
	} while (true);
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	finish_wait(wq, &wait.wq_entry);
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}

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/*
 * When we recycle a reclaimable inode, we need to re-initialise the VFS inode
 * part of the structure. This is made more complex by the fact we store
 * information about the on-disk values in the VFS inode and so we can't just
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 * overwrite the values unconditionally. Hence we save the parameters we
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 * need to retain across reinitialisation, and rewrite them into the VFS inode
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 * after reinitialisation even if it fails.
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 */
static int
xfs_reinit_inode(
	struct xfs_mount	*mp,
	struct inode		*inode)
{
	int		error;
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	uint32_t	nlink = inode->i_nlink;
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	uint32_t	generation = inode->i_generation;
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	uint64_t	version = inode_peek_iversion(inode);
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	umode_t		mode = inode->i_mode;
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	dev_t		dev = inode->i_rdev;
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	kuid_t		uid = inode->i_uid;
	kgid_t		gid = inode->i_gid;
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	error = inode_init_always(mp->m_super, inode);

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	set_nlink(inode, nlink);
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	inode->i_generation = generation;
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	inode_set_iversion_queried(inode, version);
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	inode->i_mode = mode;
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	inode->i_rdev = dev;
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	inode->i_uid = uid;
	inode->i_gid = gid;
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	return error;
}

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/*
 * If we are allocating a new inode, then check what was returned is
 * actually a free, empty inode. If we are not allocating an inode,
 * then check we didn't find a free inode.
 *
 * Returns:
 *	0		if the inode free state matches the lookup context
 *	-ENOENT		if the inode is free and we are not allocating
 *	-EFSCORRUPTED	if there is any state mismatch at all
 */
static int
xfs_iget_check_free_state(
	struct xfs_inode	*ip,
	int			flags)
{
	if (flags & XFS_IGET_CREATE) {
		/* should be a free inode */
		if (VFS_I(ip)->i_mode != 0) {
			xfs_warn(ip->i_mount,
"Corruption detected! Free inode 0x%llx not marked free! (mode 0x%x)",
				ip->i_ino, VFS_I(ip)->i_mode);
			return -EFSCORRUPTED;
		}

		if (ip->i_d.di_nblocks != 0) {
			xfs_warn(ip->i_mount,
"Corruption detected! Free inode 0x%llx has blocks allocated!",
				ip->i_ino);
			return -EFSCORRUPTED;
		}
		return 0;
	}

	/* should be an allocated inode */
	if (VFS_I(ip)->i_mode == 0)
		return -ENOENT;

	return 0;
}

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/*
 * Check the validity of the inode we just found it the cache
 */
static int
xfs_iget_cache_hit(
	struct xfs_perag	*pag,
	struct xfs_inode	*ip,
	xfs_ino_t		ino,
	int			flags,
	int			lock_flags) __releases(RCU)
{
	struct inode		*inode = VFS_I(ip);
	struct xfs_mount	*mp = ip->i_mount;
	int			error;

	/*
	 * check for re-use of an inode within an RCU grace period due to the
	 * radix tree nodes not being updated yet. We monitor for this by
	 * setting the inode number to zero before freeing the inode structure.
	 * If the inode has been reallocated and set up, then the inode number
	 * will not match, so check for that, too.
	 */
	spin_lock(&ip->i_flags_lock);
	if (ip->i_ino != ino) {
		trace_xfs_iget_skip(ip);
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		XFS_STATS_INC(mp, xs_ig_frecycle);
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		error = -EAGAIN;
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		goto out_error;
	}


	/*
	 * If we are racing with another cache hit that is currently
	 * instantiating this inode or currently recycling it out of
	 * reclaimabe state, wait for the initialisation to complete
	 * before continuing.
	 *
	 * XXX(hch): eventually we should do something equivalent to
	 *	     wait_on_inode to wait for these flags to be cleared
	 *	     instead of polling for it.
	 */
	if (ip->i_flags & (XFS_INEW|XFS_IRECLAIM)) {
		trace_xfs_iget_skip(ip);
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		XFS_STATS_INC(mp, xs_ig_frecycle);
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		error = -EAGAIN;
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		goto out_error;
	}

	/*
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	 * Check the inode free state is valid. This also detects lookup
	 * racing with unlinks.
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	 */
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	error = xfs_iget_check_free_state(ip, flags);
	if (error)
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		goto out_error;

	/*
	 * If IRECLAIMABLE is set, we've torn down the VFS inode already.
	 * Need to carefully get it back into useable state.
	 */
	if (ip->i_flags & XFS_IRECLAIMABLE) {
		trace_xfs_iget_reclaim(ip);

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		if (flags & XFS_IGET_INCORE) {
			error = -EAGAIN;
			goto out_error;
		}

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		/*
		 * We need to set XFS_IRECLAIM to prevent xfs_reclaim_inode
		 * from stomping over us while we recycle the inode.  We can't
		 * clear the radix tree reclaimable tag yet as it requires
		 * pag_ici_lock to be held exclusive.
		 */
		ip->i_flags |= XFS_IRECLAIM;

		spin_unlock(&ip->i_flags_lock);
		rcu_read_unlock();

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		ASSERT(!rwsem_is_locked(&inode->i_rwsem));
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		error = xfs_reinit_inode(mp, inode);
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		if (error) {
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			bool wake;
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			/*
			 * Re-initializing the inode failed, and we are in deep
			 * trouble.  Try to re-add it to the reclaim list.
			 */
			rcu_read_lock();
			spin_lock(&ip->i_flags_lock);
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			wake = !!__xfs_iflags_test(ip, XFS_INEW);
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			ip->i_flags &= ~(XFS_INEW | XFS_IRECLAIM);
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			if (wake)
				wake_up_bit(&ip->i_flags, __XFS_INEW_BIT);
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			ASSERT(ip->i_flags & XFS_IRECLAIMABLE);
			trace_xfs_iget_reclaim_fail(ip);
			goto out_error;
		}

		spin_lock(&pag->pag_ici_lock);
		spin_lock(&ip->i_flags_lock);

		/*
		 * Clear the per-lifetime state in the inode as we are now
		 * effectively a new inode and need to return to the initial
		 * state before reuse occurs.
		 */
		ip->i_flags &= ~XFS_IRECLAIM_RESET_FLAGS;
		ip->i_flags |= XFS_INEW;
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		xfs_inode_clear_reclaim_tag(pag, ip->i_ino);
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		inode->i_state = I_NEW;
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		ip->i_sick = 0;
		ip->i_checked = 0;
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		spin_unlock(&ip->i_flags_lock);
		spin_unlock(&pag->pag_ici_lock);
	} else {
		/* If the VFS inode is being torn down, pause and try again. */
		if (!igrab(inode)) {
			trace_xfs_iget_skip(ip);
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			error = -EAGAIN;
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			goto out_error;
		}

		/* We've got a live one. */
		spin_unlock(&ip->i_flags_lock);
		rcu_read_unlock();
		trace_xfs_iget_hit(ip);
	}

	if (lock_flags != 0)
		xfs_ilock(ip, lock_flags);

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	if (!(flags & XFS_IGET_INCORE))
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		xfs_iflags_clear(ip, XFS_ISTALE);
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	XFS_STATS_INC(mp, xs_ig_found);
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	return 0;

out_error:
	spin_unlock(&ip->i_flags_lock);
	rcu_read_unlock();
	return error;
}


static int
xfs_iget_cache_miss(
	struct xfs_mount	*mp,
	struct xfs_perag	*pag,
	xfs_trans_t		*tp,
	xfs_ino_t		ino,
	struct xfs_inode	**ipp,
	int			flags,
	int			lock_flags)
{
	struct xfs_inode	*ip;
	int			error;
	xfs_agino_t		agino = XFS_INO_TO_AGINO(mp, ino);
	int			iflags;

	ip = xfs_inode_alloc(mp, ino);
	if (!ip)
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		return -ENOMEM;
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	error = xfs_imap(mp, tp, ip->i_ino, &ip->i_imap, flags);
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	if (error)
		goto out_destroy;

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	/*
	 * For version 5 superblocks, if we are initialising a new inode and we
	 * are not utilising the XFS_MOUNT_IKEEP inode cluster mode, we can
	 * simply build the new inode core with a random generation number.
	 *
	 * For version 4 (and older) superblocks, log recovery is dependent on
	 * the di_flushiter field being initialised from the current on-disk
	 * value and hence we must also read the inode off disk even when
	 * initializing new inodes.
	 */
	if (xfs_sb_version_has_v3inode(&mp->m_sb) &&
	    (flags & XFS_IGET_CREATE) && !(mp->m_flags & XFS_MOUNT_IKEEP)) {
		VFS_I(ip)->i_generation = prandom_u32();
	} else {
		struct xfs_dinode	*dip;
		struct xfs_buf		*bp;

		error = xfs_imap_to_bp(mp, tp, &ip->i_imap, &dip, &bp, 0);
		if (error)
			goto out_destroy;

		error = xfs_inode_from_disk(ip, dip);
		if (!error)
			xfs_buf_set_ref(bp, XFS_INO_REF);
		xfs_trans_brelse(tp, bp);

		if (error)
			goto out_destroy;
	}

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	trace_xfs_iget_miss(ip);

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	/*
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	 * Check the inode free state is valid. This also detects lookup
	 * racing with unlinks.
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	 */
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	error = xfs_iget_check_free_state(ip, flags);
	if (error)
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		goto out_destroy;

	/*
	 * Preload the radix tree so we can insert safely under the
	 * write spinlock. Note that we cannot sleep inside the preload
	 * region. Since we can be called from transaction context, don't
	 * recurse into the file system.
	 */
	if (radix_tree_preload(GFP_NOFS)) {
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		error = -EAGAIN;
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		goto out_destroy;
	}

	/*
	 * Because the inode hasn't been added to the radix-tree yet it can't
	 * be found by another thread, so we can do the non-sleeping lock here.
	 */
	if (lock_flags) {
		if (!xfs_ilock_nowait(ip, lock_flags))
			BUG();
	}

	/*
	 * These values must be set before inserting the inode into the radix
	 * tree as the moment it is inserted a concurrent lookup (allowed by the
	 * RCU locking mechanism) can find it and that lookup must see that this
	 * is an inode currently under construction (i.e. that XFS_INEW is set).
	 * The ip->i_flags_lock that protects the XFS_INEW flag forms the
	 * memory barrier that ensures this detection works correctly at lookup
	 * time.
	 */
	iflags = XFS_INEW;
	if (flags & XFS_IGET_DONTCACHE)
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		d_mark_dontcache(VFS_I(ip));
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	ip->i_udquot = NULL;
	ip->i_gdquot = NULL;
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	ip->i_pdquot = NULL;
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	xfs_iflags_set(ip, iflags);

	/* insert the new inode */
	spin_lock(&pag->pag_ici_lock);
	error = radix_tree_insert(&pag->pag_ici_root, agino, ip);
	if (unlikely(error)) {
		WARN_ON(error != -EEXIST);
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		XFS_STATS_INC(mp, xs_ig_dup);
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		error = -EAGAIN;
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		goto out_preload_end;
	}
	spin_unlock(&pag->pag_ici_lock);
	radix_tree_preload_end();

	*ipp = ip;
	return 0;

out_preload_end:
	spin_unlock(&pag->pag_ici_lock);
	radix_tree_preload_end();
	if (lock_flags)
		xfs_iunlock(ip, lock_flags);
out_destroy:
	__destroy_inode(VFS_I(ip));
	xfs_inode_free(ip);
	return error;
}

/*
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 * Look up an inode by number in the given file system.  The inode is looked up
 * in the cache held in each AG.  If the inode is found in the cache, initialise
 * the vfs inode if necessary.
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 *
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 * If it is not in core, read it in from the file system's device, add it to the
 * cache and initialise the vfs inode.
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604 605
 *
 * The inode is locked according to the value of the lock_flags parameter.
606 607
 * Inode lookup is only done during metadata operations and not as part of the
 * data IO path. Hence we only allow locking of the XFS_ILOCK during lookup.
D
Dave Chinner 已提交
608 609 610
 */
int
xfs_iget(
611 612 613 614 615 616
	struct xfs_mount	*mp,
	struct xfs_trans	*tp,
	xfs_ino_t		ino,
	uint			flags,
	uint			lock_flags,
	struct xfs_inode	**ipp)
D
Dave Chinner 已提交
617
{
618 619 620 621
	struct xfs_inode	*ip;
	struct xfs_perag	*pag;
	xfs_agino_t		agino;
	int			error;
D
Dave Chinner 已提交
622 623 624 625 626

	ASSERT((lock_flags & (XFS_IOLOCK_EXCL | XFS_IOLOCK_SHARED)) == 0);

	/* reject inode numbers outside existing AGs */
	if (!ino || XFS_INO_TO_AGNO(mp, ino) >= mp->m_sb.sb_agcount)
627
		return -EINVAL;
D
Dave Chinner 已提交
628

629
	XFS_STATS_INC(mp, xs_ig_attempts);
630

D
Dave Chinner 已提交
631 632 633 634 635 636 637 638 639 640 641 642 643 644 645
	/* get the perag structure and ensure that it's inode capable */
	pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ino));
	agino = XFS_INO_TO_AGINO(mp, ino);

again:
	error = 0;
	rcu_read_lock();
	ip = radix_tree_lookup(&pag->pag_ici_root, agino);

	if (ip) {
		error = xfs_iget_cache_hit(pag, ip, ino, flags, lock_flags);
		if (error)
			goto out_error_or_again;
	} else {
		rcu_read_unlock();
646
		if (flags & XFS_IGET_INCORE) {
647
			error = -ENODATA;
648 649
			goto out_error_or_again;
		}
650
		XFS_STATS_INC(mp, xs_ig_missed);
D
Dave Chinner 已提交
651 652 653 654 655 656 657 658 659 660 661

		error = xfs_iget_cache_miss(mp, pag, tp, ino, &ip,
							flags, lock_flags);
		if (error)
			goto out_error_or_again;
	}
	xfs_perag_put(pag);

	*ipp = ip;

	/*
662
	 * If we have a real type for an on-disk inode, we can setup the inode
D
Dave Chinner 已提交
663 664
	 * now.	 If it's a new inode being created, xfs_ialloc will handle it.
	 */
665
	if (xfs_iflags_test(ip, XFS_INEW) && VFS_I(ip)->i_mode != 0)
666
		xfs_setup_existing_inode(ip);
D
Dave Chinner 已提交
667 668 669
	return 0;

out_error_or_again:
670
	if (!(flags & XFS_IGET_INCORE) && error == -EAGAIN) {
D
Dave Chinner 已提交
671 672 673 674 675 676 677
		delay(1);
		goto again;
	}
	xfs_perag_put(pag);
	return error;
}

678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711
/*
 * "Is this a cached inode that's also allocated?"
 *
 * Look up an inode by number in the given file system.  If the inode is
 * in cache and isn't in purgatory, return 1 if the inode is allocated
 * and 0 if it is not.  For all other cases (not in cache, being torn
 * down, etc.), return a negative error code.
 *
 * The caller has to prevent inode allocation and freeing activity,
 * presumably by locking the AGI buffer.   This is to ensure that an
 * inode cannot transition from allocated to freed until the caller is
 * ready to allow that.  If the inode is in an intermediate state (new,
 * reclaimable, or being reclaimed), -EAGAIN will be returned; if the
 * inode is not in the cache, -ENOENT will be returned.  The caller must
 * deal with these scenarios appropriately.
 *
 * This is a specialized use case for the online scrubber; if you're
 * reading this, you probably want xfs_iget.
 */
int
xfs_icache_inode_is_allocated(
	struct xfs_mount	*mp,
	struct xfs_trans	*tp,
	xfs_ino_t		ino,
	bool			*inuse)
{
	struct xfs_inode	*ip;
	int			error;

	error = xfs_iget(mp, tp, ino, XFS_IGET_INCORE, 0, &ip);
	if (error)
		return error;

	*inuse = !!(VFS_I(ip)->i_mode);
712
	xfs_irele(ip);
713 714 715
	return 0;
}

716 717 718 719 720 721 722 723
/*
 * 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

724 725 726 727 728 729
/*
 * Decide if the given @ip is eligible to be a part of the inode walk, and
 * grab it if so.  Returns true if it's ready to go or false if we should just
 * ignore it.
 */
STATIC bool
730
xfs_inode_walk_ag_grab(
731 732
	struct xfs_inode	*ip,
	int			flags)
733 734
{
	struct inode		*inode = VFS_I(ip);
735
	bool			newinos = !!(flags & XFS_INODE_WALK_INEW_WAIT);
736

737 738
	ASSERT(rcu_read_lock_held());

739
	/* Check for stale RCU freed inode */
740 741 742 743 744
	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 */
745 746
	if ((!newinos && __xfs_iflags_test(ip, XFS_INEW)) ||
	    __xfs_iflags_test(ip, XFS_IRECLAIMABLE | XFS_IRECLAIM))
747 748 749
		goto out_unlock_noent;
	spin_unlock(&ip->i_flags_lock);

750 751
	/* nothing to sync during shutdown */
	if (XFS_FORCED_SHUTDOWN(ip->i_mount))
752
		return false;
753 754 755

	/* If we can't grab the inode, it must on it's way to reclaim. */
	if (!igrab(inode))
756
		return false;
757 758

	/* inode is valid */
759
	return true;
760 761 762

out_unlock_noent:
	spin_unlock(&ip->i_flags_lock);
763
	return false;
764 765
}

766 767 768 769
/*
 * For a given per-AG structure @pag, grab, @execute, and rele all incore
 * inodes with the given radix tree @tag.
 */
770
STATIC int
771
xfs_inode_walk_ag(
D
Dave Chinner 已提交
772
	struct xfs_perag	*pag,
773
	int			iter_flags,
774
	int			(*execute)(struct xfs_inode *ip, void *args),
775
	void			*args,
776
	int			tag)
777
{
778
	struct xfs_mount	*mp = pag->pag_mount;
779 780 781
	uint32_t		first_index;
	int			last_error = 0;
	int			skipped;
782
	bool			done;
783
	int			nr_found;
784 785

restart:
786
	done = false;
787 788
	skipped = 0;
	first_index = 0;
789
	nr_found = 0;
790
	do {
791
		struct xfs_inode *batch[XFS_LOOKUP_BATCH];
792
		int		error = 0;
793
		int		i;
794

795
		rcu_read_lock();
796

797
		if (tag == XFS_ICI_NO_TAG)
798
			nr_found = radix_tree_gang_lookup(&pag->pag_ici_root,
799 800
					(void **)batch, first_index,
					XFS_LOOKUP_BATCH);
801 802 803 804 805 806
		else
			nr_found = radix_tree_gang_lookup_tag(
					&pag->pag_ici_root,
					(void **) batch, first_index,
					XFS_LOOKUP_BATCH, tag);

807
		if (!nr_found) {
808
			rcu_read_unlock();
809
			break;
810
		}
811

812
		/*
813 814
		 * Grab the inodes before we drop the lock. if we found
		 * nothing, nr == 0 and the loop will be skipped.
815
		 */
816 817 818
		for (i = 0; i < nr_found; i++) {
			struct xfs_inode *ip = batch[i];

819
			if (done || !xfs_inode_walk_ag_grab(ip, iter_flags))
820 821 822
				batch[i] = NULL;

			/*
823 824 825 826 827 828 829 830 831 832
			 * 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.
833
			 */
834 835
			if (XFS_INO_TO_AGNO(mp, ip->i_ino) != pag->pag_agno)
				continue;
836 837
			first_index = XFS_INO_TO_AGINO(mp, ip->i_ino + 1);
			if (first_index < XFS_INO_TO_AGINO(mp, ip->i_ino))
838
				done = true;
839
		}
840 841

		/* unlock now we've grabbed the inodes. */
842
		rcu_read_unlock();
843

844 845 846
		for (i = 0; i < nr_found; i++) {
			if (!batch[i])
				continue;
847
			if ((iter_flags & XFS_INODE_WALK_INEW_WAIT) &&
848 849
			    xfs_iflags_test(batch[i], XFS_INEW))
				xfs_inew_wait(batch[i]);
850
			error = execute(batch[i], args);
851
			xfs_irele(batch[i]);
852
			if (error == -EAGAIN) {
853 854 855
				skipped++;
				continue;
			}
856
			if (error && last_error != -EFSCORRUPTED)
857
				last_error = error;
858
		}
859 860

		/* bail out if the filesystem is corrupted.  */
861
		if (error == -EFSCORRUPTED)
862 863
			break;

864 865
		cond_resched();

866
	} while (nr_found && !done);
867 868 869 870 871 872 873 874

	if (skipped) {
		delay(1);
		goto restart;
	}
	return last_error;
}

875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891
/* Fetch the next (possibly tagged) per-AG structure. */
static inline struct xfs_perag *
xfs_inode_walk_get_perag(
	struct xfs_mount	*mp,
	xfs_agnumber_t		agno,
	int			tag)
{
	if (tag == XFS_ICI_NO_TAG)
		return xfs_perag_get(mp, agno);
	return xfs_perag_get_tag(mp, agno, tag);
}

/*
 * Call the @execute function on all incore inodes matching the radix tree
 * @tag.
 */
int
892
xfs_inode_walk(
893 894 895 896 897 898 899 900 901 902 903 904 905 906
	struct xfs_mount	*mp,
	int			iter_flags,
	int			(*execute)(struct xfs_inode *ip, void *args),
	void			*args,
	int			tag)
{
	struct xfs_perag	*pag;
	int			error = 0;
	int			last_error = 0;
	xfs_agnumber_t		ag;

	ag = 0;
	while ((pag = xfs_inode_walk_get_perag(mp, ag, tag))) {
		ag = pag->pag_agno + 1;
907
		error = xfs_inode_walk_ag(pag, iter_flags, execute, args, tag);
908 909 910 911 912 913 914 915 916 917
		xfs_perag_put(pag);
		if (error) {
			last_error = error;
			if (error == -EFSCORRUPTED)
				break;
		}
	}
	return last_error;
}

918 919
/*
 * Background scanning to trim post-EOF preallocated space. This is queued
920
 * based on the 'speculative_prealloc_lifetime' tunable (5m by default).
921
 */
922
void
923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939
xfs_queue_eofblocks(
	struct xfs_mount *mp)
{
	rcu_read_lock();
	if (radix_tree_tagged(&mp->m_perag_tree, XFS_ICI_EOFBLOCKS_TAG))
		queue_delayed_work(mp->m_eofblocks_workqueue,
				   &mp->m_eofblocks_work,
				   msecs_to_jiffies(xfs_eofb_secs * 1000));
	rcu_read_unlock();
}

void
xfs_eofblocks_worker(
	struct work_struct *work)
{
	struct xfs_mount *mp = container_of(to_delayed_work(work),
				struct xfs_mount, m_eofblocks_work);
940 941 942

	if (!sb_start_write_trylock(mp->m_super))
		return;
943
	xfs_icache_free_eofblocks(mp, NULL);
944 945
	sb_end_write(mp->m_super);

946 947 948
	xfs_queue_eofblocks(mp);
}

949 950 951 952 953
/*
 * Background scanning to trim preallocated CoW space. This is queued
 * based on the 'speculative_cow_prealloc_lifetime' tunable (5m by default).
 * (We'll just piggyback on the post-EOF prealloc space workqueue.)
 */
954
void
955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971
xfs_queue_cowblocks(
	struct xfs_mount *mp)
{
	rcu_read_lock();
	if (radix_tree_tagged(&mp->m_perag_tree, XFS_ICI_COWBLOCKS_TAG))
		queue_delayed_work(mp->m_eofblocks_workqueue,
				   &mp->m_cowblocks_work,
				   msecs_to_jiffies(xfs_cowb_secs * 1000));
	rcu_read_unlock();
}

void
xfs_cowblocks_worker(
	struct work_struct *work)
{
	struct xfs_mount *mp = container_of(to_delayed_work(work),
				struct xfs_mount, m_cowblocks_work);
972 973 974

	if (!sb_start_write_trylock(mp->m_super))
		return;
975
	xfs_icache_free_cowblocks(mp, NULL);
976 977
	sb_end_write(mp->m_super);

978 979 980
	xfs_queue_cowblocks(mp);
}

981 982
/*
 * Grab the inode for reclaim exclusively.
983 984 985 986 987 988 989 990 991 992 993 994 995 996
 *
 * We have found this inode via a lookup under RCU, so the inode may have
 * already been freed, or it may be in the process of being recycled by
 * xfs_iget(). In both cases, the inode will have XFS_IRECLAIM set. If the inode
 * has been fully recycled by the time we get the i_flags_lock, XFS_IRECLAIMABLE
 * will not be set. Hence we need to check for both these flag conditions to
 * avoid inodes that are no longer reclaim candidates.
 *
 * Note: checking for other state flags here, under the i_flags_lock or not, is
 * racy and should be avoided. Those races should be resolved only after we have
 * ensured that we are able to reclaim this inode and the world can see that we
 * are going to reclaim it.
 *
 * Return true if we grabbed it, false otherwise.
997
 */
998
static bool
999
xfs_reclaim_inode_grab(
1000
	struct xfs_inode	*ip)
1001
{
1002 1003
	ASSERT(rcu_read_lock_held());

1004
	spin_lock(&ip->i_flags_lock);
1005 1006 1007
	if (!__xfs_iflags_test(ip, XFS_IRECLAIMABLE) ||
	    __xfs_iflags_test(ip, XFS_IRECLAIM)) {
		/* not a reclaim candidate. */
1008
		spin_unlock(&ip->i_flags_lock);
1009
		return false;
1010 1011 1012
	}
	__xfs_iflags_set(ip, XFS_IRECLAIM);
	spin_unlock(&ip->i_flags_lock);
1013
	return true;
1014 1015
}

1016
/*
1017 1018 1019 1020 1021
 * Inode reclaim is non-blocking, so the default action if progress cannot be
 * made is to "requeue" the inode for reclaim by unlocking it and clearing the
 * XFS_IRECLAIM flag.  If we are in a shutdown state, we don't care about
 * blocking anymore and hence we can wait for the inode to be able to reclaim
 * it.
1022
 *
1023 1024 1025 1026
 * We do no IO here - if callers require inodes to be cleaned they must push the
 * AIL first to trigger writeback of dirty inodes.  This enables writeback to be
 * done in the background in a non-blocking manner, and enables memory reclaim
 * to make progress without blocking.
1027
 */
1028
static void
1029
xfs_reclaim_inode(
1030
	struct xfs_inode	*ip,
1031
	struct xfs_perag	*pag)
1032
{
1033
	xfs_ino_t		ino = ip->i_ino; /* for radix_tree_delete */
1034

1035
	if (!xfs_ilock_nowait(ip, XFS_ILOCK_EXCL))
1036
		goto out;
1037
	if (xfs_iflags_test_and_set(ip, XFS_IFLUSHING))
1038
		goto out_iunlock;
1039

1040 1041
	if (XFS_FORCED_SHUTDOWN(ip->i_mount)) {
		xfs_iunpin_wait(ip);
1042
		xfs_iflush_abort(ip);
1043 1044
		goto reclaim;
	}
1045
	if (xfs_ipincount(ip))
1046
		goto out_clear_flush;
1047
	if (!xfs_inode_clean(ip))
1048
		goto out_clear_flush;
1049

1050
	xfs_iflags_clear(ip, XFS_IFLUSHING);
1051
reclaim:
1052

1053 1054 1055
	/*
	 * Because we use RCU freeing we need to ensure the inode always appears
	 * to be reclaimed with an invalid inode number when in the free state.
1056
	 * We do this as early as possible under the ILOCK so that
1057 1058 1059 1060 1061
	 * xfs_iflush_cluster() and xfs_ifree_cluster() can be guaranteed to
	 * detect races with us here. By doing this, we guarantee that once
	 * xfs_iflush_cluster() or xfs_ifree_cluster() has locked XFS_ILOCK that
	 * it will see either a valid inode that will serialise correctly, or it
	 * will see an invalid inode that it can skip.
1062 1063 1064 1065 1066 1067
	 */
	spin_lock(&ip->i_flags_lock);
	ip->i_flags = XFS_IRECLAIM;
	ip->i_ino = 0;
	spin_unlock(&ip->i_flags_lock);

1068
	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1069

1070
	XFS_STATS_INC(ip->i_mount, xs_ig_reclaims);
1071 1072 1073 1074 1075 1076 1077
	/*
	 * 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.
	 */
1078
	spin_lock(&pag->pag_ici_lock);
1079
	if (!radix_tree_delete(&pag->pag_ici_root,
1080
				XFS_INO_TO_AGINO(ip->i_mount, ino)))
1081
		ASSERT(0);
1082
	xfs_perag_clear_reclaim_tag(pag);
1083
	spin_unlock(&pag->pag_ici_lock);
1084 1085 1086 1087 1088 1089 1090

	/*
	 * 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
1091
	 * unlocked after the lookup before we go ahead and free it.
1092
	 */
1093
	xfs_ilock(ip, XFS_ILOCK_EXCL);
1094
	xfs_qm_dqdetach(ip);
1095
	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1096
	ASSERT(xfs_inode_clean(ip));
1097

1098
	__xfs_inode_free(ip);
1099
	return;
1100

1101 1102
out_clear_flush:
	xfs_iflags_clear(ip, XFS_IFLUSHING);
1103
out_iunlock:
1104
	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1105
out:
1106
	xfs_iflags_clear(ip, XFS_IRECLAIM);
1107 1108
}

1109 1110 1111 1112 1113
/*
 * 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.
1114 1115 1116 1117
 *
 * Returns non-zero if any AGs or inodes were skipped in the reclaim pass
 * so that callers that want to block until all dirty inodes are written back
 * and reclaimed can sanely loop.
1118
 */
1119
static void
1120 1121 1122 1123 1124
xfs_reclaim_inodes_ag(
	struct xfs_mount	*mp,
	int			*nr_to_scan)
{
	struct xfs_perag	*pag;
1125
	xfs_agnumber_t		ag = 0;
1126 1127 1128 1129

	while ((pag = xfs_perag_get_tag(mp, ag, XFS_ICI_RECLAIM_TAG))) {
		unsigned long	first_index = 0;
		int		done = 0;
1130
		int		nr_found = 0;
1131 1132 1133

		ag = pag->pag_agno + 1;

1134
		first_index = READ_ONCE(pag->pag_ici_reclaim_cursor);
1135
		do {
1136 1137
			struct xfs_inode *batch[XFS_LOOKUP_BATCH];
			int	i;
1138

1139
			rcu_read_lock();
1140 1141 1142 1143
			nr_found = radix_tree_gang_lookup_tag(
					&pag->pag_ici_root,
					(void **)batch, first_index,
					XFS_LOOKUP_BATCH,
1144 1145
					XFS_ICI_RECLAIM_TAG);
			if (!nr_found) {
1146
				done = 1;
1147
				rcu_read_unlock();
1148 1149 1150 1151
				break;
			}

			/*
1152 1153
			 * Grab the inodes before we drop the lock. if we found
			 * nothing, nr == 0 and the loop will be skipped.
1154
			 */
1155 1156 1157
			for (i = 0; i < nr_found; i++) {
				struct xfs_inode *ip = batch[i];

1158
				if (done || !xfs_reclaim_inode_grab(ip))
1159 1160 1161 1162 1163 1164 1165 1166
					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.
1167 1168 1169 1170 1171 1172 1173
				 *
				 * 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.
1174
				 */
1175 1176 1177
				if (XFS_INO_TO_AGNO(mp, ip->i_ino) !=
								pag->pag_agno)
					continue;
1178 1179 1180 1181
				first_index = XFS_INO_TO_AGINO(mp, ip->i_ino + 1);
				if (first_index < XFS_INO_TO_AGINO(mp, ip->i_ino))
					done = 1;
			}
1182

1183
			/* unlock now we've grabbed the inodes. */
1184
			rcu_read_unlock();
1185 1186

			for (i = 0; i < nr_found; i++) {
1187 1188
				if (batch[i])
					xfs_reclaim_inode(batch[i], pag);
1189 1190 1191
			}

			*nr_to_scan -= XFS_LOOKUP_BATCH;
1192
			cond_resched();
1193
		} while (nr_found && !done && *nr_to_scan > 0);
1194

1195 1196 1197
		if (done)
			first_index = 0;
		WRITE_ONCE(pag->pag_ici_reclaim_cursor, first_index);
1198 1199 1200 1201
		xfs_perag_put(pag);
	}
}

1202
void
1203
xfs_reclaim_inodes(
1204
	struct xfs_mount	*mp)
1205
{
1206 1207
	int		nr_to_scan = INT_MAX;

1208
	while (radix_tree_tagged(&mp->m_perag_tree, XFS_ICI_RECLAIM_TAG)) {
1209
		xfs_ail_push_all_sync(mp->m_ail);
1210
		xfs_reclaim_inodes_ag(mp, &nr_to_scan);
1211
	}
1212 1213 1214
}

/*
1215 1216 1217 1218 1219
 * The shrinker infrastructure determines how many inodes we should scan for
 * reclaim. We want as many clean inodes ready to reclaim as possible, so we
 * push the AIL here. We also want to proactively free up memory if we can to
 * minimise the amount of work memory reclaim has to do so we kick the
 * background reclaim if it isn't already scheduled.
1220
 */
1221
long
1222 1223 1224
xfs_reclaim_inodes_nr(
	struct xfs_mount	*mp,
	int			nr_to_scan)
1225
{
1226
	/* kick background reclaimer and push the AIL */
1227
	xfs_reclaim_work_queue(mp);
1228
	xfs_ail_push_all(mp->m_ail);
1229

1230
	xfs_reclaim_inodes_ag(mp, &nr_to_scan);
1231
	return 0;
1232
}
1233

1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244
/*
 * Return the number of reclaimable inodes in the filesystem for
 * the shrinker to determine how much to reclaim.
 */
int
xfs_reclaim_inodes_count(
	struct xfs_mount	*mp)
{
	struct xfs_perag	*pag;
	xfs_agnumber_t		ag = 0;
	int			reclaimable = 0;
1245

1246 1247
	while ((pag = xfs_perag_get_tag(mp, ag, XFS_ICI_RECLAIM_TAG))) {
		ag = pag->pag_agno + 1;
1248 1249
		reclaimable += pag->pag_ici_reclaimable;
		xfs_perag_put(pag);
1250 1251 1252 1253
	}
	return reclaimable;
}

1254
STATIC bool
1255 1256 1257 1258
xfs_inode_match_id(
	struct xfs_inode	*ip,
	struct xfs_eofblocks	*eofb)
{
1259 1260
	if ((eofb->eof_flags & XFS_EOF_FLAGS_UID) &&
	    !uid_eq(VFS_I(ip)->i_uid, eofb->eof_uid))
1261
		return false;
1262

1263 1264
	if ((eofb->eof_flags & XFS_EOF_FLAGS_GID) &&
	    !gid_eq(VFS_I(ip)->i_gid, eofb->eof_gid))
1265
		return false;
1266

1267
	if ((eofb->eof_flags & XFS_EOF_FLAGS_PRID) &&
1268
	    ip->i_d.di_projid != eofb->eof_prid)
1269
		return false;
1270

1271
	return true;
1272 1273
}

1274 1275 1276 1277
/*
 * A union-based inode filtering algorithm. Process the inode if any of the
 * criteria match. This is for global/internal scans only.
 */
1278
STATIC bool
1279 1280 1281 1282 1283 1284
xfs_inode_match_id_union(
	struct xfs_inode	*ip,
	struct xfs_eofblocks	*eofb)
{
	if ((eofb->eof_flags & XFS_EOF_FLAGS_UID) &&
	    uid_eq(VFS_I(ip)->i_uid, eofb->eof_uid))
1285
		return true;
1286 1287 1288

	if ((eofb->eof_flags & XFS_EOF_FLAGS_GID) &&
	    gid_eq(VFS_I(ip)->i_gid, eofb->eof_gid))
1289
		return true;
1290 1291

	if ((eofb->eof_flags & XFS_EOF_FLAGS_PRID) &&
1292
	    ip->i_d.di_projid == eofb->eof_prid)
1293
		return true;
1294

1295
	return false;
1296 1297
}

1298 1299 1300 1301 1302 1303 1304 1305 1306 1307
/*
 * Is this inode @ip eligible for eof/cow block reclamation, given some
 * filtering parameters @eofb?  The inode is eligible if @eofb is null or
 * if the predicate functions match.
 */
static bool
xfs_inode_matches_eofb(
	struct xfs_inode	*ip,
	struct xfs_eofblocks	*eofb)
{
1308
	bool			match;
1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327

	if (!eofb)
		return true;

	if (eofb->eof_flags & XFS_EOF_FLAGS_UNION)
		match = xfs_inode_match_id_union(ip, eofb);
	else
		match = xfs_inode_match_id(ip, eofb);
	if (!match)
		return false;

	/* skip the inode if the file size is too small */
	if ((eofb->eof_flags & XFS_EOF_FLAGS_MINFILESIZE) &&
	    XFS_ISIZE(ip) < eofb->eof_min_file_size)
		return false;

	return true;
}

1328 1329 1330 1331
/*
 * 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
1332
 * goes low.
1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345
 */
void
xfs_reclaim_worker(
	struct work_struct *work)
{
	struct xfs_mount *mp = container_of(to_delayed_work(work),
					struct xfs_mount, m_reclaim_work);
	int		nr_to_scan = INT_MAX;

	xfs_reclaim_inodes_ag(mp, &nr_to_scan);
	xfs_reclaim_work_queue(mp);
}

1346 1347 1348 1349 1350
STATIC int
xfs_inode_free_eofblocks(
	struct xfs_inode	*ip,
	void			*args)
{
1351 1352 1353 1354 1355
	struct xfs_eofblocks	*eofb = args;
	bool			wait;
	int			ret;

	wait = eofb && (eofb->eof_flags & XFS_EOF_FLAGS_SYNC);
1356

1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367
	if (!xfs_can_free_eofblocks(ip, false)) {
		/* inode could be preallocated or append-only */
		trace_xfs_inode_free_eofblocks_invalid(ip);
		xfs_inode_clear_eofblocks_tag(ip);
		return 0;
	}

	/*
	 * If the mapping is dirty the operation can block and wait for some
	 * time. Unless we are waiting, skip it.
	 */
1368
	if (!wait && mapping_tagged(VFS_I(ip)->i_mapping, PAGECACHE_TAG_DIRTY))
1369 1370
		return 0;

1371 1372
	if (!xfs_inode_matches_eofb(ip, eofb))
		return 0;
1373

1374 1375 1376 1377
	/*
	 * If the caller is waiting, return -EAGAIN to keep the background
	 * scanner moving and revisit the inode in a subsequent pass.
	 */
1378
	if (!xfs_ilock_nowait(ip, XFS_IOLOCK_EXCL)) {
1379 1380 1381
		if (wait)
			return -EAGAIN;
		return 0;
1382
	}
1383

1384
	ret = xfs_free_eofblocks(ip);
1385
	xfs_iunlock(ip, XFS_IOLOCK_EXCL);
1386 1387 1388 1389

	return ret;
}

1390 1391 1392 1393 1394
int
xfs_icache_free_eofblocks(
	struct xfs_mount	*mp,
	struct xfs_eofblocks	*eofb)
{
1395
	return xfs_inode_walk(mp, 0, xfs_inode_free_eofblocks, eofb,
1396
			XFS_ICI_EOFBLOCKS_TAG);
1397 1398
}

1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413
static inline unsigned long
xfs_iflag_for_tag(
	int		tag)
{
	switch (tag) {
	case XFS_ICI_EOFBLOCKS_TAG:
		return XFS_IEOFBLOCKS;
	case XFS_ICI_COWBLOCKS_TAG:
		return XFS_ICOWBLOCKS;
	default:
		ASSERT(0);
		return 0;
	}
}

1414
static void
1415
__xfs_inode_set_blocks_tag(
1416 1417 1418 1419 1420
	xfs_inode_t	*ip,
	void		(*execute)(struct xfs_mount *mp),
	void		(*set_tp)(struct xfs_mount *mp, xfs_agnumber_t agno,
				  int error, unsigned long caller_ip),
	int		tag)
1421 1422 1423 1424 1425
{
	struct xfs_mount *mp = ip->i_mount;
	struct xfs_perag *pag;
	int tagged;

1426 1427 1428 1429
	/*
	 * Don't bother locking the AG and looking up in the radix trees
	 * if we already know that we have the tag set.
	 */
1430
	if (ip->i_flags & xfs_iflag_for_tag(tag))
1431 1432
		return;
	spin_lock(&ip->i_flags_lock);
1433
	ip->i_flags |= xfs_iflag_for_tag(tag);
1434 1435
	spin_unlock(&ip->i_flags_lock);

1436 1437 1438
	pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
	spin_lock(&pag->pag_ici_lock);

1439
	tagged = radix_tree_tagged(&pag->pag_ici_root, tag);
1440
	radix_tree_tag_set(&pag->pag_ici_root,
1441
			   XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino), tag);
1442 1443 1444 1445 1446
	if (!tagged) {
		/* propagate the eofblocks 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),
1447
				   tag);
1448
		spin_unlock(&ip->i_mount->m_perag_lock);
1449 1450

		/* kick off background trimming */
1451
		execute(ip->i_mount);
1452

1453
		set_tp(ip->i_mount, pag->pag_agno, -1, _RET_IP_);
1454 1455 1456 1457 1458 1459 1460
	}

	spin_unlock(&pag->pag_ici_lock);
	xfs_perag_put(pag);
}

void
1461
xfs_inode_set_eofblocks_tag(
1462
	xfs_inode_t	*ip)
1463 1464
{
	trace_xfs_inode_set_eofblocks_tag(ip);
1465
	return __xfs_inode_set_blocks_tag(ip, xfs_queue_eofblocks,
1466 1467 1468 1469 1470
			trace_xfs_perag_set_eofblocks,
			XFS_ICI_EOFBLOCKS_TAG);
}

static void
1471
__xfs_inode_clear_blocks_tag(
1472 1473 1474 1475
	xfs_inode_t	*ip,
	void		(*clear_tp)(struct xfs_mount *mp, xfs_agnumber_t agno,
				    int error, unsigned long caller_ip),
	int		tag)
1476 1477 1478 1479
{
	struct xfs_mount *mp = ip->i_mount;
	struct xfs_perag *pag;

1480
	spin_lock(&ip->i_flags_lock);
1481
	ip->i_flags &= ~xfs_iflag_for_tag(tag);
1482 1483
	spin_unlock(&ip->i_flags_lock);

1484 1485 1486 1487
	pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
	spin_lock(&pag->pag_ici_lock);

	radix_tree_tag_clear(&pag->pag_ici_root,
1488 1489
			     XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino), tag);
	if (!radix_tree_tagged(&pag->pag_ici_root, tag)) {
1490 1491 1492 1493
		/* clear the eofblocks 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),
1494
				     tag);
1495
		spin_unlock(&ip->i_mount->m_perag_lock);
1496
		clear_tp(ip->i_mount, pag->pag_agno, -1, _RET_IP_);
1497 1498 1499 1500 1501 1502
	}

	spin_unlock(&pag->pag_ici_lock);
	xfs_perag_put(pag);
}

1503 1504 1505 1506 1507
void
xfs_inode_clear_eofblocks_tag(
	xfs_inode_t	*ip)
{
	trace_xfs_inode_clear_eofblocks_tag(ip);
1508
	return __xfs_inode_clear_blocks_tag(ip,
1509 1510 1511 1512
			trace_xfs_perag_clear_eofblocks, XFS_ICI_EOFBLOCKS_TAG);
}

/*
1513 1514 1515
 * Set ourselves up to free CoW blocks from this file.  If it's already clean
 * then we can bail out quickly, but otherwise we must back off if the file
 * is undergoing some kind of write.
1516
 */
1517 1518
static bool
xfs_prep_free_cowblocks(
1519
	struct xfs_inode	*ip)
1520
{
1521 1522 1523 1524
	/*
	 * Just clear the tag if we have an empty cow fork or none at all. It's
	 * possible the inode was fully unshared since it was originally tagged.
	 */
1525
	if (!xfs_inode_has_cow_data(ip)) {
1526 1527
		trace_xfs_inode_free_cowblocks_invalid(ip);
		xfs_inode_clear_cowblocks_tag(ip);
1528
		return false;
1529 1530 1531 1532 1533 1534
	}

	/*
	 * If the mapping is dirty or under writeback we cannot touch the
	 * CoW fork.  Leave it alone if we're in the midst of a directio.
	 */
1535 1536
	if ((VFS_I(ip)->i_state & I_DIRTY_PAGES) ||
	    mapping_tagged(VFS_I(ip)->i_mapping, PAGECACHE_TAG_DIRTY) ||
1537 1538
	    mapping_tagged(VFS_I(ip)->i_mapping, PAGECACHE_TAG_WRITEBACK) ||
	    atomic_read(&VFS_I(ip)->i_dio_count))
1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561
		return false;

	return true;
}

/*
 * Automatic CoW Reservation Freeing
 *
 * These functions automatically garbage collect leftover CoW reservations
 * that were made on behalf of a cowextsize hint when we start to run out
 * of quota or when the reservations sit around for too long.  If the file
 * has dirty pages or is undergoing writeback, its CoW reservations will
 * be retained.
 *
 * The actual garbage collection piggybacks off the same code that runs
 * the speculative EOF preallocation garbage collector.
 */
STATIC int
xfs_inode_free_cowblocks(
	struct xfs_inode	*ip,
	void			*args)
{
	struct xfs_eofblocks	*eofb = args;
1562
	bool			wait;
1563 1564
	int			ret = 0;

1565 1566
	wait = eofb && (eofb->eof_flags & XFS_EOF_FLAGS_SYNC);

1567
	if (!xfs_prep_free_cowblocks(ip))
1568 1569
		return 0;

1570 1571
	if (!xfs_inode_matches_eofb(ip, eofb))
		return 0;
1572

1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586
	/*
	 * If the caller is waiting, return -EAGAIN to keep the background
	 * scanner moving and revisit the inode in a subsequent pass.
	 */
	if (!xfs_ilock_nowait(ip, XFS_IOLOCK_EXCL)) {
		if (wait)
			return -EAGAIN;
		return 0;
	}
	if (!xfs_ilock_nowait(ip, XFS_MMAPLOCK_EXCL)) {
		if (wait)
			ret = -EAGAIN;
		goto out_iolock;
	}
1587

1588 1589 1590 1591
	/*
	 * Check again, nobody else should be able to dirty blocks or change
	 * the reflink iflag now that we have the first two locks held.
	 */
1592
	if (xfs_prep_free_cowblocks(ip))
1593
		ret = xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF, false);
1594

1595
	xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
1596
out_iolock:
1597
	xfs_iunlock(ip, XFS_IOLOCK_EXCL);
1598 1599 1600 1601 1602 1603 1604 1605 1606

	return ret;
}

int
xfs_icache_free_cowblocks(
	struct xfs_mount	*mp,
	struct xfs_eofblocks	*eofb)
{
1607
	return xfs_inode_walk(mp, 0, xfs_inode_free_cowblocks, eofb,
1608 1609 1610 1611 1612 1613 1614
			XFS_ICI_COWBLOCKS_TAG);
}

void
xfs_inode_set_cowblocks_tag(
	xfs_inode_t	*ip)
{
1615
	trace_xfs_inode_set_cowblocks_tag(ip);
1616
	return __xfs_inode_set_blocks_tag(ip, xfs_queue_cowblocks,
1617
			trace_xfs_perag_set_cowblocks,
1618 1619 1620 1621 1622 1623 1624
			XFS_ICI_COWBLOCKS_TAG);
}

void
xfs_inode_clear_cowblocks_tag(
	xfs_inode_t	*ip)
{
1625
	trace_xfs_inode_clear_cowblocks_tag(ip);
1626
	return __xfs_inode_clear_blocks_tag(ip,
1627
			trace_xfs_perag_clear_cowblocks, XFS_ICI_COWBLOCKS_TAG);
1628
}
1629 1630 1631

/* Disable post-EOF and CoW block auto-reclamation. */
void
1632
xfs_stop_block_reaping(
1633 1634 1635 1636 1637 1638 1639 1640
	struct xfs_mount	*mp)
{
	cancel_delayed_work_sync(&mp->m_eofblocks_work);
	cancel_delayed_work_sync(&mp->m_cowblocks_work);
}

/* Enable post-EOF and CoW block auto-reclamation. */
void
1641
xfs_start_block_reaping(
1642 1643 1644 1645 1646
	struct xfs_mount	*mp)
{
	xfs_queue_eofblocks(mp);
	xfs_queue_cowblocks(mp);
}
1647 1648 1649 1650 1651 1652

/*
 * Run cow/eofblocks scans on the quotas applicable to the inode. For inodes
 * with multiple quotas, we don't know exactly which quota caused an allocation
 * failure. We make a best effort by including each quota under low free space
 * conditions (less than 1% free space) in the scan.
1653 1654 1655 1656
 *
 * Callers must not hold any inode's ILOCK.  If requesting a synchronous scan
 * (XFS_EOF_FLAGS_SYNC), the caller also must not hold any inode's IOLOCK or
 * MMAPLOCK.
1657
 */
1658
int
1659
xfs_blockgc_free_quota(
1660 1661
	struct xfs_inode	*ip,
	unsigned int		eof_flags)
1662 1663 1664 1665
{
	struct xfs_eofblocks	eofb = {0};
	struct xfs_dquot	*dq;
	bool			do_work = false;
1666
	int			error;
1667 1668

	/*
1669 1670
	 * Run a scan to free blocks using the union filter to cover all
	 * applicable quotas in a single scan.
1671
	 */
1672
	eofb.eof_flags = XFS_EOF_FLAGS_UNION | eof_flags;
1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701

	if (XFS_IS_UQUOTA_ENFORCED(ip->i_mount)) {
		dq = xfs_inode_dquot(ip, XFS_DQTYPE_USER);
		if (dq && xfs_dquot_lowsp(dq)) {
			eofb.eof_uid = VFS_I(ip)->i_uid;
			eofb.eof_flags |= XFS_EOF_FLAGS_UID;
			do_work = true;
		}
	}

	if (XFS_IS_GQUOTA_ENFORCED(ip->i_mount)) {
		dq = xfs_inode_dquot(ip, XFS_DQTYPE_GROUP);
		if (dq && xfs_dquot_lowsp(dq)) {
			eofb.eof_gid = VFS_I(ip)->i_gid;
			eofb.eof_flags |= XFS_EOF_FLAGS_GID;
			do_work = true;
		}
	}

	if (XFS_IS_PQUOTA_ENFORCED(ip->i_mount)) {
		dq = xfs_inode_dquot(ip, XFS_DQTYPE_PROJ);
		if (dq && xfs_dquot_lowsp(dq)) {
			eofb.eof_prid = ip->i_d.di_projid;
			eofb.eof_flags |= XFS_EOF_FLAGS_PRID;
			do_work = true;
		}
	}

	if (!do_work)
1702
		return 0;
1703

1704 1705 1706 1707 1708
	error = xfs_icache_free_eofblocks(ip->i_mount, &eofb);
	if (error)
		return error;

	return xfs_icache_free_cowblocks(ip->i_mount, &eofb);
1709
}
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