// SPDX-License-Identifier: GPL-2.0 /* * Copyright (c) 2000-2005 Silicon Graphics, Inc. * All Rights Reserved. */ #include "xfs.h" #include "xfs_fs.h" #include "xfs_shared.h" #include "xfs_format.h" #include "xfs_log_format.h" #include "xfs_trans_resv.h" #include "xfs_mount.h" #include "xfs_inode.h" #include "xfs_trans.h" #include "xfs_trans_priv.h" #include "xfs_inode_item.h" #include "xfs_quota.h" #include "xfs_trace.h" #include "xfs_icache.h" #include "xfs_bmap_util.h" #include "xfs_dquot_item.h" #include "xfs_dquot.h" #include "xfs_reflink.h" #include "xfs_ialloc.h" #include "xfs_ag.h" #include "xfs_log_priv.h" #include <linux/iversion.h> /* Radix tree tags for incore inode tree. */ /* inode is to be reclaimed */ #define XFS_ICI_RECLAIM_TAG 0 /* Inode has speculative preallocations (posteof or cow) to clean. */ #define XFS_ICI_BLOCKGC_TAG 1 /* * The goal for walking incore inodes. These can correspond with incore inode * radix tree tags when convenient. Avoid existing XFS_IWALK namespace. */ enum xfs_icwalk_goal { /* Goals directly associated with tagged inodes. */ XFS_ICWALK_BLOCKGC = XFS_ICI_BLOCKGC_TAG, XFS_ICWALK_RECLAIM = XFS_ICI_RECLAIM_TAG, }; static int xfs_icwalk(struct xfs_mount *mp, enum xfs_icwalk_goal goal, struct xfs_icwalk *icw); static int xfs_icwalk_ag(struct xfs_perag *pag, enum xfs_icwalk_goal goal, struct xfs_icwalk *icw); /* * Private inode cache walk flags for struct xfs_icwalk. Must not * coincide with XFS_ICWALK_FLAGS_VALID. */ /* Stop scanning after icw_scan_limit inodes. */ #define XFS_ICWALK_FLAG_SCAN_LIMIT (1U << 28) #define XFS_ICWALK_FLAG_RECLAIM_SICK (1U << 27) #define XFS_ICWALK_FLAG_UNION (1U << 26) /* union filter algorithm */ #define XFS_ICWALK_PRIVATE_FLAGS (XFS_ICWALK_FLAG_SCAN_LIMIT | \ XFS_ICWALK_FLAG_RECLAIM_SICK | \ XFS_ICWALK_FLAG_UNION) /* * Allocate and initialise an xfs_inode. */ struct xfs_inode * xfs_inode_alloc( struct xfs_mount *mp, xfs_ino_t ino) { struct xfs_inode *ip; /* * XXX: If this didn't occur in transactions, we could drop GFP_NOFAIL * and return NULL here on ENOMEM. */ ip = alloc_inode_sb(mp->m_super, xfs_inode_cache, GFP_KERNEL | __GFP_NOFAIL); if (inode_init_always(mp->m_super, VFS_I(ip))) { kmem_cache_free(xfs_inode_cache, ip); return NULL; } /* VFS doesn't initialise i_mode or i_state! */ VFS_I(ip)->i_mode = 0; VFS_I(ip)->i_state = 0; mapping_set_large_folios(VFS_I(ip)->i_mapping); XFS_STATS_INC(mp, vn_active); 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_cowfp = NULL; memset(&ip->i_af, 0, sizeof(ip->i_af)); ip->i_af.if_format = XFS_DINODE_FMT_EXTENTS; memset(&ip->i_df, 0, sizeof(ip->i_df)); ip->i_flags = 0; ip->i_delayed_blks = 0; ip->i_diflags2 = mp->m_ino_geo.new_diflags2; ip->i_nblocks = 0; ip->i_forkoff = 0; ip->i_sick = 0; ip->i_checked = 0; INIT_WORK(&ip->i_ioend_work, xfs_end_io); INIT_LIST_HEAD(&ip->i_ioend_list); spin_lock_init(&ip->i_ioend_lock); ip->i_next_unlinked = NULLAGINO; ip->i_prev_unlinked = NULLAGINO; 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); switch (VFS_I(ip)->i_mode & S_IFMT) { case S_IFREG: case S_IFDIR: case S_IFLNK: xfs_idestroy_fork(&ip->i_df); break; } xfs_ifork_zap_attr(ip); if (ip->i_cowfp) { xfs_idestroy_fork(ip->i_cowfp); kmem_cache_free(xfs_ifork_cache, ip->i_cowfp); } if (ip->i_itemp) { ASSERT(!test_bit(XFS_LI_IN_AIL, &ip->i_itemp->ili_item.li_flags)); xfs_inode_item_destroy(ip); ip->i_itemp = NULL; } kmem_cache_free(xfs_inode_cache, ip); } static void __xfs_inode_free( struct xfs_inode *ip) { /* asserts to verify all state is correct here */ ASSERT(atomic_read(&ip->i_pincount) == 0); ASSERT(!ip->i_itemp || list_empty(&ip->i_itemp->ili_item.li_bio_list)); XFS_STATS_DEC(ip->i_mount, vn_active); call_rcu(&VFS_I(ip)->i_rcu, xfs_inode_free_callback); } void xfs_inode_free( struct xfs_inode *ip) { ASSERT(!xfs_iflags_test(ip, XFS_IFLUSHING)); /* * 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); __xfs_inode_free(ip); } /* * Queue background inode reclaim work if there are reclaimable inodes and there * isn't reclaim work already scheduled or in progress. */ 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(); } /* * Background scanning to trim preallocated space. This is queued based on the * 'speculative_prealloc_lifetime' tunable (5m by default). */ static inline void xfs_blockgc_queue( struct xfs_perag *pag) { struct xfs_mount *mp = pag->pag_mount; if (!xfs_is_blockgc_enabled(mp)) return; rcu_read_lock(); if (radix_tree_tagged(&pag->pag_ici_root, XFS_ICI_BLOCKGC_TAG)) queue_delayed_work(pag->pag_mount->m_blockgc_wq, &pag->pag_blockgc_work, msecs_to_jiffies(xfs_blockgc_secs * 1000)); rcu_read_unlock(); } /* Set a tag on both the AG incore inode tree and the AG radix tree. */ static void xfs_perag_set_inode_tag( struct xfs_perag *pag, xfs_agino_t agino, unsigned int tag) { struct xfs_mount *mp = pag->pag_mount; bool was_tagged; lockdep_assert_held(&pag->pag_ici_lock); was_tagged = radix_tree_tagged(&pag->pag_ici_root, tag); radix_tree_tag_set(&pag->pag_ici_root, agino, tag); if (tag == XFS_ICI_RECLAIM_TAG) pag->pag_ici_reclaimable++; if (was_tagged) return; /* propagate the tag up into the perag radix tree */ spin_lock(&mp->m_perag_lock); radix_tree_tag_set(&mp->m_perag_tree, pag->pag_agno, tag); spin_unlock(&mp->m_perag_lock); /* start background work */ switch (tag) { case XFS_ICI_RECLAIM_TAG: xfs_reclaim_work_queue(mp); break; case XFS_ICI_BLOCKGC_TAG: xfs_blockgc_queue(pag); break; } trace_xfs_perag_set_inode_tag(mp, pag->pag_agno, tag, _RET_IP_); } /* Clear a tag on both the AG incore inode tree and the AG radix tree. */ static void xfs_perag_clear_inode_tag( struct xfs_perag *pag, xfs_agino_t agino, unsigned int tag) { struct xfs_mount *mp = pag->pag_mount; lockdep_assert_held(&pag->pag_ici_lock); /* * Reclaim can signal (with a null agino) that it cleared its own tag * by removing the inode from the radix tree. */ if (agino != NULLAGINO) radix_tree_tag_clear(&pag->pag_ici_root, agino, tag); else ASSERT(tag == XFS_ICI_RECLAIM_TAG); if (tag == XFS_ICI_RECLAIM_TAG) pag->pag_ici_reclaimable--; if (radix_tree_tagged(&pag->pag_ici_root, tag)) return; /* clear the tag from the perag radix tree */ spin_lock(&mp->m_perag_lock); radix_tree_tag_clear(&mp->m_perag_tree, pag->pag_agno, tag); spin_unlock(&mp->m_perag_lock); trace_xfs_perag_clear_inode_tag(mp, pag->pag_agno, tag, _RET_IP_); } /* * 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 * overwrite the values unconditionally. Hence we save the parameters we * need to retain across reinitialisation, and rewrite them into the VFS inode * after reinitialisation even if it fails. */ static int xfs_reinit_inode( struct xfs_mount *mp, struct inode *inode) { int error; uint32_t nlink = inode->i_nlink; uint32_t generation = inode->i_generation; uint64_t version = inode_peek_iversion(inode); umode_t mode = inode->i_mode; dev_t dev = inode->i_rdev; kuid_t uid = inode->i_uid; kgid_t gid = inode->i_gid; error = inode_init_always(mp->m_super, inode); set_nlink(inode, nlink); inode->i_generation = generation; inode_set_iversion_queried(inode, version); inode->i_mode = mode; inode->i_rdev = dev; inode->i_uid = uid; inode->i_gid = gid; mapping_set_large_folios(inode->i_mapping); return error; } /* * Carefully nudge an inode whose VFS state has been torn down back into a * usable state. Drops the i_flags_lock and the rcu read lock. */ static int xfs_iget_recycle( struct xfs_perag *pag, struct xfs_inode *ip) __releases(&ip->i_flags_lock) { struct xfs_mount *mp = ip->i_mount; struct inode *inode = VFS_I(ip); int error; trace_xfs_iget_recycle(ip); /* * We need to make it look like the inode is being reclaimed to prevent * the actual reclaim workers from stomping over us while we recycle * the inode. We can't clear the radix tree 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(); ASSERT(!rwsem_is_locked(&inode->i_rwsem)); error = xfs_reinit_inode(mp, inode); if (error) { /* * 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); ip->i_flags &= ~(XFS_INEW | XFS_IRECLAIM); ASSERT(ip->i_flags & XFS_IRECLAIMABLE); spin_unlock(&ip->i_flags_lock); rcu_read_unlock(); trace_xfs_iget_recycle_fail(ip); return 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; xfs_perag_clear_inode_tag(pag, XFS_INO_TO_AGINO(mp, ip->i_ino), XFS_ICI_RECLAIM_TAG); inode->i_state = I_NEW; spin_unlock(&ip->i_flags_lock); spin_unlock(&pag->pag_ici_lock); return 0; } /* * 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_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; } /* Make all pending inactivation work start immediately. */ static void xfs_inodegc_queue_all( struct xfs_mount *mp) { struct xfs_inodegc *gc; int cpu; for_each_online_cpu(cpu) { gc = per_cpu_ptr(mp->m_inodegc, cpu); if (!llist_empty(&gc->list)) mod_delayed_work_on(cpu, mp->m_inodegc_wq, &gc->work, 0); } } /* * 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) goto out_skip; /* * If we are racing with another cache hit that is currently * instantiating this inode or currently recycling it out of * reclaimable state, wait for the initialisation to complete * before continuing. * * If we're racing with the inactivation worker we also want to wait. * If we're creating a new file, it's possible that the worker * previously marked the inode as free on disk but hasn't finished * updating the incore state yet. The AGI buffer will be dirty and * locked to the icreate transaction, so a synchronous push of the * inodegc workers would result in deadlock. For a regular iget, the * worker is running already, so we might as well wait. * * 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 | XFS_INACTIVATING)) goto out_skip; if (ip->i_flags & XFS_NEED_INACTIVE) { /* Unlinked inodes cannot be re-grabbed. */ if (VFS_I(ip)->i_nlink == 0) { error = -ENOENT; goto out_error; } goto out_inodegc_flush; } /* * Check the inode free state is valid. This also detects lookup * racing with unlinks. */ error = xfs_iget_check_free_state(ip, flags); if (error) goto out_error; /* Skip inodes that have no vfs state. */ if ((flags & XFS_IGET_INCORE) && (ip->i_flags & XFS_IRECLAIMABLE)) goto out_skip; /* The inode fits the selection criteria; process it. */ if (ip->i_flags & XFS_IRECLAIMABLE) { /* Drops i_flags_lock and RCU read lock. */ error = xfs_iget_recycle(pag, ip); if (error) return error; } else { /* If the VFS inode is being torn down, pause and try again. */ if (!igrab(inode)) goto out_skip; /* 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); if (!(flags & XFS_IGET_INCORE)) xfs_iflags_clear(ip, XFS_ISTALE); XFS_STATS_INC(mp, xs_ig_found); return 0; out_skip: trace_xfs_iget_skip(ip); XFS_STATS_INC(mp, xs_ig_frecycle); error = -EAGAIN; out_error: spin_unlock(&ip->i_flags_lock); rcu_read_unlock(); return error; out_inodegc_flush: spin_unlock(&ip->i_flags_lock); rcu_read_unlock(); /* * Do not wait for the workers, because the caller could hold an AGI * buffer lock. We're just going to sleep in a loop anyway. */ if (xfs_is_inodegc_enabled(mp)) xfs_inodegc_queue_all(mp); return -EAGAIN; } 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) return -ENOMEM; error = xfs_imap(mp, tp, ip->i_ino, &ip->i_imap, flags); if (error) goto out_destroy; /* * For version 5 superblocks, if we are initialising a new inode and we * are not utilising the XFS_FEAT_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 i_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_has_v3inodes(mp) && (flags & XFS_IGET_CREATE) && !xfs_has_ikeep(mp)) { VFS_I(ip)->i_generation = get_random_u32(); } else { struct xfs_buf *bp; error = xfs_imap_to_bp(mp, tp, &ip->i_imap, &bp); if (error) goto out_destroy; error = xfs_inode_from_disk(ip, xfs_buf_offset(bp, ip->i_imap.im_boffset)); if (!error) xfs_buf_set_ref(bp, XFS_INO_REF); xfs_trans_brelse(tp, bp); if (error) goto out_destroy; } trace_xfs_iget_miss(ip); /* * Check the inode free state is valid. This also detects lookup * racing with unlinks. */ error = xfs_iget_check_free_state(ip, flags); if (error) 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)) { error = -EAGAIN; 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) d_mark_dontcache(VFS_I(ip)); ip->i_udquot = NULL; ip->i_gdquot = NULL; ip->i_pdquot = NULL; 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); XFS_STATS_INC(mp, xs_ig_dup); error = -EAGAIN; 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; } /* * 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. * * 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. * * The inode is locked according to the value of the lock_flags parameter. * 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. */ int xfs_iget( struct xfs_mount *mp, struct xfs_trans *tp, xfs_ino_t ino, uint flags, uint lock_flags, struct xfs_inode **ipp) { struct xfs_inode *ip; struct xfs_perag *pag; xfs_agino_t agino; int error; 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) return -EINVAL; XFS_STATS_INC(mp, xs_ig_attempts); /* 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(); if (flags & XFS_IGET_INCORE) { error = -ENODATA; goto out_error_or_again; } XFS_STATS_INC(mp, xs_ig_missed); 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; /* * If we have a real type for an on-disk inode, we can setup the inode * now. If it's a new inode being created, xfs_init_new_inode will * handle it. */ if (xfs_iflags_test(ip, XFS_INEW) && VFS_I(ip)->i_mode != 0) xfs_setup_existing_inode(ip); return 0; out_error_or_again: if (!(flags & XFS_IGET_INCORE) && error == -EAGAIN) { delay(1); goto again; } xfs_perag_put(pag); return error; } /* * "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); xfs_irele(ip); return 0; } /* * Grab the inode for reclaim exclusively. * * 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. */ static bool xfs_reclaim_igrab( struct xfs_inode *ip, struct xfs_icwalk *icw) { ASSERT(rcu_read_lock_held()); spin_lock(&ip->i_flags_lock); if (!__xfs_iflags_test(ip, XFS_IRECLAIMABLE) || __xfs_iflags_test(ip, XFS_IRECLAIM)) { /* not a reclaim candidate. */ spin_unlock(&ip->i_flags_lock); return false; } /* Don't reclaim a sick inode unless the caller asked for it. */ if (ip->i_sick && (!icw || !(icw->icw_flags & XFS_ICWALK_FLAG_RECLAIM_SICK))) { spin_unlock(&ip->i_flags_lock); return false; } __xfs_iflags_set(ip, XFS_IRECLAIM); spin_unlock(&ip->i_flags_lock); return true; } /* * 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. * * 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. */ static void xfs_reclaim_inode( struct xfs_inode *ip, struct xfs_perag *pag) { xfs_ino_t ino = ip->i_ino; /* for radix_tree_delete */ if (!xfs_ilock_nowait(ip, XFS_ILOCK_EXCL)) goto out; if (xfs_iflags_test_and_set(ip, XFS_IFLUSHING)) goto out_iunlock; /* * Check for log shutdown because aborting the inode can move the log * tail and corrupt in memory state. This is fine if the log is shut * down, but if the log is still active and only the mount is shut down * then the in-memory log tail movement caused by the abort can be * incorrectly propagated to disk. */ if (xlog_is_shutdown(ip->i_mount->m_log)) { xfs_iunpin_wait(ip); xfs_iflush_shutdown_abort(ip); goto reclaim; } if (xfs_ipincount(ip)) goto out_clear_flush; if (!xfs_inode_clean(ip)) goto out_clear_flush; xfs_iflags_clear(ip, XFS_IFLUSHING); reclaim: trace_xfs_inode_reclaiming(ip); /* * 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. * We do this as early as possible under the ILOCK so that * 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. */ spin_lock(&ip->i_flags_lock); ip->i_flags = XFS_IRECLAIM; ip->i_ino = 0; ip->i_sick = 0; ip->i_checked = 0; spin_unlock(&ip->i_flags_lock); ASSERT(!ip->i_itemp || ip->i_itemp->ili_item.li_buf == NULL); xfs_iunlock(ip, XFS_ILOCK_EXCL); XFS_STATS_INC(ip->i_mount, 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, ino))) ASSERT(0); xfs_perag_clear_inode_tag(pag, NULLAGINO, XFS_ICI_RECLAIM_TAG); 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. */ xfs_ilock(ip, XFS_ILOCK_EXCL); ASSERT(!ip->i_udquot && !ip->i_gdquot && !ip->i_pdquot); xfs_iunlock(ip, XFS_ILOCK_EXCL); ASSERT(xfs_inode_clean(ip)); __xfs_inode_free(ip); return; out_clear_flush: xfs_iflags_clear(ip, XFS_IFLUSHING); out_iunlock: xfs_iunlock(ip, XFS_ILOCK_EXCL); out: xfs_iflags_clear(ip, XFS_IRECLAIM); } /* Reclaim sick inodes if we're unmounting or the fs went down. */ static inline bool xfs_want_reclaim_sick( struct xfs_mount *mp) { return xfs_is_unmounting(mp) || xfs_has_norecovery(mp) || xfs_is_shutdown(mp); } void xfs_reclaim_inodes( struct xfs_mount *mp) { struct xfs_icwalk icw = { .icw_flags = 0, }; if (xfs_want_reclaim_sick(mp)) icw.icw_flags |= XFS_ICWALK_FLAG_RECLAIM_SICK; while (radix_tree_tagged(&mp->m_perag_tree, XFS_ICI_RECLAIM_TAG)) { xfs_ail_push_all_sync(mp->m_ail); xfs_icwalk(mp, XFS_ICWALK_RECLAIM, &icw); } } /* * 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. */ long xfs_reclaim_inodes_nr( struct xfs_mount *mp, unsigned long nr_to_scan) { struct xfs_icwalk icw = { .icw_flags = XFS_ICWALK_FLAG_SCAN_LIMIT, .icw_scan_limit = min_t(unsigned long, LONG_MAX, nr_to_scan), }; if (xfs_want_reclaim_sick(mp)) icw.icw_flags |= XFS_ICWALK_FLAG_RECLAIM_SICK; /* kick background reclaimer and push the AIL */ xfs_reclaim_work_queue(mp); xfs_ail_push_all(mp->m_ail); xfs_icwalk(mp, XFS_ICWALK_RECLAIM, &icw); return 0; } /* * Return the number of reclaimable inodes in the filesystem for * the shrinker to determine how much to reclaim. */ long xfs_reclaim_inodes_count( struct xfs_mount *mp) { struct xfs_perag *pag; xfs_agnumber_t ag = 0; long reclaimable = 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; } STATIC bool xfs_icwalk_match_id( struct xfs_inode *ip, struct xfs_icwalk *icw) { if ((icw->icw_flags & XFS_ICWALK_FLAG_UID) && !uid_eq(VFS_I(ip)->i_uid, icw->icw_uid)) return false; if ((icw->icw_flags & XFS_ICWALK_FLAG_GID) && !gid_eq(VFS_I(ip)->i_gid, icw->icw_gid)) return false; if ((icw->icw_flags & XFS_ICWALK_FLAG_PRID) && ip->i_projid != icw->icw_prid) return false; return true; } /* * A union-based inode filtering algorithm. Process the inode if any of the * criteria match. This is for global/internal scans only. */ STATIC bool xfs_icwalk_match_id_union( struct xfs_inode *ip, struct xfs_icwalk *icw) { if ((icw->icw_flags & XFS_ICWALK_FLAG_UID) && uid_eq(VFS_I(ip)->i_uid, icw->icw_uid)) return true; if ((icw->icw_flags & XFS_ICWALK_FLAG_GID) && gid_eq(VFS_I(ip)->i_gid, icw->icw_gid)) return true; if ((icw->icw_flags & XFS_ICWALK_FLAG_PRID) && ip->i_projid == icw->icw_prid) return true; return false; } /* * Is this inode @ip eligible for eof/cow block reclamation, given some * filtering parameters @icw? The inode is eligible if @icw is null or * if the predicate functions match. */ static bool xfs_icwalk_match( struct xfs_inode *ip, struct xfs_icwalk *icw) { bool match; if (!icw) return true; if (icw->icw_flags & XFS_ICWALK_FLAG_UNION) match = xfs_icwalk_match_id_union(ip, icw); else match = xfs_icwalk_match_id(ip, icw); if (!match) return false; /* skip the inode if the file size is too small */ if ((icw->icw_flags & XFS_ICWALK_FLAG_MINFILESIZE) && XFS_ISIZE(ip) < icw->icw_min_file_size) return false; return true; } /* * 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. */ void xfs_reclaim_worker( struct work_struct *work) { struct xfs_mount *mp = container_of(to_delayed_work(work), struct xfs_mount, m_reclaim_work); xfs_icwalk(mp, XFS_ICWALK_RECLAIM, NULL); xfs_reclaim_work_queue(mp); } STATIC int xfs_inode_free_eofblocks( struct xfs_inode *ip, struct xfs_icwalk *icw, unsigned int *lockflags) { bool wait; wait = icw && (icw->icw_flags & XFS_ICWALK_FLAG_SYNC); if (!xfs_iflags_test(ip, XFS_IEOFBLOCKS)) return 0; /* * If the mapping is dirty the operation can block and wait for some * time. Unless we are waiting, skip it. */ if (!wait && mapping_tagged(VFS_I(ip)->i_mapping, PAGECACHE_TAG_DIRTY)) return 0; if (!xfs_icwalk_match(ip, icw)) return 0; /* * 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; } *lockflags |= XFS_IOLOCK_EXCL; if (xfs_can_free_eofblocks(ip, false)) return xfs_free_eofblocks(ip); /* inode could be preallocated or append-only */ trace_xfs_inode_free_eofblocks_invalid(ip); xfs_inode_clear_eofblocks_tag(ip); return 0; } static void xfs_blockgc_set_iflag( struct xfs_inode *ip, unsigned long iflag) { struct xfs_mount *mp = ip->i_mount; struct xfs_perag *pag; ASSERT((iflag & ~(XFS_IEOFBLOCKS | XFS_ICOWBLOCKS)) == 0); /* * Don't bother locking the AG and looking up in the radix trees * if we already know that we have the tag set. */ if (ip->i_flags & iflag) return; spin_lock(&ip->i_flags_lock); ip->i_flags |= iflag; spin_unlock(&ip->i_flags_lock); pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino)); spin_lock(&pag->pag_ici_lock); xfs_perag_set_inode_tag(pag, XFS_INO_TO_AGINO(mp, ip->i_ino), XFS_ICI_BLOCKGC_TAG); spin_unlock(&pag->pag_ici_lock); xfs_perag_put(pag); } void xfs_inode_set_eofblocks_tag( xfs_inode_t *ip) { trace_xfs_inode_set_eofblocks_tag(ip); return xfs_blockgc_set_iflag(ip, XFS_IEOFBLOCKS); } static void xfs_blockgc_clear_iflag( struct xfs_inode *ip, unsigned long iflag) { struct xfs_mount *mp = ip->i_mount; struct xfs_perag *pag; bool clear_tag; ASSERT((iflag & ~(XFS_IEOFBLOCKS | XFS_ICOWBLOCKS)) == 0); spin_lock(&ip->i_flags_lock); ip->i_flags &= ~iflag; clear_tag = (ip->i_flags & (XFS_IEOFBLOCKS | XFS_ICOWBLOCKS)) == 0; spin_unlock(&ip->i_flags_lock); if (!clear_tag) return; pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino)); spin_lock(&pag->pag_ici_lock); xfs_perag_clear_inode_tag(pag, XFS_INO_TO_AGINO(mp, ip->i_ino), XFS_ICI_BLOCKGC_TAG); spin_unlock(&pag->pag_ici_lock); xfs_perag_put(pag); } void xfs_inode_clear_eofblocks_tag( xfs_inode_t *ip) { trace_xfs_inode_clear_eofblocks_tag(ip); return xfs_blockgc_clear_iflag(ip, XFS_IEOFBLOCKS); } /* * 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. */ static bool xfs_prep_free_cowblocks( struct xfs_inode *ip) { /* * 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. */ if (!xfs_inode_has_cow_data(ip)) { trace_xfs_inode_free_cowblocks_invalid(ip); xfs_inode_clear_cowblocks_tag(ip); return false; } /* * 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. */ if ((VFS_I(ip)->i_state & I_DIRTY_PAGES) || mapping_tagged(VFS_I(ip)->i_mapping, PAGECACHE_TAG_DIRTY) || mapping_tagged(VFS_I(ip)->i_mapping, PAGECACHE_TAG_WRITEBACK) || atomic_read(&VFS_I(ip)->i_dio_count)) 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, struct xfs_icwalk *icw, unsigned int *lockflags) { bool wait; int ret = 0; wait = icw && (icw->icw_flags & XFS_ICWALK_FLAG_SYNC); if (!xfs_iflags_test(ip, XFS_ICOWBLOCKS)) return 0; if (!xfs_prep_free_cowblocks(ip)) return 0; if (!xfs_icwalk_match(ip, icw)) return 0; /* * If the caller is waiting, return -EAGAIN to keep the background * scanner moving and revisit the inode in a subsequent pass. */ if (!(*lockflags & XFS_IOLOCK_EXCL) && !xfs_ilock_nowait(ip, XFS_IOLOCK_EXCL)) { if (wait) return -EAGAIN; return 0; } *lockflags |= XFS_IOLOCK_EXCL; if (!xfs_ilock_nowait(ip, XFS_MMAPLOCK_EXCL)) { if (wait) return -EAGAIN; return 0; } *lockflags |= XFS_MMAPLOCK_EXCL; /* * Check again, nobody else should be able to dirty blocks or change * the reflink iflag now that we have the first two locks held. */ if (xfs_prep_free_cowblocks(ip)) ret = xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF, false); return ret; } void xfs_inode_set_cowblocks_tag( xfs_inode_t *ip) { trace_xfs_inode_set_cowblocks_tag(ip); return xfs_blockgc_set_iflag(ip, XFS_ICOWBLOCKS); } void xfs_inode_clear_cowblocks_tag( xfs_inode_t *ip) { trace_xfs_inode_clear_cowblocks_tag(ip); return xfs_blockgc_clear_iflag(ip, XFS_ICOWBLOCKS); } /* Disable post-EOF and CoW block auto-reclamation. */ void xfs_blockgc_stop( struct xfs_mount *mp) { struct xfs_perag *pag; xfs_agnumber_t agno; if (!xfs_clear_blockgc_enabled(mp)) return; for_each_perag(mp, agno, pag) cancel_delayed_work_sync(&pag->pag_blockgc_work); trace_xfs_blockgc_stop(mp, __return_address); } /* Enable post-EOF and CoW block auto-reclamation. */ void xfs_blockgc_start( struct xfs_mount *mp) { struct xfs_perag *pag; xfs_agnumber_t agno; if (xfs_set_blockgc_enabled(mp)) return; trace_xfs_blockgc_start(mp, __return_address); for_each_perag_tag(mp, agno, pag, XFS_ICI_BLOCKGC_TAG) xfs_blockgc_queue(pag); } /* Don't try to run block gc on an inode that's in any of these states. */ #define XFS_BLOCKGC_NOGRAB_IFLAGS (XFS_INEW | \ XFS_NEED_INACTIVE | \ XFS_INACTIVATING | \ XFS_IRECLAIMABLE | \ XFS_IRECLAIM) /* * Decide if the given @ip is eligible for garbage collection of speculative * preallocations, and grab it if so. Returns true if it's ready to go or * false if we should just ignore it. */ static bool xfs_blockgc_igrab( struct xfs_inode *ip) { struct inode *inode = VFS_I(ip); ASSERT(rcu_read_lock_held()); /* Check for stale RCU freed inode */ spin_lock(&ip->i_flags_lock); if (!ip->i_ino) goto out_unlock_noent; if (ip->i_flags & XFS_BLOCKGC_NOGRAB_IFLAGS) goto out_unlock_noent; spin_unlock(&ip->i_flags_lock); /* nothing to sync during shutdown */ if (xfs_is_shutdown(ip->i_mount)) return false; /* If we can't grab the inode, it must on it's way to reclaim. */ if (!igrab(inode)) return false; /* inode is valid */ return true; out_unlock_noent: spin_unlock(&ip->i_flags_lock); return false; } /* Scan one incore inode for block preallocations that we can remove. */ static int xfs_blockgc_scan_inode( struct xfs_inode *ip, struct xfs_icwalk *icw) { unsigned int lockflags = 0; int error; error = xfs_inode_free_eofblocks(ip, icw, &lockflags); if (error) goto unlock; error = xfs_inode_free_cowblocks(ip, icw, &lockflags); unlock: if (lockflags) xfs_iunlock(ip, lockflags); xfs_irele(ip); return error; } /* Background worker that trims preallocated space. */ void xfs_blockgc_worker( struct work_struct *work) { struct xfs_perag *pag = container_of(to_delayed_work(work), struct xfs_perag, pag_blockgc_work); struct xfs_mount *mp = pag->pag_mount; int error; trace_xfs_blockgc_worker(mp, __return_address); error = xfs_icwalk_ag(pag, XFS_ICWALK_BLOCKGC, NULL); if (error) xfs_info(mp, "AG %u preallocation gc worker failed, err=%d", pag->pag_agno, error); xfs_blockgc_queue(pag); } /* * Try to free space in the filesystem by purging inactive inodes, eofblocks * and cowblocks. */ int xfs_blockgc_free_space( struct xfs_mount *mp, struct xfs_icwalk *icw) { int error; trace_xfs_blockgc_free_space(mp, icw, _RET_IP_); error = xfs_icwalk(mp, XFS_ICWALK_BLOCKGC, icw); if (error) return error; xfs_inodegc_flush(mp); return 0; } /* * Reclaim all the free space that we can by scheduling the background blockgc * and inodegc workers immediately and waiting for them all to clear. */ void xfs_blockgc_flush_all( struct xfs_mount *mp) { struct xfs_perag *pag; xfs_agnumber_t agno; trace_xfs_blockgc_flush_all(mp, __return_address); /* * For each blockgc worker, move its queue time up to now. If it * wasn't queued, it will not be requeued. Then flush whatever's * left. */ for_each_perag_tag(mp, agno, pag, XFS_ICI_BLOCKGC_TAG) mod_delayed_work(pag->pag_mount->m_blockgc_wq, &pag->pag_blockgc_work, 0); for_each_perag_tag(mp, agno, pag, XFS_ICI_BLOCKGC_TAG) flush_delayed_work(&pag->pag_blockgc_work); xfs_inodegc_flush(mp); } /* * Run cow/eofblocks scans on the supplied dquots. We don't know exactly which * quota caused an allocation failure, so we make a best effort by including * each quota under low free space conditions (less than 1% free space) in the * scan. * * Callers must not hold any inode's ILOCK. If requesting a synchronous scan * (XFS_ICWALK_FLAG_SYNC), the caller also must not hold any inode's IOLOCK or * MMAPLOCK. */ int xfs_blockgc_free_dquots( struct xfs_mount *mp, struct xfs_dquot *udqp, struct xfs_dquot *gdqp, struct xfs_dquot *pdqp, unsigned int iwalk_flags) { struct xfs_icwalk icw = {0}; bool do_work = false; if (!udqp && !gdqp && !pdqp) return 0; /* * Run a scan to free blocks using the union filter to cover all * applicable quotas in a single scan. */ icw.icw_flags = XFS_ICWALK_FLAG_UNION | iwalk_flags; if (XFS_IS_UQUOTA_ENFORCED(mp) && udqp && xfs_dquot_lowsp(udqp)) { icw.icw_uid = make_kuid(mp->m_super->s_user_ns, udqp->q_id); icw.icw_flags |= XFS_ICWALK_FLAG_UID; do_work = true; } if (XFS_IS_UQUOTA_ENFORCED(mp) && gdqp && xfs_dquot_lowsp(gdqp)) { icw.icw_gid = make_kgid(mp->m_super->s_user_ns, gdqp->q_id); icw.icw_flags |= XFS_ICWALK_FLAG_GID; do_work = true; } if (XFS_IS_PQUOTA_ENFORCED(mp) && pdqp && xfs_dquot_lowsp(pdqp)) { icw.icw_prid = pdqp->q_id; icw.icw_flags |= XFS_ICWALK_FLAG_PRID; do_work = true; } if (!do_work) return 0; return xfs_blockgc_free_space(mp, &icw); } /* Run cow/eofblocks scans on the quotas attached to the inode. */ int xfs_blockgc_free_quota( struct xfs_inode *ip, unsigned int iwalk_flags) { return xfs_blockgc_free_dquots(ip->i_mount, xfs_inode_dquot(ip, XFS_DQTYPE_USER), xfs_inode_dquot(ip, XFS_DQTYPE_GROUP), xfs_inode_dquot(ip, XFS_DQTYPE_PROJ), iwalk_flags); } /* XFS Inode Cache Walking Code */ /* * 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 /* * Decide if we want to grab this inode in anticipation of doing work towards * the goal. */ static inline bool xfs_icwalk_igrab( enum xfs_icwalk_goal goal, struct xfs_inode *ip, struct xfs_icwalk *icw) { switch (goal) { case XFS_ICWALK_BLOCKGC: return xfs_blockgc_igrab(ip); case XFS_ICWALK_RECLAIM: return xfs_reclaim_igrab(ip, icw); default: return false; } } /* * Process an inode. Each processing function must handle any state changes * made by the icwalk igrab function. Return -EAGAIN to skip an inode. */ static inline int xfs_icwalk_process_inode( enum xfs_icwalk_goal goal, struct xfs_inode *ip, struct xfs_perag *pag, struct xfs_icwalk *icw) { int error = 0; switch (goal) { case XFS_ICWALK_BLOCKGC: error = xfs_blockgc_scan_inode(ip, icw); break; case XFS_ICWALK_RECLAIM: xfs_reclaim_inode(ip, pag); break; } return error; } /* * For a given per-AG structure @pag and a goal, grab qualifying inodes and * process them in some manner. */ static int xfs_icwalk_ag( struct xfs_perag *pag, enum xfs_icwalk_goal goal, struct xfs_icwalk *icw) { struct xfs_mount *mp = pag->pag_mount; uint32_t first_index; int last_error = 0; int skipped; bool done; int nr_found; restart: done = false; skipped = 0; if (goal == XFS_ICWALK_RECLAIM) first_index = READ_ONCE(pag->pag_ici_reclaim_cursor); else first_index = 0; nr_found = 0; do { struct xfs_inode *batch[XFS_LOOKUP_BATCH]; int error = 0; int i; rcu_read_lock(); nr_found = radix_tree_gang_lookup_tag(&pag->pag_ici_root, (void **) batch, first_index, XFS_LOOKUP_BATCH, goal); if (!nr_found) { done = true; 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_icwalk_igrab(goal, ip, icw)) 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 = true; } /* unlock now we've grabbed the inodes. */ rcu_read_unlock(); for (i = 0; i < nr_found; i++) { if (!batch[i]) continue; error = xfs_icwalk_process_inode(goal, batch[i], pag, icw); if (error == -EAGAIN) { skipped++; continue; } if (error && last_error != -EFSCORRUPTED) last_error = error; } /* bail out if the filesystem is corrupted. */ if (error == -EFSCORRUPTED) break; cond_resched(); if (icw && (icw->icw_flags & XFS_ICWALK_FLAG_SCAN_LIMIT)) { icw->icw_scan_limit -= XFS_LOOKUP_BATCH; if (icw->icw_scan_limit <= 0) break; } } while (nr_found && !done); if (goal == XFS_ICWALK_RECLAIM) { if (done) first_index = 0; WRITE_ONCE(pag->pag_ici_reclaim_cursor, first_index); } if (skipped) { delay(1); goto restart; } return last_error; } /* Walk all incore inodes to achieve a given goal. */ static int xfs_icwalk( struct xfs_mount *mp, enum xfs_icwalk_goal goal, struct xfs_icwalk *icw) { struct xfs_perag *pag; int error = 0; int last_error = 0; xfs_agnumber_t agno; for_each_perag_tag(mp, agno, pag, goal) { error = xfs_icwalk_ag(pag, goal, icw); if (error) { last_error = error; if (error == -EFSCORRUPTED) { xfs_perag_put(pag); break; } } } return last_error; BUILD_BUG_ON(XFS_ICWALK_PRIVATE_FLAGS & XFS_ICWALK_FLAGS_VALID); } #ifdef DEBUG static void xfs_check_delalloc( struct xfs_inode *ip, int whichfork) { struct xfs_ifork *ifp = xfs_ifork_ptr(ip, whichfork); struct xfs_bmbt_irec got; struct xfs_iext_cursor icur; if (!ifp || !xfs_iext_lookup_extent(ip, ifp, 0, &icur, &got)) return; do { if (isnullstartblock(got.br_startblock)) { xfs_warn(ip->i_mount, "ino %llx %s fork has delalloc extent at [0x%llx:0x%llx]", ip->i_ino, whichfork == XFS_DATA_FORK ? "data" : "cow", got.br_startoff, got.br_blockcount); } } while (xfs_iext_next_extent(ifp, &icur, &got)); } #else #define xfs_check_delalloc(ip, whichfork) do { } while (0) #endif /* Schedule the inode for reclaim. */ static void xfs_inodegc_set_reclaimable( struct xfs_inode *ip) { struct xfs_mount *mp = ip->i_mount; struct xfs_perag *pag; if (!xfs_is_shutdown(mp) && ip->i_delayed_blks) { xfs_check_delalloc(ip, XFS_DATA_FORK); xfs_check_delalloc(ip, XFS_COW_FORK); ASSERT(0); } 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); trace_xfs_inode_set_reclaimable(ip); ip->i_flags &= ~(XFS_NEED_INACTIVE | XFS_INACTIVATING); ip->i_flags |= XFS_IRECLAIMABLE; xfs_perag_set_inode_tag(pag, XFS_INO_TO_AGINO(mp, ip->i_ino), XFS_ICI_RECLAIM_TAG); spin_unlock(&ip->i_flags_lock); spin_unlock(&pag->pag_ici_lock); xfs_perag_put(pag); } /* * Free all speculative preallocations and possibly even the inode itself. * This is the last chance to make changes to an otherwise unreferenced file * before incore reclamation happens. */ static void xfs_inodegc_inactivate( struct xfs_inode *ip) { trace_xfs_inode_inactivating(ip); xfs_inactive(ip); xfs_inodegc_set_reclaimable(ip); } void xfs_inodegc_worker( struct work_struct *work) { struct xfs_inodegc *gc = container_of(to_delayed_work(work), struct xfs_inodegc, work); struct llist_node *node = llist_del_all(&gc->list); struct xfs_inode *ip, *n; WRITE_ONCE(gc->items, 0); if (!node) return; ip = llist_entry(node, struct xfs_inode, i_gclist); trace_xfs_inodegc_worker(ip->i_mount, READ_ONCE(gc->shrinker_hits)); WRITE_ONCE(gc->shrinker_hits, 0); llist_for_each_entry_safe(ip, n, node, i_gclist) { xfs_iflags_set(ip, XFS_INACTIVATING); xfs_inodegc_inactivate(ip); } } /* * Expedite all pending inodegc work to run immediately. This does not wait for * completion of the work. */ void xfs_inodegc_push( struct xfs_mount *mp) { if (!xfs_is_inodegc_enabled(mp)) return; trace_xfs_inodegc_push(mp, __return_address); xfs_inodegc_queue_all(mp); } /* * Force all currently queued inode inactivation work to run immediately and * wait for the work to finish. */ void xfs_inodegc_flush( struct xfs_mount *mp) { xfs_inodegc_push(mp); trace_xfs_inodegc_flush(mp, __return_address); flush_workqueue(mp->m_inodegc_wq); } /* * Flush all the pending work and then disable the inode inactivation background * workers and wait for them to stop. */ void xfs_inodegc_stop( struct xfs_mount *mp) { if (!xfs_clear_inodegc_enabled(mp)) return; xfs_inodegc_queue_all(mp); drain_workqueue(mp->m_inodegc_wq); trace_xfs_inodegc_stop(mp, __return_address); } /* * Enable the inode inactivation background workers and schedule deferred inode * inactivation work if there is any. */ void xfs_inodegc_start( struct xfs_mount *mp) { if (xfs_set_inodegc_enabled(mp)) return; trace_xfs_inodegc_start(mp, __return_address); xfs_inodegc_queue_all(mp); } #ifdef CONFIG_XFS_RT static inline bool xfs_inodegc_want_queue_rt_file( struct xfs_inode *ip) { struct xfs_mount *mp = ip->i_mount; if (!XFS_IS_REALTIME_INODE(ip)) return false; if (__percpu_counter_compare(&mp->m_frextents, mp->m_low_rtexts[XFS_LOWSP_5_PCNT], XFS_FDBLOCKS_BATCH) < 0) return true; return false; } #else # define xfs_inodegc_want_queue_rt_file(ip) (false) #endif /* CONFIG_XFS_RT */ /* * Schedule the inactivation worker when: * * - We've accumulated more than one inode cluster buffer's worth of inodes. * - There is less than 5% free space left. * - Any of the quotas for this inode are near an enforcement limit. */ static inline bool xfs_inodegc_want_queue_work( struct xfs_inode *ip, unsigned int items) { struct xfs_mount *mp = ip->i_mount; if (items > mp->m_ino_geo.inodes_per_cluster) return true; if (__percpu_counter_compare(&mp->m_fdblocks, mp->m_low_space[XFS_LOWSP_5_PCNT], XFS_FDBLOCKS_BATCH) < 0) return true; if (xfs_inodegc_want_queue_rt_file(ip)) return true; if (xfs_inode_near_dquot_enforcement(ip, XFS_DQTYPE_USER)) return true; if (xfs_inode_near_dquot_enforcement(ip, XFS_DQTYPE_GROUP)) return true; if (xfs_inode_near_dquot_enforcement(ip, XFS_DQTYPE_PROJ)) return true; return false; } /* * Upper bound on the number of inodes in each AG that can be queued for * inactivation at any given time, to avoid monopolizing the workqueue. */ #define XFS_INODEGC_MAX_BACKLOG (4 * XFS_INODES_PER_CHUNK) /* * Make the frontend wait for inactivations when: * * - Memory shrinkers queued the inactivation worker and it hasn't finished. * - The queue depth exceeds the maximum allowable percpu backlog. * * Note: If the current thread is running a transaction, we don't ever want to * wait for other transactions because that could introduce a deadlock. */ static inline bool xfs_inodegc_want_flush_work( struct xfs_inode *ip, unsigned int items, unsigned int shrinker_hits) { if (current->journal_info) return false; if (shrinker_hits > 0) return true; if (items > XFS_INODEGC_MAX_BACKLOG) return true; return false; } /* * Queue a background inactivation worker if there are inodes that need to be * inactivated and higher level xfs code hasn't disabled the background * workers. */ static void xfs_inodegc_queue( struct xfs_inode *ip) { struct xfs_mount *mp = ip->i_mount; struct xfs_inodegc *gc; int items; unsigned int shrinker_hits; unsigned long queue_delay = 1; trace_xfs_inode_set_need_inactive(ip); spin_lock(&ip->i_flags_lock); ip->i_flags |= XFS_NEED_INACTIVE; spin_unlock(&ip->i_flags_lock); gc = get_cpu_ptr(mp->m_inodegc); llist_add(&ip->i_gclist, &gc->list); items = READ_ONCE(gc->items); WRITE_ONCE(gc->items, items + 1); shrinker_hits = READ_ONCE(gc->shrinker_hits); /* * We queue the work while holding the current CPU so that the work * is scheduled to run on this CPU. */ if (!xfs_is_inodegc_enabled(mp)) { put_cpu_ptr(gc); return; } if (xfs_inodegc_want_queue_work(ip, items)) queue_delay = 0; trace_xfs_inodegc_queue(mp, __return_address); mod_delayed_work(mp->m_inodegc_wq, &gc->work, queue_delay); put_cpu_ptr(gc); if (xfs_inodegc_want_flush_work(ip, items, shrinker_hits)) { trace_xfs_inodegc_throttle(mp, __return_address); flush_delayed_work(&gc->work); } } /* * Fold the dead CPU inodegc queue into the current CPUs queue. */ void xfs_inodegc_cpu_dead( struct xfs_mount *mp, unsigned int dead_cpu) { struct xfs_inodegc *dead_gc, *gc; struct llist_node *first, *last; unsigned int count = 0; dead_gc = per_cpu_ptr(mp->m_inodegc, dead_cpu); cancel_delayed_work_sync(&dead_gc->work); if (llist_empty(&dead_gc->list)) return; first = dead_gc->list.first; last = first; while (last->next) { last = last->next; count++; } dead_gc->list.first = NULL; dead_gc->items = 0; /* Add pending work to current CPU */ gc = get_cpu_ptr(mp->m_inodegc); llist_add_batch(first, last, &gc->list); count += READ_ONCE(gc->items); WRITE_ONCE(gc->items, count); if (xfs_is_inodegc_enabled(mp)) { trace_xfs_inodegc_queue(mp, __return_address); mod_delayed_work(mp->m_inodegc_wq, &gc->work, 0); } put_cpu_ptr(gc); } /* * 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. * * We always use background reclaim here because even if the inode is clean, it * still may be under IO and hence we have wait for IO completion to occur * before we can reclaim the inode. The background reclaim path handles this * more efficiently than we can here, so simply let background reclaim tear down * all inodes. */ void xfs_inode_mark_reclaimable( struct xfs_inode *ip) { struct xfs_mount *mp = ip->i_mount; bool need_inactive; XFS_STATS_INC(mp, vn_reclaim); /* * We should never get here with any of the reclaim flags already set. */ ASSERT_ALWAYS(!xfs_iflags_test(ip, XFS_ALL_IRECLAIM_FLAGS)); need_inactive = xfs_inode_needs_inactive(ip); if (need_inactive) { xfs_inodegc_queue(ip); return; } /* Going straight to reclaim, so drop the dquots. */ xfs_qm_dqdetach(ip); xfs_inodegc_set_reclaimable(ip); } /* * Register a phony shrinker so that we can run background inodegc sooner when * there's memory pressure. Inactivation does not itself free any memory but * it does make inodes reclaimable, which eventually frees memory. * * The count function, seek value, and batch value are crafted to trigger the * scan function during the second round of scanning. Hopefully this means * that we reclaimed enough memory that initiating metadata transactions won't * make things worse. */ #define XFS_INODEGC_SHRINKER_COUNT (1UL << DEF_PRIORITY) #define XFS_INODEGC_SHRINKER_BATCH ((XFS_INODEGC_SHRINKER_COUNT / 2) + 1) static unsigned long xfs_inodegc_shrinker_count( struct shrinker *shrink, struct shrink_control *sc) { struct xfs_mount *mp = container_of(shrink, struct xfs_mount, m_inodegc_shrinker); struct xfs_inodegc *gc; int cpu; if (!xfs_is_inodegc_enabled(mp)) return 0; for_each_online_cpu(cpu) { gc = per_cpu_ptr(mp->m_inodegc, cpu); if (!llist_empty(&gc->list)) return XFS_INODEGC_SHRINKER_COUNT; } return 0; } static unsigned long xfs_inodegc_shrinker_scan( struct shrinker *shrink, struct shrink_control *sc) { struct xfs_mount *mp = container_of(shrink, struct xfs_mount, m_inodegc_shrinker); struct xfs_inodegc *gc; int cpu; bool no_items = true; if (!xfs_is_inodegc_enabled(mp)) return SHRINK_STOP; trace_xfs_inodegc_shrinker_scan(mp, sc, __return_address); for_each_online_cpu(cpu) { gc = per_cpu_ptr(mp->m_inodegc, cpu); if (!llist_empty(&gc->list)) { unsigned int h = READ_ONCE(gc->shrinker_hits); WRITE_ONCE(gc->shrinker_hits, h + 1); mod_delayed_work_on(cpu, mp->m_inodegc_wq, &gc->work, 0); no_items = false; } } /* * If there are no inodes to inactivate, we don't want the shrinker * to think there's deferred work to call us back about. */ if (no_items) return LONG_MAX; return SHRINK_STOP; } /* Register a shrinker so we can accelerate inodegc and throttle queuing. */ int xfs_inodegc_register_shrinker( struct xfs_mount *mp) { struct shrinker *shrink = &mp->m_inodegc_shrinker; shrink->count_objects = xfs_inodegc_shrinker_count; shrink->scan_objects = xfs_inodegc_shrinker_scan; shrink->seeks = 0; shrink->flags = SHRINKER_NONSLAB; shrink->batch = XFS_INODEGC_SHRINKER_BATCH; return register_shrinker(shrink, "xfs-inodegc:%s", mp->m_super->s_id); }