diff options
Diffstat (limited to 'fs/xfs/xfs_icache.c')
| -rw-r--r-- | fs/xfs/xfs_icache.c | 2251 |
1 files changed, 2251 insertions, 0 deletions
diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c new file mode 100644 index 000000000..d884cba1d --- /dev/null +++ b/fs/xfs/xfs_icache.c @@ -0,0 +1,2251 @@ +// 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 bool +xfs_inodegc_queue_all( + struct xfs_mount *mp) +{ + struct xfs_inodegc *gc; + int cpu; + bool ret = false; + + 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); + ret = true; + } + } + + return ret; +} + +/* + * 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; + + ASSERT(gc->cpu == smp_processor_id()); + + 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. Caller must hold sb->s_umount to + * coordinate changes in the inodegc_enabled state. + */ +void +xfs_inodegc_stop( + struct xfs_mount *mp) +{ + bool rerun; + + if (!xfs_clear_inodegc_enabled(mp)) + return; + + /* + * Drain all pending inodegc work, including inodes that could be + * queued by racing xfs_inodegc_queue or xfs_inodegc_shrinker_scan + * threads that sample the inodegc state just prior to us clearing it. + * The inodegc flag state prevents new threads from queuing more + * inodes, so we queue pending work items and flush the workqueue until + * all inodegc lists are empty. IOWs, we cannot use drain_workqueue + * here because it does not allow other unserialized mechanisms to + * reschedule inodegc work while this draining is in progress. + */ + xfs_inodegc_queue_all(mp); + do { + flush_workqueue(mp->m_inodegc_wq); + rerun = xfs_inodegc_queue_all(mp); + } while (rerun); + + trace_xfs_inodegc_stop(mp, __return_address); +} + +/* + * Enable the inode inactivation background workers and schedule deferred inode + * inactivation work if there is any. Caller must hold sb->s_umount to + * coordinate changes in the inodegc_enabled state. + */ +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_on(current_cpu(), 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_on(current_cpu(), 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); +} |