/* * Inodes in different states need to be treated differently. The following * table lists the inode states and the reclaim actions necessary: * * inode state iflush ret required action * --------------- ---------- --------------- * bad - reclaim * shutdown EIO unpin and reclaim * clean, unpinned 0 reclaim * stale, unpinned 0 reclaim * clean, pinned(*) 0 requeue * stale, pinned EAGAIN requeue * dirty, async - requeue * dirty, sync 0 reclaim * * (*) dgc: I don't think the clean, pinned state is possible but it gets * handled anyway given the order of checks implemented. * * Also, because we get the flush lock first, we know that any inode that has * been flushed delwri has had the flush completed by the time we check that * the inode is clean. * * Note that because the inode is flushed delayed write by AIL pushing, the * flush lock may already be held here and waiting on it can result in very * long latencies. Hence for sync reclaims, where we wait on the flush lock, * the caller should push the AIL first before trying to reclaim inodes to * minimise the amount of time spent waiting. For background relaim, we only * bother to reclaim clean inodes anyway. * * Hence the order of actions after gaining the locks should be: * bad => reclaim * shutdown => unpin and reclaim * pinned, async => requeue * pinned, sync => unpin * stale => reclaim * clean => reclaim * dirty, async => requeue * dirty, sync => flush, wait and reclaim */ STATIC int xfs_reclaim_inode( struct xfs_inode *ip, struct xfs_perag *pag, int sync_mode) { struct xfs_buf *bp = NULL; int error; restart: error = 0; xfs_ilock(ip, XFS_ILOCK_EXCL); if (!xfs_iflock_nowait(ip)) { if (!(sync_mode & SYNC_WAIT)) goto out; xfs_iflock(ip); } if (is_bad_inode(VFS_I(ip))) goto reclaim; if (XFS_FORCED_SHUTDOWN(ip->i_mount)) { xfs_iunpin_wait(ip); xfs_iflush_abort(ip, false); goto reclaim; } if (xfs_ipincount(ip)) { if (!(sync_mode & SYNC_WAIT)) goto out_ifunlock; xfs_iunpin_wait(ip); } if (xfs_iflags_test(ip, XFS_ISTALE)) goto reclaim; if (xfs_inode_clean(ip)) goto reclaim; /* * Never flush out dirty data during non-blocking reclaim, as it would * just contend with AIL pushing trying to do the same job. */ if (!(sync_mode & SYNC_WAIT)) goto out_ifunlock; /* * Now we have an inode that needs flushing. * * Note that xfs_iflush will never block on the inode buffer lock, as * xfs_ifree_cluster() can lock the inode buffer before it locks the * ip->i_lock, and we are doing the exact opposite here. As a result, * doing a blocking xfs_imap_to_bp() to get the cluster buffer would * result in an ABBA deadlock with xfs_ifree_cluster(). * * As xfs_ifree_cluser() must gather all inodes that are active in the * cache to mark them stale, if we hit this case we don't actually want * to do IO here - we want the inode marked stale so we can simply * reclaim it. Hence if we get an EAGAIN error here, just unlock the * inode, back off and try again. Hopefully the next pass through will * see the stale flag set on the inode. */ error = xfs_iflush(ip, &bp); if (error == EAGAIN) { xfs_iunlock(ip, XFS_ILOCK_EXCL); /* backoff longer than in xfs_ifree_cluster */ delay(2); goto restart; } if (!error) { error = xfs_bwrite(bp); xfs_buf_relse(bp); } xfs_iflock(ip); reclaim: xfs_ifunlock(ip); xfs_iunlock(ip, XFS_ILOCK_EXCL); XFS_STATS_INC(xs_ig_reclaims); /* * Remove the inode from the per-AG radix tree. * * Because radix_tree_delete won't complain even if the item was never * added to the tree assert that it's been there before to catch * problems with the inode life time early on. */ spin_lock(&pag->pag_ici_lock); if (!radix_tree_delete(&pag->pag_ici_root, XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino))) ASSERT(0); __xfs_inode_clear_reclaim(pag, ip); spin_unlock(&pag->pag_ici_lock); /* * Here we do an (almost) spurious inode lock in order to coordinate * with inode cache radix tree lookups. This is because the lookup * can reference the inodes in the cache without taking references. * * We make that OK here by ensuring that we wait until the inode is * unlocked after the lookup before we go ahead and free it. */ xfs_ilock(ip, XFS_ILOCK_EXCL); xfs_qm_dqdetach(ip); xfs_iunlock(ip, XFS_ILOCK_EXCL); xfs_inode_free(ip); return error; out_ifunlock: xfs_ifunlock(ip); out: xfs_iflags_clear(ip, XFS_IRECLAIM); xfs_iunlock(ip, XFS_ILOCK_EXCL); /* * We could return EAGAIN here to make reclaim rescan the inode tree in * a short while. However, this just burns CPU time scanning the tree * waiting for IO to complete and the reclaim work never goes back to * the idle state. Instead, return 0 to let the next scheduled * background reclaim attempt to reclaim the inode again. */ return 0; }
/* * 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. * This flag parameter indicates how and if the inode's IO lock and inode lock * should be taken. * * mp -- the mount point structure for the current file system. It points * to the inode hash table. * tp -- a pointer to the current transaction if there is one. This is * simply passed through to the xfs_iread() call. * ino -- the number of the inode desired. This is the unique identifier * within the file system for the inode being requested. * lock_flags -- flags indicating how to lock the inode. See the comment * for xfs_ilock() for a list of valid values. */ int xfs_iget( xfs_mount_t *mp, xfs_trans_t *tp, xfs_ino_t ino, uint flags, uint lock_flags, xfs_inode_t **ipp) { xfs_inode_t *ip; int error; xfs_perag_t *pag; xfs_agino_t agino; /* * xfs_reclaim_inode() uses the ILOCK to ensure an inode * doesn't get freed while it's being referenced during a * radix tree traversal here. It assumes this function * aqcuires only the ILOCK (and therefore it has no need to * involve the IOLOCK in this synchronization). */ 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; /* 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(); XFS_STATS_INC(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 set ops(&unlock) * now. If it's a new inode being created, xfs_ialloc will handle it. */ if (xfs_iflags_test(ip, XFS_INEW) && ip->i_d.di_mode != 0) xfs_setup_inode(ip); return 0; out_error_or_again: if (error == EAGAIN) { delay(1); goto again; } xfs_perag_put(pag); return error; }
STATIC int xfs_inode_ag_walk( struct xfs_mount *mp, struct xfs_perag *pag, int (*execute)(struct xfs_inode *ip, struct xfs_perag *pag, int flags, void *args), int flags, void *args, int tag) { uint32_t first_index; int last_error = 0; int skipped; int done; int nr_found; restart: done = 0; skipped = 0; first_index = 0; nr_found = 0; do { struct xfs_inode *batch[XFS_LOOKUP_BATCH]; int error = 0; int i; rcu_read_lock(); if (tag == -1) nr_found = radix_tree_gang_lookup(&pag->pag_ici_root, (void **)batch, first_index, XFS_LOOKUP_BATCH); else nr_found = radix_tree_gang_lookup_tag( &pag->pag_ici_root, (void **) batch, first_index, XFS_LOOKUP_BATCH, tag); if (!nr_found) { rcu_read_unlock(); break; } /* * Grab the inodes before we drop the lock. if we found * nothing, nr == 0 and the loop will be skipped. */ for (i = 0; i < nr_found; i++) { struct xfs_inode *ip = batch[i]; if (done || xfs_inode_ag_walk_grab(ip)) batch[i] = NULL; /* * Update the index for the next lookup. Catch * overflows into the next AG range which can occur if * we have inodes in the last block of the AG and we * are currently pointing to the last inode. * * Because we may see inodes that are from the wrong AG * due to RCU freeing and reallocation, only update the * index if it lies in this AG. It was a race that lead * us to see this inode, so another lookup from the * same index will not find it again. */ if (XFS_INO_TO_AGNO(mp, ip->i_ino) != pag->pag_agno) continue; first_index = XFS_INO_TO_AGINO(mp, ip->i_ino + 1); if (first_index < XFS_INO_TO_AGINO(mp, ip->i_ino)) done = 1; } /* unlock now we've grabbed the inodes. */ rcu_read_unlock(); for (i = 0; i < nr_found; i++) { if (!batch[i]) continue; error = execute(batch[i], pag, flags, args); IRELE(batch[i]); 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(); } while (nr_found && !done); if (skipped) { delay(1); goto restart; } return last_error; }
/* * Walk the AGs and reclaim the inodes in them. Even if the filesystem is * corrupted, we still want to try to reclaim all the inodes. If we don't, * then a shut down during filesystem unmount reclaim walk leak all the * unreclaimed inodes. */ STATIC int xfs_reclaim_inodes_ag( struct xfs_mount *mp, int flags, int *nr_to_scan) { struct xfs_perag *pag; int error = 0; int last_error = 0; xfs_agnumber_t ag; int trylock = flags & SYNC_TRYLOCK; int skipped; restart: ag = 0; skipped = 0; while ((pag = xfs_perag_get_tag(mp, ag, XFS_ICI_RECLAIM_TAG))) { unsigned long first_index = 0; int done = 0; int nr_found = 0; ag = pag->pag_agno + 1; if (trylock) { if (!mutex_trylock(&pag->pag_ici_reclaim_lock)) { skipped++; xfs_perag_put(pag); continue; } first_index = pag->pag_ici_reclaim_cursor; } else mutex_lock(&pag->pag_ici_reclaim_lock); do { struct xfs_inode *batch[XFS_LOOKUP_BATCH]; int i; rcu_read_lock(); nr_found = radix_tree_gang_lookup_tag( &pag->pag_ici_root, (void **)batch, first_index, XFS_LOOKUP_BATCH, XFS_ICI_RECLAIM_TAG); if (!nr_found) { done = 1; rcu_read_unlock(); break; } /* * Grab the inodes before we drop the lock. if we found * nothing, nr == 0 and the loop will be skipped. */ for (i = 0; i < nr_found; i++) { struct xfs_inode *ip = batch[i]; if (done || xfs_reclaim_inode_grab(ip, flags)) batch[i] = NULL; /* * Update the index for the next lookup. Catch * overflows into the next AG range which can * occur if we have inodes in the last block of * the AG and we are currently pointing to the * last inode. * * Because we may see inodes that are from the * wrong AG due to RCU freeing and * reallocation, only update the index if it * lies in this AG. It was a race that lead us * to see this inode, so another lookup from * the same index will not find it again. */ if (XFS_INO_TO_AGNO(mp, ip->i_ino) != pag->pag_agno) continue; first_index = XFS_INO_TO_AGINO(mp, ip->i_ino + 1); if (first_index < XFS_INO_TO_AGINO(mp, ip->i_ino)) done = 1; } /* unlock now we've grabbed the inodes. */ rcu_read_unlock(); for (i = 0; i < nr_found; i++) { if (!batch[i]) continue; error = xfs_reclaim_inode(batch[i], pag, flags); if (error && last_error != EFSCORRUPTED) last_error = error; } *nr_to_scan -= XFS_LOOKUP_BATCH; cond_resched(); } while (nr_found && !done && *nr_to_scan > 0); if (trylock && !done) pag->pag_ici_reclaim_cursor = first_index; else pag->pag_ici_reclaim_cursor = 0; mutex_unlock(&pag->pag_ici_reclaim_lock); xfs_perag_put(pag); } /* * if we skipped any AG, and we still have scan count remaining, do * another pass this time using blocking reclaim semantics (i.e * waiting on the reclaim locks and ignoring the reclaim cursors). This * ensure that when we get more reclaimers than AGs we block rather * than spin trying to execute reclaim. */ if (skipped && (flags & SYNC_WAIT) && *nr_to_scan > 0) { trylock = 0; goto restart; } return XFS_ERROR(last_error); }
static int xfs_iget_cache_miss( struct xfs_mount *mp, struct xfs_perag *pag, xfs_trans_t *tp, xfs_ino_t ino, struct xfs_inode **ipp, int flags, int lock_flags) { struct xfs_inode *ip; int error; xfs_agino_t agino = XFS_INO_TO_AGINO(mp, ino); int iflags; ip = xfs_inode_alloc(mp, ino); if (!ip) return ENOMEM; error = xfs_iread(mp, tp, ip, flags); if (error) goto out_destroy; trace_xfs_iget_miss(ip); if ((ip->i_d.di_mode == 0) && !(flags & XFS_IGET_CREATE)) { error = ENOENT; 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) iflags |= XFS_IDONTCACHE; ip->i_udquot = NULL; ip->i_gdquot = 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(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; }
/* * Return stat information in bulk (by-inode) for the filesystem. */ int /* error status */ xfs_bulkstat( xfs_mount_t *mp, /* mount point for filesystem */ xfs_ino_t *lastinop, /* last inode returned */ int *ubcountp, /* size of buffer/count returned */ bulkstat_one_pf formatter, /* func that'd fill a single buf */ size_t statstruct_size, /* sizeof struct filling */ char __user *ubuffer, /* buffer with inode stats */ int *done) /* 1 if there are more stats to get */ { xfs_buf_t *agbp; /* agi header buffer */ xfs_agino_t agino; /* inode # in allocation group */ xfs_agnumber_t agno; /* allocation group number */ xfs_btree_cur_t *cur; /* btree cursor for ialloc btree */ size_t irbsize; /* size of irec buffer in bytes */ xfs_inobt_rec_incore_t *irbuf; /* start of irec buffer */ int nirbuf; /* size of irbuf */ int ubcount; /* size of user's buffer */ struct xfs_bulkstat_agichunk ac; int error = 0; /* * Get the last inode value, see if there's nothing to do. */ agno = XFS_INO_TO_AGNO(mp, *lastinop); agino = XFS_INO_TO_AGINO(mp, *lastinop); if (agno >= mp->m_sb.sb_agcount || *lastinop != XFS_AGINO_TO_INO(mp, agno, agino)) { *done = 1; *ubcountp = 0; return 0; } ubcount = *ubcountp; /* statstruct's */ ac.ac_ubuffer = &ubuffer; ac.ac_ubleft = ubcount * statstruct_size; /* bytes */; ac.ac_ubelem = 0; *ubcountp = 0; *done = 0; irbuf = kmem_zalloc_greedy(&irbsize, PAGE_SIZE, PAGE_SIZE * 4); if (!irbuf) return -ENOMEM; nirbuf = irbsize / sizeof(*irbuf); /* * Loop over the allocation groups, starting from the last * inode returned; 0 means start of the allocation group. */ while (agno < mp->m_sb.sb_agcount) { struct xfs_inobt_rec_incore *irbp = irbuf; struct xfs_inobt_rec_incore *irbufend = irbuf + nirbuf; bool end_of_ag = false; int icount = 0; int stat; error = xfs_ialloc_read_agi(mp, NULL, agno, &agbp); if (error) break; /* * Allocate and initialize a btree cursor for ialloc btree. */ cur = xfs_inobt_init_cursor(mp, NULL, agbp, agno, XFS_BTNUM_INO); if (agino > 0) { /* * In the middle of an allocation group, we need to get * the remainder of the chunk we're in. */ struct xfs_inobt_rec_incore r; error = xfs_bulkstat_grab_ichunk(cur, agino, &icount, &r); if (error) goto del_cursor; if (icount) { irbp->ir_startino = r.ir_startino; irbp->ir_freecount = r.ir_freecount; irbp->ir_free = r.ir_free; irbp++; } /* Increment to the next record */ error = xfs_btree_increment(cur, 0, &stat); } else { /* Start of ag. Lookup the first inode chunk */ error = xfs_inobt_lookup(cur, 0, XFS_LOOKUP_GE, &stat); } if (error || stat == 0) { end_of_ag = true; goto del_cursor; } /* * Loop through inode btree records in this ag, * until we run out of inodes or space in the buffer. */ while (irbp < irbufend && icount < ubcount) { struct xfs_inobt_rec_incore r; error = xfs_inobt_get_rec(cur, &r, &stat); if (error || stat == 0) { end_of_ag = true; goto del_cursor; } /* * If this chunk has any allocated inodes, save it. * Also start read-ahead now for this chunk. */ if (r.ir_freecount < XFS_INODES_PER_CHUNK) { xfs_bulkstat_ichunk_ra(mp, agno, &r); irbp->ir_startino = r.ir_startino; irbp->ir_freecount = r.ir_freecount; irbp->ir_free = r.ir_free; irbp++; icount += XFS_INODES_PER_CHUNK - r.ir_freecount; } error = xfs_btree_increment(cur, 0, &stat); if (error || stat == 0) { end_of_ag = true; goto del_cursor; } cond_resched(); } /* * Drop the btree buffers and the agi buffer as we can't hold any * of the locks these represent when calling iget. If there is a * pending error, then we are done. */ del_cursor: xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR); xfs_buf_relse(agbp); if (error) break; /* * Now format all the good inodes into the user's buffer. The * call to xfs_bulkstat_ag_ichunk() sets up the agino pointer * for the next loop iteration. */ irbufend = irbp; for (irbp = irbuf; irbp < irbufend && ac.ac_ubleft >= statstruct_size; irbp++) { error = xfs_bulkstat_ag_ichunk(mp, agno, irbp, formatter, statstruct_size, &ac, &agino); if (error) break; cond_resched(); } /* * If we've run out of space or had a formatting error, we * are now done */ if (ac.ac_ubleft < statstruct_size || error) break; if (end_of_ag) { agno++; agino = 0; } } /* * Done, we're either out of filesystem or space to put the data. */ kmem_free(irbuf); *ubcountp = ac.ac_ubelem; /* * We found some inodes, so clear the error status and return them. * The lastino pointer will point directly at the inode that triggered * any error that occurred, so on the next call the error will be * triggered again and propagated to userspace as there will be no * formatted inodes in the buffer. */ if (ac.ac_ubelem) error = 0; /* * If we ran out of filesystem, lastino will point off the end of * the filesystem so the next call will return immediately. */ *lastinop = XFS_AGINO_TO_INO(mp, agno, agino); if (agno >= mp->m_sb.sb_agcount) *done = 1; return error; }
/* * Return inode number table for the filesystem. */ int /* error status */ xfs_inumbers( struct xfs_mount *mp,/* mount point for filesystem */ xfs_ino_t *lastino,/* last inode returned */ int *count,/* size of buffer/count returned */ void __user *ubuffer,/* buffer with inode descriptions */ inumbers_fmt_pf formatter) { xfs_agnumber_t agno = XFS_INO_TO_AGNO(mp, *lastino); xfs_agino_t agino = XFS_INO_TO_AGINO(mp, *lastino); struct xfs_btree_cur *cur = NULL; struct xfs_buf *agbp = NULL; struct xfs_inogrp *buffer; int bcount; int left = *count; int bufidx = 0; int error = 0; *count = 0; if (agno >= mp->m_sb.sb_agcount || *lastino != XFS_AGINO_TO_INO(mp, agno, agino)) return error; bcount = MIN(left, (int)(PAGE_SIZE / sizeof(*buffer))); buffer = kmem_alloc(bcount * sizeof(*buffer), KM_SLEEP); do { struct xfs_inobt_rec_incore r; int stat; if (!agbp) { error = xfs_ialloc_read_agi(mp, NULL, agno, &agbp); if (error) break; cur = xfs_inobt_init_cursor(mp, NULL, agbp, agno, XFS_BTNUM_INO); error = xfs_inobt_lookup(cur, agino, XFS_LOOKUP_GE, &stat); if (error) break; if (!stat) goto next_ag; } error = xfs_inobt_get_rec(cur, &r, &stat); if (error) break; if (!stat) goto next_ag; agino = r.ir_startino + XFS_INODES_PER_CHUNK - 1; buffer[bufidx].xi_startino = XFS_AGINO_TO_INO(mp, agno, r.ir_startino); buffer[bufidx].xi_alloccount = XFS_INODES_PER_CHUNK - r.ir_freecount; buffer[bufidx].xi_allocmask = ~r.ir_free; if (++bufidx == bcount) { long written; error = formatter(ubuffer, buffer, bufidx, &written); if (error) break; ubuffer += written; *count += bufidx; bufidx = 0; } if (!--left) break; error = xfs_btree_increment(cur, 0, &stat); if (error) break; if (stat) continue; next_ag: xfs_btree_del_cursor(cur, XFS_BTREE_ERROR); cur = NULL; xfs_buf_relse(agbp); agbp = NULL; agino = 0; agno++; } while (agno < mp->m_sb.sb_agcount); if (!error) { if (bufidx) { long written; error = formatter(ubuffer, buffer, bufidx, &written); if (!error) *count += bufidx; } *lastino = XFS_AGINO_TO_INO(mp, agno, agino); } kmem_free(buffer); if (cur) xfs_btree_del_cursor(cur, (error ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR)); if (agbp) xfs_buf_relse(agbp); return error; }
static int xfs_iget_cache_miss( struct xfs_mount *mp, struct xfs_perag *pag, xfs_trans_t *tp, xfs_ino_t ino, struct xfs_inode **ipp, int flags, int lock_flags) { struct xfs_inode *ip; int error; xfs_agino_t agino = XFS_INO_TO_AGINO(mp, ino); ip = xfs_inode_alloc(mp, ino); if (!ip) return ENOMEM; error = xfs_iread(mp, tp, ip, flags); if (error) goto out_destroy; trace_xfs_iget_miss(ip); if ((ip->i_d.di_mode == 0) && !(flags & XFS_IGET_CREATE)) { error = ENOENT; 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. */ if (radix_tree_preload(GFP_KERNEL)) { 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(); } spin_lock(&pag->pag_ici_lock); /* insert the new inode */ error = radix_tree_insert(&pag->pag_ici_root, agino, ip); if (unlikely(error)) { WARN_ON(error != -EEXIST); XFS_STATS_INC(xs_ig_dup); error = EAGAIN; goto out_preload_end; } /* These values _must_ be set before releasing the radix tree lock! */ ip->i_udquot = ip->i_gdquot = NULL; xfs_iflags_set(ip, XFS_INEW); 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. * This flag parameter indicates how and if the inode's IO lock and inode lock * should be taken. * * mp -- the mount point structure for the current file system. It points * to the inode hash table. * tp -- a pointer to the current transaction if there is one. This is * simply passed through to the xfs_iread() call. * ino -- the number of the inode desired. This is the unique identifier * within the file system for the inode being requested. * lock_flags -- flags indicating how to lock the inode. See the comment * for xfs_ilock() for a list of valid values. */ int xfs_iget( xfs_mount_t *mp, xfs_trans_t *tp, xfs_ino_t ino, uint flags, uint lock_flags, xfs_inode_t **ipp) { xfs_inode_t *ip; int error; xfs_perag_t *pag; xfs_agino_t agino; /* reject inode numbers outside existing AGs */ if (!ino || XFS_INO_TO_AGNO(mp, ino) >= mp->m_sb.sb_agcount) return EINVAL; /* 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(); XFS_STATS_INC(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; ASSERT(ip->i_df.if_ext_max == XFS_IFORK_DSIZE(ip) / sizeof(xfs_bmbt_rec_t)); /* * If we have a real type for an on-disk inode, we can set ops(&unlock) * now. If it's a new inode being created, xfs_ialloc will handle it. */ if (xfs_iflags_test(ip, XFS_INEW) && ip->i_d.di_mode != 0) xfs_setup_inode(ip); return 0; out_error_or_again: if (error == EAGAIN) { delay(1); goto again; } xfs_perag_put(pag); return error; }
/* * Sync all the inodes in the given AG according to the * direction given by the flags. */ STATIC int xfs_sync_inodes_ag( xfs_mount_t *mp, int ag, int flags) { xfs_perag_t *pag = &mp->m_perag[ag]; int nr_found; uint32_t first_index = 0; int error = 0; int last_error = 0; int fflag = XFS_B_ASYNC; if (flags & SYNC_DELWRI) fflag = XFS_B_DELWRI; if (flags & SYNC_WAIT) fflag = 0; /* synchronous overrides all */ do { struct inode *inode; xfs_inode_t *ip = NULL; int lock_flags = XFS_ILOCK_SHARED; /* * use a gang lookup to find the next inode in the tree * as the tree is sparse and a gang lookup walks to find * the number of objects requested. */ read_lock(&pag->pag_ici_lock); nr_found = radix_tree_gang_lookup(&pag->pag_ici_root, (void**)&ip, first_index, 1); if (!nr_found) { read_unlock(&pag->pag_ici_lock); break; } /* * Update the index for the next lookup. Catch overflows * into the next AG range which can occur if we have inodes * in the last block of the AG and we are currently * pointing to the last inode. */ first_index = XFS_INO_TO_AGINO(mp, ip->i_ino + 1); if (first_index < XFS_INO_TO_AGINO(mp, ip->i_ino)) { read_unlock(&pag->pag_ici_lock); break; } /* nothing to sync during shutdown */ if (XFS_FORCED_SHUTDOWN(mp)) { read_unlock(&pag->pag_ici_lock); return 0; } /* * If we can't get a reference on the inode, it must be * in reclaim. Leave it for the reclaim code to flush. */ inode = VFS_I(ip); if (!igrab(inode)) { read_unlock(&pag->pag_ici_lock); continue; } read_unlock(&pag->pag_ici_lock); /* avoid new or bad inodes */ if (is_bad_inode(inode) || xfs_iflags_test(ip, XFS_INEW)) { IRELE(ip); continue; } /* * If we have to flush data or wait for I/O completion * we need to hold the iolock. */ if ((flags & SYNC_DELWRI) && VN_DIRTY(inode)) { xfs_ilock(ip, XFS_IOLOCK_SHARED); lock_flags |= XFS_IOLOCK_SHARED; error = xfs_flush_pages(ip, 0, -1, fflag, FI_NONE); if (flags & SYNC_IOWAIT) xfs_ioend_wait(ip); } xfs_ilock(ip, XFS_ILOCK_SHARED); if ((flags & SYNC_ATTR) && !xfs_inode_clean(ip)) { if (flags & SYNC_WAIT) { xfs_iflock(ip); if (!xfs_inode_clean(ip)) error = xfs_iflush(ip, XFS_IFLUSH_SYNC); else xfs_ifunlock(ip); } else if (xfs_iflock_nowait(ip)) { if (!xfs_inode_clean(ip)) error = xfs_iflush(ip, XFS_IFLUSH_DELWRI); else xfs_ifunlock(ip); } } xfs_iput(ip, lock_flags); if (error) last_error = error; /* * bail out if the filesystem is corrupted. */ if (error == EFSCORRUPTED) return XFS_ERROR(error); } while (nr_found); return last_error; }
/* * like add_aginode_uncertain() only it needs an xfs_mount_t * * to perform the inode number conversion. */ void add_inode_uncertain(xfs_mount_t *mp, xfs_ino_t ino, int free) { add_aginode_uncertain(mp, XFS_INO_TO_AGNO(mp, ino), XFS_INO_TO_AGINO(mp, ino), free); }
/* * Allocate an inode. * * The caller selected an AG for us, and made sure that free inodes are * available. */ STATIC int xfs_dialloc_ag( struct xfs_trans *tp, struct xfs_buf *agbp, xfs_ino_t parent, xfs_ino_t *inop) { struct xfs_mount *mp = tp->t_mountp; struct xfs_agi *agi = XFS_BUF_TO_AGI(agbp); xfs_agnumber_t agno = be32_to_cpu(agi->agi_seqno); xfs_agnumber_t pagno = XFS_INO_TO_AGNO(mp, parent); xfs_agino_t pagino = XFS_INO_TO_AGINO(mp, parent); struct xfs_perag *pag; struct xfs_btree_cur *cur, *tcur; struct xfs_inobt_rec_incore rec, trec; xfs_ino_t ino; int error; int offset; int i, j; pag = xfs_perag_get(mp, agno); ASSERT(pag->pagi_init); ASSERT(pag->pagi_inodeok); ASSERT(pag->pagi_freecount > 0); restart_pagno: cur = xfs_inobt_init_cursor(mp, tp, agbp, agno); /* * If pagino is 0 (this is the root inode allocation) use newino. * This must work because we've just allocated some. */ if (!pagino) pagino = be32_to_cpu(agi->agi_newino); error = xfs_check_agi_freecount(cur, agi); if (error) goto error0; /* * If in the same AG as the parent, try to get near the parent. */ if (pagno == agno) { int doneleft; /* done, to the left */ int doneright; /* done, to the right */ int searchdistance = 10; error = xfs_inobt_lookup(cur, pagino, XFS_LOOKUP_LE, &i); if (error) goto error0; XFS_WANT_CORRUPTED_GOTO(i == 1, error0); error = xfs_inobt_get_rec(cur, &rec, &j); if (error) goto error0; XFS_WANT_CORRUPTED_GOTO(i == 1, error0); if (rec.ir_freecount > 0) { /* * Found a free inode in the same chunk * as the parent, done. */ goto alloc_inode; } /* * In the same AG as parent, but parent's chunk is full. */ /* duplicate the cursor, search left & right simultaneously */ error = xfs_btree_dup_cursor(cur, &tcur); if (error) goto error0; /* * Skip to last blocks looked up if same parent inode. */ if (pagino != NULLAGINO && pag->pagl_pagino == pagino && pag->pagl_leftrec != NULLAGINO && pag->pagl_rightrec != NULLAGINO) { error = xfs_ialloc_get_rec(tcur, pag->pagl_leftrec, &trec, &doneleft); if (error) goto error1; error = xfs_ialloc_get_rec(cur, pag->pagl_rightrec, &rec, &doneright); if (error) goto error1; } else { /* search left with tcur, back up 1 record */ error = xfs_ialloc_next_rec(tcur, &trec, &doneleft, 1); if (error) goto error1; /* search right with cur, go forward 1 record. */ error = xfs_ialloc_next_rec(cur, &rec, &doneright, 0); if (error) goto error1; } /* * Loop until we find an inode chunk with a free inode. */ while (!doneleft || !doneright) { int useleft; /* using left inode chunk this time */ if (!--searchdistance) { /* * Not in range - save last search * location and allocate a new inode */ xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR); pag->pagl_leftrec = trec.ir_startino; pag->pagl_rightrec = rec.ir_startino; pag->pagl_pagino = pagino; goto newino; } /* figure out the closer block if both are valid. */ if (!doneleft && !doneright) { useleft = pagino - (trec.ir_startino + XFS_INODES_PER_CHUNK - 1) < rec.ir_startino - pagino; } else { useleft = !doneleft; } /* free inodes to the left? */ if (useleft && trec.ir_freecount) { rec = trec; xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR); cur = tcur; pag->pagl_leftrec = trec.ir_startino; pag->pagl_rightrec = rec.ir_startino; pag->pagl_pagino = pagino; goto alloc_inode; } /* free inodes to the right? */ if (!useleft && rec.ir_freecount) { xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR); pag->pagl_leftrec = trec.ir_startino; pag->pagl_rightrec = rec.ir_startino; pag->pagl_pagino = pagino; goto alloc_inode; } /* get next record to check */ if (useleft) { error = xfs_ialloc_next_rec(tcur, &trec, &doneleft, 1); } else { error = xfs_ialloc_next_rec(cur, &rec, &doneright, 0); } if (error) goto error1; } /* * We've reached the end of the btree. because * we are only searching a small chunk of the * btree each search, there is obviously free * inodes closer to the parent inode than we * are now. restart the search again. */ pag->pagl_pagino = NULLAGINO; pag->pagl_leftrec = NULLAGINO; pag->pagl_rightrec = NULLAGINO; xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR); xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR); goto restart_pagno; } /* * In a different AG from the parent. * See if the most recently allocated block has any free. */ newino: if (agi->agi_newino != cpu_to_be32(NULLAGINO)) { error = xfs_inobt_lookup(cur, be32_to_cpu(agi->agi_newino), XFS_LOOKUP_EQ, &i); if (error) goto error0; if (i == 1) { error = xfs_inobt_get_rec(cur, &rec, &j); if (error) goto error0; if (j == 1 && rec.ir_freecount > 0) { /* * The last chunk allocated in the group * still has a free inode. */ goto alloc_inode; } } } /* * None left in the last group, search the whole AG */ error = xfs_inobt_lookup(cur, 0, XFS_LOOKUP_GE, &i); if (error) goto error0; XFS_WANT_CORRUPTED_GOTO(i == 1, error0); for (;;) { error = xfs_inobt_get_rec(cur, &rec, &i); if (error) goto error0; XFS_WANT_CORRUPTED_GOTO(i == 1, error0); if (rec.ir_freecount > 0) break; error = xfs_btree_increment(cur, 0, &i); if (error) goto error0; XFS_WANT_CORRUPTED_GOTO(i == 1, error0); } alloc_inode: offset = xfs_lowbit64(rec.ir_free); ASSERT(offset >= 0); ASSERT(offset < XFS_INODES_PER_CHUNK); ASSERT((XFS_AGINO_TO_OFFSET(mp, rec.ir_startino) % XFS_INODES_PER_CHUNK) == 0); ino = XFS_AGINO_TO_INO(mp, agno, rec.ir_startino + offset); rec.ir_free &= ~XFS_INOBT_MASK(offset); rec.ir_freecount--; error = xfs_inobt_update(cur, &rec); if (error) goto error0; be32_add_cpu(&agi->agi_freecount, -1); xfs_ialloc_log_agi(tp, agbp, XFS_AGI_FREECOUNT); pag->pagi_freecount--; error = xfs_check_agi_freecount(cur, agi); if (error) goto error0; xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR); xfs_trans_mod_sb(tp, XFS_TRANS_SB_IFREE, -1); xfs_perag_put(pag); *inop = ino; return 0; error1: xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR); error0: xfs_btree_del_cursor(cur, XFS_BTREE_ERROR); xfs_perag_put(pag); return error; }
/* * Inodes in different states need to be treated differently, and the return * value of xfs_iflush is not sufficient to get this right. The following table * lists the inode states and the reclaim actions necessary for non-blocking * reclaim: * * * inode state iflush ret required action * --------------- ---------- --------------- * bad - reclaim * shutdown EIO unpin and reclaim * clean, unpinned 0 reclaim * stale, unpinned 0 reclaim * clean, pinned(*) 0 requeue * stale, pinned EAGAIN requeue * dirty, delwri ok 0 requeue * dirty, delwri blocked EAGAIN requeue * dirty, sync flush 0 reclaim * * (*) dgc: I don't think the clean, pinned state is possible but it gets * handled anyway given the order of checks implemented. * * As can be seen from the table, the return value of xfs_iflush() is not * sufficient to correctly decide the reclaim action here. The checks in * xfs_iflush() might look like duplicates, but they are not. * * Also, because we get the flush lock first, we know that any inode that has * been flushed delwri has had the flush completed by the time we check that * the inode is clean. The clean inode check needs to be done before flushing * the inode delwri otherwise we would loop forever requeuing clean inodes as * we cannot tell apart a successful delwri flush and a clean inode from the * return value of xfs_iflush(). * * Note that because the inode is flushed delayed write by background * writeback, the flush lock may already be held here and waiting on it can * result in very long latencies. Hence for sync reclaims, where we wait on the * flush lock, the caller should push out delayed write inodes first before * trying to reclaim them to minimise the amount of time spent waiting. For * background relaim, we just requeue the inode for the next pass. * * Hence the order of actions after gaining the locks should be: * bad => reclaim * shutdown => unpin and reclaim * pinned, delwri => requeue * pinned, sync => unpin * stale => reclaim * clean => reclaim * dirty, delwri => flush and requeue * dirty, sync => flush, wait and reclaim */ STATIC int xfs_reclaim_inode( struct xfs_inode *ip, struct xfs_perag *pag, int sync_mode) { int error; restart: error = 0; xfs_ilock(ip, XFS_ILOCK_EXCL); if (!xfs_iflock_nowait(ip)) { if (!(sync_mode & SYNC_WAIT)) goto out; xfs_iflock(ip); } if (is_bad_inode(VFS_I(ip))) goto reclaim; if (XFS_FORCED_SHUTDOWN(ip->i_mount)) { xfs_iunpin_wait(ip); goto reclaim; } if (xfs_ipincount(ip)) { if (!(sync_mode & SYNC_WAIT)) { xfs_ifunlock(ip); goto out; } xfs_iunpin_wait(ip); } if (xfs_iflags_test(ip, XFS_ISTALE)) goto reclaim; if (xfs_inode_clean(ip)) goto reclaim; /* * Now we have an inode that needs flushing. * * We do a nonblocking flush here even if we are doing a SYNC_WAIT * reclaim as we can deadlock with inode cluster removal. * xfs_ifree_cluster() can lock the inode buffer before it locks the * ip->i_lock, and we are doing the exact opposite here. As a result, * doing a blocking xfs_itobp() to get the cluster buffer will result * in an ABBA deadlock with xfs_ifree_cluster(). * * As xfs_ifree_cluser() must gather all inodes that are active in the * cache to mark them stale, if we hit this case we don't actually want * to do IO here - we want the inode marked stale so we can simply * reclaim it. Hence if we get an EAGAIN error on a SYNC_WAIT flush, * just unlock the inode, back off and try again. Hopefully the next * pass through will see the stale flag set on the inode. */ error = xfs_iflush(ip, SYNC_TRYLOCK | sync_mode); if (sync_mode & SYNC_WAIT) { if (error == EAGAIN) { xfs_iunlock(ip, XFS_ILOCK_EXCL); /* backoff longer than in xfs_ifree_cluster */ delay(2); goto restart; } xfs_iflock(ip); goto reclaim; } /* * When we have to flush an inode but don't have SYNC_WAIT set, we * flush the inode out using a delwri buffer and wait for the next * call into reclaim to find it in a clean state instead of waiting for * it now. We also don't return errors here - if the error is transient * then the next reclaim pass will flush the inode, and if the error * is permanent then the next sync reclaim will reclaim the inode and * pass on the error. */ if (error && error != EAGAIN && !XFS_FORCED_SHUTDOWN(ip->i_mount)) { xfs_warn(ip->i_mount, "inode 0x%llx background reclaim flush failed with %d", (long long)ip->i_ino, error); } out: xfs_iflags_clear(ip, XFS_IRECLAIM); xfs_iunlock(ip, XFS_ILOCK_EXCL); /* * We could return EAGAIN here to make reclaim rescan the inode tree in * a short while. However, this just burns CPU time scanning the tree * waiting for IO to complete and xfssyncd never goes back to the idle * state. Instead, return 0 to let the next scheduled background reclaim * attempt to reclaim the inode again. */ return 0; reclaim: xfs_ifunlock(ip); xfs_iunlock(ip, XFS_ILOCK_EXCL); XFS_STATS_INC(xs_ig_reclaims); /* * Remove the inode from the per-AG radix tree. * * Because radix_tree_delete won't complain even if the item was never * added to the tree assert that it's been there before to catch * problems with the inode life time early on. */ spin_lock(&pag->pag_ici_lock); if (!radix_tree_delete(&pag->pag_ici_root, XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino))) ASSERT(0); __xfs_inode_clear_reclaim(pag, ip); spin_unlock(&pag->pag_ici_lock); /* * Here we do an (almost) spurious inode lock in order to coordinate * with inode cache radix tree lookups. This is because the lookup * can reference the inodes in the cache without taking references. * * We make that OK here by ensuring that we wait until the inode is * unlocked after the lookup before we go ahead and free it. We get * both the ilock and the iolock because the code may need to drop the * ilock one but will still hold the iolock. */ xfs_ilock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL); xfs_qm_dqdetach(ip); xfs_iunlock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL); xfs_inode_free(ip); return error; }
/* * Allocate an inode on disk. * Mode is used to tell whether the new inode will need space, and whether * it is a directory. * * The arguments IO_agbp and alloc_done are defined to work within * the constraint of one allocation per transaction. * xfs_dialloc() is designed to be called twice if it has to do an * allocation to make more free inodes. On the first call, * IO_agbp should be set to NULL. If an inode is available, * i.e., xfs_dialloc() did not need to do an allocation, an inode * number is returned. In this case, IO_agbp would be set to the * current ag_buf and alloc_done set to false. * If an allocation needed to be done, xfs_dialloc would return * the current ag_buf in IO_agbp and set alloc_done to true. * The caller should then commit the current transaction, allocate a new * transaction, and call xfs_dialloc() again, passing in the previous * value of IO_agbp. IO_agbp should be held across the transactions. * Since the agbp is locked across the two calls, the second call is * guaranteed to have a free inode available. * * Once we successfully pick an inode its number is returned and the * on-disk data structures are updated. The inode itself is not read * in, since doing so would break ordering constraints with xfs_reclaim. */ int xfs_dialloc( xfs_trans_t *tp, /* transaction pointer */ xfs_ino_t parent, /* parent inode (directory) */ mode_t mode, /* mode bits for new inode */ int okalloc, /* ok to allocate more space */ xfs_buf_t **IO_agbp, /* in/out ag header's buffer */ boolean_t *alloc_done, /* true if we needed to replenish inode freelist */ xfs_ino_t *inop) /* inode number allocated */ { xfs_agnumber_t agcount; /* number of allocation groups */ xfs_buf_t *agbp; /* allocation group header's buffer */ xfs_agnumber_t agno; /* allocation group number */ xfs_agi_t *agi; /* allocation group header structure */ xfs_btree_cur_t *cur; /* inode allocation btree cursor */ int error; /* error return value */ int i; /* result code */ int ialloced; /* inode allocation status */ int noroom = 0; /* no space for inode blk allocation */ xfs_ino_t ino; /* fs-relative inode to be returned */ /* REFERENCED */ int j; /* result code */ xfs_mount_t *mp; /* file system mount structure */ int offset; /* index of inode in chunk */ xfs_agino_t pagino; /* parent's AG relative inode # */ xfs_agnumber_t pagno; /* parent's AG number */ xfs_inobt_rec_incore_t rec; /* inode allocation record */ xfs_agnumber_t tagno; /* testing allocation group number */ xfs_btree_cur_t *tcur; /* temp cursor */ xfs_inobt_rec_incore_t trec; /* temp inode allocation record */ struct xfs_perag *pag; if (*IO_agbp == NULL) { /* * We do not have an agbp, so select an initial allocation * group for inode allocation. */ agbp = xfs_ialloc_ag_select(tp, parent, mode, okalloc); /* * Couldn't find an allocation group satisfying the * criteria, give up. */ if (!agbp) { *inop = NULLFSINO; return 0; } agi = XFS_BUF_TO_AGI(agbp); ASSERT(be32_to_cpu(agi->agi_magicnum) == XFS_AGI_MAGIC); } else { /* * Continue where we left off before. In this case, we * know that the allocation group has free inodes. */ agbp = *IO_agbp; agi = XFS_BUF_TO_AGI(agbp); ASSERT(be32_to_cpu(agi->agi_magicnum) == XFS_AGI_MAGIC); ASSERT(be32_to_cpu(agi->agi_freecount) > 0); } mp = tp->t_mountp; agcount = mp->m_sb.sb_agcount; agno = be32_to_cpu(agi->agi_seqno); tagno = agno; pagno = XFS_INO_TO_AGNO(mp, parent); pagino = XFS_INO_TO_AGINO(mp, parent); /* * If we have already hit the ceiling of inode blocks then clear * okalloc so we scan all available agi structures for a free * inode. */ if (mp->m_maxicount && mp->m_sb.sb_icount + XFS_IALLOC_INODES(mp) > mp->m_maxicount) { noroom = 1; okalloc = 0; } /* * Loop until we find an allocation group that either has free inodes * or in which we can allocate some inodes. Iterate through the * allocation groups upward, wrapping at the end. */ *alloc_done = B_FALSE; while (!agi->agi_freecount) { /* * Don't do anything if we're not supposed to allocate * any blocks, just go on to the next ag. */ if (okalloc) { /* * Try to allocate some new inodes in the allocation * group. */ if ((error = xfs_ialloc_ag_alloc(tp, agbp, &ialloced))) { xfs_trans_brelse(tp, agbp); if (error == ENOSPC) { *inop = NULLFSINO; return 0; } else return error; } if (ialloced) { /* * We successfully allocated some inodes, return * the current context to the caller so that it * can commit the current transaction and call * us again where we left off. */ ASSERT(be32_to_cpu(agi->agi_freecount) > 0); *alloc_done = B_TRUE; *IO_agbp = agbp; *inop = NULLFSINO; return 0; } } /* * If it failed, give up on this ag. */ xfs_trans_brelse(tp, agbp); /* * Go on to the next ag: get its ag header. */ nextag: if (++tagno == agcount) tagno = 0; if (tagno == agno) { *inop = NULLFSINO; return noroom ? ENOSPC : 0; } pag = xfs_perag_get(mp, tagno); if (pag->pagi_inodeok == 0) { xfs_perag_put(pag); goto nextag; } error = xfs_ialloc_read_agi(mp, tp, tagno, &agbp); xfs_perag_put(pag); if (error) goto nextag; agi = XFS_BUF_TO_AGI(agbp); ASSERT(be32_to_cpu(agi->agi_magicnum) == XFS_AGI_MAGIC); } /* * Here with an allocation group that has a free inode. * Reset agno since we may have chosen a new ag in the * loop above. */ agno = tagno; *IO_agbp = NULL; pag = xfs_perag_get(mp, agno); restart_pagno: cur = xfs_inobt_init_cursor(mp, tp, agbp, be32_to_cpu(agi->agi_seqno)); /* * If pagino is 0 (this is the root inode allocation) use newino. * This must work because we've just allocated some. */ if (!pagino) pagino = be32_to_cpu(agi->agi_newino); error = xfs_check_agi_freecount(cur, agi); if (error) goto error0; /* * If in the same AG as the parent, try to get near the parent. */ if (pagno == agno) { int doneleft; /* done, to the left */ int doneright; /* done, to the right */ int searchdistance = 10; error = xfs_inobt_lookup(cur, pagino, XFS_LOOKUP_LE, &i); if (error) goto error0; XFS_WANT_CORRUPTED_GOTO(i == 1, error0); error = xfs_inobt_get_rec(cur, &rec, &j); if (error) goto error0; XFS_WANT_CORRUPTED_GOTO(i == 1, error0); if (rec.ir_freecount > 0) { /* * Found a free inode in the same chunk * as the parent, done. */ goto alloc_inode; } /* * In the same AG as parent, but parent's chunk is full. */ /* duplicate the cursor, search left & right simultaneously */ error = xfs_btree_dup_cursor(cur, &tcur); if (error) goto error0; /* * Skip to last blocks looked up if same parent inode. */ if (pagino != NULLAGINO && pag->pagl_pagino == pagino && pag->pagl_leftrec != NULLAGINO && pag->pagl_rightrec != NULLAGINO) { error = xfs_ialloc_get_rec(tcur, pag->pagl_leftrec, &trec, &doneleft, 1); if (error) goto error1; error = xfs_ialloc_get_rec(cur, pag->pagl_rightrec, &rec, &doneright, 0); if (error) goto error1; } else { /* search left with tcur, back up 1 record */ error = xfs_ialloc_next_rec(tcur, &trec, &doneleft, 1); if (error) goto error1; /* search right with cur, go forward 1 record. */ error = xfs_ialloc_next_rec(cur, &rec, &doneright, 0); if (error) goto error1; } /* * Loop until we find an inode chunk with a free inode. */ while (!doneleft || !doneright) { int useleft; /* using left inode chunk this time */ if (!--searchdistance) { /* * Not in range - save last search * location and allocate a new inode */ xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR); pag->pagl_leftrec = trec.ir_startino; pag->pagl_rightrec = rec.ir_startino; pag->pagl_pagino = pagino; goto newino; } /* figure out the closer block if both are valid. */ if (!doneleft && !doneright) { useleft = pagino - (trec.ir_startino + XFS_INODES_PER_CHUNK - 1) < rec.ir_startino - pagino; } else { useleft = !doneleft; } /* free inodes to the left? */ if (useleft && trec.ir_freecount) { rec = trec; xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR); cur = tcur; pag->pagl_leftrec = trec.ir_startino; pag->pagl_rightrec = rec.ir_startino; pag->pagl_pagino = pagino; goto alloc_inode; } /* free inodes to the right? */ if (!useleft && rec.ir_freecount) { xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR); pag->pagl_leftrec = trec.ir_startino; pag->pagl_rightrec = rec.ir_startino; pag->pagl_pagino = pagino; goto alloc_inode; } /* get next record to check */ if (useleft) { error = xfs_ialloc_next_rec(tcur, &trec, &doneleft, 1); } else { error = xfs_ialloc_next_rec(cur, &rec, &doneright, 0); } if (error) goto error1; } /* * We've reached the end of the btree. because * we are only searching a small chunk of the * btree each search, there is obviously free * inodes closer to the parent inode than we * are now. restart the search again. */ pag->pagl_pagino = NULLAGINO; pag->pagl_leftrec = NULLAGINO; pag->pagl_rightrec = NULLAGINO; xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR); xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR); goto restart_pagno; } /* * In a different AG from the parent. * See if the most recently allocated block has any free. */ newino: if (be32_to_cpu(agi->agi_newino) != NULLAGINO) { error = xfs_inobt_lookup(cur, be32_to_cpu(agi->agi_newino), XFS_LOOKUP_EQ, &i); if (error) goto error0; if (i == 1) { error = xfs_inobt_get_rec(cur, &rec, &j); if (error) goto error0; if (j == 1 && rec.ir_freecount > 0) { /* * The last chunk allocated in the group * still has a free inode. */ goto alloc_inode; } } } /* * None left in the last group, search the whole AG */ error = xfs_inobt_lookup(cur, 0, XFS_LOOKUP_GE, &i); if (error) goto error0; XFS_WANT_CORRUPTED_GOTO(i == 1, error0); for (;;) { error = xfs_inobt_get_rec(cur, &rec, &i); if (error) goto error0; XFS_WANT_CORRUPTED_GOTO(i == 1, error0); if (rec.ir_freecount > 0) break; error = xfs_btree_increment(cur, 0, &i); if (error) goto error0; XFS_WANT_CORRUPTED_GOTO(i == 1, error0); } alloc_inode: offset = xfs_ialloc_find_free(&rec.ir_free); ASSERT(offset >= 0); ASSERT(offset < XFS_INODES_PER_CHUNK); ASSERT((XFS_AGINO_TO_OFFSET(mp, rec.ir_startino) % XFS_INODES_PER_CHUNK) == 0); ino = XFS_AGINO_TO_INO(mp, agno, rec.ir_startino + offset); rec.ir_free &= ~XFS_INOBT_MASK(offset); rec.ir_freecount--; error = xfs_inobt_update(cur, &rec); if (error) goto error0; be32_add_cpu(&agi->agi_freecount, -1); xfs_ialloc_log_agi(tp, agbp, XFS_AGI_FREECOUNT); pag->pagi_freecount--; error = xfs_check_agi_freecount(cur, agi); if (error) goto error0; xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR); xfs_trans_mod_sb(tp, XFS_TRANS_SB_IFREE, -1); xfs_perag_put(pag); *inop = ino; return 0; error1: xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR); error0: xfs_btree_del_cursor(cur, XFS_BTREE_ERROR); xfs_perag_put(pag); return error; }
/* * Allocate an inode on disk. * Mode is used to tell whether the new inode will need space, and whether * it is a directory. * * The arguments IO_agbp and alloc_done are defined to work within * the constraint of one allocation per transaction. * xfs_dialloc() is designed to be called twice if it has to do an * allocation to make more free inodes. On the first call, * IO_agbp should be set to NULL. If an inode is available, * i.e., xfs_dialloc() did not need to do an allocation, an inode * number is returned. In this case, IO_agbp would be set to the * current ag_buf and alloc_done set to false. * If an allocation needed to be done, xfs_dialloc would return * the current ag_buf in IO_agbp and set alloc_done to true. * The caller should then commit the current transaction, allocate a new * transaction, and call xfs_dialloc() again, passing in the previous * value of IO_agbp. IO_agbp should be held across the transactions. * Since the agbp is locked across the two calls, the second call is * guaranteed to have a free inode available. * * Once we successfully pick an inode its number is returned and the * on-disk data structures are updated. The inode itself is not read * in, since doing so would break ordering constraints with xfs_reclaim. */ int xfs_dialloc( xfs_trans_t *tp, /* transaction pointer */ xfs_ino_t parent, /* parent inode (directory) */ mode_t mode, /* mode bits for new inode */ int okalloc, /* ok to allocate more space */ xfs_buf_t **IO_agbp, /* in/out ag header's buffer */ boolean_t *alloc_done, /* true if we needed to replenish inode freelist */ xfs_ino_t *inop) /* inode number allocated */ { xfs_agnumber_t agcount; /* number of allocation groups */ xfs_buf_t *agbp; /* allocation group header's buffer */ xfs_agnumber_t agno; /* allocation group number */ xfs_agi_t *agi; /* allocation group header structure */ xfs_btree_cur_t *cur; /* inode allocation btree cursor */ int error; /* error return value */ int i; /* result code */ int ialloced; /* inode allocation status */ int noroom = 0; /* no space for inode blk allocation */ xfs_ino_t ino; /* fs-relative inode to be returned */ /* REFERENCED */ int j; /* result code */ xfs_mount_t *mp; /* file system mount structure */ int offset; /* index of inode in chunk */ xfs_agino_t pagino; /* parent's a.g. relative inode # */ xfs_agnumber_t pagno; /* parent's allocation group number */ xfs_inobt_rec_t rec; /* inode allocation record */ xfs_agnumber_t tagno; /* testing allocation group number */ xfs_btree_cur_t *tcur; /* temp cursor */ xfs_inobt_rec_t trec; /* temp inode allocation record */ if (*IO_agbp == NULL) { /* * We do not have an agbp, so select an initial allocation * group for inode allocation. */ agbp = xfs_ialloc_ag_select(tp, parent, mode, okalloc); /* * Couldn't find an allocation group satisfying the * criteria, give up. */ if (!agbp) { *inop = NULLFSINO; return 0; } agi = XFS_BUF_TO_AGI(agbp); ASSERT(be32_to_cpu(agi->agi_magicnum) == XFS_AGI_MAGIC); } else { /* * Continue where we left off before. In this case, we * know that the allocation group has free inodes. */ agbp = *IO_agbp; agi = XFS_BUF_TO_AGI(agbp); ASSERT(be32_to_cpu(agi->agi_magicnum) == XFS_AGI_MAGIC); ASSERT(be32_to_cpu(agi->agi_freecount) > 0); } mp = tp->t_mountp; agcount = mp->m_sb.sb_agcount; agno = be32_to_cpu(agi->agi_seqno); tagno = agno; pagno = XFS_INO_TO_AGNO(mp, parent); pagino = XFS_INO_TO_AGINO(mp, parent); /* * If we have already hit the ceiling of inode blocks then clear * okalloc so we scan all available agi structures for a free * inode. */ if (mp->m_maxicount && mp->m_sb.sb_icount + XFS_IALLOC_INODES(mp) > mp->m_maxicount) { noroom = 1; okalloc = 0; } /* * Loop until we find an allocation group that either has free inodes * or in which we can allocate some inodes. Iterate through the * allocation groups upward, wrapping at the end. */ *alloc_done = B_FALSE; while (!agi->agi_freecount) { /* * Don't do anything if we're not supposed to allocate * any blocks, just go on to the next ag. */ if (okalloc) { /* * Try to allocate some new inodes in the allocation * group. */ if ((error = xfs_ialloc_ag_alloc(tp, agbp, &ialloced))) { xfs_trans_brelse(tp, agbp); if (error == ENOSPC) { *inop = NULLFSINO; return 0; } else return error; } if (ialloced) { /* * We successfully allocated some inodes, return * the current context to the caller so that it * can commit the current transaction and call * us again where we left off. */ ASSERT(be32_to_cpu(agi->agi_freecount) > 0); *alloc_done = B_TRUE; *IO_agbp = agbp; *inop = NULLFSINO; return 0; } } /* * If it failed, give up on this ag. */ xfs_trans_brelse(tp, agbp); /* * Go on to the next ag: get its ag header. */ nextag: if (++tagno == agcount) tagno = 0; if (tagno == agno) { *inop = NULLFSINO; return noroom ? ENOSPC : 0; } down_read(&mp->m_peraglock); if (mp->m_perag[tagno].pagi_inodeok == 0) { up_read(&mp->m_peraglock); goto nextag; } error = xfs_ialloc_read_agi(mp, tp, tagno, &agbp); up_read(&mp->m_peraglock); if (error) goto nextag; agi = XFS_BUF_TO_AGI(agbp); ASSERT(be32_to_cpu(agi->agi_magicnum) == XFS_AGI_MAGIC); } /* * Here with an allocation group that has a free inode. * Reset agno since we may have chosen a new ag in the * loop above. */ agno = tagno; *IO_agbp = NULL; cur = xfs_btree_init_cursor(mp, tp, agbp, be32_to_cpu(agi->agi_seqno), XFS_BTNUM_INO, (xfs_inode_t *)0, 0); /* * If pagino is 0 (this is the root inode allocation) use newino. * This must work because we've just allocated some. */ if (!pagino) pagino = be32_to_cpu(agi->agi_newino); #ifdef DEBUG if (cur->bc_nlevels == 1) { int freecount = 0; if ((error = xfs_inobt_lookup_ge(cur, 0, 0, 0, &i))) goto error0; XFS_WANT_CORRUPTED_GOTO(i == 1, error0); do { if ((error = xfs_inobt_get_rec(cur, &rec.ir_startino, &rec.ir_freecount, &rec.ir_free, &i))) goto error0; XFS_WANT_CORRUPTED_GOTO(i == 1, error0); freecount += rec.ir_freecount; if ((error = xfs_inobt_increment(cur, 0, &i))) goto error0; } while (i == 1); ASSERT(freecount == be32_to_cpu(agi->agi_freecount) || XFS_FORCED_SHUTDOWN(mp)); } #endif /* * If in the same a.g. as the parent, try to get near the parent. */ if (pagno == agno) { if ((error = xfs_inobt_lookup_le(cur, pagino, 0, 0, &i))) goto error0; if (i != 0 && (error = xfs_inobt_get_rec(cur, &rec.ir_startino, &rec.ir_freecount, &rec.ir_free, &j)) == 0 && j == 1 && rec.ir_freecount > 0) { /* * Found a free inode in the same chunk * as parent, done. */ } /* * In the same a.g. as parent, but parent's chunk is full. */ else { int doneleft; /* done, to the left */ int doneright; /* done, to the right */ if (error) goto error0; ASSERT(i == 1); ASSERT(j == 1); /* * Duplicate the cursor, search left & right * simultaneously. */ if ((error = xfs_btree_dup_cursor(cur, &tcur))) goto error0; /* * Search left with tcur, back up 1 record. */ if ((error = xfs_inobt_decrement(tcur, 0, &i))) goto error1; doneleft = !i; if (!doneleft) { if ((error = xfs_inobt_get_rec(tcur, &trec.ir_startino, &trec.ir_freecount, &trec.ir_free, &i))) goto error1; XFS_WANT_CORRUPTED_GOTO(i == 1, error1); } /* * Search right with cur, go forward 1 record. */ if ((error = xfs_inobt_increment(cur, 0, &i))) goto error1; doneright = !i; if (!doneright) { if ((error = xfs_inobt_get_rec(cur, &rec.ir_startino, &rec.ir_freecount, &rec.ir_free, &i))) goto error1; XFS_WANT_CORRUPTED_GOTO(i == 1, error1); } /* * Loop until we find the closest inode chunk * with a free one. */ while (!doneleft || !doneright) { int useleft; /* using left inode chunk this time */ /* * Figure out which block is closer, * if both are valid. */ if (!doneleft && !doneright) useleft = pagino - (trec.ir_startino + XFS_INODES_PER_CHUNK - 1) < rec.ir_startino - pagino; else useleft = !doneleft; /* * If checking the left, does it have * free inodes? */ if (useleft && trec.ir_freecount) { /* * Yes, set it up as the chunk to use. */ rec = trec; xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR); cur = tcur; break; } /* * If checking the right, does it have * free inodes? */ if (!useleft && rec.ir_freecount) { /* * Yes, it's already set up. */ xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR); break; } /* * If used the left, get another one * further left. */ if (useleft) { if ((error = xfs_inobt_decrement(tcur, 0, &i))) goto error1; doneleft = !i; if (!doneleft) { if ((error = xfs_inobt_get_rec( tcur, &trec.ir_startino, &trec.ir_freecount, &trec.ir_free, &i))) goto error1; XFS_WANT_CORRUPTED_GOTO(i == 1, error1); } } /* * If used the right, get another one * further right. */ else { if ((error = xfs_inobt_increment(cur, 0, &i))) goto error1; doneright = !i; if (!doneright) { if ((error = xfs_inobt_get_rec( cur, &rec.ir_startino, &rec.ir_freecount, &rec.ir_free, &i))) goto error1; XFS_WANT_CORRUPTED_GOTO(i == 1, error1); } } } ASSERT(!doneleft || !doneright); } } /* * In a different a.g. from the parent. * See if the most recently allocated block has any free. */ else if (be32_to_cpu(agi->agi_newino) != NULLAGINO) { if ((error = xfs_inobt_lookup_eq(cur, be32_to_cpu(agi->agi_newino), 0, 0, &i))) goto error0; if (i == 1 && (error = xfs_inobt_get_rec(cur, &rec.ir_startino, &rec.ir_freecount, &rec.ir_free, &j)) == 0 && j == 1 && rec.ir_freecount > 0) { /* * The last chunk allocated in the group still has * a free inode. */ } /* * None left in the last group, search the whole a.g. */ else { if (error) goto error0; if ((error = xfs_inobt_lookup_ge(cur, 0, 0, 0, &i))) goto error0; ASSERT(i == 1); for (;;) { if ((error = xfs_inobt_get_rec(cur, &rec.ir_startino, &rec.ir_freecount, &rec.ir_free, &i))) goto error0; XFS_WANT_CORRUPTED_GOTO(i == 1, error0); if (rec.ir_freecount > 0) break; if ((error = xfs_inobt_increment(cur, 0, &i))) goto error0; XFS_WANT_CORRUPTED_GOTO(i == 1, error0); } } } offset = XFS_IALLOC_FIND_FREE(&rec.ir_free); ASSERT(offset >= 0); ASSERT(offset < XFS_INODES_PER_CHUNK); ASSERT((XFS_AGINO_TO_OFFSET(mp, rec.ir_startino) % XFS_INODES_PER_CHUNK) == 0); ino = XFS_AGINO_TO_INO(mp, agno, rec.ir_startino + offset); XFS_INOBT_CLR_FREE(&rec, offset); rec.ir_freecount--; if ((error = xfs_inobt_update(cur, rec.ir_startino, rec.ir_freecount, rec.ir_free))) goto error0; be32_add(&agi->agi_freecount, -1); xfs_ialloc_log_agi(tp, agbp, XFS_AGI_FREECOUNT); down_read(&mp->m_peraglock); mp->m_perag[tagno].pagi_freecount--; up_read(&mp->m_peraglock); #ifdef DEBUG if (cur->bc_nlevels == 1) { int freecount = 0; if ((error = xfs_inobt_lookup_ge(cur, 0, 0, 0, &i))) goto error0; do { if ((error = xfs_inobt_get_rec(cur, &rec.ir_startino, &rec.ir_freecount, &rec.ir_free, &i))) goto error0; XFS_WANT_CORRUPTED_GOTO(i == 1, error0); freecount += rec.ir_freecount; if ((error = xfs_inobt_increment(cur, 0, &i))) goto error0; } while (i == 1); ASSERT(freecount == be32_to_cpu(agi->agi_freecount) || XFS_FORCED_SHUTDOWN(mp)); } #endif xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR); xfs_trans_mod_sb(tp, XFS_TRANS_SB_IFREE, -1); *inop = ino; return 0; error1: xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR); error0: xfs_btree_del_cursor(cur, XFS_BTREE_ERROR); return error; }
static int xfs_iget_cache_miss( struct xfs_mount *mp, struct xfs_perag *pag, xfs_trans_t *tp, xfs_ino_t ino, struct xfs_inode **ipp, int flags, int lock_flags) { struct xfs_inode *ip; int error; xfs_agino_t agino = XFS_INO_TO_AGINO(mp, ino); int iflags; ip = xfs_inode_alloc(mp, ino); if (!ip) return ENOMEM; error = xfs_iread(mp, tp, ip, flags); if (error) goto out_destroy; trace_xfs_iget_miss(ip); if ((ip->i_d.di_mode == 0) && !(flags & XFS_IGET_CREATE)) { error = ENOENT; goto out_destroy; } if (radix_tree_preload(GFP_KERNEL)) { error = EAGAIN; goto out_destroy; } if (lock_flags) { if (!xfs_ilock_nowait(ip, lock_flags)) BUG(); } iflags = XFS_INEW; if (flags & XFS_IGET_DONTCACHE) iflags |= XFS_IDONTCACHE; ip->i_udquot = ip->i_gdquot = NULL; xfs_iflags_set(ip, iflags); 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(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; }