Protect i_state updates with i_lock Signed-off-by: Nick Piggin <npiggin@xxxxxxx> --- fs/drop_caches.c | 9 ++++-- fs/fs-writeback.c | 37 +++++++++++++++++++----- fs/inode.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++-------- fs/nilfs2/gcdat.c | 1 fs/quota/dquot.c | 14 +++++++-- 5 files changed, 117 insertions(+), 25 deletions(-) Index: linux-2.6/fs/drop_caches.c =================================================================== --- linux-2.6.orig/fs/drop_caches.c +++ linux-2.6/fs/drop_caches.c @@ -19,11 +19,14 @@ static void drop_pagecache_sb(struct sup spin_lock(&inode_lock); spin_lock(&sb_inode_list_lock); list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { - if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE|I_NEW)) - continue; - if (inode->i_mapping->nrpages == 0) + spin_lock(&inode->i_lock); + if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE|I_NEW) + || inode->i_mapping->nrpages == 0) { + spin_unlock(&inode->i_lock); continue; + } __iget(inode); + spin_unlock(&inode->i_lock); spin_unlock(&sb_inode_list_lock); spin_unlock(&inode_lock); invalidate_mapping_pages(inode->i_mapping, 0, -1); Index: linux-2.6/fs/fs-writeback.c =================================================================== --- linux-2.6.orig/fs/fs-writeback.c +++ linux-2.6/fs/fs-writeback.c @@ -398,10 +398,12 @@ static void inode_wait_for_writeback(str wait_queue_head_t *wqh; wqh = bit_waitqueue(&inode->i_state, __I_SYNC); - while (inode->i_state & I_SYNC) { + while (inode->i_state & I_SYNC) { + spin_unlock(&inode->i_lock); spin_unlock(&inode_lock); __wait_on_bit(wqh, &wq, inode_wait, TASK_UNINTERRUPTIBLE); spin_lock(&inode_lock); + spin_lock(&inode->i_lock); } } @@ -455,6 +457,7 @@ writeback_single_inode(struct inode *ino /* Set I_SYNC, reset I_DIRTY_PAGES */ inode->i_state |= I_SYNC; inode->i_state &= ~I_DIRTY_PAGES; + spin_unlock(&inode->i_lock); spin_unlock(&inode_lock); ret = do_writepages(mapping, wbc); @@ -476,8 +479,10 @@ writeback_single_inode(struct inode *ino * write_inode() */ spin_lock(&inode_lock); + spin_lock(&inode->i_lock); dirty = inode->i_state & I_DIRTY; inode->i_state &= ~(I_DIRTY_SYNC | I_DIRTY_DATASYNC); + spin_unlock(&inode->i_lock); spin_unlock(&inode_lock); /* Don't write the inode if only I_DIRTY_PAGES was set */ if (dirty & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) { @@ -487,6 +492,7 @@ writeback_single_inode(struct inode *ino } spin_lock(&inode_lock); + spin_lock(&inode->i_lock); inode->i_state &= ~I_SYNC; if (!(inode->i_state & (I_FREEING | I_CLEAR))) { if ((inode->i_state & I_DIRTY_PAGES) && wbc->for_kupdate) { @@ -630,7 +636,9 @@ static int writeback_sb_inodes(struct su if (sb != inode->i_sb) /* finish with this superblock */ return 0; + spin_lock(&inode->i_lock); if (inode->i_state & (I_NEW | I_WILL_FREE)) { + spin_unlock(&inode->i_lock); requeue_io(inode); continue; } @@ -638,8 +646,10 @@ static int writeback_sb_inodes(struct su * Was this inode dirtied after sync_sb_inodes was called? * This keeps sync from extra jobs and livelock. */ - if (inode_dirtied_after(inode, wbc->wb_start)) + if (inode_dirtied_after(inode, wbc->wb_start)) { + spin_unlock(&inode->i_lock); return 1; + } BUG_ON(inode->i_state & (I_FREEING | I_CLEAR)); __iget(inode); @@ -652,6 +662,7 @@ static int writeback_sb_inodes(struct su */ redirty_tail(inode); } + spin_unlock(&inode->i_lock); spin_unlock(&inode_lock); iput(inode); cond_resched(); @@ -1090,6 +1101,7 @@ void __mark_inode_dirty(struct inode *in block_dump___mark_inode_dirty(inode); spin_lock(&inode_lock); + spin_lock(&inode->i_lock); if ((inode->i_state & flags) != flags) { const int was_dirty = inode->i_state & I_DIRTY; @@ -1134,6 +1146,7 @@ void __mark_inode_dirty(struct inode *in } } out: + spin_unlock(&inode->i_lock); spin_unlock(&inode_lock); } EXPORT_SYMBOL(__mark_inode_dirty); @@ -1178,12 +1191,17 @@ static void wait_sb_inodes(struct super_ list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { struct address_space *mapping; - if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE|I_NEW)) - continue; mapping = inode->i_mapping; if (mapping->nrpages == 0) continue; + + spin_lock(&inode->i_lock); + if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE|I_NEW)) { + spin_unlock(&inode->i_lock); + continue; + } __iget(inode); + spin_unlock(&inode->i_lock); spin_unlock(&sb_inode_list_lock); spin_unlock(&inode_lock); /* @@ -1287,7 +1305,9 @@ int write_inode_now(struct inode *inode, might_sleep(); spin_lock(&inode_lock); + spin_lock(&inode->i_lock); ret = writeback_single_inode(inode, &wbc); + spin_unlock(&inode->i_lock); spin_unlock(&inode_lock); if (sync) inode_sync_wait(inode); @@ -1311,7 +1331,9 @@ int sync_inode(struct inode *inode, stru int ret; spin_lock(&inode_lock); + spin_lock(&inode->i_lock); ret = writeback_single_inode(inode, wbc); + spin_unlock(&inode->i_lock); spin_unlock(&inode_lock); return ret; } Index: linux-2.6/fs/inode.c =================================================================== --- linux-2.6.orig/fs/inode.c +++ linux-2.6/fs/inode.c @@ -32,10 +32,13 @@ * s_inodes, i_sb_list * inode_hash_lock protects: * inode hash table, i_hash + * inode->i_lock protects: + * i_state * * Ordering: * inode_lock * sb_inode_list_lock + * inode->i_lock * inode_lock * inode_hash_lock */ @@ -301,6 +304,8 @@ static void init_once(void *foo) */ void __iget(struct inode *inode) { + assert_spin_locked(&inode->i_lock); + if (atomic_inc_return(&inode->i_count) != 1) return; @@ -401,16 +406,21 @@ static int invalidate_list(struct list_h if (tmp == head) break; inode = list_entry(tmp, struct inode, i_sb_list); - if (inode->i_state & I_NEW) + spin_lock(&inode->i_lock); + if (inode->i_state & I_NEW) { + spin_unlock(&inode->i_lock); continue; + } invalidate_inode_buffers(inode); if (!atomic_read(&inode->i_count)) { list_move(&inode->i_list, dispose); WARN_ON(inode->i_state & I_NEW); inode->i_state |= I_FREEING; + spin_unlock(&inode->i_lock); count++; continue; } + spin_unlock(&inode->i_lock); busy = 1; } /* only unused inodes may be cached with i_count zero */ @@ -490,12 +500,15 @@ static void prune_icache(int nr_to_scan) inode = list_entry(inode_unused.prev, struct inode, i_list); + spin_lock(&inode->i_lock); if (inode->i_state || atomic_read(&inode->i_count)) { list_move(&inode->i_list, &inode_unused); + spin_unlock(&inode->i_lock); continue; } if (inode_has_buffers(inode) || inode->i_data.nrpages) { __iget(inode); + spin_unlock(&inode->i_lock); spin_unlock(&inode_lock); if (remove_inode_buffers(inode)) reap += invalidate_mapping_pages(&inode->i_data, @@ -506,12 +519,16 @@ static void prune_icache(int nr_to_scan) if (inode != list_entry(inode_unused.next, struct inode, i_list)) continue; /* wrong inode or list_empty */ - if (!can_unuse(inode)) + spin_lock(&inode->i_lock); + if (!can_unuse(inode)) { + spin_unlock(&inode->i_lock); continue; + } } list_move(&inode->i_list, &freeable); WARN_ON(inode->i_state & I_NEW); inode->i_state |= I_FREEING; + spin_unlock(&inode->i_lock); nr_pruned++; } inodes_stat.nr_unused -= nr_pruned; @@ -574,8 +591,14 @@ repeat: hlist_for_each_entry(inode, node, head, i_hash) { if (inode->i_sb != sb) continue; - if (!test(inode, data)) + if (!spin_trylock(&inode->i_lock)) { + spin_unlock(&inode_hash_lock); + goto repeat; + } + if (!test(inode, data)) { + spin_unlock(&inode->i_lock); continue; + } if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)) { spin_unlock(&inode_hash_lock); __wait_on_freeing_inode(inode); @@ -604,6 +627,10 @@ repeat: continue; if (inode->i_sb != sb) continue; + if (!spin_trylock(&inode->i_lock)) { + spin_unlock(&inode_hash_lock); + goto repeat; + } if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)) { spin_unlock(&inode_hash_lock); __wait_on_freeing_inode(inode); @@ -630,10 +657,10 @@ __inode_add_to_lists(struct super_block struct inode *inode) { inodes_stat.nr_inodes++; - list_add(&inode->i_list, &inode_in_use); spin_lock(&sb_inode_list_lock); list_add(&inode->i_sb_list, &sb->s_inodes); spin_unlock(&sb_inode_list_lock); + list_add(&inode->i_list, &inode_in_use); if (head) { spin_lock(&inode_hash_lock); hlist_add_head(&inode->i_hash, head); @@ -690,9 +717,9 @@ struct inode *new_inode(struct super_blo inode = alloc_inode(sb); if (inode) { spin_lock(&inode_lock); - __inode_add_to_lists(sb, NULL, inode); inode->i_ino = ++last_ino; inode->i_state = 0; + __inode_add_to_lists(sb, NULL, inode); spin_unlock(&inode_lock); } return inode; @@ -759,8 +786,8 @@ static struct inode *get_new_inode(struc if (set(inode, data)) goto set_failed; - __inode_add_to_lists(sb, head, inode); inode->i_state = I_NEW; + __inode_add_to_lists(sb, head, inode); spin_unlock(&inode_lock); /* Return the locked inode with I_NEW set, the @@ -775,6 +802,7 @@ static struct inode *get_new_inode(struc * allocated. */ __iget(old); + spin_unlock(&old->i_lock); spin_unlock(&inode_lock); destroy_inode(inode); inode = old; @@ -783,6 +811,7 @@ static struct inode *get_new_inode(struc return inode; set_failed: + spin_unlock(&inode->i_lock); spin_unlock(&inode_lock); destroy_inode(inode); return NULL; @@ -806,8 +835,8 @@ static struct inode *get_new_inode_fast( old = find_inode_fast(sb, head, ino); if (!old) { inode->i_ino = ino; - __inode_add_to_lists(sb, head, inode); inode->i_state = I_NEW; + __inode_add_to_lists(sb, head, inode); spin_unlock(&inode_lock); /* Return the locked inode with I_NEW set, the @@ -822,6 +851,7 @@ static struct inode *get_new_inode_fast( * allocated. */ __iget(old); + spin_unlock(&old->i_lock); spin_unlock(&inode_lock); destroy_inode(inode); inode = old; @@ -863,6 +893,7 @@ ino_t iunique(struct super_block *sb, in res = counter++; head = inode_hashtable + hash(sb, res); inode = find_inode_fast(sb, head, res); + spin_unlock(&inode->i_lock); } while (inode != NULL); spin_unlock(&inode_lock); @@ -872,7 +903,10 @@ EXPORT_SYMBOL(iunique); struct inode *igrab(struct inode *inode) { + struct inode *ret = inode; + spin_lock(&inode_lock); + spin_lock(&inode->i_lock); if (!(inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE))) __iget(inode); else @@ -881,9 +915,11 @@ struct inode *igrab(struct inode *inode) * called yet, and somebody is calling igrab * while the inode is getting freed. */ - inode = NULL; + ret = NULL; + spin_unlock(&inode->i_lock); spin_unlock(&inode_lock); - return inode; + + return ret; } EXPORT_SYMBOL(igrab); @@ -916,6 +952,7 @@ static struct inode *ifind(struct super_ inode = find_inode(sb, head, test, data); if (inode) { __iget(inode); + spin_unlock(&inode->i_lock); spin_unlock(&inode_lock); if (likely(wait)) wait_on_inode(inode); @@ -949,6 +986,7 @@ static struct inode *ifind_fast(struct s inode = find_inode_fast(sb, head, ino); if (inode) { __iget(inode); + spin_unlock(&inode->i_lock); spin_unlock(&inode_lock); wait_on_inode(inode); return inode; @@ -1118,6 +1156,7 @@ int insert_inode_locked(struct inode *in struct inode *old = NULL; spin_lock(&inode_lock); +repeat: spin_lock(&inode_hash_lock); hlist_for_each_entry(old, node, head, i_hash) { if (old->i_ino != ino) @@ -1126,6 +1165,10 @@ int insert_inode_locked(struct inode *in continue; if (old->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)) continue; + if (!spin_trylock(&old->i_lock)) { + spin_unlock(&inode_hash_lock); + goto repeat; + } break; } if (likely(!node)) { @@ -1136,6 +1179,7 @@ int insert_inode_locked(struct inode *in } spin_unlock(&inode_hash_lock); __iget(old); + spin_unlock(&old->i_lock); spin_unlock(&inode_lock); wait_on_inode(old); if (unlikely(!hlist_unhashed(&old->i_hash))) { @@ -1160,6 +1204,7 @@ int insert_inode_locked4(struct inode *i struct inode *old = NULL; spin_lock(&inode_lock); +repeat: spin_lock(&inode_hash_lock); hlist_for_each_entry(old, node, head, i_hash) { if (old->i_sb != sb) @@ -1168,6 +1213,10 @@ int insert_inode_locked4(struct inode *i continue; if (old->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)) continue; + if (!spin_trylock(&old->i_lock)) { + spin_unlock(&inode_hash_lock); + goto repeat; + } break; } if (likely(!node)) { @@ -1178,6 +1227,7 @@ int insert_inode_locked4(struct inode *i } spin_unlock(&inode_hash_lock); __iget(old); + spin_unlock(&old->i_lock); spin_unlock(&inode_lock); wait_on_inode(old); if (unlikely(!hlist_unhashed(&old->i_hash))) { @@ -1240,12 +1290,14 @@ void generic_delete_inode(struct inode * { const struct super_operations *op = inode->i_sb->s_op; - list_del_init(&inode->i_list); spin_lock(&sb_inode_list_lock); + spin_lock(&inode->i_lock); + list_del_init(&inode->i_list); list_del_init(&inode->i_sb_list); spin_unlock(&sb_inode_list_lock); WARN_ON(inode->i_state & I_NEW); inode->i_state |= I_FREEING; + spin_unlock(&inode->i_lock); inodes_stat.nr_inodes--; spin_unlock(&inode_lock); @@ -1284,19 +1336,27 @@ int generic_detach_inode(struct inode *i { struct super_block *sb = inode->i_sb; + spin_lock(&sb_inode_list_lock); + spin_lock(&inode->i_lock); if (!hlist_unhashed(&inode->i_hash)) { if (!(inode->i_state & (I_DIRTY|I_SYNC))) list_move(&inode->i_list, &inode_unused); inodes_stat.nr_unused++; if (sb->s_flags & MS_ACTIVE) { + spin_unlock(&inode->i_lock); + spin_unlock(&sb_inode_list_lock); spin_unlock(&inode_lock); return 0; } WARN_ON(inode->i_state & I_NEW); inode->i_state |= I_WILL_FREE; + spin_unlock(&inode->i_lock); + spin_unlock(&sb_inode_list_lock); spin_unlock(&inode_lock); write_inode_now(inode, 1); spin_lock(&inode_lock); + spin_lock(&sb_inode_list_lock); + spin_lock(&inode->i_lock); WARN_ON(inode->i_state & I_NEW); inode->i_state &= ~I_WILL_FREE; inodes_stat.nr_unused--; @@ -1305,12 +1365,12 @@ int generic_detach_inode(struct inode *i spin_unlock(&inode_hash_lock); } list_del_init(&inode->i_list); - spin_lock(&sb_inode_list_lock); list_del_init(&inode->i_sb_list); spin_unlock(&sb_inode_list_lock); WARN_ON(inode->i_state & I_NEW); inode->i_state |= I_FREEING; inodes_stat.nr_inodes--; + spin_unlock(&inode->i_lock); spin_unlock(&inode_lock); return 1; } @@ -1558,6 +1618,8 @@ EXPORT_SYMBOL(inode_wait); * wake_up_inode() after removing from the hash list will DTRT. * * This is called with inode_lock held. + * + * Called with i_lock held and returns with it dropped. */ static void __wait_on_freeing_inode(struct inode *inode) { @@ -1565,6 +1627,7 @@ static void __wait_on_freeing_inode(stru DEFINE_WAIT_BIT(wait, &inode->i_state, __I_NEW); wq = bit_waitqueue(&inode->i_state, __I_NEW); prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE); + spin_unlock(&inode->i_lock); spin_unlock(&inode_lock); schedule(); finish_wait(wq, &wait.wait); Index: linux-2.6/fs/nilfs2/gcdat.c =================================================================== --- linux-2.6.orig/fs/nilfs2/gcdat.c +++ linux-2.6/fs/nilfs2/gcdat.c @@ -27,6 +27,7 @@ #include "page.h" #include "mdt.h" +/* XXX: what protects i_state? */ int nilfs_init_gcdat_inode(struct the_nilfs *nilfs) { struct inode *dat = nilfs->ns_dat, *gcdat = nilfs->ns_gc_dat; Index: linux-2.6/fs/quota/dquot.c =================================================================== --- linux-2.6.orig/fs/quota/dquot.c +++ linux-2.6/fs/quota/dquot.c @@ -886,18 +886,26 @@ static void add_dquot_ref(struct super_b spin_lock(&inode_lock); spin_lock(&sb_inode_list_lock); list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { - if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE|I_NEW)) + spin_lock(&inode->i_lock); + if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE|I_NEW)) { + spin_unlock(&inode->i_lock); continue; + } #ifdef CONFIG_QUOTA_DEBUG if (unlikely(inode_get_rsv_space(inode) > 0)) reserved = 1; #endif - if (!atomic_read(&inode->i_writecount)) + if (!atomic_read(&inode->i_writecount)) { + spin_unlock(&inode->i_lock); continue; - if (!dqinit_needed(inode, type)) + } + if (!dqinit_needed(inode, type)) { + spin_unlock(&inode->i_lock); continue; + } __iget(inode); + spin_unlock(&inode->i_lock); spin_unlock(&sb_inode_list_lock); spin_unlock(&inode_lock); -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html