Remove the global inode_lock, it has been made redundant by the previous lock breakup. Signed-off-by: Nick Piggin --- Documentation/filesystems/Locking | 2 Documentation/filesystems/porting | 10 +++- Documentation/filesystems/vfs.txt | 2 fs/buffer.c | 2 fs/drop_caches.c | 4 - fs/fs-writeback.c | 47 ++++-------------- fs/inode.c | 95 +++++++------------------------------- fs/notify/inode_mark.c | 11 +--- fs/ntfs/inode.c | 4 - fs/ocfs2/inode.c | 2 fs/quota/dquot.c | 16 ++---- include/linux/fs.h | 2 include/linux/writeback.h | 1 mm/backing-dev.c | 4 - mm/filemap.c | 6 +- mm/rmap.c | 6 +- 16 files changed, 60 insertions(+), 154 deletions(-) Index: linux-2.6/fs/buffer.c =================================================================== --- linux-2.6.orig/fs/buffer.c 2010-10-19 14:17:23.000000000 +1100 +++ linux-2.6/fs/buffer.c 2010-10-19 14:18:59.000000000 +1100 @@ -1145,7 +1145,7 @@ * inode list. * * mark_buffer_dirty() is atomic. It takes bh->b_page->mapping->private_lock, - * mapping->tree_lock and the global inode_lock. + * and mapping->tree_lock. */ void mark_buffer_dirty(struct buffer_head *bh) { Index: linux-2.6/fs/drop_caches.c =================================================================== --- linux-2.6.orig/fs/drop_caches.c 2010-10-19 14:18:58.000000000 +1100 +++ linux-2.6/fs/drop_caches.c 2010-10-19 14:19:25.000000000 +1100 @@ -16,7 +16,6 @@ { struct inode *inode, *toput_inode = NULL; - spin_lock(&inode_lock); spin_lock(&sb_inode_list_lock); list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { spin_lock(&inode->i_lock); @@ -28,15 +27,12 @@ __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); iput(toput_inode); toput_inode = inode; - spin_lock(&inode_lock); spin_lock(&sb_inode_list_lock); } spin_unlock(&sb_inode_list_lock); - spin_unlock(&inode_lock); iput(toput_inode); } Index: linux-2.6/fs/fs-writeback.c =================================================================== --- linux-2.6.orig/fs/fs-writeback.c 2010-10-19 14:18:59.000000000 +1100 +++ linux-2.6/fs/fs-writeback.c 2010-10-19 14:19:31.000000000 +1100 @@ -194,7 +194,7 @@ static void inode_sync_complete(struct inode *inode) { /* - * Prevent speculative execution through spin_unlock(&inode_lock); + * Prevent speculative execution through spin_unlock(&inode->i_lock); */ smp_mb(); wake_up_bit(&inode->i_state, __I_SYNC); @@ -294,18 +294,16 @@ while (inode->i_state & I_SYNC) { spin_unlock(&wb_inode_list_lock); 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); spin_lock(&wb_inode_list_lock); } } /* - * Write out an inode's dirty pages. Called under inode_lock. Either the - * caller has ref on the inode (either via __iget or via syscall against an fd) - * or the inode has I_WILL_FREE set (via generic_forget_inode) + * Write out an inode's dirty pages. Either the caller has ref on the inode + * (either via __iget or via syscall against an fd) or the inode has + * I_WILL_FREE set (via generic_forget_inode) * * If `wait' is set, wait on the writeout. * @@ -313,7 +311,8 @@ * starvation of particular inodes when others are being redirtied, prevent * livelocks, etc. * - * Called under inode_lock. + * Called under wb_inode_list_lock and i_lock. May drop the locks but returns + * with them locked. */ static int writeback_single_inode(struct inode *inode, struct writeback_control *wbc) @@ -354,7 +353,6 @@ inode->i_state &= ~I_DIRTY_PAGES; spin_unlock(&wb_inode_list_lock); spin_unlock(&inode->i_lock); - spin_unlock(&inode_lock); ret = do_writepages(mapping, wbc); @@ -374,12 +372,10 @@ * due to delalloc, clear dirty metadata flags right before * 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)) { int err = write_inode(inode, wbc); @@ -387,7 +383,6 @@ ret = err; } - spin_lock(&inode_lock); spin_lock(&inode->i_lock); spin_lock(&wb_inode_list_lock); inode->i_state &= ~I_SYNC; @@ -537,10 +532,8 @@ } spin_unlock(&wb_inode_list_lock); spin_unlock(&inode->i_lock); - spin_unlock(&inode_lock); iput(inode); cond_resched(); - spin_lock(&inode_lock); spin_lock(&wb_inode_list_lock); if (wbc->nr_to_write <= 0) { wbc->more_io = 1; @@ -560,7 +553,6 @@ if (!wbc->wb_start) wbc->wb_start = jiffies; /* livelock avoidance */ - spin_lock(&inode_lock); again: spin_lock(&wb_inode_list_lock); @@ -588,7 +580,6 @@ break; } spin_unlock(&wb_inode_list_lock); - spin_unlock(&inode_lock); /* Leave any unwritten inodes on b_io */ } @@ -597,13 +588,11 @@ { WARN_ON(!rwsem_is_locked(&sb->s_umount)); - spin_lock(&inode_lock); spin_lock(&wb_inode_list_lock); if (!wbc->for_kupdate || list_empty(&wb->b_io)) queue_io(wb, wbc->older_than_this); writeback_sb_inodes(sb, wb, wbc, true); spin_unlock(&wb_inode_list_lock); - spin_unlock(&inode_lock); } /* @@ -714,14 +703,12 @@ * we'll just busyloop. */ retry: - spin_lock(&inode_lock); spin_lock(&wb_inode_list_lock); if (!list_empty(&wb->b_more_io)) { inode = list_entry(wb->b_more_io.prev, struct inode, i_list); if (!spin_trylock(&inode->i_lock)) { spin_unlock(&wb_inode_list_lock); - spin_unlock(&inode_lock); goto retry; } trace_wbc_writeback_wait(&wbc, wb->bdi); @@ -729,7 +716,6 @@ spin_unlock(&inode->i_lock); } spin_unlock(&wb_inode_list_lock); - spin_unlock(&inode_lock); } return wrote; @@ -993,7 +979,6 @@ if (unlikely(block_dump)) 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; @@ -1048,7 +1033,6 @@ } out: spin_unlock(&inode->i_lock); - spin_unlock(&inode_lock); if (wakeup_bdi) bdi_wakeup_thread_delayed(bdi); @@ -1082,7 +1066,6 @@ */ WARN_ON(!rwsem_is_locked(&sb->s_umount)); - spin_lock(&inode_lock); spin_lock(&sb_inode_list_lock); /* @@ -1110,14 +1093,12 @@ __iget(inode); spin_unlock(&inode->i_lock); spin_unlock(&sb_inode_list_lock); - spin_unlock(&inode_lock); /* - * We hold a reference to 'inode' so it couldn't have - * been removed from s_inodes list while we dropped the - * inode_lock. We cannot iput the inode now as we can - * be holding the last reference and we cannot iput it - * under inode_lock. So we keep the reference and iput - * it later. + * We hold a reference to 'inode' so it couldn't have been + * removed from s_inodes list while we dropped the + * sb_inode_list_lock. We cannot iput the inode now as we can + * be holding the last reference and we cannot iput it under + * spinlock. So we keep the reference and iput it later. */ iput(old_inode); old_inode = inode; @@ -1126,11 +1107,9 @@ cond_resched(); - spin_lock(&inode_lock); spin_lock(&sb_inode_list_lock); } spin_unlock(&sb_inode_list_lock); - spin_unlock(&inode_lock); iput(old_inode); } @@ -1235,13 +1214,11 @@ wbc.nr_to_write = 0; might_sleep(); - spin_lock(&inode_lock); spin_lock(&inode->i_lock); spin_lock(&wb_inode_list_lock); ret = writeback_single_inode(inode, &wbc); spin_unlock(&wb_inode_list_lock); spin_unlock(&inode->i_lock); - spin_unlock(&inode_lock); if (sync) inode_sync_wait(inode); return ret; @@ -1263,13 +1240,11 @@ { int ret; - spin_lock(&inode_lock); spin_lock(&inode->i_lock); spin_lock(&wb_inode_list_lock); ret = writeback_single_inode(inode, wbc); spin_unlock(&wb_inode_list_lock); spin_unlock(&inode->i_lock); - spin_unlock(&inode_lock); return ret; } EXPORT_SYMBOL(sync_inode); Index: linux-2.6/fs/inode.c =================================================================== --- linux-2.6.orig/fs/inode.c 2010-10-19 14:18:59.000000000 +1100 +++ linux-2.6/fs/inode.c 2010-10-19 14:19:31.000000000 +1100 @@ -41,11 +41,10 @@ * i_sb_list * * Ordering: - * inode_lock - * sb_inode_list_lock - * inode->i_lock - * wb_inode_list_lock - * inode_hash_lock + * sb_inode_list_lock + * inode->i_lock + * wb_inode_list_lock + * inode_hash_lock */ /* * This is needed for the following functions: @@ -104,7 +103,6 @@ * NOTE! You also have to own the lock if you change * the i_state of an inode while it is in use.. */ -DEFINE_SPINLOCK(inode_lock); DEFINE_SPINLOCK(sb_inode_list_lock); DEFINE_SPINLOCK(wb_inode_list_lock); static DEFINE_SPINLOCK(inode_hash_lock); @@ -136,7 +134,7 @@ static void wake_up_inode(struct inode *inode) { /* - * Prevent speculative execution through spin_unlock(&inode_lock); + * Prevent speculative execution through spin_unlock(&inode->i_lock); */ smp_mb(); wake_up_bit(&inode->i_state, __I_NEW); @@ -308,7 +306,7 @@ } /* - * inode_lock must be held + * i_lock must be held */ void __iget(struct inode *inode) { @@ -372,16 +370,14 @@ evict(inode); - spin_lock(&inode_lock); spin_lock(&sb_inode_list_lock); spin_lock(&inode->i_lock); spin_lock(&inode_hash_lock); hlist_del_init(&inode->i_hash); spin_unlock(&inode_hash_lock); list_del_init(&inode->i_sb_list); - spin_unlock(&sb_inode_list_lock); spin_unlock(&inode->i_lock); - spin_unlock(&inode_lock); + spin_unlock(&sb_inode_list_lock); wake_up_inode(inode); destroy_inode(inode); @@ -407,7 +403,6 @@ * change during umount anymore, and because iprune_sem keeps * shrink_icache_memory() away. */ - cond_resched_lock(&inode_lock); cond_resched_lock(&sb_inode_list_lock); next = next->next; @@ -452,12 +447,10 @@ LIST_HEAD(throw_away); down_write(&iprune_sem); - spin_lock(&inode_lock); spin_lock(&sb_inode_list_lock); fsnotify_unmount_inodes(&sb->s_inodes); busy = invalidate_list(&sb->s_inodes, &throw_away); spin_unlock(&sb_inode_list_lock); - spin_unlock(&inode_lock); dispose_list(&throw_away); up_write(&iprune_sem); @@ -481,7 +474,7 @@ /* * Scan `goal' inodes on the unused list for freeable ones. They are moved to - * a temporary list and then are freed outside inode_lock by dispose_list(). + * a temporary list and then are freed outside LRU lock by dispose_list(). * * Any inodes which are pinned purely because of attached pagecache have their * pagecache removed. We expect the final iput() on that inode to add it to @@ -500,7 +493,6 @@ unsigned long reap = 0; down_read(&iprune_sem); - spin_lock(&inode_lock); again: spin_lock(&wb_inode_list_lock); for (nr_scanned = 0; nr_scanned < nr_to_scan; nr_scanned++) { @@ -524,12 +516,10 @@ spin_unlock(&wb_inode_list_lock); __iget(inode); spin_unlock(&inode->i_lock); - spin_unlock(&inode_lock); if (remove_inode_buffers(inode)) reap += invalidate_mapping_pages(&inode->i_data, 0, -1); iput(inode); - spin_lock(&inode_lock); again2: spin_lock(&wb_inode_list_lock); @@ -556,7 +546,6 @@ __count_vm_events(KSWAPD_INODESTEAL, reap); else __count_vm_events(PGINODESTEAL, reap); - spin_unlock(&inode_lock); spin_unlock(&wb_inode_list_lock); dispose_list(&freeable); @@ -704,9 +693,9 @@ * @inode: inode to mark in use * * When an inode is allocated it needs to be accounted for, added to the in use - * list, the owning superblock and the inode hash. This needs to be done under - * the inode_lock, so export a function to do this rather than the inode lock - * itself. We calculate the hash list to add to here so it is all internal + * list, the owning superblock and the inode hash. + * + * We calculate the hash list to add to here so it is all internal * which requires the caller to have already set up the inode number in the * inode to add. */ @@ -714,12 +703,10 @@ { struct hlist_head *head = inode_hashtable + hash(sb, inode->i_ino); - spin_lock(&inode_lock); spin_lock(&sb_inode_list_lock); spin_lock(&inode->i_lock); __inode_add_to_lists(sb, head, inode); spin_unlock(&inode->i_lock); - spin_unlock(&inode_lock); } EXPORT_SYMBOL_GPL(inode_add_to_lists); @@ -745,18 +732,14 @@ static atomic_t last_ino = ATOMIC_INIT(0); struct inode *inode; - spin_lock_prefetch(&inode_lock); - inode = alloc_inode(sb); if (inode) { - spin_lock(&inode_lock); spin_lock(&sb_inode_list_lock); spin_lock(&inode->i_lock); inode->i_ino = (unsigned int)atomic_inc_return(&last_ino); inode->i_state = 0; __inode_add_to_lists(sb, NULL, inode); spin_unlock(&inode->i_lock); - spin_unlock(&inode_lock); } return inode; } @@ -815,7 +798,6 @@ if (inode) { struct inode *old; - spin_lock(&inode_lock); /* We released the lock, so.. */ old = find_inode(sb, head, test, data); if (!old) { @@ -827,7 +809,6 @@ inode->i_state = I_NEW; __inode_add_to_lists(sb, head, inode); spin_unlock(&inode->i_lock); - spin_unlock(&inode_lock); /* Return the locked inode with I_NEW set, the * caller is responsible for filling in the contents @@ -842,7 +823,6 @@ */ __iget(old); spin_unlock(&old->i_lock); - spin_unlock(&inode_lock); destroy_inode(inode); inode = old; wait_on_inode(inode); @@ -852,7 +832,6 @@ set_failed: spin_unlock(&inode->i_lock); spin_unlock(&sb_inode_list_lock); - spin_unlock(&inode_lock); destroy_inode(inode); return NULL; } @@ -870,7 +849,6 @@ if (inode) { struct inode *old; - spin_lock(&inode_lock); /* We released the lock, so.. */ old = find_inode_fast(sb, head, ino); if (!old) { @@ -880,7 +858,6 @@ inode->i_state = I_NEW; __inode_add_to_lists(sb, head, inode); spin_unlock(&inode->i_lock); - spin_unlock(&inode_lock); /* Return the locked inode with I_NEW set, the * caller is responsible for filling in the contents @@ -895,7 +872,6 @@ */ __iget(old); spin_unlock(&old->i_lock); - spin_unlock(&inode_lock); destroy_inode(inode); inode = old; wait_on_inode(inode); @@ -951,7 +927,6 @@ static unsigned int counter; ino_t res; - spin_lock(&inode_lock); spin_lock(&unique_lock); do { if (counter <= max_reserved) @@ -959,7 +934,6 @@ res = counter++; } while (!is_ino_hashed(sb, res)); spin_unlock(&unique_lock); - spin_unlock(&inode_lock); return res; } @@ -969,7 +943,6 @@ { struct inode *ret = inode; - spin_lock(&inode_lock); spin_lock(&inode->i_lock); if (!(inode->i_state & (I_FREEING|I_WILL_FREE))) __iget(inode); @@ -981,7 +954,6 @@ */ ret = NULL; spin_unlock(&inode->i_lock); - spin_unlock(&inode_lock); return ret; } @@ -1004,7 +976,7 @@ * * Otherwise NULL is returned. * - * Note, @test is called with the inode_lock held, so can't sleep. + * Note, @test is called with the i_lock held, so can't sleep. */ static struct inode *ifind(struct super_block *sb, struct hlist_head *head, int (*test)(struct inode *, void *), @@ -1012,17 +984,14 @@ { struct inode *inode; - spin_lock(&inode_lock); 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); return inode; } - spin_unlock(&inode_lock); return NULL; } @@ -1046,16 +1015,13 @@ { struct inode *inode; - spin_lock(&inode_lock); 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; } - spin_unlock(&inode_lock); return NULL; } @@ -1078,7 +1044,7 @@ * * Otherwise NULL is returned. * - * Note, @test is called with the inode_lock held, so can't sleep. + * Note, @test is called with the i_lock held, so can't sleep. */ struct inode *ilookup5_nowait(struct super_block *sb, unsigned long hashval, int (*test)(struct inode *, void *), void *data) @@ -1106,7 +1072,7 @@ * * Otherwise NULL is returned. * - * Note, @test is called with the inode_lock held, so can't sleep. + * Note, @test is called with the i_lock held, so can't sleep. */ struct inode *ilookup5(struct super_block *sb, unsigned long hashval, int (*test)(struct inode *, void *), void *data) @@ -1157,7 +1123,7 @@ * inode and this is returned locked, hashed, and with the I_NEW flag set. The * file system gets to fill it in before unlocking it via unlock_new_inode(). * - * Note both @test and @set are called with the inode_lock held, so can't sleep. + * Note both @test and @set are called with the i_lock held, so can't sleep. */ struct inode *iget5_locked(struct super_block *sb, unsigned long hashval, int (*test)(struct inode *, void *), @@ -1219,7 +1185,6 @@ struct hlist_node *node; struct inode *old = NULL; - spin_lock(&inode_lock); repeat: spin_lock(&inode_hash_lock); hlist_for_each_entry(old, node, head, i_hash) { @@ -1238,13 +1203,11 @@ if (likely(!node)) { hlist_add_head(&inode->i_hash, head); spin_unlock(&inode_hash_lock); - spin_unlock(&inode_lock); return 0; } 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))) { iput(old); @@ -1267,7 +1230,6 @@ struct hlist_node *node; struct inode *old = NULL; - spin_lock(&inode_lock); repeat: spin_lock(&inode_hash_lock); hlist_for_each_entry(old, node, head, i_hash) { @@ -1286,13 +1248,11 @@ if (likely(!node)) { hlist_add_head(&inode->i_hash, head); spin_unlock(&inode_hash_lock); - spin_unlock(&inode_lock); return 0; } 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))) { iput(old); @@ -1315,13 +1275,11 @@ { struct hlist_head *head = inode_hashtable + hash(inode->i_sb, hashval); - spin_lock(&inode_lock); spin_lock(&inode->i_lock); spin_lock(&inode_hash_lock); hlist_add_head(&inode->i_hash, head); spin_unlock(&inode_hash_lock); spin_unlock(&inode->i_lock); - spin_unlock(&inode_lock); } EXPORT_SYMBOL(__insert_inode_hash); @@ -1333,13 +1291,11 @@ */ void remove_inode_hash(struct inode *inode) { - spin_lock(&inode_lock); spin_lock(&inode->i_lock); spin_lock(&inode_hash_lock); hlist_del_init(&inode->i_hash); spin_unlock(&inode_hash_lock); spin_unlock(&inode->i_lock); - spin_unlock(&inode_lock); } EXPORT_SYMBOL(remove_inode_hash); @@ -1391,16 +1347,13 @@ if (sb->s_flags & MS_ACTIVE) { spin_unlock(&inode->i_lock); spin_unlock(&sb_inode_list_lock); - spin_unlock(&inode_lock); return; } 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); @@ -1418,15 +1371,12 @@ WARN_ON(inode->i_state & I_NEW); inode->i_state |= I_FREEING; spin_unlock(&inode->i_lock); - spin_unlock(&inode_lock); evict(inode); - spin_lock(&inode_lock); spin_lock(&inode->i_lock); spin_lock(&inode_hash_lock); hlist_del_init(&inode->i_hash); spin_unlock(&inode_hash_lock); spin_unlock(&inode->i_lock); - spin_unlock(&inode_lock); wake_up_inode(inode); BUG_ON(inode->i_state != (I_FREEING | I_CLEAR)); destroy_inode(inode); @@ -1446,17 +1396,12 @@ if (inode) { BUG_ON(inode->i_state & I_CLEAR); -retry1: +retry: spin_lock(&inode->i_lock); if (inode->i_count == 1) { - if (!spin_trylock(&inode_lock)) { -retry2: - spin_unlock(&inode->i_lock); - goto retry1; - } if (!spin_trylock(&sb_inode_list_lock)) { - spin_unlock(&inode_lock); - goto retry2; + spin_unlock(&inode->i_lock); + goto retry; } inode->i_count--; iput_final(inode); @@ -1643,8 +1588,6 @@ * It doesn't matter if I_NEW is not set initially, a call to * 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) @@ -1654,10 +1597,8 @@ 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); - spin_lock(&inode_lock); } static __initdata unsigned long ihash_entries; Index: linux-2.6/include/linux/writeback.h =================================================================== --- linux-2.6.orig/include/linux/writeback.h 2010-10-19 14:18:58.000000000 +1100 +++ linux-2.6/include/linux/writeback.h 2010-10-19 14:19:30.000000000 +1100 @@ -9,7 +9,6 @@ struct backing_dev_info; -extern spinlock_t inode_lock; extern spinlock_t sb_inode_list_lock; extern spinlock_t wb_inode_list_lock; extern struct list_head inode_in_use; Index: linux-2.6/fs/quota/dquot.c =================================================================== --- linux-2.6.orig/fs/quota/dquot.c 2010-10-19 14:18:58.000000000 +1100 +++ linux-2.6/fs/quota/dquot.c 2010-10-19 14:19:25.000000000 +1100 @@ -76,7 +76,7 @@ #include #include #include -#include /* for inode_lock, oddly enough.. */ +#include #include @@ -897,7 +897,6 @@ int reserved = 0; #endif - spin_lock(&inode_lock); spin_lock(&sb_inode_list_lock); list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { spin_lock(&inode->i_lock); @@ -921,21 +920,18 @@ __iget(inode); spin_unlock(&inode->i_lock); spin_unlock(&sb_inode_list_lock); - spin_unlock(&inode_lock); iput(old_inode); __dquot_initialize(inode, type); /* We hold a reference to 'inode' so it couldn't have been - * removed from s_inodes list while we dropped the inode_lock. - * We cannot iput the inode now as we can be holding the last - * reference and we cannot iput it under inode_lock. So we - * keep the reference and iput it later. */ + * removed from s_inodes list while we dropped the + * sb_inode_list_lock. We cannot iput the inode now as we can + * be holding the last reference and we cannot iput it under + * lock. So we keep the reference and iput it later. */ old_inode = inode; - spin_lock(&inode_lock); spin_lock(&sb_inode_list_lock); } spin_unlock(&sb_inode_list_lock); - spin_unlock(&inode_lock); iput(old_inode); #ifdef CONFIG_QUOTA_DEBUG @@ -1016,7 +1012,6 @@ struct inode *inode; int reserved = 0; - spin_lock(&inode_lock); spin_lock(&sb_inode_list_lock); list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { /* @@ -1032,7 +1027,6 @@ } } spin_unlock(&sb_inode_list_lock); - spin_unlock(&inode_lock); #ifdef CONFIG_QUOTA_DEBUG if (reserved) { printk(KERN_WARNING "VFS (%s): Writes happened after quota" Index: linux-2.6/fs/notify/inode_mark.c =================================================================== --- linux-2.6.orig/fs/notify/inode_mark.c 2010-10-19 14:18:58.000000000 +1100 +++ linux-2.6/fs/notify/inode_mark.c 2010-10-19 14:19:25.000000000 +1100 @@ -22,7 +22,7 @@ #include #include #include -#include /* for inode_lock */ +#include #include @@ -232,9 +232,8 @@ * fsnotify_unmount_inodes - an sb is unmounting. handle any watched inodes. * @list: list of inodes being unmounted (sb->s_inodes) * - * Called with inode_lock held, protecting the unmounting super block's list - * of inodes, and with iprune_mutex held, keeping shrink_icache_memory() at bay. - * We temporarily drop inode_lock, however, and CAN block. + * Called with iprune_mutex held, keeping shrink_icache_memory() at bay. + * sb_inode_list_lock to protect the super block's list of inodes. */ void fsnotify_unmount_inodes(struct list_head *list) { @@ -287,13 +286,12 @@ } /* - * We can safely drop inode_lock here because we hold + * We can safely drop sb_inode_list_lock here because we hold * references on both inode and next_i. Also no new inodes * will be added since the umount has begun. Finally, * iprune_mutex keeps shrink_icache_memory() away. */ spin_unlock(&sb_inode_list_lock); - spin_unlock(&inode_lock); if (need_iput_tmp) iput(need_iput_tmp); @@ -305,7 +303,6 @@ iput(inode); - spin_lock(&inode_lock); spin_lock(&sb_inode_list_lock); } } Index: linux-2.6/mm/backing-dev.c =================================================================== --- linux-2.6.orig/mm/backing-dev.c 2010-10-19 14:18:58.000000000 +1100 +++ linux-2.6/mm/backing-dev.c 2010-10-19 14:19:21.000000000 +1100 @@ -73,7 +73,6 @@ struct inode *inode; nr_wb = nr_dirty = nr_io = nr_more_io = 0; - spin_lock(&inode_lock); spin_lock(&wb_inode_list_lock); list_for_each_entry(inode, &wb->b_dirty, i_list) nr_dirty++; @@ -82,7 +81,6 @@ list_for_each_entry(inode, &wb->b_more_io, i_list) nr_more_io++; spin_unlock(&wb_inode_list_lock); - spin_unlock(&inode_lock); global_dirty_limits(&background_thresh, &dirty_thresh); bdi_thresh = bdi_dirty_limit(bdi, dirty_thresh); @@ -684,13 +682,11 @@ if (bdi_has_dirty_io(bdi)) { struct bdi_writeback *dst = &default_backing_dev_info.wb; - spin_lock(&inode_lock); spin_lock(&wb_inode_list_lock); list_splice(&bdi->wb.b_dirty, &dst->b_dirty); list_splice(&bdi->wb.b_io, &dst->b_io); list_splice(&bdi->wb.b_more_io, &dst->b_more_io); spin_unlock(&wb_inode_list_lock); - spin_unlock(&inode_lock); } bdi_unregister(bdi); Index: linux-2.6/mm/filemap.c =================================================================== --- linux-2.6.orig/mm/filemap.c 2010-10-19 14:17:28.000000000 +1100 +++ linux-2.6/mm/filemap.c 2010-10-19 14:18:59.000000000 +1100 @@ -80,7 +80,7 @@ * ->i_mutex * ->i_alloc_sem (various) * - * ->inode_lock + * ->i_lock * ->sb_lock (fs/fs-writeback.c) * ->mapping->tree_lock (__sync_single_inode) * @@ -98,8 +98,8 @@ * ->zone.lru_lock (check_pte_range->isolate_lru_page) * ->private_lock (page_remove_rmap->set_page_dirty) * ->tree_lock (page_remove_rmap->set_page_dirty) - * ->inode_lock (page_remove_rmap->set_page_dirty) - * ->inode_lock (zap_pte_range->set_page_dirty) + * ->i_lock (page_remove_rmap->set_page_dirty) + * ->i_lock (zap_pte_range->set_page_dirty) * ->private_lock (zap_pte_range->__set_page_dirty_buffers) * * ->task->proc_lock Index: linux-2.6/mm/rmap.c =================================================================== --- linux-2.6.orig/mm/rmap.c 2010-10-19 14:17:23.000000000 +1100 +++ linux-2.6/mm/rmap.c 2010-10-19 14:18:59.000000000 +1100 @@ -31,11 +31,11 @@ * swap_lock (in swap_duplicate, swap_info_get) * mmlist_lock (in mmput, drain_mmlist and others) * mapping->private_lock (in __set_page_dirty_buffers) - * inode_lock (in set_page_dirty's __mark_inode_dirty) - * sb_lock (within inode_lock in fs/fs-writeback.c) + * i_lock (in set_page_dirty's __mark_inode_dirty) + * sb_lock (within i_lock in fs/fs-writeback.c) * mapping->tree_lock (widely used, in set_page_dirty, * in arch-dependent flush_dcache_mmap_lock, - * within inode_lock in __sync_single_inode) + * within i_lock in __sync_single_inode) * * (code doesn't rely on that order so it could be switched around) * ->tasklist_lock Index: linux-2.6/Documentation/filesystems/Locking =================================================================== --- linux-2.6.orig/Documentation/filesystems/Locking 2010-10-19 14:17:22.000000000 +1100 +++ linux-2.6/Documentation/filesystems/Locking 2010-10-19 14:19:25.000000000 +1100 @@ -114,7 +114,7 @@ destroy_inode: dirty_inode: (must not sleep) write_inode: -drop_inode: !!!inode_lock!!! +drop_inode: !!!i_lock, sb_inode_list_lock!!! evict_inode: put_super: write write_super: read Index: linux-2.6/Documentation/filesystems/vfs.txt =================================================================== --- linux-2.6.orig/Documentation/filesystems/vfs.txt 2010-10-19 14:17:22.000000000 +1100 +++ linux-2.6/Documentation/filesystems/vfs.txt 2010-10-19 14:19:25.000000000 +1100 @@ -246,7 +246,7 @@ should be synchronous or not, not all filesystems check this flag. drop_inode: called when the last access to the inode is dropped, - with the inode_lock spinlock held. + with the i_lock and sb_inode_list_lock spinlock held. This method should be either NULL (normal UNIX filesystem semantics) or "generic_delete_inode" (for filesystems that do not Index: linux-2.6/fs/ntfs/inode.c =================================================================== --- linux-2.6.orig/fs/ntfs/inode.c 2010-10-19 14:17:23.000000000 +1100 +++ linux-2.6/fs/ntfs/inode.c 2010-10-19 14:19:28.000000000 +1100 @@ -54,7 +54,7 @@ * * Return 1 if the attributes match and 0 if not. * - * NOTE: This function runs with the inode_lock spin lock held so it is not + * NOTE: This function runs with the i_lock spin lock held so it is not * allowed to sleep. */ int ntfs_test_inode(struct inode *vi, ntfs_attr *na) @@ -98,7 +98,7 @@ * * Return 0 on success and -errno on error. * - * NOTE: This function runs with the inode_lock spin lock held so it is not + * NOTE: This function runs with the i_lock spin lock held so it is not * allowed to sleep. (Hence the GFP_ATOMIC allocation.) */ static int ntfs_init_locked_inode(struct inode *vi, ntfs_attr *na) Index: linux-2.6/fs/ocfs2/inode.c =================================================================== --- linux-2.6.orig/fs/ocfs2/inode.c 2010-10-19 14:17:23.000000000 +1100 +++ linux-2.6/fs/ocfs2/inode.c 2010-10-19 14:18:59.000000000 +1100 @@ -1195,7 +1195,7 @@ ocfs2_clear_inode(inode); } -/* Called under inode_lock, with no more references on the +/* Called under i_lock, with no more references on the * struct inode, so it's safe here to check the flags field * and to manipulate i_nlink without any other locks. */ int ocfs2_drop_inode(struct inode *inode) Index: linux-2.6/include/linux/fs.h =================================================================== --- linux-2.6.orig/include/linux/fs.h 2010-10-19 14:18:59.000000000 +1100 +++ linux-2.6/include/linux/fs.h 2010-10-19 14:19:31.000000000 +1100 @@ -1589,7 +1589,7 @@ }; /* - * Inode state bits. Protected by inode_lock. + * Inode state bits. Protected by i_lock. * * Three bits determine the dirty state of the inode, I_DIRTY_SYNC, * I_DIRTY_DATASYNC and I_DIRTY_PAGES. Index: linux-2.6/Documentation/filesystems/porting =================================================================== --- linux-2.6.orig/Documentation/filesystems/porting 2010-10-19 14:17:22.000000000 +1100 +++ linux-2.6/Documentation/filesystems/porting 2010-10-19 14:19:28.000000000 +1100 @@ -299,7 +299,7 @@ remaining links or not. Caller does *not* evict the pagecache or inode-associated metadata buffers; getting rid of those is responsibility of method, as it had been for ->delete_inode(). - ->drop_inode() returns int now; it's called on final iput() with inode_lock + ->drop_inode() returns int now; it's called on final iput() with i_lock held and it returns true if filesystems wants the inode to be dropped. As before, generic_drop_inode() is still the default and it's been updated appropriately. generic_delete_inode() is also alive and it consists simply of return 1. Note that @@ -318,3 +318,11 @@ may happen while the inode is in the middle of ->write_inode(); e.g. if you blindly free the on-disk inode, you may end up doing that while ->write_inode() is writing to it. + +-- +[mandatory] + inode_lock is gone, replaced by fine grained locks. See fs/inode.c +for details of what locks to replace inode_lock with in order to protect +particular things. Most of the time, a filesystem only needs ->i_lock, which +protects *all* the inode state and its membership on lists that was +previously protected with inode_lock. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/