fs-inode_lock-scale-7

Remove the global inode_lock

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

2 files changed, 18 insertions, 12 deletions

diff --git a/fs/notify/inode_mark.c b/fs/notify/inode_mark.c
index 869f94bb040f..81b5bbb3a7ee 100644
--- a/fs/notify/inode_mark.c
+++ b/fs/notify/inode_mark.c
@@ -369,13 +369,16 @@ void fsnotify_unmount_inodes(struct list_head *list)
 	list_for_each_entry_safe(inode, next_i, list, i_sb_list) {
 		struct inode *need_iput_tmp;
 
+		spin_lock(&inode->i_lock);
 		/*
 		 * We cannot __iget() an inode in state I_CLEAR, I_FREEING,
 		 * I_WILL_FREE, or I_NEW which is fine because by that point
 		 * the inode cannot have any associated watches.
 		 */
-		if (inode->i_state & (I_CLEAR|I_FREEING|I_WILL_FREE|I_NEW))
+		if (inode->i_state & (I_CLEAR|I_FREEING|I_WILL_FREE|I_NEW)) {
+			spin_unlock(&inode->i_lock);
 			continue;
+		}
 
 		/*
 		 * If i_count is zero, the inode cannot have any watches and
@@ -383,19 +386,20 @@ void fsnotify_unmount_inodes(struct list_head *list)
 		 * evict all inodes with zero i_count from icache which is
 		 * unnecessarily violent and may in fact be illegal to do.
 		 */
-		if (!inode->i_count)
+		if (!inode->i_count) {
+			spin_unlock(&inode->i_lock);
 			continue;
+		}
 
 		need_iput_tmp = need_iput;
 		need_iput = NULL;
 
 		/* In case fsnotify_inode_delete() drops a reference. */
 		if (inode != need_iput_tmp) {
-			spin_lock(&inode->i_lock);
 			__iget(inode);
-			spin_unlock(&inode->i_lock);
 		} else
 			need_iput_tmp = NULL;
+		spin_unlock(&inode->i_lock);
 
 		/* In case the dropping of a reference would nuke next_i. */
 		if (&next_i->i_sb_list != list) {
@@ -416,7 +420,6 @@ void fsnotify_unmount_inodes(struct list_head *list)
 		 * 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);
@@ -428,7 +431,6 @@ void fsnotify_unmount_inodes(struct list_head *list)
 
 		iput(inode);
 
-		spin_lock(&inode_lock);
 		spin_lock(&sb_inode_list_lock);
 	}
 }
diff --git a/fs/notify/inotify/inotify.c b/fs/notify/inotify/inotify.c
index 44e90ef0b0a3..7846758db7da 100644
--- a/fs/notify/inotify/inotify.c
+++ b/fs/notify/inotify/inotify.c
@@ -394,13 +394,16 @@ void inotify_unmount_inodes(struct list_head *list)
 		struct inode *need_iput_tmp;
 		struct list_head *watches;
 
+		spin_lock(&inode->i_lock);
 		/*
 		 * We cannot __iget() an inode in state I_CLEAR, I_FREEING,
 		 * I_WILL_FREE, or I_NEW which is fine because by that point
 		 * the inode cannot have any associated watches.
 		 */
-		if (inode->i_state & (I_CLEAR|I_FREEING|I_WILL_FREE|I_NEW))
+		if (inode->i_state & (I_CLEAR|I_FREEING|I_WILL_FREE|I_NEW)) {
+			spin_unlock(&inode->i_lock);
 			continue;
+		}
 
 		/*
 		 * If i_count is zero, the inode cannot have any watches and
@@ -408,18 +411,21 @@ void inotify_unmount_inodes(struct list_head *list)
 		 * evict all inodes with zero i_count from icache which is
 		 * unnecessarily violent and may in fact be illegal to do.
 		 */
-		if (!inode->i_count)
+		if (!inode->i_count) {
+			spin_unlock(&inode->i_lock);
 			continue;
+		}
 
 		need_iput_tmp = need_iput;
 		need_iput = NULL;
 		/* In case inotify_remove_watch_locked() drops a reference. */
 		if (inode != need_iput_tmp) {
-			spin_lock(&inode->i_lock);
 			__iget(inode);
-			spin_unlock(&inode->i_lock);
 		} else
 			need_iput_tmp = NULL;
+
+		spin_unlock(&inode->i_lock);
+
 		/* In case the dropping of a reference would nuke next_i. */
 		if (&next_i->i_sb_list != list) {
 			spin_lock(&next_i->i_lock);
@@ -439,7 +445,6 @@ void inotify_unmount_inodes(struct list_head *list)
 		 * 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);
@@ -459,7 +464,6 @@ void inotify_unmount_inodes(struct list_head *list)
 		mutex_unlock(&inode->inotify_mutex);
 		iput(inode);		
 
-		spin_lock(&inode_lock);
 		spin_lock(&sb_inode_list_lock);
 	}
 }