[PATCH 3.12 021/144] expand dentry_kill(dentry, 0) in shrink_dentry_list()

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

3.12-stable review patch.  If anyone has any objections, please let me know.

===============

commit ff2fde9929feb2aef45377ce56b8b12df85dda69 upstream.

Result will be massaged to saner shape in the next commits.  It is
ugly, no questions - the point of that one is to be a provably
equivalent transformation (and it might be worth splitting a bit
more).

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
 fs/dcache.c | 30 +++++++++++++++++-------------
 1 file changed, 17 insertions(+), 13 deletions(-)

diff --git a/fs/dcache.c b/fs/dcache.c
index 7575aeec1740..d66649a44f75 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -823,6 +823,7 @@ static void shrink_dentry_list(struct list_head *list)
 	struct dentry *dentry, *parent;
 
 	while (!list_empty(list)) {
+		struct inode *inode;
 		dentry = list_entry(list->prev, struct dentry, d_lru);
 		spin_lock(&dentry->d_lock);
 		/*
@@ -850,23 +851,26 @@ static void shrink_dentry_list(struct list_head *list)
 			continue;
 		}
 
-		parent = dentry_kill(dentry, 0);
-		/*
-		 * If dentry_kill returns NULL, we have nothing more to do.
-		 */
-		if (!parent)
-			continue;
-
-		if (unlikely(parent == dentry)) {
-			/*
-			 * trylocks have failed and d_lock has been held the
-			 * whole time, so it could not have been added to any
-			 * other lists. Just add it back to the shrink list.
-			 */
+		inode = dentry->d_inode;
+		if (inode && unlikely(!spin_trylock(&inode->i_lock))) {
 			d_shrink_add(dentry, list);
 			spin_unlock(&dentry->d_lock);
 			continue;
 		}
+
+		parent = NULL;
+		if (!IS_ROOT(dentry)) {
+			parent = dentry->d_parent;
+			if (unlikely(!spin_trylock(&parent->d_lock))) {
+				if (inode)
+					spin_unlock(&inode->i_lock);
+				d_shrink_add(dentry, list);
+				spin_unlock(&dentry->d_lock);
+				continue;
+			}
+		}
+
+		__dentry_kill(dentry);
 		/*
 		 * We need to prune ancestors too. This is necessary to prevent
 		 * quadratic behavior of shrink_dcache_parent(), but is also
-- 
2.1.2

--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]