From: Al Viro <[email protected]> 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 <[email protected]> Signed-off-by: Jiri Slaby <[email protected]> --- 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 [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
