From: Al Viro <[email protected]> 3.12-stable review patch. If anyone has any objections, please let me know.
=============== commit e55fd011549eae01a230e3cace6f4d031b6a3453 upstream. ... into trylocks and everything else. The latter (actual killing) is __dentry_kill(). Signed-off-by: Al Viro <[email protected]> Signed-off-by: Jiri Slaby <[email protected]> --- fs/dcache.c | 62 +++++++++++++++++++++++++++++++++++-------------------------- 1 file changed, 36 insertions(+), 26 deletions(-) diff --git a/fs/dcache.c b/fs/dcache.c index c7085b971290..7575aeec1740 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -463,36 +463,12 @@ void d_drop(struct dentry *dentry) } EXPORT_SYMBOL(d_drop); -/* - * Finish off a dentry we've decided to kill. - * dentry->d_lock must be held, returns with it unlocked. - * If ref is non-zero, then decrement the refcount too. - * Returns dentry requiring refcount drop, or NULL if we're done. - */ -static struct dentry * -dentry_kill(struct dentry *dentry, int unlock_on_failure) - __releases(dentry->d_lock) +static void __dentry_kill(struct dentry *dentry) { - struct inode *inode; struct dentry *parent = NULL; bool can_free = true; - - inode = dentry->d_inode; - if (inode && !spin_trylock(&inode->i_lock)) { -relock: - if (unlock_on_failure) { - spin_unlock(&dentry->d_lock); - cpu_relax(); - } - return dentry; /* try again with same dentry */ - } if (!IS_ROOT(dentry)) parent = dentry->d_parent; - if (parent && !spin_trylock(&parent->d_lock)) { - if (inode) - spin_unlock(&inode->i_lock); - goto relock; - } /* * The dentry is now unrecoverably dead to the world. @@ -536,10 +512,44 @@ relock: can_free = false; } spin_unlock(&dentry->d_lock); -out: if (likely(can_free)) dentry_free(dentry); +} + +/* + * Finish off a dentry we've decided to kill. + * dentry->d_lock must be held, returns with it unlocked. + * If ref is non-zero, then decrement the refcount too. + * Returns dentry requiring refcount drop, or NULL if we're done. + */ +static struct dentry * +dentry_kill(struct dentry *dentry, int unlock_on_failure) + __releases(dentry->d_lock) +{ + struct inode *inode = dentry->d_inode; + struct dentry *parent = NULL; + + if (inode && unlikely(!spin_trylock(&inode->i_lock))) + goto failed; + + if (!IS_ROOT(dentry)) { + parent = dentry->d_parent; + if (unlikely(!spin_trylock(&parent->d_lock))) { + if (inode) + spin_unlock(&inode->i_lock); + goto failed; + } + } + + __dentry_kill(dentry); return parent; + +failed: + if (unlock_on_failure) { + spin_unlock(&dentry->d_lock); + cpu_relax(); + } + return dentry; /* try again with same dentry */ } /* -- 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
