From b5c84bf6f6fa3a7dfdcb556023a62953574b60ee Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Fri, 7 Jan 2011 17:49:38 +1100 Subject: fs: dcache remove dcache_lock dcache_lock no longer protects anything. remove it. Signed-off-by: Nick Piggin --- include/linux/dcache.h | 5 ++--- include/linux/fs.h | 6 +++++- include/linux/fsnotify.h | 2 -- include/linux/fsnotify_backend.h | 11 +++++++---- include/linux/namei.h | 1 - 5 files changed, 14 insertions(+), 11 deletions(-) (limited to 'include') diff --git a/include/linux/dcache.h b/include/linux/dcache.h index c963ebada922..a2ceb94b0e38 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -183,7 +183,6 @@ struct dentry_operations { #define DCACHE_GENOCIDE 0x0200 extern spinlock_t dcache_inode_lock; -extern spinlock_t dcache_lock; extern seqlock_t rename_lock; static inline int dname_external(struct dentry *dentry) @@ -296,8 +295,8 @@ extern char *dentry_path(struct dentry *, char *, int); * destroyed when it has references. dget() should never be * called for dentries with zero reference counter. For these cases * (preferably none, functions in dcache.c are sufficient for normal - * needs and they take necessary precautions) you should hold dcache_lock - * and call dget_locked() instead of dget(). + * needs and they take necessary precautions) you should hold d_lock + * and call dget_dlock() instead of dget(). */ static inline struct dentry *dget_dlock(struct dentry *dentry) { diff --git a/include/linux/fs.h b/include/linux/fs.h index 090f0eacde29..296cf2fde945 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1378,7 +1378,7 @@ struct super_block { #else struct list_head s_files; #endif - /* s_dentry_lru and s_nr_dentry_unused are protected by dcache_lock */ + /* s_dentry_lru, s_nr_dentry_unused protected by dcache.c lru locks */ struct list_head s_dentry_lru; /* unused dentry lru */ int s_nr_dentry_unused; /* # of dentry on lru */ @@ -2446,6 +2446,10 @@ static inline ino_t parent_ino(struct dentry *dentry) { ino_t res; + /* + * Don't strictly need d_lock here? If the parent ino could change + * then surely we'd have a deeper race in the caller? + */ spin_lock(&dentry->d_lock); res = dentry->d_parent->d_inode->i_ino; spin_unlock(&dentry->d_lock); diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h index b10bcdeaef76..2a53f10712b3 100644 --- a/include/linux/fsnotify.h +++ b/include/linux/fsnotify.h @@ -17,7 +17,6 @@ /* * fsnotify_d_instantiate - instantiate a dentry for inode - * Called with dcache_lock held. */ static inline void fsnotify_d_instantiate(struct dentry *dentry, struct inode *inode) @@ -62,7 +61,6 @@ static inline int fsnotify_perm(struct file *file, int mask) /* * fsnotify_d_move - dentry has been moved - * Called with dcache_lock and dentry->d_lock held. */ static inline void fsnotify_d_move(struct dentry *dentry) { diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index 7380763595d3..69ad89b50489 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -329,9 +329,15 @@ static inline void __fsnotify_update_dcache_flags(struct dentry *dentry) { struct dentry *parent; - assert_spin_locked(&dcache_lock); assert_spin_locked(&dentry->d_lock); + /* + * Serialisation of setting PARENT_WATCHED on the dentries is provided + * by d_lock. If inotify_inode_watched changes after we have taken + * d_lock, the following __fsnotify_update_child_dentry_flags call will + * find our entry, so it will spin until we complete here, and update + * us with the new state. + */ parent = dentry->d_parent; if (parent->d_inode && fsnotify_inode_watches_children(parent->d_inode)) dentry->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED; @@ -341,15 +347,12 @@ static inline void __fsnotify_update_dcache_flags(struct dentry *dentry) /* * fsnotify_d_instantiate - instantiate a dentry for inode - * Called with dcache_lock held. */ static inline void __fsnotify_d_instantiate(struct dentry *dentry, struct inode *inode) { if (!inode) return; - assert_spin_locked(&dcache_lock); - spin_lock(&dentry->d_lock); __fsnotify_update_dcache_flags(dentry); spin_unlock(&dentry->d_lock); diff --git a/include/linux/namei.h b/include/linux/namei.h index 05b441d93642..aec730b53935 100644 --- a/include/linux/namei.h +++ b/include/linux/namei.h @@ -41,7 +41,6 @@ enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND}; * - require a directory * - ending slashes ok even for nonexistent files * - internal "there are more path components" flag - * - locked when lookup done with dcache_lock held * - dentry cache is untrusted; force a real lookup */ #define LOOKUP_FOLLOW 1 -- cgit v1.2.3-59-g8ed1b