fs: dcache remove dcache_lock

dcache_lock no longer protects anything. remove it.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>

4 files changed, 35 insertions, 29 deletions

diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h
index 9d2ae9b30d9f..0fffe1c24cec 100644
--- a/fs/autofs4/autofs_i.h
+++ b/fs/autofs4/autofs_i.h
@@ -16,6 +16,7 @@
 #include <linux/auto_fs4.h>
 #include <linux/auto_dev-ioctl.h>
 #include <linux/mutex.h>
+#include <linux/spinlock.h>
 #include <linux/list.h>
 
 /* This is the range of ioctl() numbers we claim as ours */
@@ -60,6 +61,8 @@ do {							\
                 current->pid, __func__, ##args);        \
 } while (0)
 
+extern spinlock_t autofs4_lock;
+
 /* Unified info structure.  This is pointed to by both the dentry and
    inode structures.  Each file in the filesystem has an instance of this
    structure.  It holds a reference to the dentry, so dentries are never
diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c
index 968c1434af62..2f7951d67d16 100644
--- a/fs/autofs4/expire.c
+++ b/fs/autofs4/expire.c
@@ -102,7 +102,7 @@ static struct dentry *get_next_positive_dentry(struct dentry *prev,
         if (prev == NULL)
                 return dget(prev);
 
-        spin_lock(&dcache_lock);
+        spin_lock(&autofs4_lock);
 relock:
         p = prev;
         spin_lock(&p->d_lock);
@@ -114,7 +114,7 @@ again:
 
                         if (p == root) {
                                 spin_unlock(&p->d_lock);
-                                spin_unlock(&dcache_lock);
+                                spin_unlock(&autofs4_lock);
                                 dput(prev);
                                 return NULL;
                         }
@@ -144,7 +144,7 @@ again:
         dget_dlock(ret);
         spin_unlock(&ret->d_lock);
         spin_unlock(&p->d_lock);
-        spin_unlock(&dcache_lock);
+        spin_unlock(&autofs4_lock);
 
         dput(prev);
 
@@ -408,13 +408,13 @@ found:
         ino->flags |= AUTOFS_INF_EXPIRING;
         init_completion(&ino->expire_complete);
         spin_unlock(&sbi->fs_lock);
-        spin_lock(&dcache_lock);
+        spin_lock(&autofs4_lock);
         spin_lock(&expired->d_parent->d_lock);
         spin_lock_nested(&expired->d_lock, DENTRY_D_LOCK_NESTED);
         list_move(&expired->d_parent->d_subdirs, &expired->d_u.d_child);
         spin_unlock(&expired->d_lock);
         spin_unlock(&expired->d_parent->d_lock);
-        spin_unlock(&dcache_lock);
+        spin_unlock(&autofs4_lock);
         return expired;
 }
 
diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
index 7a9ed6b88291..10ca68a96dc7 100644
--- a/fs/autofs4/root.c
+++ b/fs/autofs4/root.c
@@ -23,6 +23,8 @@
 
 #include "autofs_i.h"
 
+DEFINE_SPINLOCK(autofs4_lock);
+
 static int autofs4_dir_symlink(struct inode *,struct dentry *,const char *);
 static int autofs4_dir_unlink(struct inode *,struct dentry *);
 static int autofs4_dir_rmdir(struct inode *,struct dentry *);
@@ -142,15 +144,15 @@ static int autofs4_dir_open(struct inode *inode, struct file *file)
          * autofs file system so just let the libfs routines handle
          * it.
          */
-        spin_lock(&dcache_lock);
+        spin_lock(&autofs4_lock);
         spin_lock(&dentry->d_lock);
         if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) {
                 spin_unlock(&dentry->d_lock);
-                spin_unlock(&dcache_lock);
+                spin_unlock(&autofs4_lock);
                 return -ENOENT;
         }
         spin_unlock(&dentry->d_lock);
-        spin_unlock(&dcache_lock);
+        spin_unlock(&autofs4_lock);
 
 out:
         return dcache_dir_open(inode, file);
@@ -255,11 +257,11 @@ static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
         /* We trigger a mount for almost all flags */
         lookup_type = autofs4_need_mount(nd->flags);
         spin_lock(&sbi->fs_lock);
-        spin_lock(&dcache_lock);
+        spin_lock(&autofs4_lock);
         spin_lock(&dentry->d_lock);
         if (!(lookup_type || ino->flags & AUTOFS_INF_PENDING)) {
                 spin_unlock(&dentry->d_lock);
-                spin_unlock(&dcache_lock);
+                spin_unlock(&autofs4_lock);
                 spin_unlock(&sbi->fs_lock);
                 goto follow;
         }
@@ -272,7 +274,7 @@ static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
         if (ino->flags & AUTOFS_INF_PENDING ||
             (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs))) {
                 spin_unlock(&dentry->d_lock);
-                spin_unlock(&dcache_lock);
+                spin_unlock(&autofs4_lock);
                 spin_unlock(&sbi->fs_lock);
 
                 status = try_to_fill_dentry(dentry, nd->flags);
@@ -282,7 +284,7 @@ static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
                 goto follow;
         }
         spin_unlock(&dentry->d_lock);
-        spin_unlock(&dcache_lock);
+        spin_unlock(&autofs4_lock);
         spin_unlock(&sbi->fs_lock);
 follow:
         /*
@@ -353,14 +355,14 @@ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd)
                 return 0;
 
         /* Check for a non-mountpoint directory with no contents */
-        spin_lock(&dcache_lock);
+        spin_lock(&autofs4_lock);
         spin_lock(&dentry->d_lock);
         if (S_ISDIR(dentry->d_inode->i_mode) &&
             !d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) {
                 DPRINTK("dentry=%p %.*s, emptydir",
                          dentry, dentry->d_name.len, dentry->d_name.name);
                 spin_unlock(&dentry->d_lock);
-                spin_unlock(&dcache_lock);
+                spin_unlock(&autofs4_lock);
 
                 /* The daemon never causes a mount to trigger */
                 if (oz_mode)
@@ -377,7 +379,7 @@ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd)
                 return status;
         }
         spin_unlock(&dentry->d_lock);
-        spin_unlock(&dcache_lock);
+        spin_unlock(&autofs4_lock);
 
         return 1;
 }
@@ -432,7 +434,7 @@ static struct dentry *autofs4_lookup_active(struct dentry *dentry)
         const unsigned char *str = name->name;
         struct list_head *p, *head;
 
-        spin_lock(&dcache_lock);
+        spin_lock(&autofs4_lock);
         spin_lock(&sbi->lookup_lock);
         head = &sbi->active_list;
         list_for_each(p, head) {
@@ -465,14 +467,14 @@ static struct dentry *autofs4_lookup_active(struct dentry *dentry)
                         dget_dlock(active);
                         spin_unlock(&active->d_lock);
                         spin_unlock(&sbi->lookup_lock);
-                        spin_unlock(&dcache_lock);
+                        spin_unlock(&autofs4_lock);
                         return active;
                 }
 next:
                 spin_unlock(&active->d_lock);
         }
         spin_unlock(&sbi->lookup_lock);
-        spin_unlock(&dcache_lock);
+        spin_unlock(&autofs4_lock);
 
         return NULL;
 }
@@ -487,7 +489,7 @@ static struct dentry *autofs4_lookup_expiring(struct dentry *dentry)
         const unsigned char *str = name->name;
         struct list_head *p, *head;
 
-        spin_lock(&dcache_lock);
+        spin_lock(&autofs4_lock);
         spin_lock(&sbi->lookup_lock);
         head = &sbi->expiring_list;
         list_for_each(p, head) {
@@ -520,14 +522,14 @@ static struct dentry *autofs4_lookup_expiring(struct dentry *dentry)
                         dget_dlock(expiring);
                         spin_unlock(&expiring->d_lock);
                         spin_unlock(&sbi->lookup_lock);
-                        spin_unlock(&dcache_lock);
+                        spin_unlock(&autofs4_lock);
                         return expiring;
                 }
 next:
                 spin_unlock(&expiring->d_lock);
         }
         spin_unlock(&sbi->lookup_lock);
-        spin_unlock(&dcache_lock);
+        spin_unlock(&autofs4_lock);
 
         return NULL;
 }
@@ -763,12 +765,12 @@ static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry)
 
         dir->i_mtime = CURRENT_TIME;
 
-        spin_lock(&dcache_lock);
+        spin_lock(&autofs4_lock);
         autofs4_add_expiring(dentry);
         spin_lock(&dentry->d_lock);
         __d_drop(dentry);
         spin_unlock(&dentry->d_lock);
-        spin_unlock(&dcache_lock);
+        spin_unlock(&autofs4_lock);
 
         return 0;
 }
@@ -785,20 +787,20 @@ static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry)
         if (!autofs4_oz_mode(sbi))
                 return -EACCES;
 
-        spin_lock(&dcache_lock);
+        spin_lock(&autofs4_lock);
         spin_lock(&sbi->lookup_lock);
         spin_lock(&dentry->d_lock);
         if (!list_empty(&dentry->d_subdirs)) {
                 spin_unlock(&dentry->d_lock);
                 spin_unlock(&sbi->lookup_lock);
-                spin_unlock(&dcache_lock);
+                spin_unlock(&autofs4_lock);
                 return -ENOTEMPTY;
         }
         __autofs4_add_expiring(dentry);
         spin_unlock(&sbi->lookup_lock);
         __d_drop(dentry);
         spin_unlock(&dentry->d_lock);
-        spin_unlock(&dcache_lock);
+        spin_unlock(&autofs4_lock);
 
         if (atomic_dec_and_test(&ino->count)) {
                 p_ino = autofs4_dentry_ino(dentry->d_parent);
diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c
index 4be8f778a418..c5f8459c905e 100644
--- a/fs/autofs4/waitq.c
+++ b/fs/autofs4/waitq.c
@@ -194,14 +194,15 @@ static int autofs4_getpath(struct autofs_sb_info *sbi,
 rename_retry:
         buf = *name;
         len = 0;
+
         seq = read_seqbegin(&rename_lock);
         rcu_read_lock();
-        spin_lock(&dcache_lock);
+        spin_lock(&autofs4_lock);
         for (tmp = dentry ; tmp != root ; tmp = tmp->d_parent)
                 len += tmp->d_name.len + 1;
 
         if (!len || --len > NAME_MAX) {
-                spin_unlock(&dcache_lock);
+                spin_unlock(&autofs4_lock);
                 rcu_read_unlock();
                 if (read_seqretry(&rename_lock, seq))
                         goto rename_retry;
@@ -217,7 +218,7 @@ rename_retry:
                 p -= tmp->d_name.len;
                 strncpy(p, tmp->d_name.name, tmp->d_name.len);
         }
-        spin_unlock(&dcache_lock);
+        spin_unlock(&autofs4_lock);
         rcu_read_unlock();
         if (read_seqretry(&rename_lock, seq))
                 goto rename_retry;