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authorAl Viro <viro@zeniv.linux.org.uk>2009-08-13 23:38:37 +0400
committerAl Viro <viro@zeniv.linux.org.uk>2009-12-16 12:16:45 -0500
commit6e6b1bd1e739faf4fa259fc0d8bfcadea2493222 (patch)
treede20d84d0051852c4ff5b6200ab8c9bd9e932b75
parent2dd6d1f41852bbb1f66d66b3634ddfdaeddcf9bc (diff)
Kill cached_lookup() and real_lookup()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--fs/namei.c153
1 files changed, 66 insertions, 87 deletions
diff --git a/fs/namei.c b/fs/namei.c
index b2b22f24418..020bb082d0b 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -412,26 +412,6 @@ do_revalidate(struct dentry *dentry, struct nameidata *nd)
}
/*
- * Internal lookup() using the new generic dcache.
- * SMP-safe
- */
-static struct dentry * cached_lookup(struct dentry * parent, struct qstr * name, struct nameidata *nd)
-{
- struct dentry * dentry = __d_lookup(parent, name);
-
- /* lockess __d_lookup may fail due to concurrent d_move()
- * in some unrelated directory, so try with d_lookup
- */
- if (!dentry)
- dentry = d_lookup(parent, name);
-
- if (dentry && dentry->d_op && dentry->d_op->d_revalidate)
- dentry = do_revalidate(dentry, nd);
-
- return dentry;
-}
-
-/*
* Short-cut version of permission(), for calling by
* path_walk(), when dcache lock is held. Combines parts
* of permission() and generic_permission(), and tests ONLY for
@@ -463,70 +443,6 @@ ok:
return security_inode_permission(inode, MAY_EXEC);
}
-/*
- * This is called when everything else fails, and we actually have
- * to go to the low-level filesystem to find out what we should do..
- *
- * We get the directory semaphore, and after getting that we also
- * make sure that nobody added the entry to the dcache in the meantime..
- * SMP-safe
- */
-static struct dentry * real_lookup(struct dentry * parent, struct qstr * name, struct nameidata *nd)
-{
- struct dentry * result;
- struct inode *dir = parent->d_inode;
-
- mutex_lock(&dir->i_mutex);
- /*
- * First re-do the cached lookup just in case it was created
- * while we waited for the directory semaphore..
- *
- * FIXME! This could use version numbering or similar to
- * avoid unnecessary cache lookups.
- *
- * The "dcache_lock" is purely to protect the RCU list walker
- * from concurrent renames at this point (we mustn't get false
- * negatives from the RCU list walk here, unlike the optimistic
- * fast walk).
- *
- * so doing d_lookup() (with seqlock), instead of lockfree __d_lookup
- */
- result = d_lookup(parent, name);
- if (!result) {
- struct dentry *dentry;
-
- /* Don't create child dentry for a dead directory. */
- result = ERR_PTR(-ENOENT);
- if (IS_DEADDIR(dir))
- goto out_unlock;
-
- dentry = d_alloc(parent, name);
- result = ERR_PTR(-ENOMEM);
- if (dentry) {
- result = dir->i_op->lookup(dir, dentry, nd);
- if (result)
- dput(dentry);
- else
- result = dentry;
- }
-out_unlock:
- mutex_unlock(&dir->i_mutex);
- return result;
- }
-
- /*
- * Uhhuh! Nasty case: the cache was re-populated while
- * we waited on the semaphore. Need to revalidate.
- */
- mutex_unlock(&dir->i_mutex);
- if (result->d_op && result->d_op->d_revalidate) {
- result = do_revalidate(result, nd);
- if (!result)
- result = ERR_PTR(-ENOENT);
- }
- return result;
-}
-
static __always_inline void set_root(struct nameidata *nd)
{
if (!nd->root.mnt) {
@@ -767,7 +683,8 @@ static int do_lookup(struct nameidata *nd, struct qstr *name,
struct path *path)
{
struct vfsmount *mnt = nd->path.mnt;
- struct dentry *dentry;
+ struct dentry *dentry, *parent;
+ struct inode *dir;
/*
* See if the low-level filesystem might want
* to use its own hash..
@@ -790,7 +707,59 @@ done:
return 0;
need_lookup:
- dentry = real_lookup(nd->path.dentry, name, nd);
+ parent = nd->path.dentry;
+ dir = parent->d_inode;
+
+ mutex_lock(&dir->i_mutex);
+ /*
+ * First re-do the cached lookup just in case it was created
+ * while we waited for the directory semaphore..
+ *
+ * FIXME! This could use version numbering or similar to
+ * avoid unnecessary cache lookups.
+ *
+ * The "dcache_lock" is purely to protect the RCU list walker
+ * from concurrent renames at this point (we mustn't get false
+ * negatives from the RCU list walk here, unlike the optimistic
+ * fast walk).
+ *
+ * so doing d_lookup() (with seqlock), instead of lockfree __d_lookup
+ */
+ dentry = d_lookup(parent, name);
+ if (!dentry) {
+ struct dentry *new;
+
+ /* Don't create child dentry for a dead directory. */
+ dentry = ERR_PTR(-ENOENT);
+ if (IS_DEADDIR(dir))
+ goto out_unlock;
+
+ new = d_alloc(parent, name);
+ dentry = ERR_PTR(-ENOMEM);
+ if (new) {
+ dentry = dir->i_op->lookup(dir, new, nd);
+ if (dentry)
+ dput(new);
+ else
+ dentry = new;
+ }
+out_unlock:
+ mutex_unlock(&dir->i_mutex);
+ if (IS_ERR(dentry))
+ goto fail;
+ goto done;
+ }
+
+ /*
+ * Uhhuh! Nasty case: the cache was re-populated while
+ * we waited on the semaphore. Need to revalidate.
+ */
+ mutex_unlock(&dir->i_mutex);
+ if (dentry->d_op && dentry->d_op->d_revalidate) {
+ dentry = do_revalidate(dentry, nd);
+ if (!dentry)
+ dentry = ERR_PTR(-ENOENT);
+ }
if (IS_ERR(dentry))
goto fail;
goto done;
@@ -1144,7 +1113,17 @@ static struct dentry *__lookup_hash(struct qstr *name,
goto out;
}
- dentry = cached_lookup(base, name, nd);
+ dentry = __d_lookup(base, name);
+
+ /* lockess __d_lookup may fail due to concurrent d_move()
+ * in some unrelated directory, so try with d_lookup
+ */
+ if (!dentry)
+ dentry = d_lookup(base, name);
+
+ if (dentry && dentry->d_op && dentry->d_op->d_revalidate)
+ dentry = do_revalidate(dentry, nd);
+
if (!dentry) {
struct dentry *new;