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authorLinus Torvalds <torvalds@linux-foundation.org>2011-01-14 07:14:13 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2011-01-14 07:14:13 +0300
commitdb9effe99adc67c53e6aedadadd2aa9a02342e48 (patch)
treeefe7ebfe951972568189ef2548130f0abd515210 /fs
parent9c4bc1c2befbbdce4b9fd526e67a7a2ea143ffa2 (diff)
parentf20877d94a74557b7c28b4ed8920d834c31e0ea5 (diff)
downloadlinux-db9effe99adc67c53e6aedadadd2aa9a02342e48.tar.xz
Merge branch 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin
* 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin: fs: fix do_last error case when need_reval_dot nfs: add missing rcu-walk check fs: hlist UP debug fixup fs: fix dropping of rcu-walk from force_reval_path fs: force_reval_path drop rcu-walk before d_invalidate fs: small rcu-walk documentation fixes Fixed up trivial conflicts in Documentation/filesystems/porting
Diffstat (limited to 'fs')
-rw-r--r--fs/namei.c28
-rw-r--r--fs/nfs/dir.c6
2 files changed, 29 insertions, 5 deletions
diff --git a/fs/namei.c b/fs/namei.c
index 0b14f6910fc6..86643302079e 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -479,6 +479,14 @@ static int nameidata_dentry_drop_rcu(struct nameidata *nd, struct dentry *dentry
struct fs_struct *fs = current->fs;
struct dentry *parent = nd->path.dentry;
+ /*
+ * It can be possible to revalidate the dentry that we started
+ * the path walk with. force_reval_path may also revalidate the
+ * dentry already committed to the nameidata.
+ */
+ if (unlikely(parent == dentry))
+ return nameidata_drop_rcu(nd);
+
BUG_ON(!(nd->flags & LOOKUP_RCU));
if (nd->root.mnt) {
spin_lock(&fs->lock);
@@ -583,6 +591,13 @@ void release_open_intent(struct nameidata *nd)
fput(nd->intent.open.file);
}
+/*
+ * Call d_revalidate and handle filesystems that request rcu-walk
+ * to be dropped. This may be called and return in rcu-walk mode,
+ * regardless of success or error. If -ECHILD is returned, the caller
+ * must return -ECHILD back up the path walk stack so path walk may
+ * be restarted in ref-walk mode.
+ */
static int d_revalidate(struct dentry *dentry, struct nameidata *nd)
{
int status;
@@ -673,6 +688,9 @@ force_reval_path(struct path *path, struct nameidata *nd)
return 0;
if (!status) {
+ /* Don't d_invalidate in rcu-walk mode */
+ if (nameidata_drop_rcu(nd))
+ return -ECHILD;
d_invalidate(dentry);
status = -ESTALE;
}
@@ -2105,11 +2123,13 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
dir = nd->path.dentry;
case LAST_DOT:
if (need_reval_dot(dir)) {
- error = d_revalidate(nd->path.dentry, nd);
- if (!error)
- error = -ESTALE;
- if (error < 0)
+ int status = d_revalidate(nd->path.dentry, nd);
+ if (!status)
+ status = -ESTALE;
+ if (status < 0) {
+ error = status;
goto exit;
+ }
}
/* fallthrough */
case LAST_ROOT:
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 64ee240f3c80..df8c03a02161 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1406,11 +1406,15 @@ no_open:
static int nfs_open_revalidate(struct dentry *dentry, struct nameidata *nd)
{
struct dentry *parent = NULL;
- struct inode *inode = dentry->d_inode;
+ struct inode *inode;
struct inode *dir;
struct nfs_open_context *ctx;
int openflags, ret = 0;
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ inode = dentry->d_inode;
if (!is_atomic_open(nd) || d_mountpoint(dentry))
goto no_open;