[PATCH v3 095/110] VFS: Handle lower layer dentry/inode in pathwalk

From: Al Viro
Date: Mon May 11 2015 - 14:14:33 EST


From: David Howells <dhowells@xxxxxxxxxx>

Make use of d_backing_inode() in pathwalk to gain access to an
inode or dentry that's on a lower layer.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---
fs/namei.c | 10 +++++-----
fs/open.c | 2 +-
2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 366b0f3..bcacb31 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1423,7 +1423,7 @@ static int lookup_fast(struct nameidata *nd,
* This sequence count validates that the inode matches
* the dentry name information from lookup.
*/
- *inode = dentry->d_inode;
+ *inode = d_backing_inode(dentry);
negative = d_is_negative(dentry);
if (read_seqcount_retry(&dentry->d_seq, seq))
return -ECHILD;
@@ -1483,7 +1483,7 @@ unlazy:
path->dentry = dentry;
err = follow_managed(path, nd);
if (likely(!err))
- *inode = path->dentry->d_inode;
+ *inode = d_backing_inode(path->dentry);
return err;

need_lookup:
@@ -1618,7 +1618,7 @@ static int walk_component(struct nameidata *nd, int flags)
if (err < 0)
return err;

- inode = path.dentry->d_inode;
+ inode = d_backing_inode(path.dentry);
seq = 0; /* we are already out of RCU mode */
err = -ENOENT;
if (d_is_negative(path.dentry))
@@ -2471,7 +2471,7 @@ EXPORT_SYMBOL(__check_sticky);
*/
static int may_delete(struct inode *dir, struct dentry *victim, bool isdir)
{
- struct inode *inode = victim->d_inode;
+ struct inode *inode = d_backing_inode(victim);
int error;

if (d_is_negative(victim))
@@ -3054,7 +3054,7 @@ retry_lookup:
return error;

BUG_ON(nd->flags & LOOKUP_RCU);
- inode = path.dentry->d_inode;
+ inode = d_backing_inode(path.dentry);
seq = 0; /* out of RCU mode, so the value doesn't matter */
if (unlikely(d_is_negative(path.dentry))) {
path_to_nameidata(&path, nd);
diff --git a/fs/open.c b/fs/open.c
index 98e5a52..e0250bd 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -367,7 +367,7 @@ retry:
if (res)
goto out;

- inode = path.dentry->d_inode;
+ inode = d_backing_inode(path.dentry);

if ((mode & MAY_EXEC) && S_ISREG(inode->i_mode)) {
/*
--
2.1.4

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