From: Paolo 'Blaisorblade' Giarrusso <[email protected]>
We might need to revalidate a dentry (for instance when a process dies), so
call the underlying d_revalidate if it is defined, on the underlying
dentry.
Also, when we find a dentry in the dcache, we must call d_revalidate
ourselves.
BUT: for now, this is done with a NULL nameidata (which is only safe by
chance, given the current code). While looking into this, I realized that
the nameidata handling in calls to the underlying FS are bogus. I'm going
to fix this in next patch.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <[email protected]>
---
fs/hppfs/hppfs_kern.c | 42 +++++++++++++++++++++++++++++++++++++-----
1 files changed, 37 insertions(+), 5 deletions(-)
diff --git a/fs/hppfs/hppfs_kern.c b/fs/hppfs/hppfs_kern.c
--- a/fs/hppfs/hppfs_kern.c
+++ b/fs/hppfs/hppfs_kern.c
@@ -104,7 +104,22 @@ static char *dentry_name(struct dentry *
return(name);
}
+static int hppfs_d_revalidate(struct dentry * dentry, struct nameidata * nd)
+{
+ int (*d_revalidate)(struct dentry *, struct nameidata *);
+ struct dentry *proc_dentry;
+
+ proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry;
+ if (proc_dentry->d_op && proc_dentry->d_op->d_revalidate)
+ d_revalidate = proc_dentry->d_op->d_revalidate;
+ else
+ return 1; /* "Still valid" code */
+
+ return (*d_revalidate)(proc_dentry, nd);
+}
+
static struct dentry_operations hppfs_dentry_ops = {
+ .d_revalidate = hppfs_d_revalidate,
};
static int file_removed(struct dentry *dentry, const char *file)
@@ -157,7 +172,7 @@ static void hppfs_read_inode(struct inod
ino->i_blocks = proc_ino->i_blocks;
}
-static struct dentry *hppfs_lookup(struct inode *ino, struct dentry *dentry,
+static struct dentry *hppfs_lookup(struct inode *parent_ino, struct dentry *dentry,
struct nameidata *nd)
{
struct dentry *proc_dentry, *new, *parent;
@@ -171,10 +186,18 @@ static struct dentry *hppfs_lookup(struc
return(ERR_PTR(-ENOENT));
err = -ENOMEM;
- parent = HPPFS_I(ino)->proc_dentry;
+ parent = HPPFS_I(parent_ino)->proc_dentry;
+
+ /* This more or less matches fs/namei.c:real_lookup() - we don't have
+ * the fast path which looks up the dentry without the directory
+ * semaphore. Please keep in sync. */
+
+ /* XXX: The only difference is nameidata: we pass NULL instead of nd.
+ * Not normally allowed, would Oops if proc ever uses nd, and can Oops /
+ * leak entries if we pass the same nd we got. */
down(&parent->d_inode->i_sem);
proc_dentry = d_lookup(parent, &dentry->d_name);
- if(proc_dentry == NULL){
+ if (!proc_dentry) {
proc_dentry = d_alloc(parent, &dentry->d_name);
if(proc_dentry == NULL){
up(&parent->d_inode->i_sem);
@@ -186,13 +209,22 @@ static struct dentry *hppfs_lookup(struc
dput(proc_dentry);
proc_dentry = new;
}
+ up(&parent->d_inode->i_sem);
+ } else {
+ up(&parent->d_inode->i_sem);
+ if (proc_dentry->d_op && proc_dentry->d_op->d_revalidate) {
+ if (!proc_dentry->d_op->d_revalidate(proc_dentry, NULL) &&
+ !d_invalidate(proc_dentry)) {
+ dput(proc_dentry);
+ proc_dentry = ERR_PTR(-ENOENT);
+ }
+ }
}
- up(&parent->d_inode->i_sem);
if(IS_ERR(proc_dentry))
return(proc_dentry);
- inode = iget(ino->i_sb, 0);
+ inode = iget(parent_ino->i_sb, 0);
if(inode == NULL)
goto out_dput;
-
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