1 files changed, 93 insertions, 52 deletions

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 2060bf06b906..fd03330cadeb 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -97,7 +97,7 @@ void fuse_invalidate_attr(struct inode *inode)
  * timeout is unknown (unlink, rmdir, rename and in some cases
  * lookup)
  */
-static void fuse_invalidate_entry_cache(struct dentry *entry)
+void fuse_invalidate_entry_cache(struct dentry *entry)
 {
         fuse_dentry_settime(entry, 0);
 }
@@ -112,18 +112,16 @@ static void fuse_invalidate_entry(struct dentry *entry)
         fuse_invalidate_entry_cache(entry);
 }
 
-static void fuse_lookup_init(struct fuse_req *req, struct inode *dir,
-                             struct dentry *entry,
+static void fuse_lookup_init(struct fuse_conn *fc, struct fuse_req *req,
+                             u64 nodeid, struct qstr *name,
                              struct fuse_entry_out *outarg)
 {
-        struct fuse_conn *fc = get_fuse_conn(dir);
-
         memset(outarg, 0, sizeof(struct fuse_entry_out));
         req->in.h.opcode = FUSE_LOOKUP;
-        req->in.h.nodeid = get_node_id(dir);
+        req->in.h.nodeid = nodeid;
         req->in.numargs = 1;
-        req->in.args[0].size = entry->d_name.len + 1;
-        req->in.args[0].value = entry->d_name.name;
+        req->in.args[0].size = name->len + 1;
+        req->in.args[0].value = name->name;
         req->out.numargs = 1;
         if (fc->minor < 9)
                 req->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE;
@@ -189,7 +187,8 @@ static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd)
                 attr_version = fuse_get_attr_version(fc);
 
                 parent = dget_parent(entry);
-                fuse_lookup_init(req, parent->d_inode, entry, &outarg);
+                fuse_lookup_init(fc, req, get_node_id(parent->d_inode),
+                                 &entry->d_name, &outarg);
                 request_send(fc, req);
                 dput(parent);
                 err = req->out.h.error;
@@ -225,7 +224,7 @@ static int invalid_nodeid(u64 nodeid)
         return !nodeid || nodeid == FUSE_ROOT_ID;
 }
 
-static struct dentry_operations fuse_dentry_operations = {
+struct dentry_operations fuse_dentry_operations = {
         .d_revalidate   = fuse_dentry_revalidate,
 };
 
@@ -239,85 +238,127 @@ int fuse_valid_type(int m)
  * Add a directory inode to a dentry, ensuring that no other dentry
  * refers to this inode.  Called with fc->inst_mutex.
  */
-static int fuse_d_add_directory(struct dentry *entry, struct inode *inode)
+static struct dentry *fuse_d_add_directory(struct dentry *entry,
+                                           struct inode *inode)
 {
         struct dentry *alias = d_find_alias(inode);
-        if (alias) {
+        if (alias && !(alias->d_flags & DCACHE_DISCONNECTED)) {
                 /* This tries to shrink the subtree below alias */
                 fuse_invalidate_entry(alias);
                 dput(alias);
                 if (!list_empty(&inode->i_dentry))
-                        return -EBUSY;
+                        return ERR_PTR(-EBUSY);
+        } else {
+                dput(alias);
         }
-        d_add(entry, inode);
-        return 0;
+        return d_splice_alias(inode, entry);
 }
 
-static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
-                                  struct nameidata *nd)
+int fuse_lookup_name(struct super_block *sb, u64 nodeid, struct qstr *name,
+                     struct fuse_entry_out *outarg, struct inode **inode)
 {
-        int err;
-        struct fuse_entry_out outarg;
-        struct inode *inode = NULL;
-        struct fuse_conn *fc = get_fuse_conn(dir);
+        struct fuse_conn *fc = get_fuse_conn_super(sb);
         struct fuse_req *req;
         struct fuse_req *forget_req;
         u64 attr_version;
+        int err;
 
-        if (entry->d_name.len > FUSE_NAME_MAX)
-                return ERR_PTR(-ENAMETOOLONG);
+        *inode = NULL;
+        err = -ENAMETOOLONG;
+        if (name->len > FUSE_NAME_MAX)
+                goto out;
 
         req = fuse_get_req(fc);
+        err = PTR_ERR(req);
         if (IS_ERR(req))
-                return ERR_CAST(req);
+                goto out;
 
         forget_req = fuse_get_req(fc);
+        err = PTR_ERR(forget_req);
         if (IS_ERR(forget_req)) {
                 fuse_put_request(fc, req);
-                return ERR_CAST(forget_req);
+                goto out;
         }
 
         attr_version = fuse_get_attr_version(fc);
 
-        fuse_lookup_init(req, dir, entry, &outarg);
+        fuse_lookup_init(fc, req, nodeid, name, outarg);
         request_send(fc, req);
         err = req->out.h.error;
         fuse_put_request(fc, req);
         /* Zero nodeid is same as -ENOENT, but with valid timeout */
-        if (!err && outarg.nodeid &&
-            (invalid_nodeid(outarg.nodeid) ||
-             !fuse_valid_type(outarg.attr.mode)))
-                err = -EIO;
-        if (!err && outarg.nodeid) {
-                inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation,
-                                  &outarg.attr, entry_attr_timeout(&outarg),
-                                  attr_version);
-                if (!inode) {
-                        fuse_send_forget(fc, forget_req, outarg.nodeid, 1);
-                        return ERR_PTR(-ENOMEM);
-                }
+        if (err || !outarg->nodeid)
+                goto out_put_forget;
+
+        err = -EIO;
+        if (!outarg->nodeid)
+                goto out_put_forget;
+        if (!fuse_valid_type(outarg->attr.mode))
+                goto out_put_forget;
+
+        *inode = fuse_iget(sb, outarg->nodeid, outarg->generation,
+                           &outarg->attr, entry_attr_timeout(outarg),
+                           attr_version);
+        err = -ENOMEM;
+        if (!*inode) {
+                fuse_send_forget(fc, forget_req, outarg->nodeid, 1);
+                goto out;
         }
+        err = 0;
+
+ out_put_forget:
         fuse_put_request(fc, forget_req);
-        if (err && err != -ENOENT)
-                return ERR_PTR(err);
+ out:
+        return err;
+}
+
+static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
+                                  struct nameidata *nd)
+{
+        int err;
+        struct fuse_entry_out outarg;
+        struct inode *inode;
+        struct dentry *newent;
+        struct fuse_conn *fc = get_fuse_conn(dir);
+        bool outarg_valid = true;
+
+        err = fuse_lookup_name(dir->i_sb, get_node_id(dir), &entry->d_name,
+                               &outarg, &inode);
+        if (err == -ENOENT) {
+                outarg_valid = false;
+                err = 0;
+        }
+        if (err)
+                goto out_err;
+
+        err = -EIO;
+        if (inode && get_node_id(inode) == FUSE_ROOT_ID)
+                goto out_iput;
 
         if (inode && S_ISDIR(inode->i_mode)) {
                 mutex_lock(&fc->inst_mutex);
-                err = fuse_d_add_directory(entry, inode);
+                newent = fuse_d_add_directory(entry, inode);
                 mutex_unlock(&fc->inst_mutex);
-                if (err) {
-                        iput(inode);
-                        return ERR_PTR(err);
-                }
-        } else
-                d_add(entry, inode);
+                err = PTR_ERR(newent);
+                if (IS_ERR(newent))
+                        goto out_iput;
+        } else {
+                newent = d_splice_alias(inode, entry);
+        }
 
+        entry = newent ? newent : entry;
         entry->d_op = &fuse_dentry_operations;
-        if (!err)
+        if (outarg_valid)
                 fuse_change_entry_timeout(entry, &outarg);
         else
                 fuse_invalidate_entry_cache(entry);
-        return NULL;
+
+        return newent;
+
+ out_iput:
+        iput(inode);
+ out_err:
+        return ERR_PTR(err);
 }
 
 /*
@@ -857,7 +898,7 @@ static int fuse_access(struct inode *inode, int mask)
                 return PTR_ERR(req);
 
         memset(&inarg, 0, sizeof(inarg));
-        inarg.mask = mask;
+        inarg.mask = mask & (MAY_READ | MAY_WRITE | MAY_EXEC);
         req->in.h.opcode = FUSE_ACCESS;
         req->in.h.nodeid = get_node_id(inode);
         req->in.numargs = 1;
@@ -886,7 +927,7 @@ static int fuse_access(struct inode *inode, int mask)
  * access request is sent.  Execute permission is still checked
  * locally based on file mode.
  */
-static int fuse_permission(struct inode *inode, int mask, struct nameidata *nd)
+static int fuse_permission(struct inode *inode, int mask)
 {
         struct fuse_conn *fc = get_fuse_conn(inode);
         bool refreshed = false;
@@ -921,7 +962,7 @@ static int fuse_permission(struct inode *inode, int mask, struct nameidata *nd)
                    exist.  So if permissions are revoked this won't be
                    noticed immediately, only after the attribute
                    timeout has expired */
-        } else if (nd && (nd->flags & (LOOKUP_ACCESS | LOOKUP_CHDIR))) {
+        } else if (mask & MAY_ACCESS) {
                 err = fuse_access(inode, mask);
         } else if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) {
                 if (!(inode->i_mode & S_IXUGO)) {