1 files changed, 73 insertions, 59 deletions

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 72a5d5b04494..b7989f2ab4c4 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -182,10 +182,12 @@ static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags)
 	struct inode *inode;
 	struct dentry *parent;
 	struct fuse_conn *fc;
+	struct fuse_inode *fi;
+	int ret;
 
 	inode = ACCESS_ONCE(entry->d_inode);
 	if (inode && is_bad_inode(inode))
-		return 0;
+		goto invalid;
 	else if (fuse_dentry_time(entry) < get_jiffies_64()) {
 		int err;
 		struct fuse_entry_out outarg;
@@ -195,20 +197,23 @@ static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags)
 
 		/* For negative dentries, always do a fresh lookup */
 		if (!inode)
-			return 0;
+			goto invalid;
 
+		ret = -ECHILD;
 		if (flags & LOOKUP_RCU)
-			return -ECHILD;
+			goto out;
 
 		fc = get_fuse_conn(inode);
 		req = fuse_get_req_nopages(fc);
+		ret = PTR_ERR(req);
 		if (IS_ERR(req))
-			return 0;
+			goto out;
 
 		forget = fuse_alloc_forget();
 		if (!forget) {
 			fuse_put_request(fc, req);
-			return 0;
+			ret = -ENOMEM;
+			goto out;
 		}
 
 		attr_version = fuse_get_attr_version(fc);
@@ -224,10 +229,10 @@ static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags)
 		if (!err && !outarg.nodeid)
 			err = -ENOENT;
 		if (!err) {
-			struct fuse_inode *fi = get_fuse_inode(inode);
+			fi = get_fuse_inode(inode);
 			if (outarg.nodeid != get_node_id(inode)) {
 				fuse_queue_forget(fc, forget, outarg.nodeid, 1);
-				return 0;
+				goto invalid;
 			}
 			spin_lock(&fc->lock);
 			fi->nlookup++;
@@ -235,21 +240,33 @@ static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags)
 		}
 		kfree(forget);
 		if (err || (outarg.attr.mode ^ inode->i_mode) & S_IFMT)
-			return 0;
+			goto invalid;
 
 		fuse_change_attributes(inode, &outarg.attr,
 				       entry_attr_timeout(&outarg),
 				       attr_version);
 		fuse_change_entry_timeout(entry, &outarg);
 	} else if (inode) {
-		fc = get_fuse_conn(inode);
-		if (fc->readdirplus_auto) {
+		fi = get_fuse_inode(inode);
+		if (flags & LOOKUP_RCU) {
+			if (test_bit(FUSE_I_INIT_RDPLUS, &fi->state))
+				return -ECHILD;
+		} else if (test_and_clear_bit(FUSE_I_INIT_RDPLUS, &fi->state)) {
 			parent = dget_parent(entry);
 			fuse_advise_use_readdirplus(parent->d_inode);
 			dput(parent);
 		}
 	}
-	return 1;
+	ret = 1;
+out:
+	return ret;
+
+invalid:
+	ret = 0;
+
+	if (!(flags & LOOKUP_RCU) && check_submounts_and_drop(entry) != 0)
+		ret = 1;
+	goto out;
 }
 
 static int invalid_nodeid(u64 nodeid)
@@ -267,26 +284,6 @@ int fuse_valid_type(int m)
 		S_ISBLK(m) || S_ISFIFO(m) || S_ISSOCK(m);
 }
 
-/*
- * Add a directory inode to a dentry, ensuring that no other dentry
- * refers to this inode.  Called with fc->inst_mutex.
- */
-static struct dentry *fuse_d_add_directory(struct dentry *entry,
-					   struct inode *inode)
-{
-	struct dentry *alias = d_find_alias(inode);
-	if (alias && !(alias->d_flags & DCACHE_DISCONNECTED)) {
-		/* This tries to shrink the subtree below alias */
-		fuse_invalidate_entry(alias);
-		dput(alias);
-		if (!hlist_empty(&inode->i_dentry))
-			return ERR_PTR(-EBUSY);
-	} else {
-		dput(alias);
-	}
-	return d_splice_alias(inode, entry);
-}
-
 int fuse_lookup_name(struct super_block *sb, u64 nodeid, struct qstr *name,
 		     struct fuse_entry_out *outarg, struct inode **inode)
 {
@@ -345,6 +342,24 @@ int fuse_lookup_name(struct super_block *sb, u64 nodeid, struct qstr *name,
 	return err;
 }
 
+static struct dentry *fuse_materialise_dentry(struct dentry *dentry,
+					      struct inode *inode)
+{
+	struct dentry *newent;
+
+	if (inode && S_ISDIR(inode->i_mode)) {
+		struct fuse_conn *fc = get_fuse_conn(inode);
+
+		mutex_lock(&fc->inst_mutex);
+		newent = d_materialise_unique(dentry, inode);
+		mutex_unlock(&fc->inst_mutex);
+	} else {
+		newent = d_materialise_unique(dentry, inode);
+	}
+
+	return newent;
+}
+
 static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
 				  unsigned int flags)
 {
@@ -352,7 +367,6 @@ static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
 	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,
@@ -368,16 +382,10 @@ static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
 	if (inode && get_node_id(inode) == FUSE_ROOT_ID)
 		goto out_iput;
 
-	if (inode && S_ISDIR(inode->i_mode)) {
-		mutex_lock(&fc->inst_mutex);
-		newent = fuse_d_add_directory(entry, inode);
-		mutex_unlock(&fc->inst_mutex);
-		err = PTR_ERR(newent);
-		if (IS_ERR(newent))
-			goto out_iput;
-	} else {
-		newent = d_splice_alias(inode, entry);
-	}
+	newent = fuse_materialise_dentry(entry, inode);
+	err = PTR_ERR(newent);
+	if (IS_ERR(newent))
+		goto out_err;
 
 	entry = newent ? newent : entry;
 	if (outarg_valid)
@@ -1060,6 +1068,8 @@ static int fuse_access(struct inode *inode, int mask)
 	struct fuse_access_in inarg;
 	int err;
 
+	BUG_ON(mask & MAY_NOT_BLOCK);
+
 	if (fc->no_access)
 		return 0;
 
@@ -1147,9 +1157,6 @@ static int fuse_permission(struct inode *inode, int mask)
 		   noticed immediately, only after the attribute
 		   timeout has expired */
 	} else if (mask & (MAY_ACCESS | MAY_CHDIR)) {
-		if (mask & MAY_NOT_BLOCK)
-			return -ECHILD;
-
 		err = fuse_access(inode, mask);
 	} else if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) {
 		if (!(inode->i_mode & S_IXUGO)) {
@@ -1174,6 +1181,8 @@ static int parse_dirfile(char *buf, size_t nbytes, struct file *file,
 			return -EIO;
 		if (reclen > nbytes)
 			break;
+		if (memchr(dirent->name, '/', dirent->namelen) != NULL)
+			return -EIO;
 
 		if (!dir_emit(ctx, dirent->name, dirent->namelen,
 			       dirent->ino, dirent->type))
@@ -1275,18 +1284,10 @@ static int fuse_direntplus_link(struct file *file,
 	if (!inode)
 		goto out;
 
-	if (S_ISDIR(inode->i_mode)) {
-		mutex_lock(&fc->inst_mutex);
-		alias = fuse_d_add_directory(dentry, inode);
-		mutex_unlock(&fc->inst_mutex);
-		err = PTR_ERR(alias);
-		if (IS_ERR(alias)) {
-			iput(inode);
-			goto out;
-		}
-	} else {
-		alias = d_splice_alias(inode, dentry);
-	}
+	alias = fuse_materialise_dentry(dentry, inode);
+	err = PTR_ERR(alias);
+	if (IS_ERR(alias))
+		goto out;
 
 	if (alias) {
 		dput(dentry);
@@ -1294,6 +1295,8 @@ static int fuse_direntplus_link(struct file *file,
 	}
 
 found:
+	if (fc->readdirplus_auto)
+		set_bit(FUSE_I_INIT_RDPLUS, &get_fuse_inode(inode)->state);
 	fuse_change_entry_timeout(dentry, o);
 
 	err = 0;
@@ -1320,6 +1323,8 @@ static int parse_dirplusfile(char *buf, size_t nbytes, struct file *file,
 			return -EIO;
 		if (reclen > nbytes)
 			break;
+		if (memchr(dirent->name, '/', dirent->namelen) != NULL)
+			return -EIO;
 
 		if (!over) {
 			/* We fill entries into dstbuf only as much as
@@ -1590,6 +1595,7 @@ int fuse_do_setattr(struct inode *inode, struct iattr *attr,
 		    struct file *file)
 {
 	struct fuse_conn *fc = get_fuse_conn(inode);
+	struct fuse_inode *fi = get_fuse_inode(inode);
 	struct fuse_req *req;
 	struct fuse_setattr_in inarg;
 	struct fuse_attr_out outarg;
@@ -1617,8 +1623,10 @@ int fuse_do_setattr(struct inode *inode, struct iattr *attr,
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
-	if (is_truncate)
+	if (is_truncate) {
 		fuse_set_nowrite(inode);
+		set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
+	}
 
 	memset(&inarg, 0, sizeof(inarg));
 	memset(&outarg, 0, sizeof(outarg));
@@ -1676,16 +1684,18 @@ int fuse_do_setattr(struct inode *inode, struct iattr *attr,
 	 * FUSE_NOWRITE, otherwise fuse_launder_page() would deadlock.
 	 */
 	if (S_ISREG(inode->i_mode) && oldsize != outarg.attr.size) {
-		truncate_pagecache(inode, oldsize, outarg.attr.size);
+		truncate_pagecache(inode, outarg.attr.size);
 		invalidate_inode_pages2(inode->i_mapping);
 	}
 
+	clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
 	return 0;
 
 error:
 	if (is_truncate)
 		fuse_release_nowrite(inode);
 
+	clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
 	return err;
 }
 
@@ -1749,6 +1759,8 @@ static int fuse_setxattr(struct dentry *entry, const char *name,
 		fc->no_setxattr = 1;
 		err = -EOPNOTSUPP;
 	}
+	if (!err)
+		fuse_invalidate_attr(inode);
 	return err;
 }
 
@@ -1878,6 +1890,8 @@ static int fuse_removexattr(struct dentry *entry, const char *name)
 		fc->no_removexattr = 1;
 		err = -EOPNOTSUPP;
 	}
+	if (!err)
+		fuse_invalidate_attr(inode);
 	return err;
 }