1 files changed, 101 insertions, 51 deletions

diff --git a/fs/libfs.c b/fs/libfs.c
index 9ea0ecc325a8..ce8c496a6940 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -62,11 +62,6 @@ int always_delete_dentry(const struct dentry *dentry)
 }
 EXPORT_SYMBOL(always_delete_dentry);
 
-const struct dentry_operations simple_dentry_operations = {
-	.d_delete = always_delete_dentry,
-};
-EXPORT_SYMBOL(simple_dentry_operations);
-
 /*
  * Lookup the data. This is trivial - if the dentry didn't already
  * exist, we know it is negative.  Set d_op to delete negative dentries.
@@ -75,9 +70,11 @@ struct dentry *simple_lookup(struct inode *dir, struct dentry *dentry, unsigned
 {
 	if (dentry->d_name.len > NAME_MAX)
 		return ERR_PTR(-ENAMETOOLONG);
-	if (!dentry->d_sb->s_d_op)
-		d_set_d_op(dentry, &simple_dentry_operations);
-
+	if (!dentry->d_op && !(dentry->d_flags & DCACHE_DONTCACHE)) {
+		spin_lock(&dentry->d_lock);
+		dentry->d_flags |= DCACHE_DONTCACHE;
+		spin_unlock(&dentry->d_lock);
+	}
 	if (IS_ENABLED(CONFIG_UNICODE) && IS_CASEFOLDED(dir))
 		return NULL;
 
@@ -605,15 +602,16 @@ struct dentry *find_next_child(struct dentry *parent, struct dentry *prev)
 }
 EXPORT_SYMBOL(find_next_child);
 
-void simple_recursive_removal(struct dentry *dentry,
-                              void (*callback)(struct dentry *))
+static void __simple_recursive_removal(struct dentry *dentry,
+                              void (*callback)(struct dentry *),
+			      bool locked)
 {
 	struct dentry *this = dget(dentry);
 	while (true) {
 		struct dentry *victim = NULL, *child;
 		struct inode *inode = this->d_inode;
 
-		inode_lock(inode);
+		inode_lock_nested(inode, I_MUTEX_CHILD);
 		if (d_is_dir(this))
 			inode->i_flags |= S_DEAD;
 		while ((child = find_next_child(this, victim)) == NULL) {
@@ -625,15 +623,13 @@ void simple_recursive_removal(struct dentry *dentry,
 			victim = this;
 			this = this->d_parent;
 			inode = this->d_inode;
-			inode_lock(inode);
+			if (!locked || victim != dentry)
+				inode_lock_nested(inode, I_MUTEX_CHILD);
 			if (simple_positive(victim)) {
 				d_invalidate(victim);	// avoid lost mounts
-				if (d_is_dir(victim))
-					fsnotify_rmdir(inode, victim);
-				else
-					fsnotify_unlink(inode, victim);
 				if (callback)
 					callback(victim);
+				fsnotify_delete(inode, d_inode(victim), victim);
 				dput(victim);		// unpin it
 			}
 			if (victim == dentry) {
@@ -641,7 +637,8 @@ void simple_recursive_removal(struct dentry *dentry,
 						      inode_set_ctime_current(inode));
 				if (d_is_dir(dentry))
 					drop_nlink(inode);
-				inode_unlock(inode);
+				if (!locked)
+					inode_unlock(inode);
 				dput(dentry);
 				return;
 			}
@@ -650,8 +647,22 @@ void simple_recursive_removal(struct dentry *dentry,
 		this = child;
 	}
 }
+
+void simple_recursive_removal(struct dentry *dentry,
+                              void (*callback)(struct dentry *))
+{
+	return __simple_recursive_removal(dentry, callback, false);
+}
 EXPORT_SYMBOL(simple_recursive_removal);
 
+/* caller holds parent directory with I_MUTEX_PARENT */
+void locked_recursive_removal(struct dentry *dentry,
+                              void (*callback)(struct dentry *))
+{
+	return __simple_recursive_removal(dentry, callback, true);
+}
+EXPORT_SYMBOL(locked_recursive_removal);
+
 static const struct super_operations simple_super_operations = {
 	.statfs		= simple_statfs,
 };
@@ -684,7 +695,7 @@ static int pseudo_fs_fill_super(struct super_block *s, struct fs_context *fc)
 	s->s_root = d_make_root(root);
 	if (!s->s_root)
 		return -ENOMEM;
-	s->s_d_op = ctx->dops;
+	set_default_d_op(s, ctx->dops);
 	return 0;
 }
 
@@ -910,7 +921,7 @@ static int simple_read_folio(struct file *file, struct folio *folio)
 	return 0;
 }
 
-int simple_write_begin(struct file *file, struct address_space *mapping,
+int simple_write_begin(const struct kiocb *iocb, struct address_space *mapping,
 			loff_t pos, unsigned len,
 			struct folio **foliop, void **fsdata)
 {
@@ -935,7 +946,7 @@ EXPORT_SYMBOL(simple_write_begin);
 
 /**
  * simple_write_end - .write_end helper for non-block-device FSes
- * @file: See .write_end of address_space_operations
+ * @iocb: kernel I/O control block
  * @mapping: 		"
  * @pos: 		"
  * @len: 		"
@@ -946,7 +957,8 @@ EXPORT_SYMBOL(simple_write_begin);
  * simple_write_end does the minimum needed for updating a folio after
  * writing is done. It has the same API signature as the .write_end of
  * address_space_operations vector. So it can just be set onto .write_end for
- * FSes that don't need any other processing. i_mutex is assumed to be held.
+ * FSes that don't need any other processing. i_rwsem is assumed to be held
+ * exclusively.
  * Block based filesystems should use generic_write_end().
  * NOTE: Even though i_size might get updated by this function, mark_inode_dirty
  * is not called, so a filesystem that actually does store data in .write_inode
@@ -955,9 +967,10 @@ EXPORT_SYMBOL(simple_write_begin);
  *
  * Use *ONLY* with simple_read_folio()
  */
-static int simple_write_end(struct file *file, struct address_space *mapping,
-			loff_t pos, unsigned len, unsigned copied,
-			struct folio *folio, void *fsdata)
+static int simple_write_end(const struct kiocb *iocb,
+			    struct address_space *mapping,
+			    loff_t pos, unsigned len, unsigned copied,
+			    struct folio *folio, void *fsdata)
 {
 	struct inode *inode = folio->mapping->host;
 	loff_t last_pos = pos + copied;
@@ -973,7 +986,7 @@ static int simple_write_end(struct file *file, struct address_space *mapping,
 	}
 	/*
 	 * No need to use i_size_read() here, the i_size
-	 * cannot change under us because we hold the i_mutex.
+	 * cannot change under us because we hold the i_rwsem.
 	 */
 	if (last_pos > inode->i_size)
 		i_size_write(inode, last_pos);
@@ -1583,13 +1596,17 @@ EXPORT_SYMBOL(generic_file_fsync);
 int generic_check_addressable(unsigned blocksize_bits, u64 num_blocks)
 {
 	u64 last_fs_block = num_blocks - 1;
-	u64 last_fs_page =
-		last_fs_block >> (PAGE_SHIFT - blocksize_bits);
+	u64 last_fs_page, max_bytes;
+
+	if (check_shl_overflow(num_blocks, blocksize_bits, &max_bytes))
+		return -EFBIG;
+
+	last_fs_page = (max_bytes >> PAGE_SHIFT) - 1;
 
 	if (unlikely(num_blocks == 0))
 		return 0;
 
-	if ((blocksize_bits < 9) || (blocksize_bits > PAGE_SHIFT))
+	if (blocksize_bits < 9)
 		return -EINVAL;
 
 	if ((last_fs_block > (sector_t)(~0ULL) >> (blocksize_bits - 9)) ||
@@ -1649,12 +1666,10 @@ struct inode *alloc_anon_inode(struct super_block *s)
 	 */
 	inode->i_state = I_DIRTY;
 	/*
-	 * Historically anonymous inodes didn't have a type at all and
-	 * userspace has come to rely on this. Internally they're just
-	 * regular files but S_IFREG is masked off when reporting
-	 * information to userspace.
+	 * Historically anonymous inodes don't have a type at all and
+	 * userspace has come to rely on this.
 	 */
-	inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR;
+	inode->i_mode = S_IRUSR | S_IWUSR;
 	inode->i_uid = current_fsuid();
 	inode->i_gid = current_fsgid();
 	inode->i_flags |= S_PRIVATE | S_ANON_INODE;
@@ -1950,22 +1965,22 @@ static const struct dentry_operations generic_encrypted_dentry_ops = {
  * @sb: superblock to be configured
  *
  * Filesystems supporting casefolding and/or fscrypt can call this
- * helper at mount-time to configure sb->s_d_op to best set of dentry
- * operations required for the enabled features. The helper must be
- * called after these have been configured, but before the root dentry
- * is created.
+ * helper at mount-time to configure default dentry_operations to the
+ * best set of dentry operations required for the enabled features.
+ * The helper must be called after these have been configured, but
+ * before the root dentry is created.
  */
 void generic_set_sb_d_ops(struct super_block *sb)
 {
 #if IS_ENABLED(CONFIG_UNICODE)
 	if (sb->s_encoding) {
-		sb->s_d_op = &generic_ci_dentry_ops;
+		set_default_d_op(sb, &generic_ci_dentry_ops);
 		return;
 	}
 #endif
 #ifdef CONFIG_FS_ENCRYPTION
 	if (sb->s_cop) {
-		sb->s_d_op = &generic_encrypted_dentry_ops;
+		set_default_d_op(sb, &generic_encrypted_dentry_ops);
 		return;
 	}
 #endif
@@ -2128,6 +2143,8 @@ struct dentry *stashed_dentry_get(struct dentry **stashed)
 	dentry = rcu_dereference(*stashed);
 	if (!dentry)
 		return NULL;
+	if (IS_ERR(dentry))
+		return dentry;
 	if (!lockref_get_not_dead(&dentry->d_lockref))
 		return NULL;
 	return dentry;
@@ -2160,7 +2177,6 @@ static struct dentry *prepare_anon_dentry(struct dentry **stashed,
 
 	/* Notice when this is changed. */
 	WARN_ON_ONCE(!S_ISREG(inode->i_mode));
-	WARN_ON_ONCE(!IS_IMMUTABLE(inode));
 
 	dentry = d_alloc_anon(sb);
 	if (!dentry) {
@@ -2176,8 +2192,7 @@ static struct dentry *prepare_anon_dentry(struct dentry **stashed,
 	return dentry;
 }
 
-static struct dentry *stash_dentry(struct dentry **stashed,
-				   struct dentry *dentry)
+struct dentry *stash_dentry(struct dentry **stashed, struct dentry *dentry)
 {
 	guard(rcu)();
 	for (;;) {
@@ -2218,14 +2233,16 @@ static struct dentry *stash_dentry(struct dentry **stashed,
 int path_from_stashed(struct dentry **stashed, struct vfsmount *mnt, void *data,
 		      struct path *path)
 {
-	struct dentry *dentry;
+	struct dentry *dentry, *res;
 	const struct stashed_operations *sops = mnt->mnt_sb->s_fs_info;
 
 	/* See if dentry can be reused. */
-	path->dentry = stashed_dentry_get(stashed);
-	if (path->dentry) {
+	res = stashed_dentry_get(stashed);
+	if (IS_ERR(res))
+		return PTR_ERR(res);
+	if (res) {
 		sops->put_data(data);
-		goto out_path;
+		goto make_path;
 	}
 
 	/* Allocate a new dentry. */
@@ -2234,14 +2251,22 @@ int path_from_stashed(struct dentry **stashed, struct vfsmount *mnt, void *data,
 		return PTR_ERR(dentry);
 
 	/* Added a new dentry. @data is now owned by the filesystem. */
-	path->dentry = stash_dentry(stashed, dentry);
-	if (path->dentry != dentry)
+	if (sops->stash_dentry)
+		res = sops->stash_dentry(stashed, dentry);
+	else
+		res = stash_dentry(stashed, dentry);
+	if (IS_ERR(res)) {
+		dput(dentry);
+		return PTR_ERR(res);
+	}
+	if (res != dentry)
 		dput(dentry);
 
-out_path:
-	WARN_ON_ONCE(path->dentry->d_fsdata != stashed);
-	WARN_ON_ONCE(d_inode(path->dentry)->i_private != data);
+make_path:
+	path->dentry = res;
 	path->mnt = mntget(mnt);
+	VFS_WARN_ON_ONCE(path->dentry->d_fsdata != stashed);
+	VFS_WARN_ON_ONCE(d_inode(path->dentry)->i_private != data);
 	return 0;
 }
 
@@ -2263,3 +2288,28 @@ void stashed_dentry_prune(struct dentry *dentry)
 	 */
 	cmpxchg(stashed, dentry, NULL);
 }
+
+/* parent must be held exclusive */
+struct dentry *simple_start_creating(struct dentry *parent, const char *name)
+{
+	struct dentry *dentry;
+	struct inode *dir = d_inode(parent);
+
+	inode_lock(dir);
+	if (unlikely(IS_DEADDIR(dir))) {
+		inode_unlock(dir);
+		return ERR_PTR(-ENOENT);
+	}
+	dentry = lookup_noperm(&QSTR(name), parent);
+	if (IS_ERR(dentry)) {
+		inode_unlock(dir);
+		return dentry;
+	}
+	if (dentry->d_inode) {
+		dput(dentry);
+		inode_unlock(dir);
+		return ERR_PTR(-EEXIST);
+	}
+	return dentry;
+}
+EXPORT_SYMBOL(simple_start_creating);