1 files changed, 54 insertions, 7 deletions

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 1fbc72c5f112..2ba751d097c1 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -43,6 +43,7 @@
 #include <linux/cred.h>
 #include <linux/mnt_idmapping.h>
 #include <linux/slab.h>
+#include <linux/maple_tree.h>
 
 #include <asm/byteorder.h>
 #include <uapi/linux/fs.h>
@@ -484,10 +485,10 @@ struct address_space {
 	pgoff_t			writeback_index;
 	const struct address_space_operations *a_ops;
 	unsigned long		flags;
-	struct rw_semaphore	i_mmap_rwsem;
 	errseq_t		wb_err;
 	spinlock_t		i_private_lock;
 	struct list_head	i_private_list;
+	struct rw_semaphore	i_mmap_rwsem;
 	void *			i_private_data;
 } __attribute__((aligned(sizeof(long)))) __randomize_layout;
 	/*
@@ -909,7 +910,8 @@ static inline loff_t i_size_read(const struct inode *inode)
 	preempt_enable();
 	return i_size;
 #else
-	return inode->i_size;
+	/* Pairs with smp_store_release() in i_size_write() */
+	return smp_load_acquire(&inode->i_size);
 #endif
 }
 
@@ -931,7 +933,12 @@ static inline void i_size_write(struct inode *inode, loff_t i_size)
 	inode->i_size = i_size;
 	preempt_enable();
 #else
-	inode->i_size = i_size;
+	/*
+	 * Pairs with smp_load_acquire() in i_size_read() to ensure
+	 * changes related to inode size (such as page contents) are
+	 * visible before we see the changed inode size.
+	 */
+	smp_store_release(&inode->i_size, i_size);
 #endif
 }
 
@@ -1080,9 +1087,20 @@ static inline struct inode *file_inode(const struct file *f)
 	return f->f_inode;
 }
 
+/*
+ * file_dentry() is a relic from the days that overlayfs was using files with a
+ * "fake" path, meaning, f_path on overlayfs and f_inode on underlying fs.
+ * In those days, file_dentry() was needed to get the underlying fs dentry that
+ * matches f_inode.
+ * Files with "fake" path should not exist nowadays, so use an assertion to make
+ * sure that file_dentry() was not papering over filesystem bugs.
+ */
 static inline struct dentry *file_dentry(const struct file *file)
 {
-	return d_real(file->f_path.dentry, file_inode(file));
+	struct dentry *dentry = file->f_path.dentry;
+
+	WARN_ON_ONCE(d_inode(dentry) != file_inode(file));
+	return dentry;
 }
 
 struct fasync_struct {
@@ -2927,6 +2945,17 @@ extern bool path_is_under(const struct path *, const struct path *);
 
 extern char *file_path(struct file *, char *, int);
 
+/**
+ * is_dot_dotdot - returns true only if @name is "." or ".."
+ * @name: file name to check
+ * @len: length of file name, in bytes
+ */
+static inline bool is_dot_dotdot(const char *name, size_t len)
+{
+	return len && unlikely(name[0] == '.') &&
+		(len == 1 || (len == 2 && name[1] == '.'));
+}
+
 #include <linux/err.h>
 
 /* needed for stackable file system support */
@@ -3259,13 +3288,14 @@ extern ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos,
 		const void __user *from, size_t count);
 
 struct offset_ctx {
-	struct xarray		xa;
-	u32			next_offset;
+	struct maple_tree	mt;
+	unsigned long		next_offset;
 };
 
 void simple_offset_init(struct offset_ctx *octx);
 int simple_offset_add(struct offset_ctx *octx, struct dentry *dentry);
 void simple_offset_remove(struct offset_ctx *octx, struct dentry *dentry);
+int simple_offset_empty(struct dentry *dentry);
 int simple_offset_rename_exchange(struct inode *old_dir,
 				  struct dentry *old_dentry,
 				  struct inode *new_dir,
@@ -3279,7 +3309,16 @@ extern int generic_file_fsync(struct file *, loff_t, loff_t, int);
 
 extern int generic_check_addressable(unsigned, u64);
 
-extern void generic_set_encrypted_ci_d_ops(struct dentry *dentry);
+extern void generic_set_sb_d_ops(struct super_block *sb);
+
+static inline bool sb_has_encoding(const struct super_block *sb)
+{
+#if IS_ENABLED(CONFIG_UNICODE)
+	return !!sb->s_encoding;
+#else
+	return false;
+#endif
+}
 
 int may_setattr(struct mnt_idmap *idmap, struct inode *inode,
 		unsigned int ia_valid);
@@ -3334,6 +3373,8 @@ static inline int kiocb_set_rw_flags(struct kiocb *ki, rwf_t flags)
 		return 0;
 	if (unlikely(flags & ~RWF_SUPPORTED))
 		return -EOPNOTSUPP;
+	if (unlikely((flags & RWF_APPEND) && (flags & RWF_NOAPPEND)))
+		return -EINVAL;
 
 	if (flags & RWF_NOWAIT) {
 		if (!(ki->ki_filp->f_mode & FMODE_NOWAIT))
@@ -3344,6 +3385,12 @@ static inline int kiocb_set_rw_flags(struct kiocb *ki, rwf_t flags)
 	if (flags & RWF_SYNC)
 		kiocb_flags |= IOCB_DSYNC;
 
+	if ((flags & RWF_NOAPPEND) && (ki->ki_flags & IOCB_APPEND)) {
+		if (IS_APPEND(file_inode(ki->ki_filp)))
+			return -EPERM;
+		ki->ki_flags &= ~IOCB_APPEND;
+	}
+
 	ki->ki_flags |= kiocb_flags;
 	return 0;
 }