1 files changed, 85 insertions, 221 deletions

diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index 8be4dc050d1e..94095058da34 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -9,20 +9,11 @@
 #include <linux/xattr.h>
 #include <linux/uio.h>
 #include <linux/uaccess.h>
-#include <linux/splice.h>
 #include <linux/security.h>
-#include <linux/mm.h>
 #include <linux/fs.h>
+#include <linux/backing-file.h>
 #include "overlayfs.h"
 
-struct ovl_aio_req {
-	struct kiocb iocb;
-	refcount_t ref;
-	struct kiocb *orig_iocb;
-};
-
-static struct kmem_cache *ovl_aio_request_cachep;
-
 static char ovl_whatisit(struct inode *inode, struct inode *realinode)
 {
 	if (realinode != ovl_inode_upper(inode))
@@ -33,9 +24,6 @@ static char ovl_whatisit(struct inode *inode, struct inode *realinode)
 		return 'm';
 }
 
-/* No atime modification on underlying */
-#define OVL_OPEN_FLAGS (O_NOATIME)
-
 static struct file *ovl_open_realfile(const struct file *file,
 				      const struct path *realpath)
 {
@@ -60,8 +48,8 @@ static struct file *ovl_open_realfile(const struct file *file,
 		if (!inode_owner_or_capable(real_idmap, realinode))
 			flags &= ~O_NOATIME;
 
-		realfile = backing_file_open(&file->f_path, flags, realpath,
-					     current_cred());
+		realfile = backing_file_open(file_user_path((struct file *) file),
+					     flags, realpath, current_cred());
 	}
 	revert_creds(old_cred);
 
@@ -105,11 +93,11 @@ static int ovl_real_fdget_meta(const struct file *file, struct fd *real,
 			       bool allow_meta)
 {
 	struct dentry *dentry = file_dentry(file);
+	struct file *realfile = file->private_data;
 	struct path realpath;
 	int err;
 
-	real->flags = 0;
-	real->file = file->private_data;
+	real->word = (unsigned long)realfile;
 
 	if (allow_meta) {
 		ovl_path_real(dentry, &realpath);
@@ -125,16 +113,17 @@ static int ovl_real_fdget_meta(const struct file *file, struct fd *real,
 		return -EIO;
 
 	/* Has it been copied up since we'd opened it? */
-	if (unlikely(file_inode(real->file) != d_inode(realpath.dentry))) {
-		real->flags = FDPUT_FPUT;
-		real->file = ovl_open_realfile(file, &realpath);
-
-		return PTR_ERR_OR_ZERO(real->file);
+	if (unlikely(file_inode(realfile) != d_inode(realpath.dentry))) {
+		struct file *f = ovl_open_realfile(file, &realpath);
+		if (IS_ERR(f))
+			return PTR_ERR(f);
+		real->word = (unsigned long)f | FDPUT_FPUT;
+		return 0;
 	}
 
 	/* Did the flags change since open? */
-	if (unlikely((file->f_flags ^ real->file->f_flags) & ~OVL_OPEN_FLAGS))
-		return ovl_change_flags(real->file, file->f_flags);
+	if (unlikely((file->f_flags ^ realfile->f_flags) & ~OVL_OPEN_FLAGS))
+		return ovl_change_flags(realfile, file->f_flags);
 
 	return 0;
 }
@@ -142,10 +131,11 @@ static int ovl_real_fdget_meta(const struct file *file, struct fd *real,
 static int ovl_real_fdget(const struct file *file, struct fd *real)
 {
 	if (d_is_dir(file_dentry(file))) {
-		real->flags = 0;
-		real->file = ovl_dir_real_file(file, false);
-
-		return PTR_ERR_OR_ZERO(real->file);
+		struct file *f = ovl_dir_real_file(file, false);
+		if (IS_ERR(f))
+			return PTR_ERR(f);
+		real->word = (unsigned long)f;
+		return 0;
 	}
 
 	return ovl_real_fdget_meta(file, real, false);
@@ -221,13 +211,13 @@ static loff_t ovl_llseek(struct file *file, loff_t offset, int whence)
 	 * files, so we use the real file to perform seeks.
 	 */
 	ovl_inode_lock(inode);
-	real.file->f_pos = file->f_pos;
+	fd_file(real)->f_pos = file->f_pos;
 
 	old_cred = ovl_override_creds(inode->i_sb);
-	ret = vfs_llseek(real.file, offset, whence);
+	ret = vfs_llseek(fd_file(real), offset, whence);
 	revert_creds(old_cred);
 
-	file->f_pos = real.file->f_pos;
+	file->f_pos = fd_file(real)->f_pos;
 	ovl_inode_unlock(inode);
 
 	fdput(real);
@@ -235,10 +225,22 @@ static loff_t ovl_llseek(struct file *file, loff_t offset, int whence)
 	return ret;
 }
 
+static void ovl_file_modified(struct file *file)
+{
+	/* Update size/mtime */
+	ovl_copyattr(file_inode(file));
+}
+
+static void ovl_file_end_write(struct file *file, loff_t pos, ssize_t ret)
+{
+	ovl_file_modified(file);
+}
+
 static void ovl_file_accessed(struct file *file)
 {
 	struct inode *inode, *upperinode;
 	struct timespec64 ctime, uctime;
+	struct timespec64 mtime, umtime;
 
 	if (file->f_flags & O_NOATIME)
 		return;
@@ -251,71 +253,27 @@ static void ovl_file_accessed(struct file *file)
 
 	ctime = inode_get_ctime(inode);
 	uctime = inode_get_ctime(upperinode);
-	if ((!timespec64_equal(&inode->i_mtime, &upperinode->i_mtime) ||
-	     !timespec64_equal(&ctime, &uctime))) {
-		inode->i_mtime = upperinode->i_mtime;
+	mtime = inode_get_mtime(inode);
+	umtime = inode_get_mtime(upperinode);
+	if ((!timespec64_equal(&mtime, &umtime)) ||
+	     !timespec64_equal(&ctime, &uctime)) {
+		inode_set_mtime_to_ts(inode, inode_get_mtime(upperinode));
 		inode_set_ctime_to_ts(inode, uctime);
 	}
 
 	touch_atime(&file->f_path);
 }
 
-static rwf_t ovl_iocb_to_rwf(int ifl)
-{
-	rwf_t flags = 0;
-
-	if (ifl & IOCB_NOWAIT)
-		flags |= RWF_NOWAIT;
-	if (ifl & IOCB_HIPRI)
-		flags |= RWF_HIPRI;
-	if (ifl & IOCB_DSYNC)
-		flags |= RWF_DSYNC;
-	if (ifl & IOCB_SYNC)
-		flags |= RWF_SYNC;
-
-	return flags;
-}
-
-static inline void ovl_aio_put(struct ovl_aio_req *aio_req)
-{
-	if (refcount_dec_and_test(&aio_req->ref)) {
-		fput(aio_req->iocb.ki_filp);
-		kmem_cache_free(ovl_aio_request_cachep, aio_req);
-	}
-}
-
-static void ovl_aio_cleanup_handler(struct ovl_aio_req *aio_req)
-{
-	struct kiocb *iocb = &aio_req->iocb;
-	struct kiocb *orig_iocb = aio_req->orig_iocb;
-
-	if (iocb->ki_flags & IOCB_WRITE) {
-		struct inode *inode = file_inode(orig_iocb->ki_filp);
-
-		kiocb_end_write(iocb);
-		ovl_copyattr(inode);
-	}
-
-	orig_iocb->ki_pos = iocb->ki_pos;
-	ovl_aio_put(aio_req);
-}
-
-static void ovl_aio_rw_complete(struct kiocb *iocb, long res)
-{
-	struct ovl_aio_req *aio_req = container_of(iocb,
-						   struct ovl_aio_req, iocb);
-	struct kiocb *orig_iocb = aio_req->orig_iocb;
-
-	ovl_aio_cleanup_handler(aio_req);
-	orig_iocb->ki_complete(orig_iocb, res);
-}
-
 static ssize_t ovl_read_iter(struct kiocb *iocb, struct iov_iter *iter)
 {
 	struct file *file = iocb->ki_filp;
 	struct fd real;
-	const struct cred *old_cred;
 	ssize_t ret;
+	struct backing_file_ctx ctx = {
+		.cred = ovl_creds(file_inode(file)->i_sb),
+		.user_file = file,
+		.accessed = ovl_file_accessed,
+	};
 
 	if (!iov_iter_count(iter))
 		return 0;
@@ -324,36 +282,8 @@ static ssize_t ovl_read_iter(struct kiocb *iocb, struct iov_iter *iter)
 	if (ret)
 		return ret;
 
-	ret = -EINVAL;
-	if (iocb->ki_flags & IOCB_DIRECT &&
-	    !(real.file->f_mode & FMODE_CAN_ODIRECT))
-		goto out_fdput;
-
-	old_cred = ovl_override_creds(file_inode(file)->i_sb);
-	if (is_sync_kiocb(iocb)) {
-		ret = vfs_iter_read(real.file, iter, &iocb->ki_pos,
-				    ovl_iocb_to_rwf(iocb->ki_flags));
-	} else {
-		struct ovl_aio_req *aio_req;
-
-		ret = -ENOMEM;
-		aio_req = kmem_cache_zalloc(ovl_aio_request_cachep, GFP_KERNEL);
-		if (!aio_req)
-			goto out;
-
-		aio_req->orig_iocb = iocb;
-		kiocb_clone(&aio_req->iocb, iocb, get_file(real.file));
-		aio_req->iocb.ki_complete = ovl_aio_rw_complete;
-		refcount_set(&aio_req->ref, 2);
-		ret = vfs_iocb_iter_read(real.file, &aio_req->iocb, iter);
-		ovl_aio_put(aio_req);
-		if (ret != -EIOCBQUEUED)
-			ovl_aio_cleanup_handler(aio_req);
-	}
-out:
-	revert_creds(old_cred);
-	ovl_file_accessed(file);
-out_fdput:
+	ret = backing_file_read_iter(fd_file(real), iter, iocb, iocb->ki_flags,
+				     &ctx);
 	fdput(real);
 
 	return ret;
@@ -364,9 +294,13 @@ static ssize_t ovl_write_iter(struct kiocb *iocb, struct iov_iter *iter)
 	struct file *file = iocb->ki_filp;
 	struct inode *inode = file_inode(file);
 	struct fd real;
-	const struct cred *old_cred;
 	ssize_t ret;
 	int ifl = iocb->ki_flags;
+	struct backing_file_ctx ctx = {
+		.cred = ovl_creds(inode->i_sb),
+		.user_file = file,
+		.end_write = ovl_file_end_write,
+	};
 
 	if (!iov_iter_count(iter))
 		return 0;
@@ -374,19 +308,11 @@ static ssize_t ovl_write_iter(struct kiocb *iocb, struct iov_iter *iter)
 	inode_lock(inode);
 	/* Update mode */
 	ovl_copyattr(inode);
-	ret = file_remove_privs(file);
-	if (ret)
-		goto out_unlock;
 
 	ret = ovl_real_fdget(file, &real);
 	if (ret)
 		goto out_unlock;
 
-	ret = -EINVAL;
-	if (iocb->ki_flags & IOCB_DIRECT &&
-	    !(real.file->f_mode & FMODE_CAN_ODIRECT))
-		goto out_fdput;
-
 	if (!ovl_should_sync(OVL_FS(inode->i_sb)))
 		ifl &= ~(IOCB_DSYNC | IOCB_SYNC);
 
@@ -395,37 +321,7 @@ static ssize_t ovl_write_iter(struct kiocb *iocb, struct iov_iter *iter)
 	 * this property in case it is set by the issuer.
 	 */
 	ifl &= ~IOCB_DIO_CALLER_COMP;
-
-	old_cred = ovl_override_creds(file_inode(file)->i_sb);
-	if (is_sync_kiocb(iocb)) {
-		file_start_write(real.file);
-		ret = vfs_iter_write(real.file, iter, &iocb->ki_pos,
-				     ovl_iocb_to_rwf(ifl));
-		file_end_write(real.file);
-		/* Update size */
-		ovl_copyattr(inode);
-	} else {
-		struct ovl_aio_req *aio_req;
-
-		ret = -ENOMEM;
-		aio_req = kmem_cache_zalloc(ovl_aio_request_cachep, GFP_KERNEL);
-		if (!aio_req)
-			goto out;
-
-		aio_req->orig_iocb = iocb;
-		kiocb_clone(&aio_req->iocb, iocb, get_file(real.file));
-		aio_req->iocb.ki_flags = ifl;
-		aio_req->iocb.ki_complete = ovl_aio_rw_complete;
-		refcount_set(&aio_req->ref, 2);
-		kiocb_start_write(&aio_req->iocb);
-		ret = vfs_iocb_iter_write(real.file, &aio_req->iocb, iter);
-		ovl_aio_put(aio_req);
-		if (ret != -EIOCBQUEUED)
-			ovl_aio_cleanup_handler(aio_req);
-	}
-out:
-	revert_creds(old_cred);
-out_fdput:
+	ret = backing_file_write_iter(fd_file(real), iter, iocb, ifl, &ctx);
 	fdput(real);
 
 out_unlock:
@@ -438,27 +334,28 @@ static ssize_t ovl_splice_read(struct file *in, loff_t *ppos,
 			       struct pipe_inode_info *pipe, size_t len,
 			       unsigned int flags)
 {
-	const struct cred *old_cred;
 	struct fd real;
 	ssize_t ret;
+	struct backing_file_ctx ctx = {
+		.cred = ovl_creds(file_inode(in)->i_sb),
+		.user_file = in,
+		.accessed = ovl_file_accessed,
+	};
 
 	ret = ovl_real_fdget(in, &real);
 	if (ret)
 		return ret;
 
-	old_cred = ovl_override_creds(file_inode(in)->i_sb);
-	ret = vfs_splice_read(real.file, ppos, pipe, len, flags);
-	revert_creds(old_cred);
-	ovl_file_accessed(in);
-
+	ret = backing_file_splice_read(fd_file(real), ppos, pipe, len, flags, &ctx);
 	fdput(real);
+
 	return ret;
 }
 
 /*
  * Calling iter_file_splice_write() directly from overlay's f_op may deadlock
  * due to lock order inversion between pipe->mutex in iter_file_splice_write()
- * and file_start_write(real.file) in ovl_write_iter().
+ * and file_start_write(fd_file(real)) in ovl_write_iter().
  *
  * So do everything ovl_write_iter() does and call iter_file_splice_write() on
  * the real file.
@@ -467,30 +364,23 @@ static ssize_t ovl_splice_write(struct pipe_inode_info *pipe, struct file *out,
 				loff_t *ppos, size_t len, unsigned int flags)
 {
 	struct fd real;
-	const struct cred *old_cred;
 	struct inode *inode = file_inode(out);
 	ssize_t ret;
+	struct backing_file_ctx ctx = {
+		.cred = ovl_creds(inode->i_sb),
+		.user_file = out,
+		.end_write = ovl_file_end_write,
+	};
 
 	inode_lock(inode);
 	/* Update mode */
 	ovl_copyattr(inode);
-	ret = file_remove_privs(out);
-	if (ret)
-		goto out_unlock;
 
 	ret = ovl_real_fdget(out, &real);
 	if (ret)
 		goto out_unlock;
 
-	old_cred = ovl_override_creds(inode->i_sb);
-	file_start_write(real.file);
-
-	ret = iter_file_splice_write(pipe, real.file, ppos, len, flags);
-
-	file_end_write(real.file);
-	/* Update size */
-	ovl_copyattr(inode);
-	revert_creds(old_cred);
+	ret = backing_file_splice_write(pipe, fd_file(real), ppos, len, flags, &ctx);
 	fdput(real);
 
 out_unlock:
@@ -514,9 +404,9 @@ static int ovl_fsync(struct file *file, loff_t start, loff_t end, int datasync)
 		return ret;
 
 	/* Don't sync lower file for fear of receiving EROFS error */
-	if (file_inode(real.file) == ovl_inode_upper(file_inode(file))) {
+	if (file_inode(fd_file(real)) == ovl_inode_upper(file_inode(file))) {
 		old_cred = ovl_override_creds(file_inode(file)->i_sb);
-		ret = vfs_fsync_range(real.file, start, end, datasync);
+		ret = vfs_fsync_range(fd_file(real), start, end, datasync);
 		revert_creds(old_cred);
 	}
 
@@ -528,23 +418,13 @@ static int ovl_fsync(struct file *file, loff_t start, loff_t end, int datasync)
 static int ovl_mmap(struct file *file, struct vm_area_struct *vma)
 {
 	struct file *realfile = file->private_data;
-	const struct cred *old_cred;
-	int ret;
-
-	if (!realfile->f_op->mmap)
-		return -ENODEV;
-
-	if (WARN_ON(file != vma->vm_file))
-		return -EIO;
-
-	vma_set_file(vma, realfile);
-
-	old_cred = ovl_override_creds(file_inode(file)->i_sb);
-	ret = call_mmap(vma->vm_file, vma);
-	revert_creds(old_cred);
-	ovl_file_accessed(file);
+	struct backing_file_ctx ctx = {
+		.cred = ovl_creds(file_inode(file)->i_sb),
+		.user_file = file,
+		.accessed = ovl_file_accessed,
+	};
 
-	return ret;
+	return backing_file_mmap(realfile, vma, &ctx);
 }
 
 static long ovl_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
@@ -566,11 +446,11 @@ static long ovl_fallocate(struct file *file, int mode, loff_t offset, loff_t len
 		goto out_unlock;
 
 	old_cred = ovl_override_creds(file_inode(file)->i_sb);
-	ret = vfs_fallocate(real.file, mode, offset, len);
+	ret = vfs_fallocate(fd_file(real), mode, offset, len);
 	revert_creds(old_cred);
 
 	/* Update size */
-	ovl_copyattr(inode);
+	ovl_file_modified(file);
 
 	fdput(real);
 
@@ -591,7 +471,7 @@ static int ovl_fadvise(struct file *file, loff_t offset, loff_t len, int advice)
 		return ret;
 
 	old_cred = ovl_override_creds(file_inode(file)->i_sb);
-	ret = vfs_fadvise(real.file, offset, len, advice);
+	ret = vfs_fadvise(fd_file(real), offset, len, advice);
 	revert_creds(old_cred);
 
 	fdput(real);
@@ -636,25 +516,25 @@ static loff_t ovl_copyfile(struct file *file_in, loff_t pos_in,
 	old_cred = ovl_override_creds(file_inode(file_out)->i_sb);
 	switch (op) {
 	case OVL_COPY:
-		ret = vfs_copy_file_range(real_in.file, pos_in,
-					  real_out.file, pos_out, len, flags);
+		ret = vfs_copy_file_range(fd_file(real_in), pos_in,
+					  fd_file(real_out), pos_out, len, flags);
 		break;
 
 	case OVL_CLONE:
-		ret = vfs_clone_file_range(real_in.file, pos_in,
-					   real_out.file, pos_out, len, flags);
+		ret = vfs_clone_file_range(fd_file(real_in), pos_in,
+					   fd_file(real_out), pos_out, len, flags);
 		break;
 
 	case OVL_DEDUPE:
-		ret = vfs_dedupe_file_range_one(real_in.file, pos_in,
-						real_out.file, pos_out, len,
+		ret = vfs_dedupe_file_range_one(fd_file(real_in), pos_in,
+						fd_file(real_out), pos_out, len,
 						flags);
 		break;
 	}
 	revert_creds(old_cred);
 
 	/* Update size */
-	ovl_copyattr(inode_out);
+	ovl_file_modified(file_out);
 
 	fdput(real_in);
 	fdput(real_out);
@@ -710,9 +590,9 @@ static int ovl_flush(struct file *file, fl_owner_t id)
 	if (err)
 		return err;
 
-	if (real.file->f_op->flush) {
+	if (fd_file(real)->f_op->flush) {
 		old_cred = ovl_override_creds(file_inode(file)->i_sb);
-		err = real.file->f_op->flush(real.file, id);
+		err = fd_file(real)->f_op->flush(fd_file(real), id);
 		revert_creds(old_cred);
 	}
 	fdput(real);
@@ -737,19 +617,3 @@ const struct file_operations ovl_file_operations = {
 	.copy_file_range	= ovl_copy_file_range,
 	.remap_file_range	= ovl_remap_file_range,
 };
-
-int __init ovl_aio_request_cache_init(void)
-{
-	ovl_aio_request_cachep = kmem_cache_create("ovl_aio_req",
-						   sizeof(struct ovl_aio_req),
-						   0, SLAB_HWCACHE_ALIGN, NULL);
-	if (!ovl_aio_request_cachep)
-		return -ENOMEM;
-
-	return 0;
-}
-
-void ovl_aio_request_cache_destroy(void)
-{
-	kmem_cache_destroy(ovl_aio_request_cachep);
-}