Linux-NFS Archive on lore.kernel.org
 help / color / Atom feed
From: Dave Chinner <david@fromorbit.com>
To: linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org
Cc: olga.kornievskaia@gmail.com, linux-nfs@vger.kernel.org,
	linux-unionfs@vger.kernel.org, ceph-devel@vger.kernel.org,
	linux-cifs@vger.kernel.org
Subject: [PATCH 02/11] vfs: introduce generic_copy_file_range()
Date: Mon,  3 Dec 2018 19:34:07 +1100
Message-ID: <20181203083416.28978-3-david@fromorbit.com> (raw)
In-Reply-To: <20181203083416.28978-1-david@fromorbit.com>

From: Dave Chinner <dchinner@redhat.com>

Right now if vfs_copy_file_range() does not use any offload
mechanism, it falls back to calling do_splice_direct(). This fails
to do basic sanity checks on the files being copied. Before we
start adding this necessarily functionality to the fallback path,
separate it out into generic_copy_file_range().

generic_copy_file_range() has the same prototype as
->copy_file_range() so that filesystems can use it in their custom
->copy_file_range() method if they so choose.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
 fs/read_write.c    | 35 ++++++++++++++++++++++++++++++++---
 include/linux/fs.h |  3 +++
 2 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/fs/read_write.c b/fs/read_write.c
index 09d1816cf3cf..50114694c98b 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1540,6 +1540,36 @@ COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd,
 }
 #endif
 
+/**
+ * generic_copy_file_range - copy data between two files
+ * @file_in:	file structure to read from
+ * @pos_in:	file offset to read from
+ * @file_out:	file structure to write data to
+ * @pos_out:	file offset to write data to
+ * @len:	amount of data to copy
+ * @flags:	copy flags
+ *
+ * This is a generic filesystem helper to copy data from one file to another.
+ * It has no constraints on the source or destination file owners - the files
+ * can belong to different superblocks and different filesystem types. Short
+ * copies are allowed.
+ *
+ * This should be called from the @file_out filesystem, as per the
+ * ->copy_file_range() method.
+ *
+ * Returns the number of bytes copied or a negative error indicating the
+ * failure.
+ */
+
+ssize_t generic_copy_file_range(struct file *file_in, loff_t pos_in,
+			    struct file *file_out, loff_t pos_out,
+			    size_t len, unsigned int flags)
+{
+	return do_splice_direct(file_in, &pos_in, file_out, &pos_out,
+			len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0);
+}
+EXPORT_SYMBOL(generic_copy_file_range);
+
 /*
  * copy_file_range() differs from regular file read and write in that it
  * specifically allows return partial success.  When it does so is up to
@@ -1611,9 +1641,8 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in,
 			goto done;
 	}
 
-	ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out,
-			len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0);
-
+	ret = generic_copy_file_range(file_in, &pos_in, file_out, &pos_out,
+					len, flags);
 done:
 	if (ret > 0) {
 		fsnotify_access(file_in);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index c95c0807471f..a4478764cf63 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1874,6 +1874,9 @@ extern ssize_t vfs_readv(struct file *, const struct iovec __user *,
 		unsigned long, loff_t *, rwf_t);
 extern ssize_t vfs_copy_file_range(struct file *, loff_t , struct file *,
 				   loff_t, size_t, unsigned int);
+extern ssize_t generic_copy_file_range(struct file *file_in, loff_t pos_in,
+				struct file *file_out, loff_t pos_out,
+				size_t len, unsigned int flags);
 extern int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in,
 					 struct file *file_out, loff_t pos_out,
 					 loff_t *count,
-- 
2.19.1


  parent reply index

Thread overview: 83+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-12-03  8:34 [PATCH 0/11] fs: fixes for major copy_file_range() issues Dave Chinner
2018-12-03  8:34 ` [PATCH 01/11] vfs: copy_file_range source range over EOF should fail Dave Chinner
2018-12-03 12:46   ` Amir Goldstein
2018-12-04 15:13     ` Christoph Hellwig
2018-12-04 21:29       ` Dave Chinner
2018-12-04 21:47         ` Olga Kornievskaia
2018-12-04 22:31           ` Dave Chinner
2018-12-05 16:51             ` bfields
2019-05-20  9:10             ` Amir Goldstein
2019-05-20 13:12               ` Olga Kornievskaia
2019-05-20 13:36                 ` Amir Goldstein
2019-05-20 13:58                   ` Olga Kornievskaia
2019-05-20 14:02                     ` Amir Goldstein
2018-12-05 14:12         ` Christoph Hellwig
2018-12-05 21:08           ` Dave Chinner
2018-12-05 21:30             ` Christoph Hellwig
2018-12-03  8:34 ` Dave Chinner [this message]
2018-12-03 10:03   ` [PATCH 02/11] vfs: introduce generic_copy_file_range() Amir Goldstein
2018-12-03 23:00     ` Dave Chinner
2018-12-04 15:14   ` Christoph Hellwig
2018-12-03  8:34 ` [PATCH 03/11] vfs: no fallback for ->copy_file_range Dave Chinner
2018-12-03 10:22   ` Amir Goldstein
2018-12-03 23:02     ` Dave Chinner
2018-12-06  4:16       ` Amir Goldstein
2018-12-06 21:30         ` Dave Chinner
2018-12-07  5:38           ` Amir Goldstein
2018-12-03 18:23   ` Anna Schumaker
2018-12-04 15:16   ` Christoph Hellwig
2018-12-03  8:34 ` [PATCH 04/11] vfs: add missing checks to copy_file_range Dave Chinner
2018-12-03 12:42   ` Amir Goldstein
2018-12-03 19:04   ` Darrick J. Wong
2018-12-03 21:33   ` Olga Kornievskaia
2018-12-03 23:04     ` Dave Chinner
2018-12-04 15:18   ` Christoph Hellwig
2018-12-12 11:31   ` Luis Henriques
2018-12-12 16:42     ` Darrick J. Wong
2018-12-12 18:55     ` Olga Kornievskaia
2018-12-12 19:42       ` Matthew Wilcox
2018-12-12 20:22         ` Olga Kornievskaia
2018-12-13 10:29           ` Luis Henriques
2018-12-03  8:34 ` [PATCH 05/11] vfs: use inode_permission in copy_file_range() Dave Chinner
2018-12-03 12:47   ` Amir Goldstein
2018-12-03 18:18   ` Darrick J. Wong
2018-12-03 23:55     ` Dave Chinner
2018-12-05 17:28       ` bfields
2018-12-03 18:53   ` Eric Biggers
2018-12-04 15:19   ` Christoph Hellwig
2018-12-03  8:34 ` [PATCH 06/11] vfs: copy_file_range needs to strip setuid bits Dave Chinner
2018-12-03 12:51   ` Amir Goldstein
2018-12-04 15:21   ` Christoph Hellwig
2018-12-03  8:34 ` [PATCH 07/11] vfs: copy_file_range should update file timestamps Dave Chinner
2018-12-03 10:47   ` Amir Goldstein
2018-12-03 17:33     ` Olga Kornievskaia
2018-12-03 18:22       ` Darrick J. Wong
2018-12-03 23:19     ` Dave Chinner
2018-12-04 15:24   ` Christoph Hellwig
2018-12-03  8:34 ` [PATCH 08/11] vfs: push EXDEV check down into ->remap_file_range Dave Chinner
2018-12-03 11:04   ` Amir Goldstein
2018-12-03 19:11     ` Darrick J. Wong
2018-12-03 23:37       ` Dave Chinner
2018-12-03 23:58         ` Darrick J. Wong
2018-12-04  9:17           ` Amir Goldstein
2018-12-03 23:34     ` Dave Chinner
2018-12-03 18:24   ` Darrick J. Wong
2018-12-04  8:18   ` Olga Kornievskaia
2018-12-03  8:34 ` [PATCH 09/11] vfs: push copy_file_ranges -EXDEV checks down Dave Chinner
2018-12-03 12:36   ` Amir Goldstein
2018-12-03 17:58   ` Olga Kornievskaia
2018-12-03 18:53   ` Anna Schumaker
2018-12-03 19:27     ` Olga Kornievskaia
2018-12-03 23:40     ` Dave Chinner
2018-12-04 15:43   ` Christoph Hellwig
2018-12-04 22:18     ` Dave Chinner
2018-12-04 23:33       ` Olga Kornievskaia
2018-12-05 14:09       ` Christoph Hellwig
2018-12-05 17:01         ` Olga Kornievskaia
2018-12-03  8:34 ` [PATCH 10/11] vfs: allow generic_copy_file_range to copy across devices Dave Chinner
2018-12-03 12:54   ` Amir Goldstein
2018-12-03  8:34 ` [PATCH 11/11] ovl: allow cross-device copy_file_range calls Dave Chinner
2018-12-03 12:55   ` Amir Goldstein
2018-12-03  8:39 ` [PATCH 12/11] man-pages: copy_file_range updates Dave Chinner
2018-12-03 13:05   ` Amir Goldstein
2019-05-21  5:52   ` Amir Goldstein

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20181203083416.28978-3-david@fromorbit.com \
    --to=david@fromorbit.com \
    --cc=ceph-devel@vger.kernel.org \
    --cc=linux-cifs@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-nfs@vger.kernel.org \
    --cc=linux-unionfs@vger.kernel.org \
    --cc=linux-xfs@vger.kernel.org \
    --cc=olga.kornievskaia@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-NFS Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-nfs/0 linux-nfs/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-nfs linux-nfs/ https://lore.kernel.org/linux-nfs \
		linux-nfs@vger.kernel.org linux-nfs@archiver.kernel.org
	public-inbox-index linux-nfs


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-nfs


AGPL code for this site: git clone https://public-inbox.org/ public-inbox