From: Luis Henriques <lhenriques@suse.de>
To: Amir Goldstein <amir73il@gmail.com>,
Jeff Layton <jlayton@kernel.org>,
Steve French <sfrench@samba.org>,
Miklos Szeredi <miklos@szeredi.hu>,
Trond Myklebust <trond.myklebust@hammerspace.com>,
Anna Schumaker <anna.schumaker@netapp.com>,
Alexander Viro <viro@zeniv.linux.org.uk>,
"Darrick J. Wong" <darrick.wong@oracle.com>,
Dave Chinner <dchinner@redhat.com>,
Greg KH <gregkh@linuxfoundation.org>,
Nicolas Boichat <drinkcat@chromium.org>,
Ian Lance Taylor <iant@google.com>,
Luis Lozano <llozano@chromium.org>,
Andreas Dilger <adilger@dilger.ca>,
Olga Kornievskaia <aglo@umich.edu>,
Christoph Hellwig <hch@infradead.org>
Cc: ceph-devel@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-cifs@vger.kernel.org, samba-technical@lists.samba.org,
linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org,
Luis Henriques <lhenriques@suse.de>
Subject: [PATCH v6] vfs: fix copy_file_range regression in cross-fs copies
Date: Thu, 18 Feb 2021 17:18:06 +0000 [thread overview]
Message-ID: <20210218171806.26930-1-lhenriques@suse.de> (raw)
In-Reply-To: <87blchibaf.fsf@suse.de>
A regression has been reported by Nicolas Boichat, found while using the
copy_file_range syscall to copy a tracefs file. Before commit
5dae222a5ff0 ("vfs: allow copy_file_range to copy across devices") the
kernel would return -EXDEV to userspace when trying to copy a file across
different filesystems. After this commit, the syscall doesn't fail anymore
and instead returns zero (zero bytes copied), as this file's content is
generated on-the-fly and thus reports a size of zero.
This patch restores some cross-filesystem copy restrictions that existed
prior to commit 5dae222a5ff0 ("vfs: allow copy_file_range to copy across
devices"). Filesystems are still allowed to fall-back to the VFS
generic_copy_file_range() implementation, but that has now to be done
explicitly.
nfsd is also modified to fall-back into generic_copy_file_range() in case
vfs_copy_file_range() fails with -EOPNOTSUPP or -EXDEV.
Fixes: 5dae222a5ff0 ("vfs: allow copy_file_range to copy across devices")
Link: https://lore.kernel.org/linux-fsdevel/20210212044405.4120619-1-drinkcat@chromium.org/
Link: https://lore.kernel.org/linux-fsdevel/CANMq1KDZuxir2LM5jOTm0xx+BnvW=ZmpsG47CyHFJwnw7zSX6Q@mail.gmail.com/
Link: https://lore.kernel.org/linux-fsdevel/20210126135012.1.If45b7cdc3ff707bc1efa17f5366057d60603c45f@changeid/
Reported-by: Nicolas Boichat <drinkcat@chromium.org>
Signed-off-by: Luis Henriques <lhenriques@suse.de>
---
And v6 is upon us. Behold!
Changes since v5
- check if ->copy_file_range is NULL before calling it
Changes since v4
- nfsd falls-back to generic_copy_file_range() only *if* it gets -EOPNOTSUPP
or -EXDEV.
Changes since v3
- dropped the COPY_FILE_SPLICE flag
- kept the f_op's checks early in generic_copy_file_checks, implementing
Amir's suggestions
- modified nfsd to use generic_copy_file_range()
Changes since v2
- do all the required checks earlier, in generic_copy_file_checks(),
adding new checks for ->remap_file_range
- new COPY_FILE_SPLICE flag
- don't remove filesystem's fallback to generic_copy_file_range()
- updated commit changelog (and subject)
Changes since v1 (after Amir review)
- restored do_copy_file_range() helper
- return -EOPNOTSUPP if fs doesn't implement CFR
- updated commit description
fs/nfsd/vfs.c | 8 +++++++-
fs/read_write.c | 53 ++++++++++++++++++++++++-------------------------
2 files changed, 33 insertions(+), 28 deletions(-)
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 04937e51de56..23dab0fa9087 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -568,6 +568,7 @@ __be32 nfsd4_clone_file_range(struct nfsd_file *nf_src, u64 src_pos,
ssize_t nfsd_copy_file_range(struct file *src, u64 src_pos, struct file *dst,
u64 dst_pos, u64 count)
{
+ ssize_t ret;
/*
* Limit copy to 4MB to prevent indefinitely blocking an nfsd
@@ -578,7 +579,12 @@ ssize_t nfsd_copy_file_range(struct file *src, u64 src_pos, struct file *dst,
* limit like this and pipeline multiple COPY requests.
*/
count = min_t(u64, count, 1 << 22);
- return vfs_copy_file_range(src, src_pos, dst, dst_pos, count, 0);
+ ret = vfs_copy_file_range(src, src_pos, dst, dst_pos, count, 0);
+
+ if (ret == -EOPNOTSUPP || ret == -EXDEV)
+ ret = generic_copy_file_range(src, src_pos, dst, dst_pos,
+ count, 0);
+ return ret;
}
__be32 nfsd4_vfs_fallocate(struct svc_rqst *rqstp, struct svc_fh *fhp,
diff --git a/fs/read_write.c b/fs/read_write.c
index 75f764b43418..0348aaa9e237 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1388,28 +1388,6 @@ ssize_t generic_copy_file_range(struct file *file_in, loff_t pos_in,
}
EXPORT_SYMBOL(generic_copy_file_range);
-static ssize_t do_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)
-{
- /*
- * Although we now allow filesystems to handle cross sb copy, passing
- * a file of the wrong filesystem type to filesystem driver can result
- * in an attempt to dereference the wrong type of ->private_data, so
- * avoid doing that until we really have a good reason. NFS defines
- * several different file_system_type structures, but they all end up
- * using the same ->copy_file_range() function pointer.
- */
- if (file_out->f_op->copy_file_range &&
- file_out->f_op->copy_file_range == file_in->f_op->copy_file_range)
- return file_out->f_op->copy_file_range(file_in, pos_in,
- file_out, pos_out,
- len, flags);
-
- return generic_copy_file_range(file_in, pos_in, file_out, pos_out, len,
- flags);
-}
-
/*
* Performs necessary checks before doing a file copy
*
@@ -1427,6 +1405,25 @@ static int generic_copy_file_checks(struct file *file_in, loff_t pos_in,
loff_t size_in;
int ret;
+ /*
+ * Although we now allow filesystems to handle cross sb copy, passing
+ * a file of the wrong filesystem type to filesystem driver can result
+ * in an attempt to dereference the wrong type of ->private_data, so
+ * avoid doing that until we really have a good reason. NFS defines
+ * several different file_system_type structures, but they all end up
+ * using the same ->copy_file_range() function pointer.
+ */
+ if (file_out->f_op->copy_file_range) {
+ if (file_in->f_op->copy_file_range !=
+ file_out->f_op->copy_file_range)
+ return -EXDEV;
+ } else if (file_in->f_op->remap_file_range) {
+ if (file_inode(file_in)->i_sb != file_inode(file_out)->i_sb)
+ return -EXDEV;
+ } else {
+ return -EOPNOTSUPP;
+ }
+
ret = generic_file_rw_checks(file_in, file_out);
if (ret)
return ret;
@@ -1499,8 +1496,7 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in,
* Try cloning first, this is supported by more file systems, and
* more efficient if both clone and copy are supported (e.g. NFS).
*/
- if (file_in->f_op->remap_file_range &&
- file_inode(file_in)->i_sb == file_inode(file_out)->i_sb) {
+ if (file_in->f_op->remap_file_range) {
loff_t cloned;
cloned = file_in->f_op->remap_file_range(file_in, pos_in,
@@ -1511,11 +1507,14 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in,
ret = cloned;
goto done;
}
+ /* Resort to copy_file_range if implemented. */
+ ret = -EOPNOTSUPP;
}
- ret = do_copy_file_range(file_in, pos_in, file_out, pos_out, len,
- flags);
- WARN_ON_ONCE(ret == -EOPNOTSUPP);
+ if (file_out->f_op->copy_file_range)
+ ret = file_out->f_op->copy_file_range(file_in, pos_in,
+ file_out, pos_out,
+ len, flags);
done:
if (ret > 0) {
fsnotify_access(file_in);
next prev parent reply other threads:[~2021-02-18 19:08 UTC|newest]
Thread overview: 93+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CAOQ4uxiFGjdvX2-zh5o46pn7RZhvbGHH0wpzLPuPOom91FwWeQ@mail.gmail.com>
2021-02-15 15:43 ` [PATCH v2] vfs: prevent copy_file_range to copy across devices Luis Henriques
2021-02-15 16:02 ` Trond Myklebust
2021-02-16 0:25 ` Steve French
2021-02-15 16:34 ` Amir Goldstein
2021-02-15 16:53 ` Trond Myklebust
2021-02-15 17:24 ` Amir Goldstein
2021-02-15 18:57 ` Trond Myklebust
2021-02-15 19:43 ` Amir Goldstein
2021-02-16 11:17 ` Luis Henriques
2021-02-16 11:28 ` gregkh
2021-02-16 12:01 ` Luis Henriques
2021-02-16 12:08 ` Greg KH
2021-02-16 13:51 ` Amir Goldstein
2021-02-16 16:42 ` Luis Henriques
2021-02-16 17:44 ` Amir Goldstein
2021-02-16 18:55 ` Luis Henriques
2021-02-16 19:20 ` Amir Goldstein
2021-02-16 19:27 ` Anna Schumaker
2021-02-16 19:31 ` Steve French
2021-02-16 19:40 ` Amir Goldstein
2021-02-16 21:15 ` Steve French
2021-02-17 8:08 ` Amir Goldstein
2021-02-17 17:26 ` [PATCH v3] vfs: fix copy_file_range regression in cross-fs copies Luis Henriques
2021-02-17 20:47 ` Amir Goldstein
2021-02-18 0:56 ` Nicolas Boichat
2021-02-18 5:32 ` Olga Kornievskaia
2021-02-18 6:47 ` Amir Goldstein
2021-02-18 16:28 ` Olga Kornievskaia
2021-02-18 7:43 ` Christoph Hellwig
2021-02-18 0:50 ` [PATCH v2] vfs: prevent copy_file_range to copy across devices Andreas Dilger
2021-02-18 7:34 ` gregkh
2021-02-16 18:54 ` Andreas Dilger
2021-02-17 4:45 ` Nicolas Boichat
2021-02-18 7:42 ` Christoph Hellwig
2021-02-18 9:10 ` Amir Goldstein
2021-02-18 10:29 ` Luis Henriques
2021-02-18 12:15 ` Luis Henriques
2021-02-18 12:49 ` Amir Goldstein
2021-02-18 14:36 ` [PATCH v4] vfs: fix copy_file_range regression in cross-fs copies Luis Henriques
2021-02-18 14:58 ` Amir Goldstein
2021-02-18 15:17 ` [PATCH v5] " Luis Henriques
2021-02-18 15:53 ` Amir Goldstein
2021-02-18 16:35 ` Luis Henriques
2021-02-18 17:18 ` Luis Henriques [this message]
2021-02-19 21:18 ` [PATCH v6] " Olga Kornievskaia
2021-02-19 21:52 ` Amir Goldstein
2021-02-21 19:58 ` [PATCH v7] " Luis Henriques
2021-02-22 3:00 ` Nicolas Boichat
2021-02-22 10:24 ` [PATCH v8] " Luis Henriques
2021-02-22 10:46 ` Amir Goldstein
2021-02-22 16:25 ` dai.ngo
2021-02-23 10:32 ` Luis Henriques
2021-02-23 15:28 ` Amir Goldstein
2021-02-23 15:29 ` dai.ngo
2021-02-23 16:02 ` dai.ngo
2021-02-23 16:47 ` Amir Goldstein
2021-02-23 16:57 ` dai.ngo
[not found] ` <e3eed18b-fc7e-e687-608b-7f662017329c@oracle.com>
2021-02-23 17:33 ` Amir Goldstein
2021-02-24 0:13 ` dai.ngo
2021-02-23 17:56 ` Luis Henriques
2021-02-23 17:13 ` Olga Kornievskaia
2021-02-24 1:00 ` Olga Kornievskaia
2021-02-24 10:23 ` Luis Henriques
2021-02-24 10:44 ` Nicolas Boichat
2021-04-09 5:23 ` Nicolas Boichat
2021-04-09 13:39 ` Luis Henriques
2021-04-09 13:50 ` Amir Goldstein
2021-04-23 4:40 ` Nicolas Boichat
2021-05-03 8:54 ` Luis Henriques
2021-02-24 14:23 ` [PATCH] copy_file_range.2: Kernel v5.12 updates Luis Henriques
2021-02-24 16:10 ` Amir Goldstein
2021-02-25 10:21 ` Luis Henriques
2021-02-26 10:13 ` Alejandro Colomar (man-pages)
2021-02-26 10:34 ` Amir Goldstein
2021-02-26 11:15 ` Alejandro Colomar (man-pages)
2021-02-26 13:59 ` Jeff Layton
2021-02-26 21:26 ` Alejandro Colomar (man-pages)
2021-02-26 22:18 ` Alejandro Colomar (man-pages)
2021-02-27 5:41 ` Amir Goldstein
2021-02-27 12:20 ` Alejandro Colomar (man-pages)
2021-02-27 13:49 ` [RFC v2] copy_file_range.2: Update cross-filesystem support for 5.12 Alejandro Colomar
2021-02-27 16:00 ` Amir Goldstein
2021-02-27 23:08 ` [PATCH] copy_file_range.2: Kernel v5.12 updates Steve French
2021-02-28 7:35 ` Amir Goldstein
2021-02-28 22:25 ` Steve French
2021-03-01 6:18 ` Amir Goldstein
2021-03-01 14:41 ` [RFC v3] copy_file_range.2: Update cross-filesystem support for 5.12 Alejandro Colomar
2021-03-01 14:58 ` Amir Goldstein
2021-03-04 9:38 ` [RFC v4] " Alejandro Colomar
2021-03-04 17:13 ` Darrick J. Wong
2021-03-04 18:24 ` Alejandro Colomar (man-pages)
2021-03-04 23:50 ` Darrick J. Wong
2021-02-18 20:41 ` [PATCH v2] vfs: prevent copy_file_range to copy across devices Steve French
Reply instructions:
You may reply publicly 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=20210218171806.26930-1-lhenriques@suse.de \
--to=lhenriques@suse.de \
--cc=adilger@dilger.ca \
--cc=aglo@umich.edu \
--cc=amir73il@gmail.com \
--cc=anna.schumaker@netapp.com \
--cc=ceph-devel@vger.kernel.org \
--cc=darrick.wong@oracle.com \
--cc=dchinner@redhat.com \
--cc=drinkcat@chromium.org \
--cc=gregkh@linuxfoundation.org \
--cc=hch@infradead.org \
--cc=iant@google.com \
--cc=jlayton@kernel.org \
--cc=linux-cifs@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-nfs@vger.kernel.org \
--cc=llozano@chromium.org \
--cc=miklos@szeredi.hu \
--cc=samba-technical@lists.samba.org \
--cc=sfrench@samba.org \
--cc=trond.myklebust@hammerspace.com \
--cc=viro@zeniv.linux.org.uk \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).