5.15-stable patches

added patches:
	vfs-fix-copy_file_range-averts-filesystem-freeze-protection.patch

diff --git a/queue-5.15/series b/queue-5.15/series
index 2543f9528246238a0ad2950a3668e9315e3a66ab..232cd09287a44dae391394c255207d773075bf8e 100644 (file)
--- a/queue-5.15/series
+++ b/queue-5.15/series
@@ -1 +1,2 @@
 x86-vdso-conditionally-export-__vdso_sgx_enter_enclave.patch
+vfs-fix-copy_file_range-averts-filesystem-freeze-protection.patch

diff --git a/queue-5.15/vfs-fix-copy_file_range-averts-filesystem-freeze-protection.patch b/queue-5.15/vfs-fix-copy_file_range-averts-filesystem-freeze-protection.patch
new file mode 100644 (file)
index 0000000..bbad8cb
--- /dev/null
+++ b/queue-5.15/vfs-fix-copy_file_range-averts-filesystem-freeze-protection.patch
@@ -0,0 +1,149 @@
+From 10bc8e4af65946b727728d7479c028742321b60a Mon Sep 17 00:00:00 2001
+From: Amir Goldstein <amir73il@gmail.com>
+Date: Thu, 17 Nov 2022 22:52:49 +0200
+Subject: vfs: fix copy_file_range() averts filesystem freeze protection
+
+From: Amir Goldstein <amir73il@gmail.com>
+
+commit 10bc8e4af65946b727728d7479c028742321b60a upstream.
+
+Commit 868f9f2f8e00 ("vfs: fix copy_file_range() regression in cross-fs
+copies") removed fallback to generic_copy_file_range() for cross-fs
+cases inside vfs_copy_file_range().
+
+To preserve behavior of nfsd and ksmbd server-side-copy, the fallback to
+generic_copy_file_range() was added in nfsd and ksmbd code, but that
+call is missing sb_start_write(), fsnotify hooks and more.
+
+Ideally, nfsd and ksmbd would pass a flag to vfs_copy_file_range() that
+will take care of the fallback, but that code would be subtle and we got
+vfs_copy_file_range() logic wrong too many times already.
+
+Instead, add a flag to explicitly request vfs_copy_file_range() to
+perform only generic_copy_file_range() and let nfsd and ksmbd use this
+flag only in the fallback path.
+
+This choise keeps the logic changes to minimum in the non-nfsd/ksmbd code
+paths to reduce the risk of further regressions.
+
+Fixes: 868f9f2f8e00 ("vfs: fix copy_file_range() regression in cross-fs copies")
+Tested-by: Namjae Jeon <linkinjeon@kernel.org>
+Tested-by: Luis Henriques <lhenriques@suse.de>
+Signed-off-by: Amir Goldstein <amir73il@gmail.com>
+Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
+[backport comments for v5.15: - sb_write_started() is missing - assert was dropped ]
+Signed-off-by: Amir Goldstein <amir73il@gmail.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ fs/ksmbd/vfs.c     |    6 +++---
+ fs/nfsd/vfs.c      |    4 ++--
+ fs/read_write.c    |   17 +++++++++++++----
+ include/linux/fs.h |    8 ++++++++
+ 4 files changed, 26 insertions(+), 9 deletions(-)
+
+--- a/fs/ksmbd/vfs.c
++++ b/fs/ksmbd/vfs.c
+@@ -1788,9 +1788,9 @@ int ksmbd_vfs_copy_file_ranges(struct ks
+               ret = vfs_copy_file_range(src_fp->filp, src_off,
+                                         dst_fp->filp, dst_off, len, 0);
+               if (ret == -EOPNOTSUPP || ret == -EXDEV)
+-                      ret = generic_copy_file_range(src_fp->filp, src_off,
+-                                                    dst_fp->filp, dst_off,
+-                                                    len, 0);
++                      ret = vfs_copy_file_range(src_fp->filp, src_off,
++                                                dst_fp->filp, dst_off, len,
++                                                COPY_FILE_SPLICE);
+               if (ret < 0)
+                       return ret;
+ 
+--- a/fs/nfsd/vfs.c
++++ b/fs/nfsd/vfs.c
+@@ -574,8 +574,8 @@ ssize_t nfsd_copy_file_range(struct file
+       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);
++              ret = vfs_copy_file_range(src, src_pos, dst, dst_pos, count,
++                                        COPY_FILE_SPLICE);
+       return ret;
+ }
+ 
+--- a/fs/read_write.c
++++ b/fs/read_write.c
+@@ -1418,7 +1418,9 @@ static int generic_copy_file_checks(stru
+        * and several different sets of file_operations, but they all end up
+        * using the same ->copy_file_range() function pointer.
+        */
+-      if (file_out->f_op->copy_file_range) {
++      if (flags & COPY_FILE_SPLICE) {
++              /* cross sb splice is allowed */
++      } else 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;
+@@ -1468,8 +1470,9 @@ ssize_t vfs_copy_file_range(struct file
+                           size_t len, unsigned int flags)
+ {
+       ssize_t ret;
++      bool splice = flags & COPY_FILE_SPLICE;
+ 
+-      if (flags != 0)
++      if (flags & ~COPY_FILE_SPLICE)
+               return -EINVAL;
+ 
+       ret = generic_copy_file_checks(file_in, pos_in, file_out, pos_out, &len,
+@@ -1495,14 +1498,14 @@ ssize_t vfs_copy_file_range(struct file
+        * same sb using clone, but for filesystems where both clone and copy
+        * are supported (e.g. nfs,cifs), we only call the copy method.
+        */
+-      if (file_out->f_op->copy_file_range) {
++      if (!splice && 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);
+               goto done;
+       }
+ 
+-      if (file_in->f_op->remap_file_range &&
++      if (!splice && file_in->f_op->remap_file_range &&
+           file_inode(file_in)->i_sb == file_inode(file_out)->i_sb) {
+               ret = file_in->f_op->remap_file_range(file_in, pos_in,
+                               file_out, pos_out,
+@@ -1522,6 +1525,8 @@ ssize_t vfs_copy_file_range(struct file
+        * consistent story about which filesystems support copy_file_range()
+        * and which filesystems do not, that will allow userspace tools to
+        * make consistent desicions w.r.t using copy_file_range().
++       *
++       * We also get here if caller (e.g. nfsd) requested COPY_FILE_SPLICE.
+        */
+       ret = generic_copy_file_range(file_in, pos_in, file_out, pos_out, len,
+                                     flags);
+@@ -1576,6 +1581,10 @@ SYSCALL_DEFINE6(copy_file_range, int, fd
+               pos_out = f_out.file->f_pos;
+       }
+ 
++      ret = -EINVAL;
++      if (flags != 0)
++              goto out;
++
+       ret = vfs_copy_file_range(f_in.file, pos_in, f_out.file, pos_out, len,
+                                 flags);
+       if (ret > 0) {
+--- a/include/linux/fs.h
++++ b/include/linux/fs.h
+@@ -1990,6 +1990,14 @@ struct dir_context {
+  */
+ #define REMAP_FILE_ADVISORY           (REMAP_FILE_CAN_SHORTEN)
+ 
++/*
++ * These flags control the behavior of vfs_copy_file_range().
++ * They are not available to the user via syscall.
++ *
++ * COPY_FILE_SPLICE: call splice direct instead of fs clone/copy ops
++ */
++#define COPY_FILE_SPLICE              (1 << 0)
++
+ struct iov_iter;
+ 
+ struct file_operations {